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https://openalex.org/W2955024071
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English
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Evidence of perpetration of intimate partner violence among HIV-positive couples: a systematic scoping review protocol
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Systematic reviews
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cc-by
| 3,847
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Evidence of perpetration of intimate
partner violence among HIV-positive
couples: a systematic scoping review
protocol Felix Apiribu1,2*
, Busisiwe Purity Ncama1 and Elizabeth Joseph-Shehu1,3 Abstract The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
* Correspondence: fapiribu.chs@knust.edu.gh
1School of Nursing and Public Health, College of Health Sciences, University
of KwaZulu-Natal, Desmond Clearance Building, Howard College Campus,
Durban 4001, South Africa
2Department of Nursing, Faculty of Allied Health Sciences, College of Health
Sciences, Kwame Nkrumah University of Science and Technology, Kumasi,
Ghana
Full list of author information is available at the end of the article * Correspondence: fapiribu.chs@knust.edu.gh Apiribu et al. Systematic Reviews (2019) 8:159
https://doi.org/10.1186/s13643-019-1051-3 Apiribu et al. Systematic Reviews (2019) 8:159
https://doi.org/10.1186/s13643-019-1051-3 Abstract Background: Human immunodeficiency virus (HIV) infection and intimate partner violence (IPV) remain highly
sensitive areas that have issues to do with stigmatization in many African countries. Despite the fact that there are
several studies on the prevention of HIV, the prevalence of HIV in many African countries is still high. Literature
shows that prevention of intimate partner violence is key in the spread of HIV infection. This study will focus on
evidence of experiences of HIV positive couples with intimate partner violence and the types of violence experienced. This scoping review will map information about intimate partner violence in low- and middle-income countries as well
as other countries with intimate partner violence. There is the need to review these studies on HIV positive couples
with intimate partner violence to establish gaps and identify where primary research is necessary. The purpose of this
study will be to explore evidence of experiences of HIV-positive couples with IPV and the types of violence experiences
by HIV-positive couples. Methods: This scoping review will involve electronic databases, which will include academic search premier, CINAHL,
PsycARTICLES (EBSCO), PsycINFO (EBSCO), ScienceDirect, PubMed, MEDLINE (EBSCO) and Google Scholar. The study will
be conducted in two stages: the first stage will map out the studies descriptively while the second stage will map the
additional inclusion criteria of quality assessment. Two independent reviewers will undertake the data extraction. Relevant outcomes of the studies will be analyzed thematically using NVivo computer software. Results: Results on the evidence of the experiences of HIV-positive couples with partner violence will be coded
independently by the authors. Thereafter, the authors will critically cross-examine the relationship of the research
questions to the emerging themes from the selected articles. Conclusion: The authors hope to find studies on intimate partner violence among HIV-positive couples to establish
gaps where primary research will be necessary. Systematic review registration: PROSPERO CRD42017062190 Systematic review registration: PROSPERO CRD42017062190 Keywords: Intimate partner violence, HIV/AIDS, Couples, Disclosure, Behaviour, Low- and middle-income countries Keywords: Intimate partner violence, HIV/AIDS, Couples, Disclosure, Behaviour, Low- and middle-income countries © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. Background countries [14] which are low- and middle-income
countries. Therefore, the need to review studies on
HIV-positive couples with intimate partner violence
to establish gaps and identify where primary research
is necessary. Hence, this study will explore evidence
of experiences of HIV-positive couples with IPV and
the types of
violence experiences by HIV-positive
couples. Intimacy issues in relationships are normally very sensi-
tive and secretive especially when they are related to hu-
man immunodeficiency virus (HIV) disclosure. Although
a lot of work has been done to either minimize it or
eliminate it completely as much as possible, fear, ignor-
ance and discrimination regarding HIV continue to exact
profound human costs like abusive treatment and vio-
lence [4, 16, 18]. Spangenberg et al. identified that 46%
of mothers of sick newborns in Ghana reported some
form of violence. Women who are HIV positive are at
risk of experiencing the same forms of violence as other
women in the population but in a severe form because
of their status [17]. Research objectives The main aim of the review is to explore evidence of in-
timate partner violence among human immunodefi-
ciency virus (HIV)-positive couples. The specific objectives of the study include the
following: There is increasing evidence suggesting that HIV-
positive women and probably men in many African
countries may be at increased risk of experiencing intim-
ate partner violence (IPV) following disclosure of their
status to their partners [3, 12, 14]. These problems relat-
ing to IPV are, however, more likely to be exacerbated in
resource-poor settings like Ghana, where discrimination
and stigmatization are high [2, 3]. HIV-positive couples
in such areas are at risk of being ostracized, denied some
essential services, criticized, thrown out of their homes,
divorced and/or blamed for bringing disease into the
family or into the community [15]. Shamu et al. further
reported that 40.5% of HIV-positive pregnant women in
Zimbabwe experienced IPV after disclosure of their
HIV-positive
status
to
their
partners. HIV-positive
women are at increased risk of experiencing IPV follow-
ing disclosure of the partner’s status to each other [1,
10]. The fear of IPV (physical, sexual, psychological and
spiritual abuse) may decrease HIV-prevention behav-
iours [5, 8, 15] such as disclosure of seropositive status
to partners, which may lead to the spread of the infec-
tion. It may also prevent HIV-positive couples from stay-
ing on lifelong antiretroviral treatment and prevention
of mother-to-child transmission [6, 7, 13]. Violence
against HIV-positive women also has a consequential in-
fluence on status disclosure, which is vital to HIV pre-
vention and partner support in accessing preventive
services [8, 9]. 1. To review evidence on the types of intimate partner
violence among HIV couples g
p
2. To review evidence on the experiences of HIV couples
with intimate partner violence The study will provide answers to the following
questions: 1. What are the types of intimate partner violence
among HIV couples? 2. What are the experiences of HIV couples with
intimate partner violence? 2. What are the experiences of HIV couples with intimate partner violence? © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Page 2 of 5 Apiribu et al. Systematic Reviews (2019) 8:159 Page 2 of 5 Apiribu et al. Systematic Reviews (2019) 8:159 Apiribu et al. Systematic Reviews Search strategy and study selection This scoping review will involve electronic databases
which
will
include
PsycARTICLES
(EBSCO),
Psy-
cINFO (EBSCO), ScienceDirect, PubMed, MEDLINE
(EBSCO) and Google Scholar. The search strategy will
include all studies that addressed evidence of experi-
ences of HIV-positive couples with partner violence. All peer-reviewed studies and grey literature that ad-
dresses the research questions will be selected in the
study. Only
articles published in English between
2007 and 2018 will be used. The reason for limiting
this study to between 2007 and 2018 is due to lack of
resources. The
literature
search
results
will
be
uploaded to EndNote X8. The EndNote X8 software
will be used to find and remove duplicates. The
search will be conducted over 4 months. Intimate partner violence by men against their part-
ners is one of the most glaring indicators of women’s
lack of empowerment [3, 10]. There is often the need for
the collection of both victimization and offending data
that question both partners. This would allow for an
examination of the association between status compati-
bilities and intimate partner violence and victimization
and perpetration, as well as mutually combative behav-
iour between intimate partners [11]. Methods/designs This study protocol was registered and published with the
International Prospective Register of Systematic Reviews
(PROSPERO) with registration number CRD42017062190. Data extraction Numerical
summary and
thematic
analysis
will
be
employed to extract background information from the
selected studies. In order to answer the research ques-
tions as guided by population, interventions, comparison
and outcome (PICOS) (Table 1), the reviewers will col-
lectively design a data-chronicling form to determine the
text words, and themes to include and extract. They will
also collectively develop the data-charting form. ➢Review articles including systematic reviews, meta-
analysis, scoping reviews, peer-reviewed journal articles
and rapid reviews ➢Information and data relevant to answer the
research questions will be determined by the reviewers
collectively ➢Grey literature sources such as documents from
government and non-governmental organizations and
academic dissertations ➢All types of study designs such as cohort studies,
cross-sectional studies, qualitative studies, quantitative
studies, randomized control trial studies, quasi-
experimental study designs and pilot studies ➢Update recording of data relevant to the study
➢Relevant data will be extracted from all the eligible
studies by two independent reviewers in duplicate Data to be extracted include (i) author (s) names, (ii)
year of publication, (iii) study design and/or method-
ology, (iv) study population, (v) intervention(s), (vi)
study setting, (vii) aim of the study, (viii) geographic lo-
cation of the study and (ix) conclusions. Criteria for inclusion There is scarcity of evidence on the most effective
ways of reducing IPV and abuse among persons living
with HIV (PLWHIV) in most sub-Saharan African ➢Articles published in the English language ➢Articles published in the English language Apiribu et al. Systematic Reviews (2019) 8:159 Page 3 of 5 Page 3 of 5 ➢Literature published from January 2007 to December
2018
➢Articles that report on experiences of couples with
HIV
➢Evidence from published relevant literatures
➢Studies reporting on experiences of intimate partner
violence
➢Review articles including systematic reviews, meta-
analysis, scoping reviews, peer-reviewed journal articles
and rapid reviews
➢Grey literature sources such as documents from
government and non-governmental organizations and
academic dissertations
➢All types of study designs such as cohort studies,
cross-sectional studies, qualitative studies, quantitative
studies, randomized control trial studies, quasi-
experimental study designs and pilot studies ➢Literature published from January 2007 to December
2018
➢Articles that report on experiences of couples with
HIV
➢Evidence from published relevant literatures
➢Studies reporting on experiences of intimate partner
violence
➢Review articles including systematic reviews, meta-
analysis, scoping reviews, peer-reviewed journal articles
and rapid reviews
➢Grey literature sources such as documents from
government and non-governmental organizations and
academic dissertations
➢All types of study designs such as cohort studies,
cross-sectional studies, qualitative studies, quantitative
studies, randomized control trial studies, quasi-
experimental study designs and pilot studies Exclusion criteria ➢Intervention that does not include any form of
intimate partner violence ➢Studies not focusing on experiences of HIV-positive
couples with intimate partner violence and approaches
to reducing its prevalence Information specific to the evidence of experiences of
HIV-positive couples with partner violence will be ex-
tracted using phases of the literature search for extrac-
tion of the most specific literature for the review as seen
in Fig. 1 below. ➢Studies reporting on other infections other than
human immunodeficiency virus/acquired immune
deficiency syndrome (HIV/AIDS) ➢If necessary, a third reviewer will be consulted in
order to reach consensus ➢If necessary, a third reviewer will be consulted in
order to reach consensus ➢Non-English publications ➢Articles published before January 2007 and after
December 2018 ➢The researchers will collectively carry out a thematic
analysis to extract relevant outcomes using NVivo
software ➢The researchers will collectively carry out a thematic
analysis to extract relevant outcomes using NVivo
software ➢Articles not focusing on HIV-positive adults in
intimate relationship. Keywords search (Table 1) will be combined into a
phrase including Boolean (AND, OR) terms, as follows:
(intimate partner violence AND HIV/AIDS OR couples
OR disclosure OR behaviour OR low and middle income
countries). Patient and public involvement p
Patients and/or the public were not involved in this
study. Findings from this study will contribute to the body of
knowledge on intimate partner violence among HIV-
positive individual/couples which will have a positive im-
pact on research, practice and policy. Reduction or elim-
ination of intimate partner violence should help improve
the quality of life of HIV-positive couples and increase
their life expectancy. The findings from the study will
provide an insight on the possible means of reducing
IPV and abuse among PLWHIV. llating, summarizing and communicating results The main aim of this review is to scope for existing evi-
dence of the experiences of HIV-positive couples with
partner violence and summarize the findings as pre-
sented across the articles reviewed. The research team
will meet to carry out a thematic analysis of the data col-
lected and provide an overview of all data collected. This
process will include the following steps; Updated records of the number of publications identi-
fied during each session of the literature search will be
kept using the information. Table 1 A PICOS framework for determination of the eligibility of the review question
Criteria
Determinants
Population
The population of the study will be individuals in intimate relationship and living with HIV
Interventions
Intimate partner violence
Comparisons
None
Outcomes
Promote positive relationship among HIV couples, prevent the spread of HIV and improve quality of life
(general well-being and health)
Study settings
Low- and middle-income countries are the focus. Owing to the scarcity of literature on intimate partner
violence, we proposed not to limit the scope of this review by study setting. The rationale for this is to have a good number of publications globally for comparison Table 1 A PICOS framework for determination of the eligibility of the review question
Criteria
Determinants Table 1 A PICOS framework for determination of the eligibility of the review question Page 4 of 5 Page 4 of 5 Apiribu et al. Systematic Reviews (2019) 8:159 Apiribu et al. Systematic Reviews Step 1: Examine the bibliographic details, study designs,
number of participants, study setting and funding
sources of all included studies Step 1: Examine the bibliographic details, study designs,
number of participants, study setting and funding
sources of all included studies HIV populations in low- and middle-income countries
while campaigns have further slowed the spread of the
virus. However, these efforts are being hindered by non-
disclosure of HIV-seropositive status by some couples
for fear of being victims of intimate partner violence. Good intimate partner relationship can improve the
quality of life of HIV-positive couples and increase their
life expectancy. IPV prevention can contribute im-
mensely on the prevention of HIV/AIDs. Step 2: Results on the evidences of the experiences of
human immunodeficiency virus (HIV)-positive couples
with partner violence will be coded independently by
the authors. llating, summarizing and communicating results All the authors will then come together
and interrogate the resultant themes, critically look at
their relationship to the set research questions
Step 3: The research team will examine the implications
for future research, practice and policy based on the
main aim of the study We are not aware if there are any empirical studies or
reviews that have been done in sub-Saharan African
countries that answer the research questions outlined in
this protocol. Therefore, this study will include all stud-
ies from anywhere in the world that address the popula-
tion
of
interest,
intervention
and
any/or
all
the
outcomes listed in Table 1. Discussion/conclusion This study will generate evidence that will help to de-
scribe experiences of human immunodeficiency virus
(HIV)-positive individuals/couples with intimate partner
violence. Recent improvements in antiretroviral therapy,
coupled with nutritional supplementation, have contrib-
uted to longevity of life of persons living with HIV
(PLWHIV). Mortality and morbidity are now low in Fig. 1 A flow chart showing phases of the literature search for extraction of the most specific literature for the review Fig. 1 A flow chart showing phases of the literature search for extraction of the most specific literature for the review Page 5 of 5 Apiribu et al. Systematic Reviews (2019) 8:159 Page 5 of 5 Apiribu et al. Systematic Reviews (2019) 8:159 Apiribu et al. Systematic Reviews (2019) 8:159 The proposed systematic scoping review results will
generate findings that will describe the experiences of
HIV-positive couples with partner violence, and the
types of violence these populations experienced. The
findings from this study will help in identifying gaps in
literature on the care of the HIV-positive couples with
partner violence. It will also enhance HIV prevention
that can be used in education, clinical practice and in
making public health policies on HIV and AIDS preven-
tion. The gaps identified will help outline areas for pre-
ventive strategies to stimulate cordial coexistence among
couples in the low- and middle-income countries. How-
ever, there is no data on intimate partner violence
among HIV-positive couples in low- and middle-income
countries. A number of studies have been on HIV and
stigmatization among both men and women. Received: 21 December 2018 Accepted: 26 May 2019 Funding Funding
There was no funding of the manuscript. 15. Shamu S, Zarowsky C, Shefer T, Temmerman M, Abrahams N. Intimate
partner violence after disclosure of HIV test results among pregnant women
in Harare, Zimbabwe. PLoS One. 2014;9(10):e109447. 15. Shamu S, Zarowsky C, Shefer T, Temmerman M, Abrahams N. Intimate
partner violence after disclosure of HIV test results among pregnant women
in Harare, Zimbabwe. PLoS One. 2014;9(10):e109447. Acknowledgements This protocol is supported by the College of Health Sciences, School of
Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa. This gesture is greatly appreciated. 9. Jewkes RK, Levin J, Penn-Kekana LA. Gender inequalities, intimate partner
violence and HIV preventive practices: findings of a South African cross
sectional study. Soc Sci Med. 2003;56:125–34. 10. Joseph-Shehu EM, Ncama BP. Evidence on health-promoting lifestyle
practices and information and communication technologies: scoping review
protocol. BMJ Open. 2017;7:1–4. Abbreviations
AIDS A
i d i AIDS: Acquired immune deficiency syndrome; HIV: Human
immunodeficiency virus; HIV/AIDS: Human immunodeficiency virus/acquired
immune deficiency syndrome; IPV: Intimate partner violence;
PICO: Population, interventions, comparison, and outcome; PLWHIV: Persons
living with the human immunodeficiency virus 7. Hatcher AM, Romito P, Odero M, Bukusi EA, Onono M, Turan JM. Social
context and drivers of intimate partner violence in rural Kenya: implications
for the health of pregnant women. Cult Health Sex. 2013;15(4):404–19. https://doi.org/10.1080/13691058.2012.760205. 7. Hatcher AM, Romito P, Odero M, Bukusi EA, Onono M, Turan JM. Social
context and drivers of intimate partner violence in rural Kenya: implications
for the health of pregnant women. Cult Health Sex. 2013;15(4):404–19. https://doi.org/10.1080/13691058.2012.760205. 8. Heath and development information team (2003). HIV and AIDS Key Issues
Guide; The links between violence against women and HIV and AIDS. http://www.hivpolicy.org/Library/HPP001388.pdf. Authors’ contributions FA contributed to the conception and generation of the review, planning,
conduction, analysis and interpretation of the data as well as the design
and together with EJS wrote the manuscript. BPN reviewed the manuscript
thoroughly and gave administrative support and advice. EJS performed the
conduction, analysis and interpretation of the data together with FA. All
authors read and approved the final manuscript. 11. Kaukinen C. Status compatibility, physical violence, and emotional abuse in
intimate relationships. J Marriage Fam. 2004;66:452–71. 12. Maman S, Campbell J, Sweat MD, Gielen AC. The intersections of HIV and
violence: directions for future research and interventions. Soc Sci Med. 2000;
50(4):459–78. 13. Oduro AD, Deere CD, Catanzarite ZB. Women’s wealth and intimate partner
violence: insights from Ecuador and Ghana. Fem Econ. 2015;21(2):1–29. 13. Oduro AD, Deere CD, Catanzarite ZB. Women’s wealth and intimate partner
violence: insights from Ecuador and Ghana. Fem Econ. 2015;21(2):1–29. References 1. Addressing violence against HIV positive women. http://www.endvawnow. org/en/articles/875-addressing-violence-against-hiv-positivewomen.html. Accessed 16th August, 2018. 1. Addressing violence against HIV positive women. http://www.endvawnow. org/en/articles/875-addressing-violence-against-hiv-positivewomen.html. Accessed 16th August, 2018. 2. Amoakohene MI. Violence against women in Ghana: a look at women’s
perceptions and review of policy and social responses. Soc Sci Med. 2004;
59(11):2373–85. 2. Amoakohene MI. Violence against women in Ghana: a look at women’s
perceptions and review of policy and social responses. Soc Sci Med. 2004;
59(11):2373–85. 3. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ). Stigma and
discrimination of people living with HIV in Ghana: a major challenge in the
fight against AIDS. Accra: Deutsche Gesellschaft fürInternationale
Zusammenarbeit (GIZ) Gmb; 2011. 3. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ). Stigma and
discrimination of people living with HIV in Ghana: a major challenge in the
fight against AIDS. Accra: Deutsche Gesellschaft fürInternationale
Zusammenarbeit (GIZ) Gmb; 2011. 4. Ebotabe, A., Johan, A Lacor, B, P and Deschepper, R (2015). “It’s my secret”:
fear of disclosure among sub-Saharan African migrant women living with
HIV/AIDS in Belgium, PLoS One, 10(3): 10–1371. 5. Gyimah A, Nakua EK, Owusu-Dabo E, Easmon Otupiri E. Contraceptive
characteristics of women living with HIV in the Kumasi Metropolis, Ghana. Int J MCH AIDS. 2013;2(1):111–20. 6. Hatcher AM, Woollett N, Pallitto CC, Mokoatle K, Stockl H, MacPhail C,
DelanyMoretlwe S, Garcia-Moreno C. Bidirectional links between HIV and
intimate partner violence in pregnancy: implications for prevention of
mother-to-child transmission. J Int AIDS Soc. 2014;17:19233. 6. Hatcher AM, Woollett N, Pallitto CC, Mokoatle K, Stockl H, MacPhail C,
DelanyMoretlwe S, Garcia-Moreno C. Bidirectional links between HIV and
intimate partner violence in pregnancy: implications for prevention of
mother-to-child transmission. J Int AIDS Soc. 2014;17:19233. Authors’ information Authors information
There is no information necessary to be written. 14. Sarnquist C, Kang J, Moyo P, Stranix-Chibanda L, Tagwira V, Chang D,
Maldonado Y. Intimate partner violence and HIV-infection among women
in Zimbabwe: a complex interplay. 142nd APHA annual meeting and
exposition; 2014. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations. Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations. Competing interests
The authors declare that they have no competing interests. Ethics approval and consent to participate
Not applicable Ethics approval and consent to participate
Not applicable 18. UNAIDS. Report on the global AIDS epidemic, 2012. Geneva: UNAIDS; 2012. UNAIDS. Report on the global AIDS epidemic, 2012. Geneva: UNAID 18. UNAIDS. Report on the global AIDS epidemic, 2012. Geneva: UNAIDS; 2012. Availability of data and materials Since this manuscript is a protocol for a scoping review, there are no data to
share. However, when the study is complete we would be happy to share
the dataset. 16. Spangenberg K, Wobil P, Betts CL, Wiesner TF, Gold KJ. Intimate partner
violence among mothers of sick newborns in Ghana. Health Care Women
Int. 2015;11:1–12 6 UN Women (2012). 16. Spangenberg K, Wobil P, Betts CL, Wiesner TF, Gold KJ. Intimate partner
violence among mothers of sick newborns in Ghana. Health Care Women
Int. 2015;11:1–12 6 UN Women (2012). 17. UN-Women. (2012). Annual report 2011–2012. Retrieved from UN: http://
www.unwomen.org/en/digital-library/publications/2012/8/annual-report-
2011-2012 17. UN-Women. (2012). Annual report 2011–2012. Retrieved from UN: http://
www.unwomen.org/en/digital-library/publications/2012/8/annual-report-
2011-2012 Author details
1 Author details
1School of Nursing and Public Health, College of Health Sciences, University
of KwaZulu-Natal, Desmond Clearance Building, Howard College Campus,
Durban 4001, South Africa. 2Department of Nursing, Faculty of Allied Health
Sciences, College of Health Sciences, Kwame Nkrumah University of Science
and Technology, Kumasi, Ghana. 3Department of Nursing, Faculty of Health
Sciences, National Open University of Nigeria, Jabi, Abuja, Nigeria.
|
https://openalex.org/W2916628632
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https://hal.archives-ouvertes.fr/hal-02065971/document
|
English
| null |
Discrete Geometry from Quantum Walks
|
Condensed matter
| 2,019
|
cc-by
| 10,687
|
To cite this version: Fabrice Debbasch. Discrete Geometry from Quantum Walks. Condens.Mat., 2019, 4 (2), pp.40. 10.3390/condmat4020040. hal-02065971 Distributed under a Creative Commons Attribution 4.0 International License Received: 28 February 2019; Accepted: 9 April 2019; Published: 11 April 2019 Abstract: A particular family of Discrete Time Quantum Walks (DTQWs) simulating fermion
propagation in 2D curved space-time is revisited. Usual continuous covariant derivatives and
spin-connections are generalized into discrete covariant derivatives along the lattice coordinates and
discrete connections. The concepts of metrics and 2-beins are also extended to the discrete realm. Two slightly different Riemann curvatures are then defined on the space-time lattice as the curvatures
of the discrete spin connection. These two curvatures are closely related and one of them tends at
the continuous limit towards the usual, continuous Riemann curvature. A simple example is also
worked out in full. Keywords:
discrete time quantum walks; discrete geometry; discrete Riemann curvature;
discrete metric Fabrice Debbasch Fabrice Debbasch
Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-75005 Paris, France;
fabrice.debbasch@gmail.com Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-75005 Paris, France;
fabrice.debbasch@gmail.com
Condens. Matter 2019, 4, 40; doi:10.3390/condmat4020040 HAL Id: hal-02065971
https://hal.science/hal-02065971v1
Submitted on 1 Mar 2022 L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés. HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers. Distributed under a Creative Commons Attribution 4.0 International License www.mdpi.com/journal/condensedmatter 1. Introduction Discrete Time Quantum Walks (DTQWs) are unitary quantum automata. They have been first
considered by Feynman [1] as tools to discretise path integrals for fermions, and later introduced
in a more formal and systematic way in Aharonov [2] and Meyer [3]. DTQWs have been realized
experimentally with a wide range of physical objects and setups [4–10], and are studied in a large
variety of contexts, ranging from quantum optics [10] to quantum algorithmics [11,12], condensed
matter physics [13–17], hydrodynamics [18] and biophysics [19,20]. It has been shown recently [21–30] that several DTQWs admit as continuous limit the dynamics
of Dirac fermions coupled to arbitrary Yang–Mills gauge fields (including electromagnetic fields) and
to arbitrary relativistic gravitational fields. In addition, a DTQW coupled to a uniform electric field has
already been realized experimentally [31]. Quite remarkably, the DTQWs which converge towards fermions coupled to Yang–Mills fields
also admit exact discrete gauge invariances and discrete field strength ‘tensors’. These can be used
e.g., to build new self-consistent discrete models of Dirac fermions interacting with Yang–Mills fields,
where DTQWs are not only acted upon by gauge fields, but also act as sources to these fields. On the
contrary, no exact discrete gauge invariance has been displayed for DTQWs which converge towards
fermions coupled to gravitational fields, and no discrete field strength i.e., Riemann curvature has
been defined either. This article demonstrates how this gap can be filled. We focus on a certain family of DTQWs in
discrete 2D space-time whose continuous limit coincides the dynamics of a (massless) Dirac fermion. We first show that these admit an exact discrete Lorentz gauge invariance and then present two
alternate definitions of the Riemann curvature for these walks. More precisely, we define for each
discrete walk discrete covariant derivatives in the direction of the grid coordinates. These derivatives
generalise the usual covariant derivatives of differential geometry and allow the identification, not only
of a discrete metric and a discrete 2-bein, but also of a discrete spin-connection defined on the lattice. The basic idea is then to define the Riemann curvature tensor of the space-time lattice (or of the DTQW) Condens. Matter 2019, 4, 40; doi:10.3390/condmat4020040 www.mdpi.com/journal/condensedmatter www.mdpi.com/journal/condensedmatter 2 of 16 Condens. Matter 2019, 4, 40 as the curvature of the spin connection using as gauge group the set of Lorentz transformations acting
on spinors [32,33]. 2. Results Blueprint: The 2D Dirac Equation 2.1. Blueprint: The 2D Dirac Equation 2.1. Blueprint: The 2D Dirac Equation The curved space-time Dirac equation is usually written in the form [34,35] iγaeµ
a DµΨ = mΨ,
(1) (1) where Ψ is a spinor, and eµ
a are the n-bein coefficients, which we suppose to be symmetrical, i.e., eµ
a = ea
µ
(note that this relation makes sense because there are as many values of µ as there are values of a and
because it equates coefficients i.e., tensor components in a given basis, and not tensors). The γ’s are the
so-called Dirac operators obeying the usual Clifford algebra, and where Ψ is a spinor, and eµ
a are the n-bein coefficients, which we suppose to be symmetrical, i.e., eµ
a = ea
µ
(note that this relation makes sense because there are as many values of µ as there are values of a and
because it equates coefficients i.e., tensor components in a given basis, and not tensors). The γ’s are the
so-called Dirac operators obeying the usual Clifford algebra, and Dµ = ∂µ + 1
8ωµab
h
γa, γbi
. (2) (2) In 2D space-time, Greek and Latin indices above only take two values, conveniently denoted
by 0 and 1. The spin-connection ω has thus only two independent components ω001 = −ω010
and ω101 = −ω110. The spinor Hilbert space is also two-dimensional and is equipped with the
Hermitian product, < Ψ(x0, x1), Φ(x0, x1) >=
Z
x1∈R Ψ∗(x0, x1)Φ(x0, x1)µ(x0, x1)dx1,
(3) (3) where µ = (−det(gµν))1/2 where gµν are the metric components built from the 2-bein, which can be
defined by gµνeµ
a eν
b = ηab where (ηab) = diag(1, −1) are the components of the 2D Minkovski metric
in an orthonormal basis of the tangent space. We now choose an orthonormal basis (b−, b+) in spinor
space and represent an arbitrary spinor Ψ by its two components (Ψ−, Ψ+). We also choose the Dirac
operators γ0 and γ1 to ensure that their matrix representations in this basis coincide respectively with σx
and +iσy where y
σx =
0
1
1
0
! (4)
and
σy =
0
−i
i
0
! (5) σx =
0
1
1
0
! (4) (4) and and σy =
0
−i
i
0
! (5) (5) are the first two Pauli matrices. 1. Introduction It turns out that there are actually two ways of implementing this idea and we
therefore introduce two different discrete Riemann curvatures on the space-time lattice. The first
Riemann curvature ρ∗depends on a (nearly arbitrary) reference connection while the second one ρs
does not. It turns out that the curvature ρ∗of the DTQW essentially represents the difference between
the curvature ρs of the DTQW and the curvature ρs of the reference connection. We also show that,
in the continuous limit, the Riemann curvature tends towards the usual, continuous Riemann tensor. We finally compute the curvature ρs on a simple example before discussing all results. 2. Results The commutator then reads
γ0, γ1 = 2σz = −2diag(1, −1). Expanding the compact notation above, the Dirac therefore equation reads: (e0
0 −e0
1)
∂0ψ−−ω001
2
ψ−
+ (e1
0 −e1
1)
∂1ψ−−ω101
2
ψ−
=
−imψ+,
(e0
0 + e0
1)
∂0ψ+ + ω001
2
ψ+
+ (e1
0 + e1
1)
∂1ψ+ + ω101
2
ψ+
=
−imψ−. (6) (6) The 2-bein, the metric and the two non-vanishing connection coefficients can then be practically
read off directly from the Dirac equation. Taking the continuous limit of the QWs considered in this The 2-bein, the metric and the two non-vanishing connection coefficients can then be practically
read off directly from the Dirac equation. Taking the continuous limit of the QWs considered in this Condens. Matter 2019, 4, 40 3 of 16 article delivers this form of the Dirac equation [22]. In the next section, we will use discrete derivatives
and put the QW equations in a form similar to (6) and thus identify in the discrete equations a 2-bein,
a metric and a connection. By definition, Lorentz transformations on spinors are generated by the commutator of the
γ′s. Thus, in 2D space-time, the Lorentz transform Ψ(Λ) of a spinor Ψ has components Ψ±(Λ) =
exp(±Λ)Ψ± for an arbitrary, possibly space- and time-dependent Λ. In addition, the components
of the spin connection transform according to ωµab(Λ) = ωµab + ∂µΛ. It follows from this that
Rµνab = ∂µωνab −∂νωµab is invariant under Lorentz transformation. This quantity is the (µνab)-,
so-called mixed component of the Riemann curvature tensor. The components Rµναβ of the Riemann
curvature tensor on the coordinate basis (∂µ) are Rµναβ = RµνabEa
αEb
β where (Ea
α) are the coordinate
basis components of the inverse 2-bein: eµ
a Eb
µ = δa
b. The Ricci tensor and the scalar curvature are
defined from Rµναβ in the standard manner. Note that the expression of Rµνab is linear in the connection
because the Lorentz group is abelian in 2D space-time. In what follows, a discrete Riemann curvature
tensor will be computed by implementing Lorentz transformations on the discrete equations and
identifying an invariant quantity. 2.2. A Simple Two-Step Quantum Walk 2.2. A Simple Two-Step Quantum Walk We work with two-component wave-functions Ψ defined in 2D discrete space-time where instants
are labeled by j ∈N and spatial positions are labeled by p ∈Z and Ψj = (ψj,p)p∈Z. We introduce
a basis (bA) = (bL, bR) in Hilbert-space space and the components ΨA = (ΨL, ΨR) of the arbitrary
wave-function Ψ in this basis. The Hilbert product is defined by < ψ, φ >= ∑A,j,p(ψA)∗
j,p(φA)j,p,
which makes the basis (bA) orthonormal. Consider now the quantum walk Ψj+1 = UjTΨj where T
is the spin-dependent spatial translation operator defined by (TΨj)j,p = (ψL
j,p+1, ψR
j,p−1)T and Uj is
an SU(2) operator defined by (UjΨj)j,p = U(θj,p)ψj,p,
(7) (UjΨj)j,p = U(θj,p)ψj,p,
(7)
U(θ) =
−cos θ
i sin θ
−i sin θ
+ cos θ
! . (8) (7) where U(θ) =
−cos θ
i sin θ
−i sin θ
+ cos θ
! . (8) (8) This article focuses on the two-step QW obtained by looking at the state of the original walk at
only one in every two time steps, say the steps which correspond to even values of j (this is sometimes
called the stroboscopic approach). This article focuses on the two-step QW obtained by looking at the state of the original walk at
only one in every two time steps, say the steps which correspond to even values of j (this is sometimes
called the stroboscopic approach). Written in full, the discrete equations of the two-step QW read: Written in full, the discrete equations of the two-step QW read: ψL
j+2,p
=
cj+1,p
cj,p+1ψL
j,p+2 −isj,p+1ψR
j,p
+ sj+1,p
sj,p−1φL
j,p + icj,p−1ψR
j,p−2
,
ψR
j+2,p
=
sj+1,p
icj,p+1ψL
j,p+2 + sj,p+1ψR
j,p
−cj+1,p
isj,p−1ψL
j,p −cj,p−1ψR
j,p−2
,
(9) (9) where cj,p = cos θj,p and sj,p = sin θj,p As shown in [22], this two-step QW admits a continuous limit if
θ admits one and this limit coincides with the Dirac equation in a curved 2D space-time where the
spinor connection and curvature depend on the derivatives of θ. The aim of this article is to show that
the discrete equation can also be used to define a discrete metric, a discrete space-time connection and
a discrete Riemann ‘tensor’ i.e., a full discrete geometry. 2.3. Covariant Discrete Derivatives To define the geometry induced by this QW on the space-time lattice, it is necessary to change
basis in the wave-function Hilbert space. The easiest way to do that is to write the equations of motion
of the QW in an invariant, basis-independent manner by introducing covariant discrete derivatives in
Hilbert space. p
We start by defining the following simple, non covariant discrete derivatives: Condens. Matter 2019, 4, 40
4 of 16 Condens. Matter 2019, 4, 40 Condens. Matter 2019, 4, 40 4 of 16 4 of 16 (Dj f )jp
=
1
2 ( fj+2,p −fj,p),
(Dp f )j,p
=
1
4
fj,p+2 −fj,p−2
,
(10)
(Dpp f )j,p
=
1
4
fj,p+2 + fj,p−2 −2fj,p
, (10) where f is an arbitrary j- and p-dependent quantity. These are discrete versions of the usual partial
derivatives. Inverting the above equations delivers: where f is an arbitrary j- and p-dependent quantity. These are discrete versions of the usual partial
derivatives. Inverting the above equations delivers: fj+2,p
=
fj,p + 2(Dj f )jp,
fj,p+2
=
fj,p + 2(Dp f )j,p + 2(Dpp f )j,p,
(11)
fj,p−2
=
fj,p −2(Dp f )j,p + 2(Dpp f )j,p. (11) The equation of motion of the QW can then be rewritten as: The equation of motion of the QW can then be rewritten as: (DjΨA)j,p = (Wj,pσ3)A
B (DpΨB)j,p + (1/2)(Wj,p + Lj,p −1)A
B ΨB
j,p + (Wj,p)A
B (DppΨB)j,p,
(12) (12) where (WA
B )j,p =
cj+1,pcj,p+1
isj+1,pcj,p−1
isj+1,pcj,p+1
cj+1,pcj,p−1
! ,
(13)
(LA
B )j,p =
sj+1,psj,p+1
−icj+1,psj,p+1
−icj+1,psj,p−1
sj+1,psj,p+1
! (14) (13) (14) and σ3 is the operator represented by the third Pauli matrix in the basis (bA) i.e., σ3 is represented by
the matrix diag(1, −1) in the basis (bA). Suppose now we change spin basis and rewrite (12) in a new, possibly j- and p-dependent local
basis bα = (b−, b+). We need to introduce the operator rj,p which transforms the original basis bA into
the basis bα, (bα)j,p = (rj,p)A
α bA, and its inverse r−1
j,p . Thus, ψjp = ψA
jpbA = ψA
jp
(r−1)α
A
jp bα = ψα
jpbα so
that ψα
jp =
(r−1)α
A
jp ψA
jp and ψA
jp = (rA
α )jpψα
jp. jp
jp
jp
jp
jp
jp
Let us now define covariant time- and space-derivatives, starting with derivation with respect to
time. 2.3. Covariant Discrete Derivatives One has: jp
jp
jp
jp
jp
Let us now define covariant time- and space-derivatives, starting with derivation with respect to
time. One has: (DjψA)j,p
=
1
2
(rA
α )j+2,pψα
j+2,p −(rA
α )j,pψα
j,p
=
(rA
α )j,p + 2(DjrA
α )j,p
(Djψα)j,p + (DjrA
α )j,pψα
j,p. (15) (15) This shows that (DjψA) does not transforms as ψA under a change of basis in Hilbert space,
but this also suggests introducing a new, covariant time-derivative of the form This shows that (DjψA) does not transforms as ψA under a change of basis in Hilbert space,
but this also suggests introducing a new, covariant time-derivative of the form
Dj(A)ψA
j,p =
A1
j,p
A
B (DjψB)j,p +
A0
j,p
A
B ψB
j,p ,
(16) (16) where (A) = (A0, A1) is an arbitrary j- and p-dependent field. Using (15), one can write:
Dj(A)ψA
j,p = (rA
α )j,p
Dj(A)ψα
j,p ,
(17) (17) where
Dj(A)ψα
j,p =
A1
j,p
α
β (Djψβ)j,p +
A0
j,p
α
β ψβ
j,p,
(18)
with
(A0)α
β = (r−1)α
A(A0)A
B (rB
β) + (r−1)α
A(A1)A
B (DjrB
β)
(19) where where Dj(A)ψα
j,p =
A1
j,p
α
β (Djψβ)j,p +
A0
j,p
α
β ψβ
j,p,
(18) (18) β
β
with
(A0)α
β = (r−1)α
A(A0)A
B (rB
β) + (r−1)α
A(A1)A
B (DjrB
β)
(19) with (A0)α
β = (r−1)α
A(A0)A
B (rB
β) + (r−1)α
A(A1)A
B (DjrB
β)
(19) (A0)α
β = (r−1)α
A(A0)A
B (rB
β) + (r−1)α
A(A1)A
B (DjrB
β)
(19) (19) ens. Matter 2019, 4, 40
5 of 16 Condens. Matter 2019, 4, 40 5 of 16 and (A1)α
β = (r−1)α
A(A1)A
B (rB
γ) ×
δγ
β + 2(r−1)γ
C(DjrC
β )
,
(20) (20) and the time- and space-indices j and p have been omitted from the latest equations for readability
purposes. Equation (17) proves that Dj(A) is a covariant time-derivative. p
p
q
(
) p
j(
)
Space derivatives are slightly more complex. Using again (12), one can write: j
Space derivatives are slightly more complex. 2.3. Covariant Discrete Derivatives Using again (12), one can write: (DpψA)j,p
=
1
4
(rA
α )j,p+2ψα
j,p+2 −(rA
α )j,p−2ψα
j,p−2
=
(rA
α )j,p + 2(DpprA
α )j,p
(Dpψα)j,p + (DprA
α )j,p
ψα
j,p + 2(Dppψα)j,p
(21) (21) and (DppψA)j,p
=
1
4
(rA
α )j,p+2ψα
j,p+2 + (rA
α )j,p−2ψα
j,p−2 −2(rA
α )j,pψα
j,p
=
(rA
α )j,p + 2(DpprA
α )j,p
(Dppψα)j,p + 2(DprA
α )j,p(Dpψα)j,p + (DpprA
α )j,pψα
j,p. (22) (22) As before, this suggests defining a spatial covariant derivative by: As before, this suggests defining a spatial covariant derivative by:
Dp(A)ψA
j,p =
A1
j,p
A
B (DpψB)j,p +
A0
j,p
A
B ψB
j,p +
A2
j,p
A
B (DppψB)j,p
(23) (23) where (A) = (A0, A1, A2) is an arbitrary j- and p-dependent field and the transformation laws for
A reads (A0)α
β = (r−1)α
A(A0)A
B (rB
β) + (r−1)α
A(A1)A
B (DprB
β) + (r−1)α
A(A2)A
B (DpprB
β),
(24)
(A1)α
β = (r−1)α
A(A1)A
B (rB
γ) ×
δγ
β + 2(r−1)γ
C(DpprC
β )
+ 2(r−1)α
A(A2)A
B DprB
β
(25) (24) (25) and (A2)α
β = (r−1)α
A(A2)A
B (rB
γ) ×
δγ
β + 2(r−1)γ
C(DpprC
β )
+ 2(r−1)α
A(A1)A
B DprB
β. (26) (A2)α
β = (r−1)α
A(A2)A
B (rB
γ) ×
δγ
β + 2(r−1)γ
C(DpprC
β )
+ 2(r−1)α
A(A1)A
B DprB
β. (26) (26) The equation of motion (12) of the QW can be rewritten in terms of covariant derivatives. We introduce a time-connection A and a space-connection B, fixing only at this stage the values
of their 1- and 2-components: The equation of motion (12) of the QW can be rewritten in terms of covariant derivatives. We introduce a time-connection A and a space-connection B, fixing only at this stage the values
of their 1- and 2-components: (A1)A
B
=
δA
B ,
(27)
(B1)A
B
=
δA
B ,
(B2)A
B
=
(σ3)A
B . 2.4.1. Preliminary Gauge Change Proceeding as in [22,23], we now change gauge i.e., spin basis by defining an operator r which
puts Wj,pσ3 in diagonal form. The characteristic polynomial of Wj,pσ3 reads Proceeding as in [22,23], we now change gauge i.e., spin basis by defining an operator r which
puts Wj,pσ3 in diagonal form. The characteristic polynomial of Wj,pσ3 reads (31) Pj,p(x) = x2 + cj,pδj,px −πj,p,
(31) where δj,p = cj,p−1 −cj,p+1 and πj,p = cj,p−1cj,p+1. Let (xα)j,p, α = +, −be the two (possibly complex)
roots of Pj,p. From Equations (12) and (30), the eigenvalues (xα)j,p actually determine two local
transport velocities. More precisely, these eigenvalues actually define a set of local 2-bein coefficients
(eµ
0, eν
1)jp (see above for details) on the space-time lattice. One finds e0
0 = 1, e0
1 = 0, e1
0 = (x+ + x−)/2,
e1
1 = (x+ −x−)/2. This in turn defines the inverse metric ‘components’ on the space-time lattice
g00 = 1, g11 = x+x−and g01 = (x+ + x−)/2. The determinant of these components is −µ2 =
−(x+ −x−)2/4. In the usual differential, and thus continuous geometry, the Greek indices on n-bein coefficients,
(inverse) metric components, etc. refer to components on the so-called coordinate basis (∂µ) = (∂t, ∂x). In the discrete case, the equivalent of the basis (∂µ) is clearly the set (Dj, Dp) and we therefore define
accordingly the 2-bein ‘vectors’ e0 = ej
0Dj + ep
0Dp and e1 = ej
1Dj + ep
1Dp. The quantities gµν can be
interpreted similarly as the components of the inverse metric gjjDj ⊗Dj + 2gjpDj ⊗Dp + gppDp ⊗Dp. Changes of space-time coordinates can then be implemented in the spirit of [36]. We finally define the
discrete inverse 2-bein by the usual relations Ea
µeµ
b = δa
b where δa
b is the Kronecker symbol. µ
We now recall that, in curved space-time, a spinor is normalized to unity, not with respect to the
usual Lebesgue measure d2x , but with respect to the metric-induced measure
p
(−detg)d2x where
detg stands for the determinant of the metric components. This means that the usual Hilbert product
< ψ, φ >= ∑A,j,p(ψA)∗
j,p(φA)j,p, which makes the initial basis bA orthonormal, does not coincide with
the natural Hilbertian product to be used in spinor space. 2.4.1. Preliminary Gauge Change We therefore define the new Hilbertian
product by < ψ, φ >s= ∑A,j,p µj,p(ψA)∗
j,p(φA)j,p, a new basis (bα)j,p made of two eigenvectors of Wσ3
normalized with respect to < · >s and we define rj,p as the operator which transforms the original
basis bA into the basis bα. 2.4.2. Choice of the Mass and Space-Time-Connection 2.3. Covariant Discrete Derivatives (28) (27) (28) We also introduce a ‘mass’M and impose that We also introduce a ‘mass’M and impose that We also introduce a ‘mass’M and impose that −iMA
B + (Wσ3B0)A
B −(A0)A
B = (1/2)(W + L −1)A
B ,
(29) (29) thus ensuring that the equation of motion (12) can be written as: thus ensuring that the equation of motion (12) can be written as: thus ensuring that the equation of motion (12) can be written as: thus ensuring that the equation of motion (12) can be written as: Dj(A)ψA = (Wσ3)A
B Dp(B)ψB −iMA
B ψB. (30) (30) The 0-components of both connections and of the mass M will be specified in the next section. In addition, the status of M is discussed in the last section of this article. The 0-components of both connections and of the mass M will be specified in the next section. In addition, the status of M is discussed in the last section of this article. Equation (30) is one step closer to the continuous Dirac equation that the original form of the
equations of motion obeyed by the two-step walk. In particular, it shows that the time-connection A Condens. Matter 2019, 4, 40 6 of 16 and the space-connection B are to be understood as two components of a single, space-time connection
(A, B). This point of view will be adopted form here on. and the space-connection B are to be understood as two components of a single, space-time connection
(A, B). This point of view will be adopted form here on. The most important difference between (30) and (6) is that the operator Wσ3 is not diagonal in the
basis (bA). Changing spin basis to make this operator diagonal is the goal of the next section. and Space-Time Connection
iminary Gauge Change 2.4. Mass and Space-Time Connection 2.4.2. Choice of the Mass and Space-Time-Connection Let us now specify the 0-components of the connections A and B as well as the mass M. Equations (29), (27) and (28) lead to: −iMα
β + (Wσ3B0)α
β
−
(A0)α
β = N α
β ,
(32) (32) where N α
β
=
(1/2)(W + L −1)α
β −(r−1)α
A(A1)A
B DjrB
β + (Wσ3)α
γ(r−1)γ
A
(B1)A
B DprB
β + (B2)A
B DpprB
β
=
(1/2)(W + L −1)α
β −(r−1)α
ADjrA
β + (Wσ3)α
γ(r−1)γ
A
δA
B DprB
β + (σ3)A
B DpprB
β
. (33) (33) We now define −iMα
β as the non-diagonal part of N α
β . This fully specifies M in any basis of the
Hilbert space and it also leads to We now define −iMα
β as the non-diagonal part of N α
β . This fully specifies M in any basis of the
Hilbert space and it also leads to (Wσ3B0)α
β
−
(A0)α
β = Oα
β,
(34) (34) 7 of 16 Condens. Matter 2019, 4, 40 where Oα
β is the diagonal part of N α
β . Since r was chosen to make (Wσ3)α
β diagonal, this last equation
makes it possible to choose both (A0)α
β and (B0)α
β diagonal, and (34) becomes a system of two equations
for the four unknown (A0)−
−, (A0)+
+, (B0)−
−, (B0)+
+. In a generic situation, this system can be solved
in a unique manner by imposing a couple of extra constraints on the unknown. We choose the same
constraints as in the continuous case (see Section 2.1) i.e., (A0)−
−= −(A0)+
+ and (B0)−
−= −(B0)+
+,
which make both (A0)α
β and (B0)α
β proportional to the third Pauli matrix σz. 2.5. Local Lorentz Transformations Extending the definition of global Lorentz transformations for DTQWs proposed in [36], we now
define the local Lorentz transform of the spinor Ψ by ψ−
j,p →λj,pψ−
j,p and ψ+
j,p →λ−1
j,p ψ+
j,p for an arbitrary,
real and non-vanishing field λ defined on the 2D space-time lattice. Alternately, upon a Lorentz
transformation, ψ →exp(Λσz)ψ where λ = exp(Λ) and σz is the operator represented by the
third Pauli matrix in the basis (b−, b+), and we use the practical notation ψα(Λ) = ρα
β(Λ)ψβ where
ρα
β(Λ) = exp(Λσz). Evidently, (ρ−1)α
β(Λ) = exp(−Λσz). ρβ
p
y
ρ
β
p
Let us now compute the Lorentz transform of the DTQW equation of motion. β
β
Let us now compute the Lorentz transform of the DTQW equation of motion. The mass M is anti-diagonal, so we write The mass M is anti-diagonal, so we write The mass M is anti-diagonal, so we write M =
0
M−
+
M+
−
0
! ,
(35) (35) which is not invariant under Lorentz transformation but becomes which is not invariant under Lorentz transformation but becomes M(Λ) =
0
e−2ΛM−
+
e+2ΛM+
−
0
! . (36) (36) Note that the product M−
+M+
−, which can be interpreted as the squared mass of the walk,
is invariant under Lorentz transformation. Note that the product M−
+M+
−, which can be interpreted as the squared mass of the walk,
is invariant under Lorentz transformation. The connection matrices also change under Lorentz transformation. Of particular interest are the
diagonal parts of these connections because they obey a relatively simple transformation law. 2.5. Local Lorentz Transformations Indeed, (A0)−
−(Λ)
=
(A0)−
−+ (A1)−
−× 1
2
exp(2DjΛ) −1
,
(37)
(A0)+
+(Λ)
=
(A0)+
+ + (A1)+
+ × 1
2
exp(−2DjΛ) −1
,
(38) (A0)−
−(Λ)
=
(A0)−
−+ (A1)−
−× 1
2
exp(2DjΛ) −1
,
(37)
(A0)+
+(Λ)
=
(A0)+
+ + (A1)+
+ × 1
2
exp(−2DjΛ) −1
,
(38)
(B0)−
−(Λ)
=
(B0)−
−+ 1
2 (B1)−
−exp(2DppΛ) sinh(2DpΛ)
2
1
(39) (37) (A0)+
+(Λ)
=
(A0)+
+ + (A1)+
+ × 1
2
exp(−2DjΛ) −1
,
(38) (38) (B0)−
−(Λ)
=
(B0)−
−+ 1
2 (B1)−
−exp(2DppΛ) sinh(2DpΛ)
+
(B2)−
−× 1
2
exp(2DppΛ) cosh(2DpΛ) −1
,
(39) (39) (B0)+
+(Λ)
=
(B0)+
+ + 1
2 (B1)+
+ exp(−2DppΛ) sinh(−2DpΛ)
+
(B2)+
+ × 1
2
exp(−2DppΛ) cosh(−2DpΛ) −1
,
(40)
(B1)−
−(Λ)
=
(B1)−
−exp(2DppΛ) cosh(2DpΛ)
+
(B2)−
−exp(2DppΛ) sinh(2DpΛ),
(41) (B0)+
+(Λ)
=
(B0)+
+ + 1
2 (B1)+
+ exp(−2DppΛ) sinh(−2DpΛ)
+
(B2)+
+ × 1
2
exp(−2DppΛ) cosh(−2DpΛ) −1
,
(40)
(B1)−(Λ)
(B1)−exp(2D
Λ) cosh(2D Λ) (40) (B1)−
−(Λ)
=
(B1)−
−exp(2DppΛ) cosh(2DpΛ)
+
(B2)−
−exp(2DppΛ) sinh(2DpΛ),
(41) (41) (B1)+
+(Λ)
=
(B1)+
+ exp(−2DppΛ) cosh(−2DpΛ)
+
(B2)+
+ exp(−2DppΛ) sinh(−2DpΛ). (42) (42) The first two equations lead to The first two equations lead to ∆A0(Λ) = (A1)−
−(A1)+
+ sinh(2DjΛ),
(43) ∆A0(Λ) = (A1)−
−(A1)+
+ sinh(2DjΛ),
(43) (43) Matter 2019, 4, 40
8 of 16 Condens. Matter 2019, 4, 40 8 of 16 where ∆A0(Λ) = (A1)+
+
(A0)−
−(Λ) −(A0)−
−
−(A1)−
−
(A0)+
+(Λ) −(A0)+
+
. (44) ∆A0(Λ) = (A1)+
+
(A0)−
−(Λ) −(A0)−
−
−(A1)−
−
(A0)+
+(Λ) −(A0)+
+
. (44) (44) The following two equations lead to The following two equations lead to The following two equations lead to exp(+2DppΛ)
=
2
(B0)−
−(Λ) −(B0)−
−+ (B2)−
−/2
(B1)−
−sinh(2DpΛ) + (B2)−
−cosh(2DpΛ),
exp(−2DppΛ)
=
2
(B1)+
+(Λ) −(B0)+
+ + (B2)+
+/2
−(B1)+
+ sinh(2DpΛ) + (B2)+
+ cosh(2DpΛ),
(45) (45) while the final two equations deliver while the final two equations deliver exp(+2DppΛ)
=
(B1)−
−(Λ)
(B1)−
−cosh(2DpΛ) + (B2)−
−sinh(2DpΛ),
exp(−2DppΛ)
=
(B1)+
+(Λ)
(B1)+
+ cosh(2DpΛ) −(B2)+
+ sinh(2DpΛ). 2.5. Local Lorentz Transformations (46) (46) Equating both expressions of exp(±2DppΛ) delivers Equating both expressions of exp(±2DppΛ) delivers tanh(+2DpΛ)
=
S−
−(B(λ), B)
C−
−(B(λ), B) = T −
−(B(λ), B),
tanh(−2DpΛ)
=
S+
+(B(λ), B)
C+
+(B(λ), B) = T +
+ (B(λ), B),
(47) (47) where S−
−(B(λ), B) = −(B1)−
−
(B0)−
−(Λ) −(B0)−
−+ (B2)−
−/2
+ (B2)−
−(B1)−
−(Λ)/2,
(48)
C−
−(B(λ), B) = +(B2)−
−
(B0)−
−(Λ) −(B0)−
−+ (B2)−
−/2
−(B1)−
−(B1)−
−(Λ)/2,
(49)
S+
+(B(λ), B) = +(B1)+
+
(B0)+
+(Λ) −(B0)+
+ + (B2)+
+/2
−(B2)+
+(B1)+
+(Λ)/2,
(50)
C+
+(B(λ), B) = +(B2)+
+
(B0)+
+(Λ) −(B0)+
+ + (B2)+
+/2
−(B1)+
+(B1)−
−(Λ)/2. (51) (48) (49) (51) It is best to retain for tanh(+2DpΛ) an expression which does not favour a set of components
over the other. We therefore choose It is best to retain for tanh(+2DpΛ) an expression which does not favour a set of components
over the other. We therefore choose tanh(+2DpΛ) = 1
2
T −
−(B(Λ), B) −T +
+ (B(Λ), B)
(52) (52) as the final expression for tanh(+2DpΛ). as the final expression for tanh(+2DpΛ). 2.6. Riemann Curvature I Assuming that (A1)−
−(A1)+
+ does not vanish and inverting the functions sinh and tanh,
Equations (43) and (52) can be rewritten under the form DjΛ
=
Lj(A(Λ), A),
DpΛ
=
Lp(B(Λ), B). (53) (53) The identity [Dj, Dp] = 0 then leads to DpLj(A(Λ), A) −DjLp(B(Λ), B) = 0. (54) DpLj(A(Λ), A) −DjLp(B(Λ), B) = 0. (54) Condens. Matter 2019, 4, 40 9 of 16 Introduce now a reference connection (A∗, B∗), with the sole constraint that Lj(A∗, A) and
Lp(B∗, B) are both defined, and write Lj(A(Λ), A)
=
Lj(A∗, A) + L∗
j (A(Λ), A),
Lp(B(Λ), B)
=
Lp(B∗, B) + L∗
p(B(Λ), B). (55) (55) Note that the identities Lj(A, A) = Lp(B, B) = 0 then imply Note that the identities Lj(A, A) = Lp(B, B) = 0 then imply Note that the identities Lj(A, A) = Lp(B, B) = 0 then imply L∗
j (A, A)
=
−Lj(A∗, A),
L∗
p(B, B)
=
−Lp(B∗, B). (56) (56) We then define the discrete Riemann curvature ρ∗
jp(Λ) by ρ∗
jp(Λ) = +
DpL∗
j (A(Λ), A)
j,p −
DjL∗
p(B(Λ), B)
j,p . 2.5. Local Lorentz Transformations (57) (57) By (56), ρ∗
jp(0) = −
DpLj(A∗, A)
j,p +
DjLp(B∗, B)
j,p ,
(58) (58) which represents the discrete Riemann curvature ρ∗of the connection (A, B) i.e., the curvature ρ∗of
the DTQW. which represents the discrete Riemann curvature ρ∗of the connection (A, B) i.e., the curvature ρ∗of
the DTQW. 2.7. Riemann Curvature II 2.7. Riemann Curvature II Matter 2019, 4, 40 one then needs only one of the two variations and it is natural to retain ¯B0(Λ). The equation for DpΛ
then reads
0
0
! n needs only one of the two variations and it is natural to retain ¯B0(Λ). The equation for DpΛ
ads one then needs only one of the two variations and it is natural to retain ¯B0(Λ). The equation for DpΛ
th
d DpΛ ≈1
2
( ¯B0)−
−(Λ)
(B1)−
−
−( ¯B0)+
+(Λ)
(B1)+
+
! (63) (63) and the equation for DjΛ becomes similarly DjΛ ≈1
2
( ¯A0)−
−(Λ)
(A1)−
−
−( ¯A0)+
+(Λ)
(A1)+
+
! ,
(64) (64) where ¯A(Λ) = A(Λ) −A. where ¯A(Λ) = A(Λ) −A. where ¯A(Λ) = A(Λ) −A. where A(Λ) = A(Λ) −A. From this choice and the identity [Dj, Dp] = 0 follows ( )
( )
From this choice and the identity [Dj, Dp] = 0 follows ( )
( )
From this choice and the identity [Dj, Dp] = 0 follows From this choice and the identity [Dj, Dp] = 0 follows 0
=
1
2 Dj
( ¯B0)−
−(Λ)
(B1)−
−
−( ¯B0)+
+(Λ)
(B1)+
+
! −
1
2 Dp
( ¯A0)−
−(Λ)
(A1)−
−
−( ¯A0)+
+(Λ)
(A1)+
+
! ,
(65) (65) where the s index stands for ‘slow’. The ‘slow’ discrete Riemann curvature tensor ρs
jp(Λ) of a connection
is then defined by: ρs
jp(Λ) = 1
2 Dj
(B0(Λ))−
−
(B1)−
−
−(B0(Λ))+
+
(B1)+
+
! −1
2 Dp
(A0(Λ))−
−
(A1)−
−
−(A0(Λ))+
+
(A1)+
+
! ,
(66) (66) where the index ‘s’ stands for slow, ensuring that ρs
jp(Λ) = ρs
jp(0). In addition, the Riemann of the
DTQW is defined as ρs
jp(0). 2.7. Riemann Curvature II Suppose now that one is interested in a curvature which caracterizes only how the connection
coefficients change under Lorentz transformations which vary slowly in time and space i.e., for which
DjΛ, DpΛ and DppΛ are all much smaller than unity. At the continuous limit, all Lorentz
transformations are automatically slowly varying in both time and space because the time and space
coordinates t and x are related to j and p by tj = ϵj and xp = ϵp, where ϵ is an infinitesimal [22,23],
so that Dp ∼ϵ∂x and Dpp ∼ϵ2∂xx. However, slowly varying Lorentz transformations can also be
considered outside the continuous limit (see the example in the next section). The limit case of Lorentz transformations varying slowly in space is actually singular. Indeed, in the
general case, Equations (37)–(42) relate the two independent variations B0(Λ) −B0 and B1(Λ) −B1
to the two independent discrete derivatives DpΛ and DppΛ. Inverting these equations thus delivers
DpΛ in terms of the two independent variables B0(Λ) −B0 and B1(Λ) −B1. To study the limit case
of slowly varying Lorentz transformations, suppose DpΛ = O(ϵ) and DppΛ = O(ϵα) with α > 1. Equations (37)–(42) then read: (B0)−
−(Λ)
=
(B0)−
−+ (B1)−
−DpΛ + o(ϵ),
(59) (59) (B0)+
+(Λ)
=
(B0)+
+ −(B1)+
+DpΛ + o(ϵ),
(60) (B0)+
+(Λ)
=
(B0)+
+ −(B1)+
+DpΛ + o(ϵ),
(60) (60) (B1)−
−(Λ) = (B1)−
−+ 2(B2)−
−DpΛ + o(ϵ),
(61) (B1)−
−(Λ) = (B1)−
−+ 2(B2)−
−DpΛ + o(ϵ), (61) (B1)+
+(Λ) = (B1)+
+ −2(B2)+
+DpΛ + o(ϵ). (62) (62) At the first order in ϵ, DppΛ vanishes from the equations so both variations ¯B0(Λ) = B0(Λ) −B0
and ¯B1(Λ) = B1(Λ) −B1 depend on the single variable DpΛ and they are therefore not independent. Indeed, ¯B1(Λ) = 2B2 ¯B0(Λ). In this limit, the general problem, which depends on two variables,
thus degenerates into a single variable problem, thus making the limit singular. To define curvature, At the first order in ϵ, DppΛ vanishes from the equations so both variations ¯B0(Λ) = B0(Λ) −B0
and ¯B1(Λ) = B1(Λ) −B1 depend on the single variable DpΛ and they are therefore not independent. Indeed, ¯B1(Λ) = 2B2 ¯B0(Λ). In this limit, the general problem, which depends on two variables,
thus degenerates into a single variable problem, thus making the limit singular. To define curvature, 10 of 16 Condens. Matter 2019, 4, 40 Condens. 2.8. Relation between the Two Riemann Curvatures Let us now investigate how this second discrete Riemann tensor is related to the first one
introduced in the previous section. To do so, suppose that both connections (A∗, B∗) and (A(Λ), B(Λ))
are close to (A, B), in the sense that their coefficients in the basis (bα) are close to those of (A, B). This implies in particular that DjΛ, DpΛ and DppΛ are small (see Equations (37)–(42)) i.e., that Λ is
slowly varying in time and space. To simplify the discussion, we also suppose that there exist a Λ∗
such that (A∗, B∗) = (A(Λ∗), B(Λ∗)), and Λ∗is then also slowly varying in time and space. We now
convert Lj and Lp into a function ¯Lj of ( ¯A(Λ), A) and a function ¯Lp of ( ¯B(Λ), B) and expand these
two newly introduced functions in their first variable at first order around 0. This leads to: ¯Lj( ¯A(Λ), A)
≈
¯A(Λ)
∂¯Lj
∂¯A
! (0,A)
,
¯Lj( ¯A(Λ∗), A)
≈
¯A(Λ∗)
∂¯Lj
∂¯A
! (0,A)
,
¯Lp( ¯B(Λ), B)
≈
¯B(Λ)
∂¯Lp
∂¯B
(0,B)
,
¯Lp( ¯B(Λ∗), B)
≈
¯B(Λ∗)
∂¯Lp
∂¯B
(0,B)
. (67) (67) 11 of 16 Condens. Matter 2019, 4, 40 From this follows that From this follows that ¯L∗
j ( ¯A(Λ), A)
≈
(A(Λ) −A(Λ∗))
∂¯Lj
∂¯A
! (0,A)
,
¯L∗
p( ¯B(Λ), B)
≈
(B(Λ) −B(Λ∗))
∂¯Lp
∂¯B
(0,B)
,
(68) (68) which leads to which leads to which leads to ρ∗
jp(Λ) ≈¯ρjp(Λ) −¯ρjp(Λ∗),
(69) ρ∗
jp(Λ) ≈¯ρjp(Λ) −¯ρjp(Λ∗), (69) where ¯ρjp(Λ) = Dp
¯A(Λ)
∂¯Lj
∂¯A
! (0,A)
−Dj
¯B(Λ)
∂¯Lp
∂¯B
(0,B)
! . (70) (70) Using again (67), this becomes ¯ρjp(Λ) = Dp
¯Lj( ¯A(Λ), A)
−Dj
¯Lp( ¯B(Λ), B)
. (71) (71) Now, by definition, ¯Lj represents DjΛ and ¯Lp represents DpΛ. Since we are considering Λ’s
which vary slowly in time and space, Equations (63) and (64) are valid. Thus, ρ∗
jp(Λ) ≈ρs
jp(Λ) −ρs
jp(Λ∗). (72) (72) In particular, ρ∗
jp(0) = ρs
jp(0) −ρs
jp(Λ∗), which links the two Riemann curvatures ρ∗and ρs of the
space-time lattice. In particular, ρ∗
jp(0) = ρs
jp(0) −ρs
jp(Λ∗), which links the two Riemann curvatures ρ∗and ρs of the
space-time lattice. 2.9. Continuous Limit The discrete Riemann curvature then tends towards ϵ2/2 × Rµνab, where Rµνab is the
mixed component of the usual Riemann curvature tensor to µ = 0, ν = 1, a = 0, b = 1. This component
contains all the information one needs about the Riemann tensor because this tensor, in 2D space-times,
has only one independent component. The 1/2 in the multiplicative factor comes form the fact that the
zeroth components of the discrete connection tend towards ω/2 (as opposed to ω). The ϵ2 factor comes
from the fact that curvatures are obtained by taking second discrete or continuous derivatives and that
the above relation between (j, p) and (t, x) implies Dj = ϵ∂t and Dp = ϵ∂x. Finally, the components
Rµν01 of the continuous Riemann curvature tensor on the coordinate basis (∂µ) can be recovered by
taking the continuous limit of Ea
µEb
νρs where (Ea
µ) is the discrete inverse 2-bein. 2.9. Continuous Limit Let us now discuss the continuous limit of ρs. The continuous limit addresses situations where
the operator U and the wave-function of the walk vary on time- and space-scale much larger than
the grid cell. The physical time t and spatial coordinate x along the grid are related to j and p by
tj = ϵj and xp = ϵp where ϵ is an infinitesimal. It has been shown in [22,23] that the continuous
limit of the 2-step walk then coincides with the Dirac equation in a curved space-time with metric
(gµν) = diag(1, cos−2 θ). In particular, the matrices representing A1 and B1 in the basis (bα) then tend
towards unity while the matrix representing A0 tends towards −(ω001/2) × 1 and B0 tends towards
−(ω101/2) × 1. The discrete Riemann curvature then tends towards ϵ2/2 × Rµνab, where Rµνab is the
mixed component of the usual Riemann curvature tensor to µ = 0, ν = 1, a = 0, b = 1. This component
contains all the information one needs about the Riemann tensor because this tensor, in 2D space-times,
has only one independent component. The 1/2 in the multiplicative factor comes form the fact that the
zeroth components of the discrete connection tend towards ω/2 (as opposed to ω). The ϵ2 factor comes
from the fact that curvatures are obtained by taking second discrete or continuous derivatives and that
the above relation between (j, p) and (t, x) implies Dj = ϵ∂t and Dp = ϵ∂x. Finally, the components
Rµν01 of the continuous Riemann curvature tensor on the coordinate basis (∂µ) can be recovered by
taking the continuous limit of Ea
µEb
νρs where (Ea
µ) is the discrete inverse 2-bein. Let us now discuss the continuous limit of ρs. The continuous limit addresses situations where
the operator U and the wave-function of the walk vary on time- and space-scale much larger than
the grid cell. The physical time t and spatial coordinate x along the grid are related to j and p by
tj = ϵj and xp = ϵp where ϵ is an infinitesimal. It has been shown in [22,23] that the continuous
limit of the 2-step walk then coincides with the Dirac equation in a curved space-time with metric
(gµν) = diag(1, cos−2 θ). 2.9. Continuous Limit In particular, the matrices representing A1 and B1 in the basis (bα) then tend
towards unity while the matrix representing A0 tends towards −(ω001/2) × 1 and B0 tends towards
−(ω101/2) × 1. The discrete Riemann curvature then tends towards ϵ2/2 × Rµνab, where Rµνab is the
mixed component of the usual Riemann curvature tensor to µ = 0, ν = 1, a = 0, b = 1. This component
contains all the information one needs about the Riemann tensor because this tensor, in 2D space-times,
has only one independent component. The 1/2 in the multiplicative factor comes form the fact that the Let us now discuss the continuous limit of ρs. The continuous limit addresses situations where
the operator U and the wave-function of the walk vary on time- and space-scale much larger than
the grid cell. The physical time t and spatial coordinate x along the grid are related to j and p by
tj = ϵj and xp = ϵp where ϵ is an infinitesimal. It has been shown in [22,23] that the continuous
limit of the 2-step walk then coincides with the Dirac equation in a curved space-time with metric
(gµν) = diag(1, cos−2 θ). In particular, the matrices representing A1 and B1 in the basis (bα) then tend
towards unity while the matrix representing A0 tends towards −(ω001/2) × 1 and B0 tends towards y
p
g
(
)
−(ω101/2) × 1. The discrete Riemann curvature then tends towards ϵ2/2 × Rµνab, where Rµνab is the
mixed component of the usual Riemann curvature tensor to µ = 0, ν = 1, a = 0, b = 1. This component
contains all the information one needs about the Riemann tensor because this tensor, in 2D space-times,
has only one independent component. The 1/2 in the multiplicative factor comes form the fact that the
zeroth components of the discrete connection tend towards ω/2 (as opposed to ω). The ϵ2 factor comes
from the fact that curvatures are obtained by taking second discrete or continuous derivatives and that
the above relation between (j, p) and (t, x) implies Dj = ϵ∂t and Dp = ϵ∂x. Finally, the components
Rµν01 of the continuous Riemann curvature tensor on the coordinate basis (∂µ) can be recovered by
taking the continuous limit of Ea
µEb
νρs where (Ea
µ) is the discrete inverse 2-bein. −(ω101/2) × 1. 2.10. Example The continuous limit of the walks studied in this article corresponds to the propagation of a Dirac
spinor in a space-time metric of the form ds2 = dt2 −a2(t, x)dx2 where t and x are the continuous
coordinates corresponding to j and p and a(t) = 1/(cos θ). Fixing these coordinates i.e., retaining this
form for the metric, the simplest space-times with non vanishing curvature are realized by choosing
the function a independent of x. We now therefore choose an angle θ which depends only on j and Condens. Matter 2019, 4, 40
12 Condens. Matter 2019, 4, 40 12 of 16 proceed to compute, as an example, the first of the curvatures defined above. Since nothing depends
on the spatial position, all quantities are now indexed by j only. proceed to compute, as an example, the first of the curvatures defined above. Since nothing depends
on the spatial position, all quantities are now indexed by j only. p
p
q
y j
y
For such walks, the operators W and L take the simpler form For such walks, the operators W and L take the simpler form (WA
B )j = cj
cj+1
isj+1
isj+1
cj+1
! ,
(73) (WA
B )j = cj
cj+1
isj+1
isj+1
cj+1
! ,
(73)
(LA
B )j = sj
sj+1
−icj+1
−icj+1
sj+1
! (74) (WA
B )j = cj
cj+1
isj+1
isj+1
cj+1
! ,
(73)
(LA
B )j = sj
sj+1
−icj+1
−icj+1
sj+1
! (74) (73) (LA
B )j = sj
sj+1
−icj+1
−icj+1
sj+1
! (74) (74) and ((W + L)A
B )j =
cos(∆θj)
i sin(∆θj)
i sin(∆θj)
cos(∆θj)
! (75) and
((W + L)A
B )j =
cos(∆θj)
i sin(∆θj)
i sin(∆θj)
cos(∆θj)
! (75) (75) with ∆θj = θj+1 −θj. with ∆θj = θj+1 −θj. jj j
j+
j
A simple computation leads to (x±)j = ± | cj |. These values of (x±)j lead to (gjj)j = 1,
(gpp)j = −c2
j and (gjp)j = 0. If θj ̸= π/2, the components of the discrete metric itself read (gjj)j = 1,
(gpp)j = −c−2
j
and (gjp)j = 0. In addition, −µ2 = −c2
j . We now retain (assuming cj ̸= 0) A simple computation leads to (x±)j = ± | cj |. These values of (x±)j lead to (gjj)j = 1,
(gpp)j = −c2
j and (gjp)j = 0. 3. Conclusions We have revisited a particular family of DTQWs whose continuous limit coincides with the 2D
curved space-time Dirac dynamics written in synchronous coordinates. We have defined discrete
covariant derivatives of the spinor wave-function along the grid coordinates, thus introducing discrete
spin-connections and also generalised the notions of metric and 2-bein to the discrete lattice. We have
then defined two different discrete curvatures from the transformation properties of the discrete
spin-connections under Lorentz transformations. Both curvatures are closely related and one of them
coincides, in the continuous limit, with the usual Riemann curvature from differential geometry. We have finally computed this discrete Riemann curvature on a particularly simple example. Let us now comment on these results. In an arbitrary space-time, the most complete
characterization of curvature is given the Riemann tensor. This tensor is usually computed from
the space-time connection, but it can also be obtained from spinor connection [32,33]. The definition
and computation of discrete curvature presented in this article thus start with a definition of discrete
spinor connections for DTQWs, which is itself based upon the definition of discrete first and second
discrete partial derivatives with respect to the grid coordinates. In the discrete case, spinor connections
have a richer structure than in the continuous case because they contain more coefficients. In 2D
space-time, a continuous spinor connection is fully defined by two coefficients, whereas one needs
five coefficients to fully define a discrete spinor connection. These five coefficients can be partitioned
into two sets, one of two coefficients pertaining to discrete covariant derivatives with respect to the
discrete time index j, and one of three coefficients pertaining to covariant derivatives with respect
to the discrete space index p. Note that these two sets only mix if one performs discrete Lorentz
transformations in space-time, and these have not been considered in this article, where only Lorentz
transformations in spinor space are carried out. We have therefore chosen, for readability purposes,
to use a different letter for each set of coefficients (A defines discrete covariant time-derivatives and B
defines discrete covariant space-derivatives). In addition, the discrete space-time connection is thus
represented by (A, B). 2.10. Example If θj ̸= π/2, the components of the discrete metric itself read (gjj)j = 1,
(gpp)j = −c−2
j
and (gjp)j = 0. In addition, −µ2 = −c2
j . We now retain (assuming cj ̸= 0) A simple computation leads to (x±)j = ± | cj |. These values of (x±)j lead to (gjj)j = 1,
(gpp)j = −c2
j and (gjp)j = 0. If θj ̸= π/2, the components of the discrete metric itself read (gjj)j = 1,
(gpp)j = −c−2
j
and (gjp)j = 0. In addition, −µ2 = −c2
j . We now retain (assuming cj ̸= 0) (b−)j
=
| cj |−1/2 iσjbL + κjbR
,
(b+)j
=
| cj |−1/2 κjbL + iσjbR
,
(76) (76) where κj = cos(θj+1/2) and σj = sin(θj+1/2). The matrix (rA
α )j can be read off these equations (rA
α )j =| cj |−1/2
iσj
κj
κj
iσj
! (77) (77) and its inverse reads:
((r−1)α
A)j =| cj |+1/2
−iσj
κj
κj
−iσj
! . (78) ((r−1)α
A)j =| cj |+1/2
−iσj
κj
κj
−iσj
! . (78) (78) The components of W + L are not modified by the change of basis i.e., ((W + L)α
β)j =
cos(∆θj)
i sin(∆θj)
i sin(∆θj)
cos(∆θj)
! (79) (79) and a direct computation delivers and a direct computation delivers and a direct computation delivers (Mα
β) =
0
¯
M
¯
M
0
! (80) (Mα
β) =
0
¯
M
¯
M
0
! (80)
i h (80) with with with ¯
M = −1
2 sin(∆θ)+ | c |+1/2
κDj(| c |−1/2 σ) −σDj(| c |−1/2 κ)
,
(81) (81) where the index j tracing the time-dependence of all quantities has been suppressed for
readability purposes. y p
p
Since all angles depend only on j, only the connection B enters the curvature. One finds that Since all angles depend only on j, only the connection B enters the curvature. One finds that ((B1)α
β) = 1,
(82) (82) (B0)−
−= −| c |−1/2
κDj(| c |−1/2 κ) + σDj(| c |−1/2 σ)
+
1
2 | c |(cos ∆θ −1),
(83) (83) 13 of 16 Condens. Matter 2019, 4, 40 while (B0)+
+ = −(B0)−
−and ((B2)α
β)j =
−cos(θj+1)
−i sin(θj+1)
i sin(θj+1)
cos(θj+1)
! . 2.10. Example (84) (84) This leads to ρs
j = Dj(B0)−
−with (B0)−
−given by Equation (83). 3. Conclusions It therefore defines a Laplace operator on the
discrete structure where it lives and, thus, a Ricci curvature. Similarly, a DTQW is essentially a spin 1/2
wave propagating on the lattice. Since a spin 1/2 wave obeys the Dirac equation, a DTQW essentially
defines discrete equivalents to all quantities appearing in the Dirac equation i.e., an n-bein, and thus
a metric, and a spin-connection. Once one has a discrete equivalent of the spin-connection, one can
compute its curvature (in the sense of gauge theories), which coincides with the Riemann curvature. It is remarkable that classical Markov chains thus provide only a generalization of the Ricci curvature
while quantum walks deliver equivalents to all geometrical objects of usual interest, from the metric to
the spin-connection and, thus to the full Riemann curvature tensor. As already mentioned, curvature is often introduced in differential geometry without using
spinors. A standard approach is to first define a notion of parallel transport for tensor (including
vector and 1-form) fields and then introduce curvature as the natural object which measures how
much parallel transport along an infinitesimal closed loop modifies a tensor field. The parallel
transport generates a covariant derivative of tensor fields and, thus, a space-time connection, encoded
for example in the Christoffel symbols, which can be used to compute the space-time curvature. However, the space-time connection can also be represented by the so-called rotation coefficients,
which determine the covariant derivatives of the n-bein. Now, this space-time connection can be
extended in a canonical way to spinor fields. One can thus define the covariant derivatives of spinor
fields and these can be used to compute directly the space-time curvature. This approach presents the
advantage of being very close in spirit to Yang–Mills gauge theories: at each point in space-time the
fiber is the spinor Hilbert space, the theory is invariant under the local action of various gauge groups
(U(1), the Lorentz group, etc.) in this fiber, and one computes for each group the curvature or field
strength from the associated covariant spinor derivative. Let us add a few comments about the mass M. If one focuses on usual physics, only the
continuous limit counts and it has been shown in [22,23] that the mass M then vanishes. Thus,
at the continuous limit, the DTQW under consideration describes the continuous dynamics of massless
fermions. 3. Conclusions The computation of the Riemann tensor as the curvature of the spin connection coefficients
using as gauge group the set of Lorentz transformations in spinor space does not deliver the usual
space-time components of the tensor, but the so-called mixed components Rµνab, from which the
usual space-time components can be recovered through partial contraction with the inverse n-bein
coefficients. This applies both to the continuous and the discrete case. In 2D, there is only one
independent component to the usual continuous Riemann tensor, and the discrete one also has only
one independent component. We have proposed two different definitions of Riemann curvature for the DTQWs considered
in this article. If one is mainly interested in quantum simulation of conventional continuous physics,
the second definition, which makes use of slowly varying Lorentz transformations, is clearly the one
of choice, if only because its continuous limit gives back the usual Riemann curvature of differential
geometry. However, DTQWs are interesting in other contexts, for example in quantum computing
and quantum algorithms, where the continuous limit is not necessarily of particular importance. It is therefore useful to develop, for these contexts, a very general notion of curvature which is not
linked to what happens at the continuous limit or for slowly varying Lorentz transformations. This is
why we have offered our first definition of Riemann curvature. For technicality reasons, the first
definition makes it necessary to introduce a reference connection and the obtained Riemann curvature 14 of 16 14 of 16 Condens. Matter 2019, 4, 40 thus depends on this reference connection. In essence, the reference connection is the connection for
which the first Riemann curvature vanishes. The easiest way to see this is to go back to Equation (72). This states that the first curvature of a connection is the difference between the second curvature of
that connection and the second curvature of the reference connection. There is no canonical choice for
the reference connection i.e., the reference connection must be chosen on case by case basis, according
to the context and interests of the computation. The whole approach developed in this article is close in spirit to work which has been done in the
last fifteen years, where classical Markov chains are used to define Ricci curvatures of graphs [37–39]. Indeed, a Markov chain is essentially a discrete diffusion. 3. Conclusions By definition, the DTQW does not describe known physics outside this limit i.e., in the
discrete regime. In particular, we decided to call the matrix M the mass of the DTQW because
the form (30) of the discrete equation resembles the form (6) of the continuous equation and the
coefficient in front of Ψ in (6) is −i times the physical mass. However, this does not presuppose that
the matrix M, outside the continuous limit, shares any property with physical masses. In particular,
the two coefficients M−
+ and M+
−are not necessarily identical outside the continuous limit, where both
vanish. In this sense, the matrix M should be considered as a generalised mass, which becomes
a physical mass only at the continuous limit. Note that it is possible to construct DTQWs close to
those considered in this article and whose continuous limits describe fermions of non vanishing mass
(see, for example, [29]). Let us also recall that some DTQWs not considered in this manuscript have,
even in the continuous regime, complex mass terms [23] which thus do not share the properties of
physical masses. Let us now conclude by mentioning possible extensions of this work. One should first address
more general DTQWs coupled to arbitrary Yang–Mills fields. The extension to both higher dimensional
space-times and higher spins should also prove interesting, starting with walks defined on square
lattices, then moving on to more general grids, the ultimate goal being DTQWs on graphs. For example: 15 of 16 Condens. Matter 2019, 4, 40 what are the necessary graph properties for a DTQW to define a curvature on the graph? Or, how can
one use graph geometry to write more efficient quantum algorithms? One should finally extend all
these computations to alternate, comparable discrete models such as Lattice Gauge Theories (LGTs)
and compare the results with those obtained for DTQWs. Funding: This research received no external funding. Funding: This research received no external funding. Acknowledgments: For R.D. Acknowledgments: For R.D. Conflicts of Interest: The author declares no conflict of interest. Conflicts of Interest: The author declares no conflict of interest. References 1. Feynman, R.P.; Hibbs, A.R. Quantum Mechanics and Path Integrals; International Series in Pure and Applied
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M
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Mech. Anal. 2012, 206, 997–1038. [CrossRef] c⃝2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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English
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Forest mapping and species composition using supervised per pixel classification of Sentinel-2 imagery
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Biotechnologie, agronomie, société et environnement
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S E B A Biotechnol. Agron. Soc. Environ. 2018 22(3) S E de l’Ardenne belge, espèces d’arbre, télédétection, satellite, classification par pixel, forêt aléatoire. Mots-clés. Écorégion de l’Ardenne belge, espèces d’arbre, télédétection, satellite, classification par Forest mapping and species composition using supervised
per pixel classification of Sentinel-2 imagery Corentin Bolyn, Adrien Michez, Peter Gaucher, Philippe Lejeune, Stéphanie Bonnet
Université de Liège - Gembloux Agro-Bio Tech. TERRA Forest is life. Passage des Déportés, 2. BE-5030 Gembloux
(Belgium). E-mail: p.lejeune@uliege.be Corentin Bolyn, Adrien Michez, Peter Gaucher, Philippe Lejeune, Stéphanie Bonnet
Université de Liège - Gembloux Agro-Bio Tech. TERRA Forest is life. Passage des Déportés, 2. BE-5030 Gembloux
(Belgium). E-mail: p.lejeune@uliege.be Received 20 December 2017, accepted 20 June 2018, available online 6 August 2018. This article is distributed under the terms and conditions of the CC-BY License (http://creativecom Description of the subject. Understanding the current situation and evolution of forests is essential for a sustainable
management plan that maintains forests’ ecological and socio-economic functions. Remote sensing is a helpful tool in
developing this knowledge. Objectives. This paper investigates the new opportunities offered by using Sentinel-2 (S2) imagery for forest mapping in
Belgian Ardenne ecoregion. The first classification objective was to create a forest map at the regional scale. The second
objective was the discrimination of 11 forest classes (Fagus sylvatica L., Betula sp., Quercus sp., other broad-leaved stands,
Pseudotsuga menziesii (Mirb.) Franco, Larix sp., Pinus sylvestris L., Picea abies (L.) H.Karst., young needle-leaved stands,
other needle-leaved stands, and recent clear-cuts). Method. Two S2 scenes were used and a series of spectral indices were computed for each. We applied supervised pixel-based
classifications with a Random Forest classifier. The classification models were processed with a pure S2 dataset and with
additional 3D data to compare obtained precisions. Results. 3D data slightly improved the precision of each objective, but the overall improvement in accuracy was only
significant for objective 1. The produced forest map had an overall accuracy of 93.3%. However, the model testing tree species
discrimination was also encouraging, with an overall accuracy of 88.9%. Conclusions. Because of the simple analyses done in this study, results need to be interpreted with caution. However, this
paper confirms the great potential of S2 imagery, particularly SWIR and red-edge bands, which are the most important S2
bands in our study. i n Ardenne ecoregion, tree species, remote sensing, satellites, per-pixel classification, random forest. Keywords. Belgian Ardenne ecoregion, tree species, remote sensing, satellites, per-pixel classificat 1. INTRODUCTION & Marine Monitoring, Climate Change, Security &
Emergency Management Services). The launch of
the two Sentinel-2 (S2) satellites is an opportunity to
enhance forest characterization on a large scale. The
satellites multispectral 13-band sensors produce high-
quality images at a 5-day equatorial temporal resolution
(Suhet & Hoersch, 2015). Such an availability of free
data is unprecedented and will substantially promote
research in this topic. & Marine Monitoring, Climate Change, Security &
Emergency Management Services). The launch of
the two Sentinel-2 (S2) satellites is an opportunity to
enhance forest characterization on a large scale. The
satellites multispectral 13-band sensors produce high-
quality images at a 5-day equatorial temporal resolution
(Suhet & Hoersch, 2015). Such an availability of free
data is unprecedented and will substantially promote
research in this topic. Forest ecosystems provide important services to
society, and sustainable management and adapted
policies are essential to maintain their ecological
and socio-economic functions. Forest managers and
policy makers must consider the relationships between
forest function and ecosystem characteristics and the
evolution of forests in order to manage forests and
make regional decisions (Führer, 2000; Lindenmayer
et al., 2000). Given the globalization of today’s
society, this need has become even more important,
as understanding forests is important for international
agreements and reporting requirements (e.g. the Kyoto
Protocol). i In preparation for the arrival of the new S2
imagery, Inglada et al. (2017) present a methodology
to automatize the production of a land cover map at the
country scale using high-resolution optical image time
series. Using this methodology, the study constructs
a map of metropolitan France with a coefficient of
kappa 0.86 describing 17 land cover classes, including
broad-leaved forest and coniferous forest. In the first
study to use pre-operational S2 data, Immitzer et al. (2016) test both a pixel-and object-based classification
of tree species in Germany for 7 classes, getting an
overall accuracy (OA) of 0.64 and 0.66, respectively. These studies demonstrate the powerful potential of
satellite imagery for forest mapping, and research is
necessary to exploit the potential of these new S2 data. In their review of tree species classification studies,
Fassnacht et al. (2016) observe the increasing number
of works on this topic over the last 40 years. However,
they note that most investigations are oriented toward
optimizing classification accuracy over a relatively
small test site and it is therefore often difficult to draw
general conclusions from these studies. 1. INTRODUCTION The authors
recommend using well-defined applications in future
research in order to avoid purely data-driven studies of
limited values and increase understanding of broader
factors affecting tree species classification. For decades, field inventories have been used to
better characterize forest. National inventories exist
in countries around the world and have evolved over
time to adapt to users’ needs (Tomppo et al., 2010). Field inventories provide timely and accurate estimates
of forest resources and their evolution at a large scale. Nevertheless, this method is time-consuming and quite
expensive. Furthermore, an inventory of an entire area
is, for obvious reasons, impossible and sample-based
procedures are necessary. Therefore, technological
innovation is becoming crucial to improve the efficiency
of measurements and estimations while making the
production of inventory data simpler (McRoberts &
Tomppo, 2007). Remote sensing is one of the technological
tools at our disposal: it decreases the cost of data
acquisition, increases the area it is possible to cover
without sampling, and enables the production of
high-resolution forest attribute maps. Remote sensing
enables the production of map layers that give precious
information about the distribution of forest resources. These complement sample-based procedures in the
field and today are commonly used by researchers and
managers (McDermid et al., 2009). In this context, we use S2 imagery to investigate
image classification in European temperate forests at
the regional scale. Our study has three goals: – to create a highly accurate regional forest map using
S2 imagery; g
Today advances in technology such as satellite
remote sensing and digital photogrammetry have
increased the possible applications of remote sensing
and image classification. Light detection and ranging
(LiDAR) data and photogrammetry technologies have
made it possible to use 3D data, such as Canopy Height
Models (CHM) when investigating forests. These
technologies improve the classification accuracy of
forest classes (Waser et al., 2011). However, 3D data is
still rare at the large scale and the technology remains
expensive. – to evaluate the potential of S2 imagery in identifying
the main tree species encountered in the study area;i – to assess the benefits of incorporating 3D data into
our study of the previous two goals and therefore
determining how precise S2 data is in these
approaches. For these purposes, we implemented supervised
classification per pixel using a random forest (RF)
algorithm. We used two S2 images acquired at different
dates to take account for species seasonality. stière et composition spécifique par classification supervisée par pixel d’imagerie Sentinel-2
É Bolyn C., Michez A., Gaucher P. et al. Biotechnol. Agron. Soc. Environ. 2018 22(3) 2 stière et composition spécifique par classification supervisée par pixel d’imagerie Sentinel-2
É Cartographie forestière et composition spécifique par classification supervisée par pixel d’imagerie Sentinel-2
Description du sujet. Étudier l’état et l’évolution des forêts est essentiel pour assurer une gestion durable maintenant leurs
fonctions écologiques et socio-économiques. La télédétection est un outil précieux pour le développement de ces connaissances. Objectifs. Cette étude analyse l’opportunité offerte par l’imagerie Sentinel-2 (S2) pour cartographier les forêts de l’écorégion
de l’Ardenne belge. Le premier objectif de classification était la création d’une carte forestière à l’échelle régionale. Le second
objectif était la discrimination de 11 classes forestières (Fagus sylvatica L., Betula sp., Quercus sp., other broad-leaved stands,
Pseudotsuga menziesii (Mirb.) Franco, Larix sp., Pinus sylvestris L., Picea abies (L.) H.Karst., young needle-leaved stands,
other needle-leaved stands, and recent clear-cuts). Méthode. Deux scènes S2 ont été utilisées et une série d’indices spectraux ont été générés pour chacune d’entre elles. Nous
avons réalisé une classification supervisée par pixel avec l’algorithme de classification Random Forest. Les modèles de
classification ont été générés avec un jeu de données S2 pur et avec des données 3D supplémentaires pour comparer les
précisions obtenues. p
Résultats. Les données 3D ont légèrement amélioré la précision de chaque objectif, mais l’amélioration globale de précision
fut uniquement significative pour l’objectif 1. La carte forestière produite avait une précision globale de 93,3 %. Le modèle
testant la discrimination des espèces d’arbre fut encourageant également, avec une précision globale de 88,9 %. Conclusions. Tenant compte des simples analyses réalisées dans cette étude, les résultats doivent être interprétés avec prudence. Cependant, ce travail confirme le grand potentiel de l’imagerie S2, particulièrement les bandes SWIR et red-edge, qui jouèrent
un rôle essentiel dans ce travail. p
Résultats. Les données 3D ont légèrement amélioré la précision de chaque objectif, mais l’amélioration globale de précision
fut uniquement significative pour l’objectif 1. La carte forestière produite avait une précision globale de 93,3 %. Le modèle
testant la discrimination des espèces d’arbre fut encourageant également, avec une précision globale de 88,9 %. Conclusions Tenant compte des simples analyses réalisées dans cette étude les résultats doivent être interprétés avec prudence Conclusions. Tenant compte des simples analyses réalisées dans cette étude, les résultats doivent être interprétés avec prudence. Cependant, ce travail confirme le grand potentiel de l’imagerie S2, particulièrement les bandes SWIR et red-edge, qui jouèrent
un rôle essentiel dans ce travail Mots-clés. Écorégion de l’Ardenne belge, espèces d’arbre, télédétection, satellite, classification par pixel, forêt aléatoire. 1. INTRODUCTION Then, we
computed a range of spectral indices. After a step of
variables selection, we trained random forest classifiers
for two datasets: the first contains only S2 bands
and spectral indices, while the second also contains
3D data. The quality of the results was assessed and This may be different for satellite imagery. On 28
February 2008, the European Union (EU) and European
Space Agency (ESA) signed an agreement over the
creation of the COPERNICUS program. The aim of this
program is to provide earth surface monitoring services
(European Commission, 2015) (Land, Atmosphere 3 Forest mapping with Sentinel-2 imagery compared in terms of a confusion matrix with a strong
reference dataset. compared in terms of a confusion matrix with a strong
reference dataset. time naturally regenerated and thus present an uneven-
aged structure and a composition dominated by beech
and oak, the level of mixture being driven mainly
by soil depth and topography. Figure 1 provides an
overview of the study site. 2.1. Study site Sentinel-2. The onboard S2 sensor is a passive multi-
spectral instrument (MSI). It provides 13 spectral
bands (Table 1). In order to simplify pre-processing,
the only two available S2 images with less than 10%
cloud cover over the entire Ardenne ecoregion were
selected. Their sensing times were 2 August 2015 and
8 May 2016 (further referred as D1 and D2). These
dates have a potential interest as they could help
to difference some broad-leaved species between
themselves or from resinous species. Indeed in this
region, in May, Fagus sylvatica and Betula sp. have
begun foliation period since more than a month while
Quercus sp. have just started (https://fichierecologique. be). It is widely acknowledged that reflectance from
the Earth’s surface, called top-of-atmosphere (TOA), is
significantly modified by the atmosphere (Jensen, 2005;
Lillesand et al., 2008; Richards, 2013). There are many
remote sensing studies that have investigated how to The study was conducted for the entire Belgian
Ardenne ecoregion. This region constitutes a plateau
whose altitude increases gradually from the South-
West to the North-East, culminating at nearly 700 m. The annual mean temperature is smaller than 9 °C
and annual precipitations are nearly 1,200 mm. With
an afforestation rate of 58%, the Ardenne represents
333,850 ha of forest and is the largest forest area in
Wallonia. This forest is mainly coniferous (64%),
according to Wallonia’s Regional Forest Inventory
(RFI) (Alderweireld et al., 2015), and the most
frequently found tree species are (in order of quantity):
spruce (Picea abies [L.] H.Karst.), oak (Quercus sp.),
beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga
menziesii (Mirb.) Franco), pine (Pinus sp.), and larch
(Larix sp.). These six species represent 85.8 % of the
forest. Most of the time, coniferous stands are pure
species plantations. Deciduous stands are most of the Figure 1. The study area, the Belgian Ardenne ecoregion, is shown in yellow. A more detailed view is presented in the top left
corner (orthophoto 2016, Public Service of Wallonia) — La zone d’étude, l’écorégion de l’Ardenne belge, est en jaune. Une
vue plus détaillée est présentée dans le coin supérieur gauche (orthophoto 2016, Service Public de Wallonie). 0 5 10 20 30 40 km
N
4°0’0’’E
4°30’0’’E
5°0’0’’E
5°30’0’’E 6°0’0’’E 6°30’0’’E
50°0’0’’N
50°20’0’’N
50°40’0’’N 5°0’0’’E 5°30’0’’E 6°30’0’’E Figure 1. The study area, the Belgian Ardenne ecoregion, is shown in yellow. 2.1. Study site A more detailed view is presented in the top left
corner (orthophoto 2016, Public Service of Wallonia) — La zone d’étude, l’écorégion de l’Ardenne belge, est en jaune. Une
vue plus détaillée est présentée dans le coin supérieur gauche (orthophoto 2016, Service Public de Wallonie). Bolyn C., Michez A., Gaucher P. et al. Biotechnol. Agron. Soc. Environ. 2018 22(3) 4 reduce the effects of the atmosphere on the signal
(Kaufman et al., 1997; Song et al., 2001; Guanter
et al., 2008). This is even more important in case
of multi-temporal date analyses (Agapiou et al.,
2011; Hagolle et al., 2015), therefore we used the
atmospheric correction proposed by the Sen2Cor
processor (version 2.2.) (Müller-Wilm, 2016). Hence, Level-1C data were processed into Level-
2A (bottom-of-atmosphere corrected reflectance
images). S2 bands at 20 m of spatial resolution
were resampled at 10 m during this step (nearest
neighbor method). Then we compiled a layer
stack of 20 spectral bands with D1 and D2. Table 1. Sentinel-2 bands properties, band number, band name in this study, central wavelength (nm), bandwidth (nm), spatial resolution (m) and purpose. Only ban
numbers marked with asterisks were used in this study. Data compilation and purpose from the European Space Agency (2015) — Propriétés des bandes S2, numéro d
la bande, nom de la bande dans cette étude, longueur d’onde centrale (nm), largeur de la bande (nm), résolution spatiale (m) et objectif. Seuls les numéros de bande
annotés avec une astérisque ont été utilisés dans cette étude. Données et objectifs provenant de European Space Agency (2015). Band number Band name
Central wavelength (nm)
Bandwidth (nm)
Spatial resolution (m)
Purpose
2 *
Blue
490
65
10
Blue
3 *
Green
560
35
10
Green
4 *
Red
665
30
10
Red
8 *
NIRwide
842
115
10
Sensitive to chlorophyll, biomass and protein
5 *
Rededge 1
705
15
20
Vegetation Classification
6 *
Rededge 2
740
15
20
Vegetation Classification
7 *
Rededge 3
786
20
20
Vegetation Classification
8a *
NIRnarrow
865
20
20
Vegetation Classification
11 *
SWIR 1
1,610
90
20
Sensitive to lignin, starch and forest above ground biomas
12 *
SWIR 2
2,190
180
20
Distinction of live biomass, dead biomass and soil
1
-
443
20
60
Aerosol scattering
9
-
945
20
60
Water vapor absorption
10
-
1,375
20
60
Detection of thin cirrus Table 1. 2.1. Study site Sentinel-2 bands properties, band number, band name in this study, central wavelength (nm), bandwidth (nm), spatial resolution (m) and purpose. Only b
numbers marked with asterisks were used in this study. Data compilation and purpose from the European Space Agency (2015) — Propriétés des bandes S2, numéro
la bande, nom de la bande dans cette étude, longueur d’onde centrale (nm), largeur de la bande (nm), résolution spatiale (m) et objectif. Seuls les numéros de ban
annotés avec une astérisque ont été utilisés dans cette étude. Données et objectifs provenant de European Space Agency (2015). Band number Band name
Central wavelength (nm)
Bandwidth (nm)
Spatial resolution (m)
Purpose
2 *
Blue
490
65
10
Blue
3 *
Green
560
35
10
Green
4 *
Red
665
30
10
Red
8 *
NIRwide
842
115
10
Sensitive to chlorophyll, biomass and protein
5 *
Rededge 1
705
15
20
Vegetation Classification
6 *
Rededge 2
740
15
20
Vegetation Classification
7 *
Rededge 3
786
20
20
Vegetation Classification
8a *
NIRnarrow
865
20
20
Vegetation Classification
11 *
SWIR 1
1,610
90
20
Sensitive to lignin, starch and forest above ground biom
12 *
SWIR 2
2,190
180
20
Distinction of live biomass, dead biomass and soil
1
-
443
20
60
Aerosol scattering
9
-
945
20
60
Water vapor absorption
10
-
1,375
20
60
Detection of thin cirrus 3.1. Image classification models To accomplish our first two goals, we defined two
models of classification. The model called Objective 1
created a forest map, and was trained to identify four
classes: broad-leaved stands, coniferous stands, recent
clear-cuts, and non-forest areas. The non-forest class
dataset contained an equal proportion of observations
for agricultural lands, urban landscapes, and water
bodies. In order to create our forest map, we applied
the obtained classifier to the entire study area. We then
generated a forest land use map by merging the three
forest classes into one. By first growing a model with
four classes, clear cuts are integrated into the produced
forest map, as it forms an integral part of the forest
estate covered by management plans. DFU were used for both Objectives 1 and 2
to extract reference data for forest classes. Before
that, DFU polygons were visually interpreted to
verify eventual errors or modifications since the last
update. For each class, the chosen forest stands were
supposed to be “pure stands” according to the DFU
database (percentage > 80%). Table 3 shows by class
the number of polygons and the number of extracted
pixels. Reference polygons were delineated for non-
forest classes by visual interpretation of orthophotos. Detection of thin cirrus 3D data. Three Canopy Height Models (CHM)
and one slope layer, based on LiDAR and
photogrammetric point clouds, were used
covering the entire study area at a resolution of
1 m. A CHM was made using LiDAR (LiDAR
DSM - LiDAR DTM) and referred to as CHM3
in this paper. The average point density of
small footprint discrete airborne Lidar data was
0.8 points.m-1. Survey flights were realized by the
Public Service of Wallonia from 12 December
2012 to 21 April 2013 and from 20 December
2013 to 9 March 2014. The survey covered
Wallonia with a regional digital terrain model
(1 m ground sampling distance [GSD]). A digital
surface model (DSM) at the same resolution was
also computed and a slope layer was generated
based on the Lidar digital terrain model (DTM). For two other CHMs, raw images from
two regional orthophoto datasets (acquired by
the Public Service of Wallonia) were used to
generate two high-density photogrammetric point
clouds. Both survey flights took place between
April and September, the first in 2006 and 2007
(0.50 m GSD), the second in 2009 and 2010
(0.25 m GSD). Considering that the regional
topography did not change significantly, hybrid
CHMs were computed using photogrammetric
DSM and LiDAR DTM, as described above,
following the approach of Michez et al. (2017)
(photogrammetric DSM-LiDAR DTM). Their
spatial resolution is 1 m. The precision of this
approach has been evaluated in Michez et al. (2017) using field tree height measurements
(root mean square error smaller than 3 m). These
hybrids CHM are called CHM1 and CHM2 in this
paper. They were used in this study to improve the
detection of recent clear cuts and young stands,
adding height information in the past. These four layers (CHM1, CHM2, CHM3,
and SLOPE) were aggregated at 10 m of spatial
resolution using median value. 5 Forest mapping with Sentinel-2 imagery 3. METHODS from four bands (RGB and IR) 0.25 m resolution
orthophotos covering the entire region. These image
layers are available for the years 2006, 2009, 2012, and
2015 (http://geoportail.wallonie.be). 3.3. Variable selection and classification The following steps were executed in the same way
for Objectives 1 and 2 using Dataset 1 or 2 (Figure 2). Before building classification models, we rationally
reduced the number of variables by selecting the
most important using VSurf (Genuer et al., 2016) in
R software (R Core Team, 2016). The VSurf package
allows variable selection based on the estimation of
RF’s variable importance (Genuer et al., 2015). As
a result, the process provides two variables subsets. The first, called “variable interpretation”, is intended
to show variables highly related to the response
variable. It does not matter if there is some, or even
much, redundancy in this subset. The second, called
“prediction”, is a smaller subset with low redundancy
intended to assure a good prediction of the response
variable. y
g
p
Second
model
called
Objective 2
aims
at
classifying the tree species present in the study site to
evaluate the discrimination potential of S2 data using
a pixel-based approach. Based on the RFI, we defined
11 classes that corresponds to the main species or
types of stands: beech, birch (Betula sp.), oak, other
broad-leaved stands (OB), Douglas fir, larch, Scots
pine (Pinus sylvestris L.), spruce, young needle-leaved
stands (YN), other needle-leaved stands (ON), and
recent clear-cuts (RCC). Young stands correspond to
plantations between 4 and 12 years old, and recent
clear-cuts are stands that have been harvested in the
last four years. For each class, pixels contain at least
80% of the species or group of species. The global workflow of the study is synthesized in
figure 2. The following parameters were set to allow the
maximum performance in a reasonable time with the
used computer: 3.2. Dataset preparation After a step of variables selection, random forest classif
were trained for two datasets: the first contained only S2 bands and spectral indices (Dataset S2), while the second a
contained 3D data (Dataset S2-3D) — Workflow global de l’étude divisé en deux objectifs de classification. Le premier mod
de classification nommé Objectif 1 a généré une carte forestière et a été entrainé à identifier quatre classes : les peupleme
feuillus, les peuplements résineux, les coupes rases récentes et les surfaces non forestières. Le second modèle nommé Object
visait à classifier les espèces d’arbre présentes sur le site d’étude afin d’évaluer le potentiel discriminant des données S2
une approche par pixel. Après une étape de sélection de variables, des forêts aléatoires ont été entrainées pour deux jeux
données : le premier contenant uniquement les bandes S2 et des indices spectraux (Dataset S2), le second incluant aussi d
données 3D (Dataset S2-3D). Reference
data
Reference
polygons
Dataset
S2
Dataset
S2-3D
Sentinel 2 layer
stack 10 m,
D1 and D2
Indices
production
3D data inclusion
- 1 lidar CHM
- 2 photogrammetric CHM’s
Pixels
extraction
10% for
validation data
Objectif 2
90% for
training data
100% for
training data
Objectif 1
VSurf
variable selection
VSurf
variable selection
RF
Pixel based
classification
RF
Pixel based
classification
Independent validation
for each dataset
Independent validation
for each dataset
Forest cover
map
Independent
validation
Visual interpretation
of a systematic
grid
Application of the best model
and post-treatment Sentinel 2 layer
stack 10 m,
D1 and D2 Reference
data 3D data inclusion
- 1 lidar CHM
- 2 photogrammetric CHM’s Indices
production Dataset
S2-3D Dataset
S2 Reference
polygons 10% for
validation data Pixels
extraction 90% for
training data 100% for
training data Objectif 1 Objectif 2 VSurf
variable selection RF
Pixel based
classification RF
Pixel based
classification Visual interpretation
of a systematic
grid Independent validation
for each dataset Independent validation
for each dataset Independent validatio
for each dataset Application of the best model
and post-treatment Forest cover
map Independent
validation Figure 2. Global workflow of the study divided in two goals of classification. The first classification model called Objective 1
created a forest map, and was trained to identify four classes: broad-leaved stands, coniferous stands, recent clear-cuts, and
non-forest areas. Second model called Objective 2 aimed at classifying the tree species present in the study site to evaluate the
discrimination potential of S2 data using a pixel-based approach. 3.2. Dataset preparation – each RF was built using ntree = 1,000 trees, the
number of variables randomly sampled as candidates
at each split (mtry) was set by default (sqrt[p], where
p is the number of variables); In order to determine the most pertinent classification
variables in each model, we added a large selection of
spectral indices to the original S2 dataset. Each indice
was generated for D1 and D2. The list is presented in
table 2. – the number of random forests grown was 20 for the
three main steps of the Vsurf process: “thresholding
step”, “interpretation step”, and “prediction step”
(nfor.thres = 20, nfor.interp = 20 and nfor.pred = 20); We then created another dataset that include 3D
data and compared results of the two datasets for
each classification objective. In other words, for each
objective we tested the following datasets: the S2
bottom-of-atmosphere data D1 and D2 with spectral
indices (S2) and the S2 bottom-of-atmosphere data D1
and D2 with spectral indices and 3D data (S2-3D). – the mean jump is the threshold of decreasing mean
OOB error used in the Vsurf’s prediction step to add
variables to the model in a stepwise manner. It was
multiplied 4 times (nmj = 4) in order to make this
step more selective, considering the large number of
variables. All together, there were 10 S2 Bands, 34 indices
by sensing time, 3 CHM dates, and 1 slope layer. So,
depending on whether we included 3D data, we had 89
or 93 variables by dataset. For the two objectives, we realized supervised
classifications per pixel with a RF classifier (Breiman,
2001), using the randomForest package (Liaw &
Wiener, 2002) in R software (R Core Team, 2016). Only the variables selected during the prediction step Reference pixels were produced from delineated
management forest units (DFU) extracted from
the regional forest administration geodatabase and Biotechnol. Agron. Soc. Environ. 2018 22(3) Bolyn C., Michez A., Gaucher P. et al. 6 Figure 2. Global workflow of the study divided in two goals of classification. The first classification model called Objectiv
created a forest map, and was trained to identify four classes: broad-leaved stands, coniferous stands, recent clear-cuts, a
non-forest areas. Second model called Objective 2 aimed at classifying the tree species present in the study site to evaluate
discrimination potential of S2 data using a pixel-based approach. 3.2. Dataset preparation After a step of variables selection, random forest classifiers
were trained for two datasets: the first contained only S2 bands and spectral indices (Dataset S2), while the second also
contained 3D data (Dataset S2-3D) — Workflow global de l’étude divisé en deux objectifs de classification. Le premier modèle
de classification nommé Objectif 1 a généré une carte forestière et a été entrainé à identifier quatre classes : les peuplements
feuillus, les peuplements résineux, les coupes rases récentes et les surfaces non forestières. Le second modèle nommé Objectif 2
visait à classifier les espèces d’arbre présentes sur le site d’étude afin d’évaluer le potentiel discriminant des données S2 via
une approche par pixel. Après une étape de sélection de variables, des forêts aléatoires ont été entrainées pour deux jeux de
données : le premier contenant uniquement les bandes S2 et des indices spectraux (Dataset S2), le second incluant aussi des
données 3D (Dataset S2-3D). Forest mapping with Sentinel-2 imagery 7 Table 2. List of spectral indices generated for D1 (2 August 2015) and D2 (8 May 2016) S2 images — Liste des indices spectraux générés pour les images S2 D1 (2 aou
2015) et D2 (8 mai 2016). Indice
Name
Formula
References
BAI
Built-up Area Index
Blue - NIRnarrow
Blue + NIRnarrow
Shahi et al., 2015
Chlogreen
Chlorophyll Green index
NIRnarrow
Green + Rededge1
Datt, 1999
GEMI
Global Environment Monitoring
Vegetation Index
n x (1 - 0.25n) -Red - 0.125
1-Red
n = 2 x (NIRnarrow2 - Red2) + 1.5 x NIRnarrow + 0.5 x Red
NIRnarrow + Red + 0.5
Pinty & Verstraete, 1992
GI
Greenness Index
Green
Red
le Maire et al., 2004
gNDVI
Green normalized difference vegetation
index
NIRnarrow - Green
NIRnarrow + Green
Gitelson et al., 1996
LAnthoC
Leaf Anthocyanid Content
Rededge3
Green - Rededge1
Wulf & Stuhler, n.d. LCaroC
Leaf Carotenoid Content
Rededge3
Blue - Rededge1
Wulf & Stuhler, n.d. LChloC
Leaf Chlorophyll Content
Rededge3
Rededge1
Wulf & Stuhler, n.d. 3.2. Dataset preparation MSI
Moisture stress index
SWIR1
NIRnarrow
Vogelmann & Rock, 1985
NDrededgeSWIR
Normalized Difference of Red-edge and
SWIR2
Rededge2 - SWIR2
Rededge2 + SWIR2
Radoux et al., 2016
NDTI
Normalized Difference Tillage Index
SWIR1 - SWIR2
SWIR1 + SWIR2
Van Deventer et al., 1997
NDVI
Normalized difference vegetation index
NIRnarrow -Red
NIRnarrow+ Red
Tucker; 1979
NDVIre
Red-edge normalized difference vegetation
index
NIRnarrow - Rededge1
NIRnarrow + Rededge1
Gitelson et al., 1996
NDWI1
Normalized Difference Water Index 1
NIRnarrow - SWIR1
NIRnarrow + SWIR1
Gao, 1996
NDWI2
Normalized Difference Water Index 2
Green - NIRnarrow
Green + NIRnarrow
Gitelson et al., 1996
NHI
Normalized Humidity Index
SWIR1 - Green
SWIR1 + Green
Lacaux et al., 2007 Biotechnol. Agron. Soc. Environ. 2018 22(3) Bolyn C., Michez A., Gaucher P. et al. 8 Table 2 (continued). List of spectral indices generated for D1 (2 August 2015) and D2 (8 May 2016) S2 images — Liste des indices spectraux générés pour les image
S2 D1 (2 aout 2015) et D2 (8 mai 2016). 3.2. Dataset preparation Indice
Name
Formula
References
Norm-G
Normalized Green
Green
NIRwide + Red + Green
Sripada et al., 2006
Norm-NIR
Normalized Near Infra-red
NIRwide
NIRwide + Red + Green
Sripada et al., 2006
Norm-R
Normalized red
Red
NIRwide + Red + Green
Sripada et al., 2006
RededgePeakArea
Red-edge peak area
Red + Rededge1 + Rededge2 + Rededge3 + NIRnarrow
Filella & Penuelas, 1994
Radoux et al., 2016
RedSWIR1
Bands difference
Red - SWIR1
Jacques et al., 2014
RTVIcore
Red-edge Triangular Vegetation Index
100 x (NIRnarrow - Rededge1) - 10 x (NIRnarrow - Green) Chen et al., 2010
SAVI
Soil Adjusted Vegetation Index
NIRnarrow - Red
NIRnarrow + Red + 0.5 x 1.5
Huete, 1988
SR-BlueRededge1
Simple Blue and Red-edge 1 Ratio
Blue
Rededge1
le Maire et al., 2004
SR-BlueRededge2
Simple Blue and Red-edge 2 Ratio
Blue
Rededge2
Lichtenthaler et al., 1996
SR-BlueRededge3
Simple Blue and Red-edge 3 Ratio
Blue
Rededge3
Radoux et al., 2016
SR-NIRnarrowBlue
Simple ratio NIR narrow and Blue
NIRnarrow
Blue
Blackburn, 1998
SR-NIRnarrowGreen
Simple ratio NIR narrow and Green
NIRnarrow
Green
le Maire et al., 2004
SR-NIRnarrowRed
Simple ratio NIR narrow and Red
NIRnarrow
Red
Blackburn, 1998
SR-NIRnarrowRededge1
Simple NIR and Red-edge 1 Ratio
NIRnarrow
Rededge1
Datt, 1999
SR-NIRnarrowRededge2
Simple NIR and Red-edge 2 Ratio
NIRnarrow
Rededge2
Radoux et al., 2016
SR-NIRnarrowRededge3
Simple NIR and Red-edge 3 Ratio
NIRnarrow
Rededge3
Radoux et al., 2016
STI
Soil Tillage Index
SWIR1
SWIR2
Van Deventer et al., 1997
WBI
Water Body Index
Blue - Red
Blue + Red
Domenech & Mallet, 2014 Forest mapping with Sentinel-2 imagery 9 Table 3. The number of DFU polygons and extracted pixels by forest class: recent clear cuts (RCC), beech, birch, oak, other
broad-leaved stands (OB), Douglas fir, larch, other needle-leaved stands (ON), Scots pine, spruce, young needle-leaved
stands (YN) — Nombre de polygones DFU et nombre de pixels extraits par classe forestière : coupes récentes (RCC),
hêtre (beech), bouleau (birch), chêne (oak), autres peuplements feuillus (OB), Douglas (Douglas fir), mélèze (larch), autres
peuplements résineux (ON), pin sylvestre (Scots pine), épicéa (spruce), jeunes peuplements résineux (YN). RCC
Beech Birch
Oak
OB
Douglas
fir
Larch
ON
Scots
pine
Spruce
YN
Number of polygons
51
64
57
37
34
46
44
45
33
31
47
Number of pixels
7,068
6,327
2,589
4,572
3,623
5,929
5,799
3,251
4,180
4,028
3,858 of VSurf were considered for this classification. 3.4. Accuracy assessment All the reference data extracted from DFU polygons
were used to train Objective 1. The accuracy assessment
was carried out with a set of points systematically
distributed over the study area (1 km x 1 km, n =
5,744 points) and photo-interpreted on the orthophotos. Confusion matrices were built comparing attributed
classes for these points. S2-3D. The lowest difference in accuracy (0.4%) was
for the PA of the forest class. y
p
S2
S2-3D
OA (%)
91,7
92,6
PA forest (%)
91,9
92,3
UA forest (%)
94,5
95,5
PA non-forest (%)
91,3
93,0
UA non-forest (%)
87,5
88,2 Concerning Objective 2, 10% of the reference
data extracted from DFU polygons was randomly
selected to create a validation dataset. The number of
observations by class was randomly downsampled to
balance classes for the validation. Confusion matrices
were built using these validation data. For Objectives 1
and 2, we computed the OA (overall accuracy) as well
as producer (PA) and user accuracy (UA) for each class. S2-3D. The lowest difference in accuracy (0.4%) was
for the PA of the forest class. Selected variables. The results presented in this section
are based on the classifier trained with the S2-3D
dataset, which obtained the best precisions. Figure 3
illustrates which S2 bands were mostly identified as
relevant regarding our classification goals. A band was
counted if it was selected at the VSurf interpretation
step and each time it was used in a variable selected
during the interpretation step. For Model 1, the three
bands used the most were B8A, B11 and B12, all of
which have a 20 m GSD. 3.2. Dataset preparation The
process was executed with 2,000 trees to grow and mtry
set by default. A series of parameters combinations
were tested to find the most relevant parameters for
this study. Before training the models, the number of
observations by class was randomly downsampled to
balance classes. Table 4. Accuracy comparison of the RF classifiers
built with the S2 and S2-3D datasets for classification
Objective 1. A visual interpretation of a systematic
point grid (1 km x 1 km, n = 5,744 points) was used
to compute accuracy indices: overall accuracy (OA),
production accuracy (PA) and user accuracy (UA) by
class — Comparaison des précisions atteintes résultant
de l’utilisation des jeux de données S2 et S2-3D pour
la classification Objectif 1. Une photointerprétation
d’une grille de points systématique (1 km x 1 km, n =
5 744 points) a été utilisée pour calculer les indices de
précision : overall accuracy (OA), production accuracy
(PA) and user accuracy (UA) par classe. Table 4. Accuracy comparison of the RF classifiers
built with the S2 and S2-3D datasets for classification
Objective 1. A visual interpretation of a systematic
point grid (1 km x 1 km, n = 5,744 points) was used
to compute accuracy indices: overall accuracy (OA),
production accuracy (PA) and user accuracy (UA) by
class — Comparaison des précisions atteintes résultant
de l’utilisation des jeux de données S2 et S2-3D pour
la classification Objectif 1. Une photointerprétation
d’une grille de points systématique (1 km x 1 km, n =
5 744 points) a été utilisée pour calculer les indices de
précision : overall accuracy (OA), production accuracy
(PA) and user accuracy (UA) par classe. 4.2. Objective 2: tree species classification Table 5. Percentage of selected S2 variables by spatial
resolution and acquisition date of S2 image. The class
“mixed” lists the variables computed with 10 m S2
bands and 20 m S2 bands — Pourcentage des variables
S2 sélectionnées par résolution spatiale et par date
d’acquisition de l’image S2. La classe « mixed » concerne
les variables générées avec des bandes S2 à 10 m et des
bandes S2 à 20 m. Table 5. Percentage of selected S2 variables by spatial
resolution and acquisition date of S2 image. The class
“mixed” lists the variables computed with 10 m S2
bands and 20 m S2 bands — Pourcentage des variables
S2 sélectionnées par résolution spatiale et par date
d’acquisition de l’image S2. La classe « mixed » concerne
les variables générées avec des bandes S2 à 10 m et des
bandes S2 à 20 m. Comparing the performance of both datasets. In
order to compare the accuracies of achieved results for
both the S2 and S2-3D dataset, user accuracies of all
classes have been summarized by mean to make the
comparison easier. For dataset S2, OA and the user
accuracy mean (UA mean) were 88.5% and 88.6%
while for dataset S2-3D, it was 88.9% and 89%. As
with Model 1, the 3D dataset gave the best results
but the differences in precision can be considered as
negligible: in all cases the value was less than 0.5%. By date
(%)
By spatial resolution
(%)
8/2/2015 5/8/2016 10 m
mixed 20 m
Objective 1 32.1
67.9
7.1
21.4
71.4
Objective 2 47.4
52.6
5.3
34.2
60.5 Selected variables. The results presented in this
section concern the classifier trained with the S2-3D
dataset that obtained the best precision values. They
are summarized in figure 3 and table 5. The three
most-selected bands at the VSurf interpretation step
were B8A (NIR narrow), B5 (Red Edge 1), and B11
(SWIR 1), all of which have a 20 m GSD. Production of a forest map. The RF classifier
generated with previous variables was used to compute
a final forest map. This map was then filtered using the
Majority Filter tool of ArcMap® (Number of neighbors
to use: 8, Replacement threshold: MAJORITY). Figure 4 presents the result. A validation was carried
out for the produced map. The OA value of the
confusion matrix was 93.3%. 4.1. Objective 1: forest map Comparing the performance of both datasets. Table 4 shows the accuracy of the forest maps
generated using the S2 and S2-3D datasets. These
results were computed before post treatments and
are presented to compare dataset performances. The
presentation of the final forest map is described in
Section 4.1.3. S2-3D gave the best results, with an
overall accuracy difference of 0.9% between the two
approaches. This difference is significant (p-value =
0.002421, McNemar’s chi-squared test realized on the
contingency table of correctly classified and incorrectly
classified points). The PA of the non-forest class had the
highest difference in accuracy (1.7%) between S2 and In table 5, variables were sorted according to their
sensing date and native spatial resolution. The term
“mixed” means that S2 bands of both spatial resolutions
were used to generate the index. Fourteen variables were selected during the VSurf
prediction step. The list is presented in descending order
of occurrence: CHM2, CHM3, B11-D2, CHM1, B7-D2,
B12-D1, SLOPE, STI-D1, NDTI-D1, RTVIcore-D2,
B5-D2, MSI-D2, NDrededgeSWIR-D1, and B5-D1. Bolyn C., Michez A., Gaucher P. et al. Biotechnol. Agron. Soc. Environ. 2018 22(3) 10 Figure 3. Frequency of selection for each S2 band (Table 1) by the VSurf selection process (Genuer et al., 2016) during the
interpretation step. A band is counted if selected itself or inside a spectral indice variable — Fréquence de sélection de chaque
bande S2 (Tableau 1) par le processus de sélection VSurf (Genuer et al., 2016) durant la phase d’interprétation. Une bande
est comptabilisée si elle est sélectionnée elle-même ou au sein d’une variable d’indice spectral. Objective 1
Objective 2
Frequency
Frequency
25
20
15
10
5
0
25
20
15
10
5
0
B2 B3 B4 B5 B6 B7 B8 B8a B11 B12
B2 B3 B4 B5 B6 B7 B8 B8a B11 B12 Objective 1 Objective 2 Figure 3. Frequency of selection for each S2 band (Table 1) by the VSurf selection process (Genuer et al., 2016) during the
interpretation step. A band is counted if selected itself or inside a spectral indice variable — Fréquence de sélection de chaque
bande S2 (Tableau 1) par le processus de sélection VSurf (Genuer et al., 2016) durant la phase d’interprétation. Une bande
est comptabilisée si elle est sélectionnée elle-même ou au sein d’une variable d’indice spectral. 5.1. Variable selection It is interesting to observe the difference between
Objectives 1 and 2 in figure 3. In Objective 1, the
most selected bands were found, in order of number
of appearances, B11, B8a, and B12. In Objective 2 the
most selected bands were B8a, B5, and B11. These
results are in line with the goals of classification
models and band properties. Indeed, Objective 1 aimed
at distinguishing forest classes (coniferous stands,
broad-leaved stands, and recent clear-cuts) from non-
forest areas. The second classification objective was
separating tree species classes present on the study
site. B11 is sensitive to forest above ground biomass
and B12 facilitates distinction of live biomass, dead
biomass, and soil (Table 2), thus B11 and B12 have Selected variables were well distributed between
the two S2 images taken on different dates, especially
for Objective 2. It appears that image interaction was
useful. Choosing the time of image acquisition in
relation to species’ phenological cycle is a possible
way to improve discrimination. Immitzer et al. (2016)
test a classification of tree species in Germany for
seven classes on a single date. Their results show an
OA of 0.64, an accuracy lower than what we found
in this study, even for Dataset S2. This was probably Table 6. Confusion matrix of classification Objective 2 for Dataset S2-3D. The validation of Objective 2 was realized with
10% of the reference data. Classification Objective 2 concerned 11 classes: recent clear cuts (RCC), beech, birch, oak, other
broad-leaved stands (OB), Douglas fir, larch, other needle-leaved stands (ON), Scots pine, spruce, young needle-leaved
stands (YN). Producer accuracy (PA) and user accuracy (UA) are presented for each class — Matrice de confusion de la
classification Objectif 2 pour le jeu de données S2-3D. La validation de la classification Objectif 2 a été réalisée en utilisant
10% des données de référence. La classification Objectif 2 concernait 11 classes : coupes récentes (RCC), hêtre (Beech),
bouleau (Birch), chêne (Oak), autres peuplements feuillus (OB), douglas (Douglas fir), mélèze (Larch), autres peuplements
résineux (ON), pin sylvestre (Scots pine), épicéa (Spruce), jeunes peuplements résineux (YN). La précision du producteur
(PA) et la précision de l’utilisateur (UA) sont présentées pour chaque classe. 4.2. Objective 2: tree species classification Bolyn C., Michez A., Gaucher P. et al. Biotechnol. Agron. Soc. Environ. 2018 22(3) 12 Accuracy of the best classifier. Achieved accuracies
with the S2-3D dataset are presented in detail by a
confusion matrix (Table 6). The OA was 88.9%. The
worse PA concerned the larch (79.9%) and recent
clear cut (83.2%) classes. The worst UA were for
beech (83.8%) and larch (86.3%). Accuracy of the best classifier. Achieved accuracies
with the S2-3D dataset are presented in detail by a
confusion matrix (Table 6). The OA was 88.9%. The
worse PA concerned the larch (79.9%) and recent
clear cut (83.2%) classes. The worst UA were for
beech (83.8%) and larch (86.3%). more importance in Objective 1 where there are
non-forest classes. B5 and B8a are more related to
Objective 2; indeed, vegetation classification is the
only goal in this case. Figure 3 shows the importance
of shortwave infrared (SWIR) (B11 and B12) and the
red-edge band B5 for both models, as mentioned in
other studies (Schuster et al., 2012; Fassnacht et al.,
2016; Immitzer et al., 2016; Radoux et al., 2016). 5. DISCUSSION Looking at table 5, we can see that the most
selected variables have a GSD of 20 m. As a
consequence, the resolution of the resulting maps was
not really 10 m; even more without the use of 3D data. This confirms the relevance of spectral bands sensed
by S2 but reminds us that spectral resolution can be
more important than spatial resolution for vegetation
discrimination at a regional scale. 4.2. Objective 2: tree species classification PA and UA were 93.2%
and 95.8% for the forest class while it was 93.3% and
89.5% for the non-forest class. Eighteen variables were selected during VSurf
prediction step. The list is presented in descending
number of appearances: SLOPE, CHM1, CHM2,
CHM3, RedSWIR1-D2, B8A-D2, B7-D2, B11-D2,
NDrededgeSWIR-D1, B5D2, MSI-D2, NDWI1-D2,
B12-D2, B6-D2, B11-D1, STI-D1, B5-D1, and
LChloC-D1. 11 Forest mapping with Sentinel-2 imagery mapping with Sentinel 2 imagery
4°30’0’E
5°0’0’E
5°30’0’E 6°0’0’E 6°30’0’E
49°40’0’’N
50°0’0’’N
50°20’0’’N
50°40’0’’N
N
0 5 10 20 30 40 km
0
0,5
1
2 km 6°0’0’E 6°30’0’E 4. On the top in RGB colour composition, one of the two S2 images (05/08/2015) used in this study. On th
est map of the Belgian Ardenne ecoregion generated by merging the three forest classes of the classificat
tive 1” into one. Both maps present a more detailed view in their top left corner — En haut en compositio
une des deux images S2 (08/05/2015) utilisée dans cette étude. En bas, la carte forestière de l’écorégion de l
générée en fusionnant les trois classes forestières du résultat de la classification « Objectif 1 » en une seule. présentent une vue plus détaillée dans leur coin supérieur gauche. 4°30’0’E
5°0’0’E
5°30’0’E 6°0’0’E 6°30’0’E
4°30’0’E
5°0’0’E
5°30’0’E
6°0’0’E
49°40’0’’N
50°0’0’’N
50°20’0’’N
50°40’0’’N
49°40’0’’N
50°0’0’’
50°20’0’’N 50°40’0’’N
N
N
0 5 10 20 30 40 km
0 5 10 20 30 40 km
Forest
Non-forest
0
0,5
1
2 km
0
0,5
1
2 km 4°30’0’E
5°0’0’E
5°30’0’E
6°0’0’E
49°40’0’’N
50°0’0’’N
49°40’0’’N
50°0’0’’
50°20’0’’N 50°40’0’’N
N
N
0 5 10 20 30 40 km
0 5 10 20 30 40 km
Forest
Non-forest
0
0,5
1
2 km 50°20’0’’N 50°0’0’’ Figure 4. On the top in RGB colour composition, one of the two S2 images (05/08/2015) used in this study. On the bottom,
the forest map of the Belgian Ardenne ecoregion generated by merging the three forest classes of the classification result
“Objective 1” into one. Both maps present a more detailed view in their top left corner — En haut en composition colorée
RGB, l’une des deux images S2 (08/05/2015) utilisée dans cette étude. En bas, la carte forestière de l’écorégion de l’Ardenne
belge, générée en fusionnant les trois classes forestières du résultat de la classification « Objectif 1 » en une seule. Les deux
cartes présentent une vue plus détaillée dans leur coin supérieur gauche. Table 6. Confusion matrix of classification Objective 2 for Dataset S2-3D. The validation of Objective 2 was realized with
10% of the reference data. Classification Objective 2 concerned 11 classes: recent clear cuts (RCC), beech, birch, oak, other
broad-leaved stands (OB), Douglas fir, larch, other needle-leaved stands (ON), Scots pine, spruce, young needle-leaved
stands (YN). Producer accuracy (PA) and user accuracy (UA) are presented for each class — Matrice de confusion de la
classification Objectif 2 pour le jeu de données S2-3D. La validation de la classification Objectif 2 a été réalisée en utilisant
10% des données de référence. La classification Objectif 2 concernait 11 classes : coupes récentes (RCC), hêtre (Beech),
bouleau (Birch), chêne (Oak), autres peuplements feuillus (OB), douglas (Douglas fir), mélèze (Larch), autres peuplements
résineux (ON), pin sylvestre (Scots pine), épicéa (Spruce), jeunes peuplements résineux (YN). La précision du producteur
(PA) et la précision de l’utilisateur (UA) sont présentées pour chaque classe. 5.1. Variable selection Prediction
Reference
RCC
Beech Birch
Oak
OB
Douglas
fir
Larch ON
Scots
pine
Spruce YN
UA (%)
RCC
223
2
3
1
2
1
3
1
1
0
4
92.5
Beech
5
238
1
1
8
3
6
11
3
4
4
83.8
Birch
8
5
259
4
2
3
3
3
0
3
1
89.0
Oak
1
1
1
229
2
5
8
0
2
1
1
91.2
OB
6
0
1
5
242
3
4
2
3
2
1
90.0
Douglas fir
2
2
0
3
4
232
16
3
1
1
2
87.2
Larch
8
6
0
1
2
4
214
8
4
0
1
86.3
ON
2
7
0
2
1
7
5
236
0
1
1
90.1
Scots pine
3
2
2
4
2
0
0
0
249
4
2
92.9
Spruce
6
2
0
9
2
7
4
1
4
251
3
86.9
YN
4
3
1
9
1
3
5
3
1
1
248
88.9
PA (%)
83.2
88.8
96.6
85.4
90.3
86.6
79.9
88.1
92.9
93.7
92.5 Forest mapping with Sentinel-2 imagery 13 ecoregion. The RFI only considers forest elements
bigger than 0.1 ha and wider than 20 m. This limit
could partly explain the over-estimation; pixel groups
smaller than 10 pixels, correctly classified or not, are
common on the forest map. partially because of our use of images taken on two
dates. It would be interesting to test the use of images
taken on several dates during the vegetation period
in order to benefit from tree species phenology. Particularly for broad-leaved species, a series of dates
from March to May should help to detect differences
in foliation period. This is a task for future study; the
growing availability of free data from S2 satellites
makes this research a possibility. i The results of second objective, concerning tree
species discrimination, were encouraging (Table 6). The obtained precisions were better than those in
previous studies using S2 data (Immitzer et al., 2016)
and similar or better than those in studies using data
from other sensors with various spatial and spectral
resolution (Immitzer et al., 2012). For this number
of classes and this study area size, these results
are encouraging. This approach demonstrates the
possibility of efficiently mapping regional tree species
with S2 imagery in the future. Nevertheless, the study
did have some limitations, due to its workflow and the
reference data used. 5.1. Variable selection During the final VSurf prediction step, all 3D
data were taken into account and were among the
best variables for both objectives. The slope was
the best for Ojective 2, showing that the presence of
certain species in the study site is strongly related
to the topography. Fourteen variables were selected
for Objective 1 and 18 for Objective 2. Except NDTI
and RTVIcore, all the variables in Objective 1 were
included in Objective 2. In addition, Objective 2
included additional indices and S2 bands, which
helped to discriminate vegetation species. As
expected, this suggests that more information is
needed to solve a complex problem like separating
tree species. Just as the SWIR and red-edge bands
were the most selected S2 variable during the VSurf
interpretation step, almost all the variables selected
during the VSurf prediction step were a SWIR or red-
edge band or a spectral index computed with at least
one of these bands. First, because of the availability of data the
number of different forest stands for some species
used to extract pixels was limited (from 31 to 64,
Table 3). This means that the within-species variance
of training data sets was probably too reduced for a
large area like the Belgian Ardenne. Furthermore, the
DFU cover only public forests that represent 57% of
the study area. It will be important for future studies to
represent as best as possible the variability of species. Further research could also eventually consider
ecological gradients in analyses (e.g. water proximity,
elevation, sunlight exposure). For instance, the benefit
of using ancillary geodata in a classification process
has been studied in Forster & Kleinschmit (2014). 5.3. Contribution of 3D data compared. The precision of produced forest maps was
evaluated with a visually interpreted systematic point
grid at intervals of 1,000 m. For the second model,
the models were validated with 10% of the reference
data. In the creation of the forest map, the use of 3D data
significantly improved the precision. However,
it appears that at a large scale and at this spatial
resolution it is possible to get sufficient predictions
using only S2 imagery. The best improvements using
3D data were seen in the UA of the forest class and
in consequence for the PA of the non-forest class. Information about tree height should, most of the time,
limit confusion between other vegetation and forest;
the observed trend confirmed this idea. Furthermore,
including old clear cuts in the forest map is a
complicate task without using anterior CHM’s. Taking
into account the fact that most of the variables used in
the classification have a 20 m GSD, the 10 m spatial
resolution of the 3 CHM is probably an advantage
for the classification of edges. It could improve the
precision at those locations where 20 m pixels have
more chance to overlap the edge between forest and
non-forest classes. So the quality of geometric limits
is probably better for the forest map realized with the
S2-3D dataset. The evidence from this study suggests that this
approach enables accurate classification without 3D
data. For Objective 1, classification realized with 3D
data was significantly better, with an OA difference of
0.9%. For Objective 2, the improvement in OA was
negligible (0.4%). The produced forest map had an
OA of 93.3%. The test of tree species discrimination
was conclusive and encouraging with an OA of 88.9%. Concerning Objective 2, it is important to remember
that the present study has investigated a simplified
per-pixel classification with pixels extracted from
a limited number of pure stands. As a consequence
of these simplifications, the precision evaluated
was probably over-estimated for the application of
the classifier on the whole study site. Despite these
limitations, the results confirmed the great potential
of S2 imagery for tree species discrimination. More
specifically, the SWIR and red-edge S2 bands are
essential, as they were by far the most important in
our variable selection process. Their spatial resolution
of 20 m can lead to restrictions for detailed analyses. 5.2. Precision of the results Bolyn C., Michez A., Gaucher P. et al. Biotechnol. Agron. Soc. Environ. 2018 22(3) 14 5.3. Contribution of 3D data That is why we recommend that further research
combines S2 imagery with another data source at
very high spatial resolution in order to exploit the
undeniable discrimination power of S2 and a better
spatial precision. Along the same lines, we achieved
similar results both using a 3D dataset and without,
but precisions of edges and the detection of small
elements seemed to be improved using 3D data. That
improvement has not been evaluated in this study. The
main gain of using 3D data was the improvement of
the forest map and the clear cuts detection. In further
research, it would be interesting to generate a forest
map including clear cuts, starting from 3D data only
at a higher spatial resolution. In Objective 2, the global improvement brought
by 3D data was less important than in Objective 1. In average, precision did not increase by more than
0.5%. The only interesting exception is the PA of
the RCC class, which increased by 5%. As expected,
the 3 CHM improved the detection of recent clear
cuts. Surprisingly, the detection of YN class did
not improve. It appears that their S2 information is
already distinguishable from that of other classes
without information about height. The use of CHM
is not very relevant for the discrimination of tree
species at this spatial resolution. In contrast, a derived
variable of environment, like the slope (selected as
first variable at VSurf prediction step), seems to bring
more interesting information and improving such an
approach could be pertinent. The choice of an object-based approach and the
use of better acquisition dates are possible methods
to improve our classification results. To further our
research, we plan to work on the quality of reference
data and to develop adequate methods to surpass the
test step and create tree species classifiers operational
for the production of tree species maps at large scale
with an assessment of their precision in the best way. 6. CONCLUSIONS This paper investigates the new opportunity offered
by Sentinel-2 imagery to classify forest and forest
species at large scale. Two cloud-free S2 scenes
(02/08/2015 and 08/05/2016) were used and a series
of spectral indices were computed for each. After
variable selection, we applied supervised pixel-based
classifications with a random forest classifier. A first
model of classification aimed at creating a forest
map of the Belgian Ardenne ecoregion. A second
tested tree species discrimination for species present
on the study site. These two models of classification
were processed with both a pure S2 dataset and with
additional 3D data and the obtained precisions were 5.2. Precision of the results The produced forest map (Objective 1) had a very
good precision rate, with an OA of 93.3%. In our
reference dataset, used for classifier construction,
the non-forest class was composed of different land
cover and was less homogeneous than other classes. The non-forest class UA was worse than for the forest
class, probably for this reason. In this study, we did
not control the behavior of the classifier with small
woodland areas like isolated trees or bands of trees. The precision of the map could be negatively impacted
by fragmented landscape elements because the spatial
resolution of S2 is probably too low for this purpose,
and edge pixels represent a large proportion of the
total, increasing the bias due to sub-pixel variations
(not evaluated here) (Stratoulias et al., 2015; Immitzer
et al., 2016; Radoux et al., 2016). Hence, a possible
improvement for users of this map could be to choose
an appropriate definition for the forest that would
remove these problematic elements. According to the
Walloon Forest Inventory (Alderweireld et al., 2015),
the Belgian Ardenne ecoregion includes 333,850 ha
of forest area. Based on the forest map classification
and the confusion matrix, an area estimator of forest
was computed (Olofsson et al., 2013) at 354,761.3 ha
(± 3,695.57 ha) of forest in the Belgian Ardenne Second, we did not manage to account for species
mixing at the pixel level. Indeed, the probability
to have a single tree or stand exactly covered by a
single pixel matching its extent is low (Fassnacht et
al., 2016). The simplification done when extracting
pixels from supposedly pure stands resulted in
interesting conclusions regarding the separate nature
of species. But it is not yet sufficient to create a map
of species distribution, since the study area includes
many mixed pixels. Furthermore, for this study,
the most important S2 bands were sensed at 20 m
GSD, increasing these effects. As a consequence of
these two simplifications, the precision evaluated by
independent validation was probably over-estimated
for the application of the classifier over the whole
study site. Choosing an object-based approach and processing
segmentation with very high resolution images like
orthophotos would allow researchers to work at
the scale of one stand or tree group (Kumar, 2006). It could partly solve these issues and would give
researchers the interesting opportunity to combine
advantages from a time series of S2 images and very
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Fermentable Oligo-, Di-, and Mono-Saccharides and Polyols (FODMAPs) Consumption and Irritable Bowel Syndrome in the French NutriNet-Santé Cohort
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Nutrients
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cc-by
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Fermentable Oligo-, Di-, and Mono-Saccharides and
Polyols (FODMAPs) Consumption and Irritable Bowel
Syndrome in the French NutriNet-Santé Cohort
Elodie Schneider, Jean-Marc Sabaté, Michel Bouchoucha, Serge Hercberg,
Mathilde Touvier, Robert Benamouzig, Chantal Julia, Camille Buscail To cite this version: Elodie Schneider, Jean-Marc Sabaté, Michel Bouchoucha, Serge Hercberg, Mathilde Touvier, et al.. Fermentable Oligo-, Di-, and Mono-Saccharides and Polyols (FODMAPs) Consumption and Irri-
table Bowel Syndrome in the French NutriNet-Santé Cohort. Nutrients, 2021, 13 (12), pp.4513. 10.3390/nu13124513. hal-03623131 Distributed under a Creative Commons Attribution 4.0 International License Fermentable Oligo-, Di-, and Mono-Saccharides and Polyols
(FODMAPs) Consumption and Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort er 1,*
, Jean-Marc Sabaté 2,3, Michel Bouchoucha 2
, Serge Hercberg 1,4, Mathilde Touvier 1
uzig 2, Chantal Julia 1,4 and Camille Buscail 1,4 Elodie Schneider 1,*
, Jean-Marc Sabaté 2,3, Michel Bouchoucha 2
, Serge Hercberg 1,4, Ma
Robert Benamouzig 2, Chantal Julia 1,4 and Camille Buscail 1,4 Elodie Schneider 1,*
, Jean-Marc Sabaté 2,3, Michel Bouchoucha 2
, Serge Hercberg 1,4, Mathilde Touvier 1
,
Robert Benamouzig 2, Chantal Julia 1,4 and Camille Buscail 1,4 1
Nutritional Epidemiology Research Team (EREN), Sorbonne Paris Cité Epidemiology and Statistics Research
Center (CRESS), Inserm U1153, Inrae U1125, Cnam, Université Sorbonne Paris Nord University,
93017 Bobigny, France; s.hercberg@eren.smbh.univ-paris13.fr (S.H.);
m.touvier@eren.smbh.univ-paris13.fr (M.T.); c.julia@eren.smbh.univ-paris13.fr (C.J.);
cdebrauer@institutcancer.fr (C.B.) 2
Service de Gastroentérologie, Hôpital Avicenne, APHP, 93017 Bobigny, France;
jean-marc.sabate@aphp.fr (J.-M.S.); michel.bouchoucha@aphp.fr (M.B.); robert.benamouzig@aphp.fr (R.B.)
3
INSERM U-987, Hôpital Ambroise Paré (APHP), 92104 Boulogne-Billancourt, France
4
Département de Santé Publique, Hôpital Avicenne (APHP), 93017 Bobigny, France
*
Correspondence: e.schneider@eren.smbh.univ-paris13.fr 2
Service de Gastroentérologie, Hôpital Avicenne, APHP, 93017 Bobigny, France;
jean-marc.sabate@aphp.fr (J.-M.S.); michel.bouchoucha@aphp.fr (M.B.); robert.benamouzig@aphp.fr (R.B.)
3
INSERM U-987, Hôpital Ambroise Paré (APHP), 92104 Boulogne-Billancourt, France
4
Département de Santé Publique, Hôpital Avicenne (APHP), 93017 Bobigny, France
*
Correspondence: e.schneider@eren.smbh.univ-paris13.fr 3
INSERM U-987, Hôpital Ambroise Paré (APHP), 92104 Boulogne-Billancourt, France
4
Département de Santé Publique, Hôpital Avicenne (APHP), 93017 Bobigny, France
*
C
d
h
id
@
bh
i
i 13 f Département de Santé Publique, Hôpital Avicenne (APHP), 93017 Bobigny, France
*
Correspondence: e.schneider@eren.smbh.univ-paris13.fr p
q
,
p
(
),
g y,
*
Correspondence: e.schneider@eren.smbh.univ-paris13.fr Abstract: (1) Background: Specific foods, and more particularly, fermentable oligo-, di-, and mono-
saccharides and polyols (FODMAPs) are often considered as triggers of digestive symptoms in
Irritable Bowel Syndrome (IBS). Our aim was to study FODMAP consumption in controls and IBS
participants in a large French population-based cohort; (2) Methods: Participants from the NutriNet-
Santé cohort study completed the Rome IV and IBS-SSS questionnaire in a cross sectional study. Among them, 27,949 eligible participants had previously completed three 24-h recalls as well as
anthropometrics, socio-demographical and lifestyle data. Total FODMAP intake (in g/day) was
computed using a specific composition table. The association between FODMAPs and IBS was
estimated through multivariable logistic regression models; (3) Results: Included participants were
mainly women (75.4%) and the mean age was 43.4 ± 14.1 years. FODMAPs accounted for a mean
daily intake of 19.4 ± 9.5 g/day.
Citation: Schneider, E.; Sabaté, J.-M.;
Bouchoucha, M.; Hercberg, S.;
Touvier, M.; Benamouzig, R.; Julia, C.;
Buscail, C. Fermentable Oligo-, Di-,
and Mono-Saccharides and Polyols
(FODMAPs) Consumption and
Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort. Nutrients 2021, 13, 4513. https://
doi.org/10.3390/nu13124513 Academic Editor: Toshifumi Ohkusa Keywords: IBS; FODMAP intake; cross-sectional study; Rome IV criteria; Nutrinet-Santé cohort study Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations. Fermentable Oligo-, Di-, and Mono-Saccharides and Polyols
(FODMAPs) Consumption and Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort Overall 1295 participants (4.6%) were identified with an IBS. After
adjusting for confounding factors, IBS participants had lower intakes in FODMAPs than non-IBS ones
(aOR: 0.88, 95% CI: 0.82–0.95, p-value: 0.001). IBS severity was associated with more frequent low
FODMAP intakes (<9 g/day); (4) Conclusions: Participants tended to consume 19 g of FODMAPs
per day, but slightly less for IBS participants than for controls. In IBS participants, higher severity
was associated with lower intakes.
Citation: Schneider, E.; Sabaté, J.-M.;
Bouchoucha, M.; Hercberg, S.;
Touvier, M.; Benamouzig, R.; Julia, C.;
Buscail, C. Fermentable Oligo-, Di-,
and Mono-Saccharides and Polyols
(FODMAPs) Consumption and
Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort. Nutrients 2021, 13, 4513. https://
doi.org/10.3390/nu13124513
Academic Editor: Toshifumi Ohkusa
Received: 15 November 2021
Accepted: 13 December 2021
Published: 17 December 2021
Citation: Schneider, E.; Sabaté, J.-M.;
Bouchoucha, M.; Hercberg, S.;
Touvier, M.; Benamouzig, R.; Julia, C.;
Buscail, C. Fermentable Oligo-, Di-,
and Mono-Saccharides and Polyols
(FODMAPs) Consumption and
Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort. Nutrients 2021, 13, 4513. https://
doi.org/10.3390/nu13124513
Academic Editor: Toshifumi Ohkusa
Received: 15 November 2021
Accepted: 13 December 2021
Published: 17 December 2021 Keywords: IBS; FODMAP intake; cross-sectional study; Rome IV criteria; Nutrinet-Santé cohort study HAL Id: hal-03623131
https://cnam.hal.science/hal-03623131v1
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Citation: Schneider, E.; Sabaté, J.-M.;
Bouchoucha, M.; Hercberg, S.;
Touvier, M.; Benamouzig, R.; Julia, C.;
Buscail, C. Fermentable Oligo-, Di-,
and Mono-Saccharides and Polyols
(FODMAPs) Consumption and
Irritable Bowel Syndrome in the
French NutriNet-Santé Cohort.
Nutrients 2021, 13, 4513. https://
doi.org/10.3390/nu13124513
Academic Editor: Toshifumi Ohkusa
Received: 15 November 2021
Accepted: 13 December 2021
Published: 17 December 2021 2.2. Ethics This study was conducted in accordance with the Declaration of Helsinki, and was
approved by the Institutional Review Board of the French Institute for Health and Med-
ical Research (IRB Inserm 0000388FWA00005831) and the “Commission Nationale de
l’Informatique et des Libertés” (CNIL n 908450 and 909216). The study is registered at
clinicaltrials.gov (accessed on 21 May 2019) as NCT03335644. All participants provided an
electronic informed consent. 2.3. Data Collection 2.3.1. Irritable Bowel Syndrome 2.3.1. Irritable Bowel Syndrome An additional questionnaire was sent to the cohort in April 2018 to assess gastroin-
testinal disorders. History of digestive diseases and symptoms were collected using the
Rome IV questionnaire to define IBS (with symptoms for at least 6 months) [26]. The ques-
tionnaire also included several questions about digestive medical history and symptoms. Thus, people were not eligible to participate in this study if they had had a history of rectal
bleeding, melena, hematemesis, or significant unintentional weight loss (>5 kg) in the
past 3 months, as well as a history of oesophagus, stomach or colorectal cancer, coeliac
disease or ulcerative colitis in their family, as these symptoms were considered proxies for
an organic underlying condition. 2.1. Population The NutriNet-Santé study is a web-based prospective observational cohort study that
includes French adults from the general population (more than 160,000 recruited to date). Detailed description of the cohort is available elsewhere [25]. Briefly, it aims at studying
the relations between nutrition and health, as well as determinants of dietary patterns
and nutritional status [25]. Inclusions started in May 2009 and were still ongoing at the
time of this study. At baseline, participants completed a set of five questionnaires about
socio-demographic and lifestyle characteristics, anthropometry, health status, physical
activity and diet. These questionnaires were repeated yearly. Furthermore, during follow-
up, additional questionnaires on other specific topics dealing with determinants of food
behaviors or health were regularly sent to participants. 1. Introduction Fermentable oligo-, di-, and mono-saccharides and polyols (FODMAPs) are short
chain carbohydrates that are poorly absorbed in the gastrointestinal tract [1]. They include
fructose in excess of glucose, lactose, fructans, galacto-oligo-saccharides (GOS) and polyols. They are ubiquitous in our diet, in particular through fruits, vegetables, legumes, dairy
products, cereal products, oilseeds, seasonings, sugary products, alcoholic beverages,
sugar-free products or sweeteners, and many processed items [2–5]. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article
distributed
under
the
terms
and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/). g
p
y p
Among functional gastrointestinal disorders (FGIDs), irritable bowel syndrome (IBS) is
one of the most prevalent and has therefore been of interest in recent years, affecting about
6–11% of the general population depending on the diagnostic criteria [6–8]. On this point,
the Rome foundation recently updated the criteria used to diagnose IBS with the Rome IV
criteria [9,10]. IBS, which is defined by chronic abdominal pain associated with a change https://www.mdpi.com/journal/nutrients Nutrients 2021, 13, 4513. https://doi.org/10.3390/nu13124513 Nutrients 2021, 13, 4513 2 of 13 in bowel habits, can be responsible for an impairment in quality of life of patients with
severe disease and for an economic burden [11,12]. While IBS pathophysiology remains
unclear, nutrient and non-nutrient components of foods, including FODMAPs, are often
suspected to trigger IBS symptoms such as abdominal pain, bloating, excessive passage of
gas and also diarrhea [13–16]. In recent years, several clinical trials have suggested that a
low FODMAP diet (LFD) may be associated with a reduction in IBS symptoms [5,17–21]. (
)
y
y
p
Reviews on this association expressed a lack of large-scale data [22–24]. Moreover,
comparisons between FODMAP consumption in IBS participants and control subjects are
lacking; only Halmos et al. described similar levels of daily intakes in a study with 30 IBS
patients and 8 healthy subjects [5]. p
y
j
The main aim of this work was to study FODMAP consumption in both IBS partici-
pants and in controls and to assess the relationships between FODMAP load, IBS symptoms
and severity in a large national cohort (NutriNet-Santé). 2.3.2. Diet Participants were requested to fill a set of three 24-h diet recall interviews at base-
line and every 6 months (three non-consecutive days over a fortnight including two on
weekdays and one during a weekend) [25]. Food record relied on a meal-based approach,
asking nature and sizes of the portions of food eaten at each occasion (including meals
and snacking periods). Portion sizes were assessed using validated photographs [27],
and dietary intakes were based on the NutriNet-Santé food composition table [28]. This Nutrients 2021, 13, 4513 3 of 13 3 of 13 self-administered food record method has been validated in several studies in comparison
to urinary biomarkers and interview by a dietitian [29–31]. In this work, the first full set of
food records available was used to estimate dietary intakes for each individual. A specific composition table was used to assess FODMAP consumption [32]. This
table enables to compute total FODMAP intake (in weight, grams/day), as well as each of:
fructose in excess of glucose (excess-fructose), lactose, fructans, GOS and polyols for each
participant. For the analyses, total FODMAP intakes were divided into three categories
(<9 g/day, 9–16 g/day, ≥16 g/day) according to previous works published on low and
usual FODMAP diet [5,33,34]. Eligible participants for this study had completed at least one
full set of three 24-h food records after the inclusion and prior to the Rome IV questionnaire. Under-reporters of energy intake, identified through the Black method, were excluded
from this study [35]. 2.3.3. IBS Scoring System The IBS Symptom Scoring System (IBS-SSS) was used to assess IBS severity in partici-
pants with IBS diagnosis based on the Rome IV questionnaire. Other participants were also
asked to fill this scoring system if they were previously diagnosed with an IBS or if they
suspected they suffered from IBS (based on self-report). The IBS-SSS is divided into 5 main
items (abdominal pain severity and frequency, abdominal distension severity, bowel habit
satisfaction and impact on quality of life), ranged 1–100 each. The maximal achievable
score is 500, mild, moderate and severe cases are indicated by scores of 75 to 175, 175 to 300
and >300 respectively. This score has been validated and described in detail elsewhere [36]. 2.3.4. Covariates Information on socio-demographic characteristics was collected at baseline: age,
sex, marital status (single/living with someone), smoking status (current smoker/former
smoker/non-smoker), monthly income and composition of the household enabling to
calculate monthly income per consumption unit (c.u.) (unwilling to answer/<1110 € per
c.u./1110–2330 € per c.u./>2330 € per c.u.) [37], educational level (no diploma or primary
school/secondary school/undergraduate school/graduate school) and residence (rural
area/urban area). Self-reported weight and height at baseline were used to calculate body
mass index (BMI, in kg/m2) (<18.5/18.5–25/25–30/≥30) [38–40]. A specific questionnaire
was administered at baseline to assess physical activity level using the International Physi-
cal Activity Questionnaire (IPAQ, Intense/Moderate/Low) [41]. Total energy intake was
computed (in kcal/day). 3.1. Population
3.1. Population
Th fi
l The final sample included 27,949 people (Figure 1). Participants were mostly women
(75.4%) with a mean age of 47.8 ± 14.1 years. Overall description of the population and
comparison between non-IBS participants and IBS subjects using the Rome IV questionnaire
is shown in Table 1. The final sample included 27,949 people (Figure 1). Participants were mostly women
(75.4%) with a mean age of 47.8 ± 14.1 years. Overall description of the population and
comparison between non-IBS participants and IBS subjects using the Rome IV question-
naire is shown in Table 1. Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,94
Figure 1. Flowchart of the IBS-SSS study, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949) ics of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). cs of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Table 1. Characteristics of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Table 1. Characteristics of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019 (N = 27,949). Table 1. Characteristics of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019
Table 1. Characteristics of participants according to IBS status, NutriNet-Santé cohort, France, 2009–2019 (N Table 1. Characteristics of participants according to IBS status, NutriNet Santé cohort, France, 2009 2019 (N 27,949). 2.4. Statistical Analyses Statistical analyses were carried out
using SAS software (version 9.4; SAS Institute, Inc., Cary, NC, USA) [45]. 2.4. Statistical Analyses A description of socio-demographic, lifestyle and anthropometric characteristics,
health status, physical activity, overall diet quality and FODMAP consumption (total and
individually) was performed on the whole sample, and according to the IBS status (yes/no). Chi-square tests or Student’s t-tests were used according to the qualitative or quantitative
status of the variable. In order to adjust for the overall diet quality, a principal component analysis was
performed using food groups from the study population. The first dietary pattern was
positively correlated with fruits and vegetables, whole grains, natural oilseeds, vegetable
fat, non-sugared beverages, legumes and broth. It was negatively correlated with milky
desserts, meat and ham, sweetened beverages, cakes, cookies and pastries, bread and
processed meat. Therefore, it was labelled a “healthy” dietary pattern as previously
published [42,43] and this dimension was used as a proxy for the overall diet quality. The estimate of the first principal component was divided into 3 categories (poor qual-
ity/intermediate quality or healthy diet). Multivariate logistic regression models were applied to assess Odds Ratio (OR) and
adjusted OR (aOR) with their 95% confidence intervals (95% CI) of IBS across FODMAP
consumption. Models were successively adjusted for age and sex (model 2) as well as Nutrients 2021, 13, 4513 4 of 13
OR) and
ODMAP energy, BMI, income per consumption unit, marital status, smoking status, overall diet
quality, IPAQ, residence and educational level (model 3). All tests were two-sided and a
p-value < 0.05 was considered statistically significant. Statistical analyses were carried out
using SAS software (version 9.4; SAS Institute, Inc., Cary, NC, USA) [44]. gy,
,
p
p
,
,
g
,
q
ity, IPAQ, residence and educational level (model 3). All tests were two-sided and a p-
value < 0.05 was considered statistically significant. Statistical analyses were carried out
using SAS software (version 9.4; SAS Institute, Inc., Cary, NC, USA) [45]. energy, BMI, income per consumption unit, marital status, smoking status, overall diet
quality, IPAQ, residence and educational level (model 3). All tests were two-sided and a
p-value < 0.05 was considered statistically significant. Statistical analyses were carried out
using SAS software (version 9.4; SAS Institute, Inc., Cary, NC, USA) [44]. gy,
,
p
p
,
,
g
,
q
ity, IPAQ, residence and educational level (model 3). All tests were two-sided and a p-
value < 0.05 was considered statistically significant. 3.1. Population
3.1. Population
Th fi
l Characteristics of Participants
All
IBS (Yes)
IBS (No)
p-Value
N = 27,949
N = 1295 (4.63%) N = 26,654 (95.37%)
n
%
n
%
n
%
Age (years)
mean (SD)
47.8
(14.1)
43.4
(14.5)
48.0
(14.1)
<0.0001
Energy (kcal)
mean (SD)
1903
(495)
1859
(488)
1905
(496)
<0.0001
Sex
Men
6871
24.6
149
11.5
6722
25.2
<0.0001
Women
21,078
75.4
1146
88.5
19,932
74.8
Marital status
Single/divorced/widowed
7565
27.1
412
31.9
7153
26.9
<0.0001
Married/cohabiting
20,327
72.7
881
68.1
19,446
73.1
Educational
level
No diploma or primary
school
712
2.57
28
2.18
684
2.59
0.26
Secondary school
8573
30.9
371
28.9
8202
31.0
p
p
g
(
)
Characteristics of Participants
All
IBS (Yes)
IBS (No)
p-Value
N = 27,949
N = 1295 (4.63%)
N = 26,654 (95.37%)
n
%
n
%
n
%
Age (years)
mean (SD)
47.8
(14.1)
43.4
(14.5)
48.0
(14.1)
<0.0001
Energy
(kcal)
mean (SD)
1903
(495)
1859
(488)
1905
(496)
<0.0001
Sex
Men
6871
24.6
149
11.5
6722
25.2
<0.0001
Women
21,078
75.4
1146
88.5
19,932
74.8
Marital
status
Single/divorced/widowed
7565
27.1
412
31.9
7153
26.9
<0.0001
Married/cohabiting
20,327
72.7
881
68.1
19,446
73.1
Educational
level
No diploma or primary
school
712
2.57
28
2.18
684
2.59
0.26
Secondary school
8573
30.9
371
28.9
8202
31.0
Undergraduate
8372
30.2
407
31.7
7965
30.1
Graduate
10,059
36.3
479
37.3
9580
36.2
Income per
consump-
tion unit
(€/month)
Unwilling to answer
2034
7.50
78
6.27
1956
7.56
<0.0001
<1110
3101
11.4
198
15.9
2903
11.2
1110–2330
17,932
66.2
821
65.9
17,111
66.2
>2330
4040
14.9
148
11.9
3892
15.0
Residence
Rural area
6051
22.1
255
20.2
5796
22.2
0.10
Urban area
21,350
77.9
1007
79.8
20,343
77.8 5 of 13 Nutrients 2021, 13, 4513 Table 1. Cont. 3.2. Dietary Patterns and Proportion of IBS Cases in the Study Population 3.2. Dietary Patterns and Proportion of IBS Cases in the Study Population Overall 1295 (4.6%) subjects reported an IBS based on Rome IV criteria, with a
higher proportion in women compared to men (5.44% in women vs. 2.17% in men,
p-value < 0.0001). They were also more likely to be current smoker, younger, single, with a
lower income (all p-value < 0.0001) and to have a healthier diet than non-IBS participants
(p-value = 0.003) (Table 1). IBS subjects tended to have lower energy intakes than non-IBS ones (1859 ± 488 kcal
vs. 1906 ± 496 kcal, p-value < 0.0001). Their average total consumption of FODMAPs was
18.4 (SD = 9.6) g/day vs. 19.5 (SD = 9.5) g/day in non-IBS participants (∆= −1.1 g/day,
i.e., −6.0%, p-value < 0.0001). Moreover, IBS participants tended to have significantly
lower intakes in excess fructose (∆= −0.46 g/day, i.e., −11.0%), lactose (∆= −0.2 g/day,
i.e., −2.0%), GOS (∆= −0.03 g/day, i.e., −8.3%), fructans (∆= −0.12 g/day, i.e., −5.7%)
and polyols (∆= −0.22 g/day, i.e., −12.9%) (Table 2). Table 2. FODMAP intake in the population under study according to the IBS, NutriNet-Santé cohort, France, 2009–2019
(N = 27,949). AP intake in the population under study according to the IBS, NutriNet-Santé cohort, France, 2009–2019 Table 2. FODMAP intake in the population under study according to the IBS, NutriNet-Santé cohort, France, 2009–2019
(N = 27,949). Global
IBS (Yes)
IBS (No)
p-Value
N = 27,949
N = 1295 (4.6%)
N = 26,654 (95.4%)
Mean
SD
Mean
SD
Mean
SD
Energy (kcal)
1903
495
1859
488
1906
496
<0.0001
Total FODMAPs
(g/day)
19.4
9.5
18.4
9.6
19.5
9.5
<0.0001
Excess fructose
4.62
3.92
4.18
3.96
4.64
3.91
<0.0001
Lactose
10.3
7.5
10.1
7.3
10.3
7.5
<0.0001
GOS
0.39
0.37
0.36
0.38
0.39
0.37
<0.0001
Fructans
2.28
1.64
2.10
1.49
2.22
1.64
<0.0001
Polyols
1.92
2.05
1.71
2.00
1.93
2.06
<0.0001
IBS: Irritable bowel syndrome. 3.1. Population
3.1. Population
Th fi
l Characteristics of Participants
All
IBS (Yes)
IBS (No)
p-Value
N = 27,949
N = 1295 (4.63%)
N = 26,654 (95.37%)
n
%
n
%
n
%
Smoking
status
Current smoker
3366
12.1
204
15.8
3162
11.9
0.0001
Former
10,070
36.1
437
33.8
9633
36.2
Never
14,458
51.8
652
50.4
13,806
51.9
BMI
(kg/m2)
<18.5
1300
4.66
90
6.96
1210
4.55
<0.0001
18.5–25
17,932
64.3
784
60.6
17,148
64.4
25–30
6355
22.8
276
21.3
6079
22.8
≥30
2319
8.31
144
11.1
2175
8.17
IPAQ
Intense
8693
35.0
372
32.5
8321
35.1
0.16
Moderate
10,705
43.1
508
44.3
10,197
43.0
Low
5433
21.9
266
23.2
5167
21.8
BMI: Body Mass Index; IBS: Irritable Bowel Syndrome; IPAQ: International Physical Activity Questionnaire; SD: Standard Deviation;
p-value: Chi-square tests or Student’s t-tests were used according to the qualitative or quantitative status of the characteristics; Missing
data: Physical activity N = 3118 (11.2%); <5%: income level, residence, educational level, marital status, smoking status, BMI. Table 1. Cont. Table 1. Cont. BMI: Body Mass Index; IBS: Irritable Bowel Syndrome; IPAQ: International Physical Activity Questionnaire; SD: Standard Deviation;
p-value: Chi-square tests or Student’s t-tests were used according to the qualitative or quantitative status of the characteristics; Missing
data: Physical activity N = 3118 (11.2%); <5%: income level, residence, educational level, marital status, smoking status, BMI. 3.2. Dietary Patterns and Proportion of IBS Cases in the Study Population 3.3. Association between FODMAP Consumption and IBS After adjusting for covariates (model 3), an increase in total FODMAP intakes was as-
sociated with a reduced proportion of IBS (Table 3). The result was similar using FODMAP
consumption as continuous (aOR: 0.88, 95% CI: 0.82–0.95, p-value: 0.001) or categorical:
consumers with a high load of FODMAPs (i.e., >16 g/day) were less likely to be IBS patients
in comparison with people with a low amount of FODMAPs (i.e., <9 g/day) (aOR: 0.82,
95% CI: 0.67–1.01, p for trend: 0.009) (Table 3). Sensitivity analyses were performed using
20 multiple imputations by the Chained equations method to handle missing values for Nutrients 2021, 13, 4513 6 of 13 the following variables: IPAQ (11.2%), income level (3.0%), residence (2.0%), educational
level (0.8%), marital status (0.2%), smoking status (0.2%), BMI (0.2%) [45,46]. The results
were similar, with an association between FODMAP consumption and IBS (model 3 aOR:
0.900 95% CI: 0.827–0.980) (data not tabulated). the following variables: IPAQ (11.2%), income level (3.0%), residence (2.0%), educational
level (0.8%), marital status (0.2%), smoking status (0.2%), BMI (0.2%) [45,46]. The results
were similar, with an association between FODMAP consumption and IBS (model 3 aOR:
0.900 95% CI: 0.827–0.980) (data not tabulated). the following variables: IPAQ (11.2%), income level (3.0%), residence (2.0%), educational
level (0.8%), marital status (0.2%), smoking status (0.2%), BMI (0.2%) [45,46]. The results
were similar, with an association between FODMAP consumption and IBS (model 3 aOR:
0.900 95% CI: 0.827–0.980) (data not tabulated). Table 3. Adjusted associations between FODMAP consumption and Irritable bowel syndrome, NutriNet-Santé cohort,
France, 2009–2019 (N = 27,949). Continuous
Classes
≤9 g
9–16 g
>16 g
N =
2792
N = 8865
N = 16,292
OR
95% CI
p-Value
OR
95% CI
OR
95% CI
p-Trend
IBS
Model 1
0.88
[0.83–0.94]
<0.0001
Ref
0.90
[0.75–1.09]
0.77
[0.64–0.92]
0.0005
Model 2
0.92
[0.86–0.98]
0.0066
Ref
0.93
[0.77–1.13]
0.82
[0.69–0.99]
0.0110
Model 3
0.88
[0.82–0.95]
0.0011
Ref
0.99
[0.80–1.22]
0.82
[0.67–1.01]
0.0086
p-values obtained with logistic regression using total FODMAPs as a continuous variable. p-values for trend obtained with logistic
regression using classes as continuous variables. Model 1: Not adjusted; Model 2: Adjusted for age and sex; Model 3: Adjusted for
model 2 + energy intake, BMI, income, marital status, smoking status, diet quality, physical activity, residence, and educational level. 3.3. Association between FODMAP Consumption and IBS ions between FODMAP consumption and Irritable bowel syndrome, NutriNet-Santé cohort,
949) ed associations between FODMAP consumption and Irritable bowel syndrome, NutriNet-Santé cohort,
9 (N = 27,949). Table 3. Adjusted associations between FODMAP consumption and Irritable bowel syndrome, NutriN
France, 2009–2019 (N = 27,949). 3.4. FODMAP Consumption and IBS Severity Proportion of IBS participants with different FODMAP intakes in different categories of
severity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803). igure 2. Proportion of IBS participants with different FODMAP intakes in different categories of
everity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803). 7.7
11.7
9.9
20.0
33.3
34.5
36.8
29.3
59.0
53.7
53.3
50.7
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
Remission
Mild
Moderate
Severe
<9g
9–16g
>16g Figure 2. Proportion of IBS participants with different FODMAP intakes in different categories of
severity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803)
Figure 2. Proportion of IBS participants with different FODMAP intakes in different categories of
severity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803). gure 2. Proportion of IBS participants with different FODMAP intakes in different categories of
verity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803). Focusing specifically on each IBS-SSS individual item, among people who were di-
agnosed with an IBS through the Rome IV criteria, those who consumed less than 9 g of
total FODMAPs per day had more severe IBS symptoms in particular for abdominal pain
and distension than the others (Figure 3)
Focusing specifically on each IBS-SSS individual item, among people who were diag-
nosed with an IBS through the Rome IV criteria, those who consumed less than 9 g of total
FODMAPs per day had more severe IBS symptoms in particular for abdominal pain and
distension than the others (Figure 3). Focusing specifically on each IBS-SSS individual item, among people who were di-
gnosed with an IBS through the Rome IV criteria, those who consumed less than 9 g of
otal FODMAPs per day had more severe IBS symptoms in particular for abdominal pain
nd distension than the others (Figure 3). Figure 3. IBS-SSS individual items according to FODMAP intakes in IBS patients identified with the
0.0
10.0
20.0
30.0
40.0
50.0
60.0
Abdominal pain severity
Abdominal pain
frequency
Abdominal distension
severity
Bowel habit satisfaction
Impact on quality of life
<9g
9–16g
>16g
igure 3. IBS-SSS individual items according to FODMAP intakes in IBS patients identified with the
Rome IV criteria, NutriNet-Santé cohort, France, 2009–2019 (N = 803). 0.0
10.0
20.0
30.0
40.0
50.0
60.0
Abdominal pain severity
Abdominal pain
frequency
Abdominal distension
severity
Bowel habit satisfaction
Impact on quality of life
<9g
9–16g
>16g
Figure 3. 3.4. FODMAP Consumption and IBS Severity Out of 27,949 participants for this study, 3979 answered the IBS-SSS, based on a
self-diagnosis for IBS. Among them, 20.2% (N = 803) met the Rome IV criteria for IBS. Participants with an auto-diagnosed IBS were similarly distributed among each
FODMAP category (<9 g/day, 9–16 g/day, ≥16 g/day) with the others. Indeed, 12%
consumed less than 9 g/day of total FODMAPs in comparison with 54% who ate more
than 16 g/day of total FODMAPs. The average total consumption of FODMAPs was
18.69 ± 9.55 g/day for those with an auto-diagnosis of IBS in comparison with 19.58 ± 9.55 g/day
for the others (data not tabulated). 55% of IBS participants had at least moderate or severe symptoms according to the
IBS-SSS (Table 4). 55% of IBS participants had at least moderate or severe symptoms according to the
IBS-SSS (Table 4). Table 4. Proportion of IBS participants in different categories of severity according to the IBS-SSS,
NutriNet-Santé cohort, France, 2009-2019 (N = 803). IBS-SSS
n
%
Remission
0–75
78
9.7
Mild
75–175
281
35.0
Moderate
175–300
304
37.9
Severe
>300
140
17.4 Table 4. Proportion of IBS participants in different categories of severity according to the IBS-SSS,
NutriNet-Santé cohort, France, 2009-2019 (N = 803). Among people who ate less than 9 g per day of total FODMAPs (N = 97, 12% of
participants), the mean IBS-SSS was 228 ± 103. People who ate 9–16 g per day of total
FODMAPs had an average IBS-SSS of 199 ± 97 whereas among people who ate more than
16 g per day of total FODMAPs (N = 430, 54% of participants), the mean IBS-SSS was
197 ± 98 (data not tabulated, p-value within each class 0.06). Among severe cases of IBS participants, 20% ate less than 9 g of FODMAPs per day
contrary to 51% of severe cases of IBS participants who ate more than 16 g of FODMAPs
per day (Figure 2). 7 of 13
er day
MAPs
APs Nutrients 2021, 13, 4513 Figure 2. Proportion of IBS participants with different FODMAP intakes in different categories of
severity according to the IBS-SSS, NutriNet-Santé cohort, France, 2009–2019 (N = 803). 7.7
11.7
9.9
20.0
33.3
34.5
36.8
29.3
59.0
53.7
53.3
50.7
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
Remission
Mild
Moderate
Severe
<9g
9–16g
>16g
Figure 2. 3.4. FODMAP Consumption and IBS Severity IBS-SSS individual items according to FODMAP intakes in IBS patients identified with the
Rome IV criteria, NutriNet-Santé cohort, France, 2009–2019 (N = 803). Abdominal pain
Abdominal pain
frequency Figure 3 IBS SSS individual items according to FODMAP intakes in IBS patients identified with the
<9g
9–16g
>16g
gure 3. IBS-SSS individual items according to FODMAP intakes in IBS patients identified with the
me IV criteria NutriNet-Santé cohort France 2009–2019 (N = 803)
Figure 3. IBS-SSS individual items according to FODMAP intakes in IBS patients identified with the
Rome IV criteria, NutriNet-Santé cohort, France, 2009–2019 (N = 803). g
Rome IV criteria,
4. Discussion p
g
p p
In this study, although a small but significant difference in total FODMAP intake
was found between IBS participants and controls, both intakes in FODMAPs are in the
range of those known to be associated with symptoms in patients, i.e., over 9 g per day
(32). These intakes and higher FODMAP intakes (over 16 g/day) are therefore susceptible
to induce digestive symptoms in participants with a favoring profile for developing IBS
such as a particular microbiota [53], visceral hypersensitivity [54] or altered intestinal
permeability [55]. Interestingly, in our study, the mean daily intake in FODMAPs was slightly lower
than that of non-IBS participants, and we found an inverse relationship between the level
of FODMAP consumption and the prevalence of IBS; that is to say an increased intake in
FODMAPs was associated with a lower prevalence of IBS. Reverse causality could partly
explain these results, i.e., exposure to low loads of FODMAPs may be the consequence
of IBS incidence. Indeed, we used a cross-sectional design (even though we tried to be as
prospective as possible by choosing a dietary recall prior to the Rome IV questionnaire). One hypothesis is that patients, aware of the low FODMAP diet (LFD) benefits on
digestive symptoms, follow dietary advice to reduce their FODMAP load. This is confirmed
by the fact that patients with a more severe disease according to global IBS-SSS or individual
component of the score (pain, abdominal distension, impact on quality of life) were those
with lower FODMAP consumption as if they were following a diet. Given the nature of symptoms in IBS, directly linked in the patients’ mind to their
diet [56], it may be difficult to disentangle causality in the relationship between FODMAPs
and IBS in observational studies. However, it has been shown in the US that 60% of IBS
patients described an association between consuming foods and GI symptoms and that they
have frequent concerns about what food to avoid [57,58]. In people using the internet like
our participants to an online study, information about disease is more frequently found on
the internet and other media than in non-internet users, which could potentially lead to self-
management [59,60]. g
Rome IV criteria,
4. Discussion In this cross-sectional study performed in a large French cohort involving more than
27,000 people, we found that 4.6% of the participants had an IBS using the Rome IV criteria. Total FODMAP intake was around 19 g per day in both IBS and non IBS participants. However, IBS patients had a slightly lower intake of FODMAPs than non IBS participants
and an increased severity of disease was associated with decreased intakes in FODMAPs. The Rome IV proportion of 4.6% of IBS participants we found in this study compared
with the 10.5% in our last study using the Rome III criteria [47] is consistent with a decrease
in prevalence using the Rome IV criteria instead of the Rome III one [48,49]. p
g
To the best of our knowledge, this work is the first to assess FODMAP consumption
in both IBS and non-IBS subjects in such a large population-based study. FODMAP Nutrients 2021, 13, 4513 8 of 13 intakes have already been studied in other countries in smaller studies. In Australia, an
interventional study with a diet low in FODMAPs included 30 patients with IBS and
8 healthy controls and was associated with reduced functional gastrointestinal symptoms
in patients with IBS [5]. In this study as well as in other studies, FODMAP intakes in both
groups of IBS patients at baseline was similar at around 16 g per day [34,50,51]. These
levels are of similar range but lower than the consumption we found in our study in
both groups. Surprisingly, while we expected that the FODMAP content in the typical
Australian diet would be higher than that of a French diet, it was not confirmed. The higher
FODMAP consumption found in France in IBS subjects, around 19 g, compared with the
16.5 g per day of Australian and Swedish study is due to an increase in the excess fructose
and polyol categories while lactose and GOS intakes are similar [5,50]. However, this total
FODMAP intake of around 19 g in both groups is in accordance with our recent publication
in more than 100,000 participants of the NutriNet cohort [32] and of 117 Swedish invidious
representative of the general population [52]. g
Rome IV criteria,
4. Discussion A recent study in the US showed that half of the patients have tried an
LFD before being seen by a gastroenterologist [58] and it was the same proportion in a recent
study with patients from the French IBS association [61]. Furthermore, gastroenterologists
themselves show a growing body of interest for diets, in particular the LFD: half of the
providers now provide diet recommendations to over 75% of their IBS patients and they
mostly recommend an LFD [58]. Indeed, most interventional studies showed a decrease in
IBS severity after an LFD [5,24,50,51,62]. A prospective trial in the United States showed
an improvement of quality of life in patients with diarrhea-predominant IBS with the very
low carbohydrate diet in comparison with the standard American diet [63]. Conversely,
a randomized, controlled, single-blinded trial in Sweden concluded that both an LFD
and traditional IBS dietary advice improved IBS symptoms, but without any significant
difference between the two dietary strategies [50]. Besides, though some have argued for a causal effect of FODMAP consumption on IBS
symptoms, with small bowel luminal distension, colonic gas production varying with the Nutrients 2021, 13, 4513 9 of 13 type of FODMAP and influenced by gut microbiota [64], and visceral hypersensitivity [54],
the association between FODMAP consumption and IBS is still controversial as seen
elsewhere [22,50,65–68]. Another explanation could be that FODMAPs encompass lactose,
and lactose intolerance is an analogous condition to IBS [69]. Moreover, FODMAP effects
could be related to other food items such as fatty food or coffee that are not included in
FODMAP definition [70,71]. type of FODMAP and influenced by gut microbiota [64], and visceral hypersensitivity [54],
the association between FODMAP consumption and IBS is still controversial as seen
elsewhere [22,50,65–68]. Another explanation could be that FODMAPs encompass lactose,
and lactose intolerance is an analogous condition to IBS [69]. Moreover, FODMAP effects
could be related to other food items such as fatty food or coffee that are not included in
FODMAP definition [70,71]. This study has several strengths: First, a large number of participants were involved,
allowing powerful analyses. Besides, for IBS definition, we used a validated question-
naire [10,72], as well as validated methods to assess FODMAP intakes [32]. The Rome
IV questionnaire is also believed to select a more severe subpopulation from the IBS
patients who were defined with the Rome III questionnaire [73–75]. g
Rome IV criteria,
4. Discussion Furthermore, socio-
demographic characteristics of IBS patients in this study are consistent with the literature:
IBS is more prevalent among young women and those with lower incomes [7,8,11]. This
study also had a high specificity as the eligibility criteria—in particular regarding self-
reported medical conditions and alert symptoms—was very restrictive, which probably
led to the exclusion of healthy people. NutriNet-Santé study is a web-based study, thus
enablingthe collection of data from various socio-demographic profiles, which allowed
the use of multiple covariates to adjust for confounders. The results were adjusted for age,
sex, energy, BMI, income per consumption unit, marital status, smoking status, overall
diet quality, physical activity, residence and educational level, therefore minimizing some
potentially confounding factors. Several limitations of this study should be discussed. First, even though the work was
designed to be as prospective as possible by choosing dietary records prior to the Rome
IV questionnaire, it is still a cross-sectional study. Because of the observational design of
the study, causal links cannot be asserted and the question of whether they were following
a diet, and in particular an LFD was not directly asked to the participants. However, the
hypothesis of reverse causality was reinforced by the analyses performed using the IBS-SSS. Indeed, since the LFD is increasingly known among IBS patients, they might have modified
their dietary behavior before filling in the Rome IV questionnaire. The 9 g/day cut-off used
in our study was chosen according to previous works of the Monash group [5,33] whereas
the 16 g/day cut-off matches the usual daily amount of FODMAPs reached in several
studies [5,34,50]. Further research from longitudinal studies could point out if FODMAP
intakes tend to decrease after IBS onset and diagnosis. Another limitation relates to the
voluntary profile of subjects, thus, subjects probably more interested in nutrition. They
were therefore more likely to have a healthier diet compared to the general population,
thus potentially leading to an underestimation of the associations that would be found
in the general population. Consequently, caution is needed before generalization of the
results. Another limitation is that the dietary records as well as the Rome IV questionnaire
were administered by self-administered questionnaire. Nevertheless, this food collection
system has been shown to be reliable [29–31]. Finally, even though potential confounding
factors were taken into account, the study design does not enable to exclude the hypothesis
of residual confounders. 5. Conclusions In this large prospective population-based cohort, participants had a mean intake in
FODMAPs of about 19 g per day. IBS patients had slightly lower intakes in FODMAPs
than non-IBS participants. This may be due to reverse causality, as it was reinforced by the
disease severity. Longitudinal studies are needed to better assess these findings, and to
give clinicians new data on FODMAP intakes as a triggering factor for IBS symptoms. Author Contributions: E.S. analysed the data, interpreted the results and drafted and revised the
paper. J.-M.S., M.B. and R.B. participated in the design of the study, helped in the interpretation
of the data and critically revised the manuscript for important intellectual content. M.T. and S.H. implemented the study and monitored data collection for the whole NutriNet-Santé study and
critically revised the paper for important intellectual content. C.J. participated in the design of the Nutrients 2021, 13, 4513 10 of 13 10 of 13 study, interpretation of the data and critically revised the paper for important intellectual content. C.B. supervised the statistical analysis outline, analysed the data and critically revised the paper
for important intellectual content. She has full responsibility for the conduct of the study and final
content. All authors have read and agreed to the published version of the manuscript. Funding: The NutriNet-Santé study is supported by the following public institutions: Ministère
de la Santé, Santé publique France (SPF), Institut National de la Santé et de la Recherche Médicale
(INSERM), Institut National de la Recherche Agronomique (INRA), Conservatoire National des Arts
et Métiers (CNAM), and Université Paris 13. The Société Nationale Française de Gastroentérologie
(SNFGE) funded this project in particular with a Fond d’Aide à la Recherche et à l’Evaluation
(FARE) grant. Institutional Review Board Statement: This study was conducted in accordance with the Decla-
ration of Helsinki, and was approved by the Institutional Review Board of the French Institute
for Health and Medical Research (IRB Inserm 0000388FWA00005831) and the “Commission Na-
tionale de l’Informatique et des Libertés” (CNIL n 908450 and 909216). The study is registered at
clinicaltrials.gov (accessed on 21 May 2019) as NCT03335644. All participants provided an electronic
informed consent. Informed Consent Statement: Electronic informed consent was obtained from all subjects involved
in the study. Data Availability Statement: Data available upon request due to restrictions, e.g., privacy or ethical. The data presented in this study are available upon request from the corresponding author. 5. Conclusions Acknowledgments: The authors thank Cynthia Perlin (dietitian) and Nathalie Arnault (computer
scientist) for the elaboration of the FODMAP composition table. We also thank Cédric Agaesse,
Anne-Elise Dussoulier, Vristi Desan (dietitians); Thi Hong Van Duong, Younes Esseddik (IT manager),
Paul Flanzy, Régis Gatibelza, Jagatjit Mohinder and Aladi Timera (computer scientists); Julien Allegre,
Laurent Bourhis and Fabien Szabo de Edelenyi, (supervisor) (data-manager/statisticians) for their
technical contribution to the NutriNet-Santé study and Nathalie Druesne-Pecollo, (operational
manager). We thank all the volunteers of the NutriNet-Santé cohort. Conflicts of Interest: The authors declare no conflict of interest. The funders had no role in the design
of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or
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1481–1491. [CrossRef] 73. Vork, L.; Weerts, Z.Z.R.M.; Mujagic, Z.; Kruimel, J.W.; Hesselink, M.A.M.; Muris, J.W.M.; Keszthelyi, D.; Jonkers, D.M.A.E.;
Masclee, A.A.M. Rome III vs Rome IV Criteria for Irritable Bowel Syndrome: A Comparison of Clinical Characteristics in a Large
Cohort Study. Neurogastroenterol. Motil. References Presence of Fermentable Oligo-, Di-, Monosaccharides, and Polyols (FODMAPs) in
Commonly Eaten Foods: Extension of a Database to Indicate Dietary FODMAP Content and Calculation of Intake in the General
Population from Food Diary Data. BMC Nutr. 2020, 6, 47. [CrossRef] 53. Bennet, S.M.P.; Böhn, L.; Störsrud, S.; Liljebo, T.; Collin, L.; Lindfors, P.; Törnblom, H.; Öhman, L.; Simrén, M. Multivariate
Modelling of Faecal Bacterial Profiles of Patients with IBS Predicts Responsiveness to a Diet Low in FODMAPs. Gut 2018, 67,
872–881. [CrossRef] [
]
54. Major, G.; Pritchard, S.; Murray, K.; Alappadan, J.P.; Hoad, C.L.; Marciani, L.; Gowland, P.; Spiller, R. Colon Hypersensitivity
to Distension, Rather Than Excessive Gas Production, Produces Carbohydrate-Related Symptoms in Individuals with Irritable
Bowel Syndrome. Gastroenterology 2017, 152, 124–133.e2. [CrossRef] y
gy
55. Mansueto, P.; Seidita, A.; D’Alcamo, A.; Carroccio, A. Role of FODMAPs in Patients with Irritable Bowel Syndrome. Nutr. Clin. Pract. 2015, 30, 665–682. [CrossRef] [PubMed] Vandvik, P.O.; Farup, P.G. Perceived Food Intolerance in Subjects with Irritable Bowel Syndrome—Etiology
sequences. Eur. J. Clin. Nutr. 2006, 60, 667–672. [CrossRef] 56. Monsbakken, K.W.; Vandvik, P.O.; Farup, P.G. Perceived Food Intolerance in Subjects with Irritable Bo
Prevalence and Consequences. Eur. J. Clin. Nutr. 2006, 60, 667–672. [CrossRef] 57. Halpert, A.; Dalton, C.B.; Palsson, O.; Morris, C.; Hu, Y.; Bangdiwala, S.; Hankins, J.; Norton, N.; Drossman, D. What Patients
Know about Irritable Bowel Syndrome (IBS) and What They Would like to Know. National Survey on Patient Educational Needs
in IBS and Development and Validation of the Patient Educational Needs Questionnaire (PEQ). Am. J. Gastroenterol. 2007, 102,
1972–1982. [CrossRef] [PubMed] 58. Lenhart, A.; Ferch, C.; Shaw, M.; Chey, W.D. Use of Dietary Management in Irritable Bowel Syndrome: Results of a Survey of
Over 1500 United States Gastroenterologists. J. Neurogastroenterol. Motil. 2018, 24, 437–451. [CrossRef] [PubMed] 59. Gibson, P.R.; Varney, J.; Malakar, S.; Muir, J.G. Food Components and Irritable Bowel Syndrome. Gastroenterology 2015, 148,
1158–1174.e4. [CrossRef] 60. Halpert, A.; Dalton, C.B.; Palsson, O.; Morris, C.; Hu, Y.; Bangdiwala, S.; Hankins, J.; Norton, N.; Drossman, D.A. Patient
Educational Media Preferences for Information about Irritable Bowel Syndrome (IBS). Dig. Dis. Sci. 2008, 53, 3184–3190. [CrossRef] 61. Melchior, C.; Fremaux, S.; Jouët, P.; Macaigne, G.; Raynaud, J.-J.; Facon, S.; Iglicki, F.; Taes, Y.; Sabate, J.-M. Perceived Gastrointesti-
nal Symptoms and Association with Meals in a French Cohort of Patients With Irritable Bowel Syndrome. J. Neurogastroenterol. Motil. 2021, 27, 574–580. References 2018, 30, e13189. [CrossRef] y
74. Bai, T.; Xia, J.; Jiang, Y.; Cao, H.; Zhao, Y.; Zhang, L.; Wang, H.; Song, J.; Hou, X. Comparison of the R
for IBS Diagnosis: A Cross-Sectional Survey. J. Gastroenterol. Hepatol. 2017, 32, 1018–1025. [CrossRe 75. Aziz, I.; Törnblom, H.; Palsson, O.S.; Whitehead, W.E.; Simrén, M. How the Change in IBS Criteria from Rome III to Rome IV
Impacts on Clinical Characteristics and Key Pathophysiological Factors. Am. J. Gastroenterol. 2018, 113, 1017–1025. [CrossRef]
[PubMed]
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IMPORTANCE OF LANGUAGE IN WRITING FOR NEWSPAPERS
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IMPORTANCE OF LANGUAGE IN WRITING FOR NEWSPAPERS IMPORTANCE OF LANGUAGE IN WRITING FOR NEWSPAPERS O'zbekiston Davlat Jahon tillari Universiteti, Madaniyatlararo
kommunikatsiyalarning lingvistik ta'minoti yo'nalishi 221-A guruh magistranti
Xasanova Mashhura Mirjamolovna O'zbekiston Davlat Jahon tillari Universiteti, Madaniyatlararo
kommunikatsiyalarning lingvistik ta'minoti yo'nalishi 221-A guruh magistranti
Xasanova Mashhura Mirjamolovna This article is about a number specific characteristic of the language which is used for
printed media. It is given very important points of used language and given some
suggestions for young journalists. Key words: language, journalism, mass media, journalistic language, media language. g
g
j
j
g
g
g
g
Language is especially important in journalism. Language is involved with the
precise presentation of words and phrases in writing. It contains abbreviations,
it li
ti
di
d th
i t d l
f
t Language is especially important in journalism. Language is involved with the
precise presentation of words and phrases in writing. It contains abbreviations,
capitalization, compounding, and other printed language features. The language used in journalism to present the most recent and up-to-date facts to the
public in the simplest, easiest, and most unbiased manner is referred to as journalistic
language. Journalism is a crucial kind of communication in which we spread news,
information, and knowledge to a wide number of people. It is vital to employ
straightforward and basic language for this goal. That is why it is also known as
people's language and mass communication language. Here is given some important
characteristics of journalistic language. capitalization, compounding, and other printed language features.
Simple and Easy- simple and easy language is required for journalism since the
main objective of journalism is to enlighten the general public, literate and illiterate
alike, which cannot be accomplished without simple and easy language, which is also a
key quality of journalistic language.
Unbiased- in journalistic language, we impart knowledge and send data without
any expression or personal sentiments; for example, news on television is delivered
without the newscaster's own perspective (who reads the news in news bulletin)
Reporters at newspapers do not include their sentiments and feelings when writing a
report on an incident.
Brevity- Brevity denotes "shortness." We compose news and reports in
journalistic style to be succinct and to the point, with no extraneous information.
Broadness-the broadness of journalistic language distinguishes it from other
languages. This indicates that journalistic language may describe all themes and their difficulties, whether they are social, religious, political, or educational. As we can see in
newspapers, newspapers cover all themes like as political, social, religious, showbiz,
criminal, business, and so on, but other languages just cover a subset of their concerns.
Seriousness-unlike in literary language, facts are expressed in journalistic
language in a serious manner.
Awareness- the primary goal of reporting language is to transmit and impart
knowledge and information to a big group of individuals in their current state. As a
result, the quality of reporting language raises public awareness and encourages
individuals to address their own issues.
Communication Area-because journalistic language is intended for the entire
public, it has a limitless communication area. As a result, it is straightforward and easy
to grasp for the general public.
Objectivity- to be objective, explain an event or item "as it is," without
embellishment or extraneous details. This is also an essential aspect of journalistic
language.
Media Language- journalistic language is intended for the general public. Mass
communication, on the other hand, refers to communicating with a huge number of
individuals. In summary, journalistic language is an essential source of mass
communication, which is why it is referred to as the language of media
Realism-realism refers to genuineness and actuality. Things are reported in a
realistic manner in journalistic terminology.
Realism-realism refers to genuineness and actuality. Things are reported in a
realistic manner in journalistic terminology.
Journalistic language represents all social classes. It also reflects all sorts of
individuals because newspapers are read by people of different socioeconomic
backgrounds.
Politeness- in journalism, politeness of language is required in order to catch the
attention of the general public. Otherwise, people would not pay attention to complex
words.
Grammar-correct grammar usage is essential in journalistic language; otherwise,
it will leave a negative impression on readers. Proper and accurate use of tenses such as
past, present, and future is also essential. 236
Avoid Difficult and Unfamiliar Words- we do not employ complicated and new
words in journalistic language for public comprehension.
Avoid Difficult Terms- journalism requires plain and straightforward language. And a journalist takes care of this element by using simple language and avoiding
difficult phrases while producing a report since he or she realizes that the report is for
everyone, not just one group, so he or she transforms sophisticated and tough
terminology into simple ones.
Short Phrases- because it is intended for everyone, journalistic language is built
on short and simple sentences. To sum up, the language used to present the most recent and up-to-date facts to the
public in the simplest, easiest, and most unbiased manner is referred to as journalistic
language. Language is involved with the precise presentation of words and phrases in
writing. Journalism is a crucial kind of communication in which we spread news,
information, and knowledge to a wide number of people. LIST OF REFERENCES: 1. H.D. Zavala González, The importance of journalistic language features and
functions in print media, 2010
2. Galperin, I. R. Stylistics, Moscow: Higher School, 1981 1. H.D. Zavala González, The importance of journalistic language features and
functions in print media, 2010
2
l
l
i h
S h
l 1981 1. H.D. Zavala González, The importance of journalistic language features and
functions in print media, 2010
2. Galperin, I. R. Stylistics, Moscow: Higher School, 1981 functions in print media, 2010
2. Galperin, I. R. Stylistics, Moscow: Higher School, 1981 p
2. Galperin, I. R. Stylistics, Moscow: Higher School, 1981 3. https://dailyasianage.com 3. https://dailyasianage.com 4. https://writingcenter.uagc.edu/journalistic-writing
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The influence of cycling-off criteria and pressure support slope on the respiratory and hemodynamic variables in intensive care unit patients
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P1 cells with sodium sulfide (60–300 µM) reduced the loss of cell
viability elicited by the nitric oxide donor compound (3 mM) or by
peroxynitrite (3 mM), as measured by the MTT method. Sodium
sulfide did not affect cell viability in the concentration range tested. In mice subjected to bacterial lipopolysaccharide (LPS, 5 mg/kg
i.p.), treatment of the animals with sodium sulfide (0.2 mg/kg/hour
for 4 hours, administered in Alzet minipumps) reduced the LPS-
induced increase in plasma IL-1β and TNFα levels. These
responses were attenuated when animals were pretreated with the
heme oxygenase inhibitor tin-protoporphyrin IX (6 mg/kg). The
current results point to the cytoprotective and anti-inflammatory
effects of hydrogen sulfide, in cells exposed to nitrosative stress,
and in animals subjected to endotoxemia. cells with sodium sulfide (60–300 µM) reduced the loss of cell
viability elicited by the nitric oxide donor compound (3 mM) or by
peroxynitrite (3 mM), as measured by the MTT method. Sodium
sulfide did not affect cell viability in the concentration range tested. In mice subjected to bacterial lipopolysaccharide (LPS, 5 mg/kg
i.p.), treatment of the animals with sodium sulfide (0.2 mg/kg/hour
for 4 hours, administered in Alzet minipumps) reduced the LPS-
induced increase in plasma IL-1β and TNFα levels. These
responses were attenuated when animals were pretreated with the
heme oxygenase inhibitor tin-protoporphyrin IX (6 mg/kg). The
current results point to the cytoprotective and anti-inflammatory
effects of hydrogen sulfide, in cells exposed to nitrosative stress,
and in animals subjected to endotoxemia. Infusion of sodium sulfide improves myocardial and
endothelial function in a canine model of cardiopulmonary
bypass C Szabó1, G Veres2, T Radovits2, M Karck2, G Szabó2
1Ikaria Inc., Seattle, WA, USA; 2University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P1 (doi: 10.1186/cc5161) Hydrogen sulfide is produced endogenously by a variety of
enzymes involved in cysteine metabolism. Clinical data indicate
that endogenous levels of hydrogen sulfide are diminished in
various forms of cardiovascular diseases. The aim of the current
study was to investigate the effects of hydrogen sulfide supple-
mentation on cardiac function during reperfusion in a clinically
relevant experimental model of cardiopulmonary bypass. Twelve
anesthetized dogs underwent hypothermic cardiopulmonary
bypass. After 60 minutes of hypothermic cardiac arrest, reper-
fusion was started after application of either saline vehicle (control,
n = 6), or the sodium sulfide infusion (1 mg/kg/hour, n = 6). Biventricular hemodynamic variables were measured by combined
pressure–volume–conductance catheters. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P3 Epithelial cell apoptosis is similar but hypoxic-inducible
factor expression is weaker in acute acalculous
cholecystitis than in calculous cholecystitis M Vakkala1, J Laurila1, J Saarnio2, V Koivukangas2, H Syrjälä3,
T Karttunen4, Y Soini4, T Ala-Kokko1
1Department of Anesthesiology, 2Department of Surgery,
3Department of Infection Control and 4Department of Pathology,
Oulu University Hospital, Oulu, Finland
Critical Care 2007, 11(Suppl 2):P3 (doi: 10.1186/cc5163) Introduction It has been previously shown that the two forms of
acute cholecystitis, acute acalculous cholecystitis (AAC) and acute
calculous
cholecystitis
(ACC),
have
significantly
different
histopathological features suggesting that AAC is a manifestation
of systemic critical illness whereas ACC is a local disease of the
gallbladder. A balance between cell proliferation and cell death is
essential for cell homeostasis. The purpose of this study was to
compare the markers of apoptosis, cell proliferation, and
expression of hypoxic-inducible factor alpha (HIF-1α) in AAC, ACC
and normal gallbladders. Methods The AAC group consisted of 30 patients who underwent
open cholecystectomy due to acute acalculous cholecystitis during
their ICU stay. The ACC group consisted of 21 hospitalized
patients who underwent cholecystectomy due to acute calculous
cholecystitis. The control group consisted of nine samples taken
from normal gallbladders extirpated during pancreatic tumor
surgery. The immunohistochemical analysis was done according to
the manufacturer’s recommendations and they consisted of Ki-67
(proliferation), M30 (apoptosis) and HIF-1α
antibodies. Cell
proliferation and degree of apoptosis were expressed as the
percentage of positive cells. HIF-1α expression was expressed as
absent or weak (Score 1) or strong (Score 2). P2 P2
Cytoprotective and anti-inflammatory effects of hydrogen
sulfide in macrophages and mice
C Szabo, L Kiss, E Pankotai
University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
Critical Care 2007, 11(Suppl 2):P2 (doi: 10.1186/cc5162) P1 Coronary and pulmonary
blood flow, vasodilator responses to acetylcholine and sodium-
nitroprusside and pulmonary function were also determined. Administration of sodium sulfide led to a significantly better
recovery of left and right ventricular systolic function (P < 0.05)
after 60 minutes of reperfusion. Coronary blood flow was also
significantly higher in the sodium sulfide-treated group (P < 0.05). Sodium sulfide treatment improved coronary blood flow, and
preserved the acetylcholine-induced increases in coronary and
pulmonary blood (P < 0.05). Myocardial ATP levels were markedly
improved in the sulfide-treated group. Thus, supplementation of
sulfide improves the recovery of myocardial and endothelial
function and energetic status after hypothermic cardiac arrest
during cardiopulmonary bypass. These beneficial effects occurred
without any detectable adverse hemodynamic or cardiovascular
effects of sulfide at the dose used in the current study. Critical Care Volume 11 Suppl 2, 2007
27th International Symposium on Intensive Care and Emergency
Medicine
Brussels, Belgium, 27–30 March 2007 Brussels, Belgium, 27–30 March 2007 Published online: 22 March 2007
These abstracts are available online at http://ccforum.com/supplements/11/S2
© 2007 BioMed Central Ltd Published online: 22 March 2007
These abstracts are available online at http://ccforum.com/supplements/11/S2
© 2007 BioMed Central Ltd Effect of prostaglandin E2 on ATP-induced Ca2+ responses
in human THP-1 monocytic cells Effect of prostaglandin E2 on ATP-induced Ca2+ responses
in human THP-1 monocytic cells M Goto1, M Murakawa1, J Kimura1, I Matsuoka2
1Fukushima Medical University, Fukusima, Japan;
2Takasaki University of Health and Welfare, Gunma, Japan
Critical Care 2007, 11(Suppl 2):P4 (doi: 10.1186/cc5164) Introduction To clarify the relation between ATP and prostaglandin
E2 (PGE2) in the immunologic system, we investigated the acute
and chronic effects of PGE2 on activation of purinergic signaling in
monocytes by measuring the ATP-induced elevation of intracellular
Ca2+ ([Ca]i) in fura-2-loaded THP-1 monocytes. Method THP-1 monocytes were grown for about 2 days. To
examine the chronic effects, PGE2 and dibutyryl cAMP (dbcAMP)
were added and incubated for another day. The cell suspensions
were washed, loaded with fura-2-AM, and transferred into a quartz
cuvette and placed in the thermostat-regulated sample chamber of
a dual excitation beam spectrophotometer. To examine the acute
effects, ATP was added immediately after PGE2 and dbcAMP into
the cuvette. In the chronic experiment, ATP alone was added into
the cuvette. Fura-2 fluorescence emission was measured at
510 nm. The [Ca]i
was calculated from the ratio of the
fluorescence at the two excitation wavelengths. sepsis [1]. IFNγ plays a critical role in host defense by promoting
Th1 phenotype and bacterial clearance. Low IFNγ levels are
associated with the Th2 phenotype consistent with critical illness
anergy [2]. It has been reported that 100 and 300 mM ATP
increased LPS/PHA-stimulated IL-10 secretion in human blood [3]. Higher IL-10/IFNγ ratio shifts the immune phenotype from Th1 to
Th2 response. We studied the effect of ATP on LPS-stimulated
IL-10 and IFNγ secretion in a standardized ex-vivo whole human
blood culture. Methods Venous blood from 10 healthy volunteers was drawn into
tubes containing 10 ng LPS/ml (ILCSÒ; EDI GmBH, Reutlingen,
Germany) and incubated with or without 100 mM ATP, respectively,
at 37°C for 24 hours. The supernates were separated and frozen
at –20°C. Cytokine levels were analysed on a robotic workstation
(epMotion 5075; Eppendorf AG, Hamburg, Germany) in duplicate
using the ELISA Cytokine kit (Luminex; Biosource Int., Camarillo,
CA, USA). Results ATP induced a transient increase in [Ca]i followed by a
sustained elevation of [Ca]i. Acutely, PGE2 inhibited both the
transient and sustained ATP-induced elevations of [Ca]i. However,
this acute inhibitory effect diminished gradually with time and
chronic PGE2 accelerated the transient and sustained ATP-
induced [Ca]i elevations for 24 hours. Cytoprotective and anti-inflammatory effects of hydrogen
sulfide in macrophages and mice Cytoprotective and anti-inflammatory effects of hydrogen
sulfide in macrophages and mice C Szabo, L Kiss, E Pankotai
University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
Critical Care 2007, 11(Suppl 2):P2 (doi: 10.1186/cc5162) The aim of the current study was to test potential cytoprotective
and anti-inflammatory effects of the novel biological mediator
hydrogen sulfide in murine models. Murine J774 macrophages
were grown in culture and exposed to cytotoxic concentrations of
nitrosoglutathione, or peroxynitrite (a reactive species formed from
the reaction of nitric oxide and superoxide). Pretreatment of the Results Apoptosis (median, 25th, 75th percentiles) was significantly
increased in AAC 1.3% (1.0%, 3.3%), P = 0.001 and ACC 0.93%
(0.40%, 3.25%), P = 0.011 compared with controls 0.32% (0.20%,
0.40%). Proliferation rate was also significantly increased in AAC S1 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P5) Figure 1 (abstract P5) Figure 1 (abstract P5) 8.0% (4.0%, 17.0%), P < 0.001 and ACC 14% (7.5%, 26.5%),
P = 0.001 compared with controls 1.0% (1.0%, 3.0%). Strong HIF-
1α staining was observed in 100% of ACC, in 57% of AAC and in
44% of control specimens (P < 0.001). Strong HIF-1α expression
was associated with increased cell proliferation (P = 0.002). Conclusions Cell proliferation and apoptosis were increased in
AAC and ACC. The expression of hypoxic-inducible factor was,
however, stronger in ACC compared with AAC. Effect of prostaglandin E2 on ATP-induced Ca2+ responses
in human THP-1 monocytic cells Both the acute and chronic
effects of PGE2 were mimicked by dbcAMP. In Ca2+-free solution,
ATP did not induce the sustained elevation of [Ca]i in control cells
or cells pretreated for 24 hours with dbcAMP. This indicates that
the ATP-induced sustained elevation of [Ca]i was due to Ca2+
entry. In addition, receptor-operated Ca2+
channel blockers
inhibited the sustained ATP-induced elevation of [Ca]i in control
cells and cells pretreated with for 24 hours dbcAMP. Results Added ATP reduced the mean concentration of IFNγ in LPS-
stimulated blood from 1,206 ± 1,667 pg/ml to 140 ± 128 pg/ml;
P = 0.006. There was no consistent effect of ATP on IL-10
secretion in our study (21.6 ± 16.9 pg/ml to 17.2 ± 18.8 pg/ml). Interestingly, three subjects of Indian/Indonesian origin had IL-10
levels below the assay detection limit. The mean IL-10/IFNγ ratio
was increased from 0.05 ± 0.04 to 0.16 ± 0.09 in the remaining
Caucasian subjects (P = 0.015). See Figure 1. Conclusion Acute PGE2 inhibited the ATP-induced activation of
monocytes. On the other hand, chronic PGE2 accelerated monocyte
activation by upregulation of receptor-operated Ca2+ channels
(ROCs). If this mechanism exhibits a physiological role, ROC
inhibitors should be developed as new anti-inflammatory agents. Conclusions Our results suggest an immunosuppressive effect of
extracellular ATP that is evident by the decrease of IFNγ and
therefore the relative shift of the immune response towards Th2
phenotype. Although this may represent a self-protective
mechanism, it may contribute to critical illness anergy. References Introduction Extracellular release of ATP is an important modulator
of immune response. ATP plasma concentration is increased in M Nalos1, S Huang1, A Khan2, A McLean1
1Nepean Hospital, Penrith, Australia; 2Macquarie University, North
Ryde, Australia
Critical Care 2007, 11(Suppl 2):P5 (doi: 10.1186/cc5165) Available online http://ccforum.com/supplements/11/S2 P6 Methods We enrolled 30 patients with septic shock requiring
invasive hemodynamic monitoring and norepinephrine infusion ≥
0.5 µg/kg/min to maintain MAP between 65 and 75 mmHg. Patients were randomized to receive either 10, 20, or 30 mg
enteral glibenclamide. Systemic hemodynamics, global oxygen
transport, arterial lactate concentrations, gas exchange, and
plasma glucose concentrations were determined at baseline, and
following 3, 6 and 12 hours after administration of the study drug. Methods We enrolled 30 patients with septic shock requiring
invasive hemodynamic monitoring and norepinephrine infusion ≥
0.5 µg/kg/min to maintain MAP between 65 and 75 mmHg. Patients were randomized to receive either 10, 20, or 30 mg
enteral glibenclamide. Systemic hemodynamics, global oxygen
transport, arterial lactate concentrations, gas exchange, and
plasma glucose concentrations were determined at baseline, and
following 3, 6 and 12 hours after administration of the study drug. Results Glibenclamide decreased plasma glucose concentrations
in a dose-dependent manner, but failed to reduce norepinephrine
requirements. None
of
the
doses
had
any
effects
on
cardiopulmonary hemodynamics. See Table 1. Tyrosine phosphorylation modulates rat vascular response
to experimental endotoxemia in vivo and in vitro Tyrosine phosphorylation modulates rat vascular response
to experimental endotoxemia in vivo and in vitro C Lehmann, T Hammann, O Adamek, H Erber, M Manthey,
T Wenzel, A Stier, M Wendt, D Pavlovic
Ernst-Moritz-Arndt-Universität Greifswald, Germany
Critical Care 2007, 11(Suppl 2):P6 (doi: 10.1186/cc5166) Results Glibenclamide decreased plasma glucose concentrations
in a dose-dependent manner, but failed to reduce norepinephrine
requirements. None
of
the
doses
had
any
effects
on
cardiopulmonary hemodynamics. See Table 1. Introduction Endotoxemia is characterized by vascular hypo-
reactivity, hypotension and microcirculatory changes that are
partially linked to the excess of nitric oxide production. The agents
that can influence Ca2+ transport (affect Ca-ATPase) or modulate
Ca2+ sensitivity of the smooth muscle contraction (modulate phos-
phorylation) may theoretically influence some of the above-
mentioned effects. Table 1 (abstract P7)
Plasma glucose concentration (mg/dl)
Time
Glibenclamide
0 hours
3 hours
6 hours
12 hours
10 mg
118 ± 13
110 ± 9
109 ± 10
107 ± 10
20 mg
117 ± 5
106 ± 4
93 ± 7*
98 ± 9*
30 mg
113 ± 6
86 ± 3*
89 ± 4*
98 ± 3*
Data presented as mean ± SEM. *P < 0.05 vs baseline (0 hours) within
groups. Table 1 (abstract P7) Plasma glucose concentration (mg/dl) Methods We evaluated the effects of tyrosine phosphatase or
kinase inhibitors, sodium orthovanadate (SOV) or genistein (GEN). The effects of these agents were examined in vitro, in a model of
vascular hyporeactivity of sepsis, in rings of rat aorta (RA), with or
without endothelium (±ENDO), or in human mesenteric artery
(HMA). In vivo, the intestinal microcirculation (terminal ileum) of
endotoxemic rats (LEW.1A) that received i.v. lipopolysaccharide
(LPS), 15 mg/kg BW, was examined using intravital microscopy. g g
g
py
Results In vitro. The nitric oxide production inhibitor L-NAME
(5 × 10–4) and cGMP inhibitor ODQ (5 x 10–5) abolished LPS-
induced hyporeactivity. GEN attenuated maximal tension (Tmax)
while SOV increased the response to PE; Tmax (kg/g, dry muscle):
controls vs SOV, RA (–ENDO): 0.87 ± 0.19 vs 1.42 ± 0.23
(10–7); 1.56 ± 0.28 (10–6) and 2.33 ± 0.69 (10–5); RA (+ENDO):
0.88 ± 0.21 vs 1.53 ± 0.35 (10–7); 1.35 ± 0.30 (10–6) and
2.55 ± 0.68 (10–5); and HMA (+ENDO): 1.12 ± 0.23 vs
0.37 ± 0.14 (10–7); 2.06 ± 0.21 (10–6) and 3.00 ± 0.07 (10–5). Conclusion Oral glibenclamide is an ineffective adjunct in the
treatment of catecholamine-dependent human septic shock. Molecular mechanism of glutamine induction of HSP70
involves activation of the O-linked-N-acetylglucosamine
pathway in murine embryonic fibroblast cells Molecular mechanism of glutamine induction of HSP70
involves activation of the O-linked-N-acetylglucosamine
pathway in murine embryonic fibroblast cells C Hamiel1, S Pinto2, K Singleton1, P Wischmeyer1
1University of Colorado, Denver, CO, USA; 2Valparaiso University,
IN, USA
Critical Care 2007, 11(Suppl 2):P8 (doi: 10.1186/cc5168) In vivo. In the LPS group GEN increased mucosal functional
capillary density (FCD, cm/cm2; mean ± SD; LPS vs GEN,
105.5 ± 44.6 vs 174.7 ± 39.1; P = 0.018). SOV (7.5 mg/kg)
increased FCD not only in mucosa (163.7 ± 40.0; P = 0.024) but
also in the longitudinal muscular layer (LPS vs SOV, 111.9 ± 24.0
vs 172.2 ± 19.5; P < 0.001). Surprisingly, the SOV (15 mg/kg)
alone (without LPS) increased leukocyte sticking in the venules V1
(LPS vs SOV, number of stickers/mm2, 403.3 ± 113.9 vs
669.8 ± 150.8; P = 0.027). Introduction The purpose of this study was to determine whether
glutamine (GLN)-mediated cellular protection is dependent on the
O-linked-N-acetylglucosamine (O-glcNAc) pathway. GLN can
protect against critical illness via induction of HSP70. The molecular
mechanism by which GLN enhances HSP70 is unknown. GLN can
increase flux through the hexosamine biosynthetic pathway and
activate transcription factors by O-glcNAc. We investigated GLN’s
effect on O-glcNAc levels and nuclear translocation of SP1 and
HSF-1, which are vital to HSP70 expression. To determine the
importance of O-glcNAc, we used silencing RNA (siRNA) against O-
linked-N-acetylglucosamine transferase (OGT), the enzyme that
catalyzes addition of O-glcNAc to proteins. Conclusions The tyrosine phosphorylation pathway may play an
important role in modulation of the LPS-induced vascular
hyporeactivity and could enhance terminal ileum microcirculation. This might be a result of both modulation of tyrosine
phosphorylation by genistein and sodium orthovanadate, and/or
plasma membrane Ca-ATPase inhibition by SOV. P7 Methods Mouse embryonic fibroblast cells were treated with
0 mM GLN (CT) or 10 mM GLN (GLN), heat stressed (HS) and
allowed to recover for 20 minutes. Cells were stained and mean
fluorescent intensities (MFIs) measured for total O-glcNAc and
nuclear HSF-1 and SP1. For OGT silencing, cells were transfected
with either no siRNA, siRNA to OGT, or negative control oligos (nc
siRNA) and then treated as above (but with 4 hours recovery). HSP70 and OGT were evaluated by western blot. References Interferon gamma levels are reduced by adenosine
5′-triphosphate in lipopolysaccharide-stimulated whole
human blood 1. Bours MJ, Swennen EL, Di Virgilio F, et al.: Adenosine 5′-
triphosphate and adenosine as endogenous signaling
molecules in immunity and inflammation. Pharmacol Ther
2006, 112:358-404. 1. Bours MJ, Swennen EL, Di Virgilio F, et al.: Adenosine 5′-
triphosphate and adenosine as endogenous signaling
molecules in immunity and inflammation. Pharmacol Ther
2006, 112:358-404. M Nalos1, S Huang1, A Khan2, A McLean1
1Nepean Hospital, Penrith, Australia; 2Macquarie University, North
Ryde, Australia
Critical Care 2007, 11(Suppl 2):P5 (doi: 10.1186/cc5165) 2. Ertel W, Keel M, Neidhardt R, et al.: Inhibition of the defence
system
stimulating
interleukin-12
interferon-gamma
pathway during critical illness. Blood 1997, 89:1612-1620. 3. Swennen EL, Bast A, Dagnelie PC: Immunoregulatory effects
of adenosine 5′-triphosphate on cytokine release from
stimulated whole blood. Eur J Immunol 2005, 35:852-858. Introduction Extracellular release of ATP is an important modulator
of immune response. ATP plasma concentration is increased in S2 Available online http://ccforum.com/supplements/11/S2 Glibenclamide dose response in patients with septic shock A Morelli1, C Ertmer2, M Lange2, K Broeking2, H Van Aken2,
A Orecchioni1, M Rocco1, P Pietropaoli1, M Westphal2
1University of Rome ‘La Sapienza’, Rome, Italy;
2University Hospital of Muenster, Germany
Critical Care 2007, 11(Suppl 2):P7 (doi: 10.1186/cc5167) Results Microscopy showed GLN treatment increased nuclear
MFI for HSF-1 by 40% (HS-CT: 1,005 ± 146 vs HS-
GLN:1403 ± 102, P < 0.05) and SP1 by 54% (HS-CT: 214 ± 14
vs HS-GLN: 330 ± 13, P < 0.05). Total O-glcNAc levels showed
44% MFI increase in HS-GLN compared with HS-CT (HS-CT:
360 ± 24 vs HS-GLN: 518 ± 51, P < 0.05). Following OGT
silencing, HS-GLN showed a threefold increase in HSP70 Introduction
(K+ATP)
channels
are
implicated
in
the
pathophysiology of catecholamine tachyphylaxis in septic shock. This prospective, randomized, double-blinded, clinical study was
designed to determine whether different doses of glibenclamide
have any effects on norepinephrine requirements and cardio-
pulmonary hemodynamics in patients with septic shock. Introduction
(K+ATP)
channels
are
implicated
in
the
pathophysiology of catecholamine tachyphylaxis in septic shock. This prospective, randomized, double-blinded, clinical study was
designed to determine whether different doses of glibenclamide
have any effects on norepinephrine requirements and cardio-
pulmonary hemodynamics in patients with septic shock. S3 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin (P = 0.04). These increases were completely blocked by OGT
silencing (P = 0.02 vs non-siRNA GLN groups). GLN-nc siRNA
groups did not decrease in HSP70 production. OGT was knocked
down 86% compared with controls (siRNA: 0.999 ± 0.19 vs CT:
0.131 ± 0.05). N = 3. (P = 0.04). These increases were completely blocked by OGT
silencing (P = 0.02 vs non-siRNA GLN groups). GLN-nc siRNA
groups did not decrease in HSP70 production. OGT was knocked
down 86% compared with controls (siRNA: 0.999 ± 0.19 vs CT:
0.131 ± 0.05). N = 3. vasodilatory peptide hormone with anti-inflammatory properties,
may improve the oxygen delivery–demand relationship, thereby
limiting the increase in arterial lactate concentrations in ovine endo-
toxemia. Methods Fourteen adult ewes were instrumented for chronic hemo-
dynamic monitoring. Following 16 hours of endotoxemia (Salmonella
typhosa endotoxin, 10 ng/kg/min) the animals received either a
continuous infusion of AM at incremental doses (10, 50,
100 ng/kg/min; each for 30 min) or the vehicle (normal saline; n = 7
each). The effects of N-acetylcysteine on the levels of glutathione,
serum TNFα, and tissue malondialdehyde in sepsis The effects of N-acetylcysteine on the levels of glutathione,
serum TNFα, and tissue malondialdehyde in sepsis M Gul, M Ayan, A Seydanoglu, B Cander, S Girisgin, I Erayman
Selcuk University Meram Medical School, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P9 (doi: 10.1186/cc5169) Objectives This study was designed to determine the effects of N-
acetylcysteine (NAC) as an antioxidant agent on the free oxygen
radicals and their plasma levels. Conclusions Despite decreasing MAP, infusion of AM reversed
pulmonary hypertension and improved the oxygen supply–demand
relationship in a dose-dependent manner, as indicated by a
reduced arterial lactate concentration. However, due to the
vasodilatory properties of AM, it may be rationale to combine AM
with a vasopressor agent. Methods In this study, 40 Sprague–Dawley rats were randomly
divided into three groups as sham (n = 10), sepsis (n = 10), and
sepsis + NAC (20 mg/kg/24 hours) (n = 10). An experimental
sepsis model was performed by a cecal ligation and perforation
(CLP). NAC was administered at 0, 8 and 16 hours after CLP. The
blood samples were taken at 24 hours to determine the levels of
serum TNFα and erythrocyte glutathione (GSH), and renal and liver
tissue malondialdehyde (MDA). P11 Results The serum TNFα levels were significantly decreased in
group 3 compared with group 2 (P < 0.05). The erythrocyte GSH
levels significantly increased in group 3 compared with group 2
(P < 0.05). In group 3, the liver MDA levels were decreased
compared with group 2, but not statistically significant (P > 0.05)
In group 3, the renal MDA levels were significantly decreased
compared with group 2 (P < 0.05). The lung tissue PMNL levels
significantly decreased in group 3 compared with group 2
(P < 0.05). Angiopoietin-2 correlates with pulmonary capillary
permeability and disease severity in critically ill patients Angiopoietin-2 correlates with pulmonary capillary
permeability and disease severity in critically ill patients M van der Heijden1, V van Hinsbergh2, G van Nieuw
Amerongen2, P Koolwijk2, R Musters2, J Groeneveld1
1VU University Medical Center, Amsterdam, The Netherlands;
2Institute for Cardiovascular Research, VU University Medical
Center, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P11 (doi: 10.1186/cc5171) Conclusion In an experimental sepsis model, with the administra-
tion of NAC as an antioxidant agent at lower doses, many meaning-
ful positive effects were detected on the levels of erythrocyte GSH,
serum TNFα, respiration function, and renal tissue MDA. In spite of
the low dose, NAC therapies decrease the organ function abnor-
malities; these effects were not reflected in the histopathological
investigations. These findings suggest that NAC could be a
possible therapeutic agent for sepsis and its mortality. However,
further studies are needed to elucidate the effects of these drugs
at higher doses. Introduction It has previously been shown that angiopoietin-1
(Ang1) protects the adult vasculature against plasma leakage,
whereas Ang2 and VEGF destabilize the vascular endothelium
resulting in vascular leakage. Consequently they might be involved
in the pathophysiology of acute lung injury (ALI) and acute
respiratory distress syndrome (ARDS) in sepsis patients. We
hypothesized that plasma Ang2 levels are associated with
pulmonary capillary protein permeability, the lung injury score (LIS),
length of stay on the ICU, the APACHE II score and survival in
septic patients with ALI or ARDS. Glibenclamide dose response in patients with septic shock Conclusions These results show GLN can activate the O-glcNAc
pathway and enhance nuclear translocation of HSF-1 and SP1. Inhibition of OGT blocked GLN-mediated induction of HSP70. Thus, it appears the mechanism of GLN-mediated HSP70 expres-
sion is dependent on enhanced O-glcNAc pathway activation. Results
Endotoxin infusion contributed to a hypotensive–
hyperdynamic circulation characterized by decreases in mean
arterial pressure (MAP) and systemic vascular resistance index as
well as increases in heart rate (HR), cardiac index (CI) and arterial
lactate concentrations. AM infusion at 100 ng/kg/min increased
the CI (12.2 ± 0.8 vs 7.8 ± 0.5 l/min) and oxygen delivery index
(1,734 ± 121 vs 1,075 ± 63 ml/min/m2), thereby decreasing the
arterial lactate concentration (0.7 ± 0.2 vs 1.7 ± 0.3 mg/dl) and
mean pulmonary arterial pressure (18 ± 1 vs 24 ± 1 mmHg; each
P < 0.001 vs control) noticed in the control group. However, AM
infusion at 100 ng/kg/min was linked to a decrease in MAP
(64 ± 2 vs 80 ± 4 mmHg, P < 0.001 vs control). P12 Dose-dependent effects of octreotide on plasma activities
of IL-6 and lung tissue levels of malondialdehyde in sepsis
M Gul, A Seydanoglu, M Ayan, B Cander, I Erayman, S Girisgin
Selcuk University Meram Medical School, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P12 (doi: 10.1186/cc5172) Dose-dependent effects of octreotide on plasma activities
of IL-6 and lung tissue levels of malondialdehyde in sepsis M Gul, A Seydanoglu, M Ayan, B Cander, I Erayman, S Girisgin
Selcuk University Meram Medical School, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P12 (doi: 10.1186/cc5172) Background and aim Sepsis, a complex and rapidly progressing
infectious disease with high levels of mortality, is widely regarded
as the most challenging problem in intensive care. The lung is
frequently the first failing organ during septic conditions. Although
the etiology of sepsis is multifactorial, early release of proinflam-
matory cytokines and oxidative damage are probably most impor-
tant factors that lead to cell damage, organ dysfunction, and death. This study aimed to determine the effects of treatment with octreo-
tide (OCT), on plasma activities of IL-6 and tissue levels of malon-
dialdehyde (MDA) in an experimental model of sepsis. gene expression analysis (Affymetrix) was applied to serial cardiac
biopsies of sham (n = 2) and E. coli infected pigs (n = 3). Methods Cardiac samples were taken basal and hourly after
infection for gene analysis and at the end of the experiment for
histopathological examination. Genes were determined to be
differentially regulated at a greater than or less than twofold
change and P < 0.05. gene expression analysis (Affymetrix) was applied to serial cardiac
biopsies of sham (n = 2) and E. coli infected pigs (n = 3). Methods Cardiac samples were taken basal and hourly after
infection for gene analysis and at the end of the experiment for
histopathological examination. Genes were determined to be
differentially regulated at a greater than or less than twofold
change and P < 0.05. Methods Sepsis was induced in female Sprague–Dawley rats by
cecal ligation and puncture (CLP) as previously described. Group 1
(n = 10), sham operated animals; Group 2 (n = 10), sepsis served
as control; Group 3 (n = 10) and Group 4 (n = 10), respectively,
OCT 50 µg/kg twice a day and OCT 100 µg/kg twice a day
administered subcutaneously immediately after the induction of
sepsis and at 12 hours. Rats were sacrificed 24 hours after the
surgical procedure. P12 Blood and lung tissue samples were taken
24 hours after sepsis induction. Plasma activities of IL-6 and lung
tissue levels of MDA were measured. Results Sham pigs had stable heart rate, cardiac output (CO) and
core temperature for the 5-hour period; infected pigs demon-
strated an early elevation in CO and ventricular shortening and/or
ejection (assessed by echocardiography) followed by development
of hypodynamics. In infected animals, increasing numbers of genes
were upregulated or downregulated (36, 278, 514, 842 and 1,238
at 1, 2, 3, 4 and 5 hours) (Figure 1) whereas sham infection altered
fewer (247, 67 and 384 genes at 2, 3 and 4 hours). Comparing
sham vs infected animals at the same time, numbers of significantly
altered genes increased with time (32 at basal, to 74, 189 and
601 at 2, 3 and 4 hours post infection). In hematoxylin–eosin-
stained sections, histopathological assessment revealed acute
inflammation in pericardium and myocardium in infected pigs. Results The results showed that the plasma levels of IL-6, an
inflammatory indicator, and tissue levels of MDA, an oxidative
indicator, are significantly increased during experimental model of
sepsis (P < 0.05). Increase in MDA levels and IL-6 activities after
CLP-induced sepsis was significantly prevented by OCT
(100 µg/kg, s.c.) administration (P < 0.05). Conclusions These results will provide biomarker and mechanistic
insights to pathogenesis of cardiac dysfunction of septic peritonitis
and may also help identify some altered novel gene transcription
pathways that can serve as new targets for diagnostic tools and
therapeutic strategies. All candidate genes will be validated by
quantitative PCR. Conclusion
Octreotide seems to have a dose-dependent
antioxidative and immunomodulator effect in CLP-induced sepsis in
rats. Further trials are necessary to reveal the therapeutic effect of
OCT in sepsis. On the other hand, further studies should be
performed aiming to reveal the optimal OCT doses. As a drug with a
wide margin of safety and less adverse reaction profile, OCT merits
consideration as a choice of treatment in sepsis and septic shock. P10 Methods A prospective observational study was performed in an
ICU of an university hospital on 112 patients: 38 after elective
cardiac surgery, 26 after major vascular surgery, 24 with sepsis
and 24 with trauma. Plasma levels of Ang1, Ang2 and VEGF were
measured and a mobile probe system was used to measure the
pulmonary leak index (PLI) (that is, the transvascular transport rate
of gallium-67-radiolabeled transferrin). Exogenous adrenomedullin reduces the arterial lactate
concentration and mean pulmonary arterial pressure in
ovine endotoxemia C Ertmer1, M Lange1, H Van Aken1, K Bröking1, S Vocke1,
F Daudel1, M Booke2, M Westphal3
1University of Muenster, Germany; 2Hospital of the
Main-Taunus-Kreis, Hofheim, Germany; 3UTMB, Galveston, USA
Critical Care 2007, 11(Suppl 2):P10 (doi: 10.1186/cc5170) Results Plasma levels of Ang2 and the PLI were significantly
higher in patients with sepsis compared with other patient groups. In the sepsis group, a positive linear correlation was observed
between plasma levels of Ang2 and length of stay on the ICU
(rs = 0.509, P < 0.05) as index for disease severity. For all patients
together, Ang2 had a positive linear correlation with PLI (rs = 0.374,
P < 0.01), LIS (rs = 0.489, P < 0.01) and APACHE II score
(rs = 0.287, P < 0.01). Furthermore, Ang2 was significantly increased Introduction
Sepsis-associated arterial hypotension may be
complicated by inadequate systemic and regional oxygen delivery
resulting in lactic acidosis and multiple organ failure. We hypothe-
sized that exogenous administration of adrenomedullin (AM), a Introduction
Sepsis-associated arterial hypotension may be
complicated by inadequate systemic and regional oxygen delivery
resulting in lactic acidosis and multiple organ failure. We hypothe-
sized that exogenous administration of adrenomedullin (AM), a S4 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P13) in nonsurvivors. Plasma Ang1 levels did not differ between groups. VEGF levels were undetectable in the plasma of the majority of
patients. Conclusions Our results suggest that Ang2 is a mediator of
pulmonary capillary permeability and a marker of disease severity in
critically ill patients. Furthermore, the plasma levels of Ang2 and
the ratio between Ang1 and Ang2 are more important in pulmonary
capillary permeability and disease severity than absolute levels of
Ang1 and VEGF. P14 Alkaline phosphatase treatment improves renal function in
patients with severe sepsis or septic shock P15 associated with proximal tubule injury. In several in vitro and animal
studies alkaline phosphatase (AP) was found to be effective in
attenuating the inflammatory response by dephosphorylating LPS
and may prevent organ damage. The objective of this study was to
investigate the effect of AP on renal iNOS expression and kidney
damage in patients with severe sepsis or septic shock. associated with proximal tubule injury. In several in vitro and animal
studies alkaline phosphatase (AP) was found to be effective in
attenuating the inflammatory response by dephosphorylating LPS
and may prevent organ damage. The objective of this study was to
investigate the effect of AP on renal iNOS expression and kidney
damage in patients with severe sepsis or septic shock. P15
Moderate hypothermia attenuates changes in respiratory
system mechanics and cytokine production during low
lung volume ventilation in rats
P Dostal1, M Senkerik1, V Cerny1, R Parizkova1, J Suchankova1,
D Kodejskova1, D Bares1, P Zivny1, H Zivna2
1University Hospital Hradec Kralove, Czech Republic; 2Charles University
in Prague, Faculty of Medicine Hradec Kralove, Czech Republic
Critical Care 2007, 11(Suppl 2):P15 (doi: 10.1186/cc5175) P15
Moderate hypothermia attenuates changes in respiratory
system mechanics and cytokine production during low
lung volume ventilation in rats
P Dostal1, M Senkerik1, V Cerny1, R Parizkova1, J Suchankova1,
D Kodejskova1, D Bares1, P Zivny1, H Zivna2
1University Hospital Hradec Kralove, Czech Republic; 2Charles University
in Prague, Faculty of Medicine Hradec Kralove, Czech Republic
Critical Care 2007, 11(Suppl 2):P15 (doi: 10.1186/cc5175) Moderate hypothermia attenuates changes in respiratory
system mechanics and cytokine production during low
lung volume ventilation in rats P Dostal1, M Senkerik1, V Cerny1, R Parizkova1, J Suchankova1,
D Kodejskova1, D Bares1, P Zivny1, H Zivna2
1University Hospital Hradec Kralove, Czech Republic; 2Charles University
in Prague, Faculty of Medicine Hradec Kralove, Czech Republic
Critical Care 2007, 11(Suppl 2):P15 (doi: 10.1186/cc5175) Fifteen patients (nine male/six female, age 55 ± 5 years) with
Gram-negative bacterial infection, two out of four SIRS criteria
(<24 hours) and acute onset of end-organ dysfunction (<12 hours)
were included in a randomized, double-blind, placebo-controlled
phase IIa study (2:1 ratio). An intravenous bolus injection of
67.5 U/kg bovine intestinal AP was followed by a maintenance
dose of 177.5 U/kg for 24 hours. Arterial blood and urine were
collected at different time points and analyzed for stable metabo-
lites of NO. iNOS mRNA was determined by quantitative real-time
RT-PCR using RNA isolated from renal cells in urine. P15 After 2 hours of
mechanical ventilation (FiO2 1,0, respiratory rate 60/min, tidal volume
10 ml/kg, PEEP 2 cmH2O) inspiratory pressures were recorded, rats
were sacrificed, the P–V curve of the respiratory system constructed,
and bronchoalveolar lavage and aortic blood samples obtained. NO metabolites in blood were not significantly different between
AP-treated (n = 10) and placebo-treated (n = 5) patients. However,
the urinary excretion of NO metabolites decreased by 80%
(75–85) from 227 (166–531) at baseline to 41 (28–84) µmol/
10 mmol creatinine (P < 0.05) after 24 hours of AP administration. After placebo treatment, the amount of urinary NO metabolites
increased by 70% (45–570) (from 81 (64–419) to 628 (65–
1,479) µmol/10 mmol creatinine, P < 0.05). Baseline expression
levels of iNOS in renal cells were 42-fold induced at baseline (vs
healthy subjects), and AP administration reduced this induction by
80 ± 5% (Figure 1). Creatinine clearance improved by 45%
(30–180) in patients treated with AP and declined by 25%
(15–35) in placebo-treated patients. During the first 24 hours the
amount of GSTA1-1 in urine of AP-treated patients decreased by
70% (50–80), compared with an increase of 200% (45–525) in
placebo-treated patients, which correlated with urinary NO
metabolites, indicating NO-induced proximal tubular damage. I
l
i
i
i
i
i
i
AP
l
i Methods Sixteen male adult Sprague–Dawley rats, instrumented
under ether anesthesia with vascular catheters on the previous day,
were anesthetized, tracheostomized, connected to a ventilator and
randomly allocated to groups of normothermia (37 ± 0.5°C, group N,
n = 8) or hypothermia (33 ± 0.5°C, group H, n = 8). After 2 hours of
mechanical ventilation (FiO2 1,0, respiratory rate 60/min, tidal volume
10 ml/kg, PEEP 2 cmH2O) inspiratory pressures were recorded, rats
were sacrificed, the P–V curve of the respiratory system constructed,
and bronchoalveolar lavage and aortic blood samples obtained. Results Group H animals exhibited in comparison with group N
animals a lower increase in peak inspiratory pressures (0.7 ± 1.1
vs 2.4 ± 0.5 mmHg, P < 0.001), significant shift of the P–V curve
to the left and lower total protein (113 ± 42 vs 201 ± 97 µg/ml,
P = 0.047) and TNF (23.5 ± 8.0 vs 35.2 ± 8.5 pg/ml, P = 0,022)
levels in BAL samples. Figure 1 (abstract P14) Figure 1 (abstract P14) References References Figure 1 (abstract P14) 1. Lim CM, et al.: Lung 2003, 181:23-34. 2. Suzuki S, et al.: Crit Care Med 2004, 32:144-149. 3. Hong S-B, et al.: Crit Care Med 2005, 33:2049-2055. 4. Muscedere JG, et al.: Am J Respir Crit Care Med 1994, 149:
1327-1334. 5. Fan J, et al.: J Immunol 1998, 161:440-447. 5. Fan J, et al.: J Immunol 1998, 161:440-447. 6. Kaneko A, et al.: J Surg Res 2006, 134:215-222. 6. Kaneko A, et al.: J Surg Res 2006, 134:215-222. Escherichia coli porcine peritonitis induces histological
and transcriptome evidence of cardiac injury Escherichia coli porcine peritonitis induces histological
and transcriptome evidence of cardiac injury S Heemskerk1, R Masereeuw1, O Moesker2, M Bouw2, J van
der Hoeven2,3, W Peters4, M Velders5, F Russel1, P Pickkers2
1Department of Pharmacology and Toxicology, Nijmegen Centre for
Medical Life Sciences, 2Department of Intensive Care Medicine,
3Nijmegen University Centre for Infectious Diseases and 4Department
of Gastroenterology, Radboud University Nijmegen Medical Centre,
Nijmegen, The Netherlands; 5AM-Pharma, Bunnik, The Netherlands
Critical Care 2007, 11(Suppl 2):P14 (doi: 10.1186/cc5174) R Goldfarb1, I Cinel1, S Gandhi1, L Cinel2, M Levine1, Q Wang3
A Brooks3, J Parrillo1
1Cooper University Hospital and UMDNJ, Camden, NJ, USA;
2Thomas Jefferson University Hospital, Philadelphia, PA, USA;
3EOHSI, UMDNJ, Piscataway, NJ, USA
Critical Care 2007, 11(Suppl 2):P13 (doi: 10.1186/cc5173) Introduction Cardiac dysfunction is a feature of sepsis. In order to
gain insight into the fundamental mechanisms of this phenotype, Introduction Cardiac dysfunction is a feature of sepsis. In order to
gain insight into the fundamental mechanisms of this phenotype, We previously demonstrated that upregulation of renal inducible
nitric oxide synthase (iNOS) during systemic inflammation is S5 P15 F Saunders1, M Westphal1, P Enkhbaatar1, J Wang1,
M Gonzalez1, Y Nakano1, A Hamahata1, C Jonkam1,
R Connelly1, R Cox1, H Hawkins2, F Schmalstieg1, E Horvath3,
M Lange1, C Szabo1, L Traber1, D Herndon2, D Traber1
1University of Texas Medical Branch, Galveston, TX, USA;
2Shriners Burns Hospital for Children, Galveston, TX, USA;
3University of Medicine and Dentistry of New Jersey, NJ, USA
Critical Care 2007, 11(Suppl 2):P16 (doi: 10.1186/cc5176) P15 The urinary
excretion of the cytosolic glutathione S-transferase-A1 (GSTA1-1),
a marker for proximal tubule damage, was measured using an
ELISA. Data are depicted as the median (25–75% range). Introduction Hypothermia was shown to attenuate ventilator-
induced lung injury (VILI) in high end-inspiratory lung volume
models of VILI [1-3]. Experimental evidence suggests that
moderate tidal volumes may, under certain clinical conditions that
induce alveolar instability, lead to a lung injury [4]. Recent studies
have also suggested that insults like shock [5] or surgery [6]
sensitize the lung to injury by priming for an exaggerated response
to a second stimulus. The aim of this study was to investigate
whether moderate hypothermia attenuates low lung volume injury
during low PEEP, high FiO2 and moderate tidal volume ventilation
in animals sensitized to injury by previous anesthesia and surgery. Methods Sixteen male adult Sprague–Dawley rats, instrumented
under ether anesthesia with vascular catheters on the previous day,
were anesthetized, tracheostomized, connected to a ventilator and
randomly allocated to groups of normothermia (37 ± 0.5°C, group N,
n = 8) or hypothermia (33 ± 0.5°C, group H, n = 8). After 2 hours of
mechanical ventilation (FiO2 1,0, respiratory rate 60/min, tidal volume
10 ml/kg, PEEP 2 cmH2O) inspiratory pressures were recorded, rats
were sacrificed, the P–V curve of the respiratory system constructed,
and bronchoalveolar lavage and aortic blood samples obtained. Introduction Hypothermia was shown to attenuate ventilator-
induced lung injury (VILI) in high end-inspiratory lung volume
models of VILI [1-3]. Experimental evidence suggests that
moderate tidal volumes may, under certain clinical conditions that
induce alveolar instability, lead to a lung injury [4]. Recent studies
have also suggested that insults like shock [5] or surgery [6]
sensitize the lung to injury by priming for an exaggerated response
to a second stimulus. The aim of this study was to investigate
whether moderate hypothermia attenuates low lung volume injury
during low PEEP, high FiO2 and moderate tidal volume ventilation
in animals sensitized to injury by previous anesthesia and surgery. Methods Sixteen male adult Sprague–Dawley rats, instrumented
under ether anesthesia with vascular catheters on the previous day,
were anesthetized, tracheostomized, connected to a ventilator and
randomly allocated to groups of normothermia (37 ± 0.5°C, group N,
n = 8) or hypothermia (33 ± 0.5°C, group H, n = 8). P15 In conclusion, in septic patients, infusion of AP results in an
attenuated upregulation of iNOS and, subsequent, reduced NO
production in the kidney, associated with an improvement in renal
function. Conclusion Moderate hypothermia attenuated lung injury during
low PEEP, high FiO2 and moderate tidal volume ventilation in
animals sensitized to injury by previous anesthesia and surgery. Acknowledgement Supported by the Research project MZO
00179906. Acknowledgement Supported by the Research project MZO
00179906. P17 Results
(1) The mean arterial pressure was higher post-
resuscitation (PR) in group III (62.9 ± 8.2 mmHg) than in groups I
and II (54.9 ± 1.7, 53.9 ± 4.3 mmHg; P < 0.01). The urine output
(I: 999 ± 428, II: 1,249 ± 180, III: 1,434 ± 325 ml) and the cardiac
output (CO) (I: 3.01 ± 0.66, II: 3.30 ± 0.49, III: 3.43 ± 0.57 l/min)
increased dose dependently. The volume of third space fluid loss
of group III decreased significantly (I: 157 ± 32, II: 138 ± 32, III:
82 ± 21 ml; P < 0.05). (2) Mean arterial pressure was higher PR
among
groups
IV,
V
and
VII
(71.4 ± 7.5,
71.0 ± 8.9,
72.9 ± 12.3 mmHg) compared with group VI (59.9 ± 10.9) and
CO of PR was higher in group VII (3.46 ± 0.56 l/min) than group
IV (2.99 ± 0.62; P < 0.01). Following resuscitation, the urine
output was higher, and the urine specific gravity and third space
fluid loss were lower in group VII (1,434 ± 325 ml, 1.0035,
82 ± 21 ml) compared with group VI (958 ± 390 ml, 1.0053,
125 ± 32 ml; P < 0.05). nNOS and Nox4 go nuclear: nNOS-derived and NADPH
oxidase-derived reactive oxygen/nitrogen species
promote oxidative nuclear damage in alveolar epithelial
cells nNOS and Nox4 go nuclear: nNOS-derived and NADPH
oxidase-derived reactive oxygen/nitrogen species
promote oxidative nuclear damage in alveolar epithelial
cells R Connelly, F Schmalstieg, D Traber
University of Texas Medical Branch, Galveston, TX, USA
Critical Care 2007, 11(Suppl 2):P17 (doi: 10.1186/cc5177) Emerging evidence implicates a role for angiotensin II (Ang II)-
stimulated reactive oxygen and nitrogen species (ROS/RNS)
formation in acute lung injury (ALI). However, details of the
mechanism are lacking. We hypothesized that compartmentalized
generation of superoxide (O2–) and nitric oxide (•NO) may be key
events in the Ang II-stimulated progression of ALI. In the present
study, we found that Ang II markedly enhanced ROS/RNS
production 7.4-fold, an effect blocked by the specific nNOS
inhibitor N(G)-propyl-L-arginine, the NADPH oxidase inhibitor
apocynin, or small interfering RNA (siRNA)-specific gene silencing
targeted against nNOS or Nox4. nNOS/Nox4 transiently co-
immunoprecipitates, and co-localizes at the peri-nuclear region 15
minutes post Ang II stimulation. Subsequently, confocal and
western blot analyses show that nNOS/Nox4 translocates to the
nucleus, suggesting that nNOS/Nox4 may directly regulate nuclear
signaling. Dose effects of recombinant human IL-11 on the systemic
hemodynamic function in hemorrhagic shock Methods Eleven ewes were surgically instrumented and randomly
allocated to either an injured untreated control group (40% total
body surface area flame burn and 48 breaths of cotton smoke,
n = 6), or an injury group treated with 7-NI (1 mg/kg/hour, n = 5). K Honma1, N Koles2, H Alam2, P Rhee2, J Keith, Jr3, M Pollack2
1Shin-Koga Hospital, Kurume, Fukuoka, Japan; 2Uniformed
Services University of the Health Sciences, Bethesda, MD, USA;
3Wyeth Research, Andover, MA, USA
Critical Care 2007, 11(Suppl 2):P18 (doi: 10.1186/cc5178) Results This insult was associated with systemic inflammation and
oxidative stress, as evidenced by a 2.5-fold increase in plasma
nitrite/nitrate (NOx) levels, as well as sixfold, twofold, threefold and
twofold increases in IL-8, myeloperoxidase (MPO), malondialde-
hyde (MDA) and poly-ADP-ribose-polymerase (PARP) lung tissue
concentrations, respectively. These molecular changes were linked
to severe pulmonary derangements. Compared with untreated
controls, 7-NI significantly reduced NOx plasma levels (8.4 ± 1 vs
26 ± 10 µmol/l) and decreased IL-8, MPO (3.9 ± 0.2 vs
5.8 ± 0.7 U/g tissue), MDA (2.7 ± 0.3 vs 6.6 ± 1.1 nmol/mg
protein) and PARP lung tissue content (3.4 ± 0.7 vs 6.7 ± 0.7),
thereby
decreasing
pulmonary
obstruction
(12.4 ± 2.2
vs
28.7 ± 5.2 obstruction score) and increasing the PaO2/FiO2 ratio
(456 ± 40 vs 313 ± 56, each P < 0.05). Introduction We have previously demonstrated that administration
of recombinant human IL-11 (rhIL-11) during resuscitation improves
the cardiovascular functions in a rodent model of hemorrhagic
shock. The purpose of this study was to elucidate: (1) whether
these beneficial effects were dose related, and (2) whether the
effects of rhIL-11 could be reproduced in a large animal model. p
g
Methods Swine (n = 56, weight = 25–35 kg) underwent 40%
blood volume hemorrhage, and a 1-hour shock period, followed by
resuscitation with 0.9% sodium chloride (three times the shed
blood volume). The animals were randomized to receive: (1) group
I, 5 µg/kg rhIL-11 (n = 6); group II, 20 µg/kg rhIL-11 (n = 5); group
III, 50 µg/kg rhIL-11 (n = 6) – and then, (2) group IV, sham
hemorrhage (sham, n = 10); group V, sham hemorrhage and
50 µg/kg rhIL-11 (sham + IL-11, n = 6); group VI, no drug (saline,
n = 15); group VII, 50 µg/kg rhIL-11 (IL-11, n = 14). Dose effects of recombinant human IL-11 on the systemic
hemodynamic function in hemorrhagic shock Blood
samples and urine were obtained and analyzed at baseline, the end
of hemorrhage, and at every hour. Conclusions These data suggest that nNOS-derived NO plays a
pivotal role in the pathophysiology of this double-hit injury and that
selective nNOS inhibition may represent a useful approach to
attenuate the degree of pulmonary damage. Effects of neuronal nitric oxide synthase in ovine lung injury P17
nNOS and Nox4 go nuclear: nNOS-derived and NADPH
oxidase-derived reactive oxygen/nitrogen species
promote oxidative nuclear damage in alveolar epithelial
cells
R Connelly, F Schmalstieg, D Traber
University of Texas Medical Branch, Galveston, TX, USA
Critical Care 2007, 11(Suppl 2):P17 (doi: 10.1186/cc5177) P18 P17 Furthermore, PAR polymers, which are undetectable in
resting conditions, were generated following Ang II stimulation, an
effect blocked with apocynin or N(G)-propyl-L-arginine. In
conclusion, these data suggest Ang II causes nNOS/Nox4 to co-
localize at the peri-nuclear region of A549 cells, where superoxide
produced by Nox4, and •NO produced by nNOS immediately react
to form peroxynitrite, which leads to subsequent nuclear oxidative
damage as evidenced by increased PAR polymer formation. Furthermore, these experiments demonstrate inflammatory-stimulated
nuclear translocalization of nNOS/Nox4, which has important
implications for direct ROS/RNS-mediated nuclear activities. Therefore, inhibition of nNOS/Nox4 may be an effective thera-
peutic target in patients with ALI. Conclusion The effects of rhIL-11 on the cardiovascular functions
were influenced by the dose of rhIL-11, although the relationship
did not follow simple linearity. A 50µg/kg dose rhIL-11 significantly
improves cardiovascular functions in a porcine model of hemor-
rhagic shock. Effects of neuronal nitric oxide synthase in ovine lung injury F Saunders1, M Westphal1, P Enkhbaatar1, J Wang1,
M Gonzalez1, Y Nakano1, A Hamahata1, C Jonkam1,
R Connelly1, R Cox1, H Hawkins2, F Schmalstieg1, E Horvath3,
M Lange1, C Szabo1, L Traber1, D Herndon2, D Traber1
1University of Texas Medical Branch, Galveston, TX, USA;
2Shriners Burns Hospital for Children, Galveston, TX, USA;
3University of Medicine and Dentistry of New Jersey, NJ, USA
Critical Care 2007, 11(Suppl 2):P16 (doi: 10.1186/cc5176) F Saunders1, M Westphal1, P Enkhbaatar1, J Wang1,
M Gonzalez1, Y Nakano1, A Hamahata1, C Jonkam1,
R Connelly1, R Cox1, H Hawkins2, F Schmalstieg1, E Horvath3,
M Lange1, C Szabo1, L Traber1, D Herndon2, D Traber1
1University of Texas Medical Branch, Galveston, TX, USA;
2Shriners Burns Hospital for Children, Galveston, TX, USA;
3University of Medicine and Dentistry of New Jersey, NJ, USA
Critical Care 2007, 11(Suppl 2):P16 (doi: 10.1186/cc5176) Introduction Excessive production of nitric oxide is a major factor
contributing to acute lung injury and systemic inflammation after S6 Available online http://ccforum.com/supplements/11/S2 burn and smoke inhalation injury. We hypothesized that the use of
7-nitroindazole (7-NI), a selective nNOS inhibitor, blocks molecular
mechanisms in this pathogenesis. Methods Eleven ewes were surgically instrumented and randomly
allocated to either an injured untreated control group (40% total
body surface area flame burn and 48 breaths of cotton smoke,
n = 6), or an injury group treated with 7-NI (1 mg/kg/hour, n = 5). Results This insult was associated with systemic inflammation and
oxidative stress, as evidenced by a 2.5-fold increase in plasma
nitrite/nitrate (NOx) levels, as well as sixfold, twofold, threefold and
twofold increases in IL-8, myeloperoxidase (MPO), malondialde-
hyde (MDA) and poly-ADP-ribose-polymerase (PARP) lung tissue
concentrations, respectively. These molecular changes were linked
to severe pulmonary derangements. Compared with untreated
controls, 7-NI significantly reduced NOx plasma levels (8.4 ± 1 vs
26 ± 10 µmol/l) and decreased IL-8, MPO (3.9 ± 0.2 vs
5.8 ± 0.7 U/g tissue), MDA (2.7 ± 0.3 vs 6.6 ± 1.1 nmol/mg
protein) and PARP lung tissue content (3.4 ± 0.7 vs 6.7 ± 0.7),
thereby
decreasing
pulmonary
obstruction
(12.4 ± 2.2
vs
28.7 ± 5.2 obstruction score) and increasing the PaO2/FiO2 ratio
(456 ± 40 vs 313 ± 56, each P < 0.05). Conclusions These data suggest that nNOS-derived NO plays a
pivotal role in the pathophysiology of this double-hit injury and that
selective nNOS inhibition may represent a useful approach to
attenuate the degree of pulmonary damage. P18 burn and smoke inhalation injury. We hypothesized that the use of
7-nitroindazole (7-NI), a selective nNOS inhibitor, blocks molecular
mechanisms in this pathogenesis. P18
Dose effects of recombinant human IL-11 on the systemic
hemodynamic function in hemorrhagic shock
K Honma1, N Koles2, H Alam2, P Rhee2, J Keith, Jr3, M Pollack2
1Shin-Koga Hospital, Kurume, Fukuoka, Japan; 2Uniformed
Services University of the Health Sciences, Bethesda, MD, USA;
3Wyeth Research, Andover, MA, USA
Critical Care 2007, 11(Suppl 2):P18 (doi: 10.1186/cc5178) Degradation of endothelial glycocalyx provides new insights
in the pathogenesis of septic shock microvascular failure GLX degradation plays a critical ro
in the septic vasculature and generation of free radicals durin
septic shock is potentially toxic to GLX function. P20
Exhaled breath condensate mediators in mechanically
ventilated brain-injured patients with no acute lung injury
are mostly related to markers of systemic inflammation
I Korovesi1, E Papadomichelakis2, O Livaditi1, E Giamarellos-
Bourboulis3, C Sotiropoulou1, A Koutsoukou4, I Dimopoulou2,
A Armaganidis2, C Roussos4, N Marczin5, A Kotanidou4,
S Orfanos2
1University of Athens, Greece; 2Attikon Hospital, 2nd Critical
Care Department, Haidari (Athens), Greece; 3Attikon Hospital,
4th Department of Medicine, Haidari (Athens), Greece;
4Evangelismos Hospital, Athens, Greece; 5Imperial College
London, UK
Critical Care 2007, 11(Suppl 2):P20 (doi: 10.1186/cc5180)
Introduction Mechanical ventilation may induce lung injury pathologies. In this study we identified EBC inflammatory markers
in 27 mechanically ventilated brain-injured subjects with neither
acute lung injury (ALI) nor sepsis. apparent thickness evaluated using intravital microscopy by
comparing 4 and 150 kDa dextran distribution as markers of GLX
permeable and impermeable tracers, respectively. Intravital micro-
scopy was used to characterize mesentery functional capillary
density. Because glycocalyx is extremely sensitive to free radical,
oxidative stress was evaluated by oxidation of dihydrorhodamine
(DHR) in microvascular beds and by concentrations of heart
malondialdehyde (MDA) and plasma carbonyl proteins (CP). g
j
y
p
Methods Patients were ventilated with 8 ml/kg tidal volume and
were put either on PEEP = 0 (ZEEP, n = 12) or 8 cmH2O (PEEP,
n = 15). EBC was collected using the RTube device (Respiratory
Research Inc., Charlottesville, VA, US) on the first, third, and fifth
day of mechanical ventilation, and pH, IL-10, IL-1β, IL-6, IL-8,
IL-12p70 and TNFα were measured. Applying mixed effects
models, we further investigated potential relationships of the above
EBC markers with indices of: i, lung injury (LIS score, PaO2/FiO2,
detected pathologies on lung CT); ii, brain injury (ICP, CPP, GCS,
serum (s) S100 protein, pentothal and mannitol administration); iii,
endothelial injury (sICAM-1, sVCAM-1, von Willebrand factor
antigen); iv, systemic inflammation (temperature, leukocyte counts
and neutrophil counts in blood, albumin, soluble triggering receptor
expressed on myeloid cells (sTREM), CRP, procalcitonin (PCT)
and all above-mentioned cytokines in serum or plasma); and v,
disease severity (APACHE II score, 24 hour ICU trauma score,
presence of SIRS, mean arterial pressure). Results LPS elicited a 4 hours later profound reduction in GLX
layer thickness and increase in plasma hyaluronan levels. Degradation of endothelial glycocalyx provides new insights
in the pathogenesis of septic shock microvascular failure LPS rats
had decreases in capillary continuous flow, and significant increases
in intermittent and stopped flow capillaries compared with controls. The pressor responses to norepinephrine were greatly reduced,
indicative of vascular hyporeactivity. In vivo oxidation of DHR and
levels of heart MDA and plasma CP were all increased in LPS-
treated rats. Interestingly, in LPS rats, APC reduced plasma
hyaluronan levels and GLX destruction, which was accompanied
with major improvements in vasopressor response and functional
capillary density. APC treatment also prevented increases in
biochemical and in vivo microvascular oxidative stress markers. The pressor responses to norepinephrine were greatly reduced,
indicative of vascular hyporeactivity. In vivo oxidation of DHR and
levels of heart MDA and plasma CP were all increased in LPS-
treated rats. Interestingly, in LPS rats, APC reduced plasma
hyaluronan levels and GLX destruction, which was accompanied
with major improvements in vasopressor response and functional
capillary density. APC treatment also prevented increases in
biochemical and in vivo microvascular oxidative stress markers. Results No significant differences in EBC measurements were
observed between the two groups except a time-dependent
decrease in IL-10 (P < 0.05, by ANOVA) in the PEEP group. EBC pH
and IL-10 showed no significant relationships (mixed effects models)
with any parameter measured. All other EBC cytokines were inversely
related to sTREM levels. Additional significant relationships were
obtained between individual EBC cytokines and sIL-8 (IL-8, IL-12p70,
TNFα), sIL-6 (IL-1β), PCT (IL-1β, IL-12p70), the existence of SIRS (IL-
6, IL-8), sVCAM-1 (IL-6), and pentothal administration (IL-1β). Conclusion In our model of septic shock, increased plasma
hyluronan levels and reduction in endothelial layer thickness
indicated GLX degradation. APC prevented vascular oxidative
stress and limited GLX loss. GLX degradation plays a critical role
in the septic vasculature and generation of free radicals during
septic shock is potentially toxic to GLX function. Reduced local inflammatory reactivity in septic patients
compared with healthy controls Introduction Mechanical ventilation may induce lung injury in
patients with normal lungs. Application of PEEP appears protective. Lung injury is associated with the production and release of
inflammatory mediators. Such mediators have been identified in
patients’ exhaled breath condensate (EBC) in various lung Introduction The aim of this study was to access the local
inflammatory reactivity by measurement of the cytokine response Exhaled breath condensate mediators in mechanically
ventilated brain-injured patients with no acute lung injury
are mostly related to markers of systemic inflammation Conclusion In our population of mechanically ventilated, brain-
injured patients with no ALI, ZEEP or applied PEEP did not induce
detectable changes in most lung inflammatory mediators in EBC;
the latter appear mostly related to markers of systemic
inflammation (especially sTREM-1) rather than to indices of brain
and endothelial injury. I Korovesi1, E Papadomichelakis2, O Livaditi1, E Giamarellos-
Bourboulis3, C Sotiropoulou1, A Koutsoukou4, I Dimopoulou2,
A Armaganidis2, C Roussos4, N Marczin5, A Kotanidou4,
S Orfanos2
1University of Athens, Greece; 2Attikon Hospital, 2nd Critical
Care Department, Haidari (Athens), Greece; 3Attikon Hospital,
4th Department of Medicine, Haidari (Athens), Greece;
4Evangelismos Hospital, Athens, Greece; 5Imperial College
London, UK
Critical Care 2007, 11(Suppl 2):P20 (doi: 10.1186/cc5180) I Korovesi1, E Papadomichelakis2, O Livaditi1, E Giamarellos-
Bourboulis3, C Sotiropoulou1, A Koutsoukou4, I Dimopoulou2,
A Armaganidis2, C Roussos4, N Marczin5, A Kotanidou4,
S Orfanos2 P20 Exhaled breath condensate mediators in mechanically
ventilated brain-injured patients with no acute lung injury
are mostly related to markers of systemic inflammation P21 1University of Athens, Greece; 2Attikon Hospital, 2nd Critical
Care Department, Haidari (Athens), Greece; 3Attikon Hospital,
4th Department of Medicine, Haidari (Athens), Greece;
4Evangelismos Hospital, Athens, Greece; 5Imperial College
London, UK
Critical Care 2007, 11(Suppl 2):P20 (doi: 10.1186/cc5180) Degradation of endothelial glycocalyx provides new insights
in the pathogenesis of septic shock microvascular failure Degradation of endothelial glycocalyx provides new insights
in the pathogenesis of septic shock microvascular failure
R Nevière1, R Favory2, X Marechal1
1School of Medicine, Lille, France; 2Calmette Hospital, Lille, France
Critical Care 2007, 11(Suppl 2):P19 (doi: 10.1186/cc5179) R Nevière1, R Favory2, X Marechal1
1School of Medicine, Lille, France; 2Calmette Hospital, Lille, France
Critical Care 2007, 11(Suppl 2):P19 (doi: 10.1186/cc5179) Introduction Glycocalyx (GLX) is implicated in mechanotrans-
duction of shear stress and microvascular blood flow. We tested
whether GLX loss accounts for the microvascular dysfunction in
sepsis and whether activated protein C (APC) preserves
endothelial GLX integrity. Introduction Glycocalyx (GLX) is implicated in mechanotrans-
duction of shear stress and microvascular blood flow. We tested
whether GLX loss accounts for the microvascular dysfunction in
sepsis and whether activated protein C (APC) preserves
endothelial GLX integrity. Methods Endotoxin LPS (10 mg/kg) was infused in rats treated or
not with APC (240 µg/kg/hour). Changes in GLX were assessed
by circulating levels of hyaluronan (a GLX constituent) and by GLX S7 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin apparent thickness evaluated using intravital microscopy b
comparing 4 and 150 kDa dextran distribution as markers of GL
permeable and impermeable tracers, respectively. Intravital micro
scopy was used to characterize mesentery functional capilla
density. Because glycocalyx is extremely sensitive to free radica
oxidative stress was evaluated by oxidation of dihydrorhodamin
(DHR) in microvascular beds and by concentrations of hea
malondialdehyde (MDA) and plasma carbonyl proteins (CP). Results LPS elicited a 4 hours later profound reduction in GL
layer thickness and increase in plasma hyaluronan levels. LPS rat
had decreases in capillary continuous flow, and significant increase
in intermittent and stopped flow capillaries compared with control
The pressor responses to norepinephrine were greatly reduced
indicative of vascular hyporeactivity. In vivo oxidation of DHR an
levels of heart MDA and plasma CP were all increased in LPS
treated rats. Interestingly, in LPS rats, APC reduced plasm
hyaluronan levels and GLX destruction, which was accompanie
with major improvements in vasopressor response and function
capillary density. APC treatment also prevented increases
biochemical and in vivo microvascular oxidative stress markers. Conclusion In our model of septic shock, increased plasm
hyluronan levels and reduction in endothelial layer thicknes
indicated GLX degradation. APC prevented vascular oxidativ
stress and limited GLX loss. P22 The evaluation of sivelestat sodium hydrate in acute lung
injury/acute respiratory distress syndrome patients in the
intensive care unit
T Ikeda, K Ikeda, T Ueno, Y Kuroki, T Yokoyama, K Yoshikawa
Hachiouji Medical Center, Tokyo Medical University, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P22 (doi: 10.1186/cc5182) The evaluation of sivelestat sodium hydrate in acute lung
injury/acute respiratory distress syndrome patients in the
intensive care unit Methods Male BALB/c mice were divided into three groups. Group I served for sham burns. In groups II and III, a 15% BSA full-
thickness burn was made on the dorsum under ether anesthesia,
followed by adequate fluid resuscitation. After the burn injury,
3 mg/kg prednisolone (PSL) in group III was administered sub-
cutaneously daily for 10 days. On the 11th day, 10 mg/kg
lipopolysaccharide (LPS) was injected intravenously. In the first
experiment, we observed the survival within 72 hours after LPS
injection in each group (n = 10). In the second experiment, we
sacrificed the animals at 12 hours after LPS injection, then
obtained plasma and lung tissue to determine the levels of TNFα
and macrophage inflammatory protein-2 (MIP-2, a functional homo-
logue of human IL-8 in mice) in these samples (n = 8, sandwich
ELISA). We also determined gene expression (n = 4, MIP-
2/GAPDH mRNA ratio by RT-PCR), myeloperoxidase activities
(MPO, n = 8) and histopathological findings in the lung tissue. T Ikeda, K Ikeda, T Ueno, Y Kuroki, T Yokoyama, K Yoshikawa
Hachiouji Medical Center, Tokyo Medical University, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P22 (doi: 10.1186/cc5182) The onset mechanism of ALI/ARDS and subsequent tissue injury
are considered to be associated with neutrophil elastase, and the
main causes of ALI/ARDS are considered to be sepsis or aspiration
pneumonia. In Japan, sivelestat sodium hydrate (Elaspol), a
selective elastase inhibitor, was approved in 2002 for ALI/ARDS
accompanied by SIRS, and this medicine has been evaluated in a
clinical situation. Figure 1 (abstract P21) Figure 1 (abstract P21) Figure 1 (abstract P21) S8 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Elaspol: 75%, Group Control: 52%; P < 0.001). These results
suggest that sivelestat sodium hydrate is a good option as a
treatment strategy for neutrophil elastase-associated septic
ALI/ARDS accompanied by SIRS. after catheter insertion into subcutaneous adipose tissue (SAT) of
patients with severe sepsis compared with healthy volunteers. Elaspol: 75%, Group Control: 52%; P < 0.001). These results
suggest that sivelestat sodium hydrate is a good option as a
treatment strategy for neutrophil elastase-associated septic
ALI/ARDS accompanied by SIRS. after catheter insertion into subcutaneous adipose tissue (SAT) of
patients with severe sepsis compared with healthy volunteers. Methods Eight healthy volunteers and 10 patients with severe
sepsis were included. One 18-gauge open-flow microperfusion
double-lumen catheter was inserted into SAT of the abdominal wall
and perfused with an isotonic solution at a flow rate of 1 µl/min. Blood samples and probe effluent samples from interstitial fluid of
SAT were withdrawn in two hourly intervals for a period of 8 hours
and retrospectively analysed using a Multiplex ELISA system for
IL-1β, IL-6, IL-8 and TNFα. Methods Eight healthy volunteers and 10 patients with severe
sepsis were included. One 18-gauge open-flow microperfusion
double-lumen catheter was inserted into SAT of the abdominal wall
and perfused with an isotonic solution at a flow rate of 1 µl/min. Blood samples and probe effluent samples from interstitial fluid of
SAT were withdrawn in two hourly intervals for a period of 8 hours
and retrospectively analysed using a Multiplex ELISA system for
IL-1β, IL-6, IL-8 and TNFα. P22 In this study, we performed a retrospective
comparison of the sivelestat sodium administration between two
groups of patients: Group Elaspol, consisting of 308 patients(209
males and 99 females, aged 66 ± 15 years) with ALI/ARDS
accompanied by SIRS who were treated with sivelestat sodium at
a dose of 0.2 mg/kg/hour for 72 hours or more, after approval of
this drug; and Group Control, consisting of 41 patients (28 males
and 13 females, aged 66 ± 14 years) with ALI/ARDS accompanied
by SIRS who were treated in the ICU under similar conditions, but
using traditional methods for respiratory control, prior to approval
sivelestat sodium. The APACHE II scores of Group Elaspol and
Group Control were 23 ± 9 and 23 ± 8, SOFA scores were
8.7 ± 3.8 and 8.9 ± 4.1, and the lung injury scores were 2.1 ± 0.7
and 2.1 ± 0.6, respectively, with no significant differences between
the groups. The initial PEEP value of Group Elaspol was 5.9 ± 3.3,
which was significantly higher than that of Group Control
(3.4 ± 2.7 cmH2O). The PaO2/FIO2
ratios under mechanical
ventilation management 24, 48 and 72 hours after the beginning of
drug administration were 209 ± 87, 222 ± 92, and 222 ± 82 mmHg
in
Group
Elaspol,
and
were
191 ± 91,
207 ± 91,
and
211 ± 100 mmHg in Group Control. The ventilator-free days of
Group Elaspol and Group Control were 18 ± 9 and 10 ± 12 days,
respectively, and these values showed a significant difference
(P < 0.001). Furthermore, the survival rate after 28 days was
significantly higher in Group Elaspol than in Group Control (Group Results The survival and production of cytokines are shown in Table
1. Histopathological findings in group III were obviously attenuated. Table 1 (abstract P23)
Lung
MIP-2/
Plasma
Plasma
Lung
GAPDH
Lung
Survival
TNF
MIP-2
MIP-2
mRNA
MPO
Group
(%)
(pg/ml)
(pg/ml) (pg/mg)
ratio
(U/mg)
I (sham–LPS)
100
1,190
6,396
70.0
0.345
0.405
II (burn–LPS)
0†
3,024** 13,766** 142.5**
0.975‡
0.574**
III (PSL)
50*
749§
791§
11.6§
0.052§
0.244§
Mean values are presented. *P < 0.05 vs group II, **P < 0.005 vs group I,
†P < 0.01 vs group I, ‡P < 0.05 vs group I, §P < 0.005 vs group II. Conclusions In this animal model, a pretreatment with PSL as the
cytokine synthesis inhibitor improved the survival and attenuated
the production of cytokines. P23 Pharmacological modulation with prolonged
administration of moderate doses of steroid in a murine
model of septic acute lung injury after burn insult
J Sasaki1, S Fujishima2, K Takuma1, Y Shinozawa1, N Aikawa2
1Tohoku University Hospital, Sendai, Japan;
2Keio University, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P23 (doi: 10.1186/cc5183) Results Concentrations of IL-1β, IL-6 and IL-8 were substantially
higher in SAT (13.3 (11.2; 31.0); 1,934 (1,650; 2,730); 917 (656;
2,672) pg/ml; median (25th; 75th percentile)) than in serum (0.8
(0.6; 1.3); 49.2 (3.8; 67.6); 36.1 (6.3; 89.1) pg/ml) for both
groups, whereas TNFα concentrations were similar in serum and
SAT (Figure 1). Serum concentrations of all cytokines remained
stable over time. However, a significant increase was observed for
IL-1β and IL-8 in SAT in both groups. This increase was
significantly in septic patients vs healthy controls. ritical Care 2007, 11(Suppl 2):P23 (doi: 10.1186/cc518 Introduction
Many patients who experience surgical stress
including burn injury become susceptible to severe sepsis and
septic organ dysfunction including acute lung injury (ALI), which
remains the primary contributor to morbidity and mortality in burn
patients. Proinflammatory cytokines including several chemokines
are implicated in this process. The pharmacological modulation
with steroid inhibiting the process of cytokine synthesis may serve
as effective therapy for the prevention of tissue injury and the
resultant organ dysfunction including respiratory failure. We
developed a murine model of septic ALI after burn insult and
examined the effects of prolonged administration of moderate
doses of steroid. Introduction
Many patients who experience surgical stress
including burn injury become susceptible to severe sepsis and
septic organ dysfunction including acute lung injury (ALI), which
remains the primary contributor to morbidity and mortality in burn
patients. Proinflammatory cytokines including several chemokines
are implicated in this process. The pharmacological modulation
with steroid inhibiting the process of cytokine synthesis may serve
as effective therapy for the prevention of tissue injury and the
resultant organ dysfunction including respiratory failure. We
developed a murine model of septic ALI after burn insult and
examined the effects of prolonged administration of moderate
doses of steroid. Conclusion Insertion of a catheter into subcutaneous adipose
tissue promotes a local inflammatory response in both healthy
individuals and critically ill patients. The attenuated response in
patients with severe sepsis might be caused by reduced
inflammatory reactivity in this group. Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury K Singleton, C Hamiel, P Wischmeyer
University of Colorado Health Sciences Center, Denver, CO, USA
Critical Care 2007, 11(Suppl 2):P24 (doi: 10.1186/cc5184) Methods To investigate the therapeutic effect of nicotine and
physostigmine we performed cecal ligation and puncture (CLP) in
female C57/B6 mice (each group n = 21). Substances were
administered by intraperitoneal injection. Control groups received
the same volume (50–180 µl) of LPS-free 0.9% NaCl (solvent). CLP was performed blinded to the identity of the treatment group. In addition to survival experiments we performed measurements of
cytokines in plasma and the electrophoretic mobility shift assay
(EMSA) for NF-κB in peritoneal skin, liver and kidneys. Introduction Enhanced activity of the O-glycosylation pathway (O-
glcNAc) has been shown to enhance increase heat shock protein
(HSP70) expression. Glucosamine (GA) is a vital intermediate in
this pathway. Methods Mouse fibroblast (MEF) cells underwent heat stress (HS)
at 43°C for 45 minutes. GA doses from 1.25 to 20 mM were given
immediately prior to HS. Cell survival was assessed via MTS assay. GA’s effect on HSP70 expression in vivo was assessed using a
mouse model of cecal ligation and puncture (CLP). Mice were
given 0.26 g/kg GA i.v. 1 hour post CLP. Results
(1) Animals treated with nicotine (400 µg/kg) or
physostigmine (80 µg/kg) survived significantly better than control
mice (P < 0.05). There was no difference between the treatment
groups. (2) Dose escalation of physostigmine was not superior to
the normal dose. Survival in the high-dose group, however, was still
significantly better than in the control group. (3) Proinflammatory
cytokine levels of TNFα, IL-6 and IL-1β were significantly reduced
in animals treated with physostigmine (P < 0.01). (4) Cholin-
esterase inhibition with physostigmine in CLP reduced NF-κB
activation in the peritoneum, kidney and liver compared with the
control and sham-operated group (P < 0.01). Results In MEF cells, 10 mM GA led to a 164% increase in HSP70
expression over control 4 hours post HS (P < 0.05 vs control). Further, GA treatment led to an increase in cell survival post HS
injury at all doses tested (P < 0.01 vs control). Following CLP-
induced sepsis, a single dose of GA led to an increase in lung and
heart HSP70 at 1 and 2 hours post CLP vs saline control (SC). Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury This
effect was lost at 6 and 24 hours (see Figure 1, *P < 0.05 versus
SC at each timepoint). Similarly, GA led to an increase in HSP70 in
colon tissue as well, with the effect lasting to 6 hours (*P < 0.05
versus SC). The effect in colon was lost by 24 hours. Conclusion
We show that pharmacological cholinesterase
inhibition with physostigmine improves survival in experimental
sepsis, most probably by activation of the cholinergic anti-inflam-
matory pathway. One possible mechanism is modulation of the NF-
κB pathway. Therefore, cholinesterase inhibition may have
important implications for treatment of sepsis. Conclusions To our knowledge, this is the first report that shows
GA treatment can increase HSP70 expression both in vivo and in
vitro. Previous data have demonstrated beneficial effects of GA
treatment following ischemia/reperfusion injury and hemorrhagic
shock early after injury. GA’s effect on HSP70 expression in
multiple tissues may help to explain these effects. Further, GA’s
effect on HSP70 expression may be an important factor involved in
GA’s benefits in arthritis and joint disease. P24 P24 inflammatory mechanisms. Vagus nerve stimulation showed improved
survival in sepsis; however, this seems not to be feasible in septic
patients. We therefore investigated the effect of activation of the
cholinergic anti-inflammatory pathway by pharmacologic cholin-
esterase inhibition on survival and inflammation in a septic mouse
model. P24
Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury
K Singleton, C Hamiel, P Wischmeyer
University of Colorado Health Sciences Center, Denver, CO, USA
Critical Care 2007, 11(Suppl 2):P24 (doi: 10.1186/cc5184) Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury P22 The complications associated with
sepsis after burn insults, especially ALI, could be preventable by
the pharmacological modulation with prolonged administration of
moderate doses of steroid. S9 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin 0
P24
Glucosamine enhances heat sho
in vitro and in vivo following injur
K Singleton, C Hamiel, P Wischmey
University of Colorado Health Scienc
Critical Care 2007, 11(Suppl 2):P24
Introduction Enhanced activity of the
glcNAc) has been shown to enhanc
(HSP70) expression. Glucosamine (
this pathway. Methods Mouse fibroblast (MEF) cel
at 43°C for 45 minutes. GA doses fro
immediately prior to HS. Cell survival
GA’s effect on HSP70 expression i
mouse model of cecal ligation and
given 0.26 g/kg GA i.v. 1 hour post C
Results In MEF cells, 10 mM GA led
expression over control 4 hours po
Further, GA treatment led to an inc
injury at all doses tested (P < 0.01
induced sepsis, a single dose of GA
heart HSP70 at 1 and 2 hours post C
effect was lost at 6 and 24 hours (s
SC at each timepoint). Similarly, GA l
colon tissue as well, with the effect
versus SC). The effect in colon was lo
Conclusions To our knowledge, this
GA treatment can increase HSP70 e
vitro. Previous data have demonstra
treatment following ischemia/reperfu
shock early after injury. GA’s effe
multiple tissues may help to explain
effect on HSP70 expression may be
GA’s benefits in arthritis and joint dis
P25
Pharmacologic inhibition of choli
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Sc
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25
Introduction Lethal sepsis occurs
response evolves that cannot be co
Figure 1 (abstract 24)
Lung heat shock protein (HSP70) expre
following cecal ligation and puncture. P24
Glucosamine enhances heat shock protein 70 expression
in vitro and in vivo following injury
K Singleton, C Hamiel, P Wischmeyer
University of Colorado Health Sciences Center, Denver, CO, USA
Critical Care 2007, 11(Suppl 2):P24 (doi: 10.1186/cc5184)
Introduction Enhanced activity of the O-glycosylation pathway (O
glcNAc) has been shown to enhance increase heat shock protei
(HSP70) expression. Glucosamine (GA) is a vital intermediate i
this pathway. Methods Mouse fibroblast (MEF) cells underwent heat stress (HS
at 43°C for 45 minutes. GA doses from 1.25 to 20 mM were give
immediately prior to HS. P22 Cell survival was assessed via MTS assay
GA’s effect on HSP70 expression in vivo was assessed using
mouse model of cecal ligation and puncture (CLP). Mice wer
given 0.26 g/kg GA i.v. 1 hour post CLP. Results In MEF cells, 10 mM GA led to a 164% increase in HSP7
expression over control 4 hours post HS (P < 0.05 vs control
Further, GA treatment led to an increase in cell survival post HS
injury at all doses tested (P < 0.01 vs control). Following CLP
induced sepsis, a single dose of GA led to an increase in lung an
heart HSP70 at 1 and 2 hours post CLP vs saline control (SC). Thi
effect was lost at 6 and 24 hours (see Figure 1, *P < 0.05 versu
SC at each timepoint). Similarly, GA led to an increase in HSP70 i
colon tissue as well, with the effect lasting to 6 hours (*P < 0.0
versus SC). The effect in colon was lost by 24 hours. Conclusions To our knowledge, this is the first report that show
GA treatment can increase HSP70 expression both in vivo and i
vitro. Previous data have demonstrated beneficial effects of GA
treatment following ischemia/reperfusion injury and hemorrhagi
shock early after injury. GA’s effect on HSP70 expression i
multiple tissues may help to explain these effects. Further, GA’
effect on HSP70 expression may be an important factor involved i
GA’s benefits in arthritis and joint disease. P25
Pharmacologic inhibition of cholinesterase improves
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Schneider, E Martin,
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25 (doi: 10.1186/cc5185)
Introduction Lethal sepsis occurs if an excessive inflammator
response evolves that cannot be controlled by physiological ant
Figure 1 (abstract 24)
Lung heat shock protein (HSP70) expression in glucosamine vs saline
following cecal ligation and puncture. Figure 1 (abstract 24) Y Sakamoto1, K Mashiko1, H Matsumoto1, Y Hara1,
Y Yamamoto2
1Chiba Hokusou Hospital, Nippon Medical School, Chiba, Japan;
2Department of Emergency Medicine, Nippon Medical School,
Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P26 (doi: 10.1186/cc5186) Introduction High-mobility-group box protein 1 (HMGB1) is a
highly conserved, ubiquitous protein present in the nuclei and
cytoplasm of nearly all cell types and, secreted into the extracellular
milieu, acts as a proinflammatory cytokine. The function of HMGB1
has been widely studied for sepsis and inflammation. HMGB1 was
reported as a late mediator in endotoxic shock and was known as
an abundant protein present in nuclei and cytoplasm and involved
in maintaining nucleosome structure and regulation of gene
transcription. Moreover, elevated, circulating levels of HMGB1 also
have been described in a case of human hemorrhagic shock due to
abdominal aortic aneurysm without evidence of infection. However,
the relationship between HMGB1 and trauma has not been
studied except for the report of a rat model of burn. Materials and methods The study cases consisted of 20 trauma
patients who were admitted to the emergency room by ambulance. As soon as they arrived in the emergency room, their blood sample
were collected, centrifuged, and stored at –80°C. The serum
HMGB1 concentration was measured by ELISA. We compared
the injury severity score (ISS), probability of survival values and the
revised trauma score (RTS) of the patients with the presence of Introduction High-mobility-group box protein 1 (HMGB1) is a
highly conserved, ubiquitous protein present in the nuclei and
cytoplasm of nearly all cell types and, secreted into the extracellular
milieu, acts as a proinflammatory cytokine. The function of HMGB1
has been widely studied for sepsis and inflammation. HMGB1 was
reported as a late mediator in endotoxic shock and was known as
an abundant protein present in nuclei and cytoplasm and involved
in maintaining nucleosome structure and regulation of gene
transcription. Moreover, elevated, circulating levels of HMGB1 also
have been described in a case of human hemorrhagic shock due to
abdominal aortic aneurysm without evidence of infection. However,
the relationship between HMGB1 and trauma has not been
studied except for the report of a rat model of burn. P26 Relationship between the presence of serum high-
mobility-group box protein 1 and the injury severity score
in trauma patients G
s be e s
a
s a d jo
d sease
P25
Pharmacologic inhibition of cholinesterase improves
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Schneider, E Martin,
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25 (doi: 10.1186/cc5185)
Introduction Lethal sepsis occurs if an excessive inflammatory
Figure 1 (abstract 24)
Lung heat shock protein (HSP70) expression in glucosamine vs saline
following cecal ligation and puncture. Figure 1 (abstract 24) Aggressive and moderate fluid resuscitation in septic pigs:
consequences on morbidity S Brandt, A Elftheriadis, T Regueira, H Bracht, J Gorrasi,
J Takala, S Jakob
University Hospital Inselspital, Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P28 (doi: 10.1186/cc5188) Results Our data showed that the number in group A was nine
cases and group B was 11 cases. The ISS of group A was
significantly higher than that in group B (P = 0.0013). The P value
of group A was significantly lower than in group B (P = 0.0131). The serum HMGB1 level of the >25 ISS group was significantly
higher than in the ≤25 ISS group. Introduction While early aggressive fluid administration has been
associated with improved outcome in sepsis [1], this approach
may increase the risk of lung edema and abdominal compartment
syndrome when capillary permeability is increased. The aim of this
study was to test two different approaches of volume resuscitation
in septic animals. Discussion These data suggest that HMGB1 seems to be a
primary mediator of trauma-induced pathology. Because the ISS
was significantly correlated with the presence of serum HMGB1,
HMGB1 may be expressed in severe injuries and it may be a
important parameter that indicates the severity of injury. Methods Thirty pigs were anaesthetized and invasively monitored
(systemic and regional flows and pressures). They were
randomized to control, moderate volume (C; n = 7), control, high
volume (CH; n = 8), peritonitis, moderate volume (P; n = 8) and
peritonitis, high volume (PH; n = 7). Peritonitis was induced by
instillation of 1 g/kg autologous faeces dissolved in glucose
solution. Ventilation was adjusted to maintain an arterial pO2
>100 mmHg. Groups CH and PH received 15 ml/kg/hour Ringer’s
solution plus 5 ml/kg/hour HES 6%, whereas groups C and P
received 10 ml/kg/hour Ringer’s solution. If clinical signs of
hypovolaemia were present, additional boluses of HES 6%
(maximally 100 ml/hour) were given. The animals were treated and
observed for 24 hours or until death. P28 serum HMGB1 (group A) and without the presence (group B). We
therefore divided into two groups, high ISS group (≤25) and low
ISS group (>25), and examined the relation with the serum
HMGB1 level. Figure 1 (abstract 24) P25
Pharmacologic inhibition of cholinesterase improves
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Schneider, E Martin,
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25 (doi: 10.1186/cc5185) P25
Pharmacologic inhibition of cholinesterase improves
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Schneider, E Martin,
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25 (doi: 10.1186/cc5185) P25
Pharmacologic inhibition of cholinesterase improves
survival in experimental sepsis
S Hofer, C Eisenbach, I Lukic, L Schneider, E Martin,
M Büchler, A Bierhaus, M Weigand
University of Heidelberg, Germany
Critical Care 2007, 11(Suppl 2):P25 (doi: 10.1186/cc5185) Materials and methods The study cases consisted of 20 trauma
patients who were admitted to the emergency room by ambulance. As soon as they arrived in the emergency room, their blood sample
were collected, centrifuged, and stored at –80°C. The serum
HMGB1 concentration was measured by ELISA. We compared
the injury severity score (ISS), probability of survival values and the
revised trauma score (RTS) of the patients with the presence of Introduction Lethal sepsis occurs if an excessive inflammatory
response evolves that cannot be controlled by physiological anti- S10 Available online http://ccforum.com/supplements/11/S2 Aggressive and moderate fluid resuscitation in septic pigs:
consequences on morbidity P27 Beneficial effects of antiplatelet drugs in patients with
community-acquired pneumonia and in endotoxin shock in
mice J Winning1, J Baranyai1, R Claus1, I Eisenhut2, J Hamacher2,
K Reinhart1, M Bauer1, W Lösche1
1University Hospital Jena, Germany; 2University Hospital Homburg,
Germany
Critical Care 2007, 11(Suppl 2):P27 (doi: 10.1186/cc5187) Results Cardiac output was higher in group PH as compared with
the other groups (P < 0.05), while mean arterial pressure was Aims Systemic inflammation and sepsis are associated with blood
platelet activation, which may contribute to the development of
organ failure. In this study we proved whether antiplatelet drugs
have a benefit in patients who may develop sepsis as well as in a
mouse model of endotoxin shock. Figure 1 (abstract P28) Oxygenation index. Figure 2 (abstract P28)
Survival proportion. Oxygenation index. Methods Data obtained from 224 patients with community-
acquired pneumonia (CAP) were retrospectively analysed for an
association between prehospital treatment with long-acting
antiplatelet drugs such as acetyl salicylic acid (n = 36) or
thienopyridine ADP-receptor antagonists (clopidogrel or ticlopidin,
n = 8) and clinical outcome. Use of statins was an exclusion
criterion. BALB/c mice were pretreated with clopidogrel for 4 days
prior to an intraperitoneal injection of LPS (Escherichia coli
0111:B4). For platelet counts and blood gas analysis, standard
procedures were used. Lung tissues were stained with HE or a
FITC-labelled anti-fibrin(ogen) antibody. Results CAP patients with antiplatelet drugs (n = 44) were older
than control patients (n = 180; 69 ± 7 vs 58 ± 13 years,
P < 0.00001). At the day of hospital admission there were no
differences in platelet or leukocyte counts, CRP and SOFA scores
between both groups. However, patients on antiplatelet drugs
developed organ failure less frequently than control patients (ICU
admission: 9.1% vs 26.1%; P < 0.02). In the mouse model of
endotoxin shock, clopidogrel reduced the drop in platelet count
and the degree of lung injury. Compared with controls we found
20 hours after LPS injection in the clopidogrel-treated animals a
lower number of thrombi in the lung vasculature (6.1 ± 2.3 vs
11.5 ± 4.4 thrombi per screen, P < 0.025) as well as higher blood
pH and bicarbonate levels (7.01 ± 0.01 vs 6.93 ± 0.04, P < 0.04
and 10.2 ± 0.14 vs 7.3 ± 0.14 mmol/l, P < 0.03, respectively). P29 Effects of volume resuscitation on hepatosplanchnic
oxygen consumption, liver mitochondrial function and
mortality in endotoxemia Multiple studies have stressed the importance of the contribution
of activated complement to the pathology of reperfusion injury after
tissue ischemia. Using intravital microscopy, this study explores
functional consequences of the inhibition of the classical pathway
of complement activation with C1-esterase inhibitor (C1-INH) in
the context of superior mesenteric artery occlusion (SMAO)/
reperfusion. T Regueira1, E Borotto1, S Brandt2, H Bracht1, J Gorrasi1,
P Lepper1, J Takala1, S Jakob1
1Intensive Care Medicine and 2Department of Anesthesiology,
University Hospital, Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P29 (doi: 10.1186/cc5189) Thirty anesthetized, spontaneously breathing, male Sprague–
Dawley rats underwent SMAO for 60 minutes followed by
reperfusion (4 hours). C1-esterase inhibitor (100 IU/kg, 200 IU/kg
body weight) or saline (0.9%) was given as a single bolus before
reperfusion. Sham-operated animals (n = 10) without SMAO served
as controls. Systemic hemodynamics were monitored continuously,
arterial blood gases analyzed intermittently, and leukocyte/
endothelial
interactions
in
the
mesenteric
microcirculation
quantified at intervals using intravital microscopy. Ileal lipid-binding
protein (I-LBP) levels were measured from serum samples with an
ELISA at the end of the experiments. Introduction Fluid resuscitation is necessary in sepsis, but positive
fluid balance may increase the risk of mortality. We tested the
hypothesis that a volume resuscitation strategy may modify liver
mitochondrial function and outcome. Methods Twenty-nine anesthetized pigs received for 24 hours
either endotoxin or placebo, and either Ringer’s lactate 10 ml/kg/hour
or 15 ml/kg/hour + 5 ml/hour HES. Systemic and regional hemo-
dynamics were measured. Liver mitochondrial state 3 and state 4
oxygen consumption were determined. Results Hepatosplanchnic oxygen delivery was similar in endotoxic
pigs with high (2.97 ± 1.58 ml/min/kg) vs moderate volume
administration (3.06 ± 0.6 ml/min/kg), but hepatosplanchnic VO2
was lower in animals with high (1.32 ± 0.4 ml/min/kg) vs moderate
volume administration (1.75 ± 0.3 ml/min/kg, P = 0.019). Endotoxin
high-volume pigs exhibited a decrease in state 3 respiration for
complex I and complex II (not significant) in comparison with
control high-volume and with endotoxin low-volume pigs (Figure 1). They also had an increased mortality rate during the 24-hour study
period (60% vs 0% in controls). C1-INH restored microcirculatory perfusion of postcapillary venules
to baseline levels in a dose-dependent manner and reduced
leukocyte adhesion following SMAO/reperfusion to similar levels in
both C1-INH-treated groups during reperfusion. P29 Furthermore, C1-
INH treatment efficiently prevented metabolic acidosis, and
reduced the need for intravenous fluids to support blood pressure. Furthermore, I-LBP levels decreased in a dose-dependent manner,
and were comparable with the levels of sham-operated animals at
the end of the experiments. Survival rates were 100% in controls
and after 200 IU/kg C1-INH, 90% after 100 IU/kg C1-INH, and
30% in saline-treated animals. Conclusion A prolonged high-volume resuscitation approach
during endotoxemia may be associated with impaired hepato-
splanchnic oxygen consumption, liver mitochondrial dysfunction In the setting of mesenteric ischemia, C1-INH given as a bolus
infusion shortly before reperfusion efficiently restored microcirculatory
perfusion in a dose-dependent manner, reduced local and systemic
inflammatory response, and improved outcome. I-LBP levels
correlated well with the functional consequences of mesenteric
ischemia/reperfusion and treatment at the end of the experiments. Figure 2 (abstract P28) S
Figure 2 (abstract P28)
Survival proportion. Conclusions Antiplatelet drugs may have a beneficial effect in
systemic inflammation and sepsis, and could be a novel therapy
option, at least in patients of low bleeding risk. One mechanism of
their effects could be a reduction in the microvascular thrombus
formation. Conclusions Antiplatelet drugs may have a beneficial effect in
systemic inflammation and sepsis, and could be a novel therapy
option, at least in patients of low bleeding risk. One mechanism of
their effects could be a reduction in the microvascular thrombus
formation. Survival proportion. S11 cal Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine and high mortality. The impact of aggressive and prolonged volume
administration on hepatosplanchnic oxygenation and mitochondrial
function in human sepsis should be determined. similar in all groups. While the oxygenation index (paO2/FiO2)
decreased in all groups, group PH had the lowest values after 6 hours
and throughout the rest of the experiments (P < 0.05) (Figure 1). Survival was lowest in group PH, followed by group P, while all
animals in the control groups survived until 24 hours (Figure 2). Conclusion High-volume administration decreased oxygenation
and survival in peritonitis but not in control animals. A high-volume
approach may not be generally beneficial in abdominal sepsis. Reference
1. Rivers E, et al.: N Engl J Med 2001, 345:1368-1377. Effect of C1-esterase inhibitor treatment on
microcirculatory perfusion after superior mesenteric artery
ischemia Effect of C1-esterase inhibitor treatment on
microcirculatory perfusion after superior mesenteric artery
ischemia M Lauterbach, G Horstick, N Plum, J Lotz, E Lauterbach,
L Weilemann, O Kempski
University Hospital Mainz, Germany
Critical Care 2007, 11(Suppl 2):P30 (doi: 10.1186/cc5190) 1. Rivers E, et al.: N Engl J Med 2001, 345:1368-1377. Figure 1 (abstract P29) 12
inflammatory response, and improved outcome. I-LBP levels
correlated well with the functional consequences of mesenteric
ischemia/reperfusion and treatment at the end of the experiments. P31
Dobutamine protects lymphocyctes against staurosporin-
induced apoptosis via a receptor-independent and p38-
independent pathway
F Jans1, T Piegeler2, R De Jongh1, R Heylen1, T Loop2,
M Roesslein2
1Ziekenhuis Oost-Limburg, Genk, Belgium; 2University Hospital,
Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P31 (doi: 10.1186/cc5191)
Introduction Since catecholamines have been shown to modulate
various immunological functions, the goal of this work was to
investigate their effects on staurosporin-induced apoptosis of
Jurkat T cells, a well-established model for human T lymphocytes. Figure 1 (abstract P29) P30 Conclusion High-volume administration decreased oxygenation
and survival in peritonitis but not in control animals. A high-volume
approach may not be generally beneficial in abdominal sepsis. Reference Serum vasopressin concentrations in critically ill patients
in the intensive care unit A Melissaki, A Efthymiou, T Kyriakopoulou, G Kribeni,
E Evaggelaki, A Tsikali, D Andreopoulos, A Zaglis, N Baziotis
Saint Savvas General Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P32 (doi: 10.1186/cc5192) Introduction The aim of the study is the measurement of serum
vasopressin concentrations in the mixed critically ill patients,
24 hours after admission to the ICU and just before the discharge. Methods In this study there were included patients admitted to the
ICU from June until November 2006 (n = 22; 12 males, 10
females), mean age 46.45 ± 22.03, APACHE II score 8.59 ± 4.76,
length of stay 9.68 ± 6.52. Patients with central nervous system
failure, neurosurgical patients and patients remaining in the ICU for
no longer than 72 hours were excluded. Serum vasopressin
concentrations were measured 24 hours after their admission to
the ICU and just before their discharge. The control group was 20
healthy volunteers (blood donors). Vasopressin was measured by
the radioimmunoassay method in pmol/l. The sensitivity of the
method is 0.5 pmol/l and the specificity is 100%. The statistical
analysis was done with the t test. Conclusions In catecholamine-dependent human septic shock,
terlipressin (with and without concomitant dobutamine) stabilizes
hemodynamics
and
reduces
norepinephrine
requirements. Dobutamine is a useful inotropic agent to reverse the depression in
global oxygen transport resulting from sole terlipressin infusion
without obvious side effects. Dobutamine protects lymphocyctes against staurosporin-
induced apoptosis via a receptor-independent and p38-
independent pathway F Jans1, T Piegeler2, R De Jongh1, R Heylen1, T Loop2,
M Roesslein2
1Ziekenhuis Oost-Limburg, Genk, Belgium; 2University Hospital,
Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P31 (doi: 10.1186/cc5191) Introduction Since catecholamines have been shown to modulate
various immunological functions, the goal of this work was to
investigate their effects on staurosporin-induced apoptosis of
Jurkat T cells, a well-established model for human T lymphocytes. Introduction Since catecholamines have been shown to modulate
various immunological functions, the goal of this work was to
investigate their effects on staurosporin-induced apoptosis of
Jurkat T cells, a well-established model for human T lymphocytes. S12 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Methods Jurkat T cells passages 1–12 were used. Apoptosis was
measured with a caspase-activity assay and with FACS analysis of
annexin–propidium iodide double-stained cells. than the value on admission and it approaches the value of
vasopressin in healthy volunteers. To confirm these results, more
studies will be needed. than the value on admission and it approaches the value of
vasopressin in healthy volunteers. To confirm these results, more
studies will be needed. p
p
Results Exposure of Jurkat T cells for 2 hours to staurosporin
(2 µM) induced apoptosis: the number of apoptotic cells increased
to 14.0 ± 0.8% versus 2.3 ± 0.4% in the control group. Pre-
treatment (4 hours) with dobutamine 100 and 500 µM decreased
the staurosporin-induced apoptosis to 11.6 ± 0.6% and 8.7 ± 0.7%,
respectively (P < 0.01, mean ± SEM, n = 44). Other catechol-
amines like epinephrine and norepinephrine (both up to 500 µM)
had no effect on staurosporin-induced apoptosis. To investigate
whether this protective effect of dobutamine was mediated via β-
receptors, specific β-blockers were used: neither atenolol (β1)
(100 mM), nor ICI 118,551 (β2) (10 mM) blocked the protective
effect of dobutamine. Furthermore, dobutamine (1–500 µM) did
not increase cAMP production in these cells. Therefore, the
protective effect of dobutamine is not β-receptor-mediated. Since it
was previously demonstrated that MAPKs p38 and JNK, but not
ERK, are activated by dobutamine in Jurkat T cells, we investigated
whether the activation of these MAPKs are involved in the
protection by dobutamine: inhibition of JNK activation with SP
600125 (1 µM) did not influence the protective effect of dobuta-
mine. Inhibition of p38 activation with SBI 202190 (5 µM) even
seemed to reinforce the protection afforded by dobutamine. Effects of simultaneously infused terlipressin and
dobutamine in septic shock Effects of simultaneously infused terlipressin and
dobutamine in septic shock A Morelli1, C Ertmer2, M Lange2, K Broeking2, A Orecchioni1,
M Rocco1, H Van Aken2, P Pietropaoli1, M Westphal2
1University of Rome ‘La Sapienza’, Rome, Italy; 2University Hospital
of Muenster, Germany
Critical Care 2007, 11(Suppl 2):P33 (doi: 10.1186/cc5193) Introduction Terlipressin is increasingly used in the treatment of
sepsis-associated hypotension. However, terlipressin may reduce
cardiac output and global oxygen supply. Introduction Terlipressin is increasingly used in the treatment of
sepsis-associated hypotension. However, terlipressin may reduce
cardiac output and global oxygen supply. Methods We performed a prospective, randomized, controlled
clinical study to determine whether dobutamine may counter-
balance the depressions in cardiac index and mixed-venous oxygen
saturation resulting from sole terlipressin infusion. We enrolled 60
septic shock patients requiring high doses of norepinephrine
(0.9 µg/kg/min) to maintain mean arterial pressure at 70 ± 5 mmHg. Patients were randomly allocated to be treated either with (a) 1 mg
terlipressin, (b) 1 mg terlipressin followed by incremental dobuta-
mine doses to reverse the anticipated reductions in mixed-venous
oxygen saturation, or (c) sole norepinephrine infusion (control;
each n = 20). Conclusions These experiments demonstrate that dobutamine
pretreatment protects T cells from staurosporin-induced apoptosis. This protective effect is not β-receptor-mediated. Also, activation of
MAPKs p38 or JNK by dobutamine is not responsible for the
protective effect. The molecular mechanisms by which dobutamine
exerts this protective effect remain to be elucidated. Results Data from right heart catheterization, thermo-dye dilution
catheter, gastric tonometry, as well as organ function and
coagulation were obtained at baseline and after 2 and 4 hours. Terlipressin (with and without dobutamine) infusion preserved the
mean arterial pressure at threshold values of 70 ± 5 mmHg, while
allowing one to reduce norepinephrine doses to 0.18 ± 0.04 and
0.2 ± 0.05 µg/kg/min, respectively (vs 1.4 ± 0.07 µg/kg/min in
controls at 4 hours; each P < 0.01). The terlipressin-linked
decrease in mixed-venous oxygen saturation was reversed by
dobutamine (at 4 hours: 59 ± 2 vs 69 ± 3%, P = 0.023). No
statistically significant differences were found intra-group and
between groups in terms of differences between gastric mucosal
and arterial carbon dioxide partial pressure, blood clearance of
indocyanine green, as well as the plasma disappearance rate of
indocyanine green P32 Serum vasopressin concentrations in critically ill patients
in the intensive care unit Serum vasopressin concentrations in critically ill patients
in the intensive care unit Vasopressin substitution causes microcirculatory changes
in patients with septic shock Vasopressin substitution causes microcirculatory changes
in patients with septic shock S Klinzing, C Reinhard, T Simon, T Schürholz, Y Sakr,
K Reinhart, G Marx
Friedrich Schiller Universität, Jena, Germany
Critical Care 2007, 11(Suppl 2):P34 (doi: 10.1186/cc5194) Results Vasopressin serum concentrations at 24 hours after
admission were 32,618 ± 20,570 pmol/l. Vasopressin serum
concentrations in critically ill patients were significantly higher than
in the healthy control group (11,302 ± 31,002, P < 0.001). Serum
vasopressin concentrations on admission compared with vaso-
pressin concentrations at discharge were statistically significantly
increased (P < 0.001). Introduction We tested the effects of arginine vasopressin on
tissue oxygenation, microvascular reactivity and oral mucosa
microcirculation in patients with septic shock. Conclusions Serum vasopressin concentrations in critically ill
patients in a mixed ICU are increased 24 hours after admission
compared with the control group. The value at discharge is lower Methods In 20 patients with septic shock, tissue microcirculation
was determined before treatment with AVP (2 IU/hour), after
2 hours of treatment and 2 hours after treatment. S13 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Table 1 (abstract P34)
Base level
2 hours AVP
2 hours after AVP
P value step 1
P value step 2
SO2 1 mm (%)
79; 40–99
72.5; 59–88
83; 45–93
<0.05
<0.05
SO2 4 mm (%)
79; 48–97
68; 50–93
81; 24–99
<0.05
<0.01
Flow 1 mm
56; 11–390
33; 10–212
39; 10–249
<0.01
<0.01
Flow 4 mm
332.5; 149–517
280; 119–511
331; 150–581
<0.05
<0.05
Velocity 1 mm
22.5; 12–45
17.5; 11–33
20; 11–33
<0.01
<0.05 The thenar muscle StO2
was measured by near-infrared
spectroscopy (InSpectra; Hutchinson Technology, Hutchinson,
MN, USA). Oral mucosal tissue oxygen saturation, microcirculatory
blood flow and blood flow velocity were measured in depths of 1
and 4 mm with a laser Doppler flowmetry and remission
spectroscopy system (O2C). Methods Sixteen ewes were chronically instrumented to determine
the hemodynamics of the systemic and pulmonary circulation. After
16 hours of endotoxin infusion, all sheep exhibited a hypotensive–
hyperdynamic circulation. Thereafter, the animals were randomized
to be treated with either a continuous (2 mg over 24 hours) or
bolus infusion (1 mg every 6 hours) of terlipressin. y y
2
Results See Table 1. Rebound hypotension following terlipressin bolus infusion
can be prevented by continuous low-dose infusion of
terlipressin Rebound hypotension following terlipressin bolus infusion
can be prevented by continuous low-dose infusion of
terlipressin Vasopressin substitution causes microcirculatory changes
in patients with septic shock Vasopressin infusion led to a significant
decrease of oral mucosal oxygen saturation and blood flow, and a
significant decrease of flow velocity in a depth of 1 mm. Changes
in thenar tissue perfusion were not detectable. Results Continuous infusion of terlipressin reversed the endotoxin-
induced decrease in MAP during the entire 24-hour study period
(P < 0.001). Intermittent bolus injections of terlipressin contributed
to overshooting increases in MAP, as well as in systemic and
pulmonary vascular resistance index (each P < 0.001), which were
followed by sudden and strong rebound effects (Figure 1). Conclusion Vasopressin causes a deterioration of oral mucosal
blood flow but not in thenar tissue perfusion. Conclusion A goal-directed continuous infusion of terlipressin may
be superior to terlipressin bolus injection to treat patients with
sepsis-related arterial hypotension. Apparent heterogenity in splanchnic vascular response to
norepinephrine during sepsis M Lange1, K Bröking1, C Ertmer1, D Traber2, C Hucklenbruch1,
H Van Aken1, M Westphal1
1University of Münster, Germany; 2The University of Texas Medical
Branch, Galveston, TZ, USA
Critical Care 2007, 11(Suppl 2):P35 (doi: 10.1186/cc5195) J Gorrasi1, V Krejci2, L Hiltebrand2, S Brand2, H Bracht1,
B Balsiger3, J Takala1, S Jakob1
1Department of Intensive Care Medicine, 2Department of
Anesthesia and 3Departament of Gastroenterology, University
Hospital Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P36 (doi: 10.1186/cc5196) Introduction Bolus infusion of terlipressin, a vasopressin analog,
increases the mean arterial pressure (MAP) in patients with sepsis-
related arterial hypotension. However, bolus infusion of terlipressin
may be associated with severe side effects like excessive systemic
and pulmonary vasoconstriction. We hypothesized that continuous
low-dose infusion of terlipressin may reverse arterial hypotension
with reduced side effects. Introduction Sepsis alters vascular reactivity. We studied the
impact of peritonitis and endotoxemia on hepatic and superior
mesenteric arterial contractility. Materials and methods We studied fecal peritonitis (P, n = 7),
endotoxin-infusion (E, n = 8) and control (C, n = 6) for 24 hours
after abdominal surgery and eight control pigs without surgery
(SPA). Systemic and regional hemodynamics and ex-vivo
splanchnic vascular reactivity to norepinephrine (NE; tissue bath)
were measured and cumulative dose–response curves to NE were
constructed. Tension was expressed in grams. Figure 1 (abstract P35) Figure 1 (abstract P35) Figure 1 (abstract P35) Figure 1 (abstract P35)
Mean arterial pressure (MAP) during continuous and intermittent bolus
infusion of terlipressin in endotexemic ewes. g
Results CO increased (P < 0.05) in P and E. SMA flow (median
(range)) decreased in C from 24 (15–30) to 15 (11–21) ml/kg/min
(P = 0.022) (Table 1). Table 1 (abstract P36)
N of arterial rings
SMA (g)
HA (g)
C (17)
3 (2–4)
2 (1–3)
P (21)
3 (2–4)
3 (2–4)
E (17)
1 (0.3–2)*;‡
2 (1–3)
SPA (18)
10 (8–16)**,†
8 (7–10)**,†
Data presented as median (range). *P = 0.002 E vs P and C; **P < 0.01 vs
C, P, and E; †P < 0.001 vs C, E and P; ‡P = 0.008 vs C. Effect of norepinephrine on cardiac output and preload in
septic shock patients Effect of norepinephrine on cardiac output and preload in
septic shock patients Methods With ethics committee approval, 10 male Sprague–
Dawley rats were studied. Anesthesia was induced with alfaxalone
and maintained with isofluorane. Mechanical ventilation was
performed via tracheostomy. All rats received 0.9% NaCl 3 ml/hour
via a carotid line. Immediately after baseline assessment (T = 0),
rats received 1 ml/kg i.v. infusion over 30 minutes (study group
(n = 5), endotoxin 10 mg/ml (Escherichia coli O55:B5; Sigma,
MO, USA); control group, 0.9% NaCl). Echocardiography was
performed (15 MHz transducer, Vivid5; GE Healthcare) at T = 0,
60 minutes (T = 60) and 2.5 hours (T = 150). Measurements
included the heart rate, mean arterial pressure (MAP), femoral
venous pressure, LV outflow tract diameter and flow (peak velocity
(Vpeak), cardiac output (CO)), peak early diastolic mitral inflow (E),
peak systolic mitral annulus velocity (S′) and E′. O Hamzaoui, H Ksouri, C Richard, J Teboul
Bicetre Hospital, Le Krêmlin Bicetre, France
Critical Care 2007, 11(Suppl 2):P37 (doi: 10.1186/cc5197) Introduction Norepinephrine (NE) is a first-line vasopressor used
in patients with septic shock. Because of its predominant α-
agonist effect, it is assumed to increase vasomotor tone and hence
the mean arterial pressure (MAP) without significant effect on the
cardiac index (CI). However, a potential beneficial effect on CI can
be expected from its venoconstrictor α-agonist-mediated effect
combined with an inotropic β1 agonist effect, provided that the
increase in left ventricular afterload is not excessive (high levels of
MAP). The aim of our study was to examine the cardiovascular
effect of NE when it induces marked changes in MAP. Results There was no significant difference in mean ± SD weight
(study 539 ± 88 g, control 504 ± 108 g, P = 0.6) or hemodynamic
variables at T = 0. At T = 60, only Vpeak was higher in the study
group compared with controls (1.29 ± 0.24 vs 0.86 ± 0.21 m/s,
P = 0.03). The study group demonstrated lower MAP, E and E′ at
T = 150 (Table 1). Methods In an observational study of patients (n = 37) resuscitated
for septic shock, we analysed hemodynamic PiCCO data at two
consecutive time points where the MAP changed by more than
15% in response to either initiation or to change of doses of NE. Two subgroups of patients were identified. P39 Hemodynamic and cardiac peptide in septic myocardial
depression: the effects of calcium sensitizer Hemodynamic and cardiac peptide in septic myocardial
depression: the effects of calcium sensitizer C Cariello, F Guarracino, L Giannecchini, P Giomi, S Lorenzini
University Hospital, Pisa, Italy
Critical Care 2007, 11(Suppl 2):P39 (doi: 10.1186/cc5199) Introduction The aim of this retrospective study is to evaluate
hemodynamic and neurohormonal effects of levosimendan in
cardiac patients with sepsis-induced cardiac dysfunction. Septic
shock is characterized by profound cardiovascular alterations
including myocardial depression. Levosimendan has recently been
shown to improve cardiac function in septic shock. Conclusion In our septic shock patients, changes in MAP resulting
from increases or decreases in the doses of NE, were associated
with changes in CI related to changes in GEDVi (cardiac preload)
and in some patients to changes in systolic left ventricular function
evaluated by GEF. These findings suggest that administration of
NE in septic shock is associated not only with an increase in MAP
but also with an increase in systemic blood flow. Methods Fifteen patients with myocardial depression related to
septic shock were enrolled. All patients had SIRS criteria, culture
isolation of one or more pathogens, positive procalcitonin, SBP
< 90 mmHg unresponsive to load challenge. We defined myo-
cardial depression as a reduced SvO2 in the presence of increased
brain natriuretic peptide secretion and Troponin I release, and
systolic and/or diastolic dysfunction by transoesophageal echo
evaluation of ejection fraction and mitral annulus tissue Doppler
imaging velocities. All patients received levosimendan infusion for
24 hours at 0.1 µg/kg/min combined with norepinephrine. Effect of norepinephrine on cardiac output and preload in
septic shock patients The first subgroup
(MAPincr) consisted of 21 patients in whom the MAP increased by
more than 15% in response to either initiation of NE infusion
(n = 8) or increase in NE dose (from 1.7 ± 1.7 to 2.2 ± 1.4 mg/hour;
n = 13). The second subgroup (MAPdecr) consisted of 16 patients
in whom the MAP decreased by more than 15% in response to the
decrease in NE doses. For both subgroups, the time between the
two consecutive sets of measurements did not exceed 2 hours and
no other treatments that may alter hemodynamics were adminis-
tered within this period (fluids, hemofiltration, diuretics or other
catecholamines). Table 1 (abstract P38)
Control
Study
P
MAP (mmHg)
118 ± 21
75 ± 35
0.05
CO (l/min)
0.156 ± 0.02
0.181 ± 0.07
0.5
E (m/s)
1.02 ± 0.2
0.76 ± 0.11
0.04
E′ (m/s)
0.095 ± 0.02
0.061 ± 0.02
0.03 Conclusion In this model, endotoxemia was associated with a
decrease in E and E′. This decrease in E′ suggests a decreased
rate of myocardial relaxation. This has not previously been reported. Results In the MAPincr subgroup, MAP increased from 56 ± 17 to
84 ± 12 mmHg (P < 0.05) while significant increases in CI (from
3.4 ± 1.0 to 3.7 ± 0.9 l/min/m2), stroke volume index (SVi) (from
37 ± 12 to 41 ± 11 ml/m2) and global end diastolic volume index
(GEDVi) (from 706 ± 203 to 767 ± 225 ml/m2) were observed. Neither the heart rate nor the global ejection fraction (GEF) signifi-
cantly changed. In seven patients, the GEF markedly increased by
>15% in parallel to the increase in SVi. In the MAPdecr subgroup,
MAP decreased from 95 ± 12 to 70 ± 9 mmHg (P < 0.05). The CI
(from 3.5 ± 1.4 to 3.0 ± 0.9 l/min/m2) and GEDVi (from 815 ± 319
to 721 ± 253 ml/m2) decreased significantly, while the heart rate,
SVi (P = 0.07) and GEF did not change. Table 1 (abstract P36) Mean arterial pressure (MAP) during continuous and intermittent bolus
infusion of terlipressin in endotexemic ewes. Conclusions
The splanchnic vascular response to NE is
heterogenous in sepsis, and SMA is most affected. This may
modify blood flow distribution if high NE doses are used. S14 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P37 endotoxemia. This study sought to determine the effect of
endotoxemia upon TDI variables. P42 A network system for the treatment of pediatric septic shock
M Sasse1, M Kirschstein2, H Köditz1, K Seidemann1, A Wessel1
1Medical University Children’s Hospital, Hannover, Germany;
2Children Hospital AKH Celle, Germany
Critical Care 2007, 11(Suppl 2):P42 (doi: 10.1186/cc5202) M Sasse1, M Kirschstein2, H Köditz1, K Seidemann1, A Wessel1
1Medical University Children’s Hospital, Hannover, Germany;
2Children Hospital AKH Celle, Germany
Critical Care 2007, 11(Suppl 2):P42 (doi: 10.1186/cc5202) Introduction We show the effect of a network system in the
treatment of pediatric septic shock, especially for children with
Waterhouse–Friderichsen syndrome. In 2003 we founded a
pediatric intensive care network with 15 children’s hospitals in
Lower Saxony, Germany. The aims were the standardisation of
clinical therapies, implementation of training programs and the
installation of an emergency system in the region of lower Saxony. Introduction We show the effect of a network system in the
treatment of pediatric septic shock, especially for children with
Waterhouse–Friderichsen syndrome. In 2003 we founded a
pediatric intensive care network with 15 children’s hospitals in
Lower Saxony, Germany. The aims were the standardisation of
clinical therapies, implementation of training programs and the
installation of an emergency system in the region of lower Saxony. Methods The first standard was implemented for the treatment of
the Waterhouse–Friderichsen syndrome. At first, we started with
the educational program. The program included different central
symposia about septic shock in children. The second step was the
standardisation of the diagnosis and the therapy, including the
administration of human protein C concentrate (PC), and the
clinical pathways. We implemented a round-the-clock emergency
system with the possibility for transportation of critically ill patients,
permanent consultation of the tertiary medical center and onsite
treatment through the tertiary center staff if the patient could not be
transferred. All patients were announced to the tertiary medical Results Spontaneous oxidative burst activity in group H increased
significantly from baseline (30.19 ± 4.79) to H (57.45 ± 9.86) and
60H (56.26 ± 14.64) (P < 0.01) while the control group did not
present significant variation. Between groups there were
significant differences at H (ANH = 57.45 ± 9.86; control =
23.18 ± 7.16; P = 0.0007), 60H (ANH = 56.26 ± 14.64; control =
34.53 ± 9.06; P = 0.0225), 120H (ANH = 43.59 ± 5.46; control =
28.65 ± 10.44; P = 0.0220) and 60BI (ANH = 38.60 ± 1.85;
control = 25.59 ± 8.12; P = 0.0082). Table 1 (abstract P41) Introduction In recent years there has been increasing evidence
that a resuscitation strategy with different fluids can have widely
divergent impacts on the immune response, neutrophil activation
and tissue injury. This prospective study was undertaken to
determine the neutrophil oxidative burst in the swine model during
an acute normovolemic hemodilution (ANH) procedure with
hydroxyethyl starch. Methods
Twelve pigs were anesthetized, instrumented and
randomized into two groups: control and hemodilution (H). The
control group was only anesthetized and instrumented while
animals in the ANH group were submitted to acute normovolemic
hemodilution to a target hematocrit of 15% with volume
replacement performed with hydroxyethyl starch 130/0.4 at a 1:1
ratio. The withdrawn blood was returned to the animals
120 minutes after the end of hemodilution. Neutrophil oxidative
burst was performed with blood samples collected at the femoral
vein at the following time points: before ANH (baseline), after
instrumentation (INST), immediately after ANH (H), 60 minutes
after ANH (60H), 120 minutes after ANH (120H), 60 minutes after
blood infusion (60BI) and 120 minutes after blood infusion
(120BI), and determined with a flow cytometer. Spontaneous and
stimulated oxidative burst activation of neutrophils were performed
with dichlorofluorescein diacetate and phorbol myristate acetate. Statistical analyses were performed using one-way analysis of
variance followed by a Dunnett test or t test. A P value of 0.05 was
considered statistically significant. Tissue Doppler imaging suggests an association between
endotoxemia and impaired myocardial relaxation D Sturgess, B Haluska, B Venkatesh
University of Queensland, Brisbane, Australia
Critical Care 2007, 11(Suppl 2):P38 (doi: 10.1186/cc5198) D Sturgess, B Haluska, B Venkatesh
University of Queensland, Brisbane, Australia
Critical Care 2007, 11(Suppl 2):P38 (doi: 10.1186/cc5198) Results Data were obtained by evaluating the average of the
percentage variation between T0
(starting infusion) and T1
(24 hours after infusion), T2
(48 hours), T3
(72 hours), T4
(96 hours), T5 (120 hours) and T6 (144 hours). Levosimendan
significantly increased SvO2 and ejection fraction, and decreased Introduction Tissue Doppler imaging (TDI) is a novel technique
that measures myocardial velocity. The peak early diastolic mitral
annulus velocity (E′) offers a relatively preload-insensitive measure
of LV relaxation. There are scant data regarding its use in sepsis or Introduction Tissue Doppler imaging (TDI) is a novel technique
that measures myocardial velocity. The peak early diastolic mitral
annulus velocity (E′) offers a relatively preload-insensitive measure
of LV relaxation. There are scant data regarding its use in sepsis or S15 Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Troponin I and brain natriuretic peptide. Levosimendan improved
diastolic function by increasing the E′ velocity at tissue Doppler
imaging at 48 hours. All data were analysed by the Fisher F test. Troponin I and brain natriuretic peptide. Levosimendan improved
diastolic function by increasing the E′ velocity at tissue Doppler
imaging at 48 hours. All data were analysed by the Fisher F test. P41 P40 P40
Neutrophil oxidative burst evaluation during acute
normovolemic hemodilution: preliminary results
M Kahvegian, D Tabacchi Fantoni, DA Otsuki, C Holms,
C Oliveira Massoco, J Costa Auler Jr
University of São Paulo Medical School, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P40 (doi: 10.1186/cc5200) Neutrophil oxidative burst evaluation during acute
normovolemic hemodilution: preliminary results Table 1 (abstract P41)
IL-12 (pg/ml)
TSH (mIU/l)
fT3 (pg/ml)
fT4 (ng/dl)
Control group
4.8 ± 2.1
2.25 ± 2.1
2.93 ± 0.5
1.18 ± 0.14
Septic patients
19.05 ± 10.7
1.173 ± 1.85
1.56 ± 0.6
1.06 ± 0.3
P
<0.001
0.001
<0.001
0.118
Conclusion According to our findings, IL-12 has a role in HPT
dysfunction in most critically ill patients. Relationship of IL-12 and thyroid indices in sepsis Relationship of IL-12 and thyroid indices in sepsis E Karakoc, I Karayaylali, T Sunbul
Cukurova University, Adana, Turkey
Critical Care 2007, 11(Suppl 2):P41 (doi: 10.1186/cc5201) Table 1 (abstract P39)
T0
T1
T2
T3
T4
T5
T6
SvO2 (%)
0
4
10
17
22
19
22
Trop I (ng/ml)
0
–65
–86
–82
–78
–62
–62
BNP (%)
0
–45
–41
–56
–50
–42
–44
E′ (cm/s)
<8
>8
>8
>8
>8
>8
>8
EF (%)
<30
>40
>40
>40
>40
>40
>40
Conclusions
Levosimendan
seems
to
improve
systemic
hemodynamics and neurohormonal cardiac function in patients
with septic cardiac dysfunction. Introduction Sickeuthroid syndrome is very frequent in critically ill
patients. Cytokines may have a role in this syndrome. IL-12 is
involved in the central regulation of the hypothalamic–pituitary–
thyroid (HPT) axis during illness. The aim of this study is to evaluate
the relationship of IL-12 and thyroid functions in septic patients. Introduction Sickeuthroid syndrome is very frequent in critically ill
patients. Cytokines may have a role in this syndrome. IL-12 is
involved in the central regulation of the hypothalamic–pituitary–
thyroid (HPT) axis during illness. The aim of this study is to evaluate
the relationship of IL-12 and thyroid functions in septic patients. Materials and methods Twenty-four septic patients and 18
healthy controls were enrolled into the study with the mean ages of
49.9 ± 20.6 and 45.8 ± 22.3 years, respectively. Hyperthyroid and
hypothyroid patients were excluded. Free triiodothyronine (fT3),
free thyroxine (fT4) and TSH were measured simultaneously with
IL-12. Materials and methods Twenty-four septic patients and 18
healthy controls were enrolled into the study with the mean ages of
49.9 ± 20.6 and 45.8 ± 22.3 years, respectively. Hyperthyroid and
hypothyroid patients were excluded. Free triiodothyronine (fT3),
free thyroxine (fT4) and TSH were measured simultaneously with
IL-12. Results The mean IL-12, fT3, fT4 and TSH values of septic
patients and the control group are presented in Table 1. IL-12 was
significantly higher in septic patients (19.05 ± 10.7 pg/ml vs
4.8 ± 2.0 pg/ml, P < 0.005). fT3 and TSH values were significantly
low in septic patients. There was a significantly strong correlation
between IL-12 and fT4 in septic patients but not fT3 and TSH
(r = 0.88, P = 000). There was no correlation between IL-12 and
other thyroid indices in the control group. P44
Optimization of antibacterial treatment in pediatric
intensive care units using procalcitonin center directly after admission into the network hospitals. The final
step was the presentation of the project in the different hospitals. Results We treated 10 children with Waterhouse–Friderichsen
syndrome in the network. Three of them were attended on site and
seven were transferred in the tertiary center. The announcement
time in eight cases was 15 minutes–1 hour. Primarily, a
consultation was accomplishing routinely. The transportation team
of the tertiary center continued the treatment on site and
afterwards in the center. All patients showed typical signs of
Waterhouse–Friderichsen syndrome with purpura fulminans and
severe multiorgan failure. No patient died and only one patient had
necrosis of the skin, which existed already at admission. The others
had a restitution ad integrum. No adverse effects were observed
with the PC concentrate administration. center directly after admission into the network hospitals. The final
step was the presentation of the project in the different hospitals. Results We treated 10 children with Waterhouse–Friderichsen
syndrome in the network. Three of them were attended on site and
seven were transferred in the tertiary center. The announcement
time in eight cases was 15 minutes–1 hour. Primarily, a
consultation was accomplishing routinely. The transportation team
of the tertiary center continued the treatment on site and
afterwards in the center. All patients showed typical signs of
Waterhouse–Friderichsen syndrome with purpura fulminans and
severe multiorgan failure. No patient died and only one patient had
necrosis of the skin, which existed already at admission. The others
had a restitution ad integrum. No adverse effects were observed
with the PC concentrate administration. N Beloborodova1, D Popov1, M Traube2, E Ochakovskaya1,
E Chernevskaya1
1Bakoulev Scientific Center for Cardiovascular Surgery, Moscow,
Russian Federation; 2Filatov Children’s Hospital, Moscow, Russia
Federation
Critical Care 2007, 11(Suppl 2):P44 (doi: 10.1186/cc5204) Introduction Neonates and infants in the ICU are at high risk of
severe infections and sepsis. Often it is not easy to diagnose
sepsis based only on clinical findings; reliable biomarkers are
needed to prove the diagnosis. Conclusions The network system and the standard treatment with
PC worked without severe problems. The survival rate and the
outcome in our small study group were excellent. Our experience
allows us to enlarge the system on other diseases. Objective To study the value of procalcitonin (PCT) as a marker,
verifying the diagnosis, which enables the start of de-escalating
ABT in patients with clinical signs of sepsis. Intensive care unit outcome versus haemodynamic status
on arrival at a general intensive care unit Intensive care unit outcome versus haemodynamic status
on arrival at a general intensive care unit T Reynolds, A Theodoraki, I Ketchley, A Tillyard, R Lawson,
N Al-Subaie, M Cecconi, R Grounds, A Rhodes
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P43 (doi: 10.1186/cc5203) Introduction Goal-directed therapeutic protocols such as that
described by Rivers and colleagues [1] have taken an important
place in efforts to increase survival in septic patients. We looked at
ICU outcomes for patients meeting the haemodynamic criteria of
the Rivers trial on admission to our general ICU. Results Group A. Sepsis was diagnosed in 16/50 (32%) patients. PCT > 2 ng/ml was observed in 23/50 (46%) cases, including
15/16 (94%) patients with clinically diagnosed sepsis. In patients
with PCT > 2 ng/ml the mortality rate was 7.7% if carbapenems
(meropenem or imipenem/cilastatin) were administered (n = 13),
compared with 20% with different ABT (n = 10) – although in
patients with PCT < 2 ng/ml (n = 27), ABT with carbapenems
(n = 12) resulted in paradoxically higher mortality compared with
other ABT schemes (n = 15): 17% vs 6.6%. Group B. Sepsis was
defined in 24/324 (7.4%) patients. PCT > 2 ng/ml was in 53/324
(16%) cases, including all patients with clinically diagnosed sepsis. Early ABT with meropenem, combined with vancomycin or
linezolid, allowed one to decrease sepsis-related mortality in these
patients to 29%, which used to be as high as 74% before the
introduction of this algorithm (P = 0.0028). Methods We prospectively recorded haemodynamic parameters
of 98 consecutive patients admitted to a mixed medical/surgical
ICU and compared these with the ICU outcome. Patients who met
systemic inflammatory response syndrome (SIRS) criteria [2] and
had lactate ≥4 mmol/l or systolic blood pressure ≤90 mmHg met
the Rivers criteria. Results We included 98 patients admitted to the ICU (60 males)
of mean age 61 ± 17 years. Fourteen patients (14%) died in the
ICU, and the median length of stay was 3 (IQR 3) days. Overall 16
of the 98 patients met the Rivers criteria, four of whom died (25%). The median length of ICU stay for the Rivers patients was 5 (1.25)
days (see Table 1). Conclusions Sixteen out of 98 patients (16%) met Rivers criteria. Of medical and surgical emergency patients, this proportion rose
to 16 of 55 patients (29%). P42 Methods The first standard was implemented for the treatment of
the Waterhouse–Friderichsen syndrome. At first, we started with
the educational program. The program included different central
symposia about septic shock in children. The second step was the
standardisation of the diagnosis and the therapy, including the
administration of human protein C concentrate (PC), and the
clinical pathways. We implemented a round-the-clock emergency
system with the possibility for transportation of critically ill patients,
permanent consultation of the tertiary medical center and onsite
treatment through the tertiary center staff if the patient could not be
transferred. All patients were announced to the tertiary medical Conclusion ANH with hydroxyethyl starch influences oxidative
burst activity under experimental conditions. S16 Available online http://ccforum.com/supplements/11/S2 P44
Optimization of antibacterial treatment in pediatric
intensive care units using procalcitonin Methods Three hundred and seventy-four patients on artificial lung
ventilation from two pediatric ICUs of two Russian hospitals were
enrolled. Blood samples for PCT testing (PCT LIA; BRAHMS AG,
Germany) were taken under suspicion of sepsis or exacerbation of
bacterial infection. In the first stage (January–December 2005), 50
neonates (age 6 (4–12) days) with various perinatal pathologies
were studied (Group A), and routine ABT was prescribed, with
blood samples taken and stored for further PCT assessment. In the
second stage (January–November 2006), 324 infants (age 6
(1.5–9.4) months) after cardiac surgery were enrolled (Group B),
and ABT was adjusted based on PCT-testing results. PCT
> 2 ng/ml indicative of systemic bacterial inflammation in addition
to clinical signs of sepsis was an indication for ABT with
carbapenems. Data are shown as the median and interquartile
range. P45 approximately equivalent to an endotoxin concentration of
25–50 pg/ml, and a level of 0.6 is approximately equivalent to a LPS
concentration of 100–200 pg/ml. Data were analysed according to
EA ranges: low (EA < 0.4), intermediate (0.4 ≤EA < 0.6), and high
(EA ≥0.6). Differences between ranges of EA were assessed by
analysis of variance (Sigma Stat, SPSS), accepting P < 0.05 as
significant. Data are expressed as the mean ± SD. M Assuncao1, F Machado1, N Akamine2, G Cardoso1, P Mello3,
J Telles4, A Nunes5, M Oliveira6, A Rea-Neto7, R Clleva8, F Dias9
1Universidade Federal de Sao Paulo, Brazil; 2Latin American
Sepsis Institute, Sao Paulo, Brazil; 3Universidade Estadual do
Piaui, Teresina, Brazil; 4Hospital Portugues, Salvador, Brazil;
5Hospital Sao Camilo, Sao Paulo, Brazil; 6Hospital Santa Luzia,
Brasilia, Brazil; 7Universidade Federal do Parana, Curitiba, Brazil;
8Faculdade de Medicina da USP, Sao Paulo, Brazil; 9Hospital Sao
Lucas – PUC-RS, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P45 (doi: 10.1186/cc5205) M Assuncao1, F Machado1, N Akamine2, G Cardoso1, P Mello3,
J Telles4, A Nunes5, M Oliveira6, A Rea-Neto7, R Clleva8, F Dias9
1Universidade Federal de Sao Paulo, Brazil; 2Latin American
Sepsis Institute, Sao Paulo, Brazil; 3Universidade Estadual do
Piaui, Teresina, Brazil; 4Hospital Portugues, Salvador, Brazil;
5Hospital Sao Camilo, Sao Paulo, Brazil; 6Hospital Santa Luzia,
Brasilia, Brazil; 7Universidade Federal do Parana, Curitiba, Brazil;
8Faculdade de Medicina da USP, Sao Paulo, Brazil; 9Hospital Sao
Lucas – PUC-RS, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P45 (doi: 10.1186/cc5205) Results In our case mix, patients were 68 (65%) in the low group,
17 (17%) in the intermediate group and 19 (18%) in the high
group. Age (61 ± 17 years) was not significantly different in the
three groups (P = 0.493). Functional and severity scores were not
significantly different between groups. Average values were as
follows: WBC 11,093 ± 4605 n/mm3 (P = 0.385), HR 76 ± 16 bpm
(P = 0.898),
MAP
88.8 ± 13.6 mmHg
(P = 0.576),
lactate
1.18 ± 0.77 mmol/l (P = 0.370), PaO2/FiO2 383 ± 109 mmHg
(P = 0.474), APACHE II score 8.3 ± 3.7 (P = 0.542) and SOFA
score 1.5 ± 1.4 (P = 0.245). Interestingly, those patients with
higher levels of EA were characterized by longer length of stay in
the ICU. P45 The ICU length of stay was 1.9 ± 3.1 days in the low
group, 8.7 ± 6.7 days in the intermediate group and 4.7 ± 7.7 days
in the high group (P = 0.038). Introduction The aim of this study was evaluation of physicians’
knowledge about SIRS, sepsis, severe sepsis and septic shock. Methods A multicenter study in 21 ICUs in seven university, five
public and seven private hospitals. A questionnaire with five clinical
cases was first validated by five critical care boarded intensivists
(INT) with 100% agreement. All interviewed physicians (Phys)
received each question separately, in a predefined sequence, and
no answer could be reviewed. After answering, the questionnaire
was put in a sealed envelope with no identification. Statistical
analysis was performed: chi-square, Kruskall–Wallis and linear
correlation tests. P < 0.05 was considered statistically significant. Results A total of 917 Phys (mean age 32.7 ± 7.21 years, 61.9%
males, 38.1% females) were enrolled with 20.0% (n = 55) INT and
80.0% (n = 220) of nonintensivists (non-INT). Phys correctly
recognized SIRS, infection, and septic shock in 80.4%, 92.4% and
85.1% of the cases, respectively. The lowest rate of recognition
was observed in sepsis and severe sepsis cases (26.5% and
55.6%). Considering all questions, the overall percentage of
correct answers was 68.1 ± 21.1%. INT performed better than
non-INT (84.7 ± 17.2% and 64.0 ± 20.0%, P < 0.00001). Phys
working at public and university hospitals performed better
(70.2 ± 18.7% and 71.2 ± 19.5%) than those in private hospitals
(59.7 ± 23.4%, P = 0.001). Introduction The aim of this study was evaluation of physicians’
knowledge about SIRS, sepsis, severe sepsis and septic shock. Methods A multicenter study in 21 ICUs in seven university, five
public and seven private hospitals. A questionnaire with five clinical
cases was first validated by five critical care boarded intensivists
(INT) with 100% agreement. All interviewed physicians (Phys)
received each question separately, in a predefined sequence, and
no answer could be reviewed. After answering, the questionnaire
was put in a sealed envelope with no identification. Statistical
analysis was performed: chi-square, Kruskall–Wallis and linear
correlation tests P < 0 05 was considered statistically significant Conclusions A rather high number of patients admitted to the ICU
following elective surgery are characterized by intermediate-high
levels of endotoxemia, as assessed by the EA assay, despite their
relative low level of complexity on admission. Reference 1. Romaschin AD, et al.: J Immunol Methods 1998, 212:169-
185. 1. Romaschin AD, et al.: J Immunol Methods 1998, 212:169-
185. Intensive care unit outcome versus haemodynamic status
on arrival at a general intensive care unit Conclusion Early verification of sepsis using PCT combined with
carbapenems-based ABT enables decreasing sepsis-related
mortality in critically ill infants and newborns staying in the ICU. 1. Rivers E, et al.: N Engl J Med 2001, 345:1368-1377. 2. Levy M, et al.: Crit Care Med 2003, 31:1250-1256. 1. Rivers E, et al.: N Engl J Med 2001, 345:1368-1377. 2
L
M
l C i C
M d 2003 31 1250 1256 S
Table 1 (abstract P43)
Patients
Patients reaching Rivers criteria
Mortality
Median length of stay
Mortality
Median length of stay
n
(n (%))
(days)
n
(n (%))
(days)
Total
98
14 (14%)
3 (IQR 3)
16
4 (25%)
5 (IQR 1.25)
Medical
33
9 (27%)
5 (IQR 2)
11
3 (27%)
5 (IQR 1.5)
Elective surgical
43
1 (2%)
2 (IQR 1)
0
Emergency surgical
22
4 (18%)
3 (IQR 4.5)
5
1 (20%)
5 (IQR 1) Table 1 (abstract P43) Table 1 (abstract P43) S17 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin sTREM-1 is not suitable to discriminate survivors and
nonsurvivors in surgical patients with severe sepsis or
septic shock sTREM-1 is not suitable to discriminate survivors and
nonsurvivors in surgical patients with severe sepsis or
septic shock C Bopp1, S Hofer1, P Kienle1, S Meyer1, E Martin1, A Bouchon2,
M Buechler1, M Weigand1
1University of Heidelberg, Germany; 2Bayer CropScience,
Monheim, Germany
Critical Care 2007, 11(Suppl 2):P47 (doi: 10.1186/cc5207) Conclusion The recognition of sepsis and its severity are not
satisfactory, mostly among non-INT and those working at private
hospitals. Possibly, reviewing sepsis-related and organ dysfunction
concepts are necessary for early identification of septic patients. Objectives To evaluate in septic patients the plasma levels of
sTREM-1, a soluble form of TREM-1, which seems to play an
important role in inflammatory diseases, and to determine whether
plasma sTREM-1 could be used as a diagnostic and prognostic
marker in sepsis in the surgical ICU. P45 High levels of EA
were associated with a longer length of stay. correlation tests. P < 0.05 was considered statistically significant. Results A total of 917 Phys (mean age 32.7 ± 7.21 years, 61.9%
males, 38.1% females) were enrolled with 20.0% (n = 55) INT and
80.0% (n = 220) of nonintensivists (non-INT). Phys correctly
recognized SIRS, infection, and septic shock in 80.4%, 92.4% and
85.1% of the cases, respectively. The lowest rate of recognition
was observed in sepsis and severe sepsis cases (26.5% and
55.6%). Considering all questions, the overall percentage of
correct answers was 68.1 ± 21.1%. INT performed better than
non-INT (84.7 ± 17.2% and 64.0 ± 20.0%, P < 0.00001). Phys
working at public and university hospitals performed better
(70.2 ± 18.7% and 71.2 ± 19.5%) than those in private hospitals
(59.7 ± 23.4%, P = 0.001). Reference Prevalence of endotoxemia in a population of patients
admitted to an intensive care unit after elective surgery Design An observational clinical study. Design An observational clinical study. F Valenza, L Fagnani, S Coppola, S Froio, C Tedesco,
C Marenghi, C Galbusera, P Caironi, L Gattinoni
Fondazione IRCCS Ospedale Maggiore Policlinico Mangiagalli
Regina Elena, Milano, Italy
Critical Care 2007, 11(Suppl 2):P46 (doi: 10.1186/cc5206) Valenza, L Fagnani, S Coppola, S Froio, C Tedesco, Setting The surgical ICU of the University Hospital of Heidelberg,
Germany. Setting The surgical ICU of the University Hospital of Heidelberg,
Germany. Patients Patients admitted to the ICU over a 6-month period with
clinical evidence of severe sepsis or septic shock. Patients Patients admitted to the ICU over a 6-month period with
clinical evidence of severe sepsis or septic shock. Can plasma-free DNA concentration be a diagnostic tool in
critically ill septic patients? Can plasma-free DNA concentration be a diagnostic tool in
critically ill septic patients? Introduction Inadequate tissue perfusion and an uncontrolled
systemic inflammatory response are associated with poor outcome
in critically ill surgical patients. An increased concentration of un-
measured anions, reflecting hypoperfusion, and the magnitude of
the early inflammatory response both correlate strongly with
mortality. Our aim was to assess the relationship between these
factors, and their ability in combination to predict outcome. Introduction Inadequate tissue perfusion and an uncontrolled
systemic inflammatory response are associated with poor outcome
in critically ill surgical patients. An increased concentration of un-
measured anions, reflecting hypoperfusion, and the magnitude of
the early inflammatory response both correlate strongly with
mortality. Our aim was to assess the relationship between these
factors, and their ability in combination to predict outcome. Methods In a prospective study we evaluated 108 consecutive
patients admitted to a surgical high dependency unit. Regional
Ethics Committee approval was obtained. Serum electrolytes,
albumin, phosphate, lactate and C-reactive protein (CRP) were
measured on admission and on day 1. We derived the calculated
ion gap (CIG) using a simplified modification of the Stewart–Figge
equations. B Orbey1, H Cuhruk1, M Tulunay1, M Oral2, N Unal1, H Ozdag3
1Ankara University Medical Faculty, Anesthesiology and ICM,
Ankara, Turkey; 2AÜTF, Anesthesiology and ICU, Ankara, Turkey;
3Ankara University, Biotechnology Institute, Ankara, Turkey
Critical Care 2007, 11(Suppl 2):P48 (doi: 10.1186/cc5208) Methods In a prospective study we evaluated 108 consecutive
patients admitted to a surgical high dependency unit. Regional
Ethics Committee approval was obtained. Serum electrolytes,
albumin, phosphate, lactate and C-reactive protein (CRP) were
measured on admission and on day 1. We derived the calculated
ion gap (CIG) using a simplified modification of the Stewart–Figge
equations. Recent evidence suggests that the plasma-free DNA concentration
has potential use as a prognostic marker in many clinical situations
including sepsis, trauma, and acute stroke [1]. However, its
predictive value is arguable. We hypothesized that plasma DNA is
increased in septic patients admitted to the ICU compared with
nonseptic ICU patients, and it is correlated with disease severity
and clinical outcome. Results Based on previous work, thresholds of 10 mmol/l for CIG
and 100 mg/l for CRP were used to categorise patients. Of the
patients with a CRP < 100 mg/l, 15.4% had an elevated CIG. Of
the patients with a CRP > 100 mg/l, 36.7% had an elevated CIG
(P = 0.016, chi-square test). Can plasma-free DNA concentration be a diagnostic tool in
critically ill septic patients? Patients (n = 63) with a CIG
< 10 mmol/l and CRP < 100 mg/l had a 1.5% mortality, whereas
those (n = 11) with a CIG > 10 mmol/l and CRP > 100 mg/l had a
54.5% mortality (P < 0.0001, chi-square test) (Table 1). Forty-two consecutive patients (11 septic, 31 nonseptic) admitted
to a mixed ICU and mechanically ventilated were recruited. Plasma-
free DNA concentration was measured by real-time PCR assay for
the β-globin gene, and the APACHE II score, SOFA score, serum
C-reactive protein (CRP) concentrations, procalcitonin (PCT)
concentrations, serum lipid concentrations, and clinical outcome
(ICU/hospital days and mortality) were assessed on admission to
the ICU. Assessments and samplings were repeated as the
diagnosis of the patients changed (sepsis, severe sepsis and
septic shock). Finally, 86 plasma samples were collected. Descrip-
tive statistics, Mann–Whitney U, Kruskall–Wallis and Spearman’s
tests, and receiver operating characteristic analysis were used
when appropriate. Table 1 (abstract P49)
CRP < 100 mg/l,
CRP > 100 mg/l,
CIG < 10 mmol/l
CIG > 10 mmol/l
Inhospital mortality
1.5% (n = 63)
54.5% (n = 11) Demographic data were similar. ICU and hospital mortalities were
26.2% and 33.3%, respectively. The mean DNA concentrations on
admission were significantly higher in ICU patients compared with
healthy subjects (n = 11) (13,405 GE/ml versus 390 GE/ml,
P < 0.05) and septic patients compared with nonseptic patients
(33,170 GE/ml versus 1,171 GE/ml, P < 0.001). Furthermore,
during the overall ICU stay, increased DNA concentration asso-
ciated with the increase of severity of illness was noted; however,
this increase was statistically significant only between septic and
septic shock samples (26,624 GE/ml versus 42,861 GE/ml,
P < 0.05). The area under the curve obtained for the plasma-free
DNA concentration in distinguishing between septic and nonseptic
patients on admission was 0.9 (sensitivity 84%, specificity, 95%;
cutoff 4,083 GE/ml). Also, the plasma-free DNA concentration was
found to be higher in patients who died in the ICU compared with
patients who survived, although not statistically significant. The
DNA concentration demonstrated a significant correlation with
CRP (P = 0.037, r = 0.365), PCT (P = 0.007, r = 0.457) and high-
density lipoprotein (P = 0.015, r = –0.415) concentrations. Conclusion Inflammation is a potent cause of oxidative stress,
which in turn results in endothelial damage and increased
concentrations of unmeasured anions. Interventions None. Measurements and results Sixty-six intensive care patients were
enrolled in the study within the first 24 hours after the onset of
severe sepsis or septic shock. Twenty-one healthy individuals
served as controls. At day 0, day 1 and day 3 after diagnosis of
severe sepsis or septic shock, plasma sTREM-1 was measured by
ELISA. Plasma sTREM-1 concentrations of healthy controls did not
differ from patients with severe sepsis or septic shock at day 0
(42.8 ± 44.9 pg/ml vs 40.8 ± 45.5 pg/ml, not significant), day 1
(42.8 ± 44.9 pg/ml vs 48.6 ± 57.2 pg/ml, not significant) nor at
day 3 (42.8 ± 44.9 pg/ml vs 51.9 ± 52.8 pg/ml, not significant). Survivors were defined as patients surviving to at least day 28. There were no differences of plasma sTREM-1 between survivors
and nonsurvivors at day 0, day 1 and day 3 (34.8 ± 44 52.4 pg/ml Introduction The aim of this study was to investigate the
prevalence of endotoxemia early after elective surgical procedures
in patients admitted to an ICU of a university hospital. Introduction The aim of this study was to investigate the
prevalence of endotoxemia early after elective surgical procedures
in patients admitted to an ICU of a university hospital. Methods One hundred and four nonselect patients were recruited. Patients were excluded if they were admitted during the weekend
or from another ICU and if they were on chronic dialysis. Within
4 hours of admission functional data were collected and severity
scores (APACHE, SOFA) calculated. Arterial blood samples were
also taken and processed according to Spectral Diagnostics’
endotoxin activity (EA) assay [1]. The method allows one to
express EA as a function of each patient’s neutrophil chemi-
luminescence activity (on a scale from 0 to 1). An EA level of 0.4 is S18 Available online http://ccforum.com/supplements/11/S2 1.
Rhodes A, et al.: Plasma DNA concentration as a predictor
of mortality and sepsis in critically ill patients. Crit Care
2006, 10:142. Can plasma-free DNA concentration be a diagnostic tool in
critically ill septic patients? The combination of CRP
and the CIG, as markers of inflammation and inadequate tissue
perfusion, respectively, is a powerful predictor of mortality in the
critically ill surgical patient. P49 vs 49.5 ± 35.9 pg/ml, 42.6 ± 61.1 pg/ml vs 59.6 ± 47.1 pg/ml,
and 47.9 ± 60.2 pg/ml vs 58.2 ± 37.1 pg/ml, not significant). Conclusion In this study including surgical patients with severe
sepsis or septic shock, plasma sTREM-1 is not elevated compared
with healthy controls. Furthermore, the measurement of plasma
sTREM-1 did not allow one to differ between survivors and
nonsurvivors. The suggested role of sTREM-1 as a diagnostic and
prognostic marker in sepsis was not confirmed in this study. vs 49.5 ± 35.9 pg/ml, 42.6 ± 61.1 pg/ml vs 59.6 ± 47.1 pg/ml,
and 47.9 ± 60.2 pg/ml vs 58.2 ± 37.1 pg/ml, not significant). Conclusion In this study including surgical patients with severe
sepsis or septic shock, plasma sTREM-1 is not elevated compared
with healthy controls. Furthermore, the measurement of plasma
sTREM-1 did not allow one to differ between survivors and
nonsurvivors. The suggested role of sTREM-1 as a diagnostic and
prognostic marker in sepsis was not confirmed in this study. Greater than the sum of its parts: C-reactive protein and
the calculated ion gap together are superior in predicting
mortality in critically ill surgical patients F Leitch1, E Dickson1, A McBain1, S Robertson2, D O’Reilly1,
C Imrie1
1Glasgow Royal Infirmary, Glasgow, UK; 2Johannesburg Hospital,
Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P49 (doi: 10.1186/cc5209) C-reactive protein predicts mortality on admission to a
surgical high-dependency unit Introduction C-reactive protein (CRP) is a non-specific marker that
may be used to assess the magnitude of the inflammatory response
in critically ill surgical patients. Our aim was to determine the
temporal relationship between CRP measurement and mortality. Methods In a prospective study conducted in a surgical high-
dependency unit (HDU), 132 consecutive patients were evaluated. Regional Ethics Committee approval was obtained. Serum CRP In conclusion, plasma DNA may be a potentially valuable tool to
confirm the diagnosis of sepsis on admission to the ICU and to
monitor disease severity. The biphasic aPTT waveform to diagnose sepsis in
patients with systemic inflammatory response syndrome The biphasic aPTT waveform to diagnose sepsis in
patients with systemic inflammatory response syndrome D Hagg, S Malkoski, C Phillips, D Nichols, D Jacoby
Oregon Health & Science University, Portland, OR, USA
Critical Care 2007, 11(Suppl 2):P51 (doi: 10.1186/cc5211) Results We included 65 patients. The total mortality rate was
16.9% (11 patients). Introduction We tested the ability of the biphasic aPTT waveform to
diagnosis sepsis in patients presenting to the Emergency Department
(ED) with the systemic inflammatory response syndrome (SIRS). The
biphasic aPTT waveform (BPW), which results from rapid complexing
of VLDL and C-reactive protein during aPTT testing, has
demonstrated promise as an early diagnostic test for sepsis. Table 1 (abstract P52)
n = 65
FPC
Lactate
P
Mortality (%)
Group I
30.9 ± 9
15.7 ± 5.8
<0.05
78
Group II
58.1 ± 13
1.8 ± 0.35
22
Group III
100.8 ± 12.8
1.3 ± 0.9
<0.05
0 Methods A prospective, observational study was designed in
which all patients presenting to the ED of an urban university
hospital were screened for SIRS. Patients with SIRS unrelated to
trauma or myocardial infarction were eligible. Plasma for BPW
testing was obtained at the time of enrollment and daily for 7 days
in admitted subjects. The primary outcome was a diagnosis of
sepsis related to the presence of a BPW at enrollment. Secondary
measures were mortality related to the BPW, correlation of any
positive BPW with sepsis, and of the BPW with statin therapy. Two criteria for a positive test, light transmittance at 18 seconds
(TL18) and the initial slope of the waveform (slope) are used. Two
independent experts made the final diagnosis. Conclusions We found a direct and a progressive relation with
statistical significance between the higher mortality rate and the
lower protein C values. The results could mean that the level of
protein C can be used as an evolution marker in septic patients. Functional protein C levels in septic patients E Lafuente, I Pratima, M Fernandes, J Gomes da Silva,
F Moura, F Santos, I Guimaraes, R Lopes, P Santos
Padre Americo, Penafiel, Portugal
Critical Care 2007, 11(Suppl 2):P52 (doi: 10.1186/cc5212) Table 1 (abstract P50) CRP <100 mg/l CRP >100 mg/l
P value
Inhospital mortality
2.2% (n = 93)
25.6% (n = 39)
<0.0001
(chi-square) Objective To know whether functional protein C (FPC) levels in
critical septic patients could be intended as an evolution marker
correlated with prognosis and mortality. Materials and methods A prospective study with determination of
FPC levels in all septic patients admitted to the ICU. We used the
IL test™ PC kit (Instrumentation Laboratory; synthetic chromogenic
substrate). We considered an abnormal low FPC when levels were
below 40%, normal FPC when levels were above 80% and low
FPC when levels where between 40% and 80%. Data included
patient age, diagnosis, SAPS II, SOFA score, OSF and mortality. The analytical data included serum lactate and FPC. Patients were
divided into three groups: group I (FPC below 40%), group II (FPC
40–80%) and group III (FPC above 80%). The statistical study
was performed with the Analyse-it® program. The severity was
defined by the usual criteria of SAPS II score and lactate levels and
then compared with the different FPC groups. Mortality was
considered. Conclusion CRP on admission to the surgical HDU is a powerful
predictor of mortality (P < 0.0001), but this correlation does not
persist after the initial measurement. Our data suggest that early
CRP measurement should be undertaken in all critically ill surgical
patients in order to quantify the ultimate magnitude of the
inflammatory response and the associated mortality. Reference 1. Rhodes A, et al.: Plasma DNA concentration as a predictor
of mortality and sepsis in critically ill patients. Crit Care
2006, 10:142. S19 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin was measured on admission, day 1 and day 2 and was evaluated
with respect to inhospital mortality. Conclusion The BPW has no utility in the ED to predict the
development of sepsis in at-risk patients. The development of a
BPW at any time during the hospital stay correlates with an
increased risk of sepsis and mortality. Baseline statin therapy may
reduce the chance of developing a BPW. Results CRP on admission to HDU discriminated survivors from
nonsurvivors (P < 0.0001, analysis of variance). A CRP greater
than 100 mg/l correlated very strongly with mortality. The mortality
in patients with a CRP less than 100 mg/l (n = 93) was 2.2%. The
mortality in patients with a CRP greater than 100 mg/l (n = 39)
was 25.6% (P < 0.0001, chi-square test), (Table 1). However,
there were no significant differences in CRP with respect to
mortality on day 1 or day 2 (P = 0.136 and 0.236, respectively). Severe protein C deficiency association with organ
dysfunction and mortality in patients with severe sepsis Results We screened 5,400 consecutive admissions to the ED,
identified 207 eligible subjects and enrolled 105 participants. The
BPW was present at enrollment in 12 subjects by TL18 and in 28
subjects by slope. Forty-six out of 105 subjects eventually
developed a BPW, 54 were diagnosed with sepsis. The sensitivity
and specificity for sepsis were 17% (95% CI, 7–27.6) and 93.8%
(95% CI, 87–100) by TL18 and 26.9% (95% CI, 14.9–38.9) and
71.4% (95% CI, 58.7–84.1) by slope. The positive predictive value
of the test was 75 by TL18 and 50 by slope criteria. The AUC for
ROC analysis of the BPW for diagnosis of sepsis is 0.469 by TL18
and 0.560 by slope. The odds ratio for developing sepsis related to
any positive BPW was 2.977. The odds ratio for development of a
BPW in patients on a statin at the time of presentation was 0.597. Five subjects died by 28 days, 4/5 having a BPW. Introduction We sought to determine whether severe protein C
(PC) deficiency was associated with organ dysfunction (OD) and
mortality in adult patients with severe sepsis. Introduction We sought to determine whether severe protein C
(PC) deficiency was associated with organ dysfunction (OD) and
mortality in adult patients with severe sepsis. Introduction We sought to determine whether severe protein C
(PC) deficiency was associated with organ dysfunction (OD) and
mortality in adult patients with severe sepsis. Methods Retrospective examination of Lilly trials in adult patients
with severe sepsis in which PC measurements were obtained at
baseline. Severe PC deficiency was defined as ≤40% of normal. The Student t test was used to compare mean APACHE II and OD
differences, while the chi-squared or Fisher’s exact test was used
for mortality. Introduction We sought to determine whether severe protein C
(PC) deficiency was associated with organ dysfunction (OD) and
mortality in adult patients with severe sepsis. Methods Retrospective examination of Lilly trials in adult patients
with severe sepsis in which PC measurements were obtained at
baseline. Severe PC deficiency was defined as ≤40% of normal. The Student t test was used to compare mean APACHE II and OD
differences, while the chi-squared or Fisher’s exact test was used
for mortality. Methods Retrospective examination of Lilly trials in adult patients
with severe sepsis in which PC measurements were obtained at
baseline. Severe PC deficiency was defined as ≤40% of normal. P51 The biphasic aPTT waveform to diagnose sepsis in
patients with systemic inflammatory response syndrome The biphasic aPTT waveform to diagnose sepsis in
patients with systemic inflammatory response syndrome
D Hagg, S Malkoski, C Phillips, D Nichols, D Jacoby
Oregon Health & Science University, Portland, OR, USA
Critical Care 2007, 11(Suppl 2):P51 (doi: 10.1186/cc5211) Human protein C concentrate in the treatment of hemolytic
uremic syndrome Human protein C concentrate in the treatment of hemolytic
uremic syndrome M Sasse, L Pape, H Koeditz, A Wessel, K Seidemann,
J Thomas, B Brent
Medical University Children’s Hospital, Hannover, Germany
Critical Care 2007, 11(Suppl 2):P54 (doi: 10.1186/cc5214) In severe sepsis, microcirculatory dysfunction caused by inflam-
mation, endothelial activation and procoagulant response leads to
mithocondrial dysfunction (termed microcirculatory and mito-
chondrial distress syndrome). If undetected, this condition can lead
to parenchymal cellular distress and so to organ failure. As regional
and microcirculatory distress are independent of systemic hemo-
dynamic-derived and oxygen-derived variables, we recorded the
course of microvascular parameters with a Microscan Video Micro-
scope (Microvision, The Netherlands) in four patients with severe
sepsis. We studied the sublingual region because of its embryo-
logic correlation to splanchnic circulation, its thin mucosa. The
instrument used a new improved imaging modality for observation
of the microcirculation called sidestream dark-field imaging. We
consider here four patients with severe sepsis related to
esophagectomy, severe polytrauma with splanchnic organ damage
and mediastinitis treated with drotrecogin alpha (activated) (DA) at
24 µg/kg/hour for 96 hours. The patients were admitted to the
ICU, ventilated mechanically, monitored hemodynamically via a
PICCO system and supported with dobutamine. Videomicroscopy
was made before administration of DA and was repeated every
24 hours during the treatment with DA and at 24 hours after its
suspension. We recorded values of blood pressure, cardiac func-
tion, lactate levels, acid–base balance, temperature and dobuta-
mine dosage. Introduction Human protein C (PC) concentrate may anticipate
thrombotic microangiopathy and facilitate fibrinolysis in the severe
hemolytic uremic syndrome (HUS). We report the effects of PC in
six HUS patients. HUS is characterized by a simultaneous occur-
rence of hemolytic anemia, thrombocytopenia and acute renal
failure. Postdiarrheal HUS is often based on an infection with
EHEC producing Shiga toxins. Our current pathogenetic under-
standing is that Shiga toxins cause endothelial injury, leading to
thrombotic microangiopathy. There is still a 5% rate of mortality
particularly caused by cerebral involvement. Methods We treated six children with a severe cerebral manifes-
tation, five of them suffered from a multiple organ dysfunction
syndrome (MODS), of HUS with PC over 7–10 days. All patients
suffered peritoneal dialysis, one patient a plasmapheresis. In
addition to the treatment of the MODS, all of them received
100–200 U/day PC. Results All of the patients showed signs of disseminated
intravascular coagulation. P55 A Donati, M Romanelli, L Romagnoli, M Ruzzi, V Beato,
V Gabbanelli, S Nataloni, T Principi, P Pelaia
AOU Umberto I Ancona, Rianimazione Clinica, Ancona, Italy
Critical Care 2007, 11(Suppl 2):P55 (doi: 10.1186/cc5215) Severe protein C deficiency association with organ
dysfunction and mortality in patients with severe sepsis The Student t test was used to compare mean APACHE II and OD
differences, while the chi-squared or Fisher’s exact test was used
for mortality. S20 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P53)
Study
EVAA
PROWESS
ENHANCE
ADDRESS
Protein C
≤40%
>40%
≤40%
>40%
≤40%
>40%
≤40%
>40%
n
65
60
615
959
795
1127
593
1154
Mean APACHE II
17.4
17.1
P = 0.79
25.9
24.1
P < 0.001
23.2
20.9
P < 0.001
18.5
18.1
P = 0.14
score
Mean OD
1.5
1.4
P = 0.42
2.8
2.2
P < 0.001
3.1
2.4
P < 0.001
1.6
1.4
P < 0.001
Placebo mortality
50.0%
20.0%
P = 0.07
41.8%
25.3%
P < 0.001
19.7%
12.0%
P = 0.002 Table 1 (abstract P53) patients yield hope that PC treatment may be an effective therapy
regimen in the treatment of severe HUS. Results Severe PC deficiency was associated with a statistically
significant increase in the mean APACHE II score in two of four
trials, a significant increase in the mean OD in three of four trials,
and a significant increase in mortality in two of three trials (Table 1). Conclusion Severe PC deficiency at baseline appears to be
associated with a greater degree of organ dysfunction, and
increased mortality in adult patients with severe sepsis. P56 Results A total number of 61 patients, aged 18–65 years, were
included in the analysis. The pathogens and infection location were
different. Patients were diagnosed according to recommendations
of the Polish Sepsis Group and treatment with APC was
introduced. The increase in number was: in 2004 vs 2003, 200%;
in 2005 vs 2004, 111%; in 2006 up to 10 December vs 2005,
57.8%. The surviving ratio increased every year but in 2006 it
decreased compared with 2005. Multicentre audit of the use of drotrecogin alfa (activated)
in UK critical care units Multicentre audit of the use of drotrecogin alfa (activated)
in UK critical care units Human protein C concentrate in the treatment of hemolytic
uremic syndrome We found typical hypodense lesions in
basal ganglia and edema of the brain in CT. During the therapy
with PC, MODS was remarkable improved and abnormal D-dimer
and PAI-1 levels could be normalised. All of the patients recovered
a nearly normal kidney function. Two patients persisted in a severe
reduced neurological status. The others showed only slight or no
neurological disabilities on discharge. No adverse effects were
observed with the PC concentrate administration. At admission the sublingual microcirculation showed a low
capillary density, vessel heterogeneity with a qualitative low flow
and flow–no flow. After the first 24 hours from the beginning of DA
infusion, sublingual flow showed an increase of vessel density,
particularly of the number of small vessels, and the number of
continuously perfused vessels increased during and post therapy
with DA. We analyzed the microvascular flow with a simple semi-
quantitative method dividing the images into four equal quadrants
and quantificating flow (hyperdynamic, continuous, sluggish,
flow–no flow, no flow) for each cohort of vessel diameter (small,
medium, large). We analyzed the mean value of results of three
images for each patient pre and post DA therapy. Data are
presented as the median. Before starting therapy with DA, the
microvascular flow index (MFI) was 2.06 for small vessels, 2.09 for
medium vessels, and 2.37 for large vessels. After DA infusion, the
MFI was 3, 3, and 3, respectively, for small, medium and large Conclusions There is no generally accepted therapy regimen to
treat HUS in case of neurological involvement. Mortality in HUS
accompanied with cerebral microangiopathy is high and difficult to
alter. This is the first trial of human PC concentrate administration
to anticipate thrombotic microangiopathy in HUS. All of our
patients
showed
rapid
clinical
improvement
under
PC
administration. Four of six patients were discharged in a healthy
condition despite their severe disease. The containment of the
severe neurological involvement and the lack of side effects in the
treatment with human PC concentrate administration in our S21 Table 1 (abstract P57) Table 1 (abstract P57)
2003
2004
2005
2006 (10 Dec)
Number of treated
3
9
19
30
patients
Surviving ratio
33% (1/3)
43.5% (4/9)
62.7%
47% Methods A data collection form was developed and tested to mirror
the information collected in PROWESS. This form was completed
for every admission that received DrotAA and a senior clinician
confirmed completeness. Data were entered centrally and validated. Analysis Admissions receiving DrotAA and with severe sepsis and
two or more organ dysfunctions in the first 24 hours following
admission to the unit were matched to controls on: source of
admission; organ dysfunctions; ICNARC physiology score; and
age. Four pools of control patients were used for matching: (a)
historic admissions (January 2000–August 2002) from the same
unit; (b) contemporaneous admissions from the same unit; (c)
contemporaneous admissions from units that never used DrotAA;
and (d) contemporaneous admissions from units prior to their first
use of DrotAA. Analyses were undertaken using conditional, fixed-
effects, Poisson regression. Discussion During 4 years of treatment of severe sepsis in the
ICU with APC, important changes were observed: faster
recognition and diagnosis, transfer to the reference hospital, and
introduction of adequate therapy. The decrease in the surviving
ratio in 2006 is probably due to a more serious state of the
admitted patients – more initial infection located in the abdomen
after surgery. Conclusion The education program is essential in increasing the
number of fast recognitions, which influences the surviving ratio. P58 Results One hundred and twelve units participated in the audit;
1,079 admissions (one in 16) with severe sepsis and two or more
organ dysfunctions in the first 24 hours following admission to the
unit received DrotAA. For the four control pools, matching was
successful for: (a) 657 (61%); (b) 820 (76%); (c) 702 (65%); and
(d) 965 (89%). Matched cases were older, more acutely ill and had
higher hospital mortality than unmatched cases. The relative risks
(95% confidence interval) associated with DrotAA were: (a) 0.84
(0.77–0.92); (b) 0.85 (0.78–0.93); (c) 0.75 (0.68–0.83); and (d)
0.80 (0.73–0.86). A priori subgroup analyses indicated greater
effect for patients with three or more organ dysfunctions. A large, single-centre UK registry of drotrecogin
alfa-activated use Surviving ratio of severe sepsis treated with activated
protein C in one university intensive care unit during
2003–2006 Surviving ratio of severe sepsis treated with activated
protein C in one university intensive care unit during
2003–2006 A Tokarz, T Gaszynski, W Gaszynski
Medical University of Lodz, Poland
Critical Care 2007, 11(Suppl 2):P57 (doi: 10.1186/cc5217) Introduction Treatment of severe sepsis with infusion of activated
protein C (APC) (Xigris) in the ICU of Barlicki University Hospital
was initiated in 2003. From 2003 the number of treated patients
increased significantly. This is due to better recognition. The
introduced program consists of education of working staff in all
hospitals in the region. Barlicki Hospital is a reference hospital for
treatment of sepsis, and patients with diagnosis of sepsis are
transferred to this ICU. University ICU doctors are teaching
workshops how to recognize and treat sepsis. Methods The surviving ratio in patients treated with APC was
estimated retrospectively. Analysis included the years from 2003 to
10 December 2006. Multicentre audit of the use of drotrecogin alfa (activated)
in UK critical care units K Rowan, C Welch, E North, D Harrison
Intensive Care National Audit & Research Centre, London, UK
Critical Care 2007, 11(Suppl 2):P56 (doi: 10.1186/cc5216) Background
Following
positive
results
from
PROWESS,
drotrecogin alfa (activated) (DrotAA) was approved for use in
Europe in August 2002. At this time, ICNARC commenced an
audit to monitor the diffusion of the drug into routine UK practice
and to undertake a nonrandomised evaluation of its effectiveness. P57 vessels. Differences between groups were assessed using the
Mann–Whitney U test. We showed a statistically significant differ-
ence with P < 0.0001 between MFI before and post DA therapy. We demonstrated a quantitative and qualitative improvement of
sublingual microcirculation with an increase of capillary density
distribution (area–width) and average velocity versus vessel width. The course of microvascular blood flow may play an important role
in sepsis and septic shock because of its relation to the
development of multiple organ failure and death. Several studies
have demonstrated that changes in microvascular perfusion are an
independent predictor of outcome. The improvement of the micro-
circulation and vascular tone in septic shock by DA is probably
related to its anticoagulant/antithrombotic and antiinflammatory
action, to the decrease of TNFα production and inhibition of iNOS
induction, and to improvement of endothelial barrier function and
inhibition of chemotaxis, but further investigations are required to
elucidate the exact mechanisms. These observations could
suggest that DA could have a particular interest in the early
management of severe sepsis. vessels. Differences between groups were assessed using the
Mann–Whitney U test. We showed a statistically significant differ-
ence with P < 0.0001 between MFI before and post DA therapy. We demonstrated a quantitative and qualitative improvement of
sublingual microcirculation with an increase of capillary density
distribution (area–width) and average velocity versus vessel width. The course of microvascular blood flow may play an important role
in sepsis and septic shock because of its relation to the
development of multiple organ failure and death. Several studies
have demonstrated that changes in microvascular perfusion are an
independent predictor of outcome. The improvement of the micro-
circulation and vascular tone in septic shock by DA is probably
related to its anticoagulant/antithrombotic and antiinflammatory
action, to the decrease of TNFα production and inhibition of iNOS
induction, and to improvement of endothelial barrier function and
inhibition of chemotaxis, but further investigations are required to
elucidate the exact mechanisms. These observations could
suggest that DA could have a particular interest in the early
management of severe sepsis. Surviving ratio of severe sepsis treated with activated
protein C in one university intensive care unit during
2003–2006 Available online http://ccforum.com/supplements/11/S2 Materials and methods From January 2003 to August 2006 we
used APC to treat 44 severely septic patients in our ICU. We
obtained complete data for 37 patients. We collected data from the
case notes, ICU charts and drotrecogin alfa (activated) data forms
and recorded relevant data on an Excel spreadsheet proforma. Results NICE guidelines. We were 100% compliant with patient
selection criteria for APC administration, which included a known
or suspected site of infection, SIRS criteria and organ dysfunction
criteria. All prescriptions were made by intensive care consultants. We were not fully compliant in excluding patients who met
exclusion criteria (2/37 patients), although these cases were
justified clinically by the consultants prior to administration. Data entry. In 90% of cases the patient selection fields were
completed, but only 30% of the exclusion and outcome fields were
completed. In 30% of patients where a lactate ≥1.5 times normal was
listed as one of the inclusion criteria, it was not associated with a pH
≤7.30 or a base deficit ≥5.0; however, all these patients had ≥3
organ-dysfunction criteria and hence still met the inclusion criteria. Outcomes. Seven patients (15.9%) died during or within 28 days
of APC administration. The standardised mortality ratio (SMR) was
lower in patients receiving APC when compared with the rest of
patients admitted over the same period (SMR ~0.5 vs ~1.0). Twenty-eight patients had an APACHE II score <25 and the
effective cost per survivor was ~€16,800. Patients with APACHE
II scores ≥25 had an effective cost per survivor of ~€22,400. Nine
patients (20.5%) had their drotrecogin alfa (activated) infusions
interrupted or discontinued for various reasons (including seven
patients who had hemorrhagic complications, three of which were
serious). respect to its use. The aim of this study was to demonstrate the
safety profile and efficacy of DrotAA treatment within a large, 29-
bed university hospital critical care unit. respect to its use. The aim of this study was to demonstrate the
safety profile and efficacy of DrotAA treatment within a large, 29-
bed university hospital critical care unit. Materials and methods From January 2003 to August 2006 we
used APC to treat 44 severely septic patients in our ICU. We
obtained complete data for 37 patients. We collected data from the
case notes, ICU charts and drotrecogin alfa (activated) data forms
and recorded relevant data on an Excel spreadsheet proforma. A large, single-centre UK registry of drotrecogin
alfa-activated use L Macchiavello, G Ellis, S Bowden, M Smithies
University Hospital of Wales, Cardiff, UK
Critical Care 2007, 11(Suppl 2):P58 (doi: 10.1186/cc5218) Introduction As one of the few treatment interventions to
demonstrate mortality efficacy at a randomized controlled trial level
[1], the prescription of drotrecogin alfa-activated (DrotAA) (Xigris™),
where appropriate, plays an important role in the management of
severe sepsis. However, concerns regarding the potential for
serious bleeding events have helped sustain a degree of
scepticism regarding the use of DrotAA [2]. As early adopters of
evidence-based medicine, Cardiff Critical Care Unit has prescribed
DrotAA since late 2002 and has considerable experience with Interpretation All results were consistent with PROWESS, but
need to be interpreted with caution due to their nonrandomised
nature and the potential existence of important unknown
confounders. In addition, the fact that only one in 16 potentially
suitable admissions received DrotAA suggests a strong possibility
for treatment bias. S22 References 1. Bernard GR, Vincent JL, Laterre PF, et al.: Efficacy and
safety of recombinant human activated protein C for
severe sepsis. N Engl J Med 2001, 344:699-709. 1. Bernard GR, Vincent JL, Laterre PF, et al.: Efficacy and
safety of recombinant human activated protein C for
severe sepsis. N Engl J Med 2001, 344:699-709. 1. Bernard GR, Vincent JL, Laterre PF, et al.: Efficacy and
safety of recombinant human activated protein C for
severe sepsis. N Engl J Med 2001, 344:699-709. C Cameron, W Plaxton
Grand River Hospital, Kitchener, Canada
Critical Care 2007, 11(Suppl 2):P60 (doi: 10.1186/cc5220) ritical Care 2007, 11(Suppl 2):P60 (doi: 10.1186/cc522 2. Mackenzie AF: Activated Protein C: do more survive? Inten-
sive Care Med 2005, 31:1624-1626. 2. Mackenzie AF: Activated Protein C: do more survive? Inten-
sive Care Med 2005, 31:1624-1626. 2. Mackenzie AF: Activated Protein C: do more survive? Inten-
sive Care Med 2005, 31:1624-1626. Introduction Grand River Hospital (GRH) is a 495-bed non-
teaching, acute care referral center in Southwestern Ontario,
supporting regional programs including dialysis, oncology, surgery
and stroke thrombolysis. Since the introduction of drotrecogin alfa
(activated) (DAA) in 2003, GRH has treated 58 patients with this
agent for severe sepsis and septic shock. We sought to compare,
where possible, GRH ICU/hospital outcomes and bleeding
complications with those from published literature. Available online http://ccforum.com/supplements/11/S2 Methods Demographic data were obtained from the unit’s daily
updated Riyadh ICU programme database and clinical data were
collected from patients’ medical notes and observation charts. All
data were prospectively entered into our DrotAA registry, the
results of which are shown below. Results NICE guidelines. We were 100% compliant with patient
selection criteria for APC administration, which included a known
or suspected site of infection, SIRS criteria and organ dysfunction
criteria. All prescriptions were made by intensive care consultants. We were not fully compliant in excluding patients who met
exclusion criteria (2/37 patients), although these cases were
justified clinically by the consultants prior to administration. Results Between October 2002 and November 2005, 133
patients with severe sepsis were treated with DrotAA. The mean
age was 61 years (range: 20–87 years) and 54% were male. The
mean admission APACHE II score was 22 (range: 11–48), and on
day 1 of DrotAA infusion the median number of organs that failed
was 2.0 (range: 0–4), 129/133 (97%) were mechanically
ventilated and 131/133 (98.5%) were on vasopressors. The
median time to start DrotAA after documented diagnosis of severe
sepsis was 12.6 hours (range: 0–41 hours) and the median
duration of DrotAA infusion was 89.5 hours (range: 10–105 hours). The incidence of serious (life-threatening) bleeding events was
2.3% (n = 3): gastrointestinal (n = 1), intraabdominal (n = 1) and
intrathoracic (n = 1); all were nonfatal and there were no
intracranial bleeds. The 28-day mortality was 31.6%, the ICU
mortality was 33.1%, the hospital mortality was 36.8% and the
1-year mortality was 47%. Data entry. In 90% of cases the patient selection fields were
completed, but only 30% of the exclusion and outcome fields were
completed. In 30% of patients where a lactate ≥1.5 times normal was
listed as one of the inclusion criteria, it was not associated with a pH
≤7.30 or a base deficit ≥5.0; however, all these patients had ≥3
organ-dysfunction criteria and hence still met the inclusion criteria. g
y
Outcomes. Seven patients (15.9%) died during or within 28 days
of APC administration. The standardised mortality ratio (SMR) was
lower in patients receiving APC when compared with the rest of
patients admitted over the same period (SMR ~0.5 vs ~1.0). Twenty-eight patients had an APACHE II score <25 and the
effective cost per survivor was ~€16,800. Patients with APACHE
II scores ≥25 had an effective cost per survivor of ~€22,400. P60 Retrospective observational outcomes for drotrecogin alfa
(activated) Retrospective observational outcomes for drotrecogin alfa
(activated) References Available online http://ccforum.com/supplements/11/S2 Nine
patients (20.5%) had their drotrecogin alfa (activated) infusions
interrupted or discontinued for various reasons (including seven
patients who had hemorrhagic complications, three of which were
serious). Conclusions This is one of the largest UK registries of DrotAA
usage published to date. Our results demonstrate a very low
incidence of serious bleeding events associated with DrotAA treat-
ment (2.3% vs 3.5% in PROWESS); it is interesting to note that all
three adverse events occurred prior to 2004. This detail, combined
with our low median time to start DrotAA infusion (which has
steadily decreased over the past 4 years), would suggest the
presence of a learning curve for DrotAA usage on ICUs. It is also
encouraging to note that our overall hospital mortality was lower
than the predicted APACHE II hospital mortality for these patients
(36.8% vs 42.4%). Finally, this is one of the first UK studies to
describe long-term mortality outcome in patients receiving DrotAA
therapy. Further studies are required to more formally assess the
impact of DrotAA treatment on long-term survival from severe
sepsis. Conclusions and recommendations We use APC in compliance
with the NICE guidelines. APC is cost-effective in patients with an
APACHE II score <25 in our ICU. 1. Bernard GR, et al.: N Engl J Med 2001, 334:699-709. 2. National Institute of Clinical Excellence [http://www.nice. org.uk/guidance/TA84] 2. National Institute of Clinical Excellence [http://www.nice. org.uk/guidance/TA84] P62 P62 59.4 years. Primary sources of infection were: intra-abdominal
36.2%, respiratory 27.6%, genitourinary 8.6%, and 27.6% from
other sources. GRH ICU mortality was 44.8% and hospital
mortality was 51.7%. Analysis by age revealed overall survival rates
of 78.6% for patients ≤50 years, 54.5% for 51–60 years, 52.9%
for 61–70 years, 20% for 71–80 years, and 0% for patients >80
years of age. Hemorrhagic complication rates were higher than in
published reports. Of 58 treatments, we recorded a total of nine
hemorrhages (15.5%). The mortality rate in this cohort was 33.3%. Conclusions These data suggest that ‘field performance’ of DAA
may not be replicating the favorable clinical endpoints as reported
in PROWESS. The Ontario Ministry of Health should consider
implementing a provincial registry system for patients with severe
sepsis and septic shock, empowering ICUs to track relevant
demographic, acuity, and outcome data with a view to optimizing
DAA use through patient selection and risk stratification. 59.4 years. Primary sources of infection were: intra-abdominal
36.2%, respiratory 27.6%, genitourinary 8.6%, and 27.6% from
other sources. GRH ICU mortality was 44.8% and hospital
mortality was 51.7%. Analysis by age revealed overall survival rates
of 78.6% for patients ≤50 years, 54.5% for 51–60 years, 52.9%
for 61–70 years, 20% for 71–80 years, and 0% for patients >80
years of age. Hemorrhagic complication rates were higher than in
published reports. Of 58 treatments, we recorded a total of nine
hemorrhages (15.5%). The mortality rate in this cohort was 33.3%. Conclusions These data suggest that ‘field performance’ of DAA
may not be replicating the favorable clinical endpoints as reported
in PROWESS. The Ontario Ministry of Health should consider
implementing a provincial registry system for patients with severe
sepsis and septic shock, empowering ICUs to track relevant
demographic, acuity, and outcome data with a view to optimizing
DAA use through patient selection and risk stratification. Three years experience with drotrecogin alfa (activated)
protein C in severe sepsis and septic shock at Salmaniya
Medical Complex, Bahrain H Mohamed, AA Hameed, M Al-Ansari
Salmaniya Medical Complex, Manama, Bahrain
Critical Care 2007, 11(Suppl 2):P62 (doi: 10.1186/cc5222) Objective To evaluate the role of activated protein C (APC) in
severe sepsis and septic shock. Method The data were collected in a prospective manner from July
2002 to November 2006 in the adult medical/surgical ICU at
Salmaniya Medical Complex Bahrain. The number of demographic
variables were collected from patients’ files. Risk/benefit analysis of activated protein C in patients with
intra-abdominal sepsis E Borthwick, D Stewart, E Mackle, C McAllister
Craigavon Area Hospital, Co. Armagh, UK
Critical Care 2007, 11(Suppl 2):P61 (doi: 10.1186/cc5221) E Borthwick, D Stewart, E Mackle, C McAllister
Craigavon Area Hospital, Co. Armagh, UK Out of the total 444 septic patients 149 were assessed for APC;
in the 85 patients fulfilling criteria for and receiving APC the
mortality was 43.5%, and for the 64 patients not receiving APC the
mortality was 64%. All suspected septic patients admitted to the
ICU received appropriate antibiotic therapy within 4 hours of ICU
admission and were upgraded/changed according to culture/
sensitivity reports if necessary. In the nonreceiving group (i.e. 64
patients) 12 patients could not receive APC due to financial
restriction because initially foreigners were not entitled to this drug
in Bahrain, but later this restriction was removed, and the remaining
52 patients could not receive either due to bleeding or very recent
surgeries. Some patients could not receive complete treatment
either due to bleeding complications or because they died. The
mortality was measured at 28 days. Introduction and objective To establish whether activated protein
C (APC) is safe in surgical patients with intra-abdominal sepsis
(IAS). APC has been used in the treatment of IAS in our hospital
since 2003. Fears persist regarding the potential for clinically
significant bleeding in this surgical subgroup of patients. Methods
Forty-four patients with IAS received APC as a
standardized regime between March 2003 and August 2006. A
retrospective medical and ICU chart review was undertaken. Data
collected included clinically significant bleeding episodes and
mortality. Descriptive subgroup analysis of unexpected non-
survivors(died in the ICU with APACHE II (APII) predicted mortality
< 50%) and unexpected survivors (survived to ICU discharge with
APII predicted mortality > 50%) was performed as statistical
analysis of such small patient numbers was inappropriate. Furthermore, as per our experience, if APC started in the early
stage of sepsis and the course is completed the outcome is better
– out of 85 patients who received APC, 45 patients received in the
early stage and completed the dose and 32 of these patients
survived at 28-day mortality. An average three (ventilator-free)
organs failed in the survival group and two (ventilator-free) organs
failed in the expired group. Risk/benefit analysis of activated protein C in patients with
intra-abdominal sepsis Seventeen patients started treatment in
the early stage and could not complete the course due to bleeding
or other complications, 11 patients expired; 13 patients started in
the late stage and completed the course, five patients expiring; and
10 patients started in the late stage and eight of these patients
expired. Results There was one episode of clinically significant bleeding
(from a mucous fistula: self-limiting). There were no intracranial
haemorrhagic events. ICU mortality was 38.6% with mean APII
predicted mortality of 37.16% and inhospital mortality of 47.7%. These exceeded rates for APC-treated surgical cohorts in the
literature [1]. Unexpected survivors (5/44) were more likely to have
been admitted from theatre. They had a shorter mean time from
hospital–ICU admission (10.5 vs 5.6 days), duration on a ventilator
(10.8 vs 17.5 days), vasopressor (9 vs 17.7 days) and renal
replacement therapy (10.5 vs 23.5 days) dependence. All un-
expected nonsurvivors (11/44) had a diagnosis of fistula or
perforation. They were more likely to have been transferred to the
ICU from another hospital or ward than from theatre. Co-
morbidities were more severe. Conclusion On the basis of our experience and the results of
multiple trials, we recommend APC should be given to the patients
who meet all the inclusion criteria. Conclusion 1. APC was very safe to use in this group of critically
ill surgical patients. 2. Although patients may fulfil standard criteria
for APC use, if there is no definitive surgical cure for the IAS, then
APC is inappropriate. 3. Delay in commencement of APC in
surgical patients due to bleeding concerns may be contributing to
the high mortality. Earlier perioperative use of APC in selected
cases may offer improved mortality benefit, and we are undertaking
a prospective audit to investigate this. P62 Results A total of 444 patients were admitted to the ICU with the
diagnosis of sepsis or severe sepsis. One hundred and forty-nine
severe septic patients were assessed for APC: 85 patients received
APC, and 64 patients could not receive APC due to financial
problems or due to bleeding, coagulation derangement or very
recent surgeries. In the total 444 septic patients admitted to the ICU,
152 patients expired (mortality 34.2%) and 141 had positive blood
culture; 233 patients received inotrops. The total average APACHE II
score was 28.9 and for expired patients was 35.1. P59 Audit of adherence to National Institute of Clinical
Excellence guidelines for the use of drotrecogin alfa
(activated) Excellence guidelines for the use of drotrecogin alfa
(activated) R Vedantham, B Iyowu
University Hospital Lewisham, London, UK
Critical Care 2007, 11(Suppl 2):P59 (doi: 10.1186/cc5219) R Vedantham, B Iyowu
University Hospital Lewisham, London, UK
Critical Care 2007, 11(Suppl 2):P59 (doi: 10.1186/cc5219) R Vedantham, B Iyowu
University Hospital Lewisham, London, UK
Critical Care 2007, 11(Suppl 2):P59 (doi: 10.1186/cc5219) Methods All charts for patients treated with DAA in our CAICU for
severe sepsis and septic shock between February 2003 and June
2006 were reviewed retrospectively for infection source, ICU/
hospital mortality, survival by age and incidence of hemorrhagic
complications. Where possible, we compare our data with those
from PROWESS, ENHANCE and a recent Ontario/Quebec-based
multicenter usage evaluation. A two-organ system failure threshold
for DAA consideration is used. Outcomes were categorized as ICU
mortality and hospital mortality, as opposed to 28-day mortality
used in PROWESS and ENHANCE. Introduction Activated protein C (APC) is an endogenous protein,
which has fibrinolytic and anti-inflammatory properties. This is
available as human recombinant APC and is used in the treatment
of patients with severe sepsis [1]. The National Institute of Clinical
Excellence (NICE) suggested guidelines for the use of APC [2]. We retrospectively audited the records of patients who received
APC during their admission to our ICU between January 2003 and
August 2006. We audited our practice against three parameters:
compliance with the NICE guidelines, accuracy of data forms, and
outcomes of treatment. Results All 58 patients who received DAA at GRH were included
in our analysis. The mean age of patients treated with DAA was Results All 58 patients who received DAA at GRH were included
in our analysis. The mean age of patients treated with DAA was S23 P61 Risk/benefit analysis of activated protein C in patients with
intra-abdominal sepsis Risk/benefit analysis of activated protein C in patients with
intra-abdominal sepsis Available online http://ccforum.com/supplements/11/S2 Results Overall, 12,492 patients with severe sepsis from 37
countries were enrolled and 882 (7%) patients received DAA
therapy. The highest rate of use of DAA was seen in the United
States at 27% (206/760). Patients who received DAA versus
those who did not receive DAA were younger (median age 59
versus 64 years), had greater organ dysfunction (cardiovascular
dysfunction (90% versus 74%), respiratory dysfunction (90%
versus 81%), renal dysfunction (60% versus 45%), metabolic
abnormalities (63% versus 42%), three or more organ dys-
functions (84% versus 67%)) and higher median APACHE II
scores (25.0 vs 23.0), all P < 0.001. The mortality rate for patients
treated with DAA was 49.6% and for those not treated with DAA
was 49.7%. Although imbalances in other baseline characteristics,
not collected in PROGRESS, may have also been present, when
adjusted for age and number of organ dysfunctions the odds ratio
for hospital mortality associated with DAA use was 0.75
(0.63–0.90, P = 0.002). Methods Fifty-seven patients with severe sepsis (age 51 ± 15
years, range 20–77 years, male:female 32:25) admitted to the ICU
were included. All patients had three or more signs of systemic
inflammation with at least two major organ dysfunctions or the
presence of ARDS. Demographic, clinical and laboratory profiles at
baseline, and during the hospital stay, development of complica-
tions, duration of hospital/ICU stay and hospital survival were
recorded. All management decisions including initiation of DA
(24 µ/kg/hour), duration of treatment as well as its discontinuation
were the prerogative of the ICU team. Results The majority of patients had a confirmed infection (n = 36,
63.2%), with the commonest site of focus being the lung (n = 25,
43.9%) followed by the abdomen (n = 13, 22.8%). A significant
number of patients had at least three major organ dysfunctions
(n = 37, 64.9%). A large number of patients had an APACHE II
score in the range 25–29 (n = 22, 38.6%). Whereas 44 patients
(77.2%) were on some kind of vasopressor support, 51 needed
ventilatory support (89.5%). A total of 20 patients (35.1%) survived
to hospital discharge. Patients received DA for a mean duration of
74.8 ± 26.2 hours (range 25–96 hours) and only 32 patients could
complete treatment (56.1%). The outcome was significantly better
in patients who could complete therapy (53.1% vs 13.6%,
P = 0.001). Available online http://ccforum.com/supplements/11/S2 Major bleeding necessitating discontinuation was seen
in four patients (7%) whereas the other 21 patients (36.9%) died
before completing 96 hours of therapy. DA was initiated within
48 hours of development of organ dysfunction in the majority of
patients (n = 31, 54.4%), and a trend towards better outcome in
patients with early treatment was noted although the difference did
not reach statistical significance (mortality rate 58% for early
treatment vs 73.1% for delayed treatment, P = not significant). Conclusion In a large global registry, patients receiving DAA
therapy were younger with higher disease severity than patients
not treated with DAA. When adjusted for age and number of organ
dysfunctions, DAA was associated with a reduction in the odds of
hospital mortality similar to that seen at day 28 in PROWESS. These data are supportive of the effectiveness of DAA in clinical
practice. Epidemiology of severe sepsis in India S Todi, S Chatterjee, M Bhattacharyya
AMRI Hospitals, Kolkata, India
Critical Care 2007, 11(Suppl 2):P65 (doi: 10.1186/cc5225) Conclusion Mortality of patients with severe sepsis remains high
despite the introduction of DA. Early institution may be associated
with better outcomes. Patients receiving a complete course of
treatment have better survival. Introduction A multicentre, prospective, observational study was
conducted in 12 intensive therapy units (ITUs) in India from June
2006 to November 2006 to determine the incidence and outcome
of severe sepsis among adult patients. P64 Methods All patients admitted to ITUs were screened daily for
SIRS, organ dysfunction and severe sepsis. Patients with severe
sepsis were further studied. Drotrecogin alfa in patients with severe sepsis: experience
from a tertiary care center in North India Drotrecogin alfa in patients with severe sepsis: experience
from a tertiary care center in North India R Chawla, S Kansal, A Lall, M Kanwar, D Rosha, A Bansal, V Sikri
Indraprastha Apollo Hospitals, New Delhi, India
Critical Care 2007, 11(Suppl 2):P63 (doi: 10.1186/cc5223) Introduction Drotrecogin alfa (DA) remains the only approved drug
for the specific treatment of severe sepsis. Although it has been in
wide clinical usage, there are no data on its use in Indian patients. 1. Barie PS, et al.: Benefit/risk profile of drotAA in surgical
patients with severe sepsis. Am J Surg 2004, 188:212-
220. S24 Available online http://ccforum.com/supplements/11/S2 Severe sepsis and drotrecogin alfa (activated) use: results
from the PROGRESS registry Results A total of 1,344 ITU admissions were studied. There were
no SIRS in 31.3% and SIRS without organ dysfunction in 51.6%. SIRS with organ dysfunction was found in 230 (17.1%) patients,
of which 54 (23.5%) were not due to sepsis and 176 (76.5%)
were due to sepsis. The incidence of severe sepsis was 13.1% of
all admissions. The mean age of the study population was 54.9
years (SD 17.6), of which 67% were male. The median APACHE II
score was 22 (IQR 17–28) with predominant (88%) medical
admission. ITU mortality of all admissions was 13.9% and that of R Beale1, F Brunkhorst2, G Martin3, M Williams4, D Nelson4,
J Janes4
1St Thomas’ Hospital, London, UK; 2Friedrich-Schiller University,
Jena, Germany; 3Emory University School of Medicine, Atlanta, GA,
USA; 4Lilly Research Laboratories, Indianapolis, IN, USA
Critical Care 2007, 11(Suppl 2):P64 (doi: 10.1186/cc5224) Introduction Since the launch of drotrecogin alfa (activated)
(DAA) a number of institutions and countries have published data
on its use in clinical practice, based on audit or registry data. Such
publications have tended to report DAA use in higher disease
severity populations together with higher mortality outcomes
compared with clinical trials. We utilized the Global PROGRESS
(Promoting Global Research Excellence in Severe Sepsis)
database to examine the baseline characteristics and outcome of
patients with and without DAA treatment. Figure 1 (abstract P65) P66 PISA: the prevalence of infection in intensive care units in
South Africa
S Bhagwanjee, J Scribante, H Perrie, F Paruk
University of the Witwatersrand and the CCSSA, Johannesburg,
South Africa
Critical Care 2007, 11(Suppl 2):P66 (doi: 10.1186/cc5226) PISA: the prevalence of infection in intensive care units in
South Africa R Goldwasser1, C David1, R Hatum2, J Salles2, O Barbosa3,
C Piras4, M Braga5, G Macedo6, G Fundo7
1Hospital Universitario-Universidade Federal do Rio de Janeiro,
Brazil; 2HCN, Niteroi, Brazil; 3Hospital Santa Joana, Recife, Brazil;
4Hospital São Lucas, Vitoria, Brazil; 5Hospital Biocor, Belo
Horizonte, Brazil; 6Hospital Universitario Sul Fluminense,
Vassouras, Brazil; 7AMIB, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P67 (doi: 10.1186/cc5227) R Goldwasser1, C David1, R Hatum2, J Salles2, O Barbosa3, S Bhagwanjee, J Scribante, H Perrie, F Paruk
University of the Witwatersrand and the CCSSA, Johannesburg,
South Africa
Critical Care 2007, 11(Suppl 2):P66 (doi: 10.1186/cc5226) Introduction Sepsis in the ICU is a major cause of morbidity and
mortality. In addition it increases the direct and indirect cost of
care. Effective intervention to improve patient outcome and ensure
optimal use of resources depends on the availability of data. No
epidemiological data are available on the prevalence of sepsis in
South Africa. This study was a 1-day sepsis prevalence study
conducted in an attempt to address this lack of data. Introduction Sepsis occurs in 16.6% of the patients in the
Brazilian ICU and is associated with a high mortality rate (46.6%). Several studies show different pathogenic agents among countries
and increased antibiotic resistance. This study aims to describe the
pathogen profile in Brazil’s ICU septic patients. Introduction Sepsis occurs in 16.6% of the patients in the
Brazilian ICU and is associated with a high mortality rate (46.6%). Several studies show different pathogenic agents among countries
and increased antibiotic resistance. This study aims to describe the
pathogen profile in Brazil’s ICU septic patients. g
Methods A prospective cohort study involving 75 ICUs all over
Brazil was performed. All patients who were admitted or developed
sepsis during a 1-month period were enrolled and followed until
the 28th day and/or until their discharge. Method Following appropriate institutional approval, 43 ICUs were
selected using the proportional probability sampling technique. This was applied to a national database of ICUs. Every seventh
bed was selected from all the serially placed units. P67 P67
Microbiology profile of sepsis in Brazil Figure 1 (abstract P65) Methods PROGRESS is a global, noninterventional, multicenter,
prospective, observational study of severe sepsis patients treated
in ICUs. Patients must have had a diagnosis of severe sepsis and
have been treated in an ICU at a participating institution. All treat-
ment modalities were as per standard of care at the participating
institutions. We analyzed baseline characteristics and hospital
mortality. We also performed an adjusted mortality analysis for
DAA patients due to baseline imbalances in patients with and
without DAA therapy. S25 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Table 1 (abstract P66)
Diagnostic concordance
Treating doctor
Assessors
None
169
54
SIRS
16
120
Sepsis
36
41
Severe sepsis
7
12
Septic shock
9
16 severe sepsis was 54.1%. Hospital mortality and 28-day mortality
of severe sepsis were 59.3% and 57.6%, respectively. The
standardized mortality ratio of severe sepsis patients was 1.40. The median duration of stay in ITUs of the severe sepsis cohort
who survived was 6 days (IQR 3–12). The number of episodes
where infection was the primary reason for admission to the ITU
was 89.8% and the rest of episodes were ITU acquired. See
Figure 1 for infection characteristics. severe sepsis was 54.1%. Hospital mortality and 28-day mortality
of severe sepsis were 59.3% and 57.6%, respectively. The
standardized mortality ratio of severe sepsis patients was 1.40. The median duration of stay in ITUs of the severe sepsis cohort
who survived was 6 days (IQR 3–12). The number of episodes
where infection was the primary reason for admission to the ITU
was 89.8% and the rest of episodes were ITU acquired. See
Figure 1 for infection characteristics. Conclusion
Sepsis was common in Indian ITUs and had
predominant medical populations. ITU mortality was higher
compared with western literature. Gram-positive infections were
less common although the incidence of parasitic and viral
infections were higher than in the West. P66 Data collected
identified the profile of the unit and the patient details for the day in
question (15 August 2005). The primary endpoint was a peer-
reviewed determination of the need for antibiotic prescription as
determined by two independent reviewers. Sepsis was defined
according to the ACCP/SCCM criteria. Secondary end-points
included determination of diagnostic ability of attending clinicians,
antibiotic prescribing patterns and appropriateness of modification
of therapy based on microbiological data. Results A total of 521 patients filled the criteria of sepsis and were
studied. The two main sources of infection were pneumonia and
the abdominal tract. Gram-negative bacteria were isolated in
40.1%, followed by Gram-positive (38.8%) and fungus (5%). The
most prevalent bacteria were Staphylococcus aureus (31.3%) and
Pseudomonas aeruginosa (26.8%). Methicilin-resistant Staphylo-
coccus aureus (MRSA) were present in 64.8%. Bacteria were
isolated in blood samples in 19.57% and S. aureus was prevalent. The prevalence of antimicrobial-resistant bacteria was 26.6% and
was associated with higher mortality at the 28th day (resistant
bacteria 50.9% vs nonresistant bacteria 43.5%). Septic shock was
related to the highest mortality, with rates ranging from 45.8%,
63.7% and 83.3% due to S. aureus, P. aeruginosa and Acineto-
bacter spp, respectively. Results The mean age of patients was 55 years (n = 248) with a
male:female ratio of 60:40. Sixty-eight per cent of patients were
admitted post surgery. There was reasonable concordance for
sepsis, severe sepsis and septic shock (Table 1). A total of
196/248 (79%) patients were deemed to require antibiotics by the
attending clinician, compared with 69/248 (28%) who were
deemed to have sepsis by independent review. Fifty-one per cent
of patients were inappropriately diagnosed as having sepsis. The
commonest site of sepsis (as determined by the assessors) was
the lung (45%) followed by the abdomen (10%). In 42% of cases
antimicrobial prescription was adjudged as being appropriate,
while in 11% of cases antimicrobials were appropriately modified
following microbiology results. The duration of therapy was
appropriate in 26% of cases. Conclusions Gram-negative bacteria were the most frequently
isolated pathogens in the ICU in septic patients. MRSA
represented the majority of S.aureus strains isolated. Antibiotic-
resistant bacteria were associated with higher mortality. It is
important to recognize the Brazilian ICU organisms’ profile and
their resistance pattern to guide rational administration of
antimicrobial agents. Implementation of early goal-directed therapy in Finland Implementation of early goal-directed therapy in Finland M Varpula
Helsinki University Hospital, Kauniainen, Finland
Critical Care 2007, 11(Suppl 2):P69 (doi: 10.1186/cc5229) Introduction The early recognition and rapid start of goal-directed
treatment (EGDT) are important elements for better outcome in
severe sepsis. These actions should take place in the emergency
department (ED) before admission to the ICU. The aim of our study
was to determine how the EGDT was performed and to evaluate
the impact of EGDT principles on mortality in septic shock in
Finland. Our study was conducted before national guidelines for
severe sepsis were published. Results There were 201 patients admitted to the unit during the
period of our study; 140 of these were neurosciences (NS)
patients and the rest (61) were general (G) (either medical or
surgical). Most of the patients were men and had a mean APACHE
II score of 39 (NS group 33, G group 45).There were in total 64
episodes of positive blood cultures (BC); 39 of these episodes
were accompanied by inflammatory signs (incidence of blood-
stream infections of 19.4% of total admissions). Twenty-five of the
episodes were not associated to clinical signs of infection. There
were more patients with at least one episode of positive BC in the
NS group (29 (20.7%)) than in the G group (10 (16.39%)). Out of
49 episodes in the NS group, 59.18% (29) were associated to
some degree of inflammatory response (SIRS, severe sepsis, and
MODS). Out of 15 episodes in the G group, 66.6% (10)
developed inflammatory response. In 59% (25) of the positive
BCs, the organism isolated was coagulase-negative staphylo-
coccus (CNS). In the G group, 47% (7) grew CNS, 33% were
diverse Gram-negatives and in 20% other Gram-positives. In the
NS group, 64% (31) of isolates grew CNS, 21% were other Gram-
positives and 15% were Gram-negatives. In 47 (73.4%) episodes
of positive BC, the patients had either a central venous catheter or
an arterial catheter. In 36 (56.2%) of the episodes the patients
were already on antibiotics at the time of the sampling. The most
frequent agent isolated was coagulase-negative Staphylococcus
aureus, in 39 (59%) of the cases. Methods A prospective observational study of patients with severe
sepsis and septic shock admitted to 21 ICUs in Finland from 1
November 2004 to 28 February 2005 (Finnsepsis). Implementation of early goal-directed therapy in Finland Only patients
with community-acquired sepsis, who fulfilled the criteria of septic
shock and were admitted directly from the ED to the ICU, were
included. The following treatment targets were evaluated: (1)
measurement of lactate during the first 6 hours from admission to
the ED; (2) obtaining the blood cultures before antibiotics; (3)
starting the antibiotics within 3 hours from admission; and reaching
the (4) mean arterial pressure over 65 mmHg, (5) central venous
pressure over 8 mmHg and (6) central venous oxygen saturation
over 70% or mixed venous oxygen saturation over 65% during the
first 6 hours with fluids and vasopressors. Results Sixty-three patients were included. The median age was
57 years (IQR 18.5) and the median APACHE II score was 28
(IQR 10). The ICU, hospital and 1-year mortality rates were 25%,
38% and 52%, respectively. Only five (8%) patients reached all
treatment targets and 24 patients (38%) reached four or more
targets (group A). The hospital mortality of group A was 29% (95% CI 15–49%)
compared with 44% (95% CI 29–59%) of those who reached only
three or less targets (group B) (P = 0.3). The median delay from
ED arrival to ICU admission in group A and group B was 1.1 and
3.7 hours (P < 0.001), and the median SOFA score for the first
day was 10 and 11 (P = 0.4), respectively. The median APACHE II
score was 28 in both groups (P = 0.9). In multivariate analysis
including all separate targets, delay for ICU admission and
APACHE II score, the APACHE II value and measurement of
lactate were independent predictors of mortality (P = 0.001 and
0.02). Only 18% of patients had serum lactate measured during
the ED stay. The 1-year mortality of group A was 42% (95% CI
24–61%) and of group B was 59% (95% CI 43–73%) (P = 0.2). The hospital mortality of group A was 29% (95% CI 15–49%)
compared with 44% (95% CI 29–59%) of those who reached only
three or less targets (group B) (P = 0.3). The median delay from
ED arrival to ICU admission in group A and group B was 1.1 and
3.7 hours (P < 0.001), and the median SOFA score for the first
day was 10 and 11 (P = 0.4), respectively. The median APACHE II
score was 28 in both groups (P = 0.9). Available online http://ccforum.com/supplements/11/S2 unit (NCCU) is at the moment unknown. It is known that being a
patient in the intensive care environment is in itself a risk factor for
the development of bacteraemia (3.2–4.1 per 100 admissions in
several papers). The higher amount of invasive procedures and the
severity of illness in this group of patients have been blamed. The
aims of our study are: (1) to identify the incidence of bacteraemia
in the NCCU, (2) to recognise the incidence of bloodstream
infection (SIRS with bacteraemia), (3) to identify the most common
pathogens associated with bacteraemia, and (4) to promote the
continuous collection of data aiming to follow the behaviour of this
problem in time. unit (NCCU) is at the moment unknown. It is known that being a
patient in the intensive care environment is in itself a risk factor for
the development of bacteraemia (3.2–4.1 per 100 admissions in
several papers). The higher amount of invasive procedures and the
severity of illness in this group of patients have been blamed. The
aims of our study are: (1) to identify the incidence of bacteraemia
in the NCCU, (2) to recognise the incidence of bloodstream
infection (SIRS with bacteraemia), (3) to identify the most common
pathogens associated with bacteraemia, and (4) to promote the
continuous collection of data aiming to follow the behaviour of this
problem in time. patients was almost the same for both groups. We noted, as well,
a larger number of deaths in the patients with sepsis and MOF. There needs to be more studies aiming to establish a casual
relationship to explain this. CNS was the most frequently isolated
organism and there was no difference among the groups. There is
a potential for increased mortality in the patients that develop
bloodstream infections in our unit, and we need to implement
urgent measures to decrease them while further research is done
in this area. P68 Conclusion The national prevalence of sepsis, the site of sepsis
and the patient profile in South Africa is similar to that described in
other studies [1]. Treating doctors are reasonably accurate in
diagnosing sepsis but prescribe antiobiotics inappropriately in the
vast majority of cases. Incidence of bacteraemia in a neurocritical care unit L Colorado, M Vizcaychipi, S Herbert, O Sule, R Burnstein
Addenbrooke’s Hospital, Cambridge, UK
Critical Care 2007, 11(Suppl 2):P68 (doi: 10.1186/cc5228) 1. An expert report of the European Society of Intensive
Care Medicine. The problem of sepsis. Intensive Care Med
1994, 20:300-304. 1. An expert report of the European Society of Intensive
Care Medicine. The problem of sepsis. Intensive Care Med
1994, 20:300-304. Introduction The incidence of bacteraemia and bloodstream
infection, as defined by the CDC, in our neurosciences critical care S26 Available online http://ccforum.com/supplements/11/S2 P69 Methods This is a prospective observational study looking at the
presence of positive blood cultures in all the patients admitted to
the NCCU during the period from 1 June to 31 August 2006. Blood cultures were taken from a peripheral site under aseptic
conditions as per the NCCU guidelines. We tried to identify how
many of the patients with positive blood cultures had evidence of
concomitant SIRS/sepsis, as described by the modified Bone
criteria, and the severity of this. An attempt was made to identify
the most frequent microorganisms involved in this problem as well
as their antibiotic susceptibility. As a secondary aim of our study
we described the number of fatalities in the patients with
bacteraemia. We tried to focus our approach to the fact that we
serve a large neurological/surgical population as well as general
patients and to see whether we could pinpoint differences in these
two groups. Awareness of the Surviving Sepsis Campaign amongst
emergency medicine and surgical trainees A Castellanos-Ortega, B Suberviola, A González-Castro,
C Gonzalez, A Ruiz, J Teja, F Ortiz
Hospital Universitario Marqués de Valdecilla, Santander, Spain
Critical Care 2007, 11(Suppl 2):P70 (doi: 10.1186/cc5230) L Evans
Queen Elizabeth Hospital, King’s Lynn, UK
Critical Care 2007, 11(Suppl 2):P71 (doi: 10.1186/cc5231) Introduction Data presented at the 2006 Barcelona conference of
the European Society of Intensive Care Medicine showed that, where
implemented, the Surviving Sepsis Campaign guidelines have
improved mortality from sepsis. However, because of overall poor
adherence to the guidelines, the stated aim of the campaign to
reduce mortality from severe sepsis by 25% is unlikely to be met. In
the United Kingdom, patients with sepsis of surgical origin will
typically be seen by emergency medicine (EM) before being admitted
to a surgical ward and are unlikely to be initially managed by the ICU. Both the EM and surgical juniors should therefore be aware of the
guidelines. The aim of this study was to determine the level of
awareness of the SSC guidelines in surgical and EM trainees. Introduction The purpose of the study was to describe the
effectiveness of the Surviving Sepsis Campaign (SSC) bundles
with regard to both implementation and outcome in patients with
septic shock. Methods This was a single-center prospective observational study
of patients admitted to the medical–surgical ICU of an urban
tertiary care teaching hospital meeting criteria for the international
sepsis definitions. Patients were entered in the database from
September 2005 to October 2006. After a widespread 2-month
educational program, implementation of SSC Resuscitation
Bundles (RB) and Management Bundles (MB) were accomplished. We determined the rate of compliance and the prognostic value of
the RB, the MB and of each bundle element. g
g
Methods A questionnaire-based survey was undertaken of all EM
and surgical trainees in the Eastern region of the United Kingdom. Participants were recruited by post, telephone, email and in person. The questionnaire assessed whether participants had experience in
critical care, were aware of the campaign or its guidelines and
assessed the level of familiarity of key concepts of the resuscitation
bundle of the guidelines. In addition, participants were encouraged
to comment on any aspect of sepsis management. Methods A questionnaire-based survey was undertaken of all EM
and surgical trainees in the Eastern region of the United Kingdom. Participants were recruited by post, telephone, email and in person. Awareness of the Surviving Sepsis Campaign amongst
emergency medicine and surgical trainees Th
i
i
d
h h
i i
h d
i
i Results We analyzed 135 consecutive episodes of septic shock. The main sources of infection were: abdomen 39.5%, lung 29.9%,
and urinary tract infection 11.1%. Global hospital mortality was
44.4%. Nonsurvivors were older (71 vs 64 years; P = 0.01), and
had a higher APACHE II score (25 vs 20; P = 0.000), a higher
SOFA score (10 vs 9; P = 0.001) and a higher number or organ
dysfunctions at sepsis presentation (4 vs 3; P = 0.007). The rate of
compliance with the RB was 38%. There were significant
differences in mortality between compliant (C) and noncompliant
(NC) groups despite the similar characteristics and the severity of
septic shock. The NC group had a 58% mortality rate and the C
group 22% (RR 2.6 (95% CI 1.49–4.5, P = 0.001)). The number
needed to treat to save one life was 3. The compliance rate with
MB was only 20%, and there were no differences in mortality
between the C and NC groups (57.9% vs 52.6%). We only found
differences in mortality between the C and NC groups in four
bundle elements: serum lactate measured before 6 hours (35.2%
vs 65.4%; P = 0.007), early broad-spectrum antibiotics (36.2.5%
vs 56.1%; P = 0.051), ScvO2 > 70% (35.7% vs 52.1%; P =
0.057) and activated protein C (65% vs 11% P = 0.000). In the
multivariate analysis, activated protein C, early broad-spectrum
antibiotics, PaO2/FiO2 < 200 and complete RB were associated
independently with mortality. The questionnaire assessed whether participants had experience in
critical care, were aware of the campaign or its guidelines and
assessed the level of familiarity of key concepts of the resuscitation
bundle of the guidelines. In addition, participants were encouraged
to comment on any aspect of sepsis management. Results Summarised in Table 1. There are 29 EM and 52 surgical
trainees in the Eastern region; responses were obtained from 22
and 34, respectively. The responses to the key concepts of the
resuscitation bundle varied greatly, even between different
participants from the same speciality in the same institution,
suggesting a lack of clear direction. Free text responses included
‘the only people that know about guidelines for sepsis are the ICU
physicians’ and ‘the only time I have heard of early goal directed
therapy was on ER’. Conclusion Awareness is reasonable amongst EM trainees but
poor amongst surgeons. P70 P70 P71 P71
Awareness of the Surviving Sepsis Campaign amongst
emergency medicine and surgical trainees P72 Compliance rates with RB during three consecutive 4.6-month
time periods were 28%, 41.4% and 33.3%, respectively. Compliance with MB was unchanged at 20%. The present dataset
is underpowered to determine whether implementation of SSC
bundles had some effect on mortality reduction. Awareness of the Surviving Sepsis Campaign amongst
emergency medicine and surgical trainees If the aims of the SSC are to be met,
consideration must be given to differences in healthcare systems in
different countries. In the United Kingdom, educational activities
should be directed towards EM and surgical trainees as well as
those working in intensive care. Impact of sepsis care bundles on hospital mortality in 135
consecutive patients with septic shock Impact of sepsis care bundles on hospital mortality in 135
consecutive patients with septic shock Implementation of early goal-directed therapy in Finland In multivariate analysis
including all separate targets, delay for ICU admission and
APACHE II score, the APACHE II value and measurement of
lactate were independent predictors of mortality (P = 0.001 and
0.02). Only 18% of patients had serum lactate measured during
the ED stay. The 1-year mortality of group A was 42% (95% CI
24–61%) and of group B was 59% (95% CI 43–73%) (P = 0.2). Conclusions The adoption of EGDT protocol was poor in Finnish
hospitals. The impaired early recognition of sepsis may lead to a
delay in ICU admission. The rate of reached EGDT targets
reflected mortality. In this study the most critical EGDT target was
the measurement of lactate during first 6 hours after arrival in the
ED. A forthcoming follow-up study will evaluate the impact of
guidelines to treatment and outcome of septic shock in Finland. From the patients that had at least one positive BC, nine died;
seven (78%) patients were in the G group, and two (22%) in the
NS group. Twenty-five (68%) patients with at least one episode of
positive BC had a systemic inflammatory response at the time of
sampling. Seven (28%) of these died during the first 30 days in the
NCCU. Nine (23%) patients had severe sepsis and four (44%) of
these died. Four (10.2%) patients had MODS and three (75%) of
these died. Conclusions We had an incidence of positive blood cultures of
almost 32% of the total admissions; 19.4% of admissions
developed bloodstream infections. These numbers are very high if
we consider the published data. Due to the specialist origin of our
unit, we had more cases in the neurosciences group than in the
general group. However, the incidence of sepsis and MOF in these S27 Compliance with the surviving sepsis guidelines: a review
of South African intensive care units S Bhagwanjee, F Paruk, J Scribante, H Perrie
University of the Witwatersrand and the CCSSA, Johannesburg,
South Africa
Critical Care 2007, 11(Suppl 2):P72 (doi: 10.1186/cc5232) Conclusions Implementation of SSC bundles was associated with
less adherence than expected. However, septic shock patients
receiving the complete resuscitation bundle had substantially lower
mortality. Efforts to increase compliance with these interventions
should be made. The poor adherence to management bundles
probably shows the many uncertainties that remain within this
group of interventions. Introduction Despite the availability of guidelines for practice in
many clinical domains, it is common for clinicians to practice
outwith these guidelines. As part of a 1-day sepsis prevalence study
in ICUs in South Africa, a review was undertaken to determine the Table 1 (abstract P71)
Worked in ICU
Claimed to be
Able to name
Any training on sepsis
Claim to be
Able to name piece of
Trainees
in past 2 years? aware of campaign
SSC
in past 2 years? aware of research
relevant research
Emergency medicine
8 (36%)
15 (68%)
10 (45%)
13 (59%)
13 (59%)
10 (45%)
Surgery
2 (6%)
6 (18%)
3 (8%)
9 (26%)
13 (38%)
8 (24%) Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 extent to which units comply with the surviving sepsis guidelines as
promulgated by the International Sepsis Forum [1]. Methods All adult patients with an APACHE III medical admission
diagnosis of nonurinary or urinary sepsis, or nonurinary or urinary
sepsis with shock, admitted directly to the ICU from the ED between
1 January 1997 and 31 December 2005 were identified. Predictor
variables for hospital mortality were analysed using logistic
regression with cross-validation (80% determination and 20%
validation) and robust, cluster-specific (ICU site) standard errors. Method Following appropriate institutional approval, 43 ICUs were
selected using the proportional probability sampling technique. This
was applied to a national database of ICUs. Every seventh bed was
selected from all the serially placed units. Data collected included
the presence of an infection control policy (including guidelines for
performance of blood cultures), recording of culture results,
microbiological support structures, glucose control protocols and
protocols for sedation analgesia and muscle relaxation. Results A total of 7,649 patients (54% male) of mean (SD) age
60.2 (18.1) years and APACHE III score 74.0 (34.7) were
identified. The number of patients admitted per year increased
progressively (1997, n = 368 (7.7 admissions per contributing
ICU); 2005, n = 1,409 (14.0 admissions per contributing ICU)). Nonurinary sepsis with shock was the most common admission
diagnosis (n = 3,394, 44.4%) and urinary sepsis with shock the
least common (n = 607, 7.9%). Overall ICU mortality and hospital
mortality were 20.9% and 27.6%, respectively. Hospital mortality
was predicted by hospital type (tertiary: 0.67 (0.51–0.90),
P = 0.007; metropolitan: 0.63 (0.48–0.83), P = 0.001; private:
0.65 (0.47–0.91), P = 0.011; reference category rural), age
(1.026 (1.019–1.034), P = 0.0001), APACHE III score (1.043
(1.038–1.048), P = 0.0001) and APACHE III score squared
(P = 0.032), sepsis category (nonurinary shock versus the other
three categories combined, 1.79 (1.48–2.16), P = 0.001), mecha-
nical ventilation within 24 hours of ICU admission (1.38
(1.14–1.66), P = 0.001) and calendar year as a single main linear
effect (0.94 (0.90–0.97), P = 0.0001). Significant interactions
were demonstrated between (i) sepsis classification and calendar
year (linear decrease in mortality, nonurinary shock x year 0.92
(0.86–0.99), P = 0.019), (ii) sepsis classification and age
(nonurinary shock x age 0.986 (0.977–0.996), P = 0.008), and (iii)
ventilation and time from hospital to ICU admission (<4.5 hours or
≥4.5 hours 1.38 (1.12–1.69), P = 0.002). Clinical simulation: caring for a critically ill patient with sepsis Clinical simulation: caring for a critically ill patient with sepsis K Giuliano, A Johannessen, S Crockett
Philips Medical Systems, Andover, MA, USA
Critical Care 2007, 11(Suppl 2):P74 (doi: 10.1186/cc5234) Reference Reference 1. Dellinger RP, Carlet JM, Masur H, et al., for the Surviving
Sepsis Campaign Management Guidelines Committee:
Guidelines for the management of severe sepsis and
septic shock. Crit Care Med 2004, 32:858-873. 1. Dellinger RP, Carlet JM, Masur H, et al., for the Surviving
Sepsis Campaign Management Guidelines Committee:
Guidelines for the management of severe sepsis and
septic shock. Crit Care Med 2004, 32:858-873. 1. Dellinger RP, Carlet JM, Masur H, et al., for the Surviving
Sepsis Campaign Management Guidelines Committee:
Guidelines for the management of severe sepsis and
septic shock. Crit Care Med 2004, 32:858-873. Introduction The purpose of this simulation research was to
assess whether bedside nurses could better apply currently
recommended therapeutic interventions for patients with sepsis by
using a horizons trends clinical decision support tool, rather than
just standard monitoring screen displays alone. Available online http://ccforum.com/supplements/11/S2 The model ROC curve
area and the P value for the Hosmer–Lemeshow C statistic were
0.86 and 0.37, respectively. Restricting the model to only those
ICUs that contributed data for all 9 years of the study period
yielded similar parameter estimates, including calendar year effect. Conclusions The reported incidence of sepsis and septic shock in
ICU patients presenting to the ED in Australia and New Zealand
has increased since 1997; hospital mortality has decreased. These
data require confirmation with a prospective study. Results Forty-three out of a total of 458 units were sampled. The
mean age of patients was 55 years with a male:female ratio of
60:40. Sixty-eight per cent of patients were admitted post surgery. An infection control policy was present in 77% of units. A practice
procedure for blood culture sampling was used in 51% of units,
with records of culture results being documented in 56% of units. Microbiologists were available in 65% of units and they were
involved in ward rounds in 26% of units. Physical consultation by a
microbiologist in 47% of units and telephone consultations in 54%
of units were possible. Sixty-one per cent of units had a glucose
control policy. Sedation, analgesia and neuromuscular blockade
protocols were present in 33%, 26% and 21% of units,
respectively. See Table 1. Table 1 (abstract P72)
Percentage of units utilizing protocols
Domain
Use (%)
Microbiologist available
65
Infection control policy
77
Glucose control protocol
61
Sedation protocol
33
Analgesia protocol
26
Neuromuscular blockade protocol
21 Table 1 (abstract P72) Table 1 (abstract P72)
Percentage of units utilizing protocols
Domain
Use (%)
Microbiologist available
65
Infection control policy
77
Glucose control protocol
61
Sedation protocol
33
Analgesia protocol
26
Neuromuscular blockade protocol
21 Percentage of units utilizing protocols Conclusion The majority of units have an infection control policy,
utilize glucose control regimens and have access to a
microbiologist. Sedation, analgesia and neuromuscular blockade
are infrequently utilized. Despite the availability of guidelines, it is
common for many recommendations not to be implemented. Further work is required to determine the reasons for
noncompliance with attention to educational programs and other
strategies to improve practice. Table 1 (abstract P71) S28 P76 Intellivue patient monitoring. Data were collected to compare the
use of bedside monitor displays with and without horizon screen
trends in the care of patients with sepsis. Group 1 (n = 37)
completed the sepsis scenario using a standard screen display, and
group 2 (n = 38) had the addition of horizon trends on the display. Results The point that marked the onset of sepsis was when each
of the physiologic parameters met the current evidence-based
screening criteria (HR > 90, RR > 20, MAP < 65, temperature
>38°C). Results of this study found statistically significant
differences between the standard screen and horizons screen
participant groups in the speed in which clinicians were able to
reach each measured outcome. This was true in each of the five
outcome measurements: onset of sepsis (P < 0.001), initiation of
fluid bolus (P < 0.001), initiation of vasopressor (P < 0.001), blood
culture order (P = 0.012), and antibiotic administration (P = 0.020). Conclusions These results support the hypothesis that monitoring
using horizons trending does indeed contribute to faster clinical
decision-making in the simulated septic patient experience. Future
research should concentrate on replicating these results in a real
clinical environment. P75 Results The incidence of VAP was reduced in the SDD group,
even though it was not statistically significant (26.9% vs 16.3%,
P = 0.138). The mortality of VAP and septic shock was reduced
respectively from 39.6% to 16.7% (P = 0.312) and from 60% to
37.5% (P = 0.835). During the SDD period, Gram-positive
infections increased while Gram-negative infections and Candida
infections showed a reduction. The percentage of resistant
species showed a reduction from 49.1% to 30.5% in all the
categories of pathogens (Table 1). Table 1 (abstract P76) Table 1 (abstract P76)
Percentages of pathogens
no-SDD
no-SDD
SDD
SDD
Infection
total
resistant
total
resistant
Gram-positive
32.5
31%
41.5
20%
(% of all
(% of all
(% of all
(% of all
VAP)
G+)
VAP)
G+)
Gram-negative
54
69%
50
44%
(% of all
(% of all
(% of all
(% of all
VAP)
G–)
VAP)
G–)
Candida
13.5
12.5%
8.5
0%
(% of all
(% of all
(% of all
(% of all
VAP)
candida)
VAP)
candida) Methods We performed a telephone survey of all NHS critical care
units in the North West of England (n = 31). Each unit was
telephoned and the duty consultant was asked a series of
questions relating to the type of microbiology input to their critical
care unit. Results We achieved a 100% response rate. The study looked at
11 teaching hospitals and 21 district general hospitals represen-
ting 12% of UK ICUs: 26 (83%) critical care units had live
computerised access to microbiology data, 21 (68%) units had an
antibiotic policy in place, and 19 (61%) units had a formal
microbiology ward round. With the frequency ranging from once
per week (one unit) to 7 days per week (four units), most units with
a microbiology ward round had this service Monday–Friday
(12 units). When asked to rate the value of this ward round, the
mean score was 8.6 out of a possible 10 (range 10–5, mode 9). In
those units without a microbiology ward round the desirability of
such a service was scored on average at 8.5 out of 10 (range
10–3, mode 9). Conclusions SDD and mupirocin were correlated to a reduced
incidence of VAP and mortality and to a reduction of resistant
species. Medical microbiology ward rounds in critical care L Wilson, G Dempsey
University Hospital Aintree, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P75 (doi: 10.1186/cc5235) Background
Direct microbiological input to critical care is
essential for the management of the septic patient. Early broad-
spectrum antimicrobial therapy with appropriate diagnostic studies
to ascertain causative organisms is well established; there should
be reassessment with the aim of using narrow-spectrum antibiotics
to prevent the development of antimicrobial resistance, to reduce
toxicity and to reduce costs [1]. In systematic analysis of ward
rounds in ICUs the information most commonly missing from a
patient’s file concerned microbiology findings [2]. Impact of a selective digestive decontamination and nasal
mupirocin on the incidence of ventilatory-associated
pneumonia and the emergence of bacterial resistance Impact of a selective digestive decontamination and nasal
mupirocin on the incidence of ventilatory-associated
pneumonia and the emergence of bacterial resistance E De Blasio, A Racca, C Pellegrini, C Di Maria, L Giunta, C Lallo,
E Bizzarro, G Prizio, A Capasso
Hospital ‘G. Rummo’, Benevento, Italy
Critical Care 2007, 11(Suppl 2):P76 (doi: 10.1186/cc5236) E De Blasio, A Racca, C Pellegrini, C Di Maria, L Giunta, C Lallo,
E Bizzarro, G Prizio, A Capasso
Hospital ‘G. Rummo’, Benevento, Italy
Critical Care 2007, 11(Suppl 2):P76 (doi: 10.1186/cc5236) Introduction Selective digestive decontamination (SDD) can
reduce the incidence of ventilatory-associated pneumonia (VAP). Some concerns have been raised about the risk of selection of
resistant bacteria. We evaluated the impact of a SDD regimen on
the incidence of VAP and the development of resistant pathogens. Introduction Selective digestive decontamination (SDD) can
reduce the incidence of ventilatory-associated pneumonia (VAP). Some concerns have been raised about the risk of selection of
resistant bacteria. We evaluated the impact of a SDD regimen on
the incidence of VAP and the development of resistant pathogens. Methods In a polyvalent eight-bed ICU, a retrospective analysis
was performed of two periods of 8 months before (no-SDD, 178
patients, mean SAPS II 44.8) and after (SDD, 110 patients, mean
SAPS II 48.9) the use of SDD with amphotericin, tobramycin and
colistin for oropharyngeal and gastric decontamination and
mupirocin for nasal decontamination. The results were analyzed
with the chi-square test. P73 The outcome of sepsis and septic shock presenting to the
Emergency Department in Australia and New Zealand Methods Simulation research participants (n = 75) were first
required to attend a didactic training session focusing on
recognition and evidence-based treatment for critically ill patients
with sepsis. Participants were then directed to apply these
treatments in a simulated sepsis experience. Data were collected
at two sites (AACN National Teaching Institute Critical Care
Nursing Conference, New Orleans, May 2005 and Long Beach
Memorial Medical Center’s Health Skills Education Center). A
METI HPS (human patient simulator) was connected to a Philips
Medical Systems Intellivue MP 70 in a simulated critical care
environment. Participants were given the patient history, and
completed the rest of their assessment using the HPS and S Peake for the ARISE Investigators, J Moran for the ANZICS
APD Management Committee
The Queen Elizabeth Hospital, Adelaide, Australia
Critical Care 2007, 11(Suppl 2):P73 (doi: 10.1186/cc5233) S Peake for the ARISE Investigators, J Moran for the ANZICS
APD Management Committee
The Queen Elizabeth Hospital, Adelaide, Australia
Critical Care 2007, 11(Suppl 2):P73 (doi: 10.1186/cc5233) Introduction The outcome of sepsis and septic shock patients
admitted to the ICU from the Emergency Department (ED) in
Australia and New Zealand was investigated using prospectively
collected data from the Australian and New Zealand Intensive Care
Society Adult Patient Database. Introduction The outcome of sepsis and septic shock patients
admitted to the ICU from the Emergency Department (ED) in
Australia and New Zealand was investigated using prospectively
collected data from the Australian and New Zealand Intensive Care
Society Adult Patient Database. S29 P76 P77 Comparison of bloodstream infections in intensive care
unit patients, due to different Gram-negative bacteria 1.
Widmer AF: Intensive Care Med 1994, 20 (Suppl 4):
S7–S11. Available online http://ccforum.com/supplements/11/S2 assess which of them is associated with higher mortality in ICU
patients. CR-BSI was used. Data were compared with historical controls at
the same ICU. Also, independent observers evaluated the
procedure for technique break (omitting any conditions listed
under MBP). Subsequently, in addition to MBP, all central venous
catheters were placed under intensivist supervision. Data analysis
included one-tailed z tests for proportions and t tests. Patients and methods This study was conducted in the 28-bed
multidisciplinary ICU of Evangelismos Hospital in Athens, during an
18-month period (August 2004–January 2006). All ICU patients
with blood cultures due to A. baumannii or P. aeruginosa or K. pneumoniae bacteremia, obtained >48 hours after ICU admission,
were studied. Patients with BSIs due to more than one of those
three pathogens were excluded. Information included patients’ age,
gender, underlying disease, admission category, hospitalization
before ICU admission, length of ICU stay, source of BSIs and ICU
mortality were compared. The illness severity was assessed by
APACHE II score on admission and on the day of BSI was
calculated prospectively for all patients. Results From 1 January 2000 to 31 December 2002 (control
period) the CR-BSI incidence was 12.1/1,000 catheter-days. Following implementation of MBP (1 January 2003–31 October
2004) the CR-BSI incidence decreased to 3.5/1,000 catheter-
days (19/5,499 catheter-days), P < 0.02; in 85 independently
observed line placements using MBP, 7/85 patients had CR-BSI
(8.2%). Technique breaks occurred in 34/85 procedures and were
associated with six CR-BSI (17.6%); the 51/85 procedures
without technique breaks had one infection (1.9%), P < 0.01. Intensivist supervision (11 January 2004 to 30 April 2006), in
addition to MBP, further reduced the incidence to 1.5/1,000
catheter-days (7/4,667 catheter-days), P < 0.04. Results During the study period, among 855 consecutively
admitted patients, with ICU stay longer than 48 hours, 197
patients developed BSIs due to A. baumannii (96 patients,
incidence 11.23%), P. aeruginosa (44 patients, incidence 5.15%)
and K. pneumoniae (57 patients, incidence 6.67%). Of these
patients, 85 developed BSIs with two or more pathogens and were
excluded. Thus, finally, 64 patients with A. baumannii BSI, 23 with
P. aeruginosa, and 25 with K. pneumoniae were compared. Hospitalization before ICU was shorter for K. pneumoniae
bacteremic patients compared with those with A. baumannii (1 vs
3 days, P = 0.028) and with those with P. aeruginosa (1 vs 6 days,
P = 0.005). On ICU admission, patients with A. P79 Risk of catheter-related bloodstream infection: higher in
more severe patients? N Cortez-Dias, A Pais de Lacerda, Z Costa e Silva, C França
Hospital de Santa Maria, Lisboa, Portugal
Critical Care 2007, 11(Suppl 2):P79 (doi: 10.1186/cc5239) Risk of catheter-related bloodstream infection: higher in
more severe patients? Risk of catheter-related bloodstream infection: higher in
more severe patients? N Cortez-Dias, A Pais de Lacerda, Z Costa e Silva, C França
Hospital de Santa Maria, Lisboa, Portugal
Critical Care 2007, 11(Suppl 2):P79 (doi: 10.1186/cc5239) Introduction Vascular devices are associated with the risk of
catheter-related bloodstream infection (Cr-BSI). The aim of this
study was to evaluate the risk of Cr-BSI in our ICU. Methods A nonconcurrent cohort study at an adult, 11-bed
medical/surgical unit, between 1 January and 31 December 2005. Data were retrospectively reviewed from clinical records and
bacteriological data concerning the presence of central venous
(CVC) or haemodialysis catheter (HDC) colonization and Cr-BSI
(no data on arterial catheters) were collected. Catheter insertion
and dressing of the insertion site were done according to CDC
guidelines for Cr-BSI prevention. Diagnosis of Cr-BSI required
microbial concordance between a culture of the removed catheter
and a separate percutaneously drawn blood culture, and the
exclusion of other overt source of bacteraemia. Intravascular
devices were cultured for evidence of colonization whenever there
was clinical suspicion of Cr-BSI. Severity scores (SOFA, SAPS II)
were assessed and analysed facing Cr-BSI data. Conclusion In ICU patients, the development of BSI due to A. baumannii is associated with a higher severity of illness on
admission compared with those due to P. aeruginosa and K. pneumoniae. However, P. aeruginosa BSI is associated with the
higher mortality. P78 y
g
Results During the study period, 378 patients were admitted to
the ICU (59% male; mean age 58.3 ± 19.8 years), the mean
SOFA score (admission) being 7.9 ± 4.0 and the mean SAPS II (at
24 hours) being 47.6 ± 19.7. In the 266 patients with CVC, the
total duration of implantation was 3.190 days, with a mean duration
of CVC placement/patient of 12 days. Positive cultures of CVC
were found in 18 patients (6.8%). The incidence density of positive
catheter cultures was 6.3/1,000 days of CVC use. CVC-related
BSI was diagnosed in 5 patients, the risk of CVC-related BSI
being 1.6/1,000 days of CVC use. Fifty-two patients also had a
HDC. Positive cultures of HDC occurred in two of these patients
(3.8%), none of them with Cr-BSI. The isolated microorganisms
from CVC and HDC were typical skin bacteria, excluding two
cases with catheter colonization in patients with other overt
sources of bacteraemia. The mean SOFA score in patients with
positive catheter cultures was 10.2 ± 3.1, the mean SAPS II was
63 ± 19.6 and the mean catheter placement duration in these
patients was 32.1 ± 15.7 days. The overall ICU mortality rate was Maximal barrier precautions, intensivist supervision, and
catheter-related bloodstream infections Available online http://ccforum.com/supplements/11/S2 baumannii had a
higher APACHE II score compared with those with K. pneumoniae
(19.53 ± 7.6 vs 15.0 ± 5.4, respectively, P = 0.017) and lower
hematocrit and hemoglobin values (29.8 ± 6.5 vs 35.4 ± 6.5,
P = 0.002 and 9.9 ± 2.2 vs 11.9 ± 2.2, P = 0.001) respectively. Also on BSI day, hematocrit was lower in patients with A. baumannii and with P. aeruginosa bacteremia, compared with
those with K. pneumoniae bacteremia (26.6 ± 4.5 vs 29.6 ± 4.5,
P = 0.016 and 26.1 ± 3.8 vs 29.6 ± 4.5, P = 0.021). The
respiratory tract was the most common source of BSIs due to A. baumannii compared with P. aeruginosa and K. pneumoniae
(56.3% vs 26.1%, P = 0.013 and 56.3% vs 12.0%, P = 0.001). Mortality was higher in the presence of P. aeruginosa and A. baumannii BSIs, compared with K. pneumoniae (56.5% vs 24.0%,
P = 0.021 and 48.4% vs 24.0%, P = 0.036, respectively). Conclusion While MBP can reduce the incidence of CR-BSI,
placement of central venous catheters by residents under
intensivist supervision can further lower the incidence. Comparison of bloodstream infections in intensive care
unit patients, due to different Gram-negative bacteria Comparison of bloodstream infections in intensive care
unit patients, due to different Gram-negative bacteria Conclusion Direct microbiological advice at the bedside is highly
valued by ICU consultants. Antibiotic prescribing is generally well
controlled, with two-thirds of units having an agreed antibiotic
policy in place. Work will continue to determine whether these
results reflect the national picture in the United Kingdom. References Conclusion Direct microbiological advice at the bedside is highly
valued by ICU consultants. Antibiotic prescribing is generally well
controlled, with two-thirds of units having an agreed antibiotic
policy in place. Work will continue to determine whether these
results reflect the national picture in the United Kingdom. M Pratikaki, E Platsouka, C Sotiropoulou, K Kritikos,
M Agrafiotis, S Kolias, S Nanas, O Paniara, C Roussos, C Routsi
Evangelismos, Athens, Greece
Critical Care 2007, 11(Suppl 2):P77 (doi: 10.1186/cc5237) Introduction To compare the incidence and risk factors of
bloodstream infections (BSIs) due to Acinetobacter baumannii,
Pseudomonas aeruginosa and Klebsiella pneumoniae and to 1. Widmer AF: Intensive Care Med 1994, 20 (Suppl 4):
S7–S11. F i
d
W J Cli
M
i S30 2. Friesdorf W: J Clin Monit 1994, 10:201-209. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P80 Background Nosocomial catheter-related bloodstream infections
(CR-BSI) have been associated with increased morbidity and
possibly increased mortality in critically ill patients. Central venous
catheters impregnated with rifampin and minocycline (RM) have
been shown to decrease rates of colonization and CR-BSI when
compared
with
controls
and
with
the
chlorhexidine/silver
sulfadiazine catheter. However, recent randomized trials challenged
the clinical impact of such catheters, showing decreased rates in
colonization but not in CR-BSI. We designed this pilot trial to
compare the rates of colonization and CR-BSI in RM catheters and
controls in a Brazilian population of critically ill patients. P80
Tunnelled central venous catheter-related infection in
cardiothoracic critical care
J Mitchell, P Shetty, F Cox, P Vuddamalay
Royal Brompton & Harefield NHS Trust, Harefield, UK
Critical Care 2007, 11(Suppl 2):P80 (doi: 10.1186/cc5240) Introduction Tunnelled central venous cannulae (CVC) are used in
cardiothoracic (CT) critical care for long-term inotrope, antibiotic
and renal replacement therapy (RRT). The incidence of blood-
stream-related infection (BSI) related to all types of CVC is
between 2.9 and 11.3 per 1,000 catheter-days [1]. In CT or
cardiology practice the incidence for all CVC-related infection is
2.9–4.5 per 1,000 catheter-days. The incidence of BSI is reduced
using tunnelled CVC, although there are little published data on
the incidence of BSI in tunnelled CVC in CT critical care. CVC-
related infection has been recognised as a priority in the UK
initiative ‘Saving Lives’ [2]. We reviewed tunnelled CVC-related
infection in a tertiary UK CT centre with a significant transplant
population. Methods A prospective, nonrandomized, controlled clinical trial
was conducted in one medico-surgical 19-bed ICU. Adult patients
needing a double or triple central venous catheter were
sequentially assigned in permuted blocks of five to undergo
insertion of a control or RM-impregnated catheter. After removal, all
tips were cultured by the roll-plate method in association with one
or two peripheral blood cultures. Rates of colonization and CR-BSI
were recorded and compared. Results Of 120 catheters inserted, 100 could be evaluated for
colonization and CR-BSI. Forty-nine in the uncoated group and 51
in the coated group. Clinical characteristics of patients and risk for
infection were similar in the two groups, use of propofol was more
frequent in the uncoated group and the presence of a vascular
device, other than the study catheter, was more frequent in the
antibiotic-coated group. P81 20.1%, being 40% in the subgroup of patients in whom Cr-BSI
was diagnosed. ANCCADI – Antibiotic Coated Catheter to Decrease
Infection: a pilot trial Conclusions Preventing Cr-BSI is important, but special care is
particularly relevant in patients with higher SAPS II scores and a
longer duration of catheter placement. More studies are needed to
confirm this possible higher risk of Cr-BSI in this more severe
patient subgroup. P Kurtz, M Kalichsztein, G Nobre, G Almeida, J Kezen, F Braga,
P Rosa, G Penna, L Drumond, R Vegni, M Freitas, M Pinto
Casa de Saude Sao Jose, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P81 (doi: 10.1186/cc5241) Maximal barrier precautions, intensivist supervision, and
catheter-related bloodstream infections Maximal barrier precautions, intensivist supervision, and
catheter-related bloodstream infections T Papadimos, S Hensley, J Hofmann, A Casabianca, M Borst,
J Fath, J Duggan
University of Toledo College of Medicine, Toledo, OH, USA
Critical Care 2007, 11(Suppl 2):P78 (doi: 10.1186/cc5238) Introduction Catheter-related bloodstream infections (CR-BSI)
have significant costs. Use of maximal barrier precautions (MBP)
may reduce the incidence of CR-BSI. We studied MBP with/
without intensivist supervision of residents on CR-BSI incidence. Methods We prospectively studied CR-BSI incidence in an ICU
following the implementation of MBP (hand washing before line
placement, sterile site preparation, draping the entire patient in
sterile fashion, use of hat, mask, gloves and gown, maintenance of
a sterile field, assistants following the same precautions, and sterile
dressing application). The Centers for Disease Control definition of S31 P81 20.1%, being 40% in the subgroup of patients in whom Cr-BSI
was diagnosed. Conclusions Preventing Cr-BSI is important, but special care is
particularly relevant in patients with higher SAPS II scores and a
longer duration of catheter placement. More studies are needed to
confirm this possible higher risk of Cr-BSI in this more severe
patient subgroup. P80 Three RM-coated catheters (5.9%) were
colonized compared with nine (18.4%) control catheters (relative
risk, 0,28; 95% confidence interval, 0.07–1.096; P = 0.05). Three
cases of CR-BSI (5.9%) occurred in patients who received RM
catheters compared with five in the control group (10.2%). There
was no significant differences in the incidence of CR-BSI between
RM-coated and uncoated catheters. Uncoated catheters were
more frequently colonized but this difference just failed to show
statistical significance. When the duration of catheter placement
were taken into consideration, Kaplan–Meier analysis showed no
significant differences in the risk of colonization or CR-BSI
between RM-coated and uncoated catheters. Rates of CR-BSI
were seven per 1,000 catheter-days in the RM-coated group
compared with 11.4 per 1,000 catheter-days in the uncoated
group (P = 0.7). Gram-positive and Gram-negative organisms were
similarly responsible for colonizing catheters in our study; there
was no difference in rates of colonization by Candida species. Conclusion In this pilot study, we showed a trend toward lower
rates of colonization in RM-coated catheters when compared with
uncoated control catheters. The incidence and rates of CR-BSI
were similar in the two groups, probably because of a small
number of catheters studied. Development of a prospective
randomized trial with a larger number of patients is underway to
confirm or refute these results. Methods A retrospective analysis from November 2001 to 2006
of culture and sensitivity results of tunnelled CVC tips (Bard
Groshong® cuffed catheter and HemoGlide®) and blood cultures
from the same patients. Results Ninety-three CT critical care patients received a tunnelled
subclavian CVC. The indications were inotropes (n = 40 (43%)),
antibiotic administration (n = 27 (29%)), RRT (n = 14 (15.1%))
and unknown (n = 10 (10.8%)). The mean duration of the catheter
remaining in situ was 36 days (SD 44.0, range 1–164). Culture
results are presented in Table 1. Twelve patients had an
established CVC-related BSI. The mean infection rate/1,000
catheter-days was 3.6. Table 1 (abstract P80)
Positive CVC
Positive
Positive
tip culture
blood culture
from both
Positive culture results (%)
36.6
18.3
12.9
Mean infection rate/
10.2
5.1
3.6
1,000 catheter-days Conclusion In this pilot study, we showed a trend toward lower
rates of colonization in RM-coated catheters when compared with
uncoated control catheters. The incidence and rates of CR-BSI
were similar in the two groups, probably because of a small
number of catheters studied. J Moon J Moon
Chonnam National University Hospital, Gwang-ju, Republic of Korea
Critical Care 2007, 11(Suppl 2):P82 (doi: 10.1186/cc5242) Introduction Blood culture was commonly performed, without any
specific indication, at the Emergency Department. However, the
true positive rate was found to be very low (1.8–5%) and patients
with true bacteremia usually had such risk factors as an indwelling
catheter, severe underlying disease or an immunocompromised
state. This study was performed to determine the usefulness of
performing blood culture for managing febrile immunocompetent
patients who present to the Emergency Department. Method We prospectively analyzed the medical characteristic and
the results of blood culture of febrile immunocompetent patients
who were more than 18 years old and who presented to the
Chonnam National University Hospital Emergency Center from
April 2005 to October 2005. Fever was defined as a single axillary
temperature higher than 38.0°C. The two sets of blood for culture
were drawn at the antecubital area by the emergency physician
who knew well how to obtain blood for culture. The bacteremia
was classified as true bacteremia or contamination, based on the
presence of clinical signs and symptoms and also on the criteria of
MacGregor. For the true bacteremia group, we further investigated
the changes that occurred with the previously administered
antibiotic therapy according to the results of blood culture. facility, over a period from February to June 2006. SIRS was
defined according to the criteria proscribed by the Society of
Critical Care Medicine. A research officer stationed in the ER
identified patients. Exclusion criteria were age < 18 years, patients
transferred from other hospitals or chronic care facilities. Demo-
graphic and study-specific data were collected. The patient was
followed until subsequent death or discharge. The primary
outcome variable was survival to hospital discharge and the
secondary outcome was length of hospitalization. An independent
t-test analysis was carried out for the primary independent variable
(timing of administration of antibiotics) and primary outcome
(mortality) for significant differences between the groups. A two-
sided P value <0.05 was considered as statistical significance. Logistic regression modeling was used to examine survival as a
function of timing of antibiotic administration. Results This study included 182 patients: of the 182 cultures, only
36 were positive with 10 contaminants (5.5%) and 26 true
positives (14.3%). P84 Introduction Despite improvements in technology and healthcare
services, mortality rates from severe sepsis have remained
unchanged over the past few decades. Exciting new data are
emerging about the benefits of early, aggressive management in
the Emergency Room (ER). We carried out this study to study the
patterns of antibiotic administration in our ER and their effects on
the length of hospitalization and survival. P83 Impact of early antibiotics on severe sepsis – are we doing
a good job? N Salahuddin, S Siddiqui, J Razzak, A Raza
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P83 (doi: 10.1186/cc5243) J Moon The most common disease that required blood
culture in the Emergency Department was respiratory infection
(57/182) and the most common disease with true bacteremia was
urinary infection (41.9%). A low initial level of albumin was the
characteristic associated with a positive blood culture result on
multivariate analysis. Management of only five patients was
influenced by the blood culture results (2.7%). Results Patients enrolled in the study numbered 111. At presen-
tation 36 patients (32.4%) had 1/4 criteria for SIRS, 67 (60.4%)
had 2/4 criteria and only eight (7.2%) patients had 3/4 criteria. Sixteen patients (14.4%) were in shock. Sepsis was confirmed by
cultures in 96 (86.5%) patients. One hundred (90.1%) patients
received intravenous antibiotics in the ER; the average time from
triage to actual administration was 2.8 (± 1.86) hours. The timing
of administration of antibiotics was statistically significant in
determining survival. Patients with sepsis and receiving antibiotics
in <1 hour had a mean survival of 99% and a length of
hospitalization of 3 days as compared with those receiving anti-
biotics in 1–4 hours (84.5% survival, LOS 5.25 days) and patients
who received antibiotics in >4 hours (76% survival, LOS 7 days,
P < 0.003). Using a Cox regression model, we were able to
demonstrate that survival dropped acutely with an hourly delay in
antibiotic administration. Overall mortality with sepsis was 34.2%. Conclusions Administration of appropriate antibiotics within
4 hours of arrival in the ER has a significantly favorable impact on
survival in patients with sepsis. Conclusion The blood cultures, as were usually ordered for febrile
immunocompetent patients in the Emergency Department, rarely
altered patient management and the results had limited usefulness. The emergency physician who initially treats these patients has to
consider this limitation of blood culture. Also, eliminating blood
cultures for immunocompetent patients may hold down unneces-
sary medical expenses. Is the blood culture useful in febrile immunocompetent
patients in the Emergency Department? Is the blood culture useful in febrile immunocompetent
patients in the Emergency Department? P80 Development of a prospective
randomized trial with a larger number of patients is underway to
confirm or refute these results. Conclusion The incidence of tunnelled CVC colonisation and
positive blood cultures in this group of CT critical care patients is
in line with previously published data for all types of CVC. Coagulase-negative staphylococcus was the predominant isolate
in both this audit and previously published data [1]. References 1. O’Grady NP, Alexander M, Dellinger EP, et al: Guidelines for
the prevention of intravascular catheter-related infections. Centers for Disease Control and Prevention, Atlanta, USA. MMWR 2002, 51(RR-10):1-29. 2. Saving Lives: The Delivery Programme to Reduce Healthcare
Associated Infections (HCAI) including MRSA. London:
Department of Health; 2005. S32 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P83) P82 Figure 1 (abstract P83) Timing of admissions and outcome of pneumonia in
intensive care units in the United Kingdom H Boralessa1, C Welch2, K Raveendran1, E Veerasingam1,
N Ibrahim1, D Harrison2
1Oldchurch Hospital, Essex, UK; 2ICNARC, London, UK
Critical Care 2007, 11(Suppl 2):P86 (doi: 10.1186/cc5246) Table 1 (abstract P85) Results A total of 101 patients were enrolled, 61 patients during
period A and 40 patients during period B. No significant
differences were found between mean age (48.6 years vs 50.4
years old), SAP II score (44.5 vs 46.5), aetiology of coma (mainly
ischaemic stroke, cardiac arrest, refractory epilepsy, intoxication),
and early-onset (n = 12 vs n = 6) or late-onset pneumonia (n = 1
vs n = 2). During period B, the time for onset of colonisation (6.6
days vs 3 days, P = 0.008) or pneumonia (8.4 days vs 4.2 days,
P = 0.03) was increased compared with period A. We did not
diagnose
multidrug-resistant
infection
or
colonisation. No
difference was found with regard to mortality and morbidity:
duration of mechanical ventilation (5.7 days vs 6.7 days) or total
hospitalisation stay (26.6 days vs 16.9 days), total mortality (n = 9
vs n = 10 patients) or at day 28 (n = 6 vs n = 7 patients),
respectively, in periods A and B. In multivariate analysis, tobacco,
cardiac arrest and ischaemic stroke were independent risk factors
of pneumonia. Appropriateness of antibiotic therapy Conclusion There are significant differences in antibiotic prescribing
practices when public and private sectors are compared. Appropriate early antibiotic prescriptions reduce mortality. Attention
to education and systems that address prescribing practices is
indicated. Conclusion In our study, contrary to previous ones [1,2], anti-
bioprophylaxy did not show a decrease in the incidence of
nosocomial pneumonia in medical comatose patients with
Glasgow Coma Score < 8 under mechanical ventilation. On the
other hand, antibiotics induce a later onset of colonisation and lung
infections. Despite a prevention of early-onset nosocomial
pneumonia, our data do not support the use of regular prophylactic
antibiotics. References 1. Sirvent JM, et al.: Protective effect of intravenously admin-
istered cefuroxime against nosocomial pneumonia in
patients with structural coma. Am J Respir Crit Care Med
1997, 155:1729-1734. Introduction This study aims to assess the association between
the timing of admission and outcome in patients admitted with
pneumonia to ICUs in the United Kingdom. 2. Acquarolo A, et al.: Antibiotic prophylaxis of early onset
pneumonia in critically ill comatose patients. A random-
ized study. Intensive Care Med 2005, 31:510-516. Methods All patients admitted to an ICU with a primary reason for
admission of pneumonia were extracted from the Case Mix
Programme Database. ‘Early’ admissions, admitted to the ICU on
the day of admission to hospital (12,475), were compared with
‘late’ admissions, admitted to the ICU on a later date (21,948). The
ICU and hospital mortality, number of organs failed, renal
dysfunction, and length of stay in hospital were compared between
the two groups. An association was sought between timing of
admission and mortality. Patients were stratified by CURB 65
score on admission to the ICU. Mortality was compared between
the two groups. Odds ratios were used to analyse data. P < 0.05
was considered significant. Protective effect of antibiotic prophylaxis against early-
onset nosocomial pneumonia in comatose patients J Navellou, C Manzon, M Puyraveau, D Perez, E Laurent,
C Patry, G Capellier
CHU Jean Minjoz, Besancon, France
Critical Care 2007, 11(Suppl 2):P84 (doi: 10.1186/cc5244) J Navellou, C Manzon, M Puyraveau, D Perez, E Laurent,
C Patry, G Capellier
CHU Jean Minjoz, Besancon, France
Critical Care 2007, 11(Suppl 2):P84 (doi: 10.1186/cc5244) Methods This was a prospective, observational cohort study that
reviewed all adult patients presenting with systemic inflammatory
response syndrome (SIRS) to the ER of the Aga Khan University
Hospital, which is a 554-bed primary care/tertiary care referral Objective To study the impact of prophylactic antibiotics on the
occurrence of early-onset nosocomial pneumonia in patients with
medical coma. S33 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin postculture modification of therapy, duration of therapy and, finally,
impact of appropriate antibiotic choice on mortality. Results See Table 1. Public-sector practice is better with respect
to pretherapy sampling and duration of treatment. Better
modification of treatment occurs in the private sector. Overall mortality of both groups was 10/82 (12%) when antibiotic
choice was appropriate compared with 28/90 (31%) (P < 0.05)
when therapy was inappropriate. postculture modification of therapy, duration of therapy and, finally,
impact of appropriate antibiotic choice on mortality. Patients and methods An open, before and after, single-center
trial, in the medical ICU of the University Hospital of Besancon,
France. A first period (A, retrospective) extended during 18 months
(April 2003–October 2004) without antibiotic prophylaxis and was
followed by a second period (B, prospective) during 18 months
(November 2004–April 2006). Patients received prophylaxis
treatment by amoxicillin and clavulanic acid, shortly after intubation
and during a 24-hour period. Inclusion criteria were medical loss of
consciousness, Glasgow Coma Score < 8, and length of intubation
> 48 hours. Results See Table 1. Public-sector practice is better with respect
to pretherapy sampling and duration of treatment. Better
modification of treatment occurs in the private sector. p
Overall mortality of both groups was 10/82 (12%) when antibiotic
choice was appropriate compared with 28/90 (31%) (P < 0.05)
when therapy was inappropriate. Table 1 (abstract P85) Table 1 (abstract P85)
Appropriateness of antibiotic therapy
Intervention
Sector
Number
Percentage
Preculture sampling
Private
27/62
43*
Public
73/120
61
Modification of antibiotics
Private
49/61
80
Public
18/27
67
Duration of treatment
Private
25/134
19*
Public
26/49
53
*P < 0.05. Table 1 (abstract P85) P88 Introduction The medical literature shows that the most important
prognosis factor in nosocomial pneumonia is the correct empirical
antimicrobial therapy. Recently the microorganisms have been
becoming more resistant to the usual antibiotics and there are
many reports of Gram-negative bacilli (GNB) only susceptible to
Polimixyn b (PB). The ATS guideline does not suggest the use of
PB as an empirical therapy, while the Brazilian Sepsis Guideline
(BG) allows the use of this antibiotic in special circumstances. The
aim of this study was to compare the efficacy of both guidelines,
based on the microbiological data. Results In our 22-bed ICU, during a 27-month period, 156
patients underwent BAL procedures due to clinical suspicion of
VAP. Out of these, 118 patients (120 BAL) had semiquantitative
tracheal aspirate (SQTA) performed 48 hours prior to the clinical
diagnosis of VAP (males 71/118; mean age 47 ± 16 years; SAPS II
35 ± 10). See Table 1 for pathogen prediction by SQTA surveil-
lance cultures. See Table 2 for concordance of SQTA–BAL when
only multiresistant microorganisms are considered. Negative BAL Methods This is a retrospective study with 93 cases of nosocomial
pneumonia diagnosed according to the ATS criteria, managed in
our ICU from 1 February 2005 to 16 September 2006. We
analyzed the efficacy of both guidelines, using them during all the
study period or stratifying the patients into two groups according
to the research median period (24 November 2005). Table 1 (abstract P87)
Concordance,
a) Same microorganisms SQTA–BAL
66/76 (87%)
76/120 (63%)
b) No significant growth
10/76 (13%)
Partial
a) 2 microorganisms SQTA–1 BAL
4/17 (24%)
concordance,
b) 1 microorganism SQTA–1 BAL
13/17 (76%)
17/120 (14%)
No concordance,
a) No significant growth
14/127
27/120 (23%)
SQTA–1 or 2 microorganisms BAL
b) Different microorganisms SQTA–1 BAL
13/27
Table 2 (abstract P87)
Multiresistant
microorganism
SQTA
BAL
Concordant
%
Ps. Reference 1. James L, Hoppe-Bauer JE: Processing and interpretation of
lower resp tract in specimens. In Clinical Microbiology Pro-
cedures Handbook. Edited by Isenberg HD. Washington, DC:
ASM Press; 1992:1.15.1–1.15.8. 1. James L, Hoppe-Bauer JE: Processing and interpretation of
lower resp tract in specimens. In Clinical Microbiology Pro-
cedures Handbook. Edited by Isenberg HD. Washington, DC:
ASM Press; 1992:1.15.1–1.15.8. H Bagnulo, M Godino, A Galiana, M Bertulo, W Pedreira
Hospital Maciel, Montevideo, Uruguay
Critical Care 2007, 11(Suppl 2):P87 (doi: 10.1186/cc5247) Introduction Most investigators discuss the predictive value of
respiratory surveillance cultures in mechanically ventilated patients
and doubt on the appropriate selection of the antibiotic therapy
based on these findings, when pneumonia develops. The aim of
our study was to evaluate whether microorganisms cultured from
semiquantitative tracheal aspirates (SQTA) in the 48 hours prior to
the clinical suspicion of ventilator-associated pneumonia (VAP)
were predictive of the etiology, compared with the bronchoalveolar
lavage (BAL) results performed on the same day that the clinical
diagnosis was considered Antibiotic prescribing practices in public and private-sector
intensive care units in South Africa S Bhagwanjee, H Perrie, J Scribante, F Paruk
University of the Witwatersrand and the CCSSA, Johannesburg,
South Africa
Critical Care 2007, 11(Suppl 2):P85 (doi: 10.1186/cc5245) Results There were small but statistically significant differences
between the two groups in mean age, APACHE II score, CURB 65
score and number of organ failures, and the presence of Introduction Considerable variability exists in antibiotic prescribing Introduction Considerable variability exists in antibiotic prescribing
practices. A dichotomous health care system in South Africa has
created the opportunity for vastly differing practices. As part of a
national 1-day sepsis prevalence study (PISA), a review was
undertaken of antibiotic prescribing practices in public and private-
sector ICUs. Table 1 (abstract P86)
CURB65
Odds ratio
95% CI
P value
1
1.02
0.9–1.16
0.8
2
1.23
1.13–1.34
<0.0001
3
1.25
1.16–1.35
<0.0001
4
1.46
1.29–1.65
<0.0001
5
1.41
1.03–1.91
0.03 Method Following appropriate institutional approval, 43 ICUs were
selected using the proportional probability sampling technique. This was applied to a national database of ICUs. Every seventh
bed was selected from all the serially placed units. Antibiotic
therapy was reviewed by two independent reviewers. Data
collected included the appropriateness of pretherapy cultures, S34 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 cultures with SQTA growth were never found. Polymicrobial SQTA
cultures: 13 concordant, seven only partial concordant, four not
concordant. There was no incidence in our results related to
previous antibiotic therapy: 33% of the concordant, 24% of the
partial concordant and 29% of the no concordant were on
antibiotics when SQTA was obtained. respiratory organ failure. There was no difference in the presence
of renal dysfunction. Late admissions with pneumonia had higher
ICU and hospital mortality, and longer hospital stay. At each CURB
65 score the late admissions had higher hospital mortality, which
was significant at scores of 2–5 (Table 1). Conclusion Early admission may reduce mortality in patients
admitted to ICUs with pneumonia. CURB 65 scores could facilitate
triage of patients with pneumonia. Conclusions In our patient population, routine surveillance SQTA
cultures accurately predict more than 60% of the etiologic agents
of VAP. This prediction increases to 80% when multiresistant
microorganisms are considered. Due to routine surveillance
cultures, our antibiotic prescriptions can become more adequate. P88 Comparing a Brazilian guideline to treat nosocomial
pneumonia with the ATS guideline in a tertiary hospital in
Brazil
M Kalichsztein, B Wajsbrot, A dos Santos, J Camillo Jorge,
B Fabricio, K Pedro, G Nobre, E Moreira, M Freitas, A Paula
Casa de Saúde São José, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P88 (doi: 10.1186/cc5248) Comparing a Brazilian guideline to treat nosocomial
pneumonia with the ATS guideline in a tertiary hospital in
Brazil M Kalichsztein, B Wajsbrot, A dos Santos, J Camillo Jorge,
B Fabricio, K Pedro, G Nobre, E Moreira, M Freitas, A Paula
Casa de Saúde São José, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P88 (doi: 10.1186/cc5248) Methods Routine SQTA were performed twice weekly in all
intubated patients for over 72 hours according to the methodology
described elsewhere [1]. Fiberoptic bronchoscopy with BAL was
preformed the same day that VAP was suspected according to
Johanson criteria (fever, leucocytosis, purulent secretions and
infiltrate on radiograph) plus gas-exchange deterioration. Results In our 22-bed ICU, during a 27-month period, 156
patients underwent BAL procedures due to clinical suspicion of
VAP. Out of these, 118 patients (120 BAL) had semiquantitative
tracheal aspirate (SQTA) performed 48 hours prior to the clinical
diagnosis of VAP (males 71/118; mean age 47 ± 16 years; SAPS II
35 ± 10). See Table 1 for pathogen prediction by SQTA surveil-
lance cultures. See Table 2 for concordance of SQTA–BAL when
only multiresistant microorganisms are considered. Negative BAL Methods Routine SQTA were performed twice weekly in all
intubated patients for over 72 hours according to the methodology
described elsewhere [1]. Fiberoptic bronchoscopy with BAL was
preformed the same day that VAP was suspected according to
Johanson criteria (fever, leucocytosis, purulent secretions and
infiltrate on radiograph) plus gas-exchange deterioration. Introduction The medical literature shows that the most important
prognosis factor in nosocomial pneumonia is the correct empirical
antimicrobial therapy. Recently the microorganisms have been
becoming more resistant to the usual antibiotics and there are
many reports of Gram-negative bacilli (GNB) only susceptible to
Polimixyn b (PB). The ATS guideline does not suggest the use of
PB as an empirical therapy, while the Brazilian Sepsis Guideline
(BG) allows the use of this antibiotic in special circumstances. The
aim of this study was to compare the efficacy of both guidelines,
based on the microbiological data. Are routine endotracheal aspirates predictive of the
etiology of ventilator-associated pneumonia? Are routine endotracheal aspirates predictive of the
etiology of ventilator-associated pneumonia? Are routine endotracheal aspirates predictive of the
etiology of ventilator-associated pneumonia? P89 the correlation between bronchoalveolar bacterial burden and the
lung inflammatory response. Outcomes from ventilator-associated pneumonia caused
by multidrug-resistant organisms or Pseudomonas: results
from 28 intensive care units Objective The aim of the present study was to evaluate the
relationship between bronchoalveolar cytokine expression and
bacterial burden in mechanically ventilated patients with suspected
pneumonia. Methods
Mechanically ventilated patients with suspected
pneumonia admitted to the ICU from November 2004 to January
2006 were prospectively enrolled. Fiberoptic bronchoalveolar
lavage (BAL) was performed with 150 ml sterile isotonic saline in
three aliquots of 50 ml; local anesthetic was not used. BAL
samples for microbiologic quantitative cultures and BAL cytokines –
IL-6, IL 8, TNFα, granulocyte colony-stimulating factor (G-CSF)
and granulocyte–monocyte colony-stimulating factor (GM-CSF) –
were measured. Introduction Patients who develop ventilator-associated pneumonia
(VAP) caused by either multidrug-resistant organisms (MDRO) or
Pseudomonas may have poor clinical outcomes. We sought to
further clarify this potential relationship using a database from a
large multicenter trial of diagnostic and therapeutic strategies in
patients who had suspected VAP. Results Fifty-nine patients were included, and most of the patients
(79.7%) had prior antibiotic therapy. Twenty-two patients (37.2%)
had a positive bacterial culture defined as a diagnostic threshold
>10,000 colony-forming units/ml. Only the concentration of TNFα
was significantly higher in the group of patients with positive BAL
(Table 1). Methods Patients receiving mechanical ventilation (MV) for ≥96 hours
and who developed suspected VAP (new or worsening pulmonary
opacities on CXR, and at least two of fever, leukocytosis, change
in sputum purulence, increased O2 needs, or isolation of potentially
pathogenic bacteria from sputum) were eligible. At enrolment, all
patients had cultures obtained from either BAL or endotracheal
aspirates. MDRO were defined as those resistant to ≥2 classes of
antibiotics. Patients were followed until 28 days after enrolment,
death, or hospital discharge. Conclusions (1) There is a significant correlation between TNFα in
BAL fluid and the lung bacterial burden. (2) BAL TNFα is an early
marker of pneumonia in mechanical ventilated patients despite
prior antibiotic therapy. Clinical implication Cytokine measurements in BAL may be a
diagnostic tool to support the diagnosis of the initial phase of
pneumonia. Results Seven hundred and thirty-nine patients from 28 ICUs in
Canada and USA were enrolled. At enrolment, cultures from
10.0% (95% CI 7.9–12.4%) of the patients grew MDRO or
Pseudomonas. The prevalence of MDRO at enrolment was 5.2%
(3.6–6.8%). P91 P91
Risk factors for treatment failure in patients with ventilator-
associated pneumonia receiving appropriate antibiotic
therapy
G Gursel, M Aydogdu, E Ozyilmaz, T Ozis
Gazi University School of Medicine, Ankara, Turkey
Critical Care 2007, 11(Suppl 2):P91 (doi: 10.1186/cc5251) Risk factors for treatment failure in patients with ventilator-
associated pneumonia receiving appropriate antibiotic
therapy Conclusion The isolation of MDRO or Pseudomonas from
respiratory tract specimens of patients with suspected VAP is
associated with prolonged MV, increased ICU and hospital stay,
and increased risk of death. Inadequate initial empiric antibiotic
treatment may be a contributing factor. Introduction Treatment failure (TF) can be anticipated in 30–40%
of patients developing ventilator-associated pneumonia (VAP). Little information about lack of response of VAP to treatment is
available. The aim of the study is to evaluate potential risk factors
for TF in patients with VAP receiving appropriate antibiotic therapy. Methods A prospective observational cohort study. Microbio-
logically confirmed (>105 colony-forming units/ml) clinical findings
(CPIS > 6) were necessary for the diagnosis of VAP. TF was
defined as a lack of clinical (in first 3 days of the therapy) and
microbiological (in first 7 days of the therapy) response to therapy. All patients had surveillance cultures for endotracheal aspirate
(every second day), urine and blood (weekly). Student’s t tests, chi-
square tests and logistic regression analyses were used for
statistical analyses. P89 There were no differences in APACHE II, MODS, or
PaO2/FiO2 at baseline between those whose specimens grew
MDRO or Pseudomonas and those whose specimens did not. Patients with MDRO or Pseudomonas had higher 28-day mortality
(RR 1.59, 95% CI 1.07–2.37, P = 0.04) and inhospital mortality
(RR 1.48, 95% CI 1.05–2.07, P = 0.05) and a trend towards
higher ICU mortality (RR 1.42, 95% CI 0.90–2.23, P = 0.14) than
those whose specimens did not grow these organisms. Median
duration of MV (12.6 vs 8.7 days), ICU length of stay (16.2 vs 12.0
days) and hospital length of stay (55.0 vs 41.8 days) was greater
in patients with MDRO or Pseudomonas than in those whose
specimens did not grow these pathogens (P = 0.05). Adequacy of
initial empiric therapy was 68.5% in patients whose specimens
grew MDRO or Pseudomonas compared with 93.9% in those
without these organisms (P < 0.001). Table 1 (abstract P90)
BAL–
BAL +
P
IL-6 BAL (pg/ml)
180.3 ± 252
293.4 ± 421
0.410
IL-8 BAL (pg/ml)
1,301 ± 1,045
1,681 ± 1,315
0.442
TNF BAL (pg/ml)
48.9 ± 80.7
222.6 ± 308
0.022
G-CSF BAL (pg/ml)
444.8 ± 565
408.1 ± 491
0.713
GM-CSF BAL (pg/ml)
14.1 ± 23.4
9.35 ± 17.32
0.126 P91 P88 aeruginosa
22
22
20/24
83
Acinetobacter
14
11
10/15
67
MRSA
8
9
8/9
89
Klebsiella
2
2
2/2
100
Stenotrophomona
1
1
1/1
100
Total multiresistant
41/51
80
microorganisms Table 1 (abstract P87)
Concordance,
a) Same microorganisms SQTA–BAL
66/76 (87%)
76/120 (63%)
b) No significant growth
10/76 (13%)
Partial
a) 2 microorganisms SQTA–1 BAL
4/17 (24%)
concordance,
b) 1 microorganism SQTA–1 BAL
13/17 (76%)
17/120 (14%)
No concordance,
a) No significant growth
14/127
27/120 (23%)
SQTA–1 or 2 microorganisms BAL
b) Different microorganisms SQTA–1 BAL
13/27 p
Results There were 67 cases of ventilator-associated pneumonia
(VAP) and 26 cases of non-VAP. The overall result shows that the
ATS would be effective in 76% (CI 67–85%) and the BG in
87.9% (CI 81–94.7%) of the cases. This difference was
statistically significant (P = 0.035). The most prevalent bacteria
were Acinetobacter sp. and Pseudomonas aeruginosa. From
February to August 2005 there were a burden of multiresistant
(MR) GNB, only susceptible to PB. Using the ATS or the BG in
this period, the guidelines would be effective in 64% (CI 51–77%)
and 84.4% (CI 74.8–94%) respectively (P = 0.017). In the second
half of the study we controlled the MR GNB, and the efficacy of
both guidelines were similar between ATS and BG (97% vs
93.9%; P = 1). Table 2 (abstract P87)
Multiresistant
microorganism
SQTA
BAL
Concordant
%
Ps. aeruginosa
22
22
20/24
83
Acinetobacter
14
11
10/15
67
MRSA
8
9
8/9
89
Klebsiella
2
2
2/2
100
Stenotrophomona
1
1
1/1
100
Total multiresistant
41/51
80
microorganisms Table 2 (abstract P87) Conclusions Our data show that the more restrictive ATS
guideline can significantly lead to a wrong empirical therapy in MR
GNB high-prevalence situations. The use of the BG can lead to a
better empirical treatment in this situation. This information
enhances the need for ICU flora knowledge, which are seasonal,
so there is no ‘all time and place perfect guideline’, although the
BG was a better option in our ICU than the ATS guideline. S35 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine P90 Bacterial burden and bronchoalveolar cytokines in
mechanically ventilated patients with suspected
pneumonia P92 Results We had 40 episodes (2,247 ventilator-days) of VAP
(40/133 patients) and 45 isolates. In early-onset pneumonia
(≤5 days, eight episodes, three with two isolates): six Acinetobacter
baumannii: meropenem, colistin, gentamicin (five); three Pseudo-
monas aeruginosa: piperacillin, aztreonam, imipenem, ceftazidime,
colistin, ciprofloxacin, cefepime, meropenem, aminoglycosides; one
Klebsiella pneumoniae: meropenem, colistin, tetracycline; Fungi 1:
no susceptibility results. In late-onset pneumonia (>5 days, 32
episodes, two with two isolates): 25 A. baumannii: four to
amoxicillin-clavulanic,
ceftazidime,
piperacillin-tazobactam, Intensive care nurses’ knowledge of evidence-based
guidelines for the prevention of ventilator-associated
pneumonia Intensive care nurses’ knowledge of evidence-based
guidelines for the prevention of ventilator-associated
pneumonia S Labeau1, D Vandijck2, P Van Aken3, B Claes3, S Blot2
1Hogeschool Ghent, Belgium; 2Ghent University Hospital, Ghent,
Belgium; 3Antwerp University Hospital, Antwerp, Belgium
Critical Care 2007, 11(Suppl 2):P92 (doi: 10.1186/cc5252) Introduction Nonadherence to evidence-based guidelines for the
prevention of ventilator-associated pneumonia (VAP) has been
reported. As a lack of knowledge may be a barrier for adherence,
this study aimed to determine intensive care nurses’ knowledge of
evidence-based guidelines for VAP prevention. aztreonam, imipenem, colistin, ciprofloxacin, cefepime, meropenem,
aminoglycosides, 19 to meropenem, gentamicin, colistin, tetracycline
and two to colistin; four P. aeruginosa: two to piperacillin-
tazobactam, two to colistin; one K. pneumoniae: piperacillin-
tazobactam, aztreonam, imipenem, ceftazidime, colistin, ciprofloxacin,
cefepime, meropenem, aminoglycosides, amoxicillin-clavulanic; Fungi
1: no susceptibility results and three unspecified isolates. Methods This study is a survey using a validated multiple-choice
questionnaire, developed to evaluate nurses’ knowledge of VAP
prevention and based on a recently published review by Dodek
and colleagues [1]. Knowledge of nine nursing-related strategies
was evaluated. The questionnaire was distributed and collected
during the Flemish Society for Intensive Care Nurses’ annual
congress (Ghent, 2005). Demographic data included were gender,
intensive care experience, number of critical beds and whether
nurses hold a special degree in emergency and intensive care. Excluding fungi and unspecified isolates, we had 8/45
multisensitive isolates and 32/45 isolates sensitive to colistin (32),
meropenem (26) and gentamicin (21). According to these data in
early and late VAP the most adequate therapeutic combination to
cover possible pathogens is meropenem + colistin. Using this
combination we cover all possible pathogens and then de-escalate
according to susceptibility results. Following the ATS/IDSA
guidelines we would cover only 8/45 isolates. Results We collected 638 questionnaires (response rate 75%). Nineteen per cent recognized the oral route as the recommended
way for intubation. pneumonia Á Estella García1, A Ruiz Robles2, A Sáinz de Baranda1,
M Calero Ruiz2, M Galán1, E Moreno1
1Critical Care Unit and 2Laboratory of Biochemistry, Hospital of
Jerez., Spain
Critical Care 2007, 11(Suppl 2):P90 (doi: 10.1186/cc5250) Introduction Cytokines play an important role in pulmonary host
defense. However, nonuniform findings have been reported about Results Eighty-one patients enrolled into the study; 40% of them
were female and the mean age was 71 ± 14. Fifty-one of the S36 Available online http://ccforum.com/supplements/11/S2 patients had TF. When the groups were compared (TF and
treatment success), patients with TF were older, had more
comorbidities, higher admission and VAP APACHE II scores,
Acinetobacter baumanni pneumonia, higher initial bacterial load
(colony-forming units/ml) and lower daily carbohydrate intake. Transfusions, bacteremia, infection with multidrug-resistant micro-
organismis and steroid therapy were similar across the groups. Among the significant parameters, age and comorbidity were not
entered into the logistic regression since the APACHE II score
covers these two parameters. VAP with A. baumanni (OR 4.4,
95% CI 1.2–16, P = 0.027), higher VAP APACHE II scores
(OR 12, 95% CI, 3–45, P = 0.0001) and lower daily carbohydrate
intake (OR 4.4, 95% CI 1.3–15, P = 0.016) were independent
predictors for TF in logistic regression analyses. P Myrianthefs1, C Ioannides1, G Fildissis1, S Karatzas1,
G Baltopoulos2
1KAT Hospital, Athens, Greece; 2General Hospital of Attiki ‘KAT’,
Kifissia, Greece
Critical Care 2007, 11(Suppl 2):P93 (doi: 10.1186/cc5253) P Myrianthefs1, C Ioannides1, G Fildissis1, S Karatzas1,
G Baltopoulos2
1KAT Hospital, Athens, Greece; 2General Hospital of Attiki ‘KAT’,
Kifissia, Greece
Critical Care 2007, 11(Suppl 2):P93 (doi: 10.1186/cc5253) Introduction ATS/IDSA [1] guidelines recommend consideration
of local microbiologic data when selecting empiric treatment for
ventilator-associated pneumonia (VAP) and broad-spectrum
empiric therapy for patients with pneumonia caused by MDR
pathogens. The purpose was to use local microbiologic data to
develop institution-specific guidelines for VAP. pathogens. The purpose was to use local microbiologic data to
develop institution-specific guidelines for VAP. Methods We prospectively recorded local microbiologic and
susceptibility data in our ICU. Respiratory specimens were tracheal
aspirates in all cases and were evaluated by quantitative criteria. Results We had 40 episodes (2,247 ventilator-days) of VAP
(40/133 patients) and 45 isolates. In early-onset pneumonia
(≤5 days, eight episodes, three with two isolates): six Acinetobacter
baumannii: meropenem, colistin, gentamicin (five); three Pseudo-
monas aeruginosa: piperacillin, aztreonam, imipenem, ceftazidime,
colistin, ciprofloxacin, cefepime, meropenem, aminoglycosides; one
Klebsiella pneumoniae: meropenem, colistin, tetracycline; Fungi 1:
no susceptibility results. In late-onset pneumonia (>5 days, 32
episodes, two with two isolates): 25 A. baumannii: four to
amoxicillin-clavulanic,
ceftazidime,
piperacillin-tazobactam,
aztreonam, imipenem, colistin, ciprofloxacin, cefepime, meropenem,
aminoglycosides, 19 to meropenem, gentamicin, colistin, tetracycline
and two to colistin; four P. aeruginosa: two to piperacillin-
tazobactam, two to colistin; one K. pneumoniae: piperacillin-
tazobactam, aztreonam, imipenem, ceftazidime, colistin, ciprofloxacin,
cefepime, meropenem, aminoglycosides, amoxicillin-clavulanic; Fungi
1: no susceptibility results and three unspecified isolates. E
l di
f
i
d
ifi d
i
l t
h d
8/45 Conclusion These results suggest that patients with higher VAP
APACHE II scores and pneumonia with A. baumanni and lower
carbohydrate intake were at risk for TF. Methods We prospectively recorded local microbiologic and
susceptibility data in our ICU. Respiratory specimens were tracheal
aspirates in all cases and were evaluated by quantitative criteria. P92 Forty-nine per cent knew that ventilator circuits
are to be changed for each new patient only. Heat and moisture
exchangers were checked as the recommended humidifier type by
55%, and 13% knew that it is recommended to change them once
weekly. Closed suction systems were identified as recommended
by 69%, and 20% knew that these must be changed for each new
patient only. Respectively 60% and 49% recognized subglottic
drainage systems and kinetic beds to reduce the incidence of VAP. Semirecumbent positioning is well known to prevent VAP (90%). The nurses’ average score was 4.2/9, while nurses with >1 year
experience and those holding a special degree both scored 4.5/9
(P < 0.001). Conclusions ATS/IDSA [1] guidelines may not be applicable in all
institutions or countries and thus clinicians should incorporate local
microbiologic data into institution-specific guidelines [2]. References 1. ATS/IDSA: Am J Respir Crit Care Med 2005, 171:388-416. 2. Beardsley JR, et al.: Chest 2006, 130:787-793. 1. ATS/IDSA: Am J Respir Crit Care Med 2005, 171:388-416. 2. Beardsley JR, et al.: Chest 2006, 130:787-793. 1.
Dodek P, et al.: Ann Intern Med 2004, 141:305-313. 1.
ATS/IDSA: Am J Respir Crit Care Med 2005, 171:388-416.
2.
Beardsley JR, et al.: Chest 2006, 130:787-793. 1.
Dodek P, et al.: Ann Intern Med 2004, 141:305-313. Administration of meropenem for the treatment of
ventilator-associated pneumonia Administration of meropenem for the treatment of
ventilator-associated pneumonia Administration of meropenem for the treatment of
ventilator-associated pneumonia K Zolotukhin, A Abubakirova
District Hospital, Ufa, Russian Federation
Critical Care 2007, 11(Suppl 2):P94 (doi: 10.1186/cc5254) K Zolotukhin, A Abubakirova
District Hospital, Ufa, Russian Federation
Critical Care 2007, 11(Suppl 2):P94 (doi: 10.1186/cc5254) Conclusion Nurses lack knowledge of evidence-based guidelines
for VAP prevention. Their schooling and continuing education
should include support from current evidence-based guidelines. Reference Conclusion Nurses lack knowledge of evidence-based guidelines
for VAP prevention. Their schooling and continuing education
should include support from current evidence-based guidelines. Reference Introduction Ventilator-associated pneumonia (VAP) is associated
with the greatest mortality among nosocomial infection. Death
rates associated with Pseudomonas spp. or with late-onset VAP
seem higher. Treatment of these infections is frequently
complicated by antibiotic resistance, a problem that has been
increasing in recent years. S37 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin infection due to pseudomonas species, acinetobacter species and
multidrug-resistant Gram-negative bacilli at enrollment (n = 56),
the adequacy of initial antibiotics was 82.4% in the combination
group versus 18.8% in the monotherapy group (P < 0.001); this
difference was associated with an increase in the microbiological
eradication of the infecting organisms (64.1% vs 29.4%, P = 0.05)
but no differences in clinical outcomes. Conclusion
In patients who have suspected VAP, empiric
treatment with combination therapy, as compared with mono-
therapy, is safe and is associated with a higher rate of adequate
antimicrobial coverage but has no effect on clinical outcomes. Acknowledgements This study was supported by grants from the
Canadian Institutes of Health Research and Physicians Services Inc. of
Ontario, and unrestricted grants from AztraZeneca Inc., and Bayer Inc. Objective and methods The goal of the study was to evaluate the
clinical efficacy of meropenem by continuous infusion administration
(CIA) or by bolus intermittent infusion (BII) for the treatment of VAP
caused by Pseudomonas aeruginosa. An historic control group with
VAP caused by P. aeruginosa who received initial empiric antibiotic
therapy with meropenem by BII (n = 32) was compared with a
prospective cohort treated with meropenem by CIA (n = 20) in a
12-bed surgical ICU, at a 400-bed surgical complex of a district
hospital. We looked for demography, APACHE II score, mortality,
attributable mortality for VAP, days on mechanical ventilation (MV),
and ICU length of stay. A randomized trial of combination therapy versus
monotherapy for the empiric treatment of suspected
ventilator-associated pneumonia D Heyland1, P Dodek2, J Muscedere3, A Day3, D Cook4
1Canadian Critical Care Trials Group, Kingston General Hospital,
Kingston, Canada; 2St Paul’s Hospital, Vancouver, Canada;
3Kingston General Hospital, Kingston, Canada; 4St Joseph’s
Healthcare, Hamilton, Canada
Critical Care 2007, 11(Suppl 2):P95 (doi: 10.1186/cc5255) Results Pneumonia was evaluated based on macroscopic grading
and microbiological (bacterial count) findings. We were able to
maintain anaesthetic, haemodynamic and respiratory support for
the study duration of 78 hours. A monobacterial pulmonary
infection was established in four out of five animals. Administration
of ceftriaxone 1 g daily effectively suppressed all other bacteria. This allowed proliferation of the single strain P. aeruginosa (PA01)
we had inoculated with no culture of other organisms. Introduction Delays in adequate antibiotic therapy for ventilator-
associated pneumonia (VAP) are associated with poor outcomes,
and early use of broad-spectrum antibiotics may improve clinical
outcomes. However, indiscriminant use of broad-spectrum
antibiotics is associated with the emergence of antibiotic-resistant
bacteria, fungal infections, and increased healthcare costs. The
purpose of this study was to determine optimal empiric treatment
of VAP by comparing a strategy of combination therapy to
monotherapy with broad-spectrum antibiotics. Introduction Delays in adequate antibiotic therapy for ventilator-
associated pneumonia (VAP) are associated with poor outcomes,
and early use of broad-spectrum antibiotics may improve clinical
outcomes. However, indiscriminant use of broad-spectrum
antibiotics is associated with the emergence of antibiotic-resistant
bacteria, fungal infections, and increased healthcare costs. The
purpose of this study was to determine optimal empiric treatment
of VAP by comparing a strategy of combination therapy to
monotherapy with broad-spectrum antibiotics. Conclusions Over a short period of time we were able to
reproduce a monoculture ventilator-associated pneumonia in a
significant percentage of animals. We successfully developed an
animal ICU model that we were able to sustain for 78 hours. This
canine model of P. aeruginosa (PA01) ventilator-associated
pneumonia is suitable for the application of molecular techniques
such as signature-tagged mutagenesis, differential fluorescence
induction, and in vivo expression technology. Methods In a multicenter trial, we randomized mechanically
ventilated adult patients with suspected VAP that developed after
96 hours in the ICU to receive either meropenem and ciprofloxacin
or meropenem alone, as initial therapy. In addition, before starting
antibiotics, diagnostic specimens were obtained using either
bronchoalveolar lavage with quantitative cultures or standard
endotracheal aspirates. P96 Results Significant differences were not found between both
groups of patients in sex, age, APACHE II score, and diagnosis. The CIA group showed significantly greater clinical cure than the
BII group (CIA 18/20 (90%) vs BII 21/32 965.6%), P = 0.041)
and smaller but not significant attributable mortality to VAP (2 of
20 (10%) vs 10 of 32 (31.3%), P = 0.288). A canine model of Pseudomonas aeruginosa ventilator-
associated pneumonia using a defined bacterial inoculum A canine model of Pseudomonas aeruginosa ventilator-
associated pneumonia using a defined bacterial inoculum A Fahy1, M Gale1, N Chow2, S Webb2
1Royal Perth Hospital, Perth, Australia; 2University of Western
Australia, Perth, Australia
Critical Care 2007, 11(Suppl 2):P96 (doi: 10.1186/cc5256) Conclusion Our results suggest that administration of meropenem
by CIA may have more clinical efficacy than administration by BII for
the treatment of VAP, but more studies are required to confirm this. Introduction This prospective pilot study set out to develop an
animal model of Pseudomonas aeruginosa that would be suitable
for the application of molecular techniques to evaluate virulence in
which instillation of a reference strain of P. aeruginosa results in a
monoculture ventilator-associated pneumonia. For this purpose,
male adult greyhounds were used in an animal research laboratory. Methods The animals were anaesthetised, orally intubated and
mechanically ventilated. An inoculum of P. aeruginosa (strain PA01)
was instilled into the oropharynx at 1 hour and 8 hours post-
intubation. The animals were terminated at 78 hours. Administration of meropenem for the treatment of
ventilator-associated pneumonia VAP was treated during 14 days with
meropenem (1 g/6 hours intravenously). The antibiotic clinical effect
was categorized as cure or failure. Difference between groups were
tested by means of Student’s t test end exact chi-square test, using
the MedCalc program. We consider values of P < 0.05 as a
significant difference. infection due to pseudomonas species, acinetobacter species and
multidrug-resistant Gram-negative bacilli at enrollment (n = 56),
the adequacy of initial antibiotics was 82.4% in the combination
group versus 18.8% in the monotherapy group (P < 0.001); this
difference was associated with an increase in the microbiological
eradication of the infecting organisms (64.1% vs 29.4%, P = 0.05)
but no differences in clinical outcomes. Conclusion
In patients who have suspected VAP, empiric
treatment with combination therapy, as compared with mono-
therapy, is safe and is associated with a higher rate of adequate
antimicrobial coverage but has no effect on clinical outcomes. Acknowledgements This study was supported by grants from the
Canadian Institutes of Health Research and Physicians Services Inc. of
Ontario, and unrestricted grants from AztraZeneca Inc., and Bayer Inc. Conclusion
In patients who have suspected VAP, empiric
treatment with combination therapy, as compared with mono-
therapy, is safe and is associated with a higher rate of adequate
antimicrobial coverage but has no effect on clinical outcomes. Acknowledgements This study was supported by grants from the
Canadian Institutes of Health Research and Physicians Services Inc. of
Ontario, and unrestricted grants from AztraZeneca Inc., and Bayer Inc. P95 A randomized trial of combination therapy versus
monotherapy for the empiric treatment of suspected
ventilator-associated pneumonia M Niederman1, J Chastre2, K Corkery3, R Fishman3, J Fink3,
C Luyt2, M Sanchez4
1Winthrop-University Hospital, Mineola, NY, USA; 25Hôpital Pitié-
Salpêtrière, Paris, France; 3Nektar Therapeutics, San Carlos, CA, USA;
4Hospital Principe de Asturias, Alcala de Henares, Madrid, Spain
Critical Care 2007, 11(Suppl 2):P97 (doi: 10.1186/cc5257) Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P97) Despite isolation, MRAB spread over and infected eight more
patients in separate rooms and different sections of the ICU
32 days later. Further transmission occurred within a few days:
three male patients with multiple trauma (42, 20, and 62 years old;
patients 2, 3, and 4), cardia carcinoma (female, 66 years old;
patient 5), necrotizing pancreatitis (female, 78 years old; patient 6),
splenomegaly owing to polycythaemia vera (male, 74 years old;
patient 7 – MRAB diagnosis postmortem), rectal carcinoma
(female, 76 years old; patient 8 – isolation because of MRSA
infection even before) and respiratory failure after gastric banding
(female, 41 years; patient 9). All patients suffered from septic
shock with high fever, needed high volume replacement and
catecholamines
several
times
and
prolonged
mechanical
ventilation. MRAB was isolated in the tracheal secretion or BAL in
all patients, in abdominal drainage (patient 6), and in central
venous catheter (patient 5). Environmental investigations showed
no problematic circumstances. Colistin i.v. is not available in
Germany so it had to be procured from the USA, which caused a
delay of treatment for a few days. Another delay occurred because
of the rapid growing number of patients who needed Colistin. Patients were treated with an adjusted dosage for 16 days. safety and i.v. antibiotic use with inhaled amikacin (AMK) during
adjunctive treatment of intubated patients with Gram-negative
pneumonia. Methods A double-blind, placebo-controlled, study of aerosol
AMK delivered via the Pulmonary Drug Delivery System (PDDS®;
Nektar Therapeutics) in ventilated patients with Gram-negative
pneumonia as an adjunctive to i.v. therapy per ATS guidelines. Patients were randomized to receive aerosol containing 400 mg
AMK daily with placebo (normal saline) 12 hours later, 400 mg
AMK twice daily or placebo twice daily. The i.v. antibiotics (agent
and duration) were determined by the attending physician. The
AMK peak serum concentration, trough concentrations and
tracheal aspirates were drawn. All patients of the ICU were isolated to avoid new infections as a
precaution. After convalescence of two patients, all MRAB patients
were moved to the IMC, which was converted to an ICU for this
period, to isolate infected patients from uninfected. Three out of
nine patients died. All these laborious measures with a great expenditure of logistics
worked well; no further transmissions were observed. Results The mean number of i.v. Available online http://ccforum.com/supplements/11/S2 antibiotics at the end of the study
(mean 7 days) were two times greater with placebo than with
twice-daily AMK (P < 0.02) (Figure 1). For daily and twice-daily
AMK, the serum Cmax were 1.3 and 1.8 µg/ml (respectively) on
day 1, and 2.3 and 3.2 µg/ml on day 3. Mean trough levels were
0.87 and 1.49 µg/ml. Tracheal aspirate levels (mean) on day 3
were 6.9 mg/ml (daily) and 16.2 mg/ml (twice daily). Aerosol AMK
was well tolerated with no difference in adverse events across
treatment groups. Multidrug-resistant Acinetobacter baumannii susceptible only
to colistin outbreak in a cardiac surgical intensive care unit Multidrug-resistant Acinetobacter baumannii susceptible only
to colistin outbreak in a cardiac surgical intensive care unit K Papadopoulos, A Tasouli, E Douka, E Manoli, G Saroglou,
S Geroulanos
Onassis Cardiac Surgery Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P99 (doi: 10.1186/cc5259) Conclusion Repeated doses of adjunctive inhaled AMK to
mechanically ventilated patients with Gram-negative pneumonia
was safe, well tolerated, and associated with less i.v. antibiotic use
than placebo. Objectives
Gram-negative bacilli including multidrug-resistant
Acinetobacter baumannii (MDR-AB) are responsible for severe
ICU-acquired infections, mainly pneumonia and bacteraemia. The
aim of this study was to determine the incidence and mortality of
this multiresistant strain of Acinetobacter in patients undergoing
cardiac surgery, to elucidate the effectiveness of treatment with
colistin and to identify whether additional measures were able to
prevent and control the dissemination of MDR-AB isolates in our
institution. Decrease in intravenous antibiotic use with adjunctive
aerosolized amikacin treatment in intubated mechanically
ventilated patients with Gram-negative pneumonia Decrease in intravenous antibiotic use with adjunctive
aerosolized amikacin treatment in intubated mechanically
ventilated patients with Gram-negative pneumonia Results We randomized 740 patients in 28 ICUs in Canada and
the United States. The baseline characteristics and etiologies of
VAP were similar between groups. There was no difference in 28-
day mortality between the combination and monotherapy groups
(RR = 1.05, 95% confidence interval 0.78–1.42; P = 0.74). The
duration of ICU and hospital stay, clinical and microbiological
response to treatment, emergence of antibiotic-resistant bacteria,
isolation of Clostridium difficile, and fungal colonization were
similar between groups. Combination therapy resulted in a higher
rate of adequate empiric therapy compared with monotherapy
(93.1% vs 85.3%, P = 0.01). In a subgroup of patients with M Niederman1, J Chastre2, K Corkery3, R Fishman3, J Fink3,
C Luyt2, M Sanchez4
1Winthrop-University Hospital, Mineola, NY, USA; 25Hôpital Pitié-
Salpêtrière, Paris, France; 3Nektar Therapeutics, San Carlos, CA, USA;
4Hospital Principe de Asturias, Alcala de Henares, Madrid, Spain
Critical Care 2007, 11(Suppl 2):P97 (doi: 10.1186/cc5257) Introduction
Aerosolized
antibiotics
may
increase
lung
concentration, reducing the need for i.v. antibiotics. We evaluated S38 P100 Hypercalcaemia resulting from the use of tigecycline in the
treatment of multidrug-resistant Acinetobacter in patients
with multiorgan failure
M Duffy, M Thomas, G Auzinger, W Bernal, E Sizer, J Wendon
Institute of Liver Studies, London, UK
Critical Care 2007, 11(Suppl 2):P100 (doi: 10.1186/cc5260) Hypercalcaemia resulting from the use of tigecycline in the
treatment of multidrug-resistant Acinetobacter in patients
with multiorgan failure Hypercalcaemia resulting from the use of tigecycline in the
treatment of multidrug-resistant Acinetobacter in patients
with multiorgan failure Methods A prospective pharmacokinetic evaluation of amino-
glycoside pharmacokinetics during CVVHDF was undertaken. Pharmacokinetic profiles of once-daily doses of intravenous
amikacin and gentamicin were obtained from blood and dialysate/
ultrafiltrate samples for 12 critically ill patients treated with
CVVHDF using varying flow rates (1 l/hour dialysate plus 2 l/hour
filtration fluid or 2 l/hour dialysate plus 2 l/hour filtration fluid,
extracorporeal blood flow 200 ml/min). Drug concentrations were
measured using an immunoassay. M Duffy, M Thomas, G Auzinger, W Bernal, E Sizer, J Wendon
Institute of Liver Studies, London, UK
Critical Care 2007, 11(Suppl 2):P100 (doi: 10.1186/cc5260) Introduction Tigecycline (Wyeth) is a new glycylcycline anti-
microbial that has been used in the treatment of deep-seated
multidrug-resistant Acinetobacter (MDRA) infections. Unexpected
changes in routine hematology or serum chemistry have not been
reported. Results The mean clearance of gentamicin due to CVVHDF was
2.3 ± 0.3 l/hour (82.1 ± 11.3% of total body clearance (TBC)). The sieving coefficient (SC) was 0.85 ± 0.05. The CVVHDF
clearance of amikacin was 2.8 ± 0.5 l/hour (93.0 ± 7.8% TBC). The SC for amikacin was 0.88 ± 0.06. The difference in
gentamicin clearance versus amikacin clearance reflects differ-
ences in CVVHDF conditions. The mean effluent flow rate among
the patient sample treated with gentamicin was 2.7 l/hour
compared with 3.5 l/hour for amikacin. There was a strong
correlation between creatinine clearance by the filter and
measured drug clearance (P < 0.001). Individual patient estimates
of aminoglycoside pharmacokinetic parameters (k, Vd) obtained
during CVVHDF were used to allow appropriate dosage
adjustment. Individualized
pharmacokinetic–pharmacodynamic
goals (e.g. Cpmax/MIC ratio) were used as indicators of adequate
aminoglycoside dosing. The mean gentamicin and amikacin half-
lives (approximately 8 hours) during CVVHDF therapy were far
shorter than those previously reported in the literature for less
efficient forms of renal replacement therapy. Failure to adjust for
increased aminoglycoside clearance capacity due to CVVHDF
carries a risk of subtherapeutic dosing and therapy failure. P100 Methods All patients were managed within the liver ICU and
received standard care. Laboratory data were collected daily and
entered onto a specialist database. MDRA-positive cultures from
blood, bronchoalveolar lavage, drain fluid or samples taken at
laparotomy in the context of systemic inflammatory response
syndrome resulted in the initiation of tigecycline 100 mg i.v. followed by 50 mg i.v. 12 hourly. Results Eleven patients received tigecycline treatment for MDRA
infections (seven male). Ten patients had a single course whilst
one patient had three courses. Underlying disease states were
necrotising pancreatitis (one), polytrauma (one), post hepatectomy
(one), acute and acute on chronic liver failure (four), and post-
orthotopic liver transplant (four). The median duration of treatment
was 9 days (range 4–23 days); courses <7 days were because of
patient death (2/11). The mean APACHE II score at initiation of
therapy was 18 (range 13–26). Four out of 11 survived to ICU
discharge and 3/11 to hospital discharge. Tigecycline was well
tolerated but increases in corrected calcium were observed in
9/11 patients. The patient that received three courses of treatment
had elevations in corrected calcium after each course. For the 11
patients, the mean corrected calcium before treatment with
tigecycline was 2.41 mmol/l. The mean corrected calcium on
finishing the course increased to 2.59 mmol/l (P = 0.012). There
was no correlation between duration of treatment with tigecycline
and degree of change in the corrected calcium level (r = 0.08). Hypercalcaemia resolved on discontinuation of the drug; 7/11
survived >7 days after treatment and had a mean corrected
calcium of 2.46 mmol/l, which was not significantly different from
pretreatment levels (P = 0.94). Conclusion Dosing strategies on the basis of pharmacokinetic
analysis of serum drug concentrations, effluent fluid drug
concentrations and CVVHDF conditions improved therapeutic
outcomes for aminoglycoside drug therapy. P101 Despite significant ‘in vitro’ activity of colistin against this virulent
organism and its acceptable safety profile, results were
discouraging as only 13% survived. In fact, cure or clinical
improvement was observed only in four patients (27%) while 11
patients (73%) developed sepsis and multiple organ failure. A pharmacokinetic basis for improving therapeutic
outcomes of aminoglycoside therapy during continuous
venovenous haemodiafiltration A Spooner1, O Corrigan1, M Donnelly2
1Trinity College Dublin, Dublin, Ireland; 2Tallaght Hospital, Dublin,
Ireland
Critical Care 2007, 11(Suppl 2):P101 (doi: 10.1186/cc5261) Scale 1 measures were implemented for the whole 12-month
period while Scale 2 for two separate 3-week periods. Following
this infection control strategy we achieved intermittent eradication
of the pathogen during a 12-month period with continuous function
of the SICU. Introduction The objective of this study was to quantify the impact
of continuous venovenous haemodiafiltration (CVVHDF) on amino-
glycoside pharmacokinetics and to suggest dosing strategies to
improve therapeutic outcomes for these drugs in critically ill
patients treated with CVVHDF. There has been limited published
data on aminoglycoside pharmacokinetics during CRRT. This data
deficit had led to subtherapeutic dosing, identified by a retro-
spective evaluation of amikacin and gentamicin serum concentra-
tions, in patients treated with CVVHDF, undertaken as part of this
research. Conclusions Increasing prevalence of MDR-AB in ICU patients
demands installation of strict screening and contact precautions. Due to significant mortality of MDR-AB-infected patients, additional
measurements like geographic isolation of all positive cases,
exclusive medical and nursing personnel, use of separate supplies
and facilities and intense environmental surveillance is highly
recommended. P98 Management of an outbreak of multiresistant
Acinetobacter baumanii infection in a surgical intensive
care unit J Lewejohann, M Prang, F Seyfried, A Henning,
C Zimmermann, M Hansen, E Muhl, H Bruch
University Medical Center Schleswig-Holstein – Campus Lübeck,
Germany
Critical Care 2007, 11(Suppl 2):P98 (doi: 10.1186/cc5258) Methods A total of 1,451 patients attended the surgical ICU
(SICU) after cardiovascular surgery from 1 September 2005 to 31
August 2006. We reviewed the prophylactic measures of the
SICU and tried to identify epidemiological links between MDR-AB-
infected patients. We implemented a two-scale multiple program. Scale 1 included classical infection control measures (that is, strict
contact and droplet isolation, surveillance of throat, nasal and anal
flora for MDR pathogens on all patients transferred from other
hospitals, separate nursing staff for each infected or colonized
case and strict antibiotic policy), while Scale 2 referred to
geographic isolation of MDR-AB cases with exclusive medical and
nursing personnel, use of separate supplies and facilities and
intense environmental surveillance. The first report of multiresistant Acinetobacter baumanii (MRAB)
was published in 1994. We report about an outbreak sensitive to
Polimyxin only. In June 2006 a German holidaymaker (male, 70
years old; patient 1) in Greece felt dyspnea, thoracic pain and
fever. He went to a hospital in Crete. CT indicated left-sided
pleural empyema, mediastinal emphysema, pericardial effusion and
pneumonia. Rapid deterioration lead to septic shock with need for
mechanical ventilation. He came to our ICU (15 beds and six IMC
beds) via air transport. Endoscopy showed esophagus perforation
with need for operation and endoscopic stenting. Several BALs
and a central venous catheter from the beginning showed MRAB
with intermediate susceptibility to meropenem/aminoglycosides
only. The patient received meropenem and gentamycin at first. Results Fifteen patients were infected by MDR-AB, of which 13
presented respiratory tract infection, one suffered deep surgical
site infection and bacteraemia and one from catheter-related
infection. They were all treated with intravenous and aerolized
colistin in combination with rifampicin or ampicillin and sulbactam. S39 P Gruber, C Gomersall, Q Tian, G Joynt
The Chinese University of Hong Kong, New Territories, Hong Kong
Critical Care 2007, 11(Suppl 2):P102 (doi: 10.1186/cc5262) P103 Patients and methods We studied 146 patients with skin and
soft tissue infections co-infected by HIV and 72 noninfected
patients with soft tissue infections aged 18–45 years. All of the
patients underwent operations aimed at surgical removal of the
dead tissues and pus and received different combinations of
antibacterial agents. Twenty-three patients after adequate surgery
received Linezolid in doses of 600 mg twice a day intravenously
during 3–4 days with oral follow-up of 600 mg twice a day. Linezolid in the treatment of HIV-infected patients with
complicated skin and soft tissue infections Linezolid in the treatment of HIV-infected patients with
complicated skin and soft tissue infections N Khachatryan1, I Dizengof2, G Smirnov2
1Moscow State University of Medicine and Dentistry, Moscow,
Russian Federation; 2Hospital of Infectious Diseases N3, Moscow,
Russian Federation
Critical Care 2007, 11(Suppl 2):P104 (doi: 10.1186/cc5264) Introduction
The incidence of HIV-infected patients with
complicated skin and soft tissue infections has risen. Because of
advanced immune suppression, slower responses to antibacterial
treatment, and increased risk of bacteraemia relative to
noninfected patients, the choice of initial appropriate empiric
antibacterial therapy is an important aspect of care for HIV-infected
patients. However, in recent years a dramatic increase of the
resistance among Staphylococci to all classes of antimicrobial
agents, including glycopeptides, has been reported. Introduction
The incidence of HIV-infected patients with
complicated skin and soft tissue infections has risen. Because of
advanced immune suppression, slower responses to antibacterial
treatment, and increased risk of bacteraemia relative to
noninfected patients, the choice of initial appropriate empiric
antibacterial therapy is an important aspect of care for HIV-infected
patients. However, in recent years a dramatic increase of the
resistance among Staphylococci to all classes of antimicrobial
agents, including glycopeptides, has been reported. Conclusions Total adsorption is low and unlikely to be of clinical
significance. Adsorption
and
the
sieving
coefficient
are
independent of the type of haemofilter membrane. The sieving
coefficient of oseltamivir carboxylate is 1, therefore clearance
during haemofiltration can be estimated from the ultrafiltration rate. Available online http://ccforum.com/supplements/11/S2 influenza A/H5N1 develop acute renal failure. A proportion will
require haemofiltration. There are no data to determine the
elimination of oseltamivir carboxylate (the active metabolite) by
haemofiltration. An in vitro study to determine elimination by
measuring the adsorption and sieving coefficient of oseltamivir
carboxylate using two haemofilter types was undertaken. and 34 once daily (OD group), for nosocomial pneumonia (n = 14),
skin and soft tissue infection (burn and nonburn including diabetic
foot) (n = 13), bacteraemia (n = 10), intra-abdominal infection
(n = 8), bone and joint infection (n = 6) and as pre-emptive therapy
for severe trauma (n = 13). In the OD group, mean trough levels
remained at 9.64 µg/ml from days 2 to 4 and peak levels remained
at a mean of 24.84 µg/ml. In the BD group, mean trough levels
increased by 5.65 µg/ml/24 hours to 21.8 µg/ml by day 4; the
mean peak level increased by 5.06 µg/ml/24 hours to 43.89 µg/ml
by day 4. Methods An in vitro one-compartment model of continuous veno-
venous haemofiltration was used. In phase 1 oseltamivir carboxy-
late adsorption to the haemofilter and circuit was studied by
circulating a blood–crystalloid mixture containing clinically relevant
concentrations of oseltamivir carboxylate through a haemofilter
circuit and returning the ultrafiltrate to the mixing chamber. In
phase 2 the ultrafiltrate was removed and replaced with a
bicarbonate-based fluid to enable calculation of the sieving
coefficient. The study was repeated 10 times with two haemofilter
types: polyamide and polyacrylonitrile (PAN). Finally, oseltamivir
carboxylate was added to the blood–crystalloid mixture without
circulation through the circuit to determine its stability in solution. Blood samples collected were assayed by HPLC-MS/MS. Conclusion Higher trough levels of glycopeptides (15–20 µg/ml)
are targeted to improve efficacy and reduce resistance
development. In the OD group the conventional target of 10 µg/ml
was achieved, whilst in the BD arm 20 µg/ml was exceeded for
60% of the time by day 2 and 100% by day 4. BD dosing is
recommended for most patients with severe infections, particularly
those that are critically ill. No premature discontinuations or
adverse events were reported during the study. P104 Results Oseltamivir carboxylate remained stable in solution (mean
percentage change from baseline at 30 min: +3.97%, at 60 min:
+1.91%, at 90 min: +2.36%). The mean ± SD initial oseltamivir
carboxylate concentrations for the PAN (346 ± 85 µg/l) and
polyamide (453 ± 185 µg/l) showed no significant difference. The
mean ± SD adsorption at 90 min was 58.18 ± 17.84 µg for PAN
and 75.22 ± 36.88 µg for polyamide haemofilters. There was no
statistical difference in adsorption between the haemofilters. The
initial drug concentration was a significant predictor of adsorption
(r2 = 0.734). The mean ± SD sieving coefficient of oseltamivir
carboxylate for PAN (1.06 ± 0.04) and polyamide (1.03 ± 0.06)
haemofilters showed no statistical difference between the
haemofilters. P102 An in vitro study of elimination of oseltamivir carboxylate
by haemofiltration P Gruber, C Gomersall, Q Tian, G Joynt
The Chinese University of Hong Kong, New Territories, Hong Kong
Critical Care 2007, 11(Suppl 2):P102 (doi: 10.1186/cc5262) Conclusion Tigecycline is well tolerated but appears to be
associated with an elevated corrected calcium in critically ill
patients. This returns to baseline values on discontinuation of the
drug. Conclusion Tigecycline is well tolerated but appears to be
associated with an elevated corrected calcium in critically ill
patients. This returns to baseline values on discontinuation of the
drug. Introduction Oseltamivir is the drug of choice for treatment of
avian influenza A/H5N1 infection. One-quarter of patients with S40 Available online http://ccforum.com/supplements/11/S2 A post-authorization survey to evaluate plasma
concentrations of teicoplanin in adult hospitalized patients
treated for sepsis in Gauteng, South Africa A Brink1, G Richards2, and the G Uts Study Group
1Du Buisson, Bruinette and Partners, Johannesburg, South Africa;
2Johannesburg Hospital, Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P103 (doi: 10.1186/cc5263) Results The most frequent pathogens are Staphylococci in both
groups of patients with soft tissue infections: 56% was noted
among the noninfected patients and 61% among the HIV-infected
patients. MRSA was identified in 30% of Staphylococci in HIV-
infected patients. Among the patients receiving Linezolid, MRSA
was identified in nine cases; in two cases vancomycin-intermediate
S. aureus strains, and in one case vancomycin-resistant S. aureus
strain. In three cases we revealed Staphylococcus bacteraemia, in
one case MRSA bacteraemia in patient with retroperitoneal
phlegmon. Objective This study measured and analyzed plasma concen-
trations of teicoplanin in patients >18 years in the first 4 days of
administration. Methods This was an open-label, multicentre, observational study
in patients receiving teicoplanin for suspected or diagnosed Gram-
positive infection. Data collection included demographics, method
of administration, loading and maintenance doses, creatinine and
adverse events. Trough and peak concentrations were determined
15 minutes prior to drug administration and 60 minutes after. Serum was separated and stored at –20°C until analysis. Levels
were determined with an Abbott TDx®/FLx® analyzer and Seradyn
Teicoplanin Innofluor assay kits. Seradyn internal teicoplanin
controls were run within and between each batch. Mean trough
and peak plasma levels were calculated for 4 days of therapy. Results Seventy-four patients with complete records were
analyzed and whilst all patients received an 800 mg loading dose
on day 1, 40 received 400 mg twice daily thereafter (BD group) A statistical difference was identified in duration of high
temperature, purulence and wound healing in comparison with
patients receiving different combinations of antibacterial agents. All
patients receiving Linezolid were discharged from the hospital. The
length of stay was 17 ± 1.67 days in comparison with patients
receiving other antibacterial agents (from 19.52 ± 1.37 to 20.3 ±
1.46 days). The length of stay in hospital among the noninfected
patients with soft tissue infection was 9.5 days. P107 Results A high incidence of ESBL producing E. coli and
Klebsiellae was observed (85.8%). Meropenem (9.3%) and
imipenem (2.8%) resistance in the ESBL producers was seen. On
multivariate analysis with logistic regression, a central venous
catheter was an independent risk factor for ESBL acquisition
(P = 0.01, OR 3.55, 95% CI 1.4–9.02). The median ICU length of
stay was 3.5 days and 3 days in the ESBL and non-ESBL groups,
respectively. The overall mortality was 13.28% and 13.6% in the
two groups, respectively. Microbiological outcomes were similar to
clinical outcome, with 83.6% microbiologic success rate among
ESBL producers. The contamination by Staphylococcus epidermidis in the
intensive care unit The contamination by Staphylococcus epidermidis in the
intensive care unit K Bruno1, D Albanese1, E Fabbri1, F Petrini1, M Scesi1,
F Bruno2
1SS Annunziata, Chieti, Italy; 2Villa Serena Clinic, Pescara, Italy
Critical Care 2007, 11(Suppl 2):P107 (doi: 10.1186/cc5267) Introduction The most important way to prevent infections in the
ICU is to respect asepsis during the numerous invasive procedures
to which patients are exposed (central venous catheter, urinary
catheter, orotracheal tube (OTT), fibrobronchoscopy (FOB),
surgical drainages, patients nursing, surgical medications). Conclusion ESBL producing E. coli
and Klebsiellae are
problematic pathogens in our ICUs. Emergence of carbapenem
resistance is of serious concern. Stringent infection control
practices such as aseptic insertion and proper handling of central
lines within the ICU should be followed by all. Methods The contaminations from Staphylococcus epidermidis
have been valued in main infection centres on 951 patients
admitted to our ICU for more than 72 hours from 1996 to 2005. From 2000, rigid asepsis protocols have been introduced for the
cleansing of staff hands with the use of disinfectants such as
Clorexidina and alcoholic gel. A clinico-microbiological study of extended spectrum
β-lactamases in the intensive care unit Y Mehta, K Bomb, S Jalota, A Arora, N Trehan
Escorts Heart Institute and Research Centre, New Delhi, India
Critical Care 2007, 11(Suppl 2):P105 (doi: 10.1186/cc5265) Introduction Extended spectrum β-lactamase (ESBL) producing
organisms are emerging as common nosocomial pathogens in the
ICU worldwide. Early detection and prevention of spread is the
primary measure to overcome the challenge posed by these
difficult to treat ESBL infections. The aim of this study was to find
the incidence, risk factors and microbiological and clinical outcome
of patients infected with ESBL producing Escherichia coli and
Klebsiellae in the ICU of a tertiary care cardiac center in India. Results Eighty-five patients in phase I and 55 patients in phase II
were enrolled. Third-generation cephalosporins were the primary
antibiotic in 75.2% of cases in phase I and in 1.8% of cases in
phase II (P < 0.001). The incidence of ESBL was 62.3% in phase I
and it came down to 34.5% in intervention phase II (P < 0.01). Conclusion Data from this intervention study support the concept
that third-generation cephalosporins are of substantial importance
in the emergence of ESBL; by decreasing the level of third-
generation cephalosporin use and increasing the piperacillin/
tazobactum use, their was a notable reduction in the acquisition
rate of ESBL producing E. coli. Methods A prospective, observational, case–control study of 150
patients was conducted from August 2004 to July 2005. ESBL
testing was performed by the phenotypic confirmatory disc
diffusion method. Clinical data and risk factors for ESBL
acquisition were analysed as well as the antimicrobial therapy, and
clinical and microbiological outcomes were studied. A post-authorization survey to evaluate plasma
concentrations of teicoplanin in adult hospitalized patients
treated for sepsis in Gauteng, South Africa Modification of
antibacterial treatment was not required in the group of patients Results Seventy-four patients with complete records were
analyzed and whilst all patients received an 800 mg loading dose
on day 1, 40 received 400 mg twice daily thereafter (BD group) S41 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin preventing their clonal outbreak, and the risk factors for ESBL
include intensive antibiotic exposure (especially third-generation
cephalosporin monotherapy). The present study was performed to
determine the impact of using piperacillin/tazobactum in reducing
the acquisition rate of ESBL producing Gram-negative bacteria in
the ICU. receiving Linezolid. No significant laboratory abnormalities and side
effects were noted. We did not reveal statistical differences in the
platelet count in group of patients receiving Linezolid (5 days after
operation 213 ± 26.0/mm3) in comparison with the group
receiving
other
antibacterial
agents
(256
±
32/mm3). Thrompocytopenia is characterized to HIV-infected patients, but
did not deteriorate in patients receiving Linezolid Methods This open-label, prospective study was carried out in
140 adult patients admitted to the ICU over a period of 9 months,
and was divided into two phases. Phase I (pre-intervention phase,
0–3 months): upon admission to the ICU, besides standard
investigations, additional rectal swab cultures were taken for
detection of ESBL within and after 48 hours of admission, and
were repeated every 7 days of the stay in the ICU. Routinely
prescribed antibiotics were allowed. Phase II (intervention phase,
4–9 months): this was subdivided into (a) first 3 months
(4–6 months): piperacillin/tazobactum was the primary antibiotic
used (more than 50% replacement of cephalosporins), and (b) last
3 months (7–9 months): here again, rectal swab cultures were
taken and piperacillin/tazobactum was the primary antibiotic used. McNemar’s test and Fisher’s exact test were used for statistical
analysis. Conclusion Linezolid in the complex treatment of HIV-infected
patients with complicated skin and soft tissue infections may
improve the results of therapy and may be used for initial empirical
intravenous-to-oral antibacterial therapy. P106 Impact of antibiotic utilization measures on acquisition
rate of extended spectrum β-lactamase enzymes
producing bacteria Available online http://ccforum.com/supplements/11/S2 P108 their critical illness status, some patients were subject to
quarantine. Improving HH was achieved by promoting alcohol-
based hand disinfection, refraining all health care workers (HCW)
from wearing hand jewellery or artificial fingernails, supplying HCW
with clip watches and by developing promotional material. Education of HCW regarding principles and techniques of HH was
provided by the IC department, supervised by link persons
selected among medical, nursing and domestic staff. The number
of new hospital-acquired MRSA infections per 1,000 admissions
was recorded. Compliance to HH was measured by observation,
microbiological analysis of total counts of colony-forming units on
fingerprints, and by monitoring the consumption of hand-rub
solutions (HH moments per patient-care day). Colonization and infection by MRSA in critically ill patients L Lorente, R Santacreu, J Iribarren, J Jimenez, M Martin, M Mora
Hospital Universitario de Canarias, Santa Cruz de Tenerife, Spain
Critical Care 2007, 11(Suppl 2):P108 (doi: 10.1186/cc5268) Objective To determine the incidence of colonization and infection
by MRSA in critically ill patients. Methods A prospective study during 30 months of the patients
admitted to the ICU for 24 hours or more. Throat swab, tracheal
aspirate and urine were taken on admission and twice weekly. The
colonization and infection by MRSA were registered. The infections
were diagnosed according to CDC criteria. The infections were
classified based on throat flora as: primary endogenous (PE) when
they were caused by germs that were already colonizing the throat
on the ICU admission; secondary endogenous (SE) when they
were caused by germs that were not colonizing the throat on the
ICU admission but were acquired during the stay in ICU; or
exogenous (EX) when they were caused by germs that were not
colonizing the throat. The infections were classified based on the
onset moment: early onset (EO) were those developed during the
first 4 days of the ICU stay; and late onset (LO) were those
developed 5 days after ICU admission. Results A selective MRSA admission screening policy increased
the carrier detection rate up to 15%, compared with 1–2% in our
preoperative outpatient clinic. The observed compliance to HH
increased from 49% to 79% and consumption of hand-rub solution
from 6 to 33 l per 1,000 patient-days. The number of HH moments
increased from 19 to 47. Total counts of colony-forming units less
than 50 improved from 39% of the analyses to 55%. P109 Methods A retrospective post-hoc analysis of the prospective,
multicentre VAP study, which enrolled patients with a clinical
suspicion of VAP, admitted to an ICU for >96 hours and on
mechanical ventilation (MV) for >48 hours. Airway cultures were
done on randomization. Patients with positive Candida cultures
from other sites were excluded. The remaining patients were
divided into two groups according to their Candida airway culture
status. Demographics, admission diagnosis, comorbidities, PaO2/
FiO2 ratio and APACHE II score were recorded at randomization. The length of MV, ICU and hospital stay were compared, as well as
hospital, ICU and 28-day mortality. Appropriate parametric
statistical tests were applied according to data. Results Of the 739 patients enrolled in the VAP study, 639 were
included for analysis: 114 had Candida airway colonization (C) and
525 did not (NC). No significant differences were noted in
demographics and APACHE II score (20 ± 6 vs 20 ± 6, P = 0.37)
except more frequent admission for sepsis (7.0% vs 2.1%,
P = 0.005) and respiratory conditions (21.9% vs 14.3%, P = 0.04)
in group C. More colonized patients were on antibiotics at
randomization (81.6% vs 56.7%, P < 0.001). A trend for increased Methods A retrospective post-hoc analysis of the prospective,
multicentre VAP study, which enrolled patients with a clinical
suspicion of VAP, admitted to an ICU for >96 hours and on
mechanical ventilation (MV) for >48 hours. Airway cultures were
done on randomization. Patients with positive Candida cultures
from other sites were excluded. The remaining patients were
divided into two groups according to their Candida airway culture
status. Demographics, admission diagnosis, comorbidities, PaO2/
FiO2 ratio and APACHE II score were recorded at randomization. The length of MV, ICU and hospital stay were compared, as well as
hospital, ICU and 28-day mortality. Appropriate parametric
statistical tests were applied according to data. Candida airway colonization is associated with worse
outcomes Candida airway colonization is associated with worse
outcomes M Delisle1, D Williamson2, M Perreault3, M Albert2, X Jiang4,
D Heyland4
1Hopital de l’Enfant-Jésus, Québec, Canada; 2Hopital du Sacré-
Coeur de Montréal, Canada; 3Hopital Général de Montréal, Centre
Universitaire de Santé McGill, Montréal, Canada; 4Queens
University, Kingston, Canada
Critical Care 2007, 11(Suppl 2):P110 (doi: 10.1186/cc5270) M Delisle1, D Williamson2, M Perreault3, M Albert2, X Jiang4,
D Heyland4 1Hopital de l’Enfant-Jésus, Québec, Canada; 2Hopital du Sacré-
Coeur de Montréal, Canada; 3Hopital Général de Montréal, Centre
Universitaire de Santé McGill, Montréal, Canada; 4Queens
University, Kingston, Canada
Critical Care 2007, 11(Suppl 2):P110 (doi: 10.1186/cc5270) Introduction
Candida
airway colonization is common in
mechanically ventilated ICU patients. Its significance and impact
on outcomes are not well defined. We aimed to describe Candida
airway colonization and assess clinical outcomes of patients with a
clinical suspicion of ventilator-associated pneumonia (VAP)
colonized with Candida. Conclusions In our series, most of the infections caused by MRSA
were pneumonias, had a late onset and were secondary
endogenous. Available online http://ccforum.com/supplements/11/S2 Concomitantly, a decrease in MRSA attack rate from six to one
new case per 1,000 patient-days was seen. Conclusion An ED tailored selective MRSA screening and contact
isolation protocol and a change in HH behaviour in the ED have
mainly contributed to a decrease of the MRSA attack rates in our
hospital far below the national rate. p
y
Results Were admitted 1,582 patients, 953 males (60.24%). The
mean age was 57.91 ± 18.83 years. The mean APACHE II score
was 13.95 ± 8.93. Admission diagnoses were: 737 (46.59%)
heart surgery, 189 cardiological (11.95%), 196 neurologic
(12.29%), 185 trauma (11.69%), 120 respiratory (7.59%), 104
digestive (6.57%) and 51 intoxication (3.22%). Mortality was
14.79% (234 patients). A total of 36 patients had colonization by
MRSA, two patients at ICU admission and 34 patients during the
ICU stay. We documented 24 infections caused by MRSA (four
EO and 20 LO; zero PE, 21 SE and three EX): 18 pneumonias
(three EO and 15 LO; zero PE, 15 SE and three EX), three primary
bacteremias (one EO and two LO; three SE), two surgical wound
infections (two LO and SE) and one pressure sore infection (one
LO and SE). Death occurred in 7/24 patients (29.17%) with
infection caused by MRSA: 6/18 (33.33%) pneumonias, 1/3
(33.33%) primary bacteremias and 0/3 other infections. Impact of an MRSA search and destroy policy in a tertiary
care emergency department Impact of an MRSA search and destroy policy in a tertiary
care emergency department Impact of antibiotic utilization measures on acquisition
rate of extended spectrum β-lactamase enzymes
producing bacteria Results From 1996 to 2005 the percentage of contamination from
S. epidermidis has been 24.7% (22% in respiratory tracts, 8% in
the urinary system, 41% in central venous catheter, 19% in the
blood, 10% in other places). From 2000 to 2005 there has been a
sensible reduction of 3%. A Gurnani1, A Jain1, S Sengupta1, G Rambhad2
1Kailash Hospital, Noida, India; 2Wyeth, Bombay, India
Critical Care 2007, 11(Suppl 2):P106 (doi: 10.1186/cc5266) A Gurnani1, A Jain1, S Sengupta1, G Rambhad2
1Kailash Hospital, Noida, India; 2Wyeth, Bombay, India
Critical Care 2007, 11(Suppl 2):P106 (doi: 10.1186/cc5266) Conclusion The introduction in the last 5 years of strict protocols
in order to control asepsis in our ICU, combined with the use of
Clorexidina and alcoholic gel, have drastically reduced the
contamination from S. epidermidis. Introduction Antibiotic resistance patterns are continually changing;
a new problem has been the emergence of Gram-negative bacteria,
primarily Escherichia coli and Klebsiellae pneumoniae, producing
extended spectrum β-lactamase enzymes (ESBL). Antibiotic use
measures are presumably the most important intervention in S42 Available online http://ccforum.com/supplements/11/S2 P112 Methods During a 2-year period (2005–2006), a study was
performed in a 17-bed general ICU, divided into two phases: a
case–control retrospective study in which controls comprising a
representative subpopulation with severe bacterial sepsis were
compared with cases (patients with Candida sepsis) with respect
to multiple demographic and clinical factors in a univariate analysis;
and a prospective phase creating a preemptive scheme based on
results from the retrospective part followed by progressively
implementing it among targeted patients. Results Over a 22-month period, 2,509 critically ill patients were
evaluated. Candida spp. was isolated from any site in 141 patients
(5.6%), while 10 patients (0.4%) presented ICU-acquired
candidemia. They were all hospitalized for more than 7 days (range
7–34 days) in the ICU and had been exposed to broad-spectrum
antibiotics (>3 agents). The mean age was 68 years (range 50–82
years) and the mean ICU stay 28 days. Candidemia appeared at a
mean of 15.8 days after ICU admission. Candida albicans was the
most common isolated pathogen. Candiduria in any count was
detected in 12 patients but none of them experienced candidemia,
while in seven patients Candida was isolated from urine and the
respiratory tract. Six patients had major postoperative complica-
tions. Mortality due to candidemia was 60%. All patients received
appropriate antifungal treatment. Prophylactic antifungal treatment
was used in patients with multifocality colonization and in patients
spending more than 7 days in the ICU after cardiac surgery. Results Identified were 28 cases with Candida sepsis and 50
controls with severe bacterial sepsis with an all-cause mortality rate
of 40.2%. The mortality rate for Candida sepsis was 46.4% with
an attributable risk of 10/100 and was associated with a worse
score of systemic injury (SAPS II = 51.7 ± 15.0), comparing with a
mortality rate of 35.7% and SAPS II = 38.8 ± 13.3 for bacterial
sepsis. Candida sepsis was always accompanied by concurrent
bacterial sepsis (2.8 ± 1.1 microorganisms/patient isolated from
blood cultures). Identified were risk factors with great significance
in addition to already known ones: Candida colonization (OR =
3.4), diabetes (OR = 3.2), number of antibiotics used (OR = 2.9),
a nothing per os regimen (OR = 2.63), ICU length of stay (OR =
1.97), length of antibiotic use (OR = 1.74), pancreatitis (OR =
1.7), shock at admission (OR = 1.54), ventilator days/ICU stay
ratio (days)(OR = 1.4), multiple resistant bacterial strains (OR =
1.5). P112 Candida colonization and risk of candidemia in a cardiac
surgical intensive care unit
E Douka A Mastoraki G Stravopodis G Saroglou S Geroulanos Candida colonization and risk of candidemia in a cardiac
surgical intensive care unit
E Douka, A Mastoraki, G Stravopodis, G Saroglou, S Geroulanos
Onassis Cardiac Surgery Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P112 (doi: 10.1186/cc5272) Candida colonization and risk of candidemia in a cardiac
surgical intensive care unit M Geube, S Milanov, G Georgiev
Pirogov Emergency Institute, Sofia, Bulgaria
Critical Care 2007, 11(Suppl 2):P111 (doi: 10.1186/cc5271) Introduction The aim of the study was to evaluate the incidence of
Candida colonization in a cardiac surgical ICU, the predisposing
risk factors and the impact of candidemia on outcome. Introduction Candida spp. is the third most common reason for
sepsis in the ICU, not differentiating our results from the classic
pattern of ICU-acquired infection. Prevention of sepsis develop-
ment and identification of potentially modifiable risk factors are
important goals in intensive care patents. Preemptive treatment of
Candida sepsis accepted by some authors is defined as an early
antifungal treatment given to patients with evidence of substantial
colonization in the presence of multiple risk factors for Candida
infection prior to establishing the diagnosis by cultures. Our aim
was to form a focused group of patients with significant risk for
Candida sepsis; to prove the feasibility and efficacy of our pre-
emptive scheme for antimycotic treatment in order to reduce the
risk of development of proved Candida sepsis. Methods In an effort to answer this question a prospective study
was conducted among patients admitted to our 16-bed cardiac
surgical intensive care unit ICU during 1 December 2004–30
October 2005. Candida
colonization and candidemia were
identified. Fungal colonization was defined as colonization index
exceeding 0.20 (3 g, at least two samples of seven growing
Candida spp.). Candidemia was defined as the isolation Candida
spp. in at least one blood culture in a patient with temporally
related clinical signs. The demographic characteristics of patients
who developed candidemia, as well as the underlying disease and
comorbidities, were recorded. P111 Fungal infections in the intensive care unit? Another
approach for defining a target group of patients who
benefit from implementing preemptive antimycotic
treatment E Dhondt, R Duerinckx, I Laes, A Schuermans
UZ Leuven, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P109 (doi: 10.1186/cc5269) ICU (21.1% vs 13.9%, P = 0.06) and 28-day mortality (23.7% vs
16.4%, P = 0.08) and a significant difference in hospital mortality
(34.2% vs 21.1%, P = 0.003) was observed in group C. A trend
was found for increased median length of ICU stay (14.1 vs 11.6
days, P = 0.07) and duration of MV (10.9 vs 8.1, P = 0.06). Hospital stay was significantly longer (59.9 vs 38.6 days,
P = 0.006) in group C. Conclusions Based on our results, we accepted an algorithm for
performing a preemptive therapy for which we observed clinical
efficacy and which we considered indicated the following target
groups of patients: with presence of clinical features of unresolving
sepsis plus three defined risk factors (PPV > 70%) in a patient
with length of ICU stay >20 days; lack of clinical improvement with
combined antibiotic treatment against established bacterial strains;
evidence of sepsis accompanied with multifocal Candida coloniza-
tion of sterile body spaces. Candida colonization without risk
factors requires continuous monitoring. The most important pre-
sumption to accept the preemptive strategy for a certain patient is
to have a serious clinical conviction that there is an invasive fungal
infection but it is still pending to be proved. Conclusion Respiratory tract Candida colonization in patients with
clinical suspicion of VAP is associated with an increased burden of
illness. Whether Candida colonization is responsible for worse
outcomes remains to be established. E Dhondt, R Duerinckx, I Laes, A Schuermans
UZ Leuven, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P109 (doi: 10.1186/cc5269) E Dhondt, R Duerinckx, I Laes, A Schuermans
UZ Leuven, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P109 (doi: 10.1186/cc5269) Introduction An emergency department (ED) is a major hospital
entrance and its case mix consists of patients at high risk of both
introducing and acquiring infections. Alerted by the rise of hospital-
acquired MRSA infections, the ED of a teaching hospital set up an
ED infection control (IC) programme. The programme and its
impact are discussed. Results Of the 739 patients enrolled in the VAP study, 639 were
included for analysis: 114 had Candida airway colonization (C) and
525 did not (NC). No significant differences were noted in
demographics and APACHE II score (20 ± 6 vs 20 ± 6, P = 0.37)
except more frequent admission for sepsis (7.0% vs 2.1%,
P = 0.005) and respiratory conditions (21.9% vs 14.3%, P = 0.04)
in group C. More colonized patients were on antibiotics at
randomization (81.6% vs 56.7%, P < 0.001). A trend for increased Methods The campaign consisted of the appliance of a proactive
MRSA admission screening protocol, selective contact isolation
(quarantine) and improving hand hygiene (HH). The MRSA
admission screening strategy took into account past medical
history or actual suspicion of MRSA carriage, transfers from other
hospitals and long-term care facilities and admission of
hospitalised patients to the ED for upgrading of care. According to S43 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusions Based on our results, we accepted an algorithm for
performing a preemptive therapy for which we observed clinical
efficacy and which we considered indicated the following target
groups of patients: with presence of clinical features of unresolving
sepsis plus three defined risk factors (PPV > 70%) in a patient
with length of ICU stay >20 days; lack of clinical improvement with
combined antibiotic treatment against established bacterial strains;
evidence of sepsis accompanied with multifocal Candida coloniza-
tion of sterile body spaces. Candida colonization without risk
factors requires continuous monitoring. The most important pre-
sumption to accept the preemptive strategy for a certain patient is
to have a serious clinical conviction that there is an invasive fungal
infection but it is still pending to be proved. P113 reticular neoplasias, solid organ transplants, and mainly in patients
with AIDS [1]. To our knowledge, the toxoplasmosis seropositivity
rate in ICU patients who have critical illness induced immuno-
suppression is not yet investigated. We studied the seropositivity
incidence of T. gondii in ICU patients by assessing IgG and IgM
antibodies. Consequences of cytomegalovirus reactivation in patients
with severe sepsis A Heininger, K Hamprecht, I Fischer, A Baumeister, C Meisner,
H Häberle
University Hospital, Tübingen, Germany
Critical Care 2007, 11(Suppl 2):P115 (doi: 10.1186/cc5275) Introduction Sepsis has been identified as a risk factor for cyto-
megalovirus (CMV) reactivation in nonimmunosuppressed patients
in the ICU setting. Here we present a double-blinded prospective
study assessing the consequences of CMV reactivation in non-
immunosuppressed patients with severe sepsis. Conclusion The observational nature of this study precludes the
establishment of any causality. This research merely documents
the experiences of ICU patients who have been prescribed i.v. fluconazole therapy. Our results showed high mortality rates in the
enrolled ICU patients. Patients developing adverse events and
complications requiring a switch in fluconazole experienced worse
outcomes u osupp essed pa e
s
se e e seps s
Methods In three (two surgical, one medical) ICUs of a German
university hospital, adult patients were screened for severe sepsis. Patients with recently occurring severe sepsis (<72 hours) were
enrolled if their anti-CMV IgG titer was positive. The exclusion
criterion was a manifest immunodeficiency. At enrollment the
SAPS II was assessed. Patients were monitored for CMV
reactivation weekly until death or hospital discharge by qualitative
and quantitative PCR and virus culture. CMV reactivation was
defined as CMV DNA detection or virus isolation. Patients with
(CMV+) and without CMV reactivation (CMV–) were compared
regarding inhospital mortality, duration of mechanical ventilation,
length of stay (LOS) in the ICU and the hospital. Data were
analysed using the Wilcoxon score rank sum test and chi-square
test. The level of significance was set to 0.05. Results CMV reactivation was observed in 38 out of 99 patients. Both groups (CMV+/CMV– patients) were quite similar in regard
to gender and age at study enrollment. Interestingly, the median
SAPS II was higher in CMV– patients (47 vs 42; P < 0.013). Accordingly, a lower mortality rate was anticipated for CMV+
patients
compared
with
the
CMV–
group. Contrary
to
expectations, mortality did not differ between both groups (CMV+
36.8% vs CMV– 42.6%; P > 0.67). This may point to a relatively pp
p
p
Methods In three (two surgical, one medical) ICUs of a German
university hospital, adult patients were screened for severe sepsis. Patients with recently occurring severe sepsis (<72 hours) were
enrolled if their anti-CMV IgG titer was positive. The exclusion
criterion was a manifest immunodeficiency. At enrollment the
SAPS II was assessed. Reference 1. Ferreira MS, Borges AS: Mem Inst Oswaldo Cruz 2002,
97:443-457. 1. Ferreira MS, Borges AS: Mem Inst Oswaldo Cruz 2002,
97:443-457. Results A total of 303 patients were enrolled. Fluconazole was
used initially as prophylaxis in 29 (9.6%) patients, preemptive
therapy in 85 (28.1%) patients, empiric therapy in 140 (46.2%)
patients and as definitive therapy in 49 (16.2%) patients. Thirty-six
patients switched from fluconazole to a broader spectrum anti-
fungal agent, and seven received a second concomitant antifungal
drug. Reasons for switching therapies included lack of response
due to suspected resistance, documented resistance or clinical
reasons other than resistance. Thirty-two patients (10.6%)
experienced fluconazole-related adverse events. The overall study
mortality rate was 41.9% (127/303 patients). Mortality was
significantly associated with switching i.v. treatment (odds ratio
5.0; 95% CI 2.3–11.1) and the presence of adverse events (odds
ratio 4.1; 95% CI 1.8–9.2). Consequences of cytomegalovirus reactivation in patients
with severe sepsis Patients were monitored for CMV
reactivation weekly until death or hospital discharge by qualitative
and quantitative PCR and virus culture. CMV reactivation was
defined as CMV DNA detection or virus isolation. Patients with
(CMV+) and without CMV reactivation (CMV–) were compared
regarding inhospital mortality, duration of mechanical ventilation,
length of stay (LOS) in the ICU and the hospital. Data were
analysed using the Wilcoxon score rank sum test and chi-square
test. The level of significance was set to 0.05. Longitudinal evaluation of intensive care unit-related
fluconazole use in Spain and Germany H Wissing1, J Ballus2, G Nocea3, K Krobot4, P Kaskel4,
R Kumar5, P Mavros5
1Universitatsklinkum Frankfurt, Germany; 2Hospital Universitari de
Bellvitge, L’Hospitalet del Llobregat, Barcelona, Spain;
3Universitaria de Bellvitge, Barcelona, Spain; 4MSD Sharpe and
Dohme GmbH, Munich, Germany; 5Merck and Co., Inc.,
Whitehouse Station, NJ, USA
Critical Care 2007, 11(Suppl 2):P113 (doi: 10.1186/cc5273) Materials and methods One hundred and three ICU patients with
the mean age of 53.9 ± 13.9 years (51 men, 52 women) and 78
healthy volunteers with the mean age of 51.4 ± 9.2 years (39 men,
29 women) as a control group were included in the study. Anti-
T. gondii IgG and IgM antibodies were determined by ELISA. Statistical analyses were done with the chi-square test and
Kolmogorov–Smirnov one-sample test. P < 0.05 was considered
as statistical significance. Objective To evaluate utilization patterns and outcomes associated
with i.v. fluconazole therapy within ICUs in Spain and Germany. Objective To evaluate utilization patterns and outcomes associated
with i.v. fluconazole therapy within ICUs in Spain and Germany. Objective To evaluate utilization patterns and outcomes associated
with i.v. fluconazole therapy within ICUs in Spain and Germany. Methods A prospective longitudinal observational study was
conducted within 14 hospital ICUs in Spain and five in Germany. Patients on i.v. fluconazole therapy were included and were
followed over one hospitalization period (admission until
discharge). Data were collected during 2004, using electronic
case report forms. Data included patient disease characteristics,
patient risk status (APACHE scores), type of fluconazole therapy,
drug-related adverse events, length of fluconazole therapy, and
length of hospital stay. Switches in fluconazole therapy, dosing
changes, additional concomitant antifungal therapy, overall mor-
tality, and clinical outcomes were also evaluated. Logistic regres-
sion models determined univariate and multivariate associations
with mortality. Results T. gondii IgG antibodies were positive in 56.3% of ICU
patients (n = 58) and in 24.3% of healthy volunteers (n = 19)
(P < 0.031). IgM antibodies were positive in 13.8% of ICU patients
(n = 15) and in 6.4% of healthy volunteers (n = 5); however, this
difference could not reach statistical significance. Conclusion The results of the study reveal that toxoplasma
seropositivity is not uncommon in ICU patients. Therefore, to
prevent the possibility of toxoplasmosis, seropositivity should be
periodically assessed in critically ill immunocompromised ICU
patients. It is clear that further studies are required to evaluate the
effects of seropositivity on ICU outcome. P115 Consequences of cytomegalovirus reactivation in patients
with severe sepsis P112 Patients with gastrointestinal surgery were at risk for
development of early fungal sepsis – by the 10th day of admission –
compared with the other clinical cases – by the 21st day of
admission. The incidence rate of positive blood cultures for
Candida in the group exposed to our scheme was calculated as
6.7% vs 18.5% in the control group. Conclusion C. albicans is the most common fungal pathogen in
our ICU. Seven percent of colonized patients developed
candidemia. Major
postoperative
complications,
excessive
antibiotic exposure and acute renal failure seem to predispose to
the development of candidemia. Patients with candidemia have
high inhospital mortality, perhaps as a reflection of illness severity. S44 Available online http://ccforum.com/supplements/11/S2 The role of plasminogen activator inhibitor 1 measurement
with endotoxin adsorption therapy (PMX-DHP) for
postoperative septic shock patients The role of plasminogen activator inhibitor 1 measurement
with endotoxin adsorption therapy (PMX-DHP) for
postoperative septic shock patients T Ikeda, K Ikeda, Y Kuroki, T Yokoyama, K Yoshikawa
Tokyo Medical University, Hachioji Medical Center, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P116 (doi: 10.1186/cc5276) Patients and methods We treated 27 septic shock patients using
DHP-PMX. The patients were separated into two groups for
analysis: those whose systolic blood pressure (SBP) increased by
more than 30 mmHg immediately after DHP-PMX (15 cases), and
those whose SBP did not increase by more than 30 mmHg after
DHP-PMX (12 cases). Furthermore, the patients were separated
into two other groups for analysis: those whose P/F ratio increased
by more than 20% immediately after DHP-PMX (15 cases), and
those whose P/F ratio did not increase by more 20% after DHP-
PMX (12 cases). Mediators were measured at four points: before
and after DHP-PMX, and 1 day and 3 days afterward. Introduction A polymyxin B immobilized fiber column (PMX; Toray
Industries Inc., Tokyo, Japan) was developed in Japan in 1994 and it
has been used for treatment of endotoxemia or septic shock patients. Materials and methods All patients received an urgent operation
due to intra-abdominal infection. In 88 cases treated with a poly-
myxin B immobilized column through direct hemoperfusion (PMX-
DHP), changes in hemodynamics, pulmonary oxygenation (PaO2/
FIO2) and various mediators (IL-6, IL-8, IL-ra, plasminogen activator
inhibitor 1 (PAI-1)) were examined before and after PMX-DHP,
stratifying with the outcome (64 survivors and 24 who died). PMX-
DHP was performed through a double lumen catheter (11.5 Fr),
placed in the femoral vein or internal jugular vein, at a blood flow
rate of 80 ml/min using nafamostat mesilate as an anticoagulant for
2 hours. Results The patient group consisted of 17 males and 10 females,
59.6 ± 12.7 years old. The average APACHE II score was
27.2 ± 9.1, and the average SOFA score was 11.7 ± 5.2 before
DHP-PMX. Nineteen patients survived and eight died. When the
changes in PAI-1, protein C, ATIII, IL-6 and high mobility group box
protein 1 (HMGB-1) were compared between the groups, only the
HMGB-1 levels had improved significantly in the SBP increased
group (P = 0.0125). The SBP increased significantly after DHP-
PMX in the HMGB-1-improved group (P < 0.0001). An improve-
ment in the P/F ratio and a reduction in 2-arachidonoyl glycerol
during DHP-PMX were significantly correlated (P = 0.0184). P117 increased mortality in CMV+ patients, although CMV disease did
not occur. There was a striking difference between the groups in
respect to the period on ventilator: 21.5 days vs 8.0 days (median)
in CMV+ and CMV– patients, respectively (P < 0.005). Similarly,
CMV+ patients had a longer median LOS after enrollment either in
the ICU (29.5 days vs 10 days, P < 0.001) and in the hospital
(49 days vs 23 days, P < 0.001). This difference was assured
when the analysis was restricted to survivors. Mechanism and effectiveness of polymyxin B-immobilized
fiber columns for removing mediators (HMBG-1,
2-arachidonoyl glycerol, anandamide, PAI-1, protein C and
IL-6) in septic shock patients
Y Sakamoto1, K Mashiko1, T Obata2, Y Yamamoto3
1Chiba Hokusou Hospital, Nippon Medical School, Chiba, Japan;
2Institute of DNA Medicine, Jikei University School of Medicine,
Tokyo, Japan; 3Department of Emergency Medicine, Nippon
Medical School, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P117 (doi: 10.1186/cc5277) Mechanism and effectiveness of polymyxin B-immobilized
fiber columns for removing mediators (HMBG-1,
2-arachidonoyl glycerol, anandamide, PAI-1, protein C and
IL-6) in septic shock patients Mechanism and effectiveness of polymyxin B-immobilized
fiber columns for removing mediators (HMBG-1, fiber columns for removing mediators (HMBG-1,
2-arachidonoyl glycerol, anandamide, PAI-1, protein C and
IL-6) in septic shock patients Y Sakamoto1, K Mashiko1, T Obata2, Y Yamamoto3
1Chiba Hokusou Hospital, Nippon Medical School, Chiba, Japan;
2Institute of DNA Medicine, Jikei University School of Medicine,
Tokyo, Japan; 3Department of Emergency Medicine, Nippon
Medical School, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P117 (doi: 10.1186/cc5277) Conclusion Our data suggest that CMV reactivation leads to
increased morbidity and treatment expenditure independently from
CMV disease. Further analysis points at a crucial role of lung
pathology due to CMV reactivation. The role of plasminogen activator inhibitor 1 measurement
with endotoxin adsorption therapy (PMX-DHP) for
postoperative septic shock patients Results PMX-DHP significantly increased systemic arterial pressure
and mean arterial pressure, with a greater increase in the survival
group. Also, there appeared to be a trend for PaO2/FIO2 improve-
ment as blood pressure increased. As the mechanism for improve-
ment of pulmonary oxygenation by PMX-DHP has not been shown
clearly, it remained to be examined further. PAI-1 values
significantly decreased in the survivor group (from 436 ± 549 to
251 ± 283 ng/ml) immediately after PMX-DHP; also intracellular
adhesion molecule-1 and endothelial leukocyte adhesion molecule-
1 tended to decrease in both groups. Conclusion We showed that the circulation dynamics of septic
shock patients can be improved by reducing HMGB-1 levels and
that respiratory function can be improved by reducing 2-
arachidonoyl glycerol levels using DHP-PMX. P114 Seropositivity incidence of anti-Toxoplasma gondii
antibodies in critically ill intensive care unit patients Seropositivity incidence of anti-Toxoplasma gondii
antibodies in critically ill intensive care unit patients ÖS Can, S Yalçin, O Memikoglu, E Özgencil, S Oba, M Tulunay,
N Ünal, M Oral
Ankara University Medical Faculty, Ankara, Turkey
Critical Care 2007, 11(Suppl 2):P114 (doi: 10.1186/cc5274) Results CMV reactivation was observed in 38 out of 99 patients. Both groups (CMV+/CMV– patients) were quite similar in regard
to gender and age at study enrollment. Interestingly, the median
SAPS II was higher in CMV– patients (47 vs 42; P < 0.013). Accordingly, a lower mortality rate was anticipated for CMV+
patients
compared
with
the
CMV–
group. Contrary
to
expectations, mortality did not differ between both groups (CMV+
36.8% vs CMV– 42.6%; P > 0.67). This may point to a relatively Introduction Toxoplasma gondii, a worldwide-distributed parasite,
could cause opportunistic infection with high mortality in immuno-
suppressive individuals. Its association with severe manifestations
of immunosuppression has been known for several decades, and
the occurrence of encephalitis and disseminated disease has since
been observed in different clinical conditions such as lympho- Introduction Toxoplasma gondii, a worldwide-distributed parasite,
could cause opportunistic infection with high mortality in immuno-
suppressive individuals. Its association with severe manifestations
of immunosuppression has been known for several decades, and
the occurrence of encephalitis and disseminated disease has since
been observed in different clinical conditions such as lympho- S45 S Livigni1, D Silengo1, M Maio1, V Perlo1, M Pozzato1,
P Selvaggi1, L Sereni1,2, M Wratten2
1San Giovanni Bosco, Turin, Italy; 2Bellco, Mirandola, Italy
Critical Care 2007, 11(Suppl 2):P118 (doi: 10.1186/cc5278) P116 Introduction Septic shock remains a major cause of multiple organ
failure with a high mortality rate. To remove an endotoxin in patient
plasma, direct hemoperfusion (DHP) using a polymyxin B-
immobilized fiber column (PMX; Toray Industries Inc., Tokyo Japan)
was developed in Japan in 1994 and has since been used for the
treatment of septic shock. The precise role of PMX is not clear. P118 Discussion
PAI-1 is elevated by endotoxin, thrombin and
cytokines, and is an indicator of vascular endothelial cell activation. In septic dissminated intravascular coagulation from Gram-nega-
tive bacilli, a massive amount of PAI-1 is produced on vascular
endothelial cells along with elevation of cytokine production and
coagulation activity. In addition, PAI-1, one of the fibrinolysis
inhibitory factors, plays an important role in regulating fibrinolysis
by inhibiting tissue plasminogen activator, which converts
plasminogen to active plasmin on fibrin, to block unnecessary
fibrinolysis. Characterization of the coupled plasma
filtration–adsorption resin cartridge adsorptive capacity for
cytokines and inflammatory mediators: adsorption profiles
from septic patient plasma and in vitro endotoxin-
stimulated whole blood S Livigni1, D Silengo1, M Maio1, V Perlo1, M Pozzato1,
P Selvaggi1, L Sereni1,2, M Wratten2
1San Giovanni Bosco, Turin, Italy; 2Bellco, Mirandola, Italy
Critical Care 2007, 11(Suppl 2):P118 (doi: 10.1186/cc5278) Conclusion The determination of PAI-1 may be a useful clinical
parameter for predicting PMX-DHP efficacy. Introduction Coupled plasma filtration–adsorption (CPFA) is an
extracorporeal therapy that uses plasma filtration associated with
an adsorbent cartridge and hemofiltration in postdilution to remove
cytokines and inflammatory mediators associated with septic shock
and severe sepsis. We evaluated the adsorptive capacity of the
resin cartridge to remove various inflammatory mediators and cyto-
kines in vitro and ex vivo. Introduction Coupled plasma filtration–adsorption (CPFA) is an
extracorporeal therapy that uses plasma filtration associated with
an adsorbent cartridge and hemofiltration in postdilution to remove
cytokines and inflammatory mediators associated with septic shock
and severe sepsis. We evaluated the adsorptive capacity of the
resin cartridge to remove various inflammatory mediators and cyto-
kines in vitro and ex vivo. S46 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P119)
Figure 2 (abstract P119) Figure 1 (abstract P119)
Figure 2 (abstract P119) Figure 1 (abstract P119) Methods
In
vitro
experiments included static and dynamic
evaluations of resin binding. Whole human blood was stimulated
with endotoxin for 4 hours at 37°C; or with the addition of added
cytokines or toxins for evaluation. For static conditions, 4 ml plasma
with 1 ml resin were incubated for up to 10 hours. Aliquots were
withdrawn between 0 and 10 hours and cytokine inflammatory
mediator and toxin adsorption were determined with standard
ELISAs, multianalyte protein arrays, HPLC and diode array
adsorption spectroscopy. Dynamic conditions involved defining the
optimal linear velocity and evaluating the adsorption capacity under
flow conditions. P118 These experiments used a closed circuit
consisting of a plasma filter and resin cartridge. Samples were
taken from a blood port and immediately before and after the
plasma cartridge. In addition, serum, pre-cartridge and post-
cartridge plasma samples were also taken from septic patients
undergoing CPFA. Results Endotoxin-stimulated blood or samples from septic patients
had high levels of cytokines and inflammatory mediators. The resin
used in the CPFA adsorptive cartridge showed higher than 80%
adsorption under both static and dynamic conditions for: IL-1α, IL-6,
IL-8, MIP-1α and MIP-1β, TNFα, MCP, myoglobin. IL-6 appeared to
be particularly adsorbed by the cartridge. Severe septic patients
had great variability and often very high levels of IL-6 ranging from
normal levels (50 pg/ml) up to 12,300 pg/ml. The mean of 10
patients treated before CPFA was 1,775 ± 3757 pg/ml, while post-
session IL-6 was 995 ± 2178 pg/ml. The plasma levels before the
cartridge ranged from 12 pg/ml to 1,750 pg/ml, while post-
cartridge levels were below the level of detection. Figure 2 (abstract P119) Conclusions The resin in CPFA has a high adsorption capacity for
several cytokines and mediators involved in severe sepsis and
septic shock. Studies are currently ongoing to correlate cytokine
reduction with clinically relevant improvements in these patients. P119 Removing endocannabinoids and reducing oxidative stress
with polymyxin-B-immobilized fibers in patients with septic
shock Y Kase, T Obata
Jikei University Hospital, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P119 (doi: 10.1186/cc5279) Y Kase, T Obata
Jikei University Hospital, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P119 (doi: 10.1186/cc5279) Introduction Arachidonylethanolamide (AEA) and 2-arachidonyl-
glycerol (2-AG) are endocannabinoids involved in septic shock,
and 8-epi prostaglandin F2α (F2-isoprostane) is a biomarker of
oxidative stress. Because the antibiotic polymyxin-B binds to
endotoxins and endocannabinoids, direct hemoperfusion therapy
with polymyxin-B-immobilized fibers (PMX-DHP) decreases serum
levels of endocannabinoids. To investigate the features of sepsis
and to determine the proper usage of PMX-DHP, we compared
perioperative changes in levels of endocannabinoids and F2-
isoprostane in patients with septic shock Conclusions Patients with septic shock are under considerable
oxidative stress, and 2-AG plays an important role in the
cardiovascular status of these patients. The removal of 2-AG by
PMX-DHP benefits patients with septic shock by stabilizing
cardiovascular status and decreasing long-term oxidative stress. Conclusions Patients with septic shock are under considerable
oxidative stress, and 2-AG plays an important role in the
cardiovascular status of these patients. The removal of 2-AG by
PMX-DHP benefits patients with septic shock by stabilizing
cardiovascular status and decreasing long-term oxidative stress. P121 The effectiveness of octreotide at different doses for
sulfonylurea-induced hypoglycemia following overdose
M Gul, B Cander, S Girisgin, M Ayan, S Kocak, A Unlu
Selcuk University Meram Medical School, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P121 (doi: 10.1186/cc5281) The effectiveness of octreotide at different doses for
sulfonylurea-induced hypoglycemia following overdose M Gul, B Cander, S Girisgin, M Ayan, S Kocak, A Unlu
Selcuk University Meram Medical School, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P121 (doi: 10.1186/cc5281) Results Forty patients admitted to the ICU were enrolled and
followed up to discharge. The median age was 35.5 years (mini-
mum 18, maximum 66). The median APACHE II score was 10.5
(minimum 2, maximum 28) and the median duration was 6 days
(minimum 1, maximum 43). D0, D3, D7 and D/C glucose concen-
trations did not differ (Kruskal–Wallis ANOVA, P = 0.98). TNFα
peaked at D3 (4.9 pg/ml) and then started decreasing. Admini-
stered insulin (InsAd) accompanied the TNFα peak at D3 (32U)
and then decreased. Adipo peaked at D7 (10,774 pg/ml) after the
TNFα peak, which coincided with the TNFα decrease at D7 to
4.76 pg/ml. Endogenous insulin indicated by CPep peaked with
Adipo at D7 (2.8 µg/l). TG levels increased in parallel with
increasing TNFα from 0.7 mmol/l at D0 to 1.1 mmol/l at D3 and
then declined. TC was lowest at D0 and increased up to D/C but
remained relatively low. Table 1 shows several variables and their
change over time from admission to discharge. Table 2 shows the
correlations between these variables. Survivors had a lower
median TNF than nonsurvivors (Mann–Whitney U test, P = 0.066). Conclusion TNF contributes to increased insulin needs. TNF is
known to cause insulin resistance. We have shown that TNF
correlates inversely with Adipo. As Adipo increases, insulin needs
are decreased (inverse correlation with InsAd). Also, TNF
contributes to increase TG indicating increased free fatty acids
(FFA) by lipolysis, which impairs glucose clearance. Adipo, an
insulin sensitizing protein, is known to negatively regulate TNF
levels as was indicated by our study. Adipo contributed to a
decrease in TG indicating lower FFA and better glucose clearance. IL-6 at D/C also contributed to a higher glucose concentration at
D/C. Increasing age contributed to lower Adipo levels at D/C,
indicating lower insulin sensitivity. Cytokines associated with insulin resistance in critically ill
patients Cytokines associated with insulin resistance in critically ill
patients Methods Twenty-four patients with septic shock induced by
peritonitis underwent laparotomy for drainage. Endocannabinoid
absorption with PMX-DHP was examined in two groups of
patients: patients in whom systolic arterial BP had increased more
than 20 mmHg (BP elevation group; n = 12) and patients in whom
BP did not increase or had increased no more than 20 mmHg (BP
constant group; n = 12). S Omar, U Wilgen, N Crowther
University of Witwatersrand, Gauteng, South Africa
Critical Care 2007, 11(Suppl 2):P120 (doi: 10.1186/cc5280) Introduction
We
examined
the
relationship
between
proinflammatory cytokines, adipocyte-derived adiponectin and
hyperglycemia. Patients requiring long periods in the ICU have a
relatively high mortality. Tight glucose control with insulin infusions
has been shown to improve survival and prevent complications. Methods A prospective, observational study at an academic ICU. A sequential sample was taken over a 2-month period. Ethics
approval was obtained from the University Ethics Committee. Introduction
We
examined
the
relationship
between
proinflammatory cytokines, adipocyte-derived adiponectin and
hyperglycemia. Patients requiring long periods in the ICU have a
relatively high mortality. Tight glucose control with insulin infusions
has been shown to improve survival and prevent complications. Introduction
We
examined
the
relationship
between
proinflammatory cytokines, adipocyte-derived adiponectin and
hyperglycemia. Patients requiring long periods in the ICU have a
relatively high mortality. Tight glucose control with insulin infusions
has been shown to improve survival and prevent complications. Methods A prospective, observational study at an academic ICU. A sequential sample was taken over a 2-month period. Ethics
approval was obtained from the University Ethics Committee. Results Levels of AEA did not change after PMX-DHP in the either
the BP constant group or the BP elevation group, whereas levels of
2-AG decreased significantly after PMX-DHP in the BP elevation
group but not in the BP constant group (Figure 1). F2-isoprostane
gradually increased after PMX-DHP. On the other hand, levels of F2-
isoprostane remained constant in the BP elevation group (Figure 2). Methods A prospective, observational study at an academic ICU. A sequential sample was taken over a 2-month period. Ethics
approval was obtained from the University Ethics Committee. S47 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Baseline bloods for TNFα, IL-6, adiponectin (Adipo), total
cholesterol (TC), triglycerides (TG), insulin, C-peptide (CPep) and
cortisol (Cort) were collected on admission (D0). P121 A higher BMI contributed to a Objective The aim of the study was to investigate the effectiveness
of octreotide at different doses in reducing the hypoglycemic
attacks and the need for dextrose in treatment of refractory and
recurrence hypoglycemia related to the toxicity of sulfonylurea. y
y
y
y
Methods In the study, 40 New Zealand type of rabbits were used
weighing between 2,500 and 3,000 g. The rabbits were randomly
divided into four groups consisting of 10 animals. All the animals
were given gliclazide 100 mg orally. For the treatment of
hypoglycemic attacks in Group I, only 15 cm3 50% dextrose
(7.5 g) intravenously (i.v.) was used; in Group II, Group III and
Group IV octreotide 25 µg, 50 µg and 100 µg single doses were
used subcutaneously, respectively. Octreotide was given in Groups
II and III and Group IV at the eighth hour (when hypoglycemic
attacks onset). Groups II, III and IV were given an additional 15 cm3
50% dextrose (7.5 g) i.v. infusion for each hypoglycemic attack
developed. Following the toxic dose, animals were given the amount
of dextrose used before and after octreotide administration and the
number of hypoglycemic attacks were recorded. Results There was a significant difference between Groups I, II,
and IV in the number of hypoglycemic attacks and the number of
dextrose requirement between 9 and 24 hours (P = 0.001). Groups receiving octreotide showed less hypoglycemic attacks
and dextrose requirements than controls. Conclusion Our experience suggests that octreotide may be used
to reduce the number of refractory and recurrence hypoglycemic
attacks developing due to overdose of sulfonylurea; large
prospective studies would be needed to validate these findings. Cytokines associated with insulin resistance in critically ill
patients These were
repeated on day 3 (D3), day 7 (D7) and discharge (D/C). Routine
bloods ordered were also used. Data on the ICU charts were also
used. No changes to ICU protocols were required. Of note, insulin
infusions were started for blood glucose concentrations greater
than 6 mmol/l. Exclusion criteria included all patients with diabetes
mellitus, chronic renal failure and liver failure or cirrhosis. higher glucose level at D0 and increased insulin needs at D0. Finally, a higher TNF level appears to be related to increased
mortality Influence of diabetes and HbA1c on the course and
outcome of sepsis in the intensive care unit Methods PBMC were isolated from peripheral blood of 10 healthy
volunteers via Ficoll gradient. Cells were incubated for 3 hours at
37°C with/without low/high concentrations of glucose, mannitol,
urea, insulin and stimulated with 0.5 ng/ml LPS. After 24 hours,
concentrations of IL-6 and IL-1β were measured with an ELISA
method. I Gornik1, O Gornik2, V Gasparovic1
1Clinical Hospital Centre, Zagreb, Croatia; 2University of Zagreb,
Croatia
Critical Care 2007, 11(Suppl 2):P124 (doi: 10.1186/cc5284) Introduction It is an accepted opinion that patients with diabetes
mellitus (DM) are at higher risk when treated for infections,
although published data are lacking. Our recent research on non-
ICU septic patients showed that admission HbA1c is in correlation
with outcome. The aim was to evaluate the impact of DM on the
course and outcome of patients with sepsis in ICU, as well as to
evaluate the value of HbA1c as an outcome predictor in the ICU Results Increasing concentrations of glucose, mannitol and urea
resulted in a significant increase of IL-6 and IL-1β cytokine
production. Insulin had no effect (Table 1). Table 1 (abstract P122)
No
Low
High
Substance
supplementation
concentration
concentration
Glucose
1,726
–
9,643
Insulin
609
555
636
Urea
2,056
3,421
3,835
Mannitol
367
–
3,269 evaluate the value of HbA1c as an outcome predictor in the ICU. Methods In a prospective, 3-year observational study, patients with
sepsis, severe sepsis and septic shock admitted to a medical ICU
were included. Patients with DM were compared with nondiabetics
in terms of course and outcome. HbA1c was measured for all
patients with DM. Hospital mortality and length of stay (LOS) in the
ICU and in hospital were the outcome measures. The incidence of
organ failure, ARDS, hospital-acquired pneumonia (HAP) and
ventilator-associated pneumonia (VAP) were used as indicators of
the disease course. Nonparametric tests, multiple regression and
logistic regression were used in statistical analyses. Conclusion High concentrations of glucose, mannitol and urea
lead to a significant increase in IL-6 and IL-1β cytokine production
by PBMC in vitro. The most profound effect was seen with
hyperglycemia. Besides hyperglycemia, also uremia and high
osmolarity seem to augment inflammation. Insulin could not reverse
the increase in inflammation. These findings may be relevant in
explaining the beneficial effects of normoglycemia on the
inflammatory response in critically ill patients. Results Two hundred and twenty-nine patients with sepsis at
admission (19.6% of all 1,169 ICU patients), 59 with DM, were
included. Influence of diabetes and HbA1c on the course and
outcome of sepsis in the intensive care unit Mortality in the ICU was 34.7%; the median ICU LOS
was 8 (95% CI 7–9.3) days. Patient with DM, compared with
nondiabetics, had higher mortality (38.9% vs 34.1%, P = 0.60)
and longer ICU LOS (median 6 vs 10 days, P < 0.001), and higher
incidence of renal failure, HAP, VAP. Surviving patients had
significantly lower HbA1c levels (6.6 vs 9.6, P = 0.001). In a
logistic regression, DM was found to be related to lethal outcome,
together with APACHE II and SOFA scores. In multiple regression,
DM related to LOS together with SOFA score and age. HbA1c
was found to be independently related to ICU outcome together
with SOFA score. P122 inflammatory mediator production can be modified by insulin
therapy. Rats subjected to bacterial lipopolysaccharide (LPS) with
or without insulin pretreatment were studied. LPS-induced PARP
activation in circulating leukocytes was measured by flow
cytometry, and production of TNFα was measured by ELISA. LPS
induced a significant hyperglycemic response, activated PARP in
circulating leukocytes and induced the production of TNFα. Insulin
treatment prevented the LPS-induced hyperglycemic response,
blocked the activation of PARP and blunted the LPS-induced
TNFα response. As hyperglycemia is known to induce the cellular
formation of reactive species, we propose that PARP activation in
endotoxin shock occurs as a result of hyperglycemia-induced
reactive oxidant and free radical generation. The current findings
may have significant implications in the context of the emerging
concept of tight glycemic control for critically ill patients. P122
Hyperglycemia and changes in osmolarity lead to an
increase in IL-6 and IL-1β cytokine production of human
peripheral blood mononuclear cells in vitro
N Otto, R Schindler, U Frei, M Oppert
Charité-Universitaetsmedizin Berlin, Germany
Critical Care 2007, 11(Suppl 2):P122 (doi: 10.1186/cc5282) Hyperglycemia and changes in osmolarity lead to an
increase in IL-6 and IL-1β cytokine production of human
peripheral blood mononuclear cells in vitro Hyperglycemia and changes in osmolarity lead to an
increase in IL-6 and IL-1β cytokine production of human
peripheral blood mononuclear cells in vitro N Otto, R Schindler, U Frei, M Oppert
Charité-Universitaetsmedizin Berlin, Germany
Critical Care 2007, 11(Suppl 2):P122 (doi: 10.1186/cc5282) Introduction Acute hyperglycemia and insulin resistance are
characteristics of metabolic and endocrine imbalances of critically
ill patients and are subject to a substantial inflammatory response
that is partly mediated by cytokines produced by peripheral blood
mononuclear cells (PBMC). Treatment with intensive insulin
therapy to keep patients normoglycemic has been shown to
reduce inflammatory responses. It is unclear whether hyper-
glycemia, insulin or osmolarity changes exert direct effects on
proinflammatory cytokines. We investigated the direct effects of
these substances on cytokine production of PBMC in vitro. Table 1 (abstract P120) Changes in glucose, insulin, cytokines and lipids in the ICU over time
Day
Glucose
InsAd
TNF
Adipo
Cpep
TG
TC
IL-6
D0
6.13
8
3.49
4,413.82
1.8
0.7
2.15
337.01
D3
6.25
32
4.9
6,925.4
2.2
1.1
2.2
127.01
D7
6.79
20
4.76
10,774.25
2.8
1
2.5
32.17
D/C
5.87
0
4.11
8,288.6
2.5
1.3
2.8
46.95
Table 2 (abstract P120)
Relevant Spearman correlations between the parameters
A
B
R
P
A
B
R
P
TNF
Adipo
–0.59
0.000
TNF
Mortality
0.25
0.060
Adipo
InsAd
–0.46
0.005
∆Adipo
LOS
0.45
0.004
TNF
TG
0.74
0.000
IL-6 D/C
Gluc D/C
0.34
0.042
Adipo
TG
–0.41
0.001
BMI
Gluc D0
0.39
0.012
TNF
Cortisol
–0.73
0.000
BMI
InsAd D0
0.31
0.053
Adipo
Cortisol
0.51
0.000
Adipo D/C
Age
–0.35
0.030
Age
InsAd D/C
0.35
0.032 Changes in glucose, insulin, cytokines and lipids in the ICU over time elevant Spearman correlations between the parameters S48 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P125
Lipid metabolism and organ dysfunction in septic patients
during intensive glycemic control S Cappi, F Soriano, A Nogueira, C Valeri, A Duarte, P Biselli,
W Hoshino, M Lins, J Barradas, D Noritomi, P Lotufo
Hospital Universitario da USP, Sao Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P125 (doi: 10.1186/cc5285) Introduction Intensive glycemic control has been widely discussed
in critical care patients. It remains unclear whether intensive insulin
therapy also improves the prognosis of patients in a medical ICU,
who often are more severely ill than are patients in a surgical ICU
and have a higher risk of death. Recently, medical patients have
been investigated, as a special group. We decided to study
possible differences in lipid profile in septic shock patients during
the first 72 hours and correlate it with different organ dysfunctions. Methods A prospective, randomized, controlled study in a 12-bed
medico-surgical ICU in a university hospital. Inclusion criteria: all
consecutive patients admitted to the ICU with severe sepsis and or
septic shock with onset in a maximum of 24 hours. Exclusion
criteria: HIV patients, pregnancy, diagnosis of leptospirosis, age
under 18, cancer patients. On admission, patients were randomly
assigned to strict normalization of blood glucose levels (80–110 mg/dl)
or to a conventional glycemic control (180–220 mg/dl) with the
use of sealed envelopes. We collected laboratory tests at 0, 24,
48 and 72 hours after initiation. For statistical analysis we per-
formed the Student t test. R
l
W
di d
i
i h
i il
d
hi
d g
y
Methods A prospective, randomized, controlled study in a 12-bed
medico-surgical ICU in a university hospital. Inclusion criteria: all
consecutive patients admitted to the ICU with severe sepsis and or
septic shock with onset in a maximum of 24 hours. Exclusion
criteria: HIV patients, pregnancy, diagnosis of leptospirosis, age
under 18, cancer patients. On admission, patients were randomly
assigned to strict normalization of blood glucose levels (80–110 mg/dl)
or to a conventional glycemic control (180–220 mg/dl) with the
use of sealed envelopes. We collected laboratory tests at 0, 24,
48 and 72 hours after initiation. For statistical analysis we per-
formed the Student t test. and HDL (not significant) were different between groups. The
mortality rate was the same but LDL and HDL had negative
correlation with organ function among nonsurvivors. Insulin therapy inhibits poly(ADP-ribose)polymerase
activation in endotoxin shock C Szabo1, E Horvath1, R Benko2, D Gero2
1University of Medicine and Dentistry of New Jersey, Newark, NJ,
USA; 2Semmelweis University, Budapest, Hungary
Critical Care 2007, 11(Suppl 2):P123 (doi: 10.1186/cc5283) Conclusion The ratio of patients with DM among ICU patients with
sepsis exceeds greatly the incidence of DM in the population. This
emphasizes the risk they have. DM was associated with worse
outcome, longer ICU and hospital LOS, and with higher incidence
of complications. HbA1c was confirmed as an outcome predictor
for ICU patients. The nuclear enzyme poly(ADP-ribose) polymerase (PARP) is
activated in various forms of circulatory shock. By triggering a
cellular energetic dysfunction, and by promoting proinflammatory
gene expression, PARP activation significantly contributes to the
pathogenesis of shock. The activation of PARP is usually triggered
by DNA strand breakage, which is typically the result of the
overproduction of reactive oxidant species. In the present study we
tested whether endotoxin-induced PARP activation and pro- S49 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 2 (abstract P125) Figure 2 (abstract P125) P125
Lipid metabolism and organ dysfunction in septic patients
during intensive glycemic control
S Cappi, F Soriano, A Nogueira, C Valeri, A Duarte, P Biselli,
W Hoshino, M Lins, J Barradas, D Noritomi, P Lotufo
Hospital Universitario da USP, Sao Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P125 (doi: 10.1186/cc5285) P125
Lipid metabolism and organ dysfunction in septic patients
during intensive glycemic control Conclusions Targeting blood glucose levels to below 110 mg/dl
with insulin therapy prevented morbidity, probably due to a better
control of lipid metabolism, expressed as a more rapid serum LDL
normalization and avoiding a greater decrease in serum HDL levels
in the first 72 hours of septic shock. Results We studied 58 patients with similar demographic data
between the two groups. The increases in serum LDL (P < 0.05) 0
Figure 1 (abstract P125) Figure 1 (abstract P125) P127 Variable adsorption of insulin at catheter materials used in
intensive care units: polyethylene vs polyurethane –
possible cause for hypoglycemia during intensive insulin p
yp g y
g
treatment? Methods A retrospective observational cohort study was conduc-
ted including 130 adult patients with a microbiologically
documented BSI admitted over a 2-year period (2003–2004) to
the ICU. Blood glucose levels were evaluated from 1 day prior to
onset of BSI (d–1) until 5 days after onset of BSI (d+5). The
contribution of hyperglycemia, divided into three subgroups
(≥150 mg/dl, ≥175 mg/dl, and ≥200 mg/dl, respectively), to in-
hospital mortality was estimated by logistic regression. S Ley, J Ammann, C Herder, M Hartmann, D Kindgen-Milles
University Hospital, Duesseldorf, Germany
Critical Care 2007, 11(Suppl 2):P127 (doi: 10.1186/cc5287) Introduction Intensive insulin therapy reduces morbidity and
mortality in postoperative critical care; however, this treatment also
increases the risk of hypoglycemia. A possible cause for unstable
blood glucose (BG) levels could be a variable adsorption of insulin
at plastic material of infusion tubings. We evaluated in vitro and in
vivo the adsorption of insulin at standard tubing materials
(polyethylene (PE) and polyurethane (PU)) and the effects of this
adsorption process on blood glucose levels. Results The mean age of the study population was 54.7 ± 19.0
years. Inhospital mortality was 36.2%. Hyperglycemia (≥175 mg/dl
and ≥200 mg/dl) was observed more often among the non-
survivors. Over the seven study days, no differences were found in
daily morning blood glucose levels between survivors (n = 83) and
nonsurvivors (n = 47) (all P > 0.05). Although in the nonsurvivors
the evolution of glycemia tended to be higher, this trend was not
statistically significant compared with the survivors. Multivariate
logistic regression revealed that age (P = 0.022), APACHE II score
(P = 0.003), antibiotic resistance (P = 0.001), and hyperglycemia
(≥200 mg/dl) upon onset of BSI (P = 0.001) were independently
associated with inhospital mortality, whereas appropriate anti-
microbial therapy ≤24 hours (P = 0.016) and previous history of
diabetes (P = 0.022) were associated with better outcome. Methods (1) In vitro, a standard perfusor syringe (Perfusor®;
BBraun, Germany) was filled with 50 IE normal insulin (Actrapid®;
NovoNordisk, Germany) dissolved in 50 ml saline 0.9%. P128 Hyperglycemia upon onset of nosocomial bloodstream
infection adversely affects outcome in a mixed intensive
care unit population Hyperglycemia upon onset of nosocomial bloodstream
infection adversely affects outcome in a mixed intensive
care unit population These findings indicate that the coagulation system did not play a
key role in mediating the survival benefit of intensive insulin therapy. References D Vandijck, S Oeyen, F Buyle, B Claus, S Blot, J Decruyenaere
Ghent University Hospital, Ghent, Belgium
Critical Care 2007, 11(Suppl 2):P128 (doi: 10.1186/cc5288) 1. Van den Berghe G, et al.: N Engl J Med 2001, 345:1359-
1367. 2. Van den Berghe G, et al.: N Engl J Med 2006, 354:449-461. Introduction Hyperglycemia in critically ill patients is frequently
related to a hypermetabolic stress-response and has been
associated with increased morbidity and mortality. The aim of this
study was to assess the relationship between blood glucose levels
and clinical outcome in a mixed cohort of critically ill patients with a
nosocomial bloodstream infection (BSI). P127 The
syringe was connected to PE or PU tubings (BBraun) and, at an
infusion rate of 1 ml/hour, the insulin concentration in the syringe
and at the end of the tubings was measured at hourly intervals for
5 hours and again after 24 hours by the Bradford protein assay. Insulin concentrations were compared using the Student t test. (2) In a prospective, double-blinded, cross-over study, approved by
the ethics committee, 10 patients on the surgical ICU received
insulin via PE or PU tubing each for 24 hours in random sequence. All blood BG values, total infused insulin solution volume, and
critical care scores were documented and statistically analysed by
the Wilcoxon test. Conclusion Trends of blood glucose levels were higher among
nonsurvivors. Hyperglycemia (≥200 mg/dl) upon onset of
nosocomial BSI adversely affects outcome in a heterogeneous ICU
population. Effect of intensive insulin therapy on coagulation and
fibrinolysis of respiratory critically ill patients L Langouche1, W Meersseman1, S Van der Perre1, I Milants1,
P Wouters1, G Hermans1, J Gjedsted2, T Hansen2, J Arnout1,
A Wilmer1, M Schetz1, G Van den Berghe1
1KU Leuven, Belgium; 2Aarhus University Hospital, Aarhus,
Denmark
Critical Care 2007, 11(Suppl 2):P126 (doi: 10.1186/cc5286) Most intensive care deaths beyond the first few days of critical
illness are attributable to nonresolving multiple organ failure (MOF),
either due to or coinciding with sepsis. One of the mechanisms
that is thought to contribute to the pathogenesis of MOF is
microvascular thrombosis. Recently, we reported improved survival
and prevention of MOF of critically ill patients with the use of
intensive insulin therapy to maintain normoglycemia for at least
several days [1,2]. We hypothesize that intensive insulin therapy
also prevents severe coagulation abnormalities, thereby contribu-
ting to less organ failure and better survival. We studied a subgroup of long-stay critically ill patients with a
respiratory disease upon ICU admission, who had been enrolled in
a randomized controlled trial evaluating the impact of intensive
insulin therapy in medical ICU patients [2]. Plasma samples were
analyzed for a panel of coagulation markers (prothrombin time,
activated partial thromboplastin time, fibrinogen and D-dimer
levels) that were used to assign points towards the International
Society of Thrombosis and Haemostasis overt disseminate
intravascular
coagulation
(DIC)
score. Circulating
plasma
thrombin–antithrombin complexes and plasminogen inhibitor type
1 levels were also determined. As markers of inflammation, we
measured circulating serum levels of several cytokines and CRP. S50 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Mortality of intensive insulin-treated patients was lower than of
conventionally treated patients for all classes of upon-admission
DIC score, except for those patients with a DIC score of 6 or
higher. There was no effect of insulin therapy on any of the
fibrinolytic, coagulation or inflammatory parameters tested. The
accuracy of the DIC score to predict mortality in this patient
sample was only moderate and comparable with that of CRP and
the SOFA score. Also, circulating plasminogen inhibitor type 1 or
thrombin–antithrombin complexes levels did not correlate well with
mortality or DIC score. insulin application to the patient is possible if different tubing
materials are used. Furthermore, variability of adsorption, a
competitive adsorption with other drugs if insulin is not infused via
a single line as well as changes of effective insulin application
following routine change of tubings, may be one cause of
unexpected hypoglycemia that can be deleterious to the patient. R Schaller1, F Feichtner1, A Fercher1, L Schaupp1,
M Bodenlenz1, H Köhler1, J Plank2, A Wutte2, M Ellmerer3,
R Hainisch4, T Pieber2
1Joanneum Research, Graz, Austria; 2Medical University Graz,
Austria; 3Medical University Hospital (MUG), Graz, Austria; 4FH
OÖ Forschungs & Entwicklungs GmbH, Linz, Austria
Critical Care 2007, 11(Suppl 2):P129 (doi: 10.1186/cc5289) P129 Hence the
usage of an automated discontinuous venous blood sampling
system might be an alternative to improve the adjustment of the
insulin therapy. The primary aim of the study was to investigate
whether the glucose concentration in manually withdrawn blood
samples correlates with automated withdrawn blood samples. Methods In a 12-hour trial, six volunteers were investigated (male/
female 5/1; age 28.2 ± 2.2 years, BMI 22.5 ± 1.3, nondiabetics). A 75 g OGTT was performed to enable a better dynamic range of
the glucose values. Two venous cannulae were inserted into the
dorsal hands for reference measurement and for connection to the
automated blood sampling system. To reduce the volunteer’s
health risk, pressure, air bubble sensor and flushing fluid monitor-
ing were integrated into the system. Blood samples were obtained
frequently in 15/30-minute intervals. Roche Microsamplers and the
OMNI S6 glucose analyser were used for determination of the
blood readings. Discussion Computerised decision-support and more intensive
monitoring did not improve BG control or reduce the incidence of
hypoglycaemia. Glargine insulin: an alternative to regular insulin for
glycemic control in critically ill patients Glargine insulin: an alternative to regular insulin for
glycemic control in critically ill patients M Bhattacharyya, SK Todi, A Majumdar
AMRI Hospitals, Kolkata, India
Critical Care 2007, 11(Suppl 2):P131 (doi: 10.1186/cc5291) Results The automated blood sampling system performed its
operation in all volunteers over the whole trial period. The median
Pearson coefficient of correlation between manual and automated
withdrawn blood was 0.983 (0.862–0.995). Furthermore, the
results (173 data pairs) were analysed via the recently published
‘Insulin Titration Error Grid Analysis’ and 99.4% were suggesting
an acceptable treatment. The results of the traditional ‘Error Grid
Analysis’ showed that 96% of the data were in zone A and 4% in
zone B. Introduction The objective of this study was to determine the
efficacy and safety of subcutaneous (s.c.) once-daily (OD) glargine
insulin, a long-acting insulin, in comparison with a s.c. regular
insulin, based on a protocolized sliding scale regimen for achieving
glycemic control in patients admitted to the ICU. Methods One hundred patients admitted to the ICU with an
admission capillary blood glucose (CBG) >150 mg/dl (8.3 mmol/l)
were involved in this prospective, randomized study. Patients with
age <18 years, pregnancy, shock, requiring continuous intra-
venous insulin infusion, renal failure were excluded. Patients were
randomly assigned to receive either s.c. glargine insulin 10 U
(CBG ≤9.9 mmol/l) or 18 U (CBG ≥10.1 mmol/l) s.c. OD (Group
G, n = 50), or s.c. regular insulin based on a 6-hourly sliding scale
(Group R, n = 50). CBGs were recorded at 6-hour intervals up to
96 hours or until ICU discharge, whichever was earlier. The target
CBG in both groups was <150 mg/dl (8.3 mmol/l). Patients in
group G received rescue doses of regular insulin, as required. Demographic characteristics, mean and median CBG, and
episodes of hypoglycemia were studied. Conclusion The automated discontinuous blood withdrawing
system provides reproducible blood samples from peripheral
venous blood. In combination with a glucose sensor and an
algorithm it might be used in future as a closed loop system for
insulin and glucose infusion at the ICU. P129 Results (1) The insulin concentration in all syringes was always
>97% of the estimated value. The initial concentrations of insulin at
the end of PE and PU tubings were lower than expected (23 ± 4%
of anticipated concentration in the first 6 min). In PE, the
concentration rose to 37 ± 2% and in PU to 78 ± 4% after
24 hours (P < 0.0001). (2) In vivo the mean BG values did not
differ
between
PE
and
PU
(PE
141 ± 17 mg/dl;
PU
132 ± 23 mg/dl (not significant)). Severity of illness was not
different between the groups: TISS 37 ± 5 (PE) vs 39 ± 5 (PU),
SAPS 43 ± 13 (PE) vs 41 ± 15 (PU) on both days; neither were
catecholamine doses and 24-hour fluid balance. However,
significantly more insulin solution was infused in PE (66 ± 18 ml/
24 hours) compared with PU (44 ± 15 ml/24 hours) (P = 0.0015). Conclusion Infusion of insulin using PE and PU tubings leads to a
relevant adsorption of the drug in both materials. Adsorption to PE
is significantly higher compared with PU. Thus, a large variation of System for automated discontinuous venous blood
withdrawal for glucose determination of patients in the
intensive care unit Introduction Intensive insulin therapy to establish normoglycaemia
reduces mortality and morbidity in critically ill patients. Frequent
glucose monitoring is restricted in critically ill patients due to the Introduction Intensive insulin therapy to establish normoglycaemia
reduces mortality and morbidity in critically ill patients. Frequent
glucose monitoring is restricted in critically ill patients due to the S51 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin 0.78 tests/hour) than the CIT group (3,609 over 8,617 hours, 0.42
tests/hour). The median (interquartile range (IQR)) proportion of
time spent in the target range 4.4–6.1 mmol/l was similar in the IIT
and CIT groups (23.21% (15.4–29.8) vs 17.9% (9.8–29.3),
respectively; P = 0.17). Similarly, time spent with a BG between
6.2 and 7.99 mmol/l was no different for the two groups (48.5%
(IQR 36.9–59.3) for IIT and 43.9% (IQR 34.7–60.9), P = 0.72). In
the IIT and CIT groups, five and six patients experienced a BG
below 2.2 mmol/l, respectively. high workload that has to be performed by the staff. Investigation of insulin clearance in severely acutely ill
patients with glucose intolerance evaluated by means of
bedside-type artificial pancreas Investigation of insulin clearance in severely acutely ill
patients with glucose intolerance evaluated by means of
bedside-type artificial pancreas M Hoshino1, Y Haraguchi2, I Mizushima1
1Tokyo Police Hospital, Tokyo, Japan; 2National Hospital
Organization Disaster Medical Center, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P132 (doi: 10.1186/cc5292) Background and purpose Glucose intolerance in acutely ill
patients is one of the risk factors of their morbidity and mortality,
and glucose control with insulin therapy improves the outcome. We investigated relationships among insulin clearance (IC), which
is considered to be one of the factors related to effectiveness of
insulin therapy, and glucose tolerance, glucose intolerance, and
severity of the diseases, in order to clarify the significance of IC on
the severity of the diseases including glucose intolerance and on
the therapies. Background and purpose Glucose intolerance in acutely ill
patients is one of the risk factors of their morbidity and mortality,
and glucose control with insulin therapy improves the outcome. We investigated relationships among insulin clearance (IC), which
is considered to be one of the factors related to effectiveness of
insulin therapy, and glucose tolerance, glucose intolerance, and
severity of the diseases, in order to clarify the significance of IC on
the severity of the diseases including glucose intolerance and on
the therapies. Methods Prospective collection of all glucose measurements for
ICU patients receiving an insulin infusion protocol between 20 May
2006 and 6 August 2006 in 64 ICU beds at a teaching hospital. We report glucose values from all ICU patients, ≥8 hours after
infusion initiation. Materials and methods Twenty-three ICU patients with glucose
intolerance in whom strict blood glucose control was performed by
means of a bedside-type artificial pancreas (NIKKISO Corp.,
Japan) were investigated. The diabetics were excluded. The items
investigated were IC (ml/kg/min) measured by the glucose clamp
method, daily mean blood glucose level as a parameter of glucose
intolerance (BGm, mg/dl), proportion of septic patients (%), SOFA
score and mortality (%) as indicators of the severity of the
diseases, and blood concentration of free fatty acid (FFA) and
stress hormones (glucagon, growth hormone, cortisol, adrenalin,
noradrenalin) as factors that might affect glucose intolerance. Evaluation of the clinical effectiveness of a computerised
decision-supported intensive insulin therapy regimen R Shulman, N Shah, P Glynne, R Greene, SJ Finney
University College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P130 (doi: 10.1186/cc5290) Introduction It has been proposed that intensive insulin therapy
(IIT) aiming for a blood glucose (BG) of 4.4–6.1 mmol/l reduces
mortality in critically ill patients when compared with conventional
insulin therapy (CIT) targeting BG at 10.0–11.1 mmol/l. Difficulties
with IIT include inadvertent hypoglycaemia and low efficacy at
achieving the target BG. We proposed that computerised decision
support may mitigate these problems. Results Demographic profiles were comparable between the two
groups. There was no significant difference in mean CBG in both
groups (Group G 152.1 mg/dl (8.4 mmol/l), Group R 149.9 mg/dl
(8.3 mmol/l), P = 0.66). Median CBGs were comparable at 6-
hourly time points in both the groups except at 0 and 6 hours in the
glargine arm (CBG at 0 and 6 hours, Group G 10.0 mmol/l and Figure 1 (abstract P131) Objective To comprehensively describe BG and outcome from
decision-supported IIT. Median capillary blood glucose (CBG) at different time points. Methods A clinical information system at each bedspace guided
staff through the IIT algorithm. The time spent within glucose
ranges was calculated assuming a linear trend between
successive measurements. Results Patient characteristics are shown in Table 1. The IIT group
had more frequent BG evaluation (7,007 over 8,944 patient-hours, 52
Table 1 (abstract P130)
IIT (n = 50)
CIT (n = 50)
P value
LOS, median (IQR)
7 (3–21)
6 (3–11)
0.05
Survivors
34 (64.2%)
24 (48.0%)
0.07
APACHE II, mean
23.2
25.4
0.17
Medical
31 (62%)
35 (70%)
0.53
Surgical
19 (38%)
15 (30%)
0.53 Table 1 (abstract P130) Median capillary blood glucose (CBG) at different time points. S52 Available online http://ccforum.com/supplements/11/S2 9.9 mmol/l, Group R 9.4 mmol/l and 8.3 mmol/l, P = 0.04 and
0.02, respectively) (Figure 1). There were three episodes of
hypoglycemia in Group G and one in Group R, which were
corrected. 9.9 mmol/l, Group R 9.4 mmol/l and 8.3 mmol/l, P = 0.04 and
0.02, respectively) (Figure 1). There were three episodes of
hypoglycemia in Group G and one in Group R, which were
corrected. Diurnal and other variations in blood glucose in intensive
care unit patients receiving insulin infusions S Smith, K Oveson, W Strauss, A Ahmann, D Hagg
OHSU, Portland, OR, USA
Critical Care 2007, 11(Suppl 2):P133 (doi: 10.1186/cc5293) Conclusion OD s.c. glargine insulin is a safe and effective
alternative to regular insulin for glycemic control in critically ill
patients. P132 Introduction Treatment of hyperglycemia in ICU patients using an
insulin infusion protocol was shown by van den Berghe and
colleagues to reduce mortality and morbidity in ICU patients. Consequently, many healthcare bodies proposed guidelines for the
control of hyperglycemia in the ICU. However, the patchy evidence
underpinning these guidelines and a high rate of complications
lead to controversy about the optimal glucose target range. Studies showing insulin infusions are effective have reported
average glucose values at single time points. However, single time
points are difficult to interpret as they do not provide information
about the proportion of glucose measurements that need to be in
range for benefit. We hypothesized that blood glucose variance
was greater if all glucose measurements were considered and
asked whether there was a diurnal pattern that accounted for some
of the variance. Investigation of insulin clearance in severely acutely ill
patients with glucose intolerance evaluated by means of
bedside-type artificial pancreas The
method of investigation involved patients being classified into four
groups according to IC, and those groups were compared with
each other; low IC group (group L: IC < 9, n = 2), normal IC group
(group N: 9 < IC < 15, n = 13), high IC group (group H: 15 < IC,
n = 8), and severely high IC group (group S: 19 < IC, n = 5)
(group S was a subgroup of group H). Results We compared the 6:00 a.m. glucose value with those
collected at all other times in 149 consecutive patients. The
6:00 a.m. values were lower than the remaining values (mean ±
SD: 112 ± 30 mg/dl (n = 477) vs 119 ± 35 mg/dl (n = 10,364);
P < 0.0001) and as hypothesized had a smaller variance by F test
(P < 0.0001). Inspection of the time-averaged data (±SE) revealed
a diurnal variation in the blood glucose with peaks occurring at
11:00 a.m. and 10:00 p.m. (Figure 1). This diurnal pattern may
account for some of the observed variation in insulin requirements
and contribute to episodes of hypoglycemia in the critically ill. Conclusion Glucose variance is increased if all time values are
considered rather than a single time point and there is a diurnal
pattern to glucose in ICU patients receiving insulin. Consideration
of this diurnal variation when treating hyperglycemia in the ICU may
avoid hypoglycemia and so facilitate better glucose control with
insulin infusions. Results (1) FFA values were low or normal in all groups. (2) There
were no significant differences in stress hormones among group N,
group H, and group S. Those hormones in group L were
significantly higher than, or had a tendency to be higher than, those
in group N, group H, and group S. (3) The mean values of BGm in
the groups had a tendency to be higher in the order of group S
(179 ± 30), group H (172 ± 25), group N (162 ± 26), and group L
(153 ± 8). (4) The severities of the diseases (sepsis (%)/SOFA
score/mortality (%)) in the groups were significantly higher in the
order group L (100%/20.0 ± 1.4/100%), group S (100%/
9.6 ± 7.0/40%), group H (88%/7.0 ± 6.5/25%), and group N
(54%/5.8 ± 5.2/15%). Severe hypoglycaemia during intensive insulin therapy: a
rare event in critically ill patients Severe hypoglycaemia during intensive insulin therapy: a
rare event in critically ill patients M Kaukonen, M Rantala, V Pettilä, M Hynninen
Helsinki University Hospital, Helsinki, Finland
Critical Care 2007, 11(Suppl 2):P134 (doi: 10.1186/cc5294) Introduction Tight glycemic control reduces mortality in surgical
intensive care patients and in long-term medical intensive care
patients. The incidence of severe hypoglycaemia (glucose
≤2.2 mmol/l) in the intensive treatment group has been 3.1–5.1%. Recently, a large study on intensive insulin therapy was
prematurely discontinued due to safety issues. The incidence of
hypoglycaemia was 9.8% in intensive treatment group and the
mortality among patients experiencing hypoglycaemia was 18.6%. As the safety of intensive insulin therapy has been questioned, we
screened all patients during a 17-month period to see the
incidence of hypoglycaemia and its effects on the prognosis of the
patients. Results Forty patients, 22 (55%) males and 18 (45%) females,
who received nutritional support for 48 hours or more were
studied. The mean (SD) age was 59.4 (14.7) years. Enteral feeding
was given in 32 (80%) and parenteral feeding in 14 (35%)
patients, while six (15%) patients received both enteral and
parenteral feeding. The mean (SD) energy in 48 hours was 3,307.4
(527.0) kcal, mean (SD) insulin was 1.37 (1.23) IU, mean (SD)
blood glucose was 7.76 (0.9) mmol/dl and total insulin to achieve
glycaemic control was 65.51 (58.6) IU. The time taken (SD) to
achieve glycaemic control was 15.16 (12.65) hours. As expected,
there was a relationship between the total insulin dose and the
time to achieve three consecutive glycaemic controls (r = –0.43,
P = 0.023). Also, between the total insulin dose and mean blood
glucose r = 0.508, P = 0.001. There was no significant relation-
ship between the total insulin dose and indication for ICU
admission, and the total insulin dose and body mass index. Methods A retrospective study was performed in two ICUs, one
eight-bed general ICU and one 10-bed surgical ICU. All patients
treated between 7 February 2005 and 30 June 2006 were
included in the study. A nurse-driven intensive insulin protocol with
a target blood glucose level of 4–6.1 mmol/l had been introduced
in 2004. All blood glucose measurements performed during the
ICU treatment were analysed. The patients were divided into two
groups according to the lowest detected blood glucose value
(≤2.2 or ≥2.3 mmol/l). P136 Implementation of glycemic control – problems and
solutions Implementation of glycemic control – problems and
solutions E Halbeck, U Jaschinski, A Scherer, A Aulmann,
M Lichtwarck-Aschoff, H Forst
Klinikum Augsburg, Germany
Critical Care 2007, 11(Suppl 2):P136 (doi: 10.1186/cc5296) Introduction Glycaemic control is another example of protocol-
driven therapy in intensive care medicine to improve outcome in
critically ill patients. While the advantage of this approach seems to
be obvious, little is known about the problems of implementing such
a protocol. The intention of this study was to evaluate problems of
implementation and to develop strategies to overcome them. Conclusions
Severe hypoglycaemia during intensive insulin
therapy is rare in protocol-driven ICU treatment compared with
previous clinical trials. When present, hypoglycaemia may have an
impact on the outcome of the patients Setting A 16-bed surgical ICU of a university teaching hospital
with 50 critical care nurses, about 30% in part-time employment. Severe hypoglycaemia during intensive insulin therapy: a
rare event in critically ill patients Conclusion Findings from this study showed that the indication for
admission did not affect either the total dose of insulin required to
achieve glycaemic control or the time it takes to achieve three
consecutive glycaemic controls. Results A total of 1,024 patients (1,124 treatment periods) were
included in the study. Thirty patients were excluded due to
incompleteness of the data. During the study period 61,203 blood
glucose measurements were performed, 1,578 (2.6%) of which
were below the target value of 4 mmol/l. Severe hypoglycaemia
(≤2.2 mmol/l) occurred in 25 patients (36 measurements). The
incidence was 0.059% of the measurements and 2.3% of the
patients. The median age, sex, APACHE II score, SAPS II or
diagnosis category did not differ between the groups. The median
(IQR) ICU and hospital length of stay was 4.3 (1.8–10.6) and 18
(8.5–39.5) days in patients with lowest blood glucose ≤2.2, and
2.7 (1.2–5.7) and 13 (7–23) days in patients with lowest blood
glucose ≥2.3 (P = 0.058 and P = 0.077, respectively). The
hospital mortalities were 25% and 15%, respectively; the
difference was not statistically significant. P134 efficacy of an intensive insulin therapy protocol in achieving
glycaemic control in patients presenting with different conditions. Methods A prospective observational study was performed over
8 weeks on patients admitted to an adult ICU who received
nutrition support for up to 48 hours. Intensive insulin therapy was
administered to those patients who developed hyperglycemia. The
demographics, blood glucose and insulin doses were documented. Haemoglobin, white cell count, neutrophil count, antioxidants, CRP
and prealbumin were measured. Outcome measures were the
mean and total insulin dose and the time to achieve glycaemic
control. P134
Severe hypoglycaemia during intensive insulin therapy: a
rare event in critically ill patients
M Kaukonen, M Rantala, V Pettilä, M Hynninen
Helsinki University Hospital, Helsinki, Finland
Critical Care 2007, 11(Suppl 2):P134 (doi: 10.1186/cc5294) Figure 1 (abstract P133) Figure 1 (abstract P133) Interpretation and conclusions The increase of IC was related to
glucose intolerance. IC increased and glucose intolerance became
severe as the severity of the diseases progressed. In the most
severe state, or in a near-terminal state, however, IC decreased
and glucose intolerance improved, although stress hormones
increased significantly. Therapies focused on the improvement of
IC were considered important in acutely ill severe patients with
glucose intolerance as well as blood glucose control by insulin
therapy. S53 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P137 Computer-advised insulin infusion in critically ill patients –
a randomized controlled trial
J Cordingley1, N Dormand1, S Squire1, M Wilinska2, L Chassin2,
R Hovorka2, C Morgan1
1Royal Brompton Hospital, London, UK; 2University of Cambridge, UK
Critical Care 2007, 11(Suppl 2):P137 (doi: 10.1186/cc5297) Computer-advised insulin infusion in critically ill patients –
a randomized controlled trial Methods This was an open randomized controlled clinical study. Fifty mechanically ventilated medical ICU patients were included
for a study period of 72 hours. Patients were randomized either to
a control group, treated by an insulin algorithm as routinely used in
the ICU, or to the MPC group, using a laptop-based fully
automated MPC algorithm. The target range for blood glucose
(BG) was 4.4–6.1 mM for both groups. Efficacy was assessed by
calculating the median BG, hyperglycaemic index (HGI) and BG
sampling interval. Safety was assessed by the number of
hypoglycaemic BG measurements < 2.2 mM. Introduction Tight blood glucose (BG) control has been shown to
decrease morbidity and mortality in patients in the surgical ICU [1]
but is difficult to achieve using standard insulin infusion protocols. We previously evaluated a software model predictive control
(MPC) insulin administration algorithm in postcardiac surgery
patients [2]. This study investigated the use of an enhanced MPC
algorithm (eMPC) in more severely ill patients over 72 hours. Results Patients were included for 72 (69–73) hours (median
(IQR)) in the control group and 71 (70–73) hours in the MPC
group. The median BG and HGI were significantly lower in MPC vs
control patients (see Table 1). A single BG measurement
< 2.2 mM was detected in the MPC group vs 0 in the control
group. The sampling frequency was significantly higher in the MPC
group. Methods Fourteen (seven male) critically ill ventilated medical and
surgical patients, mean age 65 years, with an arterial BG
> 6.7 mmol/l within 24 hours of ICU admission (RBH) or already
receiving insulin infusion, and expected to require mechanical
ventilation for more than 72 hours, were treated either with BG
control by the standard ICU insulin intravenous infusion protocol
[2] or eMPC-advised insulin infusion (n = 6) for 72 hours. The
eMPC algorithm, installed on a bedside computer, requires input of
current insulin requirements, bodyweight, carbohydrate intake and
BG concentration. The algorithm advises the time to next BG
sample (up to 4 hours) and the insulin infusion rate, targeted to
maintain BG at 4.4–6.1 mmol/l. P135 ,
p
p y
Method Over a 7-month period all patients staying longer than 48
hours in the ICU with hyperglycaemia (>150 mg%) on three
consecutive measurements were included in the study. These
patients were treated according to a protocol at the discretion of
the attending nurse. On daily rounds and every 4–5 weeks
supervision was performed, and the protocol was modified three
times during this period according to staff comments. Further on,
medical as well as nonmedical problems of implementation were
analysed and discussed. Attitudes and perceived impeding
aspects of the implementation process were recorded by means of
a questionnaire. Intensive insulin therapy and indications for intensive care
admission A Sanusi1, I Welters2, A Shenkin2, P Turner3, B Perry2
1University of Ibadan, Ibadan, Nigeria; 2University of Liverpool, UK;
3The Royal Liverpool Hospital, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P135 (doi: 10.1186/cc5295) Introduction Insulin resistance and hyperglycemia are common in
critically ill patients, and are associated with higher morbidity and
mortality in these patients if not controlled. Intensive insulin therapy
has been shown to reduce morbidity and mortality. It is not clear,
however, whether the patients’ indication for admission into the
ICU is related to the time to achieve glycaemic control or the total
dose of insulin required. This study was designed to audit the Results Since insulin sensitivity showed enormous variability,
glycaemic control required a high nursing effort. Impeding aspects
to titrate blood glucose into the target range were the absence of a
nutritional protocol (high carbohydrate intake, despite inflam-
mation/infection leading to hyperglycaemia that was difficult to S54 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P138) Table 1 (abstract P138)
MPC group (n = 25)
Control group (n = 25)
P
BG (mM)
5.9 (5.5–6.3)
7.4 (6.9–8.6)
<0.001
HGI (mM)
0.37 (0.17–0.91)
1.56 (1.06–2.45)
<0.001
Interval (min)
105 (94–139)
173 (160–194)
<0.001
Data presented as the median (IQR). Data presented as the median (IQR). Results The mean (SD) glucose concentration was significantly
lower in the eMPC group (6.0 (0.34) vs 7.1 (0.54) mmol/l,
P < 0.001). The mean insulin infusion rate was not significantly
different (4.1 (2.7) vs 3.1 (1.8) IU/hour, eMPC vs standard care). BG sampling occurred more frequently in the eMPC group, with a
mean of every 1.1 vs 1.9 hours (P < 0.05). No patients in either
group had any BG measurements <2.2 mmol/l. Conclusion The use of MPC improved BG and the HGI. This
improvement was accompanied by an increased sampling
frequency. MPC with time-variant sampling is a reliable tool for the
implementation of TGC in patients in the medical ICU. P138 control) and fear of hypoglycaemia (<60 mg%) leading to low-dose
insulin with consecutive hyperglycaemia. Lack of communication
(and therefore a loss of information) between critical care nurses
and the intensivists and poor acceptance from physicians to leave
this field of intensive care medicine to the nurses were additional
factors that slowed the implementation process. P138
Evaluation of a model predictive control algorithm using
time-variant sampling to establish tight glycaemic control
in clinical practice
C Pachler1, J Plank1, H Weinhandl1, R Hovorka2, L Chassin2,
P Kaufmann1, KH Smolle1, TR Pieber1, M Ellmerer1
1Medical University Graz, Austria; 2Addenbrooke’s Hospital,
Cambridge, UK
Critical Care 2007, 11(Suppl 2):P138 (doi: 10.1186/cc5298) Evaluation of a model predictive control algorithm using
time-variant sampling to establish tight glycaemic control
in clinical practice
C Pachler1, J Plank1, H Weinhandl1, R Hovorka2, L Chassin2,
P Kaufmann1, KH Smolle1, TR Pieber1, M Ellmerer1
1Medical University Graz, Austria; 2Addenbrooke’s Hospital,
Cambridge, UK
Critical Care 2007, 11(Suppl 2):P138 (doi: 10.1186/cc5298) Evaluation of a model predictive control algorithm using
time-variant sampling to establish tight glycaemic control
in clinical practice C Pachler1, J Plank1, H Weinhandl1, R Hovorka2, L Chassin2,
P Kaufmann1, KH Smolle1, TR Pieber1, M Ellmerer1
1Medical University Graz, Austria; 2Addenbrooke’s Hospital,
Cambridge, UK
Critical Care 2007, 11(Suppl 2):P138 (doi: 10.1186/cc5298) Conclusion Implementation of protocol-driven medicine requires a
high quality of information flow. The lack of linearity between blood
glucose and insulin dose (variability of insulin sensitivity) required a
sometimes intuitive (experienced) decision to titrate the insulin
dose. The conflict of physicians with this new role of critical care
nurses might be due to the lack of understanding of the evolution
of the nursing profession. Introduction Tight glycaemic control (TGC) in critically ill patients
significantly improves clinical outcome. Even with increased
workload for ICU nursing staff, targets for TGC are often not
achieved. The aim of the present study was to evaluate in clinical
practice a model predictive control algorithm (MPC) using time-
variant sampling, which will be used in a fully automated insulin
titration system (CLINICIP system). P139 Conclusion The eMPC algorithm was effective in maintaining tight
BG control in this more severely ill patient group without any
episodes of hypoglycaemia (BG < 2.2 mmol/l), but required more
frequent BG measurement. The effect of tighter glucose control on outcome P137 Patients in the eMPC group had
BG measured hourly (for safety) but values were only entered if
requested by the algorithm. The effect of tighter glucose control on outcome I Meynaar, P Tangkau, S Sleeswijk Visser,
M van Spreuwel-Verheijen, L Dawson
Reinier de Graaf Gasthuis, Delft, The Netherlands
Critical Care 2007, 11(Suppl 2):P139 (doi: 10.1186/cc5299) Acknowledgements This study is part of the CLINICIP project
funded by the EC (6th Framework). The University of Cambridge
also received support from EPSRC (GR/S14344/01). Critical Care 2007, 11(Suppl 2):P139 (doi: 10.1186/ Introduction Evidence is accumulating that tight glucose control
improves outcome in critically ill patients. This study was
performed to evaluate the effect of lower blood glucose levels in
critically ill patients on outcome. References 1. Van den Berghe G, et al.: Intensive insulin therapy in criti-
cally ill patients. N Engl J Med 2001, 345:1359-1367. 1. Van den Berghe G, et al.: Intensive insulin therapy in criti-
cally ill patients. N Engl J Med 2001, 345:1359-1367. 2. Plank J, et al.: Multicentric randomized controlled trial to
evaluate blood glucose control by the MPC versus routine
glucose management protocols in ICU patients. Diabetes
Care 2006, 29:271-276. Patients and methods The unit is a 10-bed closed-format
medical–surgical ICU in a general hospital. Starting in 2003 insulin
was prescribed to ICU patients using several nurse-driven S55 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P140) Figure 1 (abstract P140) computerised protocols, each subsequent protocol aiming for
lower glucose levels. From February 2004 until May 2005 protocol
1 was used, aiming for glucose between 5.0 and 9.0 mmol/l; from
July 2005 until December 2005 protocol 2 was used, aiming for
glucose between 4.5 and 7.5 mmol/l. Serum glucose was
measured at 6:00 a.m. in all patients from blood derived from
arterial lines or venous puncture. The rest of the day blood glucose
was measured either using the Glucotouch (protocol 1) or the
AccuCheck (protocol 2) devices. To eliminate differences due to
these different methods of measurement, only the 6:00 a.m. glucose measurements done by the central laboratory were
studied here. Data were derived from ICU and laboratory
databases. arterial blood measurements: Accu-chek Advantage® (Roche)
arterial, venous and capillary samples; and Precision PCx®
(Abbott) arterial samples. All samples were collected simul-
taneously. Agreement between measurements was tested with the
Bland–Altman method. Results See Table 1. The median morning glucose was reduced
from 7.5 mmol/l with protocol 1 to 6.8 mmol/l with protocol 2,
resulting in small but nonsignificant improvement in outcome. Subgroup analysis focusing on medical or surgical patients or on
patients with specific length of stay in the ICU also revealed
nonsignificant differences in outcome. Results Comparisons between pairs of measurements are shown
in Figure 1. Conclusions The two glucose meters evaluated might not be
sufficiently reliable to be used in the ICU setting, especially for
patients under strict blood glucose control. P141 Implementing tight glycaemic control: performance of
bedside glucometers D Vlasselaers1, K Vandewiele2, T Van Herpe2, B De Moor2,
G Van den Berghe1
1University Hospital Gasthuisberg, Leuven, Belgium; 2Katholieke
Universiteit Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P141 (doi: 10.1186/cc5301) Introduction Implementing tight glycaemic control (TGC) in the
ICU requires accurate blood glucose (BG) monitoring. We
evaluated the performance of two bedside glucometers (GM) in
ICU patients. Methods Four hundred and fifty-two arterial blood samples were
prospectively analysed in 37 adult ICU patients subjected to TGC. Arterial BG was simultaneously determined using a reference test
(ABL®) and two GM (Accu-Chek® and HemoCue®). Data were Conclusions A small but significant decrease in serum glucose
probably results in a small but statistically nonsignificant decrease
in mortality and length of stay. References Moreover, there are
marked differences between the equipment and a decrease in
precision if capillary or venous samples are used. Table 1 (abstract P139)
Protocol 1
Protocol 2
P
Number of patients
601
413
Number of morning
1,558
1,378
glucose measurements
Morning glucose
8.23/7.5
7.48/6.8
<0.001
(mean/median)
APACHE II score at ICU
13.6/12
13.9/12
Not significant
admission (mean/median)
Age (years, mean/median)
66.4/70.3
67.1/70.6
Not significant
ICU mortality all patients (%)
10.6
9.0
Not significant
Hospital mortality all
17.6
15.0
Not significant
patients (%)
Mean ICU length of stay
3.04/1.1
2.47/1.1
Not significant
(days, mean/median)
Mean hospital length of
17.00/10.0
13.62/9.1
Not significant
stay (days, mean/median) P143 Results Correlation between the reference method and both GM
in the overall BG range was reasonable, but not perfect (r2 ≥0.93). This was further underlined by BA analysis (Figures 1 and 2),
showing a bias to overestimate BG with GM. In the TGC range
(80–110 mg/dl) correlation was low for both GM (r2 ≤0.66). This
was confirmed by BA analysis, demonstrating broad limits of
agreement: +14.2 and –26.6 mg/dl for Accu-Chek® and +5.5 and
–31.1 mg/dl for HemoCue®. Results Correlation between the reference method and both GM
in the overall BG range was reasonable, but not perfect (r2 ≥0.93). This was further underlined by BA analysis (Figures 1 and 2),
showing a bias to overestimate BG with GM. In the TGC range
(80–110 mg/dl) correlation was low for both GM (r2 ≤0.66). This
was confirmed by BA analysis, demonstrating broad limits of
agreement: +14.2 and –26.6 mg/dl for Accu-Chek® and +5.5 and
–31.1 mg/dl for HemoCue®. Conclusions The accuracy of the tested GM in our ICU patients
was insufficient for safe clinical practice. Therefore, to avoid
potentially harmful hypoglycaemia, caution is warranted when TGC
is implemented exclusively based on BG results obtained by GM. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Figure 2 (abstract P141) arterial) and on the Rapid-Lab 1265 Bayer (GO, arterial), and each
value was compared with the reference laboratory result. Results A total of 262 matched analyses were done in 60 patients. Biases are defined as the glucose laboratory value minus point-of-
care value. The bias, 95% limits of agreement, and numbers of
observed discrepancy (d) paired results >20% and >10% are
reported in Table 1. arterial) and on the Rapid-Lab 1265 Bayer (GO, arterial), and each
value was compared with the reference laboratory result. p
y
Results A total of 262 matched analyses were done in 60 patients. Biases are defined as the glucose laboratory value minus point-of-
care value. The bias, 95% limits of agreement, and numbers of
observed discrepancy (d) paired results >20% and >10% are
reported in Table 1. Conclusions GO methods underestimate while GD methods
overestimate all blood glucose levels as compared with plasma
glucose levels measured by the reference method of hexokinase. Capillary methods have wider 95% limits of agreement than
measures carried out on arterial blood. P143 Continuous glucose monitoring for intensive care patients
using whole blood microdialysis
F Feichtner1, R Schaller1, A Fercher1, L Schaupp1, J Plank2,
A Wutte2, M Ellmerer2, T Pieber2
1Joanneum Research GmbH, Graz, Austria; 2Medical University
Graz, Austria
Critical Care 2007, 11(Suppl 2):P143 (doi: 10.1186/cc5303) Continuous glucose monitoring for intensive care patients
using whole blood microdialysis analysed using linear regression and the Bland–Altman (BA)
method. Introduction The objective of this study was to investigate whether
continuous glucose monitoring for intensive care patients could be
implemented using blood microdialysis (MD) as tight glycaemic
control reduces mortality and morbidity of critically ill patients. Currently investigated is whether the subcutaneous tissue is an
adequate and representative site for glucose monitoring. We have
designed and tested a novel system that allows continuous
measurement of glucose concentration in whole blood based on MD. Methods Na-heparin is pumped to the tip of a double lumen
catheter and the blood–heparin mixture is withdrawn continuously
at a mixing ratio of 1:1 at a flow of 4 ml/hour. The blood–heparin
mixture is microdialysed in a planar flow-through MD unit and is
discarded thereafter. The dialysate is collected and analysed for
glucose concentration via Beckman analysis and referred to
venous blood samples taken from the reference arm. Eight healthy
volunteers underwent a 12-hour investigation including an OGTT. Glucose readings from dialysate and venous blood were obtained
in a 15–30 minute interval. Introduction The objective of this study was to investigate whether
continuous glucose monitoring for intensive care patients could be
implemented using blood microdialysis (MD) as tight glycaemic
control reduces mortality and morbidity of critically ill patients. Currently investigated is whether the subcutaneous tissue is an
adequate and representative site for glucose monitoring. We have
designed and tested a novel system that allows continuous
measurement of glucose concentration in whole blood based on MD. Methods Na-heparin is pumped to the tip of a double lumen
catheter and the blood–heparin mixture is withdrawn continuously
at a mixing ratio of 1:1 at a flow of 4 ml/hour. The blood–heparin
mixture is microdialysed in a planar flow-through MD unit and is
discarded thereafter. The dialysate is collected and analysed for
glucose concentration via Beckman analysis and referred to
venous blood samples taken from the reference arm. Eight healthy
volunteers underwent a 12-hour investigation including an OGTT. Glucose readings from dialysate and venous blood were obtained
in a 15–30 minute interval. Figure 1 (abstract P141) Reliability of arterial, capillary and venous point-of-care
glucose measurements in the intensive care unit setting:
evaluation of two glucometers
A Pereira, A Cavalcanti, T Correa, F Almeida, E Figueiredo, E Silva
Hospital Israelita Albert Einstein, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P140 (doi: 10.1186/cc5300) A Pereira, A Cavalcanti, T Correa, F Almeida, E Figueiredo, E Silva
Hospital Israelita Albert Einstein, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P140 (doi: 10.1186/cc5300) Introduction Increased risk of hypoglycemia is the major drawback
of strict glycemic control, which has been extensively used in
critically ill patients. Fast and precise glucose measurements are
therefore mandatory. Our aim was to evaluate the accuracy of two
methods of bedside point-of-care testing for glucose measure-
ments using arterial, capillary and venous blood samples in ICU
patients. Methods A cross-sectional study with prospective data collection
included 86 patients admitted to a 40-bed clinical-surgical ICU of
a tertiary care hospital. Results from two different methods of
glucose measurement were compared with central laboratory S56 Available online http://ccforum.com/supplements/11/S2 P144 Subcutaneous glucose monitoring in patients with severe
sepsis Subcutaneous glucose monitoring in patients with severe
sepsis JK Mader1, S Korsatko1, D Ikeoka1, J Plank1, M Bodenlenz2,
M Suppan2, F Sinner2, KH Smolle1, TR Pieber1, M Ellmerer1
1Medical University Graz, Austria; 2Joanneum Research GmbH,
Graz, Austria
Critical Care 2007, 11(Suppl 2):P144 (doi: 10.1186/cc5304) Results During 2 months 55 patients (male 47%, female 53%)
were admitted, including 47 (85%) emergency admissions. Thirty-
three (60%) patients stayed in the unit for >48 hours with an
average stay of 7.1 days. Thirty-two (58%) patients received NS,
and 26 (81%) of these were within 48 hours of admission. Enteral
and parenteral routes were used in 26 (81%) and six (18%)
patients, respectively. In five (15%) patients both methods were
used during the change of route of administration. The daily calorie
intake expressed as a percentage of the recommended intake is
presented in Table 1. HE was more than 300 in 70% of the 570
measurements. Blood sugar was between 6.3 and 6.9 mmol/l. Gastro Prokinetics was used in 80%. There was no feeding
protocol in the unit and low GRVTs were used before
abandonment of the enteral regime. Introduction Tight glycemic control (TGC) to improve mortality and
morbidity in ICU patients requires frequent blood glucose
measurements and thus increases the workload for medical staff. TGC could be simplified by subcutaneous glucose monitoring as
suggested for diabetes care. Due to altered tissue perfusion as
often seen in critically ill patients, it remains unclear whether
subcutaneous adipose tissue (SAT) is a reliable measurement site. In this study we evaluated clinically whether SAT can be used as
safe, alternative site to establish TGC in patients with severe sepsis. Methods For 26 hours, arterial blood and SAT microdialysis
samples were taken from 10 patients with severe sepsis. Hourly
SAT glucose concentrations were calibrated to arterial blood
glucose (Bg) by one-point calibration either 1 hour (BgSAT1h) or
6 hours (BgSAT6h) after catheter insertion. The relation between
Bg and calibrated SAT glucose readings was clinically evaluated
applying a well-established insulin titration error grid analysis. ( Table 1 (abstract P145)
Total days (%)
Calories (%)
Nitrogen (%)
Nasogastric feeds
155 (71.5)
80.21
63.5
Total parenteral nutrition
48 (22.22)
151.52
118.1
Nasogastric feeds +
13 (6.06)
158.01
126.9
total parenteral nutrition Results Arterial and SAT glucose readings were comparable (Bg:
143 (122–167) mg/dl; BgSAT1h: 147 (130–177) mg/dl; BgSAT6h:
146 (117–181) mg/dl; median (IQR)). P144 Relative differences
between Bg vs BgSAT1h and BgSAT6h indicated –2 (–193 to
30)% and –4 (–42 to 25)%; median (5th and 95th percentiles)),
respectively. Clinical evaluation of the data indicated that 86%
(BgSAT1h) and 95% (BgSAT6h) of the glucose readings from SAT
would allow correct treatment according to an insulin-titration
guideline. Fourteen percent of the data for BgSAT1h and 5% of the
data for BgSAT6h would cause a violation of the guideline and thus
unwanted glucose excursions and a possible risk for the patient. Conclusion We found that there was overfeeding in the parenteral
and combined routes. HE was satisfactory in 70% and more
patients could receive enteral feeds if a high GRVT was used. Small-bore tubes are easy to implement and were not practised. Reference 1. Dhaliwal R, Heyland DK: Nutrition and infection in the inten-
sive care unit: what does the evidence show? Curr Opin
Crit Care 2005, 11:461-467. P146 g
p
p
Conclusions
Clinical evaluation of subcutaneous glucose
monitoring to establish TGC indicated that only 86% of the
readings would allow acceptable treatment according to a titration
guideline. Although this result could be substantially improved by
introducing a 6-hour stabilisation period for the trauma caused by
catheter insertion, the clinical applicability of subcutaneous
glucose monitoring for patients with sepsis has to be considered
with care. Prokinetics effect on gastric emptying in critically ill
ventilated patients measured by the C13 breath test with a
novel device M Hersch, V Krasilnikov, S Einav, D Braverman, S Zevin,
P Risseman
Shaare Zedek Med. Centre, Jerusalem, Israel
Critical Care 2007, 11(Suppl 2):P146 (doi: 10.1186/cc5306) M Hersch, V Krasilnikov, S Einav, D Braverman, S Zevin,
P Risseman
Shaare Zedek Med. Centre, Jerusalem, Israel
Critical Care 2007, 11(Suppl 2):P146 (doi: 10.1186/cc5306) M Hersch, V Krasilnikov, S Einav, D Braverman, S Zevin,
P Risseman Shaare Zedek Med. Centre, Jerusalem, Israel
Critical Care 2007, 11(Suppl 2):P146 (doi: 10.1186/cc5306) Acknowledgement Funded by the European Commission as part
of CLINICIP FP6 IST 506965. Introduction Gastroparesis in critically ill ventilated patients is
relieved by prokinetics. The best prokinetic combination is not
known and may be identified by BreathID measurement of gastric
emptying (GE). Introduction Gastroparesis in critically ill ventilated patients is
relieved by prokinetics. The best prokinetic combination is not
known and may be identified by BreathID measurement of gastric
emptying (GE). Comparison of accuracy of glucose-oxidase-based and
glucose-dehydrogenase-based point-of-care glucometers Thirty-two (58%) patients received NS,
and 26 (81%) of these were within 48 hours of admission. Enteral
and parenteral routes were used in 26 (81%) and six (18%)
patients, respectively. In five (15%) patients both methods were
used during the change of route of administration. The daily calorie
intake expressed as a percentage of the recommended intake is
presented in Table 1. HE was more than 300 in 70% of the 570
measurements. Blood sugar was between 6.3 and 6.9 mmol/l. Gastro Prokinetics was used in 80%. There was no feeding
protocol in the unit and low GRVTs were used before adequate flushing sequences or by using it with central lines. Further long-term studies are necessary to test the system together
with online sensors. assess the compliance of nutritional practise in our ICU with some
aspects of recommendations of Canadian Clinical Guidelines. assess the compliance of nutritional practise in our ICU with some
aspects of recommendations of Canadian Clinical Guidelines. Method
Demographic data, head elevation (HE) from the
horizontal position, daily nitrogen and calorie intake were recorded. Daily
recommended
calorie
requirements
were
calculated
according to body weights on admission. The nasogastric tube
size and the gastric residual volume threshold (GRVT) before
abandoning enteral feeds were also recorded. Method
Demographic data, head elevation (HE) from the
horizontal position, daily nitrogen and calorie intake were recorded. Daily
recommended
calorie
requirements
were
calculated
according to body weights on admission. The nasogastric tube
size and the gastric residual volume threshold (GRVT) before
abandoning enteral feeds were also recorded. Comparison of accuracy of glucose-oxidase-based and
glucose-dehydrogenase-based point-of-care glucometers A Roman, A Janier-Dubry, C Hanicq, P Flament, F Vertongen,
E Stevens
CHU Saint-Pierre, Brussels, Belgium
Critical Care 2007, 11(Suppl 2):P142 (doi: 10.1186/cc5302) Results All eight subjects successfully completed the 12-hour trial. The coefficient of correlation between continuously withdrawn
microdialysed blood and venously taken reference blood samples
was r = 0.9834 (0.9753–0.9958). The Clark Error Grid Analysis
(EGA) revealed that 99.5% of all data pairs are in the A range (220
of 221). Applying the novel Insulin Titration EGA yielded in 100%
of data pairs the ‘acceptable treatment’ area. Introduction Bedside capillary or arterial blood glucose monitoring
is mandatory for ICU patients under tight glycemic control. Point-
of-care methods are based on glucose-oxidase (GO) or glucose-
dehydrogenase (GD) enzymatic methods whereas the laboratory
reference method is hexokinase for measuring the plasma glucose
levels. Conclusions Blood MD based on continuous blood withdrawal
and extracorporeal MD is a promising approach to obtain dialysate
reliably, safely and continuously for long-term determination of
blood glucose concentration with online sensors. The correlation
between glucose concentration of dialysate and reference venous
blood samples is excellent. The patency of the double lumen
catheter in the current form could be improved by introducing Methods In this prospective observational study, blood glucose
was simultaneously measured on the Glucocard Arkray (GO,
capillary), on the Accu-chek Inform Roche (GD, capillary and S57
Table 1 (abstract P142)
Number of
Bias
Agreement
Number >20%
Number >10%
Point-of care method
comparisons
(mg/dl)
(mg/dl)
d (%)
d (%)
Glucocard, GO capillary
262
+8.5
±36
32 (12)
103 (39)
Accu-chek, GD capillary
262
–6.3
±37
40 (15)
123 (45)
Rapid-Lab, GO arterial
262
+5.3
±11
(0)
21 (8)
Accu-chek, GD arterial
234
–7.9
±17
17 (7)
67 (29) S57 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin assess the compliance of nutritional practise in our ICU with some
aspects of recommendations of Canadian Clinical Guidelines. Method
Demographic data, head elevation (HE) from the
horizontal position, daily nitrogen and calorie intake were recorded. Daily
recommended
calorie
requirements
were
calculated
according to body weights on admission. The nasogastric tube
size and the gastric residual volume threshold (GRVT) before
abandoning enteral feeds were also recorded. Results During 2 months 55 patients (male 47%, female 53%)
were admitted, including 47 (85%) emergency admissions. Thirty-
three (60%) patients stayed in the unit for >48 hours with an
average stay of 7.1 days. P148 Proton pump inhibitors and the incidence of Clostridium
difficile on the intensive care unit
I Whitehead, J Smith, R Bellamy, S Bonner
James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P148 (doi: 10.1186/cc5308) Proton pump inhibitors and the incidence of Clostridium
difficile on the intensive care unit Proton pump inhibitors and the incidence of Clostridium
difficile on the intensive care unit percentage dose recovered (PDR), a measure of delta over
baseline reflecting the rate of substrate metabolized. The 13CO2
measurements and calculations were done by our BreathID
Computerized system (BreathID Ltd, Jerusalem, Israel) with its
sensor attached to the expiratory ventilator tubing. I Whitehead, J Smith, R Bellamy, S Bonner
James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P148 (doi: 10.1186/cc5308) Introduction Clostridium difficile associated disease (CDAD) is
recognized as a major cause of morbidity and mortality among
patients in hospital. There have been reported associations
between the use of proton pump inhibitors (PPIs) and CDAD in
community and hospital settings [1,2]. The aim of this study was to
investigate the effect of introducing PPI prophylaxis in critically ill
patients on the incidence of CDAD. Results Thirty-one patients were included. Figure 1 shows the
PDR of all patients under the different prokinetic drugs. Table 1
presents the average percentage of GE improvement over BM with
different therapies, and the average improvement of individuals’
best combination. Comparing 20 patients, BM first, with 11 at
different timings, revealed no difference of baseline or best
combination (P = 0.1, P = 0.2, respectively). p
Methods Retrospective analysis of microbiology results of patients
admitted to general and neurotrauma ICUs between February
2002 and September 2006. Prior to March 2004 the general ITU
used PPIs for all patients as gastric acid prophylaxis, and the
neurotrauma ITU used PPIs for only patients at high risk of GI
ulceration. Following instigation of ventilator care bundles in March
2004 both units gave PPIs to all ventilated patients. The incidence
of C. difficile toxin-positive samples and the number of doses of
PPI used each month were compared for before and after this time
period. The use of antibiotics was also compared between the two
units over the time period to exclude this as a confounding variable. Results We identified 92 C. difficile-positive faecal samples
during the 57-month period from February 2002 to September
2006. This averaged 1.61 cases per month. P148 The general ITU
(ITU2) presented 49 cases (53.2%), and the neurotrauma ITU
(ITU3) 43 cases (46.8%). In February 2002, PPI usage was
infrequent in the ITU3, but more common in ITU2. The C. difficile
rates were also higher in ITU2 than in ITU3. PPI usage increased in
ITU3 until, on the instigation of the ventilator care bundle, PPIs
were used for all patients from March 2004. Our preliminary data
demonstrate an increase in C. difficile rates in ITU3, to meet the
rates of ITU2, at the same time as PPI usage was increased (Figure 1). The ITUs back onto each other and share the same medical and
nursing staff. Antibiotic usage was similar across both units with
regards to cephalosporins, meropenem and pipracillin/tazobactam. Conclusion C. difficile rates have remained relatively stable on the
general ITU (ITU2) but showed a significant increase on the Conclusions In this population: 1. Metoclopramide is poor in
improving GE. 2. The combination of metoclopramide and continuous
erythromycin is the most effective. 3. The BreathID is a convenient
and novel way to monitor GE in order to study and individually tailor
the most effective (up to 85% over BM) prokinetic combination. Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P146) Results Fifty-two patients receiving ETF were observed for a total
of 7,349 hours: 67.3% of patients were surgical and 32.7%
medical. Patients received a median of 75% of their ideal calorific
requirement. Feeding was started a median of 15 hours after
admission, and a median of 5% of feeding time was interrupted
after ETF had been started. Reasons for interruption included high
gastric aspirates, starvation for procedures and displacement/
blockage of feeding tube. The time to start ETF was significantly
different according to admission categories (P = 0.033), with
abdominal and cardiothoracic surgical patients having the greatest
delays. Abdominal surgical patients also had a higher proportion of
feeding interruptions due to high gastric aspirates and starvation
for procedures. The SOFA score on day 1 significantly correlated
with the time taken to start feeding (P = 0.008), length of total
feeding interruption (P = 0.012), length of feeding interruption due
to high gastric aspirates (P = 0.043), and length of feeding
interruption due to starvation for procedures (P = 0.026). Table 1 (abstract P146)
Metoclopramide
13.7%
Metoclopramide + erythromycin continuous
50.5%
Erythromycin continuous
33.3%
Erythromycin x 2
38.7%
Best individual
85.2% Table 1 (abstract P146)
Metoclopramide
13.7%
Metoclopramide + erythromycin continuous
50.5%
Erythromycin continuous
33.3%
Erythromycin x 2
38.7%
Best individual
85.2% Table 1 (abstract P146)
Metoclopramide
13.7%
Metoclopramide + erythromycin continuous
50.5%
Erythromycin continuous
33.3%
Erythromycin x 2
38.7%
Best individual
85.2% Conclusion The majority of patients received a high proportion of
their ideal calorific requirement and began feeding within 24 hours. The data indicate that patients having had abdominal surgery or
the sickest patients may be may be more likely to experience
delays in initiation and interruptions to feeding. Nutritional support in critically ill patients S Thanthulage1, Y Yoganathan2, S Tharmalingam1, M Kumara1
1Oldchurch Hospital, Romford, UK; 2BHR NHS Trust, Brentwood,
UK
Critical Care 2007, 11(Suppl 2):P145 (doi: 10.1186/cc5305) Methods A prospective crossover study in stable ventilated ICU
patients without upper gastrointestinal pathology. GE measure-
ment: 4-hours expiratory 13CO2 recording following intragastric
administration of C13 sodium acetate in 100 ml Osmolite. Baseline
measurement (BM) and following 24 hours i.v. therapy with:
metoclopramide (10 mg every 6 hours), metoclopramide with
continuous erythromycin (10 mg/hour), continuous erythromycin
and bolus erythromycin (200 mg every 12 hours) were done in
each patient. The BM and drug administration order was altered in
a subgroup of patients. GE was assessed by calculating the Introduction Early adequate nutritional support (NS) in critically ill
patients can improve clinical outcome [1]. Although enteral
nutrition is considered the best method, it carries a risk for
developing ventilator-associated pneumonia, particularly if patients
are nursed horizontally [1]. The aim of this prospective audit is to S58 P149 Methods CRF analysis was performed on full-thickness bowel
specimens obtained from shocked trauma patients requiring
emergency abdominal surgery for penetrating injury, and from
patients undergoing small bowel resection during elective bowel
surgery. Venous blood was taken before anaesthesia, intra-
operatively and on postoperative day 1. CRF extracted from tissue
and blood was quantified using radioimmunoassay. On day 1
postoperatively, intestinal permeability was tested by urinary
lactulose:mannitol (L:M) measurement. Institutional ethical approval
was granted and patients gave written informed consent. Intestinal corticotropin-releasing factor is decreased in
shocked trauma patients and may affect gut function Intestinal corticotropin-releasing factor is decreased in
shocked trauma patients and may affect gut function W Michell, L Hill, S Hendricks, L Weight, S Kidson
University of Cape Town, South Africa
Critical Care 2007, 11(Suppl 2):P150 (doi: 10.1186/cc5310) neurotrauma ITU (ITU3), concurrent with increased PPI usage. We
believe this worthy of further investigation. Introduction The reasons for the typical bowel dysfunction
following traumatic injury are unclear. Corticotropin-releasing factor
(CRF) in peripheral blood/tissue may induce intestinal barrier
dysfunction via receptor-mediated mechanisms independently of
the hypothalamic–pituitary–adrenal axis. This mechanism seems to
involve interactions of CRF with enteric nerves and mast cells,
which results in increased gut intercellular tight junction
permeability to macromolecules, as well as increased epithelial cell
apoptosis leading to loss of mucosal integrity. We investigated
whether blood and intestinal tissue CRF is associated with
postoperative gut dysfunction in shock. References 1. Dial S, Alrasadi K, Manoukian C: Risk of Clostridium difficile
diarrhea among hospital inpatients prescribed proton
pump inhibitors: cohort and case–control studies. CMAJ
2004, 171:33-38. 1. Dial S, Alrasadi K, Manoukian C: Risk of Clostridium difficile
diarrhea among hospital inpatients prescribed proton
pump inhibitors: cohort and case–control studies. CMAJ
2004, 171:33-38. 2. Cunnigham R: Proton pump inhibitors and the risk of
Clostridium difficile associated disease: further evidence
from the community. CMAJ 2006, 175:745-748. A study of enteral tube feeding in critically ill patients A Holdsworth, T Rahman
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P147 (doi: 10.1186/cc5307) Introduction For critically ill patients unable to eat, enteral tube
feeding (ETF) is the preferred mode of feeding. The study aimed to
investigate the amount of enteral feed obtained by patients on ICU
in a busy London Teaching Hospital, the efficiency of initiation of
feeding, and possible reasons for the failure of the above. Methods A prospective observational study was carried out over
1 month on patients admitted to a general and cardiothoracic ICU,
who received ETF. Baseline data including age, reason for
admission and illness severity score (SOFA) were documented. Length of time from admission to start of feeding was noted, and
the volume of feed delivered to patients was recorded. The
quantity of calories delivered to the patient was compared with the
patient’s ideal nutritional requirement (determined by the ICU ETF
protocol). Feeding interruptions were also recorded. S59 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P148) Figure 1 (abstract P148) between changing tracheostomy (suggesting repeat procedures)
and subsequent difficulty swallowing. One patient within this group
subsequently developed a tracheal stenosis. See Table 1. Conclusion We found the percentage of patients reporting
swallowing difficulties post percutaneous tracheostomy (PCT) (Portex
Blue Line Ultra tracheostomy tube) to be higher than one would
expect. This may be confounded by neurological injury necessitating
the need for a PCT, but we feel this may be an area of concern
meriting further investigation given frequent PCT in ICU practice. between changing tracheostomy (suggesting repeat procedures)
and subsequent difficulty swallowing. One patient within this group
subsequently developed a tracheal stenosis. See Table 1. P150 Intestinal corticotropin-releasing factor is decreased in
shocked trauma patients and may affect gut function
W Michell, L Hill, S Hendricks, L Weight, S Kidson
University of Cape Town, South Africa
Critical Care 2007, 11(Suppl 2):P150 (doi: 10.1186/cc5310) Retrospective study of dysphagia following hospital
discharge of intensive care patients P Isherwood, F Baldwin
Royal Sussex County Hospital, Brighton, UK
Critical Care 2007, 11(Suppl 2):P149 (doi: 10.1186/cc5309) P Isherwood, F Baldwin Objective A retrospective study to assess the incidence and causal
factors associated with long-term dysphagia following intensive care
discharge. Results Trauma patients (n = 6, male/female = 6/0, age 27 ± 10.2
years, ISS 23 ± 6.8) were younger than elective patients (n = 6,
male/female = 4/2, age 52.8 ± 7.7 years, P < 0.0006), and had
significantly lower mean tissue [CRF] (0.034 ± 0.015 x 10–3%
total protein (TP)) than elective patients (0.117 ± 0.075 x 10–3%TP,
P = 0.023). The median (IQR) intraoperative blood CRF level was
higher in trauma patients (86.7 (5.5) pg/ml vs 59.8 (9.6) pg/ml,
P = 0.03) than elective patients. In trauma patients this correlated
negatively with postoperative L:M (r = –0.9, P = 0.037), although
intestinal permeability was greatly and equally increased in both
groups (combined mean ± SD L:M, 0.58 ± 0.55). Methods A questionnaire was sent out 4 months post ICU
discharge to 193 intensive care patients (Level 3 care with a stay
of over 48 hours). We reviewed the case notes of those patients
who reported swallowing difficulties to establish whether they had
undergone, had any characteristics of or received therapies
potentially associated with dysphagia. Results We had a 50% response rate to our questionnaire. An
overall dysphagia post ICU stay rate of 19.5% was observed. Fever and age over 65 were both common findings as one may
expect and showed the highest association with subsequent
dysphagia. We did not find any suggestion of a relationship g
p
Conclusions CRF is detectable in bowel tissue following trauma
and is significantly lower in trauma vs elective surgery patients,
while CRF in blood may be a factor associated with gut barrier
changes following shock and emergency laparotomy. Table 1 (abstract P149) S60
Table 1 (abstract P149)
Factor
Number
Percentage
Fever
14
82
Age > 65 years
11
58
Percutaneous tracheostomy
10
50
Sterds
7
37
Cardiopulmonary resuscitation
3
15
Shiley fenestrated low-pressure
2
10
cuffed tracheostomy tube
Mini-Trach II – Seldinger
1
5
(Portex Minitracheotomy Kit)
Neuromuscular Blockade
0
0 P151 Conclusions Following a severe burn, propranolol attenuates
infections, inflammatory markers and fatty acid levels while
improving cardiac work and endogenous anabolic hormone levels. We suggest that propranolol is a safe and efficacious modulator of
th
tb course and analyzed for IGF-1, IGFBP-3, and HGH. Patients
underwent weekly resting energy-expenditure measurements. Statistical analysis was performed using analysis of variance with
Bonferoni’s correction and Student’s t test where applicable. Results Propranolol treatment reduced heart rates by 10% and
significantly improved stroke volume throughout the acute hospital
stay compared with controls (P < 0.05). Resting energy expendi-
ture was significantly decreased in the propranolol group when
compared with controls at discharge (P < 0.05). Infection rates on
admission were the same for both groups (17% propranolol vs
22% control). The incidence of infection throughout hospital
course was significantly lower in the propranolol group (60%)
compared with controls (87%) (P < 0.05). Propranolol significantly
increased IGF-I, IGFBP-3, GH, and prealbumin, while it
significantly decreased CRP and fatty acids (P < 0.05). Methods We enrolled patients admitted to our ICU who required
NGT insertion for EN. A Corflow NGT with Cortrak stylet was
inserted, and the position monitored using the Cortrak magnetic
sensor. The Cortrak system tracks the trail of the stylet tip as it
progresses towards the stomach and provides a visual represen-
tation of the NGT position on a video screen, allowing rapid
determination of insertion success. The position of the NGT was
also assessed using pH paper and/or CXR, as appropriate,
according to the standard UKNPSA guidelines. Data were
analysed using a paired t test and time-to-event analysis. Conclusions Following a severe burn, propranolol attenuates
infections, inflammatory markers and fatty acid levels while
improving cardiac work and endogenous anabolic hormone levels. We suggest that propranolol is a safe and efficacious modulator of
the postburn response. Results Fifty-two patients were recruited and 57 insertions were
analysed: 32 first insertions, and 25 reinsertions. Gastric content
was successfully aspirated in 40% (23/57) of insertions, and 14%
(8/57) had pH 6 or above. Forty-six CXRs were requested, with
three patients requiring multiple CXRs. The Cortrak correctly
confirmed the position of NGT in all 57 insertions. The time
required to confirm the NGT position was significantly less with the
Cortrak than with conventional methods (mean ± SE Cortrak:
9.6 ± 1.7 min; pH paper: 11.6 ± 1.7 min; CXR: 122 ± 23 min;
P < 0.0001). P151 There was a 1.5-hour delay in starting EN in the
standard practice group compared with the Cortrak group
(mean ± SE 3.98 ± 0.5 hours vs 2.58 ± 0.4 hours, P = 0.049). If
the Cortrak results had been acted upon, 46 CXRs could have
been avoided, which equates to a saving of £2,300 (€3,220). P153 Early enteral immunonutrition following gastric and
oesophageal surgery Early enteral immunonutrition following gastric and
oesophageal surgery S Vukosavljevic, T Randjelovic, D Pavlovic, J Danojlic
KBC ‘Bezanijska Kosa’ Beograd, Belgrade, Serbia
Critical Care 2007, 11(Suppl 2):P153 (doi: 10.1186/cc5313) Introduction The study investigates the effect of early enteral
immunonutrition on patient recovery after extensive elective surgery
in the upper abdomen [1,2]. It investigates the speed of patient
recovery administering early enteral immunonutrition combined
with total parenteral nutrition [3]. Conclusions The Cortrak demonstrated 100% accuracy in
confirming the position of NGT in this patient series. It exposes
patients to less radiation, facilitates earlier EN and is cost-effective. Consideration should therefore be given to including it into the
standard UKNPSA guideline. Materials and methods The total of 40 patients who had
undergone this type of surgery were involved in this study. Near the
end of the surgery procedure a percutaneous jejunostomy was
performed in 20 patients (G1), and enteral nutrition started on the
first postoperative day with small doses of immunonutrient
(Reconvan) 10 ml/hour. After every 12 hours the tolerance was
estimated (abdominal distension, diarrhoea, vomiting). After every
24 hours the immunonutrient dose was increased by 20 ml/hour
until we reached the maximum of 80 ml/hour. In the first three
postoperative days the patients were also administered total
parenteral nutrition, and after that only enteral nutrition. The other
group of 20 patients (G2) was administered only parenteral
nutrition from the first postoperative day. Preoperatively, every
patient was measured for body weight, body height and body mass
index, and using laboratory tests we established the levels of
albumin, transferine, blood urea nitrogen and creatinine. On the
third and ninth postoperative days we repeated the same
laboratory tests, and measured the daily loss of nitrogen by
excretion of urea in urine. Reference 1. UK National Patient Safety Agency [http://www.npsa.nhs.uk] 1. UK National Patient Safety Agency [http://www.npsa.nhs.uk] P152 Propranolol attenuates factors affecting hypermetabolism
in pediatric burn patients Propranolol attenuates factors affecting hypermetabolism
in pediatric burn patients W Norbury
Shriner’s Hospital for Children, Galveston, TX, USA
Critical Care 2007, 11(Suppl 2):P152 (doi: 10.1186/cc5312) P151 Using the Cortrak magnetic device to facilitate early
enteral nutrition in critically ill patients Using the Cortrak magnetic device to facilitate early
enteral nutrition in critically ill patients K Lei, J Smith, L Camporota, R Beale
St Thomas’ Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P151 (doi: 10.1186/cc5311) K Lei, J Smith, L Camporota, R Beale
St Thomas’ Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P151 (doi: 10.1186/cc5311) Introduction Confirmation of correct nasogastric tube (NGT)
positioning is required before commencement of enteral nutrition S60 Available online http://ccforum.com/supplements/11/S2 (EN). In the ICU, however, the use of sedation, 24-hour feeding
and proton pump inhibitors can make the standard confirmatory
methods recommended by the UK National Patient Safety Agency
(UKNPSA) [1] unreliable, and result in the need for multiple chest
X-rays (CXR), increased cost and feeding delay. We studied the
role of the Cortrak® (Viasys MedSystems, USA) against standard
practice, and assessed the following outcomes: time required to
confirm correct NGT position, time to starting feeding, and
potential cost savings. (EN). In the ICU, however, the use of sedation, 24-hour feeding
and proton pump inhibitors can make the standard confirmatory
methods recommended by the UK National Patient Safety Agency
(UKNPSA) [1] unreliable, and result in the need for multiple chest
X-rays (CXR), increased cost and feeding delay. We studied the
role of the Cortrak® (Viasys MedSystems, USA) against standard
practice, and assessed the following outcomes: time required to
confirm correct NGT position, time to starting feeding, and
potential cost savings. course and analyzed for IGF-1, IGFBP-3, and HGH. Patients
underwent weekly resting energy-expenditure measurements. Statistical analysis was performed using analysis of variance with
Bonferoni’s correction and Student’s t test where applicable. Results Propranolol treatment reduced heart rates by 10% and
significantly improved stroke volume throughout the acute hospital
stay compared with controls (P < 0.05). Resting energy expendi-
ture was significantly decreased in the propranolol group when
compared with controls at discharge (P < 0.05). Infection rates on
admission were the same for both groups (17% propranolol vs
22% control). The incidence of infection throughout hospital
course was significantly lower in the propranolol group (60%)
compared with controls (87%) (P < 0.05). Propranolol significantly
increased IGF-I, IGFBP-3, GH, and prealbumin, while it
significantly decreased CRP and fatty acids (P < 0.05). Feasibility of the REDOXS study – reducing deaths due to
oxidative stress: a randomized pilot trial of glutamine and
antioxidant supplementation in critically ill patients Feasibility of the REDOXS study – reducing deaths due to
oxidative stress: a randomized pilot trial of glutamine and
antioxidant supplementation in critically ill patients Introduction Standard selenium (Se) substitution (30–75 µg/day;
0.4–0.9 µmol/l) in the critically ill is not sufficient for a sustained
plasma level (0.58–1.82 µmol/l; 46–143 µg/l). Standard Se
substitution keeps the plasma level in the range 0.28–0.42 µmol/l. High-dose Se substitution correlated with a decrease in mortality
of patients with SIRS. The influence of high-dose substitution on
selected parameters, MAP and mortality in the critically ill were
evaluated in a prospective randomized clinical trial. D Heyland, R Dhaliwal, J Muscedere, J Drover, for the Canadian
Critical Care Trials Group
Kingston General Hospital, Kingston, Canada
Critical Care 2007, 11(Suppl 2):P154 (doi: 10.1186/cc5314) Kingston General Hospital, Kingston, Canada Introduction A large randomized trial is needed to evaluate the
safety and efficacy of glutamine (GLN) and antioxidant (AOX)
supplements. However, high doses of such nutrients via enteral
and parenteral routes early in the course of critical illness is often
interrupted by high illness acuity and other treatment priorities. The
purpose of this pilot trial was to evaluate the feasibility of delivering
high-dose GLN and AOX supplements early on in the course of
critical illness, and to estimate recruitment for the larger REDOXS
study. Methods One hundred and twenty-three patients (78 males, 45
females, median age 62.7 and 60 years, respectively) were
randomized into group A (SOFA 19.27) and group B (SOFA
10.23). Group A received standard Se substitution: 30–75 µg
NaSelenite i.v./day. Group B received high-dose Se substitution
according to a protocol: 1,000 µg at day 1, followed with 500 µg
at days 2–14 of NaSelenite i.v. The plasma levels of Se,
prealbumin, albumin, CRP, PCT, cholesterol, gluthathionperoxidase
GSHPx, D-dimer, creatinine clearance and leucocytes were
examined daily. MAP trends and 28-day mortality were evaluated
as clinical markers. Methods In six Canadian centers, using a 2 x 2 factorial design,
we randomized mechanically ventilated adults who had two or
more organ failures within 24 hours of ICU admission to one of four
groups: (1) GLN (0.35 g/kg/day i.v. plus 30 g enterally), (2) AOX
(500 µg selenium i.v. and 300 µg selenium, 20 mg zinc, 10 mg
β-carotene, 500 mg vitamin E, and 1,500 mg vitamin C enterally),
(3) both AOX + GLN, and (4) placebo. P155
Effect of high-dose selenium substitution on selected
laboratory parameters and prognosis in critically ill
patients Effect of high-dose selenium substitution on selected
laboratory parameters and prognosis in critically ill
patients 1. Delaney HM, Carenevale NH, Garvey JW: Jejunostomy by a
needle catheter technique. Surgery 1973, 73:786-945. 2. Braga M, Giannoti L, Radaelli G, et al.: Perioperative
immunonutrition in patients undergoing cancer surgery:
results of a randomized double-blinded phase 3 trial. Arch
Surg 1999, 134:428-433. 3. Moore EE, Jones TN: Benefits of immediate jejunostomy
feeding after major abdominal trauma: a prospective ran-
domized study. J Trauma 1986, 26:874-881. W Norbury
Sh i
’ H Background The aim of this study was to determine the effect of
propranolol on infections and clinical parameters during the acute
phase postburn. Severe thermal injury is followed by a period of
hypermetabolism that is directly proportional to the size of insult
sustained. Infection and multiorgan failure are now the leading
cause of death from severe thermal injuries. Propranolol, an
anticatabolic agent, improves hypermetabolism postburn. However,
there is evidence that propranolol worsens immune function and
increases the incidence of infection in critically ill patients. Results and discussion Patient recovery was faster in G1. The
average patient stay in ICU was 5 ± 1 days (G1) vs 10 ± 2 days
(G2). The average hospital stay was 22 ± 3 days (G1) vs 29 ± 5
days. Peristalsis was detected on the third day as an average (G1)
vs 4.5 days (G2). A decrease in pulmonary complications was
achieved in G1 (one pleural effusion) vs G2 (eight pleural
effusions). Laboratory tests show that patients in G1 are in lower
catabolism compared with G2 patients. Conclusion Early enteral immunonutrition through jejunostomy is
an efficient and safe method of patient nutrition with fewer
postoperative complications, and also accounts for a hospital cost
decrease of 50%. Results and discussion Patient recovery was faster in G1. The
average patient stay in ICU was 5 ± 1 days (G1) vs 10 ± 2 days
(G2). The average hospital stay was 22 ± 3 days (G1) vs 29 ± 5
days. Peristalsis was detected on the third day as an average (G1)
vs 4.5 days (G2). A decrease in pulmonary complications was
achieved in G1 (one pleural effusion) vs G2 (eight pleural
effusions). Laboratory tests show that patients in G1 are in lower
catabolism compared with G2 patients. Methods Sixty-six patients with burns >40% total body surface
area were enrolled into the study and randomized to receive
standard burn care (controls, n = 33) or standard burn plus
propranolol for more than 21 days (propranolol, 0.5–1.5 mg/kg
every 6 hours, n = 33). Biopsies were taken three times a week for
microbiological determination. Clinical parameters were collected
and blood was drawn at regular intervals throughout the hospital S61 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P156 P156 Feasibility of the REDOXS study – reducing deaths due to
oxidative stress: a randomized pilot trial of glutamine and
antioxidant supplementation in critically ill patients Supplementation was
continued for a minimum of 5 days up to 28 days and was
provided independent of nutrition support. We recorded the time
from ICU admission to randomization, the time to start of
supplements and nutrition support parameters. Results The Se plasma level was significantly higher in high-dose
Se-substituted patients (0.56 µmol/l vs 0.88 µmol/l, P < 0.001). GSHPx was significantly higher in high-dose Se-substituted
patients (4,864 U/l vs 6,097 U/l, P < 0.001). No significant
differences were found in the level of albumin, prealbumin, CRP,
PCT, leucocytes, fibrinogen, cholesterol, D-dimer and creatinine
clearance and MAP. The 28-day mortality was lower in a high-dose
Se-substituted patients (33% vs 37%), but not significantly. Conclusion The critically ill have an increased demand for Se,
which is essential for synthesis of Se enzymes and Se proteins. The increased demand for Se is not covered by standard
substitution. High-dose Se substitution (500–1,000 µg/day)
normalizes its plasma level and increases the GSHPx plasma level. High-dose Se substitution has no adverse reactions. The decrease
of 28-day mortality in high-dose Se-substituted patients is not
significant. The trial on high-dose Se substitution further continues. Results From April 2005 to April 2006, 80 patients were
randomized (average 2.1/site/month). The median time from ICU
admission to randomization was 18.2 hours (range 11.6–21.1 hours). All patients received parenteral supplements, the median (range)
time to start was 2.7 hours (2.0–3.8 hours) and 78/80 (98%)
received enteral supplements with a median (range) of 2.6 hours
(1.9–4.5 hours) from randomization. The mean duration of
supplements was 11.1 days (enteral) and 12.2 days (parenteral). The mean volumes of enteral and parenteral supplements received
were 84% (range 45–102%) and 93% (range 54–100%)
prescribed volumes, respectively. The average prescribed energy
and protein intakes were 1,802 kcal/day and 86 g protein/day but
the average daily percentage energy and protein received from
nutrition support was only 65% (range 4–95%) and 62% (range
2–97%) of that prescribed, respectively. Magnesium deficiency in the surgical intensive care unit W Salem
National Cancer Institute, Cairo, Egypt
Critical Care 2007, 11(Suppl 2):P156 (doi: 10.1186/cc5316) Available online http://ccforum.com/supplements/11/S2 Methods Sixty adult patients admitted to the ICU after major GIT
surgery were enrolled in the study, on the basis of a documented
Mg serum level < 0.8 mmol/l on arrival at the ICU. Exclusion criteria
were cardiac disease, liver dysfunction or serum creatinine > 1.3. Patients were randomly allocated to one of two groups: the Mg
group received 20 mmol (5 g) Mg sulfate, infused daily over
6 hours for 3 days; and a control group received an equivalent
amount of 5% dextrose. In the Mg group the next scheduled dose
of MgSO4 was held if a serum magnesium level > 1.1 mmol/l,
hypotension or bradycardia was recorded. Baseline and daily
measurements of serum Mg, potassium, sodium, calcium and
creatinine were done. Twenty-four-hour urine collection was used
to determine the total urinary excretion of Mg. The net Mg balance
(total Mg given – total urine Mg) was calculated. In the Mg group,
Mg-deficient patients (retainers) who excreted < 70% of the Mg
given ((urine Mg in mmol / daily Mg given) x 100) and Mg
nondeficient patients (nonretainers) who excreted > 70% of the
total Mg given were recorded. Results One hundred and sixty-six patients were included in this
analysis. Among the main results, 63.69% were males and
77.78% were considered malnourished. The mean SOFA score
was 6.21, with a mean APACHE II score of 19.39. In total, 97.23%
of the PN used in Brazil were manufactured by third-party
companies and this was associated with a significant delay in the
beginning of the infusion (median time 29.76 hours), and elevated
in-ICU (50%) and inhospital (55.17%) mortality rates. A total
24.29% of the patients were immunosuppressed. The most used
lipid source was long-chain triglycerides/medium-chain triglycerides
(80.69%). Conclusions The use of PN in Brazil is associated with a
significant delay in the start of infusion and high mortality rates. The
most used lipid emulsion (long-chain triglycerides/medium-chain
triglycerides) has been associated with more apoptosis [2] and
compromised lymphocyte proliferation [3]. The overall findings of
these study indicate that strategies to reduce the delay in start of
PN and the use of better lipid sources must be adopted to provide
better assistance for patients in need of PN in Brazil. Parenteral nutrition in the intensive care unit: can we
deliver better care to our patients? Preliminary results
from a multicenter, prospective, cohort study Parenteral nutrition in the intensive care unit: can we
deliver better care to our patients? Preliminary results
from a multicenter, prospective, cohort study Introduction Ultrasound (US) significantly facilitates central
venous catheterization, reducing the percentage of failure, the
percentage of accidental arterial puncture, and the percentage of
complications
(haematoma,
haemothorax,
pneumothorax). Nonetheless, it is not clear whether US guidance (USG) (so-called
‘dynamic’ or ‘real-time’ US techniques: that is, venipuncture under
direct US control) may be better than US assistance (USA) (so-
called ‘static’ or ‘indirect’ US techniques: that is, US imaging of the
vein, with or without skin marking, and then blind venipuncture). Introduction Ultrasound (US) significantly facilitates central
venous catheterization, reducing the percentage of failure, the
percentage of accidental arterial puncture, and the percentage of
complications
(haematoma,
haemothorax,
pneumothorax). Nonetheless, it is not clear whether US guidance (USG) (so-called
‘dynamic’ or ‘real-time’ US techniques: that is, venipuncture under
direct US control) may be better than US assistance (USA) (so-
called ‘static’ or ‘indirect’ US techniques: that is, US imaging of the
vein, with or without skin marking, and then blind venipuncture). A Pontes-Arruda1, J Teles2, E Silva3, F Machado4, M Baptista
Filho5, E Rocha6, C Silva7
1Hospital Fernandes Távora, Fortaleza, Brazil; 2Hospital Português,
Salvador, Brazil; 3Hospital Albert Einstein, São Paulo, Brazil;
4Hospital São Paulo – UNIFESP, São Paulo, Brazil; 5Hospital
Bandeirantes, São Paulo, Brazil; 6Hospital Copa D’Or, Rio de
Janeiro, Brazil; 7Latin American Sepsis Institute, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P157 (doi: 10.1186/cc5317) Methods From February 2005 to September 2006, our CVC Team
adopted the following protocol for internal jugular vein (IJV)
catheterization: (a) both IJVs were evaluated to assess position,
dimensions, and other features known to affect the risk of
catheterization; (b) then, a decision was made whether to continue
with USA or USG; (c) the IJV was accessed via the low lateral
Jernigan approach; (d) after two failed USA attempts, USG
venipuncture was adopted; (d) when IJVs were not available, USG
venipuncture of other central veins was the second choice; and (e)
fluoroscopy was used only in paediatric patients, but all patients had a
postoperative chest X-ray to rule out pneumothorax and malposition. Introduction Nutrition therapy is an integrant aspect of ICU
support and can influence outcomes. A delay to starting nutrition
support after 24 hours of ICU admission is associated with
increased morbidity and mortality [1], and certain lipid emulsions
can exacerbate the inflammatory cascade. Available online http://ccforum.com/supplements/11/S2 Results Patients in the Mg group showed a statistically significant
increase in mean serum Mg at days 1, 2, and 3 compared with the
control group and with day 0 (0.73 ± 0.1, 0.81 ± 0.17, 0.8 ± 0.1,
and 0.85 ± 0.11 mmol/l at days 0, 1, 2, and 3, respectively). The
mean total amount of Mg given, the mean total urine Mg excretion
and the net Mg balance were significantly higher in the Mg group
compared with the control group (58 ± 0.17 vs 11.3 ± 2.8 mmol,
P > 0.001; 34.0 ± 2.7 vs 15.5 ± 3.8 mmol, P > 0.001; 25.6 ± 1.65
vs 5.2 ± 0.93 mmol, P > 0.001). In the Mg group, the numbers of
Mg retainer patients were 24 patients on day 1, 21 on day 2 and
nine patients on day 3. Mg nonretainer patients were six patients
on day 1, nine on day 2 and 21 patients on day 3. Patients in the
Mg group showed better haemodynamic stability and fewer
ventricular arrhythmias. Acknowledgement Supported by a research grant from Baxter
Hospitalar Ltda. References 1. Simpson F, Doig GS: Parenteral vs. enteral nutrition in the
critically ill patient: a meta-analysis of trials using the
intention to treat principle. Intensive Care Med 2005, 31:
12-23. 2. Buenestado A, Cortijo J, Sanz M-J, et al.: Olive oil-based
lipid emulsion’ s neutral effect on neutrophil functions and
leucocyte–endothelial cell interactions. J Parenter Enteral
Nutr 2006, 30:286-296. 2. Buenestado A, Cortijo J, Sanz M-J, et al.: Olive oil-based
lipid emulsion’ s neutral effect on neutrophil functions and
leucocyte–endothelial cell interactions. J Parenter Enteral
Nutr 2006, 30:286-296. 3. Cury-Boaventura M, Gorjão R, Martins de Lima T, et al.: Toxic-
ity of two lipid emulsions on human lymphocytes and neu-
trophils. Crit Care, in press. 3. Cury-Boaventura M, Gorjão R, Martins de Lima T, et al.: Toxic-
ity of two lipid emulsions on human lymphocytes and neu-
trophils. Crit Care, in press. Conclusion Mg deficiency is common in ICU patients. Mg sulfate
administered according to the above regimen is safe. Early
treatment of Mg deficiency significantly increased the serum Mg
level and provided a better magnesium, potassium and calcium
balance, resulting in a shorter ICU stay. P158 Ultrasound-guided vs ultrasound-assisted central venous
catheterization Ultrasound-guided vs ultrasound-assisted central venous
catheterization M Pittiruti, A LaGreca, G Scoppettuolo, D Sermoneta
Catholic University Hospital, Roma, Italy
Critical Care 2007, 11(Suppl 2):P158 (doi: 10.1186/cc5318) W Salem Conclusion In critically ill patients with organ failure we provided
adequate amounts of study supplements via both enteral and
parenteral routes in the early phases of acute illness, independent
of nutrition support. We estimated recruitment of at least two
patients/site/month for our future trial. Introduction Magnesium (Mg) deficiency is a common and yet
underdiagnosed problem. Mg deficiency has been demonstrated in
50% of all ICU patients. These patients have significantly higher
morbidity and mortality rate. The aim of this work was to detect the
presence of Mg deficiency using a Mg loading test and to evaluate
the safety and efficacy of Mg replacement therapy in cancer
patients after major gut surgery. Acknowledgements This study was supported by grants from the
Canadian Institutes of Health Research and Fresenius-Kabi,
Germany. S62 Available online http://ccforum.com/supplements/11/S2 P159 Advantages of ultrasound-guided peripherally inserted
venous access (PICC and midline catheters) in critically ill
patients M Pittiruti, G Scoppettuolo, A LaGreca
Catholic University Hospital, Roma, Italy
Critical Care 2007, 11(Suppl 2):P159 (doi: 10.1186/cc5319) Results The central venous catheter placement was successfully
performed from the first attempt in both groups. There were no
immediate or delayed complications noted; however, the mean
time of insertion was longer in the ultrasound-guided group
(4.55 min) compared with the external anatomical landmark group
(2 min) (Figure 1). Introduction In the critically ill, a reliable peripheral or central
venous access is of paramount importance. Nonetheless, access
may be difficult or may carry a significant risk of complications
(pneumothorax, central line infection, etc.). Peripherally inserted
venous catheters – either central (PICC) or peripheral (midline
catheters (MC)) – are associated with a low risk of catheter-related
bacteremia; also, using the ultrasound guidance and the micro-
introducer technique (UG + MIT), they can be inserted in any
patient, regardless of the availability of superficial veins. Discussion Some studies have been designed to evaluate
ultrasound-guided central venous catheter placement compared
with the conventional method based on external anatomical
landmarks. These studies demonstrated the superiority of
ultrasound-guided central venous line placement over the external
anatomical landmark technique. However, there was no time gain
demonstrated in ultrasound-guided placement [2]. On the other
hand, a number of studies have expressed several reservations
concerning the systematic use of ultrasound guidance for central
line placement [3]. In our patients we found that the use of
ultrasound neither altered the rate of complication nor the number
of attempts in central venous catheter placement. Also the duration
of placement of the central line catheter using the external We have reviewed our experience of 56 peripherally inserted
catheters in 53 patients in different ICUs (surgical ICU, trauma unit,
coronary unit, neurosurgical ICU, stroke unit, pediatric ICU, etc.);
all catheters were positioned at the mid-arm, in the basilic vein or in
the brachial veins, using UG + MIT. We assessed the feasibility of
this technique in the acutely ill and the rate of complications. Methods and results We inserted 16 PICC and 40 MC in
patients requiring prolonged venous access (estimated >15 days);
nine were septic, six had coagulopathy, 21 had tracheostomy. We
used both silicone and polyurethane 4 Fr catheters. Procedures
were performed by a team of trained physicians and nurses. Parenteral nutrition in the intensive care unit: can we
deliver better care to our patients? Preliminary results
from a multicenter, prospective, cohort study For an appropriate
evaluation of the impact of these and other recent research
findings, information regarding the use of parenteral nutrition (PN)
in the ICU is needed. Introduction Nutrition therapy is an integrant aspect of ICU
support and can influence outcomes. A delay to starting nutrition
support after 24 hours of ICU admission is associated with
increased morbidity and mortality [1], and certain lipid emulsions
can exacerbate the inflammatory cascade. For an appropriate
evaluation of the impact of these and other recent research
findings, information regarding the use of parenteral nutrition (PN)
in the ICU is needed. Methods This is the interim analysis of a multicenter, prospective,
cohort study aimed to obtain information regarding the use of PN. Data were collected during 3 months from ICU patients over
18 years of age on the use of PN in 20 adult ICUs in Brazil using a
web-based clinical research form. S63 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P160 average 5.5 years: 20 short-term + 84 tunnelled + two ports). In
adults, the procedure started as USA in 522 and as USG in 299
cases: a shift from USA to USG was necessary in 8%. USG was
the first choice in all paediatric cases. The IJV was successfully
cannulated in most adult patients, with very few exceptions
(innominate vein in 12 cases, axillary vein in two cases, femoral vein
in one case, all by USG). In one paediatric patient, the CVC was
inserted in the subclavian vein, via a supraclavicular USG
approach. Complications were: failure 0%; pneumothorax 0%;
haemothorax 0%; accidental arterial puncture 1.1% (1.7% USA vs
0.3% USG); haematoma 0.4% (only for USA); malposition (0.8%,
exclusively with the left IJV). P159 Catheter insertion was easy in most cases, and immediate
complications were few (no failure; one hematoma; no arterial or
nerve injury). Late complications were: one local infection; three
thrombosis (two requiring removal); four cases of damage of the
external catheter (due to poor nursing or to inappropriate use of
the catheter during rx procedures), all easily repaired; one
dislocation; no catheter occlusion; no catheter-related bacteremia. Most catheters stayed in place for a prolonged time (range 9–65
days, median 19 days); only three were removed because of
complications. A comparison between ultrasound-guided central venous
line placement and an anatomical landmark technique M Soliman, K Ismail
Department of Anaesthesia & Intensive Care Medicine, The Mid
Yorkshire Hospitals, UK
Critical Care 2007, 11(Suppl 2):P160 (doi: 10.1186/cc5320) Introduction Ultrasound has been introduced in the insertion of
central venous lines to reduce the complications associated with
the conventional landmark technique [1]. We compared both
techniques; we noted the number of attempts, the duration of
insertion and complications. Conclusion In conclusion, (a) we had a minimal incidence of
complications, (b) USG was associated with a relevant reduction
of the risk of accidental arterial puncture and haematoma, if
compared with USA, and (c) choosing the left IJV was associated
with a higher risk of malposition. Methods Thirty patients were randomly selected, from the
operating theatre and ICU, who required placement of a central
venous catheter. The central venous catheter placement was
performed by two experienced anaesthetists with more than
6 years experience in anaesthesia and intensive care. In 15 patients
the internal jugular venous catheter placement was performed
using the external anatomical landmark technique, and in the other
15 patients the placement was under ultrasound guidance. The
duration of insertion was recorded from the moment the needle
touched the skin until insertion of the catheter and removal of the
guide wire. The numbers of attempts as well as immediate or
delayed complications were recorded. P161 Results Out of 67 surgeries contacted, we achieved a response
rate of 65%. Thirty-three practices (49%) were able to provide
complete data, six (9%) provided partial data, and a further five
(7%) were unable or unwilling to provide any data. Twenty-three
(34%) practices did not respond. A total of 318,130 patients were
listed by the responding practices. Of these: 23 patients live with
long-term tracheostomies, a prevalence of 1 in 13,800; 65 patients
receive mechanical respiratory support at home, a prevalence of 1
in 4,900; and 207 patients receive oxygen therapy at home, a
prevalence of 1 in 1,500. P162 Thirty-three practices (49%) were able to provide
complete data, six (9%) provided partial data, and a further five
(7%) were unable or unwilling to provide any data. Twenty-three
(34%) practices did not respond. A total of 318,130 patients were
listed by the responding practices. Of these: 23 patients live with
long-term tracheostomies, a prevalence of 1 in 13,800; 65 patients
receive mechanical respiratory support at home, a prevalence of 1
in 4,900; and 207 patients receive oxygen therapy at home, a
prevalence of 1 in 1,500. Method A postal survey was sent out to practice managers in the
local catchment area. They were asked to provide data for: patients
on home ventilatory support for any reason, patients with long-term
tracheostomies, patients with COPD who are on home oxygen or
who you would classify as end stage, and the total number of
patients registered to the practice. This was followed up with a
telephone call approximately 2 weeks later. Many were then e-
mailed the same questionnaire. A further two telephone calls to
each practice were made as necessary in order to obtain data. 3. Martin MJ, Hussain, Piesman M, et al.: Is routine ultrasound
guidance for central line placement beneficial? A prospec-
tive analysis. Curr Surg 2004, 61:71-74. 3. Martin MJ, Hussain, Piesman M, et al.: Is routine ultrasound
guidance for central line placement beneficial? A prospec-
tive analysis. Curr Surg 2004, 61:71-74. Figure 1 (abstract P160) Figure 1 (abstract P160) Conclusion Our experience with PICC and MC was characterized
by an extremely low rate of infective and thrombotic complications. Venous access was achieved in any patient, even with limited
availability of peripheral veins. The use of US-inserted PICC and
MC should be considered when central access is not advisable or
is contraindicated. S64 Available online http://ccforum.com/supplements/11/S2 P162
Prevalence of respiratory support in the community – the
Surrey experience
S Burfield, L Sherrard-Smith, E Laitt, V Jamison, W Jewsbury,
S Pambakian
Frimley Park Hospital NHS Foundation Trust, Surrey, UK
Critical Care 2007, 11(Suppl 2):P162 (doi: 10.1186/cc5322) P162 anatomical landmark technique was shorter than in the ultrasound-
guided method. P162
Prevalence of respiratory support in the community – the
Surrey experience Conclusion The external anatomical landmark technique in central
line placement is considered a safe method with experienced
hands. The time of insertion of a central line using the external
anatomical landmark technique was shorter than the ultrasound-
guided placement method. It is essential for all trainees to be
taught both methods for central line placement to be able to place
a central line catheter quickly and safely in emergency situations
and when an ultrasound machine is not available. S Burfield, L Sherrard-Smith, E Laitt, V Jamison, W Jewsbury,
S Pambakian
Frimley Park Hospital NHS Foundation Trust, Surrey, UK
Critical Care 2007, 11(Suppl 2):P162 (doi: 10.1186/cc5322) Introduction This study aimed to establish the prevalence of home
ventilatory and respiratory support within the catchment area of
Frimley Park Hospital in Surrey. The number of patients receiving
respiratory support at home has been increasing nationally since
1990 [1]; however, no local data exist. This trend is likely to
continue as domiciliary ventilation gains popularity for the treatment
of obstructive sleep apnoea and certain groups of COPD patients
[2]. 1. Denys BG, Uretsky BF, Reddy PS: Ultrasound-assisted can-
nulation of the internal jugular vein. A prospective com-
parison to the external landmark-guided technique. Circulation 1993; 87:1557-1562. 2. Randolph AG, Cook DJ, Gonzales CA, Pribble CG: Ultra-
sound guidance for placement of central venous
catheters: a meta-analysis of the literature. Crit Care Med
1996, 24:2053-2058. 2. Randolph AG, Cook DJ, Gonzales CA, Pribble CG: Ultra-
sound guidance for placement of central venous
catheters: a meta-analysis of the literature. Crit Care Med
1996, 24:2053-2058. Method A postal survey was sent out to practice managers in the
local catchment area. They were asked to provide data for: patients
on home ventilatory support for any reason, patients with long-term
tracheostomies, patients with COPD who are on home oxygen or
who you would classify as end stage, and the total number of
patients registered to the practice. This was followed up with a
telephone call approximately 2 weeks later. Many were then e-
mailed the same questionnaire. A further two telephone calls to
each practice were made as necessary in order to obtain data. Results Out of 67 surgeries contacted, we achieved a response
rate of 65%. References References Data presented as the mean ± SE after 120 minutes of isolated lung perfusion. Continuous assessment of inspiratory resistive work during
different types of pulmonary oedema in isolated rat lungs Continuous assessment of inspiratory resistive work during
different types of pulmonary oedema in isolated rat lungs Y Cikirikcioglu, D Morel
University Medical Centre, Geneva, Switzerland
Critical Care 2007, 11(Suppl 2):P161 (doi: 10.1186/cc5321) We recently demonstrated in isolated blood perfused rat lungs
subjected to i.t. LPS-induced pulmonary oedema that the
continuous measurement of inspiratory resistive work is a good
indirect indicator of progressive lung oedema [1]. Here we extend
these findings to two other types of pulmonary oedema: hydrostatic
oedema induced by elevation of the left atrial pressure, and alveolar
oedema (ALV) by infusing normal saline into the trachea at two
different infusion rates (2 and 4 ml/hour for 120 min). Discussion This study suggests that the Frimley Park Hospital
population of 350,000 currently contains about 100 individuals
requiring mechanical respiratory support at home. This is of
concern as currently there is no formal support for any of these
high-risk patients other than ventilator maintenance. Simple
problems precipitate hospital admission and rapidly trigger
outreach or intensive care review. The current position is clearly
unsatisfactory and must be addressed by PCTs if patient numbers
increase. See Table 1. Our results indicate that the continuous measurement
of inspiratory resistive work is a good indicator of both permeability
and hydrostatic lung oedema, but not of pure alveolar oedema
(absence of interstitial oedema). References P163
Intensive care unit patients on mechanical ventilation at a
university hospital in southern Brazil: characteristics,
mortality, frequency, and mortality risk factors pulmonary mechanics, CO2 homeostasis and pulmonary gas
exchanges with less frequent ventilatory settings (tidal volume (TV),
respiratory rate (RR)) and lower peak inspiratory pressure (Ppeak)
and plateau pressure (Pplat) than pressure-controlled synchronised
intermittent mandatory ventilation (P-SIMV) in patients undergoing
laparocopic cholecystectomy (LP). L Fialkow1, R Sens1, L Sehn1, R Cardoso1, A Wolmeister1, A
Milani1, M Bozzetti2, S Vieira1, J Brauner1, A Guntzel1, M
Ficanha1, G Machado1
1Hospital de Clínicas de Porto Alegre, Brazil; 2FAMED-UFRGS,
Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P163 (doi: 10.1186/cc5323) Method The study group consisted of 40 patients (APV-SIMV
n = 20, P-SIMV n = 20). LP was performed under total intravenous
anesthesia. After induction of anesthesia, a RR of 12 breaths/
minute, and an inspiratory:expiratory rate of 1:2 and PEEP of
6 cmH2O were set for both groups. APV-SIMV was started with a
target TV of 8 ml/kg. P-SIMV was started with the inspiratory
pressure (Pins) that will provide 8 ml/kg TV. The settings were
changed until target parameters to maintain normocapnia and
normoxia
were
achieved
(ETCO2
30–35 mmHg,
PaCO2
35–45 mmHg and SaO2 >90%). When the target parameters
could not be achieved, the first RR was increased by 2 breaths/
minute up to 16 breaths/minute, then the volume or pressure was
titrated to induce 1 ml/kg increases in TV up to 10 ml/kg. The initial
FiO2 was set to 50%. FiO2 was increased with increments when
the SaO2 fell below 90%. PaO2/FiO2, static compliance, VD/VT,
Ppeak and Pplat, ETCO2, inspiratory and expiratory resistances, and
arterial blood gas analysis were recorded before, during and after
pneumoperitoneum. Statistical analysis were carried out using the
chi-square test, paired test and independent samples test when
appropriate. Introduction Acute respiratory failure (ARF) is a frequent cause of
admission to ICUs and frequently necessitates mechanical
ventilation (MV). Knowledge about the frequency and risk factors
associated with requirements for MV is crucial to improve
outcomes. The objectives of our study were to determine the
characteristics, frequency of MV, overall and specific mortality
rates and mortality risk factors in patients who required MV in the
ICU of a general university hospital in southern Brazil. Methods A prospective cohort of 751 adult patients admitted to
the ICU who needed MV for at least 24 hours, between March
2004 and July 2006. P163
Intensive care unit patients on mechanical ventilation at a
university hospital in southern Brazil: characteristics,
mortality, frequency, and mortality risk factors Data were collected on each patient at the
inclusion in the study and on a daily basis, during the course of MV
for up to 28 days. Results The frequency of MV was 30%; the overall and specific
mortality rates were 15% and 50%, respectively. The mean (±SD)
age was 57 ± 21 years; 52% were males; the mean APACHE II
score was 22.2 ± 8.2; 69% were medical patients; the mean
duration of MV was 11 ± 7.9 days; 93% were on invasive MV. A
multivariable analysis was performed to identify the variables
associated with death. These included sepsis (P = 0.02), MV
duration (P < 0.001), renal failure (P = 0.006) prior to MV, and the
following variables that occurred during the MV period: sepsis
(P = 0.004), acute lung injury/acute respiratory distress syndrome
(P = 0.001), renal failure (P < 0.001), haematological failure
(P = 0.02) and vasoactive drug use (P < 0.001). It should be noted
that selected ventilatory monitored variables were included in the
multivariate model. However, they were not associated with
mortality in our study sample. Results Demographic data were similar between groups. Pneumoperitoneum caused significant decreases in static
compliance and arterial pH, and increases in Ppeak and Pplat, VD/VT
and ETCO2 in both groups. However, APV-SIMV resulted in fewer
setting changes, lower peak and plateau pressures, VD/VT, and
ETCO2 levels when compared with P-SIMV (P < 0.025). Conclusion
APV-SIMV
may
provide
better
results
then
conventional P-SIMV in patients undergoing LP. P165 The influence of cycling-off criteria and pressure support
slope on the respiratory and hemodynamic variables in
intensive care unit patients T Correa, R Passos, S Kanda, C Tanigushi, C Hoelz, J Bastos,
G Janot, E Meyer, C Barbas
Hospital Israelita Albert Einstein, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P165 (doi: 10.1186/cc5325) Conclusions Our results indicate a frequency of patients on MV of
30% with an elevated specific mortality rate (50%). Sepsis, MV
duration, renal failure prior to MV, and sepsis, acute lung
injury/acute
respiratory
distress
syndrome,
renal
failure,
haematological failure and vasoactive drug use during the MV
period are risk factors for mortality in 28 days after starting MV. Identification of these factors may allow early interventions to
attempt to mitigate these poor outcomes. Introduction Modern mechanical ventilators allow changes in the
flow cycling-off criteria and the pressure slope during pressure
support ventilation (PSV). Changes in the cycling-off flow criteria of
PSV can modify the expiratory synchrony between the mechanical
and neural inspiration termination. The influences of the slope
changes on the respiratory parameters in ICU patients are still
under investigation. Reference 1. Simonds A: Eur Respir J 2003, Suppl 47:38s-46s. 1. Cikirikcioglu Y, Morel D: Eur Respir J 2006, 28:345s. 2. Consensus conference report. Chest 1999, 116:521-534. Table 1 (abstract P161)
Dynamic lung compliance
Weight gain
Inspiratory resistive work
(ml/cmH2O)
(g)
Wet/dry lung weight ratio
(ml x cmH2O)
Control (n = 6)
0.35 ± 0.06
0.54 ± 0.21
6.37 ± 0.35
0.98 ± 0.35
LPS (n = 12)
0.28 ± 0.02
4.63 ± 0.63
8.92 ± 0.21
10.45 ± 1.15
Hydrostatic (n = 7)
0.38 ± 0.06
1.97 ± 0.24
6.46 ± 0.33
1.65 ± 0.54
ALV 2 ml/hour (n = 6)
0.24 ± 0.04
2.66 ± 0.14
10.22 ± 0.60
–1.09 ± 0.54
ALV 4 ml/hour (n = 4)
0.07 ± 0.02
3.74 ± 0.79
9.08 ± 0.94
0.96 ± 1.13
Data presented as the mean ± SE after 120 minutes of isolated lung perfusion. S65 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P166) Figure 1 (abstract P166)
Minute volume/etCO2 relationship. P164 The effects of adaptive pressure ventilation–synchronised
intermittent mandatory ventilation and pressure-controlled
synchronised intermittent mandatory ventilation on
pulmonary mechanics and arterial gas analyses during
laparoscopic cholecystectomy Objectives To compare the effects of two different flow cycling-off
criteria and the effects of two different pressure slopes (150 ms or
300 ms) of PSV on the respiratory parameters of ICU mechanically
ventilated patients. M Akbaba, M Tulunay, O Can, Z Alanoglu, S Yalcin
Ankara University Medical Faculty, Ankara, Turkey
Critical Care 2007, 11(Suppl 2):P164 (doi: 10.1186/cc5324) Methods We prospectively evaluated 20 intubated and mechanically
ventilated adult ICU patients recovering from acute respiratory failure
who could be comfortably ventilated on pressure support mode
(PSV) with pressure support of 15 cmH2O, PEEP of 5 cmH2O and
FIO2 of 40%. Patients were ventilated on PSV, with 25% and 40%
of peak expiratory flow cycling criteria, and were submitted to
150 ms and 300 ms pressure slope delay. We evaluated the
respiratory rate, expiratory tidal volume, minute ventilation, VCO2,
VTCO2, ETCO2, mean arterial pressure (MAP), heart rate and SpO2. Background Hypercapnia and elevated intraabdominal pressure
from carbon dioxide (CO2) pneumoperitoneum can adversely
affect respiratory mechanics and arterial blood gases. We tested
the hypothesis that adaptive pressure ventilation–synchronised
intermittent mandatory ventilation (APV-SIMV) may provide better S66 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P165) Table 1 (abstract P165) Respiratory
Tidal
Minute volume
Slope
Heart rate
SpO2
Cycling-off (%)
rate
volume (ml)
(l/min)
VCO2
VTCO2
ETCO2
MAP
0.15
83.4
98.8
25
18.2
587.5
10.6
193.6
11.2
27.8
96.4
0.15
83.9
98.8
40
19.2
560.7
10.0
183.7
10.88
28
96.2
0.30
83.6
98.7
25
19.4
588.4
10.5
192.8
11.54
28
98.2
0.30
83.6
98.9
40
19.7
565.2
10.2
187.8
10.61
28.2
97.7 Figure 2 (abstract P166)
Parametric fit of etCO2 data. Figure 2 (abstract P166)
Parametric fit of etCO2 data. Figure 2 (abstract P166) Results Comparisons between different slope and cycling-off
values did not result in any statistically significant changes for the
evaluated variables (Table 1). Conclusion Changes in cycling-off criteria from 25% to 40% of
the peak flow and on the pressure slope from 150 ms to 300 ms
do not affect other respiratory and hemodynamic variables in
mechanically ventilated patients. P167 The impact of noninvasive versus invasive mechanical
ventilatory support on survival in hematological patients
with acute respiratory failure AUTOPILOT-BT: an approach towards automatic
mechanical ventilation AUTOPILOT-BT: an approach towards automatic
mechanical ventilation AUTOPILOT-BT: an approach towards automatic
mechanical ventilation S Lozano1, K Moeller1, C Stahl2, J Guttmann2
1Furtwangen University, Villingen-Schwenningen, Germany;
2University of Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P166 (doi: 10.1186/cc5326) Parametric fit of etCO2 data. Introduction The clinical use of ventilators is limited due to a huge
variety of different ventilation methods. The clinician – often under
high cognitive load from the complicated technical equipment on an
ICU – just uses a small subset of available parameter settings. The
aim of the present study was to develop a closed-loop ventilation
controller based on mathematical models and fuzzy logic. evaluating, for example, the etCO2 data. The course of etCO2
following the setting of optimal frequency was evaluated to
calculate the time required for equilibration of etCO2. Results A module automating the initial settings of the ventilator
according to local ICU rules is realized. Modules were added that
optimize breathing frequency with respect to PaCO2/etCO2 and
FiO2 according to SO2 whenever no PaO2 is available. A lung
simulator (Michigan Instruments Inc., Grand Rapids, MI, USA)
connected with the LS4000 (Dräger Medical) was used to
evaluate the system. Exemplary results are presented in the figures,
which show the minute volume/etCO2 relationship (Figure 1) and a
parametric fit of etCO2 data (Figure 2). The adjustment of the
frequency is based on the current etCO2 model. Methods The system was designed to track a desired end-tidal
CO2 pressure (PaCO2), to find a PEEP leading to maximum
estimated respiratory system compliance and to maintain the
arterial oxygen saturation (SaO2) at an optimal level. We developed
a program in LabView (National Instruments, Austin, TX, USA) on a
laptop that is able to read the internal data of a ventilator (Evita 4;
Dräger Medical, Germany) in real time. Respiratory signals (for
example, SaO2) are acquired from monitoring. Discrete measure-
ments (for example, PaO2) are either assumed constant until next
measurement or are interpolated using a model-based approach Conclusion Automation is a ‘sine qua non’ to achieve optimal
patient individualized ventilation support. Our system is enabled to
evaluate a therapeutic strategy and to base the settings of the
ventilator on current trends/drifts observed in the data. The impact of noninvasive versus invasive mechanical
ventilatory support on survival in hematological patients
with acute respiratory failure P168
Physiological variables predictive of survival in patients
with acute type II respiratory failure on noninvasive
ventilation
N Salahuddin, M Naeem, S Khan
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P168 (doi: 10.1186/cc5328)
Introduction There are very few data available from the Indian
subcontinent regarding the use of noninvasive ventilation (NIV). We
carried out this study to determine variables that could be used in
the emergency room to predict survival in patients placed on NIV. Methods This was a prospective
observational cohort study
statistically
significant
difference
between
the
baseline
characteristics of the groups that survived or died. The overall
survival rate for patients placed on NIV was 76.5%, the intubation
rate was 12.6% and the length of hospitalization was 11.4 days
(±10.9). Statistically significant improvements in pH and PaCO2
occurred at 24 hours and 48 hours of NIV usage compared with
Figure 1 (abstract P167)
Figure 1 (abstract P168)
Figure 2 (abstract P168) Figure 1 (abstract P167)
Figure 1 (abstract P168) Figure 1 (abstract P167) Figure 1 (abstract P168) Figure 1 (abstract P168) Figure 1 (abstract P167) Figure 1 (abstract P167) Figure 2 (abstract P168) Figure 2 (abstract P168) 62.5%, respectively (P = 0.99), but SAPS II at ICU admission was
lower in NIPPV patients (45 ± 15 vs 60 ± 18, P < 0.001). NIPPV
was the sole mode of ventilation in 15 patients and was followed
by IPPV in 41 patients (NIPPV–IPPV). ICU mortality in sole NIPPV
patients was 35% compared with 76% in NIPPV–IPPV patients. In
a multivariable analysis, the ICU mortality of ventilated patients was
associated with SAPS II at admission (OR 1.029, CI 1.009–1.048,
P = 0.003), NIPPV–IPPV (OR 2.73, CI 1.1–6.8, P = 0.03), and
bacterial infection (OR 0.39; CI 0.21–0.73, P = 0.003). The mean
change of SOFA between day 1 and day 5 was 0 (±2.6) in NIPPV
patients (n = 33) compared with –1.6 (±4.3) in IPPV patients
(n = 87) (P = 0.001) surviving beyond 5 days of ICU admission
(Figure 1). Conclusion NIPPV was not associated with better outcome in our
population of hematological patients with acute respiratory failure. NIPPV followed by IPPV was an independent predictor of mortality. P168 Physiological variables predictive of survival in patients
with acute type II respiratory failure on noninvasive
ventilation N Salahuddin, M Naeem, S Khan
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P168 (doi: 10.1186/cc5328) N Salahuddin, M Naeem, S Khan
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P168 (doi: 10.1186/cc5328) statistically
significant
difference
between
the
baseline
characteristics of the groups that survived or died. The overall
survival rate for patients placed on NIV was 76.5%, the intubation
rate was 12.6% and the length of hospitalization was 11.4 days
(±10.9). Statistically significant improvements in pH and PaCO2
occurred at 24 hours and 48 hours of NIV usage, compared with
baseline (7.28 vs 7.37, P < 0.001; 74.2 vs 65.4, P = 0.003)
(Figures 1 and 2). There was no significant change in PaO2. The
variables
predicting
survival
were
age
(62.1 ± 12.5 years,
67.8 ± 8.7 years, P = 0.025), serum creatinine (1.1 ± 0.5 mg/dl,
1.7 ± 0.8 mg/dl,
P = 0.002),
pH
at
baseline
(7.31 ± 0.09,
7.25 ± 0.9, P = 0.005), HCO3 at baseline (36.1 ± 7.5 mEq/l,
32.4 ± 9.3 mEq/l, P = 0.032), pH at 48 hours (7.39 ± 0.07, 7.33
± 0.06, P = 0.002), and need for endotracheal intubation (10%,
21%, P < 0.05). Introduction There are very few data available from the Indian
subcontinent regarding the use of noninvasive ventilation (NIV). We
carried out this study to determine variables that could be used in
the emergency room to predict survival in patients placed on NIV. Methods This was a prospective, observational cohort study
carried out from 2001 to 2005 on all patients presenting with
acute type II respiratory failure and meeting criteria for NIV use. NIV
was started in the emergency room at settings that were titrated
according to arterial blood gases. Univariate and multivariate
regression analysis was used to determine the effect on survival. P < 0.05 was considered statistically significant. The software
used was SPSS 11. Results The total number of patients enrolled was 119; 52.9%
were males, 47.1% were females. The mean age was 63.3 years
(±11.9). The most common cause of respiratory failure was COPD
in 91.6%. A total of 56.3% patients were stuporus at presentation,
and 7.5% fulfilled criteria for severe sepsis. There was no Conclusion NIV improves outcomes in our setting. The impact of noninvasive versus invasive mechanical
ventilatory support on survival in hematological patients
with acute respiratory failure P Depuydt, D Benoit, C Roosens, O Fritz, L Noens, J Decruyenaere
Ghent University Hospital, Ghent, Belgium
Critical Care 2007, 11(Suppl 2):P167 (doi: 10.1186/cc5327) Objective To assess the impact on ICU survival of noninvasive
(NIPPV) versus invasive mechanical ventilation (IPPV) as the initial
ventilatory mode in hematological patients with acute respiratory
failure. Design A retrospective evaluation of a prospectively followed
cohort of 277 hematological patients ventilated at the ICU of a
tertiary care hospital between January 1997 and June 2006. Design A retrospective evaluation of a prospectively followed
cohort of 277 hematological patients ventilated at the ICU of a
tertiary care hospital between January 1997 and June 2006. Results NIPPV was the initial ventilatory mode in 56 patients. ICU
mortality in patients with initial NIPPV versus IPPV was 62.9% and Minute volume/etCO2 relationship. Results NIPPV was the initial ventilatory mode in 56 patients. ICU
mortality in patients with initial NIPPV versus IPPV was 62.9% and S67 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P168)
Figure 2 (abstract P168) 62.5%, respectively (P = 0.99), but SAPS II at ICU admission was
lower in NIPPV patients (45 ± 15 vs 60 ± 18, P < 0.001). NIPPV
was the sole mode of ventilation in 15 patients and was followed
by IPPV in 41 patients (NIPPV–IPPV). ICU mortality in sole NIPPV
patients was 35% compared with 76% in NIPPV–IPPV patients. In
a multivariable analysis, the ICU mortality of ventilated patients was
associated with SAPS II at admission (OR 1.029, CI 1.009–1.048,
P = 0.003), NIPPV–IPPV (OR 2.73, CI 1.1–6.8, P = 0.03), and
bacterial infection (OR 0.39; CI 0.21–0.73, P = 0.003). The mean
change of SOFA between day 1 and day 5 was 0 (±2.6) in NIPPV
patients (n = 33) compared with –1.6 (±4.3) in IPPV patients
(n = 87) (P = 0.001) surviving beyond 5 days of ICU admission
(Figure 1). Conclusion NIPPV was not associated with better outcome in our
population of hematological patients with acute respiratory failure. NIPPV followed by IPPV was an independent predictor of mortality. P170 Methods This was a blinded, observational cohort trial that was
approved by the Henry Ford Hospital Institutional Review Board. Henry Ford Hospital is an urban, tertiary institution in Detroit,
Michigan with an emergency department census of 95,000 patient
visits per year. Inclusion criteria: patients > 18 years of age triaged
to Cat 1 with acute respiratory distress and for whom the decision
to intubate, use NIV or discharge the patient had not been
decided. Exclusion criteria: immediate intubation, NIV, or discharge
from Cat 1. Baseline demographics and vital signs were collected
prior to the initiation of the trial (Figure 1). The CO2SMO Plus! with
the ETCO2/flow sensor was used for obtaining bedside
measurements. Patients would breathe through the ETCO2/flow
sensor for 60 seconds with nose clips. Is threshold useful in accelerating weaning from
mechanical ventilation? S Vieira1, R Condessa1, J Brauner1, A Saul1, A Silva1, M Silva1,
L Borges2, M Moura1, M Alves1, F Kutchak1, L Biz1, C Dieterich1
1Hospital de Clínicas de Porto Alegre, Brazil; 2Hospital Moinhos de
Vento, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P170 (doi: 10.1186/cc5330) Introduction Threshold can be used as a physiotherapic tool in
order to increase muscle strength, and this effect can be useful in
weaning patients. However, there are still controversies considering
its advantages during weaning from mechanical ventilation (MV). The goal of this study is to evaluate its effects in such a situation. Results The threshold value for RSBI that discriminated best
between no NIV and the need for NIV was determined in 61
patients. Thirty-five patients who did not require ventilatory support
had a mean RSBI of 105, and 26 patients with NIV had a mean
RSBI of 222 (P = 0.0001). A receiver-operating-characteristic
curve was constructed based upon the dataset in increments of 10
for the RSBI (Figure 2). An RSBI > 120 yielded a sensitivity of
0.81 and a specificity of 0.74 for determining the need for NIV. A
likelihood ratio positive (LR+) of 3.14 further illustrates the
formidable predictive value of the 120 RSBI. Methods Patients under MV for more than 48 hours and prone to
weaning were studied. They were randomized to the control group
or to the threshold group and followed daily until extubation,
tracheostomy or death. The threshold group was trained twice
daily. All cardiorespiratory variables, maximal inspiratory (PImax)
and expiratory (PEmax) pressures were registered twice daily
during the observation period. P169 P169 Rapid shallow breathing index – a key predictor for
noninvasive ventilation Rapid shallow breathing index – a key predictor for
noninvasive ventilation J Crawford1, R Otero1, M Donnino2, J Garcia1, R Khazal1, T Lenoir1
1Henry Ford Hospital, Detroit, MI, USA; 2Beth Israel Deaconess
Medical Center, Boston, MA, USA
Critical Care 2007, 11(Suppl 2):P169 (doi: 10.1186/cc5329) Introduction The rapid shallow breathing index (RSBI) is the ratio
determined by the frequency (f) divided by the tidal volume (VT). An RSBI <105 has been widely accepted by healthcare
professionals as a criteria for weaning to extubation and has been
integrated into most mechanical ventilation weaning protocols. We
hypothesized that the converse of using the RSBI for weaning
might be useful in predicting the need for noninvasive ventilation. Advancements in technology have made it easier to accurately
attain bedside RSBI measurements. The purpose of this study was
to ascertain a threshold value of RSBI that could predict the need
for noninvasive ventilation (NIV) in patients presenting with acute
respiratory distress to the critical care area (Cat 1) in the
emergency department. Conclusion A RSBI of 120 or greater, as reflected by f/VT ratio,
may be a predictor of when NIV support should be considered. Further prospective randomized studies are needed to validate the
value of 120. Conclusion A RSBI of 120 or greater, as reflected by f/VT ratio,
may be a predictor of when NIV support should be considered. Further prospective randomized studies are needed to validate the
value of 120. P170 The length of weaning and success
or failure were registered. Variables were compared by analysis of
variance, Mann–Whitney U test and the chi-square test. Results
are shown as the median, mean and standard deviation or as
percentages. The significance level was P < 0.05. P168 Physiological
variables and the need for intubation can predict an improved
survival in these patients. S68 Available online http://ccforum.com/supplements/11/S2 Conclusion A RSBI of 120 or greater, as reflected by f/VT ratio,
may be a predictor of when NIV support should be considered. Further prospective randomized studies are needed to validate the
value of 120. Figure 2 (abstract P169) Figure 2 (abstract P169) Application of treatment bundles reduces days on
mechanical ventilation in critically ill patients Methods A total of 104 patients who had been ventilated for more
than 48 hours in the postoperative period from October 2005 to
October 2006 were enrolled in the study. After fulfilling the
weaning checklist they were randomly assigned into two groups:
SIMV+PSV group (n = 53), and ITSB group (n = 51). In patients
assigned to the SIMV+PSV group, the ventilator rate was initially
set at 6–8 breaths/minute plus PSV of 15 cmH2O and then both
reduced, if possible, by 2 breaths/minute and 2 cmH2O each time. Patients able to maintain adequate ventilation with SIMV of
2 breaths/minute and PSV of 5 cmH2O for at least 2 hours without
signs of distress were extubated. Patients assigned to the ITSB
group were disconnected from the ventilator and allowed to
breathe spontaneously through a T-tube circuit. The duration of the
trials was gradually increased. Between the trials, assist–control
ventilation was provided for at least 1 hour. Patients able to
breathe on their own for at least 2 hours without signs of distress
were extubated. F Bloos1, S Müller1, A Harz1, M Gugel1, D Geil1, K Reinhart2,
G Marx2
1University Hospital Jena, Germany; 2Friedrich-Schiller University
Jena, Germany
Critical Care 2007, 11(Suppl 2):P171 (doi: 10.1186/cc5331) Background Reduction of time on the ventilator is a key concept
to avoid complications. Recommendations include semirecumbent
positioning (SRP) [1], low tidal volume ventilation (TV = 6 ml/kg)
[2], prophylaxis for stress ulcer (SUP) [3], and deep vein
thrombosis (DVTP) [4]. The goal of this study was to investigate
whether staff training about these treatments decreases days on
ventilation. Methods All patients of a 50-bed ICU with mechanical ventilation
>24 hours were included. From June 2005 to September 2005
(Audit I), patients were examined daily for SRP >30°, low tidal
volume ventilation, DVTP, and SUP by an independent task force. Afterwards, nurses and physicians were trained for the monitored
treatments. Audit II was then performed from March 2006 to June
2006. Results Until the first attempt was made for weaning, all patients
received assist–control ventilation because of haemodynamic
instability. The following underlying conditions were present:
chronic
obstructive
pulmonary
disease
in
67
patients,
neuromuscular disorders in nine patients, acute lung injury as a
result of surgery in 14 patients, asthma in six patients and
miscellaneous causes in eight patients. P173 P173
Predicting successful weaning in a cohort of elderly
patients
C Corbellini, A Guntzel, C Trevisan, S Vieira
Hospital de Clinicas de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P173 (doi: 10.1186/cc5333) Predicting successful weaning in a cohort of elderly
patients Conclusion SRP could be successfully improved by staff training. Enhanced implementation was associated with reduction in days
on ventilation. C Corbellini, A Guntzel, C Trevisan, S Vieira
Hospital de Clinicas de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P173 (doi: 10.1186/cc5333) References
1. Drakulovic MB: Lancet 1999, 354:1851. 2. Amato MB: N Engl J Med 1998, 338:347. 3. Cash BD: Crit Care Med 2002, 30:S373. 4. Samama MM: N Engl J Med 1999, 341:793. 1. Drakulovic MB: Lancet 1999, 354:1851. 2. Amato MB: N Engl J Med 1998, 338:347. 3. Cash BD: Crit Care Med 2002, 30:S373. 4. Samama MM: N Engl J Med 1999, 341:793. 1. Drakulovic MB: Lancet 1999, 354:1851. 1. Drakulovic MB: Lancet 1999, 354:1851. 2. Amato MB: N Engl J Med 1998, 338:347. Introduction Aging causes structural and functional modifications
in the respiratory system. The evidence that these changes could
impair weaning in elderly patients, until now, was not clear. We
designed a protocol to study possible differences between an
adult group (AG, up to 60 years) and an elderly group (EG, >60
years) in a daily screening trial. g
3. Cash BD: Crit Care Med 2002, 30:S373. 4. Samama MM: N Engl J Med 1999, 341:793. Application of treatment bundles reduces days on
mechanical ventilation in critically ill patients The duration of mechanical
ventilation before weaning was 2.5 ± 0.5 days in the SIMV+PSV
group vs 2.4 ± 0.4 days in the ITSB group (P = 0.02) and the
duration of weaning was 6.2 ± 0.23 hours vs 8.3 ± 0.44 hours in
the two groups, respectively (P < 0.01). Patients who remained
extubated for 48 hours were classified as having successful
extubation – the rate of successful extubation in the first 24 hours
of starting weaning was higher for the SIMV group (79.2%) than in
the ITSB group (64.7%, P < 0.01). The total duration of
mechanical ventilation was 3.3 ± 0.3 days vs 5.2 ± 1.1 days and
the ICU length of stay was 5.6 ± 1 days vs 7.5 ± 1.7 days in the
two groups, respectively (P < 0.01). Results One hundred and thirty-three patients (1,389 ventilator-
days) were included in Audit I, 141 patients (1,002 ventilator-days)
in Audit II. Data are expressed as the median (interquartile range)
or percentage of implementation per ventilator-days (Table 1). On
average, low tidal volume ventilation was adopted. DVTP and SUP
were well implemented without training. There was no effect on
frequency of pneumonia, ICU length of stay, or survival. Table 1 (abstract P171)
Audit I
Audit II
P
APACHE II
24 (10)
25 (11)
0.387
SRP (%)
24.9
49.6
<0.001
TV (ml/kg)
6.3 (2.2)
6.4 (2.3)
0.154
DVTP (%)
89.5
91.9
0.048
SUP (%)
94.5
94.9
0.712
Days on ventilation
6.0 (13)
4.0 (7)
0.017 Conclusions The use of SIMV+PSV as a weaning method in the
surgical ICU lead to shorter duration of weaning, a higher rate of
successful extubation, a shorter duration of mechanical ventilation
and less ICU stay than the use of ITSB. P171 (ITSB) using a T-tube as two methods of weaning in a surgical
ICU. Figure 1 (abstract P169) Figure 1 (abstract P169) Figure 1 (abstract P169) Results Sixty patients were studied (52% men, mean age
64 ± 17 years, 18% with chronic obstructive pulmonary disease in
threshold group vs 15% in control group). Comparing initial versus
final cardiorespiratory variables in both groups, no important
differences were observed with exception of PImax (increased from
–33.5 ± 14.4 to –40.2 ± 13.4 cmH2O in threshold group and
changed from –37.1 ± 9.8 to –34.4 ± 9.6 cmH2O in control
group, P < 0.05) and PEmax (increased from 24.7 ± 12.7 to
29.4 ± 12.1 cmH2O in threshold group and changed from
30.9 ± 13.5 to 27.1 ± 9.4 cmH2O in control group, P < 0.05). No
reduction was observed in the length of weaning (1.87 days with
threshold versus 1.98 days in control group, P > 0.05). There was
no difference concerning weaning success (73.5% with threshold
versus 61.5% in control group, P > 0.05). Conclusions Threshold during weaning from MV can cause an
increase in both PImax and PEmax but, at least in these preliminary
results, it was not associated with a decrease in length of weaning
or an increase in weaning success. Conclusions Threshold during weaning from MV can cause an
increase in both PImax and PEmax but, at least in these preliminary
results, it was not associated with a decrease in length of weaning
or an increase in weaning success. S69 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P174 Heart rate variability during weaning from mechanical
ventilation
A Guntzel, S Vieira, E Ferlim, R Moraes
Hospital de Clínicas de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P174 (doi: 10.1186/cc5334) Introduction Acute illness adversely affects a patient’s circadian
rhythms. Minimising the delayed restoration of these rhythms may
have patient benefits. The aims of this study were to investigate the
acute effects of exogenous melatonin on the rest–activity rhythms
of patients recovering from critical illness, and furthermore to
analyse the rhythms and relationship between plasma melatonin
and cortisol levels. Heart rate variability during weaning from mechanical
ventilation A Guntzel, S Vieira, E Ferlim, R Moraes
Hospital de Clínicas de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P174 (doi: 10.1186/cc5334) Introduction Weaning from mechanical ventilation (MV) can be
associated with cardiovascular changes including elevation of
heart rate (HR) and development of arrhythmias. The behavior is
not yet known of HR variability during weaning from MV comparing
pressure support ventilation (PSV) and the T-tube (TT) in patients
with and without heart disease. The aim of this study was to
evaluate the impact on heart rate variability (HRV) in these groups
of patients during PSV and TT. Methods A randomised controlled trial in 24 critically ill patients
weaning from mechanical ventilation. Ethics committee approval
was granted and all patients provided written consent. Twelve
patients in each group received placebo or 10 mg exogenous
melatonin at 21:00 hours for four nights. Twelve plasma samples
were taken periodically from the first 18 of these patients over a
24-hour period. Actigraphy was used to monitor patient activity. Rhythm analysis of plasma levels and activity data used single
cosinor analysis and nonparametric parameters, respectively. Methods Patients with (group 1, n = 8) and without (group 2,
n = 22) heart disease, under MV for at least 48 hours, were
observed during 30 minutes of PSV or TT, in a random order. Variables analyzed were: APACHE score, length of stay in the ICU
(LOS), and cardiorespiratory variables including the HR,
respiratory rate (RR), rapid shallow breathing index (f/VT),
maximum inspiratory (PImax) and expiratory (PEmax) pressure. Continuous ECG was recorded by the Holter method. The data of
HRV were accomplished by analysis of the frequency domain. For
statistical analyses, analysis of variance and t test were used. The
level of significance was P < 0.05. Results Both groups were well matched. P172 Comparative study of two methods of weaning from
mechanical ventilation in a cancer surgical intensive care unit Comparative study of two methods of weaning from
mechanical ventilation in a cancer surgical intensive care unit Methods One hundred and forty-four patients (79 EG and 65 AG)
were studied. The primary outcome was weaning success (48
hours of spontaneous ventilation after extubation). The secondary
outcome was differences in the conventional weaning predictors. Parameters studied included: respiratory rate (f), tidal volume (VT),
frequency–tidal volume ratio (f/VT), gasometric and ventilatory
parameters. The weaning method was a spontaneous breathing
trial. Measurements were performed twice: just before the
spontaneous breathing trial (T1) and 30 minutes after (T2). The W Salem1, N Fahmy2
1National Cancer Institute, Cairo, Egypt; 2Faculty of Medicine, Ain
Shams University, Cairo, Egypt
Critical Care 2007, 11(Suppl 2):P172 (doi: 10.1186/cc5332) W Salem1, N Fahmy2
1National Cancer Institute, Cairo, Egypt; 2Faculty of Medicine, Ain
Shams University, Cairo, Egypt
Critical Care 2007, 11(Suppl 2):P172 (doi: 10.1186/cc5332) W Salem1, N Fahmy2
1National Cancer Institute, Cairo, Egypt; 2Faculty of Medicine, Ain
Shams University, Cairo, Egypt
Critical Care 2007, 11(Suppl 2):P172 (doi: 10.1186/cc5332) Introduction The aim of the study was to compare the combination
of intermittent mandatory ventilation plus pressure-support ventila-
tion (SIMV+PSV) with intermittent trials of spontaneous breathing S70 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P173)
Weaning criteria
T1 AG (n = 65)
T2 AG (n = 65)
T1 EG (n = 79)
T2 EG (n = 79)
f (breaths/min)
22 ± 59*
22 ± 5.2*
24 ± 5.5*
24 ± 5.4*
VT (ml)
560 ± 200*
550 ± 180*
470 ± 170*
480 ± 150*
f/VT
47 ± 24*
46 ± 19*
59 ± 28*
56 ± 24*
*P < 0.05 comparing AG and EG. chi-square test, analysis of variance and t test were used in the
analysis. Conclusion During weaning from MV, cardiac patients showed
higher RR and higher f/VT during TT when compared with PSV. Furthermore, there were significant changes in the RR and HR
intervals in TT. However, we did not find significant changes
comparing HRV in groups, perhaps because the frequency domain
analysis had low power to verify those changes. chi-square test, analysis of variance and t test were used in the
analysis. Results Weaning success was 86% both in EG and AG
(P = 0.989). There were no differences in gasometric and in
ventilatory parameters between groups. Assessment of melatonin, cortisol and rest–activity rhythms
in critically ill patients weaning from mechanical ventilation R Bourne
Sheffield Teaching Hospitals, Sheffield, UK
Critical Care 2007, 11(Suppl 2):P175 (doi: 10.1186/cc5335) P172 Comparisons in TI and T2
in AG and EG are presented in Table 1. Sensitivities of f/VT in
T1/T2 were: for EG, 94 (86–98)/96 (89–98); for AG, 95
(86–99)/100 (94.8–100). P175 Conclusion The weaning success in our study is similar to that
described in other trials. Older patients showed differences in f, VT
and f/VT when compared with adults. However, there were no
differences in weaning success. P174 There were no significant
differences between the groups in any of the rest–activity
measures, which were abnormal and comparable with those
previously reported [1]. There was a weak inverse correlation
between plasma melatonin and cortisol levels (r = –0.22,
P = 0.015). Seven of 18 patients had a circadian rhythm of plasma
cortisol levels, while only two patients had a normal acrophase. Four
of the nine placebo patients had a circadian rhythm of melatonin,
but only one of these had a normal amplitude and acrophase. The
plasma melatonin 24-hour area under the curve was significantly
reduced compared with healthy elderly people (128.4 (112.6;
217.0) versus 464.5 (372.5; 594.0), P < 0.001). A moderate
inverse relationship existed between the percentage plasma cortisol
rhythm and patient intradaily variability (r = –0.70, P < 0.002). Results Values for the APACHE score, LOS, PImax and PEmax
did not show significant differences comparing groups. The RR
was significantly higher during TT than during PSV in group 1
(25 ± 6; 20 ± 4; P < 0.01), but similar in group 2 (22 ± 5; 22 ± 5;
not significant (NS)). f/VT was significantly higher during TT in
relationship to PSV in group 1 (65 ± 35; 39 ± 17; P < 0.01), but
similar in group 2 (49 ± 19; 49 ± 22; NS). Changes in the RR
interval comparing PSV and TT were significantly different in the
entire group (0.48 ± 55; –30 ± 72; P = 0.02) as well as changes
in the HR interval (–0.3 ± 8; 8 ± 12; P < 0.001). Changes in HRV
by frequency domain were not significantly different comparing
groups 1 and 2 in PSV and TT. The high frequency was in PSV
(4 ± 21; 0.4 ± 11; NS), and in TT (–0.64 ± 12; 1 ± 12; NS). The
low frequency was in PSV (–11 ± 22; 3 ± 14; NS), and in TT
(–6 ± 17; 1.8 ± 19; NS). Conclusions Acute administration of exogenous melatonin did not
result in significant differences in rest–activity rhythms between the
groups. Most patients lacked circadian rhythms of plasma
melatonin and cortisol levels, which were no longer phase locked. The amplitude of plasma melatonin levels are significantly
suppressed. 1.
Vinzio S, Ruellan A, Perrin AE, et al.: Actigraphic assess-
ment of the circadian rest-activity rhythm in elderly
patients hospitalized in an acute care unit. Psychiatry Clin
Neurosci 2003, 57:53-58. Evaluation of patient parameters that predict success
using the SmartCare weaning system P Jackson, G Mills
Royal Hallamshire Hospital, Sheffield, UK
Critical Care 2007, 11(Suppl 2):P176 (doi: 10.1186/cc5336) P Jackson, G Mills
Royal Hallamshire Hospital, Sheffield, UK
Critical Care 2007, 11(Suppl 2):P176 (doi: 10.1186/cc5336) Introduction Our aim was to assess the success of the SmartCare
(SC) weaning system, to see what associated factors made a
successful wean more likely. SC is a knowledge-based weaning
system integrated into the Dräger EvitaXL ventilator, designed to
optimise the ventilator settings during weaning so that patients can
be weaned as quickly as possible. Methods The first 100 consecutive general ICU patients where
SC weaning had been attempted were identified. Patient age, sex,
APACHE score, diagnosis, worst FiO2 prior to weaning, duration
of ventilation prior to weaning, duration of weaning attempt, need
for tracheostomy and duration of stay were collected. The patients
were then subdivided into unsuccessful and successful weaning
attempts based upon whether they required subsequent ventilatory
support during the first 48 hours after their weaning ended. The
two groups were then analysed to identify the characteristics of the
patients where a successful SC wean was achieved. applied to admissions during the 3 years since introduction to
estimate the cumulative excess mortality (observed minus expected
deaths). Results After excluding patients whose weaning was interrupted
by transfer or a decision to withdraw treatment, we had 89
weaning attempts to analyse. These represented 43 successful (S)
and 46 unsuccessful (US) weans. Comparison of mean ± SD ages
(S 61 ± 14.3 years, US 57.3 ± 16.1 years, P = 0.28) and
APACHE scores (S 16.2 ± 4.9, US 17.7 ± 6.5, P = 0.23) for the
two groups showed no major differences. Logistic regression
demonstrated that the worst FiO2 prior to weaning and the
duration of ventilation prior to weaning were both significantly
associated with an unsuccessful SC weaning attempt (P = 0.002
and P = 0.005, respectively). ROC curve analysis suggested patients
with an FiO2 below 0.47 and a duration of ventilation prior to
weaning of below 43 hours were more likely to be successfully
weaned. Results There were 762 ventilated admissions prior to the
introduction of the bundle and 618 since. The cumulative excess
mortality plot suggested a reduction in mortality after introduction
of the bundle (Figure 1) but this was not statistically significant
(relative risk reduction 10.9%, 95% confidence interval –10.2% to
31.8%). P178 Hemodynamic changes due to expiratory positive airway
pressure by facial mask in the postoperative period of
cardiac surgery Conclusions SC proved most successful in those patients who
had a lower worst FiO2 prior to weaning and a lower duration of
ventilation prior to commencing weaning. S Vieira1, A Sena2, S Pinto-Ribeiro1
1Hospital de Clínicas de Porto Alegre, Brazil; 2Santa Casa de
Misericórdia de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P178 (doi: 10.1186/cc5338) Evaluation of patient parameters that predict success
using the SmartCare weaning system Interpretation The results suggest that it will be beneficial to carry
out a multicentre evaluation of the ventilator bundle in Case Mix
Programme units, and will inform the design of this study. Reference 1. Vinzio S, Ruellan A, Perrin AE, et al.: Actigraphic assess-
ment of the circadian rest-activity rhythm in elderly
patients hospitalized in an acute care unit. Psychiatry Clin
Neurosci 2003, 57:53-58. 1. Vinzio S, Ruellan A, Perrin AE, et al.: Actigraphic assess-
ment of the circadian rest-activity rhythm in elderly
patients hospitalized in an acute care unit. Psychiatry Clin
Neurosci 2003, 57:53-58. S71 Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P177) Figure 1 (abstract P177) Figure 1 (abstract P177) P179 Methods We conducted a retrospective audit of consecutive
patients receiving APRV from January 2004 to August 2006 in
three academic ICUs in Toronto. APRV was initiated at the
discretion of the attending physician; a protocol guiding the
implementation of APRV was introduced in July 2006. We
recorded data describing: baseline characteristics; how APRV was
used; its potential ramifications including oxygenation and
sedation/analgesia doses; and outcomes. Predicting successful nasal continuous positive airway
pressure treatment in newborn infants: a multivariate
analysis J Swietlinski1, T Bachman2, K Bober3, E Gajewska4,
E Helwich5, R Lauterbach6, M Manowska1, B Maruszewski1,
J Szczapa7, L Hubicki3, on behalf of the Polish Study Group
(NRSP)
1The Children’s Memorial Health Institute, Warsaw, Poland;
2California State University, San Bernardino, CA, USA; 3Medical
University of Silesia, Katowice, Poland; 4Medical University,
Wrocùaw, Poland; 5National Research Institute of Mother & Child,
Warsaw, Poland; 6Medical College Jagiellonian University, Kraków,
Poland; 7University of Medical Sciences, Poznan, Poland
Critical Care 2007, 11(Suppl 2):P179 (doi: 10.1186/cc5339) J Swietlinski1, T Bachman2, K Bober3, E Gajewska4,
E Helwich5, R Lauterbach6, M Manowska1, B Maruszewski1,
J Szczapa7, L Hubicki3, on behalf of the Polish Study Group
(NRSP) J Swietlinski1, T Bachman2, K Bober3, E Gajewska4,
E Helwich5, R Lauterbach6, M Manowska1, B Maruszewski1,
J Szczapa7, L Hubicki3, on behalf of the Polish Study Group
(NRSP) g
;
Results Thirty patients, all with ALI/ARDS, received 39 trials of
APRV during the study period – median age 52 years, 60% male,
50% pulmonary ALI risk factor, median APACHE II score 28. They
had ALI for a median of 4.5 days with a median 135 hours of CMV
before APRV. They received a median of 38 hours APRV. By 12
hours, oxygenation improved significantly (P/F ratio from 103 to
159, P < 0.01), with a concomitant decrease in FiO2 requirements
(from 0.70 to 0.50, P < 0.0006). At 72 hours, the median P/F ratio
had improved to 196 on a median FiO2 of 0.40 (both P < 0.01). Administration and dosages of sedatives (midazolam equivalents,
propofol) and analgesics (morphine equivalents) did not change
significantly over the period from 24 hours before to 24 hours after
APRV initiation. There were two episodes of barotrauma during
APRV; neither required therapeutic drainage. The 30-day mortality
was 13/30 (43%), most commonly due to multiorgan failure and
withdrawal of life-support. Assessing the impact of introducing the ‘ventilator bundle’
on outcomes for mechanically ventilated patients Comparing rest and EPAP periods, increases were
observed in: PCWP (11.9 ± 3.8 to 17.1 ± 4.9 mmHg, P < 0.001);
CVP
(8.7 ± 4.1
to
10.9 ± 4.3 mmHg,
P = 0.014);
MPAP
(21.5 ± 4.2 to 26.5 ± 5.8 mmHg, P < 0.001); MAP (76 ± 10 to
80 ± 10 mmHg, P < 0.035). All other variables did not show
significant changes. These results were observed in the total group
and when divided concerning ejection fraction >50% or <50%. Conclusions EPAP was well tolerated in this group of stable
patients after cardiac surgery and the hemodynamic changes due
to its use were an increase in the measurement of right and left
filling pressures as well as a small increase in arterial pressure. Assessing the impact of introducing the ‘ventilator bundle’
on outcomes for mechanically ventilated patients Assessing the impact of introducing the ‘ventilator bundle’
on outcomes for mechanically ventilated patients Introduction Expiratory positive airway pressure (EPAP) is used as
physiotherapic tool in the management of patients after major
surgeries such as cardiac surgery but its hemodynamic effect is
not well studied. The goal of this study was to evaluate
hemodynamic changes caused by EPAP use after cardiac surgery
in patients monitored by Swan-Ganz catheter. D Harrison, K Rowan
Intensive Care National Audit & Research Centre, London, UK
Critical Care 2007, 11(Suppl 2):P177 (doi: 10.1186/cc5337) Background The concept of bundles was developed by the
Institute for Healthcare Improvement. Individual bundle elements
are built on evidence-based practice, and the bundle concept is
that when these elements are executed together they produce
better outcomes than in isolation. There is, however, limited
evidence linking the use of bundles to demonstrable changes in
patient outcomes. As a preliminary analysis to inform a multicentre
evaluation, we explored the effect of the introduction of the
‘ventilator bundle’ on the outcomes for mechanically ventilated
patients in a single critical care unit. Methods Patients in the first or second day after cardiac surgery,
with respiratory and hemodynamic stability and with a Swan-Ganz
catheter, were included. They were evaluated at rest and after
using EPAP of 10 cm, by facial mask, in a randomized order. Variables studied were oxygen saturation (SPO2), heart rate (HR),
respiratory rate (RR), mean arterial systemic and pulmonary
pressures (MAP and MPAP), central venous pressure (CVP),
pulmonary capillary wedge pressure (PCWP), cardiac index, stroke
index, stroke work index from left and right ventricles, and systemic
and pulmonary vascular resistance. Patients were studied as a
whole group and divided into subgroups (with ejection fraction
<50% or >50%) and values were compared with a t test and
analysis of variance. Results are shown as the mean ± standard
deviation. The significance level was P < 0.05. Methods
Data were extracted for mechanically ventilated
admissions from a single unit participating in the Case Mix
Programme that was an early adopter of the ventilator bundle. A
risk prediction model was developed using data from admissions
during the 3.5 years prior to the introduction of the bundle and S72 Available online http://ccforum.com/supplements/11/S2 Results Twenty-eight patients were studied (22 men, mean age
68 ± 11 years). The most common surgery was myocardial
revascularization (n = 17). EPAP was well tolerated in the patients
studied. P179 1The Children’s Memorial Health Institute, Warsaw, Poland;
2California State University, San Bernardino, CA, USA; 3Medical
University of Silesia, Katowice, Poland; 4Medical University,
Wrocùaw, Poland; 5National Research Institute of Mother & Child,
Warsaw, Poland; 6Medical College Jagiellonian University, Kraków,
Poland; 7University of Medical Sciences, Poznan, Poland
Critical Care 2007, 11(Suppl 2):P179 (doi: 10.1186/cc5339) Background The use of nasal continuous positive airway pressure
(nCPAP) in newborn infants is common, especially for weaning
after mechanical ventilation. We have reported on the successful
transition to the use of the infant flow method as a standard of
practice in Poland. Objective The authors present results of multivariate logistic
regression (MLR) analysis of 481 newborns treated with the infant
flow method in an effort to improve related clinical guidance. Conclusions In our patients APRV use appeared safe, led to
improved
oxygenation,
but
did
not
change
needs
for
sedation/analgesia. Future studies are needed to determine the
optimal timing and methods for ARPV use; these should be
followed by randomized trials to confirm safety and document the
effects of APRV on patient-centered outcomes. Methods We collected data on the baseline demographic,
physiological characteristics and outcomes of 1,299 newborns
treated with nCPAP in 57 neonatal ICUs in Poland over a 2-year
period. We conducted a stepwise MLR of 481 newborns with the
two most common indications for use. We evaluated three
outcomes: need for intubation in newborns treated electively with
nCPAP (RDS), weaning failure requiring reintubation in the
mechanically ventilated newborns (weaning), and bad outcome. Airway pressure release ventilation in acute lung
injury/acute respiratory distress syndrome patients E Fan1, A Mullaly1, M Ko1, J Lyle1, T Pirano1, C Harris1, J Traill1,
J Rosenberg1, J Granton1, T Stewart2, N Ferguson1
1University of Toronto, Canada; 2Mount Sinai Hospital, Toronto,
Canada
Critical Care 2007, 11(Suppl 2):P180 (doi: 10.1186/cc5340) Introduction Advocates of airway pressure release ventilation
(APRV) suggest that this mode is lung-protective for patients with
ALI/ARDS, while providing additional benefits of spontaneous
breathing, including improved haemodynamics, decreased need
for sedation, and better patient comfort. However, there are few
available data on the clinical experience with APRV. P181 A
compliance-based index (CSI) directly comparable with the SI was
generated from the compliance data. convertase are scarce. We therefore investigated the expression
and activity of lung surfactant convertase and HMSE-1, a potential
macrophage-derived human convertase, under normal and acute
inflammatory conditions. Methods Convertase activity in lavage fluid (BALF) was assessed
using the in vitro cycling assay. The relative large surfactant
aggregate content was determined by phospholipid quantification
in the pellet following centrifugation at 48,000 x g. Esterase activity
was assessed by means of a chromogenic substrate assay. Expression of both convertase and HMSE upon LPS challenge
was assessed by real-time (TaqMan) PCR in murine alveolar
macrophages, murine primary type II cells, and the human
monocytic cell line U937, respectively. Results The SI and CSI highly correlated when calculation of the
CSI was based on the same database (Figure 1). According to the
resulting regression formula (Figure 1), the SI can be reliably
predicted from SLICE_SI (Figure 2). However, if SLICE_CONV
was used for calculation of the SI (Figure 3), noticeable differences
were found. Analysis of individual datasets showed three major
reasons for the observed differences: differences in excluded data
at low volumes respective to high volumes, nonlinearity of
resistance, and differences in mechanics between inspiration and
expiration. Results Lavage fluid from ARDS patients displayed an increased
esterase activity when compared with BALF from healthy controls. In addition, a pronounced large to small aggregate conversion was
observed for BALF from LPS-challenged mice or BALF from ARDS
patients. Incubation with LPS resulted in a significant increase in
convertase gene expression in primary mouse type II cells as well
as in HMSE-1 gene expression in U937 cells and monocytes from
peripheral blood. No convertase expression was found in cultured
murine alveolar macrophages. Conclusion The SI and SLICE similarly measure the nonlinearity of
compliance. The SI can be predicted from SLICE. However,
nonlinearities of the respiratory system are not restricted to
compliance alone; it might therefore be necessary to include
nonlinearities of resistance and asymmetries between inspiration
and expiration in the analysis of dynamic respiratory mechanics. Conclusions An increased convertase activity was found under
acute inflammatory conditions of the alveolar compartment, and
type II cells seem to be a relevant source of this increased
convertase activity. However, leakage of esterase activity from the
vascular space and other inflammatory cells cannot be ruled out. 1. P183 Transgenic mice expressing a surfactant protein
B–urokinase fusion protein in the distal respiratory
epithelium are protected against acute lung injury and
postinflammatory fibrosis 3. Guttmann J, et al.: Determination of volume-dependent res-
piratory system mechanics in mechanically ventilated
patients using the new SLICE method. Technol Health
Care 1994, 2:175-191. 3. Guttmann J, et al.: Determination of volume-dependent res-
piratory system mechanics in mechanically ventilated
patients using the new SLICE method. Technol Health
Care 1994, 2:175-191. P Markart1, C Ruppert1, M Wygrecka1, K Petri1, V Magdolen2,
T Weaver3, W Seeger1, A Günther1
1University of Giessen Lung Center, Giessen, Germany; 2Klinikum
rechts der Isar, Technical University of Munich, Germany;
3Children’s Hospital Medical Center, Cincinnati, OH, USA
Critical Care 2007, 11(Suppl 2):P183 (doi: 10.1186/cc5343) P181 Stahl CA, et al.: Dynamic versus static respiratory mechan-
ics in acute lung injury and acute respiratory distress syn-
drome. Crit Care Med 2006, 34:2090-2098. 2. Ranieri VM, et al.: Pressure–time curve predicts minimally
injurious ventilatory strategy in an isolated rat lung model. Anesthesiology 2000, 93:1320-1328. 2. Ranieri VM, et al.: Pressure–time curve predicts minimally
injurious ventilatory strategy in an isolated rat lung model. Anesthesiology 2000, 93:1320-1328. P181 Results In the RDS group of patients we found that nCPAP failure
was highly significantly related to estimated gestational age and
clinical risk index for babies (CRIB). While in our population less
mature RDS newborns were only slightly less likely to avoid
intubation, the MLR model showed that, controlling for initial CRIB,
they were less than one-half as likely to avoid intubation. Failure of
nCPAP in weaning was highly significantly related to only pH, prior
to beginning nCPAP. Bad outcomes were highly related to
estimated gestational age and CRIB in the RDS group, but not the
weaning population. Importance of nonlinearities to quantify mechanical
pulmonary stress under dynamic conditions: stress index
and SLICE method C Stahl1, H Meißner1, D Steinmann1, G Mols1, C Micelli2,
K Moeller3, M Ranieri4, J Guttmann1
1Anästhesiologische Universitätsklinik, Freiburg, Germany;
2Kleistek, Bari, Italy; 3HFU, Villingen-Schwenningen, Germany;
4Oespedale S. Giovanni Battista, Torino, Italy
Critical Care 2007, 11(Suppl 2):P181 (doi: 10.1186/cc5341) Conclusions We believe that understanding the risk of both
nCPAP failure and also bad outcomes for a specific patient will
enhance clinical decision-making. That is, for patients with the
highest risk of poor outcome or nCPAP failure, more aggressive
use of intubation and surfactant might be warranted. Likewise,
such aggressive therapy might also be avoided for those with a
seemingly low chance of poor outcome. Introduction Recent data suggest that dynamic measurements of
respiratory mechanics should be preferred to static measurement
for lung protection [1]. The aim of this study was to analyze
similarities and differences between dynamic methods: the stress
index (SI) [2] and SLICE [3]. S73 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figures 1-3 (abstract P181) Figures 1-3 (abstract P181) Figures 1-3 (abstract P181) Methods One hundred and two respiratory datasets from 70
patients (28 ARDS, 24 postanesthesia care, 18 other) were
analyzed. The SI and SLICE were performed using exactly the
same database (SLICE_SI) in addition to the conventional SLICE
that includes inspiratory and expiratory data (SLICE_CONV). A
compliance-based index (CSI) directly comparable with the SI was
generated from the compliance data. Methods One hundred and two respiratory datasets from 70
patients (28 ARDS, 24 postanesthesia care, 18 other) were
analyzed. The SI and SLICE were performed using exactly the
same database (SLICE_SI) in addition to the conventional SLICE
that includes inspiratory and expiratory data (SLICE_CONV). P184 Mini-bronchoalveolar lavage with and without surfactant in
the treatment of recurrent atelectasis in pediatric intensive
care patients M Karaman Iliã, I Škariã, I Kerovec
Children’s Hospital, Zagreb, Croatia
Critical Care 2007, 11(Suppl 2):P184 (doi: 10.1186/cc5344) M Karaman Iliã, I Škariã, I Kerovec
Children’s Hospital, Zagreb, Croatia
Critical Care 2007, 11(Suppl 2):P184 (doi: 10.1186/cc5344) Introduction Since traditional treatment of atelectasis is often
insufficient to reopen the collapsed airways, mini-bronchoalveolar
lavage (mini-BAL) is performed. We retrospectively compared the
treatment effects of mini-BAL only and mini-BAL combined with
surfactant in the treatment of pediatric ICU patients with recurrent
atelectasis. Methods A retrospective analysis included a heterogeneous group
of 18 mechanically ventilated pediatric ICU patients with recurrent
atelectasis. Nine patients (mean age, 4.4 ± 3.4 years) who received
surfactant after standard mini-BAL were compared with nine
patients (mean age, 4.7 ± 3.0 years) who underwent only standard
mini-BAL. Gas exchange and pulmonary mechanic parameters in
the two groups were compared. The peak inspiratory pressure
(PIP), positive end-expiratory pressure (PEEP), paO2/FiO2, and
partial arterial carbon dioxide pressure (paCO2) were analyzed with
3 x 2 multivariate analysis of variance, with the time of measurement
(before treatment, 6 and 12 hours after treatment) as a within-
subject factor and the type of treatment (mini-BAL only vs mini-BAL
with surfactant) as a between-subject factor. Results The computer-driven ventilator settings could stabilise the
ventilation of the lung-injured subject in the predefined thresholds. Compared with the beginning of the study, a reduction in
ventilation pressure and PaCO2 could be observed. Despite the
initial low PaO2/FiO2 ratio (<200 mmHg) of the subjects, FiO2
could be decreased by the system in the given time without
penetrating the thresholds for oxygenation. Results The groups did not differ in age (independent sample
t test = 0.698). The parameters significantly changed with time
after treatment (Wilks’ λ = 0.027, F = 25.277, P < 0.001), and the
treatment procedures had significantly different effects (time x
treatment, Wilks’ λ = 0.103, F = 6.070, P = 0.013). A significant
univariate time–treatment interaction was not present only for
SpO2 (F(2,32) = 2.167, P = 0.629). Subsequent analyses showed
different effect of surfactant administration on PEEP compared
with mini-BAL alone. In the mini-BAL only group, PEEP changed
from 6.44 ± 1.13 cmH2O before treatment to 5.22 ± 0.83 cmH2O
6 hours after the treatment (P = 0.019), and remained the same
12 hours after the treatment. P182 Contribution of HMSE-1 to surfactant conversion under
acute inflammatory conditions Contribution of HMSE-1 to surfactant conversion under
acute inflammatory conditions Contribution of HMSE-1 to surfactant conversion under
acute inflammatory conditions C Ruppert, P Markart, S Händel, W Seeger, A Günther
University of Giessen Lung Center, Giessen, Germany
Critical Care 2007, 11(Suppl 2):P182 (doi: 10.1186/cc5342) C Ruppert, P Markart, S Händel, W Seeger, A Günther
University of Giessen Lung Center, Giessen, Germany
Critical Care 2007, 11(Suppl 2):P182 (doi: 10.1186/cc5342) C Ruppert, P Markart, S Händel, W Seeger, A Günther
University of Giessen Lung Center, Giessen, Germany
Critical Care 2007, 11(Suppl 2):P182 (doi: 10.1186/cc5342) Introduction Persistent deposition of fibrin in the distal lung is
thought to play a significant role in the pathogenesis of acute lung
injury (ALI) and postinflammatory lung fibrosis. The therapeutic
concept of the correction of the alveolar hemostatic balance,
although effective in most models, needs further improvement in
view of specific targeting of surfactant-containing alveolar fibrin
clots. Introduction A reduced content of biophysically active large
surfactant aggregates is a common finding in acute inflammatory
lung disease. Cyclic surface area changes and a carboxylesterase
activity (surfactant convertase) are thought to mediate this subtype
conversion. However, data concerning regulation of surfactant Introduction A reduced content of biophysically active large
surfactant aggregates is a common finding in acute inflammatory
lung disease. Cyclic surface area changes and a carboxylesterase
activity (surfactant convertase) are thought to mediate this subtype
conversion. However, data concerning regulation of surfactant S74 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Methods In the present study we generated transgenic mice that
express a surfactant protein B–urokinase fusion protein (SPUC) in
the distal respiratory epithelium under the control of the 3.7 kb
human SP-C promotor. Survival was determined in a lethal ALI
model (inhalative LPS administration) in SPUC mice compared
with wild-type mice of the same genetic background. Furthermore,
the outcome, lung function, collagen content and histology were
assessed in the model of bleomycin-induced pulmonary fibrosis. had significantly lower PEEP values compared with the mini-BAL
only group 12 hours after the treatment (3.44 ± 0.72 before vs
5.22 ± 0.44 mmH2O after treatment, P = 0.025). had significantly lower PEEP values compared with the mini-BAL
only group 12 hours after the treatment (3.44 ± 0.72 before vs
5.22 ± 0.44 mmH2O after treatment, P = 0.025). 2
Conclusion Mini-BAL is efficient in the treatment of recurrent
atelectasis in pediatric ICU patients. P184 The group that received surfactant Conclusion Robust execution of an automated ARDS Network
protocol with an electronically controlled ventilator is possible and
leads to pulmonary stabilisation. Further trials have to be
undertaken before this successful approach can be realised in
ARDS patients. P182 Beneficial effects of surfactant
administration after mini-BAL should be confirmed prospectively in
a larger number of patients. Results Transgenic mice showed an improved survival after
inhalative LPS or bleomycin administration as compared with wild-
type mice. The fibrotic response to inhalative bleomycin challenge
was markedly attenuated in transgenic mice, as evident by reduced
histological
appearance
of
fibrosis,
improved
pulmonary
compliance and reduced lung hydroxyproline content. As potential
underlying mechanisms for the attenuated fibrotic response we
observed an improvement in alveolar surface activity, a decrease in
pulmonary fibrin deposition, increased hepatocyte growth factor
levels and decreased gelatinase activity in the BAL fluids of
transgenic mice as compared with control animals. Automated mechanical ventilation based on the ARDS
Network protocol in porcine acute lung injury Automated mechanical ventilation based on the ARDS
Network protocol in porcine acute lung injury T Meier1, H Luepschen2, M Großherr1, J Karsten1, S Leonhardt2
1Medical University of Schleswig Holstein, Campus Lübeck,
Germany; 2Medical Information Technology, RWTH Aachen, Germany
Critical Care 2007, 11(Suppl 2):P185 (doi: 10.1186/cc5345) Introduction The results of the ARDS Network trial [1] demon-
strated a significant reduction of mortality by using a mechanical
ventilation protocol with tidal volumes (VT) of 6 ml/kg predicated
body weight. Additionally, a computer-driven weaning protocol was
successfully performed and a reduction of mechanical ventilation
duration could be demonstrated [2]. The implementation of the
ARDS Network protocol in routine ICU practice remains modest
[3]. A possible reason is the increased organisational and temporal
burden. An automated execution of the protocol would help to
propagate its day-to-day use. To test the ability to automate such a
complex protocol, we designed a pilot study in porcine acute lung
injury using an experimental medical expert system capable of
continuously controlling respiratory parameters and global as well
as regional ventilation with electrical impedance tomography (EIT). Methods After induction of saline lavage-induced lung injury in
pigs (n = 3), automated mechanical ventilation was initiated. The
medical expert system used a closed-loop fuzzy controller with a
rule base of if/then rules based on the ARDS Network protocol
reference card. The protocol’s algorithmic rules and therapeutic
goals (oxygenation, pH, I:E, VT) were continuously controlled and
ventilatory settings electronically adjusted accordingly. The medical
attendant personnel was constantly informed with status messages
about the decisions made. During the trial, all measurements were
made using an online blood gas monitor (TrendCare Satellite;
Diametrics Medical Inc., UK), a monitor for hemodynamic
parameters (Sirecust 1281; Siemens, Germany), a capnograph
(CO2SMO+; Respironics, Inc., USA), and an EIT prototype system
(EIT Evaluation Kit; Draeger Medical, Germany). Subjects were
ventilated for between 40 and 90 minutes. Conclusions Lung-specific expression of a surfactant protein
B–urokinase fusion protein protects against ALI after inhalative
LPS challenge and prevents fibrosis associated with bleomycin-
induced lung injury. P185 Automated mechanical ventilation based on the ARDS
Network protocol in porcine acute lung injury
T Meier1, H Luepschen2, M Großherr1, J Karsten1, S Leonhardt2
1Medical University of Schleswig Holstein, Campus Lübeck,
Germany; 2Medical Information Technology, RWTH Aachen, Germany
Critical Care 2007, 11(Suppl 2):P185 (doi: 10.1186/cc5345) P188 Maximal recruitment strategy guided by thoracic CT scan
in severe acute respiratory distress syndrome patients: a
case series report Methods A systematic literature search was performed between
1966 and July 2006 to identify randomised controlled trials
evaluating prone ventilation. G De Matos1, J Borges2, E Meyer1, C Hoelz1, R Passos1,
M Rodrigues1, C Carvalho2, M Amato2, C Barbas1
1Hospital Israelita Albert Einstein, São Paulo, Brazil; 2Hospital das
Clínicas Faculdade de Medicina Universidade de São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P188 (doi: 10.1186/cc5348) Measurements and results Of 229 studies evaluating prone
ventilation, five were suitable for inclusion. Prone ventilation was
not associated with a reduction in mortality (OR = 0.99; 95% CI =
0.74–1.30), but improvement in oxygenation was significant (mean
difference 21.2; P < 0.001). There was no significant difference in
the incidence of pneumonia, ICU stay and endotracheal tube
complications. There was a trend towards an increased incidence
of pressure sores in prone-ventilated patients. The data on duration
of mechanical ventilation, intravascular catheter complications or
hospital stay were not suitable for meta-analysis. No study reported
cost-effectiveness. Introduction There is great controversy concerning protective
ventilation in ARDS. Recruitment maneuvers and PEEP titration
sufficient to avoid collapse and tidal recruitment are the major
goals of the maximal recruitment strategy (MRS). Objectives To describe clinical and demographic data. To evaluate
the incidence of complications related to transportation and to the
MRS. Conclusions The use of prone ventilation is associated with
improved oxygenation. It is not associated with a reduction in
mortality, pneumonia or ICU stay and may be associated with an
increased incidence of pressure sores. Methods Forty-three patients with ARDS were transported to CT
and submitted to the MRS, which consisted of 2-minute steps of
ventilation with a fixed PCV = 15 cmH2O and progressive PEEP
levels (10–45–25–10 cmH2O), RR = 10, I:E = 1:1, and FiO2 =
1.0. Opening (recruitment) and closing (PEEP titration) pressures
were determined according to the least amount of collapse
observed at the CT, and were used to ventilate the patients
afterwards. Efficacy of prone ventilation in adult patients with acute
respiratory failure: a meta-analysis Efficacy of prone ventilation in adult patients with acute
respiratory failure: a meta-analysis R Tiruvoipati1, M Bangash1, B Manktelow2, G Peek1
1Glenfield Hospital, Leicester, UK; 2University of Leicester, UK
Critical Care 2007, 11(Suppl 2):P186 (doi: 10.1186/cc5346) Background The use of prone ventilation in acute respiratory
failure has been investigated by several randomised controlled
trials in the recent past. To date there has been no systematic
review or meta-analysis of these trials. Conclusions PPV had a positive effect on gas exchange even after
6 hours. This effect lasts through the PPV period. Because of its
effect on the LIS, a duration of 24 hours for continuous PPV could
be useful in this patient setting. Objectives The primary objective was to assess the efficacy of
prone ventilation in reducing mortality of adult patients with acute
respiratory failure. The secondary objective was to evaluate changes
in oxygenation, incidence of pneumonia, duration of mechanical
ventilation, ICU and hospital stay, and adverse effects including
pressure sores, endotracheal tube or intravascular catheter
complications and cost-effectiveness of using prone ventilation. P186 before PPV and 256 (170–298) mmHg after 1 hour of PPV
(P = 0.001). This difference with the supine PaO2/FIO2 ratio was
sustained until the end of PPV. Initial values of PEEP were set at
15 (12–18) cmH2O by constructing a PEEP-compliance curve;
there were no differences in PEEP values along the study. Initial
values of PaCO2 were 47 (41–69) mmHg and there were no
significant differences along the study period. After 24 hours of
PPV, the LIS was significantly decreased in comparison with the
supine value before PPV: 3 (2.25–2.7) vs 2.5 (2.25–2.75),
P = 0.001. There were no significant complications. P186
Efficacy of prone ventilation in adult patients with acute
respiratory failure: a meta-analysis
R Tiruvoipati1, M Bangash1, B Manktelow2, G Peek1
1Glenfield Hospital, Leicester, UK; 2University of Leicester, UK
Critical Care 2007, 11(Suppl 2):P186 (doi: 10.1186/cc5346) References References 1. ARDS Network: N Engl J Med 2000, 342:1301-1308. 2. Lellouche et al.: Am J Respir Crit Care Med 2006, 174:894-
900. S75 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P186 Continuous long-term prone position ventilation effects in
pulmonary acute respiratory distress syndrome patients Results Clinical data are presented in Table 1. There were no
complications due to transportation and one patient developed
pneumomediatinum after the protocol. J Gorrasi, F Pracca, A Iturralde, L Moraes, D Fischer, M Cancela
Department of Intensive Care Medicine, University Hospital, School
of Medicine, Montevideo, Uruguay
Critical Care 2007, 11(Suppl 2):P187 (doi: 10.1186/cc5347) P189 Low sensitivity of measurements of respiratory mechanics
in detecting lung edema from high tidal volume
mechanical ventilation Low sensitivity of measurements of respiratory mechanics
in detecting lung edema from high tidal volume
mechanical ventilation Introduction High tidal volume mechanical ventilation (HTVMV)
leads to pulmonary edema from increased endothelial permeability. The lungs show evidence of inflammation with endothelial
adhesion molecule expression, infiltrates of white blood cells and
cytokine production. In order to understand the molecular
mechanisms responsible for the pathogenesis of ventilator injury,
mouse models are beneficial but technically difficult due to the
small size of the animal. To study the time course of lung edema
formation we compared lung elastance measured by forced
oscillations with invasive methods of lung edema detection (for
example, wet–dry weight ratio and histology). Introduction High tidal volume mechanical ventilation (HTVMV)
leads to pulmonary edema from increased endothelial permeability. The lungs show evidence of inflammation with endothelial
adhesion molecule expression, infiltrates of white blood cells and
cytokine production. In order to understand the molecular
mechanisms responsible for the pathogenesis of ventilator injury,
mouse models are beneficial but technically difficult due to the
small size of the animal. To study the time course of lung edema
formation we compared lung elastance measured by forced
oscillations with invasive methods of lung edema detection (for
example, wet–dry weight ratio and histology). Figure 2 (abstract P190) Figure 2 (abstract P190) p
y
g
gy
Methods C57Black6 mice were anesthetized with i.p. sodium
pentothal and paralyzed with succinylcholine. A tracheostomy was
performed and the animals were connected to a Flexivent ventilator
(Sqirec). The HTVMV group received a tidal volume of 25 ml/kg
and 33 breaths/minute for 4 hours. The control group received
7 ml/kg at 120 breaths/minute. Temperature was kept at 36–37°C
with the aid of a heated pad. The heart rate was monitored with
surface EKG electrodes. Lung elastance and tissue energy
dissipation were measured every 30 minutes using the forced
oscillation technique. At the end of the experiment a sternotomy
was performed. A ligature was placed around the right hilum and
the right lung was cut, briefly rinsed in PBS, blotted dry and
weighed. The dry weight was obtained following desiccation at
60°C for 48 hours. The left lung was inflated with 500 µl formalin
injected slowly into the tracheal canula and embedded in paraffin. Table 1 (abstract P188) Table 1 (abstract P188)
Mortality (%)
28
Age (years)
49 ± 17
APACHE II score
20 ± 6
SOFA D1 score
9.4 ± 3
SOFA D7 score
5.2 ± 4
Maximal recruitment pressure (cmH2O)
60 ± 5
Maximal PEEP day 1 (cmH2O)
25 ± 3
Maximal plateau pressure day 1 (cmH2O)
40 ± 5
PaO2/FiO2 ratio before recruitment protocol
130 ± 43
PaO2/FiO2 ratio after recruitment protocol
317 ± 99 Introduction The optimal duration of prone position ventilation
(PPV) in acute respiratory distress syndrome (ARDS) is uncertain. It has been pointed out that pulmonary ARDS patients respond
less than extrapulmonary ARDS patients. Objective To study effects of continuous long-term PPV on gas
exchange, PEEP, lung injury score and multiorgan failure in
pulmonary ARDS patients. Materials and methods The design was a prospective (cohort). We studied 42 PPV periods in 33 pulmonary ARDS patients. Measures were taken in the supine position before PPV and at
1 hour after PPV, and then every 6 hours until the end of PPV. Statistical values are expressed as the median and interquartile
range. Wilcoxon and Kruskal–Wallis tests were used. P < 0.05
was considered significant. Conclusions MRS was well tolerated in this series of patients,
rendered the gas distribution through the lung more homogeneous,
improved gas exchange and was related to low mortality. A RCT to
test the MRS is necessary. Results The mean age was 44 (25–57) years, the initial lung injury
score (LIS) was 3.1 (2.75–3.6), and PPV was maintained for 91
(51–117) hours. The PaO2/FIO2 ratio was 125 (99–181) mmHg S76 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P190)
Figure 2 (abstract P190) Figure 1 (abstract P190) Figure 1 (abstract P190) P189 Paraffin blocks were sectioned with a microtome at 5 µm thickness
and stained with hematoxylin–eosin. established. The pressure dependency (or volume dependency
respectively) of respiratory resistance of these patients is mostly
ignored. This study was performed to investigate the pressure
dependency of resistance in ALI and ARDS over a wide range of
pressures. Results The wet-to-dry weight ratios rose from 4.82 ± 0.16 in
control animals to 6.34 ± 0.83 in the HTVMV group (P < 0.05,
n = 4). Light microscopic examination of histologic sections showed
mononuclear white cell infiltrates around small arteries and within
the alveolar walls of mice in the HTVMV group but not in control
mice. Elastance rose nonsignificantly during the HTVMV protocol. Methods Twenty-one patients with ALI or ARDS were analyzed. Ventilation was interrupted by a respiratory manoeuvre: the volume
was increased from ZEEP in steps of 100 ml with constant
inspiratory flow until the plateau pressure reached 45 cmH2O. Each step was followed by a hold of 3 seconds. Inspiratory
resistance during each step was determined by a least-squares
fitting procedure. Conclusions In this in vivo mouse model, high tidal volume mechanical
ventilation caused pulmonary edema and lung tissue infiltration with
white blood cells. However, measurements of lung mechanics showed
minimal changes during the course of the experiment, indicating that
they are less useful in detecting early edema. Results Resistance decreased from 10.7 ± 5.1 cmH2O·s/l at
5 cmH2O to 8.1 ± 4.0 cmH2O·s/l at 40 cmH2O (P < 0.05). Figure 1
shows individual absolute values and means ± SD of all patients. Most of the decrease was found up to 20 cmH2O; at higher
pressures, changes were not uniform. The average relative
changes in inspiratory resistance (±SD) of all patients are shown in
Figure 2. Alveolar microscopy: on the automatic determination of
alveolar size during ventilation J Karsten1, H Luepschen2, M Grossherr1, H Gehring1,
S Leonhardt2, T Meier1
1University of Lübeck, Germany; 2Medical Information Technology,
Helmholtz Institute, RWTH Aachen, Germany
Critical Care 2007, 11(Suppl 2):P192 (doi: 10.1186/cc5352) D Schwenninger1, K Moeller1, C Stahl2, S Schumann2,
J Guttmann2
1Furtwangen University, Villingen-Schwenningen, Germany;
2University of Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P191 (doi: 10.1186/cc5351) Introduction Alveolar recruitment and maintenance of lung volume
are important goals in the treatment of acute lung injury (ALI) and
essential for improving oxygenation. The most usual employed
strategy to achieve this goal is the use of positive end-expiratory
pressure (PEEP). Recruitment and collapse are highly dynamic
phenomena that are difficult to monitor. Dynamic effects of regional
ventilation can be monitored by electrical impedance tomography
(EIT) at the bedside [1]. We investigated the ability of EIT for
providing a useful tool to detect dynamic changes of regional
breath by breath recruitment at the bedside during an incremental
and decremental PEEP trial in experimental lung injury. In addition,
we analyzed pressure–volume (P–V) curves computed by EIT data. Methods ALI was induced in six pigs by repetitive lung lavage. After stabilization of the lung injury model (> 1 hour) a stepwise
PEEP trial was performed consisting of 2-minute steps of tidal
ventilation (10–30 cmH2O; 30–5 cmH2O). During the PEEP trial
subjects were ventilated pressure-controlled. Global ventilatory and
gas exchange parameters were continuously recorded. Offline we
analysed EIT data by computing the amount of breath by breath
recruitment (∆V EIT) at each pressure level before and after lung
lavage. Nondependent and dependent regions of interest were
defined in the tomograms. ∆V EIT was defined as the mean increase
or decrease in end-expiratory global impedance per breath. Introduction Alveolar microscopy seems to provide important
insight into alveolar dynamics during mechanical ventilation [1,2]. The utility of this method is limited due to high efforts needed to
evaluate sequences of images with respect to alveolar geometry. The evaluation – done by hand – is time consuming, places a high
cognitive load on the examiner and is error prone. Reproducibility
of results is low. This project aims to establish a computer-assisted
tool that provides semi-automatic evaluation of video sequences
acquired with alveolar endoscopy. Methods We developed a computer program based on Matlab
(Mathworks, Natick, MA, USA), which analyses video sequences
acquired with an alveolar endoscope (Schölly, Denzlingen,
Germany) [2]. Reference 1. Victorino et al.: Am J Respir Crit Care Med 2004, 169:791-
800. frames allows one to compensate for motion artifacts and to
analyze the intratidal changes in alveolar geometry. P193 Conclusion Given a synchronization with respiratory data, this tool
will allow one to quantify pressure-related changes of alveolar size. Thus it will allow one to monitor the alveolar distension in a variety
of animal models (for example, lavage-induced ARDS) and to
correlate these findings, for example, with outcome. Pressure dependency of respiratory resistance in patients with
acute lung injury and acute respiratory distress syndrome Conclusion Inspiratory resistance in ALI and ARDS is not
constant. Especially at higher pressures, individual resistance may
change unpredictably. The assumption of a constant resistance
should therefore be avoided. C Stahl1, H Knorpp1, S Schumann1, D Steinmann1, K Möller1,
J Guttmann1
1Anästhesiologische Universitätsklinik, Freiburg, Germany;
2Biomedical Engineering, HFU, Villingen-Schwenningen, Germany
Critical Care 2007, 11(Suppl 2):P190 (doi: 10.1186/cc5350) C Stahl1, H Knorpp1, S Schumann1, D Steinmann1, K Möller1,
J Guttmann1 1Anästhesiologische Universitätsklinik, Freiburg, Germany;
2Biomedical Engineering, HFU, Villingen-Schwenningen, Germany
Critical Care 2007, 11(Suppl 2):P190 (doi: 10.1186/cc5350) Introduction
The analysis of the nonlinearity of respiratory
compliance to guide ventilator settings in ALI and ARDS is well S77 P191
Alveolar microscopy: on the automatic determination of
alveolar size during ventilation
D Schwenninger1, K Moeller1, C Stahl2, S Schumann2,
J Guttmann2
1Furtwangen University, Villingen-Schwenningen, Germany;
2University of Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P191 (doi: 10.1186/cc5351) Alveolar microscopy: on the automatic determination of
alveolar size during ventilation The user has to provide a pointer to the alveoli that
shall be traced and whose changes in size and shape are to be
determined. Filters, smoothing splines and expectation-driven fine
tuning is performed to achieve robust and predictable results of the
intratidal change in alveolar geometry. Results Animal studies related to alveolar mechanics during
artificial ventilation were conducted. Figure 1a shows a plot of a
frame taken from a video obtained during an experiment performed
on a healthy anesthetized rat. Overlaid circles indicate identified
boundaries of a selected alveolus. Figure 1b presents a trace of
alveolar diameter during a tidal breath. Evaluation of successive Results Ventilatory parameters clearly showed a recruitment of
nonaerated lung areas at the descending part of the pressure ramp. The shape of the P–V curve from EIT data, in particular the
increasing slope (lower level > upper level), reflected the recruitment
of poorly ventilated lung regions. The flattening of the curve at higher
pressures, especially at the upper level, reflected less amount of
recruitment
but
more
overdistension. Regional
pulmonary
recruitment/derecruitment was very high in the lower level. These
phenomena were more impressive after induced lung injury. Figure 1 (abstract 191)
(a) Marked areas of a traced alveolus. (b) Changes in diameter during
ventilation. Figure 1 (abstract 191) Conclusions Stepwise PEEP recruitment maneuvers can open
collapsed lungs and certain PEEP levels are necessary to keep the
lungs open. Monitoring of ∆V EIT is capable of detecting the
dynamic process of recruitment and derecruitment at bedside. Plotting regional P–V curves from EIT data provides continuous
information that may be of use in determining the PEEP level to
maintain recruitment in acute lung injury. (a) Marked areas of a traced alveolus. (b) Changes in diameter during
ventilation. 1.
Victorino et al.: Am J Respir Crit Care Med 2004, 169:791-
800. frames allows one to compensate for motion artifacts and to
analyze the intratidal changes in alveolar geometry.
Conclusion Given a synchronization with respiratory data, this tool
will allow one to quantify pressure-related changes of alveolar size.
Thus it will allow one to monitor the alveolar distension in a variety
of animal models (for example, lavage-induced ARDS) and to
correlate these findings, for example, with outcome.
References
1.
Schiller et al.: Crit Care Med 2001, 29:1049-1055.
2.
Stahl CA, et al.: Crit Care 2006, 10(Suppl 1):S2. 1.
Schiller et al.: Crit Care Med 2001, 29:1049-1055. H Knorpp1, C Stahl2, S Schumann2, M Lichtwarck-Aschoff3,
J Guttmann2
1UT Southwestern, Dallas, TX, USA; 2University of Freiburg,
Germany; 3Zentralklinikum, Augsburg, Germany
Critical Care 2007, 11(Suppl 2):P193 (doi: 10.1186/cc5353) 2.
Stahl CA, et al.: Crit Care 2006, 10(Suppl 1):S2. Nonlinearity of intratidal airway resistance H Knorpp1, C Stahl2, S Schumann2, M Lichtwarck-Aschoff3,
J Guttmann2
1UT Southwestern, Dallas, TX, USA; 2University of Freiburg,
Germany; 3Zentralklinikum, Augsburg, Germany
Critical Care 2007, 11(Suppl 2):P193 (doi: 10.1186/cc5353) Introduction Acute respiratory distress syndrome is a disease
associated with high mortality. Understanding the interdependence S78 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P194) Figure 1 (abstract P194) Figure 1 (abstract P193) objective of this study was to evaluate plasma cytokine behavior
after an ARM in healthy volunteers. Methods After obtaining ethical committee approval and informed
consent, a basal blood sample was collected in 10 healthy
volunteers. Continuous positive airway pressure (CPAP) was
noninvasively applied (BiPAP Vision®; Respironics, USA) using a
total face mask. CPAP was increased by 3 cmH2O from 5 to
20 cmH2O every five breaths. At CPAP of 20 cmH2O, an
inspiratory pressure of 20 cmH2O above CPAP was implemented
during 10 breaths. After that, CPAP was stepwise decreased in an
inverse fashion. Pulse oximetry, arterial pressure and heart rate
were measured before and after ARM. Additional blood samples
were drawn at 30 minutes, 2 and 12 hours. TNFα, IL-1β, IL-6, IL-8,
IL-10 and IL-12 were measured by the flow cytometry technique
(Cytometric Bead Array BD™ Kit). The highest cytokine value at
30 minutes or 2 hours after ARM was considered the peak value
measurement. Data were analyzed using a paired t test and one-
way RM ANOVA. P < 0.05 was significant. of ventilator settings and respiratory mechanics is crucial for further
developments of protective lung ventilation. Up to now, the
nonlinearity of compliance has mainly been the focus of interest. We hypothesized that airway resistance also changes intratidally. Therefore, this study was performed to analyze the dependence of
resistance on tidal gas volume. Methods After induction of anesthesia and tracheotomy, the lungs
of 14 surfactant-depleted piglets were ventilated at zero end-
expiratory pressure with three different tidal volumes (8, 12, 16 ml/kg)
in a randomized order. In addition, baseline measurements
(12 ml/kg) were performed before saline lavage. Before any
change of the ventilator settings a recruitment maneuver was
performed. The nonlinear intratidal airway resistance was analyzed
using the SLICE method [1]. Results Figure 1 shows the intratidal resistance before lavage
(grey) and after surfactant depletion (black) plotted against the
alveolar pressure. Each curve in the diagram represents the
intratidal course of resistance for one ventilator setting. P194 K Moeller1, T Sivenova1, C Stahl2, S Schumann2, J Guttmann2
1Furtwangen University, Villingen-Schwenningen, Germany;
2University of Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P195 (doi: 10.1186/cc5355) P195 Recruitment/derecruitment models fitted to respiratory
data of acute respiratory distress syndrome/acute lung
injury patients Nonlinearity of intratidal airway resistance Resistance
is increased after surfactant depletion and is intratidally declining
before and after lavage. Results Four men and six women with a mean age of 26 ± 1 years
and mean BMI of 23.8 ± 3.6 kg/m2 were studied. No changes
were observed in heart rate or MAP after ARM, while pulse
oximetry increased from 97.2 ± 0.8% to 98.4 ± 0.7% (P = 0.009). As shown in Figure 1, ARM induced a significant increase in the
peak plasma level concentration of all cytokines that returned to
basal levels within 12 hours. No adverse effects were observed
during and after ARM. Conclusion The analysis of resistance shows a dependence on
intratidal volume. The nonlinear course of intratidal resistance can
be interpreted as a volume-related caliber effect leading to an
increase of cross-sectional area of the large and small airways. Conclusions Despite beneficial effects in reversing atelectasis,
ARM-induced lung stretching was associated with an inflammatory
response in healthy volunteers. Reference 1. Guttmann J, Eberhard L, Fabry B, et al.: Determination of
volume-dependent respiratory system mechanics in
mechanically ventilated patients using the new slice
method. Technol Health Care 1994, 2:175-191. Noninvasive alveolar recruitment maneuver induces
cytokine release in healthy volunteers The FRC, ratio (PaO2/FiO2) and static
compliance (Cstat) are registered in three clinical steps: 1: ICU
arrival; 2: after pulmonary recruitment with high inspiratory
pressure; and 3: 3 hours after recruitment. Data are shown as the
mean ± standard deviation; intragroup variables are analyzed with
the Wilcoxon test (W), and intergroups variables are analyzed with
the Mann–Whitney test (MW). P < 0.05 is taken as statistically
significant. Results A multistep optimization process is performed to reduce
the difference between measured data and model prediction. At
any moment during a tidal breath or during some respiratory
maneuver the current state of the model can be visualized. The
inflated volume splits up into extension of open alveoli and into
temporal or pressure-dependent recruitment. Distribution of these
compartments over time during a tidal inflation is depicted in Figure 1a. The pressure vs time and flow vs time curves are shown in Figure 1b. Conclusion The fitting of recruitment models provides interesting
insight into not directly observable R/D. It may be used for
monitoring trends and drifts in recruitment. Currently results rely on
certain assumptions; for example, distribution and quantity of
superimposed pressure. With modern imaging techniques (for
example, CT, EIT) a validation of the fitted models will come into
reach and will be performed as a next step. Results FRC increase in group A is statistically significant (W)
(step 1: 1,525 ± 360 ml; step 2: 1,937 ± 583 ml, P < 0.05 vs step
1; step 3: 2,592 ± 659 ml, P < 0.05 vs step 2 and P < 0.01 vs step
1) while the FRC increase in group B is not significant (step 1:
1,697 ± 210 ml; step 2: 1,757 ± 367 ml; step 3: 1,982 ± 365 ml);
the FRC of group A is statistically higher than the FRC of group B
in step 2 (P < 0.05 MW) and in step 3 (P < 0.01 MW). Noninvasive alveolar recruitment maneuver induces
cytokine release in healthy volunteers Noninvasive alveolar recruitment maneuver induces
cytokine release in healthy volunteers L Malbouisson1, T Szeles1, C Carvalho1, P Pelosi2,
M Carmona1, J Auler1
1São Paulo University Medical School, São Paulo, Brazil;
2University of Insubria, Varese, Italy
Critical Care 2007, 11(Suppl 2):P194 (doi: 10.1186/cc5354) Introduction Recruitment/derecruitment (R/D) seems to play an
important role in the development of VILI [1]. Many clinicians base
their determination of PEEP settings during mechanical ventilation
of ARDS/ALI patients on an estimate of alveolar recruitability [2]. This project aims to establish an online tool that provides estimates
of R/D in patients at the bedside. Introduction Recruitment/derecruitment (R/D) seems to play an
important role in the development of VILI [1]. Many clinicians base
their determination of PEEP settings during mechanical ventilation
of ARDS/ALI patients on an estimate of alveolar recruitability [2]. This project aims to establish an online tool that provides estimates
of R/D in patients at the bedside. Introduction Alveolar recruitment maneuver (ARM) using high
airway pressures has been shown to re-expand atelectasis and to
improve gas exchanges after general anesthesia; however, ARM
may lead to lung stretching-induced inflammatory response. The Introduction Alveolar recruitment maneuver (ARM) using high
airway pressures has been shown to re-expand atelectasis and to
improve gas exchanges after general anesthesia; however, ARM
may lead to lung stretching-induced inflammatory response. The Methods We developed a computer simulation of R/D based on
Matlab (Mathworks, Natick, MA, USA), which incorporates different S79 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P195) Figure 1 (abstract P195) Figure 1 (abstract P195) recruitment range (group A) and in patients with low recruitment
range (group B). approaches [1,3,4]. Our model is fitted (currently offline) to patient
data acquired during controlled mechanical ventilation. For data
acquisition the internal respiratory data of a ventilator (Evita 4;
Dräger Medical, Lübeck, Germany) is read in real time. The
simulation assumes a quantitative partition into pressure-
dependent and time-dependent recruitment. Pure pressure-related
approaches (for example [1]) are not able to describe transients
(for example, a volume shift after a change in PEEP). Methods Five patients without pulmonary disease (group A)
admitted to the ICU for a postoperative course and five patients
admitted to the ICU for acute respiratory failure (group B) were
studied with the Engström Carestation FRC system based on the
evaluation of nitrogen wash-in and washout by the COVX
metabolic module. References 1. Hickling KG: Am J Respir Crit Care Med 2001, 163:69-78. 2. Gattinoni L, et al.: N Engl J Med 2006, 354:1775-1786. 3. Bates JH, et al.: J Appl Physiol 2002, 93:705-713. 4. Möller K, et al.: Crit Care 2005, 9(Suppl 1):S44-S45. 1. Hickling KG: Am J Respir Crit Care Med 2001, 163:69-78. 2. Gattinoni L, et al.: N Engl J Med 2006, 354:1775-1786. 3. Bates JH, et al.: J Appl Physiol 2002, 93:705-713. 4. Möller K, et al.: Crit Care 2005, 9(Suppl 1):S44-S45. 3. Bates JH, et al.: J Appl Physiol 2002, 93:705-713. 4. Möller K, et al.: Crit Care 2005, 9(Suppl 1):S44-S45. Noninvasive alveolar recruitment maneuver induces
cytokine release in healthy volunteers The ratio
increase in group A is statistically significant (W) (step 1:
256 ± 133; step 2: 407 ± 187, P < 0.01 vs step 1; step 3:
379 ± 169, P < 0.05 vs step 1) while the ratio increase in group B
is not significant (step 1: 194 ± 50; step 2: 253 ± 83; step 3:
276 ± 73); the ratio of group A is statistically higher than the ratio
of group B in step 2 (P < 0.01 MW) and in step 3 (P < 0.05 MW). The Cstat increase in both groups is not significant, but in group A
Cstat is statistically higher than Cstat of group B in every step
(P < 0.05 MW) (step 1: 38 ± 2 ml/cmH2O for group A vs
28 ± 7 ml/cmH2O for group B; step 2: 44 ± 6 ml/cmH2O vs
36 ± 8 ml/cmH2O; step 3: 47 ± 5 ml/cmH2O vs 36 ± 8 ml/cmH2O). Conclusion With the limit of low sample size, these preliminary
data suggest that the FRC evaluation system is a good parameter
to optimize pulmonary recruitment and seems to be in a position to
overcome the Cstat limit for the evaluation of pulmonary recruitable
parenchyma. High-frequency oscillatory ventilation for trauma patients
with acute respiratory distress syndrome who fail
conventional mechanical ventilation High-frequency oscillatory ventilation for trauma patients
with acute respiratory distress syndrome who fail
conventional mechanical ventilation F Eng, M Ferri, S Rizoli, L Tremblay
Sunnybrook Health Sciences Centre, Toronto, Canada
Critical Care 2007, 11(Suppl 2):P197 (doi: 10.1186/cc5357) F Eng, M Ferri, S Rizoli, L Tremblay
Sunnybrook Health Sciences Centre, Toronto, Canada
Critical Care 2007, 11(Suppl 2):P197 (doi: 10.1186/cc5357) Introduction The purpose of this study is to report our clinical
experience with high-frequency oscillatory ventilation (HFOV) for
rescuing trauma patients with acute respiratory distress syndrome
(ARDS) and severe hypoxemia despite optimal conventional
ventilation. Experimental and clinical data suggest mechanical
ventilation can contribute to mortality in ARDS, and modern
ventilatory strategies require protective measures such as low tidal
volume, low airway pressure and fraction of inspired oxygen (FIO2),
which is not always possible with conventional ventilation. HFOV
could be an alternative to achieve protective ventilation and
adequate oxygenation. Methods Patients having a PO2/FiO2 ratio ≤150, PEEP >12 cm
and FiO2 requirement ≥0.7 on VCV (6 ml/kg) were switched to
HFOV. The initial continuous distending pressure (CDP) of HFOV
was 5 cm above the mean airway pressure during VCV. Other
HFOV settings were FiO2 1, bias flow 30 l/min, amplitude 70 cm
and frequency 7 Hz. The CDP was adjusted to maintain oxygen
saturation >88%. Fluid bolus before switching to HFOV was
avoided. All the patients were sedated and paralysed during the
study period. A drop in the mean arterial pressure (MAP) ≤65 mm
or cardiac index (CI) ≤2.5 l/min/m2 were treated with escalation of
inotrope if required. Hemodynamic monitoring was done with the
Flotrac-Vigileo monitoring system. Methods We retrospectively analyzed nine trauma patients who
presented with ARDS criteria and failed conventional mechanical
ventilation requiring HFOV. The mean airway pressure was initially
set 3–5 cmH2O higher than that for conventional ventilation and
was subsequently adjusted to maintain oxygen saturation >90%
and FiO2 <0.6. The PaCO2 target range was 35–60 mmHg with a
pH >7.25. We collected demographic data, injury severity scale
(ISS), APACHE II score, time to HFOV, time spent on HFOV,
ventilation settings and arterial blood gas before and after HFOV
and mortality. Results Eight ARDS patients needing vasopressor support were
switched to HFOV from VCV. Baseline data of these patients
were: age 58.87 ± 11.69 years, APACHE II score 21.02 ± 8.14,
mean CDP of HFOV 26.67 ± 3.22 cm, frequency 7 Hz, amplitude
70 cm. P196 A novel system for evaluation of pulmonary functional
residual capacity in the intensive care unit: preliminary data G Falzetti, T Principi, P Pelaia
Anaesthesia and Intensive Care Clinic – Politechnical University of
Marche, Ancona, Italy
Critical Care 2007, 11(Suppl 2):P196 (doi: 10.1186/cc5356) Introduction The aim of this study is to evaluate the efficacy of
pulmonary recruitment by the use of functional residual capacity
(FRC) measurement with the Engström Carestation FRC INview™
system (GE Healthcare), in patients with high pulmonary S80 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P198) Figure 1 (abstract P198) Figure 1 (abstract P198) Outcome predictors of high-frequency oscillatory
ventilation in acute respiratory distress syndrome S Jog, P Akole, P Rajhans, B Pawar
Deenanath Mangeshkar Hospital and Research Centre, Pune, India
Critical Care 2007, 11(Suppl 2):P199 (doi: 10.1186/cc5359) Conclusion HFOV is a possible alternative for safely correcting
oxygenation failure associated with ARDS in trauma patients. Further research is necessary to identify the best strategy and
patients for HFOV. Introduction Outcome predictors of high-frequency oscillatory
ventilation (HFOV) in severe ARDS are not well studied. Objective To evaluate outcome predictors of HFOV in adult
patients with ARDS. Introduction Outcome predictors of high-frequency oscillatory
ventilation (HFOV) in severe ARDS are not well studied. Objective To evaluate outcome predictors of HFOV in adult
patients with ARDS. Methods ARDS patients receiving mechanical ventilation as per
the ARDSnet protocol with PO2/FiO2 <150, PEEP ≥12 cm and
FiO2 ≥0.7 were considered for HFOV. The continuous distending
pressure (CDP), frequency, amplitude, inspiratory time and bias
flow of HFOV were optimised, guided by frequent blood gas
analysis. Weaning from HFOV to pressure support ventilation was
attempted once the PO2/FiO2 ratio remained ≥200 with CDP
≤18 cm FiO2 ≤0.5. Responders (R) were defined as patients who
were successfully weaned to a state without any ventilatory
support for >12 hours. Nonresponders (NR) could not be weaned
off any ventilatory assistance. High-frequency oscillatory ventilation for trauma patients
with acute respiratory distress syndrome who fail
conventional mechanical ventilation Figure 1 presents the trends of hemodynamic parameters
during the study period. Only one patient needed escalation of the
dopamine dose during the trial period. Results Data on nine trauma patients were available for analysis;
the severity of respiratory dysfunction can be estimated by the
mean PaO2/FiO2 of our patients, 131. Two patients received a trial
of inhaled nitric oxide as part of the management of ARDS failing
conventional ventilation. The last mean measurements before
initiation of HFOV were: pH 7.24, PaO2 116, PCO2 67.4, FiO2
0.899. No significant hemodynamic instability was associated with
initiation and administration of HFOV. The mean frequency was 4.3
(mode 4), mean power was 8.5, mean FiO2 was 0.83. The
successful weaning rate from HFOV to extubation or trach mask
was 70%, and mean total time of mechanical ventilation
(conventional + HFOV) was 347.76 hours and the time spent on
HFOV was 107.5 hours. Conclusion Switching of an ARDS patient from VCV to HFOV
does not impart significant hemodynamic instabilities and can be
safely done. P197 P197
High-frequency oscillatory ventilation for trauma patients
with acute respiratory distress syndrome who fail
conventional mechanical ventilation
F Eng, M Ferri, S Rizoli, L Tremblay
Sunnybrook Health Sciences Centre, Toronto, Canada
Critical Care 2007, 11(Suppl 2):P197 (doi: 10.1186/cc5357) pH: an overlooked criterion for success in high-frequency
oscillatory ventilation in acute respiratory distress syndrome? pH: an overlooked criterion for success in high-frequency
oscillatory ventilation in acute respiratory distress syndrome? K Madhusudana, K Black, C Melville
Hull Royal Infirmary, Hull, UK
Critical Care 2007, 11(Suppl 2):P201 (doi: 10.1186/cc5361) K Madhusudana, K Black, C Melville Introduction High-frequency oscillatory ventilation (HFOV) is used
for patients with refractory hypoxia and or severe oxygenation
failure in our ICU. There is a unit policy regarding the timing of
initiation of HFOV, and all patients were initiated with a single
static recruitment manoeuvre and then managed according to local
guidelines. The aim of this study was to understand which
ventilatory parameters best predicted successful outcome
following HFOV. that in the NR group. The difference in improvement in the
oxygenation index (OI) of the two groups at 6 and 24 hours was
also statistically significant. The rate of improvement in the
PO2/FiO2 ratio and OI in NR was slower than that in R, and this
difference was statistically significant (trend test). See Figure 1. Conclusion A lower PO2/FiO2 ratio and higher OI prior to HFOV
and slow improvement in the PO2/FiO2 ratio and OI at 6 and 24
hours on HFOV are significant negative outcome predictors of
HFOV in ARDS. that in the NR group. The difference in improvement in the
oxygenation index (OI) of the two groups at 6 and 24 hours was
also statistically significant. The rate of improvement in the
PO2/FiO2 ratio and OI in NR was slower than that in R, and this
difference was statistically significant (trend test). See Figure 1. y
g
g
Conclusion A lower PO2/FiO2 ratio and higher OI prior to HFOV
and slow improvement in the PO2/FiO2 ratio and OI at 6 and 24
hours on HFOV are significant negative outcome predictors of
HFOV in ARDS. Methods After institutional approval, we retrospectively reviewed
the case notes all the adult patients who were ventilated with
HFOV during the 18-month period between January 2005 and July
2006. The data were analysed using SPSS® version 13 software. Results There were 33 episodes of HFOV in 31 patients; 19
females and 12 males; mean age of 56 years. First-day median
APACHE II scores and predicted mortality were 23 and 41%,
respectively. All the patients had acute respiratory distress
syndrome (ARDS) at the time of initiation of HFOV. pH: an overlooked criterion for success in high-frequency
oscillatory ventilation in acute respiratory distress syndrome? The main
causes of ARDS were pneumonia leading to sepsis (50%), sepsis
from other sources (18%), postoperative emergency laparotomy
and abdominal aortic aneurysm repair (18%). Patients were
ventilated with conventional ventilation for a median period of
35 hours (0–519 hours) before being ventilated with HFOV for a
median period of 58 hours (7–1,080 hours). Fourteen patients
(45%) were successfully weaned to conventional ventilation while
two (7%) died because of cardiac arrest and in the remaining 15
patients (48%) treatment was withdrawn. Eight patients (25.8%)
survived to discharge to the ward. An admission pH of less than
7.20 was found to be significantly associated (P = 0.09) with
failure of treatment. P200 Monitoring slow recruitment manoeuvres with high-
frequency oscillatory ventilation in adult acute respiratory
distress syndrome patients using electrical impedance
tomography
L Camporota, J Smith, K Lei, T Sherry, R Beale
Guy’s and St Thomas’ NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P200 (doi: 10.1186/cc5360) Monitoring slow recruitment manoeuvres with high-
frequency oscillatory ventilation in adult acute respiratory
distress syndrome patients using electrical impedance
tomography L Camporota, J Smith, K Lei, T Sherry, R Beale
Guy’s and St Thomas’ NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P200 (doi: 10.1186/cc5360) Introduction Recruitment manoeuvres (RM) during high-frequency
oscillatory ventilation (HFOV) are increasingly used in ARDS. However, the changes in lung volume during a RM (lung
recruitability) are difficult to quantify at the bedside, and the use of
CT is impractical in patients on HFOV. We studied the effects of a
standardised protocol of slow RM (SRM) on regional lung volumes
assessed noninvasively by electrical impedance tomography (EIT). Methods SRM were performed by progressive increases of
continuing distending pressure (CDP) starting from the mean airway
pressure on CMV + 5 cmH2O, by increments of 3 cmH2O every
10 minutes until a CDP of 50 cmH2O was reached or haemo-
dynamic instability ensued. Subsequently, CDP was reduced by
2 cmH2O every 5 minutes until optimal CDP was established on gas
exchange. EIT measurements were performed using 16 electrodes,
acquired via the Goe-MF II EIT system (Viasys Healthcare, USA). Offline analysis of EIT measurements was performed using the
AUSPEX software (University of Amsterdam). Changes in
impedance (∆Z) during tidal breathing were calibrated against set
tidal volumes during conventional mechanical ventilation. Changes in
lung volume after each increase in CDP on HFOV were expressed
as the fold change compared with the previous CDP level. Conclusion Although we believed that the unit’s approach to
HFOV was one of ‘treatment’ rather than ‘rescue’, our results
suggest we are still using HFOV in a ‘rescue’ mode. While our
results support the findings of other studies that earlier initiation of
HFOV shows a trend towards improved outcome in adult patients
with ARDS, further studies are still required to identify appropriate
parameters for selecting patients in a timely manner who may
benefit from HFOV. However, progressive acidosis in ARDS
appears to be a relatively more important predictive criterion than
parameters of failing oxygenation and ventilation. P202 Acoustic monitoring of one-lung ventilation with vibration
response imaging Hemodynamic effects of high-frequency oscillatory
ventilation in acute respiratory distress syndrome Hemodynamic effects of high-frequency oscillatory
ventilation in acute respiratory distress syndrome S Jog, P Akole, S Gadgil, P Rajhans
Deenanath Mangeshkar Hospital and Research Centre, Pune, India
Critical Care 2007, 11(Suppl 2):P198 (doi: 10.1186/cc5358) Introduction High-frequency oscillatory ventilation (HFOV) is a
promising ventilatory modality for ARDS patients having refractory
hypoxemia despite standard ARDS ventilation. Hemodynamic
alterations while switching the patient from volume-controlled
ventilation (VCV) to HFOV are not yet well studied. Introduction High-frequency oscillatory ventilation (HFOV) is a
promising ventilatory modality for ARDS patients having refractory
hypoxemia despite standard ARDS ventilation. Hemodynamic
alterations while switching the patient from volume-controlled
ventilation (VCV) to HFOV are not yet well studied. Results Fifteen out of the total 28 patients were R and 13 were
NR. Both the groups were similar prior to HFOV in terms of
APACHE II score, number of organ failures, PEEP and plateau
pressures, and duration of ventilation before HFOV. The baseline
PO2/FiO2 ratio and improvement in it at 6 hours and 24 hours in
the R group were statistically significantly higher as compared with Objective To evaluate immediate (within 3 hours) hemodynamic
effects of HFOV in ARDS patients with septic shock needing
vasopressor support. S81 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P199)
VCV, volume controlled ventilation. Figure 1 (abstract P199) Conclusion EIT can noninvasively assess lung recruitability and
quantify the changes in global and regional lung volume during
SRM with HFOV in ARDS patients. Conclusion EIT can noninvasively assess lung recruitability and
quantify the changes in global and regional lung volume during
SRM with HFOV in ARDS patients. Correlation of lung vibration and airflow Figure 2 (abstract P202) S Jean, I Cinel, C Tay, Z Wang, D McGinly
Robert Wood Johnson School of Medicine, UMDNJ, Cooper
University Hospital, Camden, NJ, USA
Critical Care 2007, 11(Suppl 2):P203 (doi: 10.1186/cc5363) Introduction Airflow into a mechanically ventilated patient is easily
measured in the inspiratory limb of the ventilator. Regional airflow
inside the lungs, up to this point, is a black box. Vibration response
imaging (VRI) is a novel technology that measures vibration energy
from the lungs to create a real-time structural and functional image
of regional vibration during respiration. Sophisticated surface skin
sensors are placed on the subject’s back to record, analyze and
display vibrations noninvasively. Our goal was to assess the
correlation of vibration measured at the chest wall with airflow into
the lungs. Methods To assess the effect of constant inspiratory flow on lung
vibration, VRI was performed on a mechanically ventilated patient
on assist volume control, and airflow in the tubing was recorded
concurrently. To assess the effect of increasing flow rates on lung
vibration, healthy subjects were recorded several times with VRI
while taking tidal volumes of 200–1,300 ml at the same respiratory
rate. The inspiratory tidal volume was recorded. Figure 2 (abstract P202) Figure 2 (abstract P202) S83
Figure 1 (abstract P203)
Figure 2 (abstract P203) Figure 1 (abstract P203)
Figure 2 (abstract P203) Figure 1 (abstract P203) Figure 1 (abstract P203) inaccurate for the detection of OLV with a high margin, up to 60%
error [1]. Vibration response imaging (VRI) is a novel technology
that measures vibration energy from the lungs and displays
regional intensity in both visual and graphic format. The time from
the start of the procedure to display takes less than 1.5 minutes. We investigated the effectiveness of VRI to detect OLV using a
double-lumen endotracheal tube in lung surgery patients. Methods Double-lumen tubes were placed at the time of surgery. Tracheal and endobronchial lumens were alternately clamped to
produce unilateral lung ventilation of the right and left lungs. VRI
was performed after each occlusion. Two images were excluded a
priori (prior to analysis) due to technical failure (external artifact). Figure 2 (abstract P203) Figure 2 (abstract P203) S83 Results The right and left lung distribution of vibration intensity is
shown in Figure 1. P203 Correlation of lung vibration and airflow Acoustic monitoring of one-lung ventilation with vibration
response imaging Results Four patients with ARDS, who underwent rescue HFOV,
were enrolled. Following the SRM, there was a mean 2.38-fold
increase in PaO2/FiO2 and a 19.7% reduction in PaCO2. EIT
showed a mean 4.66-fold increase in global lung volume, with
preferential ventilation of the ventral regions (59.4% of global
volume change). Despite these differences, both dorsal and ventral
regions showed a similar degree of volume change compared with
their own baseline (V/D of 4.7/4.5-fold). This may be consistent
with a more homogeneous recruitment with HFOV. The inflation
limb of the changes in lung volumes during SRM fitted the
Venegas–Harris equation (r2 = 0.99). I Cinel, S Jean, I Gratz, E Deal, C Tay, J Littman
Robert Wood Johnson School of Medicine, UMDNJ, Cooper
University Hospital, Camden, NJ, USA
Critical Care 2007, 11(Suppl 2):P202 (doi: 10.1186/cc5362) Introduction Inadvertent endobronchial intubation and one-lung
ventilation (OLV) with a standard endotracheal tube may lead to
serious complications, such as a nonventilated lung, pneumothorax
and hypoxemia. Auscultation of breath sounds was found to be Introduction Inadvertent endobronchial intubation and one-lung
ventilation (OLV) with a standard endotracheal tube may lead to
serious complications, such as a nonventilated lung, pneumothorax
and hypoxemia. Auscultation of breath sounds was found to be S82 Available online http://ccforum.com/supplements/11/S2 P203 Figure 1 (abstract P202) P205 Functional residual capacity measurement during
mechanical ventilation in order to find the optimal positive
end-expiratory pressure Introduction Focusing on lung-protective ventilation, the analysis
of nonlinear dynamic respiratory mechanics appears crucial. Based
on the SLICE method we developed the Gliding-SLICE method as
a tool to determine respiratory system mechanics. This tool was
tested in a nonlinear water-filled two-chamber lung model. I Bikker, D Reis Miranda, J Van Bommel, J Bakker, D Gommers
Erasmus MC, Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P205 (doi: 10.1186/cc5365) Introduction In patients with ALI/ARDS, a protective ventilation
strategy has been introduced in order to diminish ventilator-
induced lung injury. It has become clear that these patients require
sufficient levels of PEEP to prevent alveolar derecruitment, but also
not too much PEEP that alveolar overdistension occur. To achieve
the optimal level of PEEP in patients with ALI/ARDS, different
concepts have been introduced. GE Healthcare, along with Dr Ola
Stenqvist, has developed a technology to measure functional
residual capacity (FRC) in ventilated patients without interruption
of the ventilation. The aim of this study was to test the feasibility of
this device and to test whether decreasing the PEEP affects FRC
in mechanically ventilated patients with and without lung disease. Methods The classic SLICE method [1] determines parameters of
the respiratory system for abutted volume ranges. The Gliding-
SLICE method enhances this method by moving a window of
analysis along the volume axis. This way, a quasi-continual course
of intratidal mechanics can be determined. To test the new method
we build up a physical model that consists of two connected
chambers filled with water. During inspiration water is displaced
from one chamber to the other resulting in a counter pressure. Using wedges of certain shapes we simulated volume-dependent
nonlinear compliances. Results Using the Gliding-SLICE method we determined a
nonlinear course of compliance in a patient (Figure 1) and in model
data (Figure 2). Methods For this survey we examined 10 patients under mechanical
ventilation. The FRC examinations were performed with the
Engström Carestation equipped with the FRC Inview™ monitoring
feature. FRC is determined using the change of lung nitrogen volume
after a step change in the inspired oxygen fraction. With this system,
there is no need to use supplementary gases or specialized gas
monitoring devices. Furthermore, a series of FRC measurements can
automatically be obtained at different PEEP levels that can be
chosen prior to the measurement. Correlation of lung vibration and airflow The mean percentage change of vibration
intensity clearly demonstrates the increased vibration in ventilated
lungs (89.1 ± 5.47% vs 10.9 ± 5.4%, P < 0.05) (Figure 2). Conclusions
Auscultation
is
insensitive
to
endobronchial
intubation and chest radiography may not be immediately available. VRI offers the potential to rapidly and noninvasively determine
endobronchial intubation. Currently VRI is performed in the sitting
position, but the capability of supine imaging will soon be available. Reference 1. Brunel
W,
et
al.:
Assessment
of
routine
chest
roentgenograms and the physical examination to confirm
endotracheal tube position. Chest 1989; 96:1043-1045. S83 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Reference
1. Guttmann et al.: Technol Health Care 1994, 2:175-191. Figure 2 (abstract P204) Figure 2 (abstract P204) Figure 2 (abstract P204) Results In the mechanically ventilated patient, when there is
minimal flow, the vibration was at its lowest. When flow begins at
the ventilator, the vibration measured over the lungs increases and
when the flow stops, the vibration decreases. An inspiratory hold
was performed to separate inspiratory from expiratory vibrations
(Figure 1). As the subject takes increasing tidal volumes, the
vibration during the breath cycle increases linearly. A sample
subject is shown in Figure 2 (R2 = 0.81). Conclusion Vibration measured using VRI correlates with lung
airflow. Given the difficulty in assessing airflow in the lungs,
measuring lung vibration could potentially serve as a surrogate for
regional lung airflow. P204 The Gliding-SLICE method: an enhanced tool for
estimation of intratidal respiratory mechanics Reference Reference
1. Guttmann et al.: Technol Health Care 1994, 2:175-191. S Schumann1, C Stahl1, D Steinmann1, K Möller2, J Guttmann1
1University Hospital, Freiburg, Germany; 2HFU, Furtwangen,
Germany
Critical Care 2007, 11(Suppl 2):P204 (doi: 10.1186/cc5364) P205 During this procedure, all
ventilator settings will remain constant other than the FiO2 and the
PEEP settings. In patients with ALI, the PEEP was decreased from
25 to 5 cmH2O in five steps and the FRC was measured. In the
patients without lung disease, PEEP was decreased from 15 to
0 cmH2O in four steps and the FRC was measured. Conclusion The Gliding-SLICE method allows one to calculate
mechanical parameters of the respiratory system quasi-continually. This allows a more intuitive interpretation of data. The method is
not limited to principle constrictions but can be enhanced by
ventilatory maneuvers; for example, for separated view on
inspiratory and expiratory respiratory mechanics. P208 Dry powder nebulization of a recombinant surfactant
protein C-based surfactant for treatment of acute
respiratory distress syndrome C Ruppert, T Kuchenbuch, S Schmidt, P Markart, T Gessler,
T Schmehl, W Seeger, A Guenther
University of Giessen Lung Center, Giessen, Germany
Critical Care 2007, 11(Suppl 2):P208 (doi: 10.1186/cc5368) Results The R-squared (R2) values for the correlation between
lnPaO2 and %Vnon of lung and the slice combinations juxta, 3new
and 3old were 0.61, 0.60, 0.57 and 0.55, respectively. The %Vnon
of lung correlated best with the %Vnon of slice combinations juxta
and 3new (R2 = 0.96 and 0.95, respectively). Comparison of these
slice combinations with lung also resulted in the least bias in the
Bland–Altman analyses (6.3 and 5.9%, respectively). R2 for the
correlation between lung and 3old was 0.93, and the bias for lung
vs 3old in the Bland–Altman analysis was 6.8%. Introduction Nebulization of pulmonary surfactant for treatment of
ARDS represents a desirable therapeutic approach but was
hitherto impossible under clinical conditions due to the technical
limitations of currently available devices. In the present study we
investigated a new dry powder nebulizer for administration of a
recombinant surfactant protein C (rSP-C)-based surfactant. Introduction Nebulization of pulmonary surfactant for treatment of
ARDS represents a desirable therapeutic approach but was
hitherto impossible under clinical conditions due to the technical
limitations of currently available devices. In the present study we
investigated a new dry powder nebulizer for administration of a
recombinant surfactant protein C (rSP-C)-based surfactant. y
Conclusion Depending on the precision required, the use of single
juxtadiaphragmatic CT slices can help to speed up the analysis
process and thereby propel the clinical implementation of CT-
derived information. Our data suggest that juxtadiaphragmatic
slices may be better suited than the ‘traditional’ combination of
apical, hiliar and juxtadiaphragmatic slices. Methods The nebulizer device consists of a cylindrical glass
housing that, at the bottom, ends up in a spherical lower housing
part that serves as the dry powder reservoir. A gas inlet portion
with a nozzle at its end is coaxially aligned with the housing, almost
reaches the bottom of the dry powder reservoir, and induces
aerosol generation when gas pressures between 1 and 2 bar are
applied. The upper portion of the housing contains a cap with an
aerosol exit port. Several nozzles ensure a discharge of unsuitably
large aerosol particles. Aerosol characteristics were determined by
laser diffractometry. Available online http://ccforum.com/supplements/11/S2 Results At Time 1, the control group (n = 21) had ratio of arterial
partial pressure of oxygen to fraction of inspired oxygen (PaO2/
FiO2) and partial arterial carbon dioxide pressure (PaCO2) of
167.7 ± 56.2 and 40.3 ± 10.1, respectively, and the intervention
group (n = 19) had PaO2/FiO2 of 180.5 ± 67.0 and PaCO2 of
38.6 ± 10.5. At Time 2, the control group had, respectively, PaO2/
FiO2 and PaCO2 of 165.9 ± 63.8 and 38.9 ± 10.3, and the inter-
vention group of 177.2 ± 4.5 and 39.0 ± 10.8. No variable was signifi-
cantly different between the groups at Time 1 and Time 2 (P > 0.05). Conclusion The proposed maneuver was not beneficial for gas
exchange in the sample studied. Methods The patients with the diagnosis of ALI and ARDS who met
the inclusion criteria were randomized to one of the two groups:
those of the intervention group were subjected to a pulmonary
expansion and bronchial disobstruction maneuvers, for approximately
10 minutes by the association of the following physiotherapy
techniques:
sighs,
side-lying
position,
expiratory
rib-cage
compression and endotracheal suctioning with a closed system and
after observed for 10 minutes; the patients of the control group did
not receive any treatment, they were only observed for 20 minutes. Ventilatory parameters and arterial blood gases were measured
before (Time 1) and 10 minutes after the procedures (Time 2). The
analysis of variance test for repeated measurements was used for
comparing variables at different times. Results are shown as the
mean and standard deviation. The significant level was P < 0.05. P208 The efficacy of an inhalative rSP-C surfactant
application was assessed in three animal models of acute lung
injury, including rabbits with acute lung injury due to either
repetitive lavage with prolonged and injurious ventilation, or due to
inhalative application of bleomycin at day 4, and bleomycin-
challenged, spontaneously breathing mice. Analysis of the nonaerated lung volume in combinations of
single computed tomography slices – is extrapolation to
the entire lung feasible? Analysis of the nonaerated lung volume in combinations of
single computed tomography slices – is extrapolation to
the entire lung feasible? AW Reske, P Hepp, C Heine, K Schmidt, M Seiwerts,
U Gottschaldt, AP Reske
Universitaetsklinikum Leipzig, Germany
Critical Care 2007, 11(Suppl 2):P206 (doi: 10.1186/cc5366) Introduction The nonaerated lung volume (Vnon) can be quantified
from computed tomography (CT) images. Analysis of the CT slices
covering the entire lung is time-consuming and thus limits potential
clinical and experimental applications. This could be improved by
analyzing only a few representative CT slices. The number and ana-
tomical location of CT images required for analyses that are represen-
tative for the entire lung, however, is discussed controversially. Results At Time 1, the control group (n = 21) had ratio of arterial
partial pressure of oxygen to fraction of inspired oxygen (PaO2/
FiO2) and partial arterial carbon dioxide pressure (PaCO2) of
167.7 ± 56.2 and 40.3 ± 10.1, respectively, and the intervention
group (n = 19) had PaO2/FiO2 of 180.5 ± 67.0 and PaCO2 of
38.6 ± 10.5. At Time 2, the control group had, respectively, PaO2/
FiO2 and PaCO2 of 165.9 ± 63.8 and 38.9 ± 10.3, and the inter-
vention group of 177.2 ± 4.5 and 39.0 ± 10.8. No variable was signifi-
cantly different between the groups at Time 1 and Time 2 (P > 0.05). Conclusion The proposed maneuver was not beneficial for gas
exchange in the sample studied. Methods The percentage of Vnon (%Vnon) relative to the total lung
volume was quantified in CT-image series (n = 21) of sheep with
gross anesthesia-induced atelectasis. This was performed for
different combinations of number and anatomical location of CT
slices and the results were compared with the %Vnon of the entire
lung (lung). The combinations were: one juxtadiaphragmatic slice
(juxta), three apical, hiliar and juxtadiaphragmatic slices (3old), and
three consecutive juxtadiaphragmatic slices (3new). The correla-
tion between %Vnon and the arterial oxygen partial pressure (PaO2)
was examined for all combinations. The PaO2 was measured at the
time of the CT and transformed logarithmically (lnPaO2) to linearize
the relation between PaO2 and %Vnon. Linear regression and
Bland–Altman plots were used for statistical analysis. Figure 1 (abstract P204) 2
p
Results The best FRC measurements were obtained in well-
sedated patients during controlled mechanical ventilation. During
pressure support ventilation, a constant breathing pattern is
necessary for accurate FRC measurements. In patients that
received pressure support ventilation, FRC values were lower at
the highest studied PEEP level. In two patients that received
controlled ventilation, lower levels of FRC were found at the
highest PEEP level but this was due to a pneumothorax that was
diagnosed a day later. In patients with ALI, the FRC decreased
after each PEEP reduction step. However, the FRC decreased
more when PEEP was lowered from 15 to 10 cmH2O in these
patients. In patients without lung disease, the FRC did not S84 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 decrease after PEEP was reduced from 15 to 5 cmH2O but
decreased after PEEP was reduced from 5 to 0 cmH2O. Conclusion Accurate measurements of FRC are obtained during a
constant breathing pattern that is easier to obtain during controlled
ventilation in comparison with pressure-support ventilation. In
patients with ALI/ARDS, the FRC decreased during each PEEP
reduction, but whether the largest change in FRC indicates the
optimal PEEP needs further research. decrease after PEEP was reduced from 15 to 5 cmH2O but
decreased after PEEP was reduced from 5 to 0 cmH2O. Conclusion Accurate measurements of FRC are obtained during a
constant breathing pattern that is easier to obtain during controlled
ventilation in comparison with pressure-support ventilation. In
patients with ALI/ARDS, the FRC decreased during each PEEP
reduction, but whether the largest change in FRC indicates the
optimal PEEP needs further research. few studies on the effect on gas exchange in patients with acute
lung injury (ALI) and acute respiratory distress syndrome (ARDS)
and physiotherapy techniques. The purpose of this study was to
assess the effect of a pulmonary expansion and disobstruction
maneuver with a closed system on the gas exchange of patients
with ALI and ARDS. Conclusion Accurate measurements of FRC are obtained during a
constant breathing pattern that is easier to obtain during controlled
ventilation in comparison with pressure-support ventilation. In
patients with ALI/ARDS, the FRC decreased during each PEEP
reduction, but whether the largest change in FRC indicates the
optimal PEEP needs further research. S
Methods The patients with the diagnosis of ALI and ARDS who met
the inclusion criteria were randomized to one of the two groups:
those of the intervention group were subjected to a pulmonary
expansion and bronchial disobstruction maneuvers, for approximately
10 minutes by the association of the following physiotherapy
techniques:
sighs,
side-lying
position,
expiratory
rib-cage
compression and endotracheal suctioning with a closed system and
after observed for 10 minutes; the patients of the control group did
not receive any treatment, they were only observed for 20 minutes. Ventilatory parameters and arterial blood gases were measured
before (Time 1) and 10 minutes after the procedures (Time 2). The
analysis of variance test for repeated measurements was used for
comparing variables at different times. Results are shown as the
mean and standard deviation. The significant level was P < 0.05. P211 Results Fifty-eight critically ill patients undergoing mechanical
ventilation were included. Following the BAL, compliance of the
respiratory system (Crs) decreased from 50.9 ± 36.1 to 35.6 ±
14.8 ml/cmH2O (P < 0.01) and airway resistance increased from
16.2 ± 7.6 to 18.1 ± 11.3 cm H2O/l/seg (P < 0.05); 90 minutes
later, both parameters had returned to pre-BAL values (P = not
significant). Patients who showed >20% decrease in Crs had
higher pre-BAL Crs than patients with less severe decrease (55.8
± 20.1 vs 36.9 ± 14.1; P < 0.001). On the contrary, neither pre-
BAL airway resistance nor the extension of the radiographic
infiltrates were related to the changes in respiratory mechanics. P207 Pulmonary expansion and disobstruction maneuver with a
closed system in patients with acute lung injury and acute
distress syndrome, and its effect on gas exchange J Belato, S Barreto, C Santos, S Vieira
Hospital de Clínicas de Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P207 (doi: 10.1186/cc5367) Introduction Respiratory physiotherapy is ever more utilized for the
treatment of critical patients. However, it is known that there are Introduction Respiratory physiotherapy is ever more utilized for the
treatment of critical patients. However, it is known that there are Results The generated aerosol had a mass median aerodynamic
diameter of 1.6 µm, with 85% of all particles being smaller than S85 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin lesions at the bedside in the emergency department is difficult. Clinical examination (CE) and chest X-ray (X-ray) have limited
sensibility and specificity. Contrast-enhanced computed tomo-
graphy (CT scan) is the gold standard. CT scan has limitations: it
takes time to be performed, implies transport of severely injured
patients, and has ionising effects. Thoracic ultrasonography (US)
can be quickly performed at the bedside in the emergency room. It
has good diagnosis accuracy in ARDS patients [2]. The purpose of
this study is to evaluate the diagnosis accuracy of US in severely
injured patients in the emergency room. 5 µm, and the average mass of surfactant being nebulized under
these conditions was approximately 1 g/min. Biochemical and
biophysical studies showed that the composition and surface
tension reducing properties of the rSP-C surfactant remained
unaltered after nebulization. In both rabbit models, administration of
130 mg/kg body weight rSP-C surfactant resulted in a far-reaching
restoration of gas exchange and compliance. In bleomycin-
challenged, spontaneously breathing mice, surfactant aerosoliza-
tion resulted in a restoration of compliance. Conclusions Nebulizer characteristics and results from the in vivo
studies suggest that the herein-described dry powder nebulizer
might proffer for surfactant therapy of ARDS. Methods We prospectively evaluated 90 patients (median age: 41
(7–89) years) who were admitted to the emergency room of the
Grenoble University Hospital over a period of 9 months. Pneumothorax, hemothorax and alveolar consolidation were diag-
nosed by CE, X-ray and US. The physician who performed the US
was not involved in the patient’s management. The diagnosis
accuracy of each technique is compared with the CT scan
interpreted by the radiologist. P209 Changes in respiratory mechanics after fiberoptic
bronchoscopy with bronchoalveolar lavage in mechanically
ventilated patients
Á Estella García, A Gil Cano, J Díaz Monrove, I Monge García
Critical Care Unit, Hospital of Jerez, Spain
Critical Care 2007, 11(Suppl 2):P209 (doi: 10.1186/cc5369) Changes in respiratory mechanics after fiberoptic
bronchoscopy with bronchoalveolar lavage in mechanically
ventilated patients Á Estella García, A Gil Cano, J Díaz Monrove, I Monge García
Critical Care Unit, Hospital of Jerez, Spain
Critical Care 2007, 11(Suppl 2):P209 (doi: 10.1186/cc5369) Results Sixty percent of patients had a chest trauma IGS II 22
(8–104), ISS 20 (0–59), thorax AIS 2 (0–5), SOFA 1 (0–11),
oxygen saturation at the entrance 100% (74–100), mechanical
ventilation for 56% of patients. We studied 179 hemithorax. For
hemothorax (n = 16), the sensitivity/specificity/positive predictive
value/negative predictive values (%) were CE: 13/95/18/92; X-ray:
13/95/20/92; US: 63/95/56/96. For pneumothorax (n = 30), CE:
20/96/50/86; X-ray: 17/100/100/86; US: 53/93/62/91. For
alveolar consolidation (n
= 100), CE: 17/95/81/47; X-ray:
29/98/94/52; US: 69/82/83/67. Introduction Nonuniform findings have been reported about the
effects of bronchoalveolar lavage (BAL) on respiratory mechanics. Objectives (1) To study the effects of BAL on respiratory
mechanics in mechanically ventilated patients with suspected
pneumonia, and (2) to find out whether these effects are related to
the extension of radiographic infiltrate and preceding respiratory
mechanics measurements. Introduction Nonuniform findings have been reported about the
effects of bronchoalveolar lavage (BAL) on respiratory mechanics. Conclusion Ultrasonography has a better sensitivity than CE and
X-ray with a comparable specificity. In the emergency room it is a
reliable modality for the diagnosis of pneumothorax, hemothorax
and alveolar consolidation in the severely injured patient. References Methods BAL was performed with 150 ml sterile isotonic saline in
three aliquots of 50 ml. Respiratory mechanics (static compliance and
airway resistance) was measured using the rapid airway occlusion
technique immediately before and after the BAL and 90 minutes later. The heart rate, arterial blood pressure and body temperature were
recorded continuously in all patients. Patients were classified
according to the presence of unilateral or bilateral infiltrates. 1. Klein et al.: Anaesthesist 2006, 55:1172-1188. 2. Lichtenstein et al.: Anesthesiology 2004, 100:9-15. 1. Klein et al.: Anaesthesist 2006, 55:1172-1188. 2. Lichtenstein et al.: Anesthesiology 2004, 100:9-15. 1. Klein et al.: Anaesthesist 2006, 55:1172-1188. 2. Lichtenstein et al.: Anesthesiology 2004, 100:9-15. Prehospital emergency endotracheal intubation using the
Bonfils intubation fiberscope C Byhahn1, R Breitkreutz1, S Viehmeyer1, F Walcher1, B Zwissler2
1J.W. Goethe-University Hospital, Frankfurt, Germany; 2Klinikum
der Johann Wolfgang Goethe University, Frankfurt, Germany
Critical Care 2007, 11(Suppl 2):P211 (doi: 10.1186/cc5371) Objective Difficult intubating conditions are prevalent in 7–10% of
patients who require out-of-hospital emergency endotracheal intu-
bation. Airway anatomy can further be deteriorated through trauma,
bleeding, and the use of cervical spine (CS) immobilization collars. We evaluated the feasibility of the Bonfils intubation fiberscope for
prehospital emergency endotracheal intubation. Conclusions (1) BAL in mechanically ventilated patients can lead
to a significant but transitory deterioration on pulmonary mechanics
characterized by a decrease in Crs and an increase in airway
resistance. (2) Patients with better initial Crs showed the more
severe affectation. p
p
g
y
Materials and methods The Bonfils intubation fiberscope (Karl
Storz GmbH, Tuttlingen, Germany) is a reusable, rigid, straight
fiberoptic device with a 40° curved tip, 40 cm long and 5 mm in
diameter. A flexible eyepiece is mounted on the handle of the
scope. The fiberscope has a connector that fits onto the 15-mm
tracheal tube adapter and thereby allows oxygen insufflation. A
cold light source or a small battery handle (powered by two 1.5 V
alkaline batteries) can be attached to the stylet handle. The tip of
the Bonfils intubation fiberscope is positioned just proximal to the
tip of the attached endotracheal tube, thereby preventing the lens
from being soiled with blood or secretions. Having adopted the
Bonfils technique in our institution, we felt that because of its
battery-powered light source the Bonfils intubation fiberscope
could also be used in prehospital settings, independent of a P210 Diagnosis accuracy of thoracic ultrasonography in severely
injured patients A Hyacinthe1, C Broux1, G Francony1, G Ferretti2, J Payen1,
C Jacquot1
1Service de réanimation polyvalente et chirurgicale, CHU,
Grenoble, France; 2Radiologie, CHU, Grenoble, France
Critical Care 2007, 11(Suppl 2):P210 (doi: 10.1186/cc5370) A Hyacinthe1, C Broux1, G Francony1, G Ferretti2, J Payen1,
C Jacquot1
1 Introduction Thirty-three percent of severely injured patients suffer
from thoracic trauma [1]. Diagnosis of pleural and pulmonary Introduction Thirty-three percent of severely injured patients suffer
from thoracic trauma [1]. Diagnosis of pleural and pulmonary S86 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P212)
Airway equipment available on ICUs. A score of 6/6 is considered the
minimum. Figure 1 (abstract P212) 110/220 V cold light source. After appropriate inhospital training
with the Bonfils intubation in anesthetized patients, our hospital’s
mobile emergency unit staffed with an emergency physician was
equipped with a battery-powered Bonfils intubation fiberscope. Results During 123 missions, 15 adult patients underwent pre-
hospital endotracheal intubation (cardiac arrest n = 9, multiple
injuries n = 4, drug poisoning n = 1, pulmonary edema n = 1) with
the Bonfils intubation fiberscope, the use of which was either
planned (n = 13) or unplanned (n = 2). All intubations were
successful in the first attempt, even in two cardiac arrest victims
who had an unexpected difficult airway (Cormack&Lehane grade IV
under direct laryngoscopy). In those patients with multiple injuries
the cervical immobilization collar did not need to be unfastened or
removed for endotracheal intubation. Sufficient retropharyngeal
space – which is mandatory for sufficient use of the Bonfils – was
created by a digital jaw thrust maneuver in the first three patients. Using a standard Mackintosh laryngoscope blade significantly
enhanced ease of insertion of the Bonfils fiberscope and
visualization of the glottic aperture, thereby decreasing the
procedure time from 35–40 seconds to 20–25 seconds. Conclusion Despite this first promising series of in-the-field use,
physicians and paramedics should familiarize themselves with the
Bonfils device under optimal clinical conditions before using it
under emergency or prehospital conditions. In our experience, the
learning curve with the Bonfils device is steep, and 10 intubations
supervised by an instructor usually prove effective for achieving
sufficient skills to use the Bonfils on one’s own and under less
optimal conditions. In summary, we believe that the Bonfils
fiberscope will prove its value as an additional airway management
device in both, emergency and prehospital settings. J Koyama Acknowledgement The Bonfils intubation fiberscope was
generously provided by Karl Storz GmbH, Tuttlingen, Germany. Introduction Occasionally, rescuers are confronted with a hard
situation to establish tracheal intubation compared with doctors in
the anesthetic room. Especially in the confined space, the tracheal
intubation must enter technical difficulties with any supporting
device. This may be caused by the fact that there was no device
developed specially from a standpoint in the clinical emergency use. Objective The AirWay Scope (AWS) is one of the newest
intubation devices, manufactured using modern technology to
alleviate the tracheal intubation in emergency scenes. The AWS is
equipped with a full-colored CCD, a LCD monitor and a specially
configured introducer guiding a tracheal tube into the glottis
(Figure 1). The aim of this study is to confirm the potential of the
AWS as an intubation-supporting device in emergency scenes. M th d Si d
i
h
d
ll d i P212 P210 Airway equipment available on ICUs. A score of 6/6 is considered the
minimum. P213
Potential of the AirWay Scope for tracheal intubation in a
confined space
J Koyama
Shinshu University, Matsumoto, Japan
Critical Care 2007, 11(Suppl 2):P213 (doi: 10.1186/cc5373) Airway equipment on the intensive care unit for
management of the unanticipated difficult intubation J Craig1, R Green1, B Kyle1, M Jonas2
1Poole General Hospital, Poole, UK; 2Southampton General
Hospital, Southampton, UK
Critical Care 2007, 11(Suppl 2):P212 (doi: 10.1186/cc5372) Introduction This study was designed to assess the ability of ICUs
to deal with the unanticipated difficult intubation. The ICU is a
location in which the incidence of difficult intubation has been
found to be significantly higher than in theatre (8–22.5% vs 1.5%). Method We contacted all adult general ICUs in the South of
England and invited the physician responsible for airway
management to take part in a structured interview. The interview
was designed to follow the Difficult Airway Society (DAS)
guidelines. We designed six equipment-related questions that
identified a unit as achieving the minimum levels of equipment
necessary. These
included
availability
of
laryngoscopes,
capnography, LMA/ILMA, and rescue techniques. Method Six doctors in the emergency department were enrolled in
this study. All doctors have experienced using the AWS in cases
on the operation table but have no experience in special situations
such as patients on the ground (POG) or no space over the head
of the patient (NSH). Doctors tried intubation with the AWS and
Macintosh Laryngoscope (Mac) in the simulated POG and NSH
situations using a Laerdal Airway manikin. Technical training was
not carried out in advance. The NSH/Mac situation was not
investigated because it was theoretically impossible. The time to
intubate (TTI) was recorded. Method We contacted all adult general ICUs in the South of
England and invited the physician responsible for airway
management to take part in a structured interview. The interview
was designed to follow the Difficult Airway Society (DAS)
guidelines. We designed six equipment-related questions that
identified a unit as achieving the minimum levels of equipment
necessary. These
included
availability
of
laryngoscopes,
capnography, LMA/ILMA, and rescue techniques. Result All doctors successfully established intubation in each
situation, POG/Mac, POG/AWS and NSH/AWS. Although the
intubation of a manikin having no space over the head was thought
to be difficult without prior training, all doctors successfully
achieved the intubation from the foot using the AWS. The TTI (s)
was 12.0 ± 1.5 in POG/Mac, 7.4 ± 1.1 in POG/AWS and
12.9 ± 1.4 in NSH/AWS. The TTI with AWS in POG situation was
significantly shorter than that with Mac (P = 0.0135). Results Forty-five of 51 units responded (88%). Mandatory
equipment levels are shown in Figure 1. P213 Potential of the AirWay Scope for tracheal intubation in a
confined space J Koyama
Shinshu University, Matsumoto, Japan
Critical Care 2007, 11(Suppl 2):P213 (doi: 10.1186/cc5373) J Koyama
Shinshu University, Matsumoto, Japan
Critical Care 2007, 11(Suppl 2):P213 (doi: 10.1186/cc5373) A comparison of two types of new bronchial blockers,
Uniblocker™ and Coopdech endotracheal blocker tube, for
one-lung ventilation during thoracoscopy T Iizuka1, M Tanno2, Y Hamada1, T Shiga1, Y Ohe1
1Toho University Medical Center Ohashi Hospital, Meguro, Tokyo,
Japan; 2National Mito Medical Center, Mito, Japan
Critical Care 2007, 11(Suppl 2):P214 (doi: 10.1186/cc5374) Methods Benchtop model. Four tracheal tubes (8 mm internal
diameter) were studied; the LoTrach, Portex SoftSeal, Microcuff and
Mallincrokdt HiLo Evac. The model trachea had an internal diameter
of 2.4 cm and the cuff was inflated with a Tracoe constant pressure
device. The cuff was overpressured while fluid was instilled above
the cuff to a height of 50 cm. The stopwatch was started as the
pressure was reduced to the test pressure of 30 cmH2O. The rate of
fall of the resulting column of fluid was then measured. Introduction The purpose of this study was to compare the use of a
wire-guided bronchial blocker, Uniblocker™ (Fuji Systems Corporation,
Tokyo, Japan), with a spread type of bronchial blocker, Coopdech
endotracheal blocker tube (Daiken Medical Corporation, Osaka,
Japan), for lung isolation during elective thoracic surgical cases. Clinical study. Intubated patients underwent a staged recruitment
manoeuvre while the intracuff pressure was maintained with a Tracoe
cuff inflator. The PEEP was set to 15 cmH2O and then increased in
5 cmH2O increments every 5 seconds until 40 cmH2O was
achieved. A second observer auscultated the anterior neck and the
pressure at which air leak was heard was recorded. Two tubes were
studied; LoTrach (at 80 cmH2O intracuff pressure = 30 cmH2O
calculated wall pressure) and Portex Soft Seal (30 cmH2O). p
g
g
g
Materials and methods Twenty ASA I–II patients signed written
informed consent before being enrolled into the study. We
designed a prospective, randomized trial to compare the
effectiveness of lung isolation among the two types of bronchial
blockers: Uniblocker™ group (UBB; n = 10), and Coopdech
endotracheal blocker tube group (CBB; n = 10). Patients were
randomized to intubate with a single-lumen tube with concomitant
use of a UBB or a CBB. Both groups were subdivided in two:
bronchial blocker placed in the right mainstem bronchus
(UBBR/CBBR), and in the left mainstem bronchus (UBBL/CBBL). Comparisons between groups included: (1) the number of
unsuccessful placement attempts with the blinded insertion
technique, (2) the number of malpositions of the devices, (3) the
time required to place the device in the correct position, (4)
surgical satisfaction with the lung deflation, (5) complications and
(6) the quality of lung deflation. P214 A comparison of two types of new bronchial blockers,
Uniblocker™ and Coopdech endotracheal blocker tube, for
one-lung ventilation during thoracoscopy P215 Comparison of the LoTrach and the Portex Soft Seal cuff:
tracheal wall pressure and fluid leakage in a benchtop
study and a clinical study
L Evans, M Blunt, C Arunachalam, P Young
Queen Elizabeth Hospital, King’s Lynn, UK
Critical Care 2007, 11(Suppl 2):P215 (doi: 10.1186/cc5375) Comparison of the LoTrach and the Portex Soft Seal cuff:
tracheal wall pressure and fluid leakage in a benchtop
study and a clinical study L Evans, M Blunt, C Arunachalam, P Young
Queen Elizabeth Hospital, King’s Lynn, UK
Critical Care 2007, 11(Suppl 2):P215 (doi: 10.1186/cc5375) Introduction The objective of the study is to demonstrate two
methods of measuring tracheal wall pressure (in vitro and in
patients), with the LoTrach (LVLP) cuff and with conventional high-
volume low-pressure (HVLP) cuffs. The LoTrach (VTSL, Singapore)
is a new tracheal tube designed for use for mechanical ventilation
in the critically ill. The LoTrach has been shown to prevent the
ubiquitous problem of micro-aspiration of secretions associated
with conventional HVLP cuffs [1]. Aspiration prevention is achieved
by the properties of the LoTrach’s low-volume low-pressure (LVLP)
cuff, and these have been previously described [1,2]. It is important
that, alongside achieving aspiration prevention, there is also
tracheal wall pressure control. The LoTrach LVLP cuff is calibrated
such that the sum of the elastic forces within the cuff remain
constant throughout the inflation profile. Thus, at the working intra-
cuff pressure of 80 cmH2O, only a consistent and acceptable
30 cmH2O is transmitted to the tracheal wall [2]. Conclusion With its portability, easy handiness, excellent visual
information and the tube-guiding function of the introducer, the
AWS may have potential to alleviate the various difficulties in
intubation in emergency scenes, even in a confined space. Conclusion With its portability, easy handiness, excellent visual
information and the tube-guiding function of the introducer, the
AWS may have potential to alleviate the various difficulties in
intubation in emergency scenes, even in a confined space. Airway equipment on the intensive care unit for
management of the unanticipated difficult intubation Results Forty-five of 51 units responded (88%). Mandatory
equipment levels are shown in Figure 1. Discussion Difficult intubation is more likely on the ICU, yet only
20% of units keep sufficient equipment immediately available. The
most serious omissions were the 29% of units without a rescue
technique immediately available and the one-third of units not
routinely employing capnography. S87 Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P213) A comparison of two types of new bronchial blockers,
Uniblocker™ and Coopdech endotracheal blocker tube, for
one-lung ventilation during thoracoscopy 2
Results Conventional HVLP cuffs do not prevent leakage of fluid
past the cuff, hence the negative slope on the graphs. The LoTrach
cuff does not leak and therefore the line is horizontal (see Figure
1). The clinical study shows that both the LoTrach and Portex cuffs
demonstrate a gross air leak at equal and acceptable tracheal wall
pressures at 33.4 and 29.7 cmH2O, respectively (see Table 1). Table 1 (abstract P215)
Number of
Tracheal wall
Type of tube
measurements
pressure (cmH2O)
LoTrach (LVLP)
45
29.7 (SD = 3.7)
Soft Seal (HVLP)
41
33.4 (SD = 3.1) Safety of semi-open percutaneous tracheotomy when
performed in critically ill burn patients K Gerold, K Dhanjani, L Price, D Noppenberger, S Milner
Johns Hopkins School of Medicine, Baltimore, MD, USA
Critical Care 2007, 11(Suppl 2):P216 (doi: 10.1186/cc5376) Results One hundred and eight tracheostomies were performed in
intensive care in the 2-year period. Sixty-two patients were
discharged with tracheostomy in situ and were reviewed by the
outreach team for a cumulative total of 710 days until decannulation. There were 383 days whereby patients with a tracheostomy in situ
had been noninvasively ventilated. There were three reported critical
events relating to tracheostomy and no deaths. Introduction Lung injury and generalized edema from a burn and
resuscitation complicates airway management and patient care. The need for long-term ventilation and multiple surgeries warrant
early tracheostomy. Percutaneous techniques are well described;
however, the burned and swollen neck increases all of its
recognized complications. We report a modified semi-open
technique for performing percutaneous tracheotomies (PT) in
acutely burned patients, which we consider safer. Conclusion More than 60% of patients who had a tracheostomy
inserted are discharged from critical care with a tracheostomy in
situ. With the support of the outreach team these patients were
successfully managed in Level 2 and Level 1 areas. This reduced
the requirement for critical care (Level 3) bed-days. There was a
low rate of complications. We concluded that outreach services
can facilitate early and safe discharge of tracheostomy patients
from critical care. Methods We reviewed the medical records of 20 patients
admitted to a regional burn center requiring tracheostomy for
prolonged mechanical ventilation. The procedure took place in the
OR if burn excision was planned; otherwise it was performed at the
bedside. The Blue Rhino tracheostomy kit was used for all PT. Major differences from other approaches included dissecting down
to the pretracheal fascia, allowing the trachea to be seen and
palpated; bleeding was controlled using an electrocautery, and
blood vessels were retracted from the field or ligated. The trachea
was palpated as the endotracheal tube was withdrawn into the
proximal trachea and a flexible bronchoscope was used only to
confirm the proper placement of the guidewire. Proper placement
of the tracheal tube was confirmed by capnography. In patients
with a deep trachea due to severe neck swelling, a proximal-long
tracheostomy tube was substituted for the standard one. In the
event that the airway or ventilation became compromised, this
technique could be converted rapidly to an open procedure. P218 Prevention of airway control loss during percutaneous
tracheostomy References References
1. Young PJ, Pakeerathan S, Blunt MC, Subramanya S: A low-
volume, low-pressure tracheal tube cuff reduces pul-
monary aspiration. Crit Care Med 2006, 34:632-639. 2. Young PJ, Young WH: Inflation of a pressure-limited cuff
inside a model trachea. Med Eng Phys 2003, 25:465-473. 1. Young PJ, Pakeerathan S, Blunt MC, Subramanya S: A low-
volume, low-pressure tracheal tube cuff reduces pul-
monary aspiration. Crit Care Med 2006, 34:632-639. Methods A retrospective analysis of the ICU database was
undertaken to identify all patients who had a tracheostomy
(percutaneous or surgical) inserted in the ICU, and a chart review
of patients discharged from the ICU with a tracheostomy in situ
was performed. The following variables were collected: patient
demographics; diagnosis; number of days of tracheostomy in situ;
number of days on noninvasive ventilation (CPAP); and tracheos-
tomy-related complications. A review of the risk management
database was performed to identify any tracheostomy-related
reported adverse events. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 References
1. Young PJ, Pakeerathan S, Blunt MC, Subramanya S: A low-
volume, low-pressure tracheal tube cuff reduces pul-
monary aspiration. Crit Care Med 2006, 34:632-639. 2. Young PJ, Young WH: Inflation of a pressure-limited cuff
inside a model trachea. Med Eng Phys 2003, 25:465-473. P216
Safety of semi-open percutaneous tracheotomy when
performed in critically ill burn patients
K Gerold, K Dhanjani, L Price, D Noppenberger, S Milner
Johns Hopkins School of Medicine, Baltimore, MD, USA
Critical Care 2007, 11(Suppl 2):P216 (doi: 10.1186/cc5376)
Figure 1 (abstract P215) Figure 1 (abstract P215) performed within an average of 10 days from admission (range
0–32 days). Overall mortality in the tracheostomy group was 35%. There were no short-term complications associated with this
method. Conclusion PT can be performed safely in severely burned
patients using a semi-open percutaneous technique. Exposing the
trachea and palpating the trachea avoids the risk of losing the
airway and permits immediate access to the trachea in the event of
an untoward loss of the airway. We believe that this method is
safer than the more commonly used technique requiring
bronchoscopic visualization. Outreach-led tracheostomy service in a cardiothoracic
centre: early and safe facilitated discharge from critical care Outreach-led tracheostomy service in a cardiothoracic
centre: early and safe facilitated discharge from critical care
P Wilton, J Mitchell, T Apps, R Subramanian
Harefield Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P217 (doi: 10.1186/cc5377) P Wilton, J Mitchell, T Apps, R Subramanian P Wilton, J Mitchell, T Apps, R Subramanian
Harefield Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P217 (doi: 10.1186/cc5377) p
,
,
al Care 2007, 11(Suppl 2):P217 (doi: 10.1186/cc5377) Introduction A retrospective analysis of a year cohort of tracheos-
tomies discharged from intensive care in a specialist cardio-
thoracic centre was undertaken to analyse whether facilitated
outreach-led discharge was safe. Table 1 (abstract P215) Table 1 (abstract P215) Results The number of unsuccessful placement attempts was none
in the UBBR group (0/10) and one in the CBBR group (1/10), two
in the UBBL group (2/10) and five in the CBBL group (5/10). A
fiberoptic aided technique should be more appropriate for the left-
sided blocker in both groups. There was no statistical difference in
bronchial blocker malpositions, the lung to collapse and the number
of complications among the two groups. Furthermore, for elective
thoracic surgical cases, once the lung was isolated, the
management seemed to be similar for both groups. Discussion
This study demonstrates that the wire-guided
bronchial blocker (Uniblocker™) provides a high torque control and
can be easily manipulated into the desired site of the lungs. In
conclusion, our study shows that the Uniblocker™ is more useful
than the Coopdech bronchial blocker tube. Results The number of unsuccessful placement attempts was none
in the UBBR group (0/10) and one in the CBBR group (1/10), two
in the UBBL group (2/10) and five in the CBBL group (5/10). A
fiberoptic aided technique should be more appropriate for the left-
sided blocker in both groups. There was no statistical difference in
bronchial blocker malpositions, the lung to collapse and the number
of complications among the two groups. Furthermore, for elective
thoracic surgical cases, once the lung was isolated, the
management seemed to be similar for both groups. Conclusions In the benchtop model, the LoTrach LVLP cuff
demonstrates an acceptable wall pressure of 30 cmH2O (at an
intracuff pressure of 80 cmH2O), while achieving the prevention
of leakage of fluid past the cuff. The clinical study demonstrates
that the tracheal wall pressure was both acceptable and equal
for both the Portex HVLP and the LoTrach LVLP cuffs. The
LoTrach prevents micro-aspiration in the benchtop model with
acceptable tracheal wall pressures in both the benchtop and
clinical studies. Discussion
This study demonstrates that the wire-guided
bronchial blocker (Uniblocker™) provides a high torque control and
can be easily manipulated into the desired site of the lungs. In
conclusion, our study shows that the Uniblocker™ is more useful
than the Coopdech bronchial blocker tube. S88 Available online http://ccforum.com/supplements/11/S2 Prevention of airway control loss during percutaneous
tracheostomy A Pirogov1, M Croitoru2, R Badaev3, N Davidova1,
S Krimerman2, E Altman4
1Ural Academy of Medicine, Ekaterinburg, Russian Federation;
2Bnai Zion Medical Center, Haifa, Israel; 3Crmel Hospital, Haifa,
Israel; 4Western Galilee Hospital, Naharyia, Israel
Critical Care 2007, 11(Suppl 2):P218 (doi: 10.1186/cc5378) Background
Loss of airway control during percutaneous
tracheostomy (PCT) is one of the serious complications. It may
happen due to an unstable position of the endotracheal tube (ETT)
with its tip in the larynx and cuff above the vocal cords. This Results Of 350 patients admitted to the burn center from July
2005 to December 2006, 20 (6%) required a tracheostomy. Eighteen were performed percutaneously, 13 at the bedside. The
total burn surface area averaged 46% (range 2–95%). PT were S89 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Table 1 (abstract P219)
New problem seen
Number (%)
on CXR (n (%))
Two CXRs reviewed
Uncomplicated PDT
167 (57)
15 (5)
Complicated PDT
69 (24)
10 (3)
One CXR reviewed
Uncomplicated PDT
36 (12)
0
Complicated PDT
8 (3)
0
Total
280
25 position of the ETT is the main request for PCT performance. We
retrospectively reviewed our experience with additional use of the
fiberoptic bronchoscope (FOB) and tube exchanger (TE) for
stabilization of ETT during PCT. Patients and methods From the 160 adult critically ill patients that
underwent PCT by the Griggs technique between January 2000 and
August 2001, we selected 33 patients receiving anesthesia from
the same anesthetist. From this group 12 patients were ventilated
through ETT by the standard technique: in 11 patients a pediatric
FOB was used to control and stabilize the position of ETT during
PCT, and in the remaining 10 patients a 15-Fr TE was used with
the same aim instead of a pediatric FOB. The optimal diameters of
FOB and TE suitable for ETT (7.5 mm, 8 mm) were found in our
previous experiments, using a mechanical lung simulator. Results Loss of airway control during PCT occurred in three
patients, where ventilation through the ETT was performed by the
standard technique. This complication was corrected by
expeditious actions of the anesthetist and surgeon. Routine chest radiography following percutaneous
dilatational tracheostomy Routine chest radiography following percutaneous
dilatational tracheostomy F Paladino, G Guiotto, F Lanni, F Longo, E Ruggiero, F Schirald
Hospital Sao Paulo, Napoli, Italy
Critical Care 2007, 11(Suppl 2):P220 (doi: 10.1186/cc5380) M Vijaya Kumar, M Huges, E Hill, G Dempsey
University Hospital Aintree, Liverpool, UK M Vijaya Kumar, M Huges, E Hill, G Dempsey M Vijaya Kumar, M Huges, E Hill, G Dempsey
University Hospital Aintree, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P219 (doi: 10.1186/cc5379) Objective To evaluate the efficacy of early electric cardioversion
(EC) with a biphasic defibrillator and the impact on atrial function in
recent-onset atrial fibrillation (AF). Critical Care 2007, 11(Suppl 2):P219 (doi: 10.1186/cc5 Background and objective The role of routine chest radiography
(CXR) following percutaneous dilatational tracheostomy (PDT) has
recently been questioned [1]. Methods The study population consisted of 21 consecutive
patients (mean age 58 years; range 35–76 years) with AF lasting
from less than 48 hours. Hemodynamically stable AF was treated
via DC shock if sinus rhythm (SR) was not restored in 6 hours after
i.v. antiarrhythmic drug therapy. All patients were pretreated with
heparin 5,000 U i.v. The defibrillator used was the Heartstart MRX
using a biphasic waveform and low energy (70–120 J). A trans-
thoracic echo was performed pre-EC and 1 hour post-EC. All
patients were sedated with midazolam (in vivo titolation). Atrial
function (ejection fraction, surface area, A wave) and ventricular
function (ejection fraction) were evaluated. The patients returned to
the emergency department after 7 days for follow-up. Data were
analyzed using descriptive statistics (Table 1). Materials
and
methods
We
performed
a
prospective
observational study, on a mixed medical–surgical critical care unit,
in 291 patients undergoing PDT under bronchoscopic guidance to
assess the utility of routine postoperative CXR. Data were
collected on all patients undergoing PDT from 1 November 2003
to 5 December 2006. Two postprocedure CXRs were reviewed
and compared with those taken prior to PDT. Significant findings
were barotraumas (pneumothorax, pneumomediastinum) and
consolidation not noted on the preprocedure film. Postprocedural
films reviewed were those taken immediately after PDT and, to
exclude the possibility of overlooking evidence of minor
barotrauma, one further film taken between 24 and 96 hours. Results DC shock was successful for all patients (100%) and in
19/21(90.4%) at first shock. There was a significant increase in
atrial function with the reappearance of the A wave. There were no Results A total of 291 patients underwent PDT. Biphasic DC shock as a first-line therapy in recent-onset
stable atrial fibrillation in the emergency department Biphasic DC shock as a first-line therapy in recent-onset
stable atrial fibrillation in the emergency department Prevention of airway control loss during percutaneous
tracheostomy In the other
patients, additional use of a pediatric FOB or TE has created
secure and proper position of the ETT and PCT passed smoothly
without complications. Moreover, we could not register a negative
influence of a pediatric FOB and 15-Fr TE presence in the ETT on
ventilation parameters during PCT performance. Conclusions
Routine
CXR
following
uncomplicated
PDT
performed under bronchoscopic guidance appears unwarranted. Review of later films failed to reveal new abnormalities. The role of
CXR following PDT appears to be restricted to those patients
undergoing complicated procedures. This will lead to reductions in
both medical costs [2] and exposure to ionising radiation. References
1. Datta D, Onyirimba F, McNamee MJ: Chest 2003, 123:1603-
1606. 2. Tarnoff M, Moncure M, Jones F, et al.: Chest 1998, 113:1647-
1649. 1. Datta D, Onyirimba F, McNamee MJ: Chest 2003, 123:1603-
1606. Conclusions Stabilization of the ETT position and prevention of
airway control loss during PCT performance can be reached by
use of a pediatric FOB or by 15-Fr TE with the same reliable
results. Employment of a pediatric FOB is more expensive than a
TE. 2. Tarnoff M, Moncure M, Jones F, et al.: Chest 1998, 113:1647-
1649. Routine chest radiography following percutaneous
dilatational tracheostomy Two hundred and
six (71%) were uncomplicated. Complications were recorded in 85
(29%) patients. Of these, 71 (24%) were minor procedural
complications (multiple attempts at needle insertion (>2), minor
bleeding, tracheal ring fracture) and there were 14 (5%) major
complications (malplacement, major bleeding). Two hundred and
thirty-six (81%) patients had two postprocedural CXRs reviewed. Of the remainder, 44 (15%) patients had at least one CXR
reviewed after PDT and in 11 (4%) patients neither the report nor
the CXR could be reviewed. New abnormalities were noted on 25
(9.0%) postprocedure CXRs. No new pneumothoraces were seen
(Table 1). In 11 (4%) patients, neither the report nor the CXR
could be reviewed. Table 1 (abstract P220)
Pre-EC
Post-EC
Number of patients
21
Age average
59
Sinusal rhythm restoration
21/21
Left atrial ejection fraction two chambers
30
35 (P = 0.02)
Left atrial ejection fraction four chambers
29
35 (P = 0.02)
Left ventricular ejection fraction
52
54 (P = NS)
A wave (m/s)
0.54 S90 Available online http://ccforum.com/supplements/11/S2 thromboembolic complications. After 7 days, results showed that
19/21 (90.4%) patients were in SR. P223 The ADHERE classification and regression tree model
overestimates mortality rates in clinical trials: results from
REVIVE I & II
R Thakkar1, J Teerlink2, W Colucci3, J Young4, B Massie2
1Abbott, Abbott Park, IL, USA; 2SFVAMC/University of California –
San Francisco, CA, USA; 3Boston University, Boston, MA, USA;
4Cleveland Clinic, Cleveland, OH, USA
Critical Care 2007, 11(Suppl 2):P223 (doi: 10.1186/cc5383) The ADHERE classification and regression tree model
overestimates mortality rates in clinical trials: results from
REVIVE I & II R Thakkar1, J Teerlink2, W Colucci3, J Young4, B Massie2
1Abbott, Abbott Park, IL, USA; 2SFVAMC/University of California –
San Francisco, CA, USA; 3Boston University, Boston, MA, USA;
4Cleveland Clinic, Cleveland, OH, USA
Critical Care 2007, 11(Suppl 2):P223 (doi: 10.1186/cc5383) Troponin T was determined in 13 patients and found to be
elevated in 10 patients (34.5% of AF patients). Transthoracic
echocardiography was performed on 10 patients with persistent
AF (34.5%). Seven patients had valve pathology whereas left
ventricular dysfunction was present in five patients. Only one
echocardiography was reported normal. Patients were treated
according to local guidelines with amiodarone (19 (65.5%)),
digoxin (5 (17.2%)) and β-blockers (4 (13.8%)), and DC cardio-
version was used in only one patient. Eighteen (62.1%) patients
were successfully cardioverted. Background Blood urea nitrogen (BUN), systolic blood pressure
(SBP), and serum creatinine (Cr) were significant predictors of
inhospital mortality by classification and regression tree (CART)
analysis of ADHERE. REVIVE I & II (REVIVE) compared levosimen-
dan with placebo, in addition to standard-of-care (SOC), in
patients with acute decompensated heart failure. We hypothesized
that mortality in REVIVE would be similar to ADHERE in all CART-
defined risk subgroups. Conclusion Apart from known risk factors for AF such as
increased age, hypertension or ischaemic heart disease, sepsis
and inotropes increase susceptibility for AF. Less frequently
associated causes such as congenital heart disease, obesity and
diabetes can contribute towards AF. Echocardiography could
reveal less obvious causes of AF like valvular pathologies and left
ventricular dysfunction, and could be a useful diagnostic tool in
critically ill patients with AF. Methods REVIVE (n = 700) mortality data were mapped using the
same variables/cut-points as the ADHERE CART analysis. Methods REVIVE (n = 700) mortality data were mapped using the
same variables/cut-points as the ADHERE CART analysis. P222 The calcium sensitizer levosimendan reduces the brain
natriuretic peptide levels as compared with dobutamine in
intensive care unit septic patients with decompensated
heart failure Conclusion
Early electric cardioversion in the emergency
department setting is a simple technique that allows the restoration
of SR without complications. The biphasic waveform uses lower
energy with a positive impact on atrial function. Higher energy can
cause transient tissue damage due to electroporation that can
affect the outcome of defibrillation therapy being both pro-
arrhythmic and anti-arrhythmic. The recovery of atrial function is
also due to the short duration of arrhythmia. The early cardioversion
avoids atrial remodelling and allows a longer duration of SR. H Michalopoulou, P Stamatis, A Bakhal, T Kelgiorgis,
A Foundouli, A Basile, J Vaitsis, E Reinou, P Batika, D Pragastis
Metaxa Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P222 (doi: 10.1186/cc5382) H Michalopoulou, P Stamatis, A Bakhal, T Kelgiorgis Introduction The brain natriuretic peptide (BNP) is a useful index
to follow-up patients with heart failure as well as a special
diagnostic and prognostic tool. This study aims at investigating the
impact of levosimendan in comparison with dobutamine on the
BNP levels in ICU patients with decompensated heart failure
related to septic shock. The role of levosimendan in septic patients
is still under consideration. P221 Incidence and diagnosis of patients developing atrial
fibrillation in intensive care Methods Twenty-nine patients (20 males and nine females) of a
70.5 ± 9.2 average age rate with persisting left ventricular
dysfunction related to severe sepsis, after receiving a 48-hour
conventional
treatment
including
inotropic
agents,
were
randomised to either 24-hour i.v. levosimendan (0.2 γ/kg/min) (n =
15) (Group A) or dobutamine (5 γ/kg/min) (n = 14) (Group B)
therapy. Serial BNP measurements were performed before, at 48
hours and 5 days later. R Shankar1, I Welters2
1Burton Hospitals NHS, Burton-on-Trent, UK; 2Academic Unit of
Critical Care Medicine, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P221 (doi: 10.1186/cc5381) Introduction
Atrial fibrillation (AF) is a common arrhythmia
encountered in critically ill patients. In this study we evaluated the
incidence and risk factors associated with the occurrence of AF in
a general ICU. Results Levosimendan therapy significantly reduced the BNP
levels both in 48 hours and in 5 days as compared with
dobutamine. Group A: 1,138 ± 93.7, 740.2 ± 106, 445 ± 118.3
and Group B: 1,561 ± 370.2, 1,436 ± 368, 1,850 ± 520.5,
before, 48 hours and 5 days later, respectively. P = 0.025 for 48
hours and P = 0.037 for 5 days. Methods One hundred and ten patients admitted to the ICU
during a 3-month period were screened for AF. Case notes and
daily management charts of these patients were analysed
retrospectively. Results Twenty-nine (26.3%) out of 110 patients developed AF. The mean age of patients was 71.8 (±9.2) years and the APACHE
II score was 21.3 (±6.3). Electrolytes were within the normal range
in 85% of the patients. The main cardiac factors identified in our
patients with AF were hypertension (71.4%) and coronary artery
disease (48.3%). Less commonly encountered cardiac diagnoses
were congenital heart disease and history of previous atrial
fibrillation. Inotropic support and sepsis were the leading
noncardiac factors found in 24 (82.8%) and 22 (75.9%) patients,
respectively. Diabetes mellitus and obesity contributed in 17.2% of
patients. Conclusion Levosimendan therapy reduces BNP levels, reflecting
a beneficial haemodynamic effect on the ICU patient with septic
myocardial depression. Levosimendan in patients with acute cardiogenic shock,
not responders to conventional therapy Levosimendan in patients with acute cardiogenic shock,
not responders to conventional therapy L Vetrugno, F Bassi, F Giordano
Azienda Ospedaliero-Universitaria, Udine, Italy
Critical Care 2007, 11(Suppl 2):P224 (doi: 10.1186/cc5384) Introduction Levosimendan is a new, effective inodilator agent,
which is a new alternate drug beside conventional inotropic drugs
in treatment of acute and chronic heart failure. Positive inotropic
effects of levosimendan is based on myocardial Ca-sensitising. Few clinical data are available about the occurrence of
proarrhythmic effects of levosimendan, particularly administered in
parallel with catecholamines. Introduction Cardiogenic shock remains the leading cause of death
in patients hospitalized for myocardial infarction, acute valvular
disease and after cardiac surgery. Levosimendan (LS) is a new
inodilator that has been shown to improve hemodynamic function in
patients with decompensated systolic heart failure without increased
myocardial oxygen consumption. The aim of this study was to
evaluate the use of LS as rescue medication in patients with low
ejection fraction (EF) that are not responders to conventional therapy. Methods Twelve patients with acute cardiogenic shock admitted
to the ICU were enrolled. The diagnosis of cardiogenic shock was
made on cardiac index (CI) measured by thermodilution catheter
<2.5 l/min/m2, and baseline echocardiography with EF measured
by the biplan Simpson method <30%. LS (Orion Pharma, Helsinki,
Finland) at the dose of 0.1 γ/kg/min for 24 hours continuous
infusion was added to standard inotropic agents (dobutamine,
enoximone, epinephrine) or IABP when CI and EF seemed not to
improve or when the patient’s condition worsened. Hemodynamic
measurements and echocardiography data were recorded at ICU
admission and when pharmacological therapy was changed at 24,
48 and 72 hours. Method From 1 January 2006 until 30 July, 41 levosimendan-
treated patients’ data were processed in our retrospective study. Indication of levosimendan therapy was acute heart failure due to
myocardial infarction in 23 cases and acute progression of chronic
heart failure (NYHA III–IV) in 18 cases. After a 10-minute bolus
levosimendan infusion was administered at rate of 0.1 µg/kg/min
for 6 hours and 24 hours in each group, respectively. We investi-
gated the occurrence of sustained ventricular or supraventricular
arrhythmias for the first 48 hours from the beginning of infusion. Results The ratio of hypertension, diabetes, earlier myocardial
infarction and ACBG were 58%, 27%, 32% and 15%,
respectively, in the monitored population (13 females, 28 males;
mean age: 68 years). Retrospective study of proarrhythmic effects of
levosimendan during the therapy of heart failure Retrospective study of proarrhythmic effects of
levosimendan during the therapy of heart failure E Zima, G Szucs, A Soltesz, D Becker, G Fulop, L Molnar,
G Barczi, B Merkely
Semmelweis University, Budapest, Hungary
Critical Care 2007, 11(Suppl 2):P225 (doi: 10.1186/cc5385) P223 Results Compared with ADHERE, proportionately more patients in
REVIVE had SBP <115 mmHg (56.4% vs 18.6%; P < 0.001) with
more patients (3.0% vs 1.9%; P < 0.05) in the highest mortality
risk subgroup (SBP <115 mmHg, BUN ≥43 mg/dl, and Cr
≥2.75 mg/dl). For the total population and for every CART-defined
subgroup, REVIVE inhospital mortality rates were lower than those
from ADHERE. See Figure 1. S91 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P224) Figure 1 (abstract P223)
Mortality rates from REVIVE for subgroups defined by the ADHERE
classification and regression tree model. Figure 1 (abstract P224) Figure 1 (abstract P224) Figure 1 (abstract P223)
Mortality rates from REVIVE for subgroups defined by the ADHERE
classification and regression tree model. Figure 1 (abstract P224) Figure 1 (abstract P223) Figure 1 (abstract P223) Mortality rates from REVIVE for subgroups defined by the ADHERE
classification and regression tree model. Conclusion Clinical trials (REVIVE) may enroll proportionately
more patients at increased risk of mortality in comparison with the
general population (ADHERE). Despite the predicted increased
mortality risk, mortality rates were lower in REVIVE than in
ADHERE for the total population and for every CART-defined risk
subgroup. Differences in SOC or additional risk factors, such as
age or other comorbid conditions, may contribute to the poorer
prognosis in nontrial populations. different mechanism of action. Catecholamines increase Ca2+
availability and LS increases myocardial cell calcium sensibility. Levosimendan in myocardial depression due to severe sepsis M Malik, Y Mandourah
Riyadh Millitary Hospital, Riyadh, Saudi Arabia
Critical Care 2007, 11(Suppl 2):P226 (doi: 10.1186/cc5386) Objective and method To assess the secondary preventative
treatment received by the elderly ACS patient. Retrospective
analysis of our Myocardial Infarction National Audit Project
(MINAP) database 2003–2006. Patients were divided into three
age groups: <50 years, 50–75 years and >75 years old. Data
were collected from hospital admission to discharge. Introduction Myocardial depression in sepsis, among other
factors, is due to calcium (Ca2+) desensitization in the myofilament. So using a Ca2+ sensitizer drug may play a beneficial role in this
situation. Levosimendan has a dual mechanism; it causes Ca2+
sensitization through binding to Troponin C and opening of ATP-
dependent K+ channels in vascular smooth muscle. Results A total of 1,501 consecutive patients were included in the
analysis, 530 patients (35.3%) were >75 years, mean age 83.6
years (±5.1). The discharge diagnosis was ST elevation myocardial
infarction in 619, UA/NSTEMI in 870 and unspecified in 12
patients. The overall inpatient all-cause mortality rate was 8.06%
(121/1,501). See Table 1. Methods A prospective observational case-series study extending
over a period of 18 months from November 2004 to April 2006. We analyze the data of 18 patients receiving levosimendan for
myocardial depression due to severe sepsis and compare them
with our historical data in the previous year of the same group of
patients regarding mortality. All those patients were included in the
study who had a pulmonary artery catheter (PAC) and who after
initial resuscitation (early goal-directed therapy (EGDT)) did not
respond to treatment and their cardiac index (CI) was <2.2. Each
patient than received an infusion of levosimendan at 0.1 µg/kg/min
without a loading dose. Hemodynamic parameters such as the CI,
mixed venous saturation (SvO2) and mean arterial pressure (MAP)
were recorded at 0, 12, 24 and 48 hours. Noradrenaline was used
to maintain a MAP above 65 mmHg. Patients were followed for
30 days to document the 7th-day and 30th-day mortality. SPSS 11
was used for statistical analysis. The Student t test was used as a
test of significance. Table 1 (abstract P227)
<50 years
50–75 years
>75 years
Total
149
822
530
STEMI
84
364
172
Inhospital mortality
0
33 (4%)
88 (17%)
Aspirin (%)
98.7
94.5
90.4*
ACE-I (%)
84.6
83.4
66.4*
β-Blocker (%)
93.8
82.4
72.9*
Statin (%)
96.5
95.6
89*
*P < 0.001, chi-squared. P226 P226 treatment strategies and secondary prevention, despite the elderly
being the fastest growing section of the population. The literature
suggests the elderly do not receive appropriate therapy in this
setting. What is the current UK experience? Long-term prognosis of octagenarian patients with
ST-elevation acute myocardial infarction treated by
primary angioplasty E Abu Assi
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P228 (doi: 10.1186/cc5388) Conclusion It is evident from our study that levosimendan
improves hemodynamic response in septic patients. Although it
improves the mortality, we cannot say with full confidence that
these improved hemodynamic parameters are responsible. Randomised control trials are needed to answer this question,
which are underway. Introduction The incidence of acute myocardial infarction (AMI) in
old patients is increasing due to rapid aging of the population. This
is of particular concern because AMI in patients who are ≥80 years
old is associated with high mortality. However, the role of
reperfusion therapies is not clear in these patients. Levosimendan in myocardial depression due to severe sepsis Conclusions The elderly ACS patient forms a high-risk group. The
therapeutic approach in this group should be justifiably as
aggressive as that in younger patients, balancing risks with
benefits. The elderly patient should be prescribed secondary
preventative measures, and our data show considerably greater
numbers can benefit from standard treatment than suggested by
the published literature. Results The average age was 67.6 ± 10.39 years and the
APACHE II score was 26.33 ± 2.37. Patients were divided into
three subgroups: survivors, 7th-day and 30th-day mortality groups. There was no significant difference in these subgroups regarding
age and APACHE II score. Levosimendan group 7th-day and 30th-
day mortality was 33% and 66% as compared with historical data
of 37% and 71%, respectively. The change in CI in the survivor
group was significant (P = 0.021), from 2.11 ± 0.17 to 3.8 ± 0.28,
while in the 7th-day and 30th-day mortality groups it was
insignificant. SvO2 increased in the survivor and 30th-day mortality
groups significantly (P = 0.011 and P = 0.035, respectively). It did
not show any significant improvement in the other group. MAP also
showed significant improvement in the survivor group (P = 0.026)
and insignificant in others. Levosimendan in patients with acute cardiogenic shock,
not responders to conventional therapy Three ventricular arrhythmias and one
supraventricular arrhythmia were observed during the 48-hour
period, all of them occurred in acute heart failure patients with
acute myocardial infarction. Parallel usage of catecholamines
(noradrenalin and/or dopamine) and levosimendan therapy was
observed in three cases, in one of them ventricular tachycardia was
observed 3 hours after starting levosimendan infusion. No
arrhythmia was observed in chronic heart failure patients. The
incidence of proarrhythmic effects during levosimendan therapy
was 9.75% of the whole analysed population and was 17.4% at
acute heart failure during acute myocardial infarction. Results The data collection showed: an increase in CI (baseline to
standard therapy) of 2.6 ± 0.51 (P < 0.001), and standard therapy
to LS of 2.93 ± 0.67 (P < 0.003) that seem to be additive. Significant increase in EF was noted in comparison with standard
therapy
(29.88 ± 6.15,
P < 0.035)
and
after
LS
therapy
(38.44 ± 6.56, P < 0.001) (Figure 1). To find differences between
baseline and pharmacological therapy changes at 24, 48 and
72 hours a t test was performed. Conclusion With these results the authors would like to draw
attention to the proarrhythmic effects of levosimendan during acute
heart failure therapy, especially in the case of parallel usage with
catecholamines. Conclusion We found an additive effect of dobutamine,
enoximone and LS that theoretically can be explained by the S92 Available online http://ccforum.com/supplements/11/S2 P228 P228
Long-term prognosis of octagenarian patients with
ST-elevation acute myocardial infarction treated by
primary angioplasty
E Abu Assi
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P228 (doi: 10.1186/cc5388) Long-term prognosis of octagenarian patients with
ST-elevation acute myocardial infarction treated by
primary angioplasty Long-term prognosis of octagenarian patients with
ST-elevation acute myocardial infarction treated by
primary angioplasty Outcome in myocardial infarction is related to the
morphologic pattern of ST elevation Introduction Early percutaneous coronary intervention (PCI) is the
most effective treatment for acute coronary syndrome (ACS, ST-
elevation myocardial infarction (STEMI), non-STEMI, unstable
angina pectoris) complicated by states Killip 3 and 4. R García-Borbolla1, I Nuñez Gil2, J García Rubira2,
A Fernández Ortiz2, L Perez Isla2, M Cobos2, C Macaya2
1Hospital Universitario Puerta del Mar, Cádiz, Spain; 2Hospital
Clínico San Carlos, Madrid, Spain
Critical Care 2007, 11(Suppl 2):P229 (doi: 10.1186/cc5389) Method A total of 1,187 patients suffering from high-risk acute
coronary syndrome (hrACS) were treated in our center in 2005. States Killip 3 and 4 have developed perioperatively in 186 of
these patients. International studies have proven high mortality in
these patient groups – especially in state Killip 4. Our aim was to
analyze the inhospital mortality of the state Killip 3 and 4 patient
group treated in our center in 2005. Purpose Although invasive management of ST-segment elevation
myocardial infarction (STEMI) has improved the clinical outcome,
early mortality remains an important issue. Our purpose is to
assess the utility of the initial electrocardiographic (ECG) pattern in
detecting patients who are at increased risk despite the current
recommendations of revascularization. Results Seven hundred and two patients with STEMI and 485
patients with hrACS were admitted to our center in 2005. The
mortality of these patients was 4.84% (STEMI) and 3.71%
(hrACS), and the main cause of this mortality (37.7%) was the
Killip 3/4 state, which was observed in 11.9% of the STEMI
patients and in 17.9% of hrACS patients (n = 84 and 87). The
mean age of the Killip 3/4 patients was 70 ± 10 years. Angio-
logically successful PCI was performed in 97.9% of the cases. The
ratio of revascularized coronaries was left anterior descending
coronary artery (LAD): 66 (35.9%), right coronary artery (RCA): 33
(17.9%), circumflex coronary artery (CX): 28 (15.2%), PCI in left
main coronary artery: 28 (12.5%), LAD + CX: 15 (8.15%), RCA +
LAD: 7 (3.8%), CX + RCA: 6 (3.26%), venous bypass graft: 2
(1.1%). No PCI was performed in two cases. Adjuvant therapies of
intraaortic balloon counterpulsation in 67 (36%), mechanical
ventilation in 62 (33.3%), continuous veno-venous hemofiltration in
12 (6.45%), and levosimendan therapy in 86 (46.2%) patients
were used. Ten (5.4%) of the patients had advanced adult life
support (cardiopulmonary resuscitation) (AALS) before arrival at
our center, and AALS was performed in the perioperative period in
16 (8.6%) patients. P227 Objective To evaluate the mid-term and long-term prognosis of
octogenarian patients with ST-elevation myocardial infarction
(STEMI) treated with primary coronary angioplasty (PCA). The elderly acute coronary syndrome patient: a neglected
population? A Turley1, A Roberts1, A McDermott2, P Adams2
1The James Cook University Hospital, Middlesbrough, UK; 2Royal
Victoria Infirmary, Newcastle upon Tyne, UK
Critical Care 2007, 11(Suppl 2):P227 (doi: 10.1186/cc5387) Methods We studied retrospectively, from January 2000 to March
2005, 73 patients ≥80 years with STEMI treated with PCA. At the
end of follow-up, we assessed the incidence of death, myocardial
infarction and necessity of new procedures of revascularization of
the treated vessel. Introduction Cardiovascular disease is the commonest cause of
death in the elderly (>75 years). The elderly acute coronary
syndrome (ACS) patient forms a particular high-risk cohort. Clinical
trials traditionally concentrate on younger patients for both ACS Results The average age was 84 ± 3.6 years, 39 (58%) were
women. The location of the AMI was anterior in 56%, and 25%
were diabetic. The average follow-up time was 19 ± 17 months. During the follow-up, 43 patients developed events, most of them S93 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 1 (abstract P228) Figure 1 (abstract P229) Figure 1 (abstract P229) Figure 1 (abstract P228) pattern of group 1 remained significantly related to mortality
(P = 0.013) together with the number of leads with STE. Conclusion The initial STE pattern is useful in detecting patients at
higher risk of death or cardiogenic shock, despite the adequate
revascularization therapy in STEMI. (n = 28) consisting of death (23 by cardiac death). However, most
of these events occurred in the first month after the admission, the
mortality between 1 month and 3 years being low (Figure 1). Percutaneous coronary intervention in acute coronary
syndrome complicated by states Killip 3 and 4 in 2005 Percutaneous coronary intervention in acute coronary
syndrome complicated by states Killip 3 and 4 in 2005 E Zima, G Szabo, D Becker, G Fulop, L Geller, L Molnar,
G Barczi, S Toth, A Horvath, A Apor, B Merkely
Semmelweis University, Budapest, Hungary
Critical Care 2007, 11(Suppl 2):P230 (doi: 10.1186/cc5390) P230 Conclusion Our data show that the octogenarian patients with
STEMI treated by primary PCA developed a very high mortality. However, this mortality especially concentrates in the first month
after the procedure, being low between 1 month and 3 years. Abstract withdrawn Abstract withdrawn Outcome in myocardial infarction is related to the
morphologic pattern of ST elevation The early inhospital mortality of hrACS
aggravated by state Killip 3/4 was 10.7% (20 patients) –
according to subgroup: Killip 3: 0.06%; Killip 4: 30.5%. Methods We analyzed 446 consecutive patients (age 61.9 ± 13.8
years, 76.5% male) admitted in the first 12 hours of STEMI to our
coronary unit. Exclusion criteria were left bundle branch block at
admission or previous myocardial infarction. Most patients (87%)
were treated with primary angioplasty. Patients treated with
thrombolytics and with early reperfusion criteria were programmed
to coronary angiography the following day. Two groups were
defined according to the presence of ST-segment elevation (STE)
together with distortion of the terminal portion of the QRS in two or
more adjacent leads (group 1) or the absence of this pattern
(group 2) (Figure 1). Results There were 102 (22.8%) patients in group 1 and 344
(77.2%) in group 2. No differences in age or risk factors were seen
between both groups. The number of diseased vessels was similar. Group 1 had higher CK, MB-CK and cardiac troponin I. The
maximal Killip class was >2 during hospitalisation in 38% of group
1 vs 24% (P = 0.009). Group 1 had more mortality (8.8% vs 2.6%,
P = 0.005) and more cardiogenic shock. Other ECG character-
istics related to mortality were the sum of STE in all leads, the
number of leads with STE and ST segment depression. After a
logistic regression analysis including all ECG characteristics, the S94 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P233) Figure 1 (abstract P233) Conclusion The prognosis of state Killip 3/4 and successive
multiorgan failure as the high-mortality complication of hrACS can
be improved by early successful PCI, and the concomitant
pharmacologic and nonpharmacologic supportive therapy. Figure 1 (abstract P233) P232 Table 1 (abstract P232)
<2
2–4
4–6
>6
Symptom to balloon time
hours
hours
hours
hours
P value
ST-segment resolution (%)
95
92
86
78
0.0001
Procedural success (%)
97
95
91
84
0.03
Mortality (%)
6
9
12
29
<0.001 Conclusion ST elevation with distortion of the terminal portion of
QRS predicts impaired CC. Early recognition of this pattern should
warrant prompt treatment. P234 Hemoglobin concentration on admission influences the
rate of inhospital 30-day mortality and complications in
patients with acute myocardial infarction: a retrospective
analysis of 660 Chinese patients Conclusion This study shows that, in patients with STEMI treated
by PCA, SBT is related to ST-segment resolution, to PS and to
mortality Y Zhao, W Gao, H Wu, J Li
Institute of Geriatric Cardiology, Beijing, China
Critical Care 2007, 11(Suppl 2):P234 (doi: 10.1186/cc5394) P232 Symptom onset to balloon time in patients with ST-
segment elevation myocardial infarction treated by primary
coronary angioplasty: influence on ST-segment resolution
and on mortality therapeutic and prognostic implications. Our purpose was to
correlate the electrocardiogram (ECG) pattern and CC in STEMI. Methods We analyzed ECG and angiographic CC in 242
consecutive patients (62 ± 14 years, 79% male) with STEMI
treated with primary angioplasty. Patients were divided into two
groups based on the magnitude of ST elevation with/without
distortion of the terminal portion of the QRS (group 1/group 2). The degree of collateral filling (Rentrop) was assessed as grade 0 =
none, grade 1 = filling of side branches of the occluded artery,
grade 2 = partial epicardial filling, and grade 3 = complete
epicardial filling of the occluded artery. therapeutic and prognostic implications. Our purpose was to
correlate the electrocardiogram (ECG) pattern and CC in STEMI. M th d
W
l
d ECG
d
i
hi
CC i
2 2 Introduction With controversy in the field, we wanted to assess
the influence of symptom onset to balloon time in ST-segment
elevation myocardial infarction (STEMI) treated by primary coronary
angioplasty (PCA), on ST-segment resolution and on the 1-year
mortality. Introduction With controversy in the field, we wanted to assess
the influence of symptom onset to balloon time in ST-segment
elevation myocardial infarction (STEMI) treated by primary coronary
angioplasty (PCA), on ST-segment resolution and on the 1-year
mortality. Methods
Retrospectively (January 1998–August 2004), we
studied 558 consecutive patients with STEMI treated by PCA. The
symptom to balloon time (SBT) was defined as the elapsed time
between symptom onset and the first balloon inflation, and the
procedural success (PS) as the TIMI III flow post-PCA with
estenosis <50%. Results ST elevation with distortion of the terminal portion of QRS
were present at initial ECG in 55 patients (23%). This group had a
lower incidence of Rentrop grade 2/3 than group 2 (P = 0.006,
Figure 1). Moreover, group 1 had higher enzyme release, worse
maximal Killip class and more frequently the combined variable
death/shock. Group 1 more often had proximal occlusion of the
infarction-related artery and nonreflow. Multivariate analysis found
ECG to be an independent predictor of outcome. Results Table 1 summarises clinical features according to SBT. After adjustment of potentially confounding variables, SBT was the
variable associated with less ST-segment resolution (HR 1.772,
95% CI 1.46–4.15, P = 0.02). P233 Conclusion It is demonstrated in this study that a reve
relationship between baseline hemoglobin values
adverse cardiovascular events is observed in patient
myocardial infarction. There is a greater incidence of
a hemoglobin concentration on admission in the elder
than that in the younger one. P235
Anaemia at the moment of admittance is associ
higher heart failure and mortality among patient
acute coronary syndrome
J Garcia Acuña, A López Lago, E González Babarro
B Cid Alvarez, E Abu Assi, M Jaquet Herter, A Amar
M Santás Alvarez, S De Lange, J González Juanatey
Clinic Universitary Hospital of Santiago, Santiago de C
Spain
Critical Care 2007, 11(Suppl 2):P235 (doi: 10.1186/c
Background The search for novel and modifiable ri
d
(ACS) Results Patients with hemoglobin values between 140 and 159 g/l
were used as the reference; cardiovascular mortality increased as
hemoglobin levels fell below 140 g/l or rose ≥160 g/l. The in-
hospital 30-day mortality was 25.0% in patients with hemoglobin
concentrations <100 g/l, 20.4% in patients with hemoglobin
concentrations of 100–119 g/l, 10.6% in patients with hemoglobin
concentrations of 120–139 g/l, 4.3% in patients with hemoglobin
concentrations of 140–159 g/l, and 8.5% in patients with hemo-
globin concentrations of 160 g/l or greater. The increase in risk of
complications associated with a low hemoglobin concentration
was more pronounced in patients with anemia than in patients
without. Compared with patients with hemoglobin concentrations
of 140–159 g/l, those with hemoglobin concentrations <140 g/l
had more inhospital complications and those with hemoglobin
concentrations ≥160 g/l also had more arrhythmia and pneumonia
(P < 0.001, respectively). As expected, a significant inverse corre-
lation between hemoglobin concentrations and ages (r = –0.51;
P < 0.001) was observed, and a significant positive correlation
between hemoglobin concentrations and albumin concentrations
and in the patients with acute myocardial infarction. worse intrahospital prognosis: major incidence of cardiac
insufficiency (42% to 20%, P = 0.0001), refractory angina pectoris
(14% to 6%, P = 0.01), more electric complications (12% to 9%,
P = 0.01) and a higher mortality (14% to 7%, P = 0.009). The
presence of anaemia was an independent predictor of cardiac
insufficiency and death at the moment of admittance to the CCU
(OR = 2.20, 95% CI = 1.10–4.35; P = 0.002) Conclusion The presence of anaemia is a powerful predictor of a
worse prognosis in patients with ACS. Long-term prognostic impact of anemia in patients with
ST-elevation acute myocardial infarction treated by primary
coronary angioplasty E Abu Assi, F Soto, R Vidal, E Pardes, A Amaro
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P236 (doi: 10.1186/cc5396) Conclusion It is demonstrated in this study that a reverse J-shaped
relationship between baseline hemoglobin values and major
adverse cardiovascular events is observed in patients with acute
myocardial infarction. There is a greater incidence of patients with
a hemoglobin concentration on admission in the elderly population
than that in the younger one. Introduction Anemia has been shown to be a powerful and
independent predictor of 30-day outcomes among patients
presenting with acute coronary syndrome. However, there are
limited and conflicting data about its long-term independent
predictive value in this setting. Introduction Anemia has been shown to be a powerful and
independent predictor of 30-day outcomes among patients
presenting with acute coronary syndrome. However, there are
limited and conflicting data about its long-term independent
predictive value in this setting. Objectives To investigate the long-term prognostic impact of
anemia in patients with ST-elevation acute myocardial infarction
(STEMI) treated by primary coronary angioplasty (PCA). P233 Anaemia is associated with
other factors of a worse prognosis such as renal dysfunction,
peripheral artery disease and diabetes mellitus. P235 Anaemia at the moment of admittance is associated with
higher heart failure and mortality among patients with
acute coronary syndrome Methods Retrospectively, from January 2001 to December 2003,
we studied 298 consecutive patients with STEMI treated with
PCA. Patients were classified into two groups according to having
anemia or nonanemia at admission (for men Hb < 13 vs ≥13 g/dl,
and for women Hb < 12 vs ≥12 g/dl). We defined the composite
endpoint as death or rehospitalization for heart failure or acute
coronary event. The average follow-up time was 24 months and
was determined in 97%. J Garcia Acuña, A López Lago, E González Babarro,
B Cid Alvarez, E Abu Assi, M Jaquet Herter, A Amaro Cendon,
M Santás Alvarez, S De Lange, J González Juanatey
Clinic Universitary Hospital of Santiago, Santiago de Compostela,
Spain
Critical Care 2007, 11(Suppl 2):P235 (doi: 10.1186/cc5395) Results Anemia was present in 41 patients (14%). At the end of
follow-up, 109 patients (37%) developed ≥1 component of the
composite endpoint (52 deaths and 66 rehospitalization). The
event-free survival was 62% in the group with anemia versus 82%
in the other group (P < 0.001). After controlling for a variety of
baseline clinical, laboratory, and angiographic variables, anemia
was a strong and independent predictor of death or rehospitaliza-
tion for heart failure or acute coronary event (HR 1.96, 95% CI
1.21–3.17, P = 0.006). Figure 1 shows that patients with anemia
present a worse prognosis. Background The search for novel and modifiable risk factors in
acute coronary syndrome (ACS) can open new strategies. We
decided to evaluate the prevalence of anaemia and determine its
influence on the prognosis of hospitalized ACS patients. Patients
and
methods
Four
hundred
and
twenty-eight
consecutive patients hospitalized for ACS between 2005 and
2006 in a coronary care unit (CCU) of a cardiology department of
a tertiary hospital were studied. During their hospitalization we
registered cardiovascular risk factors; we determined the presence
of microalbuminuria (>3 mg/dl) in a 24-hour urine sample. We also
took blood samples during the first 24 hours of their admittance to
the CCU for a complete haemogram, levels of total cholesterol,
HDL cholesterol, LDL cholesterol, triglycerides, creatinine, creatinine
clearance (Cockroft–Gault equation), glucose, HbAc1, high-
sensibility C-reactive protein and a follow-up of levels of Troponin,
CK and CK-MB. Figure 1 (abstract P236) P233 Coronary collateral circulation status is correlated with the
initial electrocardiographic pattern in ST-elevation
myocardial infarction
I Nuñez Gil1, R Garcia de la Borbolla2, J Garcia Rubira1,
A Fernandez Ortiz1, M Manzano Nieto1, R Hernandez Antolin1,
C Macaya1
1Hospital Clínico San Carlos, Madrid, Spain; 2Hospital Universitario
Puerta del Mar, Cadiz, Spain
Critical Care 2007, 11(Suppl 2):P233 (doi: 10.1186/cc5393) Objective To determine the association between hemoglobin
concentrations on admission and inhospital 30-day cardiac
mortality and complications among patients with acute myocardial
infarction during their hospital course. I Nuñez Gil1, R Garcia de la Borbolla2, J Garcia Rubira1,
A Fernandez Ortiz1, M Manzano Nieto1, R Hernandez Antolin1,
C Macaya1
1Hospital Clínico San Carlos, Madrid, Spain; 2Hospital Universitario
Puerta del Mar, Cadiz, Spain
Critical Care 2007, 11(Suppl 2):P233 (doi: 10.1186/cc5393) Methods We conducted a retrospective study of data on 660
Chinese patients who were hospitalized with acute myocardial
infarction. Patients were categorized according to the hemoglobin
concentration on admission, and data were evaluated to determine
whether there was an association between the hemoglobin
concentrations on admission and inhospital 30-day mortality and
complications. Complications were defined as cardiogenic shock,
congestive heart failure, arrhythmia, ventricular tachycardia or
fibrillation and pneumonia. Introduction The status of coronary collateral circulation (CC) in
the first hours of ST-elevation myocardial infarction (STEMI) may
influence outcome. Early recognition of the CC status may have S95 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Results Patients with hemoglobin values between 140
were used as the reference; cardiovascular mortality
hemoglobin levels fell below 140 g/l or rose ≥160
hospital 30-day mortality was 25.0% in patients with
concentrations <100 g/l, 20.4% in patients with
concentrations of 100–119 g/l, 10.6% in patients with
concentrations of 120–139 g/l, 4.3% in patients with
concentrations of 140–159 g/l, and 8.5% in patients
globin concentrations of 160 g/l or greater. The incre
complications associated with a low hemoglobin c
was more pronounced in patients with anemia than
without. Compared with patients with hemoglobin co
of 140–159 g/l, those with hemoglobin concentratio
had more inhospital complications and those with
concentrations ≥160 g/l also had more arrhythmia an
(P < 0.001, respectively). As expected, a significant in
lation between hemoglobin concentrations and age
P < 0.001) was observed, and a significant positiv
between hemoglobin concentrations and albumin co
and in the patients with acute myocardial infarction. P237 Cardiogenic shock in the Aachen Digital Myocardial
Infarction Registry
A Kersten, M Merx, H Dückers, M Kelm, W Lepper
UK Aachen, Germany
Critical Care 2007, 11(Suppl 2):P237 (doi: 10.1186/cc5397) Cardiogenic shock in the Aachen Digital Myocardial
Infarction Registry Cardiogenic shock in the Aachen Digital Myocardial
Infarction Registry Introduction Evaluation of hemodynamics in patients with acute
myocardial infarction (AMI) is crucial. Hemodynamic changes
during intra-aortic balloon counterpulsation (IABC) are monitored
using invasive methods for assessment of hemodynamics in
patients with cardiogenic shock (CS). A Kersten, M Merx, H Dückers, M Kelm, W Lepper
UK Aachen, Germany
Critical Care 2007, 11(Suppl 2):P237 (doi: 10.1186/cc5397) Introduction Guideline-oriented therapy of acute coronary
syndrome (ACS) with ST-elevation myocardial infarction (STEMI)
calls for quick and early treatment. The creation of an infarct
network has been associated with streamlined treatment and a
reduction of hospital mortality. Whether patients with cardiogenic
shock (CS) receive similar, optimized treatment as regular STEMI
patients is unclear. Objective To evaluate hemodynamic indices in patients with AMI,
complicated by CS and managed with IABC during initial days of
treatment. Methods Hemodynamic indices including cardiac output (CO),
cardiac index (CI), mean pulmonary artery pressure (MPAP) and
pulmonary capillary wedge pressure (PCWP) were measured by
pulmonary artery catheterization using an intermittent thermo-
dilution technique for patients with AMI complicated by CS,
admitted within 12 hours from the onset of pain and managed by
IABC. All measurements were performed within 48 hours after
initiation of IABC. Methods We created the Aachen Digital Myocardial Infarction
Registry (ADMIRE) database according to the European Cardiology
Audit and Registration Data standards for clinical cardiology
practice. Patients were labelled according to the presenting form
of ACS. The infarct network included local ambulance services
(LA), local hospitals (LH) and the interventional center with an
emergency department (ED) and a 24/7 cath lab crew. To improve
performance we introduced prehospital triage, fax-transmission of
ECG, and direct alert of the cath lab crew by telephone. We
determined treatment variables, median index-to-door (IDT) and
door-to-sheath (DST) times and hospital mortality. Results Twenty-nine patients were investigated according to the
study protocol: 15 (51.7%) men and 14 (48.3%) women. Average
age was 71.4 ± 6.9 years. Anterior AMI was diagnosed for 19
(65.5%) patients, and inferior in 10 (34.5%) patients. P237 Primary
percutaneous transluminal coronary angioplasty (PTCA) was
successfully performed for 22 (75.9%) patients, primary PTCA
was unsuccessful for four (13.8%) patients, and seven (24.1%)
patients underwent scheduled cardiac surgery within the first
2 weeks. The inhospital mortality rate was 41.4% (12 patients). Results Between April and December 2006 we treated 593
patients including 119 STEMI (20.1%) and 45 CS patients
(7.6%); 66.7% were male, mean age was 67.4 years. CS
presented with ST elevation in 48.9%, as non-STEMI in 33.3%,
rescue percutaneous coronary intervention (PCI) in 11.1% or with
subacute ACS in 6.7%; 30.4% of CS were admitted through LA,
67.4% through LH and only one patient through the ED. Upon
admission, 50% of CS had required CPR, 69.6% were on
mechanical ventilation. In total 89.1% of CS underwent
angiography, with revascularization in 69.8% and intra-aortal
balloon pump treatment in 68.1%. The median DST for CS vs
STEMI was 82 vs 59.5 minutes (P = 0.07), and the IDT was
shorter for CS (172 vs 385 min, P < 0.05). Stratified by admission
source, the DST was equal between LA and LH (66 vs 84 min,
P = 0.75). CS patients with ST elevation were not treated
significantly faster than those without or CS with rescue PCI (64 vs
84 vs 94 min, P > 0.05 for each). Prehospital CPR did not lead to
significantly altered DST. The DST was <60 minutes in 31.3% of
CS compared with 50% STEMI patients. Mortality in CS patients
was significantly higher than that of STEMI patients (56.5% vs
7.6%, P < 0.05) but equal among CS subgroups (50% for ST-
elevation CS, 80% for non-STEMI CS, 40% for rPCI CS, no
deaths for CS with subacute ACS). It did not differ by admission
source and was not influenced by a DST < 60 minutes, intra-aortal
balloon pump or revascularization status. The initial (after initiation of IABC) CO was 3.7 ± 1.2 l/min, CI was
1.9 ± 0.7 l/min/m2, MPAP was 30 ± 7.1 mmHg (maximum
43 mmHg), PCWP was 19.1 ± 5.1 mmHg (maximum 26 mmHg). After the first 24 hours of IABC, the CO was 3.8 ± 1.6 l/min, CI
was 2 ± 0.9 l/min/m2, MPAP was 23.7 ± 7.1 mmHg (maximum
36 mmHg), PCWP was 16.8 ± 4 mmHg (maximum 24 mmHg). P238 Conclusion Our data demonstrate that baseline anemia is a strong
and independent predictor of future adverse events at 2 years in
patients with STEMI treated with PCA. P238
Intra-aortic balloon counterpulsation: impact on patient
hemodynamics in acute myocardial infarction complicated
by cardiogenic shock
J Brazdzionyte, A Macas, A Mickeviciene, G Baksyte
Kaunas University of Medicine, Kaunas, Lithuania
Critical Care 2007, 11(Suppl 2):P238 (doi: 10.1186/cc5398) P238
Intra-aortic balloon counterpulsation: impact on patient
hemodynamics in acute myocardial infarction complicated
by cardiogenic shock
J Brazdzionyte, A Macas, A Mickeviciene, G Baksyte
Kaunas University of Medicine, Kaunas, Lithuania
Critical Care 2007, 11(Suppl 2):P238 (doi: 10.1186/cc5398) Intra-aortic balloon counterpulsation: impact on patient
hemodynamics in acute myocardial infarction complicated
by cardiogenic shock J Brazdzionyte, A Macas, A Mickeviciene, G Baksyte
Kaunas University of Medicine, Kaunas, Lithuania
Critical Care 2007, 11(Suppl 2):P238 (doi: 10.1186/cc5398) Figure 1 (abstract P236) Figure 1 (abstract P236) Results The prevalence of anaemia (Hb < 11 g/dl in women and
Hb < 12 g/dl in men) in patients with an ACS was 15.4%. This
group was characterised by the following: woman (P < 0.0001),
higher age (P = 0.0001), less weight (P = 0.01), higher frequency
of high blood pressure (P
= 0.0001), diabetes mellitus
(P = 0.0001), history of ischaemic heart disease (P = 0.002) and
peripheral artery disease (P = 0.0001). This group presented a
major proportion of the NSTEMI (P = 0.015), higher level of renal
dysfunction (77% to 32%, P = 0.0001), and microalbuminuria
(61% to 32%, P = 0.0001). Patients with anaemia presented a S96 Available online http://ccforum.com/supplements/11/S2 P239 Elevation of Troponin T in critically ill septic patients is
common: but does it matter? A Thornley, A Turley, M Johnson, B Kunadian, M de Belder,
J Gedney
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P239 (doi: 10.1186/cc5399) P237 After 48 hours of IABC, CO was 4.1 ± 1.7 l/min, CI was 2.1 ± 0.8
l/min/m2, MPAP was 23.8 ± 6.5 mmHg (maximum 44 mmHg),
PCWP was 16.8 ± 4.6 mmHg (maximum 24 mmHg). Conclusion Intra-aortic balloon counterpulsation has a positive
impact on hemodynamic changes of patients with acute myocardial
infarction complicated by cardiogenic shock during the initial days
of treatment. Elevation of Troponin T in critically ill septic patients is
common: but does it matter? A Thornley, A Turley, M Johnson, B Kunadian, M de Belder,
J Gedney
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P239 (doi: 10.1186/cc5399) Background Troponin T (TnT) is an established marker of adverse
outcome in acute coronary syndrome patients and aids risk
stratification. Myocardial dysfunction and elevated of TnT are
common in critically ill patients and cardiology advice is often
sought. Conclusion Despite their higher complexity, patients with CS were
treated as fast as patients with STEMI, yet there was room for
improvement to increase the number of patients treated within the
first hour of admission for both STEMI and CS. Structural changes
and further implementation of standard operating procedures might
achieve this. We could not show a mortality difference for any of
our treatment variables, which might be due to the low number of
patients. Objective To evaluate the role of TnT as a predictor of all-cause
mortality in patients with severe sepsis/septic shock as defined by
international criteria. S97 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin (odds ratio 1.29 for 1,000 units) and no administration of inotropic
drug on day 1 (odds ratio 34.5) decrease the probability of
inhospital complications. The average efficacy of prognostication
reached 96.5%; the presence of complications was correctly
predicted in 88.9% of cases, and the absence of complications in
100% of cases. Methods A prospective observational study was performed on
patients admitted to a general adult ICU within 24 hours of the
development of severe sepsis/septic shock. Serial TnT samples
were taken over the first 96 hours. Patients were grouped into
three groups: A, TnT < 0.01 ng/ml; B, TnT 0.01–0.099 ng/ml; and
C, TnT > 0.099 ng/ml. Conclusion The HRV parameter LF on day 3, and LV ESV, atrial
fibrillation/flutter and inotropic agent administration on day 1 are
statistically significant independent predictors of inhospital
complications of MI with an average predictive efficacy of 96.5%. Results Blood from 49 patients was analysed. The peak Troponin
level was elevated (>0.01 ng/ml) in 39/49 patients (80%). There
was no significant difference between the three groups in terms of
hypertension, history of angina, myocardial infarction or systolic
blood pressure at time of ICU admission. Table 1 (abstract P239) Introduction The aim of this study was to investigate the
relationship between blood pressure and plasma magnesium levels
in patients referred to the emergency department with hypertensive
attack. Epidemiological evidence on the effects of magnesium on
blood pressure is inconsistent. Metabolic and experimental studies
suggest that magnesium may have a role in the regulation of blood
pressure. Magnesium regulates various ion channels in many
tissues, including those of the cardiovascular system. Magnesium
is the second most abundant intracellular cation, and the important
element that has numerous biological functions in the cardio-
vascular system. Furthermore, magnesium acts as a calcium
antagonist, regulating the calcium metabolism. Conclusions Elevated biochemical markers of cardiac myocyte
damage are common in patients with severe sepsis/septic shock. TnT elevation is a predictor of 6-month all-cause mortality. Clinicians should be aware of the significance of an elevated TnT
assay in this patient population. Prognostic markers in the acute phase of myocardial
infarction G Baksyte1, A Macas1, J Brazdzionyte1, V Saferis1,
M Tamosiunas2, A Krisciukaitis1
1Kaunas University of Medicine, Kaunas, Lithuania; 2Institute for
Biomedical Research, Kaunas, Lithuania
Critical Care 2007, 11(Suppl 2):P240 (doi: 10.1186/cc5400) Results Seventy-three patients (35 of whom were female, 38
males) were included in the study. The average age was 47 ± 6.3
(ranging from 33 to 68 years). The average blood pressure of the
patients was found as systolic 200 ± 10 (range 185–240) mmHg,
diastolic 105 ± 7 (range 95–110) mmHg. The average plasma
magnesium levels were 1.4 ± 0.3 (range 0.9–2.2) mg/l. The
plasma magnesium levels were low in 29 patients (ranging from
0.9 to 1.7 mg/l). There was a negative relationship systolic blood
pressure and plasma magnesium level (P < 0.05). In addition, there
was a negative relationship diastolic blood pressure and plasma
magnesium level (P < 0.05). Introduction The aim of the study was to assess the prognostic
value of heart rate variability, arrhythmias and left ventricular
systolic and diastolic function for the course and the outcome of
myocardial infarction (MI). Methods We prospectively studied 57 consecutive patients
admitted to the ICU of the Department of Cardiology of Kaunas
Medical University Hospital between 2002 and 2004 with acute
MI. The study protocol included 24-hour ECG monitoring on the
first day and the third day of admission and echocardiography
performed at days 2–4. Inhospital prognostic endpoints were
death and nonfatal events: postinfarction angina, progressive heart
failure, pulmonary edema and cardiogenic shock. Heart rate
variability (HRV) was assessed at days 1 and 3 by a 24-hour
recording using the ‘HeartLab’ system. A logistic regression model
was used to select the combination of statistically significant
variables and predict the complications. Conclusion Low plasma magnesium levels would be an important
factor for elevated blood pressure and hypertensive attack. Elevation of Troponin T in critically ill septic patients is
common: but does it matter? Patients with
undetectable TnT levels (<0.01 g/ml) had significantly lower 6-
month mortality rates than those with detectable levels (group A
2/10 (20%) vs Group B/C 23/39 (59%), P = 0.037; group B 8/15
(53%), group C 15/24 (63%)). See Table 1. The relationship between blood pressure and plasma
magnesium level in hypertensive patients The relationship between blood pressure and plasma
magnesium level in hypertensive patients A Bayir, B Cander, A Ak, S Girisgin
University, Meram Faculty of Medicine, Konya, Turkey
Critical Care 2007, 11(Suppl 2):P241 (doi: 10.1186/cc5401) Table 1 (abstract P239)
APACHE II
Mean
Inotropic
Group
Number
score
age (years)
support
Mortality
A
10
18.5 (8.2)
52 (17)
8
2/10
B
15
20 (5.7)
63 (15)
15
8/15
C
24
22.2 (6.8)
65 (14)
22
15/24 P240 Methods Patients were included who were taken to the emer-
gency department due to hypertensive attack. Their age, gender,
systolic and diastolic blood pressure were recorded. In order to
see the plasma magnesium levels, venous blood samples were
taken. The results were compared with a chi-square test. The
values P < 0.05 were accepted as significant. Prognostic markers in the acute phase of myocardial
infarction P241 The relationship between blood pressure and plasma
magnesium level in hypertensive patients Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P242) Objective To investigate the clinical and prognostic value of TnI
release in adult with acute Pc. Figure 1 (abstract P242) Objective To investigate the clinical and prognostic value of TnI
release in adult with acute Pc. Methods From January 2000 to March 2006 we retrospectively
studied 89 patients with the final diagnosis of acute myocarditis
(Mc), of which 66 (74%) fulfilled at least two criteria of acute Pc
(typical chest pain, pericardial friction rub, and/or alterations in the
ECG). We only included those diagnosed with idiopathic or viral
Pc with elevation of TnI over the level of cut for AMI in our hospital
(≥0.6 ng/dl). We divided patients into tertiles according to the
value of TnI (22 in each group). An echocardiographic (Echoc)
study and a ECG monitorization was performed at admission in all. The coronariography was done in 24 (36%), which did not show
lesions. The average follow-up was 24 ± 18 months and included
Echoc in 61 (92%). Methods From January 2000 to March 2006 we retrospectively
studied 89 patients with the final diagnosis of acute myocarditis
(Mc), of which 66 (74%) fulfilled at least two criteria of acute Pc
(typical chest pain, pericardial friction rub, and/or alterations in the
ECG). We only included those diagnosed with idiopathic or viral
Pc with elevation of TnI over the level of cut for AMI in our hospital
(≥0.6 ng/dl). We divided patients into tertiles according to the
value of TnI (22 in each group). An echocardiographic (Echoc)
study and a ECG monitorization was performed at admission in all. The coronariography was done in 24 (36%), which did not show
lesions. The average follow-up was 24 ± 18 months and included
Echoc in 61 (92%). Results Age 28 ± 9 years, 87% men; two (3%) patients had
antecedents of idiopathic Pc and only one of Mc. The average of
the peak of TnI was 17 ± 11 ng/dl, being the average of the values
of TnI in each group of 6 ± 3 (first tertile), 15 ± 2 (second tertile)
and 30 ± 11 ng/dl (third tertile). LVEF% was ≥55 in 61 (92%) and
there were no differences in the age and sex between the three
groups. The elevation of TnI did not correlate with the LVEF%
(62 ± 5 vs 61 ± 4 vs 60 ± 7; P = 0.60). Available online http://ccforum.com/supplements/11/S2 P243
Clinical meaning and prognosis of the elevation degree of
cardiac Troponin I in pericarditis of the adult: short-term
and mid-term follow-up results
E Abu Assi, C Peña Gil, R Vidal Perez, J Garcia Acuña,
A Amaro Cendon
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P243 (doi: 10.1186/cc5403)
Introduction The inflammatory process of acute pericarditis (Pc)
may involve the epicardium and cause myocardial damage, as
reflected by cardiac Troponin I (TnI) release. Studies performed surgery patients as well as severely hypertensive patients. Clevidipine is an ultrashort-acting, vascular and arterial-selective
calcium antagonist currently under development for treating acute
hypertension. Methods We analyzed data from two double-blinded, placebo-
controlled trials (ESCAPE-1 and ESCAPE-2) that evaluated the
ability of clevidipine to control BP in high-risk cardiovascular
surgery patients. In addition, we evaluated the design of a recently
initiated trial that analyzes clevidipine in severe hypertension
(VELOCITY trial). Results
In
both
ESCAPE-1
and
ESCAPE-2,
clevidipine
demonstrated a statistically significant decrease in mean arterial
pressure from baseline (P < 0.0001) compared with placebo at
the 5-minute time point. A BP lowering effect was observed within
1–2 minutes with clevidipine, with the median time to achieve
target systolic blood pressure (SBP) of 6 and 5.3 minutes,
respectively (see Figure 1). In the patients with acute severe
hypertension, the VELOCITY trial studies the percentage of
patients in whom the SBP falls below the lower limit of a patient-
specific predetermined target range at the initial dose of 2.0
mg/hour within 3 minutes of initiating the infusion, as well as the
percentage of patients who reach the prespecified target SBP
range within 30 minutes of the beginning of the study drug. Conclusion In adults with acute Pc, the elevation degree of TnI is
associated with the degree of elevation of the ST segment but it is
not a negative prognosis indicator. Emergency electrocardiography-guided pericardiocentesis
in cardiac tamponade Emergency electrocardiography-guided pericardiocentesis
in cardiac tamponade E Charalambous, S Manousakis, A Kioulpalis, A Skrivanou,
G Vrouchos
Venizelio General Hospital of Heraklion, Greece
Critical Care 2007, 11(Suppl 2):P244 (doi: 10.1186/cc5404) E Charalambous, S Manousakis, A Kioulpalis, A Skrivanou,
G Vrouchos Conclusion In both the ESCAPE-1 and ESCAPE-2 studies,
clevidipine demonstrated the ability to precisely achieve target
blood pressure reductions in a short period of time, in a high-risk
patient population. Further analysis of the rapid decreases noted
with clevidipine is being conducted in patients with acute severe
hypertension in the VELOCITY trial. Introduction Pericardiocentesis (PC) and pericardial fluid drainage
is the method of choice in cardiac tamponade (CT). It is usually
performed under echocardiography control. The objective of the
study was the description of CT etiology, symptoms and clinical
findings and the evaluation of the electrocardiography (ECG)-
guided PC procedure. P242 Precise and ultrarapid control of blood pressure with
clevidipine, an arterial selective calcium channel blocker J Varon1, J Levy2, C Dyke3, P Acosta4, S Aronson5
1The University of Texas, Houston, TX, USA; 2Emory Healthcare,
Atlanta, GA, USA; 3Gaston Medical Center, Gastonia, NC, USA;
4Dorrington Medical Associates, Houston, TX, USA; 5DUMC,
Durham, NC, USA
Critical Care 2007 11(Suppl 2):P242 (doi: 10 1186/cc5402) Results In our model statistically significant independent variables
for prediction of inhospital MI complications were HRV frequency
domain parameter low-frequency power (LF) on day 3, and left
ventricular end-systolic volume (LV ESV), atrial fibrillation/flutter
and inotropic agent administration on day 1. According to the
results, atrial fibrillation/flutter (odds ratio 25.6) and increased LV
ESV (odds ratio 1.067 (6.7%) for increase in 1 ml) increase the
probability of inhospital complications, while increased LF on day 3 Introduction Precise, rapid control of blood pressure (BP) is
important in emergency and critical care settings as uncontrolled
hypertension is associated with morbidity and mortality in high-risk S98 Available online http://ccforum.com/supplements/11/S2 Only the values of TnI in
the third tertile were associated with the elevation of the ST
segment in ≥5 derivations (P = 0.001), and with abnormal
ventricular wall motion (P = 0.046). There was no association with
the presence of pericardial effusion, arrhythmias nor cardiac failure. During follow-up, two (3%) patients presented Mc, and three Pc
without elevation of TnI. The remaining patients (92%) were
asymptomatic and without cardiac dysfunction. The average
LVEF% was >55% in all of them surgery patients as well as severely hypertensive patients. Clevidipine is an ultrashort-acting, vascular and arterial-selective
calcium antagonist currently under development for treating acute
hypertension. Methods We analyzed data from two double-blinded, placebo-
controlled trials (ESCAPE-1 and ESCAPE-2) that evaluated the
ability of clevidipine to control BP in high-risk cardiovascular
surgery patients. In addition, we evaluated the design of a recently
initiated trial that analyzes clevidipine in severe hypertension
(VELOCITY trial). Results
In
both
ESCAPE-1
and
ESCAPE-2,
clevidipine
demonstrated a statistically significant decrease in mean arterial
pressure from baseline (P < 0.0001) compared with placebo at
the 5-minute time point. A BP lowering effect was observed within
1–2 minutes with clevidipine, with the median time to achieve
target systolic blood pressure (SBP) of 6 and 5.3 minutes,
respectively (see Figure 1). In the patients with acute severe
hypertension, the VELOCITY trial studies the percentage of
patients in whom the SBP falls below the lower limit of a patient-
specific predetermined target range at the initial dose of 2.0
mg/hour within 3 minutes of initiating the infusion, as well as the
percentage of patients who reach the prespecified target SBP
range within 30 minutes of the beginning of the study drug. Conclusion In both the ESCAPE-1 and ESCAPE-2 studies,
clevidipine demonstrated the ability to precisely achieve target
blood pressure reductions in a short period of time, in a high-risk
patient population. Further analysis of the rapid decreases noted
with clevidipine is being conducted in patients with acute severe
hypertension in the VELOCITY trial. P245 Diagnostic accuracy of automated computerised
electrocardiogram interpretation compared with a panel of
experienced cardiologists Methods Four hundred and twenty-eight patients with an ACS,
admitted to our coronary care unit (CCU), were studied
prospectively. Sixty-three per cent presented a non-ST-segment
elevation myocardial infarction (NSTEMI) and 37% a ST-segment
elevation myocardial infarction (STEMI). During their hospitalization
we registered cardiovascular risk factors: we determined the
presence of microalbuminuria (>3 mg/dl) in a 24-hour urine
sample. We also took blood samples during the first 24 hours of
their admittance to the CCU for a complete hemogram, levels of
total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides,
creatinine,
creatinine
clearance
(Cockroft–Gault
equation),
glucose, HbAc1, high-sensibility C-reactive protein, Cystatin C and
a follow-up of levels of Troponin, CK and CK-MB. All patients were
submitted to a coronary angiography in the first 72 hours to give a
clinical score to their coronary artery disease (disease of one, two
or three arteries). A Turley1, A Roberts1, K Evemy2, I Haq2, T Irvine2, P Adams2
1The James Cook University Hospital, Middlesbrough, UK; 2Royal
Victoria Infirmary, Newcastle upon Tyne, UK
Critical Care 2007, 11(Suppl 2):P245 (doi: 10.1186/cc5405) S100
Introduction Computerised electrocardiogram (ECG) int
tation is widely applied, especially within the clinical settin
primary care and surgical preadmission. Concerns have
raised over the accuracy of computerised ECG interpretatio
aim was to compare the performance of computer-based
interpretation with that of a panel of experienced cardiologist
Methods All consecutive ECGs performed in a hospital card
department over a 1-week period were analysed. Two c
were assessed, open access patients from primary car
surgical preoperative assessment patients. Cardiologists
blinded
to
clinical
details
and
the
computerised
interpretation. ECGs were analysed by a panel of cardio
with the consensus view taken as the reference standard. were interpreted in relation to ‘rhythm’ and ‘other abnorm
and were classified as normal or abnormal. Results Seventy consecutive ECGs were analysed, 47 from
access and 23 from surgical preassessment. The cohort’s m
age was 60 years (range 27–87 years, male n = 30). Twen
ECGs were normal. There was complete disagreement ov
computerised ECG interpretation of one ECG, which was deem
major clinical significance. Partial disagreement occurred
remainder. The greatest level of disagreement related t
interpretation of left ventricular hypertrophy and ECG eviden
myocardial ischaemia/infarction. P246 Cystatin C in the prognostic stratification of patients with
an acute coronary syndrome A Lopez Lago, E González Babarro, J García Acuña,
S De Lange, E Abu Assi, R Vidal Pérez, M Santás Alvarez,
M Jaquet Herter, B Cid Alvárez, J González Juanatey
Clinic Universitary Hospital of Santiago, Santiago de Compostela,
Spain
Critical Care 2007, 11(Suppl 2):P246 (doi: 10.1186/cc5406) Conclusions ‘Classical’ symptoms and signs (low BP, pulsus
paradoxus, deep heart sounds or low voltage) can be absent in CT. Emergency PC with ECG intrapericardial ECG recording, after
meticulous TTE, can be safe. Appearance of nonmalignant
arrhythmias could be a rare complication. Introduction Early risk stratification is essential in the management
of
patients
with
an
acute
coronary
syndrome
(ACS). Measurements of renal function such as serum creatinine and
estimation of creatinine clearance carry independent prognostic
information in this population. Cystatin C is a new and better
marker of renal function than creatinine. The aim was therefore to
evaluate the prognostic value of cystatin C in this population. Methods Four hundred and twenty-eight patients with an ACS,
admitted to our coronary care unit (CCU), were studied
prospectively. Sixty-three per cent presented a non-ST-segment
elevation myocardial infarction (NSTEMI) and 37% a ST-segment
elevation myocardial infarction (STEMI). During their hospitalization
we registered cardiovascular risk factors: we determined the
presence of microalbuminuria (>3 mg/dl) in a 24-hour urine
sample. We also took blood samples during the first 24 hours of
their admittance to the CCU for a complete hemogram, levels of
total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides,
creatinine,
creatinine
clearance
(Cockroft–Gault
equation),
glucose, HbAc1, high-sensibility C-reactive protein, Cystatin C and
a follow-up of levels of Troponin, CK and CK-MB. All patients were
submitted to a coronary angiography in the first 72 hours to give a
clinical score to their coronary artery disease (disease of one, two
or three arteries). Introduction Early risk stratification is essential in the management
of
patients
with
an
acute
coronary
syndrome
(ACS). Measurements of renal function such as serum creatinine and
estimation of creatinine clearance carry independent prognostic
information in this population. Cystatin C is a new and better
marker of renal function than creatinine. The aim was therefore to
evaluate the prognostic value of cystatin C in this population. P243 Sixty-five percent of patients
showed repolarization changes, and only 16% had low voltage. On
TTE, 3/4 of patients had right atrium/right ventricle collapse and
the intapericardial space measured 1.8–3.8 cm. Only 39% of
patients exhibited cardiac enzyme increase (cardiac troponin I, CK-
MB), while the majority had elevated CRP. The underlying
diagnosis for CT in 35% of cases was lung adenocarcinoma/
nonsmall cell carcinoma or breast carcinoma. In 35% the final
diagnosis was that of idiopathic pericarditis. Seventy percent of
pericardial fluid samples were exudates and 74% were
sanguineous/serosanguineous. Four patients had pericardial fluid
under pressure. The mean volume drained was 1,540 ml (850–3,010),
the mean period of drainage was 56 hours (3 hours–14 days). No
major complications occurred; 23% patients had nonmalignant
arrhythmias (AF, NSVT). recognized in 39% and pulsus paradoxus was present in 29% of
cases. Only 12% had pericardial knock and pericardial friction rub
was absent in all patients. On ECG there was sinus rhythm in
71%, the rest being atrial fibrillation. Sixty-five percent of patients
showed repolarization changes, and only 16% had low voltage. On
TTE, 3/4 of patients had right atrium/right ventricle collapse and
the intapericardial space measured 1.8–3.8 cm. Only 39% of
patients exhibited cardiac enzyme increase (cardiac troponin I, CK-
MB), while the majority had elevated CRP. The underlying
diagnosis for CT in 35% of cases was lung adenocarcinoma/
nonsmall cell carcinoma or breast carcinoma. In 35% the final
diagnosis was that of idiopathic pericarditis. Seventy percent of
pericardial fluid samples were exudates and 74% were
sanguineous/serosanguineous. Four patients had pericardial fluid
under pressure. The mean volume drained was 1,540 ml (850–3,010),
the mean period of drainage was 56 hours (3 hours–14 days). No
major complications occurred; 23% patients had nonmalignant
arrhythmias (AF, NSVT). calculated for negative results as there were no false negative results. LR for abnormal ECG ‘rhythm’ were 18.3 (6.7–53.4) and for
abnormal ECG ‘other abnormalities’ were 3.15 (2.13–5.11) (Table 1). Conclusions Need exists to improve the diagnostic algorithms
used by computerised ECG interpretation. It is essential that all
automated computerised ECG interpretations be over read by a
physician. P243 Methods Thirty-nine consecutive patients (nine females) with CT,
mean age 56 years, underwent 41 emergency PC between
November 1998 and November 2006. There was full data registry
for 31 patients and 33 PC. We used a subxiphoidal approach in
31 and an apical approach in two cases. Catheters used were
Cordigan
(Braun)
and
C-PCS-830-LOCK
(Cook). A
full
transthoracic echocardiography (TTE) study preceded and PC was
performed under ECG monitoring (intrapericardial ECG recording). Results Patients with CT had the following symptoms or clinical
findings: dyspnea (77%), pleural effusion (68%), chest pain (48%),
weight loss (29%), fever (23%), cough (19%), peripheral edema
(12%), abdominal pain (12%), hoarseness (12%), jugular vein
distension (6%). Forty-five percent of patients were hemo-
dynamically stable, while 26% had high BP. The mean heart rate
on admission was 94/minute. Seventy-one percent of patients
exhibited hypoxemia (half of them mild). Deep heart sounds were Clinical meaning and prognosis of the elevation degree of
cardiac Troponin I in pericarditis of the adult: short-term
and mid-term follow-up results E Abu Assi, C Peña Gil, R Vidal Perez, J Garcia Acuña,
A Amaro Cendon
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P243 (doi: 10.1186/cc5403) E Abu Assi, C Peña Gil, R Vidal Perez, J Garcia Acuña,
A Amaro Cendon
Hospital Clínico Universitario, Santiago de Compostela, Spain
Critical Care 2007, 11(Suppl 2):P243 (doi: 10.1186/cc5403) Introduction The inflammatory process of acute pericarditis (Pc)
may involve the epicardium and cause myocardial damage, as
reflected by cardiac Troponin I (TnI) release. Studies performed
with TnI demonstrated that the temporal pattern of this release is
similar to that of an acute myocardial infarction (AMI); however, the
true prognostic significance of TnI remains unknown in this setting. Introduction The inflammatory process of acute pericarditis (Pc)
may involve the epicardium and cause myocardial damage, as
reflected by cardiac Troponin I (TnI) release. Studies performed
with TnI demonstrated that the temporal pattern of this release is
similar to that of an acute myocardial infarction (AMI); however, the
true prognostic significance of TnI remains unknown in this setting. S99 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin recognized in 39% and pulsus paradoxus was present in 29% of
cases. Only 12% had pericardial knock and pericardial friction rub
was absent in all patients. On ECG there was sinus rhythm in
71%, the rest being atrial fibrillation. P245 Likelihood ratios (LR) wer
Table 1 (abstract P245)
Abnormality
Kappa
Sensitivity
Rhythm
0.92 (0.84–1)
1 (0.88–1)
Other
0.68 (0.52–0.84)
1 (0.91–1) Introduction Computerised electrocardiogram (ECG) interpre-
tation is widely applied, especially within the clinical settings of
primary care and surgical preadmission. Concerns have been
raised over the accuracy of computerised ECG interpretation. Our
aim was to compare the performance of computer-based ECG
interpretation with that of a panel of experienced cardiologists. Methods All consecutive ECGs performed in a hospital cardiology
department over a 1-week period were analysed. Two cohorts
were assessed, open access patients from primary care and
surgical preoperative assessment patients. Cardiologists were
blinded
to
clinical
details
and
the
computerised
ECG
interpretation. ECGs were analysed by a panel of cardiologists
with the consensus view taken as the reference standard. ECGs
were interpreted in relation to ‘rhythm’ and ‘other abnormalities’
and were classified as normal or abnormal. Results We determined the Cystatin C level in 59 patients (16
females and 43 males). In 36% (21 patients) we found normal
levels (<0.95; 0.80 ± 0.9), called group 1. In the other group
(group 2) we found higher levels of Cystatin C (>0.95;
1.63 ± 0.77). Patients in group 2 presented a higher age, a higher
frequency of high blood pressure, worse Killip class score at the
moment of admittance, higher inflammatory activity (leucocytosis,
P = 0.001 and higher levels of C reactive protein, P = 0.005),
higher grade of renal dysfunction (P = 0.001) and anaemia
(P = 0.06). Patients in group 2 presented a worse intrahospital
prognosis with a higher incidence of cardiac insufficiency (45% to
14%, P = 0.01), ventricular arrhythmias (29% to 5%, P = 0.05),
pericardial effusion (18% to 0%, P = 0.05) and a higher mortality
(21% to 5%, P = 0.08). In the multivariant analysis, Cystatin C was
an independent predictor of cardiac insufficiency (OR = 4.5, 95%
CI 1.1–20.8, P = 0.05). Results Seventy consecutive ECGs were analysed, 47 from open
access and 23 from surgical preassessment. The cohort’s median
age was 60 years (range 27–87 years, male n = 30). Twenty-four
ECGs were normal. There was complete disagreement over the
computerised ECG interpretation of one ECG, which was deemed of
major clinical significance. Partial disagreement occurred in the
remainder. The greatest level of disagreement related to the
interpretation of left ventricular hypertrophy and ECG evidence of
myocardial ischaemia/infarction. P247 P247
The reduction of the glomerular filtration rate and the
presence of microalbuminuria at the moment of
admittance reduce the prognostics of patients with an
acute coronary syndrome
A Lopez Lago, J Garcia Acuña, S De Lange, E González
Babarro, M Jaquet Herter, E Abu Assi, A Amaro Cendon,
M Santás Alvárez, J González Juanatey
Clinic Universitary Hospital of Santiago, Santiago de Compostela,
Spain
Critical Care 2007, 11(Suppl 2):P247 (doi: 10.1186/cc5407) P247
The reduction of the glomerular filtration rate and the
presence of microalbuminuria at the moment of
admittance reduce the prognostics of patients with an
acute coronary syndrome
A Lopez Lago, J Garcia Acuña, S De Lange, E González
Babarro, M Jaquet Herter, E Abu Assi, A Amaro Cendon,
M Santás Alvárez, J González Juanatey
Clinic Universitary Hospital of Santiago, Santiago de Compostela,
Spain
Critical Care 2007, 11(Suppl 2):P247 (doi: 10.1186/cc5407) The reduction of the glomerular filtration rate and the
presence of microalbuminuria at the moment of
admittance reduce the prognostics of patients with an
acute coronary syndrome Background Elevated circulating levels of TNFα, brain natriuretic
peptide (BNP) and cardiac Troponin I (cTnI) have been connected
with adverse prognosis in patients with chronic heart failure (CHF). However, there are scant data about the predictive value of these
biomarkers in combination. Methods A total of 577 consecutive patients (mean age: 73 ± 9
years), who were hospitalized for acute decompensation of NYHA
class III/IV (65.3% of ischemic etiology) low-output (mean LVEF:
22 ± 5) CHF, were studied. Biochemical markers were measured
upon admission. The incidence of 31-day death was the
prespecified primary endpoint. Introduction Determination of the glomerular filtration rate (GFR)
in patients with an acute coronary syndrome (ACS) has an
important prognostic value. The presence of microalbuminuria
(MA) is a known risk factor in patients with hypertension and
diabetes. We know less about the effect of reduction of the GFR
on patients with an ACS. Results The incidence of the primary endpoint was 17.7%. By
multivariate Cox analysis, including baseline characteristics and the
study biomarkers, elevated circulating levels of TNFα (RR = 2.1;
P < 0.001), BNP (RR = 3.5; P < 0.001) and cTnI (RR = 3.8;
P < 0.001) were independently associated with the primary
endpoint. P248 Circulating levels of tumor necrosis factor alpha, brain
natriuretic peptide and cardiac Troponin I upon admission
and 31-day mortality in patients with acute
decompensated chronic heart failure P Batika Zairis1, M Zairis2, E Adamopoulou2,
H Michalopoulou1, S Foussas2
1Metaxa Hospital, Piraeus, Greece; 2Tzanio Hospital, Piraeus,
Greece
Critical Care 2007, 11(Suppl 2):P248 (doi: 10.1186/cc5408) P Batika Zairis1, M Zairis2, E Adamopoulou2, H Michalopoulou1, S Foussas2 P245 Likelihood ratios (LR) were not Table 1 (abstract P245)
Abnormality
Kappa
Sensitivity
Specificity
NPV
PPV
Rhythm
0.92 (0.84–1)
1 (0.88–1)
0.95 (0.85–0.98)
1 (0.93–1)
0.9 (0.76–0.97)
Other
0.68 (0.52–0.84)
1 (0.91–1)
0.68 (0.68–0.53)
1 (0.88–1)
0.75 (0.62–0.85) S100 Available online http://ccforum.com/supplements/11/S2 Conclusion Higher levels of Cystatin C (>0.95) in patients with an
ACS indicate a worse intrahospital prognosis and also a higher
inflammatory activity and renal dysfunction. Conclusion Higher levels of Cystatin C (>0.95) in patients with an
ACS indicate a worse intrahospital prognosis and also a higher
inflammatory activity and renal dysfunction. P247 When the patients were divided according to the number
of positive biomarkers (estimated by ROC analysis) there was a
significant gradual increase in the rate of the primary endpoint with
increasing of the number of the positive biomarkers (4.1%, 10%,
21.5% and 53.5% 31-day mortality rate for patients with zero, one,
two and three positive biomarkers, respectively; P < 0.001) (Figure 1). Method Four hundred and twenty-eight patients with an ACS,
admitted to our coronary care unit (CCU), were studied
prospectively. Sixty-three percent presented a non-ST-segment
elevation myocardial infarction and 37% a ST-segment elevation
myocardial infarction. During their hospitalization we registered
cardiovascular risk factors; we determined the presence of MA
(>3 mg/dl) in a 24-hour urine sample. We also took blood samples
during the first 24 hours of their admittance to the CCU for a
complete hemogram, levels of total cholesterol, HDL cholesterol,
LDL cholesterol, triglycerides, creatinine, creatinine clearance
(Cockroft–Gault equation), glucose, HbAc1, high-sensibility C-
reactive protein and a follow-up of levels of Troponin, CK and CK-
MB. P250 P250
Cardiopulmonary exercise testing as a screening test for
perioperative management of major cancer surgery: a pilot
study
R Raobaikady, S Dinesh, M Hacking, T Wigmore
The Royal Marsden NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P250 (doi: 10.1186/cc5410) Cardiopulmonary exercise testing as a screening test for
perioperative management of major cancer surgery: a pilot
study R Raobaikady, S Dinesh, M Hacking, T Wigmore
The Royal Marsden NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P250 (doi: 10.1186/cc5410) Introduction Cardiopulmonary exercise testing is an important
screening test to evaluate cardiorespiratory function before major
body cavity surgery. Introduction Cardiopulmonary exercise testing is an important
screening test to evaluate cardiorespiratory function before major
body cavity surgery. Introduction Over the past decade, coronary revascularisation has
helped reduce mortality and morbidity rates from coronary artery
disease. In addition to revascularisation, long-term prognosis is
dependent on successful implementation of secondary prevention,
in particular the use of aspirin, statins, angiotensin-converting
enzyme (ACE) inhibitors and, in many, β-blockers. Previous studies
have highlighted the under-utilisation of secondary preventative
strategies in this patient population. A focused review of secondary
preventative medication at the time of revascularisation provides an
excellent opportunity to ensure optimal use of these agents. Our
aim was to identify the proportion of patients undergoing
nonemergency surgical revascularisation discharged on these four
secondary preventative medications. Objective To develop a clinical strategy for the identification and
management of high-risk major cancer surgical patients in order to
reduce perioperative morbidity and mortality. Methods Forty-one major cancer surgery patients underwent a
cardiopulmonary exercise test (CPX) as part of their preoperative
assessment. Their cardiac and pulmonary risk factors were
analysed. Depending on the anaerobic threshold (AT) values,
patients are considered poor risk, moderate risk or very low risk for
surgery. Results Three patients did not complete the test. Two of them had
very poor cardiopulmonary reserve and one had leg fatigue with
good pulmonary function. Seven patients were considered high
risk with AT < 10. The remaining 31 patients had AT > 11 and
underwent major cancer surgery. In total, 10 surgical procedures
were cancelled based on poor CPX performance. Two patients
with low AT underwent surgery after preoptimisation with no
complications. There are no deaths related to cardiopulmonary
complications in any patient deemed fit for major cancer surgery
and intensive care management, as determined by CPX testing. P250 The average intensive care stay was 8.9 days (range 1–19 days). The surgical procedure was altered in two patients based on CPX
results. Methods A retrospective analysis of our inhouse cardiothoracic
surgical database was performed. All patients had undergone
surgical revascularisation between January 2003 and November
2006. Only patients undergoing coronary artery bypass grafting
were included. Results A total of 2,749 consecutive patients were included in the
analysis, mean age 65.5 years (±9.2). In total, 2,302 isolated
coronary artery bypass grafting procedures and 447 combined
procedures were performed. See Table 1. Table 1 (abstract P249)
2003
2004
2005
2006
Total
522
758
767
702
Previous myocardial
296
364
353
347
infarction
(56.7%)
(48%)
(46%)
(49.4%)
Left ventricular
113
145
175
186
systolic dysfunction
(21.6%)
(19.1%)
(22.8%)
(26.5%)
EuroSCORE
3.8 (2.7)
3.9 (3)
3.9 (2.8)
4.3 (2.9)
Aspirin
490
694
700
652
(93.9%)
(91.6%)
(91.3%)
(92.9%)
ACE inhibitor/
285/34
421/43
430/53
382/49
angiotensin receptor
(61%)
(61%)
(63%)
(61%)
blocker
β-Blocker
412
632
587
540
(78.9%)
(83.4%)
(76.5%)
(76.9%)
Statin
470
700
710
638
(90%)
(92.3%)
(92.6%)
(90.9%) Discussion CPX testing is an important screening test for major
surgery to determine the cardiorespiratory risk factors. It is useful in
reducing surgical perioperative mortality and avoids unnecessary
intensive care admissions after major body cavity surgeries. The
CPX test is also useful in perioperative anaesthetic management. It
may not predict morbidity and the average intensive care stay. It is
very useful in selecting patients for preoptimisation before major
cancer surgery. Conclusion Preoperative screening using CPX testing is useful in
identification of high-risk cancer surgical patients and the
appropriate selection of perioperative management. Figure 1 (abstract P248) Conclusions The present results suggest that in patients
hospitalized due to acutely decompensated severe low-output
CHF, serum levels of TNFα, BNP and cTnI can be used in
combination for enhanced early risk stratification. Results Thirty-nine percent of the patients with an ACS presented
a GFR less than 60 ml/minute, and 36% presented MA at the
moment of admittance to the CCU. Forty-four percent of the
patients with a GFR less than 60 ml/minute also presented MA; on
the contrary, only 32% of the patients with a GFR more than 60
ml/minute did so (P = 0.01). This group contains significantly more
women (P = 0.001), more history of ischemic brain events and
peripheral artery disease (P = 0.03), worse Killip score at the
moment of admittance (P = 0.001), more development of cardiac
insufficiency (P = 0.003) and a higher mortality during hospital stay
(P = 0.03). The intrahospital survival of patients with GFR less than 60
ml/minute and MA was 79%, to 96% in patients without MA and a
GFR more than 60 ml/minute (P = 0.01; Log-rank test = 6). Patients with a GFR less than 60 ml/minute but without MA
presented an intrahospital survival of 85%. In the multivariant
analysis a GFR less than 60 ml/minute (OR = 2.0; 95% CI
1.13–3.53) and the presence of MA (OR = 2.30; 95% CI
1.37–3.86) were independent predictive factors of cardiac
insufficiency and mortality. Conclusions The present results suggest that in patients
hospitalized due to acutely decompensated severe low-output
CHF, serum levels of TNFα, BNP and cTnI can be used in
combination for enhanced early risk stratification. Conclusions The presence of a GFR less than 60 ml/minute and
MA at the moment of admittance of a patient with an ACS
identifies a group of patients with a bad prognosis. Future studies
can reveal whether an improvement of the renal function can be
beneficial for this group of patients. S101 P249
Secondary prevention following surgical revascularisation:
continuing under-use of angiotensin-converting enzyme
inhibitors
A Turley, A Thornley, A Roberts, R Morley, W Owens,
M de Belder
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P249 (doi: 10.1186/cc5409) P249
Secondary prevention following surgical revascularisation:
continuing under-use of angiotensin-converting enzyme
inhibitors
A Turley, A Thornley, A Roberts, R Morley, W Owens,
M de Belder
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P249 (doi: 10.1186/cc5409) Low-dose dobutamine after surgery in high-risk patients:
effects on postoperative complications Low-dose dobutamine after surgery in high-risk patients:
effects on postoperative complications Low-dose dobutamine after surgery in high-risk patients:
effects on postoperative complications S Lobo, A Arantes, A Christiano Junior, S de Abreu,
J de Moraes, J Gandolfi, L Leite
Faculdade de Medicina de São José do Rio Preto, Brazil
Critical Care 2007, 11(Suppl 2):P251 (doi: 10.1186/cc5411) S Lobo, A Arantes, A Christiano Junior, S de Abreu,
J de Moraes, J Gandolfi, L Leite
Faculdade de Medicina de São José do Rio Preto, Brazil
Critical Care 2007, 11(Suppl 2):P251 (doi: 10.1186/cc5411) Conclusion Although the utilisation of these preventive therapies
has improved compared with previous studies, additional
improvements could be made and in particular there is a continuing
under-utilisation of ACE inhibitors. There are several reasons why
ACE inhibitors might not be used in the early postoperative phase
(hypotension, temporary renal dysfunction, etc.). These results
reinforce the need to review these patients following recovery from
surgery with a view to optimising secondary preventive treatment. This may best be done in community secondary prevention clinics
with agreed guidelines. Introduction Dobutamine may have a role in increasing splanchnic
perfusion, thereby protecting this area from further injury. We
aimed to investigate the effects of low-dose dobutamine
(5 µg/kg/min) on tissue perfusion and postoperative complications
in high-risk patients. Introduction Dobutamine may have a role in increasing splanchnic
perfusion, thereby protecting this area from further injury. We
aimed to investigate the effects of low-dose dobutamine
(5 µg/kg/min) on tissue perfusion and postoperative complications
in high-risk patients. Methods
A prospective, randomized, blinded and placebo-
controlled study. One hundred surgical patients admitted to a step-
down unit were evaluated and 82 patients were enrolled, 42 for the
control group (saline) and 40 for the dobutamine group
(5 µg/kg/hour during 24 hours). The same therapeutic goals were S102 Available online http://ccforum.com/supplements/11/S2 P252 Results Gastrointestinal complications occurred in 63 patients,
while in 35 patients appeared transient episodes of gut mucosal
ischemia. Sixteen patients presented mesenteric ischemia, six
paralytic ileus, six colonic obstruction, two lower gastrointestinal
bleeding, two upper gastrointestinal bleeding, two perforated
duodenal ulcer and one rectal perforation. Intestinal complications
correlated with advanced age (67.5 ± 12 years), preoperative
congestive heart failure and peripheral vascular disease, prolonged
bypass time (156 ± 91.7 min) and aortic cross-clump time
(97.6 ± 44.45 min), the number of blood and plasma transfusions,
re-exploration of the chest, the administration of inotrops (70%)
and the usage of a intra-aortic balloon pump (42%). The mean
EuroSCORE value was 12.72 ± 3.8. The majority of patients
presented at the end of the first postoperative week. Fifteen
patients died (48%). Methods A prospective survey was conducted among 4,588 patients
undergoing cardiac surgery and attending the surgical ICU from 1
January 2002 to 31 December 2004. All case histories of patients
were objected to meticulous analysis searching for complications
involving gastrointestinal tract and requiring surgical consultation. Patients with minor disorders were excluded from the study. We
performed a multivariable logistic regression analysis to identify the
risk factors for development of postoperative intestinal complications. Results Gastrointestinal complications occurred in 63 patients,
while in 35 patients appeared transient episodes of gut mucosal
ischemia. Sixteen patients presented mesenteric ischemia, six
paralytic ileus, six colonic obstruction, two lower gastrointestinal
bleeding, two upper gastrointestinal bleeding, two perforated
duodenal ulcer and one rectal perforation. Intestinal complications
correlated with advanced age (67.5 ± 12 years), preoperative
congestive heart failure and peripheral vascular disease, prolonged
bypass time (156 ± 91.7 min) and aortic cross-clump time
(97.6 ± 44.45 min), the number of blood and plasma transfusions,
re-exploration of the chest, the administration of inotrops (70%)
and the usage of a intra-aortic balloon pump (42%). The mean
EuroSCORE value was 12.72 ± 3.8. The majority of patients
presented at the end of the first postoperative week. Fifteen
patients died (48%). Conclusion Various predictors of hypoperfusion have been tested
in critically ill patients and correlations have been found for O2 and
CO2 derived parameters. Long ECC time plays a major role in the
balance between VO2 and DO2; O2 and CO2 derived parameters
could be useful markers to detect anaerobic metabolism in cardiac
surgical patients. Combined metabolic parameters and gas exchange to
predict morbidity after extracorporeal circulation Combined metabolic parameters and gas exchange to
predict morbidity after extracorporeal circulation S Scolletta, E Maglioni, F Franchi, P Giomarelli, B Biagioli
University of Siena, Italy
Critical Care 2007, 11(Suppl 2):P253 (doi: 10.1186/cc5413) Results Complications occurred in 35% and 50% of the patients
in the dobutamine and control groups, respectively (RR 0.70, 95%
CI 0.41–1.17; not significant). The patients in whom dobutamine
was interrupted due to persistent tachycardia despite fluid
replacement had more complications (75% vs 40.6%; RR 1.85,
95% CI 1.03–3.29, P < 0.05), higher mortality (62.5% vs 12.5%;
RR 5.0, 95% CI 1.72–14.46, P < 0.05) and lower central venous
oxygen saturation (55% ± 15% vs 70% ± 16%; P = 0.021) in
comparison with patients tolerant to dobutamine infusion. Introduction Under normal resting conditions, the oxygen delivery
(DO2) matches the overall metabolic demands of the organs, the
oxygen consumption (VO2) is about 25% of the DO2, and energy
is produced basically through the aerobic mechanism. In cardiac
surgery with extracorporeal circulation (ECC), several factors (for
example, hemodilutional anemia, myocardial stunning resulting in a
low cardiac output (CO)) can determine an imbalance between O2
demand and DO2 and may affect the outcome. Below the critical
DO2 there is a linear decrease of both VO2 and CO2 production
(VCO2), but due to the anaerobic VCO2 the respiratory quotient
increases. This study is aimed to evaluate the role of O2 and CO2
derived parameters to predict postoperative morbidity in cardiac
surgery. Conclusion Low-dose dobutamine after surgical trauma has no
effects on the prevalence of postoperative complications in high-
risk surgical patients. Morbimortality was significantly higher in
patients with severe occult hypoperfusion. P253 applied for both groups. The presence of tachycardia or
hypotension in response to study drug infusion was considered a
signal of occult hypoperfusion and deemed a need for fluid
replacement, which was given according to an algorithm. Results Complications occurred in 35% and 50% of the patients
in the dobutamine and control groups, respectively (RR 0.70, 95%
CI 0.41–1.17; not significant). The patients in whom dobutamine
was interrupted due to persistent tachycardia despite fluid
replacement had more complications (75% vs 40.6%; RR 1.85,
95% CI 1.03–3.29, P < 0.05), higher mortality (62.5% vs 12.5%;
RR 5.0, 95% CI 1.72–14.46, P < 0.05) and lower central venous
oxygen saturation (55% ± 15% vs 70% ± 16%; P = 0.021) in
comparison with patients tolerant to dobutamine infusion. applied for both groups. The presence of tachycardia or
hypotension in response to study drug infusion was considered a
signal of occult hypoperfusion and deemed a need for fluid
replacement, which was given according to an algorithm. P252 Intestinal complications associated with cardiovascular
surgical procedures
S Mastoraki, E Mastoraki, L Douka, I Kriaras, S Geroulanos
Onassis Cardiac Surgery Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P252 (doi: 10.1186/cc5412) Intestinal complications associated with cardiovascular
surgical procedures Methods Eight hundred and twenty-seven consecutive adult
patients who underwent coronary surgery were studied. We
selected 38 intraoperative and postoperative O2 and CO2 derived
parameters, which could be associated with postoperative
morbidity. Postoperative data were collected in the first 3 hours
after admission to the ICU. The influence of each predictor on
outcome was analyzed. Morbidity was defined as one or more of
the following events: cardiovascular, respiratory, neurological,
renal, infectious, and hemorrhagic complications. Univariate and
multivariate analyses were performed. ROC curve analysis was
also used to define the best predictive variables. S Mastoraki, E Mastoraki, L Douka, I Kriaras, S Geroulanos
Onassis Cardiac Surgery Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P252 (doi: 10.1186/cc5412) Introduction Intestinal complications after cardiopulmonary bypass
procedures are infrequent but they carry a significant incidence of
morbidity and mortality. Predictors of these complications are not
well developed, and the role of fundamental variables remains
controversial. The purpose of this study was to ascertain the
frequency of intestinal complications following open heart surgery,
to assess preoperative predisposing factors and to elucidate that
prompt diagnosis and institution of therapy are the most common
factors to improve the outcome. Results Intraoperative predictors of morbidity were ECC and
aortic cross-clamp times, and lowest hematocrit during ECC. The
area under the ROC curve (AUC) was 0.74 for the lowest
hematocrit on ECC, and its cutoff value was 24%. Among the
postoperative variables, DO2, oxygen extraction ratio (O2ER),
DO2/VCO2 ratio, and VCO2/CO ratio were related to morbidity. The AUCs for oxygen and CO2 derived parameters were 0.80,
0.76, 0.75, and 0.70 (DO2, O2ER, DO2/VCO2
ratio, and
VCO2/CO ratio, respectively). The best predictive cutoff values
were 590 ml/minute, 38%, 3.9, and 40, for DO2, O2ER,
DO2/VCO2 ratio, and VCO2/CO ratio, respectively. p
Methods A prospective survey was conducted among 4,588 patients
undergoing cardiac surgery and attending the surgical ICU from 1
January 2002 to 31 December 2004. All case histories of patients
were objected to meticulous analysis searching for complications
involving gastrointestinal tract and requiring surgical consultation. Patients with minor disorders were excluded from the study. We
performed a multivariable logistic regression analysis to identify the
risk factors for development of postoperative intestinal complications. P255 Role of plasminogen activator inhibitor-1 polymorphism on
the development of vasoplegic syndrome associated with
cardiopulmonary bypass J Jimenez, J Iribarren, M Brouard, Y Barrios, J Raya, L Lorente,
R Perez, C Garcia, J Martinez, R Martinez, M Mora
Hospital Universitario de Canarias, La Laguna, Santa Cruz,
Tenerife, Spain
Critical Care 2007, 11(Suppl 2):P255 (doi: 10.1186/cc5415) Introduction Vasoplegic syndrome (VS) after cardiac surgery with
cardiopulmonary bypass (CPB) can vary from mild to severe
complication and it appears with an incidence ranging between
5% and 15%. The etiology is not completely elucidated but risk
factors such as temperature and duration of cardiopulmonary
bypass and preoperative treatment with angiotensin-converting
enzyme (ACE) inhibitors have been associated [1]. We wanted to
investigate the possible role of several genetic polymorphisms in
patients with VS after elective CPB. Introduction Vasoplegic syndrome (VS) after cardiac surgery with
cardiopulmonary bypass (CPB) can vary from mild to severe
complication and it appears with an incidence ranging between
5% and 15%. The etiology is not completely elucidated but risk
factors such as temperature and duration of cardiopulmonary
bypass and preoperative treatment with angiotensin-converting
enzyme (ACE) inhibitors have been associated [1]. We wanted to
investigate the possible role of several genetic polymorphisms in
patients with VS after elective CPB. Results Seventeen (34%) patients had VS, 11 (65%) men and six
(35%) women. Longer aortic clamping time (P = 0.007) and CPB
time (P = 0.013) were associated with VS. These patients showed
a higher cardiac index at 4 hours (P < 0.001) and lactic acid within
the first 24 hours. Seven of these patients (41%) fulfilled
vasoplegic shock criteria (P < 0.001). We found higher levels of
IL-6 at 0 hours (P = 0.02) and 4 hours (P = 0.001), and soluble
TNF receptor at 0 hours (P = 0.044). At ICU admission (0 hours)
there was a higher coagulation activation: INR (P = 0.005),
fibrinogen (P = 0.001), antithrombin (P = 0.007); lower levels of
plasminogen activator inhibitor-1 (P = 0.023) as well as lower
plasminogen activator inhibitor-1/tissue-plasminogen activator ratio
(P = 0.021), and higher levels of D-dimer (P = 0.041); lower levels
of C3 (P = 0.023), B factor (P = 0.013), C4 (P = 0.015) as well as
a significantly higher decrease between preoperative and 0-hour
levels of C1-inhibitor, C4, C3 and B factor. Lower levels of leptins
at 0, 4 and 24 hours were found. P254 Vasoplegic syndrome after cardiopulmonary bypass
surgery – associated factors and clinical outcomes:
a nested case–control study
J Iribarren, J Jimenez, M Brouard, J Lorenzo, R Perez,
L Lorente, C Nuñez, L Lorenzo, C Henry, R Martinez, M Mora
Hospital Universitario de Canarias, La Laguna, Santa Cruz,
Tenerife, Spain
Critical Care 2007, 11(Suppl 2):P254 (doi: 10.1186/cc5414) Vasoplegic syndrome after cardiopulmonary bypass
surgery – associated factors and clinical outcomes:
a nested case–control study J Iribarren, J Jimenez, M Brouard, J Lorenzo, R Perez,
L Lorente, C Nuñez, L Lorenzo, C Henry, R Martinez, M Mora
Hospital Universitario de Canarias, La Laguna, Santa Cruz,
Tenerife, Spain
Critical Care 2007, 11(Suppl 2):P254 (doi: 10.1186/cc5414) Conclusions Intestinal complications after cardiac surgery are
uncommon but life-threatening and may result from ischemic
mucosal injury, which increases mucosal permeability and
promotes the translocation of bacterial toxins and the release of
mediators. Clinical features are often subtle and a high index of
suspicion is necessary for an early diagnosis and the institution of
appropriate treatment. Introduction Vasoplegic syndrome (VS) following heart surgery
using cardiopulmonary bypass (CPB) has been recently
recognized and implicated in life-threatening complications. The Introduction Vasoplegic syndrome (VS) following heart surgery
using cardiopulmonary bypass (CPB) has been recently
recognized and implicated in life-threatening complications. The S103 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusions VS post-CPB was associated with activation of serin
protease systems, which leads to higher blood loss and excessive
bleeding. aim of this study was to identify associated factors for the
development of VS after CPB. Methods We performed a nested case–control study of 50
patients undergoing CPB, 27 (54%) men and 23 (46) women,
mean age 66.5 (SD 9.6) years. VS was defined as systemic
vascular resistance index <1,600 dyn•seg/cm5/m2 and cardiac
index >2.5 l/min/m2
within the first postoperative 4 hours. Vasoplegic shock was defined as vasoplegic patients that needed
norepinephrine for at least 4 hours, after failure to respond to
appropriate volume expansion. Excessive bleeding was defined as
blood loss >1 l/24 hours, while total bleeding was considered as
blood loss until chest tube withdrawal. Demographic variables,
surgical procedures and postoperative variables were collected. We recorded data related to coagulation, fibrinolysis, complement,
inflammation, blood loss at different time points, preoperative, at 0,
4 and 24 hours after surgery, and hemoderivative requirements. P254 We used the Pearson chi-squared test, the Fisher exact test, the
Student t test and the Mann–Whitney U test for nonparametric
variables. SPSS version 12.1 was used. P255 Vasoplegic patients showed
higher blood losses along all time points (Figure 1), higher
incidence of excessive bleeding (60% vs 40%; P = 0.011) and
required more hemoderivatives during the ICU stay, plasma
(P = 0.016) and platelets (P = 0.002). Methods We performed a nested case–control study of 50
patients undergoing CPB, 27 (54%) men and 23 (46) women,
mean age 66.5 (SD 9.6) years. VS was defined as systemic
vascular resistance index lower than 1,600 dyn•seg/cm5/m2 and a
cardiac index greater than 2.5 l/min/m2 within the first 4 hours after
surgery. We recorded data related to hemodynamic parameters at
different postoperative time points, at ICU admission (0 hours), 4
and 24 hours after surgery, and the polymorphism of the following
genes: plasminogen activator inhibitor-1 (PAI-1) and β-TNF + 250. In addition, 23 neutral markers were genotyped to follow genomic
control strategies that would detect spurious associations due to
population substructure. We used the Pearson chi-squared test
and binary logistic regression. SPSS version 12.1 was used. Results We observed 17 (34%) patients with vasoplegia criteria,
11 (65%) men and six (35%) women, age 67 (61–72) years. The
only one associated with VS was the PAI-1 polymorphism, and its
distribution in the study population was: 4G/G genotype in 10
(20%) patients, 4G/5G in 26 (52%) patients, and 5G/G in 14 Available online http://ccforum.com/supplements/11/S2 Methods We performed a nested case–control study of 26
patients, who did not receive antifibrinolytic prophylaxis. We used
Bray’s classification for BMI: lower than 27 kg/m2; 27–30 kg/m2;
higher than 30 kg/m2. Variables were collected preoperatively, at
ICU admission (0 hours), and at 4 and 24 hours after surgery. Excessive bleeding was defined as blood loss higher than 1 l in the
first 24 hours after intervention. The associations of BMI with
demographic factors, leptin levels, coagulation, fibrinolysis and
complement parameters were analyzed. Pearson’s chi-squared test
and Fisher’s exact test were used, the Student t test for independent
groups and the Mann–Whitney U test for nonparametric variables. Conclusions The PAI-1 polymorphism (homozygous 5G/G) was
independently associated with the onset of VS. 1. Carrel T, Englberger L, Mohacsi P, Neidhart P, Schmidli J:
Low systemic vascular resistance after cardiopulmonary
bypass: incidence, etiology, and clinical importance. J Card Surg 2000, 15:347-353. P256 Results In total, 61.5% of patients showed BMI >27 kg/m2
(median 28 kg/m2, range 25.2–30.7 kg/m2). Patients with BMI
lower than 26.4 kg/m2 (25–28 kg/m2) presented excessive
bleeding (P = 0.026). Leptin levels after adjusting by BMI were
significantly associated with excessive bleeding at all postoperative
time points (P < 0.001, P < 0.001 and P = 0.004, respectively)
(Figure 1). BMI presented a direct correlation with leptins,
fibrinogen and plasminogen activator inhibitor-1 (PAI-1) on arrival,
meanwhile 24-hour bleeding showed an inverse correlation with
the same parameters and BMI (Table 1). Patients with BMI
< 27 kg/m2 had significantly greater coagulation, fibrinolysis and
complement
activation. Therefore
these
patients
required
significantly greater hemoderivatives. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 postoperative bleeding after cardiopulmonary bypass (CPB) has
been found in several studies recently. Nevertheless the strong
relationship between a low BMI and excessive bleeding remains
unexplained. We sought to investigate the BMI role on
postoperative bleeding and its relationship with leptin levels,
coagulation, fibrinolysis and complement parameters. Methods We performed a nested case–control study of 26
patients, who did not receive antifibrinolytic prophylaxis. We used
Bray’s classification for BMI: lower than 27 kg/m2; 27–30 kg/m2;
higher than 30 kg/m2. Variables were collected preoperatively, at
ICU admission (0 hours), and at 4 and 24 hours after surgery. Excessive bleeding was defined as blood loss higher than 1 l in the
first 24 hours after intervention. The associations of BMI with
demographic factors, leptin levels, coagulation, fibrinolysis and
complement parameters were analyzed. Pearson’s chi-squared test
and Fisher’s exact test were used, the Student t test for independent
groups and the Mann–Whitney U test for nonparametric variables. Results In total, 61.5% of patients showed BMI >27 kg/m2
(median 28 kg/m2, range 25.2–30.7 kg/m2). Patients with BMI
lower than 26.4 kg/m2 (25–28 kg/m2) presented excessive
bleeding (P = 0.026). Leptin levels after adjusting by BMI were
significantly associated with excessive bleeding at all postoperative
time points (P < 0.001, P < 0.001 and P = 0.004, respectively)
(Figure 1). BMI presented a direct correlation with leptins,
fibrinogen and plasminogen activator inhibitor-1 (PAI-1) on arrival,
meanwhile 24-hour bleeding showed an inverse correlation with
the same parameters and BMI (Table 1). Patients with BMI
< 27 kg/m2 had significantly greater coagulation, fibrinolysis and
complement
activation. Therefore
these
patients
required
significantly greater hemoderivatives. (28%) patients. According to the PAI-1 polymorphism, vasoplegia
criteria were found in one (5.5%) 4G/G carrier, in seven (39%)
4G/5G carriers and in 10 (55.5%) 5G/G carriers (P = 0.012)
(Figure 1). The post-hoc power for PAI-1 polymorphism and
vasoplegia was 0.85. After controlling for temperature, clamping
time, antifibrinolytics, body mass index and ACE inhibitors, the
5G/G genotype was independently associated with vasoplegia
(P = 0.017); OR: 24.6 (95% CI: 1.8–342). postoperative bleeding after cardiopulmonary bypass (CPB) has
been found in several studies recently. Nevertheless the strong
relationship between a low BMI and excessive bleeding remains
unexplained. We sought to investigate the BMI role on
postoperative bleeding and its relationship with leptin levels,
coagulation, fibrinolysis and complement parameters. Figure 1 (abstract P257) Methods We performed a nested case–control study of 50 patients
undergoing CPB, 27 (54%) men and 23 (46) women, mean age 66.5
(SD 9.6) years. Excessive bleeding (EB) was defined as blood loss
higher than 1 l over the 24 hours. Demographic variables, comorbid
conditions, surgical procedures and postoperative variables were
collected. We recorded data related to coagulation, fibrinolysis,
complement, and blood loss at different time points, preoperative, at
ICU admission (0 hours) and 4 and 24 hours after surgery. We used
the Pearson chi-squared test, the Fisher exact test, the Student t test
and the Mann–Whitney U test for nonparametric variables and
Spearman’s rho for nonparametric correlations. Figure 1 (abstract P257) Results EB patients had higher activation of classical, alternative
and final pathways of complement at 0 and 4 hours. Also we found
a significantly higher decreasing of several components of
complement from preoperative values to postoperative values (0
and 4 hours) associated with EB. This decrease of complement
was correlated with a similar decrease of platelets and anti-
thrombin levels between the preoperative period and 0 hours, and
an increase of D-dimer levels in the first 4 hours. Conclusions Complement activation was associated with EB due, in
part, to a greater activation of platelets, coagulation and fibrinolysis. Table 1 (abstract P257)
ICU arrival
BMI
24-hour bleeding
Rho
P
Rho
P
Leptins
0.46
0.02
–0.57
0.02
Fibrinogen
0.51
<0.01
–0.49
<0.01
PAI-1
0.40
0.04
–0.64
<0.01
Conclusions Lower BMI was associated with higher postoperative
bleeding and lower procoagulant factor levels. Table 1 (abstract P257) P257 Impact of body mass index on postoperative bleeding in
cardiopulmonary bypass Complement activation and excessive bleeding in
cardiopulmonary bypass surgery J Iribarren, J Jimenez, M Brouard, R Galvan, L Lorente, R Perez,
B Alarco, M Diaz, J Malaga, S Huidobro, R Martinez, M Mora
Hospital Universitario de Canarias, La Laguna, Santa Cruz,
Tenerife, Spain
Critical Care 2007, 11(Suppl 2):P256 (doi: 10.1186/cc5416) Introduction Complement activation has been associated with
postoperative bleeding. We investigated the association between
complement activation, coagulation and fibrinolysis systems, and
postoperative excessive bleeding in cardiopulmonary bypass
(CPB) surgery. Introduction Complement activation has been associated with
postoperative bleeding. We investigated the association between
complement activation, coagulation and fibrinolysis systems, and
postoperative excessive bleeding in cardiopulmonary bypass
(CPB) surgery. Figure 1 (abstract P254) Figure 1 (abstract P254) 4
Figure 1 (abstract P254)
Figure 1 (abstract P255) Figure 1 (abstract P255) Figure 1 (abstract P255) S104 Available online http://ccforum.com/supplements/11/S2 E Borotto1, D Tüller1, S Krähenbühl2, D Mettler1, J Takala1,
S Jakob1
1University Hospital Bern, Switzerland; 2University Hospital Basel,
Switzerland
Critical Care 2007, 11(Suppl 2):P258 (doi: 10.1186/cc5418) Introduction Endotoxemia and hemorrhage may both affect
mitochondrial function. We aimed to characterize the impact of a
short-term, three-hit hemorrhage/endotoxemia model on liver and
skeletal muscle mitochondrial respiration. Results Hyperdynamic circulation developed in F with increasing
DO2,h and decreasing VO2,h (Table 1). Complex II activity signifi-
cantly decreased from 19.3 ± 4.2 to 9.5 ± 2.6 (P < 0.05 vs BL
and between groups) in F compared with C. Complex I–III–IV
function decreased in parallel in F. Methods Seven anesthetized pigs were bled (blood loss 20%)
and retransfused to euvolemia before and after endotoxin infusion
(0.4 µg/kg/hour for 2 hours). The cardiac index (CI) (thermodilution)
and systemic mean arterial pressure (MAP) were recorded. State
3/4 respiration (nanoatom O2/min/mg protein for glutamate) was
assayed from tissue samples at baseline (muscle) and the end of
the experiment (muscle and liver). Hepatic mitochondrial
respiration was compared with controls (n = 6). Table 1 (abstract P259)
BL
12 hours
24 hours
MAP F
78 ± 22
98 ± 25
81 ± 19
MAP C
91 ± 4
101 ± 12
94 ± 6
TLF F
17 ± 1
46 ± 11*
50 ± 5*
TLF C
23 ± 7
35 ± 4
39 ± 7†
DO2,h F
2.0 ± 0.6
3.8 ± 0.2
5.4 ± 1†
DO2,h C
1.9 ± 0.4
3.2 ± 0.4
3.5 ± 0.4
VO2,h F
0.8 ± 0.2
0.6 ± 0.1
0.5 ± 0.1
VO2,h C
1.5 ± 0.7
1.1 ± 0.1
0.9 ± 0.4
*P < 0.05 vs BL and between groups. †P < 0.05 vs BL. Results One pig died earlier (not included). Data are presented as
the median (range). P < 0.05, Friedman test. Muscle mitochondrial
respiration was similar at baseline and the end of experiment; state
3 (317 (222–594) vs 409 (295–468)), state 4 (29 (22–58) vs 40
(31–49)), respiratory control ratio (11 (7–15) vs 10 (9–11)) (not
significant). Hepatic mitochondrial state 4 was higher (27 (16–31)
vs 19 (13–22)) and respiratory control ratio lower (3 (3–4) vs 5
(4–6)) in the hemorrhage/endotoxemia group, compared with
controls. *P < 0.05 vs BL and between groups. †P < 0.05 vs BL. Real-time monitoring of mitochondrial function in the
urethral wall Real-time monitoring of mitochondrial function in the
urethral wall Real-time monitoring of mitochondrial function in the
urethral wall
S Preisman1, E Segal1, V Glauber1, E Heldenberg1, R Walden1,
D Givony2, N Dekel2, L Oren2, E Pewzner2, A Mayevsky3, A Perel1
1Sheba Medical Center, Tel-Hashomer, Rama-Gan, Israel;
2CritiSense Ltd, Givat Shmuel, Israel; 3Bar-Ilan University,
Ramat-Gan, Israel
Critical Care 2007, 11(Suppl 2):P260 (doi: 10.1186/cc5420) PAP, pulmonary artery pressure. P < 0.05, Friedman test. Conclusions Repeated ischemia/reperfusion episodes plus short-
term endotoxemia decreased the efficiency of hepatic but not
muscle mitochondrial respiration. Mitochondrial dysfunction under
these experimental circumstances seems to be organ specific. References S Preisman1, E Segal1, V Glauber1, E Heldenberg1, R Walden1,
D Givony2, N Dekel2, L Oren2, E Pewzner2, A Mayevsky3, A Perel1
1Sheba Medical Center, Tel-Hashomer, Rama-Gan, Israel;
2CritiSense Ltd, Givat Shmuel, Israel; 3Bar-Ilan University,
Ramat-Gan, Israel
Critical Care 2007, 11(Suppl 2):P260 (doi: 10.1186/cc5420) References 1. Porta F, et al.: Crit Care 2006, 10:R118. 2. Rhee P, et al.: Crit Care Med 1997, 25:166-170. Monitoring of the mitochondrial NADH redox state (an indicator of
intracellular oxygen levels) together with microcirculatory blood
flow (TBF) and with oxygenation (HbO2) could serve as a preferred
approach to evaluate tissue O2
balance or viability. We
hypothesize that in the presence of reduced oxygen delivery and
extraction, blood flow will be redistributed in order to protect the
most vital organs by increasing their regional blood flow, while O2
delivery to the less vital organs will diminish. Thus, the NADH redox
state of less vital organs could serve as an indicator of overall O2
imbalance as well as an endpoint of resuscitation. We have
therefore developed an optical device embedded in a Foley
catheter to provide real-time data on the NADH redox state, TBF
and HbO2 in critically ill patients. Impact of body mass index on postoperative bleeding in
cardiopulmonary bypass Conclusions Lower BMI was associated with higher postoperative
bleeding and lower procoagulant factor levels. Introduction Body mass index (BMI) has been described as a risk
factor for coronary artery disease, but association with S105 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Table 1 (abstract P258) Conclusion While increasing DO2,h far exceeded decreasing
VO2,h in the setting of hyperdynamic fluid-resuscitated septic
shock, hepatic mitochondrial function was significantly impaired
compared with control. E Borotto1, D Tüller1, S Krähenbühl2, D Mettler1, J Takala1,
S Jakob1
1University Hospital Bern, Switzerland; 2University Hospital Basel,
Switzerland
Critical Care 2007, 11(Suppl 2):P258 (doi: 10.1186/cc5418) Table 1 (abstract P258)
After
After
End of
Baseline
bleeding
endotoxin
experiment
MAP (mmHg)
69 (52–70)
36 (30–46)
67 (49–84)
47 (19–109)
CI (ml/kg/min)
85 (62–95)
55 (42–76)
95 (78–113)
69 (16–151)
PAP (mmHg)
14 (10–17)
12 (9–13)
45 (40–51)
32 (17–38)
SvO2 (%)
49 (41–56)
33 (25–37)
54 (47–68)
46 (14–66)
PAP, pulmonary artery pressure. P < 0.05, Friedman test. P258 hepatic mitochondrial dysfunction was present in a clinically
relevant porcine model of fluid-resuscitated septic shock. hepatic mitochondrial dysfunction was present in a clinically
relevant porcine model of fluid-resuscitated septic shock. Methods Anesthetized and ventilated pigs (40 ± 3 kg) were
randomly assigned to septic shock by fecal peritonitis (F, n = 3) or
control (C, n = 3) after placement of portal/hepatic vein catheters
and portal vein and hepatic artery flow probes. F and C received
8 ± 13 ml/kg/hour and 5 ± 7 ml/kg/hour ringer lactate + starch,
respectively. The mean arterial pressure (MAP), total liver flow
(TLF), hepatic O2 delivery (DO2,h) and hepatic O2 consumption
(VO2,h) were recorded at baseline (BL), 12 and 24 hours
(ml/kg/min). Activities of mitochondrial respiratory chain enzymes
(complex I–IV) were assessed by spectrophotometry in snap-
frozen liver samples. Data are presented as the mean ± SD. Methods Anesthetized and ventilated pigs (40 ± 3 kg) were
randomly assigned to septic shock by fecal peritonitis (F, n = 3) or
control (C, n = 3) after placement of portal/hepatic vein catheters
and portal vein and hepatic artery flow probes. F and C received
8 ± 13 ml/kg/hour and 5 ± 7 ml/kg/hour ringer lactate + starch,
respectively. The mean arterial pressure (MAP), total liver flow
(TLF), hepatic O2 delivery (DO2,h) and hepatic O2 consumption
(VO2,h) were recorded at baseline (BL), 12 and 24 hours
(ml/kg/min). Activities of mitochondrial respiratory chain enzymes
(complex I–IV) were assessed by spectrophotometry in snap-
frozen liver samples. Data are presented as the mean ± SD. Cytokines monitored by microdialysis detect rejection
earlier than current methods in liver transplantation Cytokines monitored by microdialysis detect rejection
earlier than current methods in liver transplantation L Wælgaard, EB Thorgersen, P Line, T Mollnes, T Tonnessen
Rikshospitalet, Oslo, Norway
Critical Care 2007, 11(Suppl 2):P261 (doi: 10.1186/cc5421) Introduction The outcome of liver transplantation is steadily
improving. There is still need for earlier detection of complications
such as hepatic artery thrombosis and rejection. In an earlier in
vitro study we showed that the CMA microdialysis system with a
100 kDa pore size membrane can be used to measure the
selected cytokines and complement. We monitored patients
undergoing liver transplantation with microdialysis continuously for
a week postoperatively, and analyzed both parameters to detect
ischemia, and cytokines and anaphylatoxins to explore whether
rejection was detected earlier than with the standard methods. Results During cardiac luxations, the oxygen availability in the
sublingual microcirculation decreased (µHbO2
64.2 ± 9.1 to
48.6 ± 8.7%; P < 0.01) while the functional capillary density did
not change (15.9 ± 1.1 to 15.6 ± 1.3 mm/mm2; P = 0.65). Although the small vessels (0–20 µm) did not fall out they did
show hypoperfusion (Vmax
895 ± 209 to 396 ± 178 µm/s;
P < 0.01), whereas in the medium vessels (20–50 µm) there was
no significant change in blood velocity (Vmax 751 ± 239 to
596 ± 192 µm/s; P = 0.18) as observed with sidestream dark field
imaging and calculated with microvascular analysis software. Methods Twenty patients undergoing 22 liver transplantations
were included. Two microdialysis catheter were introduced in the
liver and one in subcutaneous tissue. We analyzed metabolic
parameters (glucose, pyruvate, glycerol and lactate), and IL-6, IL-8,
MCP-1, IP-10, and C5a. Conclusion
Alterations in sublingual microcirculation hemo-
dynamics reflect the direct effects of obstructive shock and
elucidate the microcirculatory autoregulation. Results
Fourteen
patients
had
an
uneventful
course
postoperatively, judged clinically and by routine biochemical
markers and ultrasound Doppler. These patients had a median
lactate starting at 3.5 mM (2 hours after reperfusion) falling to
below 2 mM during the first 24 hours, and thereafter staying low. The L/P ratio (a specific measure of ischemia) dropped from about
20 to below 10. These patients had a steady rise in IP-10 from 200
to 3,000 pg/ml, and also a slight raise in IL-6 initially. Case 1. The
male patient had a steadily increasing L/P ratio during the 7 days
of microdialysis measurements, indicating an insufficient blood
supply. P261 Methods During cardiac luxations, in 12 patients reflectance
spectrophotometry (O2C®; Lea Medizintechnik, Germany) was
used to measure oxygen availability and in 12 other patients
sidestream dark field imaging (MicroScan®; MicroVision Medical,
The Netherlands) was used to directly visualize the sublingual
microcirculatory hemodynamics in a single network of micro-
vessels. Microvascular analysis software (MAS®; MicroVision
Medical) was used to analyze the vessel density and blood flow. Synchronously, systemic hemodynamics were recorded and the
cardiac output was calculated by pulse contour analysis of arterial
pressure (PulseCO®; LiDCO, UK) in all patients. P262 These preliminary swine model and human studies confirm the
feasibility of collecting information about mitochondrial function
from the urethral wall. The main effects of graded hemorrhage
started when the blood volume decreased by 30%. At 40% blood
loss, minimal levels of TBF and HbO2 were correlated to the
maximal NADH levels. The values of the three parameters returned
to baseline after retransfusion of the shed blood. Aortic clamping in
patients led to a significant decrease in TBF and HbO2 while
NADH levels increased. After aortic declamping, the parameters
recovered to normal values. Cytokines monitored by microdialysis detect rejection
earlier than current methods in liver transplantation He underwent surgery 5 days later and a hepatic artery
thrombosis was found. A biopsy was done during the operation
showing an acute rejection. There was a significant rise in IP-10 to
13,000 pg/ml 7 days before the diagnosis of rejection. Case 2. The female patient had an acute rejection verified by biopsies on
day 10 postoperatively. Her IL-8, IP-10 and C5a increased 10-fold
to 100-fold in the liver 3 days earlier than an increase in liver
enzymes and 5 days before the rejection was verified by biopsy. Conclusion We have described the normal course of the four
cytokines IL-6, IL-8, MCP-1 and IP-10 and complement C5a after
liver transplantation, as well as metabolic parameters to detect Microcirculatory hemodynamic alterations during cardiac
luxation in off-pump coronary artery bypass grafting surgery Microcirculatory hemodynamic alterations during cardiac
luxation in off-pump coronary artery bypass grafting surgery B Atasever1, R Speekenbrink2, J Seyffert2, C Ince3
1Erasmus Medical Center Rotterdam, The Netherlands; 2Onze
Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands; 3Academic
Medical Center, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P262 (doi: 10.1186/cc5422) Introduction During luxation of the beating heart in off-pump
coronary artery bypass grafting surgery the cardiac output drops
and causes hypotension (<60 mmHg). It is expected that this state
of obstructive shock is detrimental for adequate perfusion and
oxygenation of organ tissue. However, it is unknown whether these
luxations cause microcirculatory dysfunction. In this study we have
explored the hemodynamics of the sublingual microcirculation
during mechanical manipulations of the beating heart. Our preliminary results show that the CritiView may be a useful tool
for the detection of O2 imbalance and the development of an
emergency metabolic state in nonvital tissues. Reference 1. Mayevsky et al.: SPIE Proc 2006, 6083:OZ1-OZ10. Hepatic mitochondrial dysfunction in fluid-resuscitated
porcine septic shock Hepatic mitochondrial dysfunction in fluid-resuscitated
porcine septic shock J Wauters1, I Vanhorebeek2, A Dieudonne1, G Van den Berghe1,
A Wilmer3 J Wauters1, I Vanhorebeek2, A Dieudonne1, G Van den Berghe1,
A Wilmer3
1University Hospital Gasthuisberg, Leuven, Belgium; 2Catholic
University of Leuven, Belgium; 3UZ Gasthuisberg, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P259 (doi: 10.1186/cc5419) J Wauters1, I Vanhorebeek2, A Dieudonne1, G Van den Berghe1,
A Wilmer3
1University Hospital Gasthuisberg, Leuven, Belgium; 2Catholic
University of Leuven, Belgium; 3UZ Gasthuisberg, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P259 (doi: 10.1186/cc5419) 1University Hospital Gasthuisberg, Leuven, Belgium; 2Catholic
University of Leuven, Belgium; 3UZ Gasthuisberg, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P259 (doi: 10.1186/cc5419) Background Sepsis-induced multiple organ failure may crucially
depend on the development of mitochondrial dysfunction and
consequent cellular energetic failure. We investigated whether The CritiView is a computerized optical device that integrates
hardware and software in order to provide real-time information of S106 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 tissue viability [1]. A modified three-way Foley catheter that
contains a fiberoptic probe connects the CritiView to the mucosal
side of the urethral wall. We have used this device in five female
pigs that underwent graded hemorrhage, and in four patients who
were monitored during aortic abdominal aneurysm operations. ischemia. In two patients with rejection we found a large increase
in IP-10, IL-8 and complement split-product C5a in the liver but not
in the subcutis 3–5 days before any other parameter of liver injury. P264 Methods Twelve patients were included. Anesthesia consisted of
thoracic epidural analgesia, restrictive peroperative fluid therapy
(net peroperative fluid balance below 4 l) and early extubation. In
the ICU, fluid infusion was adjusted in order to maintain hourly
urine production of 0.5 ml/kg. The mean arterial pressure was
maintained at or above 60 mmHg with administration of nor-
adrenalin if necessary. Microcirculation was visualized in the
sublingual tissue with the MicroScan, a sidestream dark field
imager. Data were collected at five time points: immediately after
induction, after gastric tube reconstruction, directly postoperative,
and days 1 and 2 postoperatively. Video data collected with the
MicroScan were analysed according to semiquantitative analysis
described by Boerma and colleagues [1]. We divided the vessels
into three categories: small (5–10 µm), medium (10–15 µm) and
large (>15 µm). By dividing the images into four quadrants and
categorizing the flow per vessel-size per quadrant, we calculated
the microvascular flow index (MFI) Sublingual microcirculation is impaired during
cardiopulmonary bypass in cardiac surgery C den Uil1, W Lagrand1, P Spronk2, J Hofland1, C Luthen1,
M van der Ent1, R van Thiel1, A Bogers1, M Simoons1
1Erasmus MC, Rotterdam, The Netherlands; 2Gelre Hospitals,
Apeldoorn, The Netherlands
Critical Care 2007, 11(Suppl 2):P264 (doi: 10.1186/cc5424) Introduction
Cardiac surgery patients are at low risk for
postoperative complications, but these may involve multiple organ
failure with a high mortality rate. These complications may be
related to occurrence of organ ischemia and reperfusion during
and just after surgery. We investigated whether microcirculatory
flow alterations occur during cardiac surgery. Methods We observed 10 consecutive patients who underwent
cardiac surgery with cardiopulmonary bypass (CPB). The micro-
circulation was studied using sidestream dark field (SDF) imaging. The sublingual capillary flow was estimated using a semi-
quantitative microvascular flow index (MFI) in small (diameter
10–25 µm), medium (25–50 µm), and large (50–100 µm) sized
microvessels (0 = none, 1 = intermittent, 2 = sluggish, 3 =
continuous flow). SDF imaging was performed at least three times
per time period (that is, at baseline, after starting CPB and after
surgery) in each patient. Data are presented as the median and
interquartile range. Muscle microcirculation alterations increase with disease
severity in chronic heart failure patients Muscle microcirculation alterations increase with disease
severity in chronic heart failure patients V Gerovasili, C Pierakos, S Dimopoulos, E Kaldara,
S Kourtidou, S Sarafoglou, M Kravari, J Venetsanakos,
G Tzanis, S Nanas
National and Kapodestrian University of Athens, Greece
Critical Care 2007, 11(Suppl 2):P263 (doi: 10.1186/cc5423) Objective To evaluate skeletal muscle microcirculation by near-
infrared spectroscopy (NIRS) in patients with chronic heart failure
(CHF). Background Skeletal muscle microcirculation is impaired in
patients with CHF, and this impairment seems to correlate with
disease severity. Methods We evaluated 49 patients with CHF (mean age: 58 ± 12
years) and 12 healthy volunteers. Of the CHF patients, 14 had S107 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin surgery. Despite maintaining common circulatory parameters
during CPB, the nonpulsatile status, hypothermia, and the
temporary drop in MAP after starting CPB were associated with
decreased sublingual MFI, which normalized after surgery. Further
studies should reveal whether these changes are related to outcome. end-stage heart failure (ESCHF) and were undergoing treatment
with intermittent inotropic agent infusion during the period of the
study protocol. The thenar muscle tissue oxygen saturation
(StO2%) was measured noninvasively by NIRS before, during and
after 3-minute occlusion of the brachial artery (occlusion technique). Results Patients with ESCHF (n = 14) and CHF (n = 35) presen-
ted a significantly lower tissue oxygen saturation (StO2) than healthy
subjects (75 ± 6%, 77 ± 8% and 85 ± 5%, P = 0.001 respec-
tively). The oxygen consumption rate during the occlusion of the
brachial artery differed significantly between patients with ESCHF,
CHF and healthy subjects (22.4 ± 9%/min, 29 ± 10%/min and
38.1 ± 11.1%/min, P = 0.001 respectively). The reperfusion rate
differed significantly between patients with ESCHF, CHF and
healthy
subjects
(302 ± 136%/min,
393 ± 134%/min
and
480 ± 133%/min, P = 0.002 respectively). P265 Sublingual microcirculation is impaired on the first day
postoperatively in patients undergoing gastric tube
reconstruction
J Van Bommel, H Tilanus, J Bakker, D Gommers
Erasmus MC, Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P265 (doi: 10.1186/cc5425) Sublingual microcirculation is impaired on the first day
postoperatively in patients undergoing gastric tube
reconstruction Sublingual microcirculation is impaired on the first day
postoperatively in patients undergoing gastric tube
reconstruction J Van Bommel, H Tilanus, J Bakker, D Gommers
Erasmus MC, Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P265 (doi: 10.1186/cc5425) Introduction Complications of oesophagectomy with gastric tube
reconstruction include leakage and stenosis. This can be explained
by compromised local perfusion, although it is unclear to which
extent local and systemic factors contribute to this process. The
aim of this study was to observe the microvascular blood flow in an
unaffected, distant tissue during the perioperative period. Conclusions Peripheral muscle microcirculation assessed by
NIRS is impaired in CHF patients. The degree of dysfunction is
associated with disease severity and is acutely partially reversed
with inotropic agent infusion. Changes in sublingual microvascular flow during
experimental human endotoxemia Changes in sublingual microvascular flow during
experimental human endotoxemia Results Nonsurvivors demonstrated a significantly higher MODS
score when compared with survivors (P = 0.004). Norepinephrine
requirements were higher in nonsurvivors (P = 0.018). Non-
survivors had higher arterial lactate levels (P = 0.046), decreased
arterial pH levels (P = 0.001), and decreased arterial PO2 values
(P = 0.013) when compared with survivors. A higher oscillation
frequency of skin microvasculature at rest (P = 0.033) and after an
ischemic stimulus (P = 0.009) was observed in nonsurvivors. No
differences were observed in reactive hyperemia response
between groups. The flowmotion frequency observed in reactive
hyperemia was associated with the severity of the MODS
(P = 0.009), and – although not statistically significant – arterial
lactate concentration (P = 0.052). R Bemelmans1, A Draisma2, J van der Hoeven2, P Pickkers2,
P Spronk1
1Gelre Ziekenhuizen, Apeldoorn, The Netherlands; 2UMCN,
Nijmegen, The Netherlands
Critical Care 2007, 11(Suppl 2):P268 (doi: 10.1186/cc5428) R Bemelmans1, A Draisma2, J van der Hoeven2, P Pickkers2,
P Spronk1 1Gelre Ziekenhuizen, Apeldoorn, The Netherlands; 2UMCN,
Nijmegen, The Netherlands
Critical Care 2007, 11(Suppl 2):P268 (doi: 10.1186/cc5428) Introduction We examined sublingual microvascular changes in
experimental human endotoxemia. Changes in microcirculation and
mitochondrial dysfunction appear to be key mechanisms in sepsis,
since they can lead to regional mismatch of oxygen supply and
demand. Lipopolysaccharide (LPS) can be used to induce endo-
toxemia as a model of sepsis, but the effects on microcirculatory
perfusion have not been tested before, particularly after tolerance
induction during repeated challenges of LPS. Conclusion An increased skin microvascular oscillation frequency
during rest and after an ischemic stimulus is associated with
increased mortality in patients suffering from MODS. We suggest
that the underlying mechanism of the increased flowmotion could
be a response of the skin microvasculature to hypoxia or to an
impaired oxygen utilization of the skin tissue. Methods Six healthy volunteers received an intravenous injection
of 2 ng/kg Escherichia coli LPS to induce endotoxemia on five
consecutive days. Microvascular perfusion was sublingually
measured using sidestream darkfield imaging just before, and 2
and 4 hours after LPS injection on day 1. All measurements were
repeated on day 5 of LPS administration. Sublingual capillary flow
was estimated using a semiquantative microvascular flow index
(MFI) in small (10–25 µm), medium (25–50 µm) and large-sized
(50–100 µm) microvessels (no flow, 0; intermittent flow, 1;
sluggish flow, 2; and continuous flow, 3). Effect of intermittent positive pressure ventilation on the
skeletal muscle and small intestine microcirculation in rats Effect of intermittent positive pressure ventilation on the
skeletal muscle and small intestine microcirculation in rats V Cerny, Z Turek, R Parizkova, P Dostal
University Hospital Hradec Kralove, Czech Republic
Critical Care 2007, 11(Suppl 2):P267 (doi: 10.1186/cc5427) Introduction Intermittent positive pressure ventilation (IPPV) may
be accompanied by alteration of microcirculation [1,2]; however,
the effect of IPPV is not mentioned in the interpretation of the
results of studies evaluating microcirculation using orthogonal
polarization spectral or sidestream dark-field imaging. This study
aimed to evaluate the effect of IPPV on microcirculation in the
skeleton muscles and in the serosa of the small intestine in rats. Introduction Intermittent positive pressure ventilation (IPPV) may
be accompanied by alteration of microcirculation [1,2]; however,
the effect of IPPV is not mentioned in the interpretation of the
results of studies evaluating microcirculation using orthogonal
polarization spectral or sidestream dark-field imaging. This study
aimed to evaluate the effect of IPPV on microcirculation in the
skeleton muscles and in the serosa of the small intestine in rats. Methods Ten animals were tracheostomized and prepared for
microcirculation study; after tissue preparation, five rats were
allowed to breath spontaneously (Group SB = spontaneous
breathing), and five rats (Group IPPV) were connected to a small
animal ventilator (IPPV: FiO2 0.21, respiratory rate 60/min, tidal
volume 10 ml/kg, inspiratory time 50% of respiratory cycle, and Results Two hours after the induction of endotoxemia (n = 6),
sublingual flow in small (2 (1.7–2.3)), medium-sized (1.5
(1.2–1.9)), and large microvessels (2.5 (1.2–2.7)) did not differ
from baseline values (2.3 (1.5–2.8), 2.3 (1.4–2.5), and 2.3
(1.3–2.5), respectively, all P = not significant). Microvascular flow
did not change in the subsequent 2 hours. In addition, no
difference in microvascular flow could be demonstrated between
timepoints on day 1 and day 5 of intermittent endotoxemia. Conclusion In this small pilot study in experimental human
endotoxemia, no significant effect of LPS administration on
microcirculatory perfusion could be observed, nor any sign of
tolerance. Further studies should reveal whether microvascular
impairment does not occur in early human experimental Results Two hours after the induction of endotoxemia (n = 6),
sublingual flow in small (2 (1.7–2.3)), medium-sized (1.5
(1.2–1.9)), and large microvessels (2.5 (1.2–2.7)) did not differ
from baseline values (2.3 (1.5–2.8), 2.3 (1.4–2.5), and 2.3
(1.3–2.5), respectively, all P = not significant). Microvascular flow
did not change in the subsequent 2 hours. References 1. Saner FH, et al.: Eur J Anaesth 2006, 23:766-771. 2. De Backer D, et al.: Am Heart J 2004, 147:91-99. 1. Saner FH, et al.: Eur J Anaesth 2006, 23:766-771. 2. De Backer D, et al.: Am Heart J 2004, 147:91-99. 1. Saner FH, et al.: Eur J Anaesth 2006, 23:766-771. 2. De Backer D, et al.: Am Heart J 2004, 147:91-99. 1. Saner FH, et al.: Eur J Anaesth 2006, 23:766-771. 2. De Backer D, et al.: Am Heart J 2004, 147:91-99. Changes in sublingual microvascular flow during
experimental human endotoxemia Changes were evaluated
with the paired Wilcoxon test and sign test. P < 0.05 was judged
to indicate a significant difference. Values are expressed as the
median (P25–P75). P266 2 cmH2O PEEP). Sidestream dark-field images were obtained from
the quadriceps femoris muscle (QFM) and serosa surface of the
ileum. The arterial blood pressure and rectal temperature were also
recorded. The functional capillary density (FCD) and small and
medium vessels rate were analysed offline using AVA V1.0 soft-
ware (AMC, University of Amsterdam, The Netherlands), P ≤0.05. Results The FCD was decreased significantly in QFM in rats with
IPPV with respect to Group SB (184 ± 27 resp. 197 ± 61 cm/cm2),
but the FCD of the intestinal serosa was not affected by IPPV
(265 ± 46 resp. 267 ± 25 cm/cm2). There were no differences in
mean blood pressure and temperature between groups (128 ± 7
Torr and 36.6 ± 0.1°C in Group SB, or 128 ± 10 Torr and
36.5 ± 0.1°C in Group IPPV). Figure 1 (abstract P265) Sublingual microvascular perfusion. Results
The MFI decreased in all sizes of microvessels
<15 minutes after starting CPB in comparison with baseline
(P < 0.05, Table 1). After starting CPB, the mean arterial pressure
(MAP) was lower (61 mmHg (53–65 mmHg)) than at baseline
(100 mmHg (92–118 mmHg); P = 0.01). After return to the ICU,
the MFI increased (P < 0.05) and returned to baseline values in all
microvessels. Sublingual microvascular perfusion. Conclusions SDF imaging can be used as a bedside tool to
evaluate sublingual microcirculatory changes during cardiac Table 1 (abstract P264)
Baseline
CPB
Postsurgery
MFI small
3 (3–3)
2 (0.4–3)
3 (2.9–3)
MFI medium
3 (2.2–3)
1.9 (0.8–3)
3 (2.9–3)
MFI large
3 (3–3)
2.4 (0.9–3)
3 (3–3)
MAP
100 (92–118)
61 (53–65)
79 (71–85) Conclusion The sublingual microcirculation is decreased on the
first day postoperatively in patients undergoing gastric tube
reconstruction. 1. Boerma EC, Mathura KR, van der Voort PH, et al.: Quantify-
ing bedside-derived imaging of microcirculatory abnor-
malities in septic patients: a prospective validation study. Crit Care 2005, 9:R601-R606. S108 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Oscillation frequency of skin microvascular blood flow is
associated with mortality in critically ill patients Oscillation frequency of skin microvascular blood flow is
associated with mortality in critically ill patients Oscillation frequency of skin microvascular blood flow is
associated with mortality in critically ill patients H Knotzer1, S Maier1, W Pajk1, M Dünser2, W Hasibeder3
1Innsbruck Medical University, Innsbruck, Austria; 2University
Hospital Bern, Switzerland; 3Krankenhaus der Barmherzigen
Schwestern Ried, Ried, Austria
Critical Care 2007, 11(Suppl 2):P266 (doi: 10.1186/cc5426) Introduction Microcirculatory dysfunction has been hypothesized
to play a key role in the pathophysiology of multiple organ failure,
and consequently to patient outcome. The objective of the present
study was to investigate differences in reactive hyperemia
response and oscillation frequencies in survivors and nonsurvivors
of patients with multiple organ dysfunction syndrome (MODS). Introduction Microcirculatory dysfunction has been hypothesized
to play a key role in the pathophysiology of multiple organ failure,
and consequently to patient outcome. The objective of the present
study was to investigate differences in reactive hyperemia
response and oscillation frequencies in survivors and nonsurvivors
of patients with multiple organ dysfunction syndrome (MODS). Conclusion The use of IPPV should be taken into account in the
interpretation
of
the
studies
examining
the
changes
in
microcirculation in rats. Methods Twenty-nine patients (15 survivors; 14 nonsurvivors) with
two or more organ failures were eligible for study entry. All patients
were hemodynamically stabilized, and demographic and clinical
data were recorded. A laser Doppler flowmeter was used to
measure the cutaneous microcirculatory response. Reactive
hyperemia and oscillatory changes in the Doppler signal were
measured during 3 minutes before and after a 5-minute period of
forearm ischemia during hyperemia. Acknowledgement Research project MZO 00179906. References Acknowledgement Research project MZO 00179906. References Reference 1. Boekstegers P, Weidenhofer S, Kapsner T, Werdan K: Skele-
tal muscle partial pressure of oxygen in patients with
sepsis. Crit Care Med 1994, 22:640-650. 1. Boekstegers P, Weidenhofer S, Kapsner T, Werdan K: Skele-
tal muscle partial pressure of oxygen in patients with
sepsis. Crit Care Med 1994, 22:640-650. 1. Boekstegers P, Weidenhofer S, Kapsner T, Werdan K: Skele-
tal muscle partial pressure of oxygen in patients with
sepsis. Crit Care Med 1994, 22:640-650. Effect of intermittent positive pressure ventilation on the
skeletal muscle and small intestine microcirculation in rats In addition, no
difference in microvascular flow could be demonstrated between
timepoints on day 1 and day 5 of intermittent endotoxemia. Methods Ten animals were tracheostomized and prepared for
microcirculation study; after tissue preparation, five rats were
allowed to breath spontaneously (Group SB = spontaneous
breathing), and five rats (Group IPPV) were connected to a small
animal ventilator (IPPV: FiO2 0.21, respiratory rate 60/min, tidal
volume 10 ml/kg, inspiratory time 50% of respiratory cycle, and Conclusion In this small pilot study in experimental human
endotoxemia, no significant effect of LPS administration on
microcirculatory perfusion could be observed, nor any sign of
tolerance. Further studies should reveal whether microvascular
impairment does not occur in early human experimental S109 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 2 (abstract P269) Figure 2 (abstract P269) endotoxemia, or that sidestream darkfield imaging is not useful in
this specific setting. endotoxemia, or that sidestream darkfield imaging is not useful in
this specific setting. Occurrence and functional consequences of shunting of
the microcirculation after mesenteric ischemia Occurrence and functional consequences of shunting of
the microcirculation after mesenteric ischemia M Lauterbach, G Horstick, N Plum, L Weilemann, T Münzel,
O Kempski
University Hospital Mainz, Germany
Critical Care 2007, 11(Suppl 2):P270 (doi: 10.1186/cc5430) Results In the control group, all parameters were not changed
during the observation period of 400 minutes. In the experimental
group, the mean arterial pressure (MAP) remained fairly stable until
300 minutes after injection of LPS, and the MAP gradually
decreased subsequently. While the MAP was maintained, the PtO2
gradually decreased linearly (Figure 1). TL increased with time
linearly. Meanwhile, BL did not change from 150 to 250 minutes;
after 300 minutes it increased abruptly in the experimental group
(Figure 2). Shunting of the microcirculation contributes to the pathology of
sepsis and septic shock. In this study, we hypothesize that
shunting of the microcirculation occurs after superior mesenteric
artery (SMA) ischemia (occlusion) and reperfusion, and we explore
functional consequences using intravital microscopy. Conclusions In our experimental endotoxemia model it has been
shown that partial pressure of oxygen in subcutaneous tissue
decreased even if systemic blood pressure was maintained. Boekstegers and colleagues [1] revealed that mean skeletal q
g
py
Spontaneously breathing animals (rats) (n = 30) underwent
occlusion of the SMA for 0 (controls), 30 or 60 minutes followed by
reperfusion (4 hours) with normal saline. Leukocyte–endothelial
interactions in mesenteric venules were quantified in an exteriorized
ileal loop using intravital microscopy. Abdominal blood flow was
recorded continuously, and arterial blood gases were analyzed at
intervals. Continuous SMA blood flow measurements were
performed in comparable groups without exteriorizing an ileal loop. Adherent leukocytes increased shortly after reperfusion in ischemia
groups, and plateaued in these groups. The centerline velocity and
shear rate in the recorded venules were significantly reduced after
reperfusion down to low-flow/no-flow in animals undergoing 60
minutes of mesenteric artery occlusion compared with animals with
30 minutes occlusion and controls, whereas perfusion of the SMA
and ileal vessels persisted. The microcirculatory changes in
animals with 60 minutes occlusion were accompanied by
progressive metabolic acidosis, substantially larger volumes of
intravenous fluids needed to support arterial blood pressure and
significantly reduced survival (30%). In the groups with continuous
SMA blood flow measurements, SMA blood flow increased in Spontaneously breathing animals (rats) (n = 30) underwent
occlusion of the SMA for 0 (controls), 30 or 60 minutes followed by
reperfusion (4 hours) with normal saline. Occurrence and functional consequences of shunting of
the microcirculation after mesenteric ischemia Leukocyte–endothelial
interactions in mesenteric venules were quantified in an exteriorized
ileal loop using intravital microscopy. Abdominal blood flow was
recorded continuously, and arterial blood gases were analyzed at
intervals. Continuous SMA blood flow measurements were
performed in comparable groups without exteriorizing an ileal loop. 0
Figure 1 (abstract P269) P269 Biochemical changes detected by microdialysis in
subcutaneous tissue during experimental endotoxemia in
rat H Ohashi, Y Taira, Y Masui, K Morisawa, H Takahashi,
Y Fujinawa, T Kashimura, K Akashi
St Marianna University School of Medicine, Kawasaki, Japan
Critical Care 2007, 11(Suppl 2):P269 (doi: 10.1186/cc5429) Introduction Shock is defined currently as tissue oxygen metabolic
disorders. It is most important to understand oxygen metabolic
disorders in individual tissue. Microdialysis allows the deter-
mination of the metabolic condition in regional tissue and it
appears ideal to determine the regional metabolic tissue conditions
during endotoxemia. muscle PO2 was increased in patients with sepsis compared with
patients with limited infection. We obtained conflicting results to
those of Boekstegers and colleagues. The reason for this is
unknown. BL abruptly increased during 50–150 minutes, probably
from abnormal metabolism induced by LPS in whole-body organs. It is considered that BL did not show a rise during 150–250
minutes due to metabolization of lactate in liver and muscle. TL,
which is insusceptible of lactate metabolism by other organs, may
reflect abnormality of tissue metabolism precisely. Objective This study was designed to assess the regional
metabolic tissue conditions on markers of tissue metabolism
(lactate in regional tissue: tissue lactate (TL)) and tissue partial
oxygen pressure (PtO2) during severe endotoxemia and to
compare them with variables determined by standard monitoring
(hemodynamics, blood gas analysis, blood lactate (BL)). Materials and methods Male Wister rats (body weight 270–300 g)
were used for this study. The rats in the control group (n = 6) were
injected with saline of 2 ml intraperitoneally, and the rats in the
experimental group (n = 6) were treated with intraperitoneal
injection of lipopolysaccharide (LPS) of 40 mg/kg. The hemo-
dynamic parameters, arterial blood gas analysis, BL and PtO2 were
measured in both groups. TL and pyruvate in subcutaneous tissue
were measured using microdialysis. These parameters were
measured every 50 minutes until 400 minutes after LPS was
administered. P271 Changes in tissue oxygen saturation reflect changes in
targeted oxygen delivery in postoperatively optimised
patients M Hamilton, M Canete, M Cecconi, N Al-subaie, A Vercuil,
J Fawcett, D Dawson, A Rhodes
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P271 (doi: 10.1186/cc5431) use of noninvasive tissue oxygenation devices in surgical
optimisation. p
Reference Introduction Targeting oxygen delivery in the postoperative period
has been shown to reduce hospital length of stay and complica-
tions [1]. Using a near-infrared spectroscopy device such as the
Inspectra™ 325 allows the measurement of tissue oxygen satura-
tion (STO2) noninvasively as well as a rudimentary measure of
blood flow beneath the probe. It is plausible, then, that changes in
oxygen delivery (DO2) during postoperative optimisation may be
reflected in changes in STO2 and provide a noninvasive surrogate
of DO2. 1. Pearse et al.: Early goal-directed therapy after major
surgery reduces complications and duration of hospital
stay. Crit Care 2005, 9:R687-R693. Figure 1 (abstract P269) Figure 1 (abstract P269) Adherent leukocytes increased shortly after reperfusion in ischemia
groups, and plateaued in these groups. The centerline velocity and
shear rate in the recorded venules were significantly reduced after
reperfusion down to low-flow/no-flow in animals undergoing 60
minutes of mesenteric artery occlusion compared with animals with
30 minutes occlusion and controls, whereas perfusion of the SMA
and ileal vessels persisted. The microcirculatory changes in
animals with 60 minutes occlusion were accompanied by
progressive metabolic acidosis, substantially larger volumes of
intravenous fluids needed to support arterial blood pressure and
significantly reduced survival (30%). In the groups with continuous
SMA blood flow measurements, SMA blood flow increased in S110 Available online http://ccforum.com/supplements/11/S2 use of noninvasive tissue oxygenation devices in surgical
optimisation. Reference
1. Pearse et al.: Early goal-directed therapy after major
surgery reduces complications and duration of hospital
stay. Crit Care 2005, 9:R687-R693. P272
General anesthesia impairs muscle microvascular
compliance
Figure 2 (abstract P271) Figure 2 (abstract P271) Figure 2 (abstract P271) Figure 2 (abstract P271) Figure 2 (abstract P271) relation to abdominal blood flow after reperfusion in animals with
60 minutes occlusion, and remained constant in animals under-
going 30 minutes occlusion and controls. Survival was 80% in
animals with 60 minutes occlusion without an exteriorized ileal loop. SMA occlusion for 60 minutes and subsequent reperfusion causes
perfusion abnormalities in the mesenteric microcirculation as often
seen in sepsis and septic shock with increased microcirculation
shunting, progressive metabolic acidosis and increased mortality. To
detect
these
significant
changes
requires
prolonged
observation periods and might help to find new treatments to
improve the poor prognosis of mesenteric ischemia. P272 General anesthesia impairs muscle microvascular
compliance General anesthesia impairs muscle microvascular
compliance General anesthesia impairs muscle microvascular
compliance M Boezi, S Palmisani, F Troisi, A Marcelli, R De Blasi
‘La Sapienza University’, 2nd Faculty of Medicine, Azienda
Ospedaliera Sant’Andrea, Rome, Italy
Critical Care 2007, 11(Suppl 2):P272 (doi: 10.1186/cc5432) 2
Methods All adult patients admitted to the ICU after surgery who
underwent
protocolised
haemodynamic
optimisation
were
included. All patients had STO2 recorded over the thenar eminence
using an Inspectra™ 325 for the first 8 hours of their stay. Introduction Drugs used to induce and maintain general
anesthesia have deep effects on the cardiovascular system. To our
knowledge there are no studies investigating microvascular
compliance during general anesthesia with a noninvasive approach
based on near-infrared spectroscopy (NIRS) technology. Results We found a significant correlation between the changes in
STO2 and oxygen delivery index (DO2I) over the first 8 hours of
intensive care stay (n = 40, correlation coefficient of 0.947,
P = 0.0001, Figure 1). We classified patients who achieved DO2I
> 600 ml/min/m2 as responders. These responders had higher
STO2 values by 3 hours of optimisation, a change that remained
significant throughout the duration of the study (Figure 2). Methods We randomized 36 healthy subjects undergoing maxillo-
facial surgery to receive general anesthesia with a sevofluorane–
remifentanil (Group S) or a propofol–remifentanil association
(Group P). We collected noninvasive measures of hemoglobin
concentration from the gastrocnemius muscle of the subjects
using a NIRS device (NIMO, NIROX srl, Italy), which performs
quantitative assessments of the [HbO2] and [Hb] exploiting
precise absorption measurements close to the absorption peak of
the water. Data were collected during a series of venous
occlusions at different cuff pressures, before and after 30 minutes
from induction of general anesthesia. The muscle blood volume
and microvascular compliance were obtained with a process
previously described elsewhere [1]. Data were analyzed with a
one-way analysis of variance test. Conclusion Changes in STO2 during postoperative optimisation
appear to mirror changes in DO2I and may allow more widespread Conclusion Changes in STO2 during postoperative optimisation
appear to mirror changes in DO2I and may allow more widespread Figure 1 (abstract P271) Figure 1 (abstract P271) Results Demographic data of the 36 subjects were similar in both
Groups S and P. General anesthesia reduced the heart rate and
mean arterial pressure and increased the total muscle blood
volume in both groups (Group S: from 2.4 ± 0.9 to 3.2 ± 1.2 ml/
100 ml; Group P: from 2.4 ± 1.2 to 3.5 ± 1.8 ml/100 ml;
P < 0.05). During general anesthesia, despite no differences in
muscle blood volume between the two groups, sevofluorane–
remifentanil significantly decreased microvascular compliance
(from 0.15 ± 0.08 to 0.09 ± 0.04 ml/mmHg/100 ml; P = 0.001)
whereas propofol–remifentanil did not (from 0.15 ± 0.08 to
0.16 ± 0.11 ml/mmHg/100 ml; P = 0.39). S111 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusion General anesthesia affects the microvascular bed of
skeletal muscle. An association between opioid and ipnotic agents
increases the muscle blood volume, whereas microvascular com-
pliance is reduced only by the sevofluorane–remifentanil association. spectroscopy is noninvasive and in the emergency setting is a
rapidly appliable method for measuring StO2. spectroscopy is noninvasive and in the emergency setting is a
rapidly appliable method for measuring StO2. Methods In a prospective observational study we included 340
consecutive medical emergency room patients. On admission,
StO2 and the rate of tissue deoxygenation during stagnant
ischemia were measured by the near-infrared spectroscopy
method (InSpectra tissue spectrometer; Hutchinson Technology
Inc., The Netherlands) and correlated with clinical signs of shock,
lactate and outcome. Methods In a prospective observational study we included 340
consecutive medical emergency room patients. On admission,
StO2 and the rate of tissue deoxygenation during stagnant
ischemia were measured by the near-infrared spectroscopy
method (InSpectra tissue spectrometer; Hutchinson Technology
Inc., The Netherlands) and correlated with clinical signs of shock,
lactate and outcome. 1. De Blasi RA, Palmisani S, Alampi D, et al.: Microvascular
dysfunction and skeletal muscle oxygenation assessed by
phase modulation near-infrared spectroscopy in patients
with septic shock. Intensive Care Med 2005, 31:1661-
1668. Results Three hundred and forty patients were included. Of 137
patients admitted, 16 (11.7%) were admitted to the ICU and 14
(10.2%) died in the hospital. The StO2 was higher in patients who
were not admitted compared with patients with LOS > 7 days
(80.2 ± 8.7% vs 76.9 ± 9.2%, P = 0.009). P274 Introduction Near-infrared spectroscopy (NIRS) noninvasively
monitors muscle tissue oxygen saturation (StO2). It may provide a
continuous measurement to identify occult hypoperfusion, guide
resuscitation, and predict the development of multiple organ
dysfunction (MOD) after severe trauma. We evaluated the
correlation between initial StO2 and the development of MOD in
multitrauma patients. Figure 1 (abstract P271) Tissue deoxygenation
was faster (16.7 ± 7.0%/min vs 12.9 ± 5.6%/min, P = 0.014) in
survivors. Tissue deoxygenation was slower in the group of
patients with clinical signs of shock compared with all patients
(11.8 ± 6.0%/min vs 16.5 ± 7.0%/min, P < 0,05). Age, lactate and
rate of tissue deoxygenation but not StO2 were significant
predictors of death (Table 1). There was weak but significant
correlation between StO2 and age (P < 0.0001, r = –0.28), StO2
and lactate (P = 0.035, r = –0.12) and StO2 and systolic blood
pressure (P < 0.0001, r = 0.26). P275 Near-infrared spectroscopy during resuscitation of trauma
patients predicts development of multiple organ
dysfunction: a prospective cohort study Conclusions Exact numerical values of StO2 are not equivalent to
those of SvO2. However, for clinical purpose, StO2 values could be
used for fast noninvasive SvO2 estimation; and the trend of StO2
may be substituted for the trend of SvO2 in severe left heart failure
without additional severe sepsis or septic shock. B Nicks, K Hill, M Chang, W Bozeman
Wake Forest University Health Sciences, Winston-Salem, NC, USA
Critical Care 2007, 11(Suppl 2):P275 (doi: 10.1186/cc5435) Skeletal muscle oxygen saturation estimates mixed venous
oxygen saturation in patients with severe left heart failure Skeletal muscle oxygen saturation estimates mixed venous
oxygen saturation in patients with severe left heart failure M Podbregar, H Mozina
University Medical Center Ljubljana, Slovenia
Critical Care 2007, 11(Suppl 2):P273 (doi: 10.1186/cc5433) M Podbregar, H Mozina
University Medical Center Ljubljana, Slovenia
Critical Care 2007, 11(Suppl 2):P273 (doi: 10.1186/cc5433) Critical Care 2007, 11(Suppl 2):P273 (doi: 10.1186 Introduction Low cardiac output states, such as left heart failure,
are characterized by a preserved oxygen extraction ratio compared
with severe sepsis. Near-infrared spectroscopy (NIRS) allows
noninvasive estimation of skeletal muscle tissue oxygenation
(StO2). The aim of study was to determine relationship between
StO2 and mixed venous oxygen saturation (SvO2) in patients with
severe left heart failure with or without additional severe sepsis or
septic shock. Table 1 (abstract P274)
Predictors of survival
Predictor
Odds ratio
P value
Age
1.083
0.004
Lactate
1.798
<0.001
Deoxygenation rate
0.895
0.046 Methods Sixty-five patients with severe left heart failure due to
primary heart disease were divided into two groups: Group A were
patients without (n = 24) and Group B were patients with (n = 41)
additional severe sepsis/septic shock. The thenar muscle StO2
was measured using NIRS. Results In Group A StO2 was lower compared with Group B and
healthy volunteers (58 ± 13% vs 90 ± 7% vs 84 ± 4%, P < 0.001). StO2 was higher in Group B compared with healthy volunteers
(P = 0.02). In Group A StO2 correlated with SvO2 (r = 0.689,
P = 0.002), and StO2 overestimated SvO2 (bias: –2.3%, precision:
4.6%). In Group A changes of StO2 correlated to changes of SvO2
(r = 0.836, P < 0.001; ∆SvO2 = 0.84 x ∆StO2 – 0.67). In Group B
important disagreement between these variables was present. Plasma lactate concentrations negatively correlated with StO2
values only in group A (r = –0.522, P = 0.009; lactate = –0.104 x
StO2 + 10.25). Conclusions StO2 and the rate of tissue deoxygenation during
stagnant ischemia are promising additional variables, which can be
measured rapidly and noninvasively in the emergency room setting. The rate of deoxygenation rather than StO2 may be helpful for early
detection of patients with inadequate tissue perfusion and worse
prognosis. Tissue oxygen saturation and the rate of tissue
deoxygenation during stagnant ischemia in the medical
emergency department M Meþnar, R Pareþnik, G Voga
General Hospital Celje, Slovenia
Critical Care 2007, 11(Suppl 2):P274 (doi: 10.1186/cc5434) P276 Setting A 16-bed medical–surgical ICU. Buccal visible light spectroscopy and laser Doppler
flowmetry: reliability analysis
V Gath, Y Sakr, S Klinzing, T Simon, K Reinhart, G Marx
Friedrich-Schiller-University Hospital, Jena, Germany
Critical Care 2007, 11(Suppl 2):P76 (doi: 10.1186/cc5436) Buccal visible light spectroscopy and laser Doppler
flowmetry: reliability analysis Materials and methods This study began about 2 years ago, and the
CVP of 41 patients in our ICU were evaluated and compared. Each
one of those 41 patients had a CVC in two different locations, one
placed in the internal jugular or subclavian veins, and a second in a
femoral vein. Simultaneous measurements of CVP were undertaken
by two different operators, with a pressure transducer zero referenced
at the mid-chest. Standard CVCs with similar features (20 cm length)
were used. The patients with an intra-abdominal pressure (IAP)
> 15 mmHg were excluded. The IAP was previously evaluated in all
patients, using the method described by Sugrue and Hillman. A linear
correlation analysis was performed, considering significance P < 0.05
and a correlation coefficient > 0.85. V Gath, Y Sakr, S Klinzing, T Simon, K Reinhart, G Marx
Friedrich-Schiller-University Hospital, Jena, Germany
Critical Care 2007, 11(Suppl 2):P76 (doi: 10.1186/cc5436) Background There are insatiable demands for new technologies
to advance basic biological investigation at the microcirculatory
level. Oxygen to see (O2C)® is a newly developed system that
combines laser Doppler flow (LDF) and visible light spectroscopy
(VLS) technology. The aim of our study was to assess the reliability
of O2C® measurements applied to the buccal mucosa and to the
thenar eminence in healthy volunteers. Results Forty-one patients were studied, and four patients were
excluded due to an IAP > 15 mmHg. The mean age was 63.7 ±
16.2 years, the ICU stay was 10.4 ± 3.5 days, the APACHE II
score was 27.8 ± 6.7, and SAPS II was 55.8 ± 11.2. The mean
CVP measured with jugular/subclavian access was 11.3 ± 4.5 mmHg,
and in the femoral access was 11.8 ± 4.4 mmHg. The linear corre-
lation between those measurements was 0.96, and P < 0.007. Methods Microcirculatory hemoglobin oxygen saturation (µHbO2,
%) and blood flow (flow, AU) were measured using an O2C® (Lea
Medizintechnik GmbH, Giessen, Germany) probe applied to the
buccal mucosa and to the thenar eminence. P277 study was the association between StO2 and the development of
MOD within the first 24 hours based on a MOD score of 6 or
greater. Clinicians were blinded from the StO2 values. Results Over a 14-month period, 78 patients were enrolled. Of the
78 patients, 26 (33.3%) developed MOD within the first 24 hours. The MOD patients had mean (SD) initial StO2 values of 53.3
(±10.3), significantly lower than those of non-MOD patients (61.1
(±10.0); P = 0.002). The MOD patient mean shock index of 0.92
(±0.28) was also significantly higher than those of non-MODS
patients (0.73 (±0.19); P = 0.0007). Lactate values were not
significantly different. study was the association between StO2 and the development of
MOD within the first 24 hours based on a MOD score of 6 or
greater. Clinicians were blinded from the StO2 values. study was the association between StO2 and the development of
MOD within the first 24 hours based on a MOD score of 6 or
greater. Clinicians were blinded from the StO2 values. P277
Central venous pressure in a femoral access: a true
evaluation? Central venous pressure in a femoral access: a true
evaluation? Results Over a 14-month period, 78 patients were enrolled. Of the
78 patients, 26 (33.3%) developed MOD within the first 24 hours. The MOD patients had mean (SD) initial StO2 values of 53.3
(±10.3), significantly lower than those of non-MOD patients (61.1
(±10.0); P = 0.002). The MOD patient mean shock index of 0.92
(±0.28) was also significantly higher than those of non-MODS
patients (0.73 (±0.19); P = 0.0007). Lactate values were not
significantly different. N Caramelo1, P Gonçalves1, A Paisana2, B Silva2, C Dias2,
S Severino2, P Henriques2, D Marcelino2, D Marum2, D Fernandes2
1Hospital Júlio de Matos, Lisbon, Portugal; 2Hospital Curry Cabral,
Lisbon, Portugal
Critical Care 2007, 11(Suppl 2):P277 (doi: 10.1186/cc5437) Introduction In patients with bad vascular access, the evaluation
of central venous pressure (CVP) obtained in a femoral vein could
be an alternative to the evaluation in central venous catheters
(CVCs) located in internal jugular or subclavian veins. Conclusions Noninvasive, continuous StO2 NIRS on initial arrival
in the TC/ED correlates with the shock index and with the
development of MOD. Objective To compare CVP measurement obtained in two different
locations (jugular or subclavian veins and femoral veins). M Meþnar, R Pareþnik, G Voga
General Hospital Celje, Slovenia
Critical Care 2007, 11(Suppl 2):P274 (doi: 10.1186/cc5434) Methods Patients presenting to our urban, academic, Level I
Trauma Center/Emergency Department (TC/ED) and meeting
standardized trauma-team activation criteria were enrolled. NIRS
monitoring with collection of StO2 at the thenar eminence was
initiated immediately on arrival at the ED and continued up to
24 hours for those admitted to the trauma ICU. Standardized
resuscitation assessment laboratory measures and clinical evalua-
tion tools were collected. The primary outcome in this prospective Hypothesis Tissue oxygen saturation (StO2) and the rate of tissue
deoxygenation during stagnant ischemia can early and reliably
detect inadequate tissue oxygenation and assess prognosis in
medical emergency room patients. Hypothesis Tissue oxygen saturation (StO2) and the rate of tissue
deoxygenation during stagnant ischemia can early and reliably
detect inadequate tissue oxygenation and assess prognosis in
medical emergency room patients. Introduction Early recognition of patients with inadequate tissue
oxygenation facilitates early diagnostic evaluation and treatment
that was correlated with improved outcome. Near-infrared S112 Available online http://ccforum.com/supplements/11/S2 P276 Measurements were
obtained simultaneously at two depths, superficial (2 mm) and
deep (6 mm), every 2 seconds for 5 minutes and were recorded for
later analysis. The procedure was repeated on another occasion at
least 1 week apart. Conclusion The CVP can be accurately measured in a femoral
vein, using standard CVC, in patients with an IAP < 15 mmHg. Results We studied 20 healthy subjects; 10 males and 10 females
(mean age = 38 ± 18 years, range 21–74 years). Both µHbO2 and
flow measurements were consistently higher when measured from
the deep tissue layers (6 mm) than those measured from the
superficial layers, regardless of the site of measurement. Buccal
mucosal µHbO2 ranged from 78% to 96% and varied only
minimally (CV: 4–7.5%), whereas there was a marked variability in
flow measurements (CV: 29–63.9%). The reproducibility of buccal
mucosal µHbO2 and flow measurements were moderate to good
(that is, intra-individual reliability, ICC: range 0.7–0.87, P < 0.05). However, only measurements from the superficial mucosal layers
showed a moderate to good degree of inter-individual agreement
(that is, inter-individual reliability, ICC: range 0.68–85, P < 0.001). LDF and VLS values measured on the thenar eminence were highly
variable, were not reproducible, and the inter-individual agreement
was poor. Table 1 (abstract P280) Methods We tested both the capability of FEER to differentiate
states of pulseless electrical activity, and its feasibility in the out-of-
hospital setting using mobile, battery-powered ultrasound systems. Trained emergency physicians (EP) applied FEER to assessing
basic ventricular function by ‘eye-balling’ in less than 10 seconds
in prehospital cardiac arrest victims who were being resuscitated. True pulseless electrical activity (PEA) was defined according to
the ERC as ‘clinical absence of cardiac output despite electrical
activity’. In contrast, any PEA was classified as a ‘pseudo-PEA’
when cardiac output was visualized by echocardiography. Conclusion We conclude that TTE is feasible in a noncoronary
ICU, most parameters being obtained. A routine utilization of TTE
detected 53 (7.5%) patients with severe unsuspected diseases. Results Seventy-eight CPR cases (age 66 ± 19 years) were
included. On arrival of the EP on the scene, a true PEA was
suspected in 31/78 cases. However, in 20/31 PEA cases cardiac
wall movement was detected (pseudo-PEA) and correctable
causes such as pericardial tamponade (four cases), poor
ventricular function (14 cases) and hypovolemia (two cases) were
treated. Fourteen out of 20 pseudo-PEA cases survived to hospital
admission. In 11/30 PEA cases, no cardiac wall movement was
visible (true PEA). All such patients died on the scene. FEER-
based changes in therapy were induced in 25/31 cases. The effectiveness of transthoracic echocardiography as a
screening examination in a noncoronary intensive care unit The effectiveness of transthoracic echocardiography as a
screening examination in a noncoronary intensive care unit P Marcelino1, S Marum1, A Fernandes1, M Lopes2, L Mourao1
1Hospital Curry Cabral, Lisbon, Portugal; 2Lisbon Faculty of
Medicine, Lisbon, Portugal
Critical Care 2007, 11(Suppl 2):P280 (doi: 10.1186/cc5440) Table 1 (abstract P278)
Variable
OR (95% CI)
P
APACHE III score (/10)
1.2 (1–1.4)
0.017
E/E′ (/10)
1.3 (0.6–2.8)
0.5
LV end diastolic volume (/100 ml)
2.0 (1.2–3.3)
0.0059
LV end systolic volume (/100 ml)
2.2 (1.3–3.8)
0.0047 Introduction The authors tested the feasibility of transthoracic
echocardiography (TTE) as a routine technique in a medical/
surgical ICU. Methods The study was carried out in a 16-bed noncoronary ICU
during 18 months. For this purpose, a TTE was performed within
the first 24 hours of admission. The issues addressed were: data
acquisition possibilities, quantification of selected echocardio-
graphic parameters (cardiac chamber dimensions, left ventricular
function, cardiac output, and Doppler examination), detection of
any structural echocardiographic alteration, as well as new severe
conditions. Conclusion In this cohort of critically ill patients, increased
echocardiographic LV end systolic volume, but not filling pressure,
is a highly significant predictor of mortality that adds incremental
value to APACHE III prediction. P279 Results In this study 704 consecutive patients were enrolled, with
a mean age of 61.5 ± 17.5 years, an ICU stay of 10.6 ± 17.1 days,
APACHE II score of 22.6 ± 8.9, and SAPS II of 52.7 ± 20.4. In
four patients TTE could not be performed. The data are presented
in Table 1. At least an echocardiographic alteration was detected
in 234 (33%) patients. The most common alterations were left
atrial enlargement (n = 163), and left ventricular dysfunction
(n = 132). Patients with these alterations were older (66 ± 16.5 vs
58.1 ± 17.4 years, P < 0.001), presented a higher APACHE II
score (24.4 ± 8.7 vs 21.1 ± 8.9, P < 0.001) and a higher mortality
(40.1 vs 25.4%, P
< 0.001). Severe previously unknown
echocardiographic diagnoses were detected in 53 (7.5%)
patients. The most frequent condition was severe left ventricular
dysfunction. By multivariate logistic regression analysis, TTE
parameters did not correlate with mortality or ICU stay. Mortality
was related to ICU stay (CI 1.0–1.019, P < 0.001). Left ventricular volumes but not filling pressure are
determinants of mortality in critically ill patients D Sturgess, T Marwick, C Joyce, M Jones, B Venkatesh
University of Queensland, Brisbane, Australia
Critical Care 2007, 11(Suppl 2):P278 (doi: 10.1186/cc5438) Introduction Transthoracic echocardiography (TTE) is gaining
acceptance as a powerful diagnostic tool in critical illness. It can
assess left ventricular (LV) volumes, as well as indices of ventri-
cular filling pressure (including the ratio of mitral E velocity/mitral
annular velocity [E/E′]). TTE evidence of raised filling pressure is
associated with mortality following myocardial infarction but its
prognostic value in critical illness is undefined. The aim of this
study was to evaluate the prognostic significance of echo-
cardiographic LV volumes and filling pressure in the critically ill. Conclusion O2C® provides reliable measurement of buccal
µHbO2 and microvascular flow. Skin measurements on the thenar
eminence are highly variable and unreliable. Methods A consecutive group of 94 patients (66 males, mean ±
SD age 61 ± 15 years) who had standard TTE supplemented by
measurement of E/E′ in a tertiary referral ICU were enrolled. TTE
was performed 5 ± 6 days after ICU admission. Severity of critical
illness was assessed using APACHE III. Cox proportional hazards
regression analysis was based on 28-day mortality from the date of
echo with survivors censored on hospital discharge. Results The mean APACHE III score was 72 ± 25. Hospital
mortality was 33% (n = 31). Table 1 summarises correlates of 28- S113 day mortality. The independent predictors of mortality were
APACHE III risk of hospital death (HR 1.3 (1.1–1.5), P = 0.003),
and increased LV end systolic volume (HR 2.1 (1.2–3.7), P = 0.007). Indices of ventricular filling pressure (E/E′, left atrial area/volume)
were not predictors of mortality. Prehospital echocardiography in pulseless electrical
activity victims using portable, handheld ultrasound C Byhahn1, E Müller2, F Walcher1, H Steiger2, F Seeger1,
R Breitkreutz1
1JW Goethe-University Hospital, Frankfurt, Germany;
2Emergency Medical Service, Darmstadt, Germany
Critical Care 2007, 11(Suppl 2):P279 (doi: 10.1186/cc5439) C Byhahn1, E Müller2, F Walcher1, H Steiger2, F Seeger1,
R Breitkreutz1
1JW Goethe-University Hospital, Frankfurt, Germany;
2Emergency Medical Service, Darmstadt, Germany
Critical Care 2007, 11(Suppl 2):P279 (doi: 10.1186/cc5439) Objective Potentially treatable causes of sudden cardiac arrest,
such as pericardial tamponade, myocardial insufficiency or hypo-
volemia, should be identified as soon as possible (that is, at the
scene). Although these diagnoses are mainly made by echo-
cardiography, old and new ERC or ILCOR guidelines only recom-
mend pauses of ventilation or chest compressions as ‘brief interrup-
tions’ at a maximum of 10 seconds, thereby potentially limiting
transthoracic ultrasound examinations. We introduced an ALS-
based algorithm of focused echocardiographic evaluation during
resuscitation (FEER) to be performed in a time-sensitive manner. Table 1 (abstract P280)
Chamber
689
Left ventricular function
670
Inferior vena cava
571
Mitral E/A
399
Isovolumetric relaxation time
569
Tricuspid regurgitation
291
Cardiac output
610
All patients
704 P282 Determination of intravascular volume status in critically ill
patients using portable chest X-rays: measurement of the
vascular pedicle width Background Assessment of preload and goal-directed resusci-
tation are crucial parts of ICU therapy. To assess preload, clinical
parameters such as filling of the jugular veins, edema and pleural
effusions as well as X-ray are used. In addition, haemodynamic
parameters such as the central venous pressure (CVP), pulmonary
arterial wedge pressure and PiCCO-derived global end-diastolic
volume index (GEDVI) are determined. The GEDVI has been
shown to be superior to pressure-based parameters with regard to
volume responsiveness in several studies. However, PiCCO data
are not available in all patients, and frequently clinical examination,
CVP and chest X-ray are the first tools for preload assessment. It
was the aim of our study to evaluate clinical assessment, X-ray and
CVP with regard to the GEDVI and extravascular lung water index
(ELWI). N Salahuddin, I Chishti, S Siddiqui
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P282 (doi: 10.1186/cc5442) Introduction Traditionally invasive haemodynamic measurements
of pulmonary artery occlusion pressures have been used to assess
the volume status in critically ill patients. The vascular pedicle, as
seen on chest X-ray scan, is the mediastinal silhouette of the great
vessels. We hypothesized that the vascular pedicle width (VPW)
on supine, portable chest X-ray scans could be used to predict
intravascular volume overloaded status in critically ill patients. Methods We conducted a prospective, blinded observational trial
where both pulmonary artery occlusion pressures (PAOP) and
VPWs were measured in patients admitted to the ICU. We used
measurements of PAOP ≥18 mmHg as indicative of a fluid
overloaded state, and measurements of PAOP < 18 mmHg as
normal or low volume states. Standardized, portable chest X-ray
scans in the supine position were obtained within 1 hour of PAOP
measurement. Receiver-operating characteristics (ROC) curves
were constructed using different cutoffs of the VPW measurement
to identify sensitivities and specificities for each value (see Figure 1). Results Measurements were obtained from 50 patients. Using
ROC-derived cutoffs, a VPW measurement of 74.5 mm was found
to have a sensitivity of 83% and a specificity of 78% for correctly
predicting a fluid overloaded state. Methods In 86 patients of an internal ICU, clinical examination was
independently determined by a physician and investigator not
working in the ICU. P283 The role of clinical examination, chest X-ray and central
venous pressure in volume assessment in critically ill
patients: a comparison with PiCCO-derived data
W Huber, S Ringmaier, A Umgelter, K Holzapfel, W Reindl,
M Franzen, J Gaa, R Schmid
Klinikum Rechts der Isar, Technical University of Munich, Germany
Critical Care 2007, 11(Suppl 2):P283 (doi: 10.1186/cc5443) The role of clinical examination, chest X-ray and central
venous pressure in volume assessment in critically ill
patients: a comparison with PiCCO-derived data
W Huber, S Ringmaier, A Umgelter, K Holzapfel, W Reindl,
M Franzen, J Gaa, R Schmid
Klinikum Rechts der Isar, Technical University of Munich, Germany
Critical Care 2007, 11(Suppl 2):P283 (doi: 10.1186/cc5443) The role of clinical examination, chest X-ray and central
venous pressure in volume assessment in critically ill
patients: a comparison with PiCCO-derived data W Huber, S Ringmaier, A Umgelter, K Holzapfel, W Reindl,
M Franzen, J Gaa, R Schmid
Klinikum Rechts der Isar, Technical University of Munich, Germany
Critical Care 2007, 11(Suppl 2):P283 (doi: 10.1186/cc5443) P281 Patients with ischemic, dilated,
hypertrophic cardiomyopathy, severe valvular disease, uncontrolled
blood pressure and chronic atrial fibrillation were excluded. Results
No differences were observed in the LV systolic
performance by use of the conventional 2D echocardiography
between the two groups (EF: 63.8 ± 3.7% in Group A as
compared with 64 ± 4.8% in Group B, P = not significant). Nevertheless, differences were ascertained in the maximum
systolic velocities on the long axis using TDI. Sm: 8.2 ± 1.1 m/s in
Group A, 9.7 ± 1 m/s in Group B (P = 0.04), Sl: 10.6 ± 1.3 m/s in
Group A, 13.6 ± 1.4 m/s in Group B (P = 0.02). Receiver-operating characteristics curve for vascular pedicle width. The curve shows the ability of the vascular pedicle width to
differentiate between fluid overload and euvolemia at different cutoff
points. The area under the curve is 0.724. Increased vascular volume
is defined as pulmonary artery occlusion pressure ≥18 mmHg. Receiver-operating characteristics curve for vascular pedicle width. The curve shows the ability of the vascular pedicle width to
differentiate between fluid overload and euvolemia at different cutoff
points. The area under the curve is 0.724. Increased vascular volume
is defined as pulmonary artery occlusion pressure ≥18 mmHg. Conclusion
TDI echocardiography identifies LV contractility
abnormalities in ICU septic patients that appear to have a normal
EF in the conventional echocardiogram, so it provides earlier
recognition and treatment of LV dysfunction related to sepsis. P281 P281
Identification of contractility abnormalities in intensive care
unit patients with sepsis using tissue Doppler imaging
H Michalopoulou, P Stamatis, A Bakhal, T Kelgiorgis, A Basile,
J Vaitsis, E Reinou, P Batika, D Pragastis, A Foundouli
Metaxa Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P281 (doi: 10.1186/cc5441) Identification of contractility abnormalities in intensive care
unit patients with sepsis using tissue Doppler imaging H Michalopoulou, P Stamatis, A Bakhal, T Kelgiorgis, A Basile,
J Vaitsis, E Reinou, P Batika, D Pragastis, A Foundouli
Metaxa Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P281 (doi: 10.1186/cc5441) H Michalopoulou, P Stamatis, A Bakhal, T Kelgiorgis, A Basile,
J Vaitsis, E Reinou, P Batika, D Pragastis, A Foundouli
Metaxa Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P281 (doi: 10.1186/cc5441) Conclusions Application of FEER was feasible within a 10-second
time-frame of CPR interruptions. While differentiating PEA states,
FEER has the ability to identify a pseudo-PEA state, allowing
further treatment of the underlying disorder on the scene to
improve outcome. Introduction Tissue Doppler imaging (TDI), as a more recent
ultrasound technique, is a precious diagnostic tool revealing earlier S114 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P282)
Receiver-operating characteristics curve for vascular pedicle width. The curve shows the ability of the vascular pedicle width to
differentiate between fluid overload and euvolemia at different cutoff
points. The area under the curve is 0.724. Increased vascular volume
is defined as pulmonary artery occlusion pressure ≥18 mmHg. Figure 1 (abstract P282) Figure 1 (abstract P282) left ventricular (LV) contractility abnormalities as compared with the
conventional echocardiography. This study aimed at assessing the
contribution of TDI to the early diagnosis of LV systolic dysfunction
in ICU septic patients maintaining a normal ejection fraction (EF). Methods Twenty-two ICU patients of average age 57.6 ± 7.3 years
(13 males) (Group A) and 20 seemingly healthy individuals (Group
B) were studied. The ICU patients met the sepsis criteria (infection
by Gram-negative bacterium and, at least, two of the SIRS criteria). The APACHE II score mean value was 21.2 ± 4.9. All the patients
of the study were subjected to the same session in a 2D echo-
cardiogram. The EF of the left ventricle was calculated according
to Simpson’s method. The systolic velocities on the long axis were
measured by TDI, placing the sample volume 0.5 cm distance from
the mitral annular in the basic posterior interventricular septum
(Sm) and on the lateral wall (Sl). Change of therapeutic plan following advanced
cardiopulmonary monitoring in critically ill patients: a
multicenter study A Perel1, M Maggiorini2, M Malbrain3, J Teboul4, J Belda5,
E Fernández Mondéjar6, M Kirov7, J Wendon8
1Sheba Medical Center, Tel Hashomer, Israel; 2Universitatsspital,
Zurich, Switzerland; 3Ziekenhuis Netwerk Antwerpen-Hospital
Campus Stuivenberg, Antwerp, Belgium; 4Hôpital De Bicêtre, Le
Kremlin-Bicêtre, France; 5Hospital Clinico Universitario, Valencia,
Spain; 6Hospital Universitario Virgen De Las Nieves, Granada,
Spain; 7Northern State Medical University, Arkhangelsk, Russian
Federation; 8King’s College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P284 (doi: 10.1186/cc5444) A Perel1, M Maggiorini2, M Malbrain3, J Teboul4, J Belda5,
E Fernández Mondéjar6, M Kirov7, J Wendon8
1Sheba Medical Center, Tel Hashomer, Israel; 2Universitatsspital,
Zurich, Switzerland; 3Ziekenhuisnetwerk Antwerpen, Campus
Stuivenberg, Antwerp, Belgium; 4Hopital De Bicetre, Le Kremlin
Bicetre, France; 5Hospital Clinico Universitario, Valencia, Spain;
6Hospital Universitario Virgen de las Nieves, Granada, Spain;
7Northern State Medical University, Arkhangelsk, Russian
Federation; 8Liver Intensive Care Unit, London, UK
Critical Care 2007, 11(Suppl 2):P285 (doi: 10.1186/cc5445) A Perel1, M Maggiorini2, M Malbrain3, J Teboul4, J Belda5,
E Fernández Mondéjar6, M Kirov7, J Wendon8 1Sheba Medical Center, Tel Hashomer, Israel; 2Universitatsspital,
Zurich, Switzerland; 3Ziekenhuisnetwerk Antwerpen, Campus
Stuivenberg, Antwerp, Belgium; 4Hopital De Bicetre, Le Kremlin
Bicetre, France; 5Hospital Clinico Universitario, Valencia, Spain;
6Hospital Universitario Virgen de las Nieves, Granada, Spain;
7Northern State Medical University, Arkhangelsk, Russian
Federation; 8Liver Intensive Care Unit, London, UK
Critical Care 2007, 11(Suppl 2):P285 (doi: 10.1186/cc5445) Introduction Lack of evidence that more advanced monitoring
techniques improve outcome may have led to insufficient
monitoring of critically ill patients. However, clinical judgment and
conventional hemodynamic monitoring alone were shown to be
inadequate for a reliable estimate of hemodynamic status. We have
therefore compared clinicians’ prediction of advanced cardio-
pulmonary parameters with actual measurements. Introduction Many therapeutic decisions are made in the ICU on
the basis of clinical judgment and conventional monitoring alone,
although these may be inadequate for a reliable estimate of
hemodynamic status. We therefore measured the effects of more
advanced cardiopulmonary parameters (ACP) on major therapeutic
decisions. Methods Cardiopulmonary assessment was done in critically ill
patients from 12 European ICUs independently by one to four
physicians per patient just before the use of the PiCCO monitor
(Pulsion, Germany). Following cardiopulmonary evaluation and
prediction of ACP (reported elsewhere), each physician suggested
a therapeutic plan before and after the first set of PiCCO measure-
ments (cardiac output, systemic vascular resistance, global end-
diastolic volume, stroke volume variation, and extravascular lung
water), and then self-rated the accuracy of his original therapeutic
plan. Change of therapeutic plan following advanced
cardiopulmonary monitoring in critically ill patients: a
multicenter study Methods Cardiopulmonary assessment was done in critically ill
patients from 12 European ICUs just before the use of the PiCCO
monitor (Pulsion, Germany). Independent prediction of cardiac
output (CO), systemic vascular resistance (SVR), indexed global
end-diastolic volume (GEDVi), stroke volume variation (SVV), and
indexed extravascular lung water (EVLWi) was done by one to four
physicians per patient. Following the first set of PiCCO
measurements each physician self-rated the accuracy of his pre-
PiCCO predictions. Results A total of 257 questionnaires of 165 patients (67 females
and 98 males, age 59.8 ± 16.7 (range 16–93) years) were
completed by 135 residents and 122 specialists. The main
reasons for using the PiCCO included unclear fluid status (109
cases), sepsis/septic shock (70 cases), respiratory failure (42
cases), cardiogenic shock (19 cases), renal failure (27 cases), and
other (18 cases). Only 30–50% of the predicted values were
correct (±20% of measured values) (Table 1). Ranges of errors
were:
CO
(–77/+100%),
SVR
(–94/+303%),
GEDVi
(–88/+135%), SVV (–91/+367%), EVLWi (–76/+650%). There
was a significant underestimation of CO (P < 0.00001) and
GEDVi (P < 0.0003), and overestimation of SVR (P < 0.003) and
SVV (P < 0.0002). Results A total of 257 questionnaires of 165 patients (67 females
and 98 males, age ± SD 59.8 ± 16.7 (range 16–93) years) were
completed by 135 residents and 122 specialists. The main
reasons for using the PiCCO included unclear fluid status (109
cases), sepsis/septic shock (70 cases), respiratory failure (42
cases), cardiogenic shock (19 cases), renal failure (27 cases),
other (18 cases). Changes (plan-and-not-give and no-plan-and-
give) made in the pre-PiCCO therapeutic plans included: fluid,
31.8%; inotropes, 23.3%; vasoconstrictors, 23.5%; diuretics, 15%
(Table 1). The 240 overall self-ratings of the original plan (scale of
1–5, [1] = not different; [5] = very different) included – [1] 33.7%,
[2] 23.5%, [3] 25.9%, [4] 11.5%, [5] 5.3%. The mean self-rate
was 2.3 ± 1.2, with that of residents (2.3 ± 1.3, n = 129) being
similar to that of specialists (2.3 ± 1.1, n = 111), P < 0.88. Clinicians’ prediction of advanced cardiopulmonary
variables in critically ill patients: a multicenter study Change of therapeutic plan following advanced
cardiopulmonary monitoring in critically ill patients: a
multicenter study Clinicians’ prediction of advanced cardiopulmonary
variables in critically ill patients: a multicenter study P282 Subsequently, chest X-ray (analysed by an
experienced radiologist), CVP and PiCCO (Pulsion Company,
Munich, Germany) measurements were performed and these data
were correlated to clinical findings. Results Patients (n = 86; 34 females, 52 males) included 25
patients with cirrhosis, 18 patients with pancreatitis, 19 patients
with sepsis; age 63.0 ± 15.5 years; APACHE II score 23.3 ± 8.4. Leg edema significantly correlated to CVP (r = 0.247; P = 0.038)
and (negatively) to GEDVI (r = –0.258; P = 0.032). CVP and
GEDVI were not associated: r = 0.035; P = 0.784. The ELWI
significantly correlated to the degree of rales (r = 0.258; P = 0.016)
and GEDVI (r = 0.557; P < 0.001). The ELWI and CVP did not
correlate (r = 0.030; P = 0.785). Global clinical preload assess- Conclusions These results suggest that serial measurements of
the VPW can reliably be used to predict intravascular volume
overload in the ICU. S115 15.1%, [5] 4.5%. The mean self-rate was 2.8 ± 0.9, with that of
residents (2.8 ± 0.9, n = 129) being similar to that of specialists
(2.7 ± 0.8, n = 111), P < 0.31. ment (scale 1–10) was not predictive for GEDVI. Radiological
assessment significantly overestimated the GEDVI (901.41 ± 139.76
vs 782.56 ± 183.80 ml/m2; P < 0.001) and underestimated the
ELWI (7.22 ± 1.38 vs 9.77 ± 4.51 ml/kg; P < 0.001). Conclusions (1) Leg edema and increased CVP do not exclude
preload deficiency determined by the GEDVI, which was
overestimated by X-ray. (2) CVP and leg edema are poor
predictors of the ELWI, which was significantly associated with
audible rales but underestimated by X-ray. ment (scale 1–10) was not predictive for GEDVI. Radiological
assessment significantly overestimated the GEDVI (901.41 ± 139.76
vs 782.56 ± 183.80 ml/m2; P < 0.001) and underestimated the
ELWI (7.22 ± 1.38 vs 9.77 ± 4.51 ml/kg; P < 0.001). Conclusions The ability of physicians to predict advanced
cardiopulmonary parameters based on clinical evaluation and
conventional monitoring alone has considerable limitations and is
not improved by experience. Conclusions (1) Leg edema and increased CVP do not exclude
preload deficiency determined by the GEDVI, which was
overestimated by X-ray. (2) CVP and leg edema are poor
predictors of the ELWI, which was significantly associated with
audible rales but underestimated by X-ray. Acknowledgement The authors of this unsupported study are
members of Pulsion’s medical advisory board. P286 Assessment of extravascular lung water and pulmonary
vascular permeability evaluated by the pulse contour
cardiac output in systemic inflammatory response
syndrome patients K Morisawa, Y Taira
St Marianna University School of Medicine, Kwasaki-shi, Japan
Critical Care 2007, 11(Suppl 2):P286 (doi: 10.1186/cc5446) Results We found a statistically significant correlation of both
inspiratory and expiratory IVC diameter with central venous
pressure (P = 0.004 and P = 0.001), extravascular lung water
index (P = 0.001 and P < 0.001), intrathoracic blood volume index
(P = 0.026 and P = 0.05), the intrathoracic thermal volume (both
P < 0.001), and the paO2/FiO2 oxygenation index (P = 0.007 and
P = 0.008, respectively). Introduction Pulse contour cardiac output (PiCCO) provides an
estimate of the intrathoracic blood volume (ITBV), extravascular
lung water (EVLW), and pulmonary vascular permeability index
(PVPI). Few investigations have prospectively examined EVLW in
patients with severe sepsis or ARDS. Introduction Pulse contour cardiac output (PiCCO) provides an
estimate of the intrathoracic blood volume (ITBV), extravascular
lung water (EVLW), and pulmonary vascular permeability index
(PVPI). Few investigations have prospectively examined EVLW in
patients with severe sepsis or ARDS. Objective The aim of this study was compare measurements of
ITBV, EVLW, and PVPI in systemic inflammatory response
syndrome (SIRS) patients. Conclusions Sonographic determination of the IVC diameter is
useful in the assessment of volume status in mechanically
ventilated septic patients. This approach is rapidly available,
noninvasive, inexpensive, easy to learn and applicable in almost any
clinical situation without doing harm. IVC sonography may
contribute to a faster, more goal-oriented optimization of fluid
status and may help to identify patients in whom deleterious
volume expansion should be avoided. It remains to be elucidated
whether this approach influences the outcome of septic patients. Materials and methods Twenty-eight adult patients with SIRS
admitted to our ICU were studied in three groups. Group A, nine
patients with pneumonia; group B, nine patients with extrathoracic
infection; group C, 10 patients without infection were enrolled. In
each patient, PiCCO was used to measure the ITBV and EVLW for
3 days of meeting criteria for SIRS. The PVPI was calculated as
the ratio of EVLW to ITBV. EVLW values were indexed by the
predicted body weight and ITBV values were indexed by the
predicted body surface. All data are presented as mean ± standard
deviation. P287
Fluid status assessment in mechanically ventilated septic
patients J Schefold1, C Storm1, A Krüger1, M Oppert1, D Hasper2
1Charite University Medicine Berlin, Germany; 2Charite Campus
Virchow, Berlin, Germany
Critical Care 2007, 11(Suppl 2):P287 (doi: 10.1186/cc5447) Conclusions The measurement of advanced cardiopulmonary
parameters caused both specialists and residents to make
considerable changes in therapeutic decisions that were previously
made based on clinical judgment and conventional monitoring
alone. Background Early optimization of fluid status is of major
importance in the treatment of critically ill patients. It is unclear
whether sonographic measurement of the inferior vena cava (IVC)
diameter is valuable in the evaluation of fluid status in mechanically
ventilated septic patients. Acknowledgement The authors of this unsupported study are
members of Pulsion’s medical advisory board. Methods Thirty mechanically ventilated patients with severe sepsis
or septic shock (age 59.9 ± 15.4 years; APACHE II score 30.6 ± 7.7;
18 males) requiring advanced invasive hemodynamic monitoring
due to cardiovascular instability were included in a prospective
observational study in a university hospital setting with a 24-bed
medical ICU and a 14-bed anaesthesiological ICU. Volume-based
hemodynamic parameters were determined using the thermal-dye
transpulmonary dilution technique. Simultaneously, the IVC
diameter was measured throughout the respiratory cycle by trans-
abdominal ultrasonography. P286 The Kruskal–Wallis H test was performed for statistical
analysis and P < 0.05 was considered statistically significant. Change of therapeutic plan following advanced
cardiopulmonary monitoring in critically ill patients: a
multicenter study The 240 self-ratings (scale of 1–5, [1] = excellent; [5] = poor) of
predictions accuracy included – [1] 1.6%, [2] 40%, [3] 38.8%, [4] S116
Table 1 (abstract P284)
EVLWi
%
CO
%
SVR
%
GEDVi
%
SVV
%
Under
69
29.4
127*
49.6
46
18.1
72
28
85
39.7
Correct
93
39.6
99
38.6
90
35.4
93
50.2
64
29.9
Over
73
31.1
30
11.7
116
45.7
73
21
65
30.4
*Number of predictions. S116 Available online http://ccforum.com/supplements/11/S2 B. The EVLWI and PVPI were significantly higher in group B than
in group C too. Conclusion Our data indicate that the permeability of pulmonary
vessels is increased more with infection than without infection, and
is also higher with pneumonia than with extrathoracic infection in
SIRS patients. P287
Fluid status assessment in mechanically ventilated septic
patients
J Schefold1, C Storm1, A Krüger1, M Oppert1, D Hasper2
1Charite University Medicine Berlin, Germany; 2Charite Campus
Virchow, Berlin, Germany
Critical Care 2007, 11(Suppl 2):P287 (doi: 10.1186/cc5447) Table 1 (abstract P285)
Given
%
Not given
%
Fluid P
109
43
53
21
Fluid NP
28
11
65
25
Inotropes P
33
13
46
18
Inotropes NP
14
5
164
64
Vasoconstrictors P
50
20
36
14
Vasoconstrictors NP
24
9
143
57
Diuretics P
19
7
20
8
Diuretics NP
18
7
197
78
P = planned; NP = not planned. Table 1 (abstract P285) Conclusion Our data indicate that the permeability of pulmonary
vessels is increased more with infection than without infection, and
is also higher with pneumonia than with extrathoracic infection in
SIRS patients. P288 Noninvasive cardiac output: accuracy between the
ultrasound cardiac output monitor and the esophageal
Doppler monitor Results See Table 1. One hundred and forty samples of data were
collected. The mean PVPI value was within the normal range. The
EVLWI and PVPI were significantly higher in group A than in group R Bilkovski1, J Martini1, R Phillips2
1Henry Ford Hospital, Detroit, MI, USA; 2University of Queensland,
Brisbane, Australia
Critical Care 2007, 11(Suppl 2):P288 (doi: 10.1186/cc5448) Table 1 (abstract P286)
Group A
Group B
Group C
ITBVI
933 ± 256
977 ± 197
996 ± 407
EVLWI
12 ± 5
10 ± 4*
8 ± 3*,**
PVPI
2.3 ± 1.1
1.8 ± 0.8*
1.6 ± 0.7*,**
*P < 0.05 vs group A. **P < 0.05 vs group A and group B. Introduction The hypothesis is that measurement of the cardiac
index (CI) is accurate between the ultrasound cardiac output
monitor (USCOM) and the esophageal Doppler monitor (EDM). The EDM is a minimally invasive device that has demonstrated
strong correlation with cardiac output measurements obtained by
thermodilution. A disadvantage of the EDM is the need for probe
placement in the esophagus, effectively limiting its use to S117 *P < 0.05 vs group A. **P < 0.05 vs group A and group B. Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P289) mechanically ventilated patients. The USCOM, in contrast, can
measure cardiac hemodynamics by use of a CW Doppler probe
placed on the skin to measure blood flow across either the aortic
or pulmonic valve. mechanically ventilated patients. The USCOM, in contrast, can
measure cardiac hemodynamics by use of a CW Doppler probe
placed on the skin to measure blood flow across either the aortic
or pulmonic valve. Mixed venous hemoglobin oxygen saturation (SvO2) vs cardiac output
(CO) by noninvasive cardiac output monitoring and Swan on Mister197. Methods A prospective study of adult ED patients who were
intubated and managed concurrently with an EDM. Setting: urban
tertiary care center with >90,000 annual visits. Exclusion criteria:
ESRD, ascites, known valvular heart disease and pre-existing
tracheotomy. IRB approval was obtained with waiver of informed
consent. USCOM measurements of CI were obtained, blinded to
EDM values measured concurrently. Noninvasive cardiac output monitoring: a clinical validation P Squara, P Estagnasie, A Brusset, D Denjean, J Dib, C Dubois
CERIC, Neuilly-sur-Seine, France
Critical Care 2007, 11(Suppl 2):P289 (doi: 10.1186/cc5449) M Cecconi1, J Poloniecki2, G Della Rocca3, J Ball1, R Grounds1,
A Rhodes1
1St George’s Hospital, London, UK; 2St George’s University of
London, UK; 3University of Udine, Italy
Critical Care 2007, 11(Suppl 2):P290 (doi: 10.1186/cc5450) Introduction Our objective was to evaluate the clinical utility of
noninvasive cardiac output monitoring (NICOM), a new tool for
automatic continuous cardiac output (CO) monitoring based on
chest bioreactance, using continuous thermodilution as reference
(PAC-CCO). Introduction The Bland–Altman plot is the standard way of
determining agreement between two methods of measuring the
same variable. Following work by Critchley and Critchley [1],
±30% is now accepted as the cutoff point when calculating the
percentage error. This study estimates the coefficient of variation
(CV) of three different cardiac output (CO) techniques with the aim
of assessing the relative contributions to the percentage error. Introduction The Bland–Altman plot is the standard way of
determining agreement between two methods of measuring the
same variable. Following work by Critchley and Critchley [1],
±30% is now accepted as the cutoff point when calculating the
percentage error. This study estimates the coefficient of variation
(CV) of three different cardiac output (CO) techniques with the aim
of assessing the relative contributions to the percentage error. Method We included 110 consecutive adult patients immediately
after cardiac surgery in a prospective, single-center study taking
place in the ICU. CO measurements obtained from NICOM and
PAC-CCO were simultaneously recorded minute by minute (Figure
1). We evaluated the accuracy, precision, responsiveness, and
reliability of NICOM for detecting CO changes. Tolerance for each
of these parameters was specified prospectively. Materials and methods Thirty critically ill patients had their CO
measured every hour with continuous cardiac output by Vigilance
(CCO), pulse pressure analysis by LiDCO™plus (PulseCO) and
intermittent thermodilution (ITD) (average of four ITD curves). Data
were analysed with Bland–Altman plots, calculation of the
percentage error, determination of the CV of ITD, and calculation
of the overall CV for CCO and PulseCO. Results A total of 65,888 pairs of CO measurements were
collected. Mean reference values for PAC-CCO ranged from 2.79
to 9.27 l/min. P290 Method comparison – a new approach to implementing
the Bland–Altman analysis to estimate the precision of a
new method: tested on 30 critically ill patients monitored
with pulse pressure analysis and continuous cardiac
output vs intermittent thermodilution P288 Repeated pairs were obtained
every 30–60 minutes, in a similar manner. Statistical analysis:
correlation and Bland–Altman plots using SPSS 9.0. Results A total of 95 paired measures were obtained from 20
patients with an average age of 60.1 years, 60% male and 70%
African American. The mean CI was 5.2 with a range of
1.4–6.6 l/min/m2. For the aggregate, r = 0.81 (P < 0.001) and bias
was 0.14 with limits of agreement (LOA) of –1.48 to 1.76. Excess
scatter was noted at CI > 4.0 CI. For CI < 4.0, correlation was
0.80 (P < 0.001) with bias and LOA of –0.15 and –1.01 to 0.71. At CI < 2.5, greater accuracy was noted with bias of 0.01 and
LOA of 0.73 to 0.75. Mixed venous hemoglobin oxygen saturation (SvO2) vs cardiac output
(CO) by noninvasive cardiac output monitoring and Swan on Mister197. Conclusions CI measurement with the USCOM has a high degree
of agreement with the EDM, most notably when CI is below 4.0. Of
particular interest is the high degree of accuracy seen at low CI
values (<2.5). These findings support the use of the USCOM for
CI measurement in mechanically ventilated patients and a wider
range of patients in which the EDM would be impractical or difficult
to use. Conclusion CO measured by NICOM had most often acceptable
accuracy, precision, and responsiveness in a wide range of
circulatory situations. P291 P291
Comparison of vascular pedicle width and PiCCO-derived
haemodynamic measurements in patients in a general
intensive care unit
S Aloizos1, G Liapis1, D Maragiannis1, E Tsigou2, P Aravosita2,
E Evodia2
1401 General Army Hospital Athens, Greece; 2Mother General &
Surgical Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P291 (doi: 10.1186/cc5451) Comparison of vascular pedicle width and PiCCO-derived
haemodynamic measurements in patients in a general
intensive care unit Methods Our study includes 140 measurements in 10 critically ill
patients (eight males, two females, age 37–84 years, mean 64.1 ±
13.0 years) requiring hemodynamic monitoring with the PiCCO
system. Five patients had septic shock, three hepatorenal
syndrome and two acute heart failure. First the CIpc was recorded
immediately before the next calibration and afterwards the CItd
was measured three times, which resulted in a simultaneous
calibration of the pulse contour algorithm of the PiCCO system. We performed a mean of 14 ± 9.4 measurements per patient. The
time-lag between the measurements was 12 hours 54 minutes ±
7 hours 47 minutes. intensive care unit
S Aloizos1, G Liapis1, D Maragiannis1, E Tsigou2, P Aravosita2,
E Evodia2
1401 General Army Hospital Athens, Greece; 2Mother General &
Surgical Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P291 (doi: 10.1186/cc5451) Introduction Assessing clinically the intravascular volume status of
critically ill patients can be exceedingly difficult. Due to concerns
about the efficacy and safety (possible increase in mortality) of
using invasive haemodynamic monitoring, noninvasive diagnostic
testing has gained increasing importance. Results The comparison of the CIpc immediately before calibration
and the calibration-derived CItd resulted in a correlation coefficient
of 0.84 with a P value of 0.02. In the Bland–Altman analysis the
CIpc was a mean 0.14 l/min/m2 lower than the CItd. The standard
deviation was 0.72 l/min/m2. There was no correlation of the time-
lag between the calibrations and the difference of CIpc and CItd
(r = –0.03; P = 0.13). Objective To compare the reliability of vascular pedicle width
(VPW) as an indicator of overload, in patients of a general ICU,
with a method of invasive haemodynamic monitoring that has
proved its efficacy in the literature and in everyday practice. Patients and methods The VPW, which represents the media-
stinal silhouette of the great vessels, was compared with the
haemodynamic measurements, which were obtained with the
method of transpulmonary thermodilution (PiCCO Plus; Pulsion,
Munich, Germany). Reliability of the continuous cardiac index measurement
using the pulse contour analysis of the PiCCO system Reliability of the continuous cardiac index measurement
using the pulse contour analysis of the PiCCO system Conclusions In trying to understand the relative contributions of
error when testing two techniques to measure the same variable it
is vital to understand the CV of the reference technique. Using this
approach, both the PulseCO and Vigilance perform in a clinically
acceptable fashion. M Franzen, A Umgelter, S von Delius, A Weber,
J Reichenberger, M Dohmen, R Schmid, W Huber
Klinikum rechts der Isar, München, Germany
Critical Care 2007, 11(Suppl 2):P292 (doi: 10.1186/cc5452) Reference 1. Critchley LA, Critchley JA: A meta-analysis of studies using
bias and precision statistics to compare cardiac output
measurement techniques. J Clin Monit Comput 1999, 15:
85-91. 1. Critchley LA, Critchley JA: A meta-analysis of studies using
bias and precision statistics to compare cardiac output
measurement techniques. J Clin Monit Comput 1999, 15:
85-91. Introduction Reliable continuous hemodynamic monitoring of
critically ill patients is essential for effective volume management
and adequate administration of vasoactive drugs. The PiCCO
system allows continuous measurement of the cardiac index using
arterial pulse contour analysis. Calibration of this system by
transpulmonary thermodilution is recommended every 8 hours. In
this study we compared the difference of the continuous measure-
ment of the cardiac index using the arterial pulse contour analysis
(CIpc) with the cardiac index acquired by the transpulmonary
thermodilution (CItd) when calibrating the system. Noninvasive cardiac output monitoring: a clinical validation During periods of stable PAC-CCO (slope < ±10%,
2SD/mean <20%), the correlation between NICOM and PAC-
CCO was R = 0.82; bias was +0.16 ± 0.52 l/min (+4.0 ± 11.3%),
and the relative error was 9.1 ± 7.8%. In 85% of patients the
relative error was <20%. During periods of increasing CO, slopes
were similar with the two methods in 96% of patients and
intraclass correlation was positive in 96%. Corresponding values
during periods of decreasing CO were 90% and 84%,
respectively. Precision was always better with NICOM than with
PAC-CCO. During hemodynamic challenges, changes were 3.1 ±
3.8 minutes faster with NICOM (P < 0.01) and amplitude of
changes were not different (not significant). Finally, sensitivity of
the NICOM for detecting significant directional changes was 93%
and specificity was 93%. Results Two hundred and forty (eight per patient) measurements
of CO were obtained. CCO vs ITD had an overall bias (±2SD) of
0.2 ± 2.4 l/min (error 31%), mean CO (ITD + CCO) 7.7 l/min. PulseCO vs ITD had an overall bias of –0.1 ± 2.4 l/min, mean CO
(PulseCO + ITD) 7.5 l/min (error 33%). According to the above
criteria (without measuring the CV for ITD), CCO performed well
when compared with ITD (31%) but PulseCO (33%) was outside
clinically acceptable levels of agreement. The CV for a single ITD
CO measurement was 15%, and this decreased to 7.5% when
averaging four thermodilution curves. Using the CV for ITD of
7.5%, the relative CVs for the CCO and PulseCO were S118 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P292
Reliability of the continuous cardiac index measurement
using the pulse contour analysis of the PiCCO system
M Franzen, A Umgelter, S von Delius, A Weber,
J Reichenberger, M Dohmen, R Schmid, W Huber
Klinikum rechts der Isar, München, Germany
Critical Care 2007, 11(Suppl 2):P292 (doi: 10.1186/cc5452) P292 determined. The CV for CCO was 13.6% and for PulseCO was
14.7%. P291 We measured the VPW in anteroposterior
chest X-rays in the supine position, with standard parameters, in
100 patients without prior cardiac surgery, prior mediastinal
irradiation, obesity, severe acute respiratory distress syndrome and
positive end-expiratory pressure > 7.5 cmH2O. In every patient we
performed invasive haemodynamic monitoring with the PiCCO
Plus. An intrathoracic blood volume index (ITBI) > 1,000 ml/m2,
global end-diastolic index (GEDI) > 800 ml/m2, and extravascular
lung water index (ELWI) > 7.0 ml/kg were considered the markers
of significant volume overload. After further refinement, 27 patients
fulfilled the above criteria and were considered eligible to be
included in the study. Conclusion The PiCCO system allows a reliable continuous
measurement of the cardiac index using the pulse contour analysis. In our study we could not find an increased difference of CIpc and
CItd even with longer time periods between the calibrations using
transpulmonary thermodilution. Because calibration is easy to
achieve and additional data for the intrathoracic blood volume and
the extravascular lung water are obtained, a 12-hour period
between the calibrations is reasonable. PiCCO monitoring – are two injections enough? The mean CV for single lithium dilution was
12.3%. The CV for the average of n lithium dilutions was 8.6% for
n = 2, 7.1% for n = 3, 6.1% for n = 4. Results Two hundred and forty-nine triplates were collected in 25
patients with septic shock, under mechanical ventilation. There
were no significant differences in CI at each bolus. The average of
the first two iced injections M1 = 3.28 ± 1.07 l/min/m2. The
average of the triplate M2 = 5.74 ± 1.07. Conclusions The CV for one lithium dilution was higher than
clinically acceptable (12.3 > 10%). The average of two lithium
dilution measurements improves the precision by 30% and shows
an excellent CV (that is, 8.6%). When measuring cardiac output
with LiDCO an average of two lithium dilution curves provide an
excellent precision, and we suggest that in this population
(medical/surgical) this approach should always be used when
calibrating the pulse pressure algorithm (PulseCO) at the baseline. Discussion Normally, we consider that 10–15% of variation in the
CI signifies a change in the haemodynamic state. The difference
between M1 and M2 exceeds 15%. In the literature, Nilsson and
colleagues [1] demonstrated concerning the pulmonary arterial
catheter that we need an average of at least four injections to be
95% confident. Conclusion With PiCCO monitoring, certainly two injections are
not enough to have reliable measurement of the CI. Reference Conclusion With PiCCO monitoring, certainly two injections are
not enough to have reliable measurement of the CI. Reference Conclusion With PiCCO monitoring, certainly two injections are
not enough to have reliable measurement of the CI. 1. Nilsson LB, et al.: Acta Anaesthesiol Scand 2004, 48:1322-
1327. P295 P295 P294
Lithium dilution cardiac output measurement in the critically
ill patient: determination of precision of the technique Transpulmonary lithium indicator dilution: a new method of
intrathoracic blood volume measurement Transpulmonary lithium indicator dilution: a new method of
intrathoracic blood volume measurement Lithium dilution cardiac output measurement in the critically
ill patient: determination of precision of the technique M Cecconi, N Al-Subaie, M Canete, D Dawson, M Puntis,
J Poloniecki, R Grounds, A Rhodes
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P294 (doi: 10.1186/cc5454) B Maddison, T Best, C Wolff, P Jones, C Hinds, R Pearse
Barts & The London School of Medicine & Dentistry, London, UK
Critical Care 2007, 11(Suppl 2):P295 (doi: 10.1186/cc5455) S120
,
pp
(
)
Introduction Pulmonary intermittent thermodilution (from the pu
monary artery catheter), transpulmonary thermodilution (PiCCOplus
Pulsion, Munich, Germany) and transpulmonary lithium dilutio
(LiDCO™plus; LiDCO, Cambridge, UK) are all well-validated
techniques in common use in intensive care for cardiac outpu
estimation. The precision has been looked into previously and
strategies to improve it have been made (that is, averaging three o
four measurements over the respiratory cycle) yet not much i
known about the precision of transpulmonary techniques in term
of repeatability. This study aims to look into the coefficient o
variation (CV) of the lithium dilution technique in a mixed
(medical/surgical) intensive care population and propose a method
to improve its precision. Materials and methods We performed four consecutive lithium
dilution cardiac output determinations on 70 critically ill patient
requiring haemodynamic monitoring. The heart rate (HR), centra
venous pressure (CVP) and mean arterial pressure (mAP) were
documented in conjunction with cardiac output estimation. Dat
were excluded if a ±5% change in HR, CVP or mAP occurred
during the sequential measurements. The CV ((SD/mean cardiac
output) x 100) was calculated for single measurements and for the
average of repeated measurements. In order to clinically accept the
precision of the technique, we aimed to obtain a CV below 10%. Table 1 (abstract P295)
Preoperative
Post-CPB
ITBVI (ml/m2) (n = 20)
739 (612–969)
1,078 (815–1,2
PBVI (ml/m2) (n = 16)
213 (201–279)
343 (307–37
CI (l/min/m2) (n = 20)
1.92 (0.45)
1.81 (0.42) Introduction Extravascular lung water (EVLW) measurement may
improve outcome. Double indicator dilution, which is the most
accurate method of EVLW measurement, is no longer commer-
cially available. P295 Lithium indicator dilution could be used to measure
the intrathoracic blood volume index (ITBVI) and therefore EVLW. Introduction Pulmonary intermittent thermodilution (from the pul-
monary artery catheter), transpulmonary thermodilution (PiCCOplus;
Pulsion, Munich, Germany) and transpulmonary lithium dilution
(LiDCO™plus; LiDCO, Cambridge, UK) are all well-validated
techniques in common use in intensive care for cardiac output
estimation. The precision has been looked into previously and
strategies to improve it have been made (that is, averaging three or
four measurements over the respiratory cycle) yet not much is
known about the precision of transpulmonary techniques in terms
of repeatability. This study aims to look into the coefficient of
variation (CV) of the lithium dilution technique in a mixed
(medical/surgical) intensive care population and propose a method
to improve its precision. Method A single-centre, observational study. Consent was sought
from patients aged over 50 years undergoing elective cardiac
surgery with cardiopulmonary bypass (CPB). Exclusion criteria
included significant valvular regurgitation and lithium therapy. Anaesthetic, CPB, blood transfusion, ventilation and sedation
practices were standardised. Indicator dilution measurements were
performed following induction of anaesthesia, after CPB and then
2, 4 and 24 hours following surgery, using existing technology
(LiDCO Ltd, London, UK). Data are presented as the median (IQR). Results Twenty patients were recruited (age 70 years (64–75
years); Parsonnet score 10 (1–14)). No difficulties were encoun-
tered with the new method of ITBVI measurement. Absolute values
and the changes in the ITBVI were close to those anticipated. Linear regression analysis did not indicate mathematical coupling
between the cardiac index (CI) and the ITBVI (R2 = 0.22;
P < 0.001). The relationship between the pulmonary blood volume
index (PBVI) and the ITBVI was not constant. Materials and methods We performed four consecutive lithium
dilution cardiac output determinations on 70 critically ill patients
requiring haemodynamic monitoring. The heart rate (HR), central
venous pressure (CVP) and mean arterial pressure (mAP) were
documented in conjunction with cardiac output estimation. Data
were excluded if a ±5% change in HR, CVP or mAP occurred
during the sequential measurements. The CV ((SD/mean cardiac
output) x 100) was calculated for single measurements and for the
average of repeated measurements. In order to clinically accept the
precision of the technique, we aimed to obtain a CV below 10%. Conclusion Lithium indicator dilution may be a valuable new
method of ITBVI measurement, and therefore EVLW measurement. 1.
Nilsson LB, et al.: Acta Anaesthesiol Scand 2004, 48:1322-
1327. Results Sixty-five series were suitable for analysis. The CV showed
a normal distribution and no correlation with the magnitude of the
mean cardiac output. The mean CV for single lithium dilution was
12.3%. The CV for the average of n lithium dilutions was 8.6% for
n = 2, 7.1% for n = 3, 6.1% for n = 4. PiCCO monitoring – are two injections enough? S Alaya, S Abdellatif, R Nasri, H Ksouri, S Ben Lakhal
Intensive Care Unit, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P293 (doi: 10.1186/cc5453) Results The mean VPW in overloaded patients was 75.14 mm
compared with a mean of 64.71 mm for the rest. The results were
subsequently analyzed using Spearman’s nonparametric test and
we found correlation (0.785, 0.710, and 0.510) between VPW and
the GEDI, ITBI, and ELWI, respectively. The results were
considered statistically significant (P < 0.000, P < 0.000, and
P < 0.005, respectively). Introduction
PiCCO
monitoring
using
the
thermodilution
technique has become an alternative method of invasive
haemodynamic monitoring for the critically ill patient. Usually the
results of an arbitrarily chosen number (one to five) of thermal
indicator injections are averaged to increase the reliability of the
measurement. The number of injections needed to achieve a given
level of precision has, however, not previously been systematically
investigated. We tried in this study to validate the accuracy of two
injections instead of three injections. Introduction
PiCCO
monitoring
using
the
thermodilution
technique has become an alternative method of invasive
haemodynamic monitoring for the critically ill patient. Usually the
results of an arbitrarily chosen number (one to five) of thermal
indicator injections are averaged to increase the reliability of the
measurement. The number of injections needed to achieve a given
level of precision has, however, not previously been systematically
investigated. We tried in this study to validate the accuracy of two
injections instead of three injections. Conclusion The VPW, when appropriately assessed at the
bedside by the same physician and therefore avoiding the possible
bias, using portable chest X-rays, might give very useful information
regarding the volume status of the patients, results that are
comparable in their efficacy with those obtained with invasive and
more expensive methods. Methods We analysed retrospectively all data (triplate measure-
ments) obtained during the past 2 years by PiCCO monitoring:
injection of 10 ml saline solution three times by the same operator. S119 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin We compared the cardiac index (CI) obtained at each bolus, the
average of the CI obtained at the first two injections (M1) and then
the triplate (M2). Results Sixty-five series were suitable for analysis. The CV showed
a normal distribution and no correlation with the magnitude of the
mean cardiac output. P295 S120
Table 1 (abstract P295)
Time
2 hours
4 hours
24 hours
Preoperative
Post-CPB
postoperatively
postoperatively
postoperatively
ITBVI (ml/m2) (n = 20)
739 (612–969)
1,078 (815–1,262)
1,266 (1,031–1,433)
1,188 (947–1,343)
1,008 (738–1,257)
PBVI (ml/m2) (n = 16)
213 (201–279)
343 (307–371)
338 (288–449)
394 (305–545)
407 (267–464)
CI (l/min/m2) (n = 20)
1.92 (0.45)
1.81 (0.42)
2.03 (0.56)
2.20 (0.58)
2.28 (0.94) Table 1 (abstract P295) S120 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P297)
Patient
ItbiP
ItbiL
Difference (%)
1
894
960
7.4
2a
1,517
1,990
31
2b
1,572
1,078
–31.4
3
1,069
724
–32.3
4
1,280
1,318
3.0
5a
1,478
1,213
–17.9
5b
1,324
1,058
–20.1
5c
1,429
1,797
25.8
6a
732
731
–0.01
6b
787
627
–20.3 P296 P296
Comparison between uncalibrated cardiac output using
the femoral and radial arterial pressure waveform in
critically ill patients
J Smith1, C Wolff2, E Mills2, K Lei1, C Taylor1, L Camporota1,
R Beale1
1Guy’s & St Thomas’ NHS Foundation Trust, London, UK; 2LiDCO
Ltd, London, UK
Critical Care 2007, 11(Suppl 2):P296 (doi: 10.1186/cc5456) Introduction Cardiac output (CO) monitoring is often required to
manage critically ill patients. Nominal values can be determined
from analysis of arterial pressure waveforms. It is assumed that
arterial waveforms from different arterial sites give similar CO
values. The aim of this study was to compare the values of
uncalibrated CO derived from simultaneous radial (COr) and
femoral (COf) blood pressures. mean difference of LiDCO from PiCCO overall was –5.49 ±
21.3%. The correlation coefficient r = 0.73 (P = 0.0166). Conclusion There was general agreement between LiDCO and
PiCCO. There were significant differences (>30%) in only three
out of 10 measurements. Combining the results of >1 lithium
calibration may improve accuracy. These results are promising but
a larger trial will be required. mean difference of LiDCO from PiCCO overall was –5.49 ±
21.3%. The correlation coefficient r = 0.73 (P = 0.0166). Methods We enrolled 17 medical and surgical ICU patients,
requiring haemodynamic monitoring and vasoactive drugs. Simultaneous recordings of the arterial radial and femoral
waveforms were made from arterial pressure monitors via an A–D
converter and analysed to obtain CO values using the PulseCO®
algorithm of the LiDCOplus (LiDCO, London, UK). Paired CO
values were selected at several points on each recording. Calibrations were not done at each time point so the comparison
required examination of the ratio of uncalibrated COr and COf. Conclusion There was general agreement between LiDCO and
PiCCO. There were significant differences (>30%) in only three
out of 10 measurements. Combining the results of >1 lithium
calibration may improve accuracy. These results are promising but
a larger trial will be required. Impedance cardiography to assess hemodynamic status: a
comparison with transpulmonary thermodilution Impedance cardiography to assess hemodynamic status: a
comparison with transpulmonary thermodilution A Donati, R Nardella, V Gabbanelli, C Valentini, F Gabriele, P Pelaia
AOU Umberto I Ancona, Italy
Critical Care 2007, 11(Suppl 2):P298 (doi: 10.1186/cc5458) Introduction Measurement of extravascular lung water (EVLW)
obtained with transpulmonary thermodilution (PiCCO system) can
help the physician to guide fluid management of critically ill
patients [1]. The thoracic fluid content (TFC) is a parameter
deriving from the electric conductivity of the thorax, determined
from intravascular, alveolar and interstitial fluids [2,3]. To the
author's knowledge, there is no clinical study comparing PiCCO
EVLW and the TFC provided by the impedance cardiac output
(ICG) system. The aim of the study was to compare measurements
of cardiac index (CI) obtained with PiCCO (P) and ICG before and
after fluid challenge (FC), to evaluate whether the TFC can provide
a noninvasive estimate of lung fluid balance, compared with
PiCCO EVLW, in 10 critically ill patients. Conclusions CO derived from blood pressure records at radial
and femoral sites can appear similar when a patient population as a
whole is considered. However, in individual patients, the difference
between the two sites is large enough to be clinically unacceptable
without a site-specific recalibration. P298 Results The median value of the CO ratio was 0.95 (IQR
0.88–1.02), with a high variability across the patients, ranging from
0.3 to 1.41, whereas intrapatient variability was low, with a median
CV of 3.26% (IQR 1.1–5.3%). Although the ratio in COs between
the two sites varied greatly, the difference between the median
(range) arterial pressures was 2 mmHg (–3 to 8 mmHg). However,
the pulse pressure difference between the two sites was generally
large with a median (range) of 2 mmHg (–26 to 44 mmHg). Measurement of intrathoracic blood volume by lithium
dilution: comparison with thermodilution H Roberts, A Saayman, L Ala, G Findlay
University Hospital of Wales, Cardiff, UK
Critical Care 2007, 11(Suppl 2):P297 (doi: 10.1186/cc5457) Methods We studied 10 patients (eight males), aged 16-76 years
(mean 22 ± SD 38), admitted to our ICU for head injury (three
patients), septic shock (four patients), ARDS (one patient), and
postsurgical (two patients). Introduction The intrathoracic blood volume is usually measured
clinically by transpulmonary thermodilution (PiCCO system;
Pulsion Ltd). New software also allows measurement at the
bedside by lithium dilution (LiDCO system; LiDCO Ltd). We
sought to compare the new lithium dilution method with the
existing method. p
g
(
p
)
The APACHE II score was 26-36 (30 ± 5). They were all moni-
tored with the P system (PiCCO, V4.12; Pulsion Medical Systems
AG) and the ICG system (Solar ICG module; GE Medical Systems
Technology, Milwaukee, USA, 2001), to evaluate the CI. All
patients received FC to optimize the haemodynamic status. Haemo-
dynamic measurements were made before and after FC with
colloids (5 ml/kg in 30 min). Statistical analysis was performed with
Spearman nonparametric correlation and the Bland–Altman test. Results Twenty samples of data were collected. The CI P mean ±
SD was 3.91 ± 0.83 l/min/m2 before FC and 3.32–8.52 l/min/m2
after FC. The mean CI ICG value before FC was 3.44 ± 0.99 l/min/m2
(2.10–5.50) and was 4.56 ± 1.37 l/min/m2 after FC. The correlation
coefficient found was 0.526 (P < 0.05) and 0.588 after. The 95%
CI was 0.149–0.804. The overall mean CI P – CI ICG difference The APACHE II score was 26-36 (30 ± 5). They were all moni-
tored with the P system (PiCCO, V4.12; Pulsion Medical Systems
AG) and the ICG system (Solar ICG module; GE Medical Systems
Technology, Milwaukee, USA, 2001), to evaluate the CI. All
patients received FC to optimize the haemodynamic status. Haemo-
dynamic measurements were made before and after FC with
colloids (5 ml/kg in 30 min). Statistical analysis was performed with
Spearman nonparametric correlation and the Bland–Altman test. Results Twenty samples of data were collected. The CI P mean ±
SD was 3.91 ± 0.83 l/min/m2 before FC and 3.32–8.52 l/min/m2
after FC. The mean CI ICG value before FC was 3.44 ± 0.99 l/min/m2
(2.10–5.50) and was 4.56 ± 1.37 l/min/m2 after FC. The correlation
coefficient found was 0.526 (P < 0.05) and 0.588 after. The 95%
CI was 0.149–0.804. Measurement of intrathoracic blood volume by lithium
dilution: comparison with thermodilution The overall mean CI P – CI ICG difference The APACHE II score was 26-36 (30 ± 5). They were all moni-
tored with the P system (PiCCO, V4.12; Pulsion Medical Systems
AG) and the ICG system (Solar ICG module; GE Medical Systems
Technology, Milwaukee, USA, 2001), to evaluate the CI. All
patients received FC to optimize the haemodynamic status. Haemo-
dynamic measurements were made before and after FC with
colloids (5 ml/kg in 30 min). Statistical analysis was performed with
Spearman nonparametric correlation and the Bland–Altman test. Methods
Ethics approval was obtained. Nonpregnant adult
patients on the ICU with PiCCO monitoring were recruited. Consent was given by patients’ representatives. Simultaneous
calibration of PiCCO and LiDCO systems with one lithium dilution
curve and the average of three thermal dilution curves allowed
comparison of results. Results Twenty samples of data were collected. The CI P mean ±
SD was 3.91 ± 0.83 l/min/m2 before FC and 3.32–8.52 l/min/m2
after FC. The mean CI ICG value before FC was 3.44 ± 0.99 l/min/m2
(2.10–5.50) and was 4.56 ± 1.37 l/min/m2 after FC. The correlation
coefficient found was 0.526 (P < 0.05) and 0.588 after. The 95%
CI was 0.149–0.804. The overall mean CI P – CI ICG difference Results Six patients were studied (five males, one female). All
were intubated but none were receiving muscle relaxation. Mean
age was 60.6 ± 21.8 years. The mean APACHE II score was
20.8 ± 2.3. Ten paired results were obtained (see Table 1). The S121 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin (range: 19.5–48.0 kg/m2)). CO values during the observation time
ranged from 2.4 to 9.3 l/min. Bland–Altman analysis revealed a
mean bias ± 2SD (limits of agreement) of 0.20 ± 2.3 l/min for
FCO–ICO, 0.3 ± 2.7 l/min for PCO–ICO and 0.3 ± 2.5 l/min for
CCO–ICO. Mean bias ± 2SD was –3.6 ± 59.2% for δ FCO–
δ ICO, –1.6 ± 67.1% for δ PCO–δ ICO and 2.5 ± 58.8% for δ ICO–
δ CCO. was 0.70 l/min/m2, with ±1.96 SD of –2.53 and 3.23, respectively. One measurement (5%) extended beyond the lower SD limit. P300 2. Spiess B, Patel M, Soltow L: Comparison of bioimpedance
versus thermodilution cardiac output during cardiac
surgery: evaluation of a second-generation bioimpedance
device. J Cardiothor Vasc Anesth 2001, 15:567-573. 2. Spiess B, Patel M, Soltow L: Comparison of bioimpedance
versus thermodilution cardiac output during cardiac
surgery: evaluation of a second-generation bioimpedance
device. J Cardiothor Vasc Anesth 2001, 15:567-573. Flow Trac™ cardiac output determination correlates with
echocardiography Flow Trac™ cardiac output determination correlates with
echocardiography F Turani, M Falco, A De Chiara, A Belli, C Parisi, A Marineli
Aurelia European Hospital, Rome, Italy
Critical Care 2007, 11(Suppl 2):P300 (doi: 10.1186/cc5460) 3. Kunst A, Bakker J: Electrical impedance tomography in the
assessment of extravascular lung water in noncardiogenic
acute respiratory failure. Chest 1999, 116:1695-1702. 3. Kunst A, Bakker J: Electrical impedance tomography in the
assessment of extravascular lung water in noncardiogenic
acute respiratory failure. Chest 1999, 116:1695-1702. g
References 1. Bindels A, Meinders A: Pulmonary artery wedge pressure
and extravascular lung water in patients with acute cardio-
genic pulmonary edema requiring mechanical ventilation. Am J Cardiol 1999, 84:1158-1163. 1. Bindels A, Meinders A: Pulmonary artery wedge pressure
and extravascular lung water in patients with acute cardio-
genic pulmonary edema requiring mechanical ventilation. Am J Cardiol 1999, 84:1158-1163. P299 Introduction A new device may be used in intensive care to
measure the cardiac output (CO) by arterial pulse pressure
waveform analysis, but few studies have evaluated the reliability of
this method and the correlation with other methods of CO deter-
mination. The aims of this study were to evaluate the CO obtained
using the Flow Trac™ Vigileo™ and the correlation with CO
obtained by transthoracic echocardiography (TTE). Clinical evaluation of the FloTrac/Vigileo system and two
established methods for continuous cardiac output
monitoring in patients undergoing cardiac surgery Clinical evaluation of the FloTrac/Vigileo system and two
established methods for continuous cardiac output
monitoring in patients undergoing cardiac surgery References 1. Manecke G: Edwards FloTrac sensor and vigileo monitor;
easy, accurate, reliable cardiac output assessment using
the arterial pulse wave. Expert Rev Med Devices 2005,
2:523-527. 2. Opdam HI, Wan L, Bellomo R: A pilot assessment of the
FloTrac™ cardiac output monitoring system. Intensive Care
Med 2006 [Epub ahead of print]. Measurement of intrathoracic blood volume by lithium
dilution: comparison with thermodilution The
EVLW index ranges from 3.3 to 13.7 (7.86 ± 3.27) ml/kg before
FC and 3.4 to 15.1 (8.58 ± 3.52) ml/kg after FC (P = 0.015). The
TFC before FC was 34–60 (43 ± 10) ml/kg and 32–64 (46 ± 10)
ml/kg after FC (P = 0.011). The correlation coefficient found
before FC is 0.798 (P = 0.007) with 95% CI 0.656–0.940. The
correlation coefficient found after FC is 0.802 (P = 0.005) with
95% CI 0.661–0.943. was 0.70 l/min/m2, with ±1.96 SD of –2.53 and 3.23, respectively. One measurement (5%) extended beyond the lower SD limit. The
EVLW index ranges from 3.3 to 13.7 (7.86 ± 3.27) ml/kg before
FC and 3.4 to 15.1 (8.58 ± 3.52) ml/kg after FC (P = 0.015). The
TFC before FC was 34–60 (43 ± 10) ml/kg and 32–64 (46 ± 10)
ml/kg after FC (P = 0.011). The correlation coefficient found
before FC is 0.798 (P = 0.007) with 95% CI 0.656–0.940. The
correlation coefficient found after FC is 0.802 (P = 0.005) with
95% CI 0.661–0.943. Conclusion These results indicate that the FloTrac/Vigileo system
is a reliable alternative to PiCCO and the pulmonary artery catheter
for CO measurement in cardiac surgery patients. Conclusions The main findings in this study are the great
discrepancy between the two methods. CI measurements obtained
with the ICG system underestimated CI when compared with the P
system, particularly after FC. The TFC and EVLW index trends
derived from FC appear similar; TFC measurements obtained with the
ICG system show good correlation when compared with the EVLW
index of the P system and it may be a useful index of pulmonary
overloading, if supported by further randomized clinical trials. Conclusions The main findings in this study are the great
discrepancy between the two methods. CI measurements obtained
with the ICG system underestimated CI when compared with the P
system, particularly after FC. The TFC and EVLW index trends
derived from FC appear similar; TFC measurements obtained with the
ICG system show good correlation when compared with the EVLW
index of the P system and it may be a useful index of pulmonary
overloading, if supported by further randomized clinical trials. D Button, C Hofer Triemli City Hospital, Zurich, Switzerland Triemli City Hospital, Zurich, Switzerland y
p
Critical Care 2007, 11(Suppl 2):P299 (doi: 10.1186/cc5459) y
y
Materials and methods Ten critical care patients admitted to a
general ICU were enrolled in the study. All patients were
mechanically ventilated (tidal volume 6–8 ml/kg, plateau pressure
< 30 cmH2O) and connected to an integrated monitoring system
(Flow Trac™/Vigileo™; Ewdards Lifescience, Irvine, CA, USA) that
attaches to an arterial cannula. After haemodynamic stabilization
the CO was calculated from an arterial pressure-based algorithm
that utilises the relationship between pulse pressure and stroke
volume. At the same time a TTE examination was performed
(Hewlett Packard, SONO 1000) and the CO was calculated by
Doppler measurement of the left ventricular outflow area (LVOT)
and the velocity–time integral (VTI LVOT), assuming stroke volume
= cross-sectional area x VTI. Every patient had two CO
determinations by TTE during Flow Trac™ measurement. A
regression analysis and Bland–Altman analysis were used to
compare the two methods of CO determination. Introduction A new arterial pressure waveform analysis device,
which does not need external calibration (FloTrac/Vigileo; Edwards
Lifesciences, Irvine, CA, USA), became recently available for
cardiac output (CO) measurement. However, only limited validation
data for this technique are so far available [1,2]. Objective The aim of this study was to compare cardiac output
assessed by the FloTrac/Vigileo system (FCO), the PiCCOplus
system (PCO) [1] (Pulsion Medical Systems; Munich, Germany)
and continuous cardiac output (CCO) monitoring using a pulmo-
nary artery catheter (Vigilance; Edwards Lifesciences) with inter-
mittent pulmonary artery thermodilution (ICO) in cardiac surgery
patients. Methods With ethics committee approval and written patient
informed consent, patients undergoing elective cardiac surgery
were studied. The CCO, FCO and PCO were recorded in the
perioperative period after induction of anaesthesia (= study
initiation) and 1, 4, 8, 12 and 24 hours post initiation. At each
measurement point the ICO was assessed as mean of three
repeated bolus injections. Statistical analysis was done using
Bland–Altman analysis of absolute CO values and of percentage
changes (δ) between consecutive CO measurements (= trend
analysis). Results A total of 40 CO determinations were performed in 10
patients. Table 1 reports the main results. Table 1 (abstract P300)
R2
P
Bias
SD of bias
CO Flow Trac™/CO TTE
0.85
<0.0001
0.24
0.45
Conclusion CO measurements obtained by Flow Trac™ show
agreement with CO TTE with no clear bias, but comparative
studies with thermodilution are warranted. P301 P301 P302 P302
CeVOX for continuous central venous oxygenation
measurement in patients undergoing off-pump coronary
artery bypass grafting
A Rist, S Schneider, P Fodor, L Weibel, A Zollinger, C Hofer
Triemli City Hospital, Zurich, Switzerland
Critical Care 2007, 11(Suppl 2):P302 (doi: 10.1186/cc5462) A survey of cardiac output monitoring in intensive care units CeVOX for continuous central venous oxygenation
measurement in patients undergoing off-pump coronary
artery bypass grafting A survey of cardiac output monitoring in intensive care units R Green1, J Craig1, B Kyle1, M Jonas2
1Poole General Hospital, Poole, UK; 2Southampton General
Hospital, Southampton, UK
Critical Care 2007, 11(Suppl 2):P301 (doi: 10.1186/cc5461) R Green1, J Craig1, B Kyle1, M Jonas2 1Poole General Hospital, Poole, UK; 2Southampton Gen A Rist, S Schneider, P Fodor, L Weibel, A Zollinger, C Hofer
Triemli City Hospital, Zurich, Switzerland
Critical Care 2007, 11(Suppl 2):P302 (doi: 10.1186/cc5462) al Care 2007, 11(Suppl 2):P301 (doi: 10.1186/cc5461) Introduction We surveyed adult ICUs, looking at cardiac output
monitor use with a view to demonstrating a practice change over
the last 3 years. Objective The aim of this study was to compare central venous O2
saturation (ScvO2) [1] measured continuously by the CeVOX
(Pulsion Medical System, Munich, Germany) device (CScvO2) with
ScvO2 determined by blood gas co-oximetry (BScvO2). Method The senior physicians on ICUs in the South of England
were surveyed via telephone. Information was collected as to
which cardiac output monitors were available for use, which was
their first choice and how often they measured cardiac output in
severe sepsis. Methods
Twenty-five patients undergoing elective off-pump
coronary artery bypass grafting were studied during operation
(OP) and during their ICU stay (ICU). OP/ICU measurement
started after in vivo calibration of CeVOX. BScvO2 and CScvO2
readings were recorded at intervals of 30 minutes during OP and
120 minutes during ICU. Bland–Altman analysis and Pearson
correlation was performed for overall OP, overall ICU, consecutive
measurements during OP ≤1 hour, 1–2 hours and 2–3 hours after
initial calibration (OP1–OP3, respectively) as well as during ICU
≤4 hours, 4–8 hours, 8–12 hours and 12–16 hours after re-
calibration (ICU1–ICU4, respectively). Results Forty-nine out of 52 ICUs units contacted completed the
survey. Monitor availability can be seen in Figure 1 and use in
severe sepsis compared with 2003 can be seen in Table 1. D Button, C Hofer Table 1 (abstract P300)
R2
P
Bias
SD of bias
CO Flow Trac™/CO TTE
0.85
<0.0001
0.24
0.45
Conclusion CO measurements obtained by Flow Trac™ show
agreement with CO TTE with no clear bias, but comparative
t di
ith th
dil ti
t d Table 1 (abstract P300)
R2
P
Bias
SD of bias
CO Flow Trac™/CO TTE
0.85
<0.0001
0.24
0.45 Results One hundred and eighty-five matched sets of data were
available for statistical analysis from 31 patients (ASA III, male/
female ratio = 26/5, mean ± SD age = 66.58 ± 0.53 years (range:
45–84 years), mean ± SD body mass index = 28.2 ± 5.3 kg/m2 Conclusion CO measurements obtained by Flow Trac™ show
agreement with CO TTE with no clear bias, but comparative
studies with thermodilution are warranted. Conclusion CO measurements obtained by Flow Trac™ show
agreement with CO TTE with no clear bias, but comparative
studies with thermodilution are warranted. Conclusion CO measurements obtained by Flow Trac™ show
agreement with CO TTE with no clear bias, but comparative
studies with thermodilution are warranted. S122 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P301) Results Five hundred and nine matched sets of data were
obtained; the BScvO2/CScvO2 range was 36–98.9%/46.5–99.0%,
respectively. Overall mean bias ± 2SD was –1.2 ± 13.8% for
CScvO2–BScvO2 during OP and –2.6 ± 16.2% during ICU. The
correlation coefficient (r2) for CScvO2 vs BScvO2 was 0.614 (OP)
and 0.174 (ICU). Statistics for OP1–OP3 were comparable,
whereas mean bias ± 2SD increased and r2 decreased during
ICU1–ICU4 (Table 1). Conclusions The results indicate that ScvO2 can be reliably
assessed by CeVOX. In order to maintain accurate measurements,
scheduled re-calibrations at intervals <12 hours are mandatory. Reference 1. Respiration 2001, 685:279-285. Relative influence of hypoxemia and anemia on the
measurement of central venous oxygen saturation Relative influence of hypoxemia and anemia on the
measurement of central venous oxygen saturation F Valenza, S Froio, L Fagnani, S Coppola, M Maffioletti,
A Sicignano, E Riva, S Sibilla, L Gattinoni
Fondazione IRCCS Ospedale Maggiore Policlinico Mangiagalli
Regina Elena, Milano, Italy
Critical Care 2007, 11(Suppl 2):P304 (doi: 10.1186/cc5464) Methods Lithium indicator dilution and pulse power analysis were
used to measure cardiac output and to calculate DO2I (LiDCO-
plus system). We prospectively evaluated the oxygen delivery
pattern and perfusion variables of 26 high-risk patients (LiDCO
group) submitted to major surgeries and goal-directed therapy
during surgery and 8 hours postoperatively, aiming to maximize the
DO2I to levels higher than 600 ml/min/m2 using dobutamine and
either ‘restrictive’ (4 ml/kg/min) or ‘liberal’ (12 ml/kg/min) strategies
of intraoperative fluid management (partial results). Postoperatively
both groups received 1.5 ml/kg/min lactated ringer. Fluid challenge
with 250 ml colloid was done in the presence of signs of
hypovolemia and additional fluids were given if necessary. Patients
were considered responders if they achieved the therapeutic goal. A historical group of 42 high-risk surgical patients in whom the
therapeutic goals were to keep a mean arterial pressure between
80 and 110 mmHg, a central venous pressure between 6 and
12 cmH2O, hematocrit > 30% and urine output > 0.5 ml/kg/hour
in the first 24 hours after ICU admission was used as control. Introduction Central venous oxygen saturation (ScvO2) is frequently
used as a surrogate measurement of adequacy of perfusion. However, ScvO2 is also affected by arterial oxygen saturation
(SpO2), oxygen consumption, and hemoglobin (Hb) according to
the formula: ScvO2 = SpO2 – (VO2 / Q*1/Hb). The aim of this
study was to investigate the relative influence of hypoxemia and
anemia on the measurement of ScvO2. Methods A database of 700 pairs of arterial and central venous
blood gases drawn from 300 patients admitted to the ICU of a
university hospital was considered. After assessing for the
technical adequacy of sampling (defined as a discrepancy of
hematocrit and blood glucose between arterial and venous
samples lower than 5%), 462 couples were selected for analysis. Samples were then clustered according to ScvO2: <70% (low),
≥70% (high). SpO2, partial pressure of oxygen (PaO2) and Hb
were considered. Venous to arterial difference of partial pressure
of CO2 (DpCO2), arterial to venous difference of oxygen content
(DavO2) and the oxygen extraction ratio (ER) were also considered
as measures of perfusion adequacy. P303 Incidence of low central venous oxygen saturation after
standard postoperative intensive care management Introduction Targeted early postoperative management of high-
risk surgical patients has been reported to be associated with a
lower rate of complications and shorter hospital length of stay
(HLOS) compared with conventional management. A low
postoperative central venous oxygen saturation (ScVO2) has also
been shown to be associated with higher rates of complications
and of HLOS for high-risk surgical patients. Benefit from early goal-
directed therapy would be unlikely if ‘standard’ postoperative
management resulted in a low incidence of patients with a low
ScVO2 in the early postoperative period. S123
Table 1 (abstract P302)
OP1
OP2
OP3
ICU1
ICU2
ICU3
ICU4
Mean bias ± 2SD (%)
–0.2 ± 13.9
+1.3 ± 9.6
+1.8 ± 16.6
–0.1 ± 12.0
–0.6 ± 15.4
–0.5 ± 13.8
–4.6 ± 16.9
r2 (P value)
0.580 (<0.001)
0.616 (<0.001)
0.513 (<0.001)
0.416 (<0.001)
0.514 (<0.001)
0.310 (0.001)
0.030 (0.247) ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin As expected, DpCO2, DavO2 and ER were different between high
and low ScvO2 groups (P < 0.001). However, while Hb was similar
(P = 0.670), SpO2 and PaO2 were significantly lower when ScvO2
was below 70% (P < 0.001). Normalization of ScvO2 to SpO2
(ScvO2/SpO2) allowed one to overcome the effects of hypoxemia. Values were: 0.662 (0.603–0.693) in the low group and 0.794
(0.757–0.828) in the high group (P < 0.001). Conclusions When considering ScvO2 as a surrogate measure of
perfusion adequacy, it is mandatory to consider the relative effect
of hypoxemia. Anemia was less relevant in our case mix. As expected, DpCO2, DavO2 and ER were different between high
and low ScvO2 groups (P < 0.001). However, while Hb was similar
(P = 0.670), SpO2 and PaO2 were significantly lower when ScvO2
was below 70% (P < 0.001). Normalization of ScvO2 to SpO2
(ScvO2/SpO2) allowed one to overcome the effects of hypoxemia. Values were: 0.662 (0.603–0.693) in the low group and 0.794
(0.757–0.828) in the high group (P < 0.001). Methods Arterial and central venous blood gas analysis was done
on admission (T1) and after 8 hours (T2) of admission to the ICU. The HLOS and the incidence of complications were determined for
patients with low (<70%) or normal (≥70%) ScVO2. Results Sixty-three postoperative patients were screened and 23
patients were analysed. Relative influence of hypoxemia and anemia on the
measurement of central venous oxygen saturation Differences between low and
high ScvO2 samples were estimated by Mann–Whitney rank sum
test (Sigma Stat, SPSS), accepting P < 0.05 as significant. Data
are presented as median (25th–75th percentile). P305 Oxygen delivery optimization using lithium indicator
dilution and pulse power analysis during major surgery in
high-risk patients S Lobo1, N Oliveira1, F Lobo1, E Rezende2, B Borges1,
G Cunrath1, J Silva2, L Ronchi1
1Faculdade de Medicina de São José do Rio Preto, Brazil;
2Hospital do Servidor Público, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P305 (doi: 10.1186/cc5465) Conclusion A significant proportion of patients had a low ScVO2,
which was associated with increased HLOS. The results provide a
basis for the trial of postoperative early goal-directed therapy for
high-risk surgical patients admitted to our ICU. Introduction Increasing oxygen delivery in high-risk surgical
patients led to a dramatic reduction in both mortality and morbidity. Yet, it is still not widely practised due to logistical difficulties asso-
ciated with its use. We aimed to evaluate whether pulse power
analysis calibrated by the lithium dilution technique, a pragmatic
minimally invasive technique, can be used to optimize the oxygen
delivery index (DO2I) in high-risk patients during major surgery. Introduction Increasing oxygen delivery in high-risk surgical
patients led to a dramatic reduction in both mortality and morbidity. Yet, it is still not widely practised due to logistical difficulties asso-
ciated with its use. We aimed to evaluate whether pulse power
analysis calibrated by the lithium dilution technique, a pragmatic
minimally invasive technique, can be used to optimize the oxygen
delivery index (DO2I) in high-risk patients during major surgery. P303 Patients were excluded if they did not have
a central line positioned in the superior vena cava or blood had not
been sampled at both time points. Patients with pre-ICU HLOS
> 5 days (n = 10), acute spinal cord injury (n = 3), or admitted for
postoperative airway management (n = 4) were omitted. ScVO2
was low in 7/23 patients at T2 and six of these had lower
gastrointestinal surgery. The HLOS (median (IQR)) was longer in
those with low ScVO2 at T2 (17 (37.8) v 9.5 (5.0) days, P = 0.04). The incidence of complications was not different. There were no
differences between the ScVO2 groups at T2 with respect to age,
gender, standard base excess, lactate, haemoglobin, mean arterial
pressure or central venous pressure. The volume of colloid the two
groups received in the 8-hour observation period was not different
although there was a trend for the low group to receive more
crystalloid (P = 0.08). Conclusions When considering ScvO2 as a surrogate measure of
perfusion adequacy, it is mandatory to consider the relative effect
of hypoxemia. Anemia was less relevant in our case mix. Figure 1 (abstract P305) Results ScvO2 was 62.5% (56.3–66.2) in the low group (n = 180),
76.7% (73.6–80.7) in the high group (n = 282). In the low group
values were: SpO2 95.0% (95.1–98.3), PaO2 72.0 mmHg
(59.5–112.5), DpCO2 8 mmHg (6–9), DavO2 4.3 ml/100 ml
(3.4–5.2), ER 0.346 (0.310–0.399), Hb 9.9 g/dl (8.9–11.1). In the
high group values were: SpO2
98.3% (96.2–99.5), PaO2
106.5 mmHg (81.0–167.0), DpCO2 6 mmHg (4–7), DavO2 2.9 ml/
100 ml (2.3–3.6), ER 0.215 (0.185–0.250), Hb 9.9 g/dl (8.7–11.1). S124 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P305)
Control
LiDCO
Age
60 ± 17
68 ± 10
Lact1
3.5 ± 1
2.6 ± 1
Lact2
2.7 ± 1
1.9 ± 1
ScvO2-1
64 ± 18
75 ± 10
ScvO2-2
68 ± 13
72 ± 14
Complications (%)
50
15
Deaths (%)
26
7.7 Table 1 (abstract P305) correlation between Lac and RQ (R = 0.66; P < 0.01) was found. For a DO2 < 9 ml/kg, SvO2 did not correlate with Lac. Opposite, a
direct correlation between Lac and RQ (R = 0.81; P < 0.01) was
found. The DO2/VCO2 ratio showed an inverse relationship with Lac
(R = –0.75; P < 0.01). ROC curves to predict Lac+ were
constructed. The areas under the ROC curves were 0.40, 0.74, and
0.81 for SvO2, RQ, and DO2/VCO2 ratio, respectively. An optimal
cutoff value of 3.1 (sensitivity = 0.70, specificity = 0.77) was
determined for the DO2/VCO2 ratio predicting the presence of Lac+. Conclusions Our findings showed that, for a DO2 > 9 ml/kg, the
SVO2, RQ, and DO2/VCO2 ratio may be used interchangeably. For
a DO2 < 9 ml/kg, the DO2/VCO2 ratio seems a more reliable
predictor of AM than SvO2 and RQ. The DO2/VCO2 ratio can be
simply and quickly calculated at the bedside because pulse wave
analysis allows the DO2 to be frequently calculated, and because
the CO2 analyzer provides VCO2 values continuously. Combined
gas exchange and pulse wave monitoring might be a valuable and
a useful approach to detect AM in trauma patients. Results Median doses of 10 µg/kg/min and 7.5 µg/kg/min
dobutamine were used intraoperatively and postoperatively, respec-
tively. A total of 75% and 84% of the patients were responders
during surgery and postoperatively. However, a much better
pattern of DO2I during surgery was seen in the liberal group than in
the restrictive group (Figure 1). P306 Methods In this prospective, intervention and response study, 30°
PLR of both legs was performed in 20 supine patients receiving
mechanical ventilation after elective cardiothoracic surgery. The
thermodilution cardiac output (COtd), heart rate, central venous
pressure (CVP), MAP, PP, SP and SVV measurements were
performed before, during and after PLR. Oxygen delivery to carbon dioxide production ratio for
continuously detecting anaerobic metabolism in trauma
patients
F Franchi1, S Scolletta1, E Casadei1, P Mongelli2, B Biagioli1,
P Giomarelli1
1University of Siena, Italy; 2Policlinico Le Scotte, Siena, Italy
Critical Care 2007, 11(Suppl 2):P306 (doi: 10.1186/cc5466) Oxygen delivery to carbon dioxide production ratio for
continuously detecting anaerobic metabolism in trauma
patients Results The COtd, MAP, CVP, PP and SP increased after PLR. No change in heart rate and systemic vascular resistance was
observed. We found a significant correlation between PLR-
induced changes in COtd versus SVV during baseline (slope =
0.902, P = 0.003), changes in MAP (slope = 0.499, P = 0.003),
PP (slope = 0.190, P = 0.024) and SP (slope = 0.276, P = 0.021). Changes in CVP were not correlated to changes in COtd. The
area under the receiver operating curves was larger than 0.7 but
not different for MAP, PP, SP and SVV. Introduction Lactate levels have been shown to correlate with tissue
hypoxia. Unfortunately, due to their slow clearance, lactate levels may
not reflect the actual metabolic condition. Under tissue hypoxia the
carbon dioxide production (VCO2) should be less reduced than the
oxygen consumption, and the respiratory quotient (RQ) should
increase. The oxygen delivery (DO2)/VCO2 ratio could be used as an
indicator of anaerobic metabolism (AM) since it reflects the oxygen
demand and delivery, and the tissue oxygenation. We tested the
DO2/VCO2 ratio as a potential predictor of AM in trauma patients. Conclusion Not only baseline SVV but also PLR-induced changes
in MAP, PP and SP are reliable parameters to assess preload
dependence in cardiac surgery patients. In the clinical setting we
prefer the MAP approach, based on simplicity, availability and
robustness. Methods Eighty consecutive adult trauma patients were pros-
pectively studied. The DO2, VCO2, RQ, DO2/VCO2 ratio, SvO2,
and arterial lactate (Lac) values were collected at ICU admission. The DO2 was calculated using the cardiac index measured by a
pulse contour system (Hemoscan). The VCO2 was measured
under steady-state conditions using a CO2 analyzer (930 Siemens
Elema). Passive leg raising-induced changes in mean radial artery
pressure can be used to assess preload dependence Passive leg raising-induced changes in mean radial artery
pressure can be used to assess preload dependence B Geerts, R de Wilde, P van den Berg, J Jansen
Leiden University Medical Centre, Leiden, The Netherlands
Critical Care 2007, 11(Suppl 2):P307 (doi: 10.1186/cc5467) Introduction
We evaluated whether changes in, routinely
measured, mean radial artery pressure (MAP) due to passive leg
raising (PLR) can be used to assess preload dependence in
nonspontaneous breathing patients. We therefore compared the
changes in cardiac output (CO) with changes in MAP, pulse
pressure (PP) and systolic pressure (SP) as well as the stroke
volume variation (SVV) before PLR. Conclusion The use of a therapeutic approach guided by DO2I
calculated by the LiDCO plus system, intraoperatively and
postoperatively, seems to be a feasible and practical approach to
guide oxygen delivery optimization therapy during major surgery in
high-risk patients. Better perfusion and a much lower rate of
complications were seen in optimized patients. P306 The presence of AM (for example, hyperlactatemia, Lac+)
was defined by an increase in Lac >2 mmol/l. Correlation analysis
and the ROC test were applied. A Sami, S Abdellatif, R Nasri, H Ksouri, S Ben Lakhal
Rabta Hospital, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P308 (doi: 10.1186/cc5468) Figure 1 (abstract P305) The values for arterial lactate and
central venous oxygen saturation (ScvO2) on ICU admission and
24 hours later for both groups are shown in Table 1. Significantly
lower arterial lactate and higher ScvO2 were seen in optimized
patients (P < 0.05 vs control group). Major complications occurred
in 50% of the patients in the historical control group (21/42) and in
15% of the LiDCO group (4/26) (RR 0.15, 95% CI 0.037–0.600,
P < 0.05). P307 Passive leg raising-induced changes in mean radial artery
pressure can be used to assess preload dependence
B Geerts, R de Wilde, P van den Berg, J Jansen
Leiden University Medical Centre, Leiden, The Netherlands
Critical Care 2007, 11(Suppl 2):P307 (doi: 10.1186/cc5467) References 1. Kakkos SK, et al.: Int Angiol 2005, 24:330-335. 2. Kakkos SK, et al.: J Vasc Surg 2005, 42:296-303. Introduction The new sequential leg compression device (SCD)
(Tyco, Mansfield, MA, USA) pneumatically applies sequential
compression to the lower limb, while maintaining a pressure
gradient throughout the compression cycle [1,2]. We hypothesized
that the SCD Response System could shift blood volume toward
the thoracic compartment comparable with a volume challenge,
with an increase in preload index such as the intrathoracic blood
volume index (ITBVI) and stroke volume index (SVI). The aim of the
study was to evaluate the relationships between changes in SVI
(∆SVI) induced by SCD and ∆SVI induced by rapid fluid loading
(RFL) in critically ill patients. 1. Kakkos SK, et al.: Int Angiol 2005, 24:330-335. 2. Kakkos SK, et al.: J Vasc Surg 2005, 42:296-303. 1. Kakkos SK, et al.: Int Angiol 2005, 24:330-335. 2. Kakkos SK, et al.: J Vasc Surg 2005, 42:296-303. 1. Kakkos SK, et al.: Int Angiol 2005, 24:330-335. 2. Kakkos SK, et al.: J Vasc Surg 2005, 42:296-303. P309 Changes in stroke volume and intrathoracic blood volume
induced by a sequential leg compression in critically ill
patients. Conclusions The SCD Response System could shift blood
volume toward the thoracic compartment comparable with RFL
better in mechanically ventilated than in spontaneously breathing
patients. Larger population studies are needed to confirm these
preliminary data. M Costa, R Casaretti, M Tuccillo, L Girardi, P Chiarandini,
G Della Rocca
University of Udine, Italy
Critical Care 2007, 11(Suppl 2):P309 (doi: 10.1186/cc5469) University of Udine, Italy P308 Figure 2 (abstract P309) Figure 2 (abstract P309) Discussion Patients with low ∆PP seem to be of poor prognosis
because they have a low BCL, a low maximum cortisol increase
after the ACTH test, and a high death rate. Annane and colleagues
[1] found that nonsurvivors have low MAP, high lactate level, high
basal cortisol level and low maximum cortisol level increase after
the test compared with survivors. This finding is in contrast to our
patients. index, ITBVI, and SVI were recorded in the supine position before
and after treatment with the SCD Express Compression System®. The same data where collected before and after a RFL performed
with 3 ml/kg hydroxyethyl starch 6%. The relationships between
∆SVI induced by SCD and ∆SVI induced by RFL were analyzed by
linear regression analysis. Statistical significance was considered
to be at P <0.05. Conclusion Patients with low ∆PP before realizing the ACTH test
tend to have more probability of adrenal deficiency, have more
probability to receive corticosteroid and have poor prognosis. Reference 1. Annane et al.: JAMA 2000, 283:1038-1045. Results Linear regression analysis between ∆SVI induced by SCD
(∆SCD) and ∆SVI induced by RFL (∆RFL) showed r2 = 0.50
(P = 0.0002). When analyzed in a subgroup of spontaneously
breathing versus mechanically ventilated patients, the relationships
observed were respectively r2 = 0.41 (P < 0.01) (Figure 1) and
r2 = 0.73 (P < 0.007) (Figure 2). P308 Pulse pressure variation and adrenal insufficiency in septic
shock Results For a threshold value of DO2 > 9 ml/kg, Lac showed an
inverse relationship with SvO2 (R = –0.84; P < 0.01) and
DO2/VCO2 ratio (R = –0.73; P < 0.01). Conversely, a direct Introduction It is known that corticosteroid therapy improves the
hemodynamic state in patients with septic shock and relative S125 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P309)
Figure 2 (abstract P309) Figure 1 (abstract P309) adrenal insufficiency. This effect is partially due to a direct action
on vascular tone in the more vasoplegic patient, so they may be
more hypovolemic. We tried in this study to determine whether
pulse pressure variation measured just before the adreno-
corticotropin test can predict the adrenal state. Methods During a period of 3 years (January 2001–December
2003) we realized a prospective observational study. All patients
having septic shock were enrolled. Patients with arrhythmia were
excluded. We measured hemodynamic data (mean arterial
pressure (MAP), pulse pressure variation (∆PP)), then we realized
an ACTH short test (injection of 250 mg ACTH with dosage of the
cortisol level before the injection, at 30 and 60 minutes). Results One hundred and one patients were enrolled. Age was
48 ± 17 years. SAPS II = 45 ± 16, APACHE II score = 18 ± 8,
MAP = 52 ± 12 mmHg, lactate = 3.5 ± 2 mmol/l, and basal
cortisol level (BCL) = 278 ± 143 µg/l. We divided all patients into
two groups using the ∆PP cutoff: <12% (n = 30) and ≥12%
(n = 71). There is no difference in the two groups in age, SAPS II,
and MAP. Patients with low ∆PP (<12%) have a significantly
(P = 0.01) low BCL: 204 ± 127 µg/l vs 291 ± 133 µg/l, a low
increase of cortisol level in response to ACTH: 264 ± 144 µg/l vs
369 ± 142 µg/l (P = 0.02), and a low maximum variation after the
ACTH test: 59 ± 52 µg/l vs 79 ± 63 µg/l (not significant). The
relative adrenal deficiency (∆max < 90 µg/l) is more frequent in
patients with low ∆PP: 80% vs 60%. Survival is lower in the low
∆PP group, 13% vs 40%. P312 Results Respiratory variation in POP waveform amplitude could
accurately predict variation in arterial PP with a sensibility of
83.3%, specificity of 85.7%, positive predictive value (PPV) of
71.4 and negative predictive value (NPV) of 92.3. The area under
the ROC curve was 0.88 (0.79–0.97) with a best cutoff value of
14% to predict a variation in arterial PP of 13%. The kappa index
of agreement was 0.65 (P < 0.001). Eighteen (30%) patients had
variations in arterial PP above 13%, and 21 (35%) showed
variations in POP waveform amplitude above 14%. In patients
without ALI (P/F > 300) the sensibility was 100%, specificity was
93.3%, NPV was 100% and PPV was 80%. In the group with ALI
(P/F < 300) the kappa index measure of agreement was 0.55, and
in the group without ALI the kappa index was 0.85. PEEP levels
were not different between the groups. P311 Assessing fluid responsiveness in patients undergoing
abdominal major surgery: a comparison of the respiratory
systolic variation test and other indices
A Bisoffi Varani1, A Martini1, N Menestrina2, A Russo3, L Gottin1
1Policlinico GB Rossi, Verona, Italy; 2Hopital Erasme, Verona, Italy;
3Romano D’Ezzelino Vicenza, Italy
Critical Care 2007, 11(Suppl 2):P311 (doi: 10.1186/cc5471) Assessing fluid responsiveness in patients undergoing
abdominal major surgery: a comparison of the respiratory
systolic variation test and other indices Results The mean baseline FTc was 278 ms, and the mean target
FTc was 405 ms. The mean average blood loss was 3.77 l/patient. The mean preoperative urea and creatinine were 5.9 mmol/l and
95.3mmol/l, respectively. The mean 24-hour postoperative urea
and creatinine were 5.23 mmol/l and 76.77 mmol/l, respectively. See Figure 1. A Bisoffi Varani1, A Martini1, N Menestrina2, A Russo3, L Gottin1
1Policlinico GB Rossi, Verona, Italy; 2Hopital Erasme, Verona, Italy;
3Romano D’Ezzelino Vicenza, Italy
Critical Care 2007, 11(Suppl 2):P311 (doi: 10.1186/cc5471) Conclusion Goal-directed intraoperative fluid therapy aiming for
FTc of 375–425 ms as a target improved the 24-hour Introduction
Fluid
responsiveness
can
be
predicted
by
respiratory-induced changes in arterial blood pressure. In this study
we compare the predictive performance of various haemodynamic
parameters, including the respiratory systolic variation test (RSVT),
pulse pressure variation (DPP) and stroke volume variation (SVV),
in 18 patients undergoing abdominal major surgery. Figure 1 (abstract P312) Goal-directed intraoperative fluid therapy improved
postoperative renal functions in aortic surgical patients M Soliman, S Bajaj, K Ismail
Department of Anaesthesia and Intensive Care Medicine, The Mid
Yorkshire Hospitals, UK
Critical Care 2007, 11(Suppl 2):P312 (doi: 10.1186/cc5472) Introduction Goal-directed intraoperative fluid therapy reduced
the hospital stay after major surgery [1]. Aortic vascular surgery is
associated with excessive blood loss and massive fluid shift [2]. We found that postoperative urea and creatinine improved when
intravascular fluid volume was maintained using transoesophageal
Doppler. Conclusion Respiratory variation in arterial PP above 13% can be
accurately predicted by a variation in POP waveform amplitude of
14% with good correlation and agreement. Our results confirm the
findings of a recent trial and suggest that the correlation is even
stronger when ALI is absent. These findings raise potential clinical
applications of respiratory variation in POP waveform amplitude for
haemodynamic management of patients without an arterial catheter. Methods We randomly selected 40 patients who underwent
elective infrarenal aortic surgery (aortic aneurysm repair/aorto-
bifemoral grafting). All patients’ cardiac output was continuously
monitored using a transoesophageal Doppler probe (EDM™;
Deltex Medical, Inc., Irving, TX, USA). The corrected flow time
(FTc) was recorded immediately after induction as a baseline and
recorded again pre-extubation. A target FTc of 375–425 ms was
aimed for. The estimated total blood loss was calculated for each
patient at the end of surgery. Preoperative and 24-hour
postoperative urea and creatinine were recorded for comparison. Methods We randomly selected 40 patients who underwent
elective infrarenal aortic surgery (aortic aneurysm repair/aorto-
bifemoral grafting). All patients’ cardiac output was continuously
monitored using a transoesophageal Doppler probe (EDM™;
Deltex Medical, Inc., Irving, TX, USA). The corrected flow time
(FTc) was recorded immediately after induction as a baseline and
recorded again pre-extubation. A target FTc of 375–425 ms was
aimed for. The estimated total blood loss was calculated for each
patient at the end of surgery. Preoperative and 24-hour
postoperative urea and creatinine were recorded for comparison. Results The mean baseline FTc was 278 ms, and the mean target
FTc was 405 ms. The mean average blood loss was 3.77 l/patient. The mean preoperative urea and creatinine were 5.9 mmol/l and
95.3mmol/l, respectively. The mean 24-hour postoperative urea
and creatinine were 5.23 mmol/l and 76.77 mmol/l, respectively. See Figure 1. Respiratory pulse oximetry plethysmographic waveform
amplitude correlates with arterial pulse pressure variations The kappa
of agreement was 0.65 (P < 0.001). Eighteen (30%) patient
variations in arterial PP above 13%, and 21 (35%) sh
variations in POP waveform amplitude above 14%. In pa
without ALI (P/F > 300) the sensibility was 100%, specificity
93.3%, NPV was 100% and PPV was 80%. In the group wit
(P/F < 300) the kappa index measure of agreement was 0.55
in the group without ALI the kappa index was 0.85. PEEP
were not different between the groups. Conclusion Respiratory variation in arterial PP above 13% ca
accurately predicted by a variation in POP waveform amplitu
14% with good correlation and agreement. Our results confir
findings of a recent trial and suggest that the correlation is
stronger when ALI is absent. These findings raise potential c
applications of respiratory variation in POP waveform amplitud
haemodynamic management of patients without an arterial cath
P311
Assessing fluid responsiveness in patients undergoing
abdominal major surgery: a comparison of the respirat
systolic variation test and other indices
A Bisoffi Varani1, A Martini1, N Menestrina2, A Russo3, L Go
1Policlinico GB Rossi, Verona, Italy; 2Hopital Erasme, Verona,
3Romano D’Ezzelino Vicenza, Italy
Critical Care 2007, 11(Suppl 2):P311 (doi: 10.1186/cc5471)
Introduction
Fluid
responsiveness
can
be
predicted
respiratory-induced changes in arterial blood pressure. In this
we compare the predictive performance of various haemodyn
parameters including the respiratory systolic variation test (R Conclusion Functional parameters are superior to static indicators
of cardiac preload in predicting the response to fluid
administration. DPP and SVV, with their suggested threshold value,
can predict fluid responsiveness in patients undergoing major
abdominal surgery. The RSVT may be a more accurate predictor of
fluid responsiveness although its performance demands a complex
respiratory manoeuvre and is dependent on offline measurement
and calculations, which limits its clinical use. Methods Sixty patients were included in the study. Thirty-nine
(65%) had diagnosis of ALI and 21 (35%) had normal gas
exchange, defined as a relation of PaO2 to FiO2 (P/F) below and
above 300, respectively. Respiratory variation in arterial PP and
POP waveform amplitude were recorded simultaneously on a beat-
to-beat basis, and mean values of two measures for each
parameter were compared for correlation and agreement. Respiratory pulse oximetry plethysmographic waveform
amplitude correlates with arterial pulse pressure variations These findings raise
applications of respiratory variation in POP wavefor
haemodynamic management of patients without an a
P311
Assessing fluid responsiveness in patients un
abdominal major surgery: a comparison of th
systolic variation test and other indices
A Bisoffi Varani1, A Martini1, N Menestrina2, A Ru
1Policlinico GB Rossi, Verona, Italy; 2Hopital Erasme
3Romano D’Ezzelino Vicenza, Italy
Critical Care 2007, 11(Suppl 2):P311 (doi: 10.1186
Introduction
Fluid
responsiveness
can
be
respiratory-induced changes in arterial blood pressu
we compare the predictive performance of various
parameters, including the respiratory systolic variat
pulse pressure variation (DPP) and stroke volume
in 18 patients undergoing abdominal major surgery
Methods Eighteen patients, ASA I–II, were underg
surgery (whipple resection). The heart rate (HR)
pressure (CVP), arterial pressure (AP), cardiac
cardiac index (CI), stroke volume (SV), stroke volu
SVV, DPP and RSVT were measured before and
load of 7 ml/kg hydroxyethylstarch. (CO, CI, SV, SV
displayed by the Edwards Vigileo monitor with F
Receiving-operating characteristic (ROC) curves w
each parameter to evaluate its predicting valu
correlation
between
the
baseline
value
of between preoperative values of DPP, SVV and RSVT and
percentage changes in SVI after volume load (better than the
values of HR, AP, CVP). amplitude, as they both depend on the stroke volume. We
designed a prospective study to evaluate the correlation between
respiratory arterial PP variation and POP waveform amplitude
variations in ventilated patients and the influence of acute lung
injury (ALI) in this relationship. amplitude, as they both depend on the stroke volume. designed a prospective study to evaluate the correlation bet
respiratory arterial PP variation and POP waveform amp
variations in ventilated patients and the influence of acute
injury (ALI) in this relationship. Methods Sixty patients were included in the study. Thirty
(65%) had diagnosis of ALI and 21 (35%) had norma
exchange, defined as a relation of PaO2 to FiO2 (P/F) below
above 300, respectively. Respiratory variation in arterial PP
POP waveform amplitude were recorded simultaneously on a
to-beat basis, and mean values of two measures for
parameter were compared for correlation and agreement. Results Respiratory variation in POP waveform amplitude
accurately predict variation in arterial PP with a sensibil
83.3%, specificity of 85.7%, positive predictive value (PP
71.4 and negative predictive value (NPV) of 92.3. The area u
the ROC curve was 0.88 (0.79–0.97) with a best cutoff val
14% to predict a variation in arterial PP of 13%. Respiratory pulse oximetry plethysmographic waveform
amplitude correlates with arterial pulse pressure variations Respiratory pulse oximetry plethysmographic waveform
amplitude correlates with arterial pulse pressure variations G Penna, M Kalichsztein, G Nobre, F Braga, J Kezen, P Kurtz,
P Rosa
Casa de Saude Sao Jose, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P310 (doi: 10.1186/cc5470) Methods Twenty-seven patients (mean age 60 ± 9.1 years) admitted
to the ICU were studied. Each patient received conventional
monitoring plus hemodynamic–volumetric monitoring (PiCCO
System; Pulsion Medical Systems, Munich, Germany). The heart
rate, mean arterial pressure, central venous pressure, cardiac Introduction Arterial pulse pressure (PP) respiratory variation is a
good predictor of fluid responsiveness in ventilated patients. Recently, it has been shown that variation in PP may correlate with
variation in pulse oximetry plethysmographic (POP) waveform S126 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 amplitude, as they both depend on the strok
designed a prospective study to evaluate the corre
respiratory arterial PP variation and POP wave
variations in ventilated patients and the influence
injury (ALI) in this relationship. Methods Sixty patients were included in the st
(65%) had diagnosis of ALI and 21 (35%) h
exchange, defined as a relation of PaO2 to FiO2 (
above 300, respectively. Respiratory variation in
POP waveform amplitude were recorded simultane
to-beat basis, and mean values of two meas
parameter were compared for correlation and agree
Results Respiratory variation in POP waveform a
accurately predict variation in arterial PP with
83.3%, specificity of 85.7%, positive predictive
71.4 and negative predictive value (NPV) of 92.3. the ROC curve was 0.88 (0.79–0.97) with a best
14% to predict a variation in arterial PP of 13%. T
of agreement was 0.65 (P < 0.001). Eighteen (30%
variations in arterial PP above 13%, and 21
variations in POP waveform amplitude above 14
without ALI (P/F > 300) the sensibility was 100%,
93.3%, NPV was 100% and PPV was 80%. In the
(P/F < 300) the kappa index measure of agreemen
in the group without ALI the kappa index was 0.8
were not different between the groups. Conclusion Respiratory variation in arterial PP abo
accurately predicted by a variation in POP wavefo
14% with good correlation and agreement. Our res
findings of a recent trial and suggest that the cor
stronger when ALI is absent. Analysis of physiological functions of different human
serum albumin pharmaceutical preparations Analysis of physiological functions of different human
serum albumin pharmaceutical preparations M Di Giambattista, L Mascio, T Branckaert, R Laub
Central Department for Fractionation, Red Cross, Brussels, Belgium
Critical Care 2007, 11(Suppl 2):P313 (doi: 10.1186/cc5473) Aims and methods A clinical scenario was used to assess current
knowledge among medical staff regarding i.v. fluid therapy. ‘An 85-
year-old lady is brought into A&E semiconscious. Temperature
32°C, blood pressure 90/50 mmHg and BM 6.5 mmol/l. Arterial
blood gases (ABG) on room air: pH 7.12 pO2 10.8 kPa, pCO2
2.6 kPa, HCO3
– 12 mmol/l, O2 saturation 94% and base excess
–19’. Medical staff were asked to complete a questionnaire
relating to the case under supervised conditions. Introduction New information is emerging as a basis for
reconsidering albumin as a key homeostatic molecule in the critically
ill. We are only beginning to understand the full spectrum of albumin
properties and action in healthy individuals and hypoalbuminaemic
patients. Besides its function in the regulation of colloidal osmotic
pressure, albumin has an important antioxidant capacity and a role in
the transport of a wide range of drugs, hormones, ions, amino acids,
and fatty acids. Few comparative studies have as yet been
performed, and they address only a restricted number of parameters
mostly defined by the European Pharmacopeia. Results Eighty-seven questionnaires were completed by seven
SpR/consultants, 48 F2/senior house officers, 13 F1 and 19 final-
year medical students. ABG interpretation was correct in 80/87
(92%). Only 52/87 (59.8%) could calculate the anion gap and only
1/87 listed fluid as a cause of a metabolic acidosis. Eighty-three
staff (93.4%) knew that a metabolic acidosis caused an increased
respiratory rate. Normal saline was the first-choice fluid for
resuscitation in almost 60% (52/87) cases. The chloride
concentration of normal saline was known by 12/87 staff (13.8%). The serum chloride concentration was known by 28/87 staff (32%). Conclusion The majority of medical staff prescribe normal saline
as their first-choice intravenous fluid. Many medical staff are
unaware of the electrolyte composition of normal saline, the
phenomenon of hyperchloraemic metabolic acidosis, or how to
differentiate hyperchloraemic metabolic acidosis from lactic
acidosis by calculating the anion gap. A good understanding of
fluid therapy is important for all medical staff. Objective To study and compare the main albumin functions of
eight preparations of pharmaceutical-grade albumin, using a
battery of different techniques. Saline-induced hyperchloraemic metabolic acidosis: an
unrecognised phenomenon among medical staff? 1. Gan et al.: Goal-directed intraoperative fluid administration
reduces length of hospital stay after major surgery. Anes-
thesiology 2002, 97:820-826. A Turley, B Bose, J Gedney
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P314 (doi: 10.1186/cc5474) 2. Miyashita T, et al.: An analysis of risk factors of periopera-
tive bleeding in surgical repair of abdominal aortic
aneurysm. J Cardiovasc Surg 2000, 41:595-599. Introduction Hyperchloraemic acidosis is well recognised within
critical care, is implicated in the development of organ dysfunction
and is an important consequence of administration of large
volumes of chloride-containing intravenous (i.v.) fluid, such as
normal (0.9%) saline [1,2]. Within most hospitals, junior medical
staff with differing levels of experience prescribe the majority of i.v. fluid therapy. Analysis of physiological functions of different human
serum albumin pharmaceutical preparations Two additional albumin prepara-
tions, a preparation without stabilisers and a recombinant albumin
from Pichia pastoris, were also included in the study. Methods The following biochemical and physicochemical
parameters were investigated: total protein concentration (Biuret
assay) and albumin antigen (nephelometry); quantitative analysis of
contaminating proteins by nephelometry, levels of polymers and
fragments by gel filtration chromatography on Superose 6, the
binding affinity of exogenous ligands for Sudlow’s site I (warfarin)
or site II (dansylsarcosine) by steady-state spectrofluorimetry, the
reactivity of Cys34 with Ellman’s reagent, and the esterase-like
activity using p-nitrophenyl acetate as substrate by spectro-
photometry. References 1. Wilkes NJ: Anesth Analg 2001, 93:811-816. 2. McFarlane C, Lee A: Anaesthesia 1994, 49:779-781. 1. Wilkes NJ: Anesth Analg 2001, 93:811 816. 2. McFarlane C, Lee A: Anaesthesia 1994, 49:779-781. Results All pharmaceutical-grade products show a purity ranging
from 95% to 108%. The main contaminant proteins are
prealbumin, transferrin, α-1 acid glycoprotein, haptoglobulin, and
retinol-binding protein. All of them are in conformity with the
European Pharmacopeia specifications. The warfarin-binding
capacity of the 10 albumin preparations was studied. An average
binding constant of 2.6 (±0.3) x 105 M–1 (n = 1) was found. The
presence of stabilisers reduced the binding of dansylsarcosine
significantly (by 27–40%). The esterase-like activity toward p-
nitrophenyl acetate and the reactivity of Cys34 differed from
product to product. Interesting is the absence of free Cys34 in the
recombinant albumin. Figure 1 (abstract P312) S127 Methods Eighteen patients, ASA I–II, were undergoing pancreatic
surgery (whipple resection). The heart rate (HR) central venous
pressure (CVP), arterial pressure (AP), cardiac output (CO),
cardiac index (CI), stroke volume (SV), stroke volume index (SVI),
SVV, DPP and RSVT were measured before and after a volume
load of 7 ml/kg hydroxyethylstarch. (CO, CI, SV, SVI and SVV were
displayed by the Edwards Vigileo monitor with FloTrac sensor.)
Receiving-operating characteristic (ROC) curves were plotted for
each parameter to evaluate its predicting value. In addition,
correlation between the baseline value of haemodynamic
parameters RSVT, DPP, SVV and change in SVI after volume
administration was made. Results DPP, SVV and RSVT demonstrate a good predicting value
(ROC area 0.870, 0.877 and 0.943 with P = 0.010, 0.009 and
0.002, respectively). A statistically significant correlation was found ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin postoperative urea urea and creatinine in 40 aortic surgical
patients in spite of the excessive blood loss. postoperative urea urea and creatinine in 40 aortic surgical
patients in spite of the excessive blood loss. postoperative urea urea and creatinine in 40 aortic surgical
patients in spite of the excessive blood loss. P314 P315 Low-dose
dopexamine (≤1 µg/kg/min) was associated with a 49% reduction
in 28-day mortality (6.3% vs 12.3%; OR = 0.51 (95% CI
0.29–0.89), P = 0.008). The length of postoperative stay was also
reduced in the low-dose dopexamine group compared with control
(median 13 vs 15 days, HR 0.75 (95% CI 0.65–0.88), P = 0.004). High-dose dopexamine (>1 µg/kg/min) was not associated with a
difference in mortality (14.5% vs 12.3%; OR = 1.18 (95% CI
0.67–2.08), P = 0.37) or length of stay (median 17 vs 15 days, HR
1.10 (95% CI 0.90–1.34), P = 0.37) when compared with
controls. P317 Critical care utilisation following bariatric surgery
P Whiting, A Mannings, S Reynolds, S Hutchinson, R Ackroyd
Royal Hallamshire Hospital, Sheffield, UK
Critical Care 2007, 11(Suppl 2):P317 (doi: 10.1186/cc5477) Critical care utilisation following bariatric surgery P Whiting, A Mannings, S Reynolds, S Hutchinson, R Ackroyd
Royal Hallamshire Hospital, Sheffield, UK
Critical Care 2007, 11(Suppl 2):P317 (doi: 10.1186/cc5477) Introduction Following the introduction of a new bariatric surgical
service in Sheffield, we aimed to assess the impact upon critical
care services and examine how this has changed as the service
has evolved. Conclusions
Perioperative
use
of
low-dose
dopexamine
decreases mortality and duration of hospital stay in patients
undergoing major surgery. R f References Method All admissions for bariatric surgery between 1 April 2003
and 30 April 2006 were reviewed retrospectively. These proce-
dures were performed on two sites, the Royal Hallamshire Hospital
(RHH) and Thornbury Hospital (TH). The critical care admissions
and length of hospital stay (LOS) were reviewed. References
1. Boyd O, et al.: JAMA 1993, 270:2699-2707. 2. Wilson J, et al.: BMJ 1999, 318:1099-1103. 3. Takala J, et al.: Crit Care Med 2000, 28:3417-3423. 4. Stone MD, et al.: Br J Anaesth 2003, 91:619-624. 5. Pearse R, et al.: Crit Care 2005, 9:687-693. 1. Boyd O, et al.: JAMA 1993, 270:2699-2707. 2. Wilson J, et al.: BMJ 1999, 318:1099-1103. 3. Takala J, et al.: Crit Care Med 2000, 28:3417-3423. 4. Stone MD, et al.: Br J Anaesth 2003, 91:619-624. Results A total of 497 patients were identified as having had
bariatric surgery. After review of hospital and critical care
admission data, a total of 473 were identified with complete data. Of these, 94 (19.9%) were open procedures (OP), 260 (55.0%)
laparoscopic bandings (LB) and 119 (25.1%) laparoscopic gastric
bypasses (LGB). The age range was 16–68 years. P315 An individual patient meta-analysis of clinical trials using
dopexamine to increase oxygen delivery in high-risk
surgical patients J Belsey1, R Pearse2, J Cole3, D Bennet4
1JB Medical Ltd, Sudbury, UK; 2The Royal London Hospital,
London, UK; 3Cephalon UK, Stevenage, UK; 4St George’s
Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P315 (doi: 10.1186/cc5475) Introduction Postoperative outcomes may be improved if cardiac
output and oxygen delivery are maintained at optimal levels. Trials
of the use of dopexamine for this purpose have yielded
inconsistent results. This may relate to the use of high doses in
some trials. A meta-analysis of data from these trials may therefore
identify a benefit of low-dose dopexamine on postoperative
mortality and length of stay. Introduction Postoperative outcomes may be improved if cardiac
output and oxygen delivery are maintained at optimal levels. Trials
of the use of dopexamine for this purpose have yielded
inconsistent results. This may relate to the use of high doses in
some trials. A meta-analysis of data from these trials may therefore
identify a benefit of low-dose dopexamine on postoperative
mortality and length of stay. Conclusion Significant differences were observed between the 10
different human albumin preparations, recombinant or not. We
confirm that the presence of stabilisers such as tryptophan
derivatives significantly reduces the binding capacity of Sudlow’s
site II. Two important physiological properties of albumin, the
esterase-like and antioxidant activities, were also found to be
modified to different extents in all pharmaceutical-grade products
in comparison with the albumin without stabiliser. The benefits of
albumin administration should be considered carefully, taking into
account the different functions and properties of albumin. Methods A comprehensive literature review was performed to
identify published randomised trials of perioperative dopexamine
infusion in patients undergoing major surgery. Individual patient S128 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 between inflection point and systolic foot: mean ± SD = 40.0 ±
9.4 ms, intrasubject SD 4.6 ms). Retrograde coronary blood flow
during isovolumic ventricular contraction may be the origin of the
persistent end-diastolic pressure and distension perturbation. This
study shows that the duration of the isovolumic contraction can be
reliably extracted from the carotid artery distension waveform. data were obtained, allowing a meta-regression approach to
explore mortality outcomes after correction for age and dose of
dopexamine. A Cox proportional hazards model was constructed
to examine the length of stay. Results Five studies fulfilled the inclusion criteria [1-5]. P315 The average
hospital LOS for OP was 6.8 days, for LGB 4.0 days and for LB
1.9 days. Surgical procedures and HDU admissions increased
annually (2003–2006) from 74 to 249, and 21 to 107, respec-
tively. As a proportion, open procedures declined from 60% to 7%,
and laparoscopic interventions increased (LB from 40% to 63%
and LGB from 0% to 30%). There were a total of 14 admissions to
the ITU by 10 patients, of which seven had undergone an initial
OP. No admissions were elective and eight patients required
further surgical interventions. HDU admissions occurred on both
sites, with 148/277 (53.4%) of patients admitted to HDU at TH,
and 53/196 (27.6%) at RHH. At TH only three patients required
level 2 care, and 95 were discharged within 26 hours. At RHH, 16
patients required level 2 care, and 38 were discharged within 26
hours. 5. Pearse R, et al.: Crit Care 2005, 9:687-693. 5. Pearse R, et al.: Crit Care 2005, 9:687-693. Figure 1 (abstract P316) Figure 1 (abstract P316) The onset of ventricular isovolumetric contraction as
reflected in the carotid artery distension waveform The onset of ventricular isovolumetric contraction as
reflected in the carotid artery distension waveform The onset of ventricular isovolumetric contraction as
reflected in the carotid artery distension waveform M van Houwelingen, A Hoeks, R Reneman
University of Maastricht, The Netherlands
Critical Care 2007, 11(Suppl 2):P316 (doi: 10.1186/cc5476) M van Houwelingen, A Hoeks, R Reneman
University of Maastricht, The Netherlands
Critical Care 2007, 11(Suppl 2):P316 (doi: 10.1186/cc5476) The blood pressure waveform carries information about the cardiac
contraction and the impedance characteristics of the vascular bed. Here, we demonstrate that the start of isovolumic ventricular
contraction is persistently reflected as an inflection point in the
pressure wave as recorded in the aortic root (TPIC) as well as in
the carotid artery distension waveform (TDIC) as it travels down
the arterial tree. In a group of six patients with normal pressure
gradients across the aortic valve after valve replacement, the TPIC
had a small delay with respect to the onset of isovolumic
ventricular contraction (<10 ms). In a group (n = 21) of young,
presumably healthy, volunteers, the inflection point occurred
persistently in the carotid distension waveform, as recorded by
means of ultrasound, before the systolic foot (intersubject delay Discussion The requirement for ITU admission in this surgical
group is, and has remained, low, despite a significant increase in
bariatric surgical procedures. This increase is predominantly
laparoscopic surgery. HDU activity has increased as the service
has expanded; however, 90.4% of this is level 1 care, particularly
at TH, where admission to the HDU is a matter of policy rather than
clinical necessity. Availability of a level 1 facility would significantly
decrease the requirement for HDU provision – an important
consideration when introducing a new bariatric service. Figure 1 (abstract P316) Abdominal pressure volume determinants Abdominal pressure volume determinants J Mulier, B Dillemans, K Verbeke, A Luijten
AZ Sint Jan AV Brugge, Belgium
Critical Care 2007, 11(Suppl 2):P320 (doi: 10.1186/cc5480) The abdominal pressure–volume relation can be described by a
linear relation giving an elastance (E) and a pressure at zero
volume (PV0). The goal of this study was to measure this relation in
a large group of patients with different characteristics looking for
the factors that influence and explain this relation. It is believed that
obese persons have higher abdominal pressures and it is unclear
whether muscle relaxation lowers it. A large group of 70 patients, ASA class I or II, between 21 and
75 years old and scheduled for laparoscopic surgery were included
in this study with approval from the hospital ethical committee. Results CPAP determined a reduction of portal vein velocity:
30.0 ± 9.1 cm/s vs 19.7 ± 5.0 cm/s (P = 0.01). IVC diameters are
increased by CPAP: inspiratory diameter 9.49 ± 2.5 cm vs
12.05 ± 3.9 cm (P = 0.002), expiratory diameter 16.46 ± 2.9 cm
vs 18.08 ± 3.65 cm (P = 0.05). Anaesthesia was induced with propofol 200 mg, sufentanil 20 µg,
and sevoflurane 1.5 Mac in 50% O2/N2O. Some patients were fully
muscle relaxed with nimbex 20 mg while others not. Patients were
asked to empty the bladder before surgery. The stomach was
emptied by suction through a gastric tube. An Olympus insufflator
UHI-3 was initialised and the abdomen was inflated with a
stepwise flow to 7, 10, 13 and 16 mmHg. When the pressure was
reached, flow was stopped and the actual pressure and volume
measured giving four data points. E and PV0 were calculated by
fitting to a linear relation. The following recorded determinants
were evaluated by regression analysis for their effect: age, length,
weight, BMI, sex, gravidity and muscle relaxation. Conclusions The results of this study demonstrate that, in healthy
subjects, variation of intrathoracic pressure by CPAP influences
venous return. HF reduction could be due to an increased IVC
pressure, as displayed by the bigger diameters measured during
CPAP, other than a diaphragmatic descent. Ultrasonography is
able to detect this effect and could be useful in a more complete
evaluation of patient haemodynamic status in various clinical
settings. Intrathoracic pressure effects on hepatic flow and inferior
vena cava diameter: an ultrasonographic study A Graziani, E Gamberini, B Praticò, F Morgagni, F Savelli,
S Bonarelli
Oospedale Maurizio Bufalini, Cesena, Italy
Critical Care 2007, 11(Suppl 2):P318 (doi: 10.1186/cc5478) Objective To compare the effect of an increased intrathoracic
pressure on the inferior vena cava (ICV) diameter and hepatic flow
(HF) in healthy subjects. S129 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Patients and methods Ten healthy subjects (seven females, three
males; age 27.3 ± 4.5 years) were investigated in a supine position
before and after application of continuous positive airways
pressure (CPAP) of 10 cmH2O by nasal mask. The study was
performed using sonographic equipment with a multiprobe (convex
3.5–5 MHz; sector 2.5–3.5 MHz) and color-Doppler capability
(Hitachi H 21). IVC was visualized by a two-dimensional
echographic sector probe and M-mode was used to measure the
inspiratory and expiratory diameters at the origin of the supra-
hepatic veins. HF is composed of portal flow (PF) and hepatic
artery flow (HAF). Portal velocity, assessed near the liver hilum,
was used as a measure of PF, and the left intrahepatic branch
resistivity index (RI) was used as a measure of HAF. Measures
were repeated twice for each value of intrathoracic pressure by
two different examiners and the mean value was given for the
statistical analysis. Results are given as the mean ± SD. Data were
evaluated by paired t test and P < 0.05 was taken as statistically
significant. Conclusion Development of IAH significantly increases the risk of
death in patients with severe sepsis or septic shock, but not in
nonseptic patients. Conclusion Development of IAH significantly increases the risk of
death in patients with severe sepsis or septic shock, but not in
nonseptic patients. Intra-abdominal hypertension as a risk factor of death in
patients with severe sepsis or septic shock Intra-abdominal hypertension as a risk factor of death in
patients with severe sepsis or septic shock Table 1 (abstract P320)
PV0
E
Age
0.838
0.003
Length
0.356
0.245
Weight
0.012
0.294
BMI
0.054
0.272
Sex
0.596
0.536
Gravidity
0.305
0.049
Relaxation
0.001
0.376 A Reintam1, P Parm2, R Kitus2, H Kern3, J Starkopf2
1East Tallinn Central Hospital, Tallinn, Estonia; 2Tartu University
Clinics, Tartu, Estonia; 3DRK Kliniken Berlin, Germany
Critical Care 2007, 11(Suppl 2):P319 (doi: 10.1186/cc5479) Introduction Critically ill patients with severe sepsis or septic
shock have a very high mortality rate. The aim of our study was to
investigate the impact of intra-abdominal hypertension (IAH) on the
outcome of patients with or without severe sepsis/septic shock. Introduction Critically ill patients with severe sepsis or septic
shock have a very high mortality rate. The aim of our study was to
investigate the impact of intra-abdominal hypertension (IAH) on the
outcome of patients with or without severe sepsis/septic shock. Methods Two hundred and fifty-three mechanically ventilated
patients admitted to the general ICU of Tartu University Hospital
were prospectively studied. Patients who had severe sepsis or
septic shock at admission or developed it during their first week of
stay were compared with patients not suffering from severe sepsis. IAH was defined as sustained intra-abdominal pressure above or
equal to 12 mmHg developing within the first week in the ICU. Results Severe sepsis or septic shock was observed in 123
patients (48.6%). The ICU mortality among these patients was
33.3% compared with 18.5% in nonseptic patients (P = 0.005). IAH developed in 95 patients (37.0%). The incidence of IAH was
higher among septic patients (45.5% vs 28.5%, P = 0.004). Those
septic patients who developed IAH had a mortality rate of 50.0%
compared with 19.4% in septic patients without IAH (P < 0.001). Mortality among nonseptic patients was not different between the
patients with or without IAH (18.9% vs 18.3%). Development of
IAH was a significant risk factor for death in septic patients (OR
4.15; 95% CI 1.87–9.26), but not in nonseptic patients (OR 1.04;
95% CI 0.39–2.77). Methods Two hundred and fifty-three mechanically ventilated
patients admitted to the general ICU of Tartu University Hospital
were prospectively studied. Patients who had severe sepsis or
septic shock at admission or developed it during their first week of
stay were compared with patients not suffering from severe sepsis. P319 PV0 increases significantly with body weight and decreases
significantly with muscle relaxation. Intra-abdominal hypertension as a risk factor of death in
patients with severe sepsis or septic shock IAH was defined as sustained intra-abdominal pressure above or
equal to 12 mmHg developing within the first week in the ICU. P323 Results and discussion We treated 624 CPA patients in the past
2 years, 38% were cardiac and 62% were noncardiac aetiology
(3% subarachnoid haemorrhage and 5% acute aortic dissection). Restricted in cardiac aetiology patients, 13% showed a ventricular
fibrillation (VF) as a first monitored rhythm and 33% showed a VF
during resuscitation. In all patients, 50% of VF were witnessed. In
witnessed patients, 17% were witnessed by the ELST during
transfer and 81% by a layperson, most of whom are patients'
families and patients’ friends. Fifty-three per cent were witnessed
in the patients' home (35% in patients’ private room, 1% in
bathroom and 7% in lavatory), 4% in an aged people’s residence,
1% in a hotel, restaurant, office, and 3% on the road. Only 48% of
CPA patients underwent bystander CPR, and 51% of witnessed
CPA patients (24% of all CPA patients) underwent bystander CPR
by the witness; most patients underwent bystander CPR in the
patients’ home by the patients’ families. Vasopressin alone or with epinephrine may be superior to
epinephrine in asystolic out-of-hospital cardiac arrest: an
observational study M Ðpindler, Ð Grmec, Ð Mally
Center for Emergency Medicine Maribor, Slovenia
Critical Care 2007, 11(Suppl 2):P323 (doi: 10.1186/cc5483) Background In patients undergoing cardiopulmonary resusci-
tation, circulating endogenous vasopressin concentrations were
significantly higher in successfully resuscitated patients than in
patients who died. Clinical data considering vasopressin to be an
equivalent option to epinephrine in cardiopulmonary resuscitation
(CPR) are limited. The studies of out-of-hospital cardiac arrest
(OHCA) confirm an increasing part of asystole as the initial rhythm. The hypothesis of this study was that vasopressin improves the
rate of return of spontaneous circulation (ROSC) and the survival
rate in asystolic OHCA, when used early in the resuscitation effort. Methods This was a prospective cohort study, with a historic
group compared trial set in an urban emergency medical services
system, serving a population of 200,000. All nonpregnant,
normothermic adults (>18 years) suffering nontraumatic OHCA
with asystole were eligible. We compared two treatment groups of
resuscitated patients with OHCA. In the epinephrine group (EPI)
patients received epinephrine 1 mg i.v. every 3 minutes only. In the
vasopressin group (VASO) patients received arginine vasopressin
40 IU i.v. only or followed by epinephrine 1 mg every 3 minutes
during CPR. Statistics. Exact Fisher test, Wilcoxon rank-sum test,
and analysis of independent predictors with multivariate logistic
regression were used; P < 0.05. P321 P321
Bystander CPR for out-of-hospital cardiac arrest in Japan
Y Moriwaki, M Sugiyama, H Toyoda, T Kosuge, M Iwashita,
J Ishikawa, S Matsuzaki, Y Tahara, N Suzuki
Yokohama City University Medical Center, Yokohama, Japan
Critical Care 2007, 11(Suppl 2):P321 (doi: 10.1186/cc5481) P321
Bystander CPR for out-of-hospital cardiac arrest in Japan
Y Moriwaki, M Sugiyama, H Toyoda, T Kosuge, M Iwashita,
J Ishikawa, S Matsuzaki, Y Tahara, N Suzuki
Yokohama City University Medical Center, Yokohama, Japan
Critical Care 2007, 11(Suppl 2):P321 (doi: 10.1186/cc5481) q
g
p g
Results Severe sepsis or septic shock was observed in 123
patients (48.6%). The ICU mortality among these patients was
33.3% compared with 18.5% in nonseptic patients (P = 0.005). IAH developed in 95 patients (37.0%). The incidence of IAH was
higher among septic patients (45.5% vs 28.5%, P = 0.004). Those
septic patients who developed IAH had a mortality rate of 50.0%
compared with 19.4% in septic patients without IAH (P < 0.001). Mortality among nonseptic patients was not different between the
patients with or without IAH (18.9% vs 18.3%). Development of
IAH was a significant risk factor for death in septic patients (OR
4.15; 95% CI 1.87–9.26), but not in nonseptic patients (OR 1.04;
95% CI 0.39–2.77). Background and aims The aim of this study is to clarify how
Japanese citizens are interested in the importance of immediate
cardiopulmonary resuscitation (CPR) and defibrillation, and how
they understand that importance. In Japan, the out-of-hospital
emergency medical service system has been established with the
ambulance service and an emergency life saving technician (ELST)
belonging to the fire department. Subjects and methods Patients’ records were reviewed for the
past 2 years. In Yokohama (3,700,000 people), the cardio- S130 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 pulmonary arrest (CPA) patient is transferred to the nearest ED of
the selected 11 hospitals with adequate ability of CPR and
cerebral resuscitation. We perform ultrasound, chest X-ray, and
blood examination including Troponin in all CPA patients, and
cerebral plane CT (40%) or chest CT (7%). CT was not performed
in patients with a clearly known aetiology. coagulation system may contribute to reperfusion disorders and
possibly affect the outcome of these patients. Further studies need
to show whether elevation of the D-dimer level in patients after
CPR could be a prognostic marker. P323 Conclusions In Japan, CPA patients were witnessed mainly in
their home by their families or their friends. The aetiology of some
CPA patients is noncardiac (subarachnoid haemorrhage or acute
aortic dissection, etc.). However, only 24% CPA patients
underwent bystander CPR by the witness. D-Dimer level and outcome in patients after
cardiopulmonary resuscitation The plasma D-
dimer level was measured immediately after admission to the ICU. Conclusions Vasopressin was superior to epinephrine in patients
with asystole (better ROSC with admission, 24-hour survival and
discharge from hospital). Vasopressin followed by epinephrine was
more effective than epinephrine alone in the treatment of refractory
cardiac arrest. D-Dimer level and outcome in patients after
cardiopulmonary resuscitation H Busch, A Geibel, C Bode, T Schwab
UKL Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P322 (doi: 10.1186/cc5482) Background Clinical and experimental studies have demonstrated a
marked activation of blood coagulation and fibrin formation after
prolonged cardiopulmonary resuscitation (CPR). Several experimental
studies suggest that thrombolysis therapy acts directly on thrombi or
emboli but also enhances microcirculatory reperfusion. In this
retrospective study we investigated the extent of blood coagulation
and fibrin formation via the plasma D-dimer level, an indicator of
endogenous fibrinolytic activity, in patients who underwent inhospital
and out-of-hospital cardiac arrest from nontraumatic causes. Results The investigators enrolled 227 consecutive patients: in the
EPI group 183 patients (years 2001–2003) and in the VASO
group 44 patients (year 2004). Baseline (demographic and
clinical) characteristics were similar for the two groups. Comparing
the EPI and VASO groups, any ROSC was achieved in 81/183
(44%) and 34/44 (77%), P = 0.04; ROSC with admission in
61/183 (33%) and 27/44 (61%), P = 0.03; 24-hour survival in
44/183 (24%) and 23/44 (52%), P = 0.01; and discharge from
hospital in 17/183 (9%) and 10/44 (23%), P = 0.04. Vasopressin
was an independent predictor of ROSC with admission with an
odds ratio of 2.4 (95% CI = 1.24–4.98). Methods and results Forty-five patients were included from
1 January 2004 to 31 March 2005 after CPR in the case of
restoration of spontaneous circulation (ROSC). The plasma D-
dimer level was measured immediately after admission to the ICU. Results In 38 patients (84%) cardial reasons for cardiac arrest
were found. Marked activation of blood coagulation was found in
all patients. After prolonged cardiopulmonary resuscitation (ROSC
not within the first 30 min) patients showed significant elevated
serum D-dimer level compared with patients after ROSC in the first
30 minutes (663 µg/l vs 3,328 µg/ml, P < 0.0001; normal range
<0.25 µg/ml). The time period between cardiac arrest and ROSC
and plasma D-dimer level correlated significantly (r = 0.8, P < 0.01)
after CPR. Patients who died showed significant elevated serum
D-dimer level compared with the surviving patients (1,258 ± 1,587
µg/l vs 3,164 ± 1,974 µg/l, P = 0.026 median). The plasma D-
dimer level correlated significantly to the negative outcome in these
patients (r = 0.55, P < 0.01). Methods and results Forty-five patients were included from
1 January 2004 to 31 March 2005 after CPR in the case of
restoration of spontaneous circulation (ROSC). P324 Vasopressin, epinephrine, and methylprednisolone in
inhospital cardiac arrest S Mentzelopoulos, N Katsios, A Papastylianou, S Gisioti,
A Stathopoulos, E Stamataki, C Roussos, S Zakynthinos
Evaggelismos Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P324 (doi: 10.1186/cc5484) Introduction Combined vasopressin, epinephrine, and methyl-
prednisolone during cardiopulmonary resuscitation (CPR) may
improve survival in inhospital cardiac arrest. Introduction Combined vasopressin, epinephrine, and methyl-
prednisolone during cardiopulmonary resuscitation (CPR) may
improve survival in inhospital cardiac arrest. Conclusions Our data demonstrate a marked time-dependent
activation of blood coagulation and fibrin formation after prolonged
cardiac arrest and CPR in humans. These changes of the S131 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine groups; however, a striking increase was observed in patients wi
bad neurologic outcome peaking after 24 hours (16.7 ± 30.0 vs 6
± 2.1 µg/l; P < 0.013). PCT values after 24 hours were the be
predictor for a bad neurologic outcome with an area under th
curve of 0.91 (cutoff value: 0.44; sensitivity 100%/specificity 62%
Conclusion TNFα, IL-6 and IL-8 serum levels are significant
Figure 1 (abstract P324)
Figure 1 (abstract P325) Figure 1 (abstract P324) groups; however, a striking increase was observed in patients with
bad neurologic outcome peaking after 24 hours (16.7 ± 30.0 vs 6.9
± 2.1 µg/l; P < 0.013). PCT values after 24 hours were the best
predictor for a bad neurologic outcome with an area under the
curve of 0.91 (cutoff value: 0.44; sensitivity 100%/specificity 62%). Conclusion TNFα IL-6 and IL-8 serum levels are significantly
Figure 1 (abstract P324)
Figure 1 (abstract P325) Figure 1 (abstract P325) Figure 1 (abstract P325) Figure 1 (abstract P325) Figure 1 (abstract P324) groups; however, a striking increase was observed in patients with
bad neurologic outcome peaking after 24 hours (16.7 ± 30.0 vs 6.9
± 2.1 µg/l; P < 0.013). PCT values after 24 hours were the best
predictor for a bad neurologic outcome with an area under the
curve of 0.91 (cutoff value: 0.44; sensitivity 100%/specificity 62%). Conclusion TNFα, IL-6 and IL-8 serum levels are significantly
elevated in the early phase after successful CPR in patients with
bad neurological outcome. PCT increases are subsequently found
and have a high prognostic value for the neurologic outcome. P325 Introduction Mortality among patients surviving to be discharged
following inhospital cardiac arrest (IHCA) is high. The present
study assesses whether this might be explained by differences in
patient factor or in factors at resuscitation. P326 Do patient characteristics or factors at resuscitation
influence long-term outcome in patients surviving to be
discharged following inhospital cardiac arrest? influence long-term outcome in patients surviving to be
discharged following inhospital cardiac arrest? M Skrifvars1, M Castrén2, J Nurmi2, A Thorén3, S Aune3,
J Herlitz3
1Helsinki EMS and 2Department of Anaesthesiology and Intensive
Care Medicine, Helsinki University Hospital, Helsinki, Finland;
3Sahlgrenska Hospital, Gothenburg, Sweden
Critical Care 2007, 11(Suppl 2):P326 (doi: 10.1186/cc5486) Results Study group patients had higher rates of ROSC (37/44 vs
24/47; P < 0.01) and discharge either to home or to a
rehabilitation facility (7/44 vs 1/47; P < 0.05). Sixty-day survival
was improved in the study group (Figure 1). M Skrifvars1, M Castrén2, J Nurmi2, A Thorén3, S Aune3,
J Herlitz3 1Helsinki EMS and 2Department of Anaesthesiology and Intensive
Care Medicine, Helsinki University Hospital, Helsinki, Finland;
3Sahlgrenska Hospital, Gothenburg, Sweden
Critical Care 2007, 11(Suppl 2):P326 (doi: 10.1186/cc5486) Conclusions Combination treatment improves survival in inhospital
cardiac arrest. P324 Methods Ninety-one adults with cardiac arrest were randomized to
receive either vasopressin (20 IU/CPR cycle for five cycles) plus
epinephrine (1 mg/CPR cycle) plus methylprednisolone (single
dose = 40 mg) or placebo plus epinephrine (1 mg/CPR cycle) plus
placebo. Primary endpoints were return of spontaneous circulation
(ROSC) for ≥15 minutes, and survival to discharge either to home
or to a rehabilitation facility. Procalcitonin is a powerful predictor of outcome after
cardiopulmonary resuscitation C Stoppe, D Brücken, J Bickenbach, R Kuhlen, M Fries
University Hospital Aachen, Germany
Critical Care 2007, 11(Suppl 2):P325 (doi: 10.1186/cc5485) Methods An analysis of IHCA data collected from one Swedish
tertiary hospital and from five Finnish secondary hospitals over a
10-year period. The study was limited to patients surviving to be
discharged from the hospital. Multiple logistic regression analysis
was used to identify factors associated with survival at 1 year from
the arrest. Introduction We evaluated the time course and relationship of
proinflammatory cytokines and procalcitonin (PCT) serum levels
after cardiopulmonary resuscitation (CPR). We hypothesized that
an increase of cytokine levels would precede a marked increase in
PCT levels and that PCT would be the best predictor of the final
neurologic outcome. Results Of a total of 1,578 resuscitated patients, 441 (28%) survived
to hospital discharge and 359 (80%) were alive at 12 months. Factors associated with survival at 12 months were age (odds ratio
(OR) 0.96, 95% confidence interval (CI) 0.935–0.979), no renal
disease (OR 0.4, CI 0.2–0.9), good functional status at discharge
(OR 2.9, CI 1.4–6.0), and arrest occurring at (compared with arrests
at general wards) the emergency ward (OR 5.8, CI 1.8–18), cardiac
care unit (OR 2.9, CI 1.3–6.3), ICU (OR 2.6, CI 1.1–6.2), ward for
thoracic surgery (OR 12.9, CI 3.4–49.1) and unit for interventional
radiology (OR 16.4, CI 4.4–61.2). There was no difference in initial
rhythm, delay to defibrillation or delay to return of spontaneous
circulation between survivors and nonsurvivors at 12 months. Results Of a total of 1,578 resuscitated patients, 441 (28%) survived
to hospital discharge and 359 (80%) were alive at 12 months. Factors associated with survival at 12 months were age (odds ratio
(OR) 0.96, 95% confidence interval (CI) 0.935–0.979), no renal
disease (OR 0.4, CI 0.2–0.9), good functional status at discharge
(OR 2.9, CI 1.4–6.0), and arrest occurring at (compared with arrests
at general wards) the emergency ward (OR 5.8, CI 1.8–18), cardiac
care unit (OR 2.9, CI 1.3–6.3), ICU (OR 2.6, CI 1.1–6.2), ward for
thoracic surgery (OR 12.9, CI 3.4–49.1) and unit for interventional
radiology (OR 16.4, CI 4.4–61.2). There was no difference in initial
rhythm, delay to defibrillation or delay to return of spontaneous
circulation between survivors and nonsurvivors at 12 months. Conclusion Several patient factors, mainly age, functional status
and co-morbid disease, influence long-term survival following
IHCA. Out-of-hospital surface cooling with a cooling-blanket to
induce mild hypothermia in humans after cardiac arrest: a
feasibility trial Methods A 77-year-old male with a history of hypertension,
previous replacement of aortic valve and a right coronary artery
bypass was admitted to our ICU after cardiac arrest. He suffered a
collapse while walking. The emergency service arrived within
5 minutes. The initial cardiac rhythm was ventricular fibrillation. The
estimated time to return to spontaneous circulation was
20 minutes. The patient arrived in the hospital 50 minutes after
collapse and was immediately admitted to the ICU. Thirty minutes
after ICU admission, he was unconscious with a Glasgow coma
score of 5. Hypothermia was induced by the Artic Sun 2000
cooling system (Medivance, Louisville, CO, USA), and the goal
temperature was obtained 105 minutes after induction. The body
temperature was monitored continuously with a Foley catheter. Hypothermia was maintained for 24 hours at 33ºC and rewarming
to the target temperature of 37ºC was achieved over 12 hours. No
electrolyte imbalances or coagulopathies were observed. No
overcooling was observed at any moment. The patient was
extubated on day 6 after admission and discharged from the ICU
on day 10 without neurological sequelae. T Uray1, R Malzer2, A Auer2, A Zajicek2, F Sterz1, J Arrich1,
R Fleischhackl1, A Janata1, M Holzer1, A Laggner1, W Behringer1
1Medical University Vienna, Austria; 2Ambulance Service of Vienna,
Austria
Critical Care 2007, 11(Suppl 2):P327 (doi: 10.1186/cc5487) Introduction Mild hypothermia (32–34°C) is a promising new
therapy for patients resuscitated from cardiac arrest. Animal
studies suggest that early and fast cooling is crucial for beneficial
effect on neurological outcome. Inducing mild hypothermia
immediately after successful restoration of spontaneous circulation
(ROSC) in the out-of-hospital setting remains a challenge. Therefore, a novel cooling-blanket (EMCOOLSpad®), independent
of any energy source during use, was developed. The aim of the
study was to evaluate feasibility and safety of out-of-hospital
surface cooling with EMCOOLSpad® in patients successfully
resuscitated from cardiac arrest. Conclusions Careful monitoring of temperature is important during
use of therapeutic hypothermia because unintentional overcooling
below 32°C may place the patient at risk for serious complications
such as arrhythmias, infection, and coagulopathy. Cooling with a
water-circulating cooling device is fast and safe. Clinicians should
work to institute protocols for mild hypothermia treatment for such
patients as a part of their critical care treatment. Methods We included patients successfully resuscitated from out-
of-hospital cardiac arrest with an oesophageal temperature (Tes)
>34°C. References 1. Bernard SA, Gray TW, Buist MD, et al.: Treatment of
comatose survivors of out-of-hospital cardiac arrest with
induced hypothermia. N Engl J Med 2002; 346:557-563. 1. Bernard SA, Gray TW, Buist MD, et al.: Treatment of
comatose survivors of out-of-hospital cardiac arrest with
induced hypothermia. N Engl J Med 2002; 346:557-563. 2. 2005
International
Consensus
on
Cardiopulmonary
Resuscitation (CPR) and Emergency Cardiovascular Care
(ECC) Science with Treatment Recommendations. Circula-
tion 2005, 112 (Suppl):III-1-III-136. Results From September 2006 to December 2006, 10 patients,
weighing 70 (64–93) kg, were included in the study. Cooling was
initiated 14 (7–20) minutes after ROSC. The cooling-blanket
decreased the Tes from 36.5 (36.2–36.7)°C at the start of cooling
to 34.0°C within 61 (47–93) minutes, and to target temperature
Tes 33°C within 83 (61–119) minutes, resulting in a cooling rate of
2.6 (1.6–3.6)°C/hour. Hospital admission was 45 (40–53) minutes
after ROSC, and Tes 33°C was achieved 78 (32–107) minutes
after admission. In eight patients, precooled parts of the cooling-
blanket had to be applied repeatedly on the chest and abdomen to
maintain the target temperature of Tes 33°C for 24 hours. No skin
lesions were observed. 2. 2005
International
Consensus
on
Cardiopulmonary
Resuscitation (CPR) and Emergency Cardiovascular Care
(ECC) Science with Treatment Recommendations. Circula-
tion 2005, 112 (Suppl):III-1-III-136. Induction of mild hypothermia in cardiac arrest survivors
with cardiogenic shock syndrome Induction of mild hypothermia in cardiac arrest survivors
with cardiogenic shock syndrome R Skulec, J Belohlavek, V Dytrych, T Kovarnik, M Aschermann,
A Linhart Conclusion Noninvasive surface cooling with the EMCOOLSpad®
immediately after resuscitation from cardiac arrest, in the out-of-
hospital setting, was shown to be feasible and safe. Whether early
cooling, as compared with delayed cooling in the hospital, will
improve neurological outcome needs to be determined in a
prospective randomized trial. Introduction Induction of mild hypothermia (MH) in patients
resuscitated from cardiac arrest can improve their outcome. However, benefits and risks of MH induction in patients who
remain in cardiogenic shock after the return of spontaneous
circulation (ROSC) are unclear. We therefore analysed a group of
all cardiac arrest survivors who were indicated for MH induction in
our coronary care unit (CCU) and compared the outcome of
patients with cardiogenic shock syndrome after ROSC with the
outcome of those who were relatively haemodynamically stable. Procalcitonin is a powerful predictor of outcome after
cardiopulmonary resuscitation Location of the arrest also influences survival, but the initial
rhythm, the delays to defibrillation and return of spontaneous
circulation do not. Methods Data were prospectively collected from 71 patients. Blood samples were taken after admission to the hospital and after
6, 12, 24, 72 and 120 hours. PCT, IL-6, IL-8 and TNFα levels were
measured using automated assays. On day 14 patients were
divided into two neurologic outcome groups according to the
Cerebral Performance Categories (CPC 1–3: bad; CPC 4–5:
good). Differences between groups were evaluated using a t test. ROC curves were computed to analyze the predictive value of the
markers for a bad outcome. Results There was an early and significant increase in TNFα, IL-6
and IL-8 after admission to the hospital (14.4 ± 5.2, 185 ± 248
and 89 ± 81 µg/l) and in the ensuing 6 hours (15.6 ± 8.7,
209 ± 239 and 176 ± 232 µg/l) in patients with bad neurologic
outcome. Initially, PCT levels were indistinguishable between the Conclusion Several patient factors, mainly age, functional status
and co-morbid disease, influence long-term survival following
IHCA. Location of the arrest also influences survival, but the initial
rhythm, the delays to defibrillation and return of spontaneous
circulation do not. S132 Available online http://ccforum.com/supplements/11/S2 P327 Nowadays, the maintenance of hypothermia can be facilitated with
new technology to avoid unintentional overcooling. Nowadays, the maintenance of hypothermia can be facilitated with
new technology to avoid unintentional overcooling. Out-of-hospital surface cooling with a cooling-blanket to
induce mild hypothermia in humans after cardiac arrest: a
feasibility trial Out-of-hospital surface cooling with a cooling-blanket to
induce mild hypothermia in humans after cardiac arrest: a
feasibility trial The EMCOOLSpad® consists of multiple cooling units
(12 mm thick), filled with a mixture of graphite/water, which are
stored in a cooling box at –3°C in the ambulance car. Cooling was
initiated as soon as feasible by the first treating paramedics and
emergency physicians, and was continued in the emergency room. The cooling-blanket was removed when the Tes reached 34°C. The
target temperature of Tes 33°C was maintained for 24 hours. Data
are presented as the median and interquartile range (25–75%). P329 Induction of mild hypothermia in cardiac arrest survivors
with cardiogenic shock syndrome
R Skulec, J Belohlavek, V Dytrych, T Kovarnik, M Aschermann,
A Linhart
General Teaching Hospital, Prague, Czech Republic
Critical Care 2007, 11(Suppl 2):P329 (doi: 10.1186/cc5489) Reduction of magnetic resonance spectroscopy brain
temperature by convective head cooling in healthy humans Reduction of magnetic resonance spectroscopy brain
temperature by convective head cooling in healthy humans Results From 50 consecutive patients, 28 fulfilled criteria of
cardiogenic shock before MH initiation (group A), and 22 were
relatively hemodynamically stable (group B). While predicted
mortality was 83.1 ± 13.1% in group A and 63.2 ± 19.0% in group
B (P < 0.001), real inhospital mortality was 55.6% in group A and
only 18.2% in group B patients (P = 0.009). The best inhospital
neurological outcome was found favourable in 71.4% patients in
group A and in 86.3% in group B (P = 0.306). Favourable
discharge neurological outcome was reached in 100% in group A
and in 94% in group B (P = 1.000). Patients in both groups did
not differ in rate of complications. B Harris1, P Andrews1, I Marshall1, T Robinson2, G Murray1
1University of Edinburgh, UK; 2KCI, Ferndown, UK
Critical Care 2007, 11(Suppl 2):P331 (doi: 10.1186/cc5491) This pilot study assessed the effect of forced convective head and
neck cooling on brain temperature, measured by magnetic resonance
spectroscopy (MRS), in five healthy adult humans (three males). Following a 10-minute baseline, subjects received 30 minutes
head cooling followed by 30 minutes head and neck cooling. The
cooling device delivered air at 11ºC and 15 m/s through a hood
and separate neck collar made of a double layer of nylon sheeting,
the inner layer pierced with holes. Subjects wore a windproof
waistcoat taped round the base of their neck and were wrapped in
blankets from the base of the neck down. Bilateral foot warming
with chemical hot packs was used to encourage heat loss in the
presence of normothermia. Conclusions While inhospital mortality in cardiac arrest survivors
treated by MH was expectably higher in those with cardiogenic
shock than in stable patients, favourable neurological outcome was
frequent and comparable in both groups of patients. Moreover, MH
application was safe in both groups. Therefore, induction of MH
should be considered also in cardiac arrest survivors with
cardiogenic shock syndrome after ROSC. MRS temperature data were collected at the level of the basal
ganglia over the baseline and the last 10 minutes of each cooling
intervention. MRS detects naturally occurring brain metabolites
and interpretation of the relative frequencies of N-acetyl aspartate
and water allows estimation of tissue temperature in 1 cm3 voxels. P330 P330 Changes in urinary 8-hydroxy-2-deoxyguanosine in
patients with global brain ischemia undergoing brain
hypothermia therapy: comparison of whole body and
selective head cooling
K Ikeda, Y Kuroki, K Yosikawa, T Yokoyama, H Utino
Hachiouji Medical Center, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P330 (doi: 10.1186/cc5490) Changes in urinary 8-hydroxy-2-deoxyguanosine in
patients with global brain ischemia undergoing brain
hypothermia therapy: comparison of whole body and
selective head cooling Changes in urinary 8-hydroxy-2-deoxyguanosine in
patients with global brain ischemia undergoing brain
hypothermia therapy: comparison of whole body and
selective head cooling K Ikeda, Y Kuroki, K Yosikawa, T Yokoyama, H Utino
Hachiouji Medical Center, Tokyo, Japan
Critical Care 2007, 11(Suppl 2):P330 (doi: 10.1186/cc5490) The mean baseline-corrected MRS brain temperature over all
voxels reduced by –0.45ºC (SD 0.23ºC, P = 0.01, 5% CI –0.74 to
–0.17ºC) with head cooling and –0.37ºC (SD 0.30ºC, P = 0.049,
95% CI –0.74 to 0.00ºC) with head and neck cooling. Head
cooling reduced the mean baseline-corrected MRS brain
temperature in core voxels in all subjects. The formal test for
gradient was not significant (P = 0.43; 95% CI –0.15 to 0.29ºC). Head and neck cooling reduced the temperature in core voxels in
three subjects; the test for gradient was not significant (P = 0.07;
95% CI –0.03 to 0.58ºC). The mean baseline-corrected
oesophageal temperature reductions for the last 10 minutes of
each intervention were –0.16ºC (SD 0.04ºC) with head cooling
and –0.36ºC (SD 0.12ºC) with head and neck cooling. Introduction Oxygen free radicals play an important role in global
brain ischemia after cardiac arrest. Brain hypothermia therapy is
effective in suppressing free radical expression. The aim of this
study was to assess free radical expression under brain
hypothermia, and to compare the expression between whole body
and selective head cooling. Methods The subjects were 12 patients treated with mild brain
hypothermia (34 ± 1°C) after resuscitation following cardiac arrest
in our ICU; five patients received whole body cooling and seven
patients received selective head cooling. We examined the
hemodynamic changes and the urinary concentration of 8-hydroxy-
2-deoxyguanosine (determined by HPLC) during brain hypothermia
therapy. Furthermore, we compared the prognosis at 28 days after
admission to the ICU. Forced convective head cooling reduced the MRS brain
temperature at an equivalent of 1.35ºC per hour in healthy
subjects, and the reduction was apparent across the brain. P328 Mild hypothermia induction following cardiac arrest using a
water-circulating cooling device yp
g
g
water-circulating cooling device
E Miñambres, B Suberviola, A González-Castro, J San Jose,
J Gutierrez Morlote
Hospital Universitario Marques de Valdecilla, Santander, Spain
Critical Care 2007, 11(Suppl 2):P328 (doi: 10.1186/cc5488) Methods We performed retrospective analysis of all consecutive
cardiac arrest survivors treated by MH in our CCU from November
2002 to August 2006. They were classified into two groups,
according to whether they met the criteria for cardiogenic shock or
not after ROSC and just before MH initiation. Primary outcome
measures were inhospital mortality, and the best inhospital and
discharge neurological result. Predicted mortality was evaluated by
the APACHE II score, and neurological outcome by Cerebral
Performance Category score. MH was initiated as soon as Introduction The use of mild hypothermia for comatose survivors
of cardiac arrest has been endorsed by the American Heart
Association and the International Liaison Committee on Resusci-
tation [1,2]. Unintentional overcooling is common with some
techniques such as cool intravascular fluid or the use of ice packs. S133 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P331 P332 Results
The induction time for whole body cooling was
significantly shorter than that for selective head cooling. The
rewarming time for head cooling was significantly shorter than that
for whole body cooling. The mean arterial pressure and heart rate
were both stable in the head cooling group. The urinary 8-hydroxy-
2-deoxyguanosine concentrations decreased significantly in both
groups, but data were significantly lower in the whole body cooling
group compared with the selective head cooling group. Five and
seven patients, respectively, exhibited good recovery 28 days after
admission, in the whole body and selective head cooling groups. Conclusions Mild brain hypothermia therapy suppressed the
production of free radicals following global brain ischemia. Whole
body cooling had a stronger effect of suppression of free radicals
compare with selective head cooling. It is considered that selective
head cooling exhibits neuroprotection similar to whole body
cooling. Results
The induction time for whole body cooling was
significantly shorter than that for selective head cooling. The
rewarming time for head cooling was significantly shorter than that
for whole body cooling. The mean arterial pressure and heart rate
were both stable in the head cooling group. The urinary 8-hydroxy-
2-deoxyguanosine concentrations decreased significantly in both
groups, but data were significantly lower in the whole body cooling
group compared with the selective head cooling group. Five and
seven patients, respectively, exhibited good recovery 28 days after
admission, in the whole body and selective head cooling groups. Induction of therapeutic mild hypothermia after cardiac
arrest: a new combined method to achieve the target
temperature H Busch, T Schwab, K Fink, C Bode
UKL Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P332 (doi: 10.1186/cc5492) H Busch, T Schwab, K Fink, C Bode
UKL Freiburg, Germany
Critical Care 2007, 11(Suppl 2):P332 (doi: 10.1186/cc5492) Background Clinical and experimental investigations have demon-
strated that induction of mild hypothermia works after successful
cardiopulmonal resuscitation (CPR) neuroprotection. After the
presentation of controlled studies, therapeutic hypothermia moved
into the topical international guidelines. Conclusions Mild brain hypothermia therapy suppressed the
production of free radicals following global brain ischemia. Whole
body cooling had a stronger effect of suppression of free radicals
compare with selective head cooling. It is considered that selective
head cooling exhibits neuroprotection similar to whole body
cooling. Methods and results A total of 50 patients were examined after
successful CPR. Twenty-nine patients received 4°C cold infusions
after arrival in the heart catheter laboratory. Reduction of magnetic resonance spectroscopy brain
temperature by convective head cooling in healthy humans For assessment of regional cooling, voxels lying within the region
formed by joining the tips of the lateral ventricles were defined as
‘core’, voxels within approximately one voxel of the brain surface
were defined as ‘outer’, and all other voxels were defined as
‘intermediate’. The oesophageal temperature was measured
continuously with a fluoroptic thermometer. P331 possible after ROSC and patients were cooled to body
temperature 32–34ºC for 12 hours. Reduction of magnetic resonance spectroscopy brain
temperature by convective head cooling in healthy humans
B Harris1, P Andrews1, I Marshall1, T Robinson2, G Murray1
1University of Edinburgh, UK; 2KCI, Ferndown, UK
Critical Care 2007, 11(Suppl 2):P331 (doi: 10.1186/cc5491) P334 21 patients who had received a volume substitute by means of
drips from ambient temperature served as a control group. After
admission to the ICU, both groups were immediately connected to
an external cooling device (CoolGard® or Thermo Wrap®) and were
cooled to a target temperature of 33°C (bladder temperature). P332 Retrospective data of S134 Available online http://ccforum.com/supplements/11/S2 Buspirone and dexmedetomidine synergistically reduce
the shivering threshold in humans R Lenhardt, R Komatsu, M Orhan-Sungur
University of Louisville, KY, USA
Critical Care 2007, 11(Suppl 2):P334 (doi: 10.1186/cc5494) Results The average temperature at admission did not differ in
both groups (35.5 ± 0.9°C vs 35.89 ± 0.8°C). In the group with
initial cooling by means of 4°C cold infusions, a significant
temperature decrease could be reached during the invasive
coronary diagnostics to admission to the ICU of an average 0.84°C
(35.88 ± 0.9°C vs 35.04 ± 0.9°C, P < 0.0001). The middle chill
duration up to the achievement of the target temperature after
admission was significantly shorter with the combined method
(341 ± 113 min versus 553 ± 342 min, P < 0.01). The period to
the achievement of the target temperature after the beginning of
the external cooling device with the group of the combined method
was significantly shorter (163 ± 91 min versus 342 ± 258 min,
P < 0.01). Introduction Hypothermia may be therapeutically beneficial in
stroke victims; however, it provokes vigorous shivering. Buspirone,
a partial serotonin 1A antagonist, and dexmedetomidine, an α2
agonist, linearly reduce the shivering threshold (triggering core
temperature) with minimal sedation and respiratory depression. We
tested the hypothesis that buspirone and dexmedetomidine
synergistically reduce the shivering threshold without producing
substantial sedation or respiratory depression. Methods We studied four healthy male volunteers (18–40) on
4 days: (1) control (no drug); (2) buspirone only (60 mg orally); (3)
dexmedetomidine only (target plasma concentration 0.6 ng/ml);
and (4) combined buspirone and dexmedetomidine in the same
doses. Lactated Ringer’s solution (3°C) was infused via a central
venous catheter to decrease tympanic membrane temperature by
≈2.2°C/hour; the mean skin temperature was maintained at 31°C. An increase in oxygen consumption more than 25% of baseline
identified the shivering threshold. Sedation was evaluated using
the Observer’s Assessment Sedation/Alertness scale. Two-way
repeated-measures analysis of variance was used to identify
interactions between drugs. Data are presented as means ± SDs;
P < 0.05 was statistically significant. Conclusions The combined method with initial cooling with 4°C
cold solutions shows a sure and actual prestationary cooling
procedure to the introduction or realisation of mild hypothermia and
offers the possibility to reach the purpose temperature significantly
faster. Preclinical introduction of mild hypothermia by means of 4°C
cold solutions could be a beneficial criteria in the future treatment,
and probably affects the outcome of these patients. P333 A comparison of complications during therapeutic
hypothermia between surface cooling and endovascular
cooling techniques
P Hayden, A Salam, R Beale, M Gillies
Guy’s & St Thomas’ NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P333 (doi: 10.1186/cc5493) A comparison of complications during therapeutic
hypothermia between surface cooling and endovascular
cooling techniques A comparison of complications during therapeutic
hypothermia between surface cooling and endovascular
cooling techniques Results The shivering thresholds were 36.4 ± 0.5°C on the control
day; 34.9 ± 0.6°C (P < 0.01 from control) on the buspirone only
day; 36.1 ± 0.6°C (P < 0.01 from control) on the dexmedeto-
midine only day; and 34.2 ± 0.5°C (P < 0.01 from control) on the
combined buspirone and dexmedetomidine day. The calculated
mean difference between the thresholds on the combined and the
control days was 1.9 ± 0.4°C, while the measured mean difference
derived from the difference between the combined and control
days was 2.3 ± 0.4°C. There was only trivial sedation with either
drug alone or in combination. The respiratory rate and end-tidal
PCO2 were well preserved on all days. P Hayden, A Salam, R Beale, M Gillies
Guy’s & St Thomas’ NHS Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P333 (doi: 10.1186/cc5493) Introduction Therapeutic hypothermia (TH) following cardiac
arrest is associated with several complications including sympto-
matic bradycardia, coagulopathy, and pneumonia [1]. Furthermore,
hyperthermia is associated with poor outcome following brain
injury. The incidence of these complications may be increased by
excessive temperature fluctuations. We sought to compare
complications between two techniques used to induce TH; surface
cooling (SC) using ice packs, and endovascular cooling (EV),
using the Coolgard™ system (Alsius Corp., USA). Conclusion Buspirone and dexmedetomidine act synergistically to
reduce the shivering threshold with only mild sedation and no
respiratory depression. This combination might be a valid treatment
to prevent shivering in stroke patients during therapeutic
hypothermia. Methods A retrospective review was performed of all cardiac
arrest patients undergoing TH and surviving ≥48 hours between
June 2005 and November 2006. P335 Results Thirty-five patients underwent our TH protocol (SC group =
21, EV group = 14). The incidence of overcooling (<32°C) in the
SC group was significantly higher than the EV group (10 vs 1,
P = 0.01), whilst a trend towards more episodes of symptomatic
bradycardia (SC 9 vs EV 2, P = 0.07) and rebound hyperthermia
(SC 9 vs EV 2, P = 0.07) was also present. The incidence of
pneumonia (SC 7 vs EV 4, P = 0.77) and coagulopathy/bleeding
(SC 2 vs EV 3, P = 0.32) were similar between groups. Bispectral index and suppression ratio are very early
predictors of neurological outcome during therapeutic
hypothermia after cardiac arrest
D Seder, R Riker, G Fraser, H Bruce, T Robbins
Maine Medical Center, Portland, ME, USA
Critical Care 2007, 11(Suppl 2):P335 (doi: 10.1186/cc5495) Bispectral index and suppression ratio are very early
predictors of neurological outcome during therapeutic
hypothermia after cardiac arrest ,
,
,
Critical Care 2007, 11(Suppl 2):P335 (doi: 10.1186/cc Introduction The bispectral index (BIS) is calculated from fronto-
temporal electroencephalogram (EEG), and the suppression ratio
(SR) estimates the percentage of EEG suppression. We monitored
the BIS and SR during therapeutic hypothermia (TH) and
compared them with neurological outcomes of encephalopathic
survivors of out-of-hospital cardiac arrest (OHCA). Conclusions (1) SC is associated with a significantly higher
incidence of overcooling than EC and may be associated with an
increase in complications such as symptomatic bradycardia. (2)
SC may also be associated with an increase in rebound
hyperthermia. yp
Reference y
Reference 1. Polderman KH: Application of therapeutic hypothermia in
the intensive care unit. Opportunities and pitfalls of a
promising treatment modality – Part 2: practical aspects
and side effects. Intensive Care Med 2004, 30:757-769. Methods Thirty-two patients with anoxic encephalopathy after
OHCA received 18 hours of TH at 32–34°C. BIS monitoring was
initiated at the onset of TH, and neuromuscular blockade (NMB)
was dosed in response to shivering. Blinded BIS and SR data 1. Polderman KH: Application of therapeutic hypothermia in
the intensive care unit. Opportunities and pitfalls of a
promising treatment modality – Part 2: practical aspects
and side effects. Intensive Care Med 2004, 30:757-769. S135 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin have hypoxic ischaemic encephalopathy (n = 15); adding/
escalating or stopping antiseizure drugs based on the presence/
absence of seizure activity (n = 12); and continuing supportive
care in comatose patients diagnosed to have metabolic encephalo-
pathy/prolonged sedation effect as the cause for coma (n = 8). Based on these results it can be concluded that, despite limitations
such as motion artifacts and influence of sedation on electrical
signals, EEG impacts on clinical decision-making processes in
critical care. Hence it is beneficial, and more widespread use
would improve its diagnostic potential. were recorded after the first dose of NMB, and compared with the
Cerebral Performance Category (CPC) at discharge and 6 months. CPC 1 or CPC 2 was considered a good outcome (GO). have hypoxic ischaemic encephalopathy (n = 15); adding/
escalating or stopping antiseizure drugs based on the presence/
absence of seizure activity (n = 12); and continuing supportive
care in comatose patients diagnosed to have metabolic encephalo-
pathy/prolonged sedation effect as the cause for coma (n = 8). Results Fourteen out of 32 patients (44%) survived, 11 (34%)
with GO. Five of the remaining 18 patients died before neuro-
logical evaluation at 72 hours, and one patient recovered
neurological function but died of cardiogenic shock. No survivor
recalled the period of NMB. First NMB was administered a median
of 5 hours after cardiac arrest or 87 minutes after initiation of TH,
at 35.6 ± 1.7°C. Patients with GO had a higher first post-NMB BIS
(39 ± 6 vs 13 ± 14, P < 0.001) and a lower SR (10 ± 12 vs
69 ± 29, P < 0.001) than those with CPC 3–5. yp
Reference Initial NMB
reduced frontotemporal electromyogram (EMG) power from
52 ± 8 to 27 ± 1 db, P < 0.001. In 17 of the patients with
downloaded EEG data, an increase in EMG power of 17 dB (IQR
10–27) from baseline was associated with clinically detectable
shivering. Epileptiform discharges were noted on the monitor
during NMB in two patients, and seizure activity was confirmed by
formal EEG in both. Based on these results it can be concluded that, despite limitations
such as motion artifacts and influence of sedation on electrical
signals, EEG impacts on clinical decision-making processes in
critical care. Hence it is beneficial, and more widespread use
would improve its diagnostic potential. References 1. Hirsch LJ, Kull LL:Am J Electroneurodiagnostic Technol
2004, 44:137-158. 2. Newton DEF: Electrophysiological monitoring of general
intensive care patients. Intensive Care Med 1999, 25:350-
352. P337
Abstract withdrawn P337 Abstract withdrawn Conclusions In cardiac arrest survivors receiving TH, a higher
post-NMB BIS score and a lower SR are very early predictors of
neurological outcome. The potential benefits of monitoring BIS and
SR, as well as EMG power for early recognition of shivering, and
continuous frontotemporal EEG to detect seizures, warrant further
study. Aneurysmal subarachnoid hemorrhage induces the
expression of Pentraxin3 in patients G Brandi1, E Roncati Zanier1, L Longhi1, G Peri2, G De Simon3,
M Tettamanti3, A Mantovani2, N Stocchetti1
1Milan University, Ospedale Maggiore Policlinico IRCCS, Milan,
Italy; 2Clinical Institute Humanitas, Milan, Italy; 3Mario Negri
Institute, Milan, Italy
Critical Care 2007, 11(Suppl 2):P338 (doi: 10.1186/cc5498) Introduction Aneurismal subarachnoid hemorrhage (SAH) is an
extremely severe illness associated with a high mortality rate and
permanent severe neurological dysfunction in two-thirds of all
affected patients. One of the major complications of SAH is
vasospasm-associated cerebral ischemia. Clinical and experi-
mental data suggest that vasospasm is linked to the inflammatory
response associated with SAH. The goal of this study was to
investigate the expression of Pentraxin3 (PTX3), a prototypic long
pentraxin protein induced by proinflammatory signals in the brain,
in SAH patients to test the hypothesis that SAH is followed by an
upregulation of PTX3, and establish a temporal relationship
between the expression of PTX3 and the induction of vasospasm. We also attempted to establish that PTX3 is detectable in cerebro-
spinal fluid (CSF). q
Results From the 102 patients (56 men and 48 women) 38
(37.5%) died within the first 30 days, most of them in the first
10 days. Age (OR 13.801, P < 0.04), APACHE II score (OR
1.114, P < 0.008), GCS (OR 2.158, P < 0.002), ICH score (OR
1.183, P < 0.001), FiO2/pO2 (OR 0.996, P < 0.009), haemodynamic
instability (OR 2.340, P < 0.002), fever (OR 1.245, P < 0.002),
and INR (OR 13.801, P < 0.04) were the strongest associated
factors of 30-day mortality. Gender (OR 0.652, P < 0.301), prior
illness (OR 1.070, P < 0.870), MODS (OR 0.978, P < 0.803),
LOS (OR 0.988, P < 0.266), MV (OR 0.994, P < 0.356) and TT
(OR 0.990 P < 0.371) were not associated with mortality. Patients
who where operated on had higher mortality but were also more
severely ill. Methods We studied eight severe SAH patients admitted to our
neuroscience ICU with a median World Federation Neurosurgical
Score of 4 and a Fisher score of 4. Arterial, jugular venous blood
and CSF samples were routinely obtained every 12 hours for
7 days. PTX3 levels were measured by ELISA in plasma and CSF
samples. Conclusion Age, severity of illness, ICH score, hypoxemia,
haemodynamic instability, and increased temperature are directly
related with the outcome of patients with SICH. Gender, LOS, MV,
TT, and MODS did not influence mortality. Maintenance of prehospital medical systems due to clinical
advance in acute stroke K Ishii1, Y Wakabayashi1, Y Momii2, T Asano2, H Kenai2,
M Yamashita2, M Mori2, Y Hori2, H Nagatomi2
1Oita University School of Medicine, Oita, Japan; 2Nagatomi
Neurosurgical Hospital, Oita, Japan
Critical Care 2007, 11(Suppl 2):P340 (doi: 10.1186/cc5500) Introduction Recently, the medical treatment in acute stroke has
been making rapid progress. Especially, in the ischemic stroke of
acute stage, the efficacy of thrombolysis, systemic t-PA or local
transarterial urokinase infusion has been proved. However, the
effective treatment time is still quite limited. The patients must be
brought to the stroke center as soon as possible. We analyzed the
reason why most stroke patients delay coming to the stroke center. We extracted the problems and proposed some solutions. Conclusions SAH is characterized by the production of PTX3 and
the induction of vasospasm is associated with an upregulation of
PTX3 in the CSF that is not detectable in plasma. Reference 1. Muller et al.: Crit Care Med 2001, 29:1404-1407. 1. Muller et al.: Crit Care Med 2001, 29:1404-1407. Patients and methods The clinical subjects consisted of 1,112
consecutive patients with ischemic stroke in the acute stage,
hospitalized in our hospital between April 2003 and September
2006. We investigated the clinical course, especially the time from
the onset to the physical examination, and radiological exami-
nations (CT, MRI, MRA and/or cerebral angiography). The mean
age was 72.3 years. Among them, 334 patients were classified as
atherothrombosis, 232 were cardiac embolism, 439 were lacunar
infarction and 107 were transient ischemic attack. Only 19 patients
underwent acute thrombolytic therapy. Aneurysmal subarachnoid hemorrhage induces the
expression of Pentraxin3 in patients Results
Compared with plasma levels of PTX3 in normal
volunteers (<2 ng/ml [1]), SAH induced a marked increase in
plasma PTX3 expression. During the first 48 hours following SAH
(acute phase), PTX3 arterial and jugular venous levels increased to
36.93 ± 24.32 ng/ml and 33.64 ± 28.76 ng/ml, respectively, and
then subsequently decreased concomitantly with the reduction of
the inflammation (48–96 hours: subacute phase). PTX3 is
detectable in the CSF: mean CSF levels of PTX3 were
4.07 ± 3.64 ng/ml during the acute phase and 0.69 ± 0.44 ng/ml
during the subacute phase (t test: P < 0.05 compared with the
acute phase). In the presence of vasospasm (four patients), we
detected a second peak of PTX3 (4.03 ± 2.85 ng/ml) in CSF
samples (t test: P < 0.05 compared with the subacute phase) that
was not detectable in plasma. P338 Patients
who where operated on had higher mortality but were also more
severely ill. M Sartzi, A Papaeveggelou, A Stogiannidi, P Kouki,
B Romanou, E Panagiotakopoulou, G Kallitsi, K Mihas,
F Tsidemiadou, P Clouva-Molyvda
General Hospital of Eleusis, Athens, Greece
Critical Care 2007, 11(Suppl 2):P339 (doi: 10.1186/cc5499) P336 Role of bedside electroencephalogram in intensive care:
a critical review
R Jayaram Ramachandran, C Hargreaves, S Sinha
Whittington Hospital NHS Trust, London, UK
Critical Care 2007, 11(Suppl 2):P336 (doi: 10.1186/cc5496) Role of bedside electroencephalogram in intensive care:
a critical review Role of bedside electroencephalogram in intensive care:
a critical review R Jayaram Ramachandran, C Hargreaves, S Sinha
Whittington Hospital NHS Trust, London, UK
Critical Care 2007, 11(Suppl 2):P336 (doi: 10.1186/cc5496) Electroencephalogram (EEG) is an appropriate monitoring tool in
intensive care because it is linked to cerebral metabolism, is
sensitive to ischaemia/hypoxia, can detect neuronal dysfunction at
a reversible stage and is the best method to detect seizure activity. Scientific data have proved utility of continuous EEG monitoring in
intensive care [1,2]. But there is a paucity of data relating to single
recordings of EEG especially in general ICUs. A retrospective chart review of patients who had bedside EEG in a
medical–surgical ICU was done. Data were collected with a focus
on: indication for requesting EEG, technical difficulties during the
study, the report and its influence on subsequent clinical manage-
ment. Forty-two charts were reviewed. The indications were: evaluation
of persistent comatose state (n = 27), to diagnose/exclude seizure
activity and nonconvulsive status epilepsy (n = 12), and as an
adjunct to support clinical diagnosis of suspected brain death prior
to formal testing (n = 3). Movement artifacts led to technical
difficulty in four studies. EEG confirmed: moderate to severe nonspecific brain dysfunction
as the cause for persistent comatose state by the presence of
either diffuse slowing with theta/delta activity, absence of cerebral
activity, continuous rhythmic and semi rhythmic lateralized/bilateral
epileptiform discharges, burst suppression pattern or continuous
bilateral slow U-shaped waves; anoxic brain damage by absence of
changes in electrical signals following external application of
noxious stimuli; and seizure activity by epileptiform discharges. Twelve reports stated that use of sedation interfered with EEG
interpretation. The following clinical decisions were made based on the EEG
report in conjunction with clinical findings: initiating withdrawal of
life support or ‘do-not-resuscitate orders’ in patients diagnosed to S136 Available online http://ccforum.com/supplements/11/S2 P338 Methods Retrospective analysis of prospectively gathered data of
102 patients with SICH treated in our ICU during the past 8 years. On admission the following data were registered: vascular risk
factors (high blood pressure, diabetes mellitus), age, gender,
APACHE II score, GCS, hemorrhage characteristics (location, side,
volume, mass effect), surgical procedure, MODS, blood pressure
(systolic, diastolic, mean), pulse pressure, pulse rate, laboratory
parameters (hemoglobin, white cell and platelet count, INR, serum
values for Na, glucose, lactate, creatinin, bilirubin). Also registered
were length of stay (LOS), duration of mechanical ventilation (MV),
time of intubation (TT) and patient outcome. Haemodynamic
instability was defined as low mean blood pressure and support with
vasoactive and inotrop drugs. Statistical evaluation was performed
using univariate and multivariate logistic regression, Student’s t test
Pearson’s chi-square test and Fisher’s exact statistic were used. Methods Retrospective analysis of prospectively gathered data of
102 patients with SICH treated in our ICU during the past 8 years. On admission the following data were registered: vascular risk
factors (high blood pressure, diabetes mellitus), age, gender,
APACHE II score, GCS, hemorrhage characteristics (location, side,
volume, mass effect), surgical procedure, MODS, blood pressure
(systolic, diastolic, mean), pulse pressure, pulse rate, laboratory
parameters (hemoglobin, white cell and platelet count, INR, serum
values for Na, glucose, lactate, creatinin, bilirubin). Also registered
were length of stay (LOS), duration of mechanical ventilation (MV),
time of intubation (TT) and patient outcome. Haemodynamic
instability was defined as low mean blood pressure and support with
vasoactive and inotrop drugs. Statistical evaluation was performed
using univariate and multivariate logistic regression, Student’s t test
Pearson’s chi-square test and Fisher’s exact statistic were used. Results From the 102 patients (56 men and 48 women) 38
(37.5%) died within the first 30 days, most of them in the first
10 days. Age (OR 13.801, P < 0.04), APACHE II score (OR
1.114, P < 0.008), GCS (OR 2.158, P < 0.002), ICH score (OR
1.183, P < 0.001), FiO2/pO2 (OR 0.996, P < 0.009), haemodynamic
instability (OR 2.340, P < 0.002), fever (OR 1.245, P < 0.002),
and INR (OR 13.801, P < 0.04) were the strongest associated
factors of 30-day mortality. Gender (OR 0.652, P < 0.301), prior
illness (OR 1.070, P < 0.870), MODS (OR 0.978, P < 0.803),
LOS (OR 0.988, P < 0.266), MV (OR 0.994, P < 0.356) and TT
(OR 0.990 P < 0.371) were not associated with mortality. P340 Maintenance of prehospital medical systems due to clinical
advance in acute stroke General Hospital of Eleusis, Athens, Greece Introduction We evaluated the factors that may influence the
outcome of patients with spontaneous intracerebral hemorrhage
(SICH). Critical Care 2007, 11(Suppl 2):P339 (doi: 10.118 P341 Effects of intraaortic balloon counterpulsation on middle
cerebral artery blood flow velocities
A Vakalos, D Setzis, P Doukelis, S Pampori, D Matamis
Papageorgiou General Hospital, Thessaloniki, Greece
Critical Care 2007, 11(Suppl 2):P341 (doi: 10.1186/cc5501) Gram-negative bacteremia is an independent predisposing
factor for critical illness polyneuromyopathy Gram-negative bacteremia is an independent predisposing
factor for critical illness polyneuromyopathy K Kritikos, E Angelopoulos, A Siafaka, M Kontogeorgi,
S Tsikriki, D Kanaloupiti, M Pratikaki, M Poriazi, V Gerovasili,
C Routsi, C Roussos, S Nanas
Medical School, National and Kapodistrian University,
Evangelismos Hospital, Athens, Greece
Critical Care 2007, 11(Suppl 2):P343 (doi: 10.1186/cc5503) Table 1 (abstract P341)
WS vs 1:1
WS vs 1:2
WS vs 1:3
Vmax
P > 0.05
P < 0.01
P < 0.01
Vmean
P > 0.05
P < 0.001
P < 0.001 Introduction Critical illness polyneuromyopathy (CIPM) is a major
clinical problem in the ICU resulting in prolonged ICU stay and
increased morbidity and mortality. Conclusions Left ventricular support with IABP significantly
changed the flow velocity pattern of our patients. The pump
significantly increased the Vmax and the Vmean at the 1:2 and 1:3
settings because of pump inflation during the diastole. We suggest
that the velocities did not change at the 1:1 setting because the
end-diastolic flow velocities reduce during every pulse, according
to pump deflation. Objective To investigate risk factors of CIPM involved, in a general
multidisciplinary ICU. Patients and participants Four hundred and seventy-four (323
males/151 females, age 55 ± 19) consecutively admitted patients
in a 28-bed university multidisciplinary ICU were prospectively
evaluated. All patients were assigned admission APACHE II
(15 ± 7) and SOFA (6 ± 3) scores and were subsequently
evaluated for newly developed neuromuscular weakness. We
examined muscle strength according to the Medical Research
Council scale, deep tendon reflexes, sensory function and muscle
wasting. Laboratory values and medical therapy were recorded
daily. Other potential causes of new-onset generalized weakness
after ICU admission were excluded before the diagnosis of CIPM
was established. Out of the 474 patients, 185 remained in the ICU
for ≥10 days. Effects of intraaortic balloon counterpulsation on middle
cerebral artery blood flow velocities Results In 1,421 ICU patients who were evaluated in 24 studies,
655 (46%) were diagnosed with CINMA. All enrolled patients were
receiving protracted mechanical ventilation, had sepsis, or had
multiple organ failure. Diagnostic criteria for CINMA were hetero-
geneous and few reports explicitly differentiated between the
polyneuropathic, myopathic and mixed types of CINMA. CINMA
was linked in several studies to hyperglycemia, the systemic inflam-
matory response syndrome, sepsis, renal replacement therapy, and
catecholamine administration. In contrast, across studies there was
no consistent relationship between CINMA and patient age,
gender, severity of illness, multiple organ failure, and use of gluco-
corticoids, neuromuscular blockers, aminoglycosides, or midazolam. Mortality was not increased in patients with CINMA, but
mechanical ventilation and ICU and hospital stays were prolonged. Conclusions The risk of CINMA is nearly 50% in a subset of ICU
patients with sepsis, multiorgan failure, or protracted mechanical
ventilation, but there were no data to support CINMA as an
independent predictor of death. The impact of frequently cited risk
factors is uncertain, but emerging data indicate glycemic control
decreases CINMA risk in vulnerable patients. A Vakalos, D Setzis, P Doukelis, S Pampori, D Matamis
Papageorgiou General Hospital, Thessaloniki, Greece
Critical Care 2007, 11(Suppl 2):P341 (doi: 10.1186/cc5501) Introduction The intraaortic balloon pump has been shown to
improve cardiac output and diastolic coronary flow. The aim of our
study was to determine the effects of intraaortic counterpulsation
(IABP) on cerebral blood flow velocities measured on the middle
cerebral artery. Methods
In 11 cardiac surgery patients receiving IABP
postoperatively, blood flow velocities in the middle cerebral artery
were assessed by transcranial Doppler (TCD). In each patient,
measurements of Vmax, Vmean and Vmin were performed at four
different pump settings: without support (WS), and at pump assist
pulse with ratio 1:1, 1:2 and 1:3. p
Results Repeated-measures analysis of variance: P = 0.0006,
considered extremely significant variation of TCD measurements
among IABP settings. Comparing all pairs of Vmax, Vmean and Vmin
values, we found that Vmax and especially Vmean are significantly
greater at the 1:2 and 1:3 pump settings, but not at the 1:1 setting. We also found that the end diastolic velocities (Vmin) were
significant lower during the pump deflation. None of our patients
had a significant diastolic flow velocity reversal during the pump
deflation. Outcome of intensive care unit patients with spontaneous
intracerebral hemorrhage P342
Neuromuscular dysfunction acquired during
a systematic review
R Stevens, D Dowdy, R Michaels, P Mendez-Te
P Pronovost, D Needham
Johns Hopkins University School of Medicine, Ba
Critical Care 2007, 11(Suppl 2):P342 (doi: 10.11
Background Patients with critical illness can ac
of weakness and dependence on mechanical v the delayed admission is through another hospital, not a stroke
center. The patients denied their symptoms are not so rare. The
patients or their family often hesitate to request the emergency car. Conclusions The most significance point for rapid diagnosis and
therapy is that people must doubt ‘stroke’ at first. We should
further educate citizens to the warning signs of stroke and also the
necessity of emergency admission using an emergency car. In
addition, we should justly build a core stroke center in the district
and centralize the patients. the delayed admission is through another hospital, not a stroke
center. The patients denied their symptoms are not so rare. The
patients or their family often hesitate to request the emergency car. the delayed admission is through another hospital, not a stroke
center. The patients denied their symptoms are not so rare. The
patients or their family often hesitate to request the emergency car. been linked to peripheral nerve and muscle injury. Our aim was to
systematically review published data on the diagnosis, risk factors
and outcomes of patients with critical illness neuromuscular
abnormalities (CINMA). Conclusions The most significance point for rapid diagnosis and
therapy is that people must doubt ‘stroke’ at first. We should
further educate citizens to the warning signs of stroke and also the
necessity of emergency admission using an emergency car. In
addition, we should justly build a core stroke center in the district
and centralize the patients. Methods MEDLINE, EMBASE, CINAHL, and the Cochrane Library
were searched, and studies were included if they reported on ICU
patients > 16 years old who were evaluated for CINMA clinically
and electrophysiologically, and they contained sufficient data to
quantitatively measure the association between CINMA and
clinically relevant exposures and/or outcomes. Two reviewers
independently extracted data on study methodology and quality,
methods for diagnosing CINMA, and CINMA prevalence, risk
factors, and outcomes. Outcome of intensive care unit patients with spontaneous
intracerebral hemorrhage Outcome of intensive care unit patients with spontaneous
intracerebral hemorrhage Results Two hundred and forty-one patients (21.7%) were
hospitalized within 3 hours from the onset, and 365 patients
(32.9%) were within 6 hours. Among them, only 438 were admitted
by ambulance. We found the following results. The main reason for Introduction We evaluated the factors that may influence the
outcome of patients with spontaneous intracerebral hemorrhage
(SICH). S137 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin the delayed admission is through another hosp
center. The patients denied their symptoms are
patients or their family often hesitate to request the
Conclusions The most significance point for ra
therapy is that people must doubt ‘stroke’ at
further educate citizens to the warning signs of s
necessity of emergency admission using an e
addition, we should justly build a core stroke ce
and centralize the patients. P341
Effects of intraaortic balloon counterpulsati
cerebral artery blood flow velocities
A Vakalos, D Setzis, P Doukelis, S Pampori, D
Papageorgiou General Hospital, Thessaloniki, Gre
Critical Care 2007, 11(Suppl 2):P341 (doi: 10.11
Introduction The intraaortic balloon pump has
improve cardiac output and diastolic coronary flo
study was to determine the effects of intraaortic
(IABP) on cerebral blood flow velocities measu
cerebral artery. Methods
In 11 cardiac surgery patients
postoperatively, blood flow velocities in the midd
were assessed by transcranial Doppler (TCD)
measurements of Vmax, Vmean and Vmin were p
different pump settings: without support (WS), a
pulse with ratio 1:1, 1:2 and 1:3. Results Repeated-measures analysis of varian
considered extremely significant variation of TC
among IABP settings. Comparing all pairs of Vm
values, we found that Vmax and especially Vmea
greater at the 1:2 and 1:3 pump settings, but not
We also found that the end diastolic veloc
significant lower during the pump deflation. No
had a significant diastolic flow velocity reversal
deflation. Table 1 (abstract P341)
WS vs 1:1
WS vs 1:2
Vmax
P > 0.05
P < 0.01
Vmean
P > 0.05
P < 0.001
Conclusions Left ventricular support with I
changed the flow velocity pattern of our pa
significantly increased the Vmax and the Vmean a
settings because of pump inflation during the dia
that the velocities did not change at the 1:1 se
end-diastolic flow velocities reduce during every
to pump deflation. P344 Introduction The objective was to determine the relationship of
early hypothermia to multiple organ failure and mortality in severely
injured trauma patients. Interhospital cooperation after critical and emergency care
for patients with cervical–thoracic–abdominal trauma and
emergency diseases in the local medical area in a typical
urban city of Japan Methods This prospective observational study was performed at
seven Level I trauma centers over 16 months. Severely injured
patients with hypoperfusion and a need for blood transfusion
during the early hospital course were followed with near-infrared
spectroscopy-derived tissue oxygen saturation (StO2) and clinical
variables. Outcomes including multiple organ dysfunction syn-
drome (MODS) and 28-day mortality were evaluated. Hypothermia
was defined as temperature < 35°C within the first 6 hours. Y Moriwaki, M Sugiyama, S Arata, N Harunari, H Manaka,
T Katsumura, T Yamada, N Suzuki
Yokohama City University Medical Center, Yokohama, Japan
Critical Care 2007, 11(Suppl 2):P344 (doi: 10.1186/cc5504) Background Capacity of the critical care and emergency center
(CCEC) is usually restricted. Transfer of patients from CCEC is
one of the most important issues in the CCEC. p
Results Hypothermia was common (43%, 155/359). Hypothermic
patients were more likely than normothermic patients to develop
MODS (21% vs 9%, P = 0.003), but did not have increased
mortality rates (16% vs 12%, P = 0.28). The maximum base deficit
(Max BD) in hypothermic patients did not discriminate between
those who did or did not develop MODS (9.8 ± 4.6 mEq/l vs
9.4 ± 4.4 mEq/l, P = 0.56) but had good discrimination for
mortality in both hypothermic and normothermic patients. Significant
predictors of MODS using multivariate analysis included minimum
StO2 (P = 0.0002) and hypothermia (P = 0.01), but not Max BD
(P = 0.09). Predictors for mortality with multivariate analysis
included minimum StO2 (P = 0.0004) and Max BD (P = 0.01), but
not hypothermia (P = 0.74). Hypothermia remained a significant
risk factor for MODS when fluid/blood infusion volumes were
included in the multivariate model. Subjects and methods We examined interhospital cooperation
after critical and emergency care for life-threatening cervical–
thoracic–abdominal trauma (n = 501) and thoracoabdominal
emergency diseases (n = 236) who were treated with intensive
care in our CCEC and were able to be discharged or transferred to
another acute treatment hospital. P345 CIPM had a higher admission APACHE II score (18.9 ± 6.6 vs
15.6 ± 6.4, P = 0.004) and SOFA score (8.4 ± 2.9 vs 7.1 ± 2.9,
P = 0.013). Multivariate logistic regression analysis showed that
risk factors independently associated with the development of
CIPM were severity of illness at the time of admission to the ICU,
administration of aminoglycoside antibiotics and high blood
glucose levels. Analysis according to severity of illness stratifica-
tion revealed the emergence of Gram-negative bacteremia as the
most important independent predisposing factor for CIPM
development in less severely ill patients. Early hypothermia in severely injured trauma patients is a
significant risk factor for multiple organ dysfunction
syndrome but not mortality G Beilman1, T Nelson2, A Nathens3, F Moore4, P Rhee5,
J Puyana6, E Moore7, S Cohn8
1University of Minnesota, Minneapolis, MN, USA; 2Princeton
Reimbursement Group, Minneapolis, MN, USA; 3St Michaels
Hospital, Toronto, Canada; 4University of Texas–Houston,
Houston, TX, USA; 5University of Southern California, San Diego,
CA, USA; 6University of Pittsburgh, PA, USA; 7University of
Colorado, Denver, CO, USA; 8University of Texas, San Antonio,
TX, USA
Critical Care 2007 11(Suppl 2):P345 (doi: 10 1186/cc5505) Conclusions CIPM has a high incidence in the ICU setting. Our
study revealed the important association that Gram-negative
bacteremia, aminoglycosides, hyperglycemia and severity of illness
have with CIPM development. al Care 2007, 11(Suppl 2):P345 (doi: 10.1186/cc5505) P342 Neuromuscular dysfunction acquired during critical illness:
a systematic review R Stevens, D Dowdy, R Michaels, P Mendez-Tellez,
P Pronovost, D Needham
Johns Hopkins University School of Medicine, Baltimore, MD, USA
Critical Care 2007, 11(Suppl 2):P342 (doi: 10.1186/cc5502) Background Patients with critical illness can acquire a syndrome
of weakness and dependence on mechanical ventilation that has Results Forty-four (23.8%) out of those 185 patients developed
generalized weakness that met the criteria for CIPM. Patients with S138 Available online http://ccforum.com/supplements/11/S2 P344 Results Of the trauma patients directly transferred to our center,
48% were transferred to the ‘affiliated hospitals’, whose medical
staffs were dispatched from the ‘departments’ in our university,
17% were transferred to the nonaffiliated hospitals, and 34% were
directly discharged from our center. Of emergency disease
patients, 28% were transferred to the affiliated hospitals, 20%
were transferred to other hospitals, and 52% were directly
discharged. Patients staying in our center for more than 14 days
tended to be transferred to the affiliated hospital. Of trauma
patients indirectly transferred from other hospital to our center,
30% and 11% were transferred to the affiliated and nonaffiliated
hospitals, and 19% were directly discharged. Of emergency
disease patients, these values were 21%, 7%, and 13%,
respectively. Patients staying in our center for more than 14 days
tended to be transferred to the affiliated hospital. Conclusions Hypothermia is common in severely injured trauma
patients and is a risk factor for MODS but not mortality. Minimum
StO2
predicts MODS and mortality in normothermic and
hypothermic patients, while the predictive effect of BD for MODS
is blunted in the presence of hypothermia. The nonlactate gap: a novel predictor of organ failure and
mortality following major trauma The nonlactate gap: a novel predictor of organ failure and
mortality following major trauma Discussion and conclusion These results are thought to be a
common situation in a typical urban city in the world. Now, the
interhospital cooperation between city hospital and referral hospital
does not function well because of poor understanding of re-
transfer to the previous hospital, resulting in dysfunction of the
management of critical patients in the local medical area. It is
important to construct a new interhospital-cooperation system
based on the local medical area. S Robertson1, E Dickson2, G Richards1
1Johannesburg Hospital, Johannesburg, South Africa;
2Royal Glasgow Infirmary, Glasgow, UK
Critical Care 2007, 11(Suppl 2):P346 (doi: 10.1186/cc5506) y
g
y,
g
,
Critical Care 2007, 11(Suppl 2):P346 (doi: 10.1186/cc Introduction Early identification of patients who are not fully
resuscitated following major trauma improves outcome. However,
current markers of clinically occult hypoperfusion, such as lactate
and base deficit, have serious limitations, and our aim was to
establish a new endpoint of resuscitation. Methods In a prospective study conducted in a Level 1 trauma
unit, 49 consecutive patients admitted to the trauma ICU were
evaluated. Serum electrolytes, albumin, phosphate and lactate S139 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusion The combination of prehospital and emergency
department systolic blood pressure is a simple yet extremely
powerful predictor of mortality following major trauma and should
be used as a triage tool to rapidly identify the highest risk patients. were measured on admission. We derived the calculated ion gap
using a simplified Stewart–Figge equation, and subtracted the
measured serum lactate from the calculated ion gap to obtain the
nonlactate gap (NLG). Results See Table 1. The NLG discriminated survivors from non-
survivors (P = 0.008, analysis of variance). An NLG above 2 mmol/l
was associated with an increased risk of mortality (P = 0.010,
Fisher’s exact test). No patient with an NLG less than 2 mmol/l
died; 32.4% of the patients with an NLG above 2 mmol/l died. A
NLG above 2 mmol/l also correlated strongly with organ failure
(Multiple Organ Dysfunction Syndrome score P = 0.011, Sequen-
tial Organ Failure Assessment score P = 0.011, Mann–Whitney U
test). E Charalambous1, S Manousakis1, A Kapasaki1, C Chronaki2,
G Vrouchos1
1Venizelio General Hospital of Heraklion, Greece; 2ICS-FORTH,
Heraklion, Greece
Critical Care 2007, 11(Suppl 2):P348 (doi: 10.1186/cc5508) Table 1 (abstract P346)
Survived
Died
Total
NLG < 2 mmol/l
15 (39.5%)
0 (0%)
15 (30.6%)
NLG > 2 mmol/l
23 (60.5%)
11 (100%)
34 (69.4%)
Total
38 (100%)
11 (100%)
49 (100%) Introduction Blunt chest trauma is often accompanied by traumatic
cardiac injury (TCI), formerly called cardiac contusion. Severe TCI
can affect the prognosis of chest trauma patients due to cardiac
arrhythmias, heart failure, or cardiac tamponade. The objective of
this study was the detection and evaluation of TCI in chest trauma. Introduction Blunt chest trauma is often accompanied by traumatic
cardiac injury (TCI), formerly called cardiac contusion. Severe TCI
can affect the prognosis of chest trauma patients due to cardiac
arrhythmias, heart failure, or cardiac tamponade. The objective of
this study was the detection and evaluation of TCI in chest trauma. Methods
Twenty-seven consecutive patients without cardiac
disease history (five females), mean age 37.2 years (63% <35 years)
were admitted to the ICU with blunt chest trauma. Five patients had
minor head brain injury. The majority needed mechanical ventilation
support. The mean Injury Severity Score (ISS) was 21.1 (11–34). The following injuries/lesions of thorax or lung parenchyma were
identified on chest and abdominal CT scan: fractures of clavicle,
sternum, ribs, scapula or vertebral column, lung contusion,
hemo/pneumothorax, hemo/pneumomediastinum, abdominal organ
injury. TCI diagnosis was based on auscultation findings (pericardial
friction rub, new cardiac murmurs), electrocardiogram (ECG)
findings (ST–T disturbances, arrhythmias), cardiac enzymes (CE)
(cardiac Tropinin I, CK-MB), transthoracic echocardiography (TTE)
(wall motion abnormalities (WMA), reduced left ventricular ejection
fraction (LVEF) pericardial effusion (PE)), and thorax CT findings. Results Twenty-two out of 27 patients (81%) exhibited at least
one sign of TCI, 17/27 (63%) had more than two signs: ECG
changes (18/22, 81.8%), mostly ST–T disturbances of left
precordial or inferior leads, slight CE increase (17/22, 72%), PE in
TTE or CT (12/22, 54,5%), WMA, mostly of the interventricular
septum wall (6/22, 27%), reduced LVEF (5/22, 23%), or
pericardial friction rub (5/22, 23%). Patients with TCI signs had
more frequently bilateral or right-sided hemothorax (16/22, 72%),
bilateral lung contusion (15/22, 68%), right-sided rib fracture
(15/22, 68%), abdominal organ injury (spleen, left kidney/adrenal,
liver) (14/22, 63%) or right-sided pneumothorax (13/22, 59%). Two patients (one with flail chest) exhibited PE leading to cardiac
tamponade. Pericardiocentesis was performed with success. None
of the patients had severe ventricular arrhythmia. Five young
patients had mildly reduced LVEF, in almost all cases transient. E Charalambous1, S Manousakis1, A Kapasaki1, C Chronaki2,
G Vrouchos1
1Venizelio General Hospital of Heraklion, Greece; 2ICS-FORTH,
Heraklion, Greece
Critical Care 2007, 11(Suppl 2):P348 (doi: 10.1186/cc5508) There was a positive correlation between ISS and TCI severity. C
l
i
TCI i
f
i
bl
h
Addi i
l cardiac injury (TCI), formerly called cardiac contusion. Severe TCI
can affect the prognosis of chest trauma patients due to cardiac
arrhythmias, heart failure, or cardiac tamponade. The objective of
this study was the detection and evaluation of TCI in chest trauma. Methods
Twenty-seven consecutive patients without cardiac
disease history (five females), mean age 37.2 years (63% <35 years)
were admitted to the ICU with blunt chest trauma. Five patients had
minor head brain injury. The majority needed mechanical ventilation
support. The mean Injury Severity Score (ISS) was 21.1 (11–34). The following injuries/lesions of thorax or lung parenchyma were
identified on chest and abdominal CT scan: fractures of clavicle,
sternum, ribs, scapula or vertebral column, lung contusion,
hemo/pneumothorax, hemo/pneumomediastinum, abdominal organ
injury. TCI diagnosis was based on auscultation findings (pericardial
friction rub, new cardiac murmurs), electrocardiogram (ECG)
findings (ST–T disturbances, arrhythmias), cardiac enzymes (CE)
(cardiac Tropinin I, CK-MB), transthoracic echocardiography (TTE)
(wall motion abnormalities (WMA), reduced left ventricular ejection
fraction (LVEF) pericardial effusion (PE)), and thorax CT findings. Conclusions We describe the NLG for the first time, and quantify
it using simple bedside calculations derived from routine blood
investigations. The NLG is an excellent marker for organ failure and
death following major injury, and should be used to guide trauma
resuscitation. Traumatic cardiac injury in chest trauma E Charalambous1, S Manousakis1, A Kapasaki1, C Chronaki2,
G Vrouchos1
1Venizelio General Hospital of Heraklion, Greece; 2ICS-FORTH,
Heraklion, Greece
Critical Care 2007, 11(Suppl 2):P348 (doi: 10.1186/cc5508) P347 Prehospital hypotension that persists on arrival at the
emergency department is a powerful predictor of mortality
following major trauma E Dickson, S Robertson, D Van Niekerk, J Goosen, F Plani,
K Boffard
Johannesburg Hospital Trauma Unit and University of the
Witwatersrand, Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P347 (doi: 10.1186/cc5507) Results Twenty-two out of 27 patients (81%) exhibited at least
one sign of TCI, 17/27 (63%) had more than two signs: ECG
changes (18/22, 81.8%), mostly ST–T disturbances of left
precordial or inferior leads, slight CE increase (17/22, 72%), PE in
TTE or CT (12/22, 54,5%), WMA, mostly of the interventricular
septum wall (6/22, 27%), reduced LVEF (5/22, 23%), or
pericardial friction rub (5/22, 23%). Patients with TCI signs had
more frequently bilateral or right-sided hemothorax (16/22, 72%),
bilateral lung contusion (15/22, 68%), right-sided rib fracture
(15/22, 68%), abdominal organ injury (spleen, left kidney/adrenal,
liver) (14/22, 63%) or right-sided pneumothorax (13/22, 59%). Two patients (one with flail chest) exhibited PE leading to cardiac
tamponade. Pericardiocentesis was performed with success. None
of the patients had severe ventricular arrhythmia. Five young
patients had mildly reduced LVEF, in almost all cases transient. There was a positive correlation between ISS and TCI severity. Objective Outcome following major injury is time dependent. Early
identification of high-risk patients allows rapid decision-making and
correction of life-threatening disorders. Complex scoring systems
are of limited value during major trauma resuscitation. Our aim was
to evaluate the utility of a single blood pressure during the
prehospital phase in combination with the blood pressure on arrival
at the emergency department. Methods Data were collected prospectively on 1,111 patients
admitted to a Level 1 South African trauma unit over a 1-year
period. Patients were subdivided into two groups according to the
combination of their prehospital (PH) and emergency department
(ED) blood pressure. Hypotension was defined as a systolic blood
pressure less than 90 mmHg. Mortality was defined as death within
30 days. Conclusions TCI is frequent in blunt chest trauma. Additional
ECG findings and an increase in CE suggest possible TCI to be
confirmed by a bedside TTE study. TCI usually accompanies
bilateral hemothorax, lung contusion, or right-sided rib fracture. Results The mortality in patients (n = 1,031) with normal PH and
ED blood pressure was 5.4%. The mortality in patients (n = 80)
with PH and ED hypotension was significantly higher at 45%
(P < 0.0001, chi-square test) (Table 1). P349 P350
Full-body low-dosage X-ray instead of single X-ray serie
in trauma: a preliminary experience report of a modified
advanced trauma life support algorithm
A Exadaktylos, H Brunner, L Martinolli, L Benneker, F Gatter
R Soyka, H Bonel, H Zimmermann
Inselspital Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P350 (doi: 10.1186/cc5510)
Introduction Patients presenting with trauma normally req
resuscitation according to the advanced trauma life support (AT
algorithm. Techniques suggested during primary survey include
ray of C-spine, chest and pelvis. This can be time consuming a
radiation intensive. In comparison with conventional mult
radiographs, Lodox (Statscan), a full-body digital radiology dev
performs a.p. and lateral whole-body examinations in 3–5 minu
with about one-third of the irradiation and without the necessity
lifting patients. This is the first device installed in Europe. Methods This paper describes our experience with the use o implementing LODOX (median time 27 min to 24 min). In 54/94
patients an additional full body CT scan was performed as adjunct
to secondary survey. In only 14/54 patients were additional
conventional X-rays necessary to visualize the skeleton. Conclusion The implementation of a modified ATLS algorithm using
LODOX allows a complete a.p. and lateral whole-body examination
without a significant increase in the time taken for resuscitation. Since we are at the very beginning of a learning curve we are
confident that in future the time for the ATLS primary survey can be
markedly reduced. The LS imaging system seems to be a useful
tool for rapid screening and management of trauma patients. implementing LODOX (median time 27 min to 24 min). In 54/94
patients an additional full body CT scan was performed as adjunct
to secondary survey. In only 14/54 patients were additional
conventional X-rays necessary to visualize the skeleton. extravasation site computed tomography (CT). In this study we
investigated the site and extent of contrast medium extravasation
on CT findings and its effect on treatment and predicting clinical
outcome in trauma patients. Conclusion The implementation of a modified ATLS algorithm using
LODOX allows a complete a.p. and lateral whole-body examination
without a significant increase in the time taken for resuscitation. Since we are at the very beginning of a learning curve we are
confident that in future the time for the ATLS primary survey can be
markedly reduced. The LS imaging system seems to be a useful
tool for rapid screening and management of trauma patients. P351 Results The incidence of extravasation site was intraperitoneal in 33
cases (66%), retroperitoneal in 13 cases (26%), and intrapelvic in
four cases (8%). The frequency of injured vessels showing
extravasation was 18 (36%) hepatic vessels, nine (18%) splenic
vessels and six (12%) iliac vessels. There was no correlation between
the extravasation site and ICU or total hospitalization duration
(P > 0.523). Sixteen patients with intraperitoneal extravasation
required surgical intervention, six patients underwent angiography
with embolization. In patients with retroperitoneal extravasation, nine
were treated conservatively and two with embolization. Over all there
were no significant differences between the extravasation site and
treatment modality. The intraperitoneal group had the highest mortality
with 13 deaths (11/33, 39%) and the highest early mortality rate
(10/13, 76%) in the first 24 hours (P = 0.001). Peripheral oxygen extraction predicts organ failure and
mortality following major trauma Peripheral oxygen extraction predicts organ failure and
mortality following major trauma S Robertson1, E Dickson2, G Richards1
1Johannesburg Hospital, Johannesburg, South Africa;
2Royal Glasgow Infirmary, Glasgow, UK
Critical Care 2007, 11(Suppl 2):P351 (doi: 10.1186/cc5511) ritical Care 2007, 11(Suppl 2):P351 (doi: 10.1186/cc55 Introduction Current markers of occult hypoperfusion following
major trauma have serious limitations. Our aim was to evaluate
oxygen extraction as a resuscitation endpoint, and predictor of
organ failure and mortality following trauma. Methods A prospective, noninterventional study of 39 consecutive
patients admitted to a Level 1 trauma unit ICU. Blood gas analysis
was performed on samples from three locations: central venous
line, peripheral venous line, and arterial line. Blood was drawn 6-
hourly in the first 24 hours, and oxygen extraction calculated using
the Fick equation. Organ failure was assessed using MODS and
SOFA scores. Conclusion CT findings in patients with blunt abdominal trauma
showed no significant correlation between the contrast medium
extravasation site and treatment modality, ICU hospitalization
duration, or final results. However, patients with intraperitoneal
extravasation required more aggressive transfusion with packed
red cells and had a higher mortality rate in the first 24 hours. Results See Table 1. Peripheral, but not central, oxygen extraction
with a threshold of 150 ml oxygen extracted per litre of blood
distinguished survivors from nonsurvivors on admission to the trauma
ICU. Low peripheral oxygen extraction (<150 ml) had an odds ratio
for risk of death of 5.3 (P = 0.016, Fisher’s exact test) and was
associated with higher organ failure scores (P = 0.044, Mann–
Whitney U test). A trend of increasing peripheral oxygen extraction
was also a strong predictor of mortality (P = 0.019, Mann–Whitney U
test) and organ failure (P = 0.003, Mann–Whitney U test). P350 Full-body low-dosage X-ray instead of single X-ray series
in trauma: a preliminary experience report of a modified
advanced trauma life support algorithm A Exadaktylos, H Brunner, L Martinolli, L Benneker, F Gatterer,
R Soyka, H Bonel, H Zimmermann
Inselspital Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P350 (doi: 10.1186/cc5510) Table 1 (abstract P351)
Survived
Died
Total
Extract < 150 ml
8
6
14
Extract > 150 ml
23
2
25
Total
31
8
39 Introduction Patients presenting with trauma normally require
resuscitation according to the advanced trauma life support (ATLS)
algorithm. Techniques suggested during primary survey include X-
ray of C-spine, chest and pelvis. This can be time consuming and
radiation intensive. In comparison with conventional multiple
radiographs, Lodox (Statscan), a full-body digital radiology device,
performs a.p. and lateral whole-body examinations in 3–5 minutes
with about one-third of the irradiation and without the necessity for
lifting patients. This is the first device installed in Europe. Conclusions With an arterial and venous blood sample, and a
simple equation, we have for the first time demonstrated that
absolute and serial peripheral oxygen extraction are powerful
predictors of organ failure and mortality following major injury. Methods This paper describes our experience with the use of a
new low-dose X-ray technique as part of our modified ATLS
algorithm, where single–total a.p./lateral body radiographs have
been implemented as adjuncts to primary survey in favour of
several conventional X-rays. P349 Methods Fifty patients admitted to our emergency department
with blunt abdominal trauma showing contrast medium extravasa-
tion on abdominal–pelvic CT scan were included in our study for
33 months. Patients were prospectively collected and medical
records were reviewed and analyzed retrospectively. The patients’
clinical and laboratory findings, abdominal sonographic (FAST)
findings, and CT findings were reviewed. Extravasation sites were
classified as intraperitoneal, retroperitoneal, intrapelvic and correlated
with post-treatment complications, mortality and morbidity rates. P349 Prognosis of blunt abdominal trauma patients with contrast
medium extravasation on computed tomography scan K Lee, H Shin
Wonju Medical College, Wonju, Republic of Korea
Critical Care 2007, 11(Suppl 2):P349 (doi: 10.1186/cc5509) Table 1 (abstract P347)
SBP < 90 mmHg
SBP > 90 mmHg
Alive
55.0% (n = 44)
94.6% (n = 975)
Dead
45.0% (n = 36)
5.4% (n = 56) Introduction Until now there have been few studies concentrating
on the diagnostic and prognostic significance of contrast medium S140 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 extravasation site computed tomography (CT). In this study
investigated the site and extent of contrast medium extravasat
on CT findings and its effect on treatment and predicting clin
outcome in trauma patients. Methods Fifty patients admitted to our emergency departm
with blunt abdominal trauma showing contrast medium extrava
tion on abdominal–pelvic CT scan were included in our study
33 months. Patients were prospectively collected and med
records were reviewed and analyzed retrospectively. The patie
clinical and laboratory findings, abdominal sonographic (FA
findings, and CT findings were reviewed. Extravasation sites w
classified as intraperitoneal, retroperitoneal, intrapelvic and correla
with post-treatment complications, mortality and morbidity rates. Results The incidence of extravasation site was intraperitoneal in
cases (66%), retroperitoneal in 13 cases (26%), and intrapelvic
four cases (8%). The frequency of injured vessels show
extravasation was 18 (36%) hepatic vessels, nine (18%) sple
vessels and six (12%) iliac vessels. There was no correlation betw
the extravasation site and ICU or total hospitalization dura
(P > 0.523). Sixteen patients with intraperitoneal extravasa
required surgical intervention, six patients underwent angiogra
with embolization. In patients with retroperitoneal extravasation, n
were treated conservatively and two with embolization. Over all th
were no significant differences between the extravasation site
treatment modality. The intraperitoneal group had the highest morta
with 13 deaths (11/33, 39%) and the highest early mortality
(10/13, 76%) in the first 24 hours (P = 0.001). Conclusion CT findings in patients with blunt abdominal trau
showed no significant correlation between the contrast med
extravasation site and treatment modality, ICU hospitalizat
duration, or final results. However, patients with intraperiton
extravasation required more aggressive transfusion with pac
red cells and had a higher mortality rate in the first 24 hours. P352 Damage control orthopedics can improve outcome in
trauma patients
A Di Filippo, A Circelli, G Cianchi, A Peris
Anesthesia and Intensive Care Unit, Florence, Italy
Critical Care 2007, 11(Suppl 2):P352 (doi: 10.1186/cc5512) Damage control orthopedics can improve outcome in
trauma patients Results There were 94 patients (males = 59; females = 35)
between 4 October and 9 December 2006; age range from 1 to
86 years. The ISS ranged from 3 to 75 (ISS > 16 in 54/94
patients). The average time for obtaining LODOX radiographs was
3.5 minutes (range 3–6 min). The mean time in the resuscitation
room (during primary and secondary surveys) was 28.7 minutes
with the new technique compared with 29 minutes before S141
Introduction Damage control orthopedics (DCO) is a reviewed
concept used in major trauma. Advances in critical care Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin management enable surgical stabilization in the early phase of
trauma care. Logistical organization and accessibility to several
therapeutic solutions can influence a physician’s decisions
regarding a trauma patient. The aim of this study is to investigate
whether the timing of surgery and method of stabilization in trauma
patients with femoral fracture can influence the incidence of
pulmonary complication, MOF and the length of stay in the ICU. two groups: group 1 (n = 27), brain death occurred in the first
3 days; group 2 (n = 27), brain death occurred in the days after. Statistics were determined with the Student t and chi-squared
tests; P < 0.05 was considered significant. Results The significant differences between the two groups are
reported in Table 1. A strict relationship exists between early brain
death and prehospital treatment. During the ICU stay low levels of
ScVO2 and high levels of glycaemia are related to early brain
death. Method In a retrospective study performed at a Level I trauma
center, we considered all adult patients with major trauma (ISS
> 15) and femoral shaft fracture admitted between January 2003
and July 2006. Patients were separated into two groups according
to the management strategies for the femoral fracture: group 1, no
surgery within 72 hours after primary admission; group 2, surgical
stabilization within 72 hours (DCO). To compare the two groups
we considered age, ISS, RTS, TRISS, SAPS II, GCS, comorbidity,
and other associated surgery. Table 1 (abstract P353) Results We identified 48 patients, 24 for each group. The groups
were comparable regarding all the considered parameters except
for GCS at admission (group 1, 8.63 ± 5.12; group 2, 12.2 ± 3.99;
P = 0.01) and TRISS (group 1, 62.04 ± 34.55%; group 2,
82.37 ± 18.60%; P = 0.01). We observed in group 2 a significant
decrease of mortality (5 vs 0; P = 0.02), incidence of ALI–ARDS
(13 vs 4; P = 0.01) and pneumonia (18 vs 6; P = 0.01), a
decrease of SOFA score (mean SOFA score: 7.58 ± 4.11 vs
3.97 ± 2.39, P < 0.001; maximum SOFA score: 9.83 ± 4.36 vs
5.62 ± 2.97, P < 0.001; days with SOFA >6: 3.79 ± 3.08 vs
2.16 ± 2.18, P = 0.04). Conclusion The results of the study confirm that prehospital
hypotension is the main risk factor for an early evolution to brain
death in head trauma. Also, patients that have prolonged
hypoperfusion
and
neurohormonal
imbalance
after
the
postresuscitation phase present an increased risk of brain death. P354 P354
Sensitivity and specificity of a triage score dedicated to
trauma patients in a tertiary-level hospital: preliminary
results
P Masturzo1, R Regolo1, G Ferro2, G Nardi3, D Orazi2, V Maggi2
1Seconda Università, Napoli, Italy; 2San Camillo Forlanini, Roma,
Italy; 3Ospedale S. Camillo-Forlanini, Roma, Italy
Critical Care 2007, 11(Suppl 2):P354 (doi: 10.1186/cc5514) Sensitivity and specificity of a triage score dedicated to
trauma patients in a tertiary-level hospital: preliminary
results Conclusions
We observed an improvement of respiratory
parameters and SOFA score in patients treated with DCO. Furthermore, patients with worse neurological conditions at
admission do not undergo orthopaedic surgery because it could
worsen the cerebral perfusion (risk related to transfer to a far
operating room). The physician’s decisions (and therefore the
patient’s prognosis), in our experience, are limited by access to
optimal therapeutic solutions that could improve the clinical course
of the patient. P Masturzo1, R Regolo1, G Ferro2, G Nardi3, D Orazi2, V Maggi2
1Seconda Università, Napoli, Italy; 2San Camillo Forlanini, Roma,
Italy; 3Ospedale S. Camillo-Forlanini, Roma, Italy
Critical Care 2007, 11(Suppl 2):P354 (doi: 10.1186/cc5514) Introduction The aim of the study was to determine the sensitivity
and specificity of the triage criteria adopted for multiple trauma
patients in order to activate the Trauma Team in our tertiary-level
trauma centre. P353 Methods A cohort study. Between 1 September and 30 November
2006, all trauma patients admitted to the ED triaged red, yellow or
green on admission and discharged as a red code from the ED
following specific criteria were included. Triage criteria on
admission included at least one of the following: GCS < 13,
systolic BP > 220 and < 100 mmHg, SaO2 < 95% on oxygen
100% or intubated; clinical signs: penetrating wounds, spinal
injury, sternal or flail chest, two long-bone fractures, proximal crash
or amputation of limbs, post-traumatic seizures at any time, signs of
fracture of the skull; major accident mechanics: fatality in the same
vehicle, fall from a height >3 m, prolonged extrication time
(>20 min), pedestrian hit by a car, ejection, explosion in a close
environment. Severely injured patients at discharge from the ED
were defined by: invasive resuscitating procedures (that is,
tracheal intubation), invasive life-saving procedures (emergency
surgery, defibrillation) and need for admission to the ICU. Sensitivity and specificity of the triage criteria assigned on
admission were calculated and compared with the patients that
were triaged red at discharge from ED. Head trauma: risk factors for early brain death – our
experience P352 Parameters of evaluation were:
mortality in the ICU, ICU length of stay, respiratory failure and
length of ventilation, and daily SOFA collected for 8 days. Statistics were determined with the Student t and chi-squared
tests; P < 0.05 was considered significant. Table 1 (abstract P353)
Group 1 (n = 27)
Group 2 (n = 27)
P
Prehospital
Hypotension
22
13
<0.05
ICU stay
Glycaemia
170.8 ± 49.5
116.6 ± 24.4
<0.05
ScVO2 < 75%
15
7
<0.05 Table 1 (abstract P353)
Group 1 (n = 27)
Group 2 (n = 27)
P
Prehospital
Hypotension
22
13
<0.05
ICU stay
Glycaemia
170.8 ± 49.5
116.6 ± 24.4
<0.05
ScVO2 < 75%
15
7
<0.05 P355 Method
Female pigs, 25–30 kg body weight, were used. Retrograde catheterization of the internal jugular vein (SjO2) and
laparotomy was performed. A surgical knot 4 mm long was made
at the aorta, with a 3.0 diameter stitch. The abdomen was closed. Then a craniotomy and traumatic brain injury (TBI) was made. A
regional cerebral blood flow catheter (RoCBF) was placed under
the dura. After the TBI the intraabdominal hemorrhage was made
by pulling the titch (rupture of the aorta). The animals were
assigned into two groups: group A (fluid resuscitation) and group
B (hypotensive resuscitation). The animals that survived after 1
hour of hemorrhage were managed by surgical checking and with
1 hour more of fluid resuscitation. P357 Hyperoxemia improves cerebral autoregulation in severe
traumatic brain injury
R Celis, R Hlatky, C Robertson
Baylor College of Medicine, Houston, TX, USA
Critical Care 2007, 11(Suppl 2):P357 (doi: 10.1186/cc517) Head trauma: risk factors for early brain death – our
experience Out of the 76 triaged red on
admission, 53 patients were confirmed at discharge from ED. The
specificity is 70%. P356 p
y
Conclusions Even if major accident mechanics were included in
the admission triage criteria, overtriage was limited to 30%. On the
other hand, undertriage was approximate to zero, and the only two
yellow codes missed were related to miscommunication by the
prehospital team. Introduction
We
examined
the
efficacy
of
hypotensive
resuscitation, compared with fluid resuscitation, in patients with
closed abdominal trauma and coexisting severe head injury. Introduction
We
examined
the
efficacy
of
hypotensive
resuscitation, compared with fluid resuscitation, in patients with
closed abdominal trauma and coexisting severe head injury. Conjunctival and sublingual microcirculation alterations in
head trauma patients with increased intracranial pressure B Atasever, D Gommers, J Bakker
Erasmus Medical Center Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P355 (doi: 10.1186/cc5515) B Atasever, D Gommers, J Bakker
Erasmus Medical Center Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P355 (doi: 10.1186/cc5515) Introduction Both the conjunctiva and the sublingual tissue have a
common blood supply via the common carotid artery trunk. Moreover, the conjunctiva receives blood from the internal carotid
artery and the sublingual tissue receives from the external carotid
artery. We hypothesized that conjunctival and sublingual
microcirculation can be used to evaluate intracranial and
extracranial perfusion and to monitor therapy to improve cerebral
perfusion pressure in patients after head trauma. Results See Table 1: RoCBF and SjO2 before and after the
surgical checking of the hemorrhage. Conclusion In group B there was complete restoration of cerebral
blood flow and brain oxygenation, after the surgical checking of
hemorrhage. Hypotensive
resuscitation
causes
significant
reduction in mortality in patients with closed intraabdominal trauma
and coexisting head injury, without putting cerebral function in
jeopardy. Methods In three groups of patients with increased intracranial
pressure (ICP) (high ICP > 30, medium ICP 20–30 and low ICP
< 20) following head trauma, both the conjunctival and sublingual
microcirculation was measured using sidestream darkfield imaging
(MicroScan®; MicroVision Medical, The Netherlands) to evaluate
intracranial and extracranial perfusion. Using microvascular analysis
software (MAS®; MicroVision Medical), functional density of small
(<20 µm), medium (20–50 µm) and large (>50 µm) microvessels
were determined in addition to erythrocyte velocities. Head trauma: risk factors for early brain death – our
experience Head trauma: risk factors for early brain death – our
experience A Di Filippo1, S Damiani1, M Migliaccio1, M Bonizzoli2, A Peris3
1Anesthesia and Intensive Care Unit, Florence, Italy; 2Careggi
Hospital, Florence, Italy; 3Ospedale Firenze, Florence, Italy
Critical Care 2007, 11(Suppl 2):P353 (doi: 10.1186/cc5513) Introduction In a group of patients that evolved in brain death after
head trauma, we evaluated the risk factors for an early brain death
(in the first 3 days) among the parameters collected prehospital, in
the emergency room (ER) and during the ICU stay. Method All the consecutive patients admitted to the ER of Careggi
Hospital that evolved to brain death after head trauma during the
period January 2004–June 2006 were considered (n = 54). The
following parameters were considered for the study: prehospital
phase: hypoxemia (SaO2 < 95%), hypotension (SAPS II < 90 mmHg),
orotracheal intubation, fluids (>1,000 or ≤1,000 ml), and GCS; ER
phase (ATLS approach): hypoxemia, hypotension, orotracheal
intubation, fluids, GCS, blood lactate, pharyngeal temperature, and
ISS; ICU stay: SAPS II, daily SOFA score, blood lactate, core
temperature, glycaemia, and ScVO2 (>75% or ≤75%). On the
basis of the timing of brain death, the patients were divided into Results During the time span, 5,142 trauma patients were
admitted to the ED: 4,884 were triaged green, 182 yellow and 76
were triaged as red. Of the 76 red on admission, 55 patients
fulfilled the abovementioned criteria and were confirmed severely
injured at discharge from ED. Out of the 55, 53 patients were S142 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P356) 5 minutes
15 minutes 45 minutes
5 minutes
15 minutes 45 minutes
Baseline
before
before
before
after
after
after
Mortality
Group A
RoCBF (ml/min.100 ml)
31.92
35.47
19.32
5.25***
100%
SjO2 (%)
71.2
32.8
25.7
28.7***
Group B
RoCBF (ml/min.100 ml)
30.3
14.2*
14.5*
16.4
33.47
38.24
37.67
50%
SjO2 (%)
81.1
25.8***
22.7***
24.4***
38.5**
49.5**
57.1*
*P < 0.05, **P < 0.01 and ***P < 0.001 for comparison with baseline. P356
The influence of hypotensive resuscitation in hemorrhagic
shock with coexisting severe head injury: an experimental
protocol
T Vrettos, P Athanasopoulos, N Karageorgos, S Balasis,
G Gatzounis, T Siklis, K Filos
University of Patras Medical School, Patras, Greece
Critical Care 2007, 11(Suppl 2):P356 (doi: 10.1186/cc5516) correctly identified by triage criteria, while two patients were
missed. The sensitivity is 96%. P359 Haemostatic activation markers in brain injury for mortality
prediction: comparison of blood samples from the jugular
bulb and central venous line Haemostatic activation markers in brain injury for mortality
prediction: comparison of blood samples from the jugular
bulb and central venous line N Baffoun1, C Kaddour1, Z Haddad2, R Souissi1, W Gdoura1,
L Skandrani1
1National Institute of Neurology, Tunis, Tunisia; 2CHI St-Cloud,
France
Critical Care 2007, 11(Suppl 2):P359 (doi: 10.1186/cc5519) N Baffoun1, C Kaddour1, Z Haddad2, R Souissi1, W Gdoura1,
L Skandrani1
1National Institute of Neurology, Tunis, Tunisia; 2CHI St-Cloud,
France
Critical Care 2007, 11(Suppl 2):P359 (doi: 10.1186/cc5519) Hyperoxemia improves cerebral autoregulation in severe
traumatic brain injury The
neurobehavioral motor outcome was evaluated weekly (for 4 weeks)
by performing a neuroscore, and cognitive function was evaluated
at 4 weeks postinjury using the Morris water maze. Results Consistently, brain-injured mice receiving C1-INH showed
attenuated neurological motor deficits during the 4-week period
compared with injured mice receiving saline (Figure 1). At 4 weeks
postinjury we observed a trend towards a better cognitive
performance in mice receiving C1-INH compared with mice
receiving saline (n = 8 per group, P = 0.08). 2
2
2
The ARI (normal 5 ± 1) in these head-injured patients averaged
2.2 ± 1.5 on day 1 and gradually improved over the 10 days of
monitoring. The ARI significantly improved with hyperoxemia,
during the first 6 days after injury when compared with the ARI
measured at normoxemia. The mean left ARI difference during
hyperoxia was 0.4069 ± 1.7948 while the right ARI difference was
0.4708 ± 1.8413. The average change in pCO2 during hyperoxia
was 35.6468 ± 5.8778. These changes in the ARI during
hyperoxia were smaller than those observed during hyper-
ventilation. Hyperventilation increased the ARI by average
0.8519 ± 0.2310 on the left and 1.0833 ± 0.4654 on the right. The ARI (normal 5 ± 1) in these head-injured patients averaged
2.2 ± 1.5 on day 1 and gradually improved over the 10 days of
monitoring. The ARI significantly improved with hyperoxemia,
during the first 6 days after injury when compared with the ARI
measured at normoxemia. The mean left ARI difference during
hyperoxia was 0.4069 ± 1.7948 while the right ARI difference was
0.4708 ± 1.8413. The average change in pCO2 during hyperoxia
was 35.6468 ± 5.8778. These changes in the ARI during
hyperoxia were smaller than those observed during hyper-
ventilation. Hyperventilation increased the ARI by average
0.8519 ± 0.2310 on the left and 1.0833 ± 0.4654 on the right. Pressure autoregulation was impaired in these head-injured
patients. Hyperoxia significantly improved pressure autoregulation. The very small change in pCO2 induced by hyperoxia does not
seem to explain this improvement in pressure autoregulation. Vasoconstriction induced by hyperoxia may partially contribute to
the improved pressure autoregulation. Conclusion Post-traumatic administration of the endogenous
complement inhibitor C1-INH significantly attenuates neurological
motor deficits associated with traumatic brain injury. P358 Objective Our aim was the identification of coagulopathy disorders
and their relation to outcome in severely head-injured patients. Objective Our aim was the identification of coagulopathy disorders
and their relation to outcome in severely head-injured patients. C1-inhibitor attenuates neurobehavioral deficits following
controlled cortical impact brain injury in mice a d
e
e a o
o o co e
se e e y ead
j
ed pa e s
Patients and methods A prospective study was performed June
2003–March 2004. Included were critically ill patients with
isolated closed severe head trauma. Collected data were
demographics, management prior to and during ICU hospitalization
(sedation, catecolamin drug use, blood product transfusion,
intracranial pressure monitoring, neurosurgical emergency surgery,
etc.), CT-scan results, daily worst Glasgow Coma Scale score, and
admission Simplified Acute Physiology Score II. We inserted an
arterial catheter for invasive pressure monitoring, a central venous
catheter and a unilateral jugular bulb in front of the most damaged
brain hemisphere (cf. CT scan). Jugular bulb thrombosis was
prevented by continuous infusion of 2 ml/hour isotonic serum
without heparin. Blood samples were obtained simultaneously from
the central venous line (K) and jugular bulb (B) at admission,
6 hours, 12 hours, and then in case of neurological aggravation or
daily until 5 days. We measured the platelet count, prothrombin
time (PT), activated partial thromboplastin time (ACT), fibrinogen
concentration (Fib), prothrombin fraction 1+2 (F) and thrombin–
antithrombin complex (TAT). During the study only central venous
blood samples (PT, ACT, Fib and platelet count) could be available
if necessary. Otherwise blood samples were centrifuged and
preserved refrigerated for post-hoc analysis. Statistical analysis
was by Student’s t test, paired t test for paired results and analysis
of variance. Significance was set as P < 0.05. L Longhi1, C Perego2, E Zanier1, F Ortolano1, P Bianchi1,
L Bergamaschini1, N Stocchetti3, G De Simoni2
1Milan University, Ospedale Maggiore Policlinico IRCCS, Milano,
Italy; 2Mario Negri Institute, Milano, Italy; 3Ospedale Policlinico
IRCCS, Milan, Italy
Critical Care 2007, 11(Suppl 2):P358 (doi: 10.1186/cc5518) Critical Care 2007, 11(Suppl 2):P358 (doi: 10.1186/cc5518) Introduction The goal of the study was to evaluate the neuro-
behavioral effects of the C1-inhibitor (C1-INH), an endogenous
inhibitor of complement and contact-kinin pathways, following
controlled cortical impact (CCI) brain injury in mice. Figure 1 (abstract P358) Figure 1 (abstract P358) Figure 1 (abstract P358) Results The total n = 19; nine survivors (S) and 10 deaths (NS). Hyperoxemia improves cerebral autoregulation in severe
traumatic brain injury The average change in pCO2 during hyper
was 35.6468 ± 5.8778. These changes in the ARI du
hyperoxia were smaller than those observed during hy
ventilation. Hyperventilation increased the ARI by aver
0.8519 ± 0.2310 on the left and 1.0833 ± 0.4654 on the right
Pressure autoregulation was impaired in these head-inju
patients. Hyperoxia significantly improved pressure autoregula
The very small change in pCO2 induced by hyperoxia does
seem to explain this improvement in pressure autoregula
Vasoconstriction induced by hyperoxia may partially contribut
the improved pressure autoregulation. P358
C1-inhibitor attenuates neurobehavioral deficits followin
controlled cortical impact brain injury in mice
L Longhi1, C Perego2, E Zanier1, F Ortolano1, P Bianchi1,
L Bergamaschini1, N Stocchetti3, G De Simoni2
1Milan University, Ospedale Maggiore Policlinico IRCCS, Milan
Italy; 2Mario Negri Institute, Milano, Italy; 3Ospedale Policlinico
IRCCS, Milan, Italy
Critical Care 2007, 11(Suppl 2):P358 (doi: 10.1186/cc5518)
Introduction The goal of the study was to evaluate the ne
behavioral effects of the C1-inhibitor (C1-INH), an endogen
inhibitor of complement and contact-kinin pathways, follow
controlled cortical impact (CCI) brain injury in mice. Figure 1 (abstract P358) We prospectively examined 186 (aged 34.4 ± 14.99 years)
patients with severe traumatic brain injury (postresuscitation GCS
5.98 ± 3.0957) following admission to the neurosurgical ICU of a
level one trauma hospital. Hyperventilation and hyperoxia studies
were conducted, recording middle cerebral artery flow velocity and
the autoregulation index (ARI) bilaterally and simultaneously at
baseline and posthyperventilation (CO2 reactivity = %∆CBF/
∆pCO2)/hyperoxia (O2 reactivity = ∆PbtO2/∆pO2). Continuous
multimodal neuromonitoring, intracranial pressure, mean arterial
blood pressure, cerebral perfusion pressure, end-tidal CO2
(ETCO2), PbtiO2, and SjvO2, was recorded. Methods Mice were anesthetized and subjected to CCI brain
injury. At 10 minutes postinjury, animals randomly received an
intravenous infusion of either C1-INH (15 U) or saline (equal
volume, 150 µl). A second group of mice received identical
anesthesia, surgery, and saline to serve as uninjured controls. The
neurobehavioral motor outcome was evaluated weekly (for 4 weeks)
by performing a neuroscore, and cognitive function was evaluated
at 4 weeks postinjury using the Morris water maze. Methods Mice were anesthetized and subjected to CCI brain
injury. At 10 minutes postinjury, animals randomly received an
intravenous infusion of either C1-INH (15 U) or saline (equal
volume, 150 µl). A second group of mice received identical
anesthesia, surgery, and saline to serve as uninjured controls. Hyperoxemia improves cerebral autoregulation in severe
traumatic brain injury Results Conjunctival microcirculatory flow was intermittent in
patients with highest ICP, low-continuous in patients with medium
ICP, and normal-continuous in patients with lowest ICP. Intra-
cranial perfusion pressure was lowest in patients with highest ICP
and vice versa. Functional vessel densities in the conjuctiva were in
the same range in all three groups. However, the sublingual
functional capillary densities were consistently lower in all groups
as compared with controls, suggesting an active intracranial and
extracranial regional autoregulation. R Celis, R Hlatky, C Robertson
Baylor College of Medicine, Houston, TX, USA
Critical Care 2007, 11(Suppl 2):P357 (doi: 10.1186/cc517) R Celis, R Hlatky, C Robertson
Baylor College of Medicine, Houston, TX, USA
Critical Care 2007, 11(Suppl 2):P357 (doi: 10.1186/cc517) The intrinsic autoregulation mechanisms of the cerebral vessels
that normally maintain a constant cerebral blood flow (CBF)
relatively independently from the cerebral perfusion pressure
variations are frequently impaired in the severely traumatized. It has
been shown that hyperventilation can restore the cerebral
autoregulation and controlling intracranial pressure, but much less
attention has been given to the effects of the hyperoxic state in the
restoration of cerebral autoregulation. The purpose of the study
was to compare the autoregulatory response to hyperventilation vs
hyperoxia in severe traumatic brain injury. Conclusion Conjunctival microcirculatory flow analysis reflects
alterations in cranial perfusion pressure and might be a possible
noninvasive endpoint to monitor cerebral perfusion and therapy. S143 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin We prospectively examined 186 (aged 34.4 ± 14.99 ye
patients with severe traumatic brain injury (postresuscitation G
5.98 ± 3.0957) following admission to the neurosurgical ICU
level one trauma hospital. Hyperventilation and hyperoxia stu
were conducted, recording middle cerebral artery flow velocity
the autoregulation index (ARI) bilaterally and simultaneousl
baseline and posthyperventilation (CO2 reactivity = %∆C
∆pCO2)/hyperoxia (O2 reactivity = ∆PbtO2/∆pO2). Continu
multimodal neuromonitoring, intracranial pressure, mean art
blood pressure, cerebral perfusion pressure, end-tidal C
(ETCO2), PbtiO2, and SjvO2, was recorded. The ARI (normal 5 ± 1) in these head-injured patients avera
2.2 ± 1.5 on day 1 and gradually improved over the 10 day
monitoring. The ARI significantly improved with hyperoxe
during the first 6 days after injury when compared with the
measured at normoxemia. The mean left ARI difference du
hyperoxia was 0.4069 ± 1.7948 while the right ARI difference
0.4708 ± 1.8413. P360 P360
Decreased adrenal reserve after etomidate use in
moderate and severe traumatic brain injuries: clinical
implications
P Archambault, C Dionne, G Lortie, F LeBlanc, A Rioux,
G Larouche
Université Laval, Ottawa, Canada
Critical Care 2007, 11(Suppl 2):P360 (doi: 10.1186/cc5520) Introduction Etomidate is frequently used as an anesthetic
induction agent for the intubation of head trauma patients. The
clinical impacts of its effects on adrenal function are still debated. Therefore, the primary objective of this study was to determine the
length and the importance of relative adrenal insufficiency (RAI)
induced by etomidate in moderate and severe head trauma
patients. The secondary objective was to determine etomidate’s
impacts on mortality and morbidity. Conclusions These results suggest that etomidate decreases the
adrenal reserve up to 24 hours after a single dose used for the
intubation of traumatic brain injury victims. A larger randomized
controlled trial is needed to further assess etomidate’s impacts on
morbidity and mortality. P361 Methods This was a prospective cohort study. Eligible participants
were intubated moderate to severe head trauma victims aged
≥16 years, admitted to a tertiary neurosurgical reference center
between August 2003 and November 2004. The induction agent
was chosen by the physician, without any interference by the
research team. ACTH stimulation tests (250 µg) were performed
on each participant 24, 48 and 168 hours after intubation. Responses to these tests were compared between patients having
received etomidate and those having received other induction
agents. RAI was defined as an increase in cortisol levels
<248.4 nmol/l (9 µg/dl), measured 30 and 60 minutes after the
ACTH test. Logistic and linear regression models were used to
compare the two groups of patients on outcomes while taking
confounding variables into account. Differential effects of in vitro norepinephrine on platelets
isolated from severely traumatic brain injured patients Differential effects of in vitro norepinephrine on platelets
isolated from severely traumatic brain injured patients Differential effects of in vitro norepinephrine on platelets
isolated from severely traumatic brain injured patients J Stover, C Tschuor, L Asmis, J Fehr, R Stocker
University Hospital Zürich, Switzerland
Critical Care 2007, 11(Suppl 2):P361 (doi: 10.1186/cc5521) J Stover, C Tschuor, L Asmis, J Fehr, R Stocker
University Hospital Zürich, Switzerland
Critical Care 2007, 11(Suppl 2):P361 (doi: 10.1186/cc5521) y
ritical Care 2007, 11(Suppl 2):P361 (doi: 10.1186/cc55 Introduction Norepinephrine used in clinical routine to increase
cerebral perfusion following severe traumatic brain injury (TBI) may
activate α2-adrenergic receptors on platelets, thereby possibly
promoting formation of microthrombosis and inducing additional
brain injury. Methods Arterial and jugular venous platelets isolated from nor-
epinephrine-receiving TBI patients (n = 11) and healthy volunteers
(n = 36) (cubital vein) were stimulated in vitro with increasing Results Of the 94 patients eligible for this study, 40 (43%) gave
consent for the ACTH test. Fifteen patients received etomidate and Available online http://ccforum.com/supplements/11/S2 difference was observed for other tests between B vs K and S vs
NS for different paired tests. 25 received other induction agents. At 24 hours, there were no
differences in the risk of RAI between groups (OR: 1.8, 95% CI:
0.2–14.3, P = 0.59). However, at 24 hours, subjects who had
received etomidate presented a significantly lower response to
ACTH (adjusted mean: 299.7 nmol/l, 95% CI: 214.7–384.8
versus 503.8 nmol/l, 95% CI: 441.8–565.7, P = 0.002). At 48 and
168 hours, this difference disappeared. For all eligible patients
(n = 94), there was a nonsignificant trend to an increased risk in
mortality in the etomidate group (adjusted OR: 4.8, 95% CI:
0.6–35.9, P = 0.13). Etomidate was also associated with an
increased risk of pneumonia (adjusted OR: 3.0, 95% CI: 1.0–8.7). The adjusted length of stay in the ICU was not different between
groups. At discharge, the adjusted motor Functional Independence
Measure (FIM) score was significantly lower for subjects in the
etomidate group (32 versus 56, P = 0.002), but the adjusted
cognitive FIM score was not significantly different in the etomidate
group (35 versus 46, P = 0.15). 25 received other induction agents. At 24 hours, there were no
differences in the risk of RAI between groups (OR: 1.8, 95% CI:
0.2–14.3, P = 0.59). However, at 24 hours, subjects who had
received etomidate presented a significantly lower response to
ACTH (adjusted mean: 299.7 nmol/l, 95% CI: 214.7–384.8
versus 503.8 nmol/l, 95% CI: 441.8–565.7, P = 0.002). At 48 and
168 hours, this difference disappeared. For all eligible patients
(n = 94), there was a nonsignificant trend to an increased risk in
mortality in the etomidate group (adjusted OR: 4.8, 95% CI:
0.6–35.9, P = 0.13). Etomidate was also associated with an
increased risk of pneumonia (adjusted OR: 3.0, 95% CI: 1.0–8.7). The adjusted length of stay in the ICU was not different between
groups. At discharge, the adjusted motor Functional Independence
Measure (FIM) score was significantly lower for subjects in the
etomidate group (32 versus 56, P = 0.002), but the adjusted
cognitive FIM score was not significantly different in the etomidate
group (35 versus 46, P = 0.15). Conclusion Procoagulant factors (F and TAT) are valuable
prognostic factors at day 1 in closed isolated severe head trauma. P358 No differences between S and NS in demographics, management
modalities, admission GCS score (7 ± 3), CT scan, and SAPS II
(27 ± 10 vs 30 ± 17, P = 0.69). The B vs simultaneous K platelet
count was significantly lower in all drawn blood samples, with a
trend to decrease over time. S vs NS at day 2 and day 3: 191 ± 60
vs 125 ± 35 (P = 0.017). The admission B thrombin fraction was
higher in NS (1,000 ± 209 vs 460 ± 294, P = 0.014). The B day 1
TAT was higher in NS: 45 ± 20 vs 9.6 ± 12 (P = 0.02). No S144 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 P362 Patients We enrolled consecutive patients >12 years of age
expected to stay in the ICU >48 hours. We excluded patients on
systemic anticoagulation and patients with pulmonary embolism
(PE) or deep venous thrombosis (DVT) on admission to the ICU or
diagnosed within 24 hours of ICU admission. We recorded a priori
defined VTE risk factors at baseline and daily. Our ICU implements
a protocol for thromboprophylaxis, which is based on the evidence-
based ACCP guidelines. The primary endpoint was the develop-
ment of PE or DVT during ICU stay. We used multivariate
regression analysis to determine independent predictors of VTE. Patients We enrolled consecutive patients >12 years of age
expected to stay in the ICU >48 hours. We excluded patients on
systemic anticoagulation and patients with pulmonary embolism
(PE) or deep venous thrombosis (DVT) on admission to the ICU or
diagnosed within 24 hours of ICU admission. We recorded a priori
defined VTE risk factors at baseline and daily. Our ICU implements
a protocol for thromboprophylaxis, which is based on the evidence-
based ACCP guidelines. The primary endpoint was the develop-
ment of PE or DVT during ICU stay. We used multivariate
regression analysis to determine independent predictors of VTE. Results Among 277 patients with a mean APACHE II score of 25
(+9), the incidence of VTE was 7.2% (95% CI 4.5–11). We
identified three independent risk factors for ICU-acquired venous
thromboembolism: stroke (OR 13.5, 95% CI 1.9–91.19,
P = 0.008), femur fracture (OR 4.5, 95% CI 1.18–17.10, P = 0.03),
and ICU length of stay (OR for each day increment 1.08, 95% CI
1.03–1.13, P = 0.002). After adjustment for APACHE II score,
VTE was an independent predictor of mortality (OR 3.85, 95% CI
1.11–13.29, P = 0.03). P363 P363 norepinephrine concentrations (10 nM to 100 µM); thrombin
receptor activator peptide (TRAP) served as positive control. P-selectin expression was determined by flow cytometry (FACS). norepinephrine concentrations (10 nM to 100 µM); thrombin
receptor activator peptide (TRAP) served as positive control. P-selectin expression was determined by flow cytometry (FACS). Results Following TBI, the number of unstimulated P-selectin-
positive platelets was significantly decreased in the second week
by 60%. During the first week, the in vitro stimulatory effect was
significantly
reduced;
in
the
second
week,
however,
norepinephrine-mediated effects exceeded changes in controls
and the first week without a difference between arterial and jugular
venous platelets (Figure 1). Ultrasound evaluation and risk factors for deep venous
thrombosis in the intensive care unit Ultrasound evaluation and risk factors for deep venous
thrombosis in the intensive care unit M Boddi1, G Palano1, L Tini2, E Lucente1, S Berardino1,
G Gensini1, A Peris3
1Department of Medical and Surgical Critical Care, Careggi
Teaching Hospital, Florence, Italy; 2Department of Emergency,
Careggi Teaching Hospital, Florence, Italy; 3Ospedale Firenze,
Florence, Italy
Critical Care 2007, 11(Suppl 2):P362 (doi: 10.1186/cc5522) Results Among 277 patients with a mean APACHE II score of 25
(+9), the incidence of VTE was 7.2% (95% CI 4.5–11). We
identified three independent risk factors for ICU-acquired venous
thromboembolism: stroke (OR 13.5, 95% CI 1.9–91.19,
P = 0.008), femur fracture (OR 4.5, 95% CI 1.18–17.10, P = 0.03),
and ICU length of stay (OR for each day increment 1.08, 95% CI
1.03–1.13, P = 0.002). After adjustment for APACHE II score,
VTE was an independent predictor of mortality (OR 3.85, 95% CI
1.11–13.29, P = 0.03). Introduction Critically ill patients have a high risk of deep venous
thrombosis (DVT); however, data about prevalence and specific
risk factors in the ICU are conflicting and the prophylaxis strategies
are still debated. The aim of this study is to evaluate the prevalence
and risk factors in an ICU dealing with trauma and major surgery
patients. Methods We analyzed retrospectively data from 142 patients
(56 ± 4.8 years) admitted to the ICU from December 2004 to
December 2005. We recorded the history, diagnosis, SAPS II,
length of stay and major surgery. All patients received standard
prophylaxis (LMWH and/or mechanical device). For DVT diagnosis,
three compression ultrasound examinations were performed
(a) within 48 hours from admission, (b) between the 7th and 10th
days, and (c) between the 13th and 16th days. The prevalence of
DVT and risk factors were analyzed in the whole population and in
the following four groups: ≤40 years, 41–59 years, 60–74 years,
and ≥75 years. Statistics were determined using the Wilcoxon and
Mann–Whitney tests and one-way analysis of variance on SPSS;
P < 0.5 was considered significant. Conclusions VTE is relatively common complication in critically ill
patients and is associated with significant mortality. Longer ICU
length of stay, stroke and femur fracture are independent
predictors for VTE. These findings suggest the need for more
effective prophylactic strategies in critically ill patients, especially
those at higher risk. Acknowledgement Sponsored by Sanofi-Aventis. Venous thromboembolism in critically ill patients:
incidence and risk factors Results Following TBI, the number of unstimulated P-selectin-
positive platelets was significantly decreased in the second week
by 60%. During the first week, the in vitro stimulatory effect was
significantly
reduced;
in
the
second
week,
however,
norepinephrine-mediated effects exceeded changes in controls
and the first week without a difference between arterial and jugular
venous platelets (Figure 1). S Al-Qahtani, Y Arabi, A Aldawood
KIing Abdulaziz Medical City, Riyadh, Saudi Arabia
Critical Care 2007, 11(Suppl 2):P363 (doi: 10.1186/cc5523) Objective Despite the high risk of venous thromboembolism (VTE)
in ICU patients, only few studies have examined this group of
patients systematically. The objective of this study is to examine the
incidence and risk factors of VTE among critically ill patients. Conclusion Clinically relevant norepinephrine concentrations are
<25 nM. The present in vitro effects occurred at concentrations
>500 nM. Thus, a clinically relevant impact appears doubtful. Design A prospective cohort study. Setting A closed university-affiliated ICU in a medical–surgical ICU
in the Kingdom of Saudi Arabia. Figure 1 (abstract P361) Figure 1 (abstract P361)
Changes in P-selectin expression in isolated platelets stimulated in vitro with norepinephrine or TRAP. +P < 0.001 vs low-dose norepinephrine;
*P < 0.001 vs controls; #P < 0.001 vs first week. Changes in P-selectin expression in isolated platelets stimulated in vitro with norepinephrine or TRAP. +P < 0.001 vs low-dose norepinephrine;
*P < 0.001 vs controls; #P < 0.001 vs first week. S145 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P364 Cardiopulmonary bypass and recombinant plasminogen
activator for treatment of experimental fatal pulmonary
embolism g
Results One hundred (70%) patients were admitted after trauma,
15 (11%) after surgery, 27 (19%) had medical disease. The mean
SAPS II score was 45 ± 15.8 and the mean length of stay was
16 ± 9.84 days. Forty-six patients (32.4%) underwent major surgery
following the admission. The overall prevalence of DVT was 17.6%
(25/142), with the highest value (24.2%) in the 41–59 year group
and the lowest (12.5%) in the >75 year group. DVT was
diagnosed in 12/25 (48%) patients within 48 hours from ICU
admission and 7/12 (58.3%) had direct venous injury. DVT was
diagnosed in the remaining patients after 10 days. We found a
strong relationship (P < 0.06) between the length of stay and DVT
in patients <40 years. No significant differences were found
regarding SAPS. Introduction Treatment of acute pulmonary embolism (PE), which
causes life-threatening cardiovascular collapse, consists of cardio-
pulmonary bypass (CPB) and surgical embolectomy. In the clinical
practice we have treated three such patients successfully with
CPB but instead of performing embolectomy, administered
recombinant plasminogen activator (rt-PA). We studied the
circulatory and respiratory effects of this combined therapy in a
swine model of fatal PE. Introduction Treatment of acute pulmonary embolism (PE), which
causes life-threatening cardiovascular collapse, consists of cardio-
pulmonary bypass (CPB) and surgical embolectomy. In the clinical
practice we have treated three such patients successfully with
CPB but instead of performing embolectomy, administered
recombinant plasminogen activator (rt-PA). We studied the
circulatory and respiratory effects of this combined therapy in a
swine model of fatal PE. Conclusions In our experience, DVT prevalence showed a bimodal
occurrence with a first short-term peak, associated with traumatic
or surgical direct venous injury, and a medium-term peak, related to
an ICU stay >10 days. We therefore oriented the surveillance to
the two periods of higher DVT prevalence and we established a
training program for the intensivists to improve DVT detection,
relieving the workload of the ultrasound physician. Methods Seven pigs (90 kg) were i.v. anesthetized, muscle
relaxed, tracheally intubated and mechanically ventilated (FiO2
1.0). Fibrinolysis during cardiopulmonary bypass detected with
thromboelastography R Hájek, J Ruþièková, I Fluger, P Nemec, V Bruk
University Hospital, Olomouc, Czech Republic
Critical Care 2007, 11(Suppl 2):P366 (doi: 10.1186/cc5526) Results Five animals developed ventricular fibrillation, while one
animal maintained sinus rhythm. After 2 hours all animals had an
atrial rhythm. All animals were weaned off CPB and survived until
the experiment ended. Values before and after CPB (median and
range): MAP (mmHg) 101 (86, 109) and 75 (46, 106); CO (l/min)
6.7 (4.3, 11) and 6.2 (3.6, 7.8); MPAP (mmHg) 22 (19, 36) and 44
(31, 82) (P < 0.05); ETCO2 (kPa) 5.6 (4.3, 6.5) and 2.7 (2.4, 3.4)
(P < 0.05); PaCO2 (kPa) 6.2 (5.2, 7.2) and 6.1 (4.8, 7.3); PaO2
(kPa) 60 (50, 68) and 55 (30, 64). Background Fibrinolysis is a common haemostatic abnormality
during cardiopulmonary bypass (CPB). Thromboelastography
(TEG) is a good method to detect both types of fibrinolysis. Methods Four hundred and ninety-nine patients during mild
hypothermic CPB and elective surgery were monitored with TEG
(first – after the induction, second – after rewarming, third and
fourth – at the end of surgery native and heparinase). No prophy-
lactic antifibrinolytics were used. The data of the study group were
compared with a control group of 475 patients monitored only with
laboratory tests (fibrin degradation products (FDP) and D-dimers). Peroperative and 24 hour postoperative bleeding, number of
transfusions, aprotinin therapy and reexploration were recorded. Correlations between the presence of fibrinolysis and blood loss
and transfusion therapy and between aprotinin administration and
blood loss and number of transfusions were evaluated. Conclusion Although there were signs – that is, lower ETCO2 and
higher MPAP – that the massive clots were not fully dissolved after
185 minutes, this study shows that fatal PE might be treated
effectively with CPB combined with simultaneous thrombolytic
therapy. P364 A large-bore catheter (8.5 mm ID) was inserted in the right
superior vena cava (for injection of preformed blood clots) and
large-bore catheters were inserted in the inferior vena cava via the S146 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 femoral vein and in the aorta via the femoral artery (for accessing
CPB). We measured the mean arterial pressure (MAP), cardiac
output (CO), blood gases, pulmonary artery pressure measurement
(MPAP), end-tidal CO2 (ETCO2) and blood gases. Then 100–300 ml
preformed blood clot was injected until systemic circulation
ceased (systolic AP < 25 mmHg) and a 5 minute interval was
allowed before start of CPB (flow rate of 4–7 l/min). Heparin
10,000 IE was given i.v., and rt-PA 10 mg as an i.v. bolus followed
by an i.v. infusion of 90 mg during 2 hours. If ventricular fibrillation
occurred, cardioversion was performed. After 145 minutes CPB
was weaned off, and after a further 40 minutes the experiment was
ended. femoral vein and in the aorta via the femoral artery (for accessing
CPB). We measured the mean arterial pressure (MAP), cardiac
output (CO), blood gases, pulmonary artery pressure measurement
(MPAP), end-tidal CO2 (ETCO2) and blood gases. Then 100–300 ml
preformed blood clot was injected until systemic circulation
ceased (systolic AP < 25 mmHg) and a 5 minute interval was
allowed before start of CPB (flow rate of 4–7 l/min). Heparin
10,000 IE was given i.v., and rt-PA 10 mg as an i.v. bolus followed
by an i.v. infusion of 90 mg during 2 hours. If ventricular fibrillation
occurred, cardioversion was performed. After 145 minutes CPB
was weaned off, and after a further 40 minutes the experiment was
ended. procoagulant pathways. Although fibrinolysis was activated, the
inhibition of fibrinolysis was more pronounced at the same time. The coagulation inhibitors and TAT levels seem to be early
predictors of ICU mortality. Early coagulation alterations in intensive care unit burn
patients A Lavrendieva1, A Parlapani2, O Thomareis2, V Soulountsi1,
M Bitzani1
1G Papanikolaou Hospital, Thessalonki, Greece; 2Aristotelian
University, Thessaloniki, Greece
Critical Care 2007, 11(Suppl 2):P365 (doi: 10.1186/cc5525) al Care 2007, 11(Suppl 2):P365 (doi: 10.1186/cc5525) Introduction The aim of the present study was to examine the
coagulation status of patients in the early postburn period. Introduction The aim of the present study was to examine the
coagulation status of patients in the early postburn period. Method Coagulation and fibrinolysis parameters – antithrombin III
(ATIII), protein C (PrC), free protein S (PrS), plasminogen activator
inhibitor 1 (PAI-1), tissue plasminogen activator (t-PA), thrombin/
antithrombin complexes (TAT), plasmin/α2-antiplasmin complexes
(PAP), fibrin degradation products (F1.2) – were measured at ICU
admission and daily thereafter for 7 postburn days. Conclusion Fibrinolysis was usually not associated with serious
bleeding. There was no positive effect of aprotinin to reduce
bleeding or transfusion therapy. FDP and D-dimers are not useful
to detect fibrinolysis in cardiac surgery. Results Forty-five patients were screened (nine nonsurvivors and
36 survivors). All patients had a severe deficiency of the coagulation
inhibitors on admission. Normalization of these levels in survivors
was observed at day 5 for ATIII and PrC, and at day 7 for PrS. All
patients had elevated levels of TAT during the investigation period,
but survivors had significantly lower levels at day 7 postburn
(6.2 ± 4.9 vs 11.4 ± 4.5 µg/l, P < 0.001). PAP levels were within
the physiological range in both groups at day 1, remained low in
survivors, but raised significantly in nonsurvivors at day 7
(19.3 ± 14 vs 80.9 ± 10.4 µg/l, P = 0.003). The t-PA levels were
elevated permanently only in nonsurvivors. PAI-1 levels were
increased at day 1 in both groups, but returned to normal values at
day 5 in survivors. The degree of PAI-1 activation was significantly
higher than this of t-PA. The F1.2 levels were permanently elevated
and there was no statistically significant difference in both groups. A logistic regression analysis revealed that ATIII and PrS at days 3,
5 and 7, Pr C at days 5 and 7 and TAT at day 7 were independent
predictors of ICU death. P365 Results The frequency of fibrinolysis measured with TEG: before
surgery – primary 3.2%/secondary 3.4%; during CPB – 18.8%/
0.6%; after surgery – 7%/1.4% (native), 5.6%/0.6% (heparinase). Positivity of fibrinolysis detected with laboratory tests was 100%. The TEG parameter of fibrinolysis (LY30) was significantly
increased during CPB. The frequency of aprotinin administration
was 12% TEG, 10.7% control. No correlation between positivity of
fibrinolysis and peroperative/postoperative blood loss and red
blood cells (RBC) and fresh frozen plasma (FFP) transfusions were
recorded. No correlation between aprotinin administration and
peroperative/postoperative blood loss and RBC transfusion were
recorded. Positive correlation between aprotinin administration and
FFP transfusion were recorded Early coagulation alterations in intensive care unit burn
patients P366 Fibrinolysis during cardiopulmonary bypass detected with
thromboelastography Fibrinolysis during cardiopulmonary bypass detected with
thromboelastography P368 Low-frequency hemoviscoelastography: a new method of
diagnostics for coagulation disorders after abdominal
surgery for cancer
O Tarabrin, A Simovskykh, V Mazur, A Suhanov
Odessa Medical University, Marine Central Hospital, Odessa,
Ukraine
Critical Care 2007, 11(Suppl 2):P368 (doi: 10.1186/cc5528) Low-frequency hemoviscoelastography: a new method of
diagnostics for coagulation disorders after abdominal
surgery for cancer Objective Cardiac surgery, in particular when done with cardio-
pulmonary bypass (CPB), is frequently associated with excessive
intraoperative and postoperative bleeding. Here we employed the
Technothrombin® thrombin generation assay (TGA; Technoclone)
to monitor changes in perioperative haemostasis. O Tarabrin, A Simovskykh, V Mazur, A Suhanov
Odessa Medical University, Marine Central Hospital, Odessa,
Ukraine
Critical Care 2007, 11(Suppl 2):P368 (doi: 10.1186/cc5528) Methods One hundred and forty-eight patients (age 66.0 ± 9.8 years;
103 males, 45 females) with elective cardiac surgery and a CPB
time >45 minutes (mean 114 ± 56 min) were enrolled. Arterial
blood samples were obtained preoperative, postoperative and
14–18 hours postoperative and centrifuged within 30 minutes
after withdrawal, for 5 minutes at 5,000 x g. Plasma samples were
stored until analysis at –80°C. Thrombin generation (TG) induced
by the TGA RC low reagent (71.6 pM tissue factor) was measured
in 96-well multiplates using a FLUOstar OPTIMA fluorescence
reader (MWG Labtech). Critical Care 2007, 11(Suppl 2):P368 (doi: 10.1186/cc5528) Background Venous thromboembolism is one of the most
common complications seen in cancer patients and may be due to
the hypercoagulable state of the malignancy and to its surgical
treatment. Despite clinical and laboratory evidence of perioperative
hypercoagulability, there are no consistent data evaluating the
extent, duration, and specific contribution of platelets and pro-
coagulatory proteins by in vitro testing. Results Due to cardiac surgery, the lag-phase and time-to-peak of
TG increased by 45% and 35%, respectively. In parallel, the peak
thrombin concentration and maximum slope decreased by 42%
and 51%, respectively (P < 0.000001). Both the lag-phase and
time-to-peak returned to basal values within 14–18 hours
postoperative, but the peak thrombin and maximum slope of TG
rose above the preoperative values (+39% and +68%, P < 0.0005). The on-pump time was positively correlated with lag phase and
time to peak and negatively correlated with peak thrombin and
maximum slope of TG when measured at 14–18 hours
postoperative, but there was no correlation at early postoperative. P367 ROTEM® thrombelastometry in on-pump cardiac surgery
patients W Loesche, M Reinhöfer, C Macholdt, M Brauer, D Barz,
J Gummert, K Reinhart, G Marx
University Hospital Jena, Germany
Critical Care 2007, 11(Suppl 2):P367 (doi: 10.1186/cc5527) W Loesche, M Reinhöfer, C Macholdt, M Brauer, D Barz,
J Gummert, K Reinhart, G Marx
University Hospital Jena, Germany
Critical Care 2007, 11(Suppl 2):P367 (doi: 10.1186/cc5527) Objective On-pump cardiac surgery is frequently associated with
intraoperative and postoperative bleeding. ROTEM® is a point-of-
care method that reflects more closely than classical coagulation
tests the in vivo haemostatic activity and the contribution of
fibrinogen and platelets to clot formation. Methods Two hundred and thirty-two patients (age 67 ± 10 years)
with elective cardiac surgery and an on-pump time >45 minutes
(mean 112 ± 52 min) were enrolled. Preoperative, intraoperative
and postoperative blood samples were taken from an arterial
catheter. The ROTEM® system and test kits (INTEM/EXTEM = Conclusion Our findings indicate the early postburn dysregulation
of the hemostatic balance characterized by the activation of S147 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin was a 14% perioperative increase of standard MA, corresponding
to a 48% increase of Gt (P < 0. 05) and an 80–86% contribution
of the calculated Gp to Gt. We conclude that serial standard TEG
and the HVG viscoelastic test may reveal the independent
contribution of platelets and procoagulatory proteins to clot
strength. Using multiple linear regression, all coagulation, TEG and
HVG variabilities were used to model postoperative hyper-
coagulation. Results showed that some components of the TEG
failed to identify hypercoagulation (r < 0.2, P > 0.75). However,
three components of the routine coagulation assay, including
bleeding time, prothrombin time, and platelet count, could be
modeled to show prolonged postoperative hypercoagulability
(P < 0.01). We conclude that all components of the HVG test
reflect postoperative coagulopathies; these results suggest that it
may be useful in determining the coagulation status of cancer
patients perioperatively. platelets) were from Pentapharm (Munich, Germany). Results The clot formation time (CFT) and maximum clot firmness
(MCF), but not clotting time (CT), were strongly correlated with the
fibrinogen level and platelet count. Surgery significantly decreased
the ROTEM haemostatic activity, but normalised in most patients
within 14–18 h postoperation. Lowest haemostatic activity (dramatic
increase in CT and CFT, decrease in MCF) was seen when
patients were conditioned for cardiopulmonary bypass (CPB). Thrombin generation in on-pump cardiac surgery patients W Loesche, V König, V Oberle, M Reinhöfer, D Barz,
J Gummert, G Marx
University Hospital Jena, Germany
Critical Care 2007, 11(Suppl 2):P369 (doi: 10.1186/cc5529) P367 When connected to CPB, the CT and CFT turned to recover, but
MCF in EXTEM remained unchanged and MCF in FIBTEM
declined further indicating continuous fibrinogen consumption. In
12.5% of our patients, postoperative MCF in FIBTEM was reduced
to <9 mm indicating a need for fibrinogen substitution. Low
postoperative activity in ROTEM® was associated with high
postoperative blood loss. The positive predictive value and
specificity of FIBTEM were clearly superior to those of the APTT or
prothrombin time. Up to 50% of patients had an increased
haemostatic activity in preoperative ROTEM®, and this was
associated with high CRP levels and intraoperative blood loss. Conclusion Postoperative hypercoagulability, occurring for at least
1 week after major cancer abdominal surgery, may be
demonstrated by the HVG viscoelastic test. This hypercoagulability
is not reflected completely by standard coagulation monitoring and
TEG, and seems to be predominantly caused by increased platelet
reactivity. The HVG viscoelastic test provides a fast and easy to
perform bedside test to quantify in vitro hemocoagulation. Conclusions ROTEM® is a valuable tool to monitor peri-
operative haemostasis. The decreases in haemostatic activity
and postoperative bleeding are probably due to anticoagulant
therapy as well as fibrinogen and platelet consumption. An
increased preoperative haemostatic activity is probably due to
an acute phase reaction associated with advanced athero-
sclerosis, and the high intraoperative bleeding in these patients
might be due to the atherosclerotic vessels rather than due to an
insufficient haemostasis. P370 There were 12 minor bleeding events, occurring mostly during the
maintenance infusion rate adjustment period and which responded
to transient interruption and/or lowering of the infusion rate. Eleven
nonfatal major bleeding events occurred (four due to procedural
errors) and eight fatal major bleeds, two of which occurred 3 days
and 8 days after Orgaran® discontinuation. Activated clotting time (ACT) measuring devices used
simultaneously do not produce correlating ACT values I Lorenz, J Walde, C Schnuerer, C Velik-Salchner, P Muessigang,
A Jeller, J Engel, R Gruber, C Falbesoner, C Kolbitsch
University Innsbruck, Austria
Critical Care 2007, 11(Suppl 2):P370 (doi: 10.1186/cc5530) Plasma anti-FXa levels were reported for 38 patients. During seven
of the eight fatal bleeding episodes the plasma anti-FXa levels
were ≥0.8 U/ml in three patients and 0.31–0.66 U/ml (that is,
within the target range) in the other four patients. The highest anti-
FXa response of 2.00 U/ml was associated with minor bleeding
from an angiomatous malformation and stopped when the
Orgaran® dose was reduced. However, of the 11 patients
receiving >400 U/hour, four suffered major bleeding (three fatal)
and two developed minor bleeding. Most of these patients
received continuous arterio-venous haemodiafiltration treatment,
which may have been a contributory factor. Introduction The lack of a ‘gold standard’ activated clotting time
(ACT) measuring device gives rise to the broad range of ACT
measuring devices currently on the market. The present study
focused on the inter-device and intra-device differences (for
example, reproducibility of ACT measurement) in four different ACT
measuring systems. Methods (1) Hemochron celite tubes, (2) Aktalyke celite tubes,
(3) Actalyke ACT-Max tubes and (4) Hemochron Junior low-range
(LR) or high-range (HR) cartridges were simultaneously filled with
blood drawn (n = 3,997) at baseline, at 3 minutes following
administration of heparin (300 IU/ kg), 5 minutes after starting
cardiopulmonary bypass (CPB), every 30 minutes during CPB and
thereafter at 15 minutes following protamine administration. Conclusions We recommend that maintenance Orgaran® infusion
rates ≥400 U/hour should be avoided unless serious circuit
clotting is grossly affecting the haemofilter life. The infusion rate
should be monitored clinically; that is, on the basis of bleeding and
circuit clotting rather than the patients’ plasma anti-FXa responses. Results The ACT values measured simultaneously using four
different ACT measuring devices did not correlate with each other
at any measurement time. P371 Introduction Heparin-induced thrombocytopenia (HIT) presents with
thrombocytopenia and high risk for venous and/or arterial
thrombosis, as an adverse effect of heparin (especially unfractioned). Objective To evaluate the incidence of positive heparin antibody
test in a multidisciplinary ICU for the time period from 1 January
2006 to 30 November 2006. Introduction Heparin-induced thrombocytopenia (HIT) presents with
thrombocytopenia and high risk for venous and/or arterial
thrombosis, as an adverse effect of heparin (especially unfractioned). Objective To evaluate the incidence of positive heparin antibody
test in a multidisciplinary ICU for the time period from 1 January
2006 to 30 November 2006. Available online http://ccforum.com/supplements/11/S2 Conclusions The data provide clear evidence for a marked
decrease of TG during cardiac surgery followed by an excess
restoration in the postoperative phase. Factors released from
platelets and leukocytes (procoagulant microvesicles?) might
contribute to the enhanced TG observed at 14–18 hours
postoperative. Conclusions The data provide clear evidence for a marked
decrease of TG during cardiac surgery followed by an excess
restoration in the postoperative phase. Factors released from
platelets and leukocytes (procoagulant microvesicles?) might
contribute to the enhanced TG observed at 14–18 hours
postoperative. A variety of continuous extracorporeal haemofiltration circuits was
used for from 1 to 39 days (median 7 days). The Orgaran® dosing
schedule was usually initiated with a 2,000–2,500 U intravenous
bolus injection. After two step-down dose periods the subsequent
maintenance infusion was usually titrated according to each
patient’s thromboembolic and bleeding risk status. Hence most
patients received 100–400 U/hour, but 11 patients required up to
600 U/hour temporarily to control extracorporeal circuit clotting. P372 High incidence of positive heparin antibodies in a
multidisciplinary intensive care unit P Renieris, V Gerovasili, M El Ali, T Theodoridis, M Poriazi,
A Bouhla, V Markaki, S Mentzelopoulos, D Zervakis,
C Roussos, S Nanas
National and Kapodistrian University of Athens, Greece
Critical Care 2007, 11(Suppl 2):P372 (doi: 10.1186/cc5532) Conclusion The Hemochron Junior ACT measuring device
showed the smallest intra-device measuring error. No correlation,
however, could be established between ACT values measured
with the four devices tested. P370 Reproducibility of ACT measurement (for
example, intra-device difference) was, in descending order, best for
Hemochron Junior, Actalyke ACT-Max, Hemochron celite and
Aktalyke celite. P368 With respect to classical coagulation parameters, significant
correlations were observed between TG and activated partial
thromboplastin time at preoperative and 14–18 hours post-
operative, and between TG and prothrombin time at postoperative
(P < 0.025–0.001). At 14–18 hours postoperative there was a
significant correlation of TG with platelet as well as leukocyte
counts (P < 0.025). Materials and methods Patients undergoing planned curative
open surgery for abdominal cancer received MEDNORD (Ukraine
Co analyser) analysis (HVG), a viscoelastic test that measures clot
formation and includes information on the cellular, as well as the
plasmatic coagulation, system. We examined the efficacy of a
variety of coagulation tests. A complete coagulation screen,
activated clotting time, thromboelastography (TEG) and hemo-
viscoelastography (HVG) were performed before surgery, at the
end of surgery, and on postoperative days 1, 2, 3, and 7; they were
analyzed for the reaction time and the maximal amplitude (MA). We
tested the hypothesis that the parallel use of standard TEG and
HVG can assess postoperative hypercoagulability and can
estimate the independent contribution of procoagulatory proteins
and platelets. Results and discussion We calculated the elastic shear modulus
of standard MA (Gt) and HVG MA (GH), which reflect the total clot
strength and procoagulatory protein component, respectively. The
difference was an estimate of the platelet component (Gp). There S148 Available online http://ccforum.com/supplements/11/S2 P373 The antibody determination was performed using commercially
available ELISA kits. In the functional assays, heparin-induced
platelet activation/aggregation (HIPA) and a flow cytometric
technique for the detection of platelet microparticles released
(platelet microparticle assay) were included. Conclusion Exclusion of female-donor FFP was associated with a
statistically significant reduction in the incidence of ALI in patients
undergoing repair of a ruptured AAA. Results None of the negative control individuals were positive in
any applied method. In contrast, all the participants of the positive
control group were found positive in all the applied methods. No
HIT was detected in 10 patients, seven of whom were pregnant at
different gestational ages. The remaining 43 thrombocytopenic
patients were positive in HIPA and 39 of them were also positive in
the platelet microparticle assay. Out of these 39 patients, only 16
were positive in the ELISA assay. Orgaran® use in intensive care unit patients with heparin-
induced thrombocytopenia and acute renal failure H Magnani1, J Wester2
1NV Organon, Oss, The Netherlands; 2Onze Lieve Vrouwe
Gasthuis, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P371 (doi: 10.1186/cc5531) Methods We retrospectively reviewed all laboratory tests for
heparin antibodies requested from the ICU for the period of
January–November 2006. The blood sample analysis was
performed with ELISA (Asserachrom® HPIA; Diagnostica Stago,
Asnieres, France). All patients were receiving fractioned heparin
subcutaneously for prophylaxis when indicated. Flushes of
unfractioned heparin for catheter clotting prevention were given to
all patients. Only ‘positive’ results were considered positive, whilst
‘mildly positive’ and ‘uncertain’ results were considered negative. Introduction Orgaran® (danaparoid sodium) is a low-molecular-
weight, nonheparin glycosaminoglycan antithrombotic that is
currently a first-line treatment for heparin-induced thrombocyto-
penia (HIT). This study reports on the safety of Orgaran® in ICU
patients suffering from HIT and acute renal failure requiring
continuous renal replacement therapy (haemofiltration). Methods Data on 96 case reports from personal experience and
publications have been collated. Results During that period 300 patients were admitted (mean
duration of stay 15 ± 16 days, 25th–75th 4–22 days) to the ICU;
212 (70%) were survivors and 88 (30%) were nonsurvivors. All
patients presenting with thrombocytopenia (platelets < 150,000/dl)
or showing a decrease >50% of their admission day’s platelet
count were checked for heparin antibodies. Fifty-two samples
retrieved from 48 patients suspicious for HIT were sent for heparin
antibody analysis. Of the 48 patients checked, 15 (31%) were
positive and 33 (68%) negative. Three of the suspected patients Results Nineteen females and 59 males (18 unknown gender)
with a median age of 60 years (range 22–95 years) presented with
a variety of clinical problems that either preceded or complicated
their HIT; for example, postoperative/accidental trauma or overt
bleeding in 61, sepsis/septicaemia/septic shock in 37, thrombo-
embolism in 23, multiple organ dysfunction syndrome in 14,
disseminated intravascular coagulation in eight and other miscel-
laneous serious problems in 38. S149 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P373 P373 M Kounavi, C Kroupis, E Iliopoulou, D Karamichaleli,
M Katafigioti, D Degiannis, E Melissari
Onassis Cardiac Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P373 (doi: 10.1186/cc5533) Methods A before-and-after, observational, single-centre study. Subjects were 211 consecutive patients undergoing open repair of
a ruptured AAA between 1998 and 2006. Primary outcome was
development of ALI (PaO2/FiO2 < 300 and bilateral pulmonary
infiltrates on chest X-ray) in the first 6 hours after surgery. Secondary outcomes were time to extubation, and survival at
30 days. Chest X-rays were examined independently by two
radiologists who were blinded to the study hypothesis. Introduction Heparin-induced thrombocytopenia (HIT) type II is a
serious side effect of unfractionated heparin, and to a lesser extent
of low molecular weight heparins. It is mediated through an
immunological mechanism and leads to platelet aggregation. The
occurrence of HIT varies between 1% and 5% of patients
receiving heparin while a substantial fraction of them develops
thrombosis (HITT). Therefore, the rapid and accurate confirmation
of HIT is a necessity. The laboratory assays available for the
diagnosis of HIT are based on the detection of HIT antibodies or
on the consequences of platelet activation (functional methods). Results One hundred and twenty-nine patients were operated on
before and 82 after the change in FFP procurement. Groups were
well matched, with respect to age, sex, co-morbidities and severity
of illness, and received similar volumes of i.v. fluids and blood
products from admission to 6 hours postoperatively (mean units of
FFP, 8.6 before and 8.39 after, P = 0.833). The maximum tidal
volume, PEEP, and CVP were similar in both groups. Norepinephrine was given to 8.5% of patients in the before group
compared with 24.4% after (P = 0.001), otherwise inotrope use
was similar. Primary outcome: there was significantly less ALI
following the change to male-only FFP (36% before vs 21% after,
P = 0.042). Secondary outcomes were not statistically different
between groups; however, patients with ALI in either group had a
poorer 30-day survival (59% vs 80%, P = 0.005). The purpose of the present study was to improve HIT recognition by
the combination of functional and antibody determination assays. Patients
and
methods
Fifty-three patients who presented
thrombocytopenia while receiving UFH or LMWH participated in
the study. A positive control group consisting of 15 patients known
to suffer from HIT/HITT was used. Moreover, 19 healthy donors
never exposed to heparin also participated as negative controls. P374 suffered from pulmonary embolism and were treated with
therapeutic doses of i.v. unfractioned heparin; one of them was
positive for heparin antibodies. The effect of male-donor-only fresh frozen plasma on the
incidence of acute lung injury following ruptured
abdominal aortic aneurysm repair Conclusions Our findings of high incidence of positive heparin
antibodies may be mainly due to unfractioned heparin flushes. The
use of heparin flushes with the new high-quality catheters and
monitoring kit is questionable. Since low doses of unfractioned
heparin could lead to the production of antibodies and subsequently
to HIT, further studies should examine the risk-to-benefit ratio of the
use of unfractioned heparin flushes in the ICU setting. S Wright, S Athey, A Leaver, C Snowden, D Roberts,
J Clarkson, C Chapman, J Wallis
Freeman Hospital and National Blood Service, Newcastle upon
Tyne, UK
Critical Care 2007, 11(Suppl 2):P374 (doi: 10.1186/cc5534) S Wright, S Athey, A Leaver, C Snowden, D Roberts,
J Clarkson, C Chapman, J Wallis
Freeman Hospital and National Blood Service, Newcastle upon
Tyne, UK
Critical Care 2007, 11(Suppl 2):P374 (doi: 10.1186/cc5534) Introduction Transfusion-related acute lung injury, due to plasma
from female donors containing antileucocyte antibodies, may be a
common contributor to the development of acute lung injury (ALI)
in the critically ill. In July 2003 the English Blood Service stopped
using female donor plasma for the manufacture of fresh frozen
plasma (FFP). Patients undergoing repair of ruptured abdominal
aortic aneurysm (AAA) receive large amounts of FFP and often
develop ALI. We investigated whether the change to male-only
FFP was associated with a change in incidence of ALI in patients
undergoing emergency AAA repair. P373
The beneficial effects of the combined methods in
investigating heparin-induced thrombocytopenia
M Kounavi, C Kroupis, E Iliopoulou, D Karamichaleli,
M Katafigioti, D Degiannis, E Melissari
Onassis Cardiac Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P373 (doi: 10.1186/cc5533) P376 Octaplex in routine clinical use for prophylaxis and therapy
of bleeding in patients with prothrombin complex factor
deficiency Methods The objective of this prospective, open-label study was
to demonstrate that Octaplex, when individually dosed, efficiently
corrects the INR within 1 hour post infusion. Sixty patients were
included, 56 of them evaluable in terms of efficacy. T Franken1, W Rees2, N Hübner2, J Albers3, B Gansera4, M Uhl5,
C Niessner6, B Sedemund-Adip7, T Tödter8
1Octapharma GmbH, Langenfeld, Germany; 2Schüchtermannklinik,
Bad Rothenfelde, Germany; 3Klinikum der Joh Gutenberg Universität,
Mainz, Germany; 4Städt Krankenhaus München-Bogenhausen,
München, Germany; 5Klinikum Starnberg, Germany; 6Diakonissen
Krankenhaus, Karlsruhe, Germany; 7Universitätsklinikum Lübeck,
Germany; 8Albertinen-Krankenhaus, Hamburg, Germany
Critical Care 2007, 11(Suppl 2):P376 (doi: 10.1186/cc5536) Results The median total dose was 41.1 IU/kg body weight (range
15.3–83.3 IU/kg body weight). In total the mean infusion rate was
6.42 ml/minute for the first infusion. In about one-third of the
patients an average infusion rate of ≥8 ml/minute was used. The
median INR decreased from 2.8 (1.5–9.5) to 1.1 (1.0–1.9) after
10 minutes and remained at that level at measurements 30 and
60 minutes after infusion. There was a rapid increase in coagulation
factor activity within the first 10 minutes as well. This activity
remained stably elevated for at least 4–6 hours, confirming the INR
results. Of 56 patients evaluable for efficacy, for 51 (91%) the
geometric mean of postinfusion values was equal to or less than
the predetermined target INR. Overall haemostatic efficacy was
assessed as ‘excellent’ by investigators in all 56 patients. Three of
the 60 patients had minor adverse drug reactions possibly related
to Octaplex. No evidence of thrombotic side effects was observed. Conclusions Octaplex corrects quickly, effectively and safely the
INR to a predetermined level in patients with vitamin K antagonist-
related deficiency of prothrombin complex coagulation factors. Introduction Octaplex is a new prothrombin complex concentrate
that is indicated for treatment or perioperative prophylaxis of
bleeding in patients with deficiency of the prothrombin complex
coagulation factors, such as deficiency caused by treatment with
vitamin K antagonists or by liver failure, when rapid correction of
bleeding is required. The study was conducted to demonstrate
both prevention of bleeding and achievement of haemostasis in
acute bleeding and to obtain further information about the safety of
administration of Octaplex. Methods One hundred and one patients were included in this
observational study with determination of the INR as part of routine
clinical management. P375 A biochemical comparison of Octaplas with a universally
applicable development product (Uniplas) and single-
donor fresh-frozen plasmas subjected to methylene-blue
dye and white-light treatment Conclusions In comparison with the HIT-positive control group it
was found that: a 92% agreement existed between the HIPA and
the platelet microparticle assays; and the positive results in the
ELISA were significantly lower than in the functional methods,
indicating perhaps a lower sensitivity (41% agreement with the
flow cytometric method and 32% with the HIPA). Therefore, the
combination of functional and antibody detection assays is a
necessity for the HIT recognition since both could give pseudo-
positive or pseudo-negative results. A Heger, J Römisch, T Svae
Octapharma PPGmbH, Vienna, Austria
Critical Care 2007, 11(Suppl 2):P375 (doi: 10.1186/cc5535) A Heger, J Römisch, T Svae
Octapharma PPGmbH, Vienna, Austria
Critical Care 2007, 11(Suppl 2):P375 (doi: 10.1186/cc5535) Introduction The aim of this study was to perform an extensive
biochemical
comparison
of
the
pharmaceutically
licensed
coagulation active plasma Octaplas with an identical, but
universally applicable, development product (Uniplas) and single-
donor fresh-frozen plasma (FFP) units subjected to a medical
device treatment using a combination of methylene-blue dye and
subsequent white-light exposure (MB plasma). S150 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 investigators evaluated the overall efficacy of Octaplex in 84.2% of
cases as ‘very good’ and in 14.9% of cases as ‘moderate’. No
adverse drug reactions or interactions were reported. Conclusions Octaplex is effective in perioperative prophylaxis of
bleeding in patients with a coagulation deficit caused by treatment
with vitamin K antagonists. Octaplex is also effective in treatment
of acute bleeding. Octaplex was well tolerated, with no adverse
reactions being reported during the study. Methods Twenty-four batches of Octaplas of different blood
groups and different plasma sources, three batches of Uniplas
(both products manufactured by Octapharma PPGmbH, Vienna,
Austria) and 20 random commercially available bags of MB plasma
of different blood groups were analysed. Beyond the global
coagulation parameters, the activities of coagulation factors and
protease inhibitors, as well as plasminogen, activated factor VII,
plasma turbidity and lipid components, were quantified. investigators evaluated the overall efficacy of Octaplex in 84.2% of
cases as ‘very good’ and in 14.9% of cases as ‘moderate’. No
adverse drug reactions or interactions were reported. Conclusions Octaplex is effective in perioperative prophylaxis of
bleeding in patients with a coagulation deficit caused by treatment
with vitamin K antagonists. P375 Octaplex is also effective in treatment
of acute bleeding. Octaplex was well tolerated, with no adverse
reactions being reported during the study. Results Similar to Octaplas, Uniplas showed standardised levels
of coagulation factors, plasminogen and protease inhibitors
(decreased protein S and antiplasmin activities) according to the
product specifications. MB plasma revealed fibrinogen levels close
to or below the physiological range (<1.5 mg/ml). Coagulation
factor activities in single MB plasma units both below and above
the normal ranges for FFP were found in this study, reflecting the
considerable variability of clinically important plasma proteins. Moreover, MB plasma revealed a higher turbidity after thawing,
probably due to the elevated lipid parameters. P376 The endpoint of this study was perioperative
prophylaxis of bleeding or successful treatment of acute bleeding
according to clinical signs. P377 Reversal of oral anticoagulation with prothrombin complex
concentrate (Octaplex) H Riess1, A Meier-Hellmann2, J Motsch3, M Elias4, F Kursten5,
C Dempfle6
1Charité-Universitätsmedizin Berlin, Germany; 2HELIOS Klinikum
Erfurt GmbH, Erfurt, Germany; 3Universitätsklinikum Heidelberg,
Germany; 4HaEmek Medical Center, Afula, Israel; 5Octapharma
Pharmazeutika Produktions ges.m.b.H., Wien, Austria;
6Universitätsklinikum Mannheim, Germany
Critical Care 2007, 11(Suppl 2):P377 (doi: 10.1186/cc5537) Conclusion This study showed that there are significant differences
in the biochemical characteristics between Octaplas and MB
plasma, while Uniplas revealed the same high quality as Octaplas. The variability of several plasma proteins in the 20 individual MB
plasma units tested was high compared with Octaplas/Uniplas. For
plasma prescribers and physicians it is also important to consider
the significant loss of functional fibrinogen in MB plasma when
planning and monitoring the treatment of severely ill patients. Introduction Oral anticoagulant therapy with vitamin K antagonists
may need to be rapidly reversed if acute bleeding occurs or surgical
intervention is required. This can most effectively be achieved by
administering prothrombin complex concentrates (PCCs), which
correct the INR more quickly than fresh frozen plasma without the
problem of volume overload. Octaplex, a virus-inactivated PCC con-
taining balanced potencies of coagulation factors and the regulating
proteins C and S, was developed with the intention of making a
rapid contribution to coagulation whilst limiting the risk of thrombosis. Methods The objective of this prospective, open-label study was
to demonstrate that Octaplex, when individually dosed, efficiently
corrects the INR within 1 hour post infusion. Sixty patients were
included, 56 of them evaluable in terms of efficacy. P378 vein thrombosis and spinal cord infarction. Of these two, one died
secondary to coagulopathic complications post initiation of
warfarin therapy 2 weeks post surgery. vein thrombosis and spinal cord infarction. Of these two, one died
secondary to coagulopathic complications post initiation of
warfarin therapy 2 weeks post surgery. Conclusion Our results support the evidence that recombinant
factor VII is an effective haemostatic agent that can be used in
patients with uncontrolled bleeding in postcardiopulmonary bypass
surgery. Despite its high cost, there is an advantage in terms of
effectiveness to support its use. However, its potential thrombo-
embolic risk remains a concern and current evidence may restrict
its use only as a rescue therapy following failed conventional
treatment. Results
Indications for administration of the rFVIIa were
considered when there was a postsurgical bleeding (exceeding
400 ml/hour) in the absence of surgical sources of the bleeding
and lack of efficacy of the conventional hemostatic procedures. After administration of the first median dose (14.45–81.35 µg/kg)
rFVIIa bleeding stopped in 11 patients. A marked decrease
occurred in seven patients during 2 hours. The average blood lost
within 12 hours before treatment was 2,510 ml and the average
blood lost within 12 hours after treatment was 1,057 ml. The
average dynamic of bleeding before treatment was 1,057 ml/hour
and 87.90 ml/hour after treatment. The reduction in transfusion
requirements was statistically significant. Conclusion Our results support the evidence that recombinant
factor VII is an effective haemostatic agent that can be used in
patients with uncontrolled bleeding in postcardiopulmonary bypass
surgery. Despite its high cost, there is an advantage in terms of
effectiveness to support its use. However, its potential thrombo-
embolic risk remains a concern and current evidence may restrict
its use only as a rescue therapy following failed conventional
treatment. A Kogan1, E Sharoni2, A Stamler2, M Stein2, B Medalion2,
B Vidne2, E Raanani1
1Sheba Medical Center, Ramat Gan, Israel; 2Rabin Medical Center,
Petah Tiqwa, Israel
Critical Care 2007, 11(Suppl 2):P380 (doi: 10.1186/cc5540) A Kogan1, E Sharoni2, A Stamler2, M Stein2, B Medalion2,
B Vidne2, E Raanani1
1Sheba Medical Center, Ramat Gan, Israel; 2Rabin Medical Center,
Petah Tiqwa, Israel
Critical Care 2007, 11(Suppl 2):P380 (doi: 10.1186/cc5540) P378 Experience of NovoSeven administration in the
management of severe haemorrhage following cardiac
surgery of nonhaemophilic patients Results The total dose administered per patient varied from 5.6 to
63.5 IU/kg bodyweight with a median dose of 20.4 IU/kg bodyweight. The median infusion rate was 3 ml/minute; in some cases up to
10 ml/minute were administered without any adverse reactions. The
administration of Octaplex reduced the INR on average from 2.3 to
1.5. Infusion of 25 IU Octaplex per kg body weight resulted in an
average decrease of about 1.2 in INR. A subgroup analysis of those
patients with a postinfusion measurement within 1 hour after
application of Octaplex showed a fast onset of action. The G Michalska, R Stanek
Clinical Hospital, Szczecin-Police, Poland
Critical Care 2007, 11(Suppl 2):P378 (doi: 10.1186/cc5538) G Michalska, R Stanek
Clinical Hospital, Szczecin-Police, Poland
Critical Care 2007, 11(Suppl 2):P378 (doi: 10.1186/cc5538) S151
Introduction Severe bleeding in cardiac surgery is often difficult
to manage. The aim of this study is clinical evaluation of efficacy of Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P379)
Mean hourly drain output 6 hours pre and 2 hours post NovoSeven
administration. Figure 1 (abstract P379) rFVIIa in the treatment of bleeding during and after cardiac
surgery. Patients and methods rFVIIa (NovoSeven; NovoNordisk, Bagsvaerd
Denmark) was used in 20 adult patients aged between 41 and
74 years, average BMI 25.48 ± 4.03, who underwent open heart
surgery (five coronary artery bypass surgery, two valvular surgery,
four double valve operations, five combining operations (coronary
artery bypass with valve repair) and four surgery for aortic
aneurisms) in 2004–2006. All patients had normal coagulation
parameters before surgery. We used questionnaires for indications
and effectiveness of treatment. We compared the amount of blood
lost within 12 hours before and within 12 hours after giving rFVIIa,
the dynamics of bleeding (assessed in ml/hour) before and after
treatment. We also compared the haemoglobin level, haematocrit,
number of platelets and laboratory coagulation profile parameters
before treatment, 2 hours and 12 hours after treatment. NovoSeven was administered 5–49 minutes after neutralization of
heparin with protamin sulfate. The dosage of rFVIIa was 39.23 ±
20.70 µg/kg (range 14.45–81.35). We used Student’s t test for
statistical analysis the laboratory data prior to and after rFVIIa. Mean hourly drain output 6 hours pre and 2 hours post NovoSeven
administration. Factor VII for intractable bleeding after cardiac surgery Conclusions NovoSeven produces a potent haemostatic effect in
bleeding events refractory to the conventional therapy complicating
the cardiosurgical interventions, and substantially decreases the
demand for blood transfusion. The influence of severe preeclampsia on maternal cerebral
perfusion E Shifman, A Ivshin, E Gumenuk
Republican Perinatal Center, Petrozavodsk, Russian Federation
Critical Care 2007, 11(Suppl 2):P382 (doi: 10.1186/cc5542) M Liebl, F Masud, F Bostan, E Chi, S Pass, K Stuebing
The Methodist Hospital, Houston, TX, USA
Critical Care 2007, 11(Suppl 2):P381 (doi: 10.1186/cc5541) Introduction The method of transcranial color scan can be used to
improve and to simplify cerebral blood flow investigations. Combi-
nation of digital wide-range neurosonography and transcranial
energetic Doppler scan provides a possibility of effective monitoring
of cerebral blood flow. The goal of this study was to analyze
cerebral flow disturbances in pregnant patients with preeclampsia. Methods Eighty-eight patients with severe preeclampsia, age
17–32 years (mean age 26 ± 4.6 years), and 90 patients with
normal pregnancy, third trimester, without significant co-morbid
states, age 19–34 years (mean age 25.9 ± 4.2 years), were
included in the study. Patients with the following features were
excluded from both groups: potentially haemodynamically signifi-
cant stenosis or occlusion of magistral arteries of the head and
basilar region; clinical features of congestive heart failure; arrhyth-
mia. All patients underwent duplex scan of extracranial portions of
brachiocephalic arteries with a linear probe and transcranial duplex
scan (TCDS) in the area of the middle cerebral artery (MCA). By
the transtemporal approach in the MCA M1 segment we
determined the peak systolic flow velocity (Vps), maximal end-
diastolic velocity (Ved), time-adjusted maximal velocity (TAMX),
resistance index (RI), pulsative index (PI), and systolic/diastolic
ratio (S/D). Significance of mean values differences in groups was
estimated using Student t criteria. This study describes patient characteristics, recombinant activated
factor VII (RF7a) dosing and clinical outcomes of cardiovascular
surgery patients treated with RF7a for intractable bleeding. Use of
RF7a for postsurgical bleeding, trauma or other uses in non-
hemophiliac patients is considered off-label in the USA. Compre-
hensive studies evaluating RF7a in cardiac surgery patients are
limited. Published reports cite success with RF7a administration in
massive intractable bleeding. However, patient selection, dosing,
efficacy, safety and pharmacoeconomic benefit remain undefined. Patients receiving RF7a between January 2004 and September
2005 were identified via pharmacy records. Clinical databases and
electronic medical records were reviewed, collecting data
elements needed to assess study objectives. One hundred and
twenty patients were identified. Twenty-seven patients were
excluded because they lacked documentation of RF7a admini-
stration, were treated for neurologic indications or had incomplete
medical record data. Ninety-three patients were analyzed. Evaluation of the role of recombinant activated factor VII
(NovoSeven) as a rescue haemostatic therapy in
postcardiopulmonary bypass surgical patients Seven of 22 patients survived and were discharged
from the hospital surgical re-exploration and other potential related adverse events
(stroke, AMI, VTE, etc.) are forthcoming. Our study, like others
evaluating RF7a for this indication, are limited by the retrospective
scope. Randomized trials comparing RF7a doses are under way. Although RF7a therapy is costly, minimal reductions in surgical re-
exploration may offset the cost of RF7a therapy provided that
adverse events are not increased. Conclusion rFVIIa is effective in promoting hemostasis after
cardiac surgery. rFVIIa should be considered as a possible
treatment option in intractable bleeding treatment. Evaluation of the role of recombinant activated factor VII
(NovoSeven) as a rescue haemostatic therapy in
postcardiopulmonary bypass surgical patients Introduction
Recombinant
activated
factor
VII
(rFVIIa)
(NovoSeven®; Novo Nordisk, Denmark) was developed primarily
for the treatment of bleeding episodes in hemophilic patients. Little
information is available on the use of rFVIIa in other situations, such
as intractable postsurgical or post-traumatic bleeding. In the field
of cardiac surgery, only a very few cases of treatment with rFVIIa
are described. Because of the difficulty in performing randomized
trials in this setting, information based on case studies is very
valuable Z Chen1, V Rasiah1, A Dewhurst2
1St George’s Hospital NHS Trust, London, UK; 2St Georges
Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P379 (doi: 10.1186/cc5539) Objective Evaluation of the safety and efficacy of recombinant
activated factor VII (NovoSeven) when used as a rescue
haemostatic agent in refractory bleeding post bypass surgery. Methods We studied 22 consecutive patients treated with rFVIIa
due to refractory postoperative bleeding. rFVIIa was given only
after all other options, including revision, to stop bleeding was
failed. The amount of bleeding, the number of transfused units of
red cells, platelets and other blood products were recorded both
before and after administration of rFVIIa. Methods A retrospective cohort study of all postcardiopulmonary
bypass patients with uncontrolled bleeding despite conventional
treatment (platelets, fresh frozen plasma, cryoprecipitate, and
Aprotonin) who received recombinant factor VII as a rescue
therapy over 12 months in a cardiothoracic centre. Results Eight patients received NovoSeven (90 µg/kg). Seven
achieved significant reduction in blood loss. The mean blood loss
via thoracic drains 6 hours before and 2 hours after NovoSeven
administration were 341 ml/hour vs 117 ml/hour (P = 0.01) (Figure 1). On average, 5.3 units/patient packed red blood cells, 2 pools/
patient platelets, 19 ml/kg/patient fresh frozen plasma and 148 ml/
patient
cryoprecipitate
were
used
prior
to
NovoSeven
administration. Five patients required further blood transfusion with
a mean of 2.2 units/patient over the next 12 hours. Two of the eight
patients developed thromboembolic complications including portal Table 1 (abstract P380)
Treatment
Before
After
Bleeding (ml/hour)
350
135
RBC
7.8 ± 2.3
1.5 ± 1.4
FFP
8.5 ± 2.4
2.5 ± 2.4
Platelets
14.5 ± 6.2
2.4 ± 2.1
Cryo
5.1 ± 1.4
0 S152 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Results See Table 1. In all patients, bleeding was decreased
significantly. Seven of 22 patients survived and were discharged
from the hospital Results See Table 1. In all patients, bleeding was decreased
significantly. Recombinant activated factor VII treatment of severe
bleeding in cardiac surgery patients: a retrospective
analysis of dosing, and efficacy and safety outcomes Recombinant activated factor VII treatment of severe
bleeding in cardiac surgery patients: a retrospective
analysis of dosing, and efficacy and safety outcomes The influence of severe preeclampsia on maternal cerebral
perfusion P382 Recombinant activated factor VII treatment of severe
bleeding in cardiac surgery patients: a retrospective
analysis of dosing, and efficacy and safety outcomes
M Liebl, F Masud, F Bostan, E Chi, S Pass, K Stuebing
The Methodist Hospital, Houston, TX, USA
Critical Care 2007, 11(Suppl 2):P381 (doi: 10.1186/cc5541) Figure 1 (abstract P381) g
Figure 2 (abstract P381) Figure 2 (abstract P381) The influence of severe preeclampsia on maternal cerebral
perfusion RF7a
effectively achieves hemostasis in patients with intractable
bleeding, reducing blood product transfusions within 6 hours of
treatment (Figure 1). Our findings suggest differences in PRBC
transfusion reduction between RF7a doses. We observed no
additional reduction PRBC transfusions in patients administered
doses greater than 60–90 µg/kg (Figure 2). Effects of RF7a on Results All haemodynamic values in preeclamptic patients were
decreased in comparison with the same values in healthy pregnant
women: PI (mean 0.71 vs 0.84, P < 0.0001); RI (mean 0.49 vs
0.54, P < 0.0001); Vps (mean 72.8 vs 104.8 cm/s, P < 0.0001); Ved
(mean 34.7 vs 48.7 cm/s, P < 0.0001); TAMX (mean 48.5 vs
67.5 cm/s, P < 0.0001); S/D (mean 1.94 vs 2.05, P < 0.001). These pathophysiological changes of cerebral haemodynamics
were consistent with the Dopplerographic pattern of diminished
perfusion and are typical for vascular segments, which are located
proximally to the zone of abnormally high haemodynamic resistance. Conclusion The results of the performed study showed that
patients with severe preeclampsia had decreased cerebral
perfusion and TCDS is an effective method for estimation of
preeclampsia severity. Stroke and pregnancy: etiology, timing and outcome Stroke and pregnancy: etiology, timing and outcome R Souissi, W Trabelsi, Z Haddad, M Boubaker, M Lamourou,
K Baccar, C Kaddour, L Skandrani
National Institute of Neurology, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P384 (doi: 10.1186/cc5544) Patients and methods Prospective data collection as part of the
APRiMO study (Assessment of Prognosis and Risk of Mortality in
Obstetrics). Included were all obstetric patients transferred from a
referral center for high-risk pregnancies in our independent multi-
disciplinary ICU. The study period was January 1996–September
2004. Demographic data, obstetric history, morbid events, length
of stay (LOS), severity of illness scoring systems and organ
dysfunction scores at day 1 of admission were collected. Exclusion
criteria were LOS < 4 hours. The main outcome of interest was
survival status at ICU discharge. Two groups were compared:
patients with HELLP syndrome as defined alternatively by the two
classifications (Group I), and patients without hepatic dysfunction
(Group II). Results are expressed as the mean ± standard
deviation. P < 0.05 was considered significant. Discrimination of
the classifications was assessed by the area under the receiver
operator characteristic curve (AuROC). Calibration was assessed
by the Hosmer–Lemeshow (HL) goodness-of-fit test. Data were
computed on SPSS 11.5, Win-XP compatible. Background and goal Most previous studies on stroke during
pregnancy have mainly focused on incidence and risk factors. These studies have not reported details of etiology and stroke
outcome. The present study focuses on the evaluation of the
etiology, timing and outcome of stroke occurring during
pregnancy. Materials and methods We conducted a retrospective analysis
on all obstetric patients who have been diagnosed with stroke
during pregnancy or within 8 weeks postpartum. These patients
were transferred to our multidisciplinary ICU between January
1996 and December 2004. All patients were investigated with a
CT scan of the brain, and MRI and/or cerebral angiography. Results Eighty-eight patients were included, 34 of them were
excluded (incomplete investigations or nonstroke diagnosis:
reversible leucoencephalopathy, cerebral abscess, etc.). Fifty-four
patients with a diagnosis of stroke were identified: 30 patients with
ischemic stroke (IS) and 24 patients with hemorrhagic stroke (HS). The majority of events (45 patients, 83%) occurred in the third
trimester and postpartum period (P = 0.02). A specific cause was
identified in 24 patients (80%) of IS and in 21 patients (87%) of
HS. Stroke and pregnancy: etiology, timing and outcome Causes of IS include preeclampsia/eclampsia in 11 patients,
venous thrombosis and coagulopathies (deficiencies of protein C,
protein S, and activated protein C resistance) in nine patients,
valvular heart disease with history of prior stroke in four patients
and six patients had no definable cause. The major causes of HS
were preeclampsia/eclampsia in eight patients, four patients
presented with hemorrhage secondary to aneurysmal rupture,
three patients presented with bleeding from arterio-venous
malformations (AVM), bleeding as a consequence of disseminated
intravascular coagulation (DIC) occurred in two patients and seven
patients had hemorrhagic events of unknown origin. Hypertensive
disorders of pregnancy were the most common comorbid
conditions (32%). Results and discussion Differences between Group I and Group
II were statistically significant concerning obstetric hemorrhagic
complication (P < 0.001), incidence of acute renal failure
(P = 0.01), mortality (P = 0.001), LOS (6.5 ± 7 days vs 4.4 ± 4 days,
P = 0.001), SAPS-Obst score (24.5 ± 8 vs 16.8 ± 7, P < 0.001). The Mississippi classification discriminated well, but calibrated
badly. In contrary, the Tennessee classification was a poor
discriminator but calibrated very well. See Table 1. P383 HELLP syndrome: utility of specific classifications as
prognostic tools R Souissi, Z Haddad, W Trabelsi, N Baffoun, M Boubaker,
C Kaddour, L Skandrani
National Institute of Neurology, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P383 (doi: 10.1186/cc5543) R Souissi, Z Haddad, W Trabelsi, N Baffoun, M Boubaker,
C Kaddour, L Skandrani
National Institute of Neurology, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P383 (doi: 10.1186/cc5543) S153
Introduction HELLP syndrome is a specific complication of
pregnancy characterized by hemolysis, elevated liver enzymes and ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Table 1 (abstract P383) Number of patients, discrimination and calibration statistic tests
for each classification
Classification
Dead
Alive
Tennessee
n = 45 (20.3%)
n = 177
Mississippi
n = 20 (26.7%)
n = 55
ROC
HL
Tennessee
0.75
0.001
Mississippi
0.64
0.533 Number of patients, discrimination and calibration statistic tests
for each classification Nineteen deaths (35%) occurred in our study, eight patients with
infarction and 11 patients with hemorrhage. Thirty-one patients left
the hospital with neurologic deficits, requiring chronic care or
rehabilitation. Discussion and conclusion The results of the present study
complement the findings of previous studies on timing of stroke in
pregnancy [1,2]. We found that preeclampsia/eclampsia and
intracranial vascular malformations were the major causes of stroke
in pregnancy, which agrees with other findings [2,3]. Our study
shows a high mortality rate of 35%, which indicates that careful
management of at-risk patients during the first postpartum weeks is
warranted. Conclusion Both models classified patients according to different
criteria but were correlated with mortality. None of the
classifications discriminated and calibrated well at the same time. The two models seem to be complimentary. Development of an
aggregate classification could refine the models. classifications discriminated and calibrated well at the same time. The two models seem to be complimentary. Development of an
aggregate classification could refine the models. 1. Audibert F, Friedman SA, Frangieh AY, Sibai BM: Clinical
utility of strict diagnostic criteria for the HELLP syndrome. Am J Obstet Gynecol 1996, 175:460-464. P384 low platelet count. Maternal mortality was reported to be as high as
24%. Two classifications of the HELLP syndrome are widely used
(Tennessee [1] and Mississippi [2]). The aim of this study is to
determine mortality of HELLP syndrome as defined by each
classification and try assessing the most relevant. Fractional excretion of urea in the follow-up of acute renal
failure due to prerenal azotemia Fractional excretion of urea in the follow-up of acute renal
failure due to prerenal azotemia Results Six hundred and forty patients were reviewed (mortality
rate 13.3%). ARF was diagnosed in 223 patients. Main risk factors
present at admission were: acute circulatory failure, transfusion
and association with haemolysis elevated liver enzyme and low
platelet count (HELLP) syndrome. ARF patients with HELLP
syndrome on admission were most likely to develop and alter
multiple organ dysfunctions/failures. ARF is associated with an
elevated relative risk of mortality (x1.5). Anuria and a serum
creatinine level > 300 µmol/l were independent risk factors for
mortality (OR 2 and 7, respectively). The ICU mortality of ARF
patients increased with the number of failing organs on admission,
especially persistent circulatory failure over time. The LOD score is
at least as good as the SOFA score in evaluating the association
MOF–ARF with mortality. In fact, LOD cutoff values defining
cardiovascular, respiratory hepatic and hematologic organ failures
fit particularly our obstetric population. S Kuster, C Giambarba, A Kneubühl, G Keusch
Stadtspital Waid, Zürich, Switzerland
Critical Care 2007, 11(Suppl 2):P387 (doi: 10.1186/cc5547) Fractional excretion of urea (FEU) is a major issue to discriminate
between prerenal azotemia and acute tubular necrosis in acute
renal failure (ARF). Its role in the course of ARF remains unclear. The aim of this study was to evaluate FEU in the follow-up of ARF
due to prerenal azotemia in order to predict the necessity of renal
replacement therapy (RRT). The prospective study took place at the ICU of Stadtspital Waid,
Zürich. All patients admitted starting from 19 February 2006 were
evaluated for ARF according to the RIFLE classification. ARF due to
prerenal azotemia was defined as ARF combined with FEU of less
than or equal to 35%. FEU was calculated as [(urine urea/blood
urea)/(urine creatinine/plasma creatinine)] x 100. Urine specimens
were taken and FEU was calculated daily until complete or partial
renal recovery was reached or the criteria for RRT were met. The
goal of therapy was reconstitution of renal function by treatment of
the underlying condition. RRT was initiated according to the usual
criteria. Statistics were determined using Fisher’s exact test. Conclusions Most important risk factors for ARF or mortality are
often present on admission. Reference 1. Bellomo et al.: Crit Care 2004, 8:R204–R212. 1. Bellomo et al.: Crit Care 2004, 8:R204–R212. Figure 1 (abstract P387)
Fractional excretion of urea (FEU) in the follow-up of acute renal failure
(ARF) due to prerenal azotemia. Data presented as mean ± SD. n =
number of patients. Figure 1 (abstract P387) Acute renal failure in obstetrics: risk factors and outcome Methods A retrospective observational study was performed in a
general ICU at a Swedish university hospital. All adult patients
treated at the ICU during 2004–2006 were included. Reduced
kidney function was defined as ≤80 ml/min/1.73 m2. Z Haddad1, C Kaddour2, R Souissi2, T Chaaoua2,
M Laamourou2, I Pipien1, S Nagi2
1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia
Critical Care 2007, 11(Suppl 2):P385 (doi: 10.1186/cc5545) Results GFR markers are frequently ordered in the ICU. The
majority of the patients had a reduced kidney function as evaluated
by Cystatin C and/or p-creatinine. A total 92.1% of the patient test
results had Cystatin C estimated GFR (eGFR) ≤80 ml/min/1.73 m2,
75.3% had eGFR ≤50 ml/min/1.73 m2 and 30.4% had eGFR
≤20 ml/min/1.73 m2. In contrast, only 46% of the patients had
reduced renal function assessed by plasma creatinine. Introduction Acute renal failure (ARF) was newly recognized as a
specific mortality risk factor [1] and is in general associated with a
high mortality rate. Introduction Acute renal failure (ARF) was newly recognized as a
specific mortality risk factor [1] and is in general associated with a
high mortality rate. Hypothesis Identifying risk factors for ARF could help reduce
mortality. We shall try to describe them in critically ill obstetric
patients, and explain ARF association with multiple organ failure
(MOF) and outcome using the Sequential Organ Failure Assessment
(SOFA) score and Logistic Organ Dysfunction (LOD) score. y p
Conclusions The GFR is commonly assessed in the ICU. Cystatin
C is a more sensitive GFR marker than creatinine. A majority of the
ICU patients had a reduced GFR. Many of the pharmaceuticals
used in the ICU are cleared by the glomeruli. It is thus important to
monitor kidney function regularly, using an adequate assay. When
possible, drugs with a plasma concentration that is less influenced
by the GFR should be used. Methods An open prospective observational cohort study in a
multidisciplinary ICU. All critically ill obstetric patients were
analysed unless diagnosed with chronic renal failure or kidney
transplant. ARF was defined as serum creatinine ≥100 µmol/l
and/or urine output ≤500 ml/day and/or doubling of baseline
serum creatinine levels. Fractional excretion of urea in the follow-up of acute renal
failure due to prerenal azotemia During the ICU stay, other organ
failures (especially cardiovascular) are important risk factors to
develop or alter renal function, especially persistence of circulatory
shock; thus, aggressive fluid challenge and volume infusion policy
could help ARF prevention. HELLP syndrome and ARF is a
particularly morbid association because of accumulating organ
failures. Reference P385 P385 using the creatinine and Cystatin C estimated GFRs as several
pharmaceuticals are prescribed according to renal function. using the creatinine and Cystatin C estimated GFRs as several
pharmaceuticals are prescribed according to renal function. References 1. Sharshar T, Lamy C, Mas JL: Incidence and causes of
strokes associated with pregnancy and puerperium. A
study in public hospitals of Ile de France. Stroke in Preg-
nancy Study Group. Stroke 1995, 26:930-936. 1. Sharshar T, Lamy C, Mas JL: Incidence and causes of
strokes associated with pregnancy and puerperium. A
study in public hospitals of Ile de France. Stroke in Preg-
nancy Study Group. Stroke 1995, 26:930-936. 2. Martin JN Jr, Magann EF, Blake PG, et al.: Analysis of 454
pregnancies with severe preeclampsia/eclampsia HELLP
syndrome using the 3-class system of classification. Am J
Obstet Gynecol 1993, 68:386. 2. Kittner SJ, Stern BJ, Feeser BR, Hebel R, Nagey DA, Buch-
holz DW, Earley CJ, Johnson CJ, Macko RF, Sloan MA, Wityk
RJ, Wozniak MA: Pregnancy and the risk of stroke. N Engl J
Med 1996, 335:768-774. 3. Jaigobin C, Silver FL: Stroke and pregnancy. Stroke 2000,
31:2948-2951 S154 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Hemodynamic goal-directed intermittent hemodialysis S Jog, P Akole, N Gogate, S Gadgil
Deenanath Mangeshkar Hospital and Research Centre, Pune, India
Critical Care 2007, 11(Suppl 2):P388 (doi: 10.1186/cc5548) Introduction Intermittent hemodialysis (IH) is the commonest form
of renal replacement therapy (RRT) in the majority of Indian ICUs
as each continuous veno-venous hemofiltration session for 24 hours
costs around €250, against IH that costs around €25/4 hour
session. The major concern of IH in septic shock patients is
hemodynamic instability. Whether stringent hemodynamic monitor-
ing and maintaining preset goals would reduce these instabilities
and deliver optimal RRT is not clear. We undertook a prospective
study to evaluate this concept. Results There were 168 consecutive patients (86 males). The
mean age was 55 ± 19 years. The mean APACHE II score was
11 ± 8. Main reasons for ICU admission according to APACHE II
classification were gastrointestinal perforation/obstruction n = 100,
gastrointestinal surgery due to neoplasia n = 21, vascular surgery
n = 18, gastrointestinal bleeding n = 6, hemorrhagic shock n = 5,
sepsis n = 5, chronic cardiovascular disease n = 4, respiratory
failure n = 3, cardiovascular n = 3, metabolic disturbance n = 2
and renal surgery due to neoplasia n = 1. The mean LOS was
5 ± 13 days. The DAKI frequency was 6.5% (n = 11). By means of
univariable analysis, risk factors for DAKI were male sex, creatinine
level ≥1.5 mg/dl at admission, APACHE II score ≥25, use of a
pulmonary artery catheter, need for mechanical ventilation
≥48 hours, hemoglobin level ≤7 g/dl, and enteral and parenteral
nutritional support. In the multivariate analysis, only APACHE II
score ≥25 (OR 14.9; 95% CI 1.9–111.6, P = 0.008), use of
enteral support (OR 20.3; 95% CI 3.5–117.7, P < 0.001) and use
of pulmonary artery catheter (OR 10.7; 95% CI 1.3–88.5,
P = 0.028) were independent predictors of DAKI. The overall
postoperative mortality rate was 10.7%; it was 54% in patients
with DAKI compared with 7.6% in patients without DAKI. P389 Predictive factors of dialytic acute kidney injury in patients
admitted to the intensive care unit after nontraumatic
emergency abdominal surgery F De Marco, M Barbosa, A Fantauzzi, C Nascimento,
W Imanishi, A Guimares
Hospital Vivalle, Sao Jose dos Campos, Brazil
Critical Care 2007, 11(Suppl 2):P389 (doi: 10.1186/cc5549) F De Marco, M Barbosa, A Fantauzzi, C Nascimento,
W Imanishi, A Guimares
Hospital Vivalle, Sao Jose dos Campos, Brazil
Critical Care 2007, 11(Suppl 2):P389 (doi: 10.1186/cc5549) In patients presenting with ARF due to prerenal azotemia, an
increase of FEU above 35% within the first 48 hours after initiation
of conservative therapy for ARF is a valuable parameter to predict
renal
recovery. After
initiation
of
conservative
therapy,
measurement of FEU is of no value concerning discrimination of
prerenal azotemia and acute tubular necrosis in ARF. Introduction Although postoperative risk factors for dialytic acute
kidney injury (DAKI) are well described in a wide range of clinical
settings, we have few data regarding nontraumatic emergency
abdominal surgery. The aim of this study was to describe these
factors in this subgroup of patients. P386 The majority of patients in a Swedish university hospital
intensive care unit have reduced glomerular filtration rate
measured by Cystatin C Introduction Renal dysfunction is associated with increased
morbidity and mortality in intensive care patients. The aim of this
study was to investigate the use of laboratory markers in an ICU,
especially glomerular filtration rate (GFR) markers, and to compare
two GFR markers, creatinine and Cystatin C. A secondary aim was
to assess the frequency of reduced GFR in this patient group Fractional excretion of urea (FEU) in the follow-up of acute renal failure
(ARF) due to prerenal azotemia. Data presented as mean ± SD. n =
number of patients. S155 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusion Goal-directed hemodynamic management during IH
can reduce hemodynamic instability and deliver reasonably opti-
mum RRT in the absence of continuous veno-venous hemofiltration
facilities. By 7 December 2006, 15 patients met the inclusion criteria for
ARF due to prerenal azotemia (nine males, six females). The mean
age was 71 ± 11 (SD) years for male patients and 58 ± 31 years
for female patients. Twelve out of the 15 patients responded to
conservative management and had complete or partial renal
recovery. Three patients needed RRT. Two of them refused RRT
and died during the course of the disease. During the first 48 hours
after initiation of conservative therapy, FEU remains less than or
equal to 35% in all three patients who needed RRT. By contrast,
nine out of 12 patients in whom renal function recovered without
RRT showed a FEU of more than 35% within the first 48 hours
(P < 0.05) (Figure 1). P388 Methods We have conducted a retrospective cohort study in
order to identify independent risk factors. We reviewed data from
patients admitted to the ICU after nontraumatic emergency
abdominal surgery from April 2003 to October 2006. Epidemio-
logical data, outcome and ICU resource utilization were recorded. Statistical analysis was performed by univariate analysis (Fisher’s
exact test, chi-square test) followed by multivariate stepwise
logistic regression. Hemodynamic goal-directed intermittent hemodialysis Methods Preset goals of keeping the mean arterial pressure
(MAP) > 75 mm, cardiac output (CO) > 5 l/min and cardiac index
(CI) > 2.5 l/min/m2 throughout the session were attempted to
achieve by a stepwise protocol as follows: (1) fluid boluses,
(2) increase in vasopressor/inotrope dose, (3) adjustment in the
ultrafiltration rate between 250 and 700 ml/hour, and (4) adjust-
ment in the blood flow rate between 150 and 300 ml/minute on a
hemodialysis machine. Dopamine, norepinephrine, vasopressin and
dobutamine were used alone or in combination to achieve these
goals. Hemodynamic monitoring and data collection were done
with Datex S-5 and Flo-Trac Vigileo monitors. Results Nineteen IH sessions of seven patients with septic shock
were monitored and managed in the ICU. The baseline APACHE II
score was 24.10 ± 4.98 and all patients had at least three organ
failures. The average duration was 4.42 ± 1.30 hours and fluid
removal was 2,000 ± 527 ml per IH session. The preIH MAP, CO
and CI were 81.10 ± 10.80 mmHg, 6.23 ± 2.24 l/min and
3.45 ± 1.07 l/min/m2, respectively. The MAP, CO, CI were
81.42 ± 8.44 mmHg, 6.27 ± 2.24 l/min and 3.49 ± 1.07 l/min/m2
at 60 minutes; 79.36 ± 15.33 mmHg, 6.24 ± 2.65 l/min and
3.46 ± 1.31 l/min/m2 at 120 minutes; 82.83 ± 14.00 mmHg,
6.48 ± 2.36 l/min and 3.60 ± 1.06 l/min/m2 at 180 minutes; and
84.44 ± 13.98 mmHg, 6.46 ± 2.17 l/min and 3.6 ± 0.95 l/min/m2
at 240 minutes, respectively. Preset goals were maintained with
fluids alone in four patients, fluids and escalation of vasopressor
was required in seven patients, and fluids, vasopressor escalation
with ultrafiltration and blood flow adjustments in six patients. Only
2/19 sessions were terminated at 120 and 90 minutes, due to
development of new myocardial infarction in one and persistent
hypotension in other. Conclusions DAKI following nontraumatic emergency abdominal
surgery has a high mortality rate, and APACHE II score ≥25, use
of enteral nutritional support and use of pulmonary artery catheter
are its postoperative predictive factors. P390 Introduction Despite the use of several prophylactic approaches,
contrast-induced nephropathy (CIN) remains a clinical problem. P390 Long-term outcome of patients with contrast-induced
nephropathy Introduction Despite the use of several prophylactic approaches,
contrast-induced nephropathy (CIN) remains a clinical problem. Introduction Despite the use of several prophylactic approaches,
contrast-induced nephropathy (CIN) remains a clinical problem. S156 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P391) Figure 1 (abstract P391) CIN is the third leading cause of hospital-acquired renal failure. CIN is associated with several risk factors such as diabetes and
hypertension as well as with prolonged hospitalization and
increased mortality. Little is known about long-term renal outcome. Within the last 10 years we have performed nine controlled studies
on prophylaxis of CIN with a total number of about 1,200 patients. It was the aim of this study to investigate the long-term outcome of
patients with CIN within these studies. y
Within the last 10 years we have performed nine controlled studies
on prophylaxis of CIN with a total number of about 1,200 patients. It was the aim of this study to investigate the long-term outcome of
patients with CIN within these studies. Methods This study presents the data of the first 25 patients with
CIN (planned: 80 patients) including serum creatinine 1 week,
1 month, 6 months and 1 year after the contrast medium. The
outcome was investigated by chart review and telephone call. Results All patients were Caucasian and had a mean age of
69.6 ± 10.6 years. Eight were female, 17 were male. Twenty-four
patients had risk factors for CIN such as diabetes (8%), hyper-
tension (44%) or both (28%) and preexisting renal impairment
(15%) prior to contrast medium application. Their mean serum creati-
nine before contrast medium application was 1.81 ± 1.21 mg/dl. The contrast procedure was coronary angiography in 18 patients
and CT in seven patients. For prophylaxis of CIN, six patients
received N-acetylcysteine and three patients received both N-
acetylcysteine and theophylline prior to contrast medium
exposition. Mean serum creatinine 48 hours after contrast medium
was 2.36 ± 1.36 mg/dl (P < 0.01 vs 0 hours). The mean maximum
creatinine increase was 0.64 ± 0.26 mg/dl (P < 0.01 vs 0 hours). Four patients (16%) died during the first week after contrast
medium, one of them despite initiation of dialysis 2 days after
contrast application. ICU than those without ARF. Patients with ARF showed higher
incidence of liver dysfunction, and needed a longer mechanical
ventilation and ICU stay. P391 Objective To investigate the effect of the antifibrinolytic agents
aprotinin and tranexamic acid on the occurrence of acute post-
operative renal dysfunction in cardiac surgery on patients treated
preoperatively with angiotensin-converting enzyme (ACE) inhibitors. Survey of acute renal failure in patients after
cardiovascular surgery N Iguchi, H Imanaka, M Takeuchi, T Nishida, M Ichikawa,
C Takayama, S Akaeda
National Cardiovascular Center, Suita, Osaka, Japan
Critical Care 2007, 11(Suppl 2):P391 (doi: 10.1186/cc5551) Methods A total of 7,420 patients who had undergone
nonemergency coronary artery bypass graft or valve surgery in the
Bristol Royal Infirmary from January 2000 until end of March 2006
were included in a retrospective observational study. The incidence
of postoperative renal dysfunction was compared in patients given
aprotin, tranexamic acid or no antifibrinolytic agent, using
propensity-adjusted multivariable logistic regression. Further
analysis was performed comparing patients taking ACE inhibitors
preoperatively with those not taking ACE inhibitors. Renal
dysfunction was defined as creatinine higher than 200 µmol/l
and/or renal dialysis. Patients with a previous history of renal
dysfunction were excluded from the study. Introduction Acute renal failure (ARF) is one of the major
complications after cardiovascular surgery. To investigate the
incidence and prognosis of ARF after cardiac surgery, we
performed a retrospective study. Our hypothesis is that ARF is
more common in patients who underwent surgery for great vessel
diseases than in those who underwent coronary or valve surgery. Methods We enrolled patients over 18 years old who underwent
cardiovascular surgery and entered our ICU between 2004 and
2005. The background diseases were classified into two groups:
great vessel disease, and coronary/valve disease. We determined
ARF when serum creatinine increased by more than 50% of the
preoperative values, or when renal replacement therapy was newly
started. By reviewing ICU charts, we collected data before, on
admission to the ICU and during the ICU stay. Results Using propensity-adjusted multivariable logistic regression
(C-index, 0.82), the use of aprotinin in patients taking ACE
inhibitors was associated with more than doubling the risk of acute
postoperative renal failure in patients undergoing nonemergency
cardiac surgery (odds ratio 2.64; confidence interval 1.32–5.27). Tranexamic acid was also associated with a significant increase in
the risk of renal failure (odds ratio 1.59; confidence interval
1.09–2.31) in patients taking ACE inhibitors. However, in this
study, there was no association between either aprotinin (odds
ratio 1.01) or tranexamic acid (odds ratio 1.19) and postoperative
renal failure in patients not taking ACE inhibitors. Results ARF occurred more frequently in patients with great
vessel disease than in those with coronary/valve disease (33.5%
vs 11.2%, P < 0.05). The prognosis of patients with ARF was
poorer than those without ARF in both groups (Figure 1). P390 Conclusion
ARF is common after cardiovascular surgery,
especially after surgery for great vessel disease. ARF was
associated with more postoperative organ disorders. P392 One year after CIN, the mean serum creatinine in the survivors was
1.85 ± 1.39 mg/dl (P = 0.48 vs 0 hours). A clinical relevant
increase of >0.3 mg/dl compared with baseline creatinine was
found in six (24%) patients. Antifibrinolytic agents and angiotensin-converting enzyme
inhibitors: the effect on postoperative renal dysfunction in
cardiac surgery R Mouton, A Binks, I Davies
Bristol Royal Infirmary, Bristol, UK
Critical Care 2007, 11(Suppl 2):P392 (doi: 10.1186/cc5552) R Mouton, A Binks, I Davies
Bristol Royal Infirmary, Bristol, UK
(
) Conclusion CIN is a serious complication of contrast medium
administration and is associated with an increased mortality and
long-time morbidity. Survey of acute renal failure in patients after
cardiovascular surgery Patients
with ARF showed a longer operation time, larger intraoperative
bleeding and a higher level of blood lactate on admission to the Conclusion In cardiac surgery, there is a significant association
between use of the antifibrinolytic drugs aprotinin and tranexamic S157 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin acid and the occurrence of acute postoperative renal dysfunction,
in patients taking ACE inhibitors. The potential blood-saving
benefits of antifibrinolytic drugs should be weighed up against this
serious postoperative complication. A comparison of Gc globulin and neutrophil gelatinase-
associated lipocalin in patients with liver disease Introduction A number of preoperative patient-specific risk factors
contribute to increased perioperative cardiovascular risk (myo-
cardial infarction, heart failure, death) in patients undergoing major
noncardiac surgery [1]. Renal impairment is one predictor. Creatinine values are a poor reflection of true renal function. Measures of the glomerular filtration rate provide a more accurate
measure of renal function; as such, the true prevalence of renal
impairment in this population may be significantly higher than
previously appreciated. Our aim was to identify that proportion of
elective vascular patients undergoing abdominal aortic surgery that
have CKD, assessed by the estimated glomerular filtration rate
(eGFR, ml/min/1.73 m2 body surface area; creatinine, µmol/l) [2]. A Portal, M Austin, M Bruce, E Sizer, G Auzinger, M Heneghan,
J Wendon
Kings College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P394 (doi: 10.1186/cc5554) Kings College Hospital, London, UK Introduction Gc globulin, a hepatically synthesized actin binding
protein, is known to decrease in both acute and chronic liver
disease, and low levels are associated with poor prognosis. Neutrophil gelatinase-associated lipocalin (NGAL), a member of
the lipocalin family of proteins, has been shown to be an early
biomarker of ischaemic renal damage. We prospectively
investigated the use of these proteins as markers of severity of
illness and prognostication in acute and acute-on-chronic liver
failure requiring intensive care. Introduction Gc globulin, a hepatically synthesized actin binding
protein, is known to decrease in both acute and chronic liver
disease, and low levels are associated with poor prognosis. Neutrophil gelatinase-associated lipocalin (NGAL), a member of
the lipocalin family of proteins, has been shown to be an early
biomarker of ischaemic renal damage. We prospectively
investigated the use of these proteins as markers of severity of
illness and prognostication in acute and acute-on-chronic liver
failure requiring intensive care. Methods A retrospective analysis of our ‘ABC study’ database
was undertaken. The ABC study is an ongoing study looking at
preoperative risk assessment using cardiopulmonary exercise
testing in patients undergoing elective aortic surgery. Methods NGAL and Gc globulin were measured on admission to our
unit using a sandwich ELISA technique (AntibodyShop®) in 17
patients with acute liver failure (ALF) and 11 patients with acute-on-
chronic liver disease (ACLD). Biochemical and physiological variables
were collected prospectively and entered into a physiological database
(ICARE). All measurements were taken on day 1 of admission. Results
are expressed as the median and interquartile range. P393 2. K/DOQI clinical practice guidelines for chronic kidney
disease: evaluation, classification, and stratification. Am J
Kidney Dis 2002, 39:S1-S266. P393
Preoperative assessment of patients undergoing
abdominal aortic surgery: chronic kidney disease is almost
always present
A Turley, S Owen, E Kothmann, M de Belder, A Parry, G Danjoux
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P393 (doi: 10.1186/cc5553) 3. JBS 2: Joint British Societies’ guidelines on prevention of
cardiovascular disease in clinical practice. Heart 2005, 91
(Suppl 5):v1-v52. 3. JBS 2: Joint British Societies’ guidelines on prevention of
cardiovascular disease in clinical practice. Heart 2005, 91
(Suppl 5):v1-v52. A Turley, S Owen, E Kothmann, M de Belder, A Parry, G Danjoux
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P393 (doi: 10.1186/cc5553) A comparison of Gc globulin and neutrophil gelatinase-
associated lipocalin in patients with liver disease Results Sixty-six patients were included in the analysis. All patients
were Caucasians, 62 males (94%). No patient had a pre-existing
diagnosis of chronic renal impairment. No patients had stage 4/5
CKD (severely reduced kidney function, eGFR < 30). Moderately
reduced kidney function (eGFR 30–59, CKD stage 3) was seen in
20 (30%) patients, and mildly reduced kidney function (eGFR
60–89, CKD stage 2) in 44 (67%). Only two patients had normal
kidney function. The mean total cholesterol for the cohort was
4.6 mmol/l (±1 mmol/l). See Table 1. g
Results Admission parameters: serum creatinine 185 µmol/l
(89–266), urine output/24 hours: 340 ml (0–1,111), APACHE II
score 20 (15–25), lactate 2.6 (1.8–4.68), INR 2.6 (1.6–3.8) and
AST 1,404 (124–6,349). There were significant differences
between median Gc globulin in ALF patients compared with
ACLD: 25 mg/l (10–50) vs 50 mg/l (25–129), P = 0.036. No
significant differences were seen for NGAL. Gc globulin correlated
with admission creatinine (r = 0.44, P < 0.01), INR (r = 0.68,
P < 0.01), and SOFA score (r = 0.419, P < 0.01) in both patient
groups. These relationships persisted when admission Gc globulin
was examined in regard to day 5 parameters. Admission Gc
globulin correlated with D3 urine output (r = 0.619, P < 0.001). NGAL correlated with urine output throughout the first 5 days of
admission (r = –0.593 on day 1, r = –0.674 on day 3, P < 0.001)
and also with SOFA score. High admission NGAL was associated
with requirement for renal replacement therapy on day 3 (ROC
AUC 0.91 (0.895–1.022, P < 0.001)), outperforming both
admission Gc globulin and admission creatinine. A low admission
Gc globulin more accurately predicted the need for haemofiltration
on day 5 (AUC 0.889, 0.734–1.044, P < 0.007) than either NGAL
or creatinine on admission. References acid and the occurrence of acute postoperative renal dysfunction,
in patients taking ACE inhibitors. The potential blood-saving
benefits of antifibrinolytic drugs should be weighed up against this
serious postoperative complication. 1. Eagle KA, Berger PB, Calkins H, et al.: ACC/AHA guideline
update for perioperative cardiovascular evaluation for
noncardiac surgery – executive summary. A report of the
American College of Cardiology/American Heart Associa-
tion Task Force on Practice Guidelines (committee to
update the 1996 guidelines on perioperative cardiovascu-
lar evaluation for noncardiac surgery). Anesth Analg 2002,
94:1052-1064. Acknowledgement David Finch, Audit & Information Systems,
Cardiac Services, is thanked for doing the statistical analysis. P395 Fibrinogen as a prognostic indicator in hepatic failure
M Thomas, M Duffy, G Auzinger, W Bernal, E Sizer, J Wendon
King’s College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P395 (doi: 10.1186/cc5555) M Thomas, M Duffy, G Auzinger, W Bernal, E Sizer, J Wendon
King’s College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P395 (doi: 10.1186/cc5555) Of the patients not admitted to our LITU (162 to ward and 176 to
IC), 79% were deemed too well to benefit and 2% due to no beds. the mean ± SD SOFA score for the too sick to benefit group
(19%) was 11.5 ± 4.3 (63% had decompensated chronic liver
disease (d-CLD), 36% with malignancy, major sepsis or morbid
cardiocerebral event). The mean ± SD SOFA scores for the ward,
IC and LITU groups were 2.5 ± 2.4, 7.9 ± 4.6 and 7.8 ± 4.5,
respectively. The SOFA liver score was highest in all three triage
groups, overall mean of 2.3 (ward, 1.9 ± 1.4; IC, 2.6 ± 1.2; LITU,
2.4 ± 1.2), compared with other components (respiratory 0.9,
cardiovascular 0.7, coagulation 0.9, renal 1.1, central nervous
system 0.8). Patients with INR > 6 were more likely to be triaged to
LITU (OR 4.2). Introduction Fibrinogen as a prognostic test of mortality in acute
hepatic failure has not been reported. Two hundred and sixty
patients admitted to the liver intensive therapy unit (LITU) with
hepatic failure (that is, subacute, acute and fulminant) between 1
January 2004 and 30 September 2006 were identified from the
LITU database (I-Care, UK). Twelve patients without fibrinogen
testing on admission were excluded from the analysis. Methods The mean (±SD) age was 38.1 (14) years. Ninety-seven
patients were male and 151 female; 116 had taken a paracetamol
overdose (POD). The mean (±SD) fibrinogen on admission was
1.88 (1.24) g/l. Overall ICU mortality was 30.2% (POD 43.4%;
non-POD 26.1%). Forty-nine patients received a transplant (14
POD and 35 non-POD). A total of 97 patients were admitted to our LITU (five of 17 patients
triaged at referral to our hospital liver ward); six patients died
before arrival and three patients were diverted to another liver
intensive care facility for family convenience. Fifteen patients
underwent liver transplantation (10/49 with ALDF, 5/37 with
d-CLD). Mortality in the LITU group was 36%, and highest with
d-CLD (57% vs 25% with ALDF). What is the role of carboxyhaemoglobin in patients with
liver failure? What is the role of carboxyhaemoglobin in patients with
liver failure? M Austin, A Portal, J Wendon
King’s College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P397 (doi: 10.1186/cc5557) Background Patients with liver failure have haemodynamic and
respiratory instability, the aetiology of which is unclear. Unregulated
vasoactive mediators may have an important role in this
physiological phenomenon. Carbon monoxide, a vasodilator, has
been extensively studied and is easily measured using circulating
carboxyhaemoglobin (COHb). The levels of circulating COHb have
been reported as being elevated in patients with stable cirrhosis
and hepatopulmonary syndrome. It is unknown whether the levels of
COHb are elevated in patients with liver failure. P395 Mean referral, post-transfer and
48-hour SOFA scores of LITU nonsurvivors were 10.7, 12.7 and
13.9, respectively (6.5, 7.7 and 7.5 for survivors). Results Fibrinogen levels (all in g/l) in survivors were higher than in
nonsurvivors (1.98 ± 1.26 vs 1.63 ± 1.15; P = 0.033). Fibrinogen
was higher in survivors of POD (1.81 ± 1.0 vs 1.41 ± 0.94;
P = 0.039) and not significantly different between groups in non-
POD hepatic failure (2.13 ± 1.43 vs 1.85 ± 1.31; P = 0.28). Fibrino-
gen was higher in those who survived after transplant (1.49 ± 0.83
vs 1.23 ± 0.23; P = 0.27). A cutoff value of fibrinogen of ≤1 g/l has
sensitivity 0.47 and specificity 0.74 (positive predictive value (PPV)
0.44) for prediction of death in acute hepatic failure. In POD the
sensitivity is 0.51, specificity 0.81 and PPV 0.59; in non-POD
hepatic failure the values are 0.29, 0.73 and 0.31 respectively. In
those POD who did not receive a transplant, fibrinogen ≤1 g/l has
sensitivity 0.61, specificity 0.78 and PPV of 0.57 for death. Fibrinogen is higher in survivors of hepatic failure after POD. Conclusions The refusal rate to our LITU due to no beds was low. Paracetamol remains a common cause for drug-induced liver injury,
although few are severe cases. The triage decision appeared to be
influenced by the INR, d-CLD with or without a reversible cause
and the presence/absence of morbid extrahepatic diagnoses. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 0.813, P = 0.006. There were no significant differences in NGAL
values between survivors and nonsurvivors for the whole group. NGAL was significantly lower in survivors than nonsurvivors in the
ACLD group (AUC 0.875, P = 0.47). 15-bed LITU as recorded on a standardised proforma. Data
evaluated were: referral diagnoses; reasons for refusal to LITU (‘too
well to benefit’, ‘too sick to benefit’ or ‘no beds’); triaged destination
of care (‘ward’ at referral hospital or our hospital liver ward, ‘IC’ at
referral hospital high-dependency unit/ICU or ‘LITU’); and parameters
for Sequential Organ Failure Assessment (SOFA) score. Conclusion Gc globulin and NGAL are potentially useful methods
of identifying patients with a particularly poor prognosis and those
needing renal replacement therapy. Further larger prospective
studies are needed to elucidate their exact role not only in liver
disease but also in the general ITU population. Result A total of 620 calls were received for 439 referrals (37%
during the 17:00–24:00 hours period, 11% during 00:00–08:00
hours), with 38% from the London region. Drug-induced acute liver
dysfunction/failure (ALDF) was the most common reason for
consultation (39%), with paracetamol being most common
(163/172), most of whom were triaged to a referral hospital ward
(63% vs 14% to LITU). Patients with diagnosis of ‘ischaemic
hepatitis’ tended to be triaged to IC (82%), and pancreatobiliary
disease and trauma to the LITU (69% and 80%). P397 Conclusion Fibrinogen ≤1 g/l performs better than INR > 6.5 in
predicting mortality after POD (sensitivity 0.69, specificity 0.61),
but not as well as the combined King’s College Criteria (sensitivity
0.69, specificity 0.96). Fibrinogen of ≤1 g/l in POD not meeting
King’s College Criteria for transplantation may identify a group with
poor prognosis. A low fibrinogen level on admission may predict
death after transplant (more data required). A comparison of Gc globulin and neutrophil gelatinase-
associated lipocalin in patients with liver disease S158
Table 1 (abstract P393)
CKD stage
Stage 1
Stage 2
Stage 3
Total
n
2
44
20
66
Age (years)
64.7 (3.4)
69.9 (8.3)
75.5 (7.7)
71.5 (8.4)
eGFR
92.5 (0.7)
69.4 (7.2)
52.35 (7.4)
64.9 (11.6)
Creatinine
78 (1.4)
97.8 (9)
125.2 (19.9)
105.5 (18.8)
Cholesterol
4.5 (0.5)
4.8 (1.1)
4.3 (0.9)
4.6 (1)
BP
1 (50%)
21 (48%)
9 (45%)
31 (47%)
Smoking
2 (100%)
31 (70%)
14 (70%)
49 (74%)
Diabetes
0
1 (3%)
2 (10%)
3 (5%)
Conclusion The majority of vascular patients undergoing elective
aortic surgery in our unit have impaired renal function that is not
accurately reflected by creatinine values. Management of patients
with stage 2 and 3 CKD is primarily cardiovascular risk assessment
with aggressive treatment of modifiable vascular risk factors [3]. The full impact of risk factor modification on perioperative outcome
in vascular patients requires further detailed investigation. Table 1 (abstract P393)
CKD stage
Stage 1
Stage 2
Stage 3
Total
n
2
44
20
66
Age (years)
64.7 (3.4)
69.9 (8.3)
75.5 (7.7)
71.5 (8.4)
eGFR
92.5 (0.7)
69.4 (7.2)
52.35 (7.4)
64.9 (11.6)
Creatinine
78 (1.4)
97.8 (9)
125.2 (19.9)
105.5 (18.8)
Cholesterol
4.5 (0.5)
4.8 (1.1)
4.3 (0.9)
4.6 (1)
BP
1 (50%)
21 (48%)
9 (45%)
31 (47%)
Smoking
2 (100%)
31 (70%)
14 (70%)
49 (74%)
Diabetes
0
1 (3%)
2 (10%)
3 (5%) Conclusion The majority of vascular patients undergoing elective
aortic surgery in our unit have impaired renal function that is not
accurately reflected by creatinine values. Management of patients
with stage 2 and 3 CKD is primarily cardiovascular risk assessment
with aggressive treatment of modifiable vascular risk factors [3]. The full impact of risk factor modification on perioperative outcome
in vascular patients requires further detailed investigation. There were significant differences observed for Gc globulin
examining 30-day survival (transplantation from ITU being analysed
as ‘death’): 50 mg/l (29–94) vs 18 (4–40), respectively, AUC S158 P398 Methods In 14 domestic pigs fulminant hepatic failure was
induced by surgical devascularization of the liver, and animals were
monitored postoperatively for 24 hours under general anaesthesia. Seven randomly assigned pigs (DFX group) were treated with
intravenous desferrioxamine (14.5 mg/kg/hour for 6 hours and
2.4 mg/kg/hour for the next 18 hours), whereas the remaining
(control group) received standard care. Bronchoalveolar lavage
fluid (BALF) was obtained after central line placement, after
surgery, at 7 hours, and 24 hours postoperatively and was analysed
f
ll
bi
h
i
l
d
id i
k
f l
i j Predictive value of indocyanine green clearance in acute
liver failure in children: comparison with King’s College
and Clichy scores J Quintero, J Ortega, J Bueno, S Flores, J Roqueta
Vall d’Hebron, Barcelona, Spain
Critical Care 2007, 11(Suppl 2):P398 (doi: 10.1186/cc5558) Introduction Indocyanine green clearance (ICG), measured by the
percentage disappearance rate (PDR), detects alterations in liver
function and may be used as a noninvasive determinant of hepatic
reserve in liver failure as well as a marker of graft function following
liver transplantation. The administration of blood products does not
interfere with the ICG-PDR as occurs with other prognostic scores
(King’s College and Clichy scores). The aims of this study were to
compare in acute liver failure the ICG-PDR with King’s College and
Clichy scores and to determinate its predictive value. for cell counts, biochemical and oxidative markers of lung injury. Results DFX resulted in maintenance of blood pressure (mmHg)
(84 ± 27 in DFX vs 51 ± 16 in control, P < 0.05) and attenuated
the increase of intracranial pressure (mmHg) (19 ± 10 in DFX vs
36 ± 9 in control, P < 0.01) at 24 hours. Protein levels in BALF
were increased in controls whereas in the DFX group protein
(µg/ml) was significantly lower (at 7 hours 398 ± 219 vs 187 ± 67,
respectively, P < 0.01; and at 24 hours 261 ± 112 vs 162 ± 52,
respectively, P < 0.05). Nitrites in BALF were elevated at 7 hours
in controls whereas a reduction was observed in the DFX group
(3.924 ± 3.67 µM vs 0.590 ± 0.69 µM, respectively, P < 0.05). Phospholipase A2, platelet-activating factor acetylhydrolase,
nitrates, total cell counts, neutrophils and macrophages in BALF all
increased in the control and DFX groups but did not differ
significantly between them. Pulmonary effects of desferrioxamine in the treatment of
an experimental model of fulminant hepatic failure Results DFX resulted in maintenance of blood pressure (mmHg)
(84 ± 27 in DFX vs 51 ± 16 in control, P < 0.05) and attenuated
the increase of intracranial pressure (mmHg) (19 ± 10 in DFX vs
36 ± 9 in control, P < 0.01) at 24 hours. Protein levels in BALF
were increased in controls whereas in the DFX group protein
(µg/ml) was significantly lower (at 7 hours 398 ± 219 vs 187 ± 67,
respectively, P < 0.01; and at 24 hours 261 ± 112 vs 162 ± 52,
respectively, P < 0.05). Nitrites in BALF were elevated at 7 hours
in controls whereas a reduction was observed in the DFX group
(3.924 ± 3.67 µM vs 0.590 ± 0.69 µM, respectively, P < 0.05). Phospholipase A2, platelet-activating factor acetylhydrolase,
nitrates, total cell counts, neutrophils and macrophages in BALF all
increased in the control and DFX groups but did not differ
significantly between them. Conclusions These results suggest that COHb maybe an
important mediator in haemodynamic and metabolic instability in
ALF. In DCLF, COHb is an important factor in hypoxia and possible
pulmonary shunting. P396 Telephone triage for a liver intensive care unit – advise or
admit? Telephone triage for a liver intensive care unit – advise or
admit? A Chan-Dominy, G Auzinger, W Bernal, E Sizer, J Wendon
King’s College Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P396 (doi: 10.1186/cc5556) Objective To determine the referral pattern and organ dysfunction
severity of interhospital consultations, and triage practice at a
specialised liver intensive therapy unit (LITU). Objective To determine the referral pattern and organ dysfunction
severity of interhospital consultations, and triage practice at a
specialised liver intensive therapy unit (LITU). Methods Patients admitted with acute liver dysfunction to the ITU
between January 2003 and December 2005 were considered. Sixty-
eight patients with acute liver failure (ALF) and 132 patients with
decompensated chronic liver failure (DCLF) had a full dataset
available on day 1 of admission. Patient demographics, physiological Methods A prospective audit was conducted from 1 March to 30
November 2006, for all interhospital telephone referrals to our S159 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin References References 1. Crit Care Med 2004, 32:2079. 1. Crit Care Med 2004, 32:2079. 2. Am J Respir Cell Mol Biol 2003, 29:427. 1. Crit Care Med 2004, 32:2079. 2. Am J Respir Cell Mol Biol 2003, 29:427. P399 parameters, blood results and organ dysfunction were recorded
prospectively and entered into a patient management system
database (ICARE). Pulmonary effects of desferrioxamine in the treatment of
an experimental model of fulminant hepatic failure Pulmonary effects of desferrioxamine in the treatment of
an experimental model of fulminant hepatic failure Results There was no statistical difference in patient demo-
graphics, organ failure scores or physiological parameters between
the groups. The median COHb percentage for ALF was 0.9%
(0.7–1.2) and for DCLF 1.5% (1.2–1.8). In patients with DCLF,
COHb negatively correlated with PaO2 (r = –0.4, P = 0.05) and
child Pugh (r = –0.4, P = 0.07). There was significant difference
between grouped COHb and MAP in patients with ALF; there was
a trend towards statistical significance with higher COHb. The
arterial pH correlated with COHb in ALF (r = 0.4, P = 0.01). K Kalimeris, G Kostopanagiotou, C Routsi, V Smyrniotis,
N Papoutsidakis, N Arkadopoulos, G Kampouroglou,
D Kypriotis, D Panagopoulos, A Kollitza, M Lekka, G Nakos
Aretaieion Hospital, University of Athens, Greece
Critical Care 2007, 11(Suppl 2):P399 (doi: 10.1186/cc5559) Introduction Desferrioxamine (DFX) is a clinically approved iron
chelator used to treat iron overload. It has also shown beneficial
effects in experimental acute liver failure (ALF) by inhibiting oxidative
damage [1]. Lung dysfunction commonly complicates ALF. Iron-
mediated processes have been shown to contribute to it [2]. We
hypothesized that inhibition of oxidative reactions by means of iron
chelation could attenuate lung injury after ischemic ALF. Introduction Desferrioxamine (DFX) is a clinically approved iron
chelator used to treat iron overload. It has also shown beneficial
effects in experimental acute liver failure (ALF) by inhibiting oxidative
damage [1]. Lung dysfunction commonly complicates ALF. Iron-
mediated processes have been shown to contribute to it [2]. We
hypothesized that inhibition of oxidative reactions by means of iron
chelation could attenuate lung injury after ischemic ALF. Methods In 14 domestic pigs fulminant hepatic failure was
induced by surgical devascularization of the liver, and animals were
monitored postoperatively for 24 hours under general anaesthesia. Seven randomly assigned pigs (DFX group) were treated with
intravenous desferrioxamine (14.5 mg/kg/hour for 6 hours and
2.4 mg/kg/hour for the next 18 hours), whereas the remaining
(control group) received standard care. Bronchoalveolar lavage
fluid (BALF) was obtained after central line placement, after
surgery, at 7 hours, and 24 hours postoperatively and was analysed
for cell counts, biochemical and oxidative markers of lung injury. P398 Methodology Between 2003 and 2006, 114 ICG-PDRs were
performed in 38 children (mean age 2.6 years (range 1 month–
16 years)) with acute liver damage. ICG was administrated intra-
venously and its blood concentration was detected over time by
transcutaneous pulse densitometry using a commercially available
bedside monitor. The PDR was performed under hemodynamic
stability (systolic mean pressure >60 mmHg; saturation of central
venous blood saturation >70% and CO2 arterio-venous difference
<8 mmHg). Conclusion Treatment of ALF with DFX attenuates the increase of
protein and nitrites in BALF, but does not seem to significantly
affect phospholipase A2, platelet-activating factor acetylhydrolase,
nitrates, macrophages or neutrophils. The observed effects may
suggest a protective role of DFX on lung inflammation during the
first 24 hours of ALF. Results The mean number of PDRs/patient was three. The mean
PDR was 17% (range: 3.3–51%). In two out of 38 patients, the
PDR could not be detected due to hemodynamic instability. PDR <
5% was a predictor value for irreversible liver failure (P = 0.000). In
nine (25%) out of 36 patients, the PDR was <5%. Of those nine,
two patients recovered its synthetic function and seven (78%)
patients developed irreversible liver failure (four died of liver failure
and three underwent liver transplantation) (see Table 1). The relative sensitivity of serum lipase versus amylase for
radiological image-positive pancreatitis K Delaney, S Luber
UT Southwestern Medical School, Dallas, TX, USA
Critical Care 2007, 11(Suppl 2):P402 (doi: 10.1186/cc5562) Methods A retrospective study in a national four-bed liver ICU that
treated 127 patients with ALF between 2001 and 2006. Thirty-eight
of these patients were treated with terlipressin, and 10 patients
(median age 42.5 years; range 15–66 years; five females) who also
had an ICP and a microdialysis catheter placed in the cerebral cortex
were included in this study. Concomitant measurements of mean
arterial pressure (MAP), ICP, cerebral perfusion using transcranial
Doppler sonography (Vmean) and cerebral concentrations of lactate
and pyruvate were made before and after an increase in the NE
infusion rate and i.v. injection of 1 mg terlipressin. Background Due to the absence of a ‘gold standard’ test for the
diagnosis of pancreatitis, the sensitivities of pancreatic enzyme
tests for pancreatitis are still debated. We compared the relative
sensitivities of lipase and amylase at their upper limit of normal
values for image-positive pancreatitis in a large consecutive series
of patients who had simultaneous tests of amylase and lipase. Background Due to the absence of a ‘gold standard’ test for the
diagnosis of pancreatitis, the sensitivities of pancreatic enzyme
tests for pancreatitis are still debated. We compared the relative
sensitivities of lipase and amylase at their upper limit of normal
values for image-positive pancreatitis in a large consecutive series
of patients who had simultaneous tests of amylase and lipase. Methods Consecutive patients with a clinical diagnosis of
pancreatitis defined by constant epigastric pain and elevation of
the amylase or lipase to greater than 106 U/l or 59 U/l,
respectively,
were
imaged
by
abdominal
sonography
or
computerized axial tomography (CAT) scan. All included patients
had positive radiological evidence of acute pancreatitis. Results The pancreas was visualized in 399/473 (84%) patients
with suspected pancreatitis and 127/399 (38%) had radiological
evidence of pancreatitis. Elevation of the lipase to >59 U/l
detected 127/127 cases of image-positive pancreatitis, while
elevation of the amylase to >106 U/l detected 113/127 cases
(88% sensitive (0.82–0.94)). All cases of acute biliary pancreatitis
were detected by both the lipase and amylase. The amylase
missed 14 of 65 patients with nonbiliary etiologies of pancreatitis. Four of these were alcoholics. P402 aim of this study was to determine whether terlipressin increases
cerebral perfusion and to compare the effect with that of nor-
epinephrine (NE). Furthermore, the effect on intracranial pressure
(ICP) and cerebral concentrations of lactate and pyruvate were
recorded. The relative sensitivity of serum lipase versus amylase for
radiological image-positive pancreatitis P401 Relative adrenal insufficiency in patients with severe acute
pancreatitis Conclusion Our study shows a high degree of relative sensitivity
of the lipase compared with amylase for pancreatic injury that is
demonstrable on CAT or sonographic imaging. Our findings
demonstrate a relative lack of sensitivity of amylase for nonbiliary
etiologies of pancreatitis. We recognize that the absolute
sensitivity of lipase for image-positive pancreatitis cannot be
determined by this retrospective methodology that required
elevation of one marker for inclusion. J De Waele1, E Hoste1, D Baert2, K Heyndrickx3, D Rijkckaert4,
P Thibo5, P Van Biervliet6, F Colardyn1
1Ghent University Hospital, Ghent, Belgium; 2AZ Maria Middelares,
Ghent, Belgium; 3OLV, Aalst, Belgium; 4AZ St Lucas, Ghent, Belgium;
5AZ Palfijn, Ghent, Belgium; 6AZ Aurora, Oudenaarde, Belgium
Critical Care 2007, 11(Suppl 2):P401 (doi: 10.1186/cc5561) P403 Background Inadequate cortisol levels and adrenal dysfunction
may play a role in the pathophysiology of severe acute pancreatitis. This study aimed to analyse the incidence of relative adrenal
insufficiency (RAI) in these patients, to identify factors associated
with relative adrenal insufficiency and to describe how adrenal
responsiveness affects outcome. P400 Conclusions ICG-PDR < 5% is a significant predictor of
irreversible liver failure. It is a good complement of such scores for
decision-making. Comparison of terlipressin and norepinephrine on cerebral
perfusion, intracranial pressure and cerebral
concentrations of lactate and pyruvate in patients with
acute liver failure: a microdialysis study Table 1 (abstract P398)
King’s score
Clichy score
ICG-PDR
Sensitivity (%)
100
71.4
100
Specificity (%)
87
90
93
PPV (%)
64
63
78
NPV (%)
100
93
100 M Eefsen, T Dethloff, H Frederiksen, J Hauerberg,
B Adel Hansen, F Stolze Larsen
Rigshospitalet, University Hospital of Copenhagen, Denmark
Critical Care 2007, 11(Suppl 2):P400 (doi: 10.1186/cc5560) Table 1 (abstract P398) Introduction
Volume expansion and inotropic support with
catecholamines are often insufficient to ensure adequate blood
pressure and cerebral blood flow in acute liver failure (ALF). The S160 Available online http://ccforum.com/supplements/11/S2 The relative sensitivity of serum lipase versus amylase for
radiological image-positive pancreatitis Methods Consecutive patients with a clinical diagnosis of
pancreatitis defined by constant epigastric pain and elevation of
the amylase or lipase to greater than 106 U/l or 59 U/l,
respectively,
were
imaged
by
abdominal
sonography
or
computerized axial tomography (CAT) scan. All included patients
had positive radiological evidence of acute pancreatitis. Results NE infusion and terlipressin injection increased the MAP
and Vmean (P < 0.01). Also, the ICP increased during NE infusion
(P < 0.01) but not after terlipressin. The cerebral lactate
concentration was unchanged during NE infusion, while it
decreased after terlipressin (P < 0.05). p
g
p
Results The pancreas was visualized in 399/473 (84%) patients
with suspected pancreatitis and 127/399 (38%) had radiological
evidence of pancreatitis. Elevation of the lipase to >59 U/l
detected 127/127 cases of image-positive pancreatitis, while
elevation of the amylase to >106 U/l detected 113/127 cases
(88% sensitive (0.82–0.94)). All cases of acute biliary pancreatitis
were detected by both the lipase and amylase. The amylase
missed 14 of 65 patients with nonbiliary etiologies of pancreatitis. Four of these were alcoholics. Conclusion This study shows that terlipressin increases the MAP
and cerebral perfusion in patients with ALF with no influence upon
ICP and the cerebral concentrations of lactate and pyruvate. These
findings indicate that terlipressin may be valuable, as an additive, or
alternative, treatment of arterial hypotension in patients with ALF to
secure brain viability. The significance of gallbladder sludge in the patient with
acute pancreatitis The significance of gallbladder sludge in the patient with
acute pancreatitis K Delaney, L Velez
UT Southwestern Medical School, Dallas, TX, USA
Critical Care 2007, 11(Suppl 2):P403 (doi: 10.1186/cc5563) Methods In a prospective observational multicenter study, a short
Synacthen test (SST) was performed within 5 days after admission
to the hospital in 25 patients with severe acute pancreatitis, after
signed informed consent was obtained. The incidence of RAI,
defined as an increment after SST of less than 9 µg/dl, was the
primary endpoint of the study. Serum cortisol was measured at
baseline and 30 and 60 minutes after 250 µg adrenocorticotropic
hormone administration. Background The significance of gallbladder sludge as a potential
cause of acute biliary pancreatitis is debated. We report the
incidence and outcome of patients with gallbladder sludge in a
large population of patients with pancreatitis. Methods Pancreatitis was defined as constant epigastric pain with
lipase greater than three times the upper reference value for our
laboratory (177 U/l). Consecutive patients with first episodes of
acute pancreatitis were identified over a 2-year period and data
were
evaluated
retrospectively. Patients
were
followed
prospectively for 2 years more. Results The median baseline cortisol level was 26.6 µg/dl, and
increased to 43.2 µg/dl and 48.8 µg/dl after 30 and 60 minutes,
respectively. RAI was found in 16% of all patients, and in 27% of
patients with organ dysfunction. Patients with RAI were more
severely ill and had higher SOFA scores from day 4 through day 7
after admission. All patients with RAI developed pancreatic
necrosis, and all of them needed surgical intervention. Mortality
was significantly higher in patients with RAI (75% vs 10%,
P = 0.016). Patients who died had a lower increment in cortisol
levels after the SST than patients who survived. Results All patients had gallbladder ultrasound examinations. First
episodes of acute pancreatitis were identified in 356 patients. Initially 236 patients had stones directly visualized in the
gallbladder. Of the remaining 120 patients, 13 had sludge, 11 had
a dilated common bile duct, one had a positive sonographic
Murphy sign, and 95 had no abnormalities. During the time course
of the study, 23 of these 120 patients were demonstrated to have
stones; by the surgical pathology report (12), endoscopic
retrograde cholangio-pancreatography (10), and cholecystostomy Conclusion RAI is frequent in patients with severe acute pancreatitis
and organ dysfunction. Recurrence rates in patients with first episodes of acute
pancreatitis Recurrence rates in patients with first episodes of acute
pancreatitis K Delaney, S Luber
UT Southwestern Medical School, Dallas, TX, USA
Critical Care 2007, 11(Suppl 2):P404 (doi: 10.1186/cc5564) ,
,
,
Critical Care 2007, 11(Suppl 2):P404 (doi: 10.1186/cc Introduction The timing of operative intervention in patients with
suspected biliary pancreatitis is debated. Recurrence rates of
pancreatitis in patients with biliary lithiasis are compared in
operated and nonoperated patients. Recurrences in patients with
suspected nonbiliary pancreatitis are also reported. Results The two groups of 38 patients were comparable in age
(52.4 and 56.5 years), ASA physical status (1.9 and 2.0),
preoperative albumin concentration (39.0 and 38.1 g/l), duration of
operation (5.9 and 6.1 hours), transfused red blood cells (3.3 and
2.0 l) and crystalloid infusion during surgery (5.3 and 4.5 l). In both
groups there was very significant drop of albumin concentration in
the first week after surgery (P < 0.001). In group 2 albumin
concentrations were very significantly lower than in group 1 until
the fifth postoperative day (P < 0.001). The difference diminished
after the sixth postoperative day (P < 0.03). There was negative
correlation between the postoperative albumin concentration and
the duration of surgery (r = –0.44, P < 0.008). We found no
difference in the postoperative complication rate (surgical or
medical), length of stay and mortality between the groups. Introduction The timing of operative intervention in patients with
suspected biliary pancreatitis is debated. Recurrence rates of
pancreatitis in patients with biliary lithiasis are compared in
operated and nonoperated patients. Recurrences in patients with
suspected nonbiliary pancreatitis are also reported. Methods First episodes of acute pancreatitis were identified in
consecutive emergency department patients over a 2-year period. Data were evaluated retrospectively and then the identified
patients were then followed prospectively for 2 years more. Results Pancreatitis was defined clinically as constant epigastric
pain associated with elevation of the serum lipase to greater than
three times the upper reference value (177 U/l) and no other
identified cause of abdominal pain. Of 356 patients with first
episodes of acute pancreatitis, 259 had pancreatitis that was
ultimately associated with biliary lithiasis based on abdominal
ultrasound (n = 236), positive endoscopic retrograde pancreoto-
graphy (n = 11), surgical pathology report (n = 11), or cholecystos-
tomy (n = 1). Ninety-seven patients had no identified stones during
the study period. Cholecystectomy was performed in 235/259 at
the time of admission for pancreatitis. P406 Extravascular lung water following resuscitation of
hemorrhagic shock in swine: comparison between Ringers’
lactate and normal saline
C Phillips, B Tieu, D Hagg, M Schreiber
Oregon Health & Science University, Portland, OR, USA
Critical Care 2007, 11(Suppl 2):P406 (doi: 10.1186/cc5566) Extravascular lung water following resuscitation of
hemorrhagic shock in swine: comparison between Ringers’
lactate and normal saline C Phillips, B Tieu, D Hagg, M Schreiber
Oregon Health & Science University, Portland, OR, USA
Critical Care 2007, 11(Suppl 2):P406 (doi: 10.1186/cc5566) Introduction Pulmonary edema is a common consequence of
hemorrhagic shock resuscitation. The type and amount of fluid
used in resuscitation may be important determinants of the amount
of edema formed. Ringers’ lactate (RL) and normal saline (NS)
remain common resuscitative fluids. These experiments were
designed to measure the extravascular lung water (EVLW) after
resuscitation from hemorrhagic shock with RL vs NS, to determine
whether the fluid type results in differences in the amount of
EVLW, and to determine whether there exists a threshold amount
of fluid that results in the development of edema. Conclusion Cholecystectomy reduced the incidence of recurrence
of pancreatitis in patients with biliary lithiasis. Recurrence rates in patients with first episodes of acute
pancreatitis Reasons for nonoperative
management were death (three cases), medical contraindications
(15 cases), pregnancy (two cases) and delayed diagnosis due to
negative abdominal sonogram (four cases). During the study
period 10% (10/97) of patients without demonstrated stones
returned with recurrent episodes of pancreatitis. There were two
recurrences in 235 operated patients with stones (0.85%). Twelve
of 19 nonoperated survivors with biliary lithiasis returned with
complications of biliary lithiasis, including 10 recurrences of biliary
pancreatitis (53%) and two episodes of common bile duct
obstruction, one of which resulted in death from cholangitis. The
median time to recurrence of pancreatitis in nonoperated patients
with stones was 50 days, range 26–581 days. Conclusion Postoperative serum albumin concentrations were
reduced in both groups, but more in group 2 with no albumin
treatment, and in longer operations. Morbidity, mortality and length
of stay were not influenced by albumin replacement. The significance of gallbladder sludge in the patient with
acute pancreatitis It occurs in patients with more severe
pancreatitis and is associated with an increased mortality rate. S161 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin no broad consensus is reached yet on abandoning the use of
albumin in intensive care and perioperative settings for the bad
prognostic value of hypoalbuminemia. As the albumin decrease in
major surgery is mostly due to extravascular leakage of albumin
(systemic inflammatory response), we regard hypoalbuminemia just
as a marker of inflammatory response to surgery that albumin
replacement cannot change. So the postoperative morbidity,
mortality and length of stay would not differ in patients without
albumin replacement. (one). Seven of 13 patients with sludge underwent cholestectomy
and all had evidence of stones. Four of six nonoperated patients
with sludge (67%) returned with recurrent pancreatitis over the
course of the study. Ten of 97 patients (10%) with suspected
nonbiliary etiology of the pancreatitis returned with recurrent
pancreatitis over the same period. The nonoperated patients with
sludge were more likely to have other risk factors for nonbiliary
pancreatitis than were the operated patients. Conclusions
The presence of sludge on the gallbladder
ultrasound suggests the presence of stones and is associated with
a high rate of recurrence of pancreatitis in nonoperated patients. Materials
and
methods
We
retrospectively
studied
76
successive patients operated on in the abdomen at the Oncologic
Institute in Ljubljana in 1997/98 (group 1 – postoperative
hypoalbuminemia treated with 20% albumin solution) and in
2000/01 (group 2 – no albumin treatment), because of
abandoning albumin use in our surgical department. We compared
serum albumin concentrations in the first week after surgery (three
values) as well as the postoperative complication rate and the
length of hospital stay. We looked for correlation between the
postoperative albumin concentration and the duration of surgery,
amount of transfusion and amount of infusion during surgery. P405 Replacement of albumin after abdominal surgery Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 suprapubic Foley catheter placement, and splenectomy. The
spleen was weighed and, based on randomization, either LR or NS
solution was infused to replace three times the spleen weight in
grams. Following a 15-minute stabilization period, a standardized
Grade V liver injury (injury to a central hepatic vein) was then
created using a specialized clamp. Following 30 minutes of
uncontrolled hemorrhage, we blindly randomized the swine to
receive either NS or RL resuscitation at 165 ml/min. Resuscitation
fluid was administered to achieve and maintain the baseline mean
arterial pressure (MAP) for 90 minutes post injury. suprapubic Foley catheter placement, and splenectomy. The
spleen was weighed and, based on randomization, either LR or NS
solution was infused to replace three times the spleen weight in
grams. Following a 15-minute stabilization period, a standardized
Grade V liver injury (injury to a central hepatic vein) was then
created using a specialized clamp. Following 30 minutes of
uncontrolled hemorrhage, we blindly randomized the swine to
receive either NS or RL resuscitation at 165 ml/min. Resuscitation
fluid was administered to achieve and maintain the baseline mean
arterial pressure (MAP) for 90 minutes post injury. operatively. Thereafter fluid management was as in group A. Arterial
blood samples were taken preoperatively and at 5 minutes,
30 minutes, 60 minutes, 120 minutes, 240 minutes and 24 hours
post-tourniquet release for HNE and arterial blood gas analysis. Repeated measures of analysis of variance established a
significant difference in the pattern of change of HNE levels (log
transformed) and the PaO2/FiO2 ratios with time between the two
groups. Follow-up t tests revealed significantly lower levels of HNE
(Table 1) and also significantly higher PaO2/FiO2 ratios in Group B
post-tourniquet release. operatively. Thereafter fluid management was as in group A. Arterial
blood samples were taken preoperatively and at 5 minutes,
30 minutes, 60 minutes, 120 minutes, 240 minutes and 24 hours
post-tourniquet release for HNE and arterial blood gas analysis. Repeated measures of analysis of variance established a
significant difference in the pattern of change of HNE levels (log
transformed) and the PaO2/FiO2 ratios with time between the two
groups. Follow-up t tests revealed significantly lower levels of HNE
(Table 1) and also significantly higher PaO2/FiO2 ratios in Group B
post-tourniquet release. In conclusion, the results suggest that infusion of HES lowers HNE
release from activated neutrophils in postoperative knee
replacement patients and may lead to less lung injury. Toxicity of two lipid emulsions on human lymphocytes and
neutrophils Toxicity of two lipid emulsions on human lymphocytes and
neutrophils Toxicity of two lipid emulsions on human lymphocytes and
neutrophils M Cury-Boaventura1, R Gorjão2, T Martins de Lima2,
F Soriano3, R Curi2
1Cruzeiro do Sul University, São Paulo, Brazil; 2University of São
Paulo, Brazil; 3Faculdade de Medicina USP, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P408 (doi: 10.1186/cc5568) Introduction The incorporation of lipid emulsions in parenteral
diets is a requirement for energy and essential fatty acid supply,
and may prevent many metabolic disturbances associated with
intravenous feeding amino acids and glucose alone in critically ill
patients. For different parenteral fat emulsions, a significant impact
on the immune system has been shown. In this study, the toxicity of
soybean oil-based emulsion and olive oil-based emulsion on
leukocytes from healthy volunteers was investigated. Conclusion In this swine model of traumatic hemorrhagic shock,
resuscitation with RL as compared with NS required less fluid to
maintain goal MAP and resulted in less EVLW formation. The near
fourfold difference in EVLW increase was accounted for entirely by
the differences in volumes needed to maintain goal MAP with no
differences seen with fluid type. This study suggests that, in order
to limit increases in EVLW during early resuscitation of
hemorrhagic shock prior to the arrival of blood products, RL should
be used preferentially instead of NS and the volume infused limited
to approximately 60 ml/kg. Methods
Twenty-four volunteers were recruited and blood
samples were collected before infusion of a soybean oil-based
emulsion or olive oil-based emulsion, immediately afterwards and
18 hours later. The cells were studied immediately after isolation,
and after 24 hours or 48 hours in culture. The following deter-
minations were made: composition and concentration of fatty acids
in plasma, lymphocytes and neutrophils, and lymphocyte
proliferation. The toxicity was determined by plasma membrane
integrity, DNA fragmentation, phosphatidylserine externalization,
mitochondrial depolarization, production of reactive oxygen
species and neutral lipid accumulation. Available online http://ccforum.com/supplements/11/S2 Results
All animals spontaneously stopped bleeding within
12 minutes of injury after losing approximately 25% of their blood
volume. There were no differences in initial blood loss between the
two groups – estimated blood loss (mean ± standard error) RL
group 22 ± 1.7 ml/kg vs NS group 19.0 ± 1.7 ml/kg, P = 0.15. During the resuscitative phase the NS group required more fluid to
maintain the goal MAP than the RL group: 330.8 ± 38.1 ml/kg vs
148.4 ± 20.2 ml/kg, P = 0.001. There was nearly a fourfold
increase in mean EVLW between the groups: 5.24 ± 1.26 ml/kg
NS vs 1.46 ± 0.57 ml/kg RL, P = 0.013. The difference in EVLW
was accounted for entirely by the difference in the volume infused
(P = 0.008), with no difference seen with fluid type (P = 0.7). The
EVLW began to increase immediately with fluid administration
without exhibiting a threshold effect. An increase of 1 ml/kg EVLW
occurred at a resuscitative volume of 63 ± 25 ml/kg. Neutrophil elastase suppression by medium-molecular-
weight hydroxyethylstarch in orthopaedic surgery Neutrophil elastase suppression by medium-molecular-
weight hydroxyethylstarch in orthopaedic surgery R Walker1, G McCarthy2
1Craigavon Area Hospital, Craigavon, UK; 2Belfast City Hospital,
Belfast, UK
Critical Care 2007, 11(Suppl 2):P407 (doi: 10.1186/cc5567) Results Both lipid emulsions decreased lymphocyte proliferation
and induced cell death, but the effects of soybean oil-based
emulsion were more pronounced. Soybean oil-based emulsion
provoked apoptosis and necrosis, whereas olive oil-based
emulsion caused neutrophil and lymphocyte necrosis only. Evidence is presented that lipid emulsion is less toxic to
neutrophils than to lymphocytes. The mechanism of cell death
induced by this lipid emulsion involved mitochondrial membrane
depolarization and neutral lipid accumulation, but did not alter
production of reactive oxygen species. The aim of this study was to compare the effect of
hydroxyethylstarch (HES) and human albumin solution (HAS) on
human neutrophil elastase (HNE) release in patients undergoing
elective knee replacement surgery. Forty-three patients (ASA 1 or 2) were randomly allocated into two
groups. Group A (n = 21) received 5 ml/kg of 4.5% HAS pre-
operatively and a further 5 ml/kg HAS as an intraoperative replace-
ment. Postoperatively the patients received Ringers’ lactate at the
discretion of the anaesthetic team. Group B was given 5 ml/kg HES
(Fresenius-Kabi) preoperatively and a further 5 ml/kg HES intra- Conclusions Olive oil-based emulsion can be an alternative to
soybean oil-based emulsion, avoiding leukocyte death and the
susceptibility of patients to infections. Table 1 (abstract P407)
Group
Preoperative, mean (SD)
5 minutes
30 minutes*
60 minutes*
120 minutes*
240 minutes*
24 hours
A
2.31 (0.21)
2.59 (0.35)
2.74 (0.34)
2.83 (0.26)
2.74 (0.24)
2.78 (0.29)
2.68 (0.19)
B
2.39 (0.25)
2.4 (0.32)
2.41 (0.15)
2.43 (0.13)
2.54 (0.2)
2.53 (0.15)
2.65 (0.31)
*P < 0.01. Replacement of albumin after abdominal surgery K Mahkovic Hergouth1, L Kompan2
1Institute of Oncology, Ljubljana, Slovenia; 2Clinical Center,
Ljubljana, Slovenia
Critical Care 2007, 11(Suppl 2):P405 (doi: 10.1186/cc5565) K Mahkovic Hergouth1, L Kompan2
1Institute of Oncology, Ljubljana, Slovenia; 2Clinical Center,
Ljubljana, Slovenia
Critical Care 2007, 11(Suppl 2):P405 (doi: 10.1186/cc5565) Methods This was a randomized controlled trial using 20 female
Yorkshire crossbred pigs. Animals were mechanically ventilated. Anesthesia was maintained using 2% isofluorane in 100% oxygen. Continuous hemodynamic monitoring, blood sampling, and
determination of EVLW by single indicator transpulmonary dilution
was done using a PiCCO plus monitor (Pulsion Medical System,
Munich, Germany). The animals underwent a midline celiotomy, Introduction Replacement of albumin in hypoalbuminemic patients
is not proven to reduce postoperative morbidity and mortality but S162 Available online http://ccforum.com/supplements/11/S2 Haemoglobin concentration influences the chloride–
bicarbonate but not the strong ion difference–bicarbonate
relationship M Mercieri, A Marcelli, C Claroni, A Mercieri
University of Rome La Sapienza, Rome, Italy
Critical Care 2007, 11(Suppl 2):P409 (doi: 10.1186/cc5569) Methods In this retrospective case–control study we identified
patients who received more than two units of high plasma volume
components from male-only donors and compared them with
patients matched by severity of illness, postoperative state and
number of transfusions but who received high plasma volume
components from female donors. Introduction Chloride and bicarbonate concentrations share an
inverse reciprocal relationship during either acidosis or alkalosis. This relationship is, in part, due to the red cell chloride shift. However, according to the Stewart quantitative approach to acid–
base balance, it seems conceivable to expect a greater relationship
between the strong ion difference (SID) and bicarbonate, rather
then between chloride and bicarbonate. We propose that, with
decreasing haemoglobin (Hb) levels, the SID preserves its
independent role with respect to bicarbonate, while chloride
gradually loses its relationship. Results From a database of 3,567 patients who received a total of
46,101 units fresh frozen plasma and 6,251 units apheresis
platelets, we identified 112 patients who received three or more
male-only donor components and 112 matched controls. Baseline
characteristics, ALI risk factors and development of ALI were
similar between the two groups. Arterial oxygenation (PaO2/FiO2)
worsened after the female donor components (mean difference
–52, 95% CI –14 to –91, P = 0.008) but not after male-only donor
product transfusion (mean difference +22, 95% CI –23 to + 67,
P = 0.325). Male-only component recipients had more ventilator-
free days (median 28 vs 27, P = 0.006) and a trend towards lower
hospital mortality (14% vs 24%, P = 0.054). Methods We retrospectively collected blood gas analysis and
electrolytes, from 206 patients, measured on a single blood
sample taken on admission. We calculated the apparent SID
through the following formula: [Na+] + [K+] + [Ca2+] + [Mg2+] –
[Cl–] – [Lact–] (mEq/l). We divided patients into three groups
based on Hb levels: group A (n = 54) with Hb levels between 12
and 15 g/dl, group B (n = 104) with Hb levels between 9 and
12 g/dl, and group C (n = 48) with Hb levels below 9 g/dl. We
calculated
Pearson’s
coefficients
between
the
SID
and
bicarbonate and between chloride and bicarbonate in these three
groups of patients. Table 1 (abstract P409) Table 1 (abstract P409)
SID–HCO3
–,
Cl––HCO3
–,
Group
Hb (g/dl)
r/r2
P
r/r2
P
A
12–15
0.76/0.58
0.001
–0.6/0.36
0.001
B
9–12
0.83/0.70
0.001
–0.56/0.32
0.001
C
<9
0.80/0.65
0.001
–0.31/0.09
ns ical Care 2007, 11(Suppl 2):P411 (doi: 10.1186/cc557 Introduction Red blood cell (RBC) transfusion is very often
performed in critically ill patients despite its potential complications. Its effects on oxygen delivery and microcirculation are not well
known. This study aimed at evaluating RBC effects in blood lactate
levels (LAC) and central venous oxygen saturation (SvcO2) in
patients with severe sepsis and septic shock. Conclusion These results give further validation to Stewart’s
theories: the SID appears to maintain the role of an independent
variable with respect to bicarbonate even at low haemoglobin
levels, while chloride loses this relationship at haemoglobin levels
below 9 g/dl. Methods A prospective study enrolling patients admitted to an
ICU at a university hospital with severe sepsis and septic shock
presenting hemoglobin (Hb) levels below 9.0 g/dl. These patients
were randomized for maintaining Hb >9 g/dl (Group 1) or >7 g/dl
(Group 2). Before (preT) and at least 1 hour after each transfusion
(postT) LAC, SvcO2 and Hb data were collected. Data were
analysed by analysis of variance, paired t test and paired Wilcoxon
test. Results were considered significant if P ≤0.05. Table 1 (abstract P407) S163 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Haemoglobin concentration influences the chloride–
bicarbonate but not the strong ion difference–bicarbonate
relationship Conclusion In critically ill recipients of high plasma volume
components, gas exchange worsened significantly after transfusion
of female but not male donor components. Prospective studies are
needed to evaluate the effect of AABB recommendations on
outcome of transfused critically ill patients. P411 Results Correlation strength between the SID and HCO3
– was
high and significant even at a Hb concentration below 9 g/dl (see
Table 1). Pearson’s coefficients for chloride and bicarbonate
showed a moderate but significant inverse correlation in group A
and group B; eventually this correlation was completely lost in
group C. Evaluation of red blood cell transfusion effects in lactate
and central venous oxygen saturation in patients with
severe sepsis and septic shock B Mazza, M Assuncao, F Freitas, M Jackiu, H Fernandes,
F Machado
Escola Paulista de Medicina – Universidade Federal de São Paulo,
Brazil
Critical Care 2007, 11(Suppl 2):P411 (doi: 10.1186/cc5571) P409 P409
Haemoglobin concentration influences the chloride–
bicarbonate but not the strong ion difference–bicarbonate
relationship
M Mercieri, A Marcelli, C Claroni, A Mercieri
University of Rome La Sapienza, Rome, Italy
Critical Care 2007, 11(Suppl 2):P409 (doi: 10.1186/cc5569) minimize transfusion of high plasma volume components, fresh
frozen plasma and apheresis platelets, from potentially alloimunized
donors, especially females. The objective of this study was to
evaluate the effect of transfusing components from male-only vs
female donors on development of ALI, gas exchange, and outcome
in critically ill patients. P409
Haemoglobin concentration influences the chloride–
bicarbonate but not the strong ion difference–bicarbonate
relationship O Gajic1, M Yilmaz1, R Iscimen1, D Kor1, J Winters1, B Afessa2,
J Farmer1
1Mayo Clinic, Rochester, MN, USA; 2Mayo Clinic College of
Medicine, Rochester, MN, USA
Critical Care 2007, 11(Suppl 2):P410 (doi: 10.1186/cc5570) P412 Results The mean age of the transfused patients was 35.78 years. The sex ratio was 1.2. A total of 48.3% of the patients had trans-
fusion history. Allogeneic immunization and viral serology conver-
sion were reported in 2.1% of these patients. The indications were
generally carried in front of chronic medical pathologies (36.9%),
acute medical pathologies (28.2%) and surgical pathologies
(elective 11.7%, urgent 11.2%). The haemoglobin threshold for
transfusion was 7.29 g/dl and depended on the indication of the
red cell transfusion: 6.16 g/dl for urgent medical pathologies,
6.22 g/dl for chronic medical pathologies, 7.74 g/dl for urgent
surgical pathologies, 10.38 g/dl for elective surgery, 6.15 g/dl for
urgent obstetrical pathologies. The mean platelet count was
24,000 (patients transfused by platelet units). The ABO and
rhesus determination were made in 99% of the cases. A
phenotypic determination was required in only 34.5% of the cases. The search for irregular agglutinins was made in 20.7% of the
cases. The test of compatibility at the laboratory was practiced in
95.4% of the cases. The amount of blood transfused was 2 units. Immediate incidents were reported in 2.5% of the cases. The post-
transfusion haemoglobin average was of 9.15 g/dl. Transfusion profiles in intensive care units from a
university hospital M Assuncao, I Paula, L Falcao, B Mazza, M Barros, M Jackiu,
H Fernandes, F Machado
Universidade Federal de São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P412 (doi: 10.1186/cc5572) Introduction Red blood cell (RBC) transfusion is very often
performed in critically ill patients despite its potential complica-
tions. New guidelines recommend that doctors should have
conservative behavior regarding its use. The objective of this study
was to evaluate the transfusion profile among patients in ICUs at a
university hospital in Brazil. Introduction Red blood cell (RBC) transfusion is very often
performed in critically ill patients despite its potential complica-
tions. New guidelines recommend that doctors should have
conservative behavior regarding its use. The objective of this study
was to evaluate the transfusion profile among patients in ICUs at a
university hospital in Brazil. Methods A prospective evaluation of all patients admitted to six
ICUs (surgical–medical, private, neurosurgery, medical, pneu-
mology and coronary units) that have received a RBC transfusion
as indicated by assistant physicians during October/November
2005. Clinical data as well as the characteristics of the transfusion
were collected and submitted to univariate statistical analysis (chi-
squared and Student’s t test). National survey of transfusion practices N Frikha, R Ouezini, T Mestiri, M Bechikh, M Mebazaa,
M Ben Ammar
Mongi Slim Hospital, La Marsa, Tunisia
Critical Care 2007, 11(Suppl 2):P413 (doi: 10.1186/cc5573) Introduction The awakening of the residual risks of blood trans-
fusion leads, everywhere in the world, to efforts to reduce them. The
aim of the study was to assess the transfusion practices in Tunisia. Introduction The awakening of the residual risks of blood trans-
fusion leads, everywhere in the world, to efforts to reduce them. The
aim of the study was to assess the transfusion practices in Tunisia. Patients and methods A multicentric prospective observational
study of about 1,000 transfusions practiced during 2004 in
Tunisia. Data were determined by the prescriptor of the trans-
fusion. The data were analyzed with SPSS 12.0. Conclusion In patients with SvcO2 < 70 and/or Hb < 7.0 g/dl,
transfusion seems to result in an improvement of perfusion
parameters. However, in patients with SvcO2 > 70 or normal
lactate levels, transfusion seems to impair tissue perfusion. Patients and methods A multicentric prospective observational
study of about 1,000 transfusions practiced during 2004 in
Tunisia. Data were determined by the prescriptor of the trans-
fusion. The data were analyzed with SPSS 12.0. Transfusion from male-only vs female donors in critically ill
recipients of high plasma volume components Results Thirty-six transfusions were evaluated in 21 patients (mean
age 59.0 ± 15.8 years, 11 females/10 males) with APACHE II
score of 13.8 ± 4.1. Each group included 18 patients. The levels
of Hb preT and postT were 7.51 ± 1.03 and 8.48 ± 1.15
(P < 0.05). There was a significant difference between preT and
postT SvcO2 (70.9 ± 8.66 and 73.6 ± 7.2, P = 0.01) but not in
LAC levels (24.1 ± 8.9 and 22.9 ± 7.6, P = 0.45). When groups
were analyzed separately, only in Group 2 was a significant
difference found (P = 0.0005 and 0.05, respectively for SvcO2
and LAC). In 10 transfusions a worsening of SvcO2 postT was O Gajic1, M Yilmaz1, R Iscimen1, D Kor1, J Winters1, B Afessa2,
J Farmer1
1Mayo Clinic, Rochester, MN, USA; 2Mayo Clinic College of
Medicine, Rochester, MN, USA
Critical Care 2007, 11(Suppl 2):P410 (doi: 10.1186/cc5570) Objective To reduce the incidence of transfusion-related acute
lung injury (ALI), the American Association of Blood Banks (AABB)
has recently recommended rapid implementation of strategies to S164 Available online http://ccforum.com/supplements/11/S2 P412 Results were considered significant
if P ≤0.05. Discussion and conclusion The evolution of the blood transfusion
was remarkable, since the use of total blood in the 1980s, with the
acquisition of the first techniques of separation of the blood
components. The transfusion practice in Tunisia is far from being to
the standards. The results obtained make it possible to transmit to
the clinician the failures of the system, to better include how to
prescribe a blood product, to follow its effectiveness and its
possible side effects, and to apprehend the impact of the
innovated biotechnologies to improve quality of transfusion
medicine in coherence with the security requirements. Results Four hundred and eight transfusions were made in 71
patients (38 females, 33 males), 35 medical/36 surgical, with a
mean age 57.2 ± 8.4 years, mean APACHE II score 17.7 ± 5.3,
and mean SOFA score on the day of transfusion 6.09 ± 3.99. At
admission, 60 patients (84.5%) had comorbidities, 10 (14.1%)
had chronic coronary disease. At transfusion, 54.9% had sepsis,
severe sepsis or septic shock, and 9.9% had acute coronary
syndrome. The mean hemoglobin (Hb) level at ICU admission was
9.69 ± 2.3 g/dl and the mean level that triggered transfusion was
6.88 ± 1.1 g/dl. The most important transfusion indication was Hb
levels (49.8%), followed by active bleeding (31.8%). The mean
number of RBC transfused per time was 1.68 ± 0.96 and the
mean age of RBC was 14.3 ± 7.83 days (46.6% had more than
14 days). Adverse events occurred in 3.4%. The 28-day mortality
rate was 47.1%. Only the SOFA score at the day of transfusion
correlated with mortality (P = 0.004). There was no correlation with
age, type of ICU, APACHE II score, total number or age of RBC,
Hb at admission or Hb pretransfusion. There was a significant
difference between the pretransfusion Hb (P < 0.00001) and the
number of RBC transfused at the same time considering all ICU
enrolled in the study (P < 0.00001). P413 observed and all these patients had preT SvcO2 > 70%. Although
there was no significant correlation between a worsening in SvcO2
and preT Hb, eight of these patients were allocated to Group 1. Another 13 transfusions were done with a SvcO2 preT < 70, and
10 of them improved (> 5%) after transfusion (mean percentage of
improvement = 18.9%). Only four of these patients were allocated
to Group 1. Patients with high levels of preT LAC (n = 21) only
improved (reduction > 10%) in 42.9% of cases. A total 53.3% of
patients with normal preT LAC levels worsened (rising > 10%)
postT. The mean preT Hb from these patients was 8.18 ± 0.9. Conclusion In patients with SvcO2 < 70 and/or Hb < 7.0 g/dl,
transfusion seems to result in an improvement of perfusion
parameters. However, in patients with SvcO2 > 70 or normal
lactate levels, transfusion seems to impair tissue perfusion. observed and all these patients had preT SvcO2 > 70%. Although
there was no significant correlation between a worsening in SvcO2
and preT Hb, eight of these patients were allocated to Group 1. Another 13 transfusions were done with a SvcO2 preT < 70, and
10 of them improved (> 5%) after transfusion (mean percentage of
improvement = 18.9%). Only four of these patients were allocated
to Group 1. Patients with high levels of preT LAC (n = 21) only
improved (reduction > 10%) in 42.9% of cases. A total 53.3% of
patients with normal preT LAC levels worsened (rising > 10%)
postT. The mean preT Hb from these patients was 8.18 ± 0.9. observed and all these patients had preT SvcO2 > 70%. Although
there was no significant correlation between a worsening in SvcO2
and preT Hb, eight of these patients were allocated to Group 1. Another 13 transfusions were done with a SvcO2 preT < 70, and
10 of them improved (> 5%) after transfusion (mean percentage of
improvement = 18.9%). Only four of these patients were allocated
to Group 1. Patients with high levels of preT LAC (n = 21) only
improved (reduction > 10%) in 42.9% of cases. A total 53.3% of
patients with normal preT LAC levels worsened (rising > 10%)
postT. The mean preT Hb from these patients was 8.18 ± 0.9. Reference 1. Geddes J, et al.: Neuropathol Appl Neurobiol 2003, 29:14-22. P416 Patients and methods Sixty-eight patients (54 males/14 females)
participated in the study. Thirty-two patients underwent valve(s)
replacement (group A) and the remaining underwent coronary
artery bypass grafting(s) (group B). The BT determination was
performed according to the Mielke technique using Surgicutt
devices (ITC, USA). Platelet function was evaluated by the
aggregation procedure using four agonists: ADP, arachidonic acid,
collagen and ristocetin at a final concentration of 4 x 10–6 M,
0.5 mg/ml, 0.19 mg/ml and 1.2 mg/ml, respectively. Shaken baby syndrome: the classical clinical triad is still
valid in recent court rulings P414 Could the combination of bleeding time and platelet
function predict the perioperative transfusion requirements
in cardiac surgery patients? M Kataphigioti, D Karamichaleli, M Kounavi, E Iliopoulou,
G Palatianos, E Melissari
Onassis Cardiac Surgery Center, Athens, Greece
Critical Care 2007, 11(Suppl 2):P414 (doi: 10.1186/cc5574) Introduction The reduction in platelet count and function is the
most important, unsolved, nonsurgical cause of postoperative
bleeding after open heart surgery. On the other hand, the bleeding
time (BT), the only comprehensive test to explore primary
haemostasis, detects otherwise unknown defects in platelet–
vessel wall interactions. The present study was undertaken in order
to clarify whether the BT and platelet function tested preoperatively
could predict the perioperative transfusion requirements in cardiac
surgery patients. Conclusions The Hb level that triggered transfusion was in
agreement with recent guidelines regarding critically ill patients,
although there was a difference between all ICUs. Despite the fact
that there is a scarceness of RBC, the RBC were higher in age. The missing correlation with mortality can be due to the small
sample size. S165 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Shaken baby syndrome: the classical clinical triad is still
valid in recent court rulings The Geddes theory led to the speculation that
subdural and retinal haemorrhage was not caused by traumatic
shearing of subdural and retinal veins but by a combination of
cerebral hypoxia, raised intracranial pressure and raised arterial and
central venous pressure. The publication of this theory was met with
scepticism by many forensic and paediatric pathologists but was
enthusiastically embraced by defence attorneys. This dilemma
resulted in the UK with several appeals against prior convictions of
murder/manslaughter because of alleged traumatic shaking of
young children. The forensic community awaited with great interest
the ruling of the Court of Appeal in London on 21 July 2005. Conclusion In patients undergoing cardiac surgery with a negative
history of bleeding and early interruption of antiplatelet treatment,
the BT and platelet function do not offer much in the setting to
predict perioperative bleeding. g
pp
y
Court ruling of 21 July 2005 Four cases of alleged SBS were
brought to the Court of Appeal in London. Two convictions were
upheld, one conviction was dismissed and one conviction was
reduced from murder to manslaughter. In their written judgement
their Lordships clearly stated: ‘In our judgment, it follows that the
unified hypothesis can no longer be regarded as a credible or
alternative cause of the triad of injuries’. The Crown Prosecution
Service made a press release that ‘Today’s judgement sends a clear
signal validating the CPS in prosecuting Shaken Baby Syndrome
cases. The Geddes theory will no longer be used by the defence.’ Court ruling of 21 July 2005 Four cases of alleged SBS were
brought to the Court of Appeal in London. Two convictions were
upheld, one conviction was dismissed and one conviction was
reduced from murder to manslaughter. In their written judgement
their Lordships clearly stated: ‘In our judgment, it follows that the
unified hypothesis can no longer be regarded as a credible or
alternative cause of the triad of injuries’. The Crown Prosecution
Service made a press release that ‘Today’s judgement sends a clear
signal validating the CPS in prosecuting Shaken Baby Syndrome
cases. The Geddes theory will no longer be used by the defence.’ Shaken baby syndrome: the classical clinical triad is still
valid in recent court rulings M De Leeuw1, W Jacobs2
1Algemeen Stedelijk Ziekenhuis Aalst, Essene, Belgium;
2University Hospital Antwerp, Edegem, Belgium
Critical Care 2007, 11(Suppl 2):P416 (doi: 10.1186/cc5576) Introduction Subdural haemorrhage, retinal bleeding and hypoxae-
mic encephalopathy have long been considered a diagnostic clinical
triad for the so-called shaken baby syndrome (SBS). The classical
triad, however, has been challenged in the recent past by the so-
called ‘unified hypothesis’ by Geddes and colleagues [1] with
subsequent implications in court rulings in suspected cases of SBS. Judicial and scientific dilemma The unified hypothesis by Geddes
suggested an alternative cause for SBS injuries that did not involve
significant shaking. The Geddes theory led to the speculation that
subdural and retinal haemorrhage was not caused by traumatic
shearing of subdural and retinal veins but by a combination of
cerebral hypoxia, raised intracranial pressure and raised arterial and
central venous pressure. The publication of this theory was met with
scepticism by many forensic and paediatric pathologists but was
enthusiastically embraced by defence attorneys. This dilemma
resulted in the UK with several appeals against prior convictions of
murder/manslaughter because of alleged traumatic shaking of
young children. The forensic community awaited with great interest
the ruling of the Court of Appeal in London on 21 July 2005. Results (1) In the immediate postoperative time, a significant
reduction in haemoglobulin levels was observed in both groups
compared with that of the preoperative time (13.3%, P < 0.05 for
group A and 28.4%, P < 0.01 for group B). No difference existed
in haemoglobulin levels between groups postoperatively. (2) Platelet
values were slightly different between the groups. A significant
decrease in platelet count was observed in both groups
postoperatively (28.7%, P < 0.03 for group A and 22.4%, P < 0.05
for group B). (3) The results of BT and platelet activation (per-
formed preoperatively) were similar for patients who underwent
valve replacement and patients who underwent coronary artery
bypass grafting – although in this group platelet activation with
arachidonic acid and ADP was ~11% lower with both agonists. (4) The transfusion requirements were slightly higher for patients in
group A, and more patients in group B received no transfusion
(one vs four patients). Judicial and scientific dilemma The unified hypothesis by Geddes
suggested an alternative cause for SBS injuries that did not involve
significant shaking. Emergency staff is in danger B Gulalp1, O Karcioglu2
1Adana State Hospital, Adana, Turkey; 2Dokuz Eylul University,
School of Medicine, Izmir, Turkey
Critical Care 2007, 11(Suppl 2):P415 (doi: 10.1186/cc5575) Conclusions Diagnosing SBS is a very complex and delicate matter. The mere presence of the classic triad does not automatically or
necessarily lead to a diagnosis of nonaccidental head injury or a
conclusion of unlawful killing. Diagnosis of (intentional) SBS must be
based on the combination of: medical elements, elements from
police inquiry, and forensic and crime scene elements. Physicians,
particularly those working at the medico-legal interface (such as
emergency physicians), should realise that medical observations may
play a pivotal role in the diagnosis of SBS. As important is the
realisation that, despite alternative hypothesis in medical literature,
the classical triad of symptoms (subdural haemorrhage, retinal
bleeding, hypoxaemic encephalopathy) is still valid as diagnostic for
SBS according to recent (UK) court ruling. Objective
To investigate the ratio and characteristics of
aggression, threat and physical violence directed towards staff in
emergency departments as a model of state hospitals. Objective
To investigate the ratio and characteristics of
aggression, threat and physical violence directed towards staff in
emergency departments as a model of state hospitals. Methods A questionnaire were filled in by the staff working in the
emergency department of three high-volume inner-city state
hospitals. The individualized data collected were relevant to the
pattern of violence, age, sex, number of years in the profession,
nature of the job, and the behavioral characteristics of assailants,
and outcome of incidents. The data were abstracted between
1 May and 31 May 2006. Results
A total of 109 staff reports were reviewed. The
relationship of aggression with sex, age and years of experience
were insignificant (P values were 0.464, 0.692, and 0.298,
respectively), while profession was very significantly related
(P = 0.000). The relation between threat and sex is P = 0.311,
experience 0.994, profession 0.326, age 0.278. The relationship of
threat with sex, years of experience, profession and age were
insignificant (P values were 0.311, 0.994, 0.326, and 0.278,
respectively). On the other hand, physical assault was found
significantly related to sex, years of experience, profession and age
(P values were 0.042, 0.011, 0.000, and 0.000, respectively). A comparison of the confusion assessment method for the
intensive care unit and the NEECHAM confusion scale in
intensive care delirium assessment A comparison of the confusion assessment method for the
intensive care unit and the NEECHAM confusion scale in
intensive care delirium assessment Methods Were admitted to the ICU 29 patients with OPP. The data
were treated by SPSS 14 for Windows and the analysis consisted of
a descriptive study, analytic study (chi-square analysis, Spearman
association analysis) and comparison between groups (Student
t analysis, Wilcoxon Mann–Whitney and Kolmogorov–Smirnov tests). The receiver operating characteristic (ROC) was applied for the
Sequential Organ Failure Assessment (SOFA) score. B Van Rompaey1, L Bossaert2, L Shortridge-Bagett1,
M Schuurmans1, S Truijen1
1Universiteit Antwerpen, Wilrijk, Belgium; 2Universitair Ziekenhuis,
Edegem, Belgium
Critical Care 2007, 11(Suppl 2):P419 (doi: 10.1186/cc5579) B Van Rompaey1, L Bossaert2, L Shortridge-Bagett1,
M Schuurmans1, S Truijen1
1Universiteit Antwerpen, Wilrijk, Belgium; 2Universitair Ziekenhuis,
Edegem, Belgium
Critical Care 2007, 11(Suppl 2):P419 (doi: 10.1186/cc5579) Results Twenty-nine patients were included in the study, 21 males
and eight females. The mean age of the males was 47.71 years
(SD = 13.58) and of females was 41.0 years (SD = 11.66), and
62.7% were from a rural area and 37.3% from an urban area. Mortality does not have a significant statistic relation (P > 0.05)
with toxicity of organophosphate, time and doses of atropine. However, statistical significance was found between mortality and:
(a) time between ingestion of the poison and treatment (Spearman
test, rs = –0.596, P < 0.05), (b) muscarinic manifestations (chi-
square
test,
χ2 = 4.152,
P < 0.05),
(c)
time
of
oximes
(Kolmogorov–Smirnov test with Z = 1.439, P < 0.05) and doses of
oximes (Kolmogorov–Smirnov test with Z = 1.412, P < 0.05). The
ROC analysis reveals that for the respiratory SOFA at 9 days, the
area under the ROC curve was 0.917; this means that this SOFA
score can predict correctly in 91.7% of the cases. Introduction Reports indicate an incidence of intensive care
delirium of 11–87%. The confusion assessment method for the
intensive care unit (CAM-ICU) is widely used in delirium assess-
ment in ICUs. However, its binomial results constrain the evaluation
of severity. The NEECHAM confusion scale has recently been
validated for use in the ICU and uses a numeric assessment. This
scale allows the patients to be classified in four categories of
delirium severity (normal, at-risk, mild to early, moderate to severe). In this study we investigated the diagnostic value of the
NEECHAM referring to the CAM-ICU. A comparison of the confusion assessment method for the
intensive care unit and the NEECHAM confusion scale in
intensive care delirium assessment Methods A consecutive sample of 106 patients in a mixed ICU
(cardiac surgery (CS) 35%, noncardiac surgery (NCS) 26%,
internal medicine (IM) 39%, age 62 ± 14 years, male 63%) was
assessed after a stay in the ICU ≥24 hours. All patients with a
Glasgow Coma Scale ≥10 and age ≥18 years were included. A
nurse researcher simultaneously assessed both scales once daily
in the morning. A total of 272 paired observations were made. Data
were analyzed using the NEECHAM cut-off values of ≤26 (at-risk),
≤24 (mild delirium), and ≤19 (severe delirium). Conclusion In our study we concluded that the mortality rate was
increased with prolonged perfusion of oximes and with muscarinic
manifestations of OPP but not with the time and dose of atropine. The respiratory SOFA score at 9 days matches with prediction in
above 90% of the cases. P418 Results Using the CAM-ICU the overall prevalence was 15%. Prevalences in CS, NCS and IM were 9%, 14% and 21%,
respectively. Using the NEECHAM scale, the overall prevalence
was 33% (16.5% mild, 16.5% severe) and 36%, 21% and 38%
for the three patient categories, respectively. Sensitivity was
100%, specificity was 79%, positive predictive value was 46% and
negative predictive value was 100%. Using the cut-off value ≤19,
sensitivity was 83% and specificity was 96%. All positive CAM-
ICU patients were detected by the NEECHAM (85% severe, 15%
mild). However, 21% of the CAM-ICU negative patients had a
NEECHAM value that diagnoses delirium (4% severe, 17% mild). Consequently, 27% of the CS group (19% severe, 8% mild), 7%
of the NCS group (7% mild) and 17% of the IM group (2% severe,
15% mild) were diagnosed to be delirious using the NEECHAM
and not delirious using the CAM-ICU. Reference organophosphate poisoning (OPP). The aim of the study was to
determine the relation between mortality and: (a) toxicity of
organophosphate, (b) time between ingestion and management of
the patient, (c) coligernic manifestations, (d) time and doses of
oximes and atropine. Reference
1. Ely EW, et al.: Crit Care Med 2004, 32:106-112. Reference
1. Ely EW, et al.: Crit Care Med 2004, 32:106-112. Approaches of Turkish anesthesiologists to delirium
observed in intensive care unit patients Approaches of Turkish anesthesiologists to delirium
observed in intensive care unit patients Approaches of Turkish anesthesiologists to delirium
observed in intensive care unit patients N Gokmen, L Iyilikci, S Kucukguclu, B Kuvaki, L Ciftci, A Gunerli
Dokuz Eylul University, School of Medicine, Izmir, Turkey
Critical Care 2007, 11(Suppl 2):P418 (doi: 10.1186/cc5578) Objective To determine attitudes and practices of the Turkish
anesthesiologists and residents about delirium in the ICU. Methods An anonymous questionnaire consisting of 22 questions
[1] was mailed to 258 anesthesiologists and residents. [ ]
g
Results One hundred and fifty-four questionnaires were returned
(60% response). Of the respondents, 57% were male and 61%
were residents. One-half of respondents work in hospitals with
more than 800 beds; 65% of respondents had an ICU facility of
7–12 beds. Seventy-two percent of the respondents had seen
delirium in the ICU and also 70.2% of these respondents observed
delirium in <25% of patients who were on mechanical ventilation. Although delirium was accepted a significant or very serious
problem by 92.5% of the respondents, underdiagnosis was
acknowledged by 74%. Routine screening for delirium was
performed by 41.6% of the anesthesiologists and 88.1% of them
were repeating daily. Clinical assessment was used in 76.7% of
the screenings. Delirium was treated with haloperidol and
benzodiazepine by 61.5% and 24% of the respondents. Of the
respondents, 93.4% were not able to attend a meeting related to
delirium and 67.6% did not read even an article about delirium. Conclusions Turkish anesthesiologists and residents consider
delirium a relatively common and serious problem. However, they
seldom perform screening tests and try to update their knowledge
regarding delirium. Conclusion The NEECHAM delirium scale identified all cases of
delirium that were detected by the CAM-ICU. Moreover, additional
delirious patients were identified, especially in the CS group. In this
pilot experience, the NEECHAM scale was a valuable screening
tool for intensive care. Organophosphate poisoning and related mortality with
oxime perfusion Organophosphate poisoning and related mortality with
oxime perfusion A Bartolo1, O Caetano1, M Costa1, R Milheiro1, A Carvalho1, A Braga2
1Hospital Senhora Oliveira, Guimaraes, Portugal; 2University of
Minho, Braga, Portugal
Critical Care 2007, 11(Suppl 2):P417 (doi: 10.1186/cc5577) Conclusion Violence to the staff is common. There is not a
significant relationship between aggression, threat and personal
characters. However, male sex, >5 years experience, emergency
doctor, ≥31 years of age are the risk factors for physical violence. Introduction A retrospective study performed between 1 January
2001 and 31 October 2006 in patients admitted to the ICU with S166 Available online http://ccforum.com/supplements/11/S2 P422 Conclusion Delirium is badly recognized in the ICU by intensivists
and ICU nurses. In view of the impact of delirium on ICU and
hospital stay, more attention should be paid to the implementation
of a delirium screening instrument during daily ICU care. Evaluation of two sedation techniques in a casualty
department Evaluation of two sedation techniques in a casualty
department M Moustafa1, M Borai2
1Faculty of Medicine, Assiut University, Alain, United Arab
Emirates; 2Alain Hospital, Alain, AbuDhabi, United Arab Emirates
Critical Care 2007, 11(Suppl 2):P422 (doi: 10.1186/cc5582) P420 We investigated whether
intensivists and ICU nurses could clinically identify the presence of
delirium in ICU patients during daily care. Methods All patients in a 3-month period who stayed >48 hours in
the ICU were evaluated daily for the presence or absence of
delirium by treating intensivists and ICU nurses responsible for
daily care. Patients were evaluated independently for the
occurrence of delirium by a trained group of ICU nurses who were
not involved in the daily care of the patients under study. Since
communication with ventilated patients is compromised due to the
inability to speak, a specific scoring system was used (confusion
assessment method for the intensive care unit (CAM-ICU)), which
has been developed for the evaluation of the presence of delirium. Delirium as judged present by this CAM-ICU correlates well with a
DSM-IV delirium diagnosis by a trained psychiatrist. Values are
expressed as the median and interquartile range (IQR). Results During the study period, 46 patients (30 males, 16
females), age 73 (IQR = 64–80) years with an ICU stay of 6
(4–11) days were evaluated. CAM-ICU scores were obtained
during 481 patient-days. Considering the CAM-ICU as the gold
standard, delirium occurred in 50% of the patients with a duration
of 3 (1–9) days. Days with delirium were poorly recognized by
doctors (sensitivity = 29.8%; specificity = 99.7%; PPV = 99.6%)
and ICU nurses (sensitivity = 35.6%; specificity = 97.8%; PPV =
84%). Patients with a delirium were longer on the ventilator (6
(4–25) days), and had a longer ICU (9 (6–26) days) and hospital
stay (29 (21–41) days) than those without delirium during their
ICU stay (4 (1–6), P = 0.01; 5 (3–8), P = 0.002; and 19 (7–30),
P = 0.01), respectively. APACHE II and SAPS II scores were
comparable in both groups. Conclusions There is still a great educational potential for
improving the use of sedation protocols and implementing sedation
scoring systems and the wake up test in Danish ICUs. This
potential could perhaps reduce the incidence of withdrawal
symptoms. Effort should also be placed in implementing the
sedation protocol in the ICU, illustrated by the differences in
numbers of doctors and nurses having a sedation protocol. P420 The occurrence of delirium is severely underestimated by
intensivists and intensive care unit nurses during daily ICU care The occurrence of delirium is severely underestimated by
intensivists and intensive care unit nurses during daily ICU care The occurrence of delirium is severely underestimated by
intensivists and intensive care unit nurses during daily ICU care
P Spronk, B Riekerk, S Elias, J Rommes, J Hofhuis
Gelre Ziekenhuizen Location Lukas, Apeldoorn, The Netherlands
Critical Care 2007, 11(Suppl 2):P420 (doi: 10.1186/cc5580) P Spronk, B Riekerk, S Elias, J Rommes, J Hofhuis
Gelre Ziekenhuizen Location Lukas, Apeldoorn, The Netherlands
Critical Care 2007, 11(Suppl 2):P420 (doi: 10.1186/cc5580) Introduction Patients improve faster in the ICU if sedatives are
stopped as soon as possible with inherent occurrence of sleeping
disorders, and delirium, which could compromise the recovery Introduction Patients improve faster in the ICU if sedatives are
stopped as soon as possible with inherent occurrence of sleeping
disorders, and delirium, which could compromise the recovery S167 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Results Twenty-nine (82.9%) out of a total of 35 possible hospitals
answered, including 113 (57.7%) answers out of a total of 196
possible answers. Ninety-seven per cent of the physicians were
specialists in anaesthesiology. Eighty-seven per cent of the nurses
were certified intensive care nurses. Forty-seven per cent were from
university hospitals. Twenty-six per cent had a sedation protocol,
37% of the physicians and 14% of the nurses. Only one-third of the
ICUs had a protocol for sedation. Sixty-eight per cent having a
protocol used it always or often, whereas 32% never use it. Sixty-
seven per cent had a sedation scoring system in their departments. The scoring systems used was: Ramsay 49%, Sedation Agitation
Score 10% and own (locally made) scoring system 41%. Twenty-
two per cent answered that the scoring systems was always used,
58% often and in 20% the scoring systems was seldom used. Forty
per sent use the ‘wake-up call’ test, 63% physicians and 37%
nurses. Sixty per cent answered ‘no we do not use’ the wake-up call
test, 47% physicians and 53% nurses. Withdrawal symptoms were
experienced more than three times as frequently by nurses
compared with physicians (31% vs 9%). Five times as many
experienced withdrawal symptoms in the group not having a
sedation and analgesia protocol (84% vs 16%). process and prolong the ICU stay. Sedation practices in Denmark Sedation practices in Denmark We compare the efficacy, adverse events, and recovery duration of
etomidate and propofol for use in procedural sedation in the
emergency department (ED). A randomized nonblinded prospective
trial of adult patients undergoing procedural sedation for painful
procedures in the ED was made. Patients received either propofol
or etomidate. Doses, vital signs, nasal end-tidal CO2 (etco2), pulse
oximetry, and bispectral electroencephalogram analysis scores
were recorded. Subclinical respiratory depression was defined as a
change in etco2 greater than 10 mmHg, an oxygen saturation of
less than 92% at any time, or an absent etco2 waveform at any time. Clinical events related to respiratory depression, including an
increase in supplemental oxygen, the use of a bag-valve-mask
apparatus, airway repositioning, or stimulation to induce breathing,
were noted. Etomidate and propofol appear equally safe for ED
procedural sedation. Etomidate had a lower rate of procedural
success and induced myoclonus in 20% of patients (see Table 1). K Espersen1, M Skielboe2, T Jensen1
1Rigshospitalet, Copenhagen, Denmark; 2University Hospital
Gentofte, Denmark
Critical Care 2007, 11(Suppl 2):P421 (doi: 10.1186/cc5581) Critical Care 2007, 11(Suppl 2):P421 (doi: 10.1186/cc5581) Introduction The interest of sedation in ICU patients has been
increasing the last 10 years. The benefits of protocol-driven care
have become evident. Objective The aim of the study was to describe current practice of
sedation in Danish ICUs addressing the use of protocols and the
wake-up call test. Methods Two doctors and two nurses from all the Danish adult
ICUs were identified to participate in an Internet-based survey. These persons answered questions about sedation practices, use
of sedation scorings systems, and withdrawal symptoms. S168
Table 1 (abstract P422)
Agent
Etomidate (n = 53)
Propofol (n = 55)
Subclinical respiratory depression
Yes (n = 18)
No (n = 35)
Yes (n = 23)
No (n = 32)
Increased supplemental oxygen
1/9 (2.1, 0.9–11.2)
2/34 (2.9, 0.8–7.2)
2/23 (4.4, 1.2–14.4)
1/32 (1.6, 0.2–5.5)
Bag-valve mask (%)
2/18 (6.9, 1.9–13.9)
0/34 (0, 0–2.3)
2/23 (4.4, 1.4–11.9)
0/32 (0, 0–2.7)
Airway repositioning
3/18 (9.7, 2.9–16.0)
3/34 (5.1, 1.4–8.7)
3/23 (6.5, 1.5–11.6)
3/31 (4.7, 1.1–8.0)
Stimulation to induce breathing
4/18 (11.1, 5.1–19.6)
2/34 (2.9, 0.8–7.1)
3/23 (7.6, 3.2–14.5)
3/31 (4.7, 1.8–9.6) Comparison of dexmedetomidine with propofol/
midazolam in sedation of long-stay intensive care patients:
a prospective randomized, controlled, multicenter trial Comparison of dexmedetomidine with propofol/
midazolam in sedation of long-stay intensive care patients:
a prospective randomized, controlled, multicenter trial J Takala1, S Nunes2, I Parviainen3, S Jakob1, M Kaukonen4,
S Shepherd5, R Bratty5, E Ruokonen3
1University Hospital Bern, Switzerland; 2Tampere University
Hospital, Tampere, Finland; 3Kuopio University Hospital, Kuopio,
Finland; 4Helsinki University Hospital, Helsinki, Finland; 5Orion
Pharma, Helsinki, Finland
Critical Care 2007, 11(Suppl 2):P423 (doi: 10.1186/cc5583) Introduction Sedation is a major problem in long-stay intensive
care patients despite use of sedation stops and scores. We
hypothesized that the α2-adrenoceptor agonist dexmedetomidine
(DEX) is at least equivalent to standard-of-care sedation (SOC),
and may reduce the length of ICU stay and improve other clinically
relevant outcomes. Results Demographic data (age, gender, trauma severity score)
were comparable in both groups. The waking time was significantly
shorter in G2 (5 ± 8 min) compared with G1 (35 ± 20 min)
(P < 0.05). The mICP was more stable in G2 (9 ± 4 mmHg)
compared with G1 (10 ± 9 mmHg) (P = 0.02). The mCPP were
comparable in G1 (62 ± 10 mmHg) and in G2 (63 ± 0.2 mmHg)
but with a 24% swing in dose requirement adaptation of Ne in G1
compared with a 6% daily swing in G2 (P < 0.02). Methods We performed a pilot (n = 85), phase III, multicenter,
prospective, randomized, double-blind, double-dummy, active
comparator (SOC: either propofol or midazolam) study to define
the feasibility and size of a pivotal trial. Patients with expected ICU
stays ≥48 hours and a need for sedation for at least 24 hours after
randomization were included within the first 72 hours of ICU stay. The maximum duration of study sedation was 14 days, with a 45-
day follow-up from randomization. Sedation was Richmond
Agitation Sedation Scale (RASS)-score targeted, with daily
sedation stops. Conclusion By using a multimodal short-acting sedation protocol
based on remifentanil and NMDA-antagonist receptors we were
able to provide adequate sedation in brain trauma patients. Neurological parameters were respected with this regimen,
avoiding the risk of secondary patient hemodynamic destabilisation
during the waking periods. Inhalational sedation during transport to the intensive care
unit SEV
infusion was started in the ICU after gas monitoring. Twenty-one
patients scheduled for propofol sedation served as controls. During transport all patients were ventilated with Oxylog2000
(Dräger, Germany), vital parameters were monitored, and the
Ramsay Score (RS) was assessed at five time points. If necessary,
propofol injections of 0.5 mg/kg were given. Statistics were t test
for parametric data (mean ± standard deviation), U test for
nonparametric data (median (interquartile range)), SPSS 11.04. Results The age, weight, duration of anaesthesia (ACD/controls
7.3 ± 2.0/6.3 ± 2.2 hours), total sufentanil (124 ± 75/118 ± 57 µg)
and transport time (16.3 ± 2.7/17.0 ± 2.7 min) were not different
between groups, and neither were heart rates, mean arterial
pressures and RS at five time points during transport. ACD
patients needed less propofol injections (0 (0–1)/3 (2–4), P < 0.001) Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Inhalational sedation during transport to the intensive care
unit Inhalational sedation during transport to the intensive care
unit M Bellgardt, C Sirtl, M Bergmann, D Weyhe, A Terporten,
H Laubenthal, A Meiser
St Josef-Hospital, Ruhr-Universität, Bochum, Germany
Critical Care 2007, 11(Suppl 2):P425 (doi: 10.1186/cc5585) Introduction Inhalational ICU sedation is increasingly applied
since the introduction of AnaConDa® (Sedana Medical, Sweden). This anaesthetic-conserving device (ACD) retains exhaled
sevofluorane (SEV) and resupplies it during inspiration [1]. A
syringe pump delivers liquid SEV into the device. Since January
2004 we have used the ACD as a standard practice. Our patients
anaesthetised with SEV in the OR and scheduled for ICU sedation
with SEV only need propofol on transport. Could this be avoided
when using the ACD during transport? Introduction Inhalational ICU sedation is increasingly applied
since the introduction of AnaConDa® (Sedana Medical, Sweden). This anaesthetic-conserving device (ACD) retains exhaled
sevofluorane (SEV) and resupplies it during inspiration [1]. A
syringe pump delivers liquid SEV into the device. Since January
2004 we have used the ACD as a standard practice. Our patients
anaesthetised with SEV in the OR and scheduled for ICU sedation
with SEV only need propofol on transport. Could this be avoided
when using the ACD during transport? Conclusion DEX is well tolerated and comparable with SOC in
long-term sedation, but not suitable as the sole agent for deep
sedation. DEX enhances the patient’s ability to communicate. Its
effects on relevant outcomes (for example, duration of mechanical
ventilation) should be tested in a large randomized controlled trial. Methods Forty-one patients after major abdominal surgery were
included in this quality assurance project. In 20 patients the ACD
was inserted into the anaesthesia circuit to take up warmth,
humidity and SEV for 15 minutes and used for transport. SEV
infusion was started in the ICU after gas monitoring. Twenty-one
patients scheduled for propofol sedation served as controls. During transport all patients were ventilated with Oxylog2000
(Dräger, Germany), vital parameters were monitored, and the
Ramsay Score (RS) was assessed at five time points. If necessary,
propofol injections of 0.5 mg/kg were given. Statistics were t test
for parametric data (mean ± standard deviation), U test for
nonparametric data (median (interquartile range)), SPSS 11.04. Methods Forty-one patients after major abdominal surgery were
included in this quality assurance project. In 20 patients the ACD
was inserted into the anaesthesia circuit to take up warmth,
humidity and SEV for 15 minutes and used for transport. P423 during 6.4 (± 4) days were prospectively randomized into two
groups (G1 n = 32; G2 n = 36) using different sedation protocols
to reach a mean hourly Ramsay Score of 4. Sedation in G1 was
based on morphine (0.1 ± 0.1 mg/kg/hour) and midazolam
(0.4 ± 0.4 mg/kg/hour); in G2 on remifentanil (0.25 ± 0.25 µg/kg/min),
magnesium (0.08 g/kg/day), ketamine (0.15 ± 0.15 µg/kg/min),
clonidine (0.001 ± 0.001 µg/kg/min) and propofol (2 ± 1.5 mg/kg/
hour). The cerebral parameters (mean intracranial continuous
pressure (mICP); mean cerebral perfusion pressure (mCPP)) and
the needs of norepinephrine (Ne) were evaluated hourly. Preloading was adapted by a continuous central venous pressure
measurement before Ne adaptation requirements to keep the
mCPP over 60 mmHg. For statistical analysis a Shapiro–Wilk test,
a Wilcox test and a Student t test were used. P425 Results Forty-one patients received DEX and 44 SOC (28
propofol). The goal was moderate (RASS 0 to –3) sedation in most
patients (78% in DEX and 80% in SOC). Patients were at the
target RASS 55% (DEX) and 57% (SOC) of the sedation time (not
significant): for RASS target 0 to –3, 68% (DEX) and 64% (SOC)
of the time (not significant) and for RASS target –4, 31% (DEX)
and 63% (SOC), respectively (P = 0.006). Median time from
admission/randomization to ICU discharge was similar (DEX
6.6/5.7 days, SOC 6.7/5.5 days, not significant). Mechanical
ventilation was shorter for DEX with RASS target 0 to –3 (DEX
70.2 hours, SOC 92.5 hours, P = 0.027), and patients’ ability to
communicate (multidimensional visual analog scale) was better
with DEX (P < 0.001). Occurrence rates and number of patients
with overall and serious adverse events were similar. P424 Multimodal short acting sedation using NMDA antagonist
and remifentanil in brain trauma patients: a prospective
randomised study Table 1 (abstract P422) S168 Available online http://ccforum.com/supplements/11/S2 Remifentanil vs conventional sedation in The Netherlands:
a pharmacoeconomic model analysis M Al, L Hakkaart, S Tan, P Mulder, J Bakker
Erasmus MC, Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P427 (doi: 10.1186/cc5587) Conclusions AnaConDa® effectively retains SEV in patients and
permits inhalational sedation during >15 minutes transport. Hemo-
dynamic stability and depth of sedation are as good as the
standard regime with Propofol. Less SEV exhaled by the patients
during transport also means less contamination of the workplace. Reference Introduction The goal of this study was to compare the duration of
mechanical ventilation (MV), the length of stay (LOS) and the direct
medical costs of remifentanil-based sedation (RS) vs conventional
sedation (CS) in ICU patients requiring MV. 1. A Meiser, H Laubenthal: Best Pract Res Clin Anaesthesiol
2005, 19:523-538. Methods A Markov model was developed based on UltiSAFE, a
recent Dutch open-label randomized controlled study that included
patients with an expected MV time of 2–3 days. Study medication
was either CS (morphine or fentanyl combined with propofol,
midazolam or lorazepam according to Dutch guidelines) or RS
(remifentanil, combined with propofol when required). The LOS on
the ICU, the time at which the patient was eligible for weaning or
extubation and the actual time of weaning and extubation, plus all
study drugs with all adjustments in dosage, were recorded. The
model describes the patient flow on the ICU. Three states were
defined: MV before weaning, MV after weaning has started before
extubation, post-MV before discharge. At every hour, patients either
stay at the current state, move to the next state or die. Transition
probabilities and the costs of the study drugs were derived from
UltiSAFE, whereas all other direct medical costs on the ICU were
estimated in a separate Dutch monocenter micro-costing study. All
costs were measured from the hospital perspective with 2006 as
the reference year. The time horizon used in the model was 28 days. Results From the trial data, it was estimated that the costs of RS on
MV before the start of weaning amount to €22 per hour, compared
with €15 for the CS treatment. After the start of weaning, these
costs decrease to €8 per hour for RS and €2 per hour for CS. P427 and reached the ICU with a similar RS (5 (4.5–5)/5 (4.75–5)). End-tidal SEV concentrations were similar in the OR (1.3 ± 0.2/
1.2 ± 0.2 vol%), but different when arriving in the ICU (0.6 ± 0.2/
0.2 ± 0.1 vol%, P < 0.001). Pharmacokinetics of single intravenous bolus
administration of propofol in preterm and term neonates Pharmacokinetics of single intravenous bolus
administration of propofol in preterm and term neonates K Allegaert1, M Rayyan1, A Debeer1, H Devlieger2, G Naulaers1
1University Hospital Gasthuisberg, Leuven, Belgium;
2A.Z. Gasthuisberg, Leuven, Belgium
Critical Care 2007, 11(Suppl 2):P426 (doi: 10.1186/cc5586) Background The aim of this study is to describe maturational
aspects of propofol pharmacokinetics following single intravenous
bolus administration in childhood. Methods Seventy propofol blood–time profiles were collected in
nine neonates (mean weight 2.4, range 0.91–3.8 kg) by arterial
blood samples up to 24 hours after administration of a single
intravenous bolus of propofol (3 mg/kg over 10 s) before elective
chest tube removal. Concentration–time curves obtained for every
individual neonate were interpreted by two-stage analysis as two-
compartment and three-compartment open models. These newly
collected observations following intravenous bolus administration
of propofol in preterm and term neonates (n = 9) were combined
with individual pharmacokinetic estimates in toddlers (n = 12) and
young children (n = 10) [1,2]. Data were reported by the median
and range. The Wilcoxon test or linear correlation were used to
analyse the pharmacokinetic findings in neonates, toddlers and
young children. Results The blood–concentration curves obtained for every
individual patient were interpreted by two-stage analysis as a three-
compartment open model in a cohort of 31 patients with a median
weight of 11.2 (range 0.91–24) kg and a median postmenstrual
age of 108 (range 27–405) weeks. The median clearance was
36.8 (range 3.7–78.1) ml/kg/min, the median apparent volume of
distribution at steady state (Vss) was 7.6 (1.33–15.6) l/kg and the
median final serum elimination half-life was 377 (range 27–1134)
minutes. Median clearance was significantly lower in neonates
compared with toddlers and older children (P < 0.01) and these
differences remained significant after allometric scaling (ml/kg
0.75/min). A significant correlation between Vss and postmenstrual
age (r = 0.61, 95% CI 0.32–0.8, P < 0.004) was observed. Conclusion Compared with CS, RS seems to be the preferred
regimen for patients with an expected MV time of 2–3 days. It not
only significantly decreases the length of ICU stay and the total
costs but also significantly reduces the duration of MV, which is a
risk factor for ventilator-associated morbidity. Multimodal short acting sedation using NMDA antagonist
and remifentanil in brain trauma patients: a prospective
randomised study F Meurant, Z Ahdach
Kirchberg, Luxembourg State, Luxembourg
Critical Care 2007, 11(Suppl 2):P424 (doi: 10.1186/cc5584) Introduction We hypothesize that using a multimodal short-acting
sedation regimen based on remifentanil and NMDA-antagonist
receptors such as ketamine, clonidine and magnesium will improve
cerebral protection and make clinical patient examination easier
without hemodynamic impairments. Introduction We hypothesize that using a multimodal short-acting
sedation regimen based on remifentanil and NMDA-antagonist
receptors such as ketamine, clonidine and magnesium will improve
cerebral protection and make clinical patient examination easier
without hemodynamic impairments. Results The age, weight, duration of anaesthesia (ACD/controls
7.3 ± 2.0/6.3 ± 2.2 hours), total sufentanil (124 ± 75/118 ± 57 µg)
and transport time (16.3 ± 2.7/17.0 ± 2.7 min) were not different
between groups, and neither were heart rates, mean arterial
pressures and RS at five time points during transport. ACD
patients needed less propofol injections (0 (0–1)/3 (2–4), P < 0.001) Results The age, weight, duration of anaesthesia (ACD/controls
7.3 ± 2.0/6.3 ± 2.2 hours), total sufentanil (124 ± 75/118 ± 57 µg)
and transport time (16.3 ± 2.7/17.0 ± 2.7 min) were not different
between groups, and neither were heart rates, mean arterial
pressures and RS at five time points during transport. ACD
patients needed less propofol injections (0 (0–1)/3 (2–4), P < 0.001) Methods
Sixty-eight ventilated brain trauma patients (mean
Glasgow Coma Scale: 5 ± 3) with controlled invasive ventilation S169 and reached the ICU with a similar RS (5 (4.5–5)/5 (4.75–5)). End-tidal SEV concentrations were similar in the OR (1.3 ± 0.2/
1.2 ± 0.2 vol%), but different when arriving in the ICU (0.6 ± 0.2/
0.2 ± 0.1 vol%, P < 0.001). Remifentanil vs conventional sedation in The Netherlands:
a pharmacoeconomic model analysis The
LOS on the ICU was 9.2 days in the CS group vs 8.1 days in the RS
group (difference 1.1, 95% CI 0.6–1.5), whereas the length of time
on MV was 6.3 days and 5.2 days, respectively, with a difference of
1.1 day (95% CI 0.6–1.6). The average total 28-day costs were
€15,911 in the CS group vs €14,855 in the RS group, resulting in
RS related cost-savings of €1,056 (95% CI €58–2,054). 1.
Murat I, et al.: Anesthesiology 1996, 84:526-532. P428 Assessment and management of pain in children in A&E:
are we doing it the right way? A Kage, A Mohammed
Calderdale Royal Hospital, Halifax, UK
Critical Care 2007, 11(Suppl 2):P428 (doi: 10.1186/cc5588) Conclusions Propofol disposition is significantly different in
neonates compared with toddlers and young children, reflecting
both ontogeny and differences in body composition. Based on the
reduced clearance of propofol, accumulation during repeated
administration and longer recovery time are more likely to occur in
neonates. Introduction Pain management is one of the most important
components in patient care. The severity of the pain should be
assessed effectively and weight-based analgesia should be given. The BAEM Clinical Effectiveness Committee standard of analgesia
for moderate and severe pain within 20 minutes of arrival in A&E
should be applied to children in all A&E Departments Introduction Pain management is one of the most important
components in patient care. The severity of the pain should be
assessed effectively and weight-based analgesia should be given. The BAEM Clinical Effectiveness Committee standard of analgesia
for moderate and severe pain within 20 minutes of arrival in A&E
should be applied to children in all A&E Departments
Methods A retrospective study. Five casualty cards with soft tissue
injury and fractures in children under 16 years old were picked
randomly every day from January 2005. The assessment and
management of pain was recorded in each case. A validated pain
score tool – Alder Hey triage pain score – was introduced April 1.
Murat I, et al.: Anesthesiology 1996, 84:526-532.
2
Saint-Maurice C et al : Br J Anaesth 1989 63:667-670 1.
Murat I, et al.: Anesthesiology 1996, 84:526-532.
2.
Saint-Maurice C, et al.: Br J Anaesth 1989, 63:667-670. 2.
Saint-Maurice C, et al.: Br J Anaesth 1989, 63:667-670. References P431 Intravenous anesthesia with S-(+)-ketamine for ‘on-pump’
coronary artery bypass surgery: hemodynamic profile and
effect on troponin T levels Results The maximal pain intensity was significantly higher on
POD 1 and 2 (3.7 ± 2 and 3.9 ± 1.9, respectively) and lower on
POD 3 (3.2 ± 1.5). The order of overall pain scores among
activities (P < 0.001) from highest to lowest was coughing, moving
or turning in bed, getting up, deep breathing or using the incentive
spirometer, and resting. After chest tubes were discontinued,
patients had lower pain levels at rest (P = 0.01), with coughing
(P = 0.05). Age and sex was found to have an impact on pain
intensity, with patients <60 years old and male patients having a
higher pain intensity than older patients on POD 2 (4.7 ± 2.0 vs
3.2 ± 2.4, P = 0.02 and 4.5 ± 2.3 vs 2.9 ± 2.2, respectively). C Neuhaeuser1, V Preiss1, M Mueller1, S Scholz1, M Kwapizs1,
I Welters2 C Neuhaeuser1, V Preiss1, M Mueller1, S Scholz1, M Kwapizs1,
I Welters2
1University Hospital, Giessen, Germany; 2University of Liverpool,
School of Clinical Science, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P431 (doi: 10.1186/cc5591) 1University Hospital, Giessen, Germany; 2University of Liverpool,
School of Clinical Science, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P431 (doi: 10.1186/cc5591) Introduction In patients with ischemic coronary artery disease the
‘sympathomimetic’ effects of ketamine can cause myocardial
damage. However, the S-isomer of ketamine may have various
advantages. We studied the cardiovascular stability and safety of
intravenous anesthesia with S-(+)-ketamine for coronary artery
bypass graft surgery (CABGS). Introduction In patients with ischemic coronary artery disease the
‘sympathomimetic’ effects of ketamine can cause myocardial
damage. However, the S-isomer of ketamine may have various
advantages. We studied the cardiovascular stability and safety of
intravenous anesthesia with S-(+)-ketamine for coronary artery
bypass graft surgery (CABGS). Conclusions Pain relief is an important outcome of care. A
comprehensive, individualized assessment of pain that incorporates
activity levels is necessary to promote satisfactory management of
pain. We recommend the use of remifentanil infusion for
postoperative pain relief in suitable cardiac surgery patients. Methods After approval of the local ethics committee and written
informed consent, 315 patients scheduled for elective ‘on-pump’
CABGS were enrolled in the study. Patients were randomly
allocated to three anesthetic protocols: sufentanil–sevofluorane–
propofol (SSP), sufentanil–propofol (SP), and S-(+)-ketamine–
midazolam–propofol (KMP). P429 Results Stimulation with TNFα increased the percentage of DOR-
expressing cells significantly from 2.1% to 12.8% positive cells
after 6 hours. After 12 hours of stimulation 28.6%, and after 24 hours
even 68.1%, of neutrophils expressed DOR. The MFI increased
during TNFα stimulation from 47.6 ± 15.7 to 254.8 ± 110 after
6 hours, staying levelled at this height. After 6 hours of stimulation,
the MFI for KOR reached a maximum, rising from 59.5 ± 19.4 to
513.9 ± 162. During TNFα stimulation, the percentage of positive
cells increased from 5.4 to 65.0% after 24 hours (17.5% at
6 hours). Fourteen per cent of neutrophils expressed MOR after
6 hours (initially 5.4%) and up to 57.2% after 24 hours. The MOR
MFI was measured at 43.4 ± 16.3 to 410 ± 263.6 6 hours after
stimulation with TNFα. Available online http://ccforum.com/supplements/11/S2 2005. Five casualty cards were picked randomly every day from
May 2005. The assessment and management of pain in each case
was recorded. immunocyte activity. These effects are mediated by opioid receptors
(OR) on peripheral white blood cells that can be detected and
quantified by flow cytometry. We investigated OR expression on
neutrophils using polyclonal antibodies against δ-opioid, κ-opioid
and µ-opioid receptors (DOR, KOR, MOR) to assess spontaneous
and TNFα-induced OR expression on neutrophils. immunocyte activity. These effects are mediated by opioid receptors
(OR) on peripheral white blood cells that can be detected and
quantified by flow cytometry. We investigated OR expression on
neutrophils using polyclonal antibodies against δ-opioid, κ-opioid
and µ-opioid receptors (DOR, KOR, MOR) to assess spontaneous
and TNFα-induced OR expression on neutrophils. Results There were 155 patients in each month. In January, none
of the patients were assessed for the severity of their pain; 34
patients received analgesia, of which 15 received weight-based
and 19 received age-based analgesia. In May, 84 patients were
assessed for the severity of their pain with the Alder Hey triage
pain score; 63 received weight-based and two received age-based
analgesia. The rest had no pain. Methods After approval by the local ethics committee and
informed consent, 100 µl whole blood samples from 11 healthy
volunteers (EDTA served as anticoagulant) was incubated with
10 µl TNF-α (100 ng/ml) for 3, 6, 12 and 24 hours. Samples were
washed and incubated with 5 µl fluorescein-isothiocynate (FITC)-
labelled polyclonal antibodies against human MOR, KOR and
DOR. Rabbit IgG antibodies served as a negative control. After red
cell lysis, flow cytometry was performed to quantify OR expression
using live gating on neutrophils. The percentage of positive cells as
well as mean fluorescent intensities (MFIs) were determined. Conclusion The Alder Hey triage pain score should be introduced
in A&E as it serves as an effective means of assessing pain in
children of all age groups. Analgesia should be prescribed based
on the weight of the children. P431 Standard invasive hemodynamic
monitoring was performed using a pulmonary artery catheter and
hemodynamic variables were reported. Measurements were taken
after induction of anesthesia, after weaning from cardiopulmonary
bypass, and 6 hours postoperatively. Serial plasma troponin T
levels were taken: before induction of anesthesia, after surgery,
and 6 and 24 hours postoperatively. All cardiovascular adverse
events were recorded (such as electrocardiographic signs of
ischemia, myocardial infarction, 28-day mortality). Pain after cardiac surgery A Kianfar1, K Shadvar1, A Mahoori2, R Azarfarin1
1Madani Heart Center, Tabriz, Israel; 2Cardiac Anesthesia, Urumie,
Israel
Critical Care 2007 11(Suppl 2):P429 (doi: 10 1186/cc5589) Critical Care 2007, 11(Suppl 2):P429 (doi: 10.1186/cc5589) Critical Care 2007, 11(Suppl 2):P429 (doi: 10.1186/cc5589) Background Acute pain is common after cardiac surgery and can
keep patients from participating in activities that prevent postoperative
complications especially respiratory complications. Accurate assess-
ment and understanding of pain are vital for providing satisfactory
pain control and optimizing recovery. This study was performed to find
the location, distribution, and intensity of pain in a sample of adult
cardiac surgery patients during their postoperative ICU stay. Conclusion Our results display that stimulation of whole blood with
TNFα amplifies OR expression of all subtypes significantly on
neutrophils. We suggest further studies to clarify the specific actions
of opioids and their receptors in health and acute inflammation. Methods In a prospective study, pain location, distribution (number
of pain areas per patient), and intensity (0–10 numerical rating
scale) were documented on 250 consecutive adult patients on the
first, second and third postoperative day (POD). Patient
characteristics (age, sex, size, and body mass index) were analyzed
for their impact on pain intensity. There were 140 male and 110
female patients, with a mean ± SD age of 65.7 ± 13.5 years. References Methods A retrospective study. Five casualty cards with soft tissue
injury and fractures in children under 16 years old were picked
randomly every day from January 2005. The assessment and
management of pain was recorded in each case. A validated pain
score tool – Alder Hey triage pain score – was introduced April S170 S170 Available online http://ccforum.com/supplements/11/S2 P433 P433 Results Groups (SSP: n = 106; SP: n = 108, KMP: n = 101) did
not differ in preoperative data (for example, biometry, cardiac and
coronary profile and risk). Intraoperative management was
comparable among groups. Tropinin T levels were rather lower in
the KMP group, but did not differ significantly between groups at
24 hours after aortic unclamping. Cardiovascular adverse events
showed the same low incidence in all groups. Hemodynamic data
were comparable; however, the heart rate (HR) and mean arterial
pressure (MAP) after induction were significantly higher in the KMP
group (HR: 59 ± 11 vs 63 ± 32 vs 66 ± 13 beats/min (P < 0.01);
MAP: 74 ± 12 vs 81 ± 16 vs 83 ± 16 mmHg (P < 0.01)). P432 Computer management systems and protocols in intensive
care units: do we have any benefit? Table 1 (abstract P433) Methods A Medline search from 1996 to 2006 with the following
key words was performed: critical care or intensive care, and
protocol, and data management system or computer management
system or computerized documentation. Results The search revealed 21 potential articles. The language
was English in 18 of the articles, two in German and one in
Japanese. Of those 21, 10 articles were not studying CMS/P. Of
those 11 that fulfilled the criteria, computer management systems
were studied in four articles and treatment protocols in 11 articles. The combination of ICU treatment protocol and computer manage-
ment system was studied in four of the 21 articles. Conclusion
Daily FAST-HUG review on ICU rounds, with
aggressive oral care, an early extubation strategy, and aggressive
infection control practices, decreases VAP rates. P430 Opioid receptor expression on neutrophils: effect of
tumour necrosis factor alpha treatment Opioid receptor expression on neutrophils: effect of
tumour necrosis factor alpha treatment A Schmidt1, I Welters2
1University of Giessen, Germany; 2Academic Unit of Critical Care
Medicine, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P430 (doi: 10.1186/cc5590) Introduction Opioids and endogenous opioid peptides possess
immunomodulating properties and are involved in the regulation of S171 S171 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Decreasing the incidence of ventilator-associated
pneumonia using the FAST-HUG evaluation T Papadimos, S Hensley, J Duggan
University of Toledo College of Medicine, Toledo, OH, USA
Critical Care 2007, 11(Suppl 2):P433 (doi: 10.1186/cc5593) T Papadimos, S Hensley, J Duggan Introduction Ventilator-associated pneumonia (VAP) is a leading
cause of morbidity and mortality in critically ill patients. We
implemented a performance improvement project over 2 years to
reduce VAP incidence in the medical ICU (MICU) and surgical ICU
(SICU). Conclusion In our study, KMP anesthesia was safe to use for
CABGS. In comparison with SSP and SP anesthesia, no
significant rise in troponin T as a marker of myocardial damage was
observed. All three regimens resulted in stable hemodynamics. However, the use of S-(+)-ketamine as an induction agent in
patients with coronary artery disease may be limited due to its
sympathomimetic effects leading to raised HR and MAP, even if
supplemented by midazolam or propofol. Methods From 1 January 2004 to 31 December 2005 a
prospective intervention was undertaken. Results were compared
with historic controls (2003). In year 1 we introduced aggressive
oral care using chlorhexidine mouthwash, an early extubation
strategy, changing respiratory equipment only when visibly soiled
or malfunctioning, and aggressive enforcement of hand-washing
and barrier protection methods. At the end of year 1 we
augmented the project with the addition of the FAST-HUG
(feeding, analgesia, sedation, thromboembolic prevention, head of
bed elevation, ulcer prophylaxis, and glucose control) evaluation. During year 2 FAST-HUG was emphasized daily on patient rounds
by the intensivists. The CDC VAP definition was used; the
Friedman test and Wilcoxon signed ranks test were used for data
analysis. Computer management systems and protocols in intensive
care units: do we have any benefit? M Rantala, K Kaukonen, V Pettilä
Helsinki University Hospital, Helsinki, Finland
Critical Care 2007, 11(Suppl 2):P432 (doi: 10.1186/cc5592) Results The VAP rates in the MICU and SICU for the control
period, 1 January–31 December 2003, were 13.41 and 19.37
VAPs/1,000 ventilator-days, respectively. The MICU VAP rate
declined to 3.02 VAPs/1,000 ventilator-days and the SICU rate
declined to 8.16 VAPs/1,000 ventilator-days over 2 years. The
greatest declines occurred during year 2 (Table 1). Introduction
Computer management systems and treatment
protocols (CMS/P) have been recommended for their potential to
improve patient safety and outcome. Computer management systems
require substantial investments in the ICUs. In return, a high-quality,
standardised ICU treatment with software-implemented protocols as
well as decreased hand-written documentation has been aimed at. The objective of this study was to systematically review the literature
on CMS/P to evaluate their impact on outcome benefit. Table 1 (abstract P433)
2003
2004
2005
P values
MICU
13.41
10.14
3.02
NSa, <0.05b,c
SICU
19.37
16.45
8.16
NSa, <0.05b,c
NS, not significant. a2003/04. b2004/05. c2003/05. P434 Of those 11, three of the studies demonstrated that the
implementation of a protocol to computer management system
increases staff compliance to the protocol. The newer studies
showed also that the costs were not increased by the computer-
ised protocol. However, no definite benefit in patient survival or
ICU length of stay could be demonstrated (11 of 21 studies). The
combined absolute reduction rate in hospital mortality was 2%
(95% CI 0–4%) in those four (19% of 21) studies. CMS/P
increased the ICU length of stay 3.5 days (95% CI 1.6–5.4 days)
and decreased the hospital length of stay 5.9 days (95% CI
1.0–10.8 days), in two different studies. P Brindley P Brindley
University of Alberta/Capital Health, Edmonton, Canada
Critical Care 2007, 11(Suppl 2):P435 (doi: 10.1186/cc5595) This abstract outlines the use of simulated critical care telephone
calls into the education of trainees. We hope others may consider
it for their centres. Introduction A significant amount of time is spent in an ICU for
procedures and the care of critically ill patients. Introduction A significant amount of time is spent in an ICU for
procedures and the care of critically ill patients. The Capital Health Region provides advanced healthcare for
2 million people, but spread over 9,800 km. We therefore rely
heavily on transportation of critically ill patients to a single urban
centre. In addition to geographic and climatic factors, bed
pressures complicate how we triage, stabilize, transport and
receive those patients. A major strategy is the ‘Critical-Care-Line’:
a 24-hour telephone service with teleconference capabilities and
contact numbers. However, experience suggests it takes practice
to become proficient with its use. Methods We prospectively collected data regarding demo-
graphics and time in seconds required for ICU procedures. Time
was recorded as the total time (preparation and action, Time A′)
and actual time (intervention only, Time B′). Results We investigated 60 patients (43 males) of mean age
53.6 ± 3.3 years, severity of illness APACHE II score = 16.5 ± 0.3,
SAPS II = 46.4 ± 0.7 and mean ICU stay of 18.6 ± 2.9 days. The
time required for ICU procedures is shown in Table 1. Conclusions A significant amount of time is spent in an ICU for
certain procedures. The length of time required is related to
complications, failures, physicians’ level of training, and presence
of assistance. ICU staff personnel should be adequately trained to
decrease time, complications and thus the ICU stay and costs. Given the importance of optimal communication, we arrange
simulated calls. Senior trainees are paged during a normal workday
by the Critical-Care-Line: just as they will be once in independent
practice. The facilitator then assumes the role of a referring doctor
in a small town. Peer-reviewed cases are used that include
pertinent teaching points. Applicable staff at the teaching centre
are briefed of this exercise and asked to act as they normally
would. Reference 1. Royal College of Physicians and Surgeons of Canada,
CanMEDS framework [http://rcpsc] 1. Royal College of Physicians and Surgeons of Canada,
CanMEDS framework [http://rcpsc] 1. Royal College of Physicians and Surgeons of Canada,
CanMEDS framework [http://rcpsc] P435 P436 Simulated critical care calls: a simple way to teach
complex skills
P Brindley
University of Alberta/Capital Health, Edmonton, Canada
Critical Care 2007, 11(Suppl 2):P435 (doi: 10.1186/cc5595) P Brindley For example, emergency physicians, internists, senior
nurses and administrators are notified that they may be brought
into the call, depending on whether the trainee decides to involve
other services (for example, if he/she decides a patient requires
further work-up before deciding upon ICU or if he/she decides to
bring the patient to emergency if no ICU bed is currently available). All calls are recorded to aid debriefing. Required time for certain intensive care unit procedures P Myrianthefs1, G Intas1, M Pitsoli1, L Louizou1, A Gavala1,
G Baltopoulos2
1KAT Hospital, Athens, Greece; 2General Hospital of Attiki ‘KAT’,
Kifissia, Greece
Critical Care 2007, 11(Suppl 2):P436 (doi: 10.1186/cc5596) Available online http://ccforum.com/supplements/11/S2 factors in sex, age, trauma or nontrauma, whether or not PMCT,
cause of death and final diagnosis. We especially compared the
two groups: PMCT(+) and PMCT(–). referring physicians, and deal with complex ethical decisions (for
example, if a family wishes to override a patient’s previous wish; or
how aggressively to treat the terminal patient for whom no prior
discussions have occurred). It allows us to test the trainees’
knowledge, but more importantly we can determine how well that
knowledge is applied in everyday practice. Results Seventy patients (55.1%) were men, and 57 (44.9%)
were women. Autopsy was done in only three patients. The number
of trauma cases was 21 (16.5%) and nontrauma was 106
(83.5%). PMCT was done in 20 patients (15.7%) and it was
possible to decide the final diagnosis in 16 (80%). Among 20
patients, there were six trauma cases and we could diagnose the
cause of death in all of them. On the other hand, PMCT was not
done in 107 patients (84.3%) and we could estimate the cause of
death in just 43 (40.2%). In Canada, the Royal College of Physician and Surgeons has
decreed that trainees become not just medical experts, but also
proficient communicators, collaborators, and managers [1]. These
goals, while laudable, have been very difficult to capture without
novel approaches such as the one outlined. This simple and cost-
free addition to our training has been very well received. Initial
success means it will now be expanded throughout acute care
specialist training. Conclusions We must make more effort to decide the cause of
death. Reliable death diagnosis could lead to more effective
cardiopulmonary resuscitation. Our date obviously indicated that
PMCT was a very effective and powerful method for death
diagnosis, especially in trauma cases. Significance of postmortem computed tomography in
death diagnosis: investigation of the characteristics in
patients with cardiopulmonary arrest on arrival Significance of postmortem computed tomography in
death diagnosis: investigation of the characteristics in
patients with cardiopulmonary arrest on arrival Introduction Autopsy is a very useful method in analysis of the
cause of death. However, the number of those actual enforce-
ments of autopsy has been getting less and less recently. Now,
autopsy imaging is very important as an alternative method to
autopsy. We evaluated the characteristics in patients with cardio-
pulmonary arrest on arrival and studied the usefulness of
postmortem computed tomography (PMCT) in death diagnosis. Patients and methods We analyzed consecutive patients with
cardiopulmonary arrest on arrival from October 1997 to November
2006. Total number of patients was 127. We studied the multiple Introduction Autopsy is a very useful method in analysis of the
cause of death. However, the number of those actual enforce-
ments of autopsy has been getting less and less recently. Now,
autopsy imaging is very important as an alternative method to
autopsy. We evaluated the characteristics in patients with cardio-
pulmonary arrest on arrival and studied the usefulness of
postmortem computed tomography (PMCT) in death diagnosis. Introduction Autopsy is a very useful method in analysis of the
cause of death. However, the number of those actual enforce-
ments of autopsy has been getting less and less recently. Now,
autopsy imaging is very important as an alternative method to
autopsy. We evaluated the characteristics in patients with cardio-
pulmonary arrest on arrival and studied the usefulness of
postmortem computed tomography (PMCT) in death diagnosis. Conclusion Our results could not confirm any definite benefit from
computerised data management systems or treatment protocols
regarding outcome. The ICU personnel adherence to treatment
protocols seems to increase when implemented into the
computerised data management systems. Further research on this
topic is needed to justify the investments in computer management
systems. Patients and methods We analyzed consecutive patients with
cardiopulmonary arrest on arrival from October 1997 to November
2006. Total number of patients was 127. We studied the multiple S172 Available online http://ccforum.com/supplements/11/S2 Simulated critical care calls: a simple way to teach
complex skills Simulated critical care calls: a simple way to teach
complex skills P438 Robust regression methods for intensive care monitoring The ‘Aiddiag’ data-acquisition software is a standalone application
adapted to patient data recording from the biomedical devices and
caregiver’s inputs. It has a friendly designed user-interface
touchscreen at the bedside and was adapted according to
caregivers’ feedback. Data are also stored in a repository and a
selective secondary extraction is possible. Online and offline
analysis by the AI engine is allowed. Software had to consider time
specifications and uses distributed computation to achieve high
workload tasks. We complied to the French legal patient data
management constraints. M Imhoff1, K Schettlinger2, R Fried2, U Gather2, S Siebig3,
C Wrede3
1Ruhr-University Bochum, Germany; 2University of Dortmund,
Germany; 3University Hospital Regensburg, Germany
Critical Care 2007, 11(Suppl 2):P438 (doi: 10.1186/cc5598) Introduction Alarm generation of modern patient monitoring
systems still predominantly relies on simple threshold methods. This
leads to an unacceptably high rate of false positive alarms. Many
false positive alarms are generated by measurement artefacts and
measurement noise. One approach to address this problem is to
alarm on the underlying signal (that is, the noise-free time series of
the physiological variable), instead of the raw measurement. Results After 2 years, our system is fully deployed. It recorded
more than 2,500 patient-hours over a 3-month period. Signal loss
is less than 1%. Our tool allows recording of more than 40 digital
signals, eight analogical signals sampled at a rate of 1 kHz, and
caregiver comments and actions. CPU resources of the laptop are
available
for
supplemental
AI
developments
during
data
acquisition. Transfer of data to the repository is either a hotplug-
automated process or delayed with 5 days of buffering in the
laptop. Automated artefacts’ cleaning allows time-series analysis
(GARCH method) to extract behavioural models after intensive
computation. The AI engine is used for medical guideline
implementation (that is, severe brain trauma care algorithms) and
later comparison with caregiver’s behaviour. Remote use of our
system is possible and schedulable, allowing other research teams
to work on the data. Limitations have been detected during
intensive calculation. Fine-tuning of the network will suppress
these limitations. Methods Monitoring time series were simulated. Against these
data four robust regression methods were evaluated: least trimmed
squares (LTS), least median of squares (LMS), repeated median
(RM), and deepest regression (DR). Moreover, online monitoring
series from critically ill patients during multiparameter monitoring
were also compared. P439 P439
ISIS program: a new tool for medical research at the
bedside in critical care units
H Mehdaoui1, B Sarrazin1, I El Zein1, L Allart2, C Vilhelm2,
S Guerra2, D Zitouni2, M Lemdani2, R Valentino1, A Herbland1,
P Ravaux2
1Fort De France University Hospital, Fort De France, Martinique;
2Lille 2 University, Lille, France
Critical Care 2007, 11(Suppl 2):P439 (doi: 10.1186/cc5599) Results MD1 found clinically relevant events in 36%, and MD2 in
29% of all time series. In 16% of all cases both intensivists came
to different classifications. In 10% even the direction of change
was classified differently. MD2 classified 10% of all cases
differently between the first and second analysis. Even if level
changes and trends were treated as one universal pattern of
change, intra-individual variability (MD2 first analysis vs MD2
second analysis) was still 5% and inter-individual variability (MD1
vs MD2, only unequivocal classifications) was 10%. Conclusion Although this study is small with only two observers
who were investigated, it clearly shows that there is a significant
intra-individual and inter-individual variability in the classification of
monitoring events done by experienced clinicians. These findings
are supported by studies into image analysis that also found high
intra-individual and inter-individual variability. High inter-observer
and intra-observer variability is a challenge for clinical studies into
new alarm algorithms. Our findings also show a need for reliable
classification methods. Introduction The goal of this program is to develop an experi-
mental tool able to record, store and analyse data issued from
critical care patients. Due to technical limitations and medical
constraints, information systems able to manage such data flow are
difficult to deploy. Introduction The goal of this program is to develop an experi-
mental tool able to record, store and analyse data issued from
critical care patients. Due to technical limitations and medical
constraints, information systems able to manage such data flow are
difficult to deploy. Methods Data recording is done through a laptop connected to
the medical devices, allowing analogical and digital signal
transmission through a high-speed network. Several servers are
dedicated to specialised tasks: mass storage, model generation,
artificial intelligence (AI), telecommunications, and security. A 3
Teraflops supercomputer is dedicated to intensive computation
when necessary. Twenty applications are dedicated to elective
tasks, most of them running using the Linux operating system. P437 Intra-observer and inter-observer variability of clinical
annotations of monitoring data
M Imhoff1, R Fried2, U Gather2, S Siebig3, C Wrede3
1Ruhr-University Bochum, Germany; 2University of Dortmund,
Germany; 3University Hospital Regensburg, Germany
Critical Care 2007, 11(Suppl 2):P437 (doi: 10.1186/cc5597) Intra-observer and inter-observer variability of clinical
annotations of monitoring data Introduction In order to evaluate new methods for alarm genera-
tion from monitoring data, a gold standard of alarm evaluation is Introduction In order to evaluate new methods for alarm genera-
tion from monitoring data, a gold standard of alarm evaluation is Introduction In order to evaluate new methods for alarm genera-
tion from monitoring data, a gold standard of alarm evaluation is This method allows us to ascertain how trainees ask focused
histories, offer practical advice based upon the variable skill set of S173
Table 1 (abstract P436)
Failure at first
Number of
Procedure
n
Time A′
Time B′
attempt (%)
required efforts
Central line placement
120
1,791 ± 52.6
1,023.6 ± 40.3
10.4
2.6 ± 0.3
Arterial line placement
251
491.4 ± 38.5
240.6 ± 26.8
30.4
2.3 ± 0.2
Tracheal tube change
78
910.1 ± 43.7
46.4 ± 4.4
5.5
1.4 ± 0.1
Tracheostomy change
96
565.2 ± 26.8
34.3 ± 2.5
7.1
1.1 ± 7.1
Transfer for CT
76
3,375.5 ± 174.5
1,912.1 ± 87.3
0.0
1.0 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Conclusion All four methods allow one to extract the underlying
signal from physiological time series in a way that is robust against
measurement artefacts and noise. However, there are significant
differences between the methods. Overall, repeated median
regression seems the best choice for intensive care monitoring
since it is not only the most stable but also the fastest method. needed. Nearly all clinical studies into monitoring alarms used
clinician judgement and annotation as the reference standard. We
investigated the intra-observer and inter-observer variability between
two intensivists in the classification of monitoring time series. Methods A total of 3,092 time series segments (heart rate and
blood pressures) of 30 minutes each from six critically ill patients
were presented to two experienced intensivists (MD1 and MD2)
offline and were visually classified into clinically relevant patterns
(no change, level shift, trend) by the physicians separately. One
intensivist (MD2) repeated the classification 4 weeks after the first
analysis on the same dataset. Inter-rater agreement in the triage of calls to a paediatric
interhospital transfer service Inter-rater agreement in the triage of calls to a paediatric
interhospital transfer service S Riphagen, M Alasnag, S Hanna, S Manna, M McDougall
Guy’s and St Thomas’ Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P440 (doi: 10.1186/cc5600) M McDougall, S Riphagen, S Hanna, S Moganasundram,
F Bickell, A Durward, I Murdoch
Evelina Children’s Hospital @ Guy’s and St Thomas’ NHS
Foundation Trust, London, UK
Critical Care 2007, 11(Suppl 2):P441 (doi: 10.1186/cc5601) Introduction As a result of centralisation of PICU services in the
United Kingdom, transfer of critically ill children has become
common over the past decade. It is not uncommon to receive
multiple retrieval requests simultaneously, thus a tool to prioritise
the urgency of this would be beneficial. Our aim was to develop
such a tool and assess its inter-rater repeatability. Introduction The South Thames Retrieval Service (STRS) is a
specialised paediatric intensive care retrieval service, integrated
into the Evelina Children’s Hospital, the lead centre in the South
Thames Region, London. Over the last 5 years a number of
initiatives have been adopted to reduce mobilisation times (the
time from retrieval acceptance and activation to departure from the
lead centre) and improve service delivery to surrounding district
general hospitals (DGHs). The aim of this study was to evaluate
whether these initiatives led to a reduction in mobilisation time
between January 2002 and December 2006. Introduction The South Thames Retrieval Service (STRS) is a
specialised paediatric intensive care retrieval service, integrated
into the Evelina Children’s Hospital, the lead centre in the South
Thames Region, London. Over the last 5 years a number of
initiatives have been adopted to reduce mobilisation times (the
time from retrieval acceptance and activation to departure from the
lead centre) and improve service delivery to surrounding district
general hospitals (DGHs). The aim of this study was to evaluate
whether these initiatives led to a reduction in mobilisation time
between January 2002 and December 2006. Methods The tool was developed by three senior medical staff of
the South Thames Retrieval Service (operating from the PICU at
Evelina Children’s Hospital, London with 1,000 calls per annum
from 24 district general hospitals, resulting in 600 retrievals). A
modified Delphi method was used, which comprised an iterative
process including a literature review, knowledge of the underlying
conditions and a review of retrievals performed by the service over
the previous 7 years (n = 3,669). P440 P440 Figure 1 (abstract P440) Results A total of 2,761 retrievals (median age 12 months, 78%
ventilated) were performed and included for analysis during the
study period, 33 were excluded (missing mobilisation times
(n = 30) or elective transfers (n = 3). Figure 1 shows the process
introduced to improve mobilisation times with a dedicated onsite
ambulance service in 2004. There was a significant reduction in Inter-rater agreement in the triage of calls to a paediatric
interhospital transfer service Inter-rater agreement was
assessed using the weighted kappa statistic, and was measured
between various pairings of junior and senior medical staff (n = 28
combinations) on 50 retrieval episodes. Methods The STRS covers 24 DGHs within an 80 mile range
serving a population of 1.6 million children in the South Thames
region of Greater London. All calls to the service were logged on a
detailed database. Retrieval requests for potential PICU patients
were triaged and coordinated via a retrieval-specific telephone line. Once accepted, the onsite retrieval team was mobilised and
dispatched via a dedicated ambulance to the DGH. Mobilisation
includes assimilating and checking pre-packed equipment bags
(ventilators, drugs, intubation kit, monitors, and so on) and
organising a team of at least one retrieval nurse, doctor and
ambulance driver. Details of each retrieval request to the STRS,
including the time of the call, were captured on a database
containing the patient demographic and clinical details. The interval
between accepting the patient for retrieval and team departure
from the unit was termed the ‘mobilisation time’ (minutes). Data
were analysed over two time periods, before (n = 976 retrievals)
and after 2004 (n = 1,785), coincident with a dedicated
ambulance and driver on site. Nonparametric tests were used for
continuous data (Kruskall–Wallis test or Mann–Whitney test) and
the chi-squared test for categorical 2 x 2 comparisons. Results The final tool comprised five categories (three levels of
severity each) allowing for a range of scores from 0 to 15
(Figure 1). Three levels of urgency were defined: semi-urgent
(score <8), urgent (score 8–10), immediate (score >10). Overall
the tool showed a good to very good strength of inter-rater
agreement (kappa scores ranging from 0.65 to 0.88; Figure 2). There were no obvious differences between levels of staff seniority. Conclusion The score showed acceptable agreement, fullfilling
the first step of validation. P438 Results LTS and LMS showed comparable behaviour, as did RM
and DR. LMS and LTS provided only 20% efficiency, DR 61% and
RM 70% (least squares regression = 100%). RM and DR had
smaller standard deviations and smaller mean-squared errors than
LMS and LTS under different noise distributions (standard
deviation of online estimates based on sliding windows of size n =
21 for simulated standard normal errors: LMS: 0.875, LTS: 0.887,
RM: 0.500, DR: 0.533). Analyses with clinical monitoring data also
showed that LMS and LTS preserve sudden level shifts but are
unstable and perform poorly with trend changes; RM and DR blur
shifts but yield more stable estimations. Conclusion ISIS is the first program to achieve an easy-to-use
recording tool able to build a very large medical repository. Data
analysis methods and AI-controlled automated complex medical
guidelines are under evaluation. S174 Available online http://ccforum.com/supplements/11/S2 P443 The use of a track and trigger system on general medical
wards
M Lawson, A Stone, D King, A Davison
Southend University Hospital, Southend, UK
Critical Care 2007, 11(Suppl 2):P443 (doi: 10.1186/cc5603) The use of a track and trigger system on general medical
wards
M Lawson, A Stone, D King, A Davison
Southend University Hospital, Southend, UK
Critical Care 2007, 11(Suppl 2):P443 (doi: 10.1186/cc5603) The use of a track and trigger system on general medical
wards Median retrieval mobilisation times. M Lawson, A Stone, D King, A Davison
Southend University Hospital, Southend, UK
Critical Care 2007, 11(Suppl 2):P443 (doi: 10.1186/cc5603) mobilisation time from 2002 to 2006 from 55 minutes (IQR
35–80) to 30 minutes (IQR 25–50), P < 0.0001 (Kruskall–Wallis)
(Figure 2). When comparing pre-2004 and post-2004 time
periods, the median mobilisation time was significantly lower after
2004 with a fall from 45 minutes (IQR 30–70) to 35 minutes (IQR
27–55). There was also a significant increase in the incidence of
sub-30-minute mobilisation times, which almost doubled after
2004 with the availability of an onsite dedicated ambulance service
(14.3% to 25.9%, P < 0.0001). Introduction Many groups have advocated identification of critically
ill medical patients by abnormal or deteriorating physiological
parameters. In Southend Hospital a track and trigger system has
been used since 2005 to alert nurses to abnormal physiological
parameters in order to trigger urgent medical review of the unwell
patient. It is recognised that the respiratory rate is a particularly
useful predictor of significant deterioration and should be measured
with every set of observations. This audit aimed to assess the use of
the track and trigger system on the medical wards and ensure that
deteriorating critically ill patients are promptly reviewed. Conclusion
There has been a significant decrease in the
mobilisation time of the STRS over the last 5 years. Although the
presence of an onsite ambulance service in 2004 had a significant
impact on reducing retrieval mobilisation times, a number of other
factors and initiatives contributed to steadily reducing mobilisation
times over the study period. Methods Patient observation charts were reviewed for a specified
24-hour period. Data were gathered on the frequency and type of
observations taken. For patients who met criteria to trigger a
review, further data were abstracted about the nature of the
deterioration and the promptness of the review. Figure 1 (abstract P441) S175
Processes introduced to improve mobilisation times. S
Processes introduced to improve mobilisation times. Figure 2 (abstract P440) Figure 2 (abstract P440) Figure 2 (abstract P440) S175 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicine Figure 2 (abstract P441)
Median retrieval mobilisation times. Figure 2 (abstract P441)
Median retrieval mobilisation times. Table 1 (abstract P442)
Penetrating trauma
Private transport
Ambulance
Alive
98.8% (n = 254)
95.6% (n = 527)
Dead
1.2% (n = 3)
4.4% (n = 24) Table 1 (abstract P442) Conclusion The use of ambulance transportation is associated
with a 3.7-fold increase in mortality following penetrating injury. This may be related to longer times in the field resulting in delay to
definitive care in hospital. P442 Results One hundred and sixty patient-days of observations were
evaluated over seven medical wards. Twenty-nine patients met the
trigger criteria and in 16 cases this represented a deterioration. Doctors were called in two cases. Observations were recorded
with different frequency on different wards. One ward managed to
record the respiratory rate with every set of observations. Ambulance transport is associated with a higher mortality
than private transport following major penetrating trauma
in a semi-urban environment E Dickson, D Van Niekerk, S Robertson, J Goosen, F Plani,
K Boffard
Johannesburg Hospital Trauma Unit and University of the
Witwatersrand, Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P442 (doi: 10.1186/cc5602) Conclusions
Documented
deteriorations
in
physiological
observations did not trigger medical review. This may be a
communication failure or failure to recognise recorded observations
as abnormal. For this process to work well relevant observations
must be recorded regularly and accurately. The respiratory rate was
not consistently recorded between wards and the frequency of
measurement of observations was variable. Further education and
training is needed to improve recording of the respiratory rate and
work needs to be done to establish why doctors were not called
appropriately. Concerns about the volume of work generated by the
system are unfounded. A positive predictive value of 55% is
acceptable and 29 ‘triggers’ in a 24-hour period are manageable. Aims The use of private transportation has been associated with
improved outcomes in urban trauma patients. The need for patient
stabilization at the scene needs to be balanced with the need for
early operative intervention, and therefore the need for rapid
transportation to hospital. Our aim was to assess the relationship
between the mode of transport to hospital and outcome in a semi-
urban trauma environment. Methods Data were collected prospectively on 1,396 patients
admitted to a Level 1 South African trauma unit over a 1-year
period. The Revised Trauma Score was used to assess injury
severity and physiological derangement at the time of admission,
and to allow comparison between the groups. Mortality was
defined as death within 30 days. P444 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 was commissioned by the Ministry of Health and Long-term Care
to facilitate the improvement of inhospital emergency preparedness
through a System-Level Training Initiative. Objectives for the
program were to reduce mortality and improve efficiency of ICU
resource use through early identification of patients at risk of
deterioration and the provision of rapid resuscitation to abort
avoidable ICU admissions. The program was designed to train
nonphysician responders (primarily nurses and respiratory
therapists) supported by remote physician oversight, especially in
centres where ICU-trained physicians were not available. the ward, the presence of a CCOS was associated with significant
reductions in: the proportion of admissions receiving cardio-
pulmonary resuscitation during the 24 hours prior to admission
(odds ratio 0.84, 95% confidence interval 0.73–0.96); the
proportion of admissions between 22:00 and 06:59 (0.91,
0.84–0.97); and the mean ICNARC physiology score (absolute
reduction 1.2, 0.3–2.1). No significant effects of CCOS on
outcomes including hospital mortality and readmission to critical
care were identified for patients discharged to the ward. Interpretation The results of this study were mixed. While some
differences in the characteristics of patients admitted to critical
care units were found to be associated with the introduction of
CCOS, there was no evidence for an impact on the outcomes of
patients discharged from critical care. It was not possible to
identify any clear characteristics for an optimal CCOS. the ward, the presence of a CCOS was associated with significant
reductions in: the proportion of admissions receiving cardio-
pulmonary resuscitation during the 24 hours prior to admission
(odds ratio 0.84, 95% confidence interval 0.73–0.96); the
proportion of admissions between 22:00 and 06:59 (0.91,
0.84–0.97); and the mean ICNARC physiology score (absolute
reduction 1.2, 0.3–2.1). No significant effects of CCOS on
outcomes including hospital mortality and readmission to critical
care were identified for patients discharged to the ward. Interpretation The results of this study were mixed. While some
differences in the characteristics of patients admitted to critical
care units were found to be associated with the introduction of
CCOS, there was no evidence for an impact on the outcomes of
patients discharged from critical care. It was not possible to
identify any clear characteristics for an optimal CCOS. Methods Following an educational needs assessment of learners,
a multicomponent critical care response team (CCRT) training
course was developed. M Seubert M Seubert
Academic Medical Center, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P446 (doi: 10.1186/cc5606) Academic Medical Center, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P446 (doi: 10.1186/cc5606) Introduction Blood groups may be related to differences in
inflammatory responses [1]. We looked at blood group as a risk
factor for ICU mortality in general and for patients with sepsis. Introduction Blood groups may be related to differences in
inflammatory responses [1]. We looked at blood group as a risk
factor for ICU mortality in general and for patients with sepsis. Methods Data were retrospectively collected from all 11,553
patients that were admitted from 1997 to 2005 to our medical/
surgical ICU. Methods Data were retrospectively collected from all 11,553
patients that were admitted from 1997 to 2005 to our medical/
surgical ICU. Conclusions It has been demonstrated that unmet needs in critical
care education and training for allied healthcare professionals can
be identified and corrected through the development and
implementation of a multidisciplinary course designed to facilitate
creation of CCRTs in the Province of Ontario. Evaluation of the
effectiveness of these teams is ongoing. Results ICU mortality and SAPS II score for different blood groups
are shown in Table 1. P values are given for the difference
between blood groups A and O. No differences were found for
age, gender, and reason for admission. No influence of rhesus
blood group type was seen on mortality. Available online http://ccforum.com/supplements/11/S2 The 2-day course consisted of a series of
small group, interactive, case-based seminars, high-fidelity
simulation training, and the publication of a CCRT Provider Manual
and Quick Reference Cards. A database for monitoring the
effectiveness and impact of the CCRTs was also developed. P446 Results Beginning in October 2005, 24 CCRT physician instructors
were trained in one of two streams: (i) simulator instructors with skills
in constructive feedback and assessment of crisis management skills;
(ii) instructors who further refined the case-based seminars and
edited the Quick Reference Cards. Acquisition of equipment, liaisons
with participating hospitals and creation of the CCRT database were
completed in the spring of 2006. Since June 2006, 12 CCRT
courses have been run, and 263 participants have been trained as
CCRT Providers (87% nurses, and 13% respiratory therapists). Local
hospital implementation and preceptored programs occurred over a
12-week period before CCRTs we made available full time (24/7). Influence of ABO blood group polymorphism on mortality
in intensive care unit patients Reference Reference
1. Garratty G: Transfusion Med Rev 2000, 14:291. Reference
1. Garratty G: Transfusion Med Rev 2000, 14:291. e e e ce
1. Garratty G: Transfusion Med Rev 2000, 14:291. 1. Garratty G: Transfusion Med Rev 2000, 14:291. P445 Individual patient-
level data were collapsed into monthly time series for each unit
(panel data). Population-averaged panel-data models were fitted
using a generalised estimating equation approach. Various
outcomes reflecting the stated aims of CCOS were considered for
three groups of admissions: all admissions to the unit; admissions
from the ward; and unit survivors discharged to the ward. The
primary exposure variable was the presence of a formal CCOS
with secondary exposures of CCOS activities, coverage and
staffing, identified from the survey data. P445 Table 1 (abstract P446)
ABO blood group
A
B
AB
O
P value
All patients
n = 4,787 n = 1,168 n = 479
n = 5,119
ICU death (%)
9.5
10.2
10.9
11.2
<0.01
SAPS II
32 ± 16
33 ± 17
34 ± 18
33 ± 17
NS
Severe sepsis
n = 265
n = 73
n = 34
n = 318
ICU death (%)
24.9
28.8
26.5
32.4
0.05
SAPS II
49 ± 18
49 ± 18
54 ± 19
51 ± 18
NS Multicentre evaluation of the impact of the introduction of
outreach services in the United Kingdom H Gao1, D Harrison1, G Parry2, K Daly3, C Subbe4, K Rowan1
1ICNARC, London, UK; 2Children’s Hospital Boston, MA, USA;
3St Thomas’ Hospital, London, UK; 4Wrexham Maelor Hospital,
Wrexham, UK
Critical Care 2007, 11(Suppl 2):P445 (doi: 10.1186/cc5605) Background Critical care outreach services (CCOS) have been
introduced in the United Kingdom with aims to: avert or ensure timely
admission to critical care; enable discharge from critical care; and
share skills with ward staff. We aimed to assess the impact of the
introduction of CCOS at the critical care unit level, as characterised
by the case mix, outcome and activity of critical care unit admissions. Methods An interrupted time-series analysis was carried out using
data from 108 units participating in the Case Mix Programme that
had completed a survey on CCOS provision. Individual patient-
level data were collapsed into monthly time series for each unit
(panel data). Population-averaged panel-data models were fitted
using a generalised estimating equation approach. Various
outcomes reflecting the stated aims of CCOS were considered for
three groups of admissions: all admissions to the unit; admissions
from the ward; and unit survivors discharged to the ward. The
primary exposure variable was the presence of a formal CCOS
with secondary exposures of CCOS activities, coverage and
staffing, identified from the survey data. R
lt
Of 108
it
i
th
l
i
79 (73%) h d
f
l Conclusion Blood group O is associated with a higher ICU
mortality rate than blood group A. The relative risk increase for ICU
mortality was 18% for all patients and 30% for patients with severe
sepsis. y
y
Methods An interrupted time-series analysis was carried out using
data from 108 units participating in the Case Mix Programme that
had completed a survey on CCOS provision. P444 Design and implementation of needs-specific critical care
response teams R Hodder1, A Fox-Robichaud2, R Wax3, P Cardinal1, S Reynolds3
1University of Ottawa, Canada; 2McMaster University, Hamilton,
Canada; 3University of Toronto, Canada
Critical Care 2007, 11(Suppl 2):P444 (doi: 10.1186/cc5604) Results The mortality in the blunt trauma patients (n = 527) was
higher in the ambulance transport group, but this was not
statistically significant. However, the mortality in the penetrating
trauma patients (n = 808) was significantly higher in the ambu-
lance transport group (P = 0.020, chi-square; Table 1) despite
similar Revised Trauma Scores (Table 1). Introduction Following the severe acute respiratory syndrome
epidemic in Ontario Canada, the Canadian Resuscitation Institute S176 Available online http://ccforum.com/supplements/11/S2 P447 The present findings have important implications in
the understanding of the role of DEFB1 in the pathophysiology of
severe sepsis, and DEFB1 genomic variations may offer a new
means of risk stratification for patients with severe sepsis. of quantification of in vivo gene expression with QRT-PCR
providing more accurate and sensitive data when compared with
prior ELISA-based assays. Indeed, the extrapolation of functionality
from in vitro functional genetic tests after lipopolysaccharide stimu-
lation may be of questionable value. We conclude that genotypic
analysis does have a place in risk stratification in sepsis and that
genetic variants at positions –863 and –308, or sites in linkage
disequilibrium with these variants, may influence TNFα production. P447 P447 P447
Contribution of genomic variations within human β-
defensin 1 to incidence and outcome of severe sepsis
X Fang, C Lv, Q Chen, L Huang
Zhejiang University, Hangzhou, China
Critical Care 2007, 11(Suppl 2):P447 (doi: 10.1186/cc5607) Contribution of genomic variations within human β-
defensin 1 to incidence and outcome of severe sepsis Contribution of genomic variations within human β-
defensin 1 to incidence and outcome of severe sepsis X Fang, C Lv, Q Chen, L Huang
Zhejiang University, Hangzhou, China
Critical Care 2007, 11(Suppl 2):P447 (doi: 10.1186/cc5607) X Fang, C Lv, Q Chen, L Huang
Zhejiang University, Hangzhou, China
Critical Care 2007, 11(Suppl 2):P447 (doi: 10.1186/cc5607) S177
Sepsis, a systemic inflammatory response to infection, is a common
clinical syndrome in the ICU. Human β-defensin 1 (DEFB1) is a Results Of 108 units in the analysis, 79 (73%) had a formal
CCOS introduced between 1996 and 2004. For admissions from Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin multifunctional mediator in infection and inflammation, which has
been largely explored in ex vivo studies. The lack of fully
representative genetic animal models increases the importance of
analyzing the impact of defensin gene polymorphisms on the
courses of infectious and inflammatory diseases such as sepsis. This study was designed to investigate whether DEFB1 genomic
variations are associated with incidence and outcome of severe
sepsis. Six reported polymorphisms were detected in 211 patients
with severe sepsis and 157 control individuals using diverse
analytic methods. Linkage disequilibrium (LD), haplotype frequen-
cy, and statistical power for this association study were analyzed. The –44G-allele and –44G-allele carrying genotypes were
significantly associated with incidence and outcome of severe
sepsis. There was enough statistical power (1 – β > 0.8 at type I
level of 0.05) to demonstrate a significant contribution of the –44G
allele to severe sepsis. The –20G allele and GG genotype were
associated with susceptibility to severe sepsis, while the –1816G-
allele and –1816G-allele carrying genotypes influenced the
outcome of severe sepsis. SNPs –20A/G, –44C/G and –52A/G
were in strong LD. Haplotype –20A/–44C/–52G showed a
protective role against severe sepsis, whereas haplotype
–20G/–44G/–52G served as a risk factor for fatal outcome of
severe sepsis. P448 P448
TNFα promoter single nucleotide polymorphisms may
influence gene expression in patients with severe sepsis
M Odwyer1, M White1, R McManus2, T Ryan1
1St James’s Hospital, Dublin, Ireland; 2Trinity College, Dublin, Ireland
Critical Care 2007, 11(Suppl 2):P448 (doi: 10.1186/cc5608) ill systemic inflammatory response syndrome (SIRS) patients. Methods Uninfected, critically ill trauma patients with SIRS were
evaluated daily for sepsis. Patients were divided into two groups:
pre-septic = SIRS patients who developed sepsis, and uninfected
SIRS = SIRS patients remaining uninfected. Plasma samples and
whole blood (PAXgene) obtained at study entry and daily for
3 days prior to sepsis were analyzed for differential gene expression
between groups (Affymetrix Hg_U133 2.0 plus microarray, false
discovery rate < 0.5%, P < 0.005) and quantitative plasma protein
TNF and IL-1 levels (Immunoassay, Luminex™, elevated if > 3 SD
above the mean for normals). Gene expression data are the median
fold change between groups (uP = pre-septic > uninfected). P449 IL-1/tumor necrosis factor receptor gene expression
characterizes sepsis in critically ill systemic inflammatory
response syndrome patients IL-1/tumor necrosis factor receptor gene expression
characterizes sepsis in critically ill systemic inflammatory
response syndrome patients M Lissauer1, S Johnson1, C Feild1, C Whiteford2,
W Nussbaumer2, T Scalea1
1University of Maryland Medical Center, R Adams Cowley Shock
Trauma Center, Baltimore, MD, USA; 2BD Diagnostics, Sparks,
MD, USA
Critical Care 2007, 11(Suppl 2):P449 (doi: 10.1186/cc5609) Introduction The classic response to isolated endotoxin challenge
entails secretion of IL-1 and TNFα. The purpose of this study was to
longitudinally characterize the cytokine response to sepsis in critically
ill systemic inflammatory response syndrome (SIRS) patients. Methods Uninfected, critically ill trauma patients with SIRS were
evaluated daily for sepsis. Patients were divided into two groups:
pre-septic = SIRS patients who developed sepsis, and uninfected
SIRS = SIRS patients remaining uninfected. Plasma samples and
whole blood (PAXgene) obtained at study entry and daily for
3 days prior to sepsis were analyzed for differential gene expression
between groups (Affymetrix Hg_U133 2.0 plus microarray, false
discovery rate < 0.5%, P < 0.005) and quantitative plasma protein
TNF and IL-1 levels (Immunoassay, Luminex™, elevated if > 3 SD
above the mean for normals). Gene expression data are the median
fold change between groups (uP = pre-septic > uninfected). Results Gene expression on 90 patients and protein measure-
ments on 142 patients were available. Protein levels of both
subtypes of TNF and IL-1 were not elevated at any time point in
either group. IL-1α was noted to have differential gene expression
24 hours before sepsis. No differences were noted in gene
expression for TNFα, TNFβ, or IL-1β. Differential gene expression
for only two TNF family members (TNFSF10 and TNFSF13b) was
noted. However, differential gene expression for TNF and IL-1
receptors and IL-1 receptor antagonist was prominent (Table 1). Introduction The classic response to isolated endotoxin challenge
entails secretion of IL-1 and TNFα. The purpose of this study was to
longitudinally characterize the cytokine response to sepsis in critically
ill systemic inflammatory response syndrome (SIRS) patients. Introduction The classic response to isolated endotoxin challenge
entails secretion of IL-1 and TNFα. The purpose of this study was to
longitudinally characterize the cytokine response to sepsis in critically
ill systemic inflammatory response syndrome (SIRS) patients. TNFα promoter single nucleotide polymorphisms may
influence gene expression in patients with severe sepsis TNFα promoter single nucleotide polymorphisms may
influence gene expression in patients with severe sepsis M Odwyer1, M White1, R McManus2, T Ryan1
1St James’s Hospital, Dublin, Ireland; 2Trinity College, Dublin, Ireland
Critical Care 2007, 11(Suppl 2):P448 (doi: 10.1186/cc5608) Introduction We examined the association of TNFα promoter
single nucleotide polymorphisms and haplotypes with gene
expression in terms of mRNA levels and with outcome in a cohort
of patients with severe sepsis. Results Gene expression on 90 patients and protein measure-
ments on 142 patients were available. Protein levels of both
subtypes of TNF and IL-1 were not elevated at any time point in
either group. IL-1α was noted to have differential gene expression
24 hours before sepsis. No differences were noted in gene
expression for TNFα, TNFβ, or IL-1β. Differential gene expression
for only two TNF family members (TNFSF10 and TNFSF13b) was
noted. However, differential gene expression for TNF and IL-1
receptors and IL-1 receptor antagonist was prominent (Table 1). Methods Sixty-two Irish Caucasian patients presenting with severe
sepsis were enrolled. Blood sampling was carried out on day 1 and
on day 7. Mononuclear cells were isolated and TNFα mRNA
quantified using the technique of quantitative real-time polymerase
chain reaction (QRT-PCR). DNA was extracted and assayed for
four TNFα promoter polymorphisms. Haplotypes were inferred
using PHASE software. Results Twenty-seven patients died. Patients carrying an A allele
at position –863 produced more TNFα mRNA on day 1 than C
homozygotes (P = 0.037). There was a trend for patients
homozygous for the G allele at position –308 to produce more
TNFα mRNA on day 1 than those carrying an A allele (P = 0.059). Carrier status for haplotype 1 (with A at position –863 and G at
position –308) was associated with greater TNFα mRNA levels on
day 1 (P = 0.0374). Carrier status for haplotype 4 (with C at
position –863 and A at position –308) was associated with a
nonsignificant decrease in TNFα
mRNA levels on day 1
(P = 0.059). When directly compared, haplotype 1 was associated
with significantly greater levels of TNFα mRNA than with haplotype
4 on day 1 (P = 0.02). Patients homozygous for the A allele at
position –308 were more likely to succumb to severe sepsis than
those carrying the G allele (P = 0.01). A novel score based on age and cardiac biomarkers
predicts outcomes in severe sepsis and septic shock predicts outcomes in severe sepsis and septic shock
A Turley, A Thornley, A Roberts, M Johnson, M de Belder,
J Gedney
The James Cook University Hospital, Middlesbrough, UK
Critical Care 2007, 11(Suppl 2):P450 (doi: 10.1186/cc5610) F Leitch1, E Dickson1, A McBain1, S Robertson2, D O’Reilly1,
C Imrie1
1Glasgow Royal Infirmary, Glasgow, UK; 2Johannesburg Hospital,
Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P451 (doi: 10.1186/cc5611) 1Glasgow Royal Infirmary, Glasgow, UK; 2Johannesburg Hospital,
Johannesburg, South Africa
Critical Care 2007, 11(Suppl 2):P451 (doi: 10.1186/cc5611) Background Myocardial dysfunction is common among critically ill
septic patients. Elevated levels of cardiac biomarkers are predictors
of mortality in acute coronary syndrome and in unselected critically
ill patients. Our aim was to evaluate the role of the cardiac markers
NT-proBNP, Troponin T (TnT) and myoglobin as predictors of
inhospital and 6-month all-cause mortality in patients admitted to a
general adult ICU with severe sepsis/septic shock. Introduction Early identification of critically ill surgical patients who
are not fully resuscitated improves outcome. Current markers of
clinically occult hypoperfusion, such as lactate, have serious limi-
tations. Increased oxidative stress as a consequence of inadequate
cellular respiration results in elevated levels of unmeasured anions. We evaluated these anions as a novel marker of outcome. Methods We prospectively evaluated 109 consecutive patients
admitted to a surgical high-dependency unit (HDU). Regional
Ethics Committee approval was obtained. Serum electrolytes,
albumin, phosphate and lactate were measured on admission and
days 1 and 2. We derived the calculated ion gap (CIG) using our
simplified modification of the Stewart–Figge equations. Methods Serial plasma samples were taken for five sequential
days on all patients admitted with severe sepsis/septic shock. Samples were analysed for NT-proBNP, TnT and myoglobin. Results
Samples were analysed on 49 patients. Elevated
myoglobin was the only predictor of ICU mortality. Age, myoglobin
and NT-proBNP levels predicted hospital mortality. Predictors of 6-
month mortality were age, peak TnT, peak myoglobin and peak NT-
proBNP levels. The APACHE II score did not predict mortality. A
score was established dependent on TnT (<0.1 = 1, ≥0.1 = 2), age
(<65 years = 1, ≥65 years = 2), BNP (<10,000 = 1, >10,000 = 2),
and myoglobin (<750 = 1, >750 = 2). Patients were placed into
tertiles (score = 4&5, 6, 7&8) to produce survival curves (Figure 1,
P < 0.01). Results The CIG on day 1 predicted mortality (P = 0.001, analysis
of variance). A novel score based on age and cardiac biomarkers
predicts outcomes in severe sepsis and septic shock A CIG > 10 mmol/l correlated very strongly with
mortality. The mortality in patients with a CIG < 10 mmol/l (n = 86)
was 4.7%. The mortality in patients with a CIG > 10 mmol/l
(n = 23) was 26.1% (P = 0.006, chi-square test). There were no
differences in CIG with respect to mortality on admission or day 2
(P = 0.273 and 0.104, respectively). The mean hospital stay was
significantly longer in patients with a CIG > 10 mmol/l (46.6 vs
18.7 days, P = 0.015, t test) (Table 1). TNFα promoter single nucleotide polymorphisms may
influence gene expression in patients with severe sepsis Table 1 (abstract P449)
Gene symbol
Fold change
Gene symbol
Fold change
TNFRSF1A
1.30 up
IL1R1
1.50 up
TNFRSF10D
1.21 up
IL1R2
2.52 up
TNFRSF25
1.19 down
IL1RN
1.48 up
Conclusion Compared with critically ill uninfected SIRS patients,
sepsis increases IL-1α but not TNFα gene expression and does
not increase TNF and IL-1 protein levels. Interestingly differential
gene expression for TNF and IL-1 receptors exists, suggesting
receptors, more than ligands, are important in differentiating sepsis
from uninfected SIRS. Table 1 (abstract P449)
Gene symbol
Fold change
Gene symbol
Fold change
TNFRSF1A
1.30 up
IL1R1
1.50 up
TNFRSF10D
1.21 up
IL1R2
2.52 up
TNFRSF25
1.19 down
IL1RN
1.48 up Conclusion Compared with critically ill uninfected SIRS patients,
sepsis increases IL-1α but not TNFα gene expression and does
not increase TNF and IL-1 protein levels. Interestingly differential
gene expression for TNF and IL-1 receptors exists, suggesting
receptors, more than ligands, are important in differentiating sepsis
from uninfected SIRS. Conclusion Compared with critically ill uninfected SIRS patients,
sepsis increases IL-1α but not TNFα gene expression and does
not increase TNF and IL-1 protein levels. Interestingly differential
gene expression for TNF and IL-1 receptors exists, suggesting
receptors, more than ligands, are important in differentiating sepsis
from uninfected SIRS. Conclusion These results contradict previous in vitro functional
studies on the TNF2 allele. This may be secondary to the method S178 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P451) Conclusion In critically ill patients with severe sepsis/septic shock
a score based on age and increased plasma levels of cardiac
biomarkers can help risk-stratify patients and predict short-term
(<6 months) outcome. Conclusion We describe the CIG for the first time in the critically
ill surgical patient, and quantify it using simple bedside calculations
derived from routine blood investigations. Failure to normalise the
CIG by day 1 after admission to the HDU is an excellent marker for
mortality and length of hospital stay, and should be used to guide
resuscitation. Figure 1 (abstract P450) Table 1 (abstract P451)
Day 1
Day 1
CIG < 10 mmol/l
CIG > 10 mmol/l
P value
Inhospital mortality
4.7% (n = 86)
26.1% (n = 23)
P = 0.006
(χ2 test)
Length of hospital stay
18.7 days
46.6 days
P = 0.015
(t test) P454 septic shock. Secondarily, we aimed at evaluating the impact of
them in patient management Brain natriuretic peptide and left ventricular area variation
with fluid challenge in septic shock: an echocardiographic
study (preliminary results) Methods This transversal study included patients with severe
sepsis or septic shock with a central venous line in place. Blood
from a peripheral venous puncture, central venous line and arterial
line were collected, at the same timepoint each 12 hours. Peripheral lactate collection was performed carefully with the left
superior limb garroted for a maximal of 2 minutes. Data were
analysed by linear correlation test, and a Bland–Altman test was
done to verify the degree of agreement between values from
different samples. A P value <0.05 was considered significant. A Ghaddab, H Quintard, L Rami, D Grimaud, C Ichai
St Roch Hospital, Nice, France
Critical Care 2007, 11(Suppl 2):P454 (doi: 10.1186/cc5614) Introduction Myocyte stretch is the main stimulus of brain
natriuretic peptide (BNP) synthesis and release. During septic
shock, important variations of volemia can occur and a correlation
has been described between the cardiac index and the BNP level
[1]. However, the relation between the echocardiographic left
ventricule area and the BNP level has never been described. The
aim of our study was to evaluate BNP and left ventricule area
variations after an acute fluid loading in septic shock. Results Fifteen patients were enrolled, with a mean age of
57.8 years (eight males and seven females), APACHE II score of
15.3 ± 5.0 and SOFA score of 7.13 ± 3.39. A total of 129
samples were available for analysis. The linear correlation between
arterial and central venous lactate levels showed an r2 = 0.66
(95% CI: 0.71–1.12). However, Bland–Altman had a mean ±
standard deviation bias of 1.25 ± 5.0. Results were similar for
arterial and peripheral venous lactate with an r2 = 0.85 (95% CI:
0.97–1.27) and a bias of –2.44 ± 5.0. Clinical agreement between
arterial and central venous blood was 90%, arterial and peripheral
blood was 71% and central venous and peripheral blood was 64%. Conclusion Lactate from central venous blood can replaced arterial
samples. However, peripheral samples are not clinically reliable. Methods Mechanical ventilated patients with septic shock, and
without anterior cardiac disease, were included in our study. A fluid
challenge was performed with colloid (500 ml) in 30 minutes. A
BNP blood sample was drawn before and 1 hour after fluid
loading. P454 The primary endpoint was BNP variation after fluid
challenge. Median values (25–75th percentiles) were compared
with the Wilcoxon test (P < 0.05). The end-diastolic left ventricule
area was recorded before and 1 hour after fluid challenge. Linear
regression of BNP variation and left ventricular area variation was
determined and r2 was calculated. Lactate levels from arterial, central venous and peripheral
venous blood in severe sepsis and septic shock patients P453
Lung nitroxidative stress as a prognostic factor in
ventilated septic patients
J Gorrasi1, H Botti2, C Batthyany2, M Naviliat2, M Cancela1, R Ra
1University Hospital, School of Medicine, Montevideo, Uruguay;
2Center for Free Radical Biomedical Research, School of Medic
Montevideo, Uruguay
Critical Care 2007, 11(Suppl 2):P453 (doi: 10.1186/cc5613)
Introduction During sepsis and mechanical ventilation, nitric o
(•NO) is produced by lung cells. We study whether pulmonary
production is a prognostic factor in mechanically ventilated se
patients. Materials and methods We studied 50 patients with se
within the first 48 hours of sepsis. Operating room patients se
as control a group (ORCG) Nitrite and nitrate (NO –) and Lactate levels from arterial, central venous and peripheral
venous blood in severe sepsis and septic shock patients M Assuncao, A Nascente, C Guedes, B Mazza, M Jacki,
H Fernandes, F Machado
Universidade Federal de São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P452 (doi: 10.1186/cc5612) ,
Critical Care 2007, 11(Suppl 2):P452 (doi: 10.118 Conclusion In critically ill patients with severe sepsis/septic shock
a score based on age and increased plasma levels of cardiac
biomarkers can help risk-stratify patients and predict short-term
(<6 months) outcome. Introduction Serial lactate measurements are reliable and may be
useful as a prognostic marker in critically ill patients. Differences in
its levels, depending on the sample site, can lead to mis-
interpretation and inadequate treatment. The primary objective of
this study is to evaluate the relationship between lactate levels in
different compartments of the body, such as peripheral venous,
central venous and arterial blood in patients with severe sepsis and S179 septic shock. Secondarily, we aimed at evaluating the impac
them in patient management
Methods This transversal study included patients with se
sepsis or septic shock with a central venous line in place. B
from a peripheral venous puncture, central venous line and art
line were collected, at the same timepoint each 12 ho
Peripheral lactate collection was performed carefully with the
superior limb garroted for a maximal of 2 minutes. Data w
analysed by linear correlation test, and a Bland–Altman test
done to verify the degree of agreement between values
different samples. A P value <0.05 was considered significant. Results Fifteen patients were enrolled, with a mean age
57.8 years (eight males and seven females), APACHE II scor
15.3 ± 5.0 and SOFA score of 7.13 ± 3.39. A total of
samples were available for analysis. The linear correlation betw
arterial and central venous lactate levels showed an r2 = 0
(95% CI: 0.71–1.12). However, Bland–Altman had a mea
standard deviation bias of 1.25 ± 5.0. Results were simila
arterial and peripheral venous lactate with an r2 = 0.85 (95%
0.97–1.27) and a bias of –2.44 ± 5.0. Clinical agreement betw
arterial and central venous blood was 90%, arterial and periph
blood was 71% and central venous and peripheral blood was 6
Conclusion Lactate from central venous blood can replaced art
samples. However, peripheral samples are not clinically reliable. P457 Results Intravenous infusion of ANP reduced I/R-induced increase
in serum levels of blood urea nitrogen and creatinine at 24 hours
after reperfusion. ANP inhibited I/R-induced increases in renal
tissue levels of TNF and myeloperoxidase at 3 and 6 hours after
reperfusion, respectively. ANP significantly enhanced I/R-induced
increases in renal tissue levels of CGRP and 6-keto-PGF1α, a
stable metabolite of PGI2, at 1 hour after reperfusion. ANP-induced
increases in renal tissue levels of CGRP were significantly inhibited
by pretreatment with SB366791, a specific vanilloid receptor-1
antagonist. ANP-induced increases in renal tissue levels of 6-keto-
PGF1α
were
significantly
inhibited
by
pretreatment
with
SB366791, CGRP(8-37), a CGRP receptor antagonist, and
indomethacin. Reduction of I/R-induced increases in serum levels
of blood urea nitrogen and creatinine and those in renal tissue
levels of TNF and myeloperoxidase in rats treated with ANP were
completely abrogated by pretreatment with SB366791, CGRP(8-
37), and indomethacin. ANP significantly increased CGRP release
from dorsal root ganglion neurons in vitro. Conclusions These results strongly suggested that ANP might Mid-regional pro-atrial natriuretic peptide is a strong predictor
of outcome in an unselected cohort of critically ill patients Mid-regional pro-atrial natriuretic peptide is a strong predictor
of outcome in an unselected cohort of critically ill patients Mid-regional pro-atrial natriuretic peptide is a strong predictor
of outcome in an unselected cohort of critically ill patients B Meyer1, P Wexberg1, R Berger1, D Moertl1, N Morgenthaler2,
J Struck2, A Bergmann2, G Heinz1, R Pacher1, M Huelsmann1
1Medical University of Vienna, Austria; 2B.R.A.H.M.S. Ag,
Henningdorf, Germany
Critical Care 2007, 11(Suppl 2):P456 (doi: 10.1186/cc5616) Conclusion There is no increase in BNP level in patients with
septic shock after fluid challenge. To our knowledge, this
preliminary study is the first to evaluate the relationship between
BNP and left ventricule area variation in patient with septic shock. Although no statistical significance between left ventricule area
variation and BNP variation after fluid challenge, there is a trend to
correlation between these two parameters. More patients have to
be included to confirm this result. Introduction Atrial natriuretic peptide (ANP) is a strong predictor
of outcome in patients with heart failure, various other
cardiovascular diseases and in patients with systemic inflammatory
response syndrome and sepsis. Furthermore, ANP is elevated in
patients with kidney disease. We aimed to test the prognostic
potency of the precursor molecule mid-regional pro-atrial natriu-
retic peptide (MR-pro-ANP) in an unselected cohort of critically ill
patients. 1. McLean AS: The effects of acute fluid loading on plasma
B-type natriuretic peptide levels in a septic shock patient. Anesth Intensive Care 2005, 33:528-530. 1. McLean AS: The effects of acute fluid loading on plasma
B-type natriuretic peptide levels in a septic shock patient. Anesth Intensive Care 2005, 33:528-530. Methods Between August 2004 and February 2006, a total of
294 patients (191 males, age 63.8 ± 14.7 years) admitted to our
ICU were studied. The mean SAPS2 and APACHE II score were
52 ± 23 and 24 ± 11, respectively. Two hundred and three
patients (69.1%) were on intravenous inotropic support, 30 patients
had additional mechanical circulatory support (23 intraaortic
balloon counterpulsation (7.8%), eight extracorporeal membrane
oxygenation (2.7%), three left ventricular assist device (0.9%)). Two
hundred and five patients (69.7%) were mechanically ventilated,
and 59 patients (20.1%) presented with acute renal failure. Plasma
samples for determination of MR-pro-ANP were obtained on
admission in all patients. As MR-pro-ANP values were not normally
distributed, log MR-pro-ANP values were used for analysis. P455 Atrial natriuretic peptide reduces the ischemia/
reperfusion-induced renal injury in rats by enhancing
sensory neuron activation N Harada, K Okajima, Y Mizuochi
Nagoya City University Graduate School of Medical Sciences,
Nagoya, Japan
Critical Care 2007, 11(Suppl 2):P455 (doi: 10.1186/cc5615) Introduction Although carpertide, a synthetic α-human atrial
natriuretic peptide (ANP), reduces ischemia/reperfusion (I/R)-
induced tissue injury, the precise therapeutic mechanism(s)
remains to be elucidated. Calcitonin gene-related peptide (CGRP)
released from sensory neurons reduces I/R-induced liver injury by
inhibiting neutrophil activation through an increase in the
endothelial production of prostacyclin (PGI2). In the present study,
we examined in rats whether ANP reduces I/R-induced renal injury
by enhancing sensory neuron activation. Results Two hundred and thirty-five patients (79.9%) survived to
ICU discharge and 59 patients died (21.1%). Log MR-pro-ANP
plasma levels were significantly higher in patients who died than in
ICU survivors (2.76 ± 0.39 pmol/l vs 2.50 ± 0.38 pmol/l,
respectively, P < 0.0001). In the Kaplan–Meier analysis of 28-day
survival, patients with log MR-pro-ANP plasma-levels above the
median had significantly lower survival rates compared with
patients with log MR-pro-ANP plasma levels below the median
(P = 0.02). Methods The right renal vessels were clamped in rats for 45
minutes after left nephrectomy. ANP (0.3 µg/kg/min) was
continuously infused from 30 minutes before ischemia to 60
minutes after reperfusion. We attempted to determine whether
ANP promotes CGRP release from cultured dorsal root ganglion
neurons isolated from adult rats in vitro. Conclusion Our data show that elevated plasma levels of MR-pro-
ANP at ICU admission are associated with an adverse outcome in
an unselected cohort of critically ill patients. Lung nitroxidative stress as a prognostic factor in
ventilated septic patients Lung nitroxidative stress as a prognostic factor in
ventilated septic patients J Gorrasi1, H Botti2, C Batthyany2, M Naviliat2, M Cancela1, R Radi2
1University Hospital, School of Medicine, Montevideo, Uruguay;
2Center for Free Radical Biomedical Research, School of Medicine,
Montevideo, Uruguay
Critical Care 2007, 11(Suppl 2):P453 (doi: 10.1186/cc5613) Figure 1 (abstract P454) Figure 1 (abstract P454)
Figure 2 (abstract P454) Introduction During sepsis and mechanical ventilation, nitric oxide
(•NO) is produced by lung cells. We study whether pulmonary •NO
production is a prognostic factor in mechanically ventilated septic
patients. Materials and methods We studied 50 patients with sepsis
within the first 48 hours of sepsis. Operating room patients served
as control a group (ORCG). Nitrite and nitrate (NOx–) and 3-
nitrotyrosine (3NT) in plasma and bronchoalveolar lavage fluid
(BALF) were analyzed by the Griess/vanadium chloride method
and ELISA, respectively. Results were expressed as median and
interquartile range. Receiver operator curves were constructed to
compare the predictive value of NOx– values in BALF at admission
with other variables. Kaplan–Meier analysis was used to compare
survival between high and low BALF NOx– levels at admission. A P
value less than 0.05 was considered significant. Figure 2 (abstract P454) Results At study admission in the sepsis group, nonsurvivors had
higher levels of BALF NOx– than survivors: 20 (17–33) µM, 27
versus 72 (46–91) µM, 23, P = 0.0001. At day 7, BALF 3NT was
higher in nonsurvivor septic patients than in survivors: 1,666
(30–3,173) pmol/mg protein versus 291 (13–1,908) pmol/mg
protein. BALF NOx
– had the highest area under the receiver
operator curve for mortality (0.812, P = 0.001) in relation to other
variables. Septic patients with BALF NOx
– above 36 µM had a
relative risk for mortality of 4.23 and an OR of 15.84. The
difference between the low bronchoalveolar •NO group (BALF
[NOx
–] < 36 µM at admission) versus the high bronchoalveolar
•NO group (BALF [NOx
–] ≥36 µM at admission) in ICU mortality
was significant: 19% versus 78% (log rank 18.19, P = 0.00001). Conclusion During sepsis there is enhanced lung •NO production
that is associated with ICU mortality. S180 Available online http://ccforum.com/supplements/11/S2 P456 Results Eight patients (median age 68 years; six males/two females;
SOFA score = 12) were enrolled in our study. The initial BNP level
median increased from 695 (417–2,738) to 715 (478–2,596) µg/ml
after a fluid loading (P = 0.7) (Figure 1).We did not find a statistically
significant relationship between BNP variation and left ventricule
area variation after fluid challenge (P = 0.13) (Figure 2). Clinical meaning of brain natriuretic peptide in the
intensive care unit The BNP cutoff value to discriminate
group B is 274 pg/ml with sensibility 90 (IC95 =
specificity 79 (IC95 = 61–91). Conclusions Risk of weaning failure is increased f
patients with HD. BNP values of group B patients are
normal people probably because the heart of ICU
submitted to different kinds of stress; therefore the
value to consider for discrimination of patients w
patients without HD in the ICU should be higher. BN
in ICU patients with good performance of the hear
protective response to stress performed by thera
during the ICU stay, this response is absent in patie
because their hearts already work in safety mode. P458
Combining various severity of illness scoring sy
improve outcome prediction: pilot experience in
critically ill obstetric population
Z Haddad1, C Kaddour2, L Skandrani2, S Nagi2, T C
R Souissi2
1CHI St-Cloud, France; 2National Institute of Neurolog
Tunisia
Critical Care 2007, 11(Suppl 2):P458 (doi: 10.1186/c
Introduction No perfect severity score exists to
mortality, thus the search for new systems is still a pre
Hypothesis Use of many severity of illness scores si
improves mortality prediction. Patients and methods An open prospective observ
as part of the APRiMo project [1]. The study period
1996–September 2004. Inclusion criteria were
obstetric patients and ICU length of stay >24 hou
criteria were those of the used scores. The main
interest was the survival status at ICU discharge. T
was divided into two samples: development an
datasets. Development database patients were chos
(n = 414) and the remaining patients composed t
dataset (n = 229). A multivariable logistic regressio
developed to predict mortality associating the Acut
and Chronic Health Evaluation II score [2], Simp
Physiology Score II [3], Admission Mortality Pred
(MPM-H0) and Day 1 Mortality Prediction Model (MP
Di
i i
ti
d
lib
ti
d b Table 1 (abstract P458)
Development
Validation
Hosmer–Lemeshow
0.868
0.42
C-hat statistics test
ROC
0.936
0.945
Nonsurvivor prediction
28/46 (60.9%)
18/28 (64.3%)
Survivor prediction
364/368 (99%)
199/201 (99%) nominal variables were analyzed with the chi-square test and the
risk ratio (RR) with 95% confidence interval (IC95) was performed;
intragroup ordinal variables were analyzed with the Wilcoxon test
(W), intergroup ordinal variables were analyzed with the
Mann–Whitney test (MW). The receiver operative characteristic
test was used to discriminate the BNP cutoff value with sensibility,
specificity and respective IC95, between group A and group B. P < 0.01 is taken as statistically significant. References 1. Haddad Z, et al.: Critically ill obstetric patients: outcome
and predictability. Crit Care 2005, 9(Suppl 1):S92-S93. Conclusions Risk of weaning failure is increased four times in
patients with HD. BNP values of group B patients are higher than
normal people probably because the heart of ICU patients is
submitted to different kinds of stress; therefore the BNP cutoff
value to consider for discrimination of patients with HD from
patients without HD in the ICU should be higher. BNP production
in ICU patients with good performance of the heart is the right
protective response to stress performed by therapy adopted
during the ICU stay, this response is absent in patients with HD
because their hearts already work in safety mode. 2. Knaus WA, et al.: APACHE II: a severity of disease classifi-
cation system. Crit Care Med 1985, 13:818-829. 3. Le Gall JR, et al.: A new simplified acute physiology score
(SAPS II) based on a European/North American multicen-
ter study. JAMA 1993, 270:2957-2963. 4. Lemeshow S, et al.: Refining intensive care unit outcome
prediction by using changing probabilities of mortality. Crit
Care Med 1988, 16:470-477. P459 Combining various severity of illness scoring systems to
improve outcome prediction: pilot experience in the
critically ill obstetric population Z Haddad1, C Kaddour2, L Skandrani2, S Nagi2, T Chaaoua2,
R Souissi2
1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia
Critical Care 2007, 11(Suppl 2):P458 (doi: 10.1186/cc5618) Z Haddad1, C Kaddour2, L Skandrani2, S Nagi2, T Chaaoua2,
R Souissi2
1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia
Critical Care 2007, 11(Suppl 2):P458 (doi: 10.1186/cc5618) Clinical meaning of brain natriuretic peptide in the
intensive care unit Results Weaning failure in group A occurred in 50% of patients vs
12% of group B patients (P < 0.01 chi-square test; RR = 4.13,
IC95 = 1.36–12.49). BNP value differences in group A are not
significant (step 1: 662 ± 147 pg/ml; step 2: 769 ± 171 pg/ml;
step 3: 843 ± 167 pg/ml), while BNP value differences in group B
are statistically significant (W) (step 1: 130 ± 21 pg/ml; step 2:
236 ± 41 pg/ml, P < 0.01 vs step 1; step 3: 375 ± 75 pg/ml,
P < 0.001 vs step 1 and P < 0.01 vs step 2). There are statistically
significant differences between group A and group B in every step
(P < 0.01 MW). The BNP cutoff value to discriminate group A from
group B is 274 pg/ml with sensibility 90 (IC95 = 55–98) and
specificity 79 (IC95 = 61–91). Results Six hundred and forty-three patients enrolled. The overall
mortality rate was 11.51%. The new model predicted accurately
99% of survivors and more than 60% of nonsurvivors. Conclusion The ‘multiscore’ model seems to refine prognosis. This
is partly due to mixing of new evaluated parameters. Testing the
latest developed generations of scores and also organ dysfunction
systems could be interesting. Clinical meaning of brain natriuretic peptide in the
intensive care unit T Principi, D Elisei, M Strovegli, G Falzetti, P Pelaia
Anaesthesia and Intensive Care Clinic – Politechnical University of
Marche, Ancona, Italy
Critical Care 2007, 11(Suppl 2):P457 (doi: 10.1186/cc5617) Introduction The aim of this study is to evaluate differences in
brain natriuretic peptide (BNP) dosage (vn < 100 pg/ml) during
the weaning procedure, in patients with heart disease (HD) vs
patients without HD, admitted to the ICU. Introduction The aim of this study is to evaluate differences in
brain natriuretic peptide (BNP) dosage (vn < 100 pg/ml) during
the weaning procedure, in patients with heart disease (HD) vs
patients without HD, admitted to the ICU. Methods Ten patients with HD (group A) and 33 patients without
HD (group B) were studied by BNP dosage in three specific steps:
(1) admission to the ICU; (2) before the extubation (performed if
patients, after the end of mechanical ventilation and 1 hour of
connection to T-tube, were considered suitable for extubation); and
(3) 24 hours after extubation. Necessity of noninvasive ventilation
or reintubation after the extubation was considered as weaning
failure. Data are shown as the mean ± standard error of the mean; Conclusions These results strongly suggested that ANP might
reduce I/R-induced renal injury in rats by inhibiting neutrophil
activation through enhancement of sensory neuron activation. S181 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin nominal variables were analyzed with the chi-square
risk ratio (RR) with 95% confidence interval (IC95) wa
intragroup ordinal variables were analyzed with the W
(W), intergroup ordinal variables were analyze
Mann–Whitney test (MW). The receiver operative c
test was used to discriminate the BNP cutoff value wi
specificity and respective IC95, between group A a
P < 0.01 is taken as statistically significant. Results Weaning failure in group A occurred in 50% o
12% of group B patients (P < 0.01 chi-square test
IC95 = 1.36–12.49). BNP value differences in grou
significant (step 1: 662 ± 147 pg/ml; step 2: 769 ±
step 3: 843 ± 167 pg/ml), while BNP value difference
are statistically significant (W) (step 1: 130 ± 21 pg
236 ± 41 pg/ml, P < 0.01 vs step 1; step 3: 375
P < 0.001 vs step 1 and P < 0.01 vs step 2). There ar
significant differences between group A and group B
(P < 0.01 MW). Combining various severity of illness scoring systems to
improve outcome prediction: pilot experience in the
critically ill obstetric population Validation of logistic organ dysfunction score prediction
compared with APACHE II score prediction hospital
outcome in Thai patients B Khwannimit B Khwannimit
Prince of Songkla University, Songkhla, Thailand
Critical Care 2007, 11(Suppl 2):P459 (doi: 10.1186/cc5619) Introduction To assess the performance of the logistic organ
dysfunction (LOD) score and Acute Physiology and Chronic Health
Evaluation II (APACHE II) score in a mixed medical–surgical ICU of
a tertiary referral university hospital in Thailand. Introduction No perfect severity score exists to predict ICU
mortality, thus the search for new systems is still a preoccupation. Hypothesis Use of many severity of illness scores simultaneously
improves mortality prediction. Introduction No perfect severity score exists to predict ICU
mortality, thus the search for new systems is still a preoccupation. Hypothesis Use of many severity of illness scores simultaneously
improves mortality prediction. Figure 1 (abstract P459) Figure 1 (abstract P459) P460 Could we use the admission Acute Physiology and Chronic
Health Evaluation II score for outcome prediction in
critically ill obstetric patients? Objective Development of a new prognostic model based on
association of one of the generalistic severity scores (SAPS II,
APACHE II), one of the organ dysfunction scores (LOD, MODS,
SOFA) and evolution of these scores during the first 2 days of ICU
hospitalization. Z Haddad1, R Souissi2, C Kaddour2, W Trabelsi2, M Bouchnak3,
S Nagi2
1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia; 3Centre de Maternité et de Néonatologie, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P460 (doi: 10.1186/cc5620) Z Haddad1, R Souissi2, C Kaddour2, W Trabelsi2, M Bouchnak3,
S Nagi2 1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia; 3Centre de Maternité et de Néonatologie, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P460 (doi: 10.1186/cc5620) Methods An open prospective analysis part of the APRiMo study
[1] ranging from January 1996 to September 2004. Inclusion
criteria were critically ill obstetric patients with an ICU length of
stay > 24 hours. Exclusion criteria were those of the used scores. The main outcome of interest was survival status at ICU discharge. The database was divided into two samples: a development
sample by random choice of 450 patients, and the remaining
patients in the validation dataset. Multivariable logistic regression
models were developed. We chose among different developed
models the best performer as assessed by Hosmer–Lemeshow
(HL) goodness-of-fit statistics (calibration) and the area under the
receiver operating characteristic curve (AUROC) for discrimination. Accuracy of the developed model was verified on the validation
dataset using the same statistical tests. Results are expressed as
the mean ± standard deviation unless stated elsewhere. Data were
computed on SPSS 11.5 Win-XP version. Introduction The APACHE II score (APII) has widespread use in
ICUs for research and benchmarking. Physiological data for
calculation of the APII score derive from worst values in the first
24 hours after ICU admission. Hypothesis Mortality prediction by the APII system depends on
data sampling. Use of ICU admission data (first hour) could be
accurate to predict mortality. Methods An open prospective data-sampling part of the APRiMo
study. Included were critically ill obstetric patients, with ICU length
of stay (LOS) ≥6 hours. Admission (H1: first-hour worst
physiological data) and H24 (worst 24-hour physiological variables
including H1 collected data) were used to generate, respectively:
the admission APII score (H1-APII) and H24-APII. Reference 1. Knaus WA, et al.: APACHE II: a severity of disease classifi-
cation system. Crit Care Med 1985, 13:818-829. 1. Knaus WA, et al.: APACHE II: a severity of disease classifi-
cation system. Crit Care Med 1985, 13:818-829. P461 Two-day intensive care unit outcome prediction score: a
trial to improve outcome prediction in critically ill obstetric
patients Z Haddad1, S Nagi2, R Souissi2, C Kaddour2 Introduction The critically ill obstetric population median ICU stay
is 4 days, thus general severity of illness scores are supposed to
be accurate in mortality prediction. A literature review makes us
sceptical. P460 The formulae to
calculate individual mortality for H1 and H24 APII were those
validated for H24-APII as stated by Knaus and colleagues [1],
adjusting for admission diagnosis. We compared both scores by
discrimination and calibration statistical tests. P < 0.05 was the
threshold for statistical significance. Results Six hundred and forty patients included. Age 31 ± 6 years,
length of stay 5 ± 5 days, SAPS II 27 ± 16, SOFA score 5 ± 4,
LOD score 2 ± 1.7. The overall mortality rate was 13.3%. The best
model was the one combining SAPS II and LOD scores. The LOD
score and SAPS II alone discriminated well but calibrated poorly in
outcome prediction. Discrimination was optimal for the new
developed model in both development and validation datasets,
with AUROC respectively of 0.87 and 0.85. Calibration was good
in the developed and validated datasets, respectively P = 0.176
and 0.34. The developed model predicts death accurately in 2/3
cases. Results The study period was January 1996–September 2004. We included 541 patients, overall mortality was 10.5%. Mean H1-
APII and H24-APII scores. respectively. were 7.6 ± 6.1 and 8.6 ± 7,
with derived mean predicted mortality, respectively, of 8.63% and
9.86%. The H24-APII score was higher than the H1-APII score in
135 patients (25%), among those patients 32 died (24% of
patients with worsened APII) vs 6.16% if H1 = H24 (P < 0.01). Running a multiple logistic regression with mortality as the
dependent parameter, we found that worsening of the APII score
over time is not significantly associated with mortality (P = 0.791),
whereas the H1-APII score (P < 0.001) and ∆APII score (H24-APII Discussion and conclusion The SAPS II and LOD scores are
complementary. Development of dynamic models in time helps to
refine prognosis prediction. Discussion and conclusion The SAPS II and LOD scores are
complementary. Development of dynamic models in time helps to
refine prognosis prediction. Figure 1 (abstract P459) P460
Could we use the admission Acute Physiology and Chronic
Health Evaluation II score for outcome prediction in
critically ill obstetric patients? Z Haddad1, R Souissi2, C Kaddour2, W Trabelsi2, M Bouchnak3,
S Nagi2
1CHI St-Cloud, France; 2National Institute of Neurology, Tunis,
Tunisia; 3Centre de Maternité et de Néonatologie, Tunis, Tunisia
Critical Care 2007, 11(Suppl 2):P460 (doi: 10.1186/cc5620) Methods The data were collected prospectively on consecutive
patients admitted to the ICU of Songklanagarind Hospital over a
24-month period from 1 July 2004 until 30 June 2006. minus H1-APII score) (P = 0.04) are correlated with mortality. Respective ORs are 1.28 and 1.45. Overall discrimination ability
assessed by receiver operating characteristic curves was good for
H1-APII (0.78) and H24-APII (0.784) (P = 0.834). 24 month period from 1 July 2004 until 30 June 2006. Results A total of 1,962 patients were enrolled, with 432 deaths
(22%) prior to hospital discharge. Both systems provided
overprediction of hospital mortality. LOD and APACHE II scores
predicted hospital mortality of 25.4 ± 26.5 and 29.6 ± 27.8,
respectively. Both models showed excellent discrimination. The
receiver operating characteristic curves of both systems are shown in
Figure 1. The area under the receiver operating characteristic curve
(AUROC) of LOD was 0.867 (95% CI = 0.846–0.886) and the
AUROC was 0.906 (95% CI = 0.889–0.923) for APACHE II. Both
models presented a poor calibration in overall population. However,
the LOD score had good discrimination and calibration in subgroups
of nonoperative patients (AUROC 0.854, the Hosmer–Lemeshow
goodness-of-fit H statistic 11.67, P = 0.166) and patients that
exclude coronary artery disease and cardiac surgery (AUROC 0.860,
the Hosmer–Lemeshow goodness-of-fit H statistic 10.03, P = 0.263). Conclusion The LOD score showed good accuracy to predict
hospital mortality in subgroups of nonoperative critically ill patients
and excluded coronary heart disease and cardiac surgical critically
ill patients in Thailand. Conclusion To avoid variation in APII mortality prediction caused
by variable sample rates, the admission APII is reliable. Customizing mortality formulae could improve performances of
APII-H1. Figure 1 (abstract P459) Patients and methods An open prospective observational study
as part of the APRiMo project [1]. The study period was January
1996–September 2004. Inclusion criteria were critically ill
obstetric patients and ICU length of stay >24 hours. Exclusion
criteria were those of the used scores. The main outcome of
interest was the survival status at ICU discharge. The database
was divided into two samples: development and validation
datasets. Development database patients were chosen randomly
(n = 414) and the remaining patients composed the validation
dataset (n = 229). A multivariable logistic regression model was
developed to predict mortality associating the Acute Physiology
and Chronic Health Evaluation II score [2], Simplified Acute
Physiology Score II [3], Admission Mortality Prediction Model
(MPM-H0) and Day 1 Mortality Prediction Model (MPM-H24) [4]. Discrimination and calibration were assessed by goodness-of-fit
C-hat statistics and area under the ROC curve. The developed
model was then tested in the validation dataset. Good
discrimination was retained if C-hat statistics P > 0.1 and good
calibration if area under the ROC curve > 0.8. S182 Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Methods The data were collected prospectively on consecutive
patients admitted to the ICU of Songklanagarind Hospital over a
24-month period from 1 July 2004 until 30 June 2006. Results A total of 1,962 patients were enrolled, with 432 deaths
(22%) prior to hospital discharge. Both systems provided
overprediction of hospital mortality. LOD and APACHE II scores
predicted hospital mortality of 25.4 ± 26.5 and 29.6 ± 27.8,
respectively. Both models showed excellent discrimination. The
receiver operating characteristic curves of both systems are shown in
Figure 1. The area under the receiver operating characteristic curve
(AUROC) of LOD was 0.867 (95% CI = 0.846–0.886) and the
AUROC was 0.906 (95% CI = 0.889–0.923) for APACHE II. Both
models presented a poor calibration in overall population. However,
the LOD score had good discrimination and calibration in subgroups
of nonoperative patients (AUROC 0.854, the Hosmer–Lemeshow
goodness-of-fit H statistic 11.67, P = 0.166) and patients that
exclude coronary artery disease and cardiac surgery (AUROC 0.860,
the Hosmer–Lemeshow goodness-of-fit H statistic 10.03, P = 0.263). Conclusion The LOD score showed good accuracy to predict
hospital mortality in subgroups of nonoperative critically ill patients
and excluded coronary heart disease and cardiac surgical critically
ill patients in Thailand. Figure 1 (abstract P462) Results Nine out of 11 patients survived without any residual
organ damage, and the remaining two died due to MODS (Figure 1). Both these patients had five organ dysfunctions on admission, and
their SOFA scores were 18 and 20, respectively. They had a low
parasitic index of 1% and 2.5% and their PCT levels were 0.5–2
and >10 (semiquantitative method), respectively. Their APACHE II
scores were 16 and 10. Conclusion The pretreatment APACHE II score, parasite index,
PCT levels and number of organs involved have variable correlation
with mortality and are not consistent predictors of outcome. A
higher SOFA score on admission is a more reliable predictor of
mortality in malarial MODS. Model calibration and discriminatory ability: a comparison
of four derived variables from the SOFA score and the
SAPS II Model calibration and discriminatory ability: a comparison
of four derived variables from the SOFA score and the
SAPS II Median length of ICU stay in patients with an admission SOFA score
>8 vs those whose admission SOFA score was ≤8 (P = 0.001). Median length of ICU stay in patients with an admission SOFA score
>8 vs those whose admission SOFA score was ≤8 (P = 0.001). R Ouezini, N Frikha, N Belhaj, S Ouerghi, M Mebazaa,
M Ben Ammar
Mongi slim Hospital, La Marsa, Tunisia
Critical Care 2007, 11(Suppl 2):P464 (doi: 10.1186/cc5624) R Ouezini, N Frikha, N Belhaj, S Ouerghi, M Mebazaa,
M Ben Ammar
Mongi slim Hospital, La Marsa, Tunisia
Critical Care 2007, 11(Suppl 2):P464 (doi: 10.1186/cc5624) R Ouezini, N Frikha, N Belhaj, S Ouerghi, M Mebazaa,
M Ben Ammar
Mongi slim Hospital, La Marsa, Tunisia
Critical Care 2007, 11(Suppl 2):P464 (doi: 10.1186/cc5624) P462
The correlation of the Sequential Organ Failure
Assessment score with intensive care unit outcome They had a low
parasitic index of 1% and 2.5% and their PCT levels were 0.5–2
and >10 (semiquantitative method), respectively. Their APACHE II
scores were 16 and 10. Conclusion The pretreatment APACHE II score, parasite index,
PCT levels and number of organs involved have variable correlation
with mortality and are not consistent predictors of outcome. A
higher SOFA score on admission is a more reliable predictor of
mortality in malarial MODS. P464
Model calibration and discriminatory ability: a comparison
of four derived variables from the SOFA score and the
SAPS II
R Ouezini, N Frikha, N Belhaj, S Ouerghi, M Mebazaa,
M Ben Ammar
Mongi slim Hospital, La Marsa, Tunisia
Critical Care 2007, 11(Suppl 2):P464 (doi: 10.1186/cc5624) Objective We prospectively evaluated the correlation of the
APACHE II score, parasite index, procalcitonin (PCT) levels,
number of organ dysfunctions/failures and Sequential Organ Failure
Assessment (SOFA) score with the outcome of severe malaria. Methods Eleven patients with acute severe malaria with MODS
were treated in our ICU in the last 5 months. All these patients
were treated with artesunate and/or quinine as per the WHO
antimalarial treatment schedule, along with standard ICU care. The
APACHE II and SOFA scores were calculated on admission. PCT
levels were measured semiquantitatively on admission. The
parasite index was confirmed by two pathologists. Conclusion Maximum and admission SOFA scores are of
prognostic value in the intensive care setting; allowing patients
with increased risk of mortality and prolonged stay to be identified. Figure 1 (abstract P462)
Median length of ICU stay in patients with an admission SOFA score
>8 vs those whose admission SOFA score was ≤8 (P = 0.001). Figure 1 (abstract P462) P462 P462 P462
The correlation of the Sequential Organ Failure
Assessment score with intensive care unit outcome I Ketchley, A Theodoraki, T Reynolds, A Tillyard, R Lawson,
N Al-Subaie, M Cecconi, R Grounds, A Rhodes
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P462 (doi: 10.1186/cc5622) Methods We conducted a prospective observational review of
100 consecutive patients admitted to our ICU. We collected data
relating to daily maximum organ dysfunction scores. Outcome was
defined in terms of length of ICU stay and ICU mortality. Results We included 100 patients (62 males), mean age 60.9
years. Of these admissions, 45 were elective surgical, 22
emergency surgical, 33 medical. The median Sequential Organ
Failure Assessment (SOFA) score on admission was 4.50 (IQR 4). The median maximum SOFA score was 5.00 (IQR 5). The median
length of ICU stay was 3.0 days (IQR 3). The overall ICU mortality
rate was 14.0%. For patients with a maximum SOFA score ≤8,
mortality was 5.1% – vs 45.5% for those whose maximum SOFA
score was >8 (P < 0.001). Sixty-four per cent of patients scored
their maximum SOFA score on admission. In patients whose SOFA
score increased after admission, the mortality was 24.3%. Logistic
regression analysis showed the maximum SOFA score bore a
stronger correlation with mortality than admission SOFA score. See Figure 1. like India, and is associated with significant mortality. The outcome
of malarial MODS predicted in various studies is extremely variable
and dependent on many patient parameters. like India, and is associated with significant mortality. The outcome
of malarial MODS predicted in various studies is extremely variable
and dependent on many patient parameters. Objective We prospectively evaluated the correlation of the
APACHE II score, parasite index, procalcitonin (PCT) levels,
number of organ dysfunctions/failures and Sequential Organ Failure
Assessment (SOFA) score with the outcome of severe malaria. Methods Eleven patients with acute severe malaria with MODS
were treated in our ICU in the last 5 months. All these patients
were treated with artesunate and/or quinine as per the WHO
antimalarial treatment schedule, along with standard ICU care. The
APACHE II and SOFA scores were calculated on admission. PCT
levels were measured semiquantitatively on admission. The
parasite index was confirmed by two pathologists. Results Nine out of 11 patients survived without any residual
organ damage, and the remaining two died due to MODS (Figure 1). Both these patients had five organ dysfunctions on admission, and
their SOFA scores were 18 and 20, respectively. Reference 1. Haddad Z, et al.: Critically ill obstetric patients: outcome
and predictability. Crit Care 2005, 9(Suppl 1):S92-S93. 1. Haddad Z, et al.: Critically ill obstetric patients: outcome
and predictability. Crit Care 2005, 9(Suppl 1):S92-S93. S183 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P463) P462
The correlation of the Sequential Organ Failure
Assessment score with intensive care unit outcome
I Ketchley, A Theodoraki, T Reynolds, A Tillyard, R Lawson,
N Al-Subaie, M Cecconi, R Grounds, A Rhodes
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P462 (doi: 10.1186/cc5622) Figure 1 (abstract P463) Figure 1 (abstract P463) Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Figure 1 (abstract P464) Results One hundred and seventy-six patients were studied (71
males (56%), median age 51 (IQR 36–67) years, 78 (44%) with
severe sepsis, median length of ICU stay 10 days (IQR 7–16),
median admission SOFA 6 (IQR 4–9), median APACHE II score
19 (IQR 13–26), ICU mortality 27.84% (49/176 patients)). The
SOFA score and its components scores along the five admission
days
distinguished
the
survivors
from
the
nonsurvivors. Considering the SOFA score and its respiratory, neurologic and
circulatory components, survivors presented lower scores as the
days passed (P < 0.001). Mortality was increasingly higher for
those patients who persisted with a SOFA score ≥7 as the days
passed. *Classified as + if predicted mortality ≥0.5. Domax, the maximum
number of organ failures during ICU stay. *Classified as + if predicted mortality ≥0.5. Domax, the maximum
number of organ failures during ICU stay. Conclusion In the sample studied, the persistence of an elevated
SOFA score and its components during the first 5 days of
admission predicted a higher mortality. Survival appears to be
related to early organ dysfunction recovery. The SOFA score and
SOFA-related variables’ day-to-day changes in a population of
septic patients may have an important prognostic implication and
some patterns of daily evolution may distinguish those patients
with a more ominous outcome. ∆SOFA was defined by TMS minus admission SOFA (SOFAi). The
maximum SOFA was defined by the worst SOFA value during the
ICU stay. Logistic regression modeling techniques were used to
describe the association of derived SOFA variables and SAPS II
with mortality. ROC curves were used to assess the model’s
discriminatory ability and we examined the model calibration using
the Hosmer–Lemeshow goodness-of-fit test. P < 0.05 was con-
sidered significant. ∆SOFA was defined by TMS minus admission SOFA (SOFAi). The
maximum SOFA was defined by the worst SOFA value during the
ICU stay. Logistic regression modeling techniques were used to
describe the association of derived SOFA variables and SAPS II
with mortality. ROC curves were used to assess the model’s
discriminatory ability and we examined the model calibration using
the Hosmer–Lemeshow goodness-of-fit test. P < 0.05 was con-
sidered significant. P466 Results Diagnostic categories were: trauma 21.3%, postoperative
19% and medical 59.7%. Global mortality was 34.3%. Survivors had
lower average SAPS II (28.1 ± 14 against 48.6 ± 19, P < 0.01),
SOFAi score (3.7 ± 3 against 7.2 ± 4, P < 0.01), SOFAmax score
(4.6 ± 4 against 10.8 ± 3, P < 0.01), ∆SOFA (1.6 ± 6 against
4.2 ± 3, P < 0.01), DoMAX (1.6 ± 6 against 4.2 ± 3, P < 0.01)
and TMS (5 ± 3 against 11.4 ± 4, P < 0.01), and the difference
was statistically significant. Results regarding model calibration
and discriminatory ability are presented in Figure 1. Cumulative lactate load correlates with cumulative
Sequential Organ Failure Assessment score and survival in
intensive care unit patients Cumulative lactate load correlates with cumulative
Sequential Organ Failure Assessment score and survival in
intensive care unit patients Cumulative lactate load correlates with cumulative
Sequential Organ Failure Assessment score and survival in
intensive care unit patients P Spronk1, L Brander2, S Jansen1, J Rommes1
1Gelre Ziekenhuizen Location Lukas, Apeldoorn, The Netherlands;
2University Hospital, Bern, Switzerland
Critical Care 2007, 11(Suppl 2):P466 (doi: 10.1186/cc5626) Background Changes in lactate levels are used as a prognostic
marker in critically ill patients. However, the relation between the
time course of arterial blood lactate clearance and important
outcome parameters such as ICU length of stay (LOS), incidence
of organ failure and survival rate has not been established. Conclusion The SOFAmax score had the best model calibration
and could be used to compare different patient populations in
terms of mortality. Methods Case records from all ICU patients admitted between
2002 and 2004 were retrospectively identified in the ICU
database. The Sequential Organ Failure Assessment (SOFA)
score was calculated daily to assess the time course of organ
failure. All lactate levels were extracted and the total cumulative
lactate load (area under the curve above the upper normal level of
2.2 mmol/l; cum-lactate), and total cumulative SOFA score (cum-
SOFA) were calculated and related to ICU LOS and final hospital
survival. Values are the median (interquartile range). P465 P465
Sequential Organ Failure Assessment score trends and
sepsis survival in a Brazilian university hospital intensive
care unit
D Moreira Lima, B Ferreira Cordeiro de Almeida, R Cordioli,
E Tadeu Azevedo Moura, I Schimdtbauer, A Nassar, F Maria
Queiroz Silva, R Zigaib, D Forte, F Giannini, J Coelho, M Park
Hospital das Clínicas FMUSP, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P465 (doi: 10.1186/cc5625) Sequential Organ Failure Assessment score trends and
sepsis survival in a Brazilian university hospital intensive
care unit D Moreira Lima, B Ferreira Cordeiro de Almeida, R Cordioli,
E Tadeu Azevedo Moura, I Schimdtbauer, A Nassar, F Maria
Queiroz Silva, R Zigaib, D Forte, F Giannini, J Coelho, M Park
Hospital das Clínicas FMUSP, São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P465 (doi: 10.1186/cc5625) Results Observations in 1,711 ICU admissions were analyzed,
age was 69 (57–77) years, cum-lactate was 420 (94–419
min·mmol/l) and cum-SOFA was 11 (4–38). Cum-SOFA was
higher in patients with hyperlactatemia (cum-lactate > 0) during the
ICU stay (n = 782; 24 (7–71)) than in those without (5 (3–20);
P < 0.001). Cum-SOFA correlated with cum-lactate and with ICU
LOS, and cum-lactate correlated with ICU LOS (all P < 0.001). In
patients who died in the hospital (n = 329), cum-lactate (1,180
(203–3,427) min·mmol/l) and cum-SOFA (30 (10–95)) were
higher than in hospital survivors (n = 1,382; 298 (73–1,154)
min·mmol/l, and 22 (5–67); both P < 0.001). In emergency
admissions, cum-lactate (484 (113–2,031)) and cum-SOFA (27
(8–78)) were higher than in planned admissions (131 (37–454))
and (4 (3–28); both P < 0.001), respectively. Introduction Sepsis is associated with progressive organ failure. We sought to describe Sequential Organ Failure Assessment
(SOFA) score daily trends in septic patients and tried to correlate
those trends with survival. Methods Patients with severe sepsis or septic shock admitted for
at least 5 days in a seven-bed medicosurgical ICU of a Brazilian
university hospital were studied. The daily SOFA score for each
patient was calculated during the first 5 days of admission. Relevant data were prospectively acquired from March 2003 to
May 2006 and the latter retrieved from a electronic database. ICU
survivors
were
compared
with
nonsurvivors
using
the
Mann–Whitney U test. Day-to-day changes were verified within
each group using Friedman’s test. P ≤0.01 was elected as the
significance limit. Medians and interquartile ranges (IQRs) were
used to describe the sample. P463 P463
Sequential Organ Failure Assessment score as an
outcome predictor in malarial multiorgan dysfunction
syndrome
S Jog, P Akole, B Pawar, N Gogate, S Gadgil, P Rajhans
Deenanath Mangeshkar Hospital and Research Centre, Pune, India
Critical Care 2007, 11(Suppl 2):P463 (doi: 10.1186/cc5623)
Introduction Acute severe malaria is one of the leading causes of Sequential Organ Failure Assessment score as an
outcome predictor in malarial multiorgan dysfunction
syndrome Introduction We sought to compare four derived variables from
the SOFA score and the SAPS II in ICU patients in terms of
discriminatory ability and model calibration. Introduction We sought to compare four derived variables from
the SOFA score and the SAPS II in ICU patients in terms of
discriminatory ability and model calibration. Patients and methods Four hundred and fourteen patients were
included; they were evaluated on admission and every 48 hours
thereafter until ICU discharge or death. Readmission and patients
with an ICU stay shorter than 48 hours were excluded. The TMS
score was calculated by summing the worst scores for each of the
organ systems. Organ failure was defined by a SOFA score ≥3. Introduction Acute severe malaria is one of the leading causes of
multiorgan dysfunction syndrome (MODS) in a developing country S184 Available online http://ccforum.com/supplements/11/S2 P469 Results PCT serum concentrations are presented in Table 1. In
groups A, B, and C, SOFA1 was 1.31 ± 1.67 vs 1.62 ± 1.65
(P > 0.05), and 4.73 ± 2.57 (P < 0.05). SOFA2 was 0.97 ± 1.56
vs 1.34 ± 1.67 (P > 0.05), vs 4.69 ± 2.47 (P < 0.05). SOFA3 was
0.63 ± 1.11 vs 1.13 ± 1.68 (P = 0.0178), and 4.04 ± 1.81,
respectively. The ICU stay was 5.74 ± 11.49 days in group A,
6.97 ± 11.61 days (P = 0.04476) in group B, and 3.5 ± 1.11 days
in group C. The postoperative hospital stay was 12.08 ± 11.28
days vs 12.93 ± 10.73 days vs 12.25 ± 2.5 days (P > 0.05) in
group A vs group B vs group C. Inhospital mortality was 3% vs 3%
vs 2.8% (P = 0.8038) in the three groups. Simple prediction of mortality in case of readmission to
the intensive care unit
A Klimasauskas, G Kekstas
Vilnius University Hospital ‘Santariskiu Clinics’, Vilnius, Lithuania
Critical Care 2007, 11(Suppl 2):P469 (doi: 10.1186/cc5629) Simple prediction of mortality in case of readmission to
the intensive care unit A Klimasauskas, G Kekstas
Vilnius University Hospital ‘Santariskiu Clinics’, Vilnius, Lithuania
Critical Care 2007, 11(Suppl 2):P469 (doi: 10.1186/cc5629) Introduction Mortality of patients readmitted to the ICU is
significantly higher than the mortality of patients treated once in the
ICU. A simple method to predict mortality of patients readmitted to
the ICU could help to select the most seriously ill readmitted
patients. Table 1 (abstract P467)
–24 hours
6 hours
24 hours
48 hours
(preoperative)
(day of
(first post-
(second post-
operation)
operative day)
operative day)
Group A
0.23
0.33
0.34
0.56
Group C
0.25
0.75
1.07
0.88 Methods Adult patients that were admitted to all three ICUs of the
same hospital twice or more times during the same stay in the
hospital during a 3-year period were retrospectively selected. The
sex and age of surviving and nonsurviving readmitted patients were
compared. The mortality rate of patients readmitted into the ICU
during 24 and 48 hours was compared with the mortality rate of all
readmitted ICU patients. The mortality of patients that were
readmitted more than once into the ICU was compared with the
mortality of patients that were readmitted once. P467
Sequential Organ Failure Assessment score and
procalcitonin serum concentrations in patients with
systolic heart failure early after cardiac surgery Methods Intensive care medical records between 2002 and 2005
of 242 patients (151 males and 91 females) who attended our ICU
for 48 hours or more and proceeded mortally were analyzed
retrospectively. Patients were subdivided into three groups
according to the time at which mortality occurred: Group 1 08:00
a.m.–16:00 p.m., Group 2 16:00–24:00 p.m. and Group 3
00:00–08:00 a.m. Patients were also subdivided into two groups
according to the days on which they died being the weekend and a
weekday. The age, gender, primary diagnosis, ICU stay and
mechanical ventilator times, APACHE II, Glasgow Coma Scale and
SOFA scores, and mortality ratios of patients were taken and
compared according to the time period. V Maravic-Stojkovic1, T Spasic1, M Jovic1, M Borzanovic1,
B Djukanovic1, D Brunner2
1Dedinje Cardiovascular Institute, Belgrade, Serbia; 2Interlight,
Lozana, Swaziland
Critical Care 2007, 11(Suppl 2):P467 (doi: 10.1186/cc5627) V Maravic-Stojkovic1, T Spasic1, M Jovic1, M Borzanovic1,
B Djukanovic1, D Brunner2
1Dedinje Cardiovascular Institute, Belgrade, Serbia; 2Interlight,
Lozana, Swaziland
Critical Care 2007, 11(Suppl 2):P467 (doi: 10.1186/cc5627) Introduction Previously we investigated the clinical course of
patients with good left ventricle ejection fraction (EF) by assessing
the Sequential Organ Failure Assessment (SOFA) score and
procalcitonin (PCT) level early after cardiac surgery. In this study
we included patients with systolic heart failure (HF), prospectively
collecting data: B-type natriuretic peptide (BNP), PCT, and SOFA
score. Results No statistically significant difference among the three
groups was found in terms of age, gender, primary diagnosis, ICU
stay and mechanical ventilator times, and APACHE II, Glasgow
Coma Scale and SOFA scores. Also no statistically significant
difference was found between mortalities during the weekend and
a weekday. Conclusion A well-organized ICU can work functionally during the
night-time, change of shifts and weekend. In this situation, for
optimal
performance,
the
structure
and
management
of
organization come into prominence. Our results show that in ICU
patients mortality is not related to time of day when optimum
situations are provided. Methods Two hundred and seventy-five patients (subjected to
coronary artery bypass grafting, valve reconstruction or combined
operations) were divided into three groups: echocardiographically
estimated EF > 30% for the PCT group (group A, n = 102), the
control group (group B, n = 103), and patients with EF < 30% for
BNP analysis (group C, n = 70). PCT was measured pre-
operatively, 6 hours, 24 hours and 48 hours postoperatively. P467
Sequential Organ Failure Assessment score and
procalcitonin serum concentrations in patients with
systolic heart failure early after cardiac surgery The
SOFA score was assessed daily as SOFA1, SOFA2, SOFA3. BNP was measured preoperatively in patients with HF. P465 Conclusion In ICU patients, the cumulative area under the lactate
curve correlates with the ICU LOS, cumulative SOFA score, and
inhospital mortality. The prognostic value of cum-lactate requires
prospective evaluation. S185 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P468 Results A total of 13,343 patients were admitted. Eight hundred
and fifty-six patients were readmitted, 172 readmitted patients died
in the hospital (hospital mortality – 20.09%). The readmission rate
of men was higher in comparison with women (550 vs 306
patients). The mortality of readmitted men was lower than the
mortality of readmitted woman; 77 men (17.2%) died vs 95
(25.1%) women (P = 0.00001). The age of 565 patients was
lower than 70 years. The mortality of readmitted patients with age
lower than 70 years was lower than the mortality of patients older
than 70 years; 103 (18.2%) patients younger than 70 years died
vs 70 (24%) patients older than 70 years (P = 0.00001). Mortality
of patients that were readmitted during 24 or 48 hours was bigger
than the mortality of all readmitted patients (26.9% and 25.11% vs The relationship between mortality and its time of day in
intensive care unit patients
T Adanir, A Sencan, N Atasoy, M Aksun, N Karahan
Izmir Ataturk Training and Research Hospital, Izmir, Turkey
Critical Care 2007, 11(Suppl 2):P468 (doi: 10.1186/cc5628) P469 The duration of
stay in other departments before readmission into the ICU of
survivors was compared with duration of stay in other departments
of nonsurvivors. Discussion We have found that the SOFA3 score had a
predicting value in the mortality rate as well as PCT concentrations
measured 48 hours after surgical intervention. Comparison of intensive care unit mortality performances:
standardized mortality ratio vs absolute risk reduction Comparison of intensive care unit mortality performances:
standardized mortality ratio vs absolute risk reduction Comparison of intensive care unit mortality performances:
standardized mortality ratio vs absolute risk reduction Methods
Five hundred and twenty-three tacrolimus blood
concentration levels, together with 35 other relevant variables from
56 liver transplantation patients between 2002 and 2006, were
extracted from Ghent University Hospital database (ICU Information
System IZIS) (Centricity Critical Care Clinisoft; GE Healthcare). Multiple linear regression, and support vector regression with linear
and nonlinear (RBF) kernel functions were performed, after
selection of relevant data components and model parameters. Performances of the prediction models on unseen datasets were
analyzed with fivefold cross-validation. Wilcoxon signed-rank
analysis was performed to examine differences in performances
between prediction models and to analyze differences between real
and predicted tacrolimus blood concentrations. B Afessa, M Keegan, J Naessens, O Gajic
Mayo Clinic College of Medicine, Rochester, MN, USA
Critical Care 2007, 11(Suppl 2):P470 (doi: 10.1186/cc5630) Introduction The aim of this study was to assess the role of
absolute risk reduction (ARR) to measure ICU performance as an
alternative to the standardized mortality ratio (SMR). Methods This retrospective study involves patients admitted to
three ICUs of a single tertiary medical center from January 2003
through December 2005. Only the first ICU admission of each
patient was included in the study. The ICUs were staffed similarly. We abstracted data from the APACHE III database. For each ICU,
the SMR and ARR with their 95% confidence intervals (CI) were
calculated. ICU performance was categorized as shown in Table 1. When comparing ICUs, if the 95% CI of the SMR or the ARR
overlap between the units, the performances were considered
similar. If there was no overlap, the differences in performance
were considered statistically significant. Results
The mean absolute difference with the measured
tacrolimus blood concentration in the predicted regression model
was 2.34 ng/ml (SD 2.51). Linear SVM and RBF SVM prediction
models had mean absolute differences with the measured
tacrolimus blood concentration of, respectively, 2.20 ng/ml (SD
2.55) and 2.07 ng/ml (SD 2.16). These differences were within an
acceptable clinical range. Statistical analysis demonstrated
significant better performance of linear (P < 0.001) and nonlinear
(P = 0.002) SVM (Figure 1) in comparison with linear regression. P471 20.09%; P = 0.045 and P = 0.097). The mortality of patients that
were readmitted more than once (from a total 160 patients, 41
died – 25.6%) was bigger than the mortality of patients readmitted
just once (from a total 696 patients, 131 died – 18.96%)
(P = 0.12). The length of stay of nonsurviving readmitted patients
in other departments before readmission was higher than the
length of stay of survivors (mean 7.64 days vs mean 5.71 days). Conclusion Sex and age older than 70 years of patients
readmitted to the ICU, readmission during 24 hours, and length of
stay in other departments before readmission could be used for
simple prediction of mortality of patients readmitted into the ICU. The amount of single patient readmissions to the ICU cannot be
used as a predictor of death of patients readmitted to the ICU. 20.09%; P = 0.045 and P = 0.097). The mortality of patients that
were readmitted more than once (from a total 160 patients, 41
died – 25.6%) was bigger than the mortality of patients readmitted
just once (from a total 696 patients, 131 died – 18.96%)
(P = 0.12). The length of stay of nonsurviving readmitted patients
in other departments before readmission was higher than the
length of stay of survivors (mean 7.64 days vs mean 5.71 days). Conclusion Sex and age older than 70 years of patients
readmitted to the ICU, readmission during 24 hours, and length of
stay in other departments before readmission could be used for
simple prediction of mortality of patients readmitted into the ICU. The amount of single patient readmissions to the ICU cannot be
used as a predictor of death of patients readmitted to the ICU. Prediction of the tacrolimus blood concentration in liver
transplantation patients with support vector regression
during an intensive care unit stay T Verplancke1, S Van Looy2, F De Turck2, D Benoit1, E Hoste1,
G Van Maele1, S Van Hoecke2, J Decruyenaere1
1Ghent University Hospital, Ghent, Belgium; 2Ghent University,
Ghent, Belgium
Critical Care 2007, 11(Suppl 2):P471 (doi: 10.1186/cc5631) Introduction The tacrolimus blood concentration has wide intra-
individual and inter-individual variability, especially in the initial
phase after transplantation in the ICU. To insure clinical effect and
to avoid side-effects, it is crucial to monitor concentrations very
carefully. Prediction models can save time and resources, enabling
clinicians and nurses to improve clinical care. The relationship between mortality and its time of day in
intensive care unit patients The relationship between mortality and its time of day in
intensive care unit patients T Adanir, A Sencan, N Atasoy, M Aksun, N Karahan
Izmir Ataturk Training and Research Hospital, Izmir, Turkey
Critical Care 2007, 11(Suppl 2):P468 (doi: 10.1186/cc5628) T Adanir, A Sencan, N Atasoy, M Aksun, N Karahan
Izmir Ataturk Training and Research Hospital, Izmir, Turkey
Critical Care 2007, 11(Suppl 2):P468 (doi: 10.1186/cc5628) Introduction It has been known that a lot of factors are effective on
mortality in ICU. In terms of ICU organization it has also been
known that staff might be effective on mortality and morbidity. The
aim of our study is to compare the cases in terms of significant
time periods that are followed and lost in the ICU. S186 Available online http://ccforum.com/supplements/11/S2 Comparison of intensive care unit mortality performances:
standardized mortality ratio vs absolute risk reduction Moreover, the nonlinear RBF SVM required only seven data
components to perform this prediction, compared with 10 and 12 Results During the study period, 12,447 patients were admitted to
the three ICUs: 4,334 to the medical ICU, 3,275 to the mixed ICU
and 4,838 to the surgical ICU. The predicted mortality rates were
19.5%, 16.0% and 9.0% and the observed mortality rates 14.8%,
9.7% and 4.3% for the medical, mixed and surgical ICUs,
respectively. The SMR and ARR in mortality for each ICU are
presented in Table 2. S187
p
y
y
presented in Table 2. Conclusions ICU mortality performances assessed by SMR and
ARR give different results. The ARR may be a better metric when
comparing ICUs with a different case mix. Table 1 (abstract P470)
Performance
SMR, 95% CI
ARR, 95% CI
Poor
>1
<0
Average
Includes 1
Includes 0
Good
<1
>0
Table 2 (abstract P470)
ICU
SMR, 95% CI
ARR, 95% CI
Medical
0.76, 0.70–0.82
4.7%, 3.1–6.3
Mixed
0.61, 0.54–0.68
6.3%, 4.7–7.9
Surgical
0.48, 0.41–0. 4.7%, 3.7–5.7
Figure 1 (abstract P471) S187
Figure 1 (abstract P471) S187
Figure 1 (abstract P471) Figure 1 (abstract P471) P471 The performance of
linear and nonlinear support vector machines (SVM) as prediction
models for the tacrolimus blood concentration in liver trans-
plantation patients is compared with linear regression analysis. P470 Comparison of intensive care unit mortality performances:
standardized mortality ratio vs absolute risk reduction
B Afessa, M Keegan, J Naessens, O Gajic
Mayo Clinic College of Medicine, Rochester, MN, USA
Critical Care 2007, 11(Suppl 2):P470 (doi: 10.1186/cc5630) Figure 1 (abstract P471) We
wished to examine the effect of BSD on the endothelin (ET) axis. components needed, respectively, by multiple linear regression
and linear SVM. of poor postoperative outcome in lung transplantation and may
cause primary graft dysfunction (PGD). A number of processes are
thought to contribute to PGD. Relatively little is understood of the
role of brain stem death (BSD) in subsequent organ dysfunction. We
wished to examine the effect of BSD on the endothelin (ET) axis. Methods Following ethics approval, 14 Wistar–Kyoto rats were
anaesthetised, with tracheostomy and arterial and venous
cannulation. A 200 µl Fogarty’s balloon catheter was inserted via a
burr hole into the subdural vault. The balloon was inflated in the
experimental group but not the control group. Four hours of
positive pressure ventilation were followed by euthanasia and
organ retrieval. Lung tissue was stained for H&E for morphology,
and alveolar macrophages (AM) were identified by anti-CD68
staining. AM were stained with a monoclonal anti-ET-1 antibody, as
well as the polyclonal anti-ET-A and ET-B. Results All animals survived the experiment. There was a
significant increase in the ratio of AM to neutrophils (P = 0.002). The ET-1 content on the AM was significantly increased in the
experimental group (27.57 ± 5.26 vs 7.01 ± 1.75, P < 0.0001). Conclusions In this model, BSD was associated with an increase
in the ratio of AM to neutrophils, and there was significant
upregulation of the endothelin axis on these AM, as evidenced by
raised levels of ET-1, ET-A and ET-B. There may be a role for
endothelin blockade in the BSD organ donor. This may increase
the yield of organs that can be accepted for transplantation and
improve early graft function in the recipient Conclusion Performance of SVM with linear and nonlinear kernel
function was excellent and superior in comparison with the multiple
linear regression model in predicting the tacrolimus blood
concentration. Methods Following ethics approval, 14 Wistar–Kyoto rats were
anaesthetised, with tracheostomy and arterial and venous
cannulation. A 200 µl Fogarty’s balloon catheter was inserted via a
burr hole into the subdural vault. The balloon was inflated in the
experimental group but not the control group. Four hours of
positive pressure ventilation were followed by euthanasia and
organ retrieval. Lung tissue was stained for H&E for morphology,
and alveolar macrophages (AM) were identified by anti-CD68
staining. Figure 1 (abstract P471) AM were stained with a monoclonal anti-ET-1 antibody, as
well as the polyclonal anti-ET-A and ET-B. P474 Prognosis factors in lung transplant recipients readmitted
to the intensive care unit
B Suberviola, A Gonzalez Castro, J Llorca, A Vallejo,
C Gonzalez Mansilla, E Miñambres
Hospital Universitario Marques de Valdecilla, Santander, Spain
Critical Care 2007, 11(Suppl 2):P474 (doi: 10.1186/cc5634) B Suberviola, A Gonzalez Castro, J Llorca, A Vallejo,
C Gonzalez Mansilla, E Miñambres
Hospital Universitario Marques de Valdecilla, Santander, Spain
Critical Care 2007, 11(Suppl 2):P474 (doi: 10.1186/cc5634) Introduction The short-term survival after lung transplantation has
improved gradually. Despite this the peritransplant period is of high
risk. Factors influencing the readmission of lung transplant
recipients to the ICU are diverse, but respiratory failure and sepsis
are the predominant causes. The objective of our study was to
identify outcome predictors and prognostic factors for survival Results Eighty-seven per cent (n = 69) of kidneys transplanted
from optimal donors, in fact, have turned out working, 4% (n = 3)
have re-entered haemodialysis within 5 years from the surgery, and
only 9% (n = 7) have deceased in the same period. Regarding
marginal kidney receiving, it has been possible to demonstrate that
72% (n = 52) of such subjects maintained a good function of the
transplant, 11% (n = 8) re-entered haemodialysis, and 17%
passed away within 5 years of the transplant. among lung transplant recipients on readmission to the ICU. Materials
and
methods
A retrospective study of all lung
transplant recipients achieved during a 10-year period (from 1997
to 2006). Data collection included the age, gender, reason for and
type of lung transplantation. Variables specific to individual ICU
admissions included the admission diagnosis, length of stay,
duration of mechanical ventilation, interval time from transplan-
tation, Acute Physiology and Chronic Health Evaluation (APACHE)
II score on ICU admission, and the identification of systemic organ
dysfunction. We used Student’s t test (or, where appropriate, its
nonparametric equivalent) or the χ2 test for comparisons among
the patients who died and the patients who survived their ICU
admissions. Conclusions The difference between the survival of the two
receiving groups is not such to justify the exclusion of marginal
donors from the ‘pool’ of potential kidney donors. Considering that,
the use of marginal donors can be a valid system in order to supply
the lack of organs. Moreover the histological examinations,
executed on patterns captured with wedge biopsy before the
transplant, can be an effective strategy finalized for the expansion
of potential kidney donors. P472 Effects of the clinical characteristics of the organ donor on
the long-term results of the transplant and survival of the
patient, with particular reference to kidney transplants
S Pirri, R Mastrandrea, A Barcia, A Mazzola, S Salemi
University of Palermo, Italy
Critical Care 2007, 11(Suppl 2):P472 (doi: 10.1186/cc5632) Results All animals survived the experiment. There was a
significant increase in the ratio of AM to neutrophils (P = 0.002). The ET-1 content on the AM was significantly increased in the
experimental group (27.57 ± 5.26 vs 7.01 ± 1.75, P < 0.0001). Introduction To assess the role of the single clinical parameters of
the donor on the outcome of the transplant and the variability of
this in relation to the state of an optimal or borderline donor. Conclusions In this model, BSD was associated with an increase
in the ratio of AM to neutrophils, and there was significant
upregulation of the endothelin axis on these AM, as evidenced by
raised levels of ET-1, ET-A and ET-B. There may be a role for
endothelin blockade in the BSD organ donor. This may increase
the yield of organs that can be accepted for transplantation and
improve early graft function in the recipient. Methods One hundred and fifty-one receiving and deceased
donor brace subordinates to kidney transplant. Clinical parameters
investigated for every donor were: age, arterial hypertension
(≥140/80 mmHg), diabetes, blood values of creatinine. It was
chosen to classify as marginal all the donors with age >55 years,
and/or hypertension, and/or diabetes, and/or with blood values of
creatinine >1.5 mg/dl, and/or whose death has happened because
of one whichever pathology that has determined cerebral anoxia. Based on such parameters the donors’ borderline was 72/151
(47.7%), while the optimal was 79/151 (52.3%). The mean age of
the donors was 47.5 years (range 14–81 years). The population of
the 151 receiving optimal and marginal kidneys was constituted of
patients judged suitable for the transplant with typical risk factors
for a standard population of subjects on dialysis. The mean age of
receiving patients was 46 years (range 21–71 years). We have
classified receiving based on the outcome of the transplant to
5 years, as: patients alive with transplanted kidney still working,
deceased patients, and patients re-entered to haemodialysis. Figure 1 (abstract P471) Conclusions ICU mortality performances assessed by SMR and
ARR give different results. The ARR may be a better metric when
comparing ICUs with a different case mix. Table 1 (abstract P470)
Performance
SMR, 95% CI
ARR, 95% CI
Poor
>1
<0
Average
Includes 1
Includes 0
Good
<1
>0
Table 2 (abstract P470)
ICU
SMR, 95% CI
ARR, 95% CI
Medical
0.76, 0.70–0.82
4.7%, 3.1–6.3
Mixed
0.61, 0.54–0.68
6.3%, 4.7–7.9
Surgical
0.48, 0.41–0. 4.7%, 3.7–5.7 S187 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin of poor postoperative outcome in lung transplantation and may
cause primary graft dysfunction (PGD). A number of processes are
thought to contribute to PGD. Relatively little is understood of the
role of brain stem death (BSD) in subsequent organ dysfunction. We
wished to examine the effect of BSD on the endothelin (ET) axis. Methods Following ethics approval, 14 Wistar–Kyoto rats were
anaesthetised, with tracheostomy and arterial and venous
cannulation. A 200 µl Fogarty’s balloon catheter was inserted via a
burr hole into the subdural vault. The balloon was inflated in the
experimental group but not the control group. Four hours of
positive pressure ventilation were followed by euthanasia and
organ retrieval. Lung tissue was stained for H&E for morphology,
and alveolar macrophages (AM) were identified by anti-CD68
staining. AM were stained with a monoclonal anti-ET-1 antibody, as
well as the polyclonal anti-ET-A and ET-B. Results All animals survived the experiment. There was a
significant increase in the ratio of AM to neutrophils (P = 0.002). The ET-1 content on the AM was significantly increased in the
experimental group (27.57 ± 5.26 vs 7.01 ± 1.75, P < 0.0001). Conclusions In this model, BSD was associated with an increase
in the ratio of AM to neutrophils, and there was significant
upregulation of the endothelin axis on these AM, as evidenced by
raised levels of ET-1, ET-A and ET-B. There may be a role for
endothelin blockade in the BSD organ donor. This may increase
the yield of organs that can be accepted for transplantation and
improve early graft function in the recipient. of poor postoperative outcome in lung transplantation and may
cause primary graft dysfunction (PGD). A number of processes are
thought to contribute to PGD. Relatively little is understood of the
role of brain stem death (BSD) in subsequent organ dysfunction. P475 Predictors of intensive care unit readmission within 48
hours after discharge
E Boudesteijn, S Arbous, P Berg van den
LUMC, Leiden, The Netherlands
Critical Care 2007, 11(Suppl 2):P475 (doi: 10.1186/cc5635) Methods From February 1996 until May 2006 we studied all LT
patients from a single centre initially discharged from the ICU who
needed to be readmitted. Demographic data included the type and
date of LT, best post-LT FEV1, last pre-ICU readmission FEV1,
admission diagnosis, time from LT to ICU admission, mechanical
ventilation (MV) use, rejection episodes and infections. Actuarial
survival rates (ASR) were calculated with Kaplan–Meier curves. Introduction Readmission to the ICU during the same
hospitalization is associated with significant morbidity and mortality
and results in a longer length of stay and higher costs. There is
therefore growing interest to identify reliable predictors for
readmission. The aim of our study was to assess the incidence of
ICU readmissions, identify predictors of ICU readmission, and
determine patient outcome. Results A total of 103 LT patients were discharged from the ICU,
41 patients (39.8%) were readmitted (males 53.6% (22 patients)
with a mean age of 42 years (15–66)). Indications were emphy-
sema in 13 patients (31.7%), idiopathic pulmonary fibrosis in eight
patients (19.5%), bronchiectasis in five patients (12.2%), cystic
fibrosis in five patients and others in seven patients (17%). Seventeen patients underwent bilateral LT, 11 patients right LT
(26.8%) and eight patients left LT (19.5%), while five patients
received a heart–lung transplantation. Respiratory failure was the
principal ICU admission diagnosis (68.3%), followed by seizures
(7%) and septic shock (4.8%). MV was required in 35 patients
(85.3%). ICU mortality for readmitted patients was 68.3% with a
1-year, 3-year and 5-year ASR of 67.3%, 62.9% and 47.4%. The
survival median was 1,761 days (1,134–2,388). In the MV
patients, a 1-year, 3-year and 5-year ASR of 63.1%, 58.9% and
44.2% was found with a median survival of 1,618 days
(132–3,104). The time to ICU admission was 1,303 (4–3,096
days). ICU admission timing was not found to be a predictor for
early (<30 days; 53.8%) vs late (>30 days: 46.4%), P = 0.65. Deceased patients required significantly more MV (71.4% vs
38.5%; P = 0.044 (chi-square); OR: 4; 95% CI: 1–15.99). Emphysema was not more prevalent in the deceased patient
group, and neither was the pre-ICU readmission FEV1 nor the
occurrence of opportunistic infections. Steroid-resistant acute
rejection was found to correlate with mortality. P475 Methods We performed a retrospective case–control study. The
study population consisted of all patients who were discharged
alive from our 28-bed surgical, thoracic–surgical and medical ICU
in a university teaching hospital in a 1-year period. A case was
defined as a patient readmitted to the ICU within 48 hours after
discharge. For each case, three control patients were randomly
selected from the study population. The following information was
collected: demographic parameters and APACHE II score,
parameters of hemodynamic, respiratory and renal function, length
of ICU stay, duration of invasive ventilatory support (ventilator time),
and time between extubation and discharge. To determine a
predictive model, covariate selection was done by the two-sample
t test, Mann–Whitney test and univariate logistic regression. From
significant (P < 0.10), plausible and clinically relevant variables, a
predictive model was generated using multivariate logistic
regression. Results During a 1-year period 1,635 patients were admitted to our
ICU. Of 1,393 patients at risk for readmission, 25 (1.8%)
readmissions occurred in 23 patients. Nine of the 23 (39%)
readmitted patients died during their hospitalization, while the
overall ICU mortality was 10.6%. The most important reason for
readmission (68% of the cases) was respiratory deterioration. In the
univariate analysis, age, ventilator time during first admission and
time between extubation and ICU discharge were significant
predictors of readmission. In the multivariate analysis, age (OR 1.1;
95% CI 1.00–1.13; P = 0.03) and ventilator time during first
admission (OR 1.1; 95% CI 1.00–1.10; P = 0.03) were significant
predictors, corrected for patient characteristics. Furthermore,
patients who were readmitted had a significant longer duration of
total (first and second admission) ventilator time (188 vs 106 hours,
P = 0.012), and total ICU stay (400 vs 127 hours, P = 0.009). Conclusion Patients readmitted to the ICU have significant longer
overall ventilator time, ICU stay, and a higher ICU mortality. The
ventilator time during first admission (especially beyond 300 hours)
is an important predictor of readmission. The time it takes to get
patients ready for discharge after extubation also differed
significantly. The data suggest that elderly patients who have been
ventilated for a long period are at particular risk for readmission
and should receive additional care before discharge from the ICU. Results During a 1-year period 1,635 patients were admitted to our
ICU. Of 1,393 patients at risk for readmission, 25 (1.8%)
readmissions occurred in 23 patients. Upregulation of the endothelin axis in alveolar
macrophages following brain stem death in a murine model Upregulation of the endothelin axis in alveolar
macrophages following brain stem death in a murine model Results A total of 144 lung transplants were performed at our
institution. Forty-six of them died on the ICU during the immediate
perioperative period. Finally, 98 were discharged from the ICU. Twenty-eight patients were readmitted to the ICU after discharge
(28.57%). The mean of age was 51.3 ± 11.6 years. The
male/female ratio was 23/5. The mean period transcurred between
ICU discharge and ICU readmission was 107 ± 162 days. The
admission diagnosis was sepsis in 20 cases (71.4%). Seventeen
patients died during the ICU stay (60.7%). We found that an J Fraser, A Sutherland, F Kermeen, K McNeil, J Dunning
The Prince Charles Hospital, Brisbane, Australia
Critical Care 2007, 11(Suppl 2):P473 (doi: 10.1186/cc5633) Introduction Outcomes post lung transplantation continue to
improve, but early pulmonary dysfunction dictates long-term
morbidity and mortality. Ischaemia reperfusion injury is a precipitant Introduction Outcomes post lung transplantation continue to
improve, but early pulmonary dysfunction dictates long-term
morbidity and mortality. Ischaemia reperfusion injury is a precipitant S188 Available online http://ccforum.com/supplements/11/S2 P476 increase in APACHE II score, delay to ICU readmission, need of
mechanical ventilation and three or more organ dysfunctions were
significantly associated with mortality. Intensive care unit readmissions after lung transplantation:
epidemiology and outcome Intensive care unit readmissions after lung transplantation:
epidemiology and outcome Conclusions Admission to the ICU is common in lung transplant
recipients, and it is associated with a high mortality. Sepsis is the
main cause of ICU readmission and the most frequent cause of
death. Lung transplant recipients with higher APACHE II score and
three or more organ dysfunction present higher mortality. The delay
on ICU readmission is also associated with higher mortality. F Klein, P Klin, J Osses, J Díaz, A Bertolotti, R Favaloro
Favaloro Foundation, Buenos Aires, Argentina
Critical Care 2007, 11(Suppl 2):P476 (doi: 10.1186/cc5636) Introduction Significant improvement of short-term and long-term
survival after lung transplantation (LT) has been observed. Never-
theless, a significant number of patients need to be readmitted to
the ICU. The aim of our study was to analyse the epidemiology,
outcome and risk factors for LT patients readmitted to the ICU after
an initial discharge. P475 Nine of the 23 (39%)
readmitted patients died during their hospitalization, while the
overall ICU mortality was 10.6%. The most important reason for
readmission (68% of the cases) was respiratory deterioration. In the
univariate analysis, age, ventilator time during first admission and
time between extubation and ICU discharge were significant
predictors of readmission. In the multivariate analysis, age (OR 1.1;
95% CI 1.00–1.13; P = 0.03) and ventilator time during first
admission (OR 1.1; 95% CI 1.00–1.10; P = 0.03) were significant
predictors, corrected for patient characteristics. Furthermore,
patients who were readmitted had a significant longer duration of
total (first and second admission) ventilator time (188 vs 106 hours,
P = 0.012), and total ICU stay (400 vs 127 hours, P = 0.009). Conclusion ICU readmissions are frequent among LT patients. In
our study group, respiratory failure was the more prevalent
admission diagnosis. The need for MV was associated with a worse
prognosis as well as steroid-resistant acute rejection episodes. Early or late ICU admission after LT has not influenced mortality. P478 One-year survival of patients admitted to the neurological
intensive care unit
M Puntis, H Robertshaw
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P478 (doi: 10.1186/cc5638) One-year survival of patients admitted to the neurological
intensive care unit
M Puntis, H Robertshaw
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P478 (doi: 10.1186/cc5638) One-year survival of patients admitted to the neurological
intensive care unit M Puntis, H Robertshaw
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P478 (doi: 10.1186/cc5638) p
y
Method Approval for the study was granted by the local ethics
committee. We reviewed MEWS scores from all patients
(n = 2,974) admitted to a six-bed medical and surgical adult HDU
in a general hospital from July 2002 to October 2005. The MEWS
score was calculated from observations of heart rate, blood
pressure, respiratory rate, urine output, conscious level and
temperature recorded within 24 hours of admission to the HDU. Results Of the 2,974 patients reviewed, 2,447 patients had
sufficient data. Analysis using logistic regression shows a strong
relationship between the probability of death and the MEWS
score: the odds of death increase by 1.48 (confidence interval
1.41–1.56; P < 0.001) for each unit increase in the MEWS score. However, there is no reason that these data should follow a logistic
form and the estimates of uncertainty around the point estimates
from logistic regression are poor. More accurate estimates of the
death rate for each of the MEWS scores were achieved using a
‘bootstrapping’ technique (repeated sampling, with replacement,
from the dataset) 1,000 times (see Figure 1). The median death
rate (%) for each MEWS score was: 3 = 1.5%; 4 = 0.7%; 5 =
2.2%; 6 = 3.0%; 7 = 3.0%; 8 = 5.6%; 9 = 9.7%; 10 = 13.3%; 11 = Method Approval for the study was granted by the local ethics
committee. We reviewed MEWS scores from all patients
(n = 2,974) admitted to a six-bed medical and surgical adult HDU
in a general hospital from July 2002 to October 2005. The MEWS
score was calculated from observations of heart rate, blood
pressure, respiratory rate, urine output, conscious level and
temperature recorded within 24 hours of admission to the HDU. Introduction Patient survival in neurological intensive care units
(NICUs) may be obvious; however, there is currently little evidence
regarding the longer term outcome of these patients. Use of a modified early warning system to predict
outcome in patients admitted to a high dependency unit Use of a modified early warning system to predict
outcome in patients admitted to a high dependency unit Conclusion Survival rates among those readmitted are high. Those
returning from the HDU represent a cohort at higher risk of
mortality. The functional status after 2.5 years varies particularly
with the timing of readmission, readmission diagnosis and
APACHE score at readmission. C Carle, C Pritchard, S Northey, J Paddle
Royal Cornwall Hospital, Truro, UK
Critical Care 2007, 11(Suppl 2):P479 (doi: 10.1186/cc5639) C Carle, C Pritchard, S Northey, J Paddle
Royal Cornwall Hospital, Truro, UK C Carle, C Pritchard, S Northey, J Paddle
Royal Cornwall Hospital, Truro, UK
Critical Care 2007, 11(Suppl 2):P479 (doi: 10.1186/cc5639) Introduction The modified early warning system (MEWS) is a
physiological scoring system that identifies patients at risk of
deterioration who require increased levels of care [1]. The use of a
patient’s MEWS score to predict outcome in a high-dependency
unit (HDU) has not been previously described. P478 In this study
the 1-year survival of NICU patients has been defined. Introduction Patient survival in neurological intensive care units
(NICUs) may be obvious; however, there is currently little evidence
regarding the longer term outcome of these patients. In this study
the 1-year survival of NICU patients has been defined. p
Results Of the 2,974 patients reviewed, 2,447 patients had
sufficient data. Analysis using logistic regression shows a strong
relationship between the probability of death and the MEWS
score: the odds of death increase by 1.48 (confidence interval
1.41–1.56; P < 0.001) for each unit increase in the MEWS score. However, there is no reason that these data should follow a logistic
form and the estimates of uncertainty around the point estimates
from logistic regression are poor. More accurate estimates of the
death rate for each of the MEWS scores were achieved using a
‘bootstrapping’ technique (repeated sampling, with replacement,
from the dataset) 1,000 times (see Figure 1). The median death
rate (%) for each MEWS score was: 3 = 1.5%; 4 = 0.7%; 5 =
2.2%; 6 = 3.0%; 7 = 3.0%; 8 = 5.6%; 9 = 9.7%; 10 = 13.3%; 11 = Methods Between April 2004 and April 2005, all patients
admitted to the NICU requiring ≥24 hours of ≥2 organ system
support were identified (n = 175). The year following admission
was divided into three phases – early (0–30 days), middle (31–90
days) and late (91–360 days) – and mortality was recorded. Data
were analysed using Kaplan–Meier and log-rank analysis. Results Patients were admitted from many sources; interhospital
transfers (n = 90), neurosurgical admissions (n = 26), medical
admissions (n = 36), and emergency admissions (n = 15). Reasons
for admission included haemorrhage (n = 66), trauma (n = 52) and
neoplasm (n = 19). Ninety-one patients (52.0%) spent less than
7 days on the NICU and 84 (48%) required ≥7 days. Overall
survival was 70.9% at 30 days and 61.1% at 1 year. There was no
significant variation between the young (<60 years) and older
(≥60 years) groups (62.6%, n = 115 vs 58.3%, n = 60, P > 0.5). Nor was there a difference between those receiving two organ
support and those receiving ≥3 organ support (62.1%, n = 66 vs P477 The functional outcome of patients requiring intensive care
readmission N Conlon, B O’Brien, B Marsh
Mater Misericordiae University Hospital, Dublin, Ireland
Critical Care 2007, 11(Suppl 2):P477 (doi: 10.1186/cc5637) N Conlon, B O’Brien, B Marsh
Mater Misericordiae University Hospital, Dublin, Ireland
Critical Care 2007, 11(Suppl 2):P477 (doi: 10.1186/cc5637) Conclusion Patients readmitted to the ICU have significant longer
overall ventilator time, ICU stay, and a higher ICU mortality. The
ventilator time during first admission (especially beyond 300 hours)
is an important predictor of readmission. The time it takes to get
patients ready for discharge after extubation also differed
significantly. The data suggest that elderly patients who have been
ventilated for a long period are at particular risk for readmission
and should receive additional care before discharge from the ICU. Introduction Rates of readmission to the ICU are often cited as
controversial indices of quality of intensive care, adequacy of
follow-up and as guides to resource allocation. Nonetheless there
are few data on the long-term functional outcome of ICU
recidivists: we set out to study this. S189 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Methods With ethical approval, from a prospectively collected
database of all ICU admissions from 2004, we identified all
readmissions to our ICU from within the hospital. We identified
survivors from the database, and contacted them, 2–3 years later,
to assess their functional outcome, as the Glasgow Outcome
Score (GOS) and Karnofsky score. 60.6%, n = 109, P > 0.5). Mortality (deaths/30 days) varied
dramatically between the early, middle and late phases (29.1% vs
3.2% vs 0.9%, P < 0.001). Conclusions Although mortality is high during the first 30 days of
neurological critical illness there is a significant plateau in the
survival curve; patients surviving beyond the initial phase tend to
survive long term. Larger studies may be beneficial to further
evaluate subgroup variation in the survival curve profile. Results Of 97 readmissions, 79 (81%) survived the ICU. Most of
them (57%) came from the high-dependency unit (HDU), of whom
74% survived. Thirty-three per cent came from other wards and
10% from theatre: 90% of each of these groups survived the ICU. Further data on these groups’ interim survival and functional
outcomes are presented. Changes of the system of postoperative care decreases
mortality in a surgical unit 2), were selected for
comparative analysis. The selection was dictated by a few reasons. The Medical University in Lodz is the founding body of all hospitals
subjected to analysis. These hospitals are only a few kilometres
away from each other. The units have a similar number of beds,
and well-educated medical and nursing staff. Heads of the hospital
departments have all been awarded a professorship. Health
benefits are provided on the basis of the same list of benefits as
part of contract with the same payer – Lodz Provincial Branch of
the National Health Fund. Methods A prospective descriptive analysis of OCC in four SDUs
(18 beds) with an open model of care in a tertiary regional referral
centre. We administered a modified version of the previously
validated Shortell ICU nurse–physician questionnaire to all
healthcare professionals (HCPs) and physicians caring for patients
in the SDUs in May 2006. We measured opinion regarding patient
safety culture, organizational practices, perceived effectiveness of
practice, and job satisfaction. Responses were converted to item
scores, which reflect negative to positive opinion (0–100). Scores
were aggregated for each survey construct and for an overall SDU
rating. Results Surveys were completed by 68 HCPs and 69 physicians. Aggregated mean ± standard deviation item scores of HCP and
physician opinions were (presented as assessment area, HCPs,
physicians, P value): overall OCC in SDUs, 54.8 ± 19.9, 57.0 ± 20.3,
P = 0.52; patient safety culture, 52.2 ± 21.2, 50.9 ± 21.0, P = 0.72;
within-group relationships, 66.5 ± 16.0, 63.7 ± 18.2, P = 0.33;
between-group relationships, 53.8 ± 22.2, 62.4 ± 21.7, P = 0.02;
overall leadership, 52.2 ± 19.6, 54.8 ± 18.7, P = 0.42; conflict
management, 55.2 ± 20.1, 61.3 ± 20.1, P = 0.08; effectiveness of
care, 54.7 ± 16.8, 55.8 ± 19.3, P = 0.72; and job satisfaction,
67.5 ± 19.0, 77.9 ± 20.3, P = 0.002. The overall OCC score and
most subcategory scores were similar between HCPs and
physicians. Physicians had a better opinion of their relationships
with other groups and a higher job satisfaction than HCPs. Methods The study is a retrospective analysis of mortality in
general surgery units located at three university teaching hospitals:
UH No. 1, UH No. 2 and UH No. 5. The study comprised 25,921
patients treated in these units from 1 January 2003 to 30 June
2006. The available statistical material was analysed. P480 Introduction The purpose of this study was to examine
organizational culture and climate (OCC) in step-down units
(SDUs). Organizational culture is defined as the norms, values,
beliefs and expectations shared by those who work in a given unit. Organizational climate is the perception of unit culture by its
workers. In ICUs, organizational culture is an important determinant
of the quality of care delivered. In an attempt to alleviate ICU
demand and expenditures, many centers have opted to provide
graded levels of critical care with the creation of SDUs. There is a
paucity of literature specifically examining OCC in SDUs. Figure 1 (abstract P479) Distribution of bootstrapped estimates of death rates by MEWS score
(median, interquartile and observed range). 0
Figure 1 (abstract P478)
Distribution of bootstrapped estimates of death rates by MEWS score
(median, interquartile and observed range). Figure 1 (abstract P478) Distribution of bootstrapped estimates of death rates by MEWS score
(median, interquartile and observed range). S190 Available online http://ccforum.com/supplements/11/S2 Changes of the system of postoperative care decreases
mortality in a surgical unit M Piechota1, M Banach2
1Bolesùaw Szarecki University Hospital No. 5 in Lodz, Poland;
2University Hospital No. 3 in Lodz, Poland
Critical Care 2007, 11(Suppl 2):P480 (doi: 10.1186/cc5640) Introduction In 2005, 10 public health care institutions functioned
in the area of Lodz, having in their structure a surgical unit
classified as a general surgery unit. They were three university
teaching hospitals, three provincial hospitals, three county
hospitals and one departmental hospital. Mortality in university
teaching hospitals having 167 beds was 1.25%, in provincial
hospitals with 191 beds was 2.96%, and in county hospitals with
140 beds was 3.98%. The lowest percentage mortality was noted
in the surgical unit of Bolesùaw Szarecki University Teaching
Hospital No. 5 in Lodz (UH No. 5) and it was 0.35%. The authors
decided to analyse the causes of such low mortality in this hospital. Two remaining university teaching hospitals, N. Barlicki University
Teaching Hospital No. 1 in Lodz (UH No. 1) and WAM University
Teaching Hospital No. 2 in Lodz (UH No. 2), were selected for
comparative analysis. The selection was dictated by a few reasons. The Medical University in Lodz is the founding body of all hospitals
subjected to analysis. These hospitals are only a few kilometres
away from each other. The units have a similar number of beds,
and well-educated medical and nursing staff. Heads of the hospital
departments have all been awarded a professorship. Health
benefits are provided on the basis of the same list of benefits as
part of contract with the same payer – Lodz Provincial Branch of
the National Health Fund. Introduction In 2005, 10 public health care institutions functioned
in the area of Lodz, having in their structure a surgical unit
classified as a general surgery unit. They were three university
teaching hospitals, three provincial hospitals, three county
hospitals and one departmental hospital. Mortality in university
teaching hospitals having 167 beds was 1.25%, in provincial
hospitals with 191 beds was 2.96%, and in county hospitals with
140 beds was 3.98%. The lowest percentage mortality was noted
in the surgical unit of Bolesùaw Szarecki University Teaching
Hospital No. 5 in Lodz (UH No. 5) and it was 0.35%. The authors
decided to analyse the causes of such low mortality in this hospital. Two remaining university teaching hospitals, N. Barlicki University
Teaching Hospital No. 1 in Lodz (UH No. 1) and WAM University
Teaching Hospital No. 2 in Lodz (UH No. Organizational culture and climate in step-down units C McColl, J Muscedere, J Drover, M Squires, B Mahon,
D Heyland
Queen’s University, Kingston, Canada
Critical Care 2007, 11(Suppl 2):P481 (doi: 10.1186/cc5641) Conclusion The MEWS score can be used as a useful predictor of
outcome in a HDU. Changes of the system of postoperative care decreases
mortality in a surgical unit In the first
stage the statistical data were analysed by the Provincial Centre of
Public Health in Lodz. The obtained information concerned the
number of treated patients, the number of patients transferred,
discharged or dead, the number of man-days, mean bed use, mean
hospitalisation time, mean number of patients per bed and
mortality. The second stage focused on explaining the reasons for
significantly lower mortality among patients hospitalised in the
surgical unit of UH No. 5. Among others, the structure of the
hospitalised patients in each of these units was analysed, the
quantity and range of a contract signed with the unit financing the
benefits and internal principles of these units functioning. Conclusions Overall scores of OCC were poor and did not differ
between HCPs and physicians with the exception of between-
group relationships and job satisfaction. More research is needed
to determine the correlation between clinical outcomes and OCC
in SDUs and whether improvements in OCC result in better clinical
outcomes and job satisfaction. P481 15.9%; 12 = 20.9%; 13 = 32.0%; 14 = 47.2%; 15 = 51.9%; 16 =
54.6%; 17 = 66.7%. MEWS scores of 2 or less (n = 19) had no
deaths. Organizational culture and climate in step-down units Patient and family satisfaction with care in step-down units Service
consequences were bed blocking/increased workload in 20%,
delayed admission of another patient in 14%, cancelled elective
operations in 4%, and loss of unit capacity and cohesion in 7%. Conclusions We failed to achieve 100% successful plans. Small
numbers and failure to gather more than 40% of staff opinions on
causes and consequences of failed plans limit this pilot study. Documentation in (electronic) notes did not improve completion of
plans. The process and efficiency of care has an impact on at least
aspects of morbidity and length of stay, and deserve further study. patient-centered and family-centered quality care. Literature
examining patient or family satisfaction in SDUs is limited. patient-centered and family-centered quality care. Literature
examining patient or family satisfaction in SDUs is limited. Methods We administered a modified version of the previously
validated Family Satisfaction with ICU care survey to patients and
families of patients who were cared for in the SDUs (18 beds in
four separate units) of a tertiary regional referral center. We
obtained self-reported levels of patient and family satisfaction with
27 aspects of care related to SDU experience, communication,
and decision-making. Responses were converted to item scores,
which reflect poor to excellent satisfaction with care (0–100). Methods We administered a modified version of the previously
validated Family Satisfaction with ICU care survey to patients and
families of patients who were cared for in the SDUs (18 beds in
four separate units) of a tertiary regional referral center. We
obtained self-reported levels of patient and family satisfaction with
27 aspects of care related to SDU experience, communication,
and decision-making. Responses were converted to item scores,
which reflect poor to excellent satisfaction with care (0–100). p
Results A total of 120 patient surveys (60% response) and 99
family surveys (45% response) were completed. Patients had a
mean SDU length of stay of 2.5 days, APACHE II score of 9.9 and
an SDU mortality of 2.4%. The highest levels of satisfaction with
care were (mean ± standard deviation item score; presented as
aspect of care, patients, families, P value): overall care (aggregate
score), 81.1 ± 21.5, 80.1 ± 22.3, NS; concern and caring
received from SDU staff, 87.9 ± 17.1, 90.4 ± 5.0, NS; and nurses’
skill and competence, 88.7 ± 16.0, 88.8 ± 16.6, NS. Patient and family satisfaction with care in step-down units Patient and family satisfaction with care in step-down units Patient and family satisfaction with care in step-down units C McColl, J Muscedere, J Drover, M Squires, B Mahon, D Heyland
Queen’s University, Kingston, Canada
Critical Care 2007, 11(Suppl 2):P482 (doi: 10.1186/cc5642) Results Mortality in the general surgery unit of UH No. 5 was
0.40% within the period from 1 January 2003 to 30 June 2006. In
the general surgery unit of UH No. 1 and of UH No. 2, mortality
was respectively 2.70% and 2.13%. Introduction The purpose of this study was to determine the level
of satisfaction of patients and families with the care received in
step-down units (SDUs). In an effort to alleviate ICU demand, many
centers have opted to provide graded levels of critical care in
SDUs. However, there is a paucity of literature as to the
effectiveness of care delivered in SDUs. Measures of patient and
family satisfaction with healthcare are recognized as valuable tools
for the assessment of healthcare delivery including adherence to Conclusions Changes of the system of postoperative care
consisting of taking over postoperative care by physicians and
anaesthesiological nurses, intensive monitoring of postoperative
patients, and immediate transfer of patients with life hazard to the
ICU decreases significantly the mortality in a surgical unit. S191 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin unsuccessful plans, 36 were completed late, 22 were never
completed and nine had missing data. Thirty-six per cent, 34% and
18% of arbitrarily defined high-priority, medium-priority and low-
priority plans were unsuccessful. Most plans were to be actioned
by nurse or senior house officer, and 36% and 28% were unsuc-
cessful, respectively. More unsuccessful plans than successful
plans were recorded in the computerised notes, 79% vs 67%. Only 40% of data (staff opinions) on perceptions of causes and
consequences were gathered. Patient consequences of failed
plans included increased ICU stay in 24%, increased morbidity
such as risk of inadequate nutrition in 9%, delayed definitive treat-
ment in 7%, delayed weaning in 6%, increased risk of infection in
5% and no impact on patient in 44%. Consequences for family
included no impact in 53%, misinformation given in 8%, delayed
patient access in 2%, and delayed communication in 2%. P483 Abstract withdrawn Patient and family satisfaction with care in step-down units The lowest
levels of satisfaction were: frequency of communication with
physicians, 71.6 ± 27.8, 62.7 ± 32.2, P = 0.03 and decision-
making (aggregate score), 67.5 ± 29.9, 62.7 ± 30.5, NS. For the
decision-making process, a proportion of respondents felt they
were not included (patients, families, P value; 40.3%, 42.7%, NS),
not supported (31%, 38.6%, NS), and not in control (32.7%,
55.3%, P = 0.001). Patients and families were least satisfied with
the frequency of communication with physicians and participation
in decision-making. Patients and families were similar in their
assessments with the exception of the frequency of communication
with physicians and control of the care delivered. Outcome of very old patients on mechanical ventilation Outcome of very old patients on mechanical ventilation
R Espinoza, R Serafim, F Gago, F Saddy, B Tura, J Castro
Hospital Copa D’Or, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P485 (doi: 10.1186/cc5645) R Espinoza, R Serafim, F Gago, F Saddy, B Tura, J Castro
Hospital Copa D’Or, Rio de Janeiro, Brazil
Critical Care 2007, 11(Suppl 2):P485 (doi: 10.1186/cc5645) Conclusions While most patients and family members were
satisfied with care received, these data identify opportunities for
improvement. Specifically,
attention
must
be
paid
to
communication and decision-making processes in SDUs. Background The population group of 85 years old or more,
classified as very old, are the most rapidly growing group in
developed countries, although it still represents 0.46% of the
Brazilian population. Aging is associated with decreased
cardiopulmonary and renal reserve as well as the development of
progressive organ failure. P484 Objective To evaluate outcomes of very old patients in mechanical
ventilation. Causes and consequences of failure of implementation of
management plans in critical care Causes and consequences of failure of implementation of
management plans in critical care Patients and methods A prospective cohort study in the
medical/surgical ICU of a tertiary-care Brazilian hospital. Two
hundred and forty-four patients aged 85 years old or more were
selected from 7,410 patients admitted to the ICU from October
2002 to September 2006. Data were extracted from the QUATI
(Dixtal-Brazil) database and included sex, age, APACHE II score,
ventilation-days, length of stay, incidence of sepsis, tracheotomy,
dialysis therapy and hemodynamic monitoring. For statistical
analysis we used the chi-square test for evaluated difference of
proportion, and considered statistical significance as P < 0.05. Results There were 168 female (68.9%) and 75 male (30.7%)
patients. The mean age of the study population and the APACHE II
score were 89.55 ± 3.61 years and 17.98 ± 6.3, respectively. Median ventilation-days and length of stay were 6 and 8.14 days,
respectively. Tracheotomy was performed in 44.1%, dialysis
therapy in 15.2% and hemodynamic monitoring in 19.8%. Only the
group above 95 years old had a significant increase of days of
ventilation and length of stay: 18.77 vs 10.47 days (P = 0.01) and
19.74 vs 12.86 days (P = 0.07), respectively. The predicted
APACHE
II
mortality
for
the
studied
population
was
26.9 ± 17.21% and the present rate to the population studied was
47.7%. Patients in dialysis and with diagnosis of sepsis at
admission had poorer prognosis (respectively a 1.6 and 1.52 times
likely ratio to die). Patients and methods A prospective cohort study in the
medical/surgical ICU of a tertiary-care Brazilian hospital. Two
hundred and forty-four patients aged 85 years old or more were
selected from 7,410 patients admitted to the ICU from October
2002 to September 2006. Data were extracted from the QUATI
(Dixtal-Brazil) database and included sex, age, APACHE II score,
ventilation-days, length of stay, incidence of sepsis, tracheotomy,
dialysis therapy and hemodynamic monitoring. For statistical
analysis we used the chi-square test for evaluated difference of
proportion, and considered statistical significance as P < 0.05. M El Toukhy, P McQuillan
Portsmouth Hospital NHS Trust, Portsmouth, UK
Critical Care 2007, 11(Suppl 2):P484 (doi: 10.1186/cc5644) Introduction We investigated patient management plans to
ascertain the total number made, types of plan, priority, personnel
responsible and expected time frame, proportion completed and
the causes and consequences of failed plans (on the patient, the
family and the critical care service). p
p
g
Results There were 168 female (68.9%) and 75 male (30.7%)
patients. P485 Outcome of very old patients on mechanical ventilation P486 Data on resource use of diagnostics, drugs, fluids, materials,
admission and discharge were acquired from the computerized
Patient Data Management System in both hospitals. Hotel and
nutrition costs were collected from the respective financial
departments. These costs were divided by the annual number of
patient-days to calculate the cost per day. The NEMS or TISS
scores in the academic or general hospital, respectively, were used
to estimate nursing time per patient per day. The costs of medical
specialists were based on the labour costs and the number of ICU
days per year. In the academic hospital, time for consultations of
medical staff attributable to each individual patient-day was
prospectively collected using patient record forms. These costs we
assumed to be comparable in the general hospital in the absence
of detailed data. Outcome of octogenarians versus nonoctogenarians
admitted to the intensive care unit with return of
spontaneous circulation after out-of-hospital cardiac arrest
I van Stijn, R Bosman, H Oudemans-van Straaten,
P van der Voort, J Wester, D Zandstra, J van der Spoel
OLVG, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P486 (doi: 10.1186/cc5646) Outcome of octogenarians versus nonoctogenarians
admitted to the intensive care unit with return of
spontaneous circulation after out-of-hospital cardiac arrest I van Stijn, R Bosman, H Oudemans-van Straaten,
P van der Voort, J Wester, D Zandstra, J van der Spoel
OLVG, Amsterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P486 (doi: 10.1186/cc5646) Introduction The aim of this study was to evaluate the outcome of
octogenarians (O, age >79 years) versus nonoctogenarians (NO,
age <80 years) in relation to predicted outcome (APACHE II
predicted mortality, AIIPM) and length of stay in the ICU in days
(LOS) after out-of-hospital cardiac arrest (OHCA). Methods From 1 January 1997 to 1 December 2006, the AIIPM,
LOS and hospital mortality were prospectively recorded and the
standardised mortality ratio (SMR) was calculated. Patients were
categorised in cohorts of AIIPM. Unit costs of diagnostics and consumables were derived from the
financial hospital databases. Labour costs were based on
standardised costs per minute, which equalled the normative
income divided by the number of workable minutes per year. Estimates of the costs of inpatient-days and nonpatient-related
care were based on the annual account for 2005 of the hospitals. Nonpatient-related care (capital, overhead) was appointed to
patients using a marginal mark-up percentage. Available online http://ccforum.com/supplements/11/S2 Available online http://ccforum.com/supplements/11/S2 Conclusion The percentage of older patients admitted to the ICU
is increasing. The need for tracheotomy and dialysis as well as the
length of stay are increasing with this population. APACHE scores
do not seem to present a good relationship with mortality in this
population. Dialysis and sepsis were associated with a significant
increase in mortality. 200 consecutive patients admitted to a 32-bed mixed adult ICU at
an academic hospital during two periods in 2006: 16 April–15
May and 5 June–23 June. For comparison, we collected detailed
data at a general hospital that has a 10 bed-adult general ICU for
the period 1 January–1 July 2003. The costs were adjusted to
2005 using the general price index. Both times, we applied a
micro-costing approach, implying that all relevant resources were
identified and valued at a detailed level. P486 Results Hospital mortality in the NO group was 58.9%, and in the
O group was 75.4% (P = 0.001, chi-square). The LOS ICU was
similar in both groups (Table 1; PM, predicted mortality). Conclusion In octogenarians admitted in the ICU after OHCA,
hospital mortality is higher than in the younger group but still an
important proportion survives. Non-octogenarians survived more
often than predicted by APACHE II. Despite the higher mortality,
ICU treatment after out of hospital resuscitation of octogenarians
seems worthwhile. Results In the academic hospital the average total costs per ICU
day amounted to €1,775, compared with €1,703 in the general
hospital. The distribution of the costs by cost component varied. Results In the academic hospital the average total costs per ICU
day amounted to €1,775, compared with €1,703 in the general
hospital. The distribution of the costs by cost component varied. Conclusions The overall costs per day for IC in an academic
hospital were slightly higher than the costs for an ICU day in a
general hospital. These derived costs fit nicely to the official
reference costs of €1,730 for an ICU day in The Netherlands,
which is based on a global top-down approach. Conclusions The overall costs per day for IC in an academic
hospital were slightly higher than the costs for an ICU day in a
general hospital. These derived costs fit nicely to the official
reference costs of €1,730 for an ICU day in The Netherlands,
which is based on a global top-down approach. P488 L Hakkaart1, S Tan1, C Bouwmans1, M Al1, P Spronk2, J Bakker3
1Institute for Medical Technology Assessment, Rotterdam, The
Netherlands; 2Gelre Hospital, Apeldoorn, The Netherlands;
3Erasmus MC, Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P487 (doi: 10.1186/cc5647) Does the Glasgow Coma Scale correctly diagnose the
vegetative and minimally conscious states? Does the Glasgow Coma Scale correctly diagnose the
vegetative and minimally conscious states? Causes and consequences of failure of implementation of
management plans in critical care The mean age of the study population and the APACHE II
score were 89.55 ± 3.61 years and 17.98 ± 6.3, respectively. Median ventilation-days and length of stay were 6 and 8.14 days,
respectively. Tracheotomy was performed in 44.1%, dialysis
therapy in 15.2% and hemodynamic monitoring in 19.8%. Only the
group above 95 years old had a significant increase of days of
ventilation and length of stay: 18.77 vs 10.47 days (P = 0.01) and
19.74 vs 12.86 days (P = 0.07), respectively. The predicted
APACHE
II
mortality
for
the
studied
population
was
26.9 ± 17.21% and the present rate to the population studied was
47.7%. Patients in dialysis and with diagnosis of sepsis at
admission had poorer prognosis (respectively a 1.6 and 1.52 times
likely ratio to die). Methods Over seven consecutive days, details of all consultant
determined management plans were recorded by a dedicated
nurse auditor. A plan was defined as an identifiable do-able, short-
term action. Data on type, (arbitrary) priority, involved personnel
and time frame were noted. The auditor later returned at the end of
shift to determine whether plans had been completed in the
appropriate time frame (successful plan) or not (unsuccessful
plan). For unsuccessful plans, the nurse, senior nurse, senior
house officer, fellow and consultant were all independently quizzed
on causes and consequences (for patient, family, service) from a
predetermined list of possibilities. Results Of 200 plans, 130 were successful, for three plans data
were missing and 67 (34%) plans were unsuccessful. Of S192 Available online http://ccforum.com/supplements/11/S2 Does the Glasgow Coma Scale correctly diagnose the
vegetative and minimally conscious states? C Schnakers1, J Giacino2, K Kalmar2, S Piret1, E Lopez2,
M Boly1, R Malone2, S Laureys1
1University of Liege, Belgium; 2JFK Medical Center, Edison, NJ,
USA
Critical Care 2007, 11(Suppl 2):P488 (doi: 10.1186/cc5648) C Schnakers1, J Giacino2, K Kalmar2, S Piret1, E Lopez2,
M Boly1, R Malone2, S Laureys1
1University of Liege, Belgium; 2JFK Medical Center, Edison, NJ,
USA
Critical Care 2007, 11(Suppl 2):P488 (doi: 10.1186/cc5648) Introduction For most countries, there are no good estimates for
the costs of intensive care (IC) although it is known that the ICU is
a major inpatient cost driver. The aim of this study was to estimate
the real costs of IC in two hospitals in The Netherlands using a
micro-costing methodology. al Care 2007, 11(Suppl 2):P488 (doi: 10.1186/cc5648) Introduction Progress in intensive care has led to an increase in
the number of patients who survive severe brain injury and,
therefore, the number of patients with impaired consciousness. Methods The costing study was undertaken at two hospitals in
The Netherlands. We conducted a retrospective cost analysis of S
Table 1 (abstract P486)
NO
O
AIIPM
n
PM (SD)
SMR
LOS (days)
n
PM (SD)
SMR
LOS (days)
0–0.2
29
0.12 (0.07)
1.72
2.1
1
0.17
5.9
0
0.2–0.4
36
0.29 (0.05)
0.96
3.0
8
0.29 (0.07)
2.6
0.25
0.4–0.6
83
0.52 (0.06)
0.93
2.9
19
0.49 (0.06)
1.18
5.6
0.6–0.8
131
0.72 (0.06)
0.88
3.9
43
0.74 (0.06)
0.85
4.1
0.8–1.0
210
0.89 (0.05)
0.81
3.7
71
0.88 (0.05)
0.99
3.0
Total
489
0.69 (0.23)
0.85
3.5 (4.4)
142
0.75 (0.18)
1.0
3.4 (4.4) Table 1 (abstract P486) Intensive care of the elderly in Finland M Reinikainen1, A Uusaro2, M Niskanen3, E Ruokonen2
1North Karelia Central Hospital, Joensuu, Finland; 2University
Hospital, Kupio, Finland; 3Helsinki University Central Hospital,
Helsinki, Finland
Critical Care 2007, 11(Suppl 2):P489 (doi: 10.1186/cc5649) Results From 1996 to 2005, 47.3% (4,717) of admissions to the
ICU were aged ≥65 years; 24.0% (2,393) were ≥75 years. One-
year survival of the young group (51.8%) was significantly
(P < 0.001) better than the old group (37.9%). However, in those
receiving ≥3 organ support (young n = 197; old n = 199), this
significance is lost (42.2% vs 32.6%, P >0.2). Younger elective
surgical patients had better survival than older (79.4%, n = 196 vs
64.5%, n = 173). There was no survival difference between young
and old after emergency surgery (52.9%, n = 57 vs 50.4%,
n = 85; P > 0.5). There was no difference between ‘young’ and
‘old’ groups in the EQ5D weighted health index (0.67 ± 0.30 vs
0.62 ± 0.29, P > 0.5) or performance status scores (1.73 ± 0.96
vs 1.72 ± 0.98, P > 0.5). The EQ5D scores of survivors were
lower than matched population norms (0.64 vs 0.76, P < 0.01). Introduction The population is ageing. We wanted to find out how
age affects resource consumption and outcome of intensive care
in Finland. Introduction The population is ageing. We wanted to find out how
age affects resource consumption and outcome of intensive care
in Finland. Methods We analysed data on 79,361 admissions to 26 Finnish
ICUs during the years 1998–2004. We measured the severity of
illness with SAPS II scores and the intensity of care with TISS scores. Results The median age was 62 years; 8.9% of the patients were
aged 80 years or older. The hospital mortality rate was 16.2% in
the overall patient population but 28.4% for patients aged 80 years
or older. In a multivariate logistic regression analysis, old age was
an independent risk factor for hospital mortality (Table 1). Overall,
the mean length of ICU stay was 3.1 ± 5.3 days; it was 3.2 ± 5.3
days in the age group 75–79 years but only 2.4 ± 3.5 days in the
age group 80 years or older. Overall, the mean TISS score per day
was 25.8 ± 10.9; it was 27.8 ± 10.7 in the age group 75–79 years
and 25.3 ± 9.9 in the age group 80 years or older. One-year survival and functional outcome in critically ill
elderly patients M Puntis, M Cecconi, R McGoldrick, H Robertshaw, G McAnulty
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P490 (doi: 10.1186/cc5650) Results Overall, 29 patients (16 acute and 13 chronic patients)
were considered as being in a vegetative state based on the GCS. The FOUR identified four out of these 29 patients (1/16 acute and
3/13 chronic patients) as not being vegetative considering the
presence of visual pursuit. The CRS-R identified an additional
seven patients (4/16 acute and 3/13 chronic patients) showing
visual fixation meeting the criteria for a minimally conscious state
set forth by the Aspen Workgroup. Therefore, the GCS diagnosed
a total of 38% (11/29) of conscious patients (5/16 acute and 6/13
chronic patients) as being in a vegetative state. Introduction The number of elderly ICU patients is increasing [1] but
limited outcome data are available. In this pilot study we evaluated
survival and quality-of-life indicators in ICU patients aged ≥65 years. Method Retrospective analysis of admissions between 1996 and
2005 defined the number of elderly ICU patients. Then between
2004 and 2006, consecutive patients ≥65 years admitted to
general (631), cardiothoracic (722) or neurological (118) critical
care units requiring ≥24 hours of ≥2 organ support were identified. Patients were divided into ‘young’ (age 65–74 years, n = 733) and
‘old’ (age ≥75 years, n = 738). Age, sex, organ support, diagnosis,
and referral source were recorded. Patients were followed-up 1 year
after discharge. A standard telephone interview of a random
sample of survivors (young n = 15, old n = 22) assessed perfor-
mance status and the EQ5D health-related quality of life [2]. Data
were analysed using Kaplan–Meier and log rank. Conclusion Using the GCS can lead one to misdiagnose
conscious patients. This misdiagnosis can lead to major clinical,
therapeutic and ethical consequences. Using additional sensitive
tools such as the CRS-R can avoid this kind of situation. Table 1 (abstract P486) Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Behavioral assessment remains the gold standard to monitor the
level of consciousness. However, about one-third of patients
diagnosed with a vegetative state are actually conscious (or in a
minimally conscious state). We compared the ability of the famous
Glasgow Coma Scale (GCS) and other standardized behavioral
scales to correctly diagnose the vegetative state in an acute
(intensive care and neurology ward) and chronic (neuro-
rehabilitation) setting. in the age distribution of the Finnish population will increase the
demand for ICU beds by 25% by 2030. Conclusions The hospital mortality rate increased with increasing
age. The mean intensity of care and length of ICU stay were lower
for the oldest patients than for patients <80 years old. The ageing
of the population will probably cause a remarkable increase in the
need for intensive care. P490 Methods Sixty postcomatose patients (that is, GCS > 8) were
prospectively assessed using the GCS, the Full Outline of
UnResponsiveness (FOUR) and the Coma Recovery Scale-Revised
(CRS-R) in randomized order. The mean age was 50 years (range
18–86); 39 were men. Etiology was traumatic in 24 patients. One-year survival and functional outcome in critically ill
elderly patients
M Puntis, M Cecconi, R McGoldrick, H Robertshaw, G McAnulty
St George’s Hospital, London, UK
Critical Care 2007, 11(Suppl 2):P490 (doi: 10.1186/cc5650) One-year survival and functional outcome in critically ill
elderly patients Intensive care of the elderly in Finland If the need for
intensive care remains unchanged in each age group, the change Conclusion Survival is worse in older ICU patients, although initial
data suggest no difference in functional outcome. Survivors have
lower quality-of-life scores than population norms [3]. Further work
is pending. References
1. Carson SS: Crit Care Clin 2003, 19:605-617. 2. Dolan P: Med Care 1997, 35:1095-1108. 3. Kind P: CHE Discussion Paper 172. York: Centre for Health
Economics, University of York; 1999. References
1. Carson SS: Crit Care Clin 2003, 19:605-617. 2. Dolan P: Med Care 1997, 35:1095-1108. 3. Kind P: CHE Discussion Paper 172. York: Centre for Health
Economics, University of York; 1999. References
1. Carson SS: Crit Care Clin 2003, 19:605-617. 2. Dolan P: Med Care 1997, 35:1095-1108. 3. Kind P: CHE Discussion Paper 172. York: Centre for Health
Economics, University of York; 1999. 1. Carson SS: Crit Care Clin 2003, 19:605-617. 3. Kind P: CHE Discussion Paper 172. York: Centre for Health
Economics, University of York; 1999. P493 Quality of life before intensive care unit admission is a
strong predictor of survival Quality of life before intensive care unit admission is a
strong predictor of survival
P Spronk1, J Hofhuis1, H van Stel2, J Rommes1, A Schrijvers2,
J Bakker3
1Gelre Ziekenhuizen Location Lukas, Apeldoorn, The Netherlands;
2Julius Institute, Utrecht, The Netherlands; 3Erasmus MC,
Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P493 (doi: 10.1186/cc5653) Quality of life before intensive care unit admission is a
strong predictor of survival P Spronk1, J Hofhuis1, H van Stel2, J Rommes1, A Schrijvers2,
J Bakker3
1Gelre Ziekenhuizen Location Lukas, Apeldoorn, The Netherlands;
2Julius Institute, Utrecht, The Netherlands; 3Erasmus MC,
Rotterdam, The Netherlands
Critical Care 2007, 11(Suppl 2):P493 (doi: 10.1186/cc5653) P Spronk1, J Hofhuis1, H van Stel2, J Rommes1, A Schrijvers2,
J Bakker3 Conclusion We have demonstrated that, for our unit, there was no
statistically significant difference in hospital or ICU mortality
between the two groups. In fact, the group with a haematological
malignancy had a lower mortality than the control group. The
presence of haematological malignancy, of itself, does not appear
to increase the mortality risk, when compared with a population of
patients without haematological malignancy of a similar age,
APACHE II score and admission diagnosis. Objective
To examine whether health-related quality of life
(HRQOL) before admission to the ICU can be used as a predictor
of mortality Available online http://ccforum.com/supplements/11/S2 existing
disease
and
(ii)
patients
receiving
ward-based
rehabilitation with those who receive formalised rehabilitation in
dedicated facilities. 34% and 75%. Historically, these patients have been regarded as
having a poor prognosis once admitted to the ICU. We decided to
compare the ICU and hospital mortality of these patients with
patients of a similar age and severity of acute illness. Preliminary results Ten of the required 40 interviewees have so
far been recruited. Preliminary analysis confirms that survivors
experience a range of morbidity not well captured by professionally
recommended measures, and that pre-existing disease is an
important factor in both coping with new morbidity superimposed
by critical illness, and in marshalling support. The process of
rehabilitation appears to have important effects on perceptions of
recovery, self-management strategies, and perceptions of HRQoL. Conclusions This qualitative enquiry has already provided, and will
continue to provide, new and clinically relevant insights into
patients’ experiences of morbidity, the processes of rehabilitation,
recovery and perceived HRQoL following discharge into the
community. Methods Twenty-four patients were admitted to the ICU from
August 2004 to August 2006 with a haematological malignancy. These were case-matched using sex, age (±2 years), APACHE II
score (±2) and admission diagnosis with patients admitted to the
ICU without a diagnosis of haematological malignancy. Eighteen
patients were matched to one case control; however, in six
patients, two matches were found. Where it was impossible to
differentiate between cases on the grounds of diagnosis, age or
APACHE II score they were both included. We compared ICU and
hospital mortality between the two groups. Results Patients with a haematological malignancy had an ICU
mortality of 50%, and a hospital mortality of 58%. Control patients
had an ICU mortality of 60%, and a hospital mortality of 67%
(statistically nonsignificant). The length of time to admission
between the two groups was significantly longer in the
haematology group at 12.4 days, compared with 2.8 days in the
control patients (P < 0.05). The level of organ support was the
same between the two cohorts. P492 Design and methods A prospective cohort study in an university-
affiliated teaching hospital. Patients admitted to the ICU for >48
hours were included. Close relatives completed the Short-form 36
(SF-36) within the first 48 hours of admission to assess the pre-
morbid HRQOL of the patient. Mortality was evaluated from ICU
admittance until 6 months after ICU discharge. Logistic regression
and ROC analysis were used to assess the predictive value for
mortality of the first general health question of the SF-36 (‘in
general would you say the health of your relative is excellent, very
good, good, fair or poor’), as well as HRQOL measured by the
complete SF-36. The Acute Physiologic and Chronic Health
Evaluation (APACHE) II score was used as an accepted mortality
prediction model in ICU patients. Three models were constructed
including the HRQOL (model A), APACHE II score (model B), or
both (model C) to age and gender. Percentages of correct
survival/death predictions were calculated. Quality of life following prolonged critical illness: insights
from a qualitative approach
P Ramsay
Royal Infirmary of Edinburgh, UK
Critical Care 2007, 11(Suppl 2):P492 (doi: 10.1186/cc5652) P491 94
Table 1 (abstract P489)
Age group (years)
Adjusted OR
95% CI
0–39
Reference
40–59
2.05
1.8–2.3
60–69
3.17
2.8–3.6
70–74
4.14
3.7–4.7
75–79
5.41
4.8–6.1
80–
7.08
6.3–8.0 The outcome of patients admitted to an intensive care unit
with haematological malignancy: a case–control study P Hampshire, K Francis, S Davies, L Dagg
Royal Liverpool University Hospital, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P491 (doi: 10.1186/cc5651) Introduction The outcome of patients with haematological
malignancy admitted to the ICU has been reported as between S194 Available online http://ccforum.com/supplements/11/S2 P494 Methods ICU data were prospectively collected from March 2003
to November 2005. Oncologic patients were selected. QOL
aspects were evaluated through the analysis of independence to
accomplish daily living activities (IADL) after ICU discharge,
defined as the patient’s ability to walk, eat by mouth, maintain an
oriented conversation and bath himself. The number of organ
failures was assessed through the SOFA score. Severe organ
dysfunction (SOD) was defined if the patient had three or four
points in any of the six domains of the SOFA score. According to
the number of SOD, patients were divided into two groups: one
with two or less SODs and another with three or more SODs. Groups were compared using Fisher’s exact test. Introduction We believe that by explaining and answering the
questions of those relatives that wish it, we can alleviate the grief
caused by the death of a relative in critical care. Death is a
common outcome of critical illness and relatives are at high risk of
problems with complicated or unresolved grief due to the sudden,
often unexpected, manner of that death. We describe the
establishment and results of a bereavement follow-up service. Introduction We believe that by explaining and answering the
questions of those relatives that wish it, we can alleviate the grief
caused by the death of a relative in critical care. Death is a
common outcome of critical illness and relatives are at high risk of
problems with complicated or unresolved grief due to the sudden,
often unexpected, manner of that death. We describe the
establishment and results of a bereavement follow-up service. Methods All relatives, since January 2001, have been offered
bereavement follow-up. Following the death of a patient in critical
care, relatives are informed of the bereavement follow-up service. After death, a booklet is given to the next of kin with information
about the service. Four to six weeks later a condolence card is
sent, which includes a reminder of the follow-up service. We do
not offer a counseling service and details of other organizations
providing this are given. Appointments are made by telephone. The
interview usually takes place outside critical care and is led by a
consultant and a specially trained nurse. Relatives are given the
opportunity to ask questions. A monitoring form is completed. A
letter is sent to the GP detailing the issues discussed. Results Seventy out of 793 patients had an oncologic diagnosis. P Ramsay Introduction The measurement of health-related quality of life
(HRQoL) among survivors of critical illness has become a
prominent feature of our outcomes research. Local research
experience suggests that existing measures may fail to capture the
broad spectrum of morbidity that survivors experience. The
purpose of this research is to explore, through predominantly
qualitative methods, critical-illness mediated morbidity among
survivors of prolonged critical illness; a group in whom this type of
morbidity appears to be most prevalent. An important secondary
aim is to explore the contribution of the processes of rehabilitation
and recovery to perceptions of HRQoL. Results Four hundred and fifty-one patients were included at
admission to the ICU. At 6 months follow-up, 159 patients had
died and 40 patients were lost to follow-up. When the general
health item was used as an estimate of HRQOL, the area under the
curve (AUC) for model A (0.719) was comparable with model B
(0.721), and slightly better in model C (0.760). The percentage of
wrong predictions was lower in model C (survival 27%; death
37%) compared with model A (30% and 41%). Similar results
were found when using the complete SF-36. Methods Survivors who experienced prolonged critical illness
(defined as ≥14 days mechanical ventilation) were identified from
the Scottish Intensive Care Society Audit Group (SICSAG)
database, Wardwatcher®. Participants were contacted ≤6 months
following ICU discharge, and were invited to complete
professionally recommended quality-of-life questionnaires (the
Short Form 36 and EuroQol-5D) and to participate in a semi-
structured interview. Interviews explored everyday experiences of
ongoing morbidity and were analysed with regard to their corre-
lation with the domains and scores of the HRQoL questionnaires. Purposive sampling provided clinically important insights into
experiences and perceptions of health and pre-existing morbidity
and, importantly, the processes of rehabilitation and recovery; that
is, through comparison of (i) patients with/without appreciable pre- Conclusions This study shows that the pre-admission HRQOL
measured with either the one-item general health question or the
complete SF-36 are as good in predicting survival/mortality in ICU
patients as the APACHE II score and improves prediction slightly
when combined. As the one-item general health question is easily
and quickly obtained, assessment of HRQOL before admission to
the ICU may facilitate the decision process in determining which
patients will benefit from ICU treatment. Intensive care unit utilization after esophagectomy R Iscimen1,2, D Brown2, F Whalen2, T Roy2, S Cassivi2,
M Keegan2
1Uludag University Faculty of Medicine, Bursa, Turkey;
2Mayo Clinic College of Medicine, Rochester, MN, USA
Critical Care 2007, 11(Suppl 2):P496 (doi: 10.1186/cc5656) Conclusions We describe the results of a bereavement follow-up
service for families whose relatives died on the critical care unit at
University Hospital of Wales, Cardiff. In total, 5.7% of families took
up the service offered. These were usually the families of younger
than average male patients, who died with a critical care stay of
less than 1 week. We believe that by answering questions still
troubling the families 2–4 months after death, we can assist them
with their grief. We also believe that this follow-up service by
providing further communication can resolve some difficult issues
before they develop into formal complaints. Introduction At our institution, postesophagectomy patients are
usually managed in a progressive care unit with ICU admission
reserved for those of high acuity. We hypothesized that ICU
admission after esophagectomy is predictable and associated with
high mortality. Introduction At our institution, postesophagectomy patients are
usually managed in a progressive care unit with ICU admission
reserved for those of high acuity. We hypothesized that ICU
admission after esophagectomy is predictable and associated with
high mortality. Methods
A
retrospective
analysis
of
all
patients
after
esophagectomy between January 2000 and June 2004 at a tertiary
referral center. Data regarding demographics, preoperative
morbidities, perioperative complications, APACHE III predictions,
mortality, and lengths of stay were collected. P494 The male:female ratio was 2.18:1.0, and the average age of death
was 42.9 years. A length of stay before death of 1 week or less
occurred in 59.6%. Forty-seven per cent of families were seen
between 2 and 4 months after the death of their relative. The
issues most commonly raised were specific questions about the
patient (56.2%), review of information in the notes (34.8%),
complaints (23.6%), clarifying misunderstandings (18%) and
contacting other health professionals (21.3%). P494 The mean age was 52 ± 19 years, male gender 56%, medical
admission 77%, hematological malignancies 47% and mean
APACHE II score 20 ± 8. ICU mortality was 53% and inhospital
mortality was 71%. Nine (13%) patients were discharged of the
hospital with complete IADL. Mortality in the group admitted with
three or more SODs was 100%, while in the other group it was
39% (P = 0.01, OR 2.5 95% CI 1.8–3.6). During the ICU stay,
patients who developed three or more SODs had a higher ICU and
inhospital mortality than the ones who did not (89 x 23%,
P < 0.001, OR 7, 95% CI 1.8–26 and 100 x 53%, P < 0.001,
OR 2, 95% CI 1.4–2.6) and a smaller proportion of IADL after ICU
and hospital discharge (0 x 22%, P = 0.04, OR 1.7, 95% CI
1.3–2.2 and 0 x 47%, P < 0.001, OR 2, 95% CI 1.4–2.6). Methods All relatives, since January 2001, have been offered
bereavement follow-up. Following the death of a patient in critical
care, relatives are informed of the bereavement follow-up service. After death, a booklet is given to the next of kin with information
about the service. Four to six weeks later a condolence card is
sent, which includes a reminder of the follow-up service. We do
not offer a counseling service and details of other organizations
providing this are given. Appointments are made by telephone. The
interview usually takes place outside critical care and is led by a
consultant and a specially trained nurse. Relatives are given the
opportunity to ask questions. A monitoring form is completed. A
letter is sent to the GP detailing the issues discussed. Conclusion Mortality should not be the only aspect analyzed when
considering an ICU admission for an oncologic patient. The QOL,
including IADL, must be taken into account. A higher number of
SODs during the entire ICU stay is associated with higher ICU and
inhospital mortality. Beyond this association, a smaller number of
SODs may be associated with higher probability of IADL. Results In the 30-bed critical care unit in a teaching hospital,
during study period January 2001–November 2006, 8,964
admissions and 1,560 deaths (17.4% of patients) occurred
(male:female ratio 1.27:1). The average age of deaths was 64.7
years. Eighty-nine families were seen in bereavement follow-up
(5.7% of total deaths) and two families attended for a second visit. P Ramsay S195 Critical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin P494
Five years experience of critical care bereavement follow-up
S Voisey, J Davies, J Parry-Jones, N Stallard
University Hospital of Wales, Cardiff, UK
Critical Care 2007, 11(Suppl 2):P494 (doi: 10.1186/cc5654) P494 Visiting policies in Italian intensive care units: a national
survey Visiting policies in Italian intensive care units: a national
survey Methods We audited 28 ICU ward rounds. It was noted whether
the patient was sedated or not sedated, and whether they had their
eyes open or closed. Negative comments were recorded, and
defined as comments regarding a patient’s poor progress or
prognosis made at the bedside during the ward round. We also
noted whether the patient was informed that the ward round was in
progress, whether they were informed of the plan for the day, and
whether any reassurance was offered. The other members of the
team were not aware of the audit. A Giannini1, S Leoncino1, G Miccinesi2
1Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e
Regina Elena, Milan, Italy; 2Centro per lo Studio e la Prevenzione
Oncologica, Florence, Italy
Critical Care 2007, 11(Suppl 2):P497 (doi: 10.1186/cc5657) Introduction Today no published data are as yet available on
visiting policies in Italy’s approximately 600 ICUs. We carried out a
multicentre survey to evaluate visiting policies in Italian ICUs. Results Twenty-eight ward rounds were audited, a total of 328
patient reviews. The total number of patients with their eyes open
was 171, while 157 had their eyes closed. An adverse comment
was made during 8.2% of reviews within earshot of the patient. A
negative comment was made on 27 episodes, 13 of these were
when the patient was not sedated but had their eyes closed. Four
episodes occurred when the patient was not sedated and had their
eyes open, while 10 were sedated and had their eyes closed. Of
the 171 patients with their eyes open, 74 (43%) were informed
that we were the team doing the ward round, while 97 (57%) were
not spoken to at the start of the review. Fifty-three (31%) were
informed of our management plan for the day and 43 (25%) were
offered reassurance. In total, 103/171 patients (60%) with their
eyes open were spoken to during the ward round, and we did not
speak to 68 (40%). Methods An email questionnaire was sent to all 303 ICUs (general
and specialized) in the Italian collaborative Gruppo Italiano per la
Valutazione degli Interventi in Terapia Intensiva, asking about their
visiting policies. Results The response rate was 84.8% (257/303). The median
daily visiting time was 60 minutes (10th percentile: 30 minutes;
90th percentile: 120 minutes); however, 2% of ICUs allowed no
visiting whatsoever. P498 and 17.0 (11.3–33.9) days, respectively. Compared with NICUGP,
patients in ICUGP were more likely to have developed post-
operative arrhythmia (57.9% vs 12.9%, P < 0.001), were older, of
higher ASA status, and more likely to have diabetes, coronary
artery disease, hypertension, a higher cancer stage, and to have
received more intraoperative blood products. Of 352 patients
originally not sent to the ICU, 43 (12.2%) were subsequently
admitted to the ICU. These patients had higher APACHE III scores
and were more likely to have ‘aspiration’ documented, although
their mortality was not higher than direct ICU admissions. Conclusions After esophagectomy, overall mortality is low, but
many patients require ICU admission. Postoperative arrhythmias
and aspiration pneumonitis are especially problematic. and 17.0 (11.3–33.9) days, respectively. Compared with NICUGP,
patients in ICUGP were more likely to have developed post-
operative arrhythmia (57.9% vs 12.9%, P < 0.001), were older, of
higher ASA status, and more likely to have diabetes, coronary
artery disease, hypertension, a higher cancer stage, and to have
received more intraoperative blood products. Of 352 patients
originally not sent to the ICU, 43 (12.2%) were subsequently
admitted to the ICU. These patients had higher APACHE III scores
and were more likely to have ‘aspiration’ documented, although
their mortality was not higher than direct ICU admissions. P498
Communication with patients during ward rounds on the
intensive care unit: a prospective, observational, semiblind
study
K Francis, D Langhor, J Walker, I Welters
Royal Liverpool University Hospital, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P498 (doi: 10.1186/cc5658) Communication with patients during ward rounds on the
intensive care unit: a prospective, observational, semiblind
study K Francis, D Langhor, J Walker, I Welters
Royal Liverpool University Hospital, Liverpool, UK
Critical Care 2007, 11(Suppl 2):P498 (doi: 10.1186/cc5658) Introduction It is good medical practice to communicate with
patients regarding their condition and proposed treatment. Com-
munication is essential to allow them to express their concerns and
exercise their own autonomy, in a situation where they otherwise
may have little control. Poor communication may contribute to
unnecessary anxiety or depression. The aim of this audit was to
observe whether the doctors communicated with patients on ward
rounds. Conclusions After esophagectomy, overall mortality is low, but
many patients require ICU admission. Postoperative arrhythmias
and aspiration pneumonitis are especially problematic. P495 Results
Four hundred and thirty-two patients underwent
esophagectomy during the study period: 123 (28.5%) were
admitted to the ICU (ICUGP) and 309 (71.5%) were not
(NICUGP). Overall mortality was 3.7% (16 of 432 patients). Fifteen of 123 in ICUGP died in hospital (12.2%) compared with
one of 309 in NICUGP. For ICUGP, mean (±standard deviation)
acute physiology and APACHE III scores were 41.8 (±16.6) and
54.5 (±18.1), respectively. Forty-seven percent of ICUGP had a
new (versus pre-existing postoperative) infiltrate on chest X-ray,
21.8% had positive sputum/bronchial culture and 5% positive
blood culture within 48 hours of ICU admission. A total 13.8% of
ICUGP had ‘aspiration’ documented in physician notes. The
median (IQR) ICU and hospital lengths of stay were 3.6 (1.7–9.9) Quality of life aspects in oncologic patients who survived
an intensive care unit admission D Forte, O Ranzani, N Stape, F Gianinni, R Cordioli, D Lima,
J Coelho, P Nassar, R Zigaib, E Azevedo, I Schimidtbauer,
F Silva, B Cordeiro, A Toledo-Maciel, M Park
University of São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P495 (doi: 10.1186/cc5655) D Forte, O Ranzani, N Stape, F Gianinni, R Cordioli, D Lima,
J Coelho, P Nassar, R Zigaib, E Azevedo, I Schimidtbauer,
F Silva, B Cordeiro, A Toledo-Maciel, M Park
University of São Paulo, Brazil
Critical Care 2007, 11(Suppl 2):P495 (doi: 10.1186/cc5655) Introduction The number of organ failures in oncologic patients
admitted to the ICU is a good predictor of mortality. We propose
to analyze the association of this variable and quality of life (QOL)
aspects in oncologic patients who survived an ICU admission. S196 Available online http://ccforum.com/supplements/11/S2 Visiting policies in Italian intensive care units: a national
survey A total 54.8% of ICUs surveyed had only one
daily visiting slot, and 44% two. Only 1.2% had more than two
visiting slots. The number of visitors was restricted in 91.8% of
ICUs. The type of visitors (immediate family only) was restricted in
17.5% of ICUs. Children were not permitted to visit in 69.1% of
ICUs and 17.5% had a minimum age limit for visitors. In the case of
a dying patient, 20.6% of ICUs did not alter the visiting policy;
49% extended visiting hours; 44% increased the number of slots;
and 53% allowed more visitors. A gowning procedure was
compulsory for visitors in 95.3% of ICUs. No waiting room was
provided by 25.4% of ICUs. Conclusion On intensive care ward rounds, patients are often not
engaged in conversations or allowed to express their concerns. The majority of patients were not offered reassurance or informed
about the treatment plan. Improved communication skills may help
to lessen patients’ anxiety and unnecessary stress both during their
stay on ICU and following their discharge. Conclusions This is the first survey on visiting policies in Italian
ICUs. Despite the widely-held conviction that there is no sound
scientific basis for restricting visitors in ICUs [1-3], our findings
show a clear tendency in Italian ICUs to apply restricted visiting
policies (concerning visiting hours, number and type of visitors),
which are only partially liberalized when the patient is dying. Our
survey could contribute towards modifying current policies in
favour of opening ICUs that are still ‘closed’ and promoting more
appropriate and attentive care for the patient and his/her family. Hospital volume and outcome following mechanical
ventilation on the intensive care unit S Gopal1, R O’Brien1, J Pooni1, S Macfarlane2
1The Royal Wolverhampton Hospitals NHS Trust, Wolverhampton,
UK; 2ICNARC, Birmingham, UK
Critical Care 2007, 11(Suppl 2):P499 (doi: 10.1186/cc5659) Acknowledgement We thank Gruppo Italiano per la Valutazione
degli Interventi in Terapia Intensiva for their valuable help. Acknowledgement We thank Gruppo Italiano per la Valutazione
degli Interventi in Terapia Intensiva for their valuable help. Introduction
The study was undertaken to determine the
relationship between hospital volume and mortality in mechanically
ventilated adult medical and surgical patients. The regionalisation
of adult critical care services has been suggested by healthcare
providers and health policy-makers as a means of achieving the
ideal balance of providing high-quality care that is both cost-
effective and accessible. Recent studies have had conflicting
results. 1. Burchardi H: Let’s open the door! Intensive Care Med 2002,
8:1371-1372. 1. Burchardi H: Let’s open the door! Intensive Care Med 2002,
8:1371-1372. 2. Berwick DM, et al.: Restricted visiting hours in ICUs: time
to change. JAMA 2004, 292:736-737. 2. Berwick DM, et al.: Restricted visiting hours in ICUs: time
to change. JAMA 2004, 292:736-737. 3. Slota M, et al.: Perspectives on family-centered, flexible
visitation in the intensive care unit setting. Crit Care Med
2003, 31(Suppl):S362-S366. 3. Slota M, et al.: Perspectives on family-centered, flexible
visitation in the intensive care unit setting. Crit Care Med
2003, 31(Suppl):S362-S366. S197 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin Figure 1 (abstract P500) Methods The Birmingham and Black Country Critical Care
Network database was retrospectively reviewed over a 10-year
period from 1 April 1996 to 31 March 2006. The database
included 50,686 patient episodes. After exclusion (incomplete
data 9,700 episodes, unventilated patients 19,244 episodes,
mechanical ventilation for less than 24 hours 3,814 episodes,
interhospital transfers 795 episodes) the final cohort included
9,920 adult medical patients and 7,210 surgical patients. Hospitals were grouped into five volume categories to aid inter-
pretation of the results (<100; 100–149; 150–199; 200–249;
≥250 ventilation episodes/year). The odds ratio and 95% confi-
dence intervals for death on the ICU were calculated in relation to
the hospital volume of ventilation. Results For both medical and surgical patients there was no
relationship between the hospital volume of ventilation and death
on the ICU. The odds ratio remained insignificant even after
adjustment for patient demographics, APACHE II score, length of
ICU stay and urgency status. Hospital volume and outcome following mechanical
ventilation on the intensive care unit Medical patients’ adjusted odds ratio
was 0.735 (95% CI 0.604–0.894). Surgical patients’ adjusted
odds ratio was 0.771 (95% CI 0.559–1.064). Conclusion There is no relationship between hospital volume and
ICU mortality in both medical and surgical patients following
mechanical ventilation. The results of this study do not support the
argument for regionalisation of adult critical care services in the
United Kingdom. 35.8 years (24–57); 133 men, 51 women. One hundred and five
students are attending the course in order to improve their
qualification, 87 are studying for the specialist title examination, 58
to work in the ICU and 47 to acquire new knowledge. They
considered their main specialties to be: internal medicine (54),
intensive care (15), surgery (10) and anesthesiology (seven). Sixty-
five percent work in the ICU (12.7% are leaders, 19.5% daily
routine, 86.4% on duty and 6.8% play all three functions), 6% have
the specialist critical care title, 15.7% are associated with the
Brazilian critical care society, 49.45% have medical residence in
another area, 36.4% have other postgraduations. They self-
considered around grade 6 for cognitive aspects, procedural skills
and competence and near grade 8 for communication and
relationship (see Figure 1). Cardiopulmonary resuscitation,
mechanical ventilation, haemodynamics and neurointensivism are
the most desirable subjects. P501 P501
Data completeness in the Finnish Intensive Care Quality
Consortium database
P Mussalo1, J Tenhunen2
1Intensium Ltd, Kuopio, Finland; 2Tampere University Hospital,
Tampere, Finland
Critical Care 2007, 11(Suppl 2):P501 (doi: 10.1186/cc5661) Continuous education in intensive care for physicians in
Brazil: for whom and their needs R Goldwasser1, C David1, D Costa2, C Piras3, P Mello4,
G Macedo5, A Barros6
1Hospital Universitario-Universidade Federal do Rio de Janeiro,
Brazil; 2Hospital Universitario, Cuiaba, Brazil; 3SOESTI, Vitoria,
Brazil; 4SOTIPI, Terezina, Brazil; 5SOTIERJ, Vassouras, Brazil;
6SOTIPE, Recife, Brazil
Critical Care 2007, 11(Suppl 2):P500 (doi: 10.1186/cc5660) Introduction The postgraduation course had been developed by
the Brazilian Critical Care Society (AMIB) to be applied to
physicians from all regions of Brazil since 2004. The importance of
this 360-hour course is to provide continuous education and to
train abilities to make decisions and start treatment. Also, for those
who are in ICU practice, to qualify for application of specialist
examination. The main objective of this study is to identify who are
the doctors that are looking for this course. Conclusions Doctors are mainly from the fourth decade, want to
improve their qualification, and are usually working in ICUs. The
low number of specialists who works in ICU is a reality and there is
a need to expand it. The self-evaluation points to problems with
knowledge and ability; however, communications and relationships
were well adjusted. The diversity of data will assist the AMIB to
provide continuous education and qualify doctors to attend the
demand of intensivists in Brazil. g
Methods An opinion poll was collected from the students on the
first day of the class course approaching the following aspects: Methods An opinion poll was collected from the students on the
first day of the class course approaching the following aspects:
1. Profile. P500 Continuous education in intensive care for physicians in
Brazil: for whom and their needs Data completeness in the Finnish Intensive Care Quality
Consortium database auses of all incidents (irrespective of patient outcome) Methods We assessed data completeness of a Finnish ICU quality
benchmarking database from 1998 to March 2006 containing
93,964 admission records. The data completeness was defined as
a ratio of available and required data at ICU admission level. We
evaluated the dataset and selected 19 most significant admission
scheme variables to be included in completeness ratio calculations. Results The majority of data (77.5%) was collected with the
manual system and the remaining 22.5% with an integration
software. The mean admission data completeness ratio (CR)
increased from 85.3% at 1998 to 97.9% at 2005 (P = 0.01). Between the ICUs, the mean CR varied from 91.6% to 99.6%
(P = 0.01). The mean CR of the data collected with the IVT was
98.7% and with the manual system was 95.1% (P = 0.01). The
rate of 100% complete records per patient was 48.7% and it
increased from 0.0% in 1998 to 71% in 2005. Results The majority of data (77.5%) was collected with the
manual system and the remaining 22.5% with an integration
software. The mean admission data completeness ratio (CR)
increased from 85.3% at 1998 to 97.9% at 2005 (P = 0.01). Between the ICUs, the mean CR varied from 91.6% to 99.6%
(P = 0.01). The mean CR of the data collected with the IVT was
98.7% and with the manual system was 95.1% (P = 0.01). The
rate of 100% complete records per patient was 48.7% and it
increased from 0.0% in 1998 to 71% in 2005. potential or actual harm was perceived in five (15%) of the
incidents. Fifty-three per cent of events were reported by senior
house officer grade and 47% of incidents were reported by a
specialist registrar. Only one incident was reported by a nurse on
the team. Conclusion Data completeness in the FICQC has improved during
the study period, although there is still significant variation between
ICUs. Improved data completeness and decreased proportion of
missing data are most likely due to the increasingly common use of
CIS and automated data collection. We conclude that
measuring/reporting the amount of missing data is mandatory
when data collection and data management procedures for
benchmarking are being developed. Conclusions Interhospital transport of critically ill patients can
pose important risks. In our study no actual patient harm occurred
although most incidents had the potential to cause harm. P503 Maximisation of heart and lung donation in a neurosurgical
intensive care unit Maximisation of heart and lung donation in a neurosurgical
intensive care unit S Aerdts, J Hofstra
Isala Klinieken, Zwolle, The Netherlands
Critical Care 2007, 11(Suppl 2):P503 (doi: 10.1186/cc5663) S Aerdts, J Hofstra
Isala Klinieken, Zwolle, The Netherlands
Critical Care 2007, 11(Suppl 2):P503 (doi: 10.1186/cc5663) Introduction In this study we created a database to analyse the
incidence and types of critical incidents that occurred during the
interhospital transfer of critically ill patients. The transfer of critically
ill patients presents important risks and the safety of patients has
been shown to be facilitated by the development of standard
equipment and specialist teams [1]. The West of Scotland Shock
team is a designated regional transfer service based in Glasgow. We are involved in the interhospital transfer of patients and not
primary retrieval. A recent study looking at critical incidents during
the intrahospital transport of the critically ill highlighted the risks
posed, and recommended the monitoring of incidents in order to
aid the continuous improvement in patient safety [2]. No similar
study has been carried out looking at the interhospital transport of
the critically ill patient. Critical Care 2007, 11(Suppl 2):P503 (doi: 10.1186/c Introduction The number of heart-beating donors in The Netherlands
is decreasing. This decrease is only partially compensated for by
an increase of nonheart-beating donations, resulting in an
increasing shortage of donor organs, especially of donor hearts
and lungs. In 2005 compared with 2004 the number of patients
waiting for a donor heart increased from 38 to 50 (32%). In lung
donation the increase was 37% (from 79 to 108). One approach
to reduce this shortage is to maximize the number of organs per
donor by optimisation of donor treatment in the ICU. g
g
g
We are involved in the interhospital transfer of patients and not
primary retrieval. A recent study looking at critical incidents during
the intrahospital transport of the critically ill highlighted the risks
posed, and recommended the monitoring of incidents in order to
aid the continuous improvement in patient safety [2]. No similar
study has been carried out looking at the interhospital transport of
the critically ill patient. Methods We investigated the possibilities for improvement of
donor management in our ICU by a retrospective study in 37 heart-
beating organ donors hospitalised in our ICU from 1993 to 2005. Data completeness in the Finnish Intensive Care Quality
Consortium database 2. He/she is attending the course in order to: prepare for the
specialist critical care examination (), improve qualification (),
work at an ICU (), any other reason if they do not deal with
critical care patients (). P Mussalo1, J Tenhunen2
1Intensium Ltd, Kuopio, Finland; 2Tampere University Hospital,
Tampere, Finland
Critical Care 2007, 11(Suppl 2):P501 (doi: 10.1186/cc5661) 3. If he/she works at an ICU: how long (years) and the role (duty,
routine or leader). 4. Partners of AMIB (yes) (no); if they have specialist title
recognized by the AMIB (yes) (no). Introduction Benchmarking has been an essential part of intensive
care medicine in Finland since 1994. At present, web-based
quality/performance reports are shared with the 24 members of the
Finnish Intensive Care Quality Consortium (FICQC). Thirteen ICUs
collect FICQC data manually and 11 ICUs utilize data collection
software (IVT) integrated with the Clinical Information System
(CIS). In recent literature, the completeness of data between
centralized medical benchmarking registries varies widely [1,2]. We hypothesized that: (1) the completeness of data in FICQC has Introduction Benchmarking has been an essential part of intensive
care medicine in Finland since 1994. At present, web-based
quality/performance reports are shared with the 24 members of the
Finnish Intensive Care Quality Consortium (FICQC). Thirteen ICUs
collect FICQC data manually and 11 ICUs utilize data collection
software (IVT) integrated with the Clinical Information System
(CIS). In recent literature, the completeness of data between
centralized medical benchmarking registries varies widely [1,2]. We hypothesized that: (1) the completeness of data in FICQC has 5. If he/she has other postgraduation or residency program. ( 6. Self-evaluation related to the critical patient knowledge (scales
from 1 to 9, considering 9 the highest grade). 7. Interest in the subjects of intensive care medicine (scales from
1 to 9). Results From 2004 to 2005 the AMIB started eight
postgraduation courses in different regions of Brazil; 250 students
were enrolled; 184 had answered the survey. The average age was S198 Available online http://ccforum.com/supplements/11/S2 Table 1 (abstract P502)
Causes of all incidents (irrespective of patient outcome)
Communication problem
10 (29%)
Organisational delay
7 (21%)
Lack of staff
2 (6%)
Equipment failure
9 (26%)
Poor preparation of patient
5 (15%)
Staff injury
1 (3%) increased over the years and (2) the variation between the different
units still exists. P502 2. Beckmann U, Gillies D, Berenholtz S, et al.: Incidents relat-
ing to the intra-hospital transfer of critically ill patients. Intensive Care Med 2004, 30:1579-1585. References References Analysis of critical incidents during the interhospital
transport of critically ill patients Analysis of critical incidents during the interhospital
transport of critically ill patients P Doherty, B Digby
Western Infirmary, Glasgow, UK
Critical Care 2007, 11(Suppl 2):P502 (doi: 10.1186/cc5662) References 1. Faculty of Intensive Care and Australasian College for Emer-
gency Medicine: Minimum Standards for the Transport of the
Critically Ill Patient; 2003 [http://www.acem.org.au/media/
policies_and_guidelines/min_standard_crit_ill.pdf] References
1. Arts D, et al.: Intensive Care Med 2002, 28:656-659. 2. Afessa B, et al.: Intensive Care Med 2005, 31:1537-1543. Data completeness in the Finnish Intensive Care Quality
Consortium database The
majority of incidents were caused by system-based factors. This
database has allowed us to perform continuous service
development and education of staff. P504 Medical practices during the last 48 hours of life in
children admitted to seven Brazilian Pediatric intensive
care units P Lago, J Piva, P Garcia
PUCRS, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P504 (doi: 10.1186/cc5664) P Lago, J Piva, P Garcia
PUCRS, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P504 (doi: 10.1186/cc5664) P Lago, J Piva, P Garcia
PUCRS, Porto Alegre, Brazil
Critical Care 2007, 11(Suppl 2):P504 (doi: 10.1186/cc5664) Results A total of 137 physicians and critical care nurses
completed the survey. The average age was 34 years and 58%
were males. ‘Brain death’ was defined as an ‘irreversible cessation
of brainstem function’ by 85% of respondents; 77% relying on
clinical examination, 49.6% consulting neurophysicians and 28.3%
ordering further testing to confirm the diagnosis. Withdrawal of life
support is practiced by 83.2%; most frequently in the setting of
absent brainstem and cortical functioning (74.3%), followed by
acute, progressive multiorgan failure (39.8%). Physicians are more
likely (P
value 0.000) to withdraw mechanical ventilation,
compared with nurses who would withdraw vasopressors (P value
0.006). The primary physician is the most frequent caregiver
(60.2%) to start a discussion on withdrawal of life support, with
72.6% respondents consulting the Hospital Ethics Committee. Only 13.3% respondents never withdraw life support; 28.3%
considered it their responsibility to ‘sustain life at all costs’ and only
8% gave religious beliefs as a reason. Only 56.6% favored organ
harvest for transplantation from cadavers, while 64.6% supported
harvest from brain dead individuals. Nurses were significantly more
likely to support organ harvest for transplant from heart-beating,
brain dead individuals (P value 0.025) than cadavers (P value
0.000). Introduction During the last decades life support limitation (LSL)
practices have been offered more frequently in Latin American
pediatric intensive care units (PICUs). We hypothesize that,
depending on the Brazilian region, the incidence of LSL and the
medical management may differ. Objective To evaluate the incidence of LSL practices and the
medical management during the last 48 hours of life of children
admitted to seven PICUs located in regions of Brazil. Methods A multicenter, observational and retrospective chart
review study. The medical chart of all deaths occurring between
January 2003 and December 2004 in seven Brazilian PICUs
located in Porto Alegre (two), Sao Paulo (two) and Salvador
(three) were evaluated. End-of-life care in the critically ill: a description of
knowledge, attitudes and practices of physicians and
nurses from Karachi, Pakistan The primary physician is the most frequent caregiver
(60.2%) to start a discussion on withdrawal of life support, with
72.6% respondents consulting the Hospital Ethics Committee. Only 13.3% respondents never withdraw life support; 28.3%
considered it their responsibility to ‘sustain life at all costs’ and only
8% gave religious beliefs as a reason. Only 56.6% favored organ
harvest for transplantation from cadavers, while 64.6% supported
harvest from brain dead individuals. Nurses were significantly more
likely to support organ harvest for transplant from heart-beating,
brain dead individuals (P value 0.025) than cadavers (P value
0.000). Methods We carried out a cross-sectional survey of clinicians
working at three hospitals in Karachi (one private, university
hospital, one mixed public and private, tertiary care hospital and
one large government-funded hospital). A 13-question instrument
was developed to assess recognition of end-of-life in the ICU,
knowledge of commonly used terms to describe limitations of care,
and attitudes and practices towards withdrawal and limitation of
life-support measures and organ harvest for transplantation. After
measuring the frequencies for presentation of the data, differences
between the three respondent subgroups were compared using a
chi-square analysis. Fisher’s exact test was used where the
individual cell count was <5. A one-way analysis of variance was
used to compare differences in age and years of practice. A two-
sided P value of <0.05 was considered statistically significant. P503 There was no protocol for the treatment of organ donors in our
institution. Methods The study was a cross-sectional analysis of critical
incidents occurring during interhospital transport that were reported
to the West of Scotland Shock Team critical incident database set
up in September 2005. The information obtained was categorised
into: (a) where the incident took place, (b) type of incident, (c)
written description of events, (d) outcome (potential or actual harm
to the patient) and (e) designation of the staff member reporting
the incident. Results The heart was donated in 18 of 37 patients (49%). Lung
donation was possible in only eight of 37 donors (22%). Most
hearts and lungs were rejected for transplantation for valid
reasons. In some patients there was room for improvement: in two
of the three cases where hemodynamic instability impeded heart
and lung donation (one dying from subarachnoidal bleeding and
one from ischemic cerebral infarction), hemodynamic instability
was closely associated with the moment of cerebral death. In three
further patients heart donation was not carried out because of wall
movement abnormality or electrocardiogram abnormalities. None of Results A total of 199 transfers were performed over the 6-month
period. Thirty-four critical incidents were reported. Twenty-four
(70%) incidents took place before, seven (21%) during and three
(9%) after transfer. No patients sustained actual harm, 29 (85%)
were perceived by the reporter to have suffered potential harm and
the most common cause of this were delays in the transfer. No S199 ritical Care March 2007 Vol 11 Suppl 2
27th International Symposium on Intensive Care and Emergency Medicin End-of-life care in the critically ill: a description of
knowledge, attitudes and practices of physicians and
nurses from Karachi, Pakistan End-of-life care in the critically ill: a description of
knowledge, attitudes and practices of physicians and
nurses from Karachi, Pakistan N Salahuddin, A Ahmed, S Shafquat
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P505 (doi: 10.1186/cc5665) Introduction As the numbers of people admitted to ICUs are
increasing, physicians are faced with obligations beyond
attempting to reverse illness and include providing quality end-of-
life care. Barriers to this include inadequate understanding of the
dying patient and withdrawal or limitation of care. The objectives of
this study were to document the comprehensions of physicians
and nurses dealing with these situations. Conclusion On the basis of this retrospective study we conclude
that donor management in our ICU can be improved. A
management protocol with special attention for treatment of
disturbance in cardiac and pulmonary function caused by
sympathic overstimulation might considerably increase the
amount of hearts and lungs donated, contributing to a decrease
in organ shortage. and nurses dealing with these situations. Methods We carried out a cross-sectional survey of clinicians
working at three hospitals in Karachi (one private, university
hospital, one mixed public and private, tertiary care hospital and
one large government-funded hospital). A 13-question instrument
was developed to assess recognition of end-of-life in the ICU,
knowledge of commonly used terms to describe limitations of care,
and attitudes and practices towards withdrawal and limitation of
life-support measures and organ harvest for transplantation. After
measuring the frequencies for presentation of the data, differences
between the three respondent subgroups were compared using a
chi-square analysis. Fisher’s exact test was used where the
individual cell count was <5. A one-way analysis of variance was
used to compare differences in age and years of practice. A two-
sided P value of <0.05 was considered statistically significant. Results A total of 137 physicians and critical care nurses
completed the survey. The average age was 34 years and 58%
were males. ‘Brain death’ was defined as an ‘irreversible cessation
of brainstem function’ by 85% of respondents; 77% relying on
clinical examination, 49.6% consulting neurophysicians and 28.3%
ordering further testing to confirm the diagnosis. Withdrawal of life
support is practiced by 83.2%; most frequently in the setting of
absent brainstem and cortical functioning (74.3%), followed by
acute, progressive multiorgan failure (39.8%). Physicians are more
likely (P
value 0.000) to withdraw mechanical ventilation,
compared with nurses who would withdraw vasopressors (P value
0.006). P505 them had previous cardiac disease. All three had disturbances in
cardiac rhythm closely related to the occurrence of cerebral death. Two of these three patients also developed neurogenic pulmonary
edema. We speculate that in all five patients the instability leading
to the decision not to perform heart and lung donation was caused
by excessive sympathic stimulation at the time of cerebral death
leading to impaired myocardial function and neurogenic pulmonary
edema. These disturbances may be reversible within a few hours. Inotropic therapy, judicious fluid administration guided by close
hemodynamic monitoring together with a trial of treatment with
triple hormonal therapy (corticosteroid, vasopressin and thyroid
hormone) might have improved cardiac and pulmonary function,
rendering heart and lung donation possible. P505
End-of-life care in the critically ill: a description of
knowledge, attitudes and practices of physicians and
nurses from Karachi, Pakistan
N Salahuddin, A Ahmed, S Shafquat
Aga Khan University & Hospital, Karachi, Pakistan
Critical Care 2007, 11(Suppl 2):P505 (doi: 10.1186/cc5665) P506 Methods We identified original research articles on critical care in
three high impact factor journals (N Engl J Med, JAMA and The
Lancet) published from 2001 to 2005. A list of the countries where
data
collection
occurred
was
extracted. Eight
countries
contributed to ≥10 studies. A collaborator in each country was
asked to provide baseline critical care information for their country
from 2005, or as close to that date as possible. World Resources in Critical Care Study: a survey of critical
care research and resources in eight countries H Wunsch1, D Harrison2, O Collange3, N de Keizer4, R Fowler5,
E Hoste6, A Kersten7, W Linde-Zwirble8, A Sandiumenge9, D
Angus8, K Rowan2
1Columbia University, New York, USA; 2ICNARC, London, UK;
3Strasbourg University Hospital, Strasbourg, France; 4University of
Amsterdam, The Netherlands; 5Sunnybrook Health Sciences
Center, Toronto, Canada; 6Ghent University Hospital, Ghent,
Belgium; 7University Hospital Aachen, Germany; 8University of
Pittsburgh, Pittsburgh, PA, USA; 9University Hospital Joan XXIII,
Tarragona, Spain
Critical Care 2007, 11(Suppl 2):P506 (doi: 10.1186/cc5666) H Wunsch1, D Harrison2, O Collange3, N de Keizer4, R Fowler5,
E Hoste6, A Kersten7, W Linde-Zwirble8, A Sandiumenge9, D
Angus8, K Rowan2 Results Sixty-two studies involving data from 51 countries were
identified. Eight countries contributed data to ≥10 studies during
this time period: the USA (26 studies), France (18), the United
Kingdom (14), Canada (13), Belgium (12), Germany (10), The
Netherlands (10) and Spain (10). Relevant data on baseline
hospital and critical care resources for the eight countries
identified are presented in Figure 1 (data from Canada not
available). Adult ICU beds ranged from 3.3/100,000 population in
the United Kingdom to 24.6 in Germany, and represented a range
of 1.4% of all acute care hospital beds in the United Kingdom to
11.0% of all beds in the USA. 1Columbia University, New York, USA; 2ICNARC, London, UK;
3Strasbourg University Hospital, Strasbourg, France; 4University of
Amsterdam, The Netherlands; 5Sunnybrook Health Sciences
Center, Toronto, Canada; 6Ghent University Hospital, Ghent,
Belgium; 7University Hospital Aachen, Germany; 8University of
Pittsburgh, Pittsburgh, PA, USA; 9University Hospital Joan XXIII,
Tarragona, Spain
Critical Care 2007, 11(Suppl 2):P506 (doi: 10.1186/cc5666) Introduction Critical care research involves data from many
countries, but critical care resources in these countries are
unknown. We hypothesized that there are large differences in
critical care resources between countries. Conclusions Many countries contribute substantially to critical
care research. However, the underlying critical care resources vary
dramatically among these countries. P504 Two pediatric intensive care residents of
each service filled a standard protocol searching for: demographic
data, mode of death (full reanimation, nonreanimation orders or
withdrawn treatment) and medical management during the last 48
hours of life. Student’s t test, analysis of variance, chi-square test
and relative risk were used for comparing the data. Results There were 561 deaths, 36 being excluded that died with
less than 24 hours, 61 with brain death and 36 missing charts. Full
cardiopulmonary reanimation was offered to 56.5%, with
differences between the northeast and southeast regions (P <
0.001). Higher age (P = 0.02) and long length of PICU stay were
associated with nonreanimation orders. The plan for LSL was
recorded in a clear manner in just 52.7%. No respiratory support
was observed in 14 dying children. For 66% patients with do-not-
resuscitate orders the inotrope drugs were maintained or
increased in the last 48 hours. Conclusion
There are deficiencies and disparities in the
understandings of physicians and nurses on the recognition and
management of end-of-life in the ICU. Conclusions The incidence of LSV has increased among the
Brazilian PICUs with a difference between the regions. The
nonreanimation order is still the most common practice with scarce
initiative for withdrawn life support. S200 P506 Figure 1 (abstract P506)
Baseline critical care resources in eight countries. *Extrapolated from survey data, not full national data. Figure 1 (abstract P506) S201
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DRIVERS OF SUSTAINABILITY OF AGRICULTURAL COOPERATIVES IN KENYA: A CASE OF MACHAKOS COUNTY
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The strategic journal of business & change management
| 2,016
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| 12,506
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IVERS OF SUSTAINABILITY OF AGRICULTURAL COOPERATIVES IN KENYA: A CASE OF MACHAKOS COUNT IVERS OF SUSTAINABILITY OF AGRICULTURAL COOPERATIVES IN KENYA: A CASE OF MACHAKOS COUNT DRIVERS OF SUSTAINABILITY OF AGRICULTURAL COOPERATIVES IN KENYA: A CASE OF MACHAKOS COUNTY DRIVERS OF SUSTAINABILITY OF AGRICULTURAL COOPERATIVES IN KENYA: A CASE OF MACHAKOS COUNTY 1* Elizabeth Muange Kasungwa, 2* Dr. Makori Moronge 1* Student, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Kenya
2* Lecturer, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Kenya
Accepted May 3, 2016 1* Student, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Kenya
2* Lecturer, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Kenya Key Words: Sustainability, Agricultural Cooperatives, Managerial skills, Stakeholder Participation, Access to Finance,
Competitive Environment ELIZABETH MUANGE KASUNGWA, DR. MAKORI MORONGE Vol. 3, Iss. 2 (13), pp 271-295, May 3, 2016, www.strategicjournals.com, ©strategic Journals ABSTRACT Kenya has a long history of cooperative development and is recognized by the government to be a major contributor
to national development, as they are found in almost all sectors of the economy. The Kenya’s population participates
directly or indirectly in cooperative-based enterprises. According to the government of Kenya, it is estimated that 80
per cent of Kenya’s population derives their income either directly or indirectly through cooperative activities. Although significant progress has been made in the establishment of agricultural cooperatives, sustainability is a
major challenge for majority of these cooperatives. The performance and sustainability of these cooperatives in Kenya,
have been debatable, since the number of cooperatives becoming dormant (have actually closed down) is increasing
over time. This study sought to establish the determinants of sustainability of agricultural cooperatives in Kenya. The
specific objectives of the study were to examine how managerial skills, access to finance, stakeholder involvement and
competitive environment affect sustainability of agricultural cooperatives in Kenya. The study adopted a descriptive
design and the target population was 750 staff (senior and middle level management) of agricultural cooperatives
drawn from different sub-counties in Machakos County. The sample size for the study was 80 respondents. A stratified
sampling technique was carried out by involving all the targeted respondents and primary data was collected through
the use of questionnaires. The secondary data was obtained from published documents such as journals, periodicals,
magazines and reports to supplement the primary data. A pilot study was conducted for the data collection
instrument. The data was with help of SPSS version 21 and Excel. The study adopted a correlation and regression
analysis at 5% level of significance to determine strength and direction of the relationship of the variables under study. The regression analysis showed that managerial skills had the strongest positive (Pearson correlation coefficient
=.875) influence on sustainability of agricultural cooperatives. In addition, access to finance, competitive environment
and stakeholder involvement were positively correlated to sustainability of agricultural cooperatives with Pearson
correlation coefficient of .581, .690 and .806 with p-values of .009<0.05, .008<0.05 and .006<0.05 respectively. The
study established that managerial skills were the most significant factor. The study recommends for similar studies to
be undertaken in other agricultural organizations in Kenya for generalization of the findings of this study. Background of the Study The formal definition of a co-operative is ‘an
autonomous
association
of
persons
united
voluntarily to meet their common economic, social,
and cultural needs and aspirations through a jointly
owned and democratically-controlled enterprise’. The ILO (2010, 2014) and UN (2009), among other
organizations, have recognized that co-operatives in
developing countries can play an important role in
reducing poverty and improving wellbeing. The ILO
and the International Co-operative Alliance (ICA),
which federates nearly one billion cooperative
members worldwide, have also outlined how co-
operatives can contribute to the SDGs (ILO and ICA,
2014). With their particular values (self-help; self-
responsibility;
democracy;
equality;
equity;
solidarity) and principles and mode of governance
(voluntary and open membership; democratic
member control; member economic participation;
autonomy and independence; education, training
and information; co-operation among cooperatives;
concern for the community), co-operatives have
been seen as having considerable potential for
promoting economically and socially inclusive
development. ABSTRACT - 272 - government interference and failure (Develtere,
Pollet, &Wanyama, 2008) and yet, in more recent
times, have been able to grow in numbers while
serving the poor communities in the region. It has
been argued that the advent of liberalisation in the
1990s in the African context has enabled
agricultural co-operatives to develop as genuine
member-controlled
and
business-oriented
organisations which in turn have improved the
wellbeing of vulnerable people (Wanyama, 2013). However, agricultural co-operatives in the African
continent have shown a mixed-picture in terms of
performance
and
sustainability
(Francesconi&
Ruben, 2008; Francesconi&Wouterse, 2011). While
there are success stories, not all agricultural co-
operative endeavours have been sustainable but
those that have can provide key insights for co-
operative resilience Cooperatives The first agricultural cooperatives were created in
Europe in the seventeenth century in the Military
Frontier, where the wives and children of the
border
guards
lived
together
in
organized
agricultural cooperatives next to a funfair and a
public bath. The first civil agricultural cooperatives
were created also in Europe in the second half of
the nineteenth century. They spread later to North
America and the other continents. They have
become
one
of
the
tools
of
agricultural
development in emerging countries. Farmers also
cooperated to form mutual farm insurance
societies. Also related are rural credit unions. They
were created in the same periods, with the initial
purpose of offering farm loans. Some became
universal banks such as CréditAgricole or Rabobank. (Birchall, 2004) In recent decades agricultural co-operatives have
been rediscovered as organizations with the
potential to foster socio-economic development
and to reduce poverty (Bibby& Shaw, 2005; Birchall,
2003, 2004; FAO, 2012; Mu¨nkner, 2012; UN, 2011;
Vicari& De Muro, 2012). In the current economic
and financial climate there is a renaissance of co-
operatives, national and international organisations
are concerned with understanding the extent to
which cooperatives in developing countries have
been able to cope with economic and political
crises. Local Perspective of Sustainability of Agricultural
Cooperatives There is special interest in Africa where these
organisations endured decades of mismanagement, Kenya
has
a
long
history
of
cooperative
development that has been characterized by strong
growth, thus making a significant contribution to
the overall economy. (Ministry of cooperative
development & marketing, 2008) Cooperatives are
recognized by the government to be a major
contributor
to
national
development,
as
cooperatives are found in almost all sectors of the
economy. With the total population of Kenya at
approximately 37.2 million (Republic of Kenya,
2008a: 13), it is estimated that 63 per cent of
Kenya’s population participate directly or indirectly
in cooperative-based enterprises (GoK, 2008). debatable, since the number of cooperatives
becoming dormant (have actually closed down) is
increasing over time (GoK, 2013). In addition, a survey conducted by the Ministry of
Cooperative Development and Marketing reported
that from a sample of 220 cooperatives only 3.63%
were
considered
to
be
sustainable,
35%
cooperatives had an average sustainability score
and 78% were considered not sustainable. Cooperatives The
cooperatives scores were based on 3 sets of criteria;
the existence of a business plan (50%), the degree
of representation (20%) and management (30%)
(GoK, 2012).The poor sustainability of agricultural
cooperatives in Kenya has been attributed to poor
leadership, lack of managerial skills, stakeholder
involvement and competitive environment (RoK,
2012; WOCCU, 2010). Munkner, 2015; Birchall,
2011; Mazzrol et al., 2011).It is on this premise that
this study seeks to establish the drivers of
sustainability of agricultural cooperatives in Kenya
specifically Machakos county. Could managerial
skills, stakeholder involvement, access to finance
and competitive environment be drivers of
sustainability of agricultural cooperatives in Kenya? This study sought to explore more. The movement is supposed to play an important
role in wealth creation, food security and
employment generation and hence participate in
poverty alleviation. To date, there are over 11,200
registered cooperative societies country-wide. The
membership is over 6.1million and has mobilized
domestic savings estimated at over Kshs. 125
billion. The cooperatives have employed over
300,000 people, besides providing opportunities for
self-employment. Indeed, a significant number of
Kenyans, approximately 63% draw their livelihood
either directly or indirectly from cooperative-based
enterprises (Republic of Kenya 2007; International
Monetary Fund 2007; The Kenya High Commission
in the United Kingdom 2007). Statement of the Problem Cooperatives in Kenya contribute about 47% of the
GDP and 34% of the national savings; empirical
evidence indicates further that some 78% of the
Kenyan people derive their livelihood either directly
or indirectly from Cooperatives. During the year
2011, cooperatives recorded a turnover of about
Ksh.50 Billion (WOCCU, 2010). From this data, we
conclude that cooperatives have great potential as
poverty economic pillars. The sustainability of these
agricultural cooperatives in Kenya, have been General objective The main purpose of the study was to establish the
determinants of
sustainability
of
agricultural
cooperatives in Kenya. LITERATURE REVIEW This chapter reviews relevant literature on
determinants of
sustainability
of
agricultural
cooperatives in Kenya. Theoretical Framework This theory was proposed by Aaron Sapiro and E.G
Nourse in the 1930s. Strength of the Sapiro and
Nourse ideas is in specifying objectives and
organizational structures for cooperatives that
address the concerns of agricultural producers in a
context of achieving a public interest role. In both
schools of thought, cooperatives provide some
balancing of market power, whether affecting the
terms of trade for an industry-wide commodity, the
Sapiro School, or in stimulating competition in
specific markets, the Nourse School. In their
conceptions, cooperatives capture a larger share of
industry
earnings
for the membership,
but
additionally, contribute to market or industry
efficiency. In other words, their philosophies of
cooperation were grounded in a public interest
perspective, as legislatively recognized in the
Capper-Volstead Act of 1922. This section examines relevant theories to the study
variables. According to Kombo and Tromp (2009), a
theoretical framework is a collection of interrelated
ideas based on theories. Specific objectives. The specific objectives of the study were to The specific objectives of the study were to i. Find out how managerial skills influence
sustainability of agricultural cooperatives in
Kenya. ii. Determine how stakeholder involvements affect
sustainability of agricultural cooperatives in
Kenya. - 274 - iii. Examine how access to finance influence
sustainability of agricultural cooperatives in
Kenya. philosophy. (Chaves and Sajardo, 2004) This theory
supports the notion of an enabling environment
and proper leadership that will foster sustainability
in the long run. If people are motivated and given
the impetus to apply themselves through creation
of fair policies and equitable environment, then
even their attitude to work will change and a new
era of flourishing social and economic movements
will be witnessed. The theory supports the
managerial skills on sustainability of agricultural
cooperatives. iv. Establish how competitive environment affect
sustainability of agricultural cooperatives in
Kenya. Theory of the co-operative movement It was proposed by Robert Owen in 1817. Robert
Owen has been called the 'father of English
Socialism'. He was the founder of the Co-operative
movement and believed in worker control although
he was a high capitalist himself. He was the product
of self-help and a very practical man who
concentrated on the 'means to the end'. The theory
proposed that if the working man ever was to
achieve equality, then the man must change first -
in attitude. Also, the working man had to know of,
believe in and be equipped to fight for the cause. This is very much the self-help ethic. (Chambers and
Conway, 2006) Sapiro and Nourse made major contributions to the
practical
problems
of
achieving
member
commitment and cohesive organizations. Yet,
subsequent cooperative thought moved further into
examining and modeling key facets of internal
organization, developing a more coherent theory of
agricultural cooperation. Over the years since
Sapiro and Nourse, there has been some shift in
emphasis from concern with the external effects of Owen became convinced that the advancement of
humankind could be furthered by the improvement
of every individual's personal environment. He
reasoned that since character was molded by
circumstances, then improved circumstances would
lead to goodness. The environment at New Lanark,
where he tried out his ideas, reflected this - 275 - the way they respond to their members needs using
the capital at their disposal. The resource-based
view is grounded in the perspective that a firm's
internal environment, in terms of its resources and
capabilities, is more critical to the determination of
strategic action than is the external environment. "Instead of focusing on the accumulation of
resources necessary to implement the strategy
dictated by conditions and constraints in the
external environment, the resource-based view
suggests that a firm's unique resources and
capabilities provide the basis for a strategy. The
business strategy chosen should allow firms to best
exploit
its
core
competencies
relative
to
opportunities in the external environment" (Barney,
2002).The
theory
supports
the
competitive
environment
on
sustainability
of
agricultural
cooperatives. organization to the internal or micro aspects of
organizing and sustaining cooperation (Chaves and
Sajardo, 2004). This theory espouses sound
leadership in the cooperative movement and
connects proper leadership and sound governance
to a satisfied cooperative membership, proper
financial management and a thriving cooperative
movement. The theory supports the access to
finance and managerial skills on sustainability of
agricultural cooperatives. Cooperatives Dynamic Theory According to Nzuve (2009), cooperative and mutual
organizational forms arise for reasons that include
contracting problems between parties. Economic
literature
suggests
a
variety
of
allocative
inefficiencies implied by these forms that largely
have their origins in poor investment decisions. It is
demonstrated that a multi-period model and the
supplier and cooperative valuations it implies the
essentials for understanding the sources of
inefficiency and solutions to them. Using the case of
supplier
co-operative
shows
that
economic
inefficiency arises because of the common over-
supply of input induced by suppliers responding to
average, rather than marginal, revenue, and that
investment is actually efficient given the supply of
input. The presence of unknown capital is an
important source of over-supply. We show that if
the cooperative's shares are priced at the present
value of expected dividends and supplier entry and
exit decisions are taken solely on the basis of
profitability of membership then there is no
inefficiency and we describe a functioning example. Finally, our valuations show that that there is no
"time horizon" investment problem, at least from
an industry perspective (Chandler, 1962). Conceptual Framework Mugenda, (2008) defines conceptual framework as
a concise description of the phenomenon under
study accompanied by a graphical or visual
depiction of the major variables of the study. Kombo and Tromp, (2009) defines it as a set of
broad ideas and principles taken from relevant
fields of inquiry and used to structure a subsequent
presentation. It is a research tool intended to assist
a
researcher
to
develop
awareness
and
understanding of the situation under scrutiny and
to communicate this. Bell, (2010) describes it as a
diagrammatical representation that shows the
relationship between dependent and independent
variables. A conceptual framework assists a
researcher to organize their thinking and complete
an investigation successfully. It also explains the
relationship among interlinked concepts and
explains the possible connection between the
variables (Kombo & Tromp, 2009).The conceptual
framework comprises of the independent variables
also known as the exploratory variables and which
are the presumed cause of changes in the
dependent variable and the dependent variable also
called the criterion or predictor variable which the
researcher wishes to explain (Kothari, 2004). The
following framework depicts the relationship
between the independent and dependent variables
based on four independent variables and a
dependent
variable
as
represented
diagrammatically in figure 2.1. In this study,
sustainability
of
agricultural
cooperatives
is
dependent
on
managerial
skills,
member
participation, access to finance and government
policy. Co-operative Commonwealth Theory Co-operative Commonwealth Theory
In some Co-operative economics literature, the aim
is
the
achievement
of
a
Co-operative
Commonwealth; a society based on cooperative
and socialist principles. Co-operative economists -
Federalist, Individualist, and otherwise - have
presented the extension of their economic model to
its natural limits as a goal. This ideal was widely
supported in early-twentieth century U.S. and
Canadian leftist circles. This ideal, and the language
behind it, were central to the formation of the Co-
operative Commonwealth Federation in 1935,
which became Canada's largest left-wing political
party, and continues to this day as the New
Democratic Party. They were also important to the
economic principles of the Farmer-Labor Party of
the United States, particularly in the FLP's
Minnesota affiliate, where advocacy for a Co-
operative Commonwealth formed the central
theme of the Party's platform from 1934, until the
Minnesota FLP merged with the state Democratic
Party to form the Democratic–Farmer–Labor Party
in 1944 (Eias, 2010) Saccos in Kenya have proved to be dynamic in the
way they are formed Saccos exist in all spheres of
society from the urban salaried workers Saccos to
the rural farmers Saccos. All these are dynamic in - 276 - In Kenya co-operatives have been formed as social
organizations that are formed by people with a
common goal of uplifting their financial well-being
.In Kenya many co-operative societies have had
their influence in Kenya’s political scene as co-
operatives specifically cooperatives control a large
chunk of the National savings as well as over 15
million Kenyans who are members. Some giant
cooperatives mainly in Kenya have seen some of
their officials be elected as members of parliament
and have gone ahead to hold senior positions in
Government .a case in point is the former minister
of Co-operatives Mr Njeru Ndwiga who was a
former chairman of Parliament cooperatives have
also grown to become a sector of the economy to
an extent where the Government has formed the
Ministry
of
Co-operative
development
to
specifically formulate policies to regulate and
supervise them. and management of cooperatives as well as
influence of other services offered by cooperatives. The theory supports the managerial skills on
sustainability of agricultural cooperatives. Scientific Theory of Management Frederick Winslow Taylor developed the scientific
theory of management which he published in the
journal of the American Society of Mechanical
Engineers
in
1895. Scientific
Management
focuseson the efficient accomplishment of work
tasks with an attitude of work smarter, not harder. Taylor meant his methods to be both a win for
management in increasing productivity and a win
for laborers making their jobs easier. But Taylor as a
mechanical engineer focused on the physical
aspects of the job and the formal organization of
the shop. Scientific management was the seed bed
of the Efficiency Movement in the United States. His
consideration of motivation was primarily limited to
the scientific determination of fair financial
incentives for worker performance (Wren, 2005). This study focuses on drivers that influence
sustainability of agricultural Cooperatives. Such
factors include management skills that are geared
to improve productivity of cooperatives, marketing - 277 - Independent variable
Dependent variable
Figure 1 Conceptual Framework
Managerial skills
Technical
Conceptual
Human
Competitive
Environment
Product
Differentiation
Disadvantage
Edge
Fair Play
Access to Finance
Credit facility
Collateral
Cost of funds
Stakeholder
Participation
Commitment
Patronage
Loyalty
Sustainability of
Agricultural
Cooperatives
Years of operation
Number of
branches opened
Increase of profits private business organization that is jointly owned
and controlled by its members (IRG, 2005). For
the
smooth operation,
it
needs
good
management to control its daily activities through
the management committee. In a cooperative, a
management committee involves a process of
reaching consensus and then following through
with
the
group’s
decision. Management
is
therefore, crucial in the implementation of policies
and activities which continuously enhance the
operations of the cooperatives. Cooperatives being
a democratic organization are likely to experience
management
problems
which
can
lead
to
organizational failure when the cooperative fails to
adopt the most efficient policies for their members. Fulton (2001) claims that management problems
occur when cooperatives fail to elect an efficient
management
committee. The
management
committee is the highest elected executive
institution in a cooperative enterprise. It approves
all the activities that need to be carried out by the
cooperatives. Committee members are not paid for
their services and the time they devote to meetings
is limited. Figure 1 Conceptual Framework Figure 1 Conceptual Framework Scientific Theory of Management Every member of the cooperative may
present matters (personal problems, cooperative
problems or public affairs) for discussion, but only a
limited number of subjects can be considered in the
twice weekly meetings of the management
committee. Sustainability of
Agricultural
Cooperatives
Years of operation
Number of
branches opened
Increase of profits Independent variable Managerial Skills According
to
Hambrick
and
Mason
(1984)
management refers to the process of planning,
organizing, leading and controlling the efforts of
organization members and of using all other
organizational
resources
to
achieve
stated
organizational
goals. On
the
other
hand,
Veerakumaran (2006), sees “management as the
driving force in cooperative endeavours that assist
in achieving compromises among participants,
taking into account both the interests and the
needs of the members, which are often short-term
interests as well as the long-term commercial goals
(sustainability and reducing risks) of the cooperative
enterprise”. An AC is an organization that needs
management like other entities. On its own it is a Cooperatives are democratic organizations and are
likely to experience management problems that
may lead to organizational failure. Cooperatives fail
to adopt the most efficient policies for their
members. It has already been stated that,
management problems occur when cooperatives
fail to elect an efficient management committee
with relevant managerial skills (Fulton, 2001). They
encounter various managerial problems that
include poor financial management, poor credit
control (that leads to unpredictable cash flow) and - 278 - reciprocity, which is particularly important in
monitoring and sanctioning free riding behavior
(Pelling& High, 2005). In order to work equitably
and conform to co-operative values and principles,
some pre-conditions are required, according to
Munkner (2012) these include: knowledge, skills
and investment in members’ education. Informed
and skilled members are more likely to understand
and be committed with the co-operative business. Smith, Puga, &MacPherson (2005) and Majurin
(2012) also argue that members that understand or
are familiar with the co-operative values are more
likely to promote the inclusion of, often marginal,
groups
such
as
women
and
youth
within
cooperatives enterprises. lack of marketing (resulting in unresponsive
attitudes to customer requirements), management
and members’ weaknesses, failure to delegate and
train cooperative members and resistance to
outside advice. A problem of corruption in Kenya’s
ACs management has also been reported. Some of
the cooperative management problems reported
besides corruption included illiteracy and lack of
management skills for the members and their
committees (Citation). Stakeholder Involvement The activities that encompass member participation
in a cooperative include attending meetings, serving
on committees, involvement in recruitment and
patronage
(Osterberg&Nilson,
2009). The
participation of members in governance of a
cooperative is what differentiates cooperative from
other businesses organizations. Participation is an
important indicator in developing members in
understanding and appreciating of the cooperative
(Gray, Karaenzle& USDA, 1998) Access to Finance Agricultural cooperative credit has long been
identified as a major input in the development of
the agricultural sector. Credit is viewed as more
than just another resource such as labor, land,
equipment and raw materials (Rahji, 2000). One of
the reasons for the decline in the contribution of
agriculture to the economy is lack of a formal
national credit policy and paucity of credit
institutions, which can assist farmers. Credit access
helps to expand farmland size and production. (Olagunju, 2000) affirmed that credit facilities as
well as the use of agricultural capital and labor
resources accelerate the adoption process and
expand the scale of production. The availability of
credit occupies a central place of development
strategies. (Jia, 2006). Credit is important in
fostering agricultural cooperative development. The
literature
suggests
that
a membership
participation inspired by cooperative values is
crucial for co-operative sustainability. A number of
writers
have
argued
that
co-operatives’
sustainability depends on members’ sense of
identity, commitment and cohesion (Birchall, 2011;
Mazzarol et al., 2011; Mu¨nkner, 2012). As
Munkner2015) notes: ‘co-operatives are good as
their members make them’. However membership
loyalty and commitment depend on cooperatives’
ability to meet members’ needs and demands. (Olagunju, 2000) affirmed that credit facilities as
well as the use of agricultural capital and labor
resources accelerate the adoption process and
expand the scale of production. The availability of
credit occupies a central place of development
strategies. (Jia, 2006). Credit is important in
fostering agricultural cooperative development. Government and donors spend billions of shillings
supporting
credit
activities
for
agricultural
cooperatives in low income countries. Most of
these activities are justified by the impact that loans
have on ultimate borrowers: credit demand filled,
additional crops produced, changes in modern
inputs use and borrowers’ increased income. This is
because in case of nil or poor return from Satisfied members are less likely to be free riders
(Birchall,
2012;
Munkner,
2012). Trust
and
reciprocity between members are also conducive to
loyalty, which is needed when co-operatives
experience financial instability (i.e. insufficient
market demand, low prices). The literature argues
that
trust
reinforces
norms
of
generalized - 279 - agriculture, farmers can use credit to restart. In
Kenya, there are both formal and informal credit
sectors, but there is a large interest rate difference. Access to Finance This has led to
banks giving unsecured loans unlike in the past
when collateral security was necessary. Cooperative
societies on the other hand have opened up their
lending by refinancing old loans and new innovative
loans on household equipment and furniture. This
competition has brought new innovations and
created opportunities to members to enhance their
well-being (Mudibo, 2009). According to Michael Porter five competitive forces
model, firms have to continually scan the internal
and external business environment so as to
maintain or increase their market share (Pearce and
Robinson 2009). This will determine the long run
profit attractiveness of the market or market
segment. The ability of the firm to sustain
competitive advantage in an intense rivalry market
segment is very important to that company. The
entrance of NGO, Micro-Finance Institutions and
the shift in focus among some commercial banks to
tap into the micro and small enterprise niche has
brought to bear for the SACCOs that there are more
niches in rural areas than just the agricultural
sector. In a bid to remain competitive, these rural
SACCOs are aligning themselves to serve a wider
range of clientele, including salaried groups –e.g. teachers,
civil
servants;
micro
and
small
entrepreneurs; institutions, all of who play a role in
rural
economies. Banks
and
micro-finance
Institution continue to compete with cooperative
societies for the same savings from the employees
(Mudibo, 2009). This competition is very intense
and as such, each has to come up with superior
products to attract more deposits. This has led to
banks giving unsecured loans unlike in the past
when collateral security was necessary. Cooperative
societies on the other hand have opened up their
lending by refinancing old loans and new innovative
loans on household equipment and furniture. This
competition has brought new innovations and
created opportunities to members to enhance their
well-being (Mudibo, 2009). Sustainability of Agricultural Cooperatives Competitive Environment Competition is the ability of the firm to increase or
maintain its market share of its products or services,
which is always under threat by other firms in the
same industry. Competition is important because
good competition brings about quality goods and
services, innovation and efficiency in provision of
goods and services. The nature and degree of
competition in an industry hinge on the five forces
model, the threat of new entrants, the bargaining
power of customers, the bargaining power of
suppliers and the threat of substitute products or
services. (Pearce and Robinson 2009) argues that Access to Finance for company to deal with these forces and grow
despite their effects, it must understand how they
work in its industry and how they affect the
company in its particular situation. On average, credit to agricultural cooperatives is
estimated at less than 10% of the total credit
provided through the domestic financial system. (Nyangito, et al., 2004) Credit access is not only
affected by interest rate but by all characteristics of
credit. This study attempts to find out how all credit
factors in totality affect agricultural cooperatives
access to credit. Before market liberalization in
Kenya, formal agricultural credit was provided at
subsidized rates through the Agricultural Finance
Corporation
(AFC). However,
this
parastatal
experienced difficulties in recovering loan advances
and had to stop lending at subsidized rates. Even
then AFC lending rates have remained lower than
commercial rates and are more stable. Although
banks are legally required to lend between 17% and
20% of their loan portfolio to the agriculture sector,
the local banking system has been conservative in
lending to agriculture. This is probably owing to
risks in agricultural production. The situation has
been worsened by liberalization of interest rates
and lending policies. These have made it difficult for
small scale farmers to access credit. According to Michael Porter five competitive forces
model, firms have to continually scan the internal
and external business environment so as to
maintain or increase their market share (Pearce and
Robinson 2009). This will determine the long run
profit attractiveness of the market or market
segment. The ability of the firm to sustain
competitive advantage in an intense rivalry market
segment is very important to that company. The
entrance of NGO, Micro-Finance Institutions and
the shift in focus among some commercial banks to
tap into the micro and small enterprise niche has
brought to bear for the SACCOs that there are more
niches in rural areas than just the agricultural
sector. In a bid to remain competitive, these rural
SACCOs are aligning themselves to serve a wider
range of clientele, including salaried groups –e.g. teachers,
civil
servants;
micro
and
small
entrepreneurs; institutions, all of who play a role in
rural
economies. Banks
and
micro-finance
Institution continue to compete with cooperative
societies for the same savings from the employees
(Mudibo, 2009). This competition is very intense
and as such, each has to come up with superior
products to attract more deposits. Sustainability of Agricultural Cooperatives The word sustainability is derived from the Latin
sustinere(sus, up; tenere, to hold) (Atkinson, Dietz - 280 - &Neumayer, 2007). It is the long-term continuity of
an enterprise or keeping the enterprise going over
time (Bookchin, 2007). Sustainability is a call to
action, a task in progress or “journey” and therefore
a political process. It can also refer to a future
intention; “sustainable business” is not necessarily a
current situation but a goal for the future, a
prediction (Ngugi, 2012). It has also been described
as a “dialogue of values” that defies consensual
definition (Blackburn, 2007). product quality; and for competing with other
players in the market Several studies have revealed that the effect of un-
democratic processes on member’s participation. Osterberg & Nilson (2009) found that there was
significantly higher member disloyalty, when
members were dissatisfied with their cooperative’s
management. Borgen (2001) reported that a
member is seen to be more loyal to decisions in
which s/he has participated actively, rather than the
decisions in which were forced on him/ her. Osterrberg and Nilson (2009) observed that
members considered democratic control to be more
crucial and further argued that this indicates that
members regard the cooperative as a social
institution, as much as an economic one. This shows
the importance of having a well-functioning
democracy within the cooperative governance. The
more the members participate in their cooperative,
the more they will be committed to their
cooperative. Sustainability problems experienced by cooperative
management in the whole world are almost the
same. These problems result in incompetent and
poor service delivery (Chaddad and Cook, 2000). Even cooperatives which are doing well are still
facing many problems. “These problems include,
among others poor management, lack of capital
resources,
inadequate
training,
lack
of
communication and participation among members,
unclear and inadequate government policies on the
development of agricultural cooperatives and weak
linkages among the activities of the production,
credit and marketing cooperatives (Prakash, 2003)”. A number of studies have pointed out that there is
a relationship between member commitment and
sustainability of a cooperative. According to Fulton
et al (2001), noted that member commitment is
linked to the cooperatives ability to develop a
reputation, as an effective agent for the members. Members should be able to see the cooperative as
addressing their needs. Fulton and Giannaks (2001)
concluded that cooperatives must be increasingly
aware of these feedback effects and manage them
accordingly. Sustainability of Agricultural Cooperatives The authors noted that success of
cooperative as being all effective agent for
members is likely to result to increased member
commitment. Empirical review According to Nkhoma (2011), several studies have
shown that lack of adequate management skills in
management has contributed to cooperatives
failure. Keeling, Carter and Sexton (2009) conducted
a study of the Rice Growers Association in California
and found out that the closure of this organization
was primarily due to lack of board oversight and
education, coupled with ineffective management
and passive membership. Nyoro and Ngugi (2007)
identified that successful cooperatives had staff and
management committee, with relatively higher
qualifications
than
unsuccessful
cooperatives. Management with required skills will be able to
strategize on business volume, type of product and Studies such as those of Bataille-Chedotel and
Huntzinger (2004), which analyses the typology of
co-operative managers according to their origin,
training, length of stay in the post and relation with - 281 - Kothari (2004) observed that research design is a
blue print which facilitates the smooth sailing of the
various research operations, thereby making
research as efficient as possible hence yielding
maximum information with minimal expenditure of
effort, time and money. This study used descriptive
research design. This design refers to a set of
methods and procedures that describe variables. social value creation, or Cornforth (2006), which
establishes different models of manager, centre on
the power of managers. Along the same lines, Spear
(2004) points out that compared to managers in
capitalist companies, co-operative managers enjoy
positions of far greater power and much wider
margins
of
discretion,
unfettered
by
the
membership, as the attendance rates at the Annual
General Assemblies of members tend to decrease
with the age and size of the organization. Again,
Akella and Greenbaum (1988) highlight the co-
operatives’ greater permissiveness towards expense
preference behavior, in other words, the members
have a high tolerance of management power. This
behavior is accentuated with a diffuse membership
(diffused ownership), which tends to trust in
government regulation and is not prepared to bear
the cost of effective control. These tensions have an
impact on the co-operatives and alter the above-
mentioned balances, resulting in shortcomings in
co-operative governance Target Population Kothari (2004) described population as the entire
group of individuals or items under consideration in
any field of inquiry and have a common attribute. The target population the study was 750 staff
(senior
and
middle
level
management)
of
agricultural cooperatives in Machakos County. Sample and Sampling Technique A sample size is a set of observations drawn from a
population by a defined procedure (Mugenda,
2008).The manual calculation method to be used to
arrive at the sample size using the following
formula: Sample Size = n / [1 + (n/population)] In
which n = Z * Z [P (1-P)/ (D*D)]. Where, P = True
proportion of factor in the population, or the
expected frequency value D = Maximum difference
between the sample mean and the population
mean Or Expected Frequency Value minus (-) Worst
Acceptable Value Z = Area under normal curve
corresponding to the desired confidence level For
our study therefore our sample will be: n/ [1 + (n)
(E) 2 where n is the total population (750), E is the
level of significance. 750/ [1 + (750) (0.05x0.05) =
110. Our sample size therefore was 110. Gabre-Mahdhin (2006) argued that information
asymmetry and opportunistic behavior, which act as
determinants of transaction costs related to
contract enforcement, leads to enforcement related
costs. Fafchamps and Gabre-Mahdhin (2001), in an
extentnsive survey of traders in Malawi and Benin,
found incidences of contract non-perfomance, by
up to 41% in Malawi. Coutre and Onumah (2002),
also identified that lack of supportive framework
and disabling policies are amongst the issues that
affect development of market institutions such as
agricultural cooperatives. Research Instruments& Data Collection Procedure This chapter specifies the nature of the research
design and the population studied. The study relied mainly on primary data. The
researcher used questionnaire as the research
instrument. The study utilized questionnaire that
was developed for generating information on key Research Design Pilot Study According to Bordens& Abbott (2008), pilot study is
as a small-scale version of the study used to
establish procedures, materials and parameters to
be used in the full study. Pilot study was conducted
in determining if there were flaws, limitations, or
other weaknesses within the data collection
instrument to make the necessary revisions prior to
the implementation of the study. This study took
1% of the population that was not part of the
sample for pilot test. A pilot study was undertaken
on at least 27 respondents and the findings of the
pilot study were be included in the actual study Work Experience The study sought to establish how long the
respondents had been in the respective agricultural
cooperatives, this was to ascertain to what extent Research Design - 282 - From the data collected, out of the 110
questionnaires administered, 80 questionnaires
were fully completed and returned making a
response percent of 72.27%. This percentage
concurs with Mugenda and Mugenda (2003) who
argues that for generalization a response rate of
50% is adequate for analysis and reporting, 60% is
good and a response rate of 70% and over is
excellent, thus 72.27% was adequate for analysis. variables of interest from the targeted respondents
in the study. Secondary data was obtained from
literature sources or data collected by other people
for some other purposes. Age Distribution The study went further to establish the distribution
of the respondents’ age. The findings were as
indicated in Figure 4.3. From the findings, majority
(45%) indicated that they ranged between 41-50
years, followed by those who indicated that they
are 51 and above years at 35% with few (15%) and
(5%) and indicating that they were 31-40 years and
20-30 years respectively. Level of Education The respondents were requested to indicate their
highest level of academic qualifications. The study
established that majority (45%) indicated that they
had university first degree, followed by those who
indicated that they had diploma at (35%), certificate
with 3%, few (15%) indicating that they had
master’s degree and (5%) doctorate qualification
respectively and this implies that respondents were
well educated and that they were in a position to
respond to research questions with ease. Data Analysis and Presentations The
study
collected
both
qualitative
and
quantitative data. Qualitative data was applicable
since meanings was based on expressions through
words and analysis was conducted through the use
of
content
analysis. Quantitative
data
was
applicable since meanings derived from numbers
and analysis conducted through the use of diagrams
and statistics. Gender Distribution The research went further to establish the gender
of the respondents The findings as indicated a
simple majority (53%) were male respondents with
(47%) being females respondents. DATA ANALYSIS, PRESENTATION AND DISCUSSION This chapter presents the results of the study, data
analysis and discussion. The current study sought to
establish the drivers of sustainability of agricultural
cooperatives in Kenya. The specific variables of the
study
were:
managerial
skills,
stakeholder
involvement, access to finance and competitive
environment. Response Rate - 283 - sustainability their responses could be relied upon to make
conclusions for the study based on experience. The
findings as indicated a simple majority (40%) of the
respondents indicated that they had been in the
agricultural cooperatives for a period ranging from
1-10 years followed by those who indicated that
they had been in the agricultural cooperatives for a
period of 10-20 years at 30%, (20%) indicating that
they had less than one year and with only few (10%)
indicating that they had been in agricultural
cooperatives for a period more than 20 years. agricultural of about cooperativesprograms often empowers them and
promotes meaningful participation by diverse
stakeholder groups which avail to the sustainability
of agricultural cooperativessufficient and relevant
information useful for the exercise . Competitive Environment The research requested the respondents to indicate
whether
product
differentiation
influenced
performance of projects established which could
affect sustainability of agricultural cooperatives. From the study results in 66% of the respondents
stated that it increased the number of the proposed
projects, 64% of the respondents stated that it
increased
the
number
of
successfully
completed/delivered project and 68% posited that
it led to sustainability of established projects. This
can be deduced that product differentiation
influence performance of projects established
which
affect
sustainability
of
agricultural
cooperatives. Managerial Skills The research sought to find out whether technical
skills did increase influence the years of operation
of the cooperatives. Respondents stated that it
increased
the
number
of
the
completed
cooperatives projects, 70% stated that it increases
the number of number of people served with
cooperatives activities, 65% of the respondents
stated that it led to sustainability of established
cooperatives activities. This implies that technical
skills are important to increase number of years of
operation of the cooperatives. This corroborates
with the study findings of Meredith & Mantel Jr
(2011) who posited that leadership tasks and
activities
is
focusing
responsibility
for
goal
attainment. Stakeholder Involvement The study sought to find out on the key
stakeholders involved in management of the
cooperatives .The study results showed that
majority
of
the
respondents
stated
that
beneficiaries, 25% stated implementing staff, 44%
indicated the donors and 34% of the respondents
stated the government. This implies that there was
no clear key stakeholders involved for effective
monitoring
sustainability
of
agricultural
cooperatives The study results are in agreement
with literature review by Otieno (2008) who
observed that to involve stakeholders in discussions Access to Finance Based on whether cost of capital did affect
sustainability of the cooperatives, 78% of the
respondents stated that it increased the number of
the years of operation, 60% of the respondents
stated that increased the number of branches
opened and 70% of the respondents stated that it
increased the net value of the organization. Similarly Lindell & Hansson (2012) noted that the
cost of finance is very high and collateral
requirements are hard to fulfill thus affecting
sustainability of the agricultural cooperatives. Sustainability of Agricultural Cooperatives The respondents were kindly requested to indicate
number of years of operation of the cooperative. The study established that majority of the - 284 - respondents(75%) indicated less than 10 years of
operation, 10% of the respondents stated between
11 to 15 years, 5% posited 16 to 20 years, 7% of the
respondents stated 21 to 25 years and 3% of the
respondents also stated over 25 years of operation. This infers that majority of the agricultural
cooperatives were not sustainable since their years
of operation were very few years since they were
established. determine the strength and the direction of the
relationship between dependent variable and the
independent variables The analysis of correlation showed that between
access to finance and sustainability of agricultural
cooperatives there is a positive coefficient 0.602,
with p-value of 0.011. It indicates that the result is
significant at α =5% and that if the access to finance
increases it will have a positive impact on
sustainability of agricultural cooperatives. The
correlation results between managerial skills and
sustainability of agricultural cooperatives also
indicates the same type of result where the
correlation coefficient is 0.872 and a p-value of
0.001 which significant at α = 5%. The results also
show that there is a positive association between
competitive environment and sustainability of
agricultural cooperatives where the correlation
coefficient is 0.754, with a p-value of 0.009. Further,
the result shows that there is a positive association
between stakeholder involvement and sustainability
of agricultural cooperatives where the correlation
coefficient is 0.790, with a p-value of 0.002. This
therefore infers that managerial skills contributed
most to sustainability of agricultural cooperatives
followed
by
stakeholder
involvement
in
sustainability of agricultural cooperatives, then
competitive environment while access to finance
had the least influence on sustainability of
agricultural cooperatives. The correlation matrix
implies that the independent variables are very
major determinants of sustainability of agricultural
cooperatives as shown by their strong positive
relationship
with
the
dependent
variable;
sustainability of agricultural cooperatives. Correlation Analysis The
coefficient of determination (R2) explains the extent
to which changes in the dependent variable can be
explained by the change in the independent
variables or the percentage of variation in the
dependent variable and the four independent
variables that were studied explain 80.80% of the
sustainability
of
agricultural
cooperatives
as
represented by the R2. This therefore means that
other factors not studied in this research contribute
19.20%
to
the
sustainability
of
agricultura
cooperatives. This implies that these variables are
very significant therefore need to be considered in
any effort to boost sustainability of agricultura
cooperatives in the study area. The study therefore Table 1: Correlation Coefficients Sustainability
of agricultural
cooperatives
Access to
finance
Managerial
skills
Stakeholder
Involvement
Competitive
Environment
Sustainability of
agricultural
cooperatives
R
1.000
Sig. (2-tailed)
. N
Access to finance
R
.602
1.000
Sig. (2-tailed)
.011
N
80
Managerial skills
R
.872
.908
1.000
Sig. (2-tailed)
.001
.065
N
80
80
Stakeholder
Involvement
R
.790
.142
.876
1.000
Sig. (2-tailed)
.002
.001
.004
N
80
80
80
Competitive
Environment
R
.754
.037
.046
.056
1.000
Sig. (2-tailed)
.009
.000
.001
.005
N
80
80
80
80
* Correlation is significant at the 0.05 level (2-tailed) * Correlation is significant at the 0.05 level (2-tailed) * Correlation is significant at the 0.05 level (2-tailed) coefficient of determination (R2) explains the extent
to which changes in the dependent variable can be
explained by the change in the independent
variables or the percentage of variation in the
dependent variable and the four independent
variables that were studied explain 80.80% of the
sustainability
of
agricultural
cooperatives
as
represented by the R2. This therefore means that
other factors not studied in this research contribute
19.20%
to
the
sustainability
of
agricultural
cooperatives. This implies that these variables are
very significant therefore need to be considered in
any effort to boost sustainability of agricultural
cooperatives in the study area. The study therefore Correlation Analysis Pearson correlation was used to measure the
degree of association between variables under
consideration i.e. independent variables and the
dependent
variables. Pearson
correlation
coefficients range from -1 to +1. Negative values
indicates negative correlation and positive values
indicates positive correlation where Pearson
coefficient <0.3 indicates weak correlation, Pearson
coefficient >0.3<0.5 indicates moderate correlation
and
Pearson
coefficient>0.5
indicates
strong
correlation. This statistic is called a correlation
coefficient(r) which indicates the relationship
between the two variables and the bigger the
correlation the stronger the coefficient between the
two variables being compared. The direction of the
relationship is also important in that if it is positive
(+) it means that there is a positive relationship
between the two variables and this means that
when one variable increases the other variable
increases or when one variable decreases the other
variable also decreases. A negative relationship (-)
means that as one variable decreases the other
variable increase and vice versa and hence an
inverse relationship. If there is no relationship the
coefficient is equal to zero. Pearson’s Product -
moment correlation coefficient was used to - 285 - Table 1: Correlation Coefficients
Sustainability
of agricultural
cooperatives
Access to
finance
Managerial
skills
Stakeholder
Involvement
Competitive
Environment
Sustainability of
agricultural
cooperatives
R
1.000
Sig. (2-tailed)
. N
Access to finance
R
.602
1.000
Sig. (2-tailed)
.011
N
80
Managerial skills
R
.872
.908
1.000
Sig. (2-tailed)
.001
.065
N
80
80
Stakeholder
Involvement
R
.790
.142
.876
1.000
Sig. (2-tailed)
.002
.001
.004
N
80
80
80
Competitive
Environment
R
.754
.037
.046
.056
1.000
Sig. (2-tailed)
.009
.000
.001
.005
N
80
80
80
80
* Correlation is significant at the 0.05 level (2-tailed)
Multiple Regression Analysis
In addition, the researcher conducted a multiple
regression analysis so as to test relationship among
variables (independent) on the sustainability of
agricultural cooperatives. The study applied the
statistical package for social sciences (SPSS V. 21) to
code, enter and compute the measurements of the
multiple regressions for the study. According to the
model summary Table 2, R is the correlation
coefficient which shows the relationship between
the indepednt variables and depedent variable. It is
notable that there extists strong positive
relationship between the indepedent variables and
depedent variable as shown by R value (0.899). Table 3: ANOVA NB: F-critical Value = 3.765; Predictors: (Constant): Managerial skills, Access to Finance, Competitive
environment and Stakeholder involvement. taking all other independent variables at zero, a unit
increase in access to finance will lead to a 0.587
increase
in
sustainability
of
agricultural
cooperatives.; a unit increase in managerial skills
will lead to a 0.875 increase in sustainability of
agricultural cooperatives, a unit increase in
stakeholder involvement will lead to .806 increase
in sustainability of agricultural cooperatives and a
unit increase in competitive environment will lead
to 0.690 increase in sustainability of agricultural
cooperatives. This infers that managerial skills
contributed most to sustainability of agricultural
cooperatives. At 5% level of significance, access to
finance had a 0.009 level of significance; managerial
skills showed a 0.001 level of significance,
stakeholder involvement showed a 0.006 level of
significance and competitive environment showed a
0.008 level of significance hence the most
significant factor was managerial skills. taking all other independent variables at zero, a unit
increase in access to finance will lead to a 0.587
increase
in
sustainability
of
agricultural
cooperatives.; a unit increase in managerial skills
will lead to a 0.875 increase in sustainability of
agricultural cooperatives, a unit increase in
stakeholder involvement will lead to .806 increase
in sustainability of agricultural cooperatives and a
unit increase in competitive environment will lead
to 0.690 increase in sustainability of agricultural
cooperatives. This infers that managerial skills
contributed most to sustainability of agricultural
cooperatives. At 5% level of significance, access to
finance had a 0.009 level of significance; managerial
skills showed a 0.001 level of significance,
stakeholder involvement showed a 0.006 level of
significance and competitive environment showed a
0.008 level of significance hence the most
significant factor was managerial skills. The study ran the procedure of obtaining the
regression coefficients, and the results were as
shown on the Table 4 Multiple regression analysis
was conducted as to determine the relationship
between sustainability of agricultural cooperatives
and the four variables. As per the SPSS generated
table below, the model equation would be (Y = β0 +
β1X1 + β2X2 + β3X3 + β4X4 +ε) becomes: Y= 45.098+
0.587X1+ 0.875X2+ 0.690X3 + 0.806X4. Multiple Regression Analysis In addition, the researcher conducted a multiple
regression analysis so as to test relationship among
variables (independent) on the sustainability of
agricultural cooperatives. The study applied the
statistical package for social sciences (SPSS V. 21) to
code, enter and compute the measurements of the
multiple regressions for the study. According to the
model summary Table 2, R is the correlation
coefficient which shows the relationship between
the indepednt variables and depedent variable. It is
notable that there extists strong positive
relationship between the indepedent variables and
depedent variable as shown by R value (0.899). The identifies variables as critical determinants of
sustainability of agricultural cooperatives in the
study area. Table 2: Model Summary
Model
R
R Square
Adjusted R Square
Std. Error of the
Estimate
1
.899
.808
.605
.008
Further, the study revealed that the significance
value is 0.001which is less that 0.05 thus the model
is statistically significance in predicting how
managerial skills, access to finance, competitive
environment and stakeholder involvementaffect
sustainability of agricultural cooperatives. The F
critical at 5% level of significance was 20.023. Since
F calculated (20.023) is greater than the F critical
(value = 3.765), this shows that the overall model
was significant. Table 3: ANOVA
Model
Sum of Squares
Df
Mean Square
F
Sig. 1
Regression
16.980
4
4.245
20.023
.001a
Residual
15.987
75
.2120
Total
32.967
79
NB: F-critical Value = 3.765; Predictors: (Constant): Managerial skills, Access to Finance, Competitive
environment and Stakeholder involvement. The study ran the procedure of obtaining the
taking all other independent variables at zero, a unit
increase in access to finance will lead to a 0.587 identifies variables as critical determinants of
sustainability of agricultural cooperatives in the
study area. Table 2: Model Summary
Model
R
R Square
Adjusted R Square
Std. Error of the
Estimate
1
.899
.808
.605
.008
Further, the study revealed that the significance
value is 0.001which is less that 0.05 thus the model
is statistically significance in predicting how
managerial skills, access to finance, competitive
environment and stakeholder involvementaffect
sustainability of agricultural cooperatives. The F
critical at 5% level of significance was 20.023. Since
F calculated (20.023) is greater than the F critical
(value = 3.765), this shows that the overall model
was significant. Multiple Regression Analysis 1 Further, the study revealed that the significance
value is 0.001which is less that 0.05 thus the model
is statistically significance in predicting how
managerial skills, access to finance, competitive
environment and stakeholder involvementaffect Table 3: ANOVA
Model
Sum of Squares
Df
Mean Square
F
Sig. 1
Regression
16.980
4
4.245
20.023
.001a
Residual
15.987
75
.2120
Total
32.967
79
NB: F-critical Value = 3.765; Predictors: (Constant): Managerial skills, Access to Finance, Competitive
environment and Stakeholder involvement. Table 3: ANOVA Table 3: ANOVA Error
Beta
1
(Constant)
45.098
.223
2.615
.007
Access to finance
.587
.293
.402
3.098
.009
Managerial skills
.875
.150
.554
7.087
.001
Competitive environment
.690
.247
.416
6.008
.008
Stakeholder Involvement
.806
.273
.463
6.546
.006
with
Sacco activities and led to sustainability of Model with Sacco activities and led to sustainability of
established Sacco activities, increases the number
of the clients, net value of the Sacco increases and
members take loans with interests. Further, the
study revealed that the variable(Pearson correlation
coefficient =.0.875) and p-value (0.001 < 0.05)
statistically, strongly and significantly correlated to
sustainability of agricultural cooperatives at 5%
level of significance as it had a positive relationship
with
the
dependent
variable. This
reveals
managerial skills are an important factor that can
enhance sustainability of agricultural cooperatives
in the study area. This also reveals that the more
managerial
skills
improves
the
more
the
sustainability of agricultural cooperatives in the
study area Therefore, from these quantitative
results it can be deduced that the study which
sought to establish the influence of managerial skills
on sustainability of agricultural cooperatives in the
study area was achieved because it established that
managerial
skills
influenced
sustainability
of
agricultural cooperatives. SUMMARY, CONCLUSIONS AND
RECOMMENDATIONS This chapter presents the summary of the study as
guided by specific objectives, research questions
and conclusions reached based on the findings and
recommendations
for
establishing
drivers
of
sustainability of agricultural cooperatives in Kenya
as well as recommendations for further research Summary of the Findings Objective 1: To find out how managerial skills
influence sustainability of agricultural cooperatives
in Kenya Table 3: ANOVA This
indicates
that
sustainability
of
agricultural
cooperatives = 45.098 + 0.587(Access to finance) +
0.875(Managerial
skills)
+
0.690(Competitive
Environment)
+
0.806
(Stakeholder
Involvement).According to the regression equation
established, taking all factors into account (access
to
finance,
managerial
skills,
competitive
environment, stakeholder involvement) constant at
zero sustainability of agricultural cooperatives was
45.098. The data findings analyzed also shows that - 287 - Table 4: Regression Coefficient Results
Model
Unstandardized
Coefficients
Standardized
Coefficients
t
P-value. B
Std. Error
Beta
1
(Constant)
45.098
.223
2.615
.007
Access to finance
.587
.293
.402
3.098
.009
Managerial skills
.875
.150
.554
7.087
.001
Competitive environment
.690
.247
.416
6.008
.008
Stakeholder Involvement
.806
.273
.463
6.546
.006
SUMMARY, CONCLUSIONS AND
RECOMMENDATIONS
This chapter presents the summary of the study as
guided by specific objectives, research questions
and conclusions reached based on the findings and
recommendations
for
establishing
drivers
of
sustainability of agricultural cooperatives in Kenya
as well as recommendations for further research
Summary of the Findings
Objective 1: To find out how managerial skills
influence sustainability of agricultural cooperatives
in Kenya
From study results as the respondents stated that
they
mostly
met
annually
to
discuss
the
sustainability of agricultural cooperativesand senior
level management does not frequently meet
affecting decision making in regard to sustainability
of agricultural cooperatives. The study established
that leadership, planning and organizing increases
the number of the completed Sacco projects,
with Sacco activities and led to sustainability of
established Sacco activities, increases the number
of the clients, net value of the Sacco increases and
members take loans with interests. Further, the
study revealed that the variable(Pearson correlation
coefficient =.0.875) and p-value (0.001 < 0.05)
statistically, strongly and significantly correlated to
sustainability of agricultural cooperatives at 5%
level of significance as it had a positive relationship
with
the
dependent
variable. This
reveals
managerial skills are an important factor that can
enhance sustainability of agricultural cooperatives
in the study area. This also reveals that the more
managerial
skills
improves
the
more
the
sustainability of agricultural cooperatives in the
study area Therefore, from these quantitative
results it can be deduced that the study which
sought to establish the influence of managerial skills
on sustainability of agricultural cooperatives in the
study area was achieved because it established that
managerial
skills
influenced
sustainability
of
agricultural cooperatives. Table 4: Regression Coefficient Results
Model
Unstandardized
Coefficients
Standardized
Coefficients
t
P-value. B
Std. Objective 2: To determine how stakeholder
involvement influence sustainability of agricultural
cooperatives in Kenya From the descriptive analysis, the respondents
stated that it increased the number of the proposed
projects, increased the number of successfully
completed/delivered
projects
and
led
to
sustainability of established projects. This implies
that cost of capital and collateral affected
sustainability of agricultural cooperatives. The study
also established that conditions were too stringent,
corruption in giving out funds, it required security
and the process was too technical.The collateral
availability affect sustainability of the organizations
as it increases the number of the years of operation,
increases the number of number of branches
opened and increases the net value of the
organization. The access to financial medium
(financial facilitation) equally affect sustainability of
the cooperatives. Further, the study revealed that
the variable(Pearson correlation coefficient =.0.602)
and p-value (0.005 < 0.05) statistically, strongly and
significantly
correlated
to
sustainability
of
agricultural cooperatives in the study area at 5%
level of significance as it had a positive relationship
with the dependent variable. This reveals access to
finance is an important factor that can increase
sustainability of agricultural cooperatives in the
study area. This also reveals that the access to
finance is the more sustainability of agricultural
cooperatives. Therefore, from these quantitative
results it can be presumed that the study which
sought to establish the influence of access to
finance on sustainability of agricultural cooperatives
was achieved because it established that access to
finance influenced sustainability of agricultural
cooperatives in the study area. bj
i
bli h
h
i i From the descriptive analysis, the study results
revealed that majority of the respondents indicated
stakeholder involvement affect sustainability of
agricultural cooperatives in Kenya. The key
stakeholders involved in monitoring and evaluation
of the projects include beneficiaries, implementing
staff, donors, government and they normally have
stakeholder meetings on monitoring and controlling
the
activities
of
the
projects
yearly. The
stakeholders involved carrying out monitoring and
evaluation activities of the projects are rarely
adequate and different stakeholders have different
reporting requirements which are lenient and
demonstrating the long term impact of M & E of the
projects to stakeholders is rarely straightforward. Further,
the
study
revealed
that
the
variable(Pearson correlation coefficient =.790) and
p-value (0.002< 0.05) statistically, strongly and
significantly
correlated
to
sustainability
of
agricultural cooperativesat 5% level of significance
as it had a positive relationship with the dependent
variable. This reveals that stakeholder involvement
is an important factor that can boost effective
sustainability of agricultural cooperatives. Objective 2: To determine how stakeholder
involvement influence sustainability of agricultural
cooperatives in Kenya This also
reveals that the more stakeholder involvement
becomes the more the sustainability of agricultural
cooperatives Therefore, from these quantitative
results it can be deduced that the study which
sought to establish the influence of stakeholder
involvement
on
effective
sustainability
of
agricultural cooperatives was achieved because it
established that it influenced sustainability of
agricultural cooperatives. Objective 3: To examine how access to finance Objective 1: To find out how managerial skills
influence sustainability of agricultural cooperatives
in Kenya From study results as the respondents stated that
they
mostly
met
annually
to
discuss
the
sustainability of agricultural cooperativesand senior
level management does not frequently meet
affecting decision making in regard to sustainability
of agricultural cooperatives. The study established
that leadership, planning and organizing increases
the number of the completed Sacco projects,
increases the number of number of people served Objective 2: To determine how stakeholder
involvement influence sustainability of agricultural
cooperatives in Kenya Objective 4: To establish how competitive
environment
influence
sustainability
of
agricultural cooperatives in Kenya Objective 3: To examine how access to finance
influence sustainability of agricultural cooperatives
in Kenya Objective 3: To examine how access to finance
influence sustainability of agricultural cooperatives
i From the descriptive analysis, the study results
showed that the respondents stated that product
differentiation increased the number of the - 289 - proposed
projects,
number
of
successfully
completed/delivered project and sustainability of
established projects. This can be deduced that
product differentiation and fair play influence
sustainability of agricultural cooperatives as it
increased the profitability, increased the customer
base and leads to sustainability of agricultural
cooperatives. To increase the competitive gap, the
study established by adding greater value through
innovation,
routine
and
controlled
visit
to
competitors and enhancing the overall in-house
experience. The competition affected sustainability
of agricultural cooperatives by the greater selection
of products, lower prices, greater range of services,
more advertisement, greater emphasis on customer
satisfaction. Further, the study revealed that the
variable(Pearson correlation coefficient =.0.754)
and p-value (0.009< 0.05) statistically, strongly and
significantly
correlated
to
sustainability
of
agricultural cooperatives at 5% level of significance
as it had a positive relationship with the dependent
variable. This reveals competitive environment is an
important factor that can boost sustainability of
agricultural cooperatives. This also reveals that the
more competitive environment becomes the more
the sustainability of agricultural cooperatives in the
organization Therefore, from these quantitative
results it can be deduced that the study which
sought to establish the influence of competitive
environment
on
sustainability
of
agricultural
cooperatives was achieved because it established
that
competitive
environment
influenced
sustainability of agricultural cooperatives. agricultural cooperatives. The stakeholders involved
carrying out monitoring and evaluation activities of
the projects are rarely adequate and different
stakeholders have different reporting requirements
which are lenient and demonstrating the long term
impact of M & E of the projects to stakeholders is
rarely straightforward. Additionally, study results showed that the
managerial skills play an important role on
sustainability of agricultural cooperatives. The
senior level management attends fewer meetings
affecting decision making in regard to performance
of the projects. The management lacks leadership,
planning and organizing skills to implement the
projects. This also reveals that there is need for
more managerial skills to be enhanced to boost
sustainability of agricultural cooperatives. Further,
the study found out cost of capital and collateral
affected sustainability of agricultural cooperatives. Objective 4: To establish how competitive
environment
influence
sustainability
of
agricultural cooperatives in Kenya The study also established that conditions were too
stringent, corruption in giving out funds, it required
security and the process was too technical. Finally, the study established that competitive
environment play a significant role on enhancing
sustainability of agricultural cooperatives. The
product differentiation increased the number of the
proposed
projects,
number
of
successfully
completed/delivered project and sustainability of
established projects. The fair play brought by
competition affected sustainability of agricultural
cooperatives as it stated to be niche offer brand
identification,
price
differentiation
and
incorporation of attributes (quality or price). The
reasons for not winning government sustainability
of agricultural cooperatives that were provided
included corruption and favouritism, technical
process, the hard to get relevant information, the
high standard quality of work and the sustainability
of agricultural cooperatives hard to get necessary
financial
support. The
competition
affected Conclusions The study established that majority of the
respondents indicated stakeholder involvement
affect sustainability of agricultural cooperatives in
Kenya. The key stakeholders involved in monitoring
and evaluation of the projects did not meet
adequately
thus
hindering
sustainability
of - 290 - Further, in relation to cooperative marketing
theory, the specifying objectives and organizational
structures for cooperatives that address the
concerns of access to finance for agricultural
producers in a context of achieving sustainability
role for cooperatives capture a larger share of
industry
earnings
for the membership,
but
additionally, contribute to market or industry
efficiency. In other words, the external effects of
organization to the internal or micro aspects of
organizing and sustaining cooperation should have
sound leadership in the cooperative movement and
connects proper leadership and sound governance
to a satisfied cooperative membership, proper
financial management and a thriving cooperative
movement to access finance to run cooperative
activities to ensure its sustainability. The study
found out cost of capital and collateral affected
sustainability of agricultural cooperatives. The study
also established that conditions were too stringent,
corruption in giving out funds, it required security
and the process was too technical. The policies on
access to funds should be enhanced to promote
sustainability of the cooperatives. performance of the projects by the greater
selection of products, lower prices, greater range of
services, more advertisement, greater emphasis on
customer satisfaction. Recommendations The study recommends for involvement of all
stakeholders to boost sustainability of agricultural
cooperatives. The key stakeholders should meet
adequately
in
carrying
out
monitoring
and
evaluation activities of the projects that are rarely
adequate whereby different stakeholders have
different reporting requirements. In regard to Co-
operative movement theory, there is need to
ensure that there is to bring all stakeholders on
board for the success of an organization as every
individual's
personal
environment,
and
then
improved circumstances would lead to goodness. If
people are motivated and given the impetus to
apply themselves through creation of fair policies
and equitable environment when included in the
running an organization activities, then even their
attitude to work will change and a new era of
flourishing social and economic movements will be
witnessed for the sustainability of the organization. Finally, the study recommends for amendment on
policies in regard to competitive environment as it
play a significant role on enhancing sustainability of
agricultural
cooperatives. The
product
differentiation should be enhanced and fair play
brought by competition can lead to the greater
selection of products, lower prices, greater range of
services, more advertisement, greater emphasis on
customer
satisfaction
aimed
at
enhancing
sustainability of agricultural cooperatives. According
to cooperative dynamic theory, cooperative and
mutual organizational forms arise for reasons that
include contracting problems and stiff completion
between parties. The cooperative always work in a
dynamic environment that requires the government
to specifically formulate policies to regulate, Additionally,
study
recommends
for
the
management to be trained on the managerial skills
as they play an important role sustainability of
agricultural
cooperatives. The
senior
level
management should increase meetings affecting
decision making in regard to sustainability of
agricultural cooperatives.The training should focus
on leadership, planning and organizing skills. According to the scientific theory of management
the efficient accomplishment of work tasks depends
on proper management. The primary consideration
should be based on training of staff on marketing
and management of cooperatives as well as
influence of other services offered by cooperatives. - 291 - supervise and protect them from stiff competition
for their sustainability purposes. concentrated on employee behavior, satisfaction,
dissatisfaction and commitment in sustainability of
agricultural cooperatives. This study therefore
highlights the role of managers and stakeholders in
sustainability of agricultural cooperatives, an area
that has not been much explored. Recommendations for Further studies A review of literature indicated that there has been
limited
amount
of
research
on
drivers of
sustainability of agricultural cooperatives in the
Kenyan context. Thus, the findings of this study
serve as a basis for future studies on sustainability
of agricultural cooperatives and on this population. Sustainability of agricultural cooperatives, has not
been widely studied which presents gaps in African
and Kenyan contexts. The study has contributed to
knowledge by establishing that managerial skills,
stakeholder involvement and access to finance
influence sustainability of agricultural cooperatives
of this population in the Kenyan context. This study used qualitative and quantitative
techniques. It was also a cross sectional study and
hence other studies using longitudinal design could
be carried out to establish whether turnover
cognitions are actualized. Also, an exploratory study
would enrich findings because such a study would
have a wide range of factors that sustainability of
agricultural cooperatives addressed other than the
ones identified in this study. Interaction effects
should be investigated. The interaction effects may
be re-examined at a later period because of the
constant changes that take place in organizations. Some of the findings have generally vindicated the
long
held
positions
regarding
the
various
relationships that were studied. Other findings,
however, such as the role of training and
remuneration in sustainability of agricultural
cooperatives were inconsistent with pertinent
literature and results of previous studies thus
preparing ground for paradigm shift in such factors
in relation to this population. This study confined itself to the agricultural
cooperatives in Machakos County, Kenya. A
comparative study should be carried out to
compare whether the findings also apply for
agricultural cooperatives in other counties Kenya in
order to validate whether the findings can be
generalized to others in Kenya. Additionally, the
study did not tie the determinants as the only
drivers of sustainability of agricultural cooperatives. Thus, there is need to undertake another research
to examine the other factors which could be
influencing
sustainability
of
agricultural
cooperatives in Kenya. The research has clearly pointed out the role of
managerial skills and stakeholder involvement
especially
the members
in
sustainability of
agricultural
cooperatives. Studies
have - 292 - Gordon, J. 2004. "Non-traditional Analysis of Co-operative Economic Impacts: Preliminary Indicators and a Case
Study". Review of International Co-operation97(1):6-47. REFERENCES Bataille-Chedotel, F Y Huntzinger F (2004) “Directivos y gobierno de lascooperativasobreras de
producción”,CIRIEC-España, no 48. Bataille-Chedotel, F Y Huntzinger F (2004) “Directivos y gobierno de lascooperativasobreras de
producción”,CIRIEC-España, no 48. Bendick, M and M.L. Egan.2005. “Worker Ownership and Participation Enhances Economic Development in Low-
Opportunity Communities”. Journal of Community Practice2(1):61-85. Birchall, J. (2004), Co-operatives and the Millennium Development Goals, ILO, Brennan, M.A. and A.E. Luloff. 2005. “A Cooperative Approach to Rural Development in Ireland: Cultural
Artifacts and the Irish Diaspora as an Example”. Journal of International Agricultural and Extension
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Evidence from the Republic of Ireland". Anatolia: An International Journal of Tourism and Hospitality
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Discussion Paper 296. Brighton: IDS. Chaves, R and Sajardo, A (2004) “Social Economy Managers: between values and entrenchment”, Annals of
Public and Cooperative Economics, Vol 75, No 1, pp139-161 Christenson, J.A. and J.W. Robinson. 1986. Community Development in Perspective. Ames, IA: Iowa State
University Press. Coggon D. Rose G. and Barker D. (1997).Epidemiology for the Uninitiated: Case-control and cross sectional
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Micro, Small & Medium-scale Enterprises (MSMEs): A framework for understanding ICT applications for
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of Manchester. Evans, A. C. (2002), The Unpaved Road Ahead: HIV/AIDS & Microfinance: An Exploration of Kenya Credit Unions
(SACCOs), Research Monograph Series No. 21, World Council of Credit Unions, Madison, Wisconsin Evans, A. C. (2002), The Unpaved Road Ahead: HIV/AIDS & Microfinance: An Exploration of Kenya Credit Unions
(SACCOs), Research Monograph Series No. 21, World Council of Credit Unions, Madison, Wisconsin Gordon, J. 2004. "Non-traditional Analysis of Co-operative Economic Impacts: Preliminary Indicators and a Case
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and Cooperative Economics, Vol 75, No 1, pp33-59. International Cooperative Alliance (2004) http://www.coop.org/ Accessed on 2 March 2008. REFERENCES International Monetary Fund (2007) Kenya: Poverty Reduction Strategy Annual Progress Report.2004/2005, IMF
Country Report No. 07/159, International Monetary Fund. Washington, D.C. Jodahl, T. 2006. "Consumer Co-operatives in Norway".Review of International Co-operation96(1):9-16. Luloff, A.E., and J. Bridger.2006. "Community Agency and Local Development". Pp. 203-213 in, Challenges for
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International Co-operation95(1):104-114. Michels, R (1911) Political parties: a sociological study of the oligarchical tendencies of modern democracy
(Spanish version: 1969, Amorrortu, Buenos Aires) Ministry of Information & Communications (2006), 2006 Kenya ICT Strategy: Collaboration & Outsourcing for
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vironment” Approach, International Institute for Sustainable Development (IISD). Neuman, W.L (2000). Social Research Methods: Qualitative and Quantitative
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Allyn and Bacon Publishers Okello, D. (2006) ‘Open Access’ An approach for building and financing pro-poor ICT infrastructure Propoor
Community-driven Networks Seminar, 17 August 2006, Hotel Africana, Kampala. Phillips, R. 2004. "Artful Business: Using the Arts for Community Economic Development". Community
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(eds.), Handbook of Development Economics, Vol.1. Amsterdam: North Holland. The Kenya High Commission in the United Kingdom (2007) Newsletter Issue 2 - April 2007. The Ministry of Information & Communications (2006), Kenya is Running: Creating prosperity through
innovation. USDA – Rural Business Cooperative Service. 2005. Marketing Cooperative by Type, Memberships and Sales. REFERENCES http://www.rurdev.usda.gov/rbs/coops/data.htm (Accessed february 4, 2013). Verma, S.K. (2004) “Cooperative Centenary in India”, New Sector Magazine, Issue No 61, April/ May 2004. Wilkinson, K.P. 2002.The Community in Rural America. New York, NY: Greenwood Press, 2002. World Bank (2000) World Development Report. New York, Oxford University Press. - 295 -
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https://openalex.org/W4240608624
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https://zenodo.org/record/1564321/files/article.pdf
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Latin
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Passifloraceae
|
Notizblatt des Königl. botanischen Gartens und Museums zu Berlin
| 1,915
|
public-domain
| 872
|
Passifloraceae
Author(s): H. Harms
Source: Notizblatt des Königl. botanischen Gartens und Museums zu Berlin, Bd. 6, Nr. 60, R. Pilger: Plantae Uleanae novae vel minus cognitae. Heft 5 (Sep. 20, 1915), pp. 347-348
Published by: Botanischer Garten und Botanisches Museum, Berlin-Dahlem
Stable URL: http://www.jstor.org/stable/3994310 . Accessed: 15/06/2014 03:48 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of
content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms
of scholarship. For more information about JSTOR, please contact support@jstor.org. Botanischer Garten und Botanisches Museum, Berlin-Dahlem is collaborating with JSTOR to digitize,
preserve and extend access to Notizblatt des Königl. botanischen Gartens und Museums zu Berlin. This content downloaded from 195.78.109.96 on Sun, 15 Jun 2014 03:48:13 AM
All use subject to JSTOR Terms and Conditions -
347 This content downloaded from 195.78.109.96 on Sun, 15 Jun 2014 03:48:13 AM
All use subject to JSTOR Terms and Conditions H. Harms. Passiflora selerophylla Harms n. sp. (Sect. Astrophea). -
Frutex
1-2
m altus, scandens, cirrhis validiusculis, ramulis glabris vel sub-
glabris (junioribus puberulis), cortice subatro-cinereo vel sordide sub-
atro-brunneolo; folia breviter petiolata, petiolo crassiusculo puberulo
vel subglabro, circ. 5-10
mm longo vel breviore, apice biglanduloso,
ovalia vel ovata vel obovata vel oblonga, basi obtusa vel rotundata vel
emarginulata vel obtusiuscula, apice obtusa vel rotundata vel breviter
acuta, interdum emarginulata, saepius brevissime mucronulata, rigida,
coriacea, supra nitidula glabra leviter tantum reticulata, subtus distincte
elevato-reticulata et brevissime villosula, 4-7
cm longa, 3-5
cm lata;
flores axillares solitarii, bini vel terni,
folio breviores,
pedicellati,
pedicello breviter adpresse pubescente,
circ. 10-15
mm vel paullo
ultra longo; alabastra subaureo-sericea; receptaculum late infundibuli-
forme, circ. 8-9
mm longum, cum sepalis extus breviter subsericeo-
pubescens;
sepala
5
anguste
oblonga,
obtusa
vel
obtusiuscula
2,3-2,5
cm longa; petala 5, lanceolata, obtusiuscula, byalina, sepalis
paullo breviora, circ. 1,8 cm vel ultra longa; corona faucialis duplex,
filis exterioribus petalis fere aequilongis vel ea paullo superantibus in-
ferne a latere complanatis, fere medio geniculatis et sursum tenui-
filiformibus et saepe flexuosis vel corrugatis (parte basali complanata
sursum leviter dilatata oblique apiculata fere 1 cm longa), filis interi-
oribus multo brevioribus, corona versus medium receptaculi affixa in
fila numerosa fissa, circ. 3 mm alta. Guyana,
Venezuela:
Roraima: Auf dem unteren Campo (E. ULE
n. 8667 -
Dezember 1909, Bliite rotlich-braun, schwarz-purpurn ge-
sprenkelt, 1-2
m hoher Strauch). -
Ferner gehort hierher ein Blatt-
exemplar vom siudlichen Abhang des Roraima, das RICH. SCHOMBURG
n. 986 im November 1842 gesammelt bat und das unter der Bezeichnung
Astrophea emarginata Roem. in Schomburgk, Reis. Brit. Guiana (1848)
1090
aufgefiihrt ist;
das Herbarexemplar
triagt die Bezeichnung
Astrophea emaryinata Klotzsch. Passiflora leptopoda Harms n. sp. (Sect. Astrophea). -
Frutex
scandens (?), ramulis glabris, interdum leviter tenuiterque ut petioli cera
quadam lactea afflatis; folia petiolata, petiolo glabro 0,8-1,5
cm longo,
oblonga vel late lanceolata, basi rotundata vel obtusa vel levissime
emarginulata, apice obtusa vel emarginulata vel breviter obtuse vel 348 obtusiuscule acuminata, chartacea, glabra, costa subtus prominula ima
basi versus petiolum glandulis parvis paribus immersis praedita, circ. This content downloaded from 195.78.109.96 on Sun, 15 Jun 2014 03:48:13 AM
All use subject to JSTOR Terms and Conditions H. Harms. 10-16 cm longa, 5-6 cm lata; racemi terminales (?) vel e ramulis
orti, pauciflori vel pluriflori, laxi, pedicelli graciles tenuissimi penduli
glabri paullo supra basin articulati ibique bracteolis 2 minimis lineari-
setaceis praediti (articulatione a basi 5-8 mm distante), addita bractea
minima paullulo infra articulationem inserta, basi foliis reductis angustis
parvis vel raro evolutis suffulti, 4-7,5 cm longi; floris angusti glabri
saepe leviter lacteo-afflati receptaculum breviter tubulosum, basi leviter
inflatum et lineis intrusis saepe profundis longitudinalibus notatum,
intus a corona fauciali ad basin circ. 12 mm longum; sepala 5 anguste
lanceolata, circ. 5 cm longa, acuta vel obtusiuscula; petala 5 illis simi-
lia sed tenuiora vix vel paullo breviora; coronae faucialis pluriseriatae
series extima e filis longissimis tenuissimis, series insequens e filis
multo brevioribus composita, series intima plumosa deflexa e filis
brevibus densis numerosissimis formata; antherae angustae fere 1,5 cm
longae; gynophorum elongatum glabrum circ. 3,5 cm longum, ovarium
angustum subsericeo-pubescens. Brasilien:
Rio Branco, Wald bei der Serra de Carauma (E. ULE
n. 7708 -
November 1908; Bliite weiB). -
Brit. Guiana: Savanne
(RICH. SCHOMBURGK
n. 424 -
Februar 1842; genannt als A8trophea
glaberrima Klotzsch in Schomburgk, Reis. Brit. Guiana III. (1848) 1168:
In Oasen in der Umgebung von Pirara; bliiht im Juni und Juli;
windender Strauch). Die Art ist auffaullig durch die diinnen haingenden langen Blitenstiele. Die Art ist auffaullig durch die diinnen haingenden langen Blitenstiele. Von
E. Ule. Von 1. (3 a). Rhynchanthera intermedia Ule n. sp. -
Caulis ra-
mosus, ramis dense glanduloso-hirsutis;
folia breviter petiolata, mem-
branacea, ovata, longiuscule acuminata vel acuta, basi rotundata vel
subcordata, 7- vel 9-nervia,
dense pilosa;
flores in axillis foliorum
breviter paniculati; calycis tubus et lobi dense pilosi, lobi tubo longiores;
stamen unum ceteris multo majus, antherarum rostrum elongatum. Halbstrauchige, 1-2
m hohe Pflauze mit undeutlich vierkantigen,
mittelstarken Stengeln, die auBer den dichten, langen Haaren mit rost-
farbenen Filzhaaren besetzt sind. Blattstiel
1/2
1 cm lang; Bliatter
|
https://openalex.org/W3176703834
|
https://aclanthology.org/2021.acl-long.321.pdf
|
English
| null |
Reliability Testing for Natural Language Processing Systems
| null | 2,021
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cc-by
| 12,491
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Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics
and the 11th International Joint Conference on Natural Language Processing, pages 4153–4169
August 1–6, 2021. ©2021 Association for Computational Linguistics ∗Correspondence to: samson.tan@salesforce.com Abstract Figure 1: How DOCTOR can integrate with existing
system development workflows. Test (left) and sys-
tem development (right) take place in parallel, separate
teams. Reliability tests can thus be constructed inde-
pendent of the system development team, either by an
internal “red team” or by independent auditors. Questions of fairness, robustness, and trans-
parency are paramount to address before de-
ploying NLP systems. Central to these con-
cerns is the question of reliability: Can NLP
systems reliably treat different demographics
fairly and function correctly in diverse and
noisy environments? To address this, we argue
for the need for reliability testing and contextu-
alize it among existing work on improving ac-
countability. We show how adversarial attacks
can be reframed for this goal, via a framework
for developing reliability tests. We argue that
reliability testing — with an emphasis on inter-
disciplinary collaboration — will enable rigor-
ous and targeted testing, and aid in the enact-
ment and enforcement of industry standards. Figure 1: How DOCTOR can integrate with existing
system development workflows. Test (left) and sys-
tem development (right) take place in parallel, separate
teams. Reliability tests can thus be constructed inde-
pendent of the system development team, either by an
internal “red team” or by independent auditors. Reliability Testing for Natural Language Processing Systems
Samson Tan§♮∗
Shafiq Joty§‡
Kathy Baxter§
Araz Taeihagh♦♣
Gregory A. Bennett§
Min-Yen Kan♮
§Salesforce Research
‡Nanyang Technological University
♮School of Computing, National University of Singapore
♦Lee Kuan Yew School of Public Policy, National University of Singapore
♣Centre for Trusted Internet and Community, National University of Singapore Reliability Testing for Natural Language Processing Systems
Samson Tan§♮∗
Shafiq Joty§‡
Kathy Baxter§
Araz Taeihagh♦♣
Gregory A. Bennett§
Min-Yen Kan♮
§Salesforce Research
‡Nanyang Technological University
♮School of Computing, National University of Singapore
♦Lee Kuan Yew School of Public Policy, National University of Singapore
♣Centre for Trusted Internet and Community, National University of Singapore Reliability Testing for Natural Language Processing Systems
Samson Tan§♮∗
Shafiq Joty§‡
Kathy Baxter§
Araz Taeihagh♦♣
Gregory A. Bennett§
Min-Yen Kan♮
§Salesforce Research
‡Nanyang Technological University
♮School of Computing, National University of Singapore
♦Lee Kuan Yew School of Public Policy, National University of Singapore
♣Centre for Trusted Internet and Community, National University of Singapore 1
Introduction Initial research on evaluating out-of-distribution
generalization involved manually-designed chal-
lenge sets (Jia and Liang, 2017; Nie et al., 2020;
Gardner et al., 2020), counterfactuals (Kaushik
et al., 2019; Khashabi et al., 2020; Wu et al., 2021),
biased sampling (Søgaard et al., 2021) or toolk-
its for testing if a system has specific capabilities
(Ribeiro et al., 2020) or robustness to distribution
shifts (Goel et al., 2021). However, most of these
approaches inevitably overestimate a given sys-
tem’s worst-case performance since they do not
mimic the NLP system’s adversarial distribution1. Reliability. Defined by IEEE (2017) as the “de-
gree to which a system, product or component per-
forms specified functions under specified condi-
tions for a specified period of time”. We prefer
this term over robustness2 to challenge the NLP
community’s common framing of inputs from out-
side the training distribution as “noisy”. The notion
of reliability requires us to explicitly consider the
specific, diverse environments (i.e., communities)
a system will operate in. This is crucial to reducing
the NLP’s negative impact on the underrepresented. A promising technique for evaluating worst-case
performance is the adversarial attack. However, al-
though some adversarial attacks explicitly focus on
specific linguistic levels of analysis (Belinkov and
Bisk, 2018; Iyyer et al., 2018; Tan et al., 2020; Eger
and Benz, 2020), many often simply rely on word
embeddings or language models for perturbation
proposal (see §4). While the latter may be useful to
evaluate a system’s robustness to malicious actors,
they are less useful for dimension-specific testing
(e.g., reliability when encountering grammatical
variation). This is because they often perturb the
input across multiple dimensions at once, which
may make the resulting adversaries unnatural. Dimension. An axis along which variation can
occur in the real world, similar to Plank (2016)’s
variety space. A taxonomy of possible dimensions
can be found in Table 1 (Appendix). Adversarial attack. A method of perturbing the
input to degrade a target model’s accuracy (Good-
fellow et al., 2015). In computer vision, this is
achieved by adding adversarial noise to the image,
optimized to be maximally damaging to the model. §4 describes how this is done in the NLP context. Stakeholder. A person who is (in-)directly im-
pacted by the NLP system’s predictions. Stakeholder. A person who is (in-)directly im-
pacted by the NLP system’s predictions. 2The “degree to which a system or component can func-
tion correctly in the presence of invalid inputs or stressful
environmental conditions” (IEEE, 2017). 1
Introduction Rigorous testing is critical to ensuring a program
works as intended (functionality) when used un-
der real-world conditions (reliability). Hence, it is
troubling that while natural language technologies
are becoming increasingly pervasive in our every-
day lives, there is little assurance that these NLP
systems will not fail catastrophically or amplify dis-
crimination against minority demographics when
exposed to input from outside the training distribu-
tion. Recent examples include GPT-3 (Brown et al.,
2020) agreeing with suggested suicide (Rousseau
et al., 2020), the mistranslation of an innocuous
social media post resulting in a minority’s arrest
(Hern, 2017), and biased grading algorithms that
can negatively impact a minority student’s future
(Feathers, 2019). Additionally, a lack of rigorous
testing, coupled with machine learning’s (ML) im-
plicit assumption of identical training and testing
distributions, may inadvertently result in systems
that discriminate against minorities, who are often
underrepresented in the training data. This can take the form of misrepresentation of or poorer perfor-
mance for people with disabilities, specific gender,
ethnic, age, or linguistic groups (Hovy and Spruit,
2016; Crawford, 2017; Hutchinson et al., 2020). Amongst claims of NLP systems achieving human
parity in challenging tasks such as question answer-
ing (Yu et al., 2018), machine translation (Has-
san et al., 2018), and commonsense inference (De-
vlin et al., 2019), research has demonstrated these
systems’ fragility to natural and adversarial noise
(Goodfellow et al., 2015; Belinkov and Bisk, 2018)
and out-of-distribution data (Fisch et al., 2019). It is also still common practice to equate “test-
ing” with “measuring held-out accuracy”, even as
datasets are revealed to be harmfully biased (Wag-
ner et al., 2015; Geva et al., 2019; Sap et al., 2019). Many potential harms can be mitigated by detect-
ing them early and preventing the offending model
from being put into production. Hence, in addition
to being mindful of the biases in the NLP pipeline
(Bender and Friedman, 2018; Mitchell et al., 2019; 4153 Waseem et al., 2021) and holding creators account-
able via audits (Raji et al., 2020; Brundage et al.,
2020), we argue for the need to evaluate an NLP
system’s reliability in diverse operating conditions. (classification) or text (generation). We exclude
raw language models from the discussion since it
is unclear how performance, and hence worst-case
performance, should be evaluated. We do include
NLP systems that use language models internally
(e.g., BERT-based classifiers (Devlin et al., 2019)). 1
Introduction Hence, in this paper targeted at NLP researchers,
practitioners, and policymakers, we make the case
for reliability testing and reformulate adversarial
attacks as dimension-specific, worst-case tests that
can be used to approximate real-world variation. We contribute a reliability testing framework —
DOCTOR — that translates safety and fairness con-
cerns around NLP systems into quantitative tests. We demonstrate how testing dimensions for DOC-
TOR can be drafted for a specific use case. Finally,
we discuss the policy implications, challenges, and
directions for future research on reliability testing. Actor. Someone who has influence over a) the
design of an NLP system and its reliability testing
regime; b) whether the system is deployed; and
c) who it can interact with. Within the context of
our discussion, actors are likely to be regulators,
experts, and stakeholder advocates. Expert. An actor who has specialized knowl-
edge, such as ethicists, linguists, domain experts,
social scientists, or NLP practitioners. 1The distribution of adversarial cases or failure profile. 2
Terminology Definitions The accelerating interest in building NLP-based
products that impact many lives has led to ur-
gent questions of fairness, safety, and accountabil-
ity (Hovy and Spruit, 2016; Bender et al., 2021), Let’s define key terms to be used in our discussion. NLP system. The entire text processing pipeline
built to solve a specific task; taking raw text as input
and producing predictions in the form of labels 4154 prompting research into algorithmic bias (Boluk-
basi et al., 2016; Blodgett et al., 2020), explainabil-
ity (Ribeiro et al., 2016; Danilevsky et al., 2020),
robustness (Jia and Liang, 2017), etc. Research is
also emerging on best practices for productizing
ML: from detailed dataset documentation (Bender
and Friedman, 2018; Gebru et al., 2018), model
documentation for highlighting important but of-
ten unreported details such as its training data, in-
tended use, and caveats (Mitchell et al., 2019), and
documentation best practices (Partnership on AI,
2019), to institutional mechanisms such as audit-
ing (Raji et al., 2020) to enforce accountability and
red-teaming (Brundage et al., 2020) to address de-
veloper blind spots, not to mention studies on the
impact of organizational structures on responsible
AI initiatives (Rakova et al., 2020). imize model failure, they highlight serious reliabil-
ity issues for putting ML models into production
since they show that these models could fail catas-
trophically in naturally noisy, diverse, real-world
environments (Saria and Subbaswamy, 2019). Ad-
ditionally, bias can seep into the system at multiple
stages of the NLP lifecycle (Shah et al., 2020), re-
sulting in discrimination against minority groups
(O’Neil, 2016). The good news, however, is that
rigorous testing can help to highlight potential is-
sues before the systems are deployed. The need for rigorous testing in NLP is reflected in
ACL 2020 giving the Best Paper Award to Check-
List (Ribeiro et al., 2020), which applied the idea of
behavior testing from software engineering to test-
ing NLP systems. While invaluable as a first step
towards the development of comprehensive test-
ing methodology, the current implementation of
CheckList may still overestimate the reliability of
NLP systems since the individual test examples are
largely manually constructed. Importantly, with the
complexity and scale of current models, humans
cannot accurately determine a model’s adversarial
distribution (i.e., the examples that cause model
failure). Consequently, the test examples they con-
struct are unlikely to be the worst-case examples
for the model. Automated assistance is needed. 2
Terminology Definitions Calls for increased accountability and transparency
are gaining traction among governments (116th
U.S. Congress, 2019; NIST, 2019; European Com-
mission, 2020; Smith, 2020; California State Leg-
islature, 2020; FDA, 2021) and customers increas-
ingly cite ethical concerns as a reason for not en-
gaging AI service providers (EIU, 2020). While there has been significant discussion around
best practices for dataset and model creation, work
to ensure NLP systems are evaluated in a man-
ner representative of their operational conditions
has only just begun. Initial work in constructing
representative tests focuses on enabling develop-
ment teams to easily evaluate their models’ lin-
guistic capabilities (Ribeiro et al., 2020) and ac-
curacy on subpopulations and distribution shifts
(Goel et al., 2021). However, there is a clear need
for a paradigm that allows experts and stakeholder
advocates to collaboratively develop tests that are
representative of the practical and ethical concerns
of an NLP system’s target demographic. We argue
that reliability testing, by reframing the concept of
adversarial attacks, has the potential to fill this gap. Therefore, we propose to perform reliability test-
ing, which can be thought of as one component
of behavior testing. We categorize reliability tests
as average-case tests or the worst-case tests. As
their names suggest, average-case and worst-case
tests estimate the expected and lower-bound per-
formance, respectively, when the NLP system is
exposed to the phenomena modeled by the tests. Average-case tests are conceptually similar to Wu
et al. (2021)’s counterfactuals, which is contem-
poraneous work, while worst-case tests are most
similar to adversarial attacks (§4). Our approach parallels boundary value testing in
software engineering: In boundary value testing,
tests evaluate a program’s ability to handle edge
cases using test examples drawn from the extremes
of the ranges the program is expected to handle. Similarly, reliability testing aims to quantify the
system’s reliability under diverse and potentially
extreme conditions. This allows teams to perform
better quality control of their NLP systems and in-
troduce more nuance into discussions of why and
when models fail (§5). Finally, we note that reliabil- 3.1
What is reliability testing? Despite the recent advances in neural architectures
resulting in breakthrough performance on bench-
mark datasets, research into adversarial examples
and out-of-distribution generalization has found
ML systems to be particularly vulnerable to slight
perturbations in the input (Goodfellow et al., 2015)
and natural distribution shifts (Fisch et al., 2019). While these perturbations are often chosen to max- 4155 ity testing and standards are established practices
in engineering industries (e.g., aerospace (Nelson,
2003; Wilkinson et al., 2016)) and advocate for NL
engineering to be at parity with these fields. Algorithm 1 General Reliability Test Algorithm 1 General Reliability Test
Require: Data distribution Dd = {X, Y} modeling the di-
mension of interest d, NLP system M, Source dataset
X ∼X, Desired labels Y ′ ∼Y, Scoring function S. Ensure: Average- or worst-case examples X′, Result r. 1: X′ ←{∅}, r ←0
2: for x, y′ in X, Y ′ do
3:
C ←SAMPLECANDIDATES(X)
4:
switch TestType do
5:
case AverageCaseTest
6:
s ←MEAN(S(y′, M(C)))
7:
X′ ←X′ ∪C
8:
case WorstCaseTest
9:
x′, s ←arg minxc∈C S(y′, M(xc))
10:
X′ ←X′ ∪{x′}
11:
r ←r + s
12: end for
13: r ←
r
|X|
14: return X′, r go t
G
y
Require: Data distribution Dd = {X, Y} modeling the di-
mension of interest d, NLP system M, Source dataset
X ∼X, Desired labels Y ′ ∼Y, Scoring function S. Ensure: Average- or worst-case examples X′, Result r. 1: X′ ←{∅}, r ←0
2: for x, y′ in X, Y ′ do
3:
C ←SAMPLECANDIDATES(X)
4:
switch TestType do
5:
case AverageCaseTest
6:
s ←MEAN(S(y′, M(C)))
7:
X′ ←X′ ∪C
8:
case WorstCaseTest
9:
x′, s ←arg minxc∈C S(y′, M(xc))
10:
X′ ←X′ ∪{x′}
11:
r ←r + s
12: end for
13: r ←
r
|X|
14: return X′, r 3Dua et al. (2019) reports a cost of 60k USD for 96k
question–answer pairs. 3.2
Evaluating worst-case performance in a
label-scarce world A proposed approach for testing robustness to nat-
ural and adverse distribution shifts is to construct
test sets using data from different domains or writ-
ing styles (Miller et al., 2020; Hendrycks et al.,
2020), or to use a human vs. model method of con-
structing challenge sets (Nie et al., 2020; Zhang
et al., 2019b). While they are the gold standard,
such datasets are expensive to construct,3 making
it infeasible to manually create worst-case test ex-
amples for each NLP system being evaluated. Con-
sequently, these challenge sets necessarily overesti-
mate each system’s worst-case performance when
the inference distribution differs from the train-
ing one. Additionally, due to their crowdsourced
nature, these challenge sets inevitably introduce
distribution shifts across multiple dimensions at
once, and even their own biases (Geva et al., 2019),
unless explicitly controlled for. Building individ-
ual challenge sets for each dimension would be
prohibitively expensive due to combinatorial ex-
plosion, even before having to account for concept
drift (Widmer and Kubat, 1996). This coupling
complicates efforts to design a nuanced and com-
prehensive testing regime. Hence, simulating vari-
ation in a controlled manner via reliability tests
can be a complementary method of evaluating the
system’s out-of-distribution generalization ability. get model’s accuracy as the measure of success. However, this often resulted in the semantics and
expected prediction changing, leading to an over-
estimation of the attack’s success. Recent attacks
aim to preserve the original input’s semantics. A
popular approach has been to substitute words with
their synonyms using word embeddings or a lan-
guage model as a measure of semantic similarity
(Alzantot et al., 2018; Ribeiro et al., 2018; Michel
et al., 2019; Ren et al., 2019; Zhang et al., 2019a;
Li et al., 2019; Jin et al., 2020; Garg and Ramakr-
ishnan, 2020; Li et al., 2020a). Focusing on maximally degrading model accuracy
overlooks the key feature of adversarial attacks: the
ability to find the worst-case example for a model
from an arbitrary distribution. Many recent attacks
perturb the input across multiple dimensions at
once, which may make the result unnatural. By
constraining our sample perturbations to a distribu-
tion modeling a specific dimension of interest, the
performance on the generated adversaries is a valid
lower bound performance for that dimension. Said
another way, adversarial attacks can be reframed as
interpretable reliability tests if we constrain them
to meaningful distributions. 4
Adversarial Attacks as Reliability Tests We first give a brief introduction to adversarial
attacks in NLP before showing how they can be
used for reliability testing. We refer the reader to
Zhang et al. (2020b) for a comprehensive survey. Existing work on NLP adversarial attacks perturbs
the input at various levels of linguistic analysis:
phonology (Eger and Benz, 2020), orthography
(Ebrahimi et al., 2018), morphology (Tan et al.,
2020), lexicon (Alzantot et al., 2018; Jin et al.,
2020), and syntax (Iyyer et al., 2018). This is the key element of our approach as detailed
in Alg. 1. We specify either an average (Lines 5–7)
or worse case test (Lines 8–10), but conditioned
on the data distribution D that models a particular
dimension of interest d. The resultant reliability
score gauges real-world performance and the worst-
case variant returns the adversarial examples that
cause worst-case performance. When invariance to
input variation is expected, y′ is equivalent to the Early work did not place any constraints on the
attacks and merely used the degradation to a tar- 4156 source label y. Note that by ignoring the average-
case test logic and removing d, we recover the
general adversarial attack algorithm. domain experts to (b), and ethicists and social sci-
entists to (c). However, we recognize that such
collaboration may not be feasible for every NLP
system being tested. It is more realistic to expect
ethicists to be involved when applying DOCTOR at
the company and industry levels, and ethics-trained
NLP practitioners to answer these questions within
the development team. We provide a taxonomy of
potential dimensions in Table 1 (Appendix). However, the key difference between an adversar-
ial robustness mindset and a testing one is the lat-
ter’s emphasis on identifying ways in which natural
phenomena or ethical concerns can be operational-
ized as reliability tests. This change in perspective
opens up new avenues for interdisciplinary research
that will allow researchers and practitioners to have
more nuanced discussions about model reliability
and can be used to design comprehensive reliability
testing regimes. We describe such a framework for
interdisciplinary collaboration next. Since it is likely unfeasible to test every possible di-
mension, stakeholder advocates should be involved
to ensure their values and interests are accurately
represented and prioritized (Hagerty and Rubinov,
2019), while experts should ensure the dimensions
identified can be feasibly tested. A similar ap-
proach to that of community juries4 may be taken. 5
A Framework for Reliability Testing We introduce and then describe our general frame-
work, DOCTOR, for testing the reliability of NLP
systems. DOCTOR comprises six steps: 1. Define reliability requirements 2. Operationalize dimensions as distributions
3. Construct tests 2. Operationalize dimensions as distributions 3. Construct tests 4. Test system and report results 5. Observe deployed system’s behavior Next, we recommend using the same metrics
for held-out, average-case, and worst-case perfor-
mance for easy comparison. These often vary from
task to task and are still a subject of active research
(Novikova et al., 2017; Reiter, 2018; Kryscinski
et al., 2019), hence the question of the right met-
ric to use is beyond the scope of this paper. Fi-
nally, ethicists, in consultation with the other afore-
mentioned experts and stakeholders, will determine
acceptable thresholds for worst-case performance. The system under test must perform above said
thresholds when exposed to variation along those
dimensions in order to pass. For worst-case perfor-
mance, we recommend reporting thresholds as rel-
ative differences (δ) between the average-case and
worst-case performance. These questions may help
in applying this step and deciding if specific NLP
solutions should even exist (Leins et al., 2020): Next, we recommend using the same metrics
for held-out, average-case, and worst-case perfor-
mance for easy comparison. These often vary from
task to task and are still a subject of active research
(Novikova et al., 2017; Reiter, 2018; Kryscinski
et al., 2019), hence the question of the right met-
ric to use is beyond the scope of this paper. Fi-
nally, ethicists, in consultation with the other afore-
mentioned experts and stakeholders, will determine
acceptable thresholds for worst-case performance. 6. Refine reliability requirements and tests Defining reliability requirements. Before any
tests are constructed, experts and stakeholder advo-
cates should work together to understand the demo-
graphics and values of the communities the NLP
system will interact with (Friedman and Hendry,
2019) and the system’s impact on their lives. The
latter is also known as algorithmic risk assess-
ment (Ada Lovelace Institute and DataKind UK,
2021). There are three critical questions to address:
1) Along what dimensions should the model be
tested? 2) What metrics should be used to mea-
sure system performance? 3) What are acceptable
performance thresholds for each dimension? 4docs.microsoft.com/en-us/azure/.../community-jury 4
Adversarial Attacks as Reliability Tests We recommend using this question to evaluate the
feasibility of operationalizing potential dimensions:
“What is the system’s performance when exposed
to variation along dimension d?”. For example,
rather than simply “gender”, a better-defined di-
mension would be “gender pronouns”. With this
understanding, experts and policymakers can then
create a set of reliability requirements, comprising
the testing dimensions, performance metric(s), and
passing thresholds. 5
A Framework for Reliability Testing Question 1 can be further broken down into: a) gen-
eral linguistic phenomena, such as alternative
spellings or code-mixing; b) task-specific quirks,
e.g., an essay grading system should not use text
length to predict score; c) sensitive attributes, such
as gender, ethnicity, sexual orientation, age, or dis-
ability status. This presents an opportunity for inter-
disciplinary expert collaboration: Linguists are best
equipped to contribute to discussions around (a), • Who will interact with the NLP system, in what
context, and using which language varieties? • What are the distinguishing features of these va-
rieties compared to those used for training? 4157 • What is the (short- and long-term) impact on the
community’s most underrepresented members if
the system performs more poorly for them? (e.g., Morpheus (Tan et al., 2020)) or model-based
(e.g., BERT-Attack (Li et al., 2020a)). We recom-
mend constructing tests that do not require access
to the NLP model’s parameters (black-box assump-
tion); this not only yields more system-agnostic
tests, but also allows for (some) tests to be created
independently from the system development team. If the black-box assumption proves limiting, the
community can establish a standard set of items
an NLP system should export for testing purposes,
e.g., network gradients if the system uses a neural
model. Regardless of assumption, keeping the reg-
ulators’ test implementations separate and hidden
from the system developers is critical for stake-
holders and regulators to trust the results. This
separation also reduces overfitting to the test suite. We note that our framework is general enough to
be applied at various levels of organization: within
the development team, within the company (com-
pliance team, internal auditor), and within the in-
dustry (self-regulation or independent regulator). However, we expect the exact set of dimensions,
metrics and acceptable thresholds defined in Step 1
to vary depending on the reliability concerns of
the actors at each level. For example, independent
regulators will be most concerned with establishing
minimum safety and fairness standards that all NLP
systems used in their industries must meet, while
compliance teams may wish to have stricter and
more comprehensive standards for brand reasons. Developers can use DOCTOR to meet the other
two levels of requirements and understand their
system’s behaviour better with targeted testing. Testing systems. A possible model for test own-
ership is to have independently implemented tests
at the three levels of organization described above
(team, company, industry). 5
A Framework for Reliability Testing At the development
team level, reliability tests can be used to diag-
nose weaknesses with the goal of improving the
NLP system for a specific use case and set of target
users. Compared to unconstrained adversarial ex-
amples, contrasting worst-case examples that have
been constrained along specific dimensions with
non-worst-case examples will likely yield greater
intuition into the model’s inner workings. Study-
ing how modifications (to the architecture, training
data and process) affect the system’s reliability on
each dimension will also give engineers insight into
the factors affecting system reliability. These tests
should be executed and updated regularly during
development, according to software engineering
best practices such as Agile (Beck et al., 2001). Operationalizing dimensions. While the ab-
stractness of dimensions allows people who are
not NLP practitioners to participate in drafting the
set of reliability requirements, there is no way to
test NLP systems using fuzzy concepts. Therefore,
every dimension the system is to be tested along
must be operationalizable as a distribution from
which perturbed examples can be sampled in order
for NLP practitioners to realize them as tests. Since average-case tests attempt to estimate a sys-
tem’s expected performance in its deployed envi-
ronment, the availability of datasets that reflect
real-world distributions is paramount to ensure that
the tests themselves are unbiased. This is less of an
issue for worst-case tests; the tests only needs to
know which perturbations that are possible, but not
how frequently they occur in the real world. Figur-
ing out key dimensions for different classes of NLP
tasks and exploring ways of operationalizing them
as reliability tests are also promising directions for
future research. Such research would help NLP
practitioners and policymakers define reliability
requirements that can be feasibly implemented. Red teams are company-internal teams tasked with
finding security vulnerabilities in their developed
software or systems. Brundage et al. (2020) pro-
pose to apply the concept of red teaming to surface
flaws in an AI system’s safety and security. In
companies that maintain multiple NLP systems,
we propose employing similar, specialized teams
composed of NLP experts to build and maintain
reliability tests that ensure their NLP systems ad-
here to company-level reliability standards. These
tests will likely be less task-/domain-specific than
those developed by engineering teams due to their
wider scope, while the reliability standards may
be created and maintained by compliance teams
or the red teams themselves. 6
From Concerns to Dimensions dards available for public scrutiny and ensuring
their products meet them will enable companies
to build trust with their users. To ensure all NLP
systems meet the company’s reliability standards,
these reliability tests should be executed as a part
of regular internal audits (Raji et al., 2020), inves-
tigative audits after incidents, and before major
releases (especially if it is the system’s first release
or if it received a major update). They may also be
regularly executed on randomly chosen production
systems and trigger an alert upon failure. We now illustrate how reliability concerns can be
converted into concrete testing dimensions (Step 1)
by considering the scenario of applying automated
text scoring to short answers and essays from stu-
dents in the multilingual population of Singapore. We study a second scenario in Appendix A. Au-
tomated Text Scoring (ATS) systems are increas-
ingly used to grade tests and essays (Markoff, 2013;
Feathers, 2019). While they can provide instant
feedback and help teachers and test agencies cope
with large loads, studies have shown that they often
exhibit demographic and language biases, such as
scoring African- and Indian-American males lower
on the GRE Argument task compared to human
graders (Bridgeman et al., 2012; Ramineni and
Williamson, 2018). Since the results of some tests
will affect the futures of the test takers (Salaky,
2018), the scoring algorithms used must be suffi-
ciently reliable. Hence, let us imagine that Singa-
pore’s education ministry has decided to create a
standard set of reliability requirements that all ATS
systems used in education must adhere to. At the independent regulator level, reliability tests
would likely be carried out during product certifi-
cation (e.g., ANSI/ISO certification) and external
audits. These industry-level reliability standards
and tests may be developed in a similar manner to
the company-level ones. However, we expect them
to be more general and less comprehensive than
the latter, analogous to minimum safety standards
such as IEC 60335-1 (IEC, 2020). Naturally, high
risk applications and NLP systems used in regu-
lated industries should comply with more stringent
requirements (European Commission, 2021). Linguistic landscape. A mix of language vari-
eties are used in Singapore: a prestige English vari-
ety, a colloquial English variety, three other official
languages (Chinese, Malay, and Tamil), and a large
number of other languages. English is the lingua
franca, with fluency in the prestige variety corre-
lating with socioeconomic status (Vaish and Tan,
2008). 5
A Framework for Reliability Testing Making these stan- Constructing tests. Next, average- and worst-
case tests are constructed (Alg. 1). Average-case
tests can be data-driven and could take the form
of manually curated datasets or model-based per-
turbation generation (e.g., PolyJuice (Wu et al.,
2021)), while worst-case tests can be rule-based 4158 6 6
From Concerns to Dimensions models: Developers simply need to list the tested
dimensions, metrics, and score on each dimension
in the model card. Crucially, reliability tests can
be used to highlight fairness issues in NLP sys-
tems by including sensitive attributes for the target
population, but it is paramount these requirements
reflect local concerns rather than any prescriptivist
perspective (Sambasivan et al., 2021). Dimension. We can generally categorize written
tests into those that test for content correctness
(e.g., essay questions in a history test), and those
that test for language skills (e.g., proper use of
grammar). While there are tests that simultane-
ously assess both aspects, modern ATS systems
often grade them separately (Ke and Ng, 2019). We treat each aspect as a separate test here. At the same time, the ability to conduct quantitative,
targeted reliability testing along specifiable dimen-
sions paves the way for reliability standards to be
established, with varying levels of stringency and
rigor for different use cases and industries. We envi-
sion minimum safety and fairness standards being
established for applications that are non-sensitive,
not safety-critical, and used in unregulated indus-
tries, analogous to standards for household appli-
ances. Naturally, applications at greater risks (Li
et al., 2020b) of causing harm upon failure should
be held to stricter standards. Policymakers are start-
ing to propose and implement regulations to en-
force transparency and accountability in the use of
AI systems. For example, the European Union’s
General Data Protection Regulation grants data sub-
jects the right to obtain “meaningful information
about the logic involved” in automated decision
systems (EU, 2016). The EU is developing AI-
specific regulation (European Commission, 2020):
e.g., requiring developers of high-risk AI systems
to report their “capabilities and limitations, ... [and]
the conditions under which they can be expected to
function as intended”. In the U.S., a proposed bill
of the state of Washington will require public agen-
cies to report “any potential impacts of the auto-
mated decision system on civil rights and liberties
and potential disparate impacts on marginalized
communities” before using automated decision sys-
tems (Washington State Legislature, 2021). When grading students on content correctness, we
would expect the ATS system to ignore linguistic
variation and sensitive attributes as long as they do
not affect the answer’s validity. 6
From Concerns to Dimensions A significant portion of the population does
not speak English at home. Subjects other than
languages are taught in English. Our proposed framework is also highly compatible
with the use of model cards (Mitchell et al., 2019)
for auditing and transparent reporting (Raji et al.,
2020). In addition to performance on task-related
metrics, model cards surface information and as-
sumptions about a machine learning system and
training process that may not be readily available
otherwise. When a system has passed all tests and
is ready to be deployed, its average- and worst-case
performance on all tested dimensions can be in-
cluded as an extra section on the accompanying
model card. In addition, the perturbed examples
generated during testing and their labels (x′, y′)
can be stored for audit purposes or examined to
ensure that the tests are performing as expected. Stakeholder impact. The key stakeholders af-
fected by ATS systems would be students in
schools and universities. The consequences of
lower scores could be life-altering for the stu-
dent who is unable to enroll in the major of their
choice. At the population level, biases in an ATS
system trained on normally sampled data would
unfairly discriminate against already underrepre-
sented groups. Additionally, biases against dis-
fluent or ungrammatical text when they are not
the tested attributes would result in discrimination
against students with a lower socioeconomic status
or for whom English is a second language. Observing and Refining requirements. It is
crucial to regularly monitor the systems’ impact
post-launch and add, update, or re-prioritize di-
mensions and thresholds accordingly. Monitoring
large-scale deployments can be done via commu-
nity juries, in which stakeholders who will be likely
impacted (or their advocates) give feedback on their
pain points and raise concerns about potential neg-
ative effects. Smaller teams without the resources
to organize community juries can set up avenues
(e.g., online forms) for affected stakeholders to give
feedback, raise concerns, and seek remediation. Finally, NLP systems have also been known to be
overly sensitive to alternative spellings (Belinkov
and Bisk, 2018). When used to score subject tests,
this could result in the ATS system unfairly penaliz- 4159 ing dyslexic students (Coleman et al., 2009). Since
education is often credited with enabling social
mobility,5 unfair grading may perpetuate systemic
discrimination and increase social inequality. 5www.encyclopedia.com/.../education-and-mobility
6huggingface.co/models;
github.com/ivylee/model-cards-and-datasheets; 6
From Concerns to Dimensions Hence, we would
expect variation in these dimensions to have no ef-
fect on scores: answer length, language/vocabulary
simplicity, alternative spellings/misspellings of
non-keywords, grammatical variation, syntactic
variation (especially those resembling transfer from
a first language), and proxies for sensitive attributes. On the other hand, the system should be able to
differentiate proper answers from those aimed at
gaming the test (Chin, 2020; Ding et al., 2020). When grading students on language skills, however,
we would expect ATS systems to be only sensitive
to the relevant skill. For example, when assessing
grammar use, we would expect the system to be
sensitive to grammatical errors (from the perspec-
tive of the language variety the student is expected
to use), but not to the other dimensions mentioned
above (e.g., misspellings). Actors. Relevant experts include teachers of the
subjects where the ATS systems will be deployed,
linguists, and computer scientists. The stakeholders
(students) may be represented by student unions (at
the university level) or focus groups comprising a
representative sample of the student population. One may note that language in the proposed regula-
tion is intentionally vague. There are many ways to
measure bias and fairness, depending on the type
of model, context of use, and goal of the system. Today, companies developing AI systems employ
the definitions they believe most reasonable (or
perhaps easiest to implement), but regulation will
need to be more specific for there to be meaningful
compliance. DOCTOR’s requirement to explicitly
define specific dimensions instead of a vague no-
tion of reliability will help policymakers in this blog.einstein.ai/model-cards-for-ai-model-transparency 9
Conclusion Once language technologies leave the lab and start
impacting real lives, concerns around safety, fair-
ness, and accountability cease to be thought ex-
periments. While it is clear that NLP can have
a positive impact on our lives, from typing auto-
completion to revitalizing endangered languages
(Zhang et al., 2020a), it also has the potential to
perpetuate harmful stereotypes (Bolukbasi et al.,
2016; Sap et al., 2019), perform disproportionately
poorly for underrepresented groups (Hern, 2017;
Bridgeman et al., 2012), and even erase already
marginalized communities (Bender et al., 2021). Trust in our tools stems from an assurance that
stakeholders will remain unharmed, even in the
worst-case scenario. In many mature industries,
this takes the form of reliability standards. How-
ever, for standards to be enacted and enforced, we
must first operationalize “reliability”. Hence, we
argue for the need for reliability testing (especially
worst-case testing) in NLP by contextualizing it
among existing work on promoting accountability
and improving generalization beyond the training
distribution. Next, we showed how adversarial at-
tacks can be reframed as worst-case tests. Finally,
we proposed a possible paradigm, DOCTOR, for
how reliability concerns can be realized as quantita-
tive tests, and discussed how this framework can be
used at different levels of organization or industry. 8
Challenges and Future Directions While DOCTOR is a useful starting point to im-
plement reliability testing for NLP systems, we
observe key challenges to its widespread adoption. First, identifying and prioritizing the dimensions
that can attest a system’s reliability and fairness. The former is relatively straightforward and can
be achieved via collaboration with experts (e.g., as
part of the U.S. NIST’s future AI standards (NIST,
2019)). The latter, however, is a question of values
and power (Noble, 2018; Mohamed et al., 2020;
Leins et al., 2020), and should be addressed via a
code of ethics and ensuring that all stakeholders
are adequately represented at the decision table. 7
Implications for Policy There is a mounting effort to increase accountabil-
ity and transparency around the development and
use of NLP systems to prevent them from ampli-
fying societal biases. DOCTOR is highly comple-
mentary to the model card approach increasingly
adopted6 to surface oft hidden details about NLP 4160 regard, and can inform the ongoing development of
national (NIST, 2019) and international standards7. evaluation metrics for natural language generation
(Novikova et al., 2017; Reiter, 2018; Kryscinski
et al., 2019): due to the tests’ synthetic nature they
may not fully capture the nuances of reality. For
example, if a test’s objective were to test an NLP
system’s reliability when interacting with African
American English (AAE) speakers, would it be
possible to guarantee (in practice) that all gener-
ated examples fall within the distribution of AAE
texts? Potential research directions would be to
design adversary generation techniques that can
offer such guarantees or incorporate human feed-
back (Nguyen et al., 2017; Kreutzer et al., 2018;
Stiennon et al., 2020). While external algorithm audits are becoming pop-
ular, testing remains a challenge since companies
wishing to protect their intellectual property may
be resistant to sharing their code (Johnson, 2021),
and implementing custom tests for each system
is unscalable. Our approach to reliability testing
offers a potential solution to this conundrum by
treating NLP systems as black boxes. If reliabil-
ity tests become a legal requirement, regulatory
authorities will be able to mandate independently
conducted reliability tests for transparency. Such
standards, combined with certification programs
(e.g., IEEE’s Ethics Certification Program for Au-
tonomous and Intelligent Systems8), will further
incentivize the development of responsible NLP, as
the companies purchasing NLP systems will insist
on certified systems to protect them from both le-
gal and brand risk. To avoid confusion, we expect
certification to occur for individual NLP systems
(e.g., an end-to-end question answering system for
customer enquiries), rather than for general pur-
pose language models that will be further trained
to perform some specific NLP task. While con-
crete standards and certification programs that can
serve this purpose do not yet exist, we believe that
they eventually will and hope our paper will inform
their development. This multi-pronged approach
can help to mitigate NLP’s potential harms while
increasing public trust in language technology. 8standards.ieee.org/industry-connections/ecpais.html 7ethicsstandards.org/p7000
8 7ethicsstandards.org/p7000
8standards.ieee.org/industry-connections/ecpais.html Broader Impact Grenning, Jim Highsmith, Andrew Hunt, Ron Jeffries,
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§1, §3, and §7, standards and regulations for AI
systems are in the process of being developed for
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Testing Dimensions: Detecting Violent
Content on Social Media In this second case study, we apply DOCTOR for
measuring the reliability of a violent content de-
tection system for English social media posts. Al-
though we limit this discussion to the U.S., this is a
growing global problem (Laub, 2019) that can lead
to deadly outcomes (Rajagopalan et al., 2018). In
this hypothetical use case, the NLP system may au-
tomatically remove violent content or alert content
moderators to potential violations of the social me-
dia company’s acceptable use policy. Moderators
can decide if specific content should be removed,
and if necessary, notify law enforcement to avert
pending violence (e.g., threats against individuals,
planned violent events). As a result of the 1996
Communications Decency Act9, social media plat-
forms have broad latitude (Klonick, 2018) to de-
velop their own policies for acceptable content and
how they handle it. In this scenario, the compliance
officer of the company developing the system is re-
sponsible for making sure it does not discriminate
against specific user demographics. Dimensions. There are two tasks under consider-
ation here: identifying violent content and identi-
fying Hunters who “truly intend to use lethal vio-
lence” (Marsters, 2019). In the first task, the sys-
tem is looking for content that negatively targets a
socially defined group. Additionally, the content
includes not only hate speech (e.g., profanity, epi-
thets, vulgarity) but also content that incites others
to hatred or violence. Since content written in AAE
has been shown to be flagged as toxic more often
(Sap et al., 2019; Davidson et al., 2019), we must
ensure that the system is reliable when encounter-
ing dialectal variation. Additionally, due to the
casual environment of social media, multilingual
speakers often code-switch and code-mix. Hence,
we expect variation in these dimensions to have
no effect on the system’s predictions: alternative
spellings, morphosyntactic variation, word choice,
code-mixing, idioms, and references to and mani-
festations of sensitive attributes and their proxies. However, we must expect the system to be sensitive
to in-group and out-group usage of reclaimed slurs
so that the in-group usage does not result in a flag
while out-group usage result in flagged posts. Research has shown that hate speech can lead to
hateful actions (Marsters, 2019). In many cases,
individuals posted their intents online prior to com-
mitting violence (Cohen et al., 2014). 9fcc.gov/general/telecommunications-act-1996 Appendix different Latinx (Hispanic) vernacular Englishes. different Latinx (Hispanic) vernacular Englishes (
p
)
g
Stakeholder Impact. The key stakeholders that
will be impacted are those most often facing violent
threats online: minorities, women, immigrants, and
the LGBTQ community (Amnesty International,
2018; Ganesh, 2018; Davidson et al., 2019; Wake-
field, 2020). Additionally, anyone that posts con-
tent on the social media site is a stakeholder. Un-
fortunately, the very communities that are often
the target of violent posts are also often wrongly
flagged as posting toxic content themselves due to
racial biases present in the training data (Sap et al.,
2019; Davidson et al., 2019). Given the risk of
harm to victims if the system misses violent posts
from hunters or misidentifies legitimate content as
violent and notifies law enforcement, it is critical
the right balance of false positives and false nega-
tives is achieved in flagging content. Stakeholder Impact. The key stakeholders that
will be impacted are those most often facing violent
threats online: minorities, women, immigrants, and
the LGBTQ community (Amnesty International,
2018; Ganesh, 2018; Davidson et al., 2019; Wake-
field, 2020). Additionally, anyone that posts con-
tent on the social media site is a stakeholder. Un-
fortunately, the very communities that are often
the target of violent posts are also often wrongly
flagged as posting toxic content themselves due to
racial biases present in the training data (Sap et al.,
2019; Davidson et al., 2019). Given the risk of
harm to victims if the system misses violent posts
from hunters or misidentifies legitimate content as
violent and notifies law enforcement, it is critical
the right balance of false positives and false nega-
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Testing Dimensions: Detecting Violent
Content on Social Media When iden-
tifying content to remove and especially when in-
volving law enforcement, it is important to distin-
guish between “Hunters" — those who act — and
“Howlers" — those who do not (Marsters, 2019). This is to avoid wrongly detaining individuals who
have no intention of committing violence, even
if their words are indefensible. Between these ex-
tremes, posters may harass, stalk, dox, or otherwise
abuse victims from a distance, therefore it is still
necessary to flag, remove, and potentially track or
document violent content. Linguistic landscape. We focus solely on En-
glish speakers, but we acknowledge that the actual
linguistic landscape is much more complex (over
350 languages). Posters on social media may speak
English as their first language or as a second lan-
guage and they often code-switch/-mix. Standard
American English is used for business purposes
in the U.S. but there are other frequently used lan-
guage varieties including African American En-
glish (AAE), Cajun Vernacular English, and three When identifying hunters, we may expect the sys-
tem to be sensitive to uses of first person pronouns,
certainty adverbs, negative evaluative adjectives,
and modifiers (Marsters, 2019). However, in or-
der to avoid unfairly penalizing vernacular English
speakers we should expect the system’s predictions
to be equally unaffected by variation in the dimen-
sions listed for the first task. 4168 Orthography
Hyphenation
Capitalization
Punctuation
Reduplication of letters
Emojis/emoticons
Homonyms
Disemvoweling (Eger and Benz, 2020)
Homophones (e.g., accept vs. except) (Eger and Benz, 2020)
Accidental misspellings (Belinkov and Bisk, 2018)
Intentional alternative spellings (e.g., Yas, thru, startin)
Open compound concatenation (e.g., couch potato/couchpotato)
Dialectal differences (e.g., favor vs. favour) (Ribeiro et al., 2018)
Mixing writing scripts (Tan and Joty, 2021)
Transliteration
Morphology
Grammatical gender shifts
Grammatical category (Tan et al., 2020)
Dialectal differences (Tan et al., 2020)
Linguistic
Clitics
Phenomena
Lexicon
Dialectal variation (e.g., fries vs. chips)
Synonyms/Sememes (Zang et al., 2020)
Vocabulary simplicity/complexity
Cross-lingual synonyms (Tan and Joty, 2021)
Loanwords
Semantics
Idioms (e.g., finer than frog hair)
Syntax
Matching number and tense
Word/phrase order (especially for languages without strict word ordering)
Prepositional variation (e.g., stand on line vs. A
Testing Dimensions: Detecting Violent
Content on Social Media stand in line)
Syntactic variation (Iyyer et al., 2018)
Sentence simplicity/complexity
Code-mixing (Tan and Joty, 2021)
Register (e.g., formality)
Discourse
Conversational style (involvement/considerateness) (Tannen et al., 2005)
&
Discourse markers / connector words
Pragmatics
Cross-cultural differences
Code-switching
Sensitive Attributes
Gender Identity
Gender pronouns
Names
Reclaimed slurs
Genderlects (Tannen, 1991; Dunn, 2014)
Race
Names
Reclaimed slurs
Race-aligned language varieties
Age
Age/generation-aligned language styles (Hovy et al., 2020)
Religion
Names
Reclaimed slurs
Sexual Orientation
Reclaimed slurs
Disability status
Associated adjectives (Hutchinson et al., 2020)
Place of origin
Location names (e.g., cities, countries)
Figures of speech
Proxies
Geographic locations (for ethnicity, socioeconomic status)
Malicious Attacks
Black-box
Rule-based (Alzantot et al., 2018; Jin et al., 2020)
Model-based (Garg and Ramakrishnan, 2020; Li et al., 2020a)
Gradient-based
HotFlip (Ebrahimi et al., 2018), Universal Triggers (Wallace et al., 2019)
Policy-based
Adversarial negotiation agent (Cheng et al., 2019)
Table 1: Taxonomy of possible dimensions with references to linguistics literature and existing adversarial attacks
that could be used as worst-case tests. Linguists are best equipped to decide which linguistic phenomena are high Table 1: Taxonomy of possible dimensions with references to linguistics literature and existing adversarial attacks
that could be used as worst-case tests. Linguists are best equipped to decide which linguistic phenomena are high
priority for each use case, ethicists for sensitive attributes, and NLP practitioners for malicious attacks. Table 1: Taxonomy of possible dimensions with references to linguistics literature and existing adversarial attacks
that could be used as worst-case tests. Linguists are best equipped to decide which linguistic phenomena are high
priority for each use case, ethicists for sensitive attributes, and NLP practitioners for malicious attacks. 4169
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English
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Do Reproductive Factors Influence T, N, and M Classes of Ductal and Lobular Breast Cancers? A Nation-Wide Follow-Up Study
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cc-by
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Citation for published version (APA):
Mousavi, S. M., Försti, A., Sundquist, K., & Hemminki, K. (2013). Do Reproductive Factors Influence T, N, and M
Classes of Ductal and Lobular Breast Cancers? A Nation-Wide Follow-Up Study. PLoS ONE, 8(5), Article
e58867. https://doi.org/10.1371/journal.pone.0058867 Do Reproductive Factors Influence T, N, and M Classes of Ductal and Lobular Breast
Cancers? A Nation-Wide Follow-Up Study
Mousavi, Seyed Mohsen; Försti, Asta; Sundquist, Kristina; Hemminki, Kari
Published in:
PLoS ONE
DOI:
10.1371/journal.pone.0058867
2013
Link to publication
Citation for published version (APA):
Mousavi, S. M., Försti, A., Sundquist, K., & Hemminki, K. (2013). Do Reproductive Factors Influence T, N, and M
Classes of Ductal and Lobular Breast Cancers? A Nation-Wide Follow-Up Study. PLoS ONE, 8(5), Article
e58867. https://doi.org/10.1371/journal.pone.0058867
T t l
b
f
th Do Reproductive Factors Influence T, N, and M Classes of Ductal and Lobular Breast
Cancers? A Nation-Wide Follow-Up Study Link to publication Citation for published version (APA):
Mousavi, S. M., Försti, A., Sundquist, K., & Hemminki, K. (2013). Do Reproductive Factors Influence T, N, and M
Classes of Ductal and Lobular Breast Cancers? A Nation-Wide Follow-Up Study. PLoS ONE, 8(5), Article
e58867. https://doi.org/10.1371/journal.pone.0058867 Total number of authors:
4 Abstract The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Funding: This study was supported by the Deutsche Krebshilfe, the Swedish Council for Working Life and Social Resear
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manu Competing Interests: The authors have declared that no competing interests exist. * E-mail: K.Hemminki@dkfz.de Abstract Backgrounds: The clinical tumor-node-metastasis (T, N and M) classes of breast cancers provide important prognostic
information. However, the possible association of TNM classes with reproductive factors has remained largely unexplored. Because every woman has a reproductive history, implications to outcome prediction are potentially significant. Methods: During the study period from 2002 through 2008, 5,614 pre- and 27,310 postmenopausal patients were identified
in the Swedish Family-Cancer Database. Ordinal logistic regression analysis was used to estimate odds ratios (ORs) for TNM
classes of breast cancers by histology. The reproductive variables were parity, age at first and last childbirth and time
interval between first and last childbirth. Results: Among postmenopausal patients, the ORs for high-T class (T2–T4) (tumor size $2 cm) and metastasis were
decreased by parity. A late age at first and last childbirth associated with high-T class and the effects were higher for lobular
(OR for late age at first childbirth = 2.85) than ductal carcinoma. Overall, long time interval between first and last childbirth
was related to high-T class and metastasis. However, a short time interval between first and last childbirth in patients with
late age at first or last childbirth increased the risk of metastasis. Late age at last childbirth was associated with increased
occurrence of lobular carcinoma in situ. Among premenopausal ductal carcinoma patients, nulliparity and early age at first
childbirth were associated with high-T class. Conclusions: Increasing parity was protective against high-T class and metastasis; late ages at first and last childbirth were
risk factors for high-T class in postmenopausal breast cancers. The current decline in parity and delayed age at first
childbirth in many countries may negatively influence prognosis of breast cancer. ation: Mousavi SM, Fo¨rsti A, Sundquist K, Hemminki K (2013) Do Reproductive Factors Influence T, N, and M Classes of Ductal and Lob
tion-Wide Follow-Up Study. PLoS ONE 8(5): e58867. doi:10.1371/journal.pone.0058867 Editor: Tatjana Adamovic, Karolinska Institutet, Sweden Received November 19, 2012; Accepted February 7, 2013; Published May 29, 2013 Copyright: 2013 Mousavi et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This study was supported by the Deutsche Krebshilfe, the Swedish Council for Working Life and Social Research, and EU FP7/2007–2013 grant 260715. Do Reproductive Factors Influence T, N, and M Classes of
Ductal and Lobular Breast Cancers? A Nation-Wide
Follow-Up Study Seyed Mohsen Mousavi1, Asta Fo¨ rsti1,2, Kristina Sundquist2, Kari Hemminki1,2*
1 Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2 Center for Primary Health Care Research, Lund University/
Region Ska˚ne, Malmo¨, Sweden Seyed Mohsen Mousavi1, Asta Fo¨ rsti1,2, Kristina Sundquist2, Kari Hemminki1,2* y
q
1 Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2 Center for Primary Health Care Research, Lund University/
Region Ska˚ne, Malmo¨, Sweden General rights
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access to the work immediately and investigate your claim. LUND UNIVERSITY
PO Box 117
221 00 Lund
+46 46-222 00 00 Results We identified 27,310 postmenopausal and 5,614 premenopaus-
al breast cancer patients in the database. The histological type of
breast cancer among postmenopausal patients was ductal in 68.5%
of patients and lobular in 14.8% of patients, while premenopausal
carcinomas were 77.1% ductal and 10.1% lobular. Our data included 10,794 T1, 13,767 N0 and 15,186 M0 cases
of postmenopausal breast cancer (Table 1). Parity had no
significant influence on carcinoma in situ. For invasive cancer,
we calculated ORs for any T class separately. The results were
very similar for any of them. Therefore, to catch the maximum
number of cases for each group, we combined T2–T4. The OR
decreased for higher T classes (T2–T4) among patients with two
(0.82) or three (0.83) children compared to patients with one child. Multiparity was associated with a decreased risk of distant
metastases (ORs ranging from 0.65 to 0.70). For invasive breast
cancer, increasing age at first and last childbirth above 30 years
were associated with a higher T class; the OR was 1.84 and 1.45
for those with an age at first and last childbirth over 39 years,
respectively. Similarly, a time interval between first and last
childbirth $10 years associated with an increasing T. Patients
with an age at last childbirth $40 years were at an increased risk
of lymph node involvement (1.22), while those with a time interval
between first and last childbirth $5 years had a risk of distant
metastases (1.40 for time interval between first and last childbirth
5–9 years). Risk of metastasis was also increased for cases with an
age at first childbirth #19 years (1.34). Tumor size and local growth (T), regional lymph node
involvement (N) and the presence of metastasis (M) according to
the TNM classification system published by the American Joint
Committee on Cancer have been available in the FCD since 2002
[6,29]. The basis for TNM classification in the FCD was clinical or
pathological findings [28]. Numbers or letters after T, N and M
provide more details about the classification. The numbers 0
through 4 indicate increasing severity. Breast cancer patients in
native Swedish women from 2002 to 2008 were obtained from the
FCD. Parity (0, 1, 2, 3 and $4), age at first and last childbirth (#19,
20–29, 30–39 and $40), and time interval between first and last
childbirth (1–4, 5–9 and $10) were obtained from the FCD. Introduction and rapid proliferation of breast tissue during pregnancy and
lactation play a major role [9,15–17]. Demographic changes over recent decades in developed
countries and even among educated women in developing
countries have modified reproductive patterns towards delayed
childbearing and declining parity [1–4]. Reproductive factors are
strongly associated with the risk of breast cancer and, unfortu-
nately, both delayed childbearing and low parity increase the risk
of breast cancer [5]. In fact, in developed countries these two
reproductive parameters may explain as much as 30 to 40% of
breast cancer etiology [6]. Many studies have also shown that
reproductive factors differentially influence breast cancer histology
[7,8]. For example, multiparity is known to decrease the risk of
ductal and lobular carcinomas, while late age at first childbirth
increases the risk [7–11]. The influence of age at last childbirth
and birth interval remains unclear [12–14]. The underlying
mechanisms are not well known but, it is widely believed that
hormonal and other physiological changes in the mammary gland In developed countries, breast cancer is mainly a postmeno-
pausal disease. The effects of reproductive factors on histology of
breast cancer vary according to the menopausal status [8,18]. Among postmenopausal women, the effects of reproductive factors
are more strongly associated with invasive ductal than lobular
carcinoma [19]. However, for in situ breast cancer the reverse may
be true [20,21]. Among premenopausal women, reproductive risk
factors may be more strongly associated with in situ than invasive
cancers [18,22]. Only a few previous studies have examined the effect of
reproductive factors on the stage or grade of histology-specific
breast cancer [12,20,21]. These suggest that nulliparity, late age at
first childbirth, and the first two years after pregnancy are
associated with unfavorable clinical data. To our knowledge, no
previous study has analyzed the association of reproductive factors
with tumor-node-metastasis (T, N and M) classes of breast cancer 1 PLOS ONE | www.plosone.org May 2013 | Volume 8 | Issue 5 | e58867 Reproductive Factors and TNM in Breast Cancer analysis. A P-value of less than 0.05 was considered statistically
significant. which provide important prognostic information [23–25]. We
explore here the association of parity, age at first and last
childbirth, and time interval between first and last childbirth with
the TNM classes of ductal and lobular carcinomas, the most
common histological subtypes [5]. Both pre- and postmenopausal
breast cancers were included from the Swedish Cancer Registry
from 2002 through 2008. Patients and Methods We used the 2010 update of the Swedish Family-Cancer
Database (FCD), which contains population-based data from the
Swedish Cancer Registry, multigenerational registries, national
censuses and death notifications [26,27]. This database contains
information on people born in Sweden since 1932 and their
biological parents. Native Swedish women were defined as those
who, along with their parents, were born in Sweden. Introduction Our study population comprised 23,045 ductal, 4,611 lobular,
1,047 tubular and 728 mucinous carcinoma patients. The analyses
of the last two histologies are not presented in this report because
of the small numbers of cases in the TNM classes for menopausal
status and any reproductive factors. As there are correlations
between the variables age at first and last childbirth and time
interval between first and last childbirth, we stratified age at first
and last childbirth by time interval between first and last
childbirth. Alternatively, we examined the effect of parity and
the time interval between first and last childbirth by adding the age
at first or last childbirth to the adjustment; however, because of the
small numbers of premenopausal breast cancer cases in any
subclasses, this analysis was only applied to postmenopausal cases. Ethics Statement Following the start of cancer registration in 1958, data on
cancers in the FCD had a 4-digit diagnostic code according to the
seventh revision of the International Classification of Disease
(ICD). The codes for breast cancer were 170.1 and 170.2. Since
1993, ICD-O-2/ICD with histopathological data according to the
Systematized Nomenclature of Medicine (SNOMED) has been
used. This coding system gives a detailed tumor histology-
topology. We analyzed ductal (SNOMED = 8500 and 8501),
lobular (8520), tubular (8211) and mucinous (8480) carcinomas. Nonspecific adenocarcinoma (8140) was not included in our
analysis (N = 2,493). All breast cancer cases (100%) registered in
the Cancer Registry were histologically verified [28]. The Lund regional Ethics Committee approved the study
protocol. The corresponding author had full access to the FCD
and had final responsibility for the decision to submit for
publication. May 2013 | Volume 8 | Issue 5 | e58867 Results The
data for ages at menarche and menopause were not available in
the dataset. It also contains longitudinal demographic and socio-
economic data from the national censuses of 1960, 1970, 1980,
and 1990 [30]. The occupational data were grouped into white-
collar workers, blue-collar workers, privates, professionals and
others. We also divided Sweden regionally into three groups:
North, South and large cities. Ordinal logistic regression was used to calculate odds ratios
(ORs) (PROC LOGISTIC; SAS software version 9.2; SAS
Institute
Inc.,
Cary,
NC,
USA). The
parity
(number
of
children = 1), the age at first and last childbirth (20–29 years),
and the time interval between first and last childbirth (1–4 years)
were selected as references. The ORs were adjusted for age at
diagnosis, region, occupation and, in some analyses, parity. To
assess the effect of the median age at menopause, the analyses were
stratified by age (#50 and .50 years) [31,32]. Confidence
intervals (95% CI) were calculated assuming a Poisson distribution
using T1, N0 and M0 as the references for ‘‘Tis’’ (carcinoma in
situ) and ‘‘T2–T4’’, ‘‘N1–N3’’ and ‘‘M1’’, respectively. There was
missing information on 7,557 patients for T, on 8,030 patients for
N and on 8,124 patients on M in our database. We also excluded
TX (N = 1,033), T0 (1,673), NX (1,753) and MX (5,785) from our The analyses shown in Table 1 were repeated in Table 2 by
adjusting for parity and by stratifying for time interval between
first and last childbirth. Risk of distant metastases was increased in
patients with late age at first and last childbirth when children
were born in a short interval of 1–4 years; the highest significant
OR was 1.85 for an age at last childbirth of 30–39 years. A high-T
class was observed for patients with a late age at first and last
childbirth when the time interval between first and last childbirth
was 5–9 years. The OR for high-T class was 0.77 for patients with
early age at first childbirth and a time interval between first and
last childbirth of more than 9 years. Additional analyses of parity
and time interval between first and last childbirth showed that
adjustment for age at first or last childbirth did not change the
results (data not shown). May 2013 | Volume 8 | Issue 5 | e58867 PLOS ONE | www.plosone.org 2 Reproductive Factors and TNM in Breast Cancer Table 1. Results Odds ratios (ORs) for TNM classes in postmenopausal breast cancer by reproductive factors. Reproductive factors T1
Tis* vr. T1
T2–T4** vr. T1
N0
N1–N3 vr. N0
M0
M1 vr. M0
N
N
OR (95%CI)
P
N
OR (95%CI)
P
N
N
OR (95%CI)
P
N
N
OR (95%CI)
P
Parity1
1 (Ref.)
1,924
39
1.00
1,620
1.00
2,546
1,005
1.00
2,862
145
1.00
0
1,114
26
1.16 (0.70–1.93)
0.57
816
1.08 (0.96–1.21)
0.21
1,527
552
0.97 (0.85–1.09)
0.58
1,638
55
0.90 (0.65–1.24)
0.51
2
4,806
107
1.16 (0.80–1.68)
0.44
3,043
0.82 (0.76–0.89)
,0.0001
6,030
2,160
0.91 (0.84–1.00)
0.05
6,572
199
0.65 (0.52–0.82)
,0.01
3
2,185
50
1.19 (0.78–1.82)
0.43
1,457
0.83 (0.75–0.91)
,0.01
2,676
1,070
0.99 (0.90–1.10)
0.87
2,943
100
0.69 (0.53–0.89)
0.01
$4
765
12
0.79 (0.41–1.52)
0.47
687
0.98 (0.86–1.11)
0.73
988
435
1.03 (0.90-1.18)
0.68
1,171
49
0.70 (0.50–0.98)
0.04
Total
10,794
234
7,623
13,767
5,222
15,186
548
Age at first childbirth (year)2
20–29 (Ref.)
6,932
148
1.00
4,714
1.00
8,651
3,277
1.00
9,504
322
1.00
#19
1,208
30
1.16 (0.77–1.73)
0.48
742
0.93 (0.84–1.03)
0.18
1,485
601
1.05 (0.95–1.16)
0.37
1,658
74
1.34 (1.03–1.73)
0.03
30–39
1,468
30
0.89 (0.59–1.32)
0.56
1,260
1.20 (1.10–1.31)
,0.0001
1,998
740
0.99 (0.90–1.09)
0.79
2,252
92
1.20 (0.94–1.52)
0.14
$40
72
0
(2)
91
1.84 (1.33–2.53)
,0.01
106
52
1.35 (0.96–1.88)
0.08
134
5
1.14 (0.46–2.82)
0.78
Total
9,680
208
6,807
12,240
4,670
13,548
493
Age at last childbirth (year)2
20–29 (Ref.)
4,503
101
1.00
2,822
1.00
5,576
2,079
1.00
6,101
207
1.00
#19
163
4
1.07 (0.39–2.95)
0.90
119
1.12 (0.87–1.43)
0.38
223
79
0.95 (0.73–1.24)
0.70
250
11
1.25 (0.67–2.33)
0.48
30–39
4,626
95
0.88 (0.66–1.17)
0.38
3,455
1.11 (1.04–1.18)
,0.01
5,927
2,272
1.02 (0.95–1.10)
0.56
6,544
246
1.06 (0.88–1.28)
0.55
$40
388
8
0.83 (0.40–1.74)
0.63
411
1.45 (1.25–1.69)
,0.0001
514
240
1.22 (1.03–1.43)
0.02
653
29
1.12 (0.75–1.68)
0.58
Total
9,680
208
6,807
12,240
4,670
13,548
493
Time interval between first and last childbirth (year)2
1–4 (Ref.)
3,429
73
1.00
2,068
1.00
4,259
1,536
1.00
4,640
112
1.00
5–9
2,762
64
1.12 (0.80–1.58)
0.50
1,833
1.03 (0.95–1.12)
0.52
3,397
1,318
1.05 (0.96–1.14)
0.32
3,714
141
1.40 (1.08–1.80)
0.01
$10
1,524
31
0.91 (0.59–1.40)
0.66
1,268
1.20 (1.09–1.32)
,0.01
1,987
798
1.05 (0.95–1.16)
0.35
2,279
94
1.39 (1.05–1.84)
0.02
Total
7,715
168
5,169
9,643
3,652
10,633
347
Bold type: 95% CI does not include 1.00. Results The ORs were adjusted for:
1. Age at diagnosis, region, and occupation. 2. Age at diagnosis, region, occupation, and parity. *Carcinoma in situ. **The number of cases for T2 (N = 6,098), T3 (871), and T4 (654). doi:10.1371/journal.pone.0058867.t001
PLOS ONE | www.plosone.org
3
May 2013 | Volume 8 | Issue 5 | e5 May 2013 | Volume 8 | Issue 5 | e58867 May 2013 | Volume 8 | Issue 5 | e58867 May 2013 | Volume 8 | Issue 5 | e58867 3 Reproductive Factors and TNM in Breast Cancer Table 2. Odds ratios (ORs) for TNM classes in postmenopausal breast cancer by age at first and last childbirth, stratified by time interval between first and last childbirth. Age at breast cancer
diagnosis
T1
Tis* vr. T1
T2–T4** vr. T1
N0
N1–N3 vr. N0
M0
M1 vr. Results M0
N
N
OR (95%CI)
P
N
OR (95%CI)
P
N
N
OR (95%CI)
P
N
N
OR (95%CI)
P
Time interval between first and last childbirth 1-4 years
Age at first childbirth (year)
20-29 (Ref.)
2,574
55
1.00
1,503
1.00
2,607
1,145 1.00
2,863
75
1.00
#19
277
5
0.84 (0.33–2.13)
0.71
138
0.08 (0.71–1.10)
0.25
20
132
1.14 (0.92–1.42)
0.24
23
5
0.63 (0.25–1.58)
0.33
30–39
569
13
1.00 (0.54–1.87)
1.00
415
1.14 (0.99-1.32)
0.09
1,574
252
0.90 (0.77–1.06)
0.21
1,679
31
1.61 (1.04–2.50)
0.03
$40
9
0
12
2.22 (0.91–5.40)
0.08
58
7
1.79 (0.70–4.58)
0.23
75
1
2.96 (0.37–23.62)
0.31
Total
3,429
73
2,068
1,574
1,536
4,640
112
Age at last childbirth (year)
20–29 (Ref.)
2,148
49
1.00
1,212
1.00
2,607
948
1.00
2,863
53
1.00
#19
19
0
8
0.69 (0.29–1.60)
0.37
20
7
0.92 (0.39–2.20)
0.86
23
0
30–39
1,219
23
0.81 (0.48–1.35)
0.42
809
1.09 (0.97–1.22)
0.18
1,574
556
0.99 (0.87–1.12)
0.84
1,679
56
1.85 (1.25–2.74)
,0.01
$40
43
1
0.81 (0.11–6.22)
0.84
39
1.40 (0.89–2.19)
0.16
58
25
1.19 (0.73–1.92)
0.49
75
3
1.96 (0.58–6.57)
0.28
Total
3,429
73
2,068
4,259
1,536
4,640
112
Time interval between first and last childbirth 5–9 years
Age at first childbirth (year)
20–29 (Ref.)
2,142
51
1.00
1,368
1.00
2,595
1,005 1.00
2,826
104 1.00
#19
370
10
1.17 (0.58–2.37)
0.66
219
1.00 (0.83–1.20)
0.99
451
188
1.08 (0.89–1.30)
0.44
482
25
1.60 (1.01–2.53)
0.05
30–39
249
3
0.46 (0.14–1.49)
0.20
245
1.48 (1.22–1.80)
,.0001 350
124
0.92 (0.74–1.15)
0.48
404
12
0.75 (0.41–1.39)
0.36
$40
1
0
1
1.61 (0.1–27.32)
0.74
1
1
2.49 (0.16–40.04)
0.52
2
0
Total
2,762
64
1,833
3,397
1,318
3,714
141
Age at last childbirth (year)
20–29 (Ref.)
1,130
28
667
1.00
1,387
534
1.00
1,483
66
1.00
#19
0
0
1.00
0
0
0
0
0
30–39
1,577
35
0.84 (0.50–1.41)
0.51
1,104
1.14 (1.01–1.30)
0.04
1,937
749
1.02 (0.89–1.17)
0.78
2,142
70
0.73 (0.51–1.03)
0.08
$40
55
1
0.66 (0.09–5.01)
0.68
62
1.73 (1.18–2.55)
0.01
73
35
1.28 (0.84–1.96)
0.25
89
5
1.22 (0.47–3.16)
0.68
Total
2,762
64
1,833
3,397
1,318
3,714
141
Time interval between first and last childbirth $10 years
Age at first childbirth (year)
20–29 (Ref.)
1,077
18
1.00
953
1.00
1,416
571
1.00
1,625
60
1.00
#19
417
11
1.46 (0.67–3.20)
0.34
274
0.77 (0.64–0.93)
0.01
525
209
0.99 (0.82–1.20)
0.90
598
33
1.56 (1.00–2.44)
0.05
PLOS ONE | www.plosone.org
4
May 2013 | Volume 8 | Issue 5 | e5886 4 Reproductive Factors and TNM in Breast Cancer Table 2. May 2013 | Volume 8 | Issue 5 | e58867 Results Cont. Time interval between first and last childbirth $10 years
Age at first childbirth (year)
30–39
30
2
3.78 (0.80–17.9)
0.09
41
1.34 (0.82–2.18)
0.25
46
18
0.97 (0.55–1.69)
0.90
56
1
0.41 (0.06–3.07)
0.39
$40
0
0
0
0
0
0
0
Total
1,524
31
1,268
1,987
798
2,279
94
Age at last childbirth (year)
20–29 (Ref.)
1,077
0
1.00
53
1.00
112
41
1.00
131
5
1.00
0.96
#19
417
0
0
0
0
0
0
0.96
30–39
30
25
983
1.22 (0.85–1.75)
0.28
1,585
621
1.07 (0.74–1.55)
0.73
1,775
72
0.98 (0.38–2.48)
0.96
$40
0
6
232
1.41 (0.95–2.11)
0.09
290
136
1.28 (0.84–1.94)
0.25
373
17
1.00 (0.35–2.80)
0.99
Total
1,524
31
1,268
1,987
798
2,279 94
Bold type: 95% CI does not include 1.00. Women with two or more children were included. ORs were adjusted for parity, region and occupation. *Carcinoma in situ. doi:10.1371/journal.pone.0058867.t002
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5
May 2013 | Volume 8 | Issue 5 | e58867 Table 2. Cont. Time interval between first and last childbirth $10 years
Age at first childbirth (year)
30–39
30
2
3.78 (0.80–17.9)
0.09
41
1.34 (0.82–2.18)
0.25
46
18
0.97 (0.55–1.69)
0.90
56
1
0.41 (0.06–3.07)
0.39
$40
0
0
0
0
0
0
0
Total
1,524
31
1,268
1,987
798
2,279
94
Age at last childbirth (year)
20–29 (Ref.)
1,077
0
1.00
53
1.00
112
41
1.00
131
5
1.00
0.96
#19
417
0
0
0
0
0
0
0.96
30–39
30
25
983
1.22 (0.85–1.75)
0.28
1,585
621
1.07 (0.74–1.55)
0.73
1,775
72
0.98 (0.38–2.48)
0.96
$40
0
6
232
1.41 (0.95–2.11)
0.09
290
136
1.28 (0.84–1.94)
0.25
373
17
1.00 (0.35–2.80)
0.99
Total
1,524
31
1,268
1,987
798
2,279 94
Bold type: 95% CI does not include 1.00. Women with two or more children were included. ORs were adjusted for parity, region and occupation. *Carcinoma in situ. doi:10.1371/journal.pone.0058867.t002 PLOS ONE | www.plosone.org May 2013 | Volume 8 | Issue 5 | e58867 5 Reproductive Factors and TNM in Breast Cancer Table 3. Odds ratios (ORs) for TNM classes in postmenopausal ductal carcinoma by reproductive factors. Reproductive factors
T1
Tis* vr. T1
T2–T4** vr. T1
N0
N1–N3 vr. N0
M0
M1 vr. Results M0
N
N
OR (95%CI)
P
N
OR (95%CI)
P
N
N
OR (95%CI)
P
N
N
OR (95%CI)
P
Parity1
1 (Ref.)
1,399
22
1.00
1,033
1.00
1,746
717
1.00
1,979
72
1.00
0
830
20
1.54 (0.83–2.87)
0.17
553
1.08 (0.95–1.25)
0.25
1,115
402
0.92 (0.80–1.07)
0.29
1,211
30
0.90 (0.58–1.41)
0.65
2
3,519
71
1.32 (0.82–2.15)
0.26
2,004
0.84 (0.76–0.93)
,0.01
4,247
1606
0.93 (0.84–1.03)
0.17
4,699
105
0.67 (0.49–0.91)
0.01
3
1,599
31
1.31 (0.75–2.28)
0.34
958
0.85 (0.75–0.95)
,0.01
1,871
784
1.00 (0.89–1.13)
0.95
2,083
55
0.74 (0.52–1.06)
0.10
$4
534
7
0.92 (0.39–2.18)
0.85
440
1.03 (0.88–1.20)
0.73
669
307
1.03 (0.88–1.21)
0.73
799
30
0.84 (0.54–1.30)
0.44
Total
7,881
151
4,988
9,648
3,816
10,771
292
Age at first childbirth (year)2
20–29 (Ref.)
5,029
98
1.00
3,094
1.00
6,027
2394
1.00
6,724
176
1.00
#19
904
20
1.09 (0.67–1.78)
0.73
517
0.95 (0.84–1.07)
0.41
1,077
471
1.08 (0.96–1.22)
0.19
1,227
39
1.20 (0.84–1.71)
0.32
30–39
1,064
13
0.59 (0.33–1.06)
0.08
772
1.13 (1.02–1.26)
0.02
1,359
512
0.96 (0.85–1.07)
0.42
1,526
44
1.13 (0.81–1.59)
0.48
$40
54
0
(2)
52
1.51 (1.02–2.24)
0.04
70
37
1.37 (0.91–2.05)
0.13
83
3
1.46 (0.45–4.70)
0.53
Total
7,051
131
4,435
8,533
3,414
9,560
262
Age at last childbirth (year)2
20–29 (Ref.)
3,327
72
1.00
1,891
1.00
3,936
1562
1.00
4,401
111
1.00
#19
125
2
0.72 (0.17–3.00)
0.65
85
1.16 (0.87–1.55)
0.31
168
64
0.96 (0.72–1.29)
0.80
194
4
0.79 (0.29–2.17)
0.65
30–39
3,328
52
0.73 (0.51–1.06)
0.10
2,211
1.10 (1.01–1.19)
0.02
4,080
1628
1.00 (0.92–1.08)
0.95
4,544
132
1.13 (0.87–1.47)
0.34
$40
271
5
0.82 (0.33–2.06)
0.67
248
1.40 (1.16–1.68)
,0.01
349
160
1.12 (0.92–1.37)
0.25
421
15
1.26 (0.72–2.19)
0.42
Total
7,051
131
4,435
8,533
3,414
9,560
262
Time interval between first and last childbirth (year)2
1–4 (Ref.)
2,528
50
1.00
1,361
1.00
3,002
1143
1.00
3,322
58
1.00
5–9
2,016
39
1.04 (0.68–1.60)
0.84
1,210
1.05 (0.95–1.16)
0.34
2,397
966
1.03 (0.93–1.14)
0.62
2,644
82
1.55 (1.10–2.19)
0.01
$10
1,078
20
0.94 (0.55–1.61)
0.83
818
1.24 (1.10–1.39)
,0.01
1,350
578
1.07 (0.95–1.20)
0.30
1,577
50
1.45 (0.98–2.13)
0.06
Total
5,622
109
3,389
6,749
2,687
7,543
190
Bold type: 95% CI does not include 1.00. The ORs were adjusted for:
1. Age at diagnosis, region, and occupation. 2. Age at diagnosis, region, occupation, and parity. *Carcinoma in situ. Results **The number of cases for T2 (N = 4,133), T3 (484), and T4 (371). doi:10.1371/journal.pone.0058867.t003
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6
May 2013 | Volume 8 | Issue 5 | May 2013 | Volume 8 | Issue 5 | e58867 May 2013 | Volume 8 | Issue 5 | e58867 6 Reproductive Factors and TNM in Breast Cancer Table 4. Odds ratios (ORs) for TNM classes in postmenopausal lobular carcinoma by reproductive factors. Reproductive factors
T1
Tis* vr. T1
T2–T4** vr. T1
N0
N1–N3 vr. N0
M0
M1 vr. Results M0
N
N
OR (95%CI)
P
N
OR (95%CI)
P
N
N
OR (95%CI)
P
N
N
OR (95%CI)
P
Parity1
1 (Ref.)
246
3
1.00
303
1.00
404
164
1.00
459
19
1.00
0
146
2
1.04 (0.17–6.49)
0.96
152
0.95 (0.72–1.27)
0.75
216
82
0.98 (0.71–1.35)
0.91
229
6
0.74 (0.29–1.92)
0.54
2
618
11
1.61 (0.44–5.93)
0.47
555
0.77 (0.62–0.94)
0.01
858
320
0.90 (0.72–1.13)
0.37
950
28
0.75 (0.41–1.36)
0.34
3
318
6
1.57 (0.38–6.45)
0.53
277
0.72 (0.57–0.91)
0.01
430
178
0.94 (0.73–1.22)
0.66
471
19
1.01 (0.52–1.94)
0.98
$4
92
4
2.83 (0.6–13.32)
0.19
130
1.04 (0.75–1.44)
0.80
138
78
1.20 (0.85–1.68)
0.30
181
6
0.72 (0.28–1.85)
0.49
Total
1,420
26
1,417
2,046
822
2,290
78
Age at first childbirth (year)2
20–29 (Ref.)
919
17
1.00
846
1.00
1,293
513
1.00
1,423
40
1.00
#19
152
2
0.65 (0.14–2.88)
0.56
125
0.89 (0.69–1.16)
0.39
203
79
0.94 (0.71–1.26)
0.69
226
15
2.23 (1.20–4.16)
0.01
30–39
194
5
1.29 (0.46–3.64)
0.63
271
1.43 (1.16–1.77)
,0.01
315
137
1.11 (0.88–1.40)
0.36
383
17
1.50 (0.83–2.71)
0.17
$40
9
0
23
2.85 (1.29–6.28)
0.01
19
11
1.40 (0.65–3.00)
0.39
29
0
Total
1,274
24
1,265
1,830
740
2,061
72
Age at last childbirth (year)2
20–29 (Ref.)
565
2
1.00
494
1.00
801
301
1.00
876
32
1.00
#19
19
0
15
0.85 (0.42–1.72)
0.66
29
8
0.75 (0.33–1.66)
0.47
31
1
0.82 (0.11–6.32)
0.85
30–39
628
20
7.86 (1.81–34.20)
0.01
662
1.14 (0.96–1.34)
0.14
904
381
1.10 (0.91–1.32)
0.32
1,020
34
0.88 (0.53–1.45)
0.61
$40
62
2
8.08 (1.07–61.15)
0.04
94
1.51 (1.06–2.15)
0.02
96
50
1.23 (0.85–1.80)
0.27
134
5
0.85 (0.32–2.28)
0.75
Total
1,274
24
1,265
1,830
740
2,061
72
Time interval between first and last childbirth (year)2
1–4 (Ref.)
439
4
1.00
389
1.00
609
233
1.00
679
16
1.00
5–9
369
9
2.59 (0.78–8.66)
0.12
338
0.98 (0.80–1.20)
0.83
501
209
1.03 (0.82–1.29)
0.81
560
24
1.77 (0.93–3.40)
0.08
$10
214
7
2.94 (0.83–10.44)
0.10
232
1.10 (0.86–1.39)
0.45
308
132
0.99 (0.76–1.28)
0.91
355
12
1.22 (0.56–2.64)
0.62
Total
1,022
20
959
1,418
574
1,594
52
Bold type: 95% CI does not include 1.00. The ORs were adjusted for:
1. Age at diagnosis, region, and occupation. 2. Age at diagnosis, region, occupation, and parity. *Carcinoma in situ. **The number of cases for T2 (N = 1,106), T3 (236), and T4 (75). Results doi:10.1371/journal.pone.0058867.t004 May 2013 | Volume 8 | Issue 5 | e58867 May 2013 | Volume 8 | Issue 5 | e58867 May 2013 | Volume 8 | Issue 5 | e58867 7 7 Reproductive Factors and TNM in Breast Cancer Table 5. Odds ratios (ORs) for TNM classes in premenopausal ductal carcinoma by reproductive factors. Reproductive factors T1
Tis* vr. T1
T2–T4** vr. T1
N0
N1–N3 vr. N0
M0
M1 vr. Results M0
N
N
OR (95%CI)
P
N
OR (95%CI)
P
N
N
OR (95%CI)
P
N
N
OR (95%CI)
P
Parity1
1 (Ref.)
280
5
1.00
207
1.00
330
174
1.00
392
8
1.00
0
235
8
1.79 (0.57–5.59)
0.32
252
1.44 (1.11–1.85)
–0.01
343
180
0.99 (0.76–1.28)
0.93
408
14
1.67 (0.69–4.04)
0.26
2
830
24
1.67 (0.63–4.45)
0.30
528
0.86 (0.70–1.06)
0.16
949
481
0.97 (0.78–1.20)
0.76
1,079
33
1.46 (0.67–3.19)
0.35
3
358
8
1.39 (0.45–4.36)
0.57
245
0.94 (0.73–1.20)
0.59
393
235
1.14 (0.89–1.46)
0.30
488
8
0.77 (0.28–2.09)
0.61
$4
100
2
1.33 (0.25–7.11)
0.74
56
0.77 (0.53–1.13)
0.18
108
58
1.04 (0.72–1.52)
0.83
131
2
0.75 (0.15–3.62)
0.72
Total
1,803
47
1,288
2,123
1,128
2,498
65
Age at first childbirth (year)2
20–29 (Ref.)
1,037
30
1.00
640
1.00
1,159
602
1.00
1,355
37
1.00
#19
79
2
0.98 (0.22–4.28)
0.97
66
1.43 (1.01–2.03)
0.04
94
56
1.18 (0.83–1.68)
0.35
114
2
0.64 (0.15–2.75)
0.55
30–39
438
6
0.48 (0.20–1.19)
0.12
324
1.25 (1.04–1.50)
0.02
511
283
1.10 (0.92–1.32)
0.30
606
12
0.81 (0.41–1.59)
0.54
$40
14
1
2.55 (0.31–21.04)
0.38
6
0.80 (0.30–2.10)
0.65
16
7
0.90 (0.37–2.23)
0.83
15
0
Total
1,568
39
1,036
1,780
948
2,090
51
Age at last childbirth (year)2
20–29 (Ref.)
538
14
1.00
345
1.00
605
314
1.00
706
24
1.00
#19
7
0
8
1.87 (0.66–5.29)
0.24
13
4
0.67 (0.21–2.08)
0.48
15
0
30–39
973
23
1.07 (0.54–2.12)
0.86
640
1.10 (0.92–1.30)
0.30
1,094
598
1.10 (0.93–1.31)
0.28
1,288
27
0.69 (0.39–1.21)
0.19
$40
50
2
1.85 (0.40–8.59)
0.43
43
1.58 (1.02–2.44)
0.04
68
32
1.04 (0.66–1.62)
0.88
81
0
Total
1,568
39
1,036
1,780
948
2,090
51
Time interval between first and last childbirth (year)2
1–4 (Ref.)
711
18
1.00
463
1.00
814
412
1.00
927
25
1.00
5–9
382
14
1.53 (0.73–3.18)
0.26
241
1.00 (0.81–1.22)
0.98
427
233
1.11 (0.90–1.36)
0.33
505
14
1.02 (0.52–2.00)
0.96
$10
181
2
0.47 (0.11–2.10)
0.32
118
1.05 (0.81–1.37)
0.72
193
120
1.27 (0.97–1.65)
0.08
248
4
0.59 (0.20–1.75)
0.34
Total
1,274
34
822
1,434
765
1,680
43
Bold type: 95% CI does not include 1.00. The ORs were adjusted for:
1. Age at diagnosis, region, and occupation. 2. Age at diagnosis, region, occupation, and parity. *Carcinoma in situ. **The number of cases for T2 (N = 1,047), T3 (176), and T4 (65). Reproductive Factors and TNM in Breast Cancer Reproductive Factors and TNM in Breast Cancer Data for postmenopausal ductal cancer are shown in Table 3. As nearly 70% of all breast cancers were ductal, the ORs were
almost identical to those shown in Table 1. In contrast, many of
the significant effects shown in Table 1 were reinforced for lobular
cancer (Table 4). These included decreased ORs for high-T class
(0.77 and 0.72 when parity was 2 or 3, respectively, reversely,
when parity was equal or greater than 4, the OR for T4 class
increased: N = 13, OR = 2.75, 95% CI: 1.12–6.73), increased ORs
for high-T class according to age at first and last childbirth (2.85
when age at first childbirth was over 39 years) and an increased
OR for distant metastases (2.23 when age at first childbirth was
less than 20 years). A novel effect was noted for lobular carcinoma
in situ for which the OR was 7.86 when age at last childbirth was
30–39 years. metastases in pre- and postmenopausal patients [9,10]. Another
explanation could be a non-attendance at invitational mammog-
raphy screening, particularly among nulliparous women. Yet
national mammography screening is attended by 81% of those
invited in Sweden and mammography outside this program is also
available thought the country [41,42]. A study on 10,703 Danish women with breast cancer reported
that early age at first childbirth was associated with a poor breast
cancer prognosis [43]. We found accordingly that an early age at
first childbirth increased the risk of high-T class in premenopausal
ductal carcinoma (OR = 1.43) and increased the risk of metastases
in postmenopausal cancer of particularly lobular carcinoma (2.23)
while the effect on T class was opposite; this was the only instance
where low T class was associated with the risk of metastases. According to Table 2, the discrepancy between low T class and
metastasis was limited to those with early age at first childbirth
who had a long time interval between first and last childbirth. The database included 4,328 cases of premenopausal ductal
carcinoma, accounting for 77% of premenopausal cancers (Table
5). The main differences to postmenopausal ductal carcinoma
were that for premenopausal cancer nulliparity associated with
increased risk of high-T class (1.44). It was mainly caused by T4
class (N = 31, OR = 3.37, 95%CI: 1.66–6.85). Conclusions In summary, increasing parity was protective against high-T
class and metastasis. Late age at first and last childbirth were risk
factors for high-T class in almost all postmenopausal breast
cancers and the effects were stronger for lobular than ductal
histology. Low parity and long time interval between first and last
childbirth were risk factors for distant metastases. The observed
variation in the associations of reproductive factors with TNM
classes suggests that hormonal and other physiological changes
during pregnancy and menopause play an important role in
determining T class and metastatic spread, with implications to
prognosis. The current decline in parity and delayed age at first
childbirth in many global populations may counterbalance the
favorable achievements of prevention, screening and treatment of
breast cancer. Reproductive factors induce physiological changes in the
mammary gland such as rapid proliferation of breast tissue [11–
13,36]. Previous studies reported that nulliparity and late age at
first childbirth are related to aggressive tumor behavior [37–40]. Our results suggest that high-T class may mediate such effects:
nulliparity was associated with the risk of high-T class, particularly
in premenopausal ductal carcinomas and late age at first childbirth
was associated with high-T class in postmenopausal ductal and
lobular carcinomas. These findings suggest that physiological
changes related to parity and age at first childbirth during
pregnancy play a major role in the risk of high-T class and Discussion In this large nation-wide follow-up study of 32,924 Swedish
women with breast cancer, we found for postmenopausal cancer
that multiparity was associated with a decreased risk of high-T
class and distant metastases, while a late age at first or last
childbirth increased the risk of high-T class. There was a general
correlation between high-T class and distant metastases but not
with lymph node metastases, which appeared not to be affected by
reproductive factors. Risk of distant metastases was increased
particularly in patients with a late age at first or last childbirth
when the time interval between first and last childbirth was short,
which is a typical reproductive pattern of educated women [33]. A population-based study in Finland showed that short time
interval between first and last childbirth is a protective factor for
lobular carcinoma, but not for ducal carcinoma [14]. In our study,
the only significant effect was on T class in postmenopausal ductal
carcinoma. Pregnancy influences the level of estrogen and
increases the risk of breast cancer in a short term, but decreases
the risk in a long term [46–51]. Furthermore, pregnancy may also
induce changes in hormone levels that may affect tumor
progression in postmenopausal cases [52,53]. Whether the level
of estrogen influences the risk of high-T class and metastasis
remains to be investigated. Our study used information on breast cancer patients diagnosed
in the period 2002 to 2008, during which the histological
classification system did not vary. Thanks to a complete cancer
registration with verified histology, our study should be free of
selection bias [28,34]. Our findings on TNM classes, as prognostic
data for breast cancer, suggested survival effects relating to
reproductive factors but these could not be directly studied
because the TNM classification was started first in 2002 [23–25]. Several limitations should be considered in interpreting our results. Some 24% of T, N and M classes were missing in the Cancer
Registry. Neither were data available on age at menarche, breast
feeding, obesity, oral contraceptive use, mammographic breast
density, breast self-exam, hormone replacement therapy and
hormone receptor status [10,18,19,35]. Reproductive Factors and TNM in Breast Cancer High-T class was
also increased in patients with age at first childbirth of less than
20 years whereas age at first childbirth of over 39 years was not a
risk factor. Within the limits of detection, no reproductive
parameter changed the ORs for carcinoma in situ or for lymph
node or distant metastases. The association of age at last childbirth and breast cancer risk or
prognosis is unclear [12,13]. A case-control study reported an
increased risk of breast cancer of 1.10 (95CI%: 1.03–1.16) for each
5-year increase in age at last childbirth [13]. We found that a late
age at last childbirth increased the risk of high-T class in
postmenopausal ductal and lobular carcinomas and premeno-
pausal ductal carcinoma. One study reported that a late age at
childbirth and nulliparity are more strongly associated with
carcinoma in situ than invasive carcinoma in premenopausal
patients [18]. In our data, the case numbers for premenopausal
carcinoma in situ were small and only strong effects could have
been detected. However, such strong effects (OR 8.00) were noted
for postmenopausal lobular carcinoma in situ patients with a late
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at diagnosis is a key explanation of differences in breast cancer survival across
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and risk of breast cancer. Ernst Schering Found Symp Proc: 127–150. 24. Carey LA, Metzger R, Dees EC, Collichio F, Sartor CI, et al. (2005) American
Joint Committee on Cancer tumor-node-metastasis stage after neoadjuvant
chemotherapy and breast cancer outcome. J Natl Cancer Inst 97: 1137–1142. d risk of breast cancer. Ernst Schering Found Symp Proc: 127–150. 50. Kroman N, Wohlfahrt J, Andersen KW, Mouridsen HT, Westergaard T, et al. (1997) Time since childbirth and prognosis in primary breast cancer: population
based study. BMJ 315: 851–855. 25. Olivotto IA, Chua B, Allan SJ, Speers CH, Chia S, et al. (2003) Long-term
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26. Hemminki K, Ji J, Brandt A, Mousavi SM, Sundquist J (2009) The Swedish
Family-Cancer Database 2009: prospects for histology-specific and immigrant
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27. Hemminki K, Li X, Plna K, Granstrom C, Vaittinen P (2001) The nation-wide
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17. Kobayashi S, Sugiura H, Ando Y, Shiraki N, Yanagi T, et al. (2012)
Reproductive history and breast cancer risk. Breast Cancer. 43. Kroman N, Wohlfahrt J, Andersen KW, Mouridsen HT, Westergaard T, et al. (1998) Parity, age at first childbirth and the prognosis of primary breast cancer. Br J Cancer 78: 1529–1533. 18. Reinier KS, Vacek PM, Geller BM (2007) Risk factors for breast carcinoma in
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44. Lambe M, Hsieh CC, Tsaih SW, Ekbom A, Trichopoulos D, et al. (1998) Parity,
age at first birth and the risk of carcinoma in situ of the breast. Int J Cancer 77:
330–332. 19. Li CI, Malone KE, Porter PL, Weiss NS, Tang MT, et al. (2003) Reproductive
and anthropometric factors in relation to the risk of lobular and ductal breast
carcinoma among women 65–79 years of age. Int J Cancer 107: 647–651. 45. Ma H, Henderson KD, Sullivan-Halley J, Duan L, Marshall SF, et al. (2010)
Pregnancy-related factors and the risk of breast carcinoma in situ and invasive
breast cancer among postmenopausal women in the California Teachers Study
cohort. Breast Cancer Res 12: R35. 20. Albrektsen G, Heuch I, Thoresen S, Kvale G (2006) Clinical stage of breast
cancer by parity, age at birth, and time since birth: a progressive effect of
pregnancy hormones? Cancer Epidemiol Biomarkers Prev 15: 65–69. cohort. Breast Cancer Res 12: R35. 46. Persson I (2000) Estrogens in the causation of breast, endometrial and ovarian
cancers – evidence and hypotheses from epidemiological findings. J Steroid
Biochem Mol Biol 74: 357–364. 21. Wohlfahrt J, Andersen PK, Mouridsen HT, Melbye M (2001) Risk of late-stage
breast cancer after a childbirth. Author Contributions Conceived and designed the experiments: KH. Performed the experiments:
SMM KH. Analyzed the data: SMM AF KH. Contributed reagents/
materials/analysis tools: KS KH. Wrote the paper: SMM AF KH. May 2013 | Volume 8 | Issue 5 | e58867 PLOS ONE | www.plosone.org 9 Reproductive Factors and TNM in Breast Cancer References Ganz PA, Land SR (2008) Risks, benefits, and effects on quality of life of
selective estrogen-receptor modulator therapy in postmenopausal women at
increased risk of breast cancer. Menopause 15: 797–803. 28. The National Board of Health and Welfare (2010) Cancer Incidence in Sweden
2010. May 2013 | Volume 8 | Issue 5 | e58867 10 PLOS ONE | www.plosone.org
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ДОСЛІДЖЕННЯ ПОШИРЕНОСТІ ТА СПОСОБІВ ВИЯВЛЕННЯ ЕЙМЕРІОЗУ СЕРЕД КРОЛИКІВ ЗАЛЕЖНО ВІД РІЗНИХ МЕТОДІВ УТРИМАННЯ
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Vìsnik Sumsʹkogo nacìonalʹnogo agrarnogo unìversitetu. Serìâ: Veterinarna medicina
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Супрун Юлія Олександрівна Супрун Юлія Олександрівна
аспірант кафедри акушерства та хірургії
Сумський національний аграрний університет, м. Суми, Україна
ORCID: 0000-0001-8035-6282
ulianagerasimova@gmail.com Однією з ключових труднощів у процесі вирощування кроликів є еймеріоз незалежно від методів їх утримання
ця хвороба впливає на тварин усіх вікових груп призводячи до зменшення приросту ваги погіршення ефектив-
ності засвоєння корму підвищеної захворюваності. р у
щ
р
Мета дослідження було визначення поширеності та способів виявлення еймеріозу серед кроликів залежно від
різних методів утримання проводяться з метою вдосконалення стратегій боротьби з цим захворюванням і вдо-
сконалити методи карантину. р
у
Протягом періоду з 2019 по 2021 рік було проведено дослідження в господарствах з різним рівнем потужності
в чотирьох областях: Запорізька, Донецька, Харківська та Сумська. Загалом було обстежено 20 господарств, де
тримали кроликів різних порід. р
р
р
р
У фермерських та приватних кролівницьких господарствах виділяли E. іntestinalis, E. magna, E. media,
E. piriforms, E. perforans, E. irresidua. Доведено, що в зимовий період рівень ооцист був від 12±1,2 до 34±2,4
в п.з. мікроскопу. У літній період рівень інвазії на зменшувався, і коливався в межах від максимального – 15±1,2
(EI = 19 %), до мінімального – 5±2,0 (EI = 6 %). Дослідження підтвердило, що в умовах утримання в металевих
клітках у фермерських господарствах, за дотримання санітарно-гігієнічних норм та регулярної дезінфекції примі-
щень, рівень інвазії становив від 15% до 42% у зимовий період та від 6% до 19% у літній період. При аналізі даних,
отриманих з приватних господарств, де кролі утримуються в дерев'яних клітках з глибокою підстилкою, було
встановлено, що рівень інвазії становив від 56% до 100% у холодний період та від 29% до 70% у теплий період. Використання металевих кліток для утримання кролів з дотриманням санітарно-гігієнічних вимог та вчасної
дезінфекції сприяє зниженню рівня поширеності паразитарних заражень. р
р
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ова: еймеріоз кролів, біологічний цикл еймерій, інтенсивність інвазії, способи утримання кролів. ф
ц
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Ключові слова: еймеріоз кролів, біологічний цикл еймерій, інтенсивність інвазії, спо ф
ц
р
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Ключові слова: еймеріоз кролів, біологічний цикл еймерій, інтенсивність інвазії, способи утримання кролів. DOI https://doi.org/10.32782/bsnau.vet.2023.3.17 Вступ. Галузь кролівництва в Україні лише починає
набирати свої оберти. За рахунок швидкого росту та
дієтичним властивостям м’яса. Кролики – це альтерна-
тивний товар для тваринництва м'ясні запаси, а також
домашні тварини та лабораторні тварини (El-Shall et al.,
2022). Супрун Юлія Олександрівна М'ясо кролика має високий вміст білка, лінолено-
вої кислоти, кальцію і фосфору, низький вміст жиру та
холестерину, Також завдяки фізіологічним особливос-
тям кролів в процесі їх вирощування використовується
мінімальна кількість хімікотерапевтичних засобів. Тому
таку продукцію можна вважати органічною. Що наразі є
актуальним для харчової промисловості та зберігання
екологічного балансу в цілому (Saeed & Alkheraije, 2023). Вступ. Галузь кролівництва в Україні лише починає
набирати свої оберти. За рахунок швидкого росту та
дієтичним властивостям м’яса. Кролики – це альтерна-
тивний товар для тваринництва м'ясні запаси, а також
домашні тварини та лабораторні тварини (El-Shall et al.,
2022). М'ясо кролика має високий вміст білка, лінолено-
вої кислоти, кальцію і фосфору, низький вміст жиру та
холестерину, Також завдяки фізіологічним особливос-
тям кролів в процесі їх вирощування використовується
мінімальна кількість хімікотерапевтичних засобів. Тому
таку продукцію можна вважати органічною. Що наразі є
актуальним для харчової промисловості та зберігання
екологічного балансу в цілому (Saeed & Alkheraije, 2023). Підвищення інтенсивності вирощування кролів та
зосередження поголів'я на обмеженій території збіль-
шує можливість передачі захворювань. Оскільки еймерії
постійно присутні у шлунково-кишковому тракті кролів,
передача збудника від матері до дитини відбувається
навіть у перші дні життя. Ооцисти кокцидій виділяються
разом з фекаліями кролів, і вони можуть довгий час існу-
вати в навколишньому середовищі, достатньо одного ооциста для зараження нового господаря. Молоді кро-
ленята можуть заразитися цим паразитом, споживаючи
сіно, воду та навіть фекалії від матері чи одне одного
(Ogolla et al., 2018).. ( g
,
)
Кокцидіоз (еймеріоз) кролів (El-Ashram et al., 2019).,
яке спричиняється різними видами роду Eimeria з класу
Coccidia. Увідомлено про одинадцять видів еймерій
(Oryctolagus cuniculus) відноситься до паразитарних захво-
рювань (Athanasiou et al., 2023), що зустрічаються у шлун-
ково-кишковому тракті, а також один вид, що може жити у
жовчних протоках – Eimeria stiedae (Bochyńska et al., 2022). Кролики можуть заразитися кокцидіями з оточуючого
середовища, і це дуже часто стається в селекційних цен-
трах та на інших підприємствах, де зосереджена велика
кількість тварин. Для того щоб ооцисти (яйця) стали
інвазивними, потрібно принаймні два дні в умовах воло-
гості. Крім того, кролики можуть заразитися, споживаючи
траву та комбікорм, які містять заражені ооцисти ейме-
рій. У таких умовах важливо ретельно проводити дезін-
фекцію та знезаражування приміщень для утримання
тварин (Xiao et al., 2022). Кокцидіоз (еймеріоз) кролів (El-Ashram et al., 2019).,
яке спричиняється різними видами роду Eimeria з класу
Coccidia. УДК 636.4.03 УДК 636.4.03 УДК 636.4.03 Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 ДОСЛІДЖЕННЯ ПОШИРЕНОСТІ ТА СПОСОБІВ ВИЯВЛЕННЯ ЕЙМЕРІОЗУ СЕРЕД КРОЛИКІВ
ЗАЛЕЖНО ВІД РІЗНИХ МЕТОДІВ УТРИМАННЯ Шкромада Оксана Іванівна
доктор ветеринарних наук, професор
Сумський національний аграрний університет, м. Суми, Україна
ORCID: 0000-0003-1751-7009
oshkromada@gmail.com Шкромада Оксана Іванівна
доктор ветеринарних наук, професор
Сумський національний аграрний університет, м. Суми, Україна
ORCID: 0000-0003-1751-7009
oshkromada@gmail.com Супрун Юлія Олександрівна Проведення профілактичної дезінфекції кліток та
приміщень було здійснено за допомогою засобу "Тетра-
септ" (виробник: ПП «Кронос Агро», Україна) в кількості
0,05 л на 1 м2. Профілактика кокцидіозу залежить від належного
санітарного стану та збереження підстилки сухими. Не
допускати забруднення каловими масами води та їжі. Також потрібно уникати харчування кролів з підлоги. Одним з варіантів зменшення кількості ооцист є наявність
вигульних майданчиків для кролів. Сонячне ультрафіоле-
тове світло знищує яйця кокцидій (Sinha et al., 2022). Цей засіб також відомий своїми дезінвазійними
властивостями щодо ооцист еймерій. Результати. Життєвий цикл кокцидій підлягає впливу
різних чинників, таких як спосіб утримання, вік тварин,
сезон року та інші фактори. З огляду на це, для більш
докладного дослідження кокцидіозу (еймеріозу), захво-
рювання, збудником якого є кокцидії, прогнозування
зростання інвазії, розроблення планів профілактичних та
терапевтичних заходів з урахуванням сезонних варіацій,
були проведені наукові дослідження щодо виявлення
кокцидіозу у господарствах, які займаються утриманням
кролів різного типу та спрямування (див. Таблиця 1). Мета роботи: визначити географічні особливості
розповсюдженості видів кокцидій кролів та залежність
випадків захворювання від способу утримання тварин та
санітарного стану кліток. Матеріали і методи досліджень. Дослідження про-
водили з 2019 по 2021 роки у чотирьох областях: Запо- Таблиця 1 Таблиця
Склад видів кокцидій, виявлених на фермерських та приватних господарствах,
де проводиться утримання кролів
Морфологічні види еймерій
Форми власності кролівницьких господарств
фермерські
приватні
Донецька область
E. irresidua
++
+++
E. іntestinalis
–
+
E. magna
+
++
E. perforans
–
+
E. media
+
++
E. stiedae
–
+
Запорізька область
E. magna
+
++
E. media
++
+++
E. irresidua
++
+++
E. stiedae
–
+
E. іntestinalis
+
+
Сумська область
E. exigua
+
+++
E. flavescens
–
+
E. media
+
+++
E. piriforms
+
+++
E. perforans
–
+
E. magna
+
+
Харківська область
E. perforans
–
+
E. іntestinalis
+
++
E. irresidua
+
++
E. media
+
+++
E. piriforms
–
+
E. magna
–
++
римітки: «++++» – 75 – 100% розповсюдження видів «+++» – 50 – 75%; «++» – 25 -50% розповсюдженності; «+» до 25
еймерії в господарстві відсутні. Примітки: «++++» – 75 – 100% розповсюдження видів «+++» – 50 – 75%; «++» – 25 -50% розповсюдженності; «+» до 25%;
«–» – еймерії в господарстві відсутні. Примітки: «++++» – 75 – 100% розповсюдження видів «+++» – 50 – 75%; «++» – 25 -50% розповсюдженності; «+» до 25%;
«–» – еймерії в господарстві відсутні. Супрун Юлія Олександрівна Увідомлено про одинадцять видів еймерій
(Oryctolagus cuniculus) відноситься до паразитарних захво-
рювань (Athanasiou et al., 2023), що зустрічаються у шлун-
ково-кишковому тракті, а також один вид, що може жити у
жовчних протоках – Eimeria stiedae (Bochyńska et al., 2022). Кролики можуть заразитися кокцидіями з оточуючого
середовища, і це дуже часто стається в селекційних цен-
трах та на інших підприємствах, де зосереджена велика
кількість тварин. Для того щоб ооцисти (яйця) стали
інвазивними, потрібно принаймні два дні в умовах воло-
гості. Крім того, кролики можуть заразитися, споживаючи
траву та комбікорм, які містять заражені ооцисти ейме-
рій. У таких умовах важливо ретельно проводити дезін-
фекцію та знезаражування приміщень для утримання
тварин (Xiao et al., 2022). Підвищення інтенсивності вирощування кролів та
зосередження поголів'я на обмеженій території збіль-
шує можливість передачі захворювань. Оскільки еймерії
постійно присутні у шлунково-кишковому тракті кролів,
передача збудника від матері до дитини відбувається
навіть у перші дні життя. Ооцисти кокцидій виділяються
разом з фекаліями кролів, і вони можуть довгий час існу-
вати в навколишньому середовищі, достатньо одного Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 118 Серія «Ветеринарна медицина», випуск 3 (62), 2023 Печінковий кокцидіоз викликається Eimeria stiedai. Молоді кролики можуть бути дуже сприйнятливими, осо-
бливо якщо потрапляють у середовище із високим рів-
нем інвазії. Зараження тварин Eimeria stiedai може при-
звести до непрохідності жовчних протоків та фіброзних
утворень у печінці. Клінічно це виглядає як втрата ваги,
діарея, асцит, та жовтяниця, залежно від тяжкості інфек-
ції. Eimeria perforans, E. magna, E. media та E. irresidua –
це чотири основні види, що викликають кишковий кок-
цидіоз у кроликів. Кокцидії розташовані в клубовій та
товстій кишці. Часто кокцидіоз може бути діагностований
після загибелі тварини. Типові симптоми це метеоризм
кишечнику, відсутність апетиту, швидка втрата ваги, іноді
спостерігається діарея. Причина загибелі тварин це
інтоксикація організму та асфіксія (Dawod et al., 2022). різька, Донецька, Харківська та Сумська. Під час прове-
дення досліджень було враховано такі аспекти: методи
утримання кролів, характеристики приміщень та показ-
ники санітарно-гігієнічної обстановки. Загалом було проаналізовано 20 ферм, де тримають
кролів різних порід та вікових груп. З метою встановлення
діагнозу еймеріозу були проведені лабораторні аналізи
екскрементів кролів за методом Фюллеборна. Кількість
ооцист еймерій на грам екскрементів (індекс OPG) визна-
чалася згідно з методикою, запропонованою у камері Мак-
мастера (Sadhukhan, S.K. (2022), і види Eimeria були іден-
тифіковані за допомогою аналізу морфологічних критеріїв. Серія «Ветеринарна медицина», випуск 3 (62), 2023 Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 Таблиця 2 Таблиця 2
Рівень інвазії еймеріями кролів у фермерських господарствах України
при утриманні у металевих клітках, n=15
Господарства
Пора року
Кількість ооцист еймерій у п.з. мікроскопу
EI, % эймериями
1
Осінь-зима
23 ± 1,5
29
Весна-літо
15±1,2
19
2
Осінь-зима
30±3,15
38
Весна-літо
14±0,8
17
3
Осінь-зима
12±5,5
15
Весна-літо
9±0,5
11
4
Осінь-зима
12±1,2
15
Весна-літо
7±2,5
9
5
Осінь-зима
30±0,4
37
Весна-літо
6±3,4
7
6
Осінь-зима
25±0,5
31
Весна-літо
8±3,5
10
7
Осінь-зима
13±3,0
16
Весна-літо
5±2,0
6
8
Осінь-зима
34±2,4
42
Весна-літо
14±1,5
17
9
Осінь-зима
25±3,2
31
Весна-літо
10±2,0
12
10
Осінь-зима
20±1,8
25
Весна-літо
7±0,5
9
Екстенсивність інвазії – EI Рівень інвазії еймеріями кролів у фермерських господарствах України
при утриманні у металевих клітках, n=15 Екстенсивність інвазії – EI всієї групи кролів в клітці. Також суттєвим недоліком є
матеріал, з якого виконані клітки – дерево. Дерево дуже
пористий матеріал, який може накопичувати вологу, яйця
гельмінтів, ооцисти еймерій та мікроорганізми. Прово-
дити дезінфекцію та дезінвазію в таких клітках складно,
так як знезараження дерева відбувається тільки на його
поверхні, не проникаючи вглиб матеріалу. Це дає мож-
ливість розмноженню в порах деревини мікроорганізмів
та споруляції ооцист еймерій. У кожній клітці може бути
різна кількість кролів від восьми до десяти. Зразки фека-
лій для дослідження відбирали від кролів різних вікових
груп (табл. 3). а мінімальна – 12±1,2 в п.з. мікроскопу при EI = 15 %. Отримані результати пов’язані із погіршенням мікро-
клімату у приміщеннях, а саме – підвищенні вологості,
погіршенні вентиляції та інсоляції. У весняно-літній
період року рівень інвазії на еймеріоз зменшувався, і
коливався в межах від максимального – 15±1,2 (EI = 19
%) , до мінімального – 5±2,0 (EI = 6 %). За результатами
обстежень фермерських господарств із клітковим спосо-
бом утримання кролів можна стверджувати, що рівень
захворюваності кролів на еймеріоз був у межах допусти-
мих норм, і не перевищував 42 %. Утримання кролів у дерев’яних клітках приватних
господарств. У приватних присадибних господарствах
кролі утримуються у дерев’яних клітках на глибокій під-
стилці. Температура в клітках не регулюється і залежить
від пори року, вентиляція природня. Стіни та підлога клі-
ток суцільні дерев’яні, деякі елементи кліток можуть бути
виконані з металевої сітки. Проблемою утримання кро-
лів на дерев’яній підлозі з глибокою підстилкою є нако-
пичення великої кількості фекальних мас, які кролики
можуть поїдати. Таким чином відбувається інвазування Проведеними дослідженнями встановлено, що най-
більший пік інвазії кролів еймеріозом був у осінньо-зимо-
вий період. Супрун Юлія Олександрівна Вісник Сумського національного аграрного університету 119 Серія «Ветеринарна медицина», випуск 3 (62), 2023 Дані, отримані в результаті експерименту та пред-
ставлені у таблиці 1, вказують на найвищу поширеність
таких видів еймерій: Eimeria magna (25-50%), Eimeria
Іntestinalis (25-50%), Eimeria perforans (до 25%), Eimeria
irresidua (50-75%), Eimeria piriforms (25-50%) та Eimeria
media (50-75%) (див. рис. 1-6). У фермерських та приватних домашніх господар-
ствах завжди спостерігалася комбінована інвазія. Однак,
відсоток випадків захворювання на кокцидіоз вияв-
лявся вищим у приватних особистих господарствах, де
кількість кролів може сягати 100-200 голів залежно від
сезону. Це може бути пов'язано з методами утримання Рис. 1. Eimeria perforans Рис. 2. Eimeria magna
Рис. 3. Eimeria media Рис. 4. Eimeria irresidua
Рис. 5. Eimeria piriforms Рис. 6. Eimeria Іntestinalis Рис. 1. Eimeria perforans Рис. 2. Eimeria magna Рис. 2. Eimeria magna Рис. 1. Eimeria perforans Рис. 4. Eimeria irresidua Рис. 3. Eimeria media Рис. 3. Eimeria media Рис. 4. Eimeria irresidua Рис. 6. Eimeria Іntestinalis Рис. 5. Eimeria piriforms Рис. 5. Eimeria piriforms Рис. 6. Eimeria Іntestinalis Рис. 5. Eimeria piriforms кролів та станом санітарно-гігієнічних умов в приміщен-
нях. на металевих клітках та іншому обладнанні можуть
затримуватись ооцисти кокцидій. Кролі мають особли-
вості періодично облизувати навколишні предмети і
одне одного, таким чином відбувається перезараження
тварин у групі. У кожній клітці утримується до восьми
тварин. Як правило всі тварини одного віку. Але перед
посадкою в одну групу їх беруть з різних кліток від матері
і ділять на самців та самок. Таким чином формуються
групи. Тому групи отримуємо змішані з різним ступенем
інвазії. У приміщеннях-маточниках кролі утримуються у
металевих клітках у один ярус. Поїлки ніпельні, годівниці
бункерного типу, до яких доступ вільний. У клітках одна
матка з кроленятами. Освітлення у приміщенні штучне. Вентиляція примусова механічна приплинно-витяжного Кліткове утримання кролів у фермерських госпо-
дарствах. Приміщення в яких утримуються кролі двох
типів літні відкриті та закриті маточники цегляні з підігрі-
вом. Відкриті клітки у три яруси для утримання у теплий
період року (восени, влітку та навесні) виконані з мета-
левої сітки. Вентиляція в таких клітках відбувається
природнім шляхом, температура змінюється залежно
від навколишнього середовища 15-22 ºС. Основною
проблемою такого способу утримання є підтримання
санітарного стану кліток. Не зважаючи на те, що підлога
виконана із сітки і кролі не можуть їсти з підлоги, зара-
ження може відбуватись через їжу та воду. Також навіть Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 120 типу. Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 Супрун Юлія Олександрівна Температура у приміщенні взимку 17-19 ºС, а влітку
23-25 ºС. В результаті проведеного експерименту у фермер-
ських господарствах за кліткового утримання встанов-
лено, що екстенсивність інвазії кролів еймеріями була
в межах 6-42 % і змінювалась залежно від пори року. Основний пік захворюваності на еймеріоз кролів спо-
стерігали у осінньо-зимовий період. Доведено, що мак-
симальна кількість ооцист кокцидій у фекальних масах
кролів в холодну пору року складала 34±2,4 (EI = 42 %), У фермерських господарствах проводиться регу-
лярне механічне чищення кліток від кролячого посліду. Дезінфекція відбувається за допомогою мийного при-
ладу Керхер тільки під час переведення кролів з одної
вікової групи в іншу. Зразки фекалій для дослідження
відбирали від кролів різних вікових груп (табл. 2). Таблиця 2 Це пов’язано із зменшенням сонячної актив-
ності та накопиченням калових мас у клітках. При низьких
температурах відбувається примерзання посліду до клі-
ток, що ускладнює процес механічної очистки та дезінва-
зії кліток. Максимальна кількість кокцидій у фекальних
масах кролів в холодну пору року складала 80±5,4 (EI
= 100 %), а мінімальна – 45±3,8 в п.з. мікроскопу при EI Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 121 Таблиця 3 Таблиця 3
Рівень інвазії еймеріями кролів у приватних господарствах України
при утриманні у дерев’яних клітках та на підлозі, n=15
Господарства
Пора року
Кількість ооцист еймерій у п.з. мікроскопу
EI, % эймериями
11
Осінь-зима
50 ± 4,3
63
Весна-літо
46±2,5
58
12
Осінь-зима
65±2,83
81
Весна-літо
34±1,5
43
13
Осінь-зима
72±4,5
90
Весна-літо
56±2,4
70
14
Осінь-зима
62±3,2
78
Весна-літо
28±3,3
35
15
Осінь-зима
80±5,4
100
Весна-літо
42±2,8
53
16
Осінь-зима
76±4,5
95
Весна-літо
48±3,5
60
17
Осінь-зима
56±4,7
70
Весна-літо
23±2,6
29
18
Осінь-зима
45±3,8
56
Весна-літо
24±4,4
30
19
Осінь-зима
67±5,2
84
Весна-літо
43±3,0
54
20
Осінь-зима
63±1,25
80
Весна-літо
32±1,9
40
Екстенсивність інвазії – EI Рівень інвазії еймеріями кролів у приватних господарствах України
при утриманні у дерев’яних клітках та на підлозі, n=15 Екстенсивність інвазії – EI В господарствах, де металеві клітки є преобладними,
максимальний відсоток екстенсивності інвазії становив
42% у період осінньо-зимового сезону. В той же час, в
господарствах з дерев'яними клітками та суцільним
підстиланням спостерігався високий рівень, досягаючи
100% у весінньо-зимовий період. = 56 %. У весняно-літню пору року рівень інвазії значно
зменшувався, і коливався в межах від максимального –
56±2,4 (EI = 70 %), до мінімального – 23±2,6 (EI = 29 %). В результаті проведених обстежень приватних господар-
ствах України при утриманні кролів у дерев’яних клітках
та на суцільній підлозі рівень захворюваності на ейме-
ріоз складав 100 % у осінньо-зимовий період. При мінімальних значеннях, що становили 6% у фер-
мах з металевими клітками проти 29% в господарствах з
дерев'яними клітками, відображалась велика контраст-
ність у весняно-літній період. Динамка екстенсивності інвазії у кролів кокцидіозом
за різних умов утримання представлені на рис. 7-8. На графіках, представлених на рисунках 7 та 8,
ілюструється зрозуміло виражена різниця в відсотках
екстенсивності інвазії в господарствах, де використову-
ються металеві (від 1 до 10) та дерев'яні (від 11 до 20)
клітки. Обговорення. Виконано спостереження за пошире-
ністю еймеріозу на двадцяти господарствах, де утриму-
ють кролів, у чотирьох регіонах України. Вісник Сумського національного аграрного університету Таблиця 2 Зразки фекалій,
зібрані від тварин, були піддані аналізу для визначення 0
5
10
15
20
25
30
35
40
45
1
2
3
4
5
6
7
8
9
10
Осінь-зима
Весна-літо
0
20
40
60
80
100
11
12
13
14
15
16
17
18
19
20
Осінь-зима
Весна-літо
Рис.7. % Екстенсивності інвазії в господарствах
з металевими клітками
Рис.8. % Екстенсивності інвазії в господарствах
з дерев’яними клітками 0
5
10
15
20
25
30
35
40
45
1
2
3
4
5
6
7
8
9
10
Осінь-зима
Весна-літо 0
20
40
60
80
100
11
12
13
14
15
16
17
18
19
20
Осінь-зима
Весна-літо Рис.8. % Екстенсивності інвазії в господарствах
з дерев’яними клітками Рис.7. % Екстенсивності інвазії в господарствах
з металевими клітками
Рис.8. % Екстенсивності інвазії в господарствах
з дерев’яними клітками 122 кількості ооцист Eimeria. Після проведення мікроскопічних
досліджень було встановлено, що найвища поширеність
спостерігається у відношенні видів Eimeria perforans (до
25%), Eimeria Іntestinalis (25-50%), Eimeria media (50-75%),
Eimeria irresidua (50-75%), Eimeria piriforms (25-50%) та
Eimeria magna (25-50%) (Silva et al., 2015). Залежно від
інтенсивності інвазії та кліматичних умов рівень захворю-
ваності може варіюватися (Sioutas et al., 2021). але дає вірогідне уявлення про рівень інвазії та видо-
вий склад кокцидій у кролівницьких господарствах
України. Перспективи подальших досліджень. Дослідження
інтенсивності інвазування кролів на еймеріоз в залежно-
сті від методів лікування та схеми профілактики. Висновки. Результати, які були отримані, свідчать
про те, що у кролівницьких господарствах фермерського
та приватного напрямку найчастіше відбуваються інва-
зії такими видами еймерій, як E. Magna, E. irresidua, E. media, E. іntestinalis, E. piriforms, E. perforans. Практичні
дослідження підтверджують, що утримання кролів у
металевих клітках за дотримання санітарно-гігієнічних
норм та вчасна дезінвазія сприяють зниженню рівня
випадків захворювань кролів еймеріозом. Проведене дослідження дає уяву про рівень ураже-
ності крупних фермерських господарств 25-50 % та при-
ватних 75-100 % . Також має значення концентрація пого-
лів’я, система утримання кролів на металевих сітчастих
підлогах та на суцільних дерев’яних (Xie et al., 2021). Дезінфікуючі засоби, як профілактика призвели до
зменшення побічних ефектів, спричинених Eimeria spp. шляхом зменшення кількості фекальних ооцист (Sierra-
Galicia et al., 2022; Thompson Burdine et al., 2021). Практична цінність проведених дослідів полягає
у визначенні видового складу кокцидій та рівня інва-
зування еймеріозом у кролівницьких господарствах
України за різних способах утримання. Обмеження дослідження. Обмеження досліджень
полягає у недостатній кількості охоплених господарств, Бібліографічні посилання: Prevention and Control of Parasitic Zoonoses. In: Parija, S.C., Chaudhury, A. (eds) Textbook
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Blood Metabolites, and Meat Quality. Life (Basel, Switzerland), 12(12), 1987. https://doi.org/10.3390/life12121987 9. Sierra-Galicia, M. I., Rodríguez-de Lara, R., Orzuna-Orzuna, J. F., Lara-Bueno, A., García-Muñiz, J. G., Fallas-López,
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salurus ambiguus Eimeria spp and Cyniclomyces guttulatus in an Industrial Rabbit Farm in Greece Pathogens (Basel book of Parasitic Zoonoses. Microbial Zoonoses. Бібліографічні посилання: р ф
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,
,
p
g
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p
g
7. Sadhukhan, S.K. (2022). p
g
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p
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8. Saeed, Z., & Alkheraije, K. A. (2023). Botanicals: A promising approach for controlling
Frontiers in veterinary science, 10, 1157633. https://doi.org/10.3389/fvets.2023.1157633 Вісник Сумського національного аграрного університету Серія «Ветеринарна медицина», випуск 3 (62), 2023 y
,
,
p
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7. Sadhukhan, S.K. (2022). Prevention and Control of Parasitic Zoonoses. In: Parija, S.C., Chaudhury, A. (eds) Textbook
of Parasitic Zoonoses. Microbial Zoonoses. Springer, Singapore. 83-90. https://doi.org/10.1007/978-981-16-7204-0_9 Бібліографічні посилання: О., PhD student, Sumy National Agrarian University, Sumy, Ukrainef ,
,
y
g
y,
y,
y of the prevalence and methods of detection of eimeriosis among rabbits depending on different me p
,
,
y
g
y,
y,
Study of the prevalence and methods of detection of eimeriosis among rabbits depending on diffe
keeping p
,
,
y
g
y,
y,
Study of the prevalence and methods of detection of eimeriosis among rabbits depending on different methods
of keeping p
g
One of the key difficulties in the process of raising rabbits is eimeriosis, regardless of the methods of keeping them. This
disease affects animals of all age groups, leading to a decrease in weight gain, deterioration of the efficiency of assimilation
of feed, increased morbidity. ,
y
The purpose of the study was to determine the prevalence and methods of detection of eimeriosis among rabbits,
depending on different methods of keeping, with the aim of improving strategies for combating this disease and improving
quarantine methods.f q
During the period from 2019 to 2021, research was conducted in farms with different power level
Zaporizhzhya, Donetsk, Kharkiv and Sumy. In total, 20 farms where rabbits of different breeds were kept During the period from 2019 to 2021, research was conducted in farms with different power levels in four regions:
Zaporizhzhya, Donetsk, Kharkiv and Sumy. In total, 20 farms where rabbits of different breeds were kept were surveyed. In farms and private rabbit farms, E. intestinalis, E. magna, E. media, E. piriforms, E. perforans, E. irresidua were
isolated. It was proved that in the winter period the level of oocysts was from 12±1.2 to 34±2.4 in p.z. microscope In the
summer period, the level of infestation decreased and ranged from a maximum of 15±1.2 (EI = 19%) to a minimum of 5±2.0
(EI = 6%). The study confirmed that in conditions of keeping in metal cages in farms, with compliance with sanitary and
hygienic norms and regular disinfection of premises, the level of infestation was from 15% to 42% in the winter period and
from 6% to 19% in the summer period. In an analysis of data obtained from private farms where rabbits are kept in wooden
cages with deep bedding, it was found that the infestation rate was between 56% and 100% during the cold period and
between 29% and 70% during the warm period. Вісник Сумського національного аграрного університету Вісник Сумського національного аграрного університету
Серія «Ветеринарна медицина», випуск 3 (62), 2023 Бібліографічні посилання: Springer, Singapore. 59-74. https://doi.org/10.1007/978-981-16-7204-0_7
12. Sioutas, G., Evangelou, K., Vlachavas, A., & Papadopoulos, E. (2021). Deaths Due to Mixed Infections with Pas-
salurus ambiguus, Eimeria spp. and Cyniclomyces guttulatus in an Industrial Rabbit Farm in Greece. Pathogens (Basel,
Switzerland), 10(6), 756. https://doi.org/10.3390/pathogens10060756
13
S & S
G (2021)
fl 12. Sioutas, G., Evangelou, K., Vlachavas, A., & Papadopoulos, E. (2021). Deaths Due to Mixed Infections with Pas-
salurus ambiguus, Eimeria spp. and Cyniclomyces guttulatus in an Industrial Rabbit Farm in Greece. Pathogens (Basel,
Switzerland), 10(6), 756. https://doi.org/10.3390/pathogens10060756 l ),
( ),
p
g
p
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13. Thompson Burdine, J., Thorne, S., & Sandhu, G. (2021). Interpretive description: A flexible qua
for medical education research. Medical education, 55(3), 336–343. https://doi.org/10.1111/medu.14380 ),
p
g
p
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on Burdine, J., Thorne, S., & Sandhu, G. (2021). Interpretive description: A flexible qualitative methodology
tion research. Medical education, 55(3), 336–343. https://doi.org/10.1111/medu.14380 ( )
p
g
14. Xiao, J., Zheng, R., Bai, X., Pu, J., Chen, H., Gu, X., Xie, Y., He, R., Xu, J., Jing, B., Peng, X., & Yang, G. (2022). Preliminary evaluation of the protective effects of recombinant AMA1 and IMP1 against Eimeria stiedae infection in rabbits. Parasites & vectors, 15(1), 400. https://doi.org/10.1186/s13071-022-05492-4 ( )
p
g
14. Xiao, J., Zheng, R., Bai, X., Pu, J., Chen, H., Gu, X., Xie, Y., He, R., Xu, J., Jing, B., Peng, X., & Yang, G. (2022). Preliminary evaluation of the protective effects of recombinant AMA1 and IMP1 against Eimeria stiedae infection in rabbits. Parasites & vectors, 15(1), 400. https://doi.org/10.1186/s13071-022-05492-4 ( )
p
g
15. Xie, Y., Xiao, J., Zhou, X., Gu, X., He, R., Xu, J., Jing, B., Peng, X., & Yang, G. (2021). Global transcriptome
landscape of the rabbit protozoan parasite Eimeria stiedae. Parasites & vectors, 14(1), 308. https://doi.org/10.1186/
s13071-021-04811-5 15. Xie, Y., Xiao, J., Zhou, X., Gu, X., He, R., Xu, J., Jing, B., Peng, X., & Yang, G. (2021). Global transcriptome
landscape of the rabbit protozoan parasite Eimeria stiedae. Parasites & vectors, 14(1), 308. https://doi.org/10.1186/
s13071-021-04811-5 123 Серія «Ветеринарна медицина», випуск 3 (62), 2023 Серія «Ветеринарна медицина», випуск 3 (62), 2023 hkromada O. I., Doctor of Veterinary Sciences, Professor, Sumy National Agrarian University, Sumy, Ukrain ,
y
y
g
y
y
Suprun Yu. Бібліографічні посилання: g
p
The use of metal cages for keeping rabbits in compliance with sanitary and hygienic requirements and time
lps to reduce the prevalence of parasitic infections. The use of metal cages for keeping rabbits in compliance with sanitary and hygienic requirements and time
lps to reduce the prevalence of parasitic infections. K
d
bbit i
i
i
bi l
i
l
l
f i
i
i t
it
f i f
t ti
f k
i
bbit to reduce the prevalence of parasitic infections. ey words: rabbit eimeriosis, biological cycle of eimeria, intensity of infestation, ways of keeping rabbits. p
p
p
Key words: rabbit eimeriosis, biological cycle of eimeria, intensity of infestation, ways of keeping rabbits. p
p
p
Key words: rabbit eimeriosis, biological cycle of eim 124
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https://openalex.org/W2174182372
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https://ped-rheum.biomedcentral.com/counter/pdf/10.1186/1546-0096-13-S1-O74
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English
| null |
A functional inflammasome activation assaydifferentiates patients with pathogenic NLRP3mutations and symptomatic patients with lowpenetrance variants
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Pediatric rheumatology online journal
| 2,015
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cc-by
| 500
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Question confirmed pathogenic CAPS mutations compared to low
penetrance NLRP3 variants and controls. IL-1b secre-
tion in CAPS patients correlated with disease severity. TNF-a secretion was significantly reduced in CAPS
patients and NLRP3 variants when compared to healthy
controls after 4h of stimulation. The cryopyrin-associated periodic syndromes (CAPS) are
characterized by recurrent episodes of systemic inflam-
mation. CAPS is caused by mutations in the NLRP3 gene
encoding cryopyrin, an important component of the
NLRP3 inflammasome that activates caspase-1 resulting
in inflammation by excessive production of IL-1b and
others. Besides confirmed pathogenic NLRP3 mutations,
patients with CAPS-like symptoms frequently show low
penetrance variants in NLRP3. The disease relevance of
these variants is inconsistent. The analysis of IL-1b in the
serum did not prove to be a valid diagnostic test in these
individuals. © 2015 Rieber et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://
creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/
zero/1.0/) applies to the data made available in this article, unless otherwise stated. Conclusion This inflammasome activation assay differentiates
between autoinflammation patients with confirmed
pathogenic CAPS mutations and patients with low pene-
trance NLRP3 variants, and points towards alternative
pathophysiological mechanisms in low penetrance
NLRP3 variants. Methods In this study, we investigated if an inflammasome activa-
tion assay differentiates between patients with confirmed
pathogenic CAPS mutations, patients with low pene-
trance NLRP3 variants (V198M and Q703K) and healthy
controls. The study population consisted of 17 patients
with genetically proven Muckle-Wells syndrome, 11
patients with low penetrance NLRP3 variants and 15
healthy controls. Concentrations of IL-1b, IL-18, Cas-
pase-1, TNF-a and IL-6 were quantified in cell culture
supernatants after inflammasome stimulation with LPS
and LPS + ATP for several time intervals. Published: 28 September 2015 doi:10.1186/1546-0096-13-S1-O74
Cite this article as: Rieber et al.: A functional inflammasome activation
assaydifferentiates patients with pathogenic NLRP3mutations and
symptomatic patients with lowpenetrance variants. Pediatric
Rheumatology 2015 13(Suppl 1):O74. A functional inflammasome activation
assaydifferentiates patients with pathogenic
NLRP3mutations and symptomatic patients with
lowpenetrance variants N Rieber*, A Gavrilov, L Hofer, A Singh, H Öz, T Endres, I Schäfer, R Handgretinger, D Hartl, J Kümmerle-Deschner
From 8th International Congress of Familial Mediterranean Fever and Systemic Autoinflammatory Diseases
Dresden, Germany. 30 September - 3 October 2015 © 2015 Rieber et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://
creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/
zero/1.0/) applies to the data made available in this article, unless otherwise stated. Rieber et al. Pediatric Rheumatology 2015, 13(Suppl 1):O74
http://www.ped-rheum.com/content/13/S1/O74 Open Access Open Access Results The release of mature IL-1b, IL-18, and caspase-1 into
cell culture supernatants after 4h of inflammasome sti-
mulation was significantly increased in patients with Children’s hospital Tübingen, Tübingen, Germany
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https://figshare.com/articles/journal_contribution/New_i_ent_i_-kauran_diterpene_and_antioxidant_components_from_the_seed_of_i_Ipomoea_nil_i_/10259909/1/files/18528164.pdf
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New <i>ent</i>-kauran diterpene and antioxidant components from the seed of <i>Ipomoea nil</i>
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New ent-kauran diterpene and antioxidant components from the seed of Ipomoea nil
b
d
f aDepartment of Cosmeceutics, China Medical University, Taichung, Taiwan
bChinese Medicine Research and Development Center, China Medical University Hospital, Taichung,
Taiwan
cChinese Medicine Research Center, China Medical University, Taichung, Taiwan
dGraduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan
eProteomics Core Laboratory, Department of Medical Research, China Medical University Hospital,
Taichung, Taiwan
fDepartment of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical
University, Taichung, Taiwan fDepartment of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical
University, Taichung, Taiwan CONTACT Chia-Lin Lee chlilee@mail.cmu.edu.tw CONTACT Chia-Lin Lee chlilee@mail.cmu.edu.tw ABSTRACT One new ent-kauran diterpene, 7β,16β,17-trihydroxy ent-kauran 19-(6β)-olide (1), along with eight
known compounds were isolated from the seed of Ipomoea nil. Isolates caffeoylquinic acid derivatives
5−9 were found for the first time in this species. All structures were identified from various
spectroscopic data. trans-Caffeic acid 3, phenylpropanoid 4, and caffeoylquinic acid derivatives 5−9
could inhibit ROS generations induced in human keratinocyte HaCaT cells with IC50 values of
0.94−28.40 μM. Compounds 3 and 5−9 also had DPPH free radical scavenging properties (IC50 values,
14.86−68.27 μM), however, isolate 4 did not show inhibition effect. Generally, I. nil and its secondary
metabolites 3−9 could be further applied for oxidative stress damage resulted in skin disorders. KEYWORDS: Ipomoea nil; Convolvulaceae; ent-Kauran diterpenoid; Anti-ROS; Anti-DPPH KEYWORDS: Ipomoea nil; Convolvulaceae; ent-Kauran diterpenoid; Anti-ROS; Anti-DPPH S1 Figure S1. 1H NMR (500 MHz, CD3OD) of compound 1…………………..………………………......S3
Figure S2. 13C NMR (125 MHz, CD3OD) of compound 1……………………………………………S3
Figure S3. DEPT135 NMR (125 MHz, CD3OD) of compound 1.…………………………….………..S4
Figure S4. HSQC NMR (500 MHz, CD3OD) of compound 1….……………………………………….S4
Figure S5. COSY NMR (500 MHz, CD3OD) of compound 1…………………………..…..…………..S5
Figure S6. HMBC NMR (500 MHz, CD3OD) of compound 1….………………………….…………S5
Figure S7. NOESY NMR (500 MHz, CD3OD) of compound 1..…………………………………......S6
Figure S8. IR spectrum of compound 1..…………………………………….……………………….....S6
Figure S9. High ESI-MS spectrum of compound 1.………………………………………………….....S7
Figure S10. Key COSY and HMBC correlations for compound 1………………………………………S7
Figure S11. Key NOESY correlations for compound 1…………………………………………………S7
Figure S12. Anti-ROS generation in HaCaT cells (A-1 to D-1) and cytotoxicity toward HaCaT
(A-2 to D-2) of crude extract MPS, fractions MPSH, MPSB, and MPSW, respectively…...S8
Figure S13. Anti-DPPH free radical scavenging properties of
crude extract MPS, fractions MPSH, MPSB, and MPSW.………………….…………....S8
Figure S14. Cytotoxicity toward HaCaT cells of compounds 3−9.………………………………….….S9
Figure S15. Anti-ROS generation in HaCaT cells of compounds 3−9………………………………S9
Figure S16. Anti-DPPH free radical scavenging properties of compounds 3−9…………..……..….S10
Table S1. 1H and 13C NMR spectroscopic data (500 and 125 MHz, CD3OD) for 1……………………S10
Table S2. Antioxidant activities of crude extract, fractions, and pure compounds 3−9………………S11 S2 Figure S1. 1H NMR (500 MHz, CD3OD) of compound 1. Figure S2. 13C NMR (125 MHz, CD3OD) of compound 1. Figure S1. 1H NMR (500 MHz, CD3OD) of compound 1. Figure S1. 1H NMR (500 MHz, CD3OD) of compound 1. Figure S2. 13C NMR (125 MHz, CD3OD) of compound 1. Figure S2. 13C NMR (125 MHz, CD3OD) of compound 1. Figure S2. ABSTRACT 13C NMR (125 MHz, CD3OD) of compound 1. S3 S3 Figure S3. DEPT135 NMR (125 MHz, CD3OD) of compound 1. Figure S3. DEPT135 NMR (125 MHz, CD3OD) of compound 1. Figure S4. HSQC NMR (500 MHz, CD3OD) of compound 1. Figure S4. HSQC NMR (500 MHz, CD3OD) of compound 1. S4 S4 Figure S5. COSY NMR (500 MHz, CD3OD) of compound 1. Figure S5. COSY NMR (500 MHz, CD3OD) of compound 1. Figure S6. HMBC NMR (500 MHz, CD3OD) of compound 1. Figure S5. COSY NMR (500 MHz, CD3OD) of compound 1. Figure S5. COSY NMR (500 MHz, CD3OD) of compound 1. Figure S6. HMBC NMR (500 MHz, CD3OD) of compound 1. Figure S6. HMBC NMR (500 MHz, CD3OD) of compound 1. S5 S5 Figure S7. NOESY NMR (500 MHz, CD3OD) of compound 1. S6
Figure S7. NOESY NMR (500 MHz, CD3OD) of compound 1. Figure S8. IR spectrum of compound 1. Figure S7. NOESY NMR (500 MHz, CD3OD) of compound 1. Figure S8. IR spectrum of compound 1. Figure S8. IR spectrum of compound 1. S6 S6 158.8431
369.2394
389.1728
453.1664
MPSB3354112_350.d: +MS, 0.3min #17
0.0
0.5
1.0
1.5
7
x10
Intens. 100
200
300
400
500
600
m/z
Figure S9. High ESI-MS spectrum of compound 1. Figure S10. Key COSY and HMBC correlations for compound 1. 158.8431
369.2394
389.1728
453.1664
MPSB3354112_350.d: +MS, 0.3min #17
0.0
0.5
1.0
1.5
7
x10
Intens. 100
200
300
400
500
600
m/z
Figure S9. High ESI-MS spectrum of compound 1. 158.8431
369.2394
389.1728
453.1664
MPSB3354112_350.d: +MS, 0.3min #17
0.0
0.5
1.0
1.5
7
x10
Intens. 100
200
300
400
500
600
m/z Figure S9. High ESI-MS spectrum of compound 1. Figure S10. Key COSY and HMBC correlations for compound 1. Figure S10. Key COSY and HMBC correlations for compound 1. Figure S11. Key NOESY correlations for compound 1. Figure S11. Key NOESY correlations for compound 1. S7 S7 Figure S12. Anti-ROS generation in HaCaT cells (A-1 to D-1) and cytotoxicity toward HaCaT (A-2 to
D-2) of crude extract MPS, fractions MPSH, MPSB, and MPSW, respectively. Figure S12. Anti-ROS generation in HaCaT cells (A-1 to D-1) and cytotoxicity toward HaCaT (A-2 to
D-2) of crude extract MPS, fractions MPSH, MPSB, and MPSW, respectively. Figure S13 Anti-DPPH free radical scavenging properties of crude extract MPS, fractions MPSH,
MPSB, and MPSW. ABSTRACT Figure S13 Anti-DPPH free radical scavenging properties of crude extract MPS, fractions MPSH,
MPSB, and MPSW. S8 S8 Figure S14. Cytotoxicity toward HaCaT cells of compounds 3−9. Figure S15. Anti-ROS generation in HaCaT cells of compounds 3−9. Figure S14. Cytotoxicity toward HaCaT cells of compounds 3−9. Figure S14. Cytotoxicity toward HaCaT cells of compounds 3−9. Figure S15. Anti-ROS generation in HaCaT cells of compounds 3−9. Figure S15. Anti-ROS generation in HaCaT cells of compounds 3−9. S9 S9 Figure S16. Anti-DPPH free radical scavenging properties of compounds 3−9. Figure S16. Anti-DPPH free radical scavenging properties of compounds 3−9. Table S1. 1H and 13C NMR spectroscopic data (500 and 125 MHz, CD3OD) for 1. 1
position
δH (J in Hz)
δC
1
0.95, m
1.80, ma
33.1
2
1.80, ma (2H)
17.8
3
1.55, ma
1.73, ma
25.0
4
42.0
5
2.34, d (11.5)
49.1
6
4.33, dd (11.5, 1.5)
79.9
7
3.78, brs
78.7
8
51.8
9
1.52, ma
55.8
10
40.5
11
1.53, ma
2.08, ma
19.2
12
1.53, ma
1.80, ma
27.7
13
2.11, m
42.3
14
1.30, dd (13.5, 5.0)
1.90, dd (13.5, 2.0)
39.6
15
1.49, d (14.5)a
1.93, d (14.5)
49.5
16
80.4
17
3.34, d (11.0)
3.42, d (11.0)
70.7
18
1.23, s
29.8
19
185.8
20
1.13, s
17.9
a Overlapped signals Table S1. 1H and 13C NMR spectroscopic data (500 and 125 MHz, CD3OD) for 1 S10 Table S2. Antioxidant activities of crude extract, fractions, and pure compounds 3−9. Crude extract and fractions IC50 (μg/mL)
MPS
MPSH
MPSB
MPSW
Vit. C
HaCaT-ROSa
9.18±0.66
>25
6.80±0.98
19.11±1.01
-
DPPH
150.63±19.18
>500
122.21±9.50
312.63±19.42
< 7.81
Pure compound IC50 (μM)
3
4
5
6
HaCaT-ROSa
3.78±0.32
28.40±6.57
1.04±0.16
0.94±0.08
DPPH
57.24±0.59
>200
18.48±0.49
14.86±0.26
7
8
9
Vit. C
HaCaT-ROSa
1.24±0.09
1.00±0.18
2.61±0.24
< 20
DPPH
17.41±1.41
18.96±1.22
68.27±1.80
26.76±2.37
a All test compounds should inhibit ROS generations induced in HaCaT without cytotoxicity toward
HaCaT cells. Antioxidant activities of crude extract, fractions, and pure compounds 3−9. a All test compounds should inhibit ROS generations induced in HaCaT without cytotoxicity toward
HaCaT cells. S11
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https://figshare.com/articles/journal_contribution/Benefits_and_challenges_of_EMR_implementations_in_low_resource_settings_a_state-of-the-art_review/14637135/2/files/28112094.pdf
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Benefits and challenges of EMR implementations in low resource settings: a state-of-the-art review
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* Correspondence: bjawhari@ualberta.ca
1Department of Medicine, Faculty of Medicine & Dentistry, University of
Alberta, Clinical Sciences Building, 8440-112 St NW 5th floor, 5-112E, T6G 2B7
Edmonton, AB, Canada
2Innovative Canadians for Change, Edmonton, AB, Canada
Full list of author information is available at the end of the article Benefits and challenges of EMR
implementations in low resource settings:
a state-of-the-art review Badeia Jawhari1,2*, Dave Ludwick3, Louanne Keenan1, David Zakus4 and Robert Hayward1 © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116
DOI 10.1186/s12911-016-0354-8 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116
DOI 10.1186/s12911-016-0354-8 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116
DOI 10.1186/s12911-016-0354-8 Background and classification of revealed literature, as well as analysis
of the content of the selected literature. Health Information Systems (HIS), including Electronic
Medical Record (EMR) systems, show promise for fa-
cilitating health care improvement. Many sub-Saharan
African countries recognize this opportunity and ac-
tively deploy e-health technologies, including mobile
health devices, electronic medical records, electronic
health records, and risk surveillance systems. Despite
their characterization as developing countries, some
have demonstrated leadership through significant in-
vestment in recent-generation health information sys-
tems. However, relatively little is known about how the
HIS promise can be realized in resource-constrained
settings, or about the applicability of evidence arising
from well-resourced settings. This review examines
published reports about how EMRs have been deployed
in sub-Saharan African slums, which intervention attri-
butes associate with deployment success, which cat-
egories of benefits and harms are observed, what forms
of inquiry have been employed, and where important
uncertainty remains. A starter list of search concepts reflected key elements
of the review objectives. The list was modified as search
cycles were conducted and new concepts emerged in re-
trieved reports, yielding optimized inclusion and exclu-
sion criteria (Appendix 1). These were matched to
standardized Medical Subject Heading (MeSH) terms for
use in database-specific search strategies (Appendix 2). Publication dates were not specified because a relative
paucity of relevant studies and because the recent ap-
pearance of EMRs in the settings of interest made the
publication date implicit in other search criteria. Major North American (MEDLINE) and European
(EMBASE) citation databases, and one specialty citation
database (GLOBAL HEALTH) were searched in addition
to the Cochrane database of reviews and the Cochrane
controlled trial registry. A general Internet scan was
conducted using the Google search engine. The “Grey
literature,” including conference proceedings, theses,
websites, and government reports, was explored using
Google and Google Scholar. Reference lists of retrieved
publications were checked for literature not found
through searching. All databases were searched from in-
ception through start of February 2015. A preliminary search of mainstream bibliographic da-
tabases revealed few reports about experiences with
EMRs in resource-limited settings. Most focused on Hu-
man Immunodeficiency Virus (HIV) and Tuberculosis
(TB) patient management [1–3]. Little was reported
about the effects of EMRs on primary care practices or
on general health outcomes in slum settings. Background Experimen-
tal inquiry is rare and the published reports do not pro-
vide the level of detail about methods or findings
required for systematic review or meta-analytic synthesis
methods. Accordingly, this review adopts a “State-of-the-
Art” [4] approach; describing what has been published,
how insights were derived from observation, and which
issues have been explored by what method. The objective
is to provide a foundation for the future application of sys-
tematic review methods to an expanding literature about
EMR impacts in resource-constrained settings. There were challenges minimizing false positives while
avoiding false negatives associated with search strategies,
possibly because key concepts were represented differently
in different databases. For example, MEDLINE, GLOBAL
HEALTH and the COCHRANE LIBRARY used the
“Africa South of the Sahara” instead of “sub-Saharan
Africa” found in EMBASE [1, 5]. Terms for digital
health records (e.g., “Electronic Health Record,” “Elec-
tronic Medical Record,” “Patient Health Record,” etc.)
varied widely. Full-text synonym searching proved import-
ant in all indexed databases, having the greatest impact on
GOOGLE and GOOGLE SCHOLAR performance. p
The results of optimized bibliographic searches were
combined to constitute the initial “population” of 695
potentially relevant citations. Internet and grey literature
searches discovered 54 additional relevant communica-
tions. Of the 749 pooled bibliographic and grey literature
citations, 738 referenced papers or articles possibly
relevant to EMR use in resource-constrained settings. The abstracts of these were passed through more specific
setting (country, practice type, intervention type) and
methods (literature type, study type, process or outcome
focus) filters to yield 96 papers addressing EMR imple-
mentation or adoption challenges in resource-constrained
parts of sub-Saharan Africa. The introduction, objectives
and methods sections were reviewed to re-apply relevance
and methods filters, excluding 54 more reports where
EMRs were used in mainly in hospitals rather than
community-based clinics. Abstract Background: The intent of this review is to discover the types of inquiry and range of objectives and outcomes
addressed in studies of the impacts of Electronic Medical Record (EMR) implementations in limited resource settings
in sub-Saharan Africa. Methods: A state-of-the-art review characterized relevant publications from bibliographic databases and grey
literature repositories through systematic searching, concept-mapping, relevance and quality filter optimization,
methods and outcomes categorization and key article analysis. Results: From an initial population of 749 domain articles published before February 2015, 32 passed context and
methods filters to merit full-text analysis. Relevant literature was classified by type (e.g., secondary, primary), design
(e.g., case series, intervention), focus (e.g., processes, outcomes) and context (e.g., location, organization). A
conceptual framework of EMR implementation determinants (systems, people, processes, products) was developed
to represent current knowledge about the effects of EMRs in resource-constrained settings and to facilitate
comparisons with studies in other contexts. Discussion: This review provides an overall impression of the types and content of health informatics articles about
EMR implementations in sub-Saharan Africa. Little is known about the unique effects of EMR efforts in slum settings. The available reports emphasize the complexity and impact of social considerations, outweighing product and
system limitations. Summative guides and implementation toolkits were not found but could help EMR
implementers Conclusion: The future of EMR implementation in sub-Saharan Africa is promising. This review reveals various
examples and gaps in understanding how EMR implementations unfold in resource-constrained settings; and
opportunities for new inquiry about how to improve deployments in those contexts. Keywords: Electronic medical record, Electronic health record, Implementation, Urban slum, Limited resource
setting, Sub-Saharan Africa Abbreviations: EMR, Electronic medical record; HIS, Health information system; HIV, Human immunodeficiency
virus; ID, Identification card; MeSH, Medical subject heading; TB, Tuberculosis © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Page 2 of 12 Page 2 of 12 Methods The review was conducted as a step-wise process. First, a
general search strategy was derived from a concept map
linking question-appropriate concepts. Associated key-
words were discovered from multiple search-review cycles
in diverse databases. Second, specific search strategies
were optimized for each source database. Third, relevance
filters were developed and applied to the search results to
determine the prevalence of reports addressing specific
settings, interventions and outcomes of interest. Fourth,
methods descriptors were devised and used to classify the
relevant literature. Finally, papers that were both relevant
and methodologically credible were reviewed in detail. The overview results are expressed through description Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Page 3 of 12 Table 1 Relevance-filtered publications grouped by inquiry type
Inquiry type
Citations
Primary
28
Case Reports
21
Implementation focus
16
Adoption focus
5
Program Descriptions
22
EMR deployment benefits, challenges
and system design
22
Observational Inquiry
16
- Qualitative Inquiry
0
User perceptions
2
Patient perceptions
1
- Program evaluation
15
Data quality review
3
Appointment management
6
Workflow assessment
2
Time motion study
2
Experimental Inquiry
1
Uncontrolled trials
1
Secondary Literature
17
- Commentary and editorials
6
- Position statements and guidelines
2
- Narrative reviews
7
- Systematic reviews
2 Table 1 Relevance-filtered publications grouped by inquiry type
Inquiry type
Citations
Primary
28
Case Reports
21
Implementation focus
16
Adoption focus
5
Program Descriptions
22
EMR deployment benefits, challenges
and system design
22
Observational Inquiry
16
- Qualitative Inquiry
0
User perceptions
2
Patient perceptions
1
- Program evaluation
15
Data quality review
3
Appointment management
6
Workflow assessment
2
Time motion study
2
Experimental Inquiry
1
Uncontrolled trials
1
Secondary Literature
17
- Commentary and editorials
6
- Position statements and guidelines
2
- Narrative reviews
7
- Systematic reviews
2 A total of 32 reports remained for comprehensive full-
text review. Seven proved a close fit to the review objec-
tives, six about EMR implementations in Kenya and one
about Cameroon experiences [6–12]. None specifically
addressed EMR implementation challenges in slum set-
tings. Most were published within the previous 5 years
and reports published between 2000–2009 were least in-
formative about EMR challenges, most referencing EMR
technology new to low resource settings. Inquiry types Relevance-filtered publications were grouped by whether
they reported original observations or interpreted the
observations of others. The primary literature was fur-
ther subdivided by the type of inquiry used to generate
observations (Table 1). There were 21 case series reports, where a common
intervention crossed multiple EMR implementations. Foci
of reportage included paper-to-digital record transform-
ation challenges [13], clinician distraction by user interfaces
[14], training effects, and determinants of user acceptance
[14]. One case series explored hardware and software
barriers to implementation, including corrupted files
and server failures [14]. implementation or in non-implementation settings. Where
observational studies claimed overall user satisfaction
with EMRs, the authors often did not reconcile this
with their own report of user complaints respecting
training burdens, loss of productivity and difficulty
finding key information [19]. Many case studies shared experience-based recom-
mendations about best practices, with a common theme
that user involvement increases buy-in before, during and
after implementation. Such buy-in is enhanced by EMR
customization, sustainable funding and access to a digitally-
capable
workforce
[14]. Implementation
opportunities
include, for example, loss of paper storage space and im-
provements in record filing, stock control [15] and report
acceptance by government or funding agencies [11, 12, 15]. One case series shared experiences with different open-
source EMRs, including financial implications for groups
contemplating adoption in resource-limited settings [16]. g
y
Program evaluations tended to focus on the quality
and application of data accrued by EMRs while com-
menting on operational considerations like error rates,
visit duration, appointment no-shows, wait times, clinic
efficiency, and fulfillment of service delivery expecta-
tions [18, 19, 21, 22]. One evaluation included a formal
time-motion study and noted a patient visit duration
reduction of about 10 min [18]. Apparently, productiv-
ity improvements were associated with less staff time
socializing with colleagues [18]. Another program evalu-
ation reported a 30 % reduction in missed appointments,
24 % reduction in erroneous appointments, and an overall
reduction in wait times for nurse and lab technician access
[21]. An extraordinarily positive program evaluation
claimed a reduction of scheduling error rates from
66.5 to 2.1 % [17]. Of the retrieved observational studies, none used
rigorous qualitative research methods. Although survey
studies were common [17–19], few described a-priori
objectives, how survey question concepts were devel-
oped, how instrument validity was established, or how
results were interpreted in light of an analytic frame-
work. Thompson et al. Methods There were no
reports of long-term sustained initiatives. Greater weight
was given to findings reported in the last 5 years. The
detailed key paper review did not uncover new search
concepts, MeSH terms or full-text synonyms, and bibli-
ography searches did not expose reports not already
known from the iterative searching described above. Inquiry types (2010) conducted an observa-
tional study using data gathered in ethnographic field
notes, but did not report an explicit approach to data-
abstraction, coding or purposeful analysis of the recorded
observations [20]. Rarely were observations captured pre- Some observational reports provided detailed descrip-
tions of EMR designs and pilot implementations, focusing Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Page 4 of 12 Table 2 Categorization of inquiry topics
Inquiry topic
Citations
Matters of Process
22
- Patient identification
5
- Encounter and patient management
8
- Medication management
2
- Laboratory management
2
- Document and information management
7
- Systems integration
1
- Human resource utilization
7
- Clinic efficiency
3
- Continuity of care
1
- Communications and team relations
2
- Data integrity
3
- Reporting and Analytics
3
- Auditing
1
Matters of Outcome
22
- Chronic disease guideline compliance
2
- HIV/AIDS management compliance
17
- Tuberculosis management compliance
1
- Medication reconciliation
2
- Medical errors
0
- Quality of care
1
- Maternal and child health guideline compliance
1
- Clinical decision support compliance
1 Table 2 Categorization of inquiry topics
Inquiry topic
Citations
Matters of Process
22
- Patient identification
5
- Encounter and patient management
8
- Medication management
2
- Laboratory management
2
- Document and information management
7
- Systems integration
1
- Human resource utilization
7
- Clinic efficiency
3
- Continuity of care
1
- Communications and team relations
2
- Data integrity
3
- Reporting and Analytics
3
- Auditing
1
Matters of Outcome
22
- Chronic disease guideline compliance
2
- HIV/AIDS management compliance
17
- Tuberculosis management compliance
1
- Medication reconciliation
2
- Medical errors
0
- Quality of care
1
- Maternal and child health guideline compliance
1
- Clinical decision support compliance
1 Table 2 Categorization of inquiry topics on things like data models, software architecture and per-
formance specifications [1, 15–17, 23, 24]. A common
theme related to the benefits of open-source systems in
resource-limited settings, presumably because lower up-
front costs, with many focus on feature customization,
local adaptation and hidden costs of adoption [12, 14–16]. No formal clinical trials, where an EMR-exposed group
is compared to a suitable control group, were found
among relevance and methods-filtered studies. However, a
number of before-after time-series comparisons appeared. Inquiry types These tended to examine impacts on resources and bar-
riers to sustainability, such as staffing requirements, em-
ployee retention, training needs, hardware reliability and
infrastructure requirements [7, 9, 10, 13, 15, 20, 25–27]. There was a tendency to report positive impacts, with
unintended negative effects possibly not included in the
recorded observations. Positive effects included increased
access to Internet information resources [26], quicker
retrieval of patient records, timely access to clinical data,
more legible documentation and improved quality and
safety of care [1, 6, 13, 26, 28]. - Auditing - Chronic disease guideline compliance Seventeen secondary literature reports appeared among
relevance-filtered literature, commonly addressing general
facilitators and impediments to EMR implementation. Reported success factors include stakeholder engage-
ment in pre-implementation design, building trust
among stakeholders, encouraging emergence of local
leadership, nurturing embedded champions, and avoid-
ing big staffing changes. Additionally, implementers are
encouraged to use existing systems and software, collabor-
ate with other organizations (leveraging resources), invest
in backup capacity, audit user actions, provide on-site
training and track usage [10, 12, 15, 18, 25]. - Maternal and child health guideline compliance - Clinical decision support compliance this reason, the retrieved literature frequently credited
EMRs for introducing identity management [1, 6, 7, 11, 18],
with consequent improved clinic encounter management
and human resource utlization [8, 14, 19, 20, 24, 30, 31],
reduced chart filing times, improved continuity of care
[28, 31], reduced data integrity issues [13, 23, 32], and
improved accuracy of reports [18, 20, 23]. The re-
ported improvements in tracking of health exposures
and outcomes, reductions in inappropriate test dupli-
cation and overall improvement in care coordination
[1, 6, 7, 11, 18], are all contingent on the ability to
retrieve and compare multiple episodes of care for a
uniquely identified patient [12]. A unique report explored the ethical ramifications of
EMR implementations. The authors lamented a lack of eth-
ically grounded EMR policies in developing countries and
cautioned enthusiasts to heed the principle of “do no harm”
when navigating change for clinics, staff and patients [29]. Inquiry topics
d
d Considered together, the filtered literature addressed re-
curring themes about EMR design, implementation and
impact. Topics covered by both primary and secondary
literature were categorized into matters of health pro-
cesses and health outcomes (Table 2). Effective communication is another common challenge
in resource-constrained settings. Even improved legibil-
ity of communications can make a difference. One study
reported improved clarity of orders and lists post EMR
implementation, with particular improvement in pre-
scription management [14]. Others noted increased use-
fulness of health data associated with EMR structured
data entry [17, 33, 34]. The most commonly emphasized process improvements
associated with EMR implementations relate to improved
efficiency of time-consuming or error-prone tasks. The
most common of these is identity management. Resource-
constrained settings often have difficulty consistently
identifying patients from visit to visit and from clinic
to clinic, with negative impacts on continuity of care. In sub-Saharan Africa, particularly in Kenya, standardized
national personal identifiers are rare [7, 8, 18]. Perhaps for Clinics operating in resource-constrained settings are
often accountable to diverse government programs,
donor organizations and disease-specific grant programs. Page 5 of 12 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Fig. 1 Understanding EMR implementations in limited resource
settings An important reported process improvement relates to
EMR report-generating capabilities which can signifi-
cantly reduce the time taken to comply with agency
reporting requirements [8, 9, 18, 20, 23]. Resource-constrained settings also have difficulty attract-
ing, training and retaining experienced staff; process
problems compounded by the need to up-skill and up-
manage for transitions from paper to digital processes. The retrieved literature made frequent reference to
EMR impacts on human resources. Developing EMR-
permissive skills, attitudes and knowledge within a
clinic setting is a commonly reported challenge. Involv-
ing users early on in the process development is cited
as one strategy for enhancing buy-in and increasing
systems awareness [9, 20]. One study reported that user
empowerment can increase self-esteem and positive
views about the EMR-enabled health facility, with spin-
off benefits for the community [9]. Health outcomes affected by EMR implementation can
be difficult to track for slum clinics. They typically have
short-term interactions with clients, little opportunity
for follow-up, and outcomes that are hard to measure. Accordingly, the retrieved literature rarely discusses true
EMR-associated health outcomes, and tends to emphasize
surrogate outcomes like immunization and medication
dispensing rates that may be associated with improved
health outcomes. Inquiry topics
d
d However, the effects of clinical decision
support [30] on surrogate outcomes, including medication
tracking [13, 14], were not widely explored. Little in the
retrieved literature addressed chronic disease or functional
outcomes [6, 9]. Most available reports focused on
HIV/AIDS and TB management, a priority of global
granting agencies, with tracking of medication dispens-
ing and side effect monitoring presumed to improve
health outcomes. Fig. 1 Understanding EMR implementations in limited resource
settings applications. Success factors are those things that au-
thors emphasize as determinants of EMR impact con-
sistent with the goals of EMR implementation. We suggest that there are no generic facilitators or
barriers
to
EMR
implementation
applicable
in
all
resource-constrained settings. Rather, the interplay of
local systems, people, process and product consider-
ations determine which success factors best predict ef-
fective EMR use. This approach is consistent with what
the retrieved literature reveals about the variability of
facilitators and barriers to effective EMR implementa-
tions in resource-constrained settings; and it may sug-
gest an approach to planning future interventions. One
might start with a clear statement of desired outcomes,
then consider how known success factors must be
adapted and prioritized to fit with the local product,
process, people and systems opportunities and challenges
that will shape implementation experiences (Fig. 1). Conceptual framework A conceptual framework (Fig. 1) was developed to
summarize and synthesize key messages appearing in
the discovered literature. This highlights four determi-
nants of EMR impacts in resource-constrained settings:
1) Systems 2) People, 3) Processes, and 4) Products. Sys-
tems considerations include access to a reliable power
source, suitably located and protected servers and com-
puters, availability of backup systems and the speed and
reliability of network and Internet services. People con-
siderations relate to the types of human resources avail-
able, how users are trained and supported, how users
interact with technology and how users are influenced
by workplace attitudes and leadership. Process consider-
ations include change management at the time of
deployment
and
supports
post-deployment. Product
considerations relate to the electronic medical record
software in play and how it inter-operates with other Processes Descriptions of process changes, intentional or uninten-
tional, consequential or collateral, figure prominently in
the discovered literature. A number of authors observe
that EMR implementation does not, by itself, improve
the efficiency or effectiveness of health care. Instead,
digital systems tend to bring dysfunctional processes
into focus, even aggravating bad workflows. One author
suggested optimization of paper-based processes as a
pre-requisite to EMR implementation [9]. Another sug-
gests that development of structured paper-based data
collection forms can help bridge to EMR workflows [7]. Transitional retention of some kind of paper-based
workflow can reassure staff that their job will not be re-
placed or drastically changed post go-live [7]. Outcomes Desired, expected or achieved outcomes from an EMR
implementation vary in the discovered literature. In
some resource-limited settings, implementing unique
identifiers and improving patient tracking can be suf-
ficient for meeting improved care coordination goals
[6, 7]. Other settings seek more complex changes, in-
cluding the shaping of provider decisions, making
clinical decision support an important success factor
[6, 30]. Some EMR implementations are credited with
tracking patient outcomes, access to a shared medical rec-
ord, and reduction in medical errors [1, 13]. Others are
credited with improved clinic productivity [18] where bet-
ter appointment management is the outcome dependent
on systems, people, processes and product factors. While
it is commonly assumed that EMRs should improve health
care for patients and populations, some authors contend
that this is more likely when research, quality improve-
ment and disease surveillance are explicit goals [11–13]. Some process improvement claims are common. For
example, many authors emphasize the importance of user
and leadership engagement, noting how training and
support can protect against negative reactions to loss of
familiar workflows. Achieving meaningful user engage-
ment requires investment pre and post EMR deployment. Although commonly a struggle, user engagement can be
facilitated by relatively simple interventions. For example,
two reports suggested that providing patients with an
identification card (ID) allows them to feel involved in the
EMR process, even increasing buy-in because they feel
valued [8, 11], possibly by having gained visible badge of
association with a prestigeous clinic [11]. Financial incen-
tives can help overcome implementation hurdles for some
staff [12]. Details about how the incentives might be
matched to performance, and for how long, are scant. Discussion Overall, available studies of EMR implementation in
resource-constrained settings appeared methodologically
limited and at an early stage of development. The most
relevant reports appeared within the last 5 years, there
were no controlled comparison studies, and most com-
munications were descriptive in nature. Hypotheses
about factors affecting EMR implementations in slums
can be inferred, but they have not been tested. Clear
evidence-based recommendations are rare and the pre-
vailing advice is often conflicting. This is understandable
given wide variations in the systems, people, process and
product factors at play in the settings of interest. To the
extent that fundamental infrastructure (e.g., move to
wireless and mobile devices), cost (e.g., available open-
source EMR software), and support (e.g., emerging in-
formation literate workforce) challenges are dynamic,
growth in the quantity and quality of relevant literature
is anticipated. People other electronic systems [7]. Health clinics in resource-
constrained settings require well-designed, easy to use
EMR software that can be easily customized to the needs
of clinic and staff; but the published consensus is that this
has yet to be realized. p
Socio-technical factors–interactions between patients,
providers, staff and their digital environment–are fre-
quently highlighted as powerful determinants of EMR
uptake and impact. Typically cited barriers include high
staff turnover, absence of local technical support, and
low levels of computer literacy. Organizational barriers
include lack of local information system leadership or
coexistence of multiple co-deployed systems without co-
ordinated leadership [6, 9, 10, 25]. Improving end-user engagement might, for example,
require extraordinary effort to establish rapport with
clinic staff, use of multiple site visits to fully understand
how workflows and operations must change, strengthen
relationships with local partners, find and involve stake-
holders, customize product to better fit local needs, and
build reliable methods for data collection to track user
behavior change [6, 9, 10, 12]. Systems Many reports highlight the importance of appropriate
information
systems infrastructure,
such
as
reliable
power, connectivity and networking capabilities where
EMRs are deployed [7, 8, 11]. Some authors recommend
specific remedies for resource-constrained settings, in-
cluding installation of multiple power supplies of differ-
ent types (e.g., generator, solar, battery, uninterrupted
power supply) to assure continuing hardware and soft-
ware function [7, 8, 11, 25]. Where mobile EMR prod-
ucts link to centralized information systems, the location
of telecommunications towers and service centres be-
come more important considerations. Page 6 of 12 Page 6 of 12 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Products One report emphasized how limitations of currently avail-
able EMR systems contribute to user resistance; especially
bugs, missing features and poor performance [10]. Some
commonly maligned software features are mandated by
government, especially in Kenya. For example, complex
security associated with sign-on processes, unrealistically
complex
reporting
requirements,
or
time-consuming
backup rules can be beyond the means of clinics in
resource-constrained settings [7, 8]. One study suggests
that challenged clinics back up data to paper rather than Page 7 of 12 Page 7 of 12 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Since completing the literature review, two new contri-
butions have appeared [35, 36]. Fritz et al. (2015) exam-
ined facilitators, but not barriers, to EMR implementation
in limited resource settings [35]. Organizational (e.g., hu-
man resource), technical (e.g., infrastructure, Internet and
power), functional (e.g., data quality and reporting) and
training factors were emphasized, consistent with findings
reported here. In addition, “political” and “ethical” factors
were observed, which did not figure prominently in the
literature considered by this review. A review by Tierney
et al. (2015) referenced studies considered in our review,
with similar findings [7, 11, 18]. resource-limited settings. More consistent and informative
reporting about implementation studies could improve
our ability to discover the most important determinants of
success, and the most important harms to avoid. There is
a need for rigorous qualitative research before valid quan-
titative studies can be contemplated. Comparisons be-
tween emerging experiential and experimental reports
could be facilitated by reference to a conceptual frame-
work that organizes systems, people, process and product
considerations. Inclusion criteria Inclusion criteria Include papers that focused on EMRs or EHRs Include papers that referred to eHealth systems or
health information systems (that focused on EMRs
or EHRs) Include papers that include low resource settings or
limited resource settings Limiting the literature search to sub-Saharan African
countries may have limited opportunities to capture pa-
pers that may have discussed EMR implementations in
slum areas elsewhere. Given the breadth of the initial
search strategy, and the size of the initial population of
studies scanned, the impression is that any missed litera-
ture about EMRs in slum settings elsewhere would not
be more methodologically mature or likely to yield sig-
nificantly different insights. Include papers that focused on sub-Saharan Africa,
African countries Include papers that focused on Kenya and
developing countries (that focus on sub-Saharan
African countries) Include papers that focused on implementation
of EMRs/EHRs or HIS systems that also referred
to challenges/barriers/disadvantages and benefits/
advantages of implementation Appendix 1: Literature review properties
Search checklist Given the methodological state of the available litera-
ture, and the types of questions raised by that literature,
it would appear that credible qualitative studies are
needed. The human factors affecting EMR uptake in
resource-constrained environments are complex. These
need to be better characterized before good implementa-
tion impact measures are designed, assessment methods
are developed, evaluation frameworks validated and
comparative studies become doable. Include papers that focus on implementation of
EMRs and EHRs (some bibliographic databases and
countries refer to these two terms interchangeably) g
y
Include papers that focus on implementation
challenges/barriers/disadvantages/failures of EMRs/
EHRs/HIS Include papers that focus on implementation
benefits/advantages/successes of EMRs Limitations Include papers that focus on implementation of
EMRs in low resource settings We are aware of a number of limitations to the State-of-
the-Art review reported here. The literature retrieval and
iterative review process was systematic, but not validated
by checks for intra and inter-rater reliability. Portuguese,
French and Swahili are commonly spoken in sub-Saharan
Africa, but less commonly used for health informatics
communications. Nonetheless, it is possible that our
English-language constraint missed potentially important
articles. Although potentially important research data-
bases, such as CINAHL and INEEX Explorer, were not
searched, careful checks of the bibliographies of retrieved
papers suggest that the English language literature re-
trieval was comprehensive for the time period covered. Include papers that focus on implementation of
EMRs in slum settings Include papers that focus on sub-Saharan Africa
and Kenya Appendix 2: Search strategy
Medline Exclude papers that refer to EHRs/EMRs/HIS
implemented in hospital based settings Conclusion Include papers which document the implementation
or deployment of EMRs/EHRs/HIS system where
authors discuss lessons learned, risks, outcomes or
recommendations Systems, people, process and product factors play an
integral role in the fate of EMR implementations in sub-
Saharan African countries. Increased investment and
deployment is likely given growth in multi-institutional
collaborations, government support and funding prior-
ities. This State-of-the-Art review identifies both knowl-
edges gaps and learning opportunities for EMR use in Include papers that include both positive, and
negative views/results of implementations Include papers that discussed human resources,
workflow, patient outcomes, buy-in of stakeholders, Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 Page 8 of 12 Exclude papers on mental health systems or mental
health information/tracking systems staff input or involvement in the implementation
process,
information
technology
infrastructure,
privacy, confidentiality, safety, user perceptions,
user satisfaction/dissatisfaction, successes, failures,
adoption, or any other factors that are included in
the pre, during, and post, implementation of such
systems Exclude papers on medication management systems
or medication therapy management systems py
g
y
Exclude paper that focus on immunization based
systems Exclude papers that focus on dental information
systems or dental health systems y
Include both quantitative and qualitative studies y
Include both quantitative and qualitative studies Include papers that refer to or focus on
implementation in slum settings Exclude papers that focus on obstetrics health
information systems Include systematic reviews or literature reviews that
align with the inclusion criteria Exclude papers that focus on occupational health
information systems Include all papers that meet inclusion criteria
regardless of date Exclude papers that focus on animal management
information systems, animal health information
systems and animal tracking/surveillance systems Include all papers that meet inclusion criteria regardless of date Exclusion criteria Exclusion criteria Exclude papers on data management systems,
nutrition information systems, reporting systems,
surveillance systems or emergency based data health
systems that did not refer to EMRs or EHRs Exclude papers that did not include resource-
limited environments Exclude papers that focus on EMR/EHR/HIS
implementations in developed countries or countries
not in sub-Saharan Africa Exclude papers that refer to databases or systems
that manage health data such as District Health
Information System, National Health Information
Systems, National EMR/EHR/HIS implementations Embase (1974 to 2014 December 19)
Search Terms: (1974 to 2014 December 19) Search Terms: 20. Kenya.mp. [mp = title, abstract, subject headings,
heading word, drug trade name, original title,
device manufacturer, drug manufacturer, device
trade name, keyword] 1. electronic medical record/ 2. electronic medical record*.mp. [mp = title, abstract,
subject headings, heading word, drug trade name,
original title, device manufacturer, drug manufacturer,
device trade name, keyword] ,
y
]
21. 19 or 20
22. 5 and 21
23. 18 or 22 3. electronic health record*.mp. [mp = title, abstract,
subject headings, heading word, drug trade name,
original title, device manufacturer, drug manufacturer,
device trade name, keyword] Global health
(1910–2014 Week 50)
Search Terms: 4. exp medical information system/ 4. exp medical information system/ 5. 1 or 2 or 3 or 4 6. low resource*.mp. [mp = title, abstract, subject
headings, heading word, drug trade name, original
title,
device
manufacturer,
drug
manufacturer,
device trade name, keyword] 1. Medical Records Systems.mp. 1. Medical Records Systems.mp. 2. electronic medical record*.mp. [mp = abstract, title,
original title, broad terms, heading words, identifiers,
cabicodes] 7. resource poor.mp. [mp = title, abstract, subject
headings, heading word, drug trade name, original
title,
device
manufacturer,
drug
manufacturer,
device trade name, keyword] 3. electronic health record*.mp. [mp = abstract, title,
original title, broad terms, heading words, identifiers,
cabicodes] 4. health information system*.mp. [mp = abstract, title,
original title, broad terms, heading words, identifiers,
cabicodes] 8. limited resources.mp. [mp = title, abstract, subject
headings, heading word, drug trade name, original
title,
device
manufacturer,
drug
manufacturer,
device trade name, keyword] 5. 1 or 2 or 3 or 4 6. low resource*.mp. [mp = abstract, title, original title,
broad terms, heading words, identifiers, cabicodes] 9. marginalized population*.mp. [mp = title, abstract,
subject headings, heading word, drug trade name,
original title, device manufacturer, drug manufacturer,
device trade name, keyword] 7. resource poor.mp. [mp = abstract, title, original title,
broad terms, heading words, identifiers, cabicodes] 8. limited resources.mp. [mp = abstract, title, original
title,
broad
terms,
heading
words,
identifiers,
cabicodes] 10. low income.mp. [mp = title, abstract, subject
headings, heading word, drug trade name, original
title,
device
manufacturer,
drug
manufacturer,
device trade name, keyword]
d
l
/ 9. marginalized population*.mp. [mp = abstract, title,
original
title,
broad
terms,
heading
words,
identifiers, cabicodes] 11. exp developing country/ 10. low income.mp. [mp = abstract, title, original title,
broad terms, heading words, identifiers, cabicodes] 13. Ovid MEDLINE (R) In-Process & Other Non-Indexed
Citations and Ovid MEDLINE (R) 1946 to Present.
Search Terms: BMC Medical Informatics and Decision Making (2016) 16:116 Page 9 of 12 Page 9 of 12 heading word, keyword heading word, protocol
supplementary
concept
word,
rare
disease
supplementary concept word, unique identifier] heading word, keyword heading word, protocol
supplementary
concept
word,
rare
disease
supplementary concept word, unique identifier] 14. exp “Africa south of the Sahara”/ 15. 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 16. (adopt* or implement* or uptake).mp. [mp = title,
abstract, subject headings, heading word, drug
trade name, original title, device manufacturer,
drug manufacturer, device trade name, keyword] 13. (Nairobi or Kenya).mp. [mp = title, abstract,
original title, name of substance word, subject
heading word, keyword heading word, protocol
supplementary
concept
word,
rare
disease
supplementary concept word, unique identifier] 17. (challeng* or barrier* or benefit*).mp. [mp = title,
abstract, subject headings, heading word, drug
trade name, original title, device manufacturer,
drug manufacturer, device trade name, keyword] 14. 4 and 13 18. 5 and 15 and (16 or 17) 15. 12 or 14 19. Nairobi.mp. [mp = title, abstract, subject headings,
heading word, drug trade name, original title,
device manufacturer, drug manufacturer, device
trade name, keyword] 19. Nairobi.mp. [mp = title, abstract, subject headings,
heading word, drug trade name, original title,
device manufacturer, drug manufacturer, device
trade name, keyword] Ovid MEDLINE (R) In-Process & Other Non-Indexed
Citations and Ovid MEDLINE (R) 1946 to Present.
Search Terms: Ovid MEDLINE (R) In-Process & Other Non-Indexed
Citations and Ovid MEDLINE (R) 1946 to Present. Search Terms: Exclude papers that refer to hospital information
systems, hospital management information systems,
health management information systems, or health
information systems implemented in a hospital setting 1. computerized medical record system.mp. or exp
Medical Records Systems, Computerized/ y
p
p
g
Exclude papers that included or solely focused on
financial analysis, cost, return on investment of
EMRs 2. (electronic medical record* or electronic health
record* or emr or ehr).mp. [mp = title, abstract,
original title, name of substance word, subject heading
word, keyword heading word, protocol supplementary
concept word, rare disease supplementary concept
word, unique identifier] Exclude papers that just focused on computerized
physician order entry (CPOE) systems Exclude papers that focused on clinical decision
support systems or clinical summaries systems Exclude papers that exclusively focused on electronic
personal health records, electronic patient medical
records,
electronic
patient
registries,
or
patient
centered health records 3. exp Health Information Systems/ 4. 1 or 2 or 3 5. Developing Countries/ Exclude papers that focused solely on personal
digital assistant (PDA) 6. exp Poverty Areas/ or exp Poverty/ 7. exp “Africa South of the Sahara”/ 8. (low resource* or limited resource* or low income
or resource poor or poverty or developing countr* or
developing world).mp. [mp = title, abstract, original
title, name of substance word, subject heading word,
keyword
heading
word,
protocol
supplementary
concept word, rare disease supplementary concept
word, unique identifier] Exclude papers that focused on mobile health
technologies/systems, handheld technologies/systems/
computers and/or mhealth strategies/policies Exclude papers that only focused on pharmacy
stock systems or pharmacy medical systems Exclude papers on ambulance systems or
ambulatory care systems q
9. 5 or 6 or 7 or 8
10. 4 and 9 9. 5 or 6 or 7 or 8
10. 4 and 9 9. 5 or 6 or 7 or 8 Exclude papers on diabetes management systems or
chronic disease management systems 11. (adopt* or implement* or uptake or challeng* or
benefit*
or
barrier*).mp. [mp = title,
abstract,
original title, name of substance word, subject Exclude paper on laboratory information systems or
laboratory management information systems Jawhari et al. Embase (developing countr* or developing world).mp. [mp = title, abstract, subject headings, heading
word,
drug
trade
name,
original
title,
device
manufacturer,
drug
manufacturer,
device
trade
name, keyword] 11. Developing Countries/ 12. exp Poverty/ 13. exp “Africa South of Sahara”/ Page 10 of 12 Page 10 of 12 Page 10 of 12 Jawhari et al. BMC Medical Informatics and Decision Making (2016) 16:116 14. (developing countr* or developing world).mp. [mp = abstract, title, original title, broad terms,
heading words, identifiers, cabicodes]
15. 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14
16. (adopt* or implement* or uptake).mp. [mp =
abstract, title, original title, broad terms, heading
words, identifiers, cabicodes]
17. (challeng* or barrier* or benefit*).mp. [mp =
abstract, title, original title, broad terms, heading
words, identifiers, cabicodes]
18. 16 or 17
19. nairobi.mp. [mp = abstract, title, original title,
broad terms, heading words, identifiers, cabicodes]
20. kenya.mp. [mp = abstract, title, original title, broad
terms, heading words, identifiers, cabicodes]
21. 5 and 15 and 18
22. 19 or 20
23. 5 and 22
24. 21 or 23 14. (developing countr* or developing world).mp. [mp = abstract, title, original title, broad terms,
heading words, identifiers, cabicodes] 10. 4 and 9 11. (adopt* or implement* or uptake or challeng* or
benefit*
or
barrier*).mp. [mp = title,
abstract,
original title, name of substance word, subject
heading word, keyword heading word, protocol
supplementary
concept
word,
rare
disease
supplementary concept word, unique identifier] 15. 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 16. (adopt* or implement* or uptake).mp. [mp =
abstract, title, original title, broad terms, heading
words, identifiers, cabicodes] 16. (adopt* or implement* or uptake).mp. [mp =
abstract, title, original title, broad terms, heading
words, identifiers, cabicodes] 17. (challeng* or barrier* or benefit*).mp. [mp =
abstract, title, original title, broad terms, heading
words, identifiers, cabicodes]
18 16
17 12. 10 and 11 (total papers 206) 13. (Nairobi or Kenya).mp. [mp = title, abstract,
original title, name of substance word, subject
heading word, keyword heading word, protocol
supplementary
concept
word,
rare
disease
supplementary concept word, unique identifier] 19. nairobi.mp. [mp = abstract, title, original title,
broad terms, heading words, identifiers, cabicodes] pp
y
p
q
14. 4 and 13
15. 12 or 14 14. 4 and 13 14. 4 and 13
15. 12 or 14 15. 12 or 14 (All EMB Reviews) EBM Reviews - Cochrane Database of Systematic Re-
views 2005 to November 2014, EBM Reviews-ACP Journal
Club 1991 to December 2014, EBM Reviews-Database of
Abstracts of Reviews of Effects 4th Quarter 2014, EBM
Reviews-Cochrane Central Register of Controlled Trials
November 2014, EBM Reviews-Cochrane Methodology
Register 3rd Quarter 2012, EBM Reviews-Health Technol-
ogy Assessment 4th Quarter 2014, EBM Reviews-NHS
Economic Evaluation Database 4th Quarter 2014
Search Terms 3. (“electronic medical record system”) + (“challenge”
or “benefit” or “advantages” or “disadvantages” or
“implement” or “deploy” or “adopt”) + (“Nairobi” or
“Kenya”) 4. (“electronic medical record system” or “electronic
health
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Edmonton, AB, Canada. 2Innovative Canadians for Change, Edmonton, AB,
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Blaya JA, Fraser HSF, Holt B. E-Health technologies show promise in developing
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Psychosis risk research versus daily prognosis uncertainties: A qualitative study of French youth psychiatrists’ attitudes toward predictive practices
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Psychosis risk research versus daily prognosis
uncertainties: A qualitative study of French youth
psychiatrists’ attitudes toward predictive practices
L il
B
it M
i R
M
B
F li
d Ni
l
H
k Leila Benoit, Marie Rose Moro, Bruno Falissard, Nicolas Henckes To cite this version: Leila Benoit, Marie Rose Moro, Bruno Falissard, Nicolas Henckes. Psychosis risk research versus daily
prognosis uncertainties: A qualitative study of French youth psychiatrists’ attitudes toward predictive
practices. PLoS ONE, 2017, 12 (7), pp.e0179849. 10.1371/journal.pone.0179849. hal-03480076 Editor: Therese van Amelsvoort, Maastricht
University, NETHERLANDS Editor: Therese van Amelsvoort, Maastricht
University, NETHERLANDS
Received: January 12, 2017
Accepted: June 5, 2017
Published: July 19, 2017
Copyright: © 2017 Benoit et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. Editor: Therese van Amelsvoort, Maastricht
University, NETHERLANDS University, NETHERLANDS
Received: January 12, 2017
Accepted: June 5, 2017
Published: July 19, 2017 Received: January 12, 2017
Accepted: June 5, 2017
Published: July 19, 2017 Method Copyright: © 2017 Benoit et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. The Grounded Theory is an agreed-upon qualitative method in social science field that links
subjective experiences (individual narratives) to social processes (professional norms and
mental health policies). 12 French youth psychiatrists were interviewed about psychosis
early management and their daily prognosis practices with teenagers. Data Availability Statement: The study’s full-
length interviews cannot be made publicly available
due to the sensitive content and identifying
information contained in them. However, relevant
excerpts of these interviews can be made available
to interested researchers upon request to the
corresponding author at laelia@benoit.nom.fr. Data
requests cannot be directed to a committee
because sociological studies’ registrations were not
required in France when this study has been
designed. Additionally, a Supporting Information
file with relevant excerpts is included with the Psychosis risk research versus daily prognosis
uncertainties: A qualitative study of French
youth psychiatrists’ attitudes toward
predictive practices Laelia Benoit1,2*, Marie Rose Moro1,2☯, Bruno Falissard2☯, Nicolas Henckes3 Laelia Benoit1,2*, Marie Rose Moro1,2☯, Bruno Falissard2☯, Nicolas Henckes3
1 Department of Psychiatry at Cochin hospital, Paris, France, 2 CESP, INSERM U1018, Universite´ Paris-
Saclay, Univ. Paris-Sud, UVSQ, Univ. Paris-Descartes, Paris, France, 3 CERMES3, CNRS, Villejuif, France Laelia Benoit1,2*, Marie Rose Moro1,2☯, Bruno Falissard2☯, Nicolas Henckes3
1 Department of Psychiatry at Cochin hospital, Paris, France, 2 CESP, INSERM U1018, Universite´ Paris-
Saclay, Univ. Paris-Sud, UVSQ, Univ. Paris-Descartes, Paris, France, 3 CERMES3, CNRS, Villejuif, France 1 Department of Psychiatry at Cochin hospital, Paris, France, 2 CESP, INSERM U1018, Universite´ Paris-
Saclay, Univ. Paris-Sud, UVSQ, Univ. Paris-Descartes, Paris, France, 3 CERMES3, CNRS, Villejuif, France a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 ☯These authors contributed equally to this work. * laelia@benoit.nom.fr ☯These authors contributed equally to this work. * laelia@benoit.nom.fr HAL Id: hal-03480076
https://cnrs.hal.science/hal-03480076v1
Submitted on 19 Jan 2022 L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés. HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers. RESEARCH ARTICLE Background Citation: Benoit L, Moro MR, Falissard B, Henckes
N (2017) Psychosis risk research versus daily
prognosis uncertainties: A qualitative study of
French youth psychiatrists’ attitudes toward
predictive practices. PLoS ONE 12(7): e0179849. https://doi.org/10.1371/journal.pone.0179849 Over the last twenty years, predicting psychosis has become a priority of both research and
policies. Those approaches include the use of the At Risk Mental State category (ARMS)
and of standardized predictive tools. In comparison to most developed countries, early inter-
ventions programs are only little developed in France. However, cases of young patients
presenting unclear symptoms that might be a beginning psychosis or might as well reflect
some adolescent unease are commonplace in psychiatry. Yet little is known about the rou-
tine practices of youth psychiatrists regarding psychosis risk management. Do they antici-
pate mental disorders? Abstract OPEN ACCESS
Citation: Benoit L, Moro MR, Falissard B, Henckes
N (2017) Psychosis risk research versus daily
prognosis uncertainties: A qualitative study of
French youth psychiatrists’ attitudes toward
predictive practices. PLoS ONE 12(7): e0179849. https://doi.org/10.1371/journal.pone.0179849 Introduction Over the last twenty years the rise of Early Intervention in Psychiatry has stimulated the crea-
tion of centers specialized in the assessment and treatment of patients at an early stage or even
at risk of psychosis [1–3]. Yet in many countries these centers are not accessible to all patients,
who, as a consequence, are seen by psychiatrists who do not propose a standardized assess-
ment of the risk condition. Even when a specialized consultation is accessible, a psychiatrist
might have to decide whether the unclear symptoms presented by his patient might be the
early signs of a psychosis or not in order to refer him for assessment. Little is known, however,
regarding the attitudes of psychiatrists towards these situations. Competing interests: The authors have declared
that no competing interests exist. This study was conducted in France where centers of expertise in early interventions are
not fully developed. If there has been an interest from the media and the higher health admin-
istration in early intervention strategies [4–6], today only a few centers offer assessment and
care for prodromal patients, most of them in the Paris region [7]. On another hand youth psy-
chiatry is well developed thanks to the existence of an array of specialized facilities, including
university consultations centers, adolescent health centers combining different specialized
consultations—such as psychiatry, general medicine gynecology, dermatology -, as well as psy-
chiatric consultations in many community mental health centers and private consultation. France has among the highest number of practicing psychiatrists and a strong influence of psy-
choanalysis. Universal coverage of health costs creates a system accessible to young people. In
order to grasp the present implementation of early interventions, a local assessment of daily
practices appears particularly relevant. According to Christakis’ seminal work on prognosis in medicine, two different concepts of
“prognosis” can be distinguished [8]. On the one hand “prognosis” refers to the theoretical
course of a given disorder, as it is described for instance in handbooks. In that sense, even if
there is scientific evidence that its course is more favourable than traditionally thought [9–12],
schizophrenia remains usually conceived as a chronic disease in the public opinion; while
depression, for instance, should not last longer than a few months. A second meaning of prog-
nosis refers to the practice of envisioning the future course of a disorder in a given patient. Conclusion article. The transcript excerpts contained within the
Supporting Information file do not contain
information that may identify study participants. Anticipating a psychosis onset remains a highly uncertain task for psychiatrists. In France,
psychiatrists’ inconspicuous risk management might be supported by the universal costs
coverage that is not conditional on a diagnosis disclosure. Funding: This work is part of a project that
explores the development of institutions promoting
predictive psychiatry addressed for a young public
in France, Germany, and Switzerland. It received
funding from Paris City, through the project
"Psychosis risk and misfortune anticipation in
contemporary psychiatry, a sociological approach”
and from the national research funding (A.N.R.)
“PSYFRING on psychiatry fringes, an after war
history and sociology of early psychosis in France
and Germany”. Psychosis risk research versus daily prognosis uncertainties Results If all participants were aware of early intervention programs, most of them did not make use
of standardized scales. Psychiatrists’ reluctance toward a psychosis risk standardized
assessment was shaped by three difficulties: first the gap between theoretical knowledge
and practice; second their impossibility to make reliable prognoses; and third, the many
uncertainties surrounding medical judgment, adolescence and the nature of psychosis. Nev-
ertheless, they provided their young patients with multiple months follow up without disclos-
ing any risk category. 1 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Methods Participants were contacted via an email sent to the team mailing list of 4 public psychiatry
departments of the Paris Region and of 2 community mental health centers. The same email
was sent to two private practice contact-list to patients in the public services and the mailing
list of a professional society (French Society of Child and Adolescent Psychiatry, SFPEADA). The email was titled “Anticipating young patients’ future: is prognosis part of your practice?”
and proposed a one hour long interview on questions of prognosis. No retribution was offered. Twelve youth psychiatrists (6 women, 6 men) aged from 28 to 70, and working in a variety of
settings agreed to participate. In order to ensure confidentiality, numbers were used in this
article to refer to participants, Table 1. The interviews took place at their office and were semi-
structured, using a schedule comprising a series of themes to be addressed during the session. The schedule was developed after a review of the relevant psychiatric and sociological litera-
ture. The questions were meant to focus on the problem of psychosis risk and open a free dia-
logue about its daily management: when you see a teenager presenting unclear symptoms that
may be early signs of psychosis, do you feel able to predict psychotic transition? If not, do you
however expect some difficulties? What appears a priority for his future? Do you make use of
prevalence statistics or specific tools to assess psychosis risk? Do you refer your patients to
expert centers? The interviews were recorded, fully transcribed and analyzed using the
Grounded Theory (GT) methodology [13]. Inspired by ethnographical studies then theorized
by Glaser and Strauss [14], GT is an agreed-upon standard for social sciences research since
the 1960’s [15]. The Grounded Theory links social structures with processes occurring at an
individual level by focusing on themes that represent underlying phenomena, interactions and
their consequences [13]. As in other inductive methods, it is not necessary to define an exact
number of respondents before the research begins. The data are coded in order to generate cat-
egories which are then validated through constant comparisons as new interviews are done
[16]. Thus data analysis, further sampling and theoretical development are simultaneously
developed until saturation is reached allowing to build a new theory about the subject of
research [14]. Results As part of our sociological perspective, this results section reflects the opinions of the inter-
viewees—not the authors’ ones. For instance, we asked questions related to psychosis, but par-
ticipants answered focusing on schizophrenia. Later on, the discussion section will analyze
these views in the light of both medical sociology and the field of ARMS research. Introduction In
this meaning prognosis might be broken down into three components: • the first is foreseeing, that is envisioning the future of this particular patient; • the second component consists of anticipating, that is acting on the basis of this prevision in
order to prevent or manage an event that has to come; • the last component of prognosis is communicating to the patient this prevision, in other
words “predicting”. In this second meaning, prognosis is a major dimension of medical practice, and yet it
remains understudied. In a sociological perspective, this interdisciplinary study does not aim
at providing a review of scientific evidence of early intervention efficiency. We evaluated a
sample of French adolescent psychiatrists’ contemporary views regarding early intervention. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 2 / 16 Psychosis risk research versus daily prognosis uncertainties We focused on their daily practice of prognosis: To what extent do they think that psychosis
may be anticipated? How do they themselves make anticipations about the future of their
patients? Methods To ensure reliability, the analysis is repeated by more than one researcher, a pro-
cess which is called triangulation [17]. In this study, two researchers (LB and NH) indepen-
dently coded and analyzed all data [18], and their findings were discussed during meetings of
our research team (LB, NH, MRM, BF). The gap between research and practice If all participants were aware of early intervention programs, most of them did not make use
of predictive scales such as the CAARMS or the SIPS [19], nor did they refer their patients to
early management centers. Actually, it would not make sense for all practitioners to use them,
as these scales require extensive training. While ARMS assessment instruments do not predict
psychosis in an individual, our participants think that they have the ambition to do so, and 3 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 4 / 16 Psychosis risk research versus daily prognosis uncertainties « I know the center of expertise. But I prefer to handle things myself a while, even with the
first months fuzziness, than to expose the patient and his family to a check-list concluding
“you are psychotic”. Well, even colleagues working in those centers say that one should be
careful, that there is no 100% guarantee. » (psychiatrist number 5—see Table 1) Only one psychiatrist used the Comprehensive Assessment of At Risk Mental States
(CAARMS) among various diagnostic instruments in her daily work. Nevertheless, she
stressed that assessment results did not bring her any certitude about the problems a young
patient experienced. “I followed this patient for 4 years, until his late teens. In the end, I am still not sure about
his diagnosis. Parents reclaim standardized assessments. So we assess, we check things up,
we give a sort of diagnostic listing! [laugh] But I am still not sure. Well, anyway, we
evaluated.» “I followed this patient for 4 years, until his late teens. In the end, I am still not sure about
his diagnosis. Parents reclaim standardized assessments. So we assess, we check things up,
we give a sort of diagnostic listing! [laugh] But I am still not sure. Well, anyway, we
evaluated.» (7) 2. Statistics do not help to predict psychosis. Even psychiatrists involved in outcome
studies acknowledged a difficulty to match both statistical data and clinical sense. « For this girl, I would say that it will turn into a bipolar disorder. But we conducted a follow
up study among 80 teens diagnosed with a bipolar disorder type I. As adults, a third of them
had an onset of psychosis! [. . .] So, it brings a self-dialectic process, because I really feel that
it will turn into a bipolar disorder”. (7) A psychiatrist explained that outcome results from early intervention research must not be
disclosed to parents. « I know that kids with dyspraxia awake researchers’ interest. But I just can’t say to parents:
‘‘research teams believe that there is 30% risk of psychosis onset during adolescence”! We
may think it, we may conduct studies about it, but in daily work this is not possible. Any-
how, I keep an eye on them, I follow them up. » (6) Psychosis risk research versus daily prognosis uncertainties Table 1. Participants. Interview
number
Sex
Age
Setting(s): Paris Region Drug
prescription
Aware of early
intervention
programs and center
of expertise
Interest in early
intervention
research
Already worked in
partnership with
early detection
centers
Involvement in research:
personal involvement or
partnership with a research
team in youth psychiatry
1
F
55
• Public youth
psychiatry
consultation center
• Private practice
psychoanalysis
No
Yes
No
No
No
2
M
60
• Public consultation
center for children
Yes
Yes
No
No
Pharmacology history
3
M
35
• Student help
• Public youth
psychiatry
consultation center
No
Yes
No
No
No
4
M
70
• Public youth
psychiatry
consultation center
• Private practice,
psychoanalysis
No
Yes
No
No
No
5
M
70
• Public youth
psychiatry
consultation center
Yes
Yes
Yes
No
No
6
F
50
• Public center of
expertise for language
disorder. • Private practice of
psychoanalysis
No
Yes
Yes
Yes
Cohort of children with dyspraxia
in order to assess psychosis onset
rates in adolescence and young
adulthood. 7
F
42
• Public youth
psychiatry department
of a University
Hospital Center. Yes
Yes
Yes
Yes
Cohort of teens after a first bipolar
episode or psychotic episode
8
M
32
• Public youth
psychiatry department
of University Hospital
Center. Yes
Yes
No
Yes
Qualitative studies of suicide
among teens
9
F
50
• Public youth
psychiatry
consultation center
Yes
Yes
Yes
Yes
Qualitative studies about ADHD
10
M
40
• School-based
residential psychiatry
unit
Yes
Yes
No
Yes
No
11
F
50
• School-based
residential psychiatry
unit
Yes
Yes
Yes
Yes
No
12
F
28
• Public youth
psychiatry
consultation center. Yes
Yes
No
No
Pharmacological management
strategies for resistant psychosis. https://doi.org/10.1371/journal.pone.0179849.t001 Table 1. Participants. criticize it. Thus, they are reluctant to refer their patients to early management centers where
ARMS might be assessed. However, either trained or not, all participants provided their young
patients with multiple months follow up without use of an At Risk Mental State category
(ARMS) [20,21]. 1. Scales do not bring certitude. Participants were either enthusiastic about ARMS
research or not. Half of them had already worked in partnership with an early detection center,
for research or clinical purposes [Table 1]. Nevertheless, most psychiatrists did not use stan-
dardized tools to assess prodromal conditions. Impossible to predict psychosis in daily work Detection: An inescapable question without an answer. All psychiatrists considered
prognosis as an unavoidable question but they stressed the difficulty to remain informed of
their young patients’ outcomes. « I would say that prognosis is always a question, but we have no answer. We receive no
news, but is it because the young people recovered or is it because they are somewhere
else?” « I would say that prognosis is always a question, but we have no answer. We receive no
news, but is it because the young people recovered or is it because they are somewhere
else?” (10) (10) 5 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Psychosis risk research versus daily prognosis uncertainties Some psychiatrists preferred to avoid this question but fail to do so. « It isn’t useful for me to imagine that a 15 years old teen may become schizophrenic. It is
pointless. « It isn’t useful for me to imagine that a 15 years old teen may become schizophrenic. It is
pointless. - Ok. But do you still wonder about his future or not? - Yes! Yes. » - Yes! Yes. » (2) Prevention: no proof of success. Interviewees expressed doubts that early intervention
could really prevent the onset of psychosis. «—Is it possible to prevent psychosis onset? «—Is it possible to prevent psychosis onset? - (Laughing) Good question! I would be curious to hear other psychiatrists’ answers. (Seri-
ous again) I don’t know. I don’t know. I don’t know. It would be hard to prove. » - (Laughing) Good question! I would be curious to hear other psychiatrists’ answers. (Seri-
ous again) I don’t know. I don’t know. I don’t know. It would be hard to prove. » (8) Most psychiatrists actually consider that early intervention should be seen as a form of ter-
tiary prevention (aiming at reducing permanent impairment) rather than a strategy of primary
or secondary prevention (avoiding the onset of psychosis) [22]. Despite increasing waiting
lists, the French mental health system has been designed to provide free and accessible primary
care since 1960 [23]. In this context, it appears unethical to evaluate the efficacy of early inter-
vention on patients with subdued symptoms through a comparative outcome study. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Three sources of uncertainty Psychiatrists’ impossibility to predict psychosis emerges from three sources of uncertainty. Medical judgment. Each case is an individual one: Outcome statistics do not allow reli-
able predictions for a given individual. Psychiatrists’ uncertainty emerges from the limits of
their own knowledge, the limits of medical science, and their difficulty to distinguish between
both sources of uncertainty. «[Speaking about outcome after a first psychotic episode] There is one third, one third, one
third [in reference to 3 possible outcomes: psychosis, recurrent acute psychotic episodes, and no
mental trouble]. But—unless you know new studies—there is no clue to guess in which
third is your patient”. (8) Feeling relieved by uncertainty: Uncertainty disclosure may be used as a way to manage
teenagers and parents expectancies. “I tell parents that I am not a soothsayer! There are three outcomes, but there is no way to
know how it will evolve” “I tell parents that I am not a soothsayer! There are three outcomes, but there is no way to
know how it will evolve” (8) Uncertainty also supports psychiatrists’ curiosity toward their patients’ evolution, and
relieves them from the burdening responsibility of an unreliable prophecy. “If you tell me what the magic formula is to say “this one will be psychotic”, I would be glad
to have it! But it would also make the job rather boring. That is something interesting in
our job. Not to know. » “If you tell me what the magic formula is to say “this one will be psychotic”, I would be glad
to have it! But it would also make the job rather boring. That is something interesting in
our job. Not to know. » (8) Adolescence process. Is it teenage rebellion or mental trouble? Psychiatrists acknowledge
having difficulties to distinguish what may reflect adolescent unease and what may be a true
psychiatric disorder. “It is hard to set thing apart, from what is teenage rebellion and what is a deep psychic crisis. We are always providing a counterweight on the one side or on the other side ” “It is hard to set thing apart, from what is teenage rebellion and what is a deep psychic crisis. It is hard to set thing apart, from what is teenage rebellion and what is a deep psychic crisis. « Can psychiatric care avert psychosis onset? It is important to be far-sighted, but it
is difficult.» (8). (8). « Can psychiatric care avert psychosis onset? « Can psychiatric care avert psychosis onset? - What a question! I don’t know. One can assume that without proper care—I don’t know if
they would really develop schizophrenia—but they would surely have a psychological or
cognitive impairment. Without care at all, I will never know. It would mean venturing a
study following-up persons who receive care, and the same number who not receive any
care, and assess the natural course. That is questionable, ethically. » - What a question! I don’t know. One can assume that without proper care—I don’t know if
they would really develop schizophrenia—but they would surely have a psychological or
cognitive impairment. Without care at all, I will never know. It would mean venturing a
study following-up persons who receive care, and the same number who not receive any
care, and assess the natural course. That is questionable, ethically. » (10) No theory spares worries about the future. Some participants spontaneously explained
their reluctance toward predictive approaches by a theoretical choice such as psychoanalysis or
a adolescent psychiatrist’s view. Nevertheless, this attitude did not spare them worries about
the future of their young patients, and failed to provide an unequivocal answer to the prognos-
tic question. « As a psychotherapist I should break free from [the prognosis] question to elaborate the
sense of what is happening to him. But having in mind that he might be somehow delirious
[. . .] makes me suspicious of what may happen. I referred him to a colleague for a prescrip-
tion so as to break free from this problem. But, of course, I was not relieved! » « As a psychotherapist I should break free from [the prognosis] question to elaborate the
sense of what is happening to him. But having in mind that he might be somehow delirious
[. . .] makes me suspicious of what may happen. I referred him to a colleague for a prescrip-
tion so as to break free from this problem. But, of course, I was not relieved! » (1) 6 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Psychosis risk research versus daily prognosis uncertainties « The adolescent psychiatrist attitude is to face teenagers’ immediate shifts. It is different
from the attitude of an adult psychiatrist. [The long-term risk] is obviously a question when
we stop and think about it, but not in our daily work. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Three sources of uncertainty Either it wasn’t schizophrenia or they managed to recover. That is
harmful. If we have a doubt it is better not to mention it.” (10) Thus, the uncertainties surrounding medical practice, adolescence and psychosis shape
youth psychiatrists’ impossibility to predict psychosis. Thus, the uncertainties surrounding medical practice, adolescence and psychosis shape
youth psychiatrists’ impossibility to predict psychosis. Three sources of uncertainty We are always providing a counterweight on the one side or on the other side.” (10) (10) The adolescence processappears in between instability and self-construction.Youth psychia-
trists express the feeling that teenagers are moving on an irretrievable trajectory that can be
improved through psychiatric support. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 7 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Psychosis risk research versus daily prognosis uncertainties « One gets structured, during adolescence and young adulthood by symptoms and mental
suffering. When you work with teens you have this feeling that your influence allows them
not to switch on the wrong side”. (4) Nevertheless, daily practice consists in dealing with immediate changes that make every
short or long term outcome unpredictable. « When you think of something, the teen has already changed! » (8) Psychosis uncertainties. A historical vision of psychosis as a lifelong mental and social
trouble shapes psychiatrists reluctance to anticipate psychotic transition. «One may be afraid to anticipate an illness that you do not still have. It is a serious problem,
severe, resistant, with heavy treatments, side effects for sure, that impacts social and profes-
sional life. It will be a lifelong problem, and he is only a teen!” «One may be afraid to anticipate an illness that you do not still have. It is a serious problem,
severe, resistant, with heavy treatments, side effects for sure, that impacts social and profes-
sional life. It will be a lifelong problem, and he is only a teen!” (12) Psychiatrists face a paradox. The success of early intervention would contradict the vision
of this mental trouble as a social impairment. « Persons that turn out « normal » again a few years later, I am forced to consider that I was
mistaken about a schizophrenia early diagnosis. » « Persons that turn out « normal » again a few years later, I am forced to consider that I was
mistaken about a schizophrenia early diagnosis. » (5) Both eventualities of false positive patients and cases of successful care lead psychiatrists to
avoid prediction and refuse to disclose an ARMS status. Both eventualities of false positive patients and cases of successful care lead psychiatrists to
avoid prediction and refuse to disclose an ARMS status. “How many teens have been labeled schizophrenics? Time goes by and reveals that they
aren’t schizophrenics. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 The challenge of individual psychosis prediction The first source of uncertainty mentioned by participants refers to medical judgment and is
consistent with the sociological analysis of medicine. Fox argued that learning to cope with the
uncertainty of medical practice is a professional norm that is assimilated early in the curricu-
lum. She distinguished three sources of uncertainty: the limits of a physician’s knowledge, the
limits of medical science, and the inability of the physician to distinguish between those two
sources of uncertainty [25,26]. Freidson and Hunter argued that medicine is taught as a sci-
ence of individuals. Each clinical case is unique and therefore uncertain [27,28]. According to
Light, medical trainees learn to control uncertainty through specialization, involvement in
schools of thought, clinical experience, and growing autonomy [29]. Thus, claiming to belong
to a school of thought such as psychoanalysis or youth psychiatry could merely be way to cope
with uncertainty. Dealing with serious diseases, prognosis uncertainty can be functional, that
is used by doctors in order to avoid distress reactions from patients and their relatives [30] and
avoid being held responsible for the patient’s outcome [8]. In that sense, a prognosis disclosure
is a too risky commitment. This opinion is expected to persist over some period of time, to
account for the psychiatrist’s “consistent behavior”. According to Becker, commitments come
into being when a person, by making a side bet, links extraneous interests with a consistent
line of activity [31]. Side bets are often a consequence of the person’s participation in social
organizations. In daily work, a person sometimes finds that he has made side bets constraining
his present activity because the existence of general cultural expectations provides penalties for
those who violate them [31]. For instance, the cultural expectation about the behavior account-
ing for a practitioner’s trustworthiness is different from the expectation accounting for the
trustworthiness of a researcher. People feel that a practitioner ought not to change his opinion
too often and that one who does is inexperienced and untrustworthy [8]. On the contrary, a
researcher’s shifting views on a subject might account for his commitment through his consis-
tency in improving his study design. Thus, a practitioner will avoid prognosis disclosure,
instead of sharing his worries about a psychosis onset to a young patient and then changing his
opinion after a second appointment. Functional uncertainty is thus used by doctors in order to
diminish their own level of commitment. Discussion According to participants, neither the results of research, standardized instruments nor clinical
judgment enable the prediction of psychosis before its onset. The gap between ARMS research
and daily work is related to the limitations of preventive instruments, as well as that of schools
of thought. For a given teenager, detection and prevention efficiency remain impossible to
prove. Nevertheless, neither psychoanalysis nor child development theories—both focusing on
a present timeframe in order to support teenagers’ elaboration and positive identity construc-
tion [24]–spare psychiatrists worries about their young patients future. Finally, individual psy-
chosis prediction failure appears related to the many uncertainties surrounding medical PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 8 / 16 Psychosis risk research versus daily prognosis uncertainties practice, the adolescence process, and psychosis itself. In the following sections, we propose to
discuss participants’ uncertainties through two ideas. First, individual prognosis is a challenge
inherent to medical practice. Second, declared interest for or reluctance toward predictive
approaches may be shaped by health systems. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Psychosis risk research versus daily prognosis uncertainties adult population, psychotic-like experiences are strongly correlated with distress, depression
and poor functioning [41]. Participants’ third source of uncertainty was related to psychosis diagnosis and course. First, we asked questions focusing on psychosis but participants’ answers focus on schizophre-
nia (in French “schizophre´nie”) instead of psychosis (psychose). According to the Grounded
Theory, this is neither a methodological problem, nor a translation mistake, but a meaningful
result. The use of schizophrenia as a synonym for psychosis enlightens participants’ contempo-
rary representation of psychosis as an equivalent of schizophrenia. The schizophrenia label, if
still used as a reliable research category [42,43] is increasingly contested in order to reduce
stigma [44] and account for a complex and poorly understood etiology [45,46]. The Ultra
High Risk of psychosis (UHR) low prediction accuracy (15% to 25%) [47], high rates of false
positive identifications (from 50% to 84%) [48,49] and difficulties to evaluate if early treat-
ments improve long-term outcomes are stressed as current research challenges [50–54]. Research teams believe that the risk of psychosis onset during adolescence is far lower than
30% when SIPS or CARMS is applied in the general community [49]. Authors attribute this
low predictive value to low prevalence of the psychosis risk syndrome in a general adolescent
clinical population [55]. Thus, given the potential stigma associated to a Psychosis Risk syn-
drome [56] and its need to be further validated, it was not included in the DSM-V [57]. Sec-
ond, participants expressed a contradiction between the practice of a probabilistic judgment in
early diagnosis, due to the fact that psychosis diagnosis is based on a retrospective duration cri-
teria [58]. Third, our results show that the vision of psychosis as a disastrous life-long trouble
[59,60] refrains psychiatrists’ involvement in preventive approaches. Despite activism by for-
mer patients and patient advocates who have argued that psychosis did not prevent persons to
live meaningful lives and to maintain a social role in their community, as well as scientific evi-
dences that the course of schizophrenia is not always negative [9–12,61,62], schizophrenia’s
major economic costs and duration shapes the idea that “the onset of psychotic illness represents
potential personal disaster in the life-course of an individual” [63]. Thus, interviewed psychia-
trists extended the deadline before disclosing such a dreadful perspective. However, if the pri-
mary outcome of interest in at-risk research was the development of psychotic disorder—
whereby patients are categorized as either having ‘transitioned’ or ‘not transitioned’–recent
research suggest that ‘non transitioned’ persons may have a poorer quality of life [64,65]. More
than attenuated psychotic symptoms (APS), social and functioning difficulties as well as
depressive symptoms can be the highest sources of distress leading UHR patients to seek help
[66]. Thus, the term ‘outcome’ might be broadened to incorporate non-psychotic diagnoses,
functioning and negative symptoms [67]. PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 The challenge of individual psychosis prediction The second source of uncertainty mentioned by the participants to this study was the
immediacy and unpredictability of teenagers’ symptoms. The adolescent period is seen as a
social, hormonal, neurological, and psychological storm both by public opinion and by health
professionals [32,33]. As early as in 1958, Anna Freud famously suggested that calm teenagers
may hide distressful emotions: “being normal during the adolescence period is abnormal”
[34]. The participants in our study argued that they were not always able to distinguish
adolescent unease or rebellion from subdued psychotic symptoms. Interviewees’ vision of ado-
lescence as an unpredictable process combining daily mood instability and social skills devel-
opment is supported by neurosciences [35,36]. Teenagers new access to abstract thinking, if
formerly stressed by child development psychology [37] is now supported by brain imagery
studies revealing a neuronal network reconfiguration through synaptic trimming [38] that
extends into the second and third decades of life [39]. Another difficulty is related to the fact
that the incidence of positive psychotic experiences in the general population is 100 times
greater than the incidence of psychotic disorders [40]. Moreover, in the adolescent and young PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 9 / 16 Health systems beyond the research/clinic dichotomy Interactionism in sociology focuses on the way that people act and on the reasons they give to
justify their action [68]. In this perspective, a meaning does not need to be “true” to be effec-
tive. The meaning that people give to a thing or an event determines its symbolic reality, which
has the power to induce a social effect. Which reasons can be used by our participants to support their views? Even if they know
statistical data related to psychosis onset, in the end psychiatrists make decisions according to
their clinical sense. This “in-between” strategy including both rational and non-rational strate-
gies has been proven to be efficient in risk-management strategies [69]. Our results show that
participants do not expect that early diagnosis tools improve the actual care provided. They
legitimize their reluctance toward ARMS assessment by the clinic/research dichotomy. For
instance, two reasons are used by our participants to avoid the referral of their young patients PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 10 / 16 Psychosis risk research versus daily prognosis uncertainties to assessment centers: first, it is impossible to predict an individual outcome; second, it is
impossible to know if psychosis can be prevented in an individual. However, researchers of the
ARMS field already agree with those critics [49]: first, ARMS assessment instruments aim at
determining an ARMS, not predicting psychosis in an individual. Second, early interventions
for ARMS individuals aim at improving functional outcome at group level. Nevertheless,
“valid” or not in a scientific meaning, these reasons induce a real social effect: our participants’
reluctance to refer their young patients for ARMS standardized assessment. According to the
Grounded Theory, this confusion does not reveal a methodological mistake or participants’
lack of perspective, but a meaningful result. Moreover, we will argue in the following section
that participants’ inconspicuous risk management might as well be understood considering
the characteristics of the French health system. How do our participants actually act? When they suspect a psychosis onset, interviewees
start an inconspicuous risk management: multiple months follow up of this fuzzy clinical state. We suggest that this strategy may be influenced by the organization of youth mental health ser-
vices in France. In this country 77% of mental health care is provided by the public system
with a universal costs coverage [70]. A diagnosis of risk is not necessary in order to obtain
reimbursement of mental health costs. Health systems beyond the research/clinic dichotomy Thus, psychiatrists use their subjective judgment to
start a discreet follow-up. As early as in 1941, Ru¨mke described the “praecox feeling” as a feel-
ing of unease emanating in the interviewer that reflects the detachment of the patient and the
failure of an ‘affective exchange’ [71]. Praecox feeling reliability has mainly been evaluated
among persons with an ongoing psychosis. Compared with the standardized diagnostic classi-
fication the precision of the intuitive reasoning appears remarkably high [72–74]. On the con-
trary, in a U.H.R. population, Nelson and Yung showed that the clinical impression of an
incipient psychosis—that is, a clinical judgment that a particular patient may soon progress to
a full-threshold disorder—is not sufficient for predicting a psychosis outcome and may lead
physicians to improper antipsychotic medication [75]. This result stresses the need to design
more adequate follow ups for young people. Youth psychiatry (child and adolescent) services
usually stop following patients when they reach 18 years of age and are then referred to adult
services. The communication between those services remains limited both for clinical and for
research purposes. Today, despite psychosis peak onset in late adolescence—early adulthood
[76], only few youth psychiatry departments are designed for following up young patients
until 25 to 30 years. The participants to our study usually did not receive news from their
patients after they had been referred. The lack of outcome studies following young patients
from child to adult departments and of services specially designed for persons aged 15–30,
increases the youth psychiatrists’ challenge to imagine young patients’ evolution after their
18s. Study limitations and implications: Rationale for a comparison of local
mental health system changes If qualitative methods’ validity is increasingly acknowledged in medicine, the Grounded The-
ory (GT) remains rarely known in the medical field. If Interpretative Phenomenological Anal-
ysis (IPA) is the dominant method increasingly used in psychological studies—and previously
employed by our team [77]–its’ main difficulty is to develop the analysis to a sufficient inter-
pretative level [78]. IPA aims to understand the experiences (phenomenology) and meaning-
making activities (interpretation) of the research participant [18]. The analyst attempts to
make sense of the participants’ interpretation of their own experience, thus creating a double
hermeneutic [79]. Nevertheless, improving the interpretation level can be facilitated by bor-
rowing techniques from the GT [80]. Beyond the individual psychological experience PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 11 / 16 Psychosis risk research versus daily prognosis uncertainties described by IPA, the GT emphasizes its particular societal, cultural and political context. That
is, participants’ views convey some knowledge about beliefs and practices shaped by profes-
sional norms and institutions’ organization. IPA is better known than GT in the medical field
due to the historical fact that most mental health qualitative research has been designed by
psychologists in order to grasp individual experiences [81]. In the present context of positive
mental health, Grounded Theory provides a particularly relevant approach for qualitative
researches assessing the local impact of contemporary health system changes. The sampling strategy was to encounter diverse range of youth psychiatrists working in dif-
ferent settings and being either actively involved in research or not [17]. However, if psychia-
trists had distinctive clinical practices and attitudes toward research, they were unanimous
about their impossibility to commit in prognostications in their daily work. Thus, saturation
was rapidly reached. A validity criterion of qualitative studies is to expose results of the analysis
to participants. Findings were directly communicated to four participants and five oral com-
munications were addressed to more than 70 youth psychiatrists’ who agreed with our results
(oral communications in the department meetings of three hospitals Cochin, Pitie´-Salpêtrière,
and Avicenne (Paris Region), the annual conference of de French Society of Child and Adoles-
cent Psychiatry (SFPEADA) in Lyon, May 2016, the annual conference of French Society for
Psychiatric Information (SIP) in Bruxelles, September 2016). While it is not possible to gener-
alize from such a small scale study, the opinion reported here may reflect the perspectives of a
significant segment of French youth psychiatrists. Conclusion This study stressed the gap between the psychosis risk research and adolescent psychiatrists
daily prognosis uncertainties [83]. Psychiatrists’ reluctance toward early psychosis detection
was shaped by three difficulties: first the theoretical gap between research and practice; second
their impossibility to make reliable prognoses; and third, their uncertainties relating to medical
judgment, adolescence and the nature of psychosis. If our participants explained their reluc-
tance toward ARMS assessment by the clinic/research dichotomy, their inconspicuous risk
management appears merely supported by the French health system facilities. They allow free
follow ups that are not conditional on ARMS assessment. Improving the early management of
child and adolescent mental health disorders [84] is a necessity that increases the need to
acknowledge uncertainty [85]. Meanwhile, daily predictive practices appear shaped by distinc-
tive cultural, societal and political contexts, such as mental health services design and costs
coverage. Study limitations and implications: Rationale for a comparison of local
mental health system changes This study is first step to provide an account
of early interventions implementation. The W.H.O. argues that given their historical and con-
ceptual diversity, the efficiency of the mental health policies and practices in different coun-
tries is difficult to compare in an evidence based perspective [82]. Using the GT in different
countries would offer a qualitative comparison of young people access to mental health care
and a particularly relevant insight of psychosis early management implementation in psychiat-
ric services. Supporting information S1 Appendix. A supporting information file with relevant excerpts. (DOCX) Author Contributions
Conceptualization: LB. Conceptualization: LB. 12 / 16 PLOS ONE | https://doi.org/10.1371/journal.pone.0179849
July 19, 2017 Psychosis risk research versus daily prognosis uncertainties Data curation: LB. Formal analysis: LB NH. Funding acquisition: NH. Investigation: LB. Methodology: LB NH. Project administration: NH. Validation: LB NH MRM BF. Visualization: LB. Writing – original draft: LB. Writing – review & editing: LB. Data curation: LB. Formal analysis: LB NH. Funding acquisition: NH. Investigation: LB. Methodology: LB NH. Project administration: NH. Validation: LB NH MRM BF. Visualization: LB. Writing – original draft: LB. Writing – review & editing: LB. Data curation: LB. Formal analysis: LB NH. Funding acquisition: NH. Investigation: LB. Methodology: LB NH. Project administration: NH. Validation: LB NH MRM BF. Visualization: LB. Writing – original draft: LB. Writing – review & editing: LB. Data curation: LB. Formal analysis: LB NH. Funding acquisition: NH. Investigation: LB. Methodology: LB NH. Writing – original draft: LB. Writing – review & editing: LB. Writing – review & editing: LB. References 1. McGorry P, Bates T, Birchwood M. Designing youth mental health services for the 21st century: exam-
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https://openalex.org/W2214390920
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https://europepmc.org/articles/pmc2962143?pdf=render
|
Sinhala, Sinhalese
| null |
(3<i>R</i>,4<i>S</i>,5<i>S</i>)-4-Hydroxy-3-methyl-5-[(2<i>S</i>,3<i>R</i>)-3-methylpent-4-en-2-yl]tetrahydrofuran-2-one
|
Acta crystallographica. Section E
| 2,008
|
cc-by
| 4,393
|
(3R,4S,5S)-4-Hydroxy-3-methyl-5-
[(2S,3R)-3-methylpent-4-en-2-yl]tetra-
hydrofuran-2-one 1 restraint
H-atom parameters constrained
max = 0.14 e A˚ 3
min = 0.10 e A˚ 3 organic compounds b = 16.411 (3) A˚
c = 11.607 (2) A˚
= 95.46 (3)
V = 1193.4 (4) A˚ 3
Z = 4
Mo K radiation
= 0.08 mm1
T = 291 (1) K
0.30 0.28 0.20 mm
Data collection
Nonius KappaCCD diffractometer
Absorption correction: none
9263 measured reflections
2268 independent reflections
1228 reflections with I > 2(I)
Rint = 0.026
Refinement
R[F 2 > 2(F 2)] = 0.036
wR(F 2) = 0.080
S = 1.06
2268 reflections
262 parameters
1 restraint
H-atom parameters constrained
max = 0.14 e A˚ 3
min = 0.10 e A˚ 3 Acta Crystallographica Section E
Structure Reports
Online
ISSN 1600-5368 Acta Crystallographica Section E
Structure Reports
Online
ISSN 1600-5368 Mo K radiation
= 0.08 mm1
T = 291 (1) K
0.30 0.28 0.20 mm ISSN 1600-5368 Table 1 Received 30 May 2008; accepted 8 July 2008 D—H A
D—H
H A
D A
D—H A
O2—H2 O3i
0.82
2.03
2.821 (3)
163
O20—H20 O30i
0.82
1.96
2.771 (3)
171
Symmetry code: (i) x þ 1; y; z. Key indicators: single-crystal X-ray study; T = 291 K; mean (C–C) = 0.005 A˚;
R factor = 0.036; wR factor = 0.080; data-to-parameter ratio = 8.7. The title compound, C11H18O3, was synthesized to prove the
relative configuration of the corresponding acyclic C1—C8
stereopentade. It crystallizes with two molecules in the
asymmetric unit, which show only slight differences. The
molecules are linked via O—H O hydrogen bonds, resulting
in two crystallographically independent chains of molecules
propagating in the a-axis direction. The absolute configuration
was known from the synthesis. Data collection: COLLECT (Nonius, 1998); cell refinement:
DENZO and SCALEPACK (Otwinowski & Minor, 1997); data
reduction: DENZO and SCALEPACK; program(s) used to solve
structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine
structure:
SHELXL97
(Sheldrick,
2008);
molecular
graphics:
SHELXTL-Plus (Sheldrick, 2008); software used to prepare material
for publication: SHELXL97 and PLATON (Spek, 2003). Related literature Supplementary data and figures for this paper are available from the
IUCr electronic archives (Reference: HB2741). For related literature, see: Abraham, Ko¨rner & Hiersemann
(2004); Abraham, Ko¨rner, Schwab & Hiersemann (2004);
Corey & Snider (1972); Evans et al. (1981, 1999); Ko¨rner &
Hiersemann (2006, 2007); Pollex & Hiersemann (2005). References Abraham, L., Ko¨rner, M. & Hiersemann, M. (2004). Tetrahedron Lett. 45,
3647–3650. Experimental
Crystal data
C11H18O3
Mr = 198.25
Monoclinic, P21
a = 6.2934 (13) A˚ Abraham, L., Ko¨rner, M., Schwab, P. & Hiersemann, M. (2004). Adv. Synth. Catal. 346, 1281–1294. Corey, E. J. & Snider, B. B. (1972). J. Am. Chem. Soc. 94, 2549–2550. Evans, D. A., Bartroli, J. & Shih, T. L. (1981). J. Am. Chem. Soc. 103, 2127–
2129. Evans, D. A., Miller, S. J., Lectka, T. & von Matt, P. (1999). J. Am. Chem. Soc. 121, 7559–7573. Ko¨rner, M. & Hiersemann, M. (2006). Synlett, pp. 121–123. Ko¨rner, M. & Hiersemann, M. (2007). Org. Lett. 9, 4979–4982. Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlan Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands. (
)
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, twinowski, Z. & Minor, W. (1997). Methods in Enzymolo Experimental Annika Becker, Markus Schu¨rmann, Hans Preut* and
Martin Hiersemann Fakulta¨t Chemie, Technische Universita¨t Dortmund, Otto-Hahn-Strasse 6, 44221
Dortmund, Germany
Correspondence e-mail: hans.preut@udo.edu
Received 30 May 2008; accepted 8 July 2008
Key indicators: single-crystal X-ray study; T = 291 K; mean (C–C) = 0.005 A˚;
R factor = 0.036; wR factor = 0.080; data-to-parameter ratio = 8.7. Fakulta¨t Chemie, Technische Universita¨t Dortmund, Otto-Hahn-Strasse 6, 44221
Dortmund, Germany
Correspondence e-mail: hans.preut@udo.edu Table 1
Hydrogen-bond geometry (A˚ , ). D—H A
D—H
H A
D A
D—H A
O2—H2 O3i
0.82
2.03
2.821 (3)
163
O20—H20 O30i
0.82
1.96
2.771 (3)
171
Symmetry code: (i) x þ 1; y; z. Table 1
Hydrogen-bond geometry (A˚ , ). Experimental (
)
Macromolecular Crystallography, Part A, edited by C. W. Carter Jr and R. M. Sweet, pp. 307–326, New York: Academic Press. R. M. Sweet, pp. 307 326, New York: Academic Press. Pollex, A. & Hiersemann, M. (2005). Org. Lett. 7, 5705–5708. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. , pp
,
Pollex, A. & Hiersemann, M. (2005). Org. Lett. 7, 5705–5708. Sheldrick G M (2008) Acta Cryst A64 112 122 Pollex, A. & Hiersemann, M. (2005). Org. Lett. 7, 5705–570 Monoclinic, P21
a = 6.2934 (13) A˚ C11H18O3
Mr = 198.25 Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. (
)
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Becker et al. o1517 Acta Cryst. (2008). E64, o1517 Acta Cryst. (2008). E64, o1517 doi:10.1107/S1600536808021181 Comment The title compound, (I), was synthesized using a catalytic asymmetric Claisen rearrangement (Abraham et al., 2004a; Ab-
raham et al. 2004b; Pollex & Hiersemann, 2005; Körner & Hiersemann, 2006; Körner & Hiersemann, 2007), a diastereose-
lective reduction with K-Selectride (Körner & Hiersemann, 2006; Körner & Hiersemann, 2007), and an aldol addition un-
der modified Evans conditions (Evans et al., 1981). In order to verify the relative configuration of the major diastereomer
of the obtained aldol adduct (dr = 7/3), 4-(tert-butyldimethylsilyloxy)-3-hydroxy-2,5,6-trimethyloct-7-enoyl)-4-isopropyl-
oxazolidin-2-one, (II), a γ-lactone, (I), was prepared by removal of the silyl protecting group (Corey et al., 1972) and sub-
sequent in situ lactonization. Fig. 1 depicts the structure of the isolated major diastereomer (I). The configuration of the chiral
C atoms in (I) can be attributed to the stereochemical course of the aldol addition (C3 R and C4 S), the diastereoselective
reduction with K-Selectride (C5 S), and the catalytic asymmetric Claisen rearrangement (C2 S and C3 R) using the chiral
Lewis acid [Cu{(S,S)-tert-Butyl-box}](H2O)2(SbF6)2 (Evans et al., 1999). There are two molecules of (I) in the asymmetric unit (Figs. 1 and 2) with similar conformations. In the crystal, the
molecules interact via O—H···O hydrogen bonds (Table 1) to form two independent chains, both propagating in [100]. (3R,4S,5S)-4-Hydroxy-3-methyl-5-[(2S,3R)-3-methylpent-4-en-2-yl]tetrahydrofuran-2-one A. Becker, M. Schürmann, H. Preut and M. Hiersemann A. Becker, M. Schürmann, H. Preut and M. Hiersemann supplementary materials supplementary materials Acta Cryst. (2008). E64, o1517 [ doi:10.1107/S1600536808021181 ] Acta Cryst. (2008). E64, o1517 [ doi:10.1107/S1600536808021181 ] Experimental The title compound, (I), was synthesized from the corresponding anti-aldol adduct, (II), using tetrabutylammonium fluoride
(TBAF) (Corey et al., 1972) for the removal of the silyl protecting group. The subsequent lactonization proceeded in situ. TBAF (1 M in tetrahydrofuran, 0.82 ml, 3.0 eq) was added to a solution of the diastereomeric mixture of (II) (dr =
7/3, 120 mg, 0.27 mmol, 1.0 eq) in dry tetrahydrofuran (2 ml) at 273 K. The mixture was stirred at 273 K for 15 min
and then at 298 K for 30 min. The reaction was quenched by the addition of saturated aqueous NaHCO3 solution. The
phases were separated, and the aqueous phase was extracted with CH2Cl2. The combined organic layers were dried over
MgSO4 and concentrated under reduced pressure. Flash chromatography (isohexane/ethyl acetate 20/1 to 10/1) afforded (I)
as a single diastereomer and additionally a mixture of (I) and the minor diastereomer with an overall yield of 72% (38.7
mg, 0.195 mmol) as colourless crystals. Single crystals of (I) were obtained by vapor diffusion recrystallization technique
from isohexane and ethyl acetate to yield colourless cuboids: mp 412 K; Rf 0.33 (cyclohexane/ethyl acetate 2/1); 1H NMR
(CDCl3, 400 MHz, δ): 0.84 (d, J = 7.0 Hz, 3H, (1)-H), 0.97 (d, J = 7.0 Hz, 3H, (3)'-H), 1.27 (d, J = 7.3 Hz, 3H, 3'-H), 1.85
(d, J = 4.8 Hz, 1H, –OH) overlapped by 1.89 (br. s), 2.19 (dqd, J = 10.6, 7.0, 3.0 Hz, 1H, (2)-H), 2.73 (dq, J = 4.8, 7.3 Hz,
1H, 3-H) overlapped by 2.62 - 2.72 (m, 1H, (3)-H), 4.07 (dd, J = 10.6, 3.0 Hz, 1H, 5-H), 4.37 (dd, J = 7.3, 4.8 Hz, 1H, 4-H),
5.03 (dd, 3J(E) = 17.0 Hz, 2J = 1.3 Hz, 1H, (5)-H), 5.04 (dd, 3J(Z) = 11.0 Hz, 2J = 1.3 Hz, 1H, (5)-H), 5.84 (ddd, 3J(E) =
17.0 Hz, 3J(Z) = 11.0 Hz, 3J = 6.3 Hz, 1H, (4)-H); 13C NMR (CDCl3, 100 MHz, δ): 8.4 (CH3), 9.7 (CH3), 12.3 (CH3), 35.7
(CH), 36.9 (CH), 42.7 (CH), 71.7 (CH), 84.3 (CH), 114.3 (CH2), 142.7 (CH), 178.4 (C); IR (cm-1): 3435(br, nm) (ν O—H,
OH in H-bridges), 3085(w) 3020(w) (ν C—H, olefin), 2970(m) 2925(m) 2855(s) (νas,s C—H, CH2, CH3, CH), 1740(s) (ν sup-1 supplementary materials C=O, lactone), 1640(w) (ν C=C), 1465(m) (δas C—H, CH3, CH2), 1380(m) (δs C—H, CH3); Anal. Calcd. for C11H18O3:
C, 66.6; H, 9.2; Found: C, 66.5; H, 9.3; [α]D20 +2.2 (c 0.472, CHCl3). Figures Fig. 1. : The molecular structure of molecule one of (I), with displacement ellipsoids for the
non-hydrogen atoms shown at the 30% probability level. Fig. 2. : The molecular structure of molecule two of (I), with displacement ellipsoids for the
non-hydrogen atoms shown at the 30% probability level. Refinement Anomalous dispersion was negligible and Friedel pairs were merged before refinement. The H atoms were geometrically
placed (C—H = 0.93-0.98Å, O—H = 0.82Å) and refined as riding with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C, O). Figures
Fig. 1. : The molecular structure of molecule one of (I), with displacement ellipsoids for the
non-hydrogen atoms shown at the 30% probability level. Fig. 2. : The molecular structure of molecule two of (I), with displacement ellipsoids for the
non-hydrogen atoms shown at the 30% probability level. (3R,4S,5S)-4-Hydroxy-3-methyl-5-[(2S,3R)- 3-methylpent-4-en-2-yl]tetrahydrofuran-2-one Figures
F
n
F
n Extinction correction: SHELXL97 (Sheldrick, 2008), Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 Primary atom site location: structure-invariant direct
methods
Extinction coefficient: 0.042 (4) Extinction coefficient: 0.042 (4) Extinction coefficient: 0.042 (4) (3R,4S,5S)-4-Hydroxy-3-methyl-5-[(2S,3R)- 3-methylpent-4-en-2-yl]tetrahydrofuran-2-one (3R,4S,5S)-4-Hydroxy-3-methyl-5-[(2S,3R)- 3-methylpent-4-en-2-yl]tetrahydrofuran-2-one Crystal data
C11H18O3
F000 = 432
Mr = 198.25
Dx = 1.103 Mg m−3
Monoclinic, P21
Mo Kα radiation
λ = 0.71073 Å
Hall symbol: P 2yb
Cell parameters from 9263 reflections
a = 6.2934 (13) Å
θ = 3.0–25.4º
b = 16.411 (3) Å
µ = 0.08 mm−1
c = 11.607 (2) Å
T = 291 (1) K
β = 95.46 (3)º
Block, colourless
V = 1193.4 (4) Å3
0.30 × 0.28 × 0.20 mm
Z = 4
Data collection
Nonius KappaCCD
diffractometer
2268 independent reflections
Radiation source: fine-focus sealed tube
1228 reflections with I > 2σ(I)
Monochromator: graphite
Rint = 0.026
Detector resolution: 19 vertical, 18 horizontal pixels
mm-1
θmax = 25.4º
T = 291(1) K
θmin = 3.0º sup-2 supplementary materials 259 frames via ω–rotation (Δω=1%) and two times
120 s per frame (three sets at different κ–angles)
scans
h = −7→7
Absorption correction: none
k = −19→19
9263 measured reflections
l = −13→13 259 frames via ω–rotation (Δω=1%) and two times
120 s per frame (three sets at different κ–angles)
scans
h = −7→
Absorption correction: none
k = −19
9263 measured reflections
l = −13 259 frames via ω–rotation (Δω=1%) and two times
120 s per frame (three sets at different κ–angles)
scans Secondary atom site location: difference Fourier map
Hydrogen site location: inferred from neighbouring
sites H-atom parameters constrained w = 1/[σ2(Fo
2) + (0.0276P)2]
where P = (Fo
2 + 2Fc
2)/3
(Δ/σ)max = 0.001
Δρmax = 0.14 e Å−3
Δρmin = −0.10 e Å−3 Extinction correction: SHELXL97 (Sheldrick, 2008), Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance mat-
rix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations
between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of
cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, convention-
al R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-
factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large
as those based on F, and R- factors based on ALL data will be even larger. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
x
y
z
Uiso*/Ueq
O1
−0.2547 (2)
0.96841 (13)
0.63254 (16)
0.0723 (6)
O2
0.1616 (3)
0.91394 (14)
0.55403 (19)
0.0818 (7)
H2
0.2747
0.9160
0.5245
0.123*
O3
−0.4523 (3)
0.95694 (15)
0.46477 (16)
0.0804 (6)
C1
0.0831 (4)
0.99366 (19)
0.5670 (2)
0.0699 (9)
H1
0.1979
1.0342
0.5700
0.084*
C2
−0.0400 (4)
0.9980 (2)
0.6745 (2)
0.0717 (9)
H2A
−0.0512
1.0552
0.6971
0.086*
C3
−0.2854 (5)
0.9770 (2)
0.5177 (3)
0.0677 (8)
C4
−0.0916 (4)
1.0127 (2)
0.4718 (2)
0.0713 (9)
H4
−0.1101
1.0720
0.4700
0.086* sup-3 supplementary materials supplementary materials sup-4
C5
−0.0562 (5)
0.9858 (2)
0.3503 (2)
0.0963 (11)
H5A
−0.0272
0.9284
0.3501
0.144*
H5B
0.0629
1.0149
0.3246
0.144*
H5C
−0.1818
0.9971
0.2992
0.144*
C6
0.0466 (4)
0.9499 (2)
0.7790 (2)
0.0766 (9)
H6
0.0636
0.8934
0.7541
0.092*
C7
0.2689 (5)
0.9825 (2)
0.8203 (3)
0.0999 (12)
H7A
0.3668
0.9687
0.7647
0.150*
H7B
0.3165
0.9585
0.8936
0.150*
H7C
0.2628
1.0406
0.8283
0.150*
C8
−0.1058 (5)
0.9493 (3)
0.8754 (3)
0.0969 (12)
H8
−0.2441
0.9299
0.8397
0.116*
C9
−0.1446 (7)
1.0344 (3)
0.9243 (3)
0.1352 (16)
H9A
−0.2459
1.0306
0.9809
0.203*
H9B
−0.1995
1.0698
0.8626
0.203*
H9C
−0.0125
1.0560
0.9598
0.203*
C10
−0.0295 (7)
0.8869 (4)
0.9651 (4)
0.146 (2)
H10
0.0090
0.8378
0.9327
0.175*
C11
−0.0089 (10)
0.8863 (6)
1.0604 (6)
0.278 (5)
H11A
−0.0428
0.9323
1.1017
0.333*
H11B
0.0422
0.8398
1.0995
0.333*
O1'
−0.6701 (3)
0.71545 (13)
0.46394 (18)
0.0769 (6)
O2'
−0.2446 (3)
0.67928 (15)
0.3828 (2)
0.0935 (7)
H2'
−0.1359
0.6868
0.3505
0.140*
O3'
−0.8637 (4)
0.71727 (16)
0.29367 (18)
0.0963 (8)
C1'
−0.3349 (5)
0.7549 (2)
0.4080 (3)
0.0777 (9)
H1'
−0.2255
0.7974
0.4203
0.093*
C2'
−0.4615 (4)
0.7458 (2)
0.5138 (3)
0.0727 (9)
H2'1
−0.4816
0.8000
0.5465
0.087*
C3'
−0.7005 (5)
0.7353 (2)
0.3510 (3)
0.0794 (10)
C4'
−0.5091 (5)
0.7794 (2)
0.3145 (3)
0.0839 (10)
H4'
−0.5347
0.8379
0.3232
0.101*
C5'
−0.4680 (6)
0.7646 (3)
0.1898 (3)
0.1211 (15)
H5'1
−0.3427
0.7940
0.1730
0.182*
H5'2
−0.5883
0.7831
0.1396
0.182*
H5'3
−0.4468
0.7074
0.1779
0.182*
C6'
−0.3719 (4)
0.6903 (2)
0.6094 (3)
0.0726 (9)
H6'
−0.3515
0.6367
0.5749
0.087*
C7'
−0.1534 (5)
0.7211 (2)
0.6567 (3)
0.0986 (12)
H7'1
−0.0566
0.7169
0.5978
0.148*
H7'2
−0.1013
0.6888
0.7224
0.148*
H7'3
−0.1642
0.7770
0.6797
0.148*
C8'
−0.5233 (5)
0.6788 (2)
0.7046 (3)
0.0773 (9)
H8'
−0.6609
0.6623
0.6647
0.093*
C9'
−0.5664 (6)
0.7563 (3)
0.7697 (3)
0.1204 (14)
H9'1
−0.4354
0.7760
0.8091
0.181*
H9'2
−0.6664
0.7450
0.8252
0.181*
H9'3
−0.6248
0.7968
0.7161
0.181*
C10'
−0.4516 (6)
0.6101 (3)
0.7795 (4)
0.1110 (13) sup-4 supplementary materials pp
y
sup
H10'
−0.4328
0.5614
0.7408
0.133*
C11'
−0.4126 (8)
0.6067 (4)
0.8851 (4)
0.183 (3)
H11C
−0.4276
0.6530
0.9300
0.220*
H11D
−0.3679
0.5579
0.9203
0.220*
Atomic displacement parameters (Å2)
U11
U22
U33
U12
U13
U23
O1
0.0470 (10)
0.0854 (17)
0.0864 (13)
−0.0022 (11)
0.0168 (9)
0.0018 (13)
O2
0.0649 (13)
0.0683 (17)
0.1164 (16)
0.0050 (11)
0.0310 (12)
0.0017 (13)
O3
0.0569 (12)
0.0926 (18)
0.0930 (13)
−0.0018 (13)
0.0134 (11)
0.0007 (13)
C1
0.0543 (17)
0.052 (2)
0.106 (2)
−0.0006 (16)
0.0204 (16)
−0.0009 (18)
C2
0.0513 (16)
0.072 (3)
0.094 (2)
−0.0065 (16)
0.0167 (15)
−0.0091 (19)
C3
0.0549 (18)
0.063 (2)
0.088 (2)
0.0086 (17)
0.0190 (16)
0.0012 (19)
C4
0.0609 (18)
0.065 (2)
0.090 (2)
0.0004 (16)
0.0210 (16)
0.0089 (17)
C5
0.083 (2)
0.112 (3)
0.099 (2)
−0.003 (2)
0.0322 (17)
0.004 (2)
C6
0.0509 (16)
0.091 (3)
0.0888 (19)
−0.0027 (17)
0.0115 (15)
−0.007 (2)
C7
0.0603 (18)
0.125 (4)
0.115 (2)
−0.008 (2)
0.0097 (16)
−0.012 (2)
C8
0.0648 (19)
0.140 (4)
0.087 (2)
−0.003 (2)
0.0156 (18)
−0.007 (3)
C9
0.111 (3)
0.173 (5)
0.128 (3)
0.024 (3)
0.047 (3)
−0.021 (3)
C10
0.106 (3)
0.249 (7)
0.086 (3)
0.007 (4)
0.027 (3)
0.030 (4)
C11
0.147 (5)
0.476 (16)
0.222 (7)
0.051 (7)
0.075 (6)
0.165 (9)
O1'
0.0496 (11)
0.0897 (18)
0.0938 (14)
−0.0022 (11)
0.0186 (10)
0.0066 (12)
O2'
0.0718 (14)
0.0719 (18)
0.1435 (19)
0.0044 (13)
0.0446 (13)
0.0045 (15)
O3'
0.0646 (14)
0.125 (2)
0.1002 (15)
−0.0110 (15)
0.0131 (12)
0.0065 (14)
C1'
0.0634 (19)
0.056 (2)
0.117 (2)
−0.0012 (17)
0.0241 (19)
0.003 (2)
C2'
0.0534 (18)
0.060 (2)
0.106 (2)
−0.0041 (16)
0.0122 (16)
−0.003 (2)
C3'
0.060 (2)
0.086 (3)
0.095 (2)
0.0041 (19)
0.0236 (18)
0.006 (2)
C4'
0.073 (2)
0.069 (3)
0.112 (2)
−0.0002 (18)
0.0255 (19)
0.011 (2)
C5'
0.103 (3)
0.153 (4)
0.114 (3)
−0.008 (3)
0.045 (2)
0.016 (3)
C6'
0.0542 (17)
0.064 (2)
0.101 (2)
0.0017 (16)
0.0160 (16)
−0.005 (2)
C7'
0.0560 (18)
0.097 (3)
0.142 (3)
−0.0047 (19)
0.0043 (18)
−0.004 (2)
C8'
0.0616 (18)
0.079 (3)
0.092 (2)
0.0030 (18)
0.0084 (16)
0.002 (2)
C9'
0.107 (3)
0.128 (4)
0.128 (3)
0.021 (3)
0.019 (2)
−0.026 (3)
C10'
0.078 (2)
0.149 (4)
0.108 (3)
0.001 (3)
0.020 (2)
0.015 (3)
C11'
0.134 (4)
0.252 (7)
0.161 (4)
0.028 (4)
−0.001 (4)
0.069 (5)
Geometric parameters (Å, °)
O1—C3
1.336 (3)
O1'—C3'
1.347 (3)
O1—C2
1.474 (3)
O1'—C2'
1.470 (3)
O2—C1
1.411 (3)
O2'—C1'
1.408 (4)
O2—H2
0.8200
O2'—H2'
0.8200
O3—C3
1.211 (3)
O3'—C3'
1.206 (3)
C1—C4
1.515 (4)
C1'—C4'
1.521 (4)
C1—C2
1.532 (4)
C1'—C2'
1.533 (4)
C1—H1
0.9800
C1'—H1'
0.9800
C2—C6
1.504 (4)
C2'—C6'
1.503 (4)
C2—H2A
0.9800
C2'—H2'1
0.9800 Atomic displacement parameters (Å2) sup-5 supplementary materials supplementary materials 1.496 (4)
C3'—C4'
1.515 (4)
C4'—C5'
0.9800
C4'—H4'
0.9600
C5'—H5'1
0.9600
C5'—H5'2
0.9600
C5'—H5'3
1.531 (4)
C6'—C7'
1.542 (4)
C6'—C8'
0.9800
C6'—H6'
0.9600
C7'—H7'1
0.9600
C7'—H7'2
0.9600
C7'—H7'3
1.506 (7)
C8'—C10'
1.536 (6)
C8'—C9'
0.9800
C8'—H8'
0.9600
C9'—H9'1
0.9600
C9'—H9'2
0.9600
C9'—H9'3
1.102 (6)
C10'—C11'
0.9300
C10'—H10'
0.9300
C11'—H11C
0.9300
C11'—H11D
109.6 (2)
C3'—O1'—C2'
109.5
C1'—O2'—H2'
110.5 (3)
O2'—C1'—C4'
109.8 (2)
O2'—C1'—C2'
101.3 (2)
C4'—C1'—C2'
111.6
O2'—C1'—H1'
111.6
C4'—C1'—H1'
111.6
C2'—C1'—H1'
110.1 (2)
O1'—C2'—C6'
103.6 (2)
O1'—C2'—C1'
117.4 (2)
C6'—C2'—C1'
108.5
O1'—C2'—H2'1
108.5
C6'—C2'—H2'1
108.5
C1'—C2'—H2'1
120.9 (2)
O3'—C3'—O1'
128.5 (3)
O3'—C3'—C4'
110.6 (3)
O1'—C3'—C4'
114.5 (3)
C3'—C4'—C5'
102.7 (2)
C3'—C4'—C1'
117.3 (2)
C5'—C4'—C1'
107.3
C3'—C4'—H4'
107.3
C5'—C4'—H4'
107.3
C1'—C4'—H4'
109.5
C4'—C5'—H5'1
109.5
C4'—C5'—H5'2
109.5
H5'1—C5'—H5'2
109.5
C4'—C5'—H5'3 sup-6
C3—C4
1.496 (4)
C3'—C4'
C4—C5
1.515 (4)
C4'—C5'
C4—H4
0.9800
C4'—H4'
C5—H5A
0.9600
C5'—H5'1
C5—H5B
0.9600
C5'—H5'2
C5—H5C
0.9600
C5'—H5'3
C6—C7
1.531 (4)
C6'—C7'
C6—C8
1.542 (4)
C6'—C8'
C6—H6
0.9800
C6'—H6'
C7—H7A
0.9600
C7'—H7'1
C7—H7B
0.9600
C7'—H7'2
C7—H7C
0.9600
C7'—H7'3
C8—C10
1.506 (7)
C8'—C10'
C8—C9
1.536 (6)
C8'—C9'
C8—H8
0.9800
C8'—H8'
C9—H9A
0.9600
C9'—H9'1
C9—H9B
0.9600
C9'—H9'2
C9—H9C
0.9600
C9'—H9'3
C10—C11
1.102 (6)
C10'—C11'
C10—H10
0.9300
C10'—H10'
C11—H11A
0.9300
C11'—H11C
C11—H11B
0.9300
C11'—H11D
C3—O1—C2
109.6 (2)
C3'—O1'—C2'
C1—O2—H2
109.5
C1'—O2'—H2'
O2—C1—C4
110.5 (3)
O2'—C1'—C4'
O2—C1—C2
109.8 (2)
O2'—C1'—C2'
C4—C1—C2
101.3 (2)
C4'—C1'—C2'
O2—C1—H1
111.6
O2'—C1'—H1'
C4—C1—H1
111.6
C4'—C1'—H1'
C2—C1—H1
111.6
C2'—C1'—H1'
O1—C2—C6
110.1 (2)
O1'—C2'—C6'
O1—C2—C1
103.6 (2)
O1'—C2'—C1'
C6—C2—C1
117.4 (2)
C6'—C2'—C1'
O1—C2—H2A
108.5
O1'—C2'—H2'1
C6—C2—H2A
108.5
C6'—C2'—H2'1
C1—C2—H2A
108.5
C1'—C2'—H2'1
O3—C3—O1
120.9 (2)
O3'—C3'—O1'
O3—C3—C4
128.5 (3)
O3'—C3'—C4'
O1—C3—C4
110.6 (3)
O1'—C3'—C4'
C3—C4—C5
114.5 (3)
C3'—C4'—C5'
C3—C4—C1
102.7 (2)
C3'—C4'—C1'
C5—C4—C1
117.3 (2)
C5'—C4'—C1'
C3—C4—H4
107.3
C3'—C4'—H4'
C5—C4—H4
107.3
C5'—C4'—H4'
C1—C4—H4
107.3
C1'—C4'—H4'
C4—C5—H5A
109.5
C4'—C5'—H5'1
C4—C5—H5B
109.5
C4'—C5'—H5'2
H5A—C5—H5B
109.5
H5'1—C5'—H5'2
C4—C5—H5C
109.5
C4'—C5'—H5'3 1.496 (4)
C3'—C4'
1.500 (5)
1.515 (4)
C4'—C5'
1.514 (4)
0.9800
C4'—H4'
0.9800
0.9600
C5'—H5'1
0.9600
0.9600
C5'—H5'2
0.9600
0.9600
C5'—H5'3
0.9600
1.531 (4)
C6'—C7'
1.517 (4)
1.542 (4)
C6'—C8'
1.538 (4)
0.9800
C6'—H6'
0.9800
0.9600
C7'—H7'1
0.9600
0.9600
C7'—H7'2
0.9600
0.9600
C7'—H7'3
0.9600
1.506 (7)
C8'—C10'
1.469 (6)
1.536 (6)
C8'—C9'
1.516 (5)
0.9800
C8'—H8'
0.9800
0.9600
C9'—H9'1
0.9600
0.9600
C9'—H9'2
0.9600
0.9600
C9'—H9'3
0.9600
1.102 (6)
C10'—C11'
1.228 (5)
0.9300
C10'—H10'
0.9300
0.9300
C11'—H11C
0.9300
0.9300
C11'—H11D
0.9300
109.6 (2)
C3'—O1'—C2'
109.9 (2)
109.5
C1'—O2'—H2'
109.5
110.5 (3)
O2'—C1'—C4'
111.2 (3)
109.8 (2)
O2'—C1'—C2'
109.3 (3)
101.3 (2)
C4'—C1'—C2'
101.7 (2)
111.6
O2'—C1'—H1'
111.4
111.6
C4'—C1'—H1'
111.4
111.6
C2'—C1'—H1'
111.4
110.1 (2)
O1'—C2'—C6'
110.1 (2)
103.6 (2)
O1'—C2'—C1'
103.3 (2)
117.4 (2)
C6'—C2'—C1'
117.6 (2)
108.5
O1'—C2'—H2'1
108.5
108.5
C6'—C2'—H2'1
108.5
108.5
C1'—C2'—H2'1
108.5
120.9 (2)
O3'—C3'—O1'
120.8 (3)
128.5 (3)
O3'—C3'—C4'
128.8 (3)
110.6 (3)
O1'—C3'—C4'
110.4 (3)
114.5 (3)
C3'—C4'—C5'
114.1 (3)
102.7 (2)
C3'—C4'—C1'
102.4 (3)
117.3 (2)
C5'—C4'—C1'
117.5 (3)
107.3
C3'—C4'—H4'
107.4
107.3
C5'—C4'—H4'
107.4
107.3
C1'—C4'—H4'
107.4
109.5
C4'—C5'—H5'1
109.5
109.5
C4'—C5'—H5'2
109.5
109.5
H5'1—C5'—H5'2
109.5
109.5
C4'—C5'—H5'3
109.5 sup-6 supplementary materials supplementary materials 109.5
H5'1—C5'—H5'3
109.5
H5'2—C5'—H5'3
108.6 (3)
C2'—C6'—C7'
112.7 (3)
C2'—C6'—C8'
112.9 (2)
C7'—C6'—C8'
107.5
C2'—C6'—H6'
107.5
C7'—C6'—H6'
107.5
C8'—C6'—H6'
109.5
C6'—C7'—H7'1
109.5
C6'—C7'—H7'2
109.5
H7'1—C7'—H7'2
109.5
C6'—C7'—H7'3
109.5
H7'1—C7'—H7'3
109.5
H7'2—C7'—H7'3
114.5 (3)
C10'—C8'—C9'
109.1 (3)
C10'—C8'—C6'
113.1 (3)
C9'—C8'—C6'
106.5
C10'—C8'—H8'
106.5
C9'—C8'—H8'
106.5
C6'—C8'—H8'
109.5
C8'—C9'—H9'1
109.5
C8'—C9'—H9'2
109.5
H9'1—C9'—H9'2
109.5
C8'—C9'—H9'3
109.5
H9'1—C9'—H9'3
109.5
H9'2—C9'—H9'3
134.4 (8)
C11'—C10'—C8'
112.8
C11'—C10'—H10'
112.8
C8'—C10'—H10'
120.0
C10'—C11'—H11C
120.0
C10'—C11'—H11D
120.0
H11C—C11'—H11D
−148.1 (3)
C3'—O1'—C2'—C6'
−21.8 (3)
C3'—O1'—C2'—C1'
−83.7 (3)
O2'—C1'—C2'—O1'
33.2 (3)
C4'—C1'—C2'—O1'
37.9 (3)
O2'—C1'—C2'—C6'
154.7 (3)
C4'—C1'—C2'—C6'
−179.6 (3)
C2'—O1'—C3'—O3'
0.5 (3)
C2'—O1'—C3'—C4'
−30.6 (5)
O3'—C3'—C4'—C5'
149.3 (3)
O1'—C3'—C4'—C5'
−158.8 (3)
O3'—C3'—C4'—C1'
21.1 (3)
O1'—C3'—C4'—C1'
84.0 (3)
O2'—C1'—C4'—C3'
−32.4 (3)
C2'—C1'—C4'—C3'
−42.5 (4)
O2'—C1'—C4'—C5'
−158.9 (3)
C2'—C1'—C4'—C5'
−179.8 (2)
O1'—C2'—C6'—C7' H5A—C5—H5C
109.5
H5'1—C5'—H5'3
H5B—C5—H5C
109.5
H5'2—C5'—H5'3
C2—C6—C7
108.6 (3)
C2'—C6'—C7'
C2—C6—C8
112.7 (3)
C2'—C6'—C8'
C7—C6—C8
112.9 (2)
C7'—C6'—C8'
C2—C6—H6
107.5
C2'—C6'—H6'
C7—C6—H6
107.5
C7'—C6'—H6'
C8—C6—H6
107.5
C8'—C6'—H6'
C6—C7—H7A
109.5
C6'—C7'—H7'1
C6—C7—H7B
109.5
C6'—C7'—H7'2
H7A—C7—H7B
109.5
H7'1—C7'—H7'2
C6—C7—H7C
109.5
C6'—C7'—H7'3
H7A—C7—H7C
109.5
H7'1—C7'—H7'3
H7B—C7—H7C
109.5
H7'2—C7'—H7'3
C10—C8—C9
114.5 (3)
C10'—C8'—C9'
C10—C8—C6
109.1 (3)
C10'—C8'—C6'
C9—C8—C6
113.1 (3)
C9'—C8'—C6'
C10—C8—H8
106.5
C10'—C8'—H8'
C9—C8—H8
106.5
C9'—C8'—H8'
C6—C8—H8
106.5
C6'—C8'—H8'
C8—C9—H9A
109.5
C8'—C9'—H9'1
C8—C9—H9B
109.5
C8'—C9'—H9'2
H9A—C9—H9B
109.5
H9'1—C9'—H9'2
C8—C9—H9C
109.5
C8'—C9'—H9'3
H9A—C9—H9C
109.5
H9'1—C9'—H9'3
H9B—C9—H9C
109.5
H9'2—C9'—H9'3
C11—C10—C8
134.4 (8)
C11'—C10'—C8'
C11—C10—H10
112.8
C11'—C10'—H10'
C8—C10—H10
112.8
C8'—C10'—H10'
C10—C11—H11A
120.0
C10'—C11'—H11C
C10—C11—H11B
120.0
C10'—C11'—H11D
H11A—C11—H11B
120.0
H11C—C11'—H11D
C3—O1—C2—C6
−148.1 (3)
C3'—O1'—C2'—C6'
C3—O1—C2—C1
−21.8 (3)
C3'—O1'—C2'—C1'
O2—C1—C2—O1
−83.7 (3)
O2'—C1'—C2'—O1'
C4—C1—C2—O1
33.2 (3)
C4'—C1'—C2'—O1'
O2—C1—C2—C6
37.9 (3)
O2'—C1'—C2'—C6'
C4—C1—C2—C6
154.7 (3)
C4'—C1'—C2'—C6'
C2—O1—C3—O3
−179.6 (3)
C2'—O1'—C3'—O3'
C2—O1—C3—C4
0.5 (3)
C2'—O1'—C3'—C4'
O3—C3—C4—C5
−30.6 (5)
O3'—C3'—C4'—C5'
O1—C3—C4—C5
149.3 (3)
O1'—C3'—C4'—C5'
O3—C3—C4—C1
−158.8 (3)
O3'—C3'—C4'—C1'
O1—C3—C4—C1
21.1 (3)
O1'—C3'—C4'—C1'
O2—C1—C4—C3
84.0 (3)
O2'—C1'—C4'—C3'
C2—C1—C4—C3
−32.4 (3)
C2'—C1'—C4'—C3'
O2—C1—C4—C5
−42.5 (4)
O2'—C1'—C4'—C5'
C2—C1—C4—C5
−158.9 (3)
C2'—C1'—C4'—C5'
O1—C2—C6—C7
−179.8 (2)
O1'—C2'—C6'—C7' sup-7
109.5
H5'1—C5'—H5'3
109.5
109.5
H5'2—C5'—H5'3
109.5
108.6 (3)
C2'—C6'—C7'
109.2 (3)
112.7 (3)
C2'—C6'—C8'
113.0 (2)
112.9 (2)
C7'—C6'—C8'
112.5 (3)
107.5
C2'—C6'—H6'
107.3
107.5
C7'—C6'—H6'
107.3
107.5
C8'—C6'—H6'
107.3
109.5
C6'—C7'—H7'1
109.5
109.5
C6'—C7'—H7'2
109.5
109.5
H7'1—C7'—H7'2
109.5
109.5
C6'—C7'—H7'3
109.5
109.5
H7'1—C7'—H7'3
109.5
109.5
H7'2—C7'—H7'3
109.5
114.5 (3)
C10'—C8'—C9'
114.0 (3)
109.1 (3)
C10'—C8'—C6'
110.1 (3)
113.1 (3)
C9'—C8'—C6'
114.1 (3)
106.5
C10'—C8'—H8'
106.0
106.5
C9'—C8'—H8'
106.0
106.5
C6'—C8'—H8'
106.0
109.5
C8'—C9'—H9'1
109.5
109.5
C8'—C9'—H9'2
109.5
109.5
H9'1—C9'—H9'2
109.5
109.5
C8'—C9'—H9'3
109.5
109.5
H9'1—C9'—H9'3
109.5
109.5
H9'2—C9'—H9'3
109.5
134.4 (8)
C11'—C10'—C8'
130.3 (5)
112.8
C11'—C10'—H10'
114.9
112.8
C8'—C10'—H10'
114.9
120.0
C10'—C11'—H11C
120.0
120.0
C10'—C11'—H11D
120.0
120.0
H11C—C11'—H11D
120.0
−148.1 (3)
C3'—O1'—C2'—C6'
−149.0 (3)
−21.8 (3)
C3'—O1'—C2'—C1'
−22.6 (3)
−83.7 (3)
O2'—C1'—C2'—O1'
−84.1 (3)
33.2 (3)
C4'—C1'—C2'—O1'
33.5 (3)
37.9 (3)
O2'—C1'—C2'—C6'
37.4 (4)
154.7 (3)
C4'—C1'—C2'—C6'
155.1 (3)
−179.6 (3)
C2'—O1'—C3'—O3'
−178.9 (3)
0.5 (3)
C2'—O1'—C3'—C4'
1.6 (3)
−30.6 (5)
O3'—C3'—C4'—C5'
−31.2 (6)
149.3 (3)
O1'—C3'—C4'—C5'
148.3 (3)
−158.8 (3)
O3'—C3'—C4'—C1'
−159.3 (4)
21.1 (3)
O1'—C3'—C4'—C1'
20.2 (4)
84.0 (3)
O2'—C1'—C4'—C3'
84.1 (3)
−32.4 (3)
C2'—C1'—C4'—C3'
−32.2 (3)
−42.5 (4)
O2'—C1'—C4'—C5'
−41.7 (4)
−158.9 (3)
C2'—C1'—C4'—C5'
−158.0 (3)
−179.8 (2)
O1'—C2'—C6'—C7'
178.0 (2) H5A—C5—H5C
109.5
H5'1—C5'—H5'3
109.5
H5B—C5—H5C
109.5
H5'2—C5'—H5'3
109.5
C2—C6—C7
108.6 (3)
C2'—C6'—C7'
109.2 (3)
C2—C6—C8
112.7 (3)
C2'—C6'—C8'
113.0 (2)
C7—C6—C8
112.9 (2)
C7'—C6'—C8'
112.5 (3)
C2—C6—H6
107.5
C2'—C6'—H6'
107.3
C7—C6—H6
107.5
C7'—C6'—H6'
107.3
C8—C6—H6
107.5
C8'—C6'—H6'
107.3
C6—C7—H7A
109.5
C6'—C7'—H7'1
109.5
C6—C7—H7B
109.5
C6'—C7'—H7'2
109.5
H7A—C7—H7B
109.5
H7'1—C7'—H7'2
109.5
C6—C7—H7C
109.5
C6'—C7'—H7'3
109.5
H7A—C7—H7C
109.5
H7'1—C7'—H7'3
109.5
H7B—C7—H7C
109.5
H7'2—C7'—H7'3
109.5
C10—C8—C9
114.5 (3)
C10'—C8'—C9'
114.0 (3)
C10—C8—C6
109.1 (3)
C10'—C8'—C6'
110.1 (3)
C9—C8—C6
113.1 (3)
C9'—C8'—C6'
114.1 (3)
C10—C8—H8
106.5
C10'—C8'—H8'
106.0
C9—C8—H8
106.5
C9'—C8'—H8'
106.0
C6—C8—H8
106.5
C6'—C8'—H8'
106.0
C8—C9—H9A
109.5
C8'—C9'—H9'1
109.5
C8—C9—H9B
109.5
C8'—C9'—H9'2
109.5
H9A—C9—H9B
109.5
H9'1—C9'—H9'2
109.5
C8—C9—H9C
109.5
C8'—C9'—H9'3
109.5
H9A—C9—H9C
109.5
H9'1—C9'—H9'3
109.5
H9B—C9—H9C
109.5
H9'2—C9'—H9'3
109.5
C11—C10—C8
134.4 (8)
C11'—C10'—C8'
130.3 (5)
C11—C10—H10
112.8
C11'—C10'—H10'
114.9
C8—C10—H10
112.8
C8'—C10'—H10'
114.9
C10—C11—H11A
120.0
C10'—C11'—H11C
120.0
C10—C11—H11B
120.0
C10'—C11'—H11D
120.0
H11A—C11—H11B
120.0
H11C—C11'—H11D
120.0
C3—O1—C2—C6
−148.1 (3)
C3'—O1'—C2'—C6'
−149.0 (3)
C3—O1—C2—C1
−21.8 (3)
C3'—O1'—C2'—C1'
−22.6 (3)
O2—C1—C2—O1
−83.7 (3)
O2'—C1'—C2'—O1'
−84.1 (3)
C4—C1—C2—O1
33.2 (3)
C4'—C1'—C2'—O1'
33.5 (3)
O2—C1—C2—C6
37.9 (3)
O2'—C1'—C2'—C6'
37.4 (4)
C4—C1—C2—C6
154.7 (3)
C4'—C1'—C2'—C6'
155.1 (3)
C2—O1—C3—O3
−179.6 (3)
C2'—O1'—C3'—O3'
−178.9 (3)
C2—O1—C3—C4
0.5 (3)
C2'—O1'—C3'—C4'
1.6 (3)
O3—C3—C4—C5
−30.6 (5)
O3'—C3'—C4'—C5'
−31.2 (6)
O1—C3—C4—C5
149.3 (3)
O1'—C3'—C4'—C5'
148.3 (3)
O3—C3—C4—C1
−158.8 (3)
O3'—C3'—C4'—C1'
−159.3 (4)
O1—C3—C4—C1
21.1 (3)
O1'—C3'—C4'—C1'
20.2 (4)
O2—C1—C4—C3
84.0 (3)
O2'—C1'—C4'—C3'
84.1 (3)
C2—C1—C4—C3
−32.4 (3)
C2'—C1'—C4'—C3'
−32.2 (3)
O2—C1—C4—C5
−42.5 (4)
O2'—C1'—C4'—C5'
−41.7 (4)
C2—C1—C4—C5
−158.9 (3)
C2'—C1'—C4'—C5'
−158.0 (3)
O1—C2—C6—C7
−179.8 (2)
O1'—C2'—C6'—C7'
178.0 (2) 109.5
H5'1—C5'—H5'3
109.5
H5'2—C5'—H5'3
108.6 (3)
C2'—C6'—C7'
112.7 (3)
C2'—C6'—C8'
112.9 (2)
C7'—C6'—C8'
107.5
C2'—C6'—H6'
107.5
C7'—C6'—H6'
107.5
C8'—C6'—H6'
109.5
C6'—C7'—H7'1
109.5
C6'—C7'—H7'2
109.5
H7'1—C7'—H7'2
109.5
C6'—C7'—H7'3
109.5
H7'1—C7'—H7'3
109.5
H7'2—C7'—H7'3
114.5 (3)
C10'—C8'—C9'
109.1 (3)
C10'—C8'—C6'
113.1 (3)
C9'—C8'—C6'
106.5
C10'—C8'—H8'
106.5
C9'—C8'—H8'
106.5
C6'—C8'—H8'
109.5
C8'—C9'—H9'1
109.5
C8'—C9'—H9'2
109.5
H9'1—C9'—H9'2
109.5
C8'—C9'—H9'3
109.5
H9'1—C9'—H9'3
109.5
H9'2—C9'—H9'3
134.4 (8)
C11'—C10'—C8'
112.8
C11'—C10'—H10'
112.8
C8'—C10'—H10'
120.0
C10'—C11'—H11C
120.0
C10'—C11'—H11D
120.0
H11C—C11'—H11D
−148.1 (3)
C3'—O1'—C2'—C6'
−21.8 (3)
C3'—O1'—C2'—C1'
−83.7 (3)
O2'—C1'—C2'—O1'
33.2 (3)
C4'—C1'—C2'—O1'
37.9 (3)
O2'—C1'—C2'—C6'
154.7 (3)
C4'—C1'—C2'—C6'
−179.6 (3)
C2'—O1'—C3'—O3'
0.5 (3)
C2'—O1'—C3'—C4'
−30.6 (5)
O3'—C3'—C4'—C5'
149.3 (3)
O1'—C3'—C4'—C5'
−158.8 (3)
O3'—C3'—C4'—C1'
21.1 (3)
O1'—C3'—C4'—C1'
84.0 (3)
O2'—C1'—C4'—C3'
−32.4 (3)
C2'—C1'—C4'—C3'
−42.5 (4)
O2'—C1'—C4'—C5'
−158.9 (3)
C2'—C1'—C4'—C5'
−179.8 (2)
O1'—C2'—C6'—C7' sup-7 supplementary materials supplementary materials C1—C2—C6—C7
62.1 (4)
C1'—C2'—C6'—C7'
60.1 (4)
O1—C2—C6—C8
−54.0 (4)
O1'—C2'—C6'—C8'
−56.0 (4)
C1—C2—C6—C8
−172.1 (3)
C1'—C2'—C6'—C8'
−173.9 (3)
C2—C6—C8—C10
168.6 (3)
C2'—C6'—C8'—C10'
166.5 (3)
C7—C6—C8—C10
−67.9 (5)
C7'—C6'—C8'—C10'
−69.3 (4)
C2—C6—C8—C9
−62.7 (4)
C2'—C6'—C8'—C9'
−63.8 (4)
C7—C6—C8—C9
60.8 (4)
C7'—C6'—C8'—C9'
60.4 (4)
C9—C8—C10—C11
7.2 (9)
C9'—C8'—C10'—C11'
−3.6 (7)
C6—C8—C10—C11
135.1 (8)
C6'—C8'—C10'—C11'
126.1 (5)
Hydrogen-bond geometry (Å, °)
D—H···A
D—H
H···A
D···A
D—H···A
O2—H2···O3i
0.82
2.03
2.821 (3)
163
O2'—H2'···O3'i
0.82
1.96
2.771 (3)
171
Symmetry codes: (i) x+1, y, z. Hydrogen-bond geometry (Å, °) sup-8 supplementary materials Fig. 1 Fig. 1 sup-9 supplementary materials Fig. 2 Fig. 2 Fig. 2 sup-10
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Heteroclinic switching between chimeras in a ring of six oscillator populations
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RESEARCH ARTICLE | JUNE 05 2023
Heteroclinic switching between chimeras in a ring of six
oscillator populations
Special Collection: Chimera states: from theory and experiments to technology and living systems
Seungjae Lee
; Katharina Krischer
Chaos 33, 063120 (2023)
https://doi.org/10.1063/5.0147228
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Online
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20 May 2024 10:05:47
Chaos
ARTICLE
scitation.org/journal/cha
Heteroclinic switching between chimeras
in a ring of six oscillator populations
Cite as: Chaos 33, 063120 (2023); doi: 10.1063/5.0147228
Submitted: 20 February 2023 · Accepted: 15 May 2023 ·
Published Online: 5 June 2023
Seungjae Leea)
View Online
Export Citation
CrossMark
and Katharina Krischerb)
AFFILIATIONS
Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
Note: This paper is part of the Focus Issue on Chimera states from theory and experiments to technology and living systems.
Electronic mail: seungjae.lee@tum.de
b)
Author to whom correspondence should be addressed: krischer@tum.de
a)
ABSTRACT
© 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license
(http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/5.0147228
The synchronization of many coupled oscillators is a well-known
phenomenon. An illustrative example is the synchronous flashing
of fireflies in bushes in Southeast Asia.1 Let us now do a gedankenexperiment and consider six bushes full of fireflies arranged in
a ring. Let us further assume that the fireflies within one bush
exchange information on their respective “firing state” with a
strong signal and to the fireflies on the neighboring bushes to the
left and right with a weaker signal. We suggest in this paper that
one possible outcome of such an interaction is that the fireflies in
five of the six bushes still flash synchronously within each bush
and with a phase difference of approximately 2π/6 to the other
ones. In the sixth bush, however, the flashing occurs incoherently.
Moreover, after some time, the incoherently flashing population
becomes synchronized but a neighboring one loses synchrony
and goes into incoherent flashing until a corresponding switching occurs between the next synchronously flashing population
and the incoherent one. In this paper, we demonstrate with a simple generic model for six oscillator populations that such a cyclic
Chaos 33, 063120 (2023); doi: 10.1063/5.0147228
© Author(s) 2023
switching between coherence and incoherence may, in fact, occur
in systems of coupled oscillators.
I. INTRODUCTION
Collective dynamics of ensembles of coupled oscillators is of
paramount importance in various interdisciplinary nonlinear sciences from physical systems to biological manifestations.1,2 Chimera
states are symmetry-broken states emerging in a system of coupled
oscillators in diverse fields of study. In the workshop, From theory
and experiments to technology and living systems, an impressive
collection of examples was presented.3
The archetypal chimera states were observed in a ring geometry with nonlocal interactions as a spatiotemporal dynamics.4–7 To
simplify the nonlocal couplings on the ring while preserving its
essential properties, many researchers have investigated systems of
oscillator populations with all-to-all intra- and inter-population
33, 063120-1
20 May 2024 10:05:47
In a network of coupled oscillators, a symmetry-broken dynamical state characterized by the coexistence of coherent and incoherent parts
can spontaneously form. It is known as a chimera state. We study chimera states in a network consisting of six populations of identical
Kuramoto–Sakaguchi phase oscillators. The populations are arranged in a ring, and oscillators belonging to one population are uniformly
coupled to all oscillators within the same population and to those in the two neighboring populations. This topology supports the existence of
different configurations of coherent and incoherent populations along the ring, but all of them are linearly unstable in most of the parameter
space. Yet, chimera dynamics is observed from random initial conditions in a wide parameter range, characterized by one incoherent and five
synchronized populations. These observable states are connected to the formation of a heteroclinic cycle between symmetric variants of saddle
chimeras, which gives rise to a switching dynamics. We analyze the dynamical and spectral properties of the chimeras in the thermodynamic
limit using the Ott–Antonsen ansatz and in finite-sized systems employing Watanabe–Strogatz reduction. For a heterogeneous frequency
distribution, a small heterogeneity renders a heteroclinic switching dynamics asymptotically attracting. However, for a large heterogeneity,
the heteroclinic orbit does not survive; instead, it is replaced by a variety of attracting chimera states.
Chaos
II. GOVERNING EQUATIONS AND SADDLE CHIMERAS
We study the dynamics of a network of six populations of
Kuramoto–Sakaguchi phase oscillators: φj(a) (t) ∈ [−π , π ) =: T for
j = 1, . . . , N (oscillator index) and a = 1, . . . , 6 (population index).
Chaos 33, 063120 (2023); doi: 10.1063/5.0147228
© Author(s) 2023
scitation.org/journal/cha
The 6N microscopic governing equations are given by
(a)
d (a)
−iφ
φj = ωj(a) + Im Ha (t)e j e−iα
dt
= ωj(a) +
6
X
N
Kab
b=1
1 X
sin φk(b) − φj(a) − α ,
N
(1)
k=1
with j = 1, . . . , N and a = 1, . . . , 6. Ha (t) denotes an effective forcing function18 acting on the oscillators in population a defined by
P
Ha (t) := 6b=1 Kab 0b (t), where 0a (t) ∈ C is the complex Kuramoto
order parameter of each population defined as
N
0a (t) :=
1 X iφj(a) (t)
e
N j=1
(2)
for a = 1, . . . , 6. The coupling matrix (Kab ) is given by
(
µ=1
for a = b,
Kab =
ν = 1 − A for a = b ± 1 mod 6,
with a, b = 1, . . . , 6 (from here on, population indices are taken
modulo 6). The coupling matrix defines a network topology that
is schematically depicted in Fig. 1(a): each oscillator is coupled to
all oscillators within the same population with coupling strength
µ = 1 and connected to all oscillators in the two neighboring populations with ν = 1 − A, where A ∈ [0, 1]. The phase-lag parameter
α is taken as α = π2 − β with a fixed value of β = 0.008 throughout
the paper unless otherwise noted.
First, we consider the thermodynamic limit in which, for each
population, N → ∞. In this limit, the state function is a continuous distribution function fa (φ (a) , ω(a) , t) governed by the continuity
equation,
∂
∂
(a)
(a)
(a)
(a)
(a)
(a)
fa (φ , ω , t) = − (a) fa (φ , ω , t)va (φ , ω , t)
∂t
∂φ
(3)
va (φ (a) , ω(a) , t) := ω(a) + Im Ha (t)e−iφ
(a) e−iα
for a = 1, . . . , 6, and the Kuramoto order parameter of each population reads
Z Z
(a)
0a (t) =
fa φ (a) , ω(a) , t eiφ dφ (a) dω(a) .
R
T
Exploiting the so-called Ott–Antonsen ansatz,38,39 the ensemble
dynamics can be expressed through the dynamics of the order
parameter. In the Ott–Antonsen invariant manifold, the Fourier
series expansion of the oscillator phase density function can be written in terms of the first harmonic Za (ω(a) , t) ∈ C only, all the higher
Fourier harmonics being a power of Za (ω(a) , t),
!
∞ h
i
X
g(ω(a) )
n −inφ (a)
(a)
fa =
(4)
Za (ω , t) e
+ c.c .
1+
2π
n=1
Here, c.c. stands for the complex conjugate and g(ω) specifies
the natural frequency distribution, which we assume to be a
Cauchy–Lorentz distribution with half-width γ ∈ R and zero mean:
33, 063120-2
20 May 2024 10:05:47
coupling with different intra- and inter-population coupling
strengths. Emphasis was initially on two-population networks8–13
and was later extended to three-population and multi-population
networks.14–17 The chimera states in these networks exhibit a variety
of dynamics distinguished by the temporal behavior of the degree of
coherence of the incoherent populations. Examples range from stationary order parameter dynamics, over periodic breathing chimera
states9,10 to quasiperiodic18,19 and chaotic chimera states.20–24
Also, more complex variants of chimera states, known as
alternating or switching chimeras, have been reported. This state
is characterized by continuously exchanging the coherent and
the incoherent domains. Previous investigations have shown that
switching chimeras occur in systems that exhibit either metastable
states or heteroclinic cycles. In the former case, the switching is
either triggered by large enough fluctuations,25–28 or by arbitrarily
small noise with power-law scaling originating from intermingled
basins of attraction,29 whereas in the latter case, the switching occurs
between saddle states.30–36
In this paper, we investigate switching dynamics along a heteroclinic cycle between saddle chimeras in phase space. In previous works on this type of heteroclinic switching, populations of
phase oscillators, governed by a non-pairwise sinusoidal coupling
with a higher-order interaction were considered.30,31 Each oscillator was coupled to the oscillators in the same population and to
those in the two nearest populations. The author demonstrated
how the interplay between higher-order interactions and network
topology enables switching dynamics between localized frequency
synchronization patterns (so-called weak chimeras24,37) existing in
populations with few oscillators.
Our study here considers a similar network topology, i.e., a
ring of oscillator populations with global intra-population coupling,
whereby we focus on six populations. In contrast to the former
works, we consider identical phase oscillators with harmonic or
sinusoidal pairwise coupling, so-called Kuramoto–Sakaguchi oscillators. Furthermore, we study the dynamics both in the thermodynamic limit and in finite-sized ensembles with dimension reductions
for each population, namely, the Ott–Antonsen (OA) ansatz38–40 and
Watanabe–Strogatz (WS) transformation,18,19,41 respectively.42
In Sec. II, we introduce governing equations of the system
in the thermodynamic limit using the Ott–Antonsen ansatz and
show that the system possesses various saddle chimera states. In
Sec. III, we study the dynamical and spectral properties of the saddle chimera states and demonstrate a heteroclinic switching between
them, which is observed both in the thermodynamic limit and finitesized ensembles. In the deterministic system, the switching fades
away after a long time transient. However, a small noise renders
the switching persistent and the average switching period exhibits a
power-law scaling. The impact of a heterogeneous natural frequency
distribution on the system’s dynamics is considered in Sec. IV.
Finally, we summarize the results in Sec. V.
ARTICLE
Chaos
ARTICLE
scitation.org/journal/cha
FIG. 1. (a) Schematic of the considered network topology. The intra-population coupling is all-to-all with strength µ = 1 and the inter-population coupling is also all-to-all but
only between the nearest-neighbor populations and with strength ν = 1 − A. (b) A normalized histogram of occurrence of chimera states from 300 random initial conditions
at t = 5 × 104 .
1
1
d
za (t) = −γ za + Ha (t)e−iα − z2a Ha (t)eiα .
dt
2
2
(5)
For simplification, we write Eq. (5) in polar coordinates
6
1 − ρa2 X
dρa
Kab ρb cos(ϕb − ϕa − α)
= −γρa +
dt
2
b=1
1 − ρa2
= −γρa +
νρa+1 cos(ϕa+1 − ϕa − α)
2
+ νρa−1 cos(ϕa−1 − ϕa − α) + µρa cos α
(6)
and
6
1 + ρa2 X
dϕa
Kab ρb sin(ϕb − ϕa − α)
=
dt
2ρa
b=1
1 + ρa2
=
νρa+1 sin(ϕa+1 − ϕa − α)
2ρa
+ νρa−1 sin(ϕa−1 − ϕa − α) − µρa sin α ,
(7)
where za (t) = ρa (t)eiϕa (t) for a = 1, . . . , 6. Up to Sec. IV, we only
consider identical oscillators. Hence, first, we set γ = 0. Then, in
terms of the OA variables, a synchronized (S) population is characterized by ρa = 1 and a common phase ϕa ∈ T while we denote a
population as desynchronized (D) if 0 < ρa < 1. In the latter case,
Chaos 33, 063120 (2023); doi: 10.1063/5.0147228
© Author(s) 2023
ϕa represents the mean phase.14 Solving Eqs. (6) and (7) and substituting the results into Eq. (4), the continuous distribution function
is of the form
(
δ ϕa − φ (a)
for ρa = 1,
(a)
fa (φ , t) =
(8)
Pρa (ϕa − φ (a) ) for 0 < ρa < 1,
where δ(θ ) is the Dirac delta distribution characterizing the syn2
is the normalized
chronized population and Pr (θ ) = 2π1 1−2r1−r
cos θ +r2
Poisson kernel corresponding to the desynchronized population.43
Possible solutions of Eqs. (6) and (7) are S6 = S · · · S (6 times)
states in which ρa (t) = 1 and ϕa (t) = t + 2π6 q a with the common
frequency for a = 1, . . . , 6 and q ∈ {0,±1, ±2}. From Eqs. (6)
and (7), we obtain = −(µ + 2ν cos π3q ) sin α. Each population
is internally synchronized while their mean phases follow a twisted
state in a ring.44 Note that the case where all the populations have
the same phase is q = 0. The linear stability analysis reveals that the
S6 states with q = 0, ±1 are stable fixed points in a rotating reference frame, whereas those for q = ±2 are unstable. The real parts of
the eigenvalues of the Jacobian matrix evaluated at S6 for q = 0, ±1
are all negative, except for one, which is zero and reflects the phase
shift invariance. Furthermore, there are fixed points corresponding to chimera states. These fixed points are unstable in nearly the
entire parameter regime. Their structure is dictated by the network
2
symmetry.45–47 Examples are (SD)3 = SDSDSD, (DS2 ) = DS2 DS2
5
or DS = DSSSSS and so on. Note that the equations of motion (6)
and (7) are invariant under the group of transformation Z6 := Z/6Z
such that cyclic permutations of the populations of the mentioned
fixed points are fixed points as well with the same properties.30 In
a large interval of A, the Jacobian matrix evaluated at each chimera
state has at least one eigenvalue with positive real part. For instance,
2
for A = 0.3, (DS2 ) shows four real positive eigenvalues, (SD)3 has
33, 063120-3
20 May 2024 10:05:47
1
g(ω) = πγ ω2 +γ
2 . Using Eq. (4), continuity equation (3) yields the socalled Ott–Antonsen equation, an evolution equation for the order
parameter za (t) := Za (iγ , t) = 0a (t) for a = 1, . . . , 6,
Chaos
ARTICLE
scitation.org/journal/cha
a pair of complex conjugate eigenvalues with positive real parts, and
DS5 has one positive real eigenvalue. In summary, no stable chimera
fixed point solution is found for A > 0.2; they all are saddle chimera
solutions.
To test for possible nontrivial long-term dynamics in the A − β
parameter plane, we performed numerical integrations48 of Eqs. (6)
and (7) from 300 random initial conditions at each set of parameters
for A ∈ [0.2, 0.7] and β ∈ [0.002, 0.01]. In a considerable number of
these simulations, the trajectory settles down to the DS5 chimera
state or one of its cyclic permutations. The histogram depicted in
Fig. 1(b) quantifies the probability with which a trajectory attains
such a chimera dynamics in the long-term limit in the parameter
plane. None other than a DS5 -type chimera was obtained. The latter
observation is remarkable since in the considered parameter range
all DS5 -type chimeras are unstable, and, starting from random initial
conditions, one would not expect that trajectories approach a saddle fixed point. In Secs. III and IV, we will discuss the phase space
structure that allows for this peculiar behavior in detail.
III. HETEROCLINIC SWITCHING BETWEEN SADDLE
CHIMERA STATES
A. Stationary saddle chimeras
q :=
M
1 X
1a+1,a ∈ Z,
2π a=1
(9)
where 1a,b := ϕa − ϕb . In all cases, we obtain numerically q
∈ {+1, −1}. Let us first consider q = 1. The chimera state is found
to be an unstable fixed point in a rotating reference frame, i.e., {DS5 }
⊂ [0, 1]6 × T6 is an invariant saddle point under the flow of Eqs. (6)
and (7). Likewise, all the five cyclic permutations of it are unstable
fixed points. In Fig. 2(a), eigenvalues of the Jacobian matrix evaluated at DS5 are depicted in the complex plane: there is one positive
real eigenvalue λ1 > 0 as well as one zero eigenvalue reflecting the
phase shift invariance. All the other eigenvalues have negative real
parts. Hence, the DS5 state is indeed a saddle chimera state with a
one-dimensional unstable manifold Wu (DS5 ). The eigenvector corresponding to λ1 has a form of v1 = (A+ , 0, 0, 0, 0, A− , δϕ)> ∈ R12 ,
where A+ , A− ∈ R and δϕ denotes a perturbation on phase variables
which does not prominently affect the dynamics in this context.
From now on, we consider only the perturbation directions of the
Chaos 33, 063120 (2023); doi: 10.1063/5.0147228
© Author(s) 2023
radial variables: v1 = (A+ , 0, 0, 0, 0, A− )> . Here, A+ A− < 0, which
means that a small perturbation along the unstable manifold of
DS5 raises (A+ > 0) the radial variable of the incoherent population ρ1 < 1, while it lowers (A− < 0) the radial variable of the
nearest synchronized population ρ6 = 1 as schematically depicted
in Fig. 2(b). Corresponding unstable directions are found for all
symmetric variants of the DS5 . For q = −1, the radial parts of the
eigenvector corresponding to the positive real eigenvalue is of the
form v1 = (A+ , A− , 0, 0, 0, 0)> , and, therefore, the unstable perturbation lowers the radial variable of the nearest sync population on
the other side of D.
In numerical simulations, starting from DS5 and imposing a
small perturbation along v1 , the trajectory jumps to S5 D for q = 1
and to SDS4 for q = −1. This implies that the one-dimensional
unstable manifold of DS5 is connected to the stable manifold of
S5 D for q = 1, particularly, via the most contracting eigendirection:
Wu (DS5 ) ∩ Ws (S5 D) 6= ∅. Furthermore, both manifolds intersect
the invariant subspace Z1 S4 Z6 , where the populations two to five are
synchronized and Z1,6 denotes the state of the first and the sixth populations, respectively. In this reduced subspace, DS5 is a saddle and
S5 D a sink. Considering the Z6 symmetry of the full system, the heteroclinic connection between DS5 and S5 D implies30 that there is a
heteroclinic cycle of six saddle chimera states that forms an invariant
subspace of the phase space,
(
[DS5 → S5 D → · · · → SDS4 → DS5 ] for q = 1,
C(q) :=
[DS5 → SDS4 → · · · → S5 D → DS5 ] for q = −1,
(10)
33, 063120-4
20 May 2024 10:05:47
As mentioned above, for A ∈ (0.071, 0.45) and starting from
random initial conditions, the long-term dynamics observed in
numerical integration of Eqs. (6) and (7) frequently approaches a
DS5 chimera state or one of its Z6 -symmetric counterparts. In fact,
in numerics, the six saddle chimeras are obtained equally often from
random initial conditions. For the moment, we focus on DS5 at
A = 0.3 for simplicity. This stationary chimera state is characterized
by ρ1 (t) = ρ0 < 1, ρa (t) = 1 for a = 2, . . . , 6. The phase dynamics is locked at the common frequency and follows nearly a
twisted state. Yet, the distribution of the ϕa (t) exhibits small deviations from a “pure” twisted state, which arise from ρ1 6= ρa = 1 for
a = 2, . . . , 6; cf. the S6 state above for which ρa = 1 for a = 1, . . . , 6.
Thus, the state shows characteristics of a nontrivial twisted state.49
Nevertheless, we can define a winding number of the phase variables
along the ring as
FIG. 2. (a) Eigenvalues of the Jacobian matrix evaluated at DS5 in the complex plane for A = 0.3. (b) Schematic of the perturbation along the unstable
eigenspace that raises the incoherent population up to sync and lowers the radial
variable of one of the two neighboring synchronized populations. (c) Schematic
of switching between saddle chimera states along the heteroclinic cycle C(±1)
defined in Eq. (10).
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population,29,30
6
dρa
1 − ρa2 X
Kab ρb cos(ϕb − ϕa − α) − η|Wa (t)|
=
dt
2
(11)
b=1
for a = 1, . . . , 6. Here, Wa (t) is Gaussian noise with unit standard
deviation and 0 < η 1 is its strength. Note that by taking the
absolute value of Wa (t) and subtracting the noise term, we ensure
that ρa (t) < 1 also for the synchronized populations for all times.
Figure 3(b) shows a persistent switching dynamics near the heteroclinic cycle of the saddle chimera states obtained for η = 10−15 .
In Fig. 3(c), it can be seen that the average switching period hT̃i
decreases with increasing noise strength η according to a power-law
scaling. Hence, one may expect that the switching dynamics is persistent near C(q) even at much smaller noise intensity than we could
achieve due to the resolution limit of the numerical simulations. In
contrast, increasing η beyond the highest value depicted in Fig. 3(c)
destroys the switching dynamics.
FIG. 3. (a) Time evolution of the radial variables of the OA dynamics from a random initial condition. (b) Time evolution of the radial variables of the OA dynamics
with an imposed noise: η = 10−15 . (c) Log–log plot of the average switching
period vs the strength of the noise. The dashed line indicates hT̃i ∼ η−0.048 .
Remaining parameters: A = 0.3 and β = 0.008.
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In Fig. 4(a), a bifurcation diagram of the stationary DS5
chimera state is depicted. It is born in a saddle-node bifurcation (LP)
at ALP = 0.0678 (red, see upper inset). One of the two DS5 branches
emerging from LP is, in fact, stable in a narrow A-interval. The other
upper branch separates the basins of attraction of the stable DS5
chimera state and the stable S6 (q = 0) solution. This upper branch
is not observable at all and is not considered further in this work.
The stable DS5 chimera and its symmetric counterparts are destabilized in a transcritical bifurcation (BP) at ABP = 0.070 08 through
an interaction with a DS4 D0 state (black), which possesses two incoherent populations that have different values of the radial variables,
ρ1 6= ρ6 . This state exchanges at ABP its stability with DS5 . The unstable direction of the latter is of the form v = (A+ , 0, 0, 0, 0, A− )> as
discussed above. Yet, close to the bifurcation point, a perturbation
along this unstable eigendirection leads the trajectory not yet to
the next symmetric variant along C(q) but to the DS4 D0 state. The
heteroclininc cycle only emerges after a sequence of further bifurcations in which the DS4 D0 state interacts with several other solution branches, which are not further discussed here. At least from
A = 0.15 on, we observe then the heteroclinic switching dynamics
in numerical integrations as described above [cf. Fig. 3(a)].
This heteroclinic switching between the stationary saddle
chimeras persists until they undergo a supercritical Hopf bifurcation
(HB) at AHB = 0.451, giving rise to a limit-cycle solution characterized by ρ1 (t) = ρ1 (t + T) < 1 and ρa = 1 for a = 2, . . . , 6 (blue),
where T denotes the period of it. Example trajectories at points (A)
and (B) along the limit-cycle solution are shown in insets (A) and
(B). The angular variables still behave like a nontrivial twisted state
with the winding number q = ±1. This periodic breathing chimera
solution is also unstable with one positive real Floquet multiplier
larger than unity. Again, as for the stationary saddle SD5 state, in
the long-term dynamics, we observe the unstable breathing chimera
solutions from random initial conditions. In order to shed light on
this observation, we calculate Lyapunov exponents (LEs)50,51 and
covariant Lyapunov vectors (CLVs)52,53 along the observed breathing chimera trajectory. In Fig. 4(b), the Lyapunov exponents of the
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the winding number q taking over the role of a direction indicator
of the heteroclinic switching. The heteroclinic cycles C(±1) are illustrated in Fig. 2(c). Note that for other chimera fixed points, such as
2
(SD)3 or (DS2 ) , neither switching nor any long-term dynamics is
detected in numerical integration of Eqs. (6) and (7).
In Fig. 3(a), a representative trajectory is depicted that shows
the switching dynamics between the six saddle chimera states. The
switching between synchronous and asynchronous dynamics occurs
always between neighboring populations and has a unique sense
of rotation. Hence, the trajectory follows the heteroclinic orbit.
The average time intervals between the switching increases until
eventually the trajectory remains in one of the saddle chimera
states. Yet, the motion along the heteroclinic orbit constitutes a
long-term switching. During this period, on average, the full symmetry of the system Eqs. (6) and (7) is recovered while a saddle
chimera state has a broken symmetry.29 Furthermore, the formation of the heteroclinic cycle explains why saddle chimera states
can be observed in a wide range of parameters, as quantified above
with Fig. 1(b).
When the switching happens, the radial dynamics of one synchronized population next to the incoherent population gets lowered along the unstable eigendirection of the saddle chimera state
and shows an oscillatory damped motion before taking on an almost
stationary value. The oscillatory transient is caused by complex
conjugate eigenvalues with negative real parts and corresponding
eigenvectors for a switching from DS5 to S5 D. Thus, upon switching, the trajectory spirals from one saddle chimera state to the next
one along C(q) in Eq. (10).
Next, for the switching dynamics between saddle chimera states
to be persistent, we add a small noise to the radial dynamics of each
B. Breathing saddle chimeras
Chaos
breathing chimera trajectory are shown. There is one positive LE,
and two zero LEs corresponding to time and phase shift invariance.
The positive LE 31 > 0 does not indicate a chaotic motion since
the breathing chimera state exhibits periodic dynamics. Rather, it
indicates a locally unstable direction of the reference trajectory in
phase space. Furthermore, the CLV corresponding to 31 has a form
v1 = (A+ , A− , 0, 0, 0, 0)> as the unstable eigenvector of the stationary saddle chimera. This suggests that all the symmetric variants
of the unstable breathing chimera also form a heteroclinic cycle of
type C(q). Indeed, we validate this conjecture with numerical integration from random initial conditions; a representative trajectory
showing the switching dynamics near a heteroclinic cycle of the saddle limit-cycle chimeras along C(−1) is depicted in Fig. 4(c). It is
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FIG. 5. Time evolutions of the radial variables of the WS dynamics in Eq. (16)
from a random initial condition: (a) A = 0.3 (stationary chimeras). (b) A = 0.5
(breathing chimeras). (c) and (d) Lyapunov exponents corresponding to the stationary and breathing chimeras for A = 0.3 and A = 0.5, respectively. The same
color scheme as in Fig. 4. All simulations were done with uniform constants of
motion and N = 20.
obtained for A = 0.5; compare the magnification of the limit-cycle
in Fig. 4(c) and the inset (A) in Fig. 4(a). We confirmed that the
switching dynamics near the heteroclinic cycle is persistent in the
presence of noise [see Eq. (11), results not shown here].
C. Finite-sized ensembles
We now turn our attention to finite-sized populations coupled
in a ring topology as in Fig. 1(a). The macroscopic dynamics of each
population can be formulated exploiting the Watanabe–Strogatz
transformation,18,41
(a)
(a)
e
iφj
= ei8a
ρa + e
i(ψj
−9a )
(a)
1 + ρa e
i(ψj
(12)
−9a )
N
for j = 1, . . . , N and a = 1, . . . , 6. Here, {ψj(a) }j=1 are N − 3 independent constants of motion for each population that satisfy three
P
P
P
constraints: Nj=1 cos ψj(a) = Nj=1 sin ψj(a) = 0 and Nj=1 ψj(a) = 0
41
for a = 1, . . . , 6. The distribution of the constants of motion takes
an important role in the dynamics. First, we use uniform constants
of motion given by ψj(a) = −π + 2π(j−1)
for j = 1, . . . , N and a
N
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FIG. 4. (a) Bifurcation diagram of the stationary chimera state DS5 . Upper inset:
Magnification close to LP. Lower insets: The time evolutions of the radial variable of the incoherent population at points (A) and (B) of the bifurcation diagram
corresponding to A = 0.5 and A = 0.6, respectively. Here, T is the period of
the breathing chimera state. HB: Hopf bifurcation, LP: saddle-node bifurcation,
and BP: transcritical bifurcation. Red (solid, dashed): (stable, unstable) unstable
stationary chimera states, Blue dashed: unstable breathing chimera states. Note
that the breathing chimera states undergo several saddle-node bifurcations. (b)
Lyapunov exponents of the breathing chimera dynamics at A = 0.5. Red, blue,
orange: positive, zero and negative LEs, respectively. (c) Switching dynamics of
the radial variables of the OA dynamics as a function of time from a random initial
condition at A = 0.5. Inset: Magnification of the times series around t = 6150.
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M
d9a
1 − ρa2 X
Kab ζb sin(ϕb − ϕa − α) + ξb cos(ϕb − ϕa − α) ,
=
dt
2ρa
b=1
ρa2
dϕa
1+
=
dt
2ρa
FIG. 6. Switching dynamics between quasiperiodic chimera states: Time evolution of the radial variables of the WS dynamics from a random initial condition
with A = 0.5 and N = 20. The nonuniform constants of motion were obtained for
p = 0.85.
= 1, . . . , 6, such that the 3M governing equations of the WS variables read
(13)
for a = 1, . . . , 6. The WS variables are linked to the complex
Kuramoto order parameter in Eq. (2) according to18,19
0a (t) = ρa (t)eiϕa (t) σa (ρa , 9a ; t)
(14)
for a = 1, . . . , 6. Here, σa is defined as
1
(ζa (t) + iξa (t))
ρa
σa =
N
:=
(a)
1 X 2ρa + (1 + ρa2 ) cos(ψk − 9a )
ρa N
1 + 2ρa cos(ψk(a) − 9a ) + ρa2
k=1
N
+i
(a)
1 X (1 − ρa2 ) sin(ψk − 9a )
ρa N
1 + 2ρa cos(ψk(a) − 9a ) + ρa2
k=1
(15)
for a = 1, . . . , 6. Using Eqs. (14) and (15), the 3M-dimensional WS
dynamics is rewritten as10,54
M
1 − ρa2 X
dρa
Kab ζb cos(ϕb − ϕa − α) − ξb sin(ϕb − ϕa − α) ,
=
dt
2
b=1
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b=1
Kab ζb sin(ϕb − ϕa − α) + ξb cos(ϕb − ϕa − α)
(16)
for a = 1, . . . , 6.
The Watanabe–Strogatz dynamics with the uniform constants of motion correspond to the finite-sized version of the
Ott–Antonsen dynamics.19,40 In fact, we observe that the motion
in both systems is qualitatively similar to each other from
N = 10 on except for some finite-size effect due to σa (ρa , 9a ; t) in
Eq. (15). Thus, the heteroclinic cycles of the stationary/breathing
saddle chimeras exist also in the corresponding finite-sized systems. Exemplary results of the WS macroscopic dynamics with
N = 20 are shown for stationary and breathing chimeras in Figs. 5(a)
and 5(b), respectively. The time series of ρa (t) and the angular
variables ϕa (t) for a = 1, . . . , 6 exhibit the same features as the
corresponding Ott–Antonsen dynamics discussed in Sec. III. The
stability analysis of the chimera trajectories in the finite-sized systems can be obtained from Lyapunov spectral analysis, which is
shown in Figs. 5(c) and 5(d) for the states depicted in Figs. 5(a)
and 5(b) after settling down to one of the saddle chimeras, respectively. Both chimera trajectories are characterized by one positive
Lyapunov exponent, which again does not indicate a chaotic motion
but rather a locally unstable direction along the reference trajectory.
The CLV corresponding to the positive LE has the same form as the
eigenvector corresponding to the positive eigenvalue in case of the
OA dynamics, namely, v1 = (A+ , A− , 0, 0, 0, 0)> with A+ A− < 0.
Note that one can distinguish the stationary and breathing chimera
dynamics by counting the number of zero Lyapunov exponents. The
breathing chimera state has one more zero LE than the stationary
chimeras due to the additional Hopf frequency.
In contrast to the OA dynamics, which is restricted to an invariant manifold, where the phases are distributed according to the
normalized Poisson kernel, taking nonuniform constants of motion
in the WS transformation, we can approach the dynamics outside
the OA manifold. The nonuniform constants of motion are gen(a)
erated from19 ψj(a) = (1 − p) π2 + π p(j−1)
and ψj+N/2
= −(1 + p) π2
N/2
with p = 0.85. A dynamical state, which cannot be cap+ π p(j−1)
N/2
tured by the OA dynamics, is the quasiperiodic chimera state
reported in Ref. 18. In our network topology, we observe the
switching dynamics between such quasiperiodic chimera states with
nonuniform constants of motion. One realization for p = 0.85,
A = 0.5, and N = 20 is shown in Fig. 6. This observation underlines
that the heteroclinic cycle is a robust phenomenon dictated by the
symmetry of the network topology.
IV. NONIDENTICAL OSCILLATORS
In Secs. IV A and IV B, we investigate nonidentical oscillators in a ring of the six oscillator populations. Here, we consider a
heterogeneity characterized by γ in Eqs. (6) and (7) for the thermodynamic limit for which the OA manifold is known to be asymptotically attracting.11,39,55,56 Furthermore, the natural frequency of the
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d
1 − ρa2
ρa =
Re Ha (t)e−iϕa e−iα ,
dt
2
d
1 − ρa2
9a =
Im Ha (t)e−iϕa e−iα ,
dt
2ρa
1 + ρa2
d
ϕa =
Im Ha (t)e−iϕa e−iα
dt
2ρa
M
X
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oscillator is generated from the Cauchy–Lorentz distribution for
finite-sized systems in Eq. (1).
A. Small heterogeneity: γ = 10−6
First, we impose a small heterogeneity characterized by
γ = 10−6 on the natural frequencies of the oscillators. This
small heterogeneity renders the Ott–Antonsen dynamics, which
is known to be neutrally stable for strictly identical oscillators,
attracting.11,39,55,56 In Fig. 7(a), time series of the radial variables of
the slightly heterogeneous systems are depicted for γ = 10−6 from
a random initial condition. First of all, here we observe persistent
switching of chimera states, which for identical oscillators was only
detected in the presence of a low noise level. Yet, the switching phenomenology appears to be somewhat different. For most of the time,
the chimera state is characterized by four S-populations and two
D-populations.57 Consider, e.g., the evolution of the “brown” population in the time interval between T1 and T3 in Fig. 7(a). In the
first half of this time interval, i.e., up to T2 , it switches roles with
the “blue” neighboring population, which becomes an S-population
while the brown one becomes a D-population. As soon as the “blue”
population has reached the S-state, the switching process with the
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other “purple” neighbor sets in. Consequently, the trajectory corresponds to a strict DS5 chimera state or its symmetric counterparts
only at periodic instants in time rather than during some time intervals. Furthermore, this persistent switching dynamics is attracting.
This conjecture is confirmed by Lyapunov analysis. In Fig. 7(b), Lyapunov exponents that were obtained along a switching trajectory are
shown. All the LEs are negative except for two zero arising from time
and phase shift invariance.
In order to study finite-sized ensembles, we need to directly
investigate the microscopic dynamics in Eq. (1) (note that the
Watanabe–Strogatz ansatz does not work for heterogeneous oscillator ensembles19). First, we obtain the natural frequencies from the
Cauchy–Lorentz distribution according to
j − 21
=
N
Z
ωj
g(ω)dω =
−∞
1
1
+ tan−1
2 π
ω̃j
γ
(17)
oN
n
. Direfor j = 1, . . . , N, which produces ωj = γ tan π(2j−1−N)
2N
j=1
ctly solving the microscopic dynamics in Eq. (1) with γ = 10−6 , we
observe a switching dynamics of the moduli of the Kuramoto order
parameters defined in Eq. (2). In Fig. 7(c), time evolution of the
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FIG. 7. (a) Time evolution of the radial variables of the OA dynamics after discarding transient behavior from a random initial condition. (b) Lyapunov exponents of the
switching dynamics calculated along the switching trajectory. (c) Time evolution of moduli of the Kuramoto order parameters obtained from the microscopic dynamics with a
random initial condition and N = 20. The two arrows indicate the instants in time at which the snapshot in (d) were taken. (d) Phase snapshots of the microscopic dynamics
for N = 20 at two points indicated in (c). Other parameters: γ = 10−6 and A = 0.3.
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FIG. 8. (a) Time evolution of the radial variables for (DS)3 chimeras at A = 0.2. (b) Eigenvalues of the Jacobian matrix evaluated at (DS)3 in the complex plane at A = 0.2.
(c) Bifurcation diagram of the (DS)3 chimera state. Solid and dashed lines indicate stable and unstable states, respectively. Black, red, blue, and green: uniform states,
stationary, breathing, and period-doubled chimera solutions, respectively.
moduli of the Kuramoto order parameters is depicted. The envelop
of them follows the same switching dynamics as in Fig. 7(a), however
with fluctuations superimposed, which stems from the finite-size
effect. Two snapshots of the microscopic phases from a random
initial condition are depicted in Fig. 7(d), which are indicated by
the two arrows in Fig. 7(a). These are exactly the points in time at
which there are five S- and one D-populations, corresponding to
DS5 . As in the DS5 chimera state of the identical oscillator ensembles, the mean phases of the populations evolve as a nearly twisted
state.
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B. Larger heterogeneity: γ = 10−4
1. Stationary chimera states
Here, we consider a somewhat larger heterogeneity characterized by γ = 0.0001 in Eqs. (6) and (7). In this case, we do not observe
any switching dynamics between chimera states from the numerical integration. We find an attracting stationary chimera state rather
than the heteroclinic orbits between saddle chimeras. The attracting chimera state is of the type (DS)3 . No other type of chimeras
is observed in our numerical integrations of Eqs. (6) and (7) from
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FIG. 9. Breathing [(a) and (b)], period-doubled [(c) and (d)], and quasiperiodic [(e) and (f)] chimera states for A = 0.274, A = 0.3, and A = 0.34, respectively. Left column:
time series of the radial variables with insets magnifying the dynamics of the nearly synchronized populations. Right column: Lyapunov exponents with the same color scheme
as in Fig. 4.
random initial conditions. Looking at the network symmetry, the
clusters C1 = {1, 3, 5} and C2 = {2, 4, 6} are, in fact, intertwined
clusters,46,58 i.e., they form a so-called ISC set (independently synchronizable cluster set).45,59 This means that the stability of each
cluster depends on the stability of the other cluster.
In Fig. 8(a), time series of the radial variables of a stationary
(DS)3 chimera starting from a random initial condition is shown
for A = 0.2. It is characterized by ρa (t) = ρD < 1 (incoherent populations) for a = 1, 3, 5 and ρb (t) = ρS ≈ 1 (nearly synchronized
populations) for b = 2, 4, 6. The phase variables are also locked at
the common frequency. The phase differences between oscillators
in the same cluster are found to be 2π3 , i.e., ϕa+2 − ϕa = 2π3 . In
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Fig. 8(b), the eigenvalues of the Jacobian matrix evaluated at (DS)3
are depicted in the complex plane. All the eigenvalues have negative real parts except for one zero corresponding to the phase shift
invariance, confirming that the (DS)3 chimera is a linearly stable
state.
In Fig. 8(c), a bifurcation diagram of the (DS)3 chimera states
is shown. For a small value of A, we find that a stable uniform solution (black) exists with ρa = ρ0 < 1 for a = 1, . . . , 6 and equally
spaced phase variables. We can interpret this uniform state as consisting of two clusters C1 and C2 that are identical in their radial
variables while the phase variables follow a twisted behavior. This
uniform state is destabilized in a pitchfork bifurcation (PF) at APF
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= 0.0323 in which one eigenvalue becomes positive. The eigenvector corresponding to the positive eigenvalue has the structure
v = (δ+ , δ− , δ+ , δ− , δ+ , δ− )> , where δ+ δ− < 0. This means the uniform state is unstable along the transverse direction between two
clusters. Due to the transversal instability, two symmetric solutions bifurcate from the uniform state in the pitchfork bifurcation, which is subcritical in our case (see Part A in Fig. 8). Each
of the two solutions possesses a nearly synchronized cluster and
an incoherent cluster which form together a chimera of the type
(DS)3 or (SD)3 , respectively. Coming from low values of A, each
of these two solution branches is born in a saddle-node bifurcation (LP) at ALP = 0.031 44 together with a stable, stationary
(SD)3 —respectively, (DS)3 —chimera state. This chimera state is
stable in a wide range of the parameter A as shown in Fig. 8(c).
2. Breathing, period-doubled and quasiperiodic
chimera states
FIG. 10. Time-parametric plot of ρ1 (t) vs ρ3 (t) for the time interval 1t = 3000
after discarding the transient behavior: breathing (blue), period-doubled (red), and
quasiperiodic (black) chimera trajectories for A = 0.274, A = 0.3, and A = 0.34,
respectively.
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all Lyapunov exponents are negative, confirming that the breathing (DS)3 -type chimera is also attracting. This state exists only in
a small interval of the parameter A. At APD = 0.279 95, it is destabilized in a supercritical period-doubling bifurcation (PD) [see Part
B of Fig. 8(c)]. Panels (c) and (d) in Fig. 9 confirm the perioddoubled characteristics of the radial variables as well as the stability
of the period-doubled chimera trajectory. Again, the radial variables exhibit the above specified spatiotemporal symmetry, with the
difference that the period is nearly twice the period in Fig. 9(a).
The period-doubled chimera state loses its stability in a supercritical torus bifurcation (TR) at ATR = 0.319 57. For A > ATR , one
can observe a quasiperiodic chimera dynamics on a torus. An example dynamics and its stability are shown in Figs. 9(e) and 9(f). The
quasiperiodic chimera is characterized by one more zero Lyapunov
exponent arising from the second incommensurate frequency. The
rich dynamics of the (DS)3 -type chimera states can be better appreciated in a time-parametric plot, where ρ1 (t) is plotted vs ρ3 (t)
(Fig. 10). The breathing chimera state appears as a simple, closed
loop (blue), whereas the period-doubled chimera state (red) follows
a double-wound loop in the projected space. In contrast, the spatiotemporal symmetry of the quasiperiodic motion on the torus is
broken (black).
V. CONCLUSION AND OUTLOOK
In this paper, we studied a system of six populations of identical Kuramoto–Sakaguchi phase oscillators in a ring topology. In
the thermodynamic limit, the Ott–Antonsen dynamics possesses
a variety of chimera solutions arising from the symmetry of the
ring, most of them being unstable in nearly the entire parameter
space. Only in a narrow interval of the inter-population coupling
strength ν = 1 − A, we obtain stable chimera states characterized
by one incoherent and five synchronized populations. These symmetric states are destabilized in a transcritical bifurcation and live in
a large parameter region as saddle chimera states with one unstable direction. The six one-dimensional unstable manifolds of the
saddle chimeras connect them in a heteroclinic cycle, rendering
the chimera states observable in numerical integration from random initial conditions. Moreover, the trajectories display transient
switching between the saddle chimera states, which becomes persistent when a small noise is imposed on the radial dynamics. At
some large value of A, the stationary saddle chimeras undergo a
Hopf bifurcation resulting in a heteroclinic orbit of saddle limitcycles. Thus, we also observe switching between breathing chimeras.
Moreover, in finite-sized populations, we observed in addition a
heteroclinic switching between quasiperiodic chimera states. A heteroclinic cycle even persists in the presence of small heterogeneity in
the oscillator natural frequencies. This robust occurrence of heteroclinic cycles with three different variants of base states (stationary,
breathing, and quasiperiodic) is in stark contrast to the dynamics of
other network topologies. When using 3, 4, 5, 7, and 8 populations
in a ring, we did not observe switching dynamics between chimera
states from random initial conditions. Currently, we do not have a
satisfactory explanation for why six populations behave differently.
However, we note that in three-population networks, switching
chimeras were obtained with different coupling functions, more precisely, pairwise intra-population coupling with higher harmonics
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The stationary (DS)3 -type chimera states are destabilized in a
supercritical Hopf bifurcation (HB) at AHB = 0.268 12 giving rise
to stable breathing chimera states. Trajectories of the radial variables are shown in Fig. 9(a) together with the Lyapunov spectrum
in Fig. 9(b) for A = 0.274. The oscillations of the three populations within one cluster are time-shifted by T/3 and 2T/3, where
T is the period of the radial variable, as can be clearly seen for the
) for a =
incoherent population: ρa (t) = ρa+2 (t − T3 ) = ρa+4 (t − 2T
3
1, . . . , 6 (indices are taken modulo 6). In addition, except the two
zero Lyapunov exponents connected to phase and time invariance,
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and sinusoidal nonpairwise inter-population coupling.30,31 It, thus,
remains an interesting problem for future studies to investigate
under which conditions observable heteroclinic cycles in oscillator
networks exist.
Finally, we considered oscillator ensembles with a wider distribution of the heterogeneous natural frequencies in the thermodynamic limit. Here, instead of saddle chimera states, attracting
chimera states with various symmetries and complex order parameter dynamics dominate in phase space over a wide range of the
parameter. The various macroscopic dynamics emerge in Hopf,
period-doubling, and torus bifurcations.
In conclusion, we have discovered several types of heteroclinic
switching observable in the macroscopic dynamics of nearly identical oscillator populations arranged in a ring. One might be tempted
to interpret this as a further step toward understanding the mechanism of the dynamics of neural oscillator networks,60,61 in particular,
for encoding sequential information.30,62,63 However, as our study on
a strong heterogeneity revealed, one has to be very careful before
drawing this conclusion for a biological system.
ACKNOWLEDGMENTS
The authors would like to thank Young Sul Cho for providing
additional computing facilities. This work has been supported by the
Deutsche Forschungsgemeinschaft (Project No. KR1189/18-2).
AUTHOR DECLARATIONS
The authors have no conflicts to disclose.
Author Contributions
Seungjae Lee: Conceptualization (equal); Formal analysis (lead);
Software (lead); Writing – original draft (lead); Writing – review
& editing (supporting). Katharina Krischer: Funding acquisition
(lead); Supervision (lead); Writing – review & editing (lead).
DATA AVAILABILITY
The data that support the findings of this study are available
from the corresponding author upon reasonable request.
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20 May 2024 10:05:47
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Measurement and Analysis of Urban Total Factor Energy Efficiency in China
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Measurement and Analysis of Urban Total Factor Energy
Efficiency in China Feifei Lu1, *, Yinling Lu2, and Na Lei3 1Management Science and Engineering, Lanzhou University of Technology, 730000Lanzhou, China
2Civil engineering, Xuchang City Planning and Design Institute, 461000Xuchang, China
3Civil engineering, Lanzhou University of Technology, 730000Lanzhou, China Abstract. The improvement of urban energy efficiency is of great significance to reduce carbon emissions
and achieve China's goal of carbon peak in 2030. Taking 266 cities as the research objects, the energy
efficiency of each city is measured by Super-SBM model. Then the energy efficiency is decomposed by
Malmquist index. The results show that: In 2006, the number of cities in high-efficiency areas is small and
high efficiency areas are mostly distributed in the northeast and southeast coastal areas. There was a
phenomenon of low efficiency areas agglomeration. But in 2017, the number of high-efficiency cities
increased significantly. The number of high-efficiency cities in Northeast China increased, the number of
high-efficiency cities in Southeast coastal areas decreased, and the number of high-efficiency cities in Central
China increased and showed a phenomenon of agglomeration of high-efficiency areas or relatively high
efficiency areas. According to the decomposition of urban energy efficiency, technological progress is the
main driving force for the improvement of energy efficiency, and the decline of technical efficiency inhibits
the improvement of energy efficiency in various cities. energy efficiency is to create as high effective output as
possible with as little resource input as possible, while
restraining undesired output [2-5]. Most literatures believe
that there is significant spatial difference in energy
efficiency in different regions. *Corresponding author: lufeifei2505@163.com
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
(http://creativecommons.org/licenses/by/4.0/). 1 Introduction The Third China Energy Industry Development Annual
Conference released the Review Framework of China's
Urban Energy Reform, which believes that cities are the
main body of the world's energy consumption and the
main body of the implementation of various national
energy policies. Analysis at the provincial level in China
is difficult to solve the problem of total energy
consumption distribution, so it is necessary to refine the
study at the city level [1]. Cities gather all kinds of
economic, technical and human support needed by energy
transformation, so the study of urban energy efficiency has
an important impact on exploring the characteristics of
regional economic development. Urban economic
development cannot be separated from energy, but
economic development and energy development have
brought serious problems of environmental degradation
and energy depletion. In order to reduce the impact of
economic
development
on
the
environment,
the
government has strengthened environmental regulation,
but a debate has emerged between "green paradox" and
"forcing emission reduction". In the face of multiple
pressures, the breakthrough to improve urban energy
efficiency is to actively explore the path of high-quality
urban
development,
predict
the
comprehensive
competitiveness of the city, and promote the sustainable
development of the city. Based on the above analysis, although many scholars
have studied energy efficiency, there are few analyses on
the spatio-temporal differences of energy efficiency at the
national level. Therefore, 266 cities in China are selected
as the research objects, and the Super-SBM model is used
to measure the energy efficiency of each city. According
to Jenks natural breakpoint classification method,
different energy efficiency zones are divided, and energy
efficiency is further decomposed by Malmquist index. https://doi.org/10.1051/e3sconf/202126101020 https://doi.org/10.1051/e3sconf/202126101020 E3S Web of Conferences 261, 01020 (2021)
ICEMEE 2021 @
EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
icenses/by/4.0/). 2.2 Establishment and explanation of China's
urban energy efficiency measurement index
system p
p
1
1
1
1
1
1
1
0
1
(
,
)
(
,
)
(
,
,
,
)
( ,
)
( ,
)
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
E x
y
E
x
y
M x
y
x y
E x y
E
x y
(2)
The Malmquist index is further decomposed as follows:
0
sech
M
pech
tech ch
(3) 1
1
1
1
1
1
1
0
1
(
,
)
(
,
)
(
,
,
,
)
( ,
)
( ,
)
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
E x
y
E
x
y
M x
y
x y
E x y
E
x y
(2) (2) The Malmquist index is further decomposed as follows:
0
sech
M
pech
tech ch
(3) According to "China City Statistical Yearbook", the
prefecture-level cities and above were selected as the
research objects, and the discontinuous data samples were
eliminated. After adjusting the caliber of the unified
administrative region, 266 cities and above were finally
selected as the research samples. The research period was
12 years of panel data from 2006 to 2017. The selected
index data and sources of China's urban energy efficiency
measurement and spatial econometric model are shown in
Table 1. (3) Where, pech represents the change of pure technical
efficiency, reflecting the problem of technological
dynamism; sech represents the change of scale efficiency,
reflecting the impact of scale change on productivity by
comparing the scale efficiency of different periods on the
same production front; tech ch represents the change of
technological progress, mainly describing the impact of
technological progress on total factor productivity. The number of urban employees at the end of the year
was used as the index of labor input. Capital stock as the
substitution variable of capital input. 2.3 Decomposition model of urban energy
efficiency in China (1) The urban energy efficiency is decomposed by the
Malmquist index. The Malmquist index can be
summarized into two aspects: one is the change of the
technical efficiency of the evaluated unit in a period of
time, the other is the change of the production technology
of the evaluated unit itself. According to the
decomposition method, the Malmquist index from period
to period is decomposed as follows: In the formula, is the effect value, m and s are
input and output,
iS and
iS are relaxation variables
of input and output respectively, and are weights. 2.2 Establishment and explanation of China's
urban energy efficiency measurement index
system The perpetual
inventory method is used to measure the capital stock, and
the adjustment is carried out based on 2005.Energy
consumption data is easy to cause errors due to different
statistical calibers, and energy consumption is mostly
output in the form of electricity, so the whole society's
electricity consumption is selected as the measurement
index of energy input. 2.1 Measurement model of urban energy
efficiency in China Data Envelopment Analysis (DEA) model is used to
construct a non-parametric "effective frontier" by using
linear programming model, which is used to analysis the
allocation of non-parametric technical efficiency of
multiple inputs and outputs. DEA model does not need to
set the weight, which can avoid the influence of subjective
factors when establishing the production function. Super-
SBM model uses the non-radial efficiency measurement
method to avoid the problem of slack between input and At present, research on urban energy efficiency has
made some progress. The core idea of optimizing urban E3S Web of Conferences 261, 01020 (2021)
ICEMEE 2021 E3S Web of Conferences 261, 01020 (2021) https://doi.org/10.1051/e3sconf/202126101020 Expected
output index
Economic
output
GDP by City (adjusted
for 2005)
Undesired
output
indicators
Pollutant
output
Industrial effluent
discharge
Industrial sulphur
dioxide emissions
Industrial soot
emissions output. At the same time, linear combination is used to
replace the decision-making unit of efficiency evaluation. When the efficiency value of decision-making unit
reaches 1, further efficiency evaluation can still be carried
out to realize the ranking of decision-making units. The
formula of Super-SBM model is: 1
0
1
0
0
1, 0
0
1, 0
1
1
1
min
1
1
(
1,2,...,
)
. . (
1,2,..., )
1;
0; ,
,
0
m
i
i
i
s
r
r
r
n
ij
j
jn
ij
j
j
n
j
j
j
S
m
X
S
s
Y
X
X
S
j
m
s t
Y
Y
S
r
s
S
S
(1) 3.1 Analysis of China's urban energy efficiency
measurement results It shows that from 2006 to
2017, with the strengthening of environmental regulation,
all cities in China can improve energy efficiency by
Table 2. Energy efficiency decomp As can be seen from Figure 1, in 2006, most of the
high-efficiency areas were distributed in the northeast and
southeast coastal areas. In the central region, except for
some cities in the high-efficiency area and the high-
efficiency area, most of the provinces were in the low-
efficiency area and the low-efficiency area. From the
overall space, there was a phenomenon of agglomeration
of low-efficiency areas. The number of cities with high
efficiency in 2017 was significantly more than that in 2006. The number of cities with high efficiency in northeast
China increased, but the number of cities with high
efficiency in southeast coastal China decreased, and the
number of cities with high efficiency in central China
increased, showing the agglomeration of high efficiency
areas or high efficiency areas. It shows that from 2006 to
2017, with the strengthening of environmental regulation,
all cities in China can improve energy efficiency by
accelerating green techno
environmental governance
technology. However, in the
promoting the rapid econom
of energy use brought by a
transfer and the problem
treatment may reduce the ene
this area. 3.2 Decomposition of urb
China
In order to further study the
changes, urban energy effici
2006 to 2017 through Malmq
shown in Table 2. Table 2. Energy efficiency decomposition results of 266 cities in China accelerating green technology innovation, reducing
environmental governance cost or improving energy
technology. However, in the southeast coastal area, while
promoting the rapid economic development, the pressure
of energy use brought by a large number of population
transfer and the problem of environmental pollution
treatment may reduce the energy efficiency of the cities in
this area. 3.2 Decomposition of urban energy efficiency in
China In order to further study the causes of energy efficiency
changes, urban energy efficiency was decomposed from
2006 to 2017 through Malmquist index, and the results are
shown in Table 2. p
gy
y
y
Table 2. Energy efficiency decomposition results of 266 cities in China. Year
Change of
technical
efficiency
Change of
technological
progress
Changes in pure
technical efficiency
Scale efficiency
variation
Energy
efficiency
variation
2006-2007
1.035
1.03
1.028
1.006
1.066
2007-2008
0.972
1.099
0.969
1.003
1.067
2008-2009
1.029
1.028
1.047
0.983
1.058
2009-2010
0.963
1.072
0.976
0.987
1.032
2010-2011
1.101
0.808
1.080
1.019
0.889
2011-2012
1.013
1.041
1.007
1.006
1.054
2012-2013
1.039
0.938
1.022
1.016
0.974
2013-2014
1.007
1.011
0.994
1.013
1.018
2014-2015
0.966
1.062
0.978
0.987
1.026
2015-2016
0.918
1.435
0.962
0.954
1.317
2016-2017
0.901
0.977
0.903
0.998
0.881
Mean
0.995
1.046
0.997
0.997
1.035
From Table 2, specific analysis shows that the
technical efficiency can be decomposed into the product
of pure technical efficiency and scale efficiency. From
2007 to 2008, the technical efficiency declined, the change
of pure technical efficiency was less than 1, and the change
of scale efficiency was greater than 1. Therefore, the
energy efficiency. 2009-2010 and 2014-2017 technical
efficiency drops, pure technical efficiency and scale
efficiency changes are less than 1, therefore during the
pure technical efficiency and scale efficiency drops to
hinder the improvement of energy efficiency, in the
meantime the city failed to embody the effect of industrial energy efficiency. 2009-2010 and 2014-2017 technical
efficiency drops, pure technical efficiency and scale
efficiency changes are less than 1, therefore during the
pure technical efficiency and scale efficiency drops to
hinder the improvement of energy efficiency, in the
meantime the city failed to embody the effect of industrial
structure optimization, to focus on industrial structure
optimization of input-output efficiency. energy efficiency. 2009-2010 and 2014-2017 technical
efficiency drops, pure technical efficiency and scale
efficiency changes are less than 1, therefore during the
pure technical efficiency and scale efficiency drops to
hinder the improvement of energy efficiency, in the
meantime the city failed to embody the effect of industrial
structure optimization, to focus on industrial structure
optimization of input-output efficiency. From Table 2, specific analysis shows that the
technical efficiency can be decomposed into the product
of pure technical efficiency and scale efficiency. 3.1 Analysis of China's urban energy efficiency
measurement results Using DEA -- Solver Pro 5.0 to measure the energy
efficiency of Chinese cities, the energy efficiency of each
city from 2006 to 2017 can be obtained. In order to clearly
express the distribution of energy efficiency, ArcGIS
software is used. According to Jenks natural breakpoint
classification method, 266 cities were divided into high
efficiency area, high efficiency area, low efficiency area
and low efficiency area. Due to space constraints, in order
to further analyze the change of energy efficiency, the
energy efficiency of each city in 2006 and 2017 is shown
in Figure 1. Table 1. Selection of indicators for measuring energy efficiency
in Chinese cities and data description. Table 1. Selection of indicators for measuring energy efficiency
in Chinese cities and data description. Table 1. Selection of indicators for measuring energy efficiency
in Chinese cities and data description. Table 1. Selection of indicators for measuring energy efficiency
in Chinese cities and data description. Indicators
Describe
Input index
Labor input
Number of urban
employees at year-end
Capital
investment
Capital stock (adjusted
for 2005)
The energy
input
Electricity consumption
by the whole society Table 1. Selection of indicators for measuring energy efficiency
in Chinese cities and data description. Indicators
Describe
Input index
Labor input
Number of urban
employees at year-end
Capital
investment
Capital stock (adjusted
for 2005)
The energy
input
Electricity consumption
by the whole society 2 2 https://doi.org/10.1051/e3sconf/202126101020 E3S Web of Conferences 261, 01020 (2021) E3S Web of Conferences 261, 01020 (2021)
ICEMEE 2021 Fig. 1. Comparison of urban energy efficiency in 2006 and 2017. Fig. 1. Comparison of urban energy efficiency in 2006 and 2017. As can be seen from Figure 1, in 2006, most of the
high-efficiency areas were distributed in the northeast and
southeast coastal areas. In the central region, except for
some cities in the high-efficiency area and the high-
efficiency area, most of the provinces were in the low-
efficiency area and the low-efficiency area. From the
overall space, there was a phenomenon of agglomeration
of low-efficiency areas. The number of cities with high
efficiency in 2017 was significantly more than that in 2006. The number of cities with high efficiency in northeast
China increased, but the number of cities with high
efficiency in southeast coastal China decreased, and the
number of cities with high efficiency in central China
increased, showing the agglomeration of high efficiency
areas or high efficiency areas. 3.2 Decomposition of urban energy efficiency in
China From
2007 to 2008, the technical efficiency declined, the change
of pure technical efficiency was less than 1, and the change
of scale efficiency was greater than 1. Therefore, the
decline of pure technical efficiency during this period
hindered the improvement of energy efficiency, indicating
that the lack of technological development impetus in each
city during this period was the reason for the decrease of 3 3 https://doi.org/10.1051/e3sconf/202126101020 E3S Web of Conferences 261, 01020 (2021)
ICEMEE 2021 E3S Web of Conferences 261, 01020 (2021) 4 Conclusions and policy
recommendations (1) From time comparison, it can be seen that in 2006,
most of the high efficiency areas were distributed in the
northeast and southeast coastal areas, while most of the
other provinces were in low efficiency and low efficiency
areas, and there was a phenomenon of agglomeration of
low efficiency areas. In 2017, the number of cities with
high efficiency areas increased, and the central region
showed the agglomeration phenomenon of high efficiency
areas or high efficiency areas. (2) From the decomposition of urban energy efficiency,
it can be seen that technological progress is the main
driving force of urban energy efficiency improvement, and
the
decline
of
technical
efficiency
inhibits
the
improvement of urban energy efficiency. Therefore, the following suggestions are proposed. Promote regional coordinated development, and promote
the overall energy efficiency of the central region in the
way that high-efficiency zones drive surrounding areas. The southeast coastal areas should pay attention to the
coordination and cooperation with the population policy
and employment policy and give full play to the
synergistic effect of the policies. Technological progress is
the main driving force for energy efficiency, and
technological innovation in energy utilization, pollution
control and recycling should be strengthened. 5. Betsill, M., and M. J. Hoffmann. REV POLICY
RES.28,83-106, (2011). Reference 1. M. Antonino, H. Lisanne, H. Oliver, F.Jimeno, G.Niki,
R. Diana. RENEW SUST ENERG REV.124, (2020). 2. W. Guan, S. Xu. J. Geogr. Sci.06, 980-992 (2015). 3. Albrizio, S.,T. Kozluk, and Zipperer. J Environ Econ
Manage81, 209-226, (2017). 4. Allen, F., J. Qian, and M. Qian. J financ econ77, 57-
116, (2005). 5. Betsill, M., and M. J. Hoffmann. REV POLICY
RES.28,83-106, (2011). 5. Betsill, M., and M. J. Hoffmann. REV POLICY
RES.28,83-106, (2011). 4
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The upper bound estimation on the spectral norm of r-circulant matrices with the Fibonacci and Lucas numbers
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Journal of inequalities and applications
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R ES EA RCH Open Access Chengyuan He*, Jiangming Ma, Kunpeng Zhang and Zhenghua Wang *Correspondence:
chengyuanh@163.com
School of Mathematics and
Computer Engineering, Xihua
University Chengdu, Sichuan,
610039, P.R. China Abstract Let us define A = Circr(a0,a1,...,an–1) to be a n × n r-circulant matrix. The entries in
the first row of A = Circr(a0,a1,...,an–1) are ai = Fi, or ai = Li, or ai = FiLi, or ai = F2
i , or
ai = L2
i (i = 0,1,...,n – 1), where Fi and Li are the ith Fibonacci and Lucas numbers,
respectively. This paper gives an upper bound estimation of the spectral norm for
r-circulant matrices with Fibonacci and Lucas numbers. The result is more accurate
than the corresponding results of S Solak and S Shen, and of J Cen, and the numerical
examples have provided further proof. Keywords: r-circulant matrices; Fibonacci number; Lucas number; spectral norm;
estimation Keywords: r-circulant matrices; Fibonacci number; Lucas number; spectral norm;
estimation He et al. Journal of Inequalities and Applications ( 2015) 2015:72
DOI 10.1186/s13660-015-0596-5 He et al. Journal of Inequalities and Applications ( 2015) 2015:72
DOI 10.1186/s13660-015-0596-5 The upper bound estimation on the spectral
norm of r-circulant matrices with the
Fibonacci and Lucas numbers Chengyuan He*, Jiangming Ma, Kunpeng Zhang and Zhenghua Wang *Correspondence:
chengyuanh@163.com
School of Mathematics and
Computer Engineering, Xihua
University Chengdu, Sichuan,
610039, P.R. China 1 Introduction 1 Introduction
For n > , the Fibonacci sequence {Fn} is defined by Fn+= Fn + Fn–, where F= and
F= . If we start by zero, then the sequence is given by For n > , the Fibonacci sequence {Fn} is defined by Fn+= Fn + Fn–, where F= and
F= . If we start by zero, then the sequence is given by n
···
Fn
···
() () If we deduce from Fn+that Ln+= Ln + Ln–, and let L= , L= , then we obtain the
Lucas sequence {Ln}, n
···
Ln
···
() n
···
Ln
···
() n
···
Ln
···
() () Furthermore, the sequences {Fn} and {Ln} satisfy the following recursion: Fn + Ln = Fn+. () () Fn + Ln = Fn+. Definition .A matrix A is an r-circulant matrix if it is of the form Definition .A matrix A is an r-circulant matrix if it is of the form A =
⎛
⎜⎜⎜⎜⎜⎜⎝
a
a
···
an–
an–
ran–
a
···
an–
an–
···
···
···
···
···
ra
ra
···
a
a
ra
ra
···
ran–
a
⎞
⎟⎟⎟⎟⎟⎟⎠
. © 2015 He et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribu-
tion License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly credited. He et al. Journal of Inequalities and Applications ( 2015) 2015:72 He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 2 of 10 Obviously, the elements of this r-circulant matrix are determined by its first row ele-
ments a,a,...,an–and the parameter r, thus we denote A = Circr(a,a,...,an–). Espe-
cially when r = , we obtain A = Circ(a,a,...,an–). Definition .A matrix A is called a symmetric r-circulant matrix if it is of the form A =
⎛
⎜⎜⎜⎜⎜⎜⎝
a
a
···
an–
an–
a
a
···
an–
ra
···
···
···
···
···
an–
an–
···
ran–
ran–
an–
ra
···
ran–
ran–
⎞
⎟⎟⎟⎟⎟⎟⎠
. Obviously, the elements of this r-circulant matrix are determined by its first row ele-
ments a,a,...,an–and the parameter r; thus we denote A = SCircr(a,a,...,an–). Es-
pecially when r = , we obtain A = SCirc(a,a,...,an–). For any A = (aij)m×n, the well-known spectral norm of the matrix A is For any A = (aij)m×n, the well-known spectral norm of the matrix A is ∥A∥=
max
≤i≤nλi
AHA
, ∥A∥=
max
≤i≤nλi
AHA
, in which λi(AHA) is the eigenvalue of AHA and AH is the conjugate transpose of matrix A. Define the maximum column length norm c(·) and the maximum row length norm r(·)
of any matrix A by in which λi(AHA) is the eigenvalue of AHA and AH is the conjugate transpose of matrix A. Define the maximum column length norm c(·) and the maximum row length norm r(·)
of any matrix A by c(A) = max
j
i
|aij| and and r(A) = max
i
j
|aij|, r(A) = max
i
j
|aij|, espectively. respectively. respectively. Let A, B, and C be m × n matrices. If A = B ◦C, then in accordance with [] we have ∥A∥≤r(B)c(C)
() ∥A∥≤r(B)c(C) () and and ∥A∥≤∥B∥∥C∥. () ∥A∥≤∥B∥∥C∥. () Here, we define B = (bij)m×n, C = (cij)m×n, and we let B ◦C be the Hadamard product of B
and C. In recent years, many authors (see [–]) were concerned with r-circulant matrices as-
sociated with a number sequence. References [–] calculate and estimate the Frobenius
norm and the spectral norm of a circulant matrix where the elements of the r-circulant
matrix are Fibonacci numbers and Lucas numbers; the authors found more accurate re-
sults of the upper bound estimated, and the numerical examples also have provided further
proof. He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 3 of 10 Theorem .(see []) Let A = Circ(F,F,...,Fn–) be a circulant matrix, then we have Theorem .(see []) Let A = Circ(F,F,...,Fn–) be a circulant matrix, then we have ∥A∥≤FnFn–, ∥A∥≤FnFn–, where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Theorem .(see []) Let A = Circ(L,L,...,Ln–) be a circulant matrix, then we have ∥A∥≤
⎧
⎨
⎩
[FnFn–+ F
n–+ Fn–Fn–+ ] × [FnFn–+ F
n–+ Fn–Fn–+ ],
n odd,
[FnFn–+ F
n–+ Fn–Fn–] × [FnFn–+ F
n–+ Fn–Fn–– ],
n even, where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. Theorem .(see []) Let A = Circr(F,F,...,Fn–) be a r-circulant matrix, in which
|r| ≥, and then Theorem .(see []) Let A = Circr(F,F,...,Fn–) be a r-circulant matrix, in which
|r| ≥, and then ∥A∥≤|r|FnFn–, where r ∈C, ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Theorem .(see []) Let A = Circr(L,L,...,Ln–) be a r-circulant matrix and |r| ≥,
then we obtain ∥A∥≤
⎧
⎨
⎩
(|r|FnFn–+ )(FnFn–+ ),
n odd,
[|r|FnFn–+ (– |r|)](FnFn–– ),
n even, where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. we get A = B ◦C. 2 Main results Theorem .Let A = Circ(F,F,...,Fn–) be a circulant matrix, then we have
∥A∥≤
(n – )FnFn–, where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Proof Since A = Circ(F,F,...,Fn–) is a circulant matrix, let the matrices B and C be Proof Since A = Circ(F,F,...,Fn–) is a circulant matrix, let the matrices B and C be B =
⎛
⎜⎜⎜⎝
F
···
F
···
···
···
···
···
···
F
⎞
⎟⎟⎟⎠,
C =
⎛
⎜⎜⎜⎜⎜⎜⎝
F
F
···
Fn–
Fn–
Fn–
F
···
Fn–
Fn–
···
···
···
···
···
F
F
···
F
F
F
F
···
Fn–
F
⎞
⎟⎟⎟⎟⎟⎟⎠
, B =
⎛
⎜⎜⎜⎝
F
···
F
···
···
···
···
···
···
F
⎞
⎟⎟⎟⎠,
C =
⎛
⎜⎜⎜⎜⎜⎜⎝
F
F
···
Fn–
Fn–
Fn–
F
···
Fn–
Fn–
···
···
···
···
···
F
F
···
F
F
F
F
···
Fn–
F
⎞
⎟⎟⎟⎟⎟⎟⎠
, we get A = B ◦C. we get A = B ◦C. He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 4 of 10 For
r(B) = max
i
j
|bij|=
√
n –
and For r(B) = max
i
j
|bij|=
√
n – and c(C) = max
j
i
|cij|= max
j
n
i=
|cin|=
n–
s=
Fs =
FnFn–. From (), we have ∥A∥≤
(n – )FnFn–. □ ∥A∥≤
(n – )FnFn–. ∥A∥≤
(n – )FnFn–. □ □ Corollary .Let A = SCirc(F,F,...,Fn–) be a symmetric circulant matrix, then we have
∥A∥≤
(n – )FnFn–, Corollary .Let A = SCirc(F,F,...,Fn–) be a symmetric circulant matrix, then we have
∥A∥≤
(n – )FnFn–, Corollary .Let A = SCirc(F,F,...,Fn–) be a symmetric circulant matrix, then we have
∥A∥≤
(n – )FnFn–, ∥A∥≤
(n – )FnFn–, where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. 2 Main results Corollary .Let A = Circ(F
,F
,...,F
n–) be a circulant matrix, then we have
∥A∥≤(n – )FnFn–, Corollary .Let A = Circ(F
,F
,...,F
n–) be a circulant matrix, then we have
∥A∥≤(n – )FnFn–, ∥A∥≤(n – )FnFn–, where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. where ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Proof Since A = Circ(F
,F
,...,F
n–) is a circulant matrix, if the matrices B = Circ(F,F,
...,Fn–), we get A = B ◦B; thus from () and Theorem .we obtain ∥A∥≤(n – )FnFn–. □ □ ∥A∥≤(n – )FnFn–. Theorem .Let A = Circ(L,L,...,Ln–) be a circulant matrix, then we have ∥A∥≤
⎧
⎨
⎩
√nFnFn–+ n,
n odd,
√nFnFn–,
n even, where ∥· ∥is the spectral norm and Ln denotes the Lucas number. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. Proof Since A = Circ(L,L,...,Ln–) is a circulant matrix, let the following matrices be
defined: B =
⎛
⎜⎜⎜⎝
···
···
···
···
···
···
···
⎞
⎟⎟⎟⎠,
C =
⎛
⎜⎜⎜⎜⎜⎜⎝
L
L
···
Ln–
Ln–
Ln–
L
···
Ln–
Ln–
···
···
···
···
···
L
L
···
L
L
L
L
···
Ln–
L
⎞
⎟⎟⎟⎟⎟⎟⎠
, then A = B ◦C. then A = B ◦C. He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 5 of 10 Page 5 of 10 We have
r(B) = max
i
j
|bij|= √n We have and Here n–
s=
F
s = FnFn–,
n–
s=
FsFs–=
⎧
⎨
⎩
F
n–,
n odd,
F
n–– ,
n even,
n–
s=
F
s–= Fn–Fn–+ , thus c(C) =
⎧
⎨
⎩
√FnFn–+ ,
n odd,
√FnFn–,
n even, c(C) =
⎧
⎨
⎩
√FnFn–+ ,
n odd,
√FnFn–,
n even, and from () we obtain and from () we obtain ∥A∥≤
⎧
⎨
⎩
√nFnFn–+ n,
n odd,
√nFnFn–,
n even. □ □ Corollary .Let A = SCirc(L,L,...,Ln–) be a symmetric circulant matrix, then we
have Corollary .Let A = SCirc(L,L,...,Ln–) be a symmetric circulant matrix, then we
have ∥A∥≤
⎧
⎨
⎩
√nFnFn–+ n,
n odd,
√nFnFn–,
n even, ∥A∥≤
⎧
⎨
⎩
√nFnFn–+ n,
n odd,
√nFnFn–,
n even, where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. Corollary .Let A = Circ(L
,L
,...,L
n–) be circulant matrices, then Corollary .Let A = Circ(L
,L
,...,L
n–) be circulant matrices, then ∥A∥≤
⎧
⎨
⎩
nFnFn–+ n,
n odd,
nFnFn–,
n even, ∥A∥≤
⎧
⎨
⎩
nFnFn–+ n,
n odd,
nFnFn–,
n even, ∥A∥≤
⎧
⎨nFnFn–+ n,
n odd, where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. Proof Since A = Circ(L
,L
,...,L
n–) is a circulant matrix, if the matrices B = Circ(L,L,
...,Ln–), we get A = B ◦B; thus from () and Theorem ., we obtain ∥A∥≤
⎧
⎨
⎩
nFnFn–+ n,
n odd,
nFnFn–,
n even. ∥A∥≤
⎧
⎨
⎩
nFnFn–+ n,
n odd,
nFnFn–,
n even. □ ∥A∥≤
⎧
⎨nFnFn–+ n,
n odd, □ He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 6 of 10 Corollary .Let A = Circ(FL,FL,...,Fn–Ln–) be circulant matrices, then Corollary .Let A = Circ(FL,FL,...,Fn–Ln–) be circulant matrices, then ∥A∥≤
⎧
⎨
⎩
√(n – )nFnFn–(FnFn–+ ),
n odd,
√(n – )nFnFn–,
n even, ∥A∥≤
⎧
⎨
⎩
√(n – )nFnFn–(FnFn–+ ),
n odd,
√(n – )nFnFn–,
n even, A∥≤
⎧
⎨√(n – )nFnFn–(FnFn–+ ),
n odd, where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. where ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci num-
bers, respectively. Proof Since A = Circ(FL,FL,...,Fn–Ln–) is a circulant matrix, if the matrices B =
Circ(F,F,...,Fn–) and C = Circ(L,L,...,Ln–), we get A = B ◦C; thus from (), The-
orems ., and ., we obtain ∥A∥≤
⎧
⎨
⎩
√(n – )nFnFn–(FnFn–+ ),
n odd,
√(n – )nFnFn–,
n even. □ □ Theorem .Let A = Circr(F,F,...,Fn–) be a r-circulant matrix, in which |r| ≥, and
then ∥A∥≤
(n – )|r|FnFn–, where r ∈C, ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Proof Since A = Circr(F,F,...,Fn–) is a r-circulant matrix, let B and C, respectively, be Proof Since A = Circr(F,F,...,Fn–) is a r-circulant matrix, let B and C, respectively, be B =
⎛
⎜⎜⎜⎜⎜⎜⎝
F
···
r
F
···
r
r
F
···
···
···
···
···
···
r
r
r
···
F
⎞
⎟⎟⎟⎟⎟⎟⎠
,
C =
⎛
⎜⎜⎜⎜⎜⎜⎝
F
F
F
···
Fn–
Fn–
F
F
···
Fn–
Fn–
Fn–
F
···
Fn–
···
···
···
···
···
F
F
F
···
F
⎞
⎟⎟⎟⎟⎟⎟⎠
, then A = B ◦C. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. For For r(B) = max
i
j
|bij|=
(n – )|r|
and r(B) = max
i
j
|bij|=
(n – )|r| and c(C) = max
j
i
|cij|=
n
i=
|cin|=
n–
s=
Fs =
FnFn–, from (), we have from (), we have □ ∥A∥≤
(n – )|r|FnFn–. He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 7 of 10 Corollary .Let A = SCircr(F,F,...,Fn–) be a symmetric r-circulant matrix, in which
|r| ≥, and then ∥A∥≤
(n – )|r|FnFn–, where r ∈C, ∥· ∥is the spectral norm and Fn denotes the nth Fibonacci number. Corollary .Let A = Circr(F
,F
,...,F
n–) be a r-circulant matrix, while |r| ≥, then
we obtain ∥A∥≤(n – )|r|FnFn–, where r ∈C, ∥· ∥is the spectral norm and Fn denotes the Fibonacci number. Proof Since A = Circr(F
,F
,...,F
n–) is a r-circulant matrix, if the matrices B = Circr(F,
F,...,Fn–) and C = Circ(F,F,...,Fn–), we get A = B ◦C; thus from (), Theorems .,
and ., we obtain ∥A∥≤(n – )|r|FnFn–. □ ∥A∥≤(n – )|r|FnFn–. □ Corollary .Let A = Circr(FL,FL,...,Fn–Ln–) be a r-circulant matrix, while
|r| ≥, then we obtain ∥A∥≤
⎧
⎨
⎩
(n – )n|r|FnFn–(FnFn–+ ),
n odd,
FnFn–
|r|(n – )n,
n even, ∥A∥≤
⎧
⎨
⎩
(n – )n|r|FnFn–(FnFn–+ ),
n odd,
FnFn–
|r|(n – )n,
n even, where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. Proof Since A = Circr(FL,FL,...,Fn–Ln–) is a r-circulant matrix, if the matrices B =
Circr(F,F,...,Fn–) and C = Circ(L,L,...,Ln–), we get A = B ◦C; thus from (), Theo-
rems ., and ., we obtain ∥A∥≤
⎧
⎨
⎩
(n – )n|r|FnFn–(FnFn–+ ),
n odd,
FnFn–
|r|(n – )n,
n even. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. □ □ Theorem .Let A = Circr(L,L,...,Ln–) be a r-circulant matrix and |r| ≥, then we
obtain Theorem .Let A = Circr(L,L,...,Ln–) be a r-circulant matrix and |r| ≥, then we
obtain ∥A∥≤
⎧
⎨
⎩
(n – )|r|+ × √FnFn–+ ,
n odd,
(n – )|r|+ × √FnFn–,
n even, where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. He et al. Journal of Inequalities and Applications ( 2015) 2015:72
Page 8 of 10 He et al. Journal of Inequalities and Applications ( 2015) 2015:72
Page 8 of 10 He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 8 of 10 Page 8 of 10 Proof Since A = Circr(L,L,...,Ln–) is a r-circulant matrix, let B and C, respectively, be Proof Since A = Circr(L,L,...,Ln–) is a r-circulant matrix, let B and C, respectively, be B =
⎛
⎜⎜⎜⎜⎜⎜⎝
···
r
···
r
r
···
···
···
···
···
···
r
r
r
···
⎞
⎟⎟⎟⎟⎟⎟⎠
,
C =
⎛
⎜⎜⎜⎜⎜⎜⎝
L
L
···
Ln–
Ln–
Ln–
L
···
Ln–
Ln–
···
···
···
···
···
L
L
···
L
L
L
L
···
Ln–
L
⎞
⎟⎟⎟⎟⎟⎟⎠
, and then A = B ◦C. We have and then A = B ◦C. We have and then A = B ◦C. We have and then A = B ◦C. and then A = B ◦C. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. Proof Since A = Circr(L
,L
,...,L
n–) is a r-circulant matrix, if the matrices B = Circ(L,L,
...,Ln–) and C = Circr(L,L,...,Ln–), we get A = B ◦C; thus from (), Theorems .,
and ., we obtain ∥A∥≤
⎧
⎨
⎩
(FnFn–+ )
n[(n – )|r|+ ],
n odd,
FnFn–
n[(n – )|r|+ ],
n even. □ □ ⎨
⎩FnFn–
n[(n – )|r|+ ],
n even. where ∥· ∥is the spectral norm and Ln denotes the Lucas number. We have We have r(B) = max
i
j
|bij|=
(n – )|r|+ and c(C) = max
j
i
|cij|=
n
i=
|cin|=
n–
s=
Ls =
n–
s=
(Fs + Fs–),
n which
n–
s=
F
s = FnFn–,
n–
s=
Fs–Fs =
⎧
⎨
⎩
F
n–,
n odd,
F
n–– ,
n even,
n–
s=
F
s–= Fn–Fn–+ , c(C) = max
j
i
|cij|=
n
i=
|cin|=
n–
s=
Ls =
n–
s=
(Fs + Fs–), in which n–
s=
F
s = FnFn–,
n–
s=
Fs–Fs =
⎧
⎨
⎩
F
n–,
n odd,
F
n–– ,
n even,
n–
s=
F
s–= Fn–Fn–+ , and we get and we get and we get c(C) =
⎧
⎨
⎩
√FnFn–+ ,
n odd,
√FnFn–,
n even. From (), we further infer From (), we further infer From (), we further infer From (), we further infer ∥A∥≤
⎧
⎨
⎩
(n – )|r|+ × √FnFn–+ ,
n odd,
(n – )|r|+ × √FnFn–,
n even. □ □ Corollary .Let A = SCircr(L,L,...,Ln–) be a symmetric r-circulant matrix and
|r| ≥, then we obtain ∥A∥≤
⎧
⎨
⎩
(n – )|r|+ × √FnFn–+ ,
n odd,
(n – )|r|+ × √FnFn–,
n even, where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. Corollary .Let A = Circr(L
,L
,...,L
n–) be a r-circulant matrix and |r| ≥, then ∥A∥≤
⎧
⎨
⎩
(FnFn–+ )
n[(n – )|r|+ ],
n odd,
FnFn–
n[(n – )|r|+ ],
n even, He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 9 of 10 where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. where r ∈C, ∥· ∥is the spectral norm, and Ln and Fn denote the nth Lucas and Fibonacci
numbers, respectively. 3 Examples Example Let A = Circ(F,F,...,Fn–) be a circulant matrix, in which Fi (i = ,,...,n–)
denotes the Fibonacci number. From Table , it is easy to find that the upper bounds for the spectral norm, of Theo-
rem .are more accurate than Theorem .when n ≥. Example Let A = Circ(L,L,...,Ln–) be a circulant matrix, where Li (i = ,,...,n – )
denotes the Lucas sequence. Let n ≥, and it is easy to find that the upper bounds for the spectral norm of Theo-
rem .are more accurate than Theorem .(see Table ). Example Let A = Circ(F,F,...,Fn–) be a -circulant matrix, in which Fi (i =
,,...,n – ) denotes the Fibonacci number. Let n ≥, and it is easy to find that the upper bounds for the spectral norm of Theo-
rem .are more precise than Theorem .(see Table ). Table 1 Numerical results of ai = Fi, r = 1
n
Theorem 2.1
Theorem 1.3
Third column
Second column
2
1
1
1
1 = 1
3
2
2
2
2 = 1
4
3
√
2
6
6
3
√
2 =
√
2
5
√
60
15
15
√
60 ≈1.936
6
√
200
40
40
√
200 = 2
√
2
n
√(n – 1)FnFn–1
FnFn–1
FnFn–1
√
(n–1)FnFn–1 =
FnFn–1
n–1 Table 1 Numerical results of ai = Fi, r = 1
n
Theorem 2.1
Theorem 1.3
Third column
Second column
2
1
1
1
1 = 1
3
2
2
2
2 = 1
4
3
√
2
6
6
3
√
2 =
√
2
5
√
60
15
15
√
60 ≈1.936
6
√
200
40
40
√
200 = 2
√
2
n
√(n – 1)FnFn–1
FnFn–1
FnFn–1
√
(n–1)FnFn–1 =
FnFn–1
n–1 Acknowledgements Acknowledgements
Project supported by Applied Fundamental Research Plan of Sichuan Province (No. 2013JY0178). Acknowledgements
Project supported by Applied Fundamental Research Plan of Sichuan Province (No. 2013JY0178). Received: 25 September 2014 Accepted: 12 February 2015 Received: 25 September 2014 Accepted: 12 February 2015 Table 4 Numerical results of ai = Li, r = 2 Table 4 Numerical results of ai = Li, r = 2
n
Theorem 2.12
Theorem 1.6
Third column
Second column
1
2
2
2
2 = 1
2
5
4
4
5 = 4
5
3
3
√
14
2
√
231
2
√
231
3
√
14 ≈2.708
4
√
390
54
54
√
390 ≈2.734
5
√1,343
152
152
√1,343 ≈4.418
6
10
√
42
394
394
10
√
342 ≈6.080 n
Theorem 2.12
Theorem 1.6
Third column
Second column
1
2
2
2
2 = 1
2
5
4
4
5 = 4
5
3
3
√
14
2
√
231
2
√
231
3
√
14 ≈2.708
4
√
390
54
54
√
390 ≈2.734
5
√1,343
152
152
√1,343 ≈4.418
6
10
√
42
394
394
10
√
342 ≈6.080 Example Let A = Circ(L,L,...,Ln–) be a -circulant matrix where Li (i = ,,...,
n – ) denotes the Lucas sequence. Example Let A = Circ(L,L,...,Ln–) be a -circulant matrix where Li (i = ,,...,
n – ) denotes the Lucas sequence. It can be seen from Table that the upper bounds for the spectral norm of Theorem .
are more precise than Theorem .when n ≥. It can be seen from Table that the upper bounds for the spectral norm of Theorem .
are more precise than Theorem .when n ≥. Competing interests Competing interests
The authors declare that they have no competing interests. Competing interests
The authors declare that they have no competing interests. Authors’ contributions
All authors contributed equally to the writing of this paper. All authors read and approved the final manuscript. Table 2 Numerical results of ai = Li, r = 1 n
Theorem 2.4
Theorem 1.4
Third column
Second column
1
2
2
2
2 = 1
2
√
10
√
10
√
10
√
10 = 1
3
√
42
√
154
√
154
√
42 ≈1.915
4
√
120
√
810
√
810
√
120 ≈2.598
5
√
395
√6,004
√6,004
√
395 ≈3.899
6
√1,200
√39,400
√39,400
√1,200 ≈5.730
n
n–1(5FnFn–1 + 1)
n odd,
n–1(5FnFn–1 – 3)
n even He et al. Journal of Inequalities and Applications ( 2015) 2015:72 Page 10 of 10 Table 3 Numerical results of ai = Fi, r = 2
n
Theorem 2.8
Theorem 1.5
Third column
Second column
2
2
2
2
2 = 1
3
4
4
4
4 = 1
4
6
√
2
12
12
6
√
2 =
√
2
5
4
√
15
√
30
30
4
√
15 ≈1.936
6
20
√
2
80
80
20
√
2 = 2
√
2
n
(n – 1)|r|2FnFn–1
|r|FnFn–1
(n – 1)–1FnFn–1 Table 4 Numerical results of ai = Li, r = 2 References References
1. Mathias, R: The spectral norm of a nonnegative matrix. Linear Algebra Appl. 131, 269-284 (1990) 1. Mathias, R: The spectral norm of a nonnegative matrix. Linear Algebra Appl. 131, 269-284 (1990) 1. Mathias, R: The spectral norm of a nonnegative matrix. Linear Algebra Appl. 131, 269 284 (1990)
2. Solak, S: On the norms of circulant matrices with the Fibonacci and Lucas numbers. Appl. Math. Comput. 160, 125-132
(2005) 2. Solak, S: On the norms of circulant matrices with the Fibonacci and Lucas numbers. Appl. Math. Comput. 160, 125-132
(2005)
3
Solak, S: Erratum to ‘On the norms of circulant matrices with the Fibonacci and Lucas numbers’ [Appl Math Comput ,
pp
p
,
(2005)
3. Solak, S: Erratum to ‘On the norms of circulant matrices with the Fibonacci and Lucas numbers’ [Appl. Math. Comput. 160 (2005) 125-132]. Appl. Math. Comput. 190, 1855-1856 (2007) (2005)
3. Solak, S: Erratum to ‘On the norms of circulant matrices with the Fibonacci and Lucas numbers’ [Appl. Math. Comput. 160 (2005) 125-132]. Appl. Math. Comput. 190, 1855-1856 (2007) pp
p
,
4. Shen, S, Cen, J: On the bounds for the norms of r-circulant matrices with the Fibonacci and Lucas numbers. Appl. Math. Comput. 216, 2891-2897 (2010) 5. Yazlik, Y, Taskara, N: On the norms of an r-circulant matrix with the generalized k-Horadam numbers. J. Inequal. Appl. 2013, 394 (2013) 6. Bozkurt, D, Tam, T-Y: Determinants and inverses of r-circulant matrices associated with a number sequence. Linear
Multilinear Algebra (2014). doi:10.1080/03081087.2014.941291
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https://openalex.org/W3211739109
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https://www.frontiersin.org/articles/10.3389/fimmu.2021.771826/pdf
|
English
| null |
Clostridium butyricum Alleviates Enterotoxigenic Escherichia coli K88-Induced Oxidative Damage Through Regulating the p62-Keap1-Nrf2 Signaling Pathway and Remodeling the Cecal Microbial Community
|
Frontiers in immunology
| 2,021
|
cc-by
| 11,468
|
ORIGINAL RESEARCH
published: 11 November 2021
doi: 10.3389/fimmu.2021.771826 ORIGINAL RESEARCH
published: 11 November 2021
doi: 10.3389/fimmu.2021.771826 Haihua Li 1, Zhiyuan Shang 2, Xuejiao Liu 1, Yingying Qiao 3,
Kewei Wang 2 and Jiayun Qiao 2* Edited by:
Hongkui Wei,
Huazhong Agricultural University,
China Edited by:
Hongkui Wei,
Huazhong Agricultural University,
China 1 Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary
Medicine, Tianjin Agricultural University, Tianjin, China, 2 Tianjin Key Laboratory of Animal and Plant Resistance, College of
Life Sciences, Tianjin Normal University, Tianjin, China, 3 Faculty of Biology and Technology, Sumy National Agrarian
University, Sumy, Ukraine Reviewed by:
Marie Van Der Merwe,
University of Memphis, United States
Xia Xiong,
Institute of Subtropical Agriculture
(CAS), China Reviewed by:
Marie Van Der Merwe,
University of Memphis, United States
Xia Xiong,
Institute of Subtropical Agriculture
(CAS), China Clostridium butyricum (CB) can enhance antioxidant capacity and alleviate oxidative
damage, but the molecular mechanism by which this occurs remains unclear. This
study used enterotoxigenic Escherichia coli (ETEC) K88 as a pathogenic model, and
the p62-Keap1-Nrf2 signaling pathway and intestinal microbiota as the starting point to
explore the mechanism through which CB alleviates oxidative damage. After pretreatment
with CB for 15 d, mice were challenged with ETEC K88 for 24 h. The results suggest that
CB pretreatment can dramatically reduce crypt depth (CD) and significantly increase villus
height (VH) and VH/CD in the jejunum of ETEC K88-infected mice and relieve
morphological lesions of the liver and jejunum. Additionally, compared with ETEC-
infected group, pretreatment with 4.4×106 CFU/mL CB can significantly reduce
malondialdehyde (MDA) level and dramatically increase superoxide dismutase (SOD)
and glutathione peroxidase (GSH-Px) levels in the serum. This pretreatment can also
greatly increase the mRNA expression levels of tight junction proteins and genes related to
the p62-Keap1-Nrf2 signaling pathway in the liver and jejunum in ETEC K88-infected
mice. Meanwhile, 16S rDNA amplicon sequencing revealed that Clostridium disporicum
was significantly enriched after ETEC K88 challenge relative to the control group, while
Lactobacillus was significantly enriched after 4.4×106 CFU/mL CB treatment. Furthermore, 4.4×106 CFU/mL CB pretreatment increased the short-chain fatty acid
(SCFA) contents in the cecum of ETEC K88-infected mice. Moreover, we found that *Correspondence:
Jiayun Qiao
skyqjy@tjnu.edu.cn *Correspondence:
Jiayun Qiao
skyqjy@tjnu.edu.cn Specialty section:
This article was submitted to
Nutritional Immunology,
a section of the journal
Frontiers in Immunology Specialty section:
This article was submitted to
Nutritional Immunology,
a section of the journal
Frontiers in Immunology
Received: 07 September 2021
Accepted: 28 October 2021
Published: 11 November 2021 Received: 07 September 2021
Accepted: 28 October 2021
Published: 11 November 2021 Abbreviations: CFU, Colony forming unit; PCR, Polymerase chain reaction;
MDA, Malondialdehyde; SOD, Superoxide dismutase; GSH-Px, Glutathione
peroxidase; qRT-PCR, Quantitative real-time polymerase chain reaction; ZO-1,
Zonula occludens-1; HO-1, Heme oxygenase-1; ROS, Reactive oxygen species;
RNS, Reactive nitrogen species; Nrf2, NF-E2-related factor 2; Keap1, Kelch-like
ECH-associated protein-1; ARE, Antioxidant response element; SCFAs, Short-
chain fatty acids; GAPDH, Glyceraldehyde-3-phosphate dehydrogenase; CTAB,
Cetyltrimethyl Ammonium Bromide; OTU, Operational taxonomic unit; VH,
Villus height; CD, Crypt depth; ATP, Adenosine triphosphate; LDA, Linear
discriminant analysis. INTRODUCTION response element (ARE) signaling pathway is a redox sensitive
signal system and can regulate the body in the redox state and
maintain the body stability. Nrf2 can respond to oxidative stress, is
an important transcription factor that regulates oxidative stress in
cells, and promotes the production of proteins involved in anti-
oxidativestress, thereby exertingan antioxidanteffect(10). Keap1is
a regulator of oxidative stress that combines with Nrf2 in the
cytoplasm to fix Nrf2 in the cytoplasm and combines with E3
ubiquitination ligase to promote the ubiquitination and
degradation of Nrf2. When the body is subjected to oxidative
stress, Keap1 is inactivated, inhibits the ubiquitination and
degradation of Nrf2, promotes Nrf2 accumulation, activates Nrf2,
enters the nucleus, binds with ARE, and induces transcription and
expression of downstream antioxidant enzyme genes to activate the
defense system and alleviate oxidative damage (11, 12). In addition,
the crossregulation between the Keap1-Nrf2 pathway and
autophagy can resist oxidative stress (12). p62 is a substrate and
active molecule involved in autophagy that can competitively bind
to Keap1 with Nrf2, promote Nrf2 nuclear transfer, activate the
Nrf2/AREsignaling pathway,andthenexert antioxidanteffectsand
maintain the body’s barrier function (11–13). And it has been
pointed out that intestinal microbiota and their metabolites are part
of the intestinal ecosystem, which together maintain the intestinal
health of humans and animals. The host provides colonization sites
for intestinal microbiota, and intestinal microbiota help the
intestine resist invasion by harmful substances, such as pathogens
(14).Intestinalmicrobiotacaninteractwiththehosttomaintainthe
integrity of the tissue morphology and barrier function and
promote intestinal health (14). Therefore, effective regulation of
p62-Keap1-Nrf2signalingpathwayandrestorationormaintenance
of intestinal microbiota may be an effective strategy to alleviate
ETEC K88-induced oxidative damage. Oxidative stress occurs when the production rate offree radicals in
the body [mainly reactive oxygen species (ROS) and reactive
nitrogen species (RNS)] exceeds the elimination rate of the body’s
antioxidant system, resulting in an imbalance in oxidant and
antioxidant effects (1). This induces lipid peroxide production,
cross-linking of DNA or RNA, oxidative impairment, and protein
configuration changes, which can cause dysfunction and diseases of
tissues and cells. Oxidative stress can occur in response to various
conditions. For example, when pathogens invade the animal body,
adenosine triphosphate (ATP) is produced through the electron
transport chain to provide immune response, but the body also
produces a large quantity of ROS, inducing oxidative stress (2, 3). Citation: Li H, Shang Z, Liu X, Qiao Y, Wang K
and Qiao J (2021) Clostridium
butyricum Alleviates Enterotoxigenic
Escherichia coli K88-Induced
Oxidative Damage Through Regulating
the p62-Keap1-Nrf2 Signaling
Pathway and Remodeling the Cecal
Microbial Community. Front. Immunol. 12:771826. doi: 10.3389/fimmu.2021.771826 November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org Li et al. CB Alleviates Oxidative Damage Lachnoclostridium, Roseburia, Lactobacillus, Terrisporobacter, Akkermansia, and
Bacteroides are closely related to SCFA contents and oxidative indicators. Taken
together, 4.4×106 CFU/mL CB pretreatment can alleviate ETEC K88-induced oxidative
damage through activating the p62-Keap1-Nrf2 signaling pathway and remodeling the
cecal microbiota community in mice. Lachnoclostridium, Roseburia, Lactobacillus, Terrisporobacter, Akkermansia, and
Bacteroides are closely related to SCFA contents and oxidative indicators. Taken
together, 4.4×106 CFU/mL CB pretreatment can alleviate ETEC K88-induced oxidative
damage through activating the p62-Keap1-Nrf2 signaling pathway and remodeling the
cecal microbiota community in mice. Keywords: Clostridium butyricum, enterotoxigenic Escherichia coli K88, oxidative damage, p62-Keap1-Nrf2
signaling pathway, cecal microbiota, mice Keywords: Clostridium butyricum, enterotoxigenic Escherichia coli K88, oxidative damage, p62-Keap1-Nrf2
signaling pathway, cecal microbiota, mice INTRODUCTION Additionally, when a pathogen is ingested, glycolysis is activated to
increase the consumption of molecular oxygen, which in turn
promotes the accumulation of ROS (2, 3). Enterotoxigenic
Escherichia coli (ETEC) K88 is a gram-negative bacterium with
adhesive flagella that can attach to intestinal epithelial cells (IECs),
promote secretion of pro-inflammatory factors by IECs, and cause
intestinal inflammation (4). After colonization, ETEC can produce
enterotoxins that damage intestinal epithelial cells, causing the
spread of pathogens to other organs, such as the spleen and liver
(5,6).Yacoubetal.(7)foundthatETECinfectionscanincreaseliver
enzyme levels, and induce reversible and irreversible liver damage. An important feature of ETEC infection is breakdown of the
oxidation/antioxidant balance accompanied by the appearance of
ROS (8). ROS, which are the main cause of impairment of normal
cells and tissues, have been shown to be an inevitable result of the
developmentofvariousdiseases.StudieshaveshownthatETECcan
promote the metabolism of methionine and cysteine, and produce
toxic homocysteine, which induces oxidative stress in the body (9). Therefore, ETEC can cause oxidative stress in the animal body. Accordingly, relieving oxidative stress has become a potential
method of reducing the symptoms of ETEC infection. Clostridium butyricum (CB)is a strict anaerobe that can resist
acid and tolerate high temperatures. This organism can colonize
the cecum and colon, and can produce beneficial substances
including a variety of digestive enzymes, vitamin B, and short-
chain fatty acids (SCFAs) in its metabolic process (15, 16). Zhao
et al. (17) found that CB can effectively reduce the inflammatory
response and epithelial barrier damage in Salmonella-infected
chickens through in vivo and in vitro studies. Similarly, our
previous study found that CB alleviated ETEC-induced
inflammatory responses in weaned piglets, and confirmed that
CB is a safe and effective feed additive (18). Additionally, studies
have reported that CB can alleviate oxidative damage (19, 20),
but its mechanism is still not very clear. Therefore, this study was
conducted to establish a pathogenic model for mice challenged Recent studies have shown that the Kelch-like ECH-associated
protein-1 (Keap1)-NF-E2-related factor 2 (Nrf2)/antioxidant November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 2 CB Alleviates Oxidative Damage Li et al. Li et al. Sample Collection and Processing Sample Collection and Processing
Blood was collected from the retrobulbar venous sinus of mice
and placed in ice for 2–3 h. Next, sera were obtained by
centrifugation at 7,000 rpm and 4°C for 20 min, after which
samples were stored at −20°C until determination of oxidation
indexes. After the blood was collected, the mice were sacrificed
by cervical dislocation (note that they were fasted for 12 h before
sacrifice, but they could drink freely before the blood was
collected). The liver and jejunum tissues were then taken
under aseptic conditions and divided into two parts. One part
was fixed in 4% paraformaldehyde and stored at room
temperature to be used for the observation of shape and
structure of tissue, while the other was put in a Ziplock bag
and then immediately placed into liquid nitrogen. Samples were
then moved to a −80°C freezer and stored until subsequent
determination of the mRNA expression levels of the target gene. The cecum contents were collected under aseptic conditions,
placed in a 1.5 mL centrifuge tube, and stored in a refrigerator at
−80°C until use for the determination of SCFAs and the
extraction of intestinal genomic DNA. Experiment 2 Effects of CB on Growth
Performance in Mice Forty-eight mice were randomly divided into three groups
[control group (CONT), low-dose group (L-CB), and high-
dose group (H-CB)], with sixteen replicates in each group. The
mice in the CONT group were gavaged with 0.2 mL normal
saline, while those in the L-CB group were gavaged with 0.2 mL
4.4 × 105 CFU/mL CB and those in the H-CB group were
gavaged with 0.2 ml 4.4 × 106 CFU/mL CB. All of the mice
were gavaged once daily at 13:00 for 15 d. The weight of the mice
was recorded on days 0, 7, and 14, after which the optimal
concentration of CB was selected. INTRODUCTION were gavaged with 0.2 mL normal saline on days 1-15 and with
0.2 mL 3.7 × 108 CFU/mL ETEC K88 on day 16; mice in the L-
CB group were gavaged with 0.2 mL 4.4 × 105 CFU/mL CB on
days 1-16; mice in the H-CB group were gavaged with 0.2 mL
4.4 × 106 CFU/mL CB on days 1-16; mice in the L-CB+H-ETEC
group were gavaged with 0.2 mL 4.4 × 105 CFU/mL CB on days
1–15 and with 0.2 mL 3.7 × 108 CFU/mL ETEC K88 on day 16;
mice in the H-CB+H-ETEC group were gavaged with 0.2 mL
4.4 × 106 CFU/mL CB on days 1–15 and 0.2 mL 3.7×108 CFU/
mL ETEC K88 on day 16. Six mice with similar body weight were
randomly selected and sacrificed in each group at 24 h after
ETEC K88 challenge. The morphological structures of the liver
and jejunum were observed, and the serum oxidation indexes
and mRNA expression levels of the tight junction proteins and
genes related to the p62-Keap1-Nrf2 signaling pathway in the
liver and jejunum were determined. with ETEC K88, and to analyze the molecular mechanism of CB
pretreatment in alleviating ETEC K88-induced oxidative damage
in mice based on the p62-Keap1-Nrf2 signaling pathway and
intestinal microbial community, in order to provide a basis for
the rational use of CB in feed. Experimental Materials CB was isolated from the feces of healthy piglets and its identity
confirmed based on colony morphology, Gram staining, and
sequencing of its 16S rDNA. ETEC K88 was obtained from the
Laboratory of College of Animal Science and Veterinary Medicine,
TianjinAgriculturalUniversity.LiveETECK88wasinoculatedinto
Luria–Bertani liquid medium and incubated at 37°C for 24 h. Live
CB was inoculated into Reinforced Clostridial Medium, a liquid
medium, and incubated at 37°C for 48 h. Bacteria liquid: glycerol
(1:1) was then stored in a refrigerator at −80°C for subsequent
experiments. CBandETECK88wereenumeratedonsolidmedium
before the experiment. Kunming mice were purchased from the
China National Institute for Food and Drug Control. Male
Kunming mice aged 9–10 weeks that were in good health and
weighed 22–25 g were selected for the experiment. Mice in the CONT, H-ETEC, H-CB and H-CB+H-ETEC
groups were selected for analysis of the microbial community
structure and its changes, and the contents of short-chain fatty
acids (SCFAs) were determined. The mouse cages were disinfected before the test, and mice were
allowedtoadapttotheenvironmentfor3d.Duringtheexperiment,
all mice were allowed to drink and eat freely, and the temperature
and humidity were controlled within ranges of 18–22°C and 50–
60%, respectively; moreover, there was a 12 h light/dark cycle, and
good ventilation was maintained. The maintenance feed for mice
was purchased from Beijing Keao Xieli Feed Co, Ltd (Beijing,
China). The composition of the feed ingredients: corn, soybean
meal, fish power, flour, bran, NaCl, calcium hydrogen phosphate,
stone powder, a variety of vitamins, a variety of trace elements,
amino acids, etc. The guaranteed values for product composition
analysis are shown in Table S1 (Supplementary Material). Experimental Designs Experiment 1 Establishment of ETEC disease model
Forty-eight mice were randomly divided into three groups
[control group (CONT), low-dose group (L-ETEC), and high-
dose group (H-ETEC)], with sixteen replicates in each group. The mice in the CONT group were gavaged with 0.2 mL normal
saline, while those in the L-ETEC group were gavaged with 0.2
mL 3.7 × 107 CFU/mL ETEC K88 and those in the H-ETEC
group were gavaged with 0.2 mL 3.7 × 108 CFU/mL ETEC K88. After 24 h, six mice with similar body weights were randomly
selected and sacrificed in each group, and their serum
antioxidant indexes were detected. The optimal concentration
of the ETEC disease model was then selected. Observation of Tissue Histopathology Ninety-six mice were randomly divided into 6 groups, with 16
mice in each group. Mice in the CONT group were gavaged with
0.2 mL normal saline on days 1-16; mice in the H-ETEC group Mice liver and jejunum tissues were fixed in 4% paraformaldehyde
for at least 48 h at room temperature. After dehydration in the November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 3 CB Alleviates Oxidative Damage Li et al. Li et al. extracted with TRIzol reagent (Takara Biotechnology, Dalian,
China) according to the manufacturer’s instructions. Following
reverse transcription of RNA into cDNA, qPCR was performed
using the primers shown in Table 1. Among them, p62 and Nrf2
specificprimersweredesignedusingprimer5andthefullsequences
of their genes obtained from NCBI. p62, Nrf2, Heme oxygenase-1
(HO-1) (22), GSH-Px (23), SOD1 (24), SOD2 (22), claudin 1 (25),
claudin 8 (26), occludin (27), and zonula occludens-1 (ZO-1) (25)
mRNA expression levels were measured using LightCycler® 480
real-time PCR and calculated based on 2-DDCt. Data are shown as
ratios of abundance of target gene transcripts in the treated mice to
those in the control group after normalization to Glyceraldehyde-3-
phosphate dehydrogenase (GAPDH) (25). Kits for nucleic acid
extraction, reverse transcription, and qRT-PCR were purchased
from GeneCopoeia (Rockville, USA). different concentrations of ethanol, the tissues were transparent
with xylene, embedded in paraffin wax and then sectioned. Paraffin
section (thickness usually 3-5 mm) were stained with hematoxylin
and eosin (H&E) for routine examination. Some main steps were
described below. First, the paraffin sections were dewaxed with
xylene, hydrated with different concentrations of ethanol and
washed with distilled water. Second, the sections were incubated
in hematoxylin and eosin solution, and rinsed with distilled water. Third, the sections were dehydrated, and ethanol was removed with
xylene. Finally, the sections were sealed by neutral balsam, and
observed using an ECHO Revolve Hybrid microscope. Additionally, the ECHO app was used to measure villus
height (VH) and crypt depth (CD) in the jejunum tissue. The
VH was measured from the villus tip to the bottom. The CD was
measured from the crypt tip to the bottom. An average of twelve
villi and crypts was expressed as a mean VH and CD for
each mouse. Detection of Serum Oxidation Indices After the collected samples were thawed, the genomic DNA of
the mice ceca was extracted by the cetyltrimethyl ammonium
bromide (CTAB) method, then stored in the refrigerator at low
temperature (−20°C) until further PCR amplification
and sequencing. The content of malondialdehyde (MDA) in the serum was
determined by the TBA colorimetric method, the content of
superoxide dismutase (SOD) in the serum was determined by the
xanthineoxidasemethod,andthecontentofglutathioneperoxidase
(GSH-Px)inthe serum was determined byvisible light colorimetry. The MDA, SOD and GSH-Px assay kits were purchased from
Nanjing Jiancheng Biology Engineering Institute (Nanjing, China). Specific testing methods referred to Sun et al. (21). The following 16S rRNA gene primers were used to amplify the
16S rRNA gene V3-V4 region of cecum microbiota: 341F: 5’-
CCTAYGGGRBGCASCAG; 806R: 5’-GGACTACNNG
GGTATCTAAT-3’. Following amplification, 2% agarose gel
electrophoresis was used to detect the purity and concentration
of the extracted genomic DNA. PCR products were then purified
and recovered with a PCR extraction kit for quantitative
determination (QIAGEN, Germany). Finally, the amplified PCR
products were sequenced on the Illumina NovaSeq 6000 platform F, shows forward primer; R, shows reverse primer. Statistical Analysis SPSS 22.0 was used to perform one-way ANOVA of the growth
performance, oxidation index, relative gene expression, and cecal
short-chain fatty acids of mice in different groups, with Duncan’s
and LSD method used to identify significant differences among
groups. For nonparametric data, Mann-Whitney U test
was performed. p
gy
As shown in Figures 2A–F, the liver structure was normal with
orderly arranged-hepatic in the CONT, L-CB and H-CB groups. In the liver of mice in H-ETEC group, a large number of
inflammatory cells gathered around the vessels (red arrows), or
inflammatory cells (blue arrows) dispersed in the vessels and
hepatic sinuses, and the hepatic sinusoidal space was slightly
enlarged. In the L-CB+H-ETEC and H-CB+H-ETEC groups,
inflammatory cells diffused in the hepatic sinus space, and there
was no large accumulation of inflammatory cells. Taken together,
these results indicated that CB pretreatment can alleviate liver
damage caused by ETEC K88 challenge. Flash V1.2.7 (28) was used to splice the sample reads after the
primer and barcode sequences to give sequences, which were
then filtered and analyzed using QIIME V1.9.1. Next, Uparse
v7.0.1001 (29) was used to cluster the sequences, with those
having more than 97% similarity being considered the same
operational taxonomic unit (OTU). Each OTU sequence was
subsequently extracted and annotated using Mothur and the
SSUrRNA database (30) of SILVA132 (31). As shown in Figures 2G–L, jejunal villi were arranged neatly
in the CONT, L-CB and H-CB groups, while in the H-ETEC
group, the jejunal villi became shorter, the number of
inflammatory cells in villi increased, intestinal epithelial cells
separated from lamina propria, and even fell off in intestinal
cavity. The degree of separation and abscission of epithelial cells
from lamina propria were alleviated to a certain extent in L-CB+
H-ETEC and H-CB+H-ETEC groups. Taken together, these
results indicated that CB pretreatment can alleviate ETEC
K88-induced jejunum tissue lesions. QIIME (version 1.9.1) was used to conduct a-diversity
analysis (including ACE, Shannon, Coverage, Chao1) for
OTUs with similarity levels greater than 97%. R (version
2.15.3) was then used to make species composition histograms
and linear discriminant analysis (LDA) distribution histograms
based on the OTUs abundance information to visually
characterize the similarities and differences in bacterial
community composition. RESULTS by Beijing Novogene Biology Information Technology Co., Ltd
(Beijing, China). All raw data have been deposited in NCBI
BioProject (accession number: PRJNA765776). Optimization of ETEC K88 and CB Doses
As shown in Figures 1A–C, after ETEC K88 challenge, the MDA
level in the serum was significantly higher than that of the CONT
group (all p < 0.001), especially in the H-ETEC group. The SOD
and GSH-Px levels in the serum in the H-ETEC group were
significantly lower than those in the CONT (all p < 0.001) and L-
ETEC groups (all p < 0.001). Based on the obtained results,
3.7×108 CFU/mL was selected as the optimal concentration for
the ETEC K88 pathogenic model. Quantitative Real-Time Polymerase Chain
Reaction (qRT-PCR) After the frozen liver and jejunum tissues of mice were
homogenized in liquid nitrogen, the RNA in the tissues was TABLE 1 | Primer sequences information. Gene names
Primer sequence/(5’!3’)
Product length/bp
Annealing temperature/°C
GenBank accession number
p62
F: CAACTGTTCAGGAGGAGACGA
R: CTGGTGGCAGATGTGGGTA
179
62
XM_036156414.1
Nrf2
F: CAGTGCTCCTATGCGTGAA
R: GCGGCTTGAATGTTTGTC
109
56
NM_010902.4
HO-1
F: CAAGGAGGTACACATCCAAGCC
R: TACAAGGAAGCCATCACCAGCT
102
56
NM_010442.2
GSH-Px
F: GAAGTGCGAAGTGAATGG
R: TGTCGATGGTACGAAAGC
224
56
X03920.1
SOD1
F: AACCAGTTGTGTTGTGAGGAC
R: CCACCATGTTTCTTAGAGTGAGG
139
56
NM_011434.2
SOD2
F: ACGCCACCGAGGAGAAGTACC
R: CGCTTGATAGCCTCCAGCAACTC
181
62
NM_013671.3
Claudin 1
F: GAGTCTCCGGTGCATCATTT
R: CAGCTTGCTAGGGAACTTGG
143
56
NM_001379248.1
Claudin 8
F: GTGCTGCGTCCGTCTTGGCT
R: TCGTCCCCCGTGCATCTGGT
79
62
NM_018778.3
Occludin
F: CCTTCTGCTTCATCGCTTCCTTA
R: CGTCGGGTTCACTCCCATTAT
164
56
NM_001360538.1
ZO-1
F: GGGAGGGTCAAATGAAGACA
R: GGCATTCCTGCTGGTTACAT
145
56
XM_036152895.1
GAPDH
F: GCACAGTCAAGGCCGAGAAT
R: GCCTTCTCCATGGTGGTGAA
151
56/62
XM_036165840.1
F, shows forward primer; R, shows reverse primer. TABLE 1 | Primer sequences information. November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org CB Alleviates Oxidative Damage Li et al. Detection of Short-Chain Fatty
Acids (SCFAs) After the collected samples were thawed, about 0.5 g of the cecal
content was put into 1.5 mL centrifuge tubes. Next, 1.25 mL of
ultrapure water was added, after which the samples were
vortexed for 3–5 min. Samples were subsequently centrifuged
at 5,000 rpm for 10 min, after which 1.5 mL of the supernatant
was collected and placed in a centrifuge. To the tubes, 0.2 mL of
25% metaphosphoric acid solution was added at a ratio of 5: 1. Samples were subsequently shaken well, placed in an ice-water
bath for 30 min, then centrifuged for 10 min at 10,000 rpm at 4°C
for 10 min. The supernatant was then collected, after which the
contents of butyrate, acetate, propionate and total SCFAs in the
cecum contents were determined by gas chromatography
(Agilent 7890B). Gas chromatographic conditions were
described below. The separation was performed on a DB-FFAP
(30 m × 0.25 mm × 0.25 mm) column. The injector temperatures
were 220°C, and the carrier gas (nitrogen) was injected at a rate
of 1.0 mL/min. The detector temperatures were 250°C. The
initial temperature was 100°C and the temperature was risen at
30°C per minute for 6 min. p
g
As shown in Figures 1D, E, the average body weight of mice
in the H-CB group was significantly higher than that of mice in
the CONT (day 7 p = 0.038, day 14 p = 0.003) and L-CB groups
(day 7 p = 0.012, day 14 p = 0.013) on day 7 and day 14. On days
0–7, the average daily weight gain of mice in the L-CB and H-CB
groups was significantly higher than that in the CONT group
(p = 0.017 and p < 0.001 respectively), and that the effects in the
H-CB group were more obvious (p < 0.001). On days 7–14, the
average daily gain of mice in the CONT group was significantly
lower than that in the L-CB and H-CB groups (all p < 0.001). But
based on the above body weight results, we are still not sure
which concentration of CB has a better therapeutic effect on
oxidative damage in mice. Therefore, 4.4 × 105 CFU/mL and
4.4×106 CFU/mL CB were used for subsequent experiments. Frontiers in Immunology | www.frontiersin.org Statistical Analysis As shown in Figure 3 and Table S2 (Supplementary
material), when compared with the CONT group, ETEC K88
treatment alone could significantly increase crypt depth, reduce
the jejunal villus height and VH/CD ratio (p = 0.031, p < 0.001
and p < 0.001, respectively). In addition, the jejunal villus height
(p = 0.043 and p < 0.001, respectively) and VH/CD ratio (p =
0.043 and p < 0.001, respectively) showed significant changes Spearman’s correlation values of species, oxidative stress
indices, and SCFA contents were calculated using the psych
package in R, and their significance was tested to identify mutual
relationships between the oxidative stress index, SCFA contents,
and microbial species richness (alpha diversity). The top 20
species based on abundance at the genus level were chosen for
correlation analysis. November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 5 Li et al. CB Alleviates Oxidative Damage A
B
D
E
C
FIGURE 1 | Effects of different levels of ETEC on (A) MDA, (B) SOD, and (C) GSH-Px in the serum of mice (n = 6 mice per group). Effects of different levels of CB
on (D) body weight and (E) average daily gain of mice (n = 16 mice per group). Values shown are the means ± SEM. Different small letters indicate significant
differences (p < 0.05). A
B
C D E E D FIGURE 1 | Effects of different levels of ETEC on (A) MDA, (B) SOD, and (C) GSH-Px in the serum of mice (n = 6 mice per group). Effects of different levels of CB
on (D) body weight and (E) average daily gain of mice (n = 16 mice per group). Values shown are the means ± SEM. Different small letters indicate significant
differences (p < 0.05). after treatment with CB alone. When compared with the H-
ETEC group, co-treatment with CB and ETEC K88 dramatically
decreased crypt depth (p = 0.047 and p < 0.001, respectively) and
significantly increased the villus height and VH/CD (all
p < 0.001). FIGURE 2 | Effects of CB and/or ETEC K88 on observation of tissular
morphology. (A–F) hematoxylin-eosin staining in the liver of mice. (A) CONT,
(B) H-ETEC, (C) L-CB, (D) H-CB, (E) L-CB+H-ETEC, (F) H-CB+H-ETEC;
(G–L) hematoxylin-eosin staining in the jejunum of mice. (G) CONT, (H) H-ETEC,
(I) L-CB, (J) H-CB, (K) L-CB+H-ETEC, (L) H-CB+H-ETEC. Bar = 100 mm. CB Helps to Maintains the Soundness of
Barrier Function in Mice As shown in Figures 4A–D, following treatment with CB alone,
the mRNA expression level of claudin 1 in the liver increased
significantly (all p < 0.001). Additionally, the mRNA expression
levels of occludin in the liver changed significantly after
treatment with 4.4 × 106 CFU/mL CB (p < 0.001). Following
challenge with 3.7 × 108 CFU/mL ETEC K88, the mRNA
expression levels of claudin 1 and occludin in the liver did not
change significantly (p = 0.815 and p = 0.210, respectively), while
the mRNA expression levels of claudin 8 and ZO-1 in the liver
were significantly reduced (all p < 0.001). CB pretreatment
reversed the downregulation of claudin 8 and ZO-1 mRNA
expression induced by ETEC K88 in a dose-dependent
manner, further promoted the expression of claudin 1 and
occludin at the transcriptional level in the liver. As shown in
Figures 4E–H, when compared with the CONT group, the
mRNA expression levels of claudin 1 in the jejunum did not
change significantly (p = 0.939), the mRNA expression level of
claudin 8 in the jejunum was significantly increased (p = 0.008),
and the mRNA expression level of ZO-1 and occludin in the
jejunum was significantly decreased (p = 0.045 and p = 0.036,
respectively) in the H-ETEC group. Additionally, in the L-CB
and H-CB groups, the mRNA expression level of claudin 1,
claudin 8, occludin, and ZO-1 in the jejunum increased
significantly (all p < 0.001). When compared with the H-ETEC
group, the mRNA expression levels of claudin 8 (p = 0.002 and FIGURE 2 | Effects of CB and/or ETEC K88 on observation of tissular
morphology. (A–F) hematoxylin-eosin staining in the liver of mice. (A) CONT,
(B) H-ETEC, (C) L-CB, (D) H-CB, (E) L-CB+H-ETEC, (F) H-CB+H-ETEC;
(G–L) hematoxylin-eosin staining in the jejunum of mice. (G) CONT, (H) H-ETEC,
(I) L-CB, (J) H-CB, (K) L-CB+H-ETEC, (L) H-CB+H-ETEC. Bar = 100 mm. November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 6 Li et al. Li et al. CB Alleviates Oxidative Damage A
B
C
FIGURE 3 | Effect of CB and/or ETEC K88 on the jejunal form of mice. (A) villus height, (B) crypt depth, (C) VH/CD (n = 6 mice per group, n =12 villi and crypts per
mouse). Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). CB Helps to Protect Mice Against ETEC
K88-Induced Oxidative Damage Through
Regulation of the p62-Keap1-Nrf2
Signaling Pathway PCR amplification and sequencing were performed on the 16S
rDNA V3-V4 region of the genomic DNA of the cecal contents. After obtaining the raw tags of 12 samples and performing
splicing, quality control, and filtering to remove the chimera, a
total of 47,918 ± 2,940 effective tags, 19,785,811 ± 1,224,633 bp
bases, and a 413 bp AvgLen (average length of effective tags) were
obtained. Based on the minimum number of sample sequences
and clustering the OTUs at 97% similarity, a total of 1296 OTUs
were obtained, including 1 kingdom, 13 phyla, 21 classes, 43
orders, 72 families, 158 genera, and 141 species. As shown in Figures 5A–C, after treatment with CB alone, the
MDA level in the serum did not differ significantly from that of
the CONT group (p = 0.960 and p = 0.468, respectively), while
the SOD and GSH-Px levels had increased significantly (all p <
0.001). Additionally, the MDA level in the H-ETEC group was
significantly increased relative to the CONT group (p < 0.001),
while the SOD and GSH-Px levels were significantly decreased
(all p < 0.001). However, CB pretreatment significantly reduced
MDA levels and increased SOD and GSH-Px levels in the serum
in a dose-dependent manner in ETEC K88-infected mice, and
4.4 × 106 CFU/mL CB significantly interfered with ETEC K88-
induced oxidative damage in mice. g
p
As shown in Figure 6A, the ACE and Chao1 indexes did not
differ significantly among the four groups (p = 0.887), indicating
that there was no significant difference in the abundance of cecal
bacteria among treatment groups. Additionally, the coverage was
around 0.99, indicating that the sequencing results fully reflected
the actual situation of the microbiota. The Shannon’s index of
the H-ETEC, H-CB, and H-CB+H-ETEC groups was lower than
that of the CONT group, and there was a significant difference
between the H-CB+H-ETEC group and CONT group (p =
0.021), indicating that the diversity of the bacterial community
tended to decrease in ceca treated with ETEC K88 and CB. At the
phylum level, the top 10 species in terms of relative abundance
were selected. The mean value of abundance was then used to
calculate the proportion of each bacterial group in the samples of
the four groups, and relative abundance histograms of the species
were made (Figure 6B). CB Helps to Protect Mice Against ETEC
K88-Induced Oxidative Damage Through
Regulation of the p62-Keap1-Nrf2
Signaling Pathway The results showed that Firmicutes and
Bacteroidetes were the dominant phyla in all groups, and that
there were no significant differences in relative abundance (p =
0.648 and p = 0.646, respectively). However, the Firmicutes/
Bacteroidetes ratio in the H-CB group was significantly higher
than that in the other three groups (p = 0.003, p = 0.011 and p =
0.010, respectively). To determine the specific cecal microbiota in
the different treatment groups, the LDA score was set at 4 at the
phylum-to-species classification level, LEfSe multi-level species
difference discriminant analysis was performed, and an
LDA distribution histogram was made (Figures 7A–D). Mice in the H-ETEC group showed lower abundance
of Bacillales, Staphylococcaceae, Staphylococcus, and
Staphylococcus_lentus than in the H-CB group (Figure 7A),
whereas unidentified_Clostridiales, unidentified_Clostridiales,
and Clostridium_disporicum in the H-ETEC group exhibited
higher abundance than in the CONT group (Figure 7B). Additionally, mice treated with 4.4 × 106 CFU/mL CB showed As shown in Figures 5D–I, the mRNA expression level of
SOD2 in the liver was significantly reduced in the H-ETEC group
compared to the CONT group (p = 0.012). In the L-CB and H-
CB group, the mRNA expression levels of Nrf2 (p = 0.001 and p <
0.001, respectively), GSH-Px (p = 0.005 and p = 0.001,
respectively), SOD1 (p = 0.014 and p = 0.018, respectively),
and SOD2 (p = 0.018 and p < 0.001, respectively) in the liver were
significantly increased compared to the CONT group. In
addition, compared to the CONT group, the mRNA expression
levels of p62 and HO-1 in the liver were significantly increased in
the H-CB group (p = 0.008 and p = 0.007, respectively). When
compared with the H-ETEC group, the mRNA expression levels
of p62 (all p < 0.001), Nrf2 (all p < 0.001), HO-1 (p = 0.024 and
p < 0.001, respectively), GSH-Px (all p < 0.001), SOD1 (all p <
0.001), and SOD2 (p = 0.033 and p < 0.001, respectively) in the
liver were significantly increased in the L-CB+H-ETEC and H-
CB+H-ETEC groups in a dose-dependent fashion. As shown in
Figures 5J–O, the mRNA expression levels of p62, Nrf2, HO-1,
GSH-Px, SOD1, and SOD2 in the jejunum were significantly
decreased in the H-ETEC group when compared with the CONT
group (p = 0.009, p = 0.002, p = 0.012, p = 0.043, p = 0.018 and
p = 0.035, respectively). CB Helps to Maintains the Soundness of
Barrier Function in Mice Taken together, these results indicated that 4.4 × 106
CFU/mL CB pretreatment can reverse the downregulation
expression of tight junction proteins (claudin 1, claudin 8,
occludin, and ZO-1) at the transcriptional level in the liver
and jejunum. they did show an upward trend. Furthermore, co-treatment with
4.4 × 106 CFU/mL CB and ETEC K88 significantly increased the
p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2 mRNA expression
levels in the jejunum when compared with the H-ETEC group
(all p < 0.001). Taken together, these results indicate that CB
pretreatment can increase the mRNA expression of p62, Nrf2,
HO-1, GSH-Px, SOD1, and SOD2 in the liver and jejunum of
ETEC K88-infected mice in a dose-dependent manner. CB Helps to Maintains the Soundness of
Barrier Function in Mice FIGURE 3 | Effect of CB and/or ETEC K88 on the jejunal form of mice. (A) villus height, (B) crypt depth, (C) VH/CD (n = 6 mice per group, n =12 villi and crypts per
mouse). Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). A
B
D
E
F
G
H
C
FIGURE 4 | Effects of CB and/or ETEC K88 on the mRNA expression levels of tight junction proteins. (A–D) The mRNA expression levels of claudin 1, claudin 8,
occludin, and ZO-1 in the livers of mice were measured by qRT-PCR (n = 6 mice per group). (E–H) The expression of claudin 1, claudin 8, occludin, and ZO-1 in the
jejunum of mice was measured by qRT-PCR (n = 6 mice per group). Data are shown as the ratios of abundance of target gene transcripts in treated mice to those in
control mice after normalization to GAPDH. Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). A B D D C E E F H G H H G FIGURE 4 | Effects of CB and/or ETEC K88 on the mRNA expression levels of tight junction proteins. (A–D) The mRNA expression levels of claudin 1, claudin 8,
occludin, and ZO-1 in the livers of mice were measured by qRT-PCR (n = 6 mice per group). (E–H) The expression of claudin 1, claudin 8, occludin, and ZO-1 in the
jejunum of mice was measured by qRT-PCR (n = 6 mice per group). Data are shown as the ratios of abundance of target gene transcripts in treated mice to those in
control mice after normalization to GAPDH. Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 7 CB Alleviates Oxidative Damage Li et al. Li et al. p< 0.001, respectively), occludin (p = 0.033 and p < 0.001,
respectively), and ZO-1 (p = 0.015 and p < 0.001, respectively)
in the jejunum were significantly increased in the L-CB+H-
ETEC and H-CB+H-ETEC groups. Additionally, the mRNA
expression level of claudin 1 in the jejunum in the H-CB+H-
ETEC group was significantly higher than that in H-ETEC group
(p < 0.001). CB Helps to Protect Mice Against ETEC
K88-Induced Oxidative Damage Through
Regulation of the p62-Keap1-Nrf2
Signaling Pathway When compared with the H-ETEC
group, co-treatment with 4.4 × 105 CFU/mL CB and ETEC
K88 significantly increased the p62, Nrf2 and GSH-Px mRNA
expression levels in the jejunum (p = 0.048, p = 0.020, and p =
0.035, respectively). Additionally, although HO-1, SOD1, and
SOD2 mRNA expression levels in the jejunum did not change
significantly (p = 0.912, p = 0.068, and p = 0.867, respectively), November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 8 Li et al. CB Alleviates Oxidative Damage A
B
D
E
F
G
I
H
J
K
L
M
N
C
O
FIGURE 5 | Effects of CB and/or ETEC K88 on the levels of MDA, SOD, GSH-Px, p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2 in mice. (A–C) The levels of MDA,
SOD, and GSH-Px in the serum of mice were measured (n = 6 mice per group). (D–I) The mRNA expression levels of p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2
in the livers of mice were measured by qRT-PCR (n = 6 mice per group). (J–O) The mRNA expression levels of p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2 in the
livers of mice were measured by qRT-PCR (n = 6 mice per group). Data are shown as ratios of abundance of target gene transcripts in the treated mice to those in
the control mice after normalization to GAPDH. Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). D E
F G
I
H J
K
L J M M N O O FIGURE 5 | Effects of CB and/or ETEC K88 on the levels of MDA, SOD, GSH-Px, p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2 in mice. (A–C) The levels of MDA,
SOD, and GSH-Px in the serum of mice were measured (n = 6 mice per group). (D–I) The mRNA expression levels of p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2
in the livers of mice were measured by qRT-PCR (n = 6 mice per group). (J–O) The mRNA expression levels of p62, Nrf2, HO-1, GSH-Px, SOD1, and SOD2 in the
livers of mice were measured by qRT-PCR (n = 6 mice per group). Data are shown as ratios of abundance of target gene transcripts in the treated mice to those in
the control mice after normalization to GAPDH. Values shown are the means ± SEM. Frontiers in Immunology | www.frontiersin.org CB Helps to Protect Mice Against ETEC
K88-Induced Oxidative Damage Through
Regulation of the p62-Keap1-Nrf2
Signaling Pathway Different small letters indicate significant differences (p < 0.05). higher levels of Bacilli, Lactobacillales, Lactobacillaceae,
Lactobacillus, Bacillales, Staphylococcaceae, and Staphylococcus
than in the CONT and H-CB+H-ETEC groups, whereas
unidentified_Lachnospiraceae, Bacteroidetes, Bacteroidia, and
Bacteroidales in the H-CB group showed lower abundance
than the CONT group (Figures 7C, D). 0.369 and p = 0.328, respectively), propionate (p = 0.124 and P =
0.192, respectively), butyrate (p = 0.374 and P = 0.478,
respectively), and total SCFAs (p = 0.082 and p = 0.209,
respectively) in the H-CB+H-ETEC group were not
significantly different compared with those in the CONT and
H-ETEC groups, but the concentrations tended to increase
compared with the H-ETEC group. These findings indicated
that CB pretreatment can increase the concentrations of SCFAs
in the cecum of ETEC K88-infected mice to a certain extent. As shown in Figure 8, the concentrations of propionate (p =
0.014) and total SCFAs (p = 0.010) in the H-ETEC group were
significantly lower than those in the CONT group. When
compared with the CONT group, there were no significant
differences in the concentrations of acetate (p = 0.211),
propionate (p = 0.602), butyrate (p = 0.107), and total SCFAs
(p = 0.238) in the H-CB group. The concentrations of acetate (p = Spearman’s correlation was used to analyze the oxidation
indicators (MDA, SOD, GSH-Px), SCFAs, and microbiota to
evaluate the correlation between ETEC K88-induced oxidative
stress and changes in the intestinal microbiota and their November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 9 Li et al. CB Alleviates Oxidative Damage A
B
A
B
A
B
FIGURE 6 | Effects of CB and/or ETEC K88 on the cecal microbial community structure. (A) Alpha diversity of cecal microbiota in mice (n = 3 mice per group). (B) Relative abundance of cecal microbiota of mice in different groups at the phylum level (n = 3 mice per group). Values shown are the means ± SEM. Different small
letters indicate significant differences (p < 0.05). BBB AA FIGURE 6 | Effects of CB and/or ETEC K88 on the cecal microbial community structure. (A) Alpha diversity of cecal microbiota in mice (n = 3 mice per group). (B) Relative abundance of cecal microbiota of mice in different groups at the phylum level (n = 3 mice per group). Values shown are the means ± SEM. Different small
letters indicate significant differences (p < 0.05). CB Helps to Protect Mice Against ETEC
K88-Induced Oxidative Damage Through
Regulation of the p62-Keap1-Nrf2
Signaling Pathway A
B
D
C
FIGURE 7 | Identification of specific microbial communities under CB and/or ETEC K88. Different bacteria communities from the phylum to species level were
evaluated by linear discriminant analysis coupled with effect size (LEfSe). (A) Among four different groups, (B) between CONT and H-ETEC groups, (C) between
CONT and H-CB groups, and (D) among CONT, H-CB and H-CB+H-ETEC groups (n = 3 mice per group). A A B A B
D C C D C FIGURE 7 | Identification of specific microbial communities under CB and/or ETEC K88. Different bacteria communities from the phylum to species level were
evaluated by linear discriminant analysis coupled with effect size (LEfSe). (A) Among four different groups, (B) between CONT and H-ETEC groups, (C) between
CONT and H-CB groups, and (D) among CONT, H-CB and H-CB+H-ETEC groups (n = 3 mice per group). metabolites (Figures 9A, B). As shown in Figure 9A, Roseburia
was significantly positively correlated with acetate and
propionate (p = 0.027 and p = 0.048, respectively), while
Lachnoclostridium was significantly positively correlated with
SCFA contents (p = 0.032, p < 0.001, p = 0.032 and p = 0.002,
respectively). Terrisporobacter was found to have a significant
negative correlation with propionate and total short-chain fatty
acids (p = 0.011 and p = 0.042, respectively). As shown in
Figure 9B, Lachnoclostridium had a significant negative
correlation with MDA (p = 0.010) and a significant positive
correlation with SOD (p = 0.006). In addition, Bacteroides was
significantly negatively correlated with GSH-Px and SOD (p <
0.001 and p = 0.011, respectively), Lactobacillus was positively
correlated with SOD (p = 0.033), and Akkermansia was positively correlated with GSH-Px (p = 0.033). It should be noted that
Lachnoclostridium, Lactobacillus, and Roseburia all belong to
Lachnospiraceae. Taken together, these results indicate that a
positive effect of CB pretreatment on ETEC K88-infected mice
may be achieved by increasing the abundance of Lactobacillus
and the contents of SCFAs. DISCUSSION In the animal body, when the oxidative and antioxidant balance
is disturbed by a pathogen infection, oxidative stress will occur
(32). The integrity of tissue morphology and barrier function is
one of the most important indicators used to evaluate the health November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 10 Li et al. CB Alleviates Oxidative Damage A
B
D
C
FIGURE 8 | Effects of CB and/or ETEC K88 on (A) acetate, (B) propionate, (C) butyrate and (D) total short-chain fatty acids in the cecum of mice (n = 3 mice per
group). Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). A B B C D C FIGURE 8 | Effects of CB and/or ETEC K88 on (A) acetate, (B) propionate, (C) butyrate and (D) total short-chain fatty acids in the cecum of mice (n = 3 mice per
group). Values shown are the means ± SEM. Different small letters indicate significant differences (p < 0.05). A
B
FIGURE 9 | Correlation among cecal microbiota, cecal SCFAs and oxidative stress indexes. (A) Spearman’s correlation analyses between the cecal SCFAs and
microbiota at the genus level (n = 3 mice per group). (B) Spearman’s correlation analyses between the cecal microbiota and oxidative stress indexes at the genus
level (n = 3 mice per group). * represents the specific genus whose abundance were significantly correlated with cecal SCFAs or oxidative stress indexes. * 0.01 < p
≤0.05, ** 0.001 < p ≤0.01. B A B A FIGURE 9 | Correlation among cecal microbiota, cecal SCFAs and oxidative stress indexes. (A) Spearman’s correlation analyses between the cecal SCFAs and
microbiota at the genus level (n = 3 mice per group). (B) Spearman’s correlation analyses between the cecal microbiota and oxidative stress indexes at the genus
level (n = 3 mice per group). * represents the specific genus whose abundance were significantly correlated with cecal SCFAs or oxidative stress indexes. * 0.01 < p
≤0.05, ** 0.001 < p ≤0.01. of animals. Additionally, villus height and crypt depth are key
factors that determine intestinal absorption and digestion of
nutrients, and their ratio reflects intestinal function (33). When
the intestinal villus height becomes shorter, the absorption area
of the intestine decreases, which affects nutrient absorption (34). DISCUSSION This study showed that ETEC K88 can reduce villus height and VH/CD ratio, increase crypt depth, which may affect digestion
and absorption in mice. Oxidative stress has been reported to be
important to impairment of barrier function. Specifically, it can
change the structure of the occludin-ZO-1 complex by
stimulating tyrosine phosphorylation, destroy tight junctions,
and destroy barrier function (35). ETEC K88 was previously November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 11 CB Alleviates Oxidative Damage Li et al. body and can regulate the expression of antioxidant enzyme
genes (42). Therefore, we determined the expression of p62,
Nrf2, HO-1, GSH-Px and SODs genes at the transcriptional level
in mouse liver and jejunum. The results suggested that after
treatment with ETEC K88 alone, the mRNA expression of genes
related to the p62-Keap1-Nrf2 signaling pathway were all
significantly lower in jejunum, while only SOD2 mRNA
expression was significantly lower in liver, indicating that
jejunum is more susceptible to ETEC K88 than liver. Moreover,
CB pretreatment increased the expression of p62, Nrf2, HO-1,
GSH-Px, and SODs genes in the liver and jejunum of ETEC K88-
infected mice. The upregulation of antioxidant enzyme genes is an
adaptation to oxidative stress. In addition, it has been confirmed in
our previous in vitro study that CB could activate the Nrf2/ARE
signaling pathway to alleviate ETEC K88-induced oxidative
damage in porcine intestinal epithelial cells (43). Therefore, it is
speculated that the role of CB in alleviating oxidative damage in
ETEC K88-infected mice may be related to the activation of the
p62-Keap1-Nrf2 signaling pathway, and the effect in the H-CB+
H-ETEC group was more obvious than that in the L-CB+H-
ETEC group. FIGURE 10 | Diagram outlining the mechanism of CB on alleviating ETEC
K88-induced oxidative damage. g
p
The intestinal microbiota constitutes a natural barrier against
invasion by exogenous pathogens, and plays an important role in
host metabolism, immunity, and evolution (44). Therefore, we
used 16S rDNA amplicon sequencing to detect changes in mouse
cecum microbiota. Firmicutes and Bacteroidetes dominate
animal intestines, and their abundance ratio is often used as a
sign of intestinal microbial disorders (45). This study found that
at the phylum level, the dominant bacteria in the ceca of mice
were Firmicutes and Bacteroidetes, and their ratio was
significantly higher in the H-CB group, indicating CB
treatment could maintain the balance of intestinal microbiota. DISCUSSION In addition, the abundance of Clostridium disporicum in ETEC
K88-challenged mice was significantly higher than that in the
CONT group, Staphylococcus_lentus and Lactobacillus were
significantly clustered in the H-CB group in this study. Clostridium_disporicum is a saccharolytic species within
Firmicutes that exists in the ceca of mice (46) and is related to
the degradation of complex organic matter (47), but its actual
effects in the intestine are unclear. However, studies have shown
that Clostridium_disporicum was found in the intestinal
microbiota of patients with gastrointestinal dysfunction (48),
so it is speculated that this organism may play a negative role in
the intestine. However, Lactobacillus are gram-positive bacteria
that can promote the fermentation of carbohydrates into lactic
acid. Moreover, the combination of Lactobacillus reuteri
CCM8617 and flaxseed can increase the concentration of
SCFAs in the intestines of mice, maintain the integrity of the
mucosa, promote the growth of intestinal epithelial cells, have a
biological antagonistic effect on the pathogenic bacteria E.coli
O149:F4, and promote intestinal health (49). It is worth noting
that Staphylococcus lentus, which was significantly enriched in
the cecum after treatment with CB, is an animal pathogen (50). Moreover, it has been reported that CB may carry virulence
genes capable of producing botulinum toxin or clostridium
toxin, which are pathogenic and interfere with the balance of FIGURE 10 | Diagram outlining the mechanism of CB on alleviating ETEC
K88-induced oxidative damage. shown to induce impairment of barrier function of pig intestinal
epithelial cells by reducing the expression of ZO-1 and occludin
(36), and these effects were confirmed in mice in the present
study. This study also revealed that CB pretreatment can increase
the villus height and VH/CD ratio in the jejunum of ETEC K88-
infected mice, promote intestinal development, and maintain the
integrity of intestinal villus structure. This pretreatment also
improves expression of the tight junction protein in the liver and
jejunum at the transcriptional level, maintains tissue barrier
function, and alleviates oxidative damage caused by ETEC K88
in mice, which is consistent with the results reported by Chen
et al. (37). Therefore, determining how CB pretreatment can
improve ETEC K88-induced oxidative damage in mice was the
focus of this study. MDA, SOD, and GSH are all important markers reflecting the
degree of oxidative stress. Frontiers in Immunology | www.frontiersin.org DISCUSSION Among these, SOD and GSH are
members of the body’s antioxidant system that can effectively
decompose peroxides and lipid peroxides; therefore, the levels of
SOD and GSH can reflect the body’s ability to scavenge oxygen
free radicals (38, 39). GSH-Px can utilizes reduced GSH to convert
H2O2 to water, effectively maintaining cell stability and protecting
cell structure (40). MDA is a lipid metabolite that can directly
reflect the intensity and rate of lipid peroxidation in the body and
indirectly reflect the extent of tissue impairment by free radicals
(41). This study revealed that CB pretreatment can reverse the
upregulation of MDA levels and the downregulation of SOD and
GSH-Px levels in the serum by ETEC K88, and alleviate oxidative
damage. The p62-Keap1-Nrf2 signaling pathway is the most
important endogenous antioxidant signaling pathway in the November 2021 | Volume 12 | Article 771826 Frontiers in Immunology | www.frontiersin.org 12 CB Alleviates Oxidative Damage Li et al. intestinal microbiota (51). Thus, the probiotic effects of CB and
factors that trigger the expression of pathogenic factors require
further investigation. Figure 10. CB can up-regulate the mRNA expression of genes
related to the p62-Keap1-Nrf2 signaling pathway, promote the
expression of tight junction proteins at the transcriptional level,
and alleviate ETEC K88-induced oxidative damage. Additionally,
it can also promote the proliferation of (Lactobacillus), compete
with pathogenic bacteria for colonization sites, produce SCFAs,
maintain body barrier function, and alleviate ETEC K88-induced
oxidative damage. However, this study did not knock out the
Nrf2 gene to further verify the role of the p62-Keap1-Nrf2
signaling pathway in the mitigation of oxidative damage by
CB, which remains to be further investigated. The metabolites of gut microbiota, which are the result of
interactions between the host and the microbiota, play key roles
in maintenance of the integrity of the mucosal structure and
tissue repair and can indirectly reflect the health of the body (14). SCFAs are derived from microbial fermented carbohydrates and
play key roles in infection by pathogens (52). Therefore, this
study determined the levels of butyrate, acetate, propionate, and
total SCFAs in the cecum contents. It was found that ETEC K88
decreased the levels of SCFAs in the cecum contents, while CB
pretreatment increased the levels of SCFAs to some extent. DISCUSSION Among SCFAs, butyrate can enhance intestinal barrier
function by regulating endogenous host defense peptides and
promote the body to clear ETEC O157:H7 (53, 54), acetate can
impair metabolic function of ETEC K88, inhibit the
accumulation of toxic homocysteine, and alleviate oxidative
damage (9), and propionate can inhibit the growth and
reproduction of Salmonella typhimurium by reducing pH (55). SCFAs can be quickly absorbed by the small intestine, after
which they act as substrates to participate in energy production,
maintain intestinal morphology and function, improve
inflammation, and relieve oxidative stress (56, 57). Therefore,
we hypothesized that CB alleviation of ETEC K88-induced
oxidative damage in mice might be achieved by increasing the
concentrations of SCFAs. ACKNOWLEDGMENTS The authors thank members of their laboratory for helpful and
constructive suggestions. SUPPLEMENTARY MATERIAL In this study, ETEC K88 was used as the disease-causing
model for in vivo tests. The results revealed that the alleviation of
oxidative damage by CB was closely related to the p62-Keap1-
Nrf2 signaling pathway and intestinal microbial community
structure via the potential mechanism of action shown in The Supplementary Material for this article can be found online at:
https://www.frontiersin.org/articles/10.3389/fimmu.2021.771826/
full#supplementary-material DATA AVAILABILITY STATEMENT The original contributions presented in the study are publicly
available. This data can be found here: https://www.ncbi.nlm.nih. gov/bioproject/, PRJNA765776. ETHICS STATEMENT The animal study was reviewed and approved by Tianjin
Agricultural University. The animal study was reviewed and approved by Tianjin
Agricultural University. FUNDING This project was financially supported by the Tianjin Natural
Science Foundation [20JCZDJC00190] and the Tianjin “131”
Innovative Talents Team [20180338]. AUTHOR CONTRIBUTIONS JQ, HL, and ZS designed the experiments. ZS, XL, YQ, and KW
performed the experiments. ZS analyzed the experimental data. JQ and HL wrote this paper. All authors contributed to
manuscript revision, read, and approved the submitted version. To better understand the relationship between intestinal
microbiota and their metabolites and oxidative stress, this
study used Spearman’s correlation analysis to determine if
there was a close relationship between Lachnospiraceae
(including Lachnoclostridium, Roseburia, and Lactobacillus),
Terrisporobacter, Akkermansia, Bacteroides, and SCFAs content
and oxidative stress indicators. It should be noted that
Lachnospiraceae are producers of SCFAs (58). The results
revealed that Terrisporobacter is positively correlated with
oxidative stress, which is consistent with the results of previous
studies (59). Moreover, Akkermansia is a Verrucomicrobia that
can promote intestinal health (60). In this study, one important
finding was that the abundance of Lactobacillus was significantly
and positively correlated with SOD, suggesting that the CB
pretreatment may have alleviated ETEC K88-induced oxidative
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distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the
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Growth hormone inhibits adipogenic differentiation and induces browning in bovine subcutaneous adipocytes
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Growth hormone inhibits adipogenic differentiation
and induces browning in bovine subcutaneous
adipocytes Tingting Li
Nanjing Agricultural University
Hui Bai
Nanjing Agricultural University
Haoyuan Fang
Nanjing Agricultural University
Liang Yang
Nanjing Agricultural University
Peishi Yan Research Article Keywords: Growth hormone, Adipocyte, Bovine, STAT5B
Posted Date: May 13th, 2022
DOI: https://doi.org/10.21203/rs.3.rs-1640988/v1
License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Additional Declarations: No competing interests reported. Version of Record: A version of this preprint was published at Growth Hormone & IGF Research on
October 1st, 2022. See the published version at https://doi.org/10.1016/j.ghir.2022.101498. Page 1/22 Page 1/22 Abstract It is well established that growth hormone (GH) has the ability to stimulate lipolysis. The effects of GH on
adipocyte differentiation and browning have not been clearly described. Therefore, the present study
aimed to elucidate the role of GH in the differentiation and browning of bovine subcutaneous adipocytes
as well as its underlying molecular mechanisms. In this study, we demonstrated that GH inhibited lipid
accumulation and decreased the expression levels of adipogenic key genes (SCD1, SREBP1, PPARγ, and
CEBPα) during adipocyte differentiation. Moreover, we observed that the inhibitory effect of GH on the
early stage of adipocyte differentiation (0–2 days) was stronger than that on the later stage of adipocyte
differentiation (2–8 days). We also found that GH promoted the expression levels of browning-related
genes such as uncoupling protein 1 (UCP1) in mature adipocytes. Concurrently, GH promoted
mitochondrial biogenesis and increased the expression levels of mitochondrial biogenesis-related genes. In addition, GH promoted phosphorylation of signal transducers and activator of transcription 5 b
(STAT5B) and contributed to translocation of STAT5B to nucleus. After blocking the expression of
STAT5B protein, GH weakened the inhibition of adipogenic key genes and reduced the promotion of
browning-related genes in bovine subcutaneous adipocytes. To sum up, our findings indicate that GH
inhibits adipocyte differentiation and promotes adipocyte browning by regulating STAT5B in bovine
subcutaneous adipocytes. Introduction As an important endocrine organ, adipose tissue can regulate energy balance and maintain metabolic
homeostasis in the body [1]. Traditionally, there are two colors of adipose tissues in humans and
animals, white and brown. Recent studies have found that the white adipocytes from white adipose
tissue (WAT) can be converted into beige or brite adipocytes in response to external stimuli such as cold
or drugs [2, 3]. Adipocytes with different colors have different functions, white adipocytes store energy,
while brown and beige adipocytes consume energy to produce heat [4]. The main reason for the different
metabolic types of adipocytes is the difference in mitochondrial content [5]. Compared with white
adipocytes, brown and beige adipocytes have more mitochondria to produce heat through the
uncoupling protein 1 (UCP1) rather than catalyzing ATP synthesis [6]. Since the process of browning can
consume excess energy and reduce fat deposition, thus combating obesity and related metabolic
diseases, more and more studies attempt to identify regulatory factors that can promote the browning of
white adipocytes. The differentiation of adipocytes is the key process for adipogenesis in adipose tissue and is regulated
by many transcription factors. Peroxisome proliferator-activated receptor gamma (PPARγ) has been
reported to significantly promote adipocyte differentiation, and the differentiation is inhibited by the
knockout of PPARγ [7, 8]. Moreover, CCAAT enhancer binding protein alpha (CEBPα) is also a key
transcription factor regulating adipogenic differentiation, which promotes differentiation combined with
PPARγ [9]. In adipocytes cultured in vitro, the differentiation of adipocytes is often induced by a medium
containing MDI (insulin + IBMX + dexamethasone). Notably, increasing evidence reveals that adding Page 2/22 Page 2/22 triiodothyronine, CL316243, and rosiglitazone to the medium during the induction stage of differentiation
can induce white adipocytes to become beige adipocytes [10–12]. This provides a new insight for the
study on inducing the browning of adipocytes in vitro. triiodothyronine, CL316243, and rosiglitazone to the medium during the induction stage of differentiation
can induce white adipocytes to become beige adipocytes [10–12]. This provides a new insight for the
study on inducing the browning of adipocytes in vitro. Growth hormone (GH) is a kind of polypeptide hormone, which participates in the regulation of body
growth and development. GH possesses multiple biological functions, especially regulating fat
deposition in adipose tissue. Previous studies have shown that GH treatment can significantly reduce
the fat mass of mice [13, 14]. Introduction A study on human subcutaneous adipose tissue has also reported that GH
supplementation markedly reduced the size of adipocytes [15]. These studies indicate that GH level is
negatively correlated with adipose tissue content. In addition, research has disclosed that GH has a
significant impact on fat distribution, and the content of subcutaneous WAT in GH knockout mice is quite
higher than that in perigonadal WAT [16]. Previous evidence also identified that the extra-/intraperitoneal
WAT ratio was upregulated in GH receptor antagonist (GHA) mice [17]. Although the inhibitory effect of
GH on fat deposition has been widely confirmed, the effect of GH on adipocytes is still controversial. Accumulating evidences have reported that GH can promote the adipocyte differentiation of 3T3-L1 and
3T3-F442A, the cell lines from mice [18–20]. Inversely, the adipogenic differentiation of preadipocytes in
primary cultures has been significantly inhibited during GH treatment [21, 22]. Furthermore, GH is also
important in inducing WAT browning. For example, GH remarkably increases the expression level of
UCP1 gene in subcutaneous WAT from mice [23]. To date, the ability of GH to induce the browning of
adipocytes, especially subcutaneous adipocytes, has not been extensively studied. Signal transducers and activator of transcription 5 (STAT5) protein plays a pivotal role in the regulation
of fat deposition by GH. Study has shown that STAT5 is activated in GH-treated mouse adipose tissue
[24]. After STAT5 knockout, GH could not continue to stimulate lipolysis in mouse adipocytes and the fat
mass was also increased in mice [25, 26]. STAT5 is divided into two subtypes, STAT5A and STAT5B. STAT5A mainly acts on mammary tissue, and researchers have found that STAT5A-deficient mice could
not lactate normally [27]. It has been reported that STAT5A plays a role in promoting adipogenesis [28]. In contrast, STAT5B has been reported to inhibit adipocyte differentiation [29]. Therefore, the regulation
of GH on STAT5B may be the key for GH to inhibit the differentiation of preadipocytes in primary
cultures. Although the lipolysis of GH on adipose tissue has been established, the effect of GH on the
differentiation and browning of bovine subcutaneous adipocytes remains unclear. In this study, we
treated bovine subcutaneous preadipocytes with GH to detect the indicators related to differentiation
and browning, and measured the expression of STAT5B protein during GH treatment. These results
provide a theoretical basis for future studies into the mechanism of GH on fat metabolism of bovine
subcutaneous adipocytes. Materials and reagents Page 3/22 GH was purchased from Prospec (Ness-Ziona, Israeli). Phosphate buffer saline (PBS), penicillin and
streptomycin, and Dulbecco’s modified Eagle’s medium/nutrient mixture F12 (DMEM/F12) were obtained
from Hyclone (Logan, UT, USA). Fetal bovine serum (FBS) was purchased from Sciencell (Carlsbad, CA,
USA). Type I collagenase, insulin, rosiglitazone, dexamethasone, 3-isobutyl-1-methylxanthine (IBMX), and
oil red O were purchased from Sigma-Aldrich (St. Louis, MO, USA). MitoTracker Red was purchased from
Warbio (Nanjing, Jiangsu, China). Cell counting kit 8 (CCK-8), BCA assay kit, and ECL kit were purchased
from Vazyme (Nanjing, Jiangsu, China). Bovine serum albumin (BSA), DAPI, RIPA buffer, and protease
inhibitor were purchased from Beyotime (Shanghai, China). Genomic DNA Extraction Kit, Trizol,
PrimeScript™ RT Master Mix, and SYBR Premix were purchased from TaKaRa (Tokyo, Japan). STAT5-IN-1
was purchased from Selleck (Houston, Texas, USA). GH was purchased from Prospec (Ness-Ziona, Israeli). Phosphate buffer saline (PBS), penicillin and
streptomycin, and Dulbecco’s modified Eagle’s medium/nutrient mixture F12 (DMEM/F12) were obtained
from Hyclone (Logan, UT, USA). Fetal bovine serum (FBS) was purchased from Sciencell (Carlsbad, CA,
USA). Type I collagenase, insulin, rosiglitazone, dexamethasone, 3-isobutyl-1-methylxanthine (IBMX), and
oil red O were purchased from Sigma-Aldrich (St. Louis, MO, USA). MitoTracker Red was purchased from
Warbio (Nanjing, Jiangsu, China). Cell counting kit 8 (CCK-8), BCA assay kit, and ECL kit were purchased
from Vazyme (Nanjing, Jiangsu, China). Bovine serum albumin (BSA), DAPI, RIPA buffer, and protease
inhibitor were purchased from Beyotime (Shanghai, China). Genomic DNA Extraction Kit, Trizol,
PrimeScript™ RT Master Mix, and SYBR Premix were purchased from TaKaRa (Tokyo, Japan). STAT5-IN-1
was purchased from Selleck (Houston, Texas, USA). Cell culture and adipogenic differentiation Bovine subcutaneous primary adipocytes were isolated from the subcutaneous adipose tissue in
Simmental cattle. Firstly, the isolated adipose tissue samples were washed with PBS, minced with
scissors, and digested with type I collagenase at 37 °C for 1 h. Next, the digested cell suspensions were
filtered through the cell strainer, then centrifuged, re-suspended in a standard medium. The standard
medium was DMEM/F12 supplemented with 10% FBS and 100 U/mL penicillin and streptomycin. Finally,
the preadipocytes were incubated in a humidified atmosphere of 5% CO2 at 37°C. The culture medium
was changed every 2 days. To induce adipogenic differentiation, the fully confluent preadipocytes were
cultured in a standard medium for 2 days (day 0), then cultured in a differentiation medium for 6 days
and finally cultured in a standard medium containing 1 μg/mL insulin for 2 days. The differentiation
medium comprised of standard medium supplemented with 1 μg/mL insulin, 2 μM rosiglitazone, 1 μM
dexamethasone, and 0.5 mM IBMX. Cell viability assay Bovine subcutaneous preadipocytes were seeded in a 96-well plate and incubated at 37℃ for 24 h. Next,
the preadipocytes were treated with GH of various concentrations (0, 10, 100, 500 ng/mL) for 48 h. Afterward, 10 μL of CCK8 solution was added to each well and incubated at 37℃ for 4 h. The
absorbance value was measured at 450 nm by using a microplate reader (Tecan, Switzerland). Oil red O staining After 8 days of adipogenic differentiation, adipocytes were washed with PBS and fixed in 4%
paraformaldehyde for 30 min. Adipocytes were then washed with PBS three times and stained with oil
red O working solution for 1 h at room temperature in dark. After washing with doubly distilled water 3-6
times, adipocytes were observed and photographed with a light microscope (CKX41, Olympus, Japan). Lipid contents in adipocytes were extracted with 100% isopropanol and the absorbance value at 510 nm
was read by a microplate reader (Tecan, Switzerland). Real-time quantitative PCR (RT-qPCR) analysis Real-time quantitative PCR (RT-qPCR) analysis Page 4/22 Page 4/22 Page 4/22 Total RNA was extracted from adipocytes by using Trizol. After that, total RNA was used as a template
for cDNA synthesis by using PrimeScript™ RT Master Mix. RT-qPCR was performed with the mixture of
SYBR Premix, primers, and cDNA on a QuantStudio 5 system (ABI, Carlsbad, CA, USA). Details of the
primer sequences for acetyl-CoA carboxylase (ACC), stearoyl-Coenzyme A desaturase 1 (SCD1), sterol
regulatory element binding protein 1 (SREBP1), PPARγ, CEBPα, UCP1, peroxisome proliferator-activated
receptor gamma coactivator 1 alpha (PGC-1α), PR domain containing 16 (PRDM16), cluster of
differentiation 137 (CD137), T-box transcription factor 1 (TBX1), cell death inducing DFFA like effector A
(CIDEA), deiodinase-2 (DIO2), mitochondrial transcription factors A (TFAM), nuclear respiratory factor 1
(NRF1), nuclear respiratory factor 2 (NRF2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are
shown in Table 1. The expression level of relative genes was calculated using 2−∆∆Ct method and
normalized to GAPDH [30]. Primers sequences for target and reference genes. Primers sequences for target and reference genes. Page 5/22 Gene
Gene ID
Primer sequences (5' to 3')
Product size (bp)
ACC
NM_174224.2
F: GCTATGGAAGTCGGCTGTGGAAG
R: GGAAGAGGCGGATGGGAATTGC
102
SCD1
NM_173959.4
F: CTACACAACCACCACCACCATCAC
R: CTCTCATTTCAGGGCGGATGTCTTC
116
SREBP1
NM_001113302.1
F: CTCCGACACCACCAGCATCAAC
R: GCAGCCCATTCATCAGCCAGAC
122
PPARγ
NM_181024.2
F: TTGACCCAGAGAGTGAGCCCTTC
R: CCACGGAGCTGATCCCAAAGTTG
117
CEBPα
NM_176784. 2
F: TGGACAAGAACAGCAACGAGTACC
R: GGCGGTCATTGTCACTGGTCAG
138
UCP1
NM_001166528.1
F: TGCGTGGCTGACATAATCACCTTC
R: GGCACTGGAGATCAGGCATTCG
96
PGC-1α
XM_024993058.1
F: AGGCAGAGGCAGAAGGCAATTAAC
R: CCTCAGTTCTGTCCGTGTTGTGTC
117
PRDM16
XM_024976786.1
F: CTTGGAGCAGCACATGGTCGTC
R: TCTGGTGGCGGATGAGGTTGG
101
CD137
NM_001035336.2
F: TGGCGTCCTTCCTGGTTCTCC
R: CCTCTTGGGCTGTTTGTACTGGTC
108
TBX1
XM_024977887.1
F: GCAGTCACCGCCTATCAGAATCAC
R: GTCACAGTCTCGGAAGCCTTTGG
84
CIDEA
NM_001083449.1
F: CCTTCCGTGTCTCCAACCATGAC
R: GCGACCACCAGTGCATCCAAG
100
DIO2
NM_001010992.7
F: CATCCGTGGCTGACTTCCTGTTG
R: CTTCCTGGTTCCGGTGCTTCTTC
117
TFAM
NM_001034016.2
F: AAACCGAAAAGACCTCGCTCAGC
R: TACCTGTGATGTGCCATCCCTAGC
81
NRF1
NM_001098002.2
F: AATTATTCGGCGGTGGCTGATGG
82 Page 6/22 NRF2
NM_001011678.2
F: TCAGCCAGCACAACACATACCATC
R: ACGGGAATGTCTCTGCCAAAAGC
128
ND1
NC_006853.1
F: CGTAGAATATGCAGCAGGACCA
R: GTTCTGGTATGTGTGGATTGTGG
125
GAPDH
NM_001034034.2
F: CGGCACAGTCAAGGCAGAGAAC
R: CCACATACTCAGCACCAGCATCAC
116
ACC, acetyl-CoA carboxylase; SCD1, stearoyl-Coenzyme A desaturase 1; SREBP1, sterol regulatory
element binding protein 1; PPARγ, peroxisome proliferator-activated receptor gamma; CEBPα, CCAAT
enhancer binding protein alpha; UCP1, uncoupling protein 1; PGC-1α, peroxisome proliferator-activated
receptor gamma coactivator 1 alpha; PRDM16, PR domain containing 16; CD137, cluster of
differentiation 137; TBX1, T-box transcription factor 1; CIDEA, cell death inducing DFFA like effector A;
DIO2, deiodinase-2; TFAM, mitochondrial transcription factors A; NRF1, nuclear respiratory factor 1;
NRF2, nuclear respiratory factor 2; ND1, NADH dehydrogenase subunit 1; GAPDH, glyceraldehyde-3-
phosphate dehydrogenase. NRF2
NM_001011678.2
F: TCAGCCAGCACAACACATACCATC
R: ACGGGAATGTCTCTGCCAAAAGC
128
ND1
NC_006853.1
F: CGTAGAATATGCAGCAGGACCA
R: GTTCTGGTATGTGTGGATTGTGG
125
GAPDH
NM_001034034.2
F: CGGCACAGTCAAGGCAGAGAAC
R: CCACATACTCAGCACCAGCATCAC
116 Mitochondrial DNA (mtDNA) quantification Adipocytes were treated with GH and performed for DNA extraction using the genomic DNA extraction
kit. The mtDNA content was quantitatively analyzed by normalizing the NADH dehydrogenase subunit 1
(ND1) gene to GAPDH using RT-qPCR. The primer sequences are available in Table 1. The mtDNA
content was calculated by using the 2−∆∆Ct method [30]. Western blot analysis The lysates of adipocytes were harvested using the mixture of RIPA buffer and protease inhibitor. After
centrifugation, the supernatant was quantified by a BCA assay kit and boiled with sodium dodecyl sulfate
sample buffer. Then, the isolated protein was loaded and run on a sodium dodecyl sulfate-
polyacrylamide gel electrophoresis and transferred onto PVDF membranes. The membranes were
blocked with fat-free milk followed by incubation with primary antibodies against PPARγ (SC-7196, Santa
Cruz, 1:1000), GAPDH (10494-1-AP, Proteintech, 1:1000), STAT5B (bs-1142R, Bioss, 1:1000), and
phosphor-STAT5B (bs-5703R, Bioss, 1:1000). The membranes were incubated with secondary antibody
(7074P2, CST, 1:4000) and visualized using an ECL kit on the ChemiDocTM imaging system (BIO-RAD,
Hercules, CA, USA). MitoTracker red staining Bovine subcutaneous adipocytes were differentiated into mature adipocytes in 6-well plates with
coverslips on the bottom. Mature adipocytes were treated with 500 ng/mL GH for 6 h and stained with
200 nM MitoTracker red at 37℃ for 30 min. After fixing with 4% paraformaldehyde and washing with
PBS, adipocytes were stained with DAPI for 10 min. Finally, coverslips containing labeled adipocytes Page 7/22 Page 7/22 were mounted on microscopic slides and the images were obtained with a laser scanning confocal
microscope (LSM900, Zeiss, Germany). Statistical analysis All data were analyzed by the independent sample t-test using SPSS 22.0 software (IBM, Chicago, IL,
USA). Data were shown as mean ± standard error of the mean (SEM). The p-values less than 0.05 were
considered statistically significant. Immunofluorescent staining Adipocytes were differentiated in culture plates with coverslips and then treated with GH for 1 h. Next,
adipocytes were fixed with 4% paraformaldehyde for 15 min and permeabilized with 0.5% Triton X-100
for 30min. After blocking with 5% BSA for 1 h, adipocytes were incubated with STAT5B antibody (bs-
1142R, Bioss, 1:200) overnight at 4 °C followed by staining with the florescent secondary antibody for 50
min. Then, the nuclei of adipocytes were counterstained with DAPI for 5 min. Fluorescence images were
taken with laser scanning confocal microscope (LSM900, Zeiss, Germany). GH promoted the browning and mitochondrial biogenesis of bovine subcutaneous adipocytes To study the effect of GH on the browning of mature adipocytes, we cultured adipocytes in a
differentiation medium for 8 days and then treated the differentiated adipocytes with GH. The expression
level of the browning key gene UCP1 was analyzed by RT-qPCR. As shown in Fig. 3a, the expression level
of UCP1 gene was significantly increased in fully differentiated adipocytes treated with 500 ng/mL GH
for 2 h and 6 h. Then, we examined the expression levels of browning-related genes (PGC-1α, PRDM16,
CD137, TBX1, CIDEA, and DIO2) in mature adipocytes treated with 500 ng/mL GH for 6 h, and found that
GH treatment significantly increased the expression levels of PGC-1α, PRDM16, TBX1, and CIDEA genes
(Fig. 3b). Mitochondrial biogenesis is one of the key characteristics of browning. We observed that 6 h of
GH treatment significantly increased the content of mtDNA in mature adipocytes, suggesting the
increased mitochondrial number (Fig. 3c). MitoTracker red staining in mature adipocytes further
demonstrated that GH treatment enhanced mitochondrial red fluorescence signal (Fig. 3d). In addition,
mitochondrial biogenesis-specific markers NRF1 and NRF2 were up-regulated in GH-treated mature
adipocytes (Fig. 3e). Together, the above results showed that GH promoted the browning and
mitochondrial biogenesis of bovine subcutaneous adipocytes. GH inhibited the differentiation of bovine subcutaneous preadipocytes RT-qPCR results showed that the expression levels of
SCD1, SREBP1, PPARγ, and CEBPα were significantly reduced after GH treatment for 1 day, and the
expression levels of ACC, SCD1, SREBP1, PPARγ, and CEBPα were significantly decreased after GH
treatment for 2 days (Fig. 2d-e). Western blot analysis showed that the expression level of PPARγ protein
decreased significantly after GH treatment for both 1 and 2 days (Fig. 2f). To further understand the inhibitory mechanism of GH on the differentiation of adipocytes, we treated
adipocytes with GH at different stages of adipogenic differentiation (Fig. 2a). Adipogenesis of
adipocytes was detected by oil red O staining. Compared with untreated adipocytes, the lipid content
was significantly decreased in adipocytes treated with 500 ng/mL GH at different stages (Fig. 2b-c). Interestingly, we observed that the inhibitory effect of GH on the early stage of adipocyte differentiation
(0-2 days) was stronger compared to the later stage of adipocyte differentiation (2-8 days). Therefore,
adipocytes were collected for analysis of adipogenic key genes and proteins after treatment with
differentiation medium and GH for 1 and 2 days. RT-qPCR results showed that the expression levels of
SCD1, SREBP1, PPARγ, and CEBPα were significantly reduced after GH treatment for 1 day, and the
expression levels of ACC, SCD1, SREBP1, PPARγ, and CEBPα were significantly decreased after GH
treatment for 2 days (Fig. 2d-e). Western blot analysis showed that the expression level of PPARγ protein
decreased significantly after GH treatment for both 1 and 2 days (Fig. 2f). GH inhibited the differentiation of bovine subcutaneous preadipocytes Firstly, we detected the cytotoxicity of GH on bovine subcutaneous preadipocytes by CCK8 assay. After
GH treatment for 48 h, the cell viability of preadipocytes was unchanged at concentrations as high as
500 ng/mL (Fig. 1a). To investigate the effect on the differentiation of preadipocytes to mature
adipocytes by GH treatment, we treated preadipocytes with different concentrations (0, 10, 100, and 500
ng/mL) of GH for 8 days during adipocyte differentiation (Fig. 1b). Oil red O staining showed clear lipid
droplets in differentiated adipocytes without GH treatment (Fig. 1c). However, treatment with GH for 8
days inhibited the accumulation of lipid droplets in differentiated adipocytes (Fig. 1c). Lipid extraction of
adipocytes after staining with oil red O showed that 100 and 500 ng/mL GH treatments significantly
reduced the lipid content of differentiated adipocytes (Fig. 1d). To further demonstrate the inhibitory
effect of GH on adipogenesis, we examined the expression levels of adipogenesis-related genes (ACC,
SCD1, SREBP1, PPARγ, and CEBPα) in differentiated adipocytes after 8 days of GH treatment. Compared
with those in the 0 ng/mL GH treatment group, 10 ng/mL GH treatment significantly inhibited the
expression level of SREBP1 gene, 100 ng/mL GH treatment significantly decreased the expression level
of PPARγ gene, and the expression levels of SCD1, SREBP1, PPARγ, and CEBPα genes were significantly
decreased in 500 ng/mL GH treatment group (Fig. 1e). These results suggested that GH inhibited the
differentiation of bovine subcutaneous preadipocytes. GH strongly suppressed the differentiation of bovine subcutaneous adipocytes at the early stage of
differentiation Page 8/22 To further understand the inhibitory mechanism of GH on the differentiation of adipocytes, we treated
adipocytes with GH at different stages of adipogenic differentiation (Fig. 2a). Adipogenesis of
adipocytes was detected by oil red O staining. Compared with untreated adipocytes, the lipid content
was significantly decreased in adipocytes treated with 500 ng/mL GH at different stages (Fig. 2b-c). Interestingly, we observed that the inhibitory effect of GH on the early stage of adipocyte differentiation
(0-2 days) was stronger compared to the later stage of adipocyte differentiation (2-8 days). Therefore,
adipocytes were collected for analysis of adipogenic key genes and proteins after treatment with
differentiation medium and GH for 1 and 2 days. STAT5B showed that STAT5B protein could be translocated to the nucleus to regulate gene transcription
(Fig. 4c). STAT5B showed that STAT5B protein could be translocated to the nucleus to regulate gene transcription
(Fig. 4c). GH-induced differentiation and browning of bovine subcutaneous adipocy To further determine the activation mechanism of GH on STAT5B, we treated adipocytes in the
differentiation stage (day 0) with GH for 1 h, with or without pretreatment with 100 μM STAT5-IN-1
(STAT5 inhibitor) for 1 h. Western blot analysis showed that 100 µM STAT5-IN-1 treatment significantly
inhibited the phosphorylation of STAT5B initiated by GH (Fig. 5a). Moreover, we treated adipocytes with
100 μM STAT5-IN-1 for 1 h followed by GH for 24 h during the differentiated process (day 0). We found
that pretreatment with STAT5-IN-1 significantly alleviated the downregulation of PPARγ and SREBP1
genes after GH treatment (Fig. 5b). In addition, treatment on fully differentiated adipocytes with STAT5-
IN-1 and GH for 1 h and 6 h, respectively, significantly inhibited GH-induced the upregulation of UCP1 and
PGC-1α genes. These results indicated that GH may inhibit adipogenic differentiation and promote the
browning of adipocytes by activating STAT5B. GH increased the phosphorylation of STAT5B in bovine subcutaneous adipocytes STAT5 is widely involved in growth and development processes including cell proliferation,
differentiation, etc. As a subtype of STAT5, STAT5B can participate in the GH-regulated lipolysis process
[31, 32]. Therefore, to clarify whether GH can activate the expression of STAT5B in bovine subcutaneous
adipocytes, we first treated preadipocytes (day 0) with a differentiation medium and 500 ng/mL GH for
indicated time to detect the phosphorylation level of STAT5B. Although incubation with GH for 10 min
and 30 min had no significant effect on the phosphorylation level of STAT5B, 60 min and 180 min of GH
treatment significantly increased the phosphorylation level of STAT5B (Fig. 4a). Then we treated fully
differentiated adipocytes with 500 ng/mL GH for 1 h and 6 h and found that both 1 h and 6 h of GH
treatment markedly promoted STAT5B activation (Fig. 4b). Furthermore, immunofluorescence staining of Page 9/22 Page 9/22 Discussion GH is an important cytokine in regulating the growth and development of the body, and accumulating
evidences have shown that GH has a significant impact on adipose tissue metabolism [33, 34]. In
particular, GH can suppress the differentiation of primary cell cultures [35]. Indeed, although GH has
been found to promote the expression of UCP1 in mouse model, the specific regulation mechanisms
need further research [23]. STAT5B is a key transcription factor in cell development regulated by GH,
which can transmit extracellular signals to the nucleus and regulate cell metabolic activities [36]. Therefore, in this research, we investigated the effects of GH on the differentiation and browning of
bovine subcutaneous adipocytes by culturing bovine subcutaneous adipocytes in vitro, and explored the
role of STAT5B protein in the regulation of GH on bovine subcutaneous adipocytes. It has been well accepted that GH can promote lipolysis and reduce WAT weight in the body [37]. Research on primary human mesenchymal stromal cells (MSCs) has confirmed that GH inhibited
adipocyte differentiation [21]. In the present study, we found that GH treatment for 8 days significantly
inhibited the lipid content of bovine subcutaneous adipocytes, which is consistent with the results of
Zhao et al. [38]. Olarescu et al. [35] also found that bovine GH (bGH) cells from mice subcutaneous WAT
displayed a decreased lipid accumulation compared to wild-type (WT) cells. Adipocyte differentiation is
promoted by many key transcription factors, among which PPARγ is the core regulator of entire terminal
differentiation [39]. In addition, CEBPα promotes adipogenic differentiation through reciprocal positive
feedback regulation with PPARγ [39]. SREBP1 can promote the expression of PPARγ and SCD1, and both
SREBP1 and SCD1 play an important role in regulating de novo lipogenesis [40, 41]. Our results
suggested that GH inhibited adipogenesis of bovine subcutaneous adipocytes by down-regulating the
expression levels of PPARγ, CEBPα, SREBP1, and SCD1 genes. This is contrary to the results in 3T3-L1
adipocytes, in which GH can significantly elevate the expression level of PPARγ protein [18, 42]. This may Page 10/22 Page 10/22 further confirm the opposite effects of GH on cell lines and primary adipocytes. The early phase of
differentiation is the most crucial phase to initiate and ensure the normal differentiation process. Our
study revealed that GH treatment had a stronger inhibitory effect on lipid accumulation in the early stage
(0–2 days) than that in the later stage (2–8 days). Discussion Additionally, we identified the inhibitory effect of GH
on the expression of key genes and proteins during adipogenic differentiation. These findings suggested
that GH exerted the ability to inhibit adipogenic differentiation, especially in the early stage of
differentiation, through inhibiting lipid accumulation and the expression of adipogenic-related genes. The browning of WAT is essential for the body to combat obesity, resist cold and increase heat
production. Accordingly, researches related to inducing browning by using in vitro and in vivo models
have attracted increasing attention. Recent work showed that compared with WT mice, the expression of
UCP1 protein in bGH transgenic mice was increased [43]. As a marker of beige adipocytes, UCP1 leads
protons to leak through the inner membrane of mitochondria and thus converting electrochemical energy
into heat, which plays a central role in heat production [44]. Our study demonstrated that GH treatment
could significantly increase the expression levels of UCP1 and browning-related key genes (PGC-1α,
PRDM16, TBX1, and CIDEA) in bovine subcutaneous adipocytes, indicating a potential role of GH in
inducing beige fat-like characteristic. Moreover, Hayashi et al. [45] also proposed that GH induced the
expression of UCP1 protein in 3T3-L1 cells, which was coincident with our results. Due to beige
adipocytes requiring more mitochondria for metabolism and thermogenesis, mitochondrial biogenesis
has become a marker process of browning. Research has shown that mitochondrial biogenesis is
dominant in the process of beige adipocytes formation [46]. The mtDNA replication is the main feature
of mitochondrial biogenesis, which reflects the increase of mitochondrial number. In this study, GH
treatment can increase mtDNA contents in bovine subcutaneous adipocytes. In addition, MitoTracker
staining further demonstrated that GH treatment promoted mitochondrial biogenesis in bovine
subcutaneous adipocytes. TFAM, NRF1, and NRF2 are key regulatory factors controlling mitochondrial
biogenesis, and PGC-1α can activate the expression of these key transcription factors, led to an increase
in mtDNA content, thus promoting mitochondrial biogenesis [47, 48]. In this work, we demonstrated that
the expression levels of PGC-1α, NRF1, and NRF2 genes were increased in GH-treated adipocytes. Overall, these findings indicated that GH can induce the browning of bovine subcutaneous adipocytes
and promote the mitochondrial biogenesis. There is increasing evidence that GH has the potential to activate STAT5B both in vivo and in vitro [18,
49]. Conclusion In conclusion, our data prove that GH can inhibit the adipogenic differentiation of bovine subcutaneous
preadipocytes, and the inhibitory effect of GH is more obvious in the early stage of differentiation than
that in the later stage. GH can also promote the browning of bovine subcutaneous adipocytes,
accompanied by mitochondrial biogenesis. In addition, studies on STAT5B, a key factor in transcriptional
regulation, found that GH regulated the differentiation and browning process of bovine subcutaneous
adipocytes through activating STAT5B. Collectively, our results suggest the inhibitory effect of GH on the
differentiation of preadipocytes and the feasibility of GH to induce the browning of adipocytes in vitro. Data availability The data that support the findings of the current study are available from the corresponding author on
reasonable request. Funding This study was supported by the National Key Research and Development Plan of China
(2016YFD0500508). Discussion Previous data have suggested that the expression of STAT5B protein was increased during
adipocyte differentiation, and STAT5B knockdown up-regulated the expression of PPARγ and CEBPα [29,
50]. Moreover, several studies also confirmed that STAT5 promoted transcription by binding to the UCP1
promoter and cold exposure could not promote UCP1 protein increase in STAT5-deficient mice [45, 51]. Therefore, we hypothesized that GH could activate STAT5B expression to regulate the differentiation and
browning of bovine subcutaneous adipocytes. As expected, our results showed that GH can activate
STAT5B in differentiating as well as full differentiated adipocytes, suggesting that STAT5B plays an
important role in GH-regulated differentiation and browning processes. STAT5B is widely present in the
cytoplasm as a monomer when cells are not stimulated by cytokines and hormones. In response to GH Page 11/22 Page 11/22 stimulation, phosphorylated STAT5B separates from its receptor and forms different polymeric forms,
which are transferred to the nucleus and activate or inhibit transcription by binding to specific DNA
sequences [52]. This transcriptional regulation of nuclear translocation is the key for STAT5B to fulfill its
function. In this study, STAT5B protein was translocated to the nucleus after GH treatment in bovine
subcutaneous adipocytes. Consistent with our findings, it has been reported that GH promotes
mitochondrial biogenesis by activating STAT5, which is then transported to the nucleus and interacts
synergistically with other growth factors [53]. Next, we used STAT5-IN-1 to block the activity of STAT5B
and found that the expression level of key genes involved in adipocyte differentiation and browning
decreased significantly, indicating that GH inhibits adipocyte differentiation and promotes adipocyte
browning in vitro by activating the expression of STAT5B protein. Author contributions TL performed the main experiments and drafted the manuscript. TL and HB designed this study. TL and
HF carried out the data collection and analysis. TL and LY performed the material preparation. PY
supervised the research and revised the manuscript. All authors reviewed and approved the final
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Committee at Nanjing Agricultural University (Permission number: SYXK-2017-0027) The collection of adipose tissue samples were approved by the Institutional Animal Care and Use The collection of adipose tissue samples were approved by the Institutional Animal Care and Use
Committee at Nanjing Agricultural University (Permission number: SYXK-2017-0027). Conflict of interest Page 12/22
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Mol Sci 22(23):13059. https://doi.org/10.3390/ijms222313059 48. Cardanho-Ramos C, Morais VA (2021) Mitochondrial biogenesis in neurons: how and where. Int J
Mol Sci 22(23):13059. https://doi.org/10.3390/ijms222313059 Page 16/22 49. References Clasen BF, Poulsen MM, Escande C, Pedersen SB, Møller N, Chini EN, Jessen N, Jørgensen JOL
(2014) Growth hormone signaling in muscle and adipose tissue of obese human subjects:
associations with measures of body composition and interaction with resveratrol treatment. J Clin
Endocrinol Metab 99(12):E2565-E2573. https://doi.org/10.1210/jc.2014-2215 50. Richard AJ, Stephens JM (2014) The role of JAK-STAT signaling in adipose tissue function. Biochim
Biophys Acta 1842(3):431-439. https://doi.org/10.1016/j.bbadis.2013.05.030 51. Kaltenecker D, Spirk K, Ruge F, Grebien F, Herling M, Rupprecht A, Kenner L, Pohl EE, Mueller KM,
Moriggl R (2020) STAT5 is required for lipid breakdown and beta-adrenergic responsiveness of
brown adipose tissue. Mol Metab 40:101026. https://doi.org/10.1016/j.molmet.2020.101026 52. Farrar MA, Heltemes-Harris LM (2011) Turning transcription on or off with STAT5: when more is
less. Nat Immunol 12(12):1139-1140. https://doi.org/10.1038/ni.2163 52. Farrar MA, Heltemes-Harris LM (2011) Turning transcription on or off with STAT5: when more is
less. Nat Immunol 12(12):1139-1140. https://doi.org/10.1038/ni.2163 53. Poudel SB, Dixit M, Neginskaya M, Nagaraj K, Pavlov E, Werner H, Yakar S (2020) Effects of GH/IGF
on the aging mitochondria. Cells 9(6):1384. https://doi.org/10.3390/cells9061384 Figures Page 17/22 Page 18/22
Figure 1
GH inhibited the differentiation of bovine subcutaneous preadipocytes. a Cell viability of bovine
subcutaneous preadipocytes treated with different concentrations (10, 100, 500 ng/mL) of GH for 48 h. b
GH treatment (10, 100, 500 ng/mL) during the adipogenic differentiation program. c Oil red O staining of
bovine subcutaneous adipocytes on day 8 after treatment with various concentrations of GH. Magnification, 200x and 100x. Scale bars, 50 µm and 100 µm. d The result of oil red O extraction. e The Figure 1
GH inhibited the differentiation of bovine subcutaneous preadipocytes. a Cell viability of bovine
subcutaneous preadipocytes treated with different concentrations (10, 100, 500 ng/mL) of GH for 48 h. b
GH treatment (10, 100, 500 ng/mL) during the adipogenic differentiation program. c Oil red O staining of
bovine subcutaneous adipocytes on day 8 after treatment with various concentrations of GH. Magnification, 200x and 100x. Scale bars, 50 µm and 100 µm. d The result of oil red O extraction. e The Figure 1 GH inhibited the differentiation of bovine subcutaneous preadipocytes. a Cell viability of bovine
subcutaneous preadipocytes treated with different concentrations (10, 100, 500 ng/mL) of GH for 48 h. b
GH treatment (10, 100, 500 ng/mL) during the adipogenic differentiation program. c Oil red O staining of
bovine subcutaneous adipocytes on day 8 after treatment with various concentrations of GH. Magnification, 200x and 100x. Scale bars, 50 µm and 100 µm. d The result of oil red O extraction. e The Page 18/22 Page 18/22 expression levels of adipogenic key genes was detected by RT-qPCR in adipocytes after GH treatment for
8 days. Data are presented as means ± SEM (n = 4). *P < 0.05, **P < 0.01 vs. the 0 ng/mL group. (
) Page 19/22
Figure 2
GH strongly suppressed the differentiation of bovine subcutaneous adipocytes at the early stage of
differentiation. a Adipocytes were treated with GH (500 ng/mL) at the indicated time point during the
differentiated process. b Oil red O staining of differentiated bovine subcutaneous adipocytes. Figure 2 Figure 2 GH strongly suppressed the differentiation of bovine subcutaneous adipocytes at the early stage of
differentiation. a Adipocytes were treated with GH (500 ng/mL) at the indicated time point during the
differentiated process. b Oil red O staining of differentiated bovine subcutaneous adipocytes. Page 19/22 Page 19/22 Page 19/22 Magnification, 200x and 100x. Scale bars, 50 µm and 100 µm. c The content of oil red O extraction. d, e
GH-treated adipocytes were collected for RT-qPCR analysis at 1 and 2 days of differentiation. f Western
blot analysis of PPARγ at 1 and 2 days of differentiation. Data are presented as means ± SEM (n = 4). *P
< 0.05, **P < 0.01 vs. the control group. Magnification, 200x and 100x. Scale bars, 50 µm and 100 µm. c The content of oil red O extraction. d, e
GH-treated adipocytes were collected for RT-qPCR analysis at 1 and 2 days of differentiation. f Western
blot analysis of PPARγ at 1 and 2 days of differentiation. Data are presented as means ± SEM (n = 4). *P
< 0.05, **P < 0.01 vs. the control group. < 0.05, P < 0.01 vs. the control group. Figure 3
GH promoted the browning and mitochondrial biogenesis of bovine subcutaneous adipocytes. a The
expression level of UCP1 gene in full differentiated adipocytes treated with 500 ng/mL GH for the
indicated times. b After 6 h of GH treatment, the expression of browning-related genes was analyzed by
RT-qPCR. c Mitochondrial DNA content quantification by RT-qPCR. d Mature bovine subcutaneous
adipocytes were stained with MitoTracker red. Magnification, 200x. Scale bars, 50 µm. e The mRNA
expression of TFAM, NRF1, and NRF2 genes in mature bovine subcutaneous adipocytes treated with 500 g
p Figure 3 Figure 3 GH promoted the browning and mitochondrial biogenesis of bovine subcutaneous adipocytes. a The
expression level of UCP1 gene in full differentiated adipocytes treated with 500 ng/mL GH for the
indicated times. b After 6 h of GH treatment, the expression of browning-related genes was analyzed by
RT-qPCR. c Mitochondrial DNA content quantification by RT-qPCR. d Mature bovine subcutaneous
adipocytes were stained with MitoTracker red. Magnification, 200x. Scale bars, 50 µm. e The mRNA
expression of TFAM, NRF1, and NRF2 genes in mature bovine subcutaneous adipocytes treated with 500
ng/mL GH for 6 h. Data are presented as means ± SEM (n = 3). *P < 0.05, **P < 0.01 vs. Figure 2 the control group. Page 20/22 Figure 4
GH increased the phosphorylation of STAT5B in bovine subcutaneous adipocytes. a Western blot
analysis of p-STAT5B and STAT5B at day 0 of adipocyte differentiation with GH (500 ng/mL) treatment
for 10, 30, 60, and 180 minutes. b Western blot analysis of p-STAT5B and STAT5B in mature adipocytes
f
(
)
f
d
h
f d
fl Figure 4
GH increased the phosphorylation of STAT5B in bovine subcutaneous adipocytes. a Western blot
analysis of p-STAT5B and STAT5B at day 0 of adipocyte differentiation with GH (500 ng/mL) treatment
for 10, 30, 60, and 180 minutes. b Western blot analysis of p-STAT5B and STAT5B in mature adipocytes
after GH (500 ng/mL) treatment for 1 and 6 hours. c Images of adipocytes STAT5B immunofluorescent
staining after GH (500 ng/mL) treatment for 60 min. Magnification, 200x. Scale bars, 50 µm. Data are
presented as means ± SEM (n = 4). *P < 0.05, **P < 0.01 vs. the control group. Figure 4 GH increased the phosphorylation of STAT5B in bovine subcutaneous adipocytes. a Western blot
analysis of p-STAT5B and STAT5B at day 0 of adipocyte differentiation with GH (500 ng/mL) treatment
for 10, 30, 60, and 180 minutes. b Western blot analysis of p-STAT5B and STAT5B in mature adipocytes
after GH (500 ng/mL) treatment for 1 and 6 hours. c Images of adipocytes STAT5B immunofluorescent
staining after GH (500 ng/mL) treatment for 60 min. Magnification, 200x. Scale bars, 50 µm. Data are
presented as means ± SEM (n = 4). *P < 0.05, **P < 0.01 vs. the control group. Page 21/22 Figure 5
GH-induced differentiation and browning of bovine subcutaneous adipocytes were mediated by STAT5B. a Adipocytes were preincubated with STAT5-IN-1 (100 μM) for 1 h and treated with GH (500 ng/mL) for 1
h during the differentiated process (day 0). Western blot was used to analyze the expression of p-
STAT5B and STAT5B proteins (n = 4). b Adipocytes were preincubated with STAT5-IN-1 (100 μM) for 1 h
and treated with GH (500 ng/mL) for 24 h during the differentiated process (day 0). RT-qPCR was used to
analyze the expression of PPARγ, CEBPα, and SREBP1 genes (n = 3). c Mature adipocytes were
preincubated with STAT5-IN-1 (100μM) for 1 h and treated with GH (500 ng/mL) for 6 h. Figure 2 RT-qPCR was
used to analyze the expression levels of UCP1, PGC-1α, and PRDM16 genes (n = 3). Data are presented
as means ± SEM. Statistical significance shows as *P < 0.05, **P < 0.01. Figure 5 Figure 5 GH-induced differentiation and browning of bovine subcutaneous adipocytes were mediated by STAT5B. a Adipocytes were preincubated with STAT5-IN-1 (100 μM) for 1 h and treated with GH (500 ng/mL) for 1
h during the differentiated process (day 0). Western blot was used to analyze the expression of p-
STAT5B and STAT5B proteins (n = 4). b Adipocytes were preincubated with STAT5-IN-1 (100 μM) for 1 h
and treated with GH (500 ng/mL) for 24 h during the differentiated process (day 0). RT-qPCR was used to
analyze the expression of PPARγ, CEBPα, and SREBP1 genes (n = 3). c Mature adipocytes were
preincubated with STAT5-IN-1 (100μM) for 1 h and treated with GH (500 ng/mL) for 6 h. RT-qPCR was
used to analyze the expression levels of UCP1, PGC-1α, and PRDM16 genes (n = 3). Data are presented
as means ± SEM. Statistical significance shows as *P < 0.05, **P < 0.01. Page 22/22
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https://openalex.org/W2524254194
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https://vestnik.vsmu.by:443/downloads/2016/2/2016_15_2_60-66.pdf
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The quality of life of patients with esophageal strictures after chemical burns following balloon dilatation
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Vestnik Vitebskogo gosudarstvennogo medicinskogo universiteta
| 2,016
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cc-by
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ХИРУРГИЯ ХИРУРГИЯ © ПЕТУХОВ А.В., 2016 © ПЕТУХОВ А.В., 2016 ПЕТУХОВ А.В. УО «Витебский государственный ордена Дружбы народов медицинский университет», г.Витебск,
Республика Беларусь Вестник ВГМУ. – 2016. – Том 15, №2. – С. 60-66. Резюме. Цель – оценить степень алиментарного истощения и биохимических нарушений, а также результаты при-
менения баллонной дилятации у пациентов со стриктурами пищевода, путем оценки качества жизни. Материал и методы. В исследование включены 36 пациентов с послеожоговыми стриктурами пищевода,
которым была произведена баллонная дилятация. У всех пациентов определялся индекс массы тела, опре-
делялся уровень основных биохимических параметров крови, уровень гемоглобина, эритроцитов, а также
степень дисфагии. Диагноз сриктуры пищевода у всех пациентов подтвержден рентгенологически и эндо-
скопически. После проведенного лечения проводилось исследование качества жизни с помощью опросни-
ка SF-36. Результаты. Установлено, что у 88,9% пациентов имеется дисфагия 3 степени, 69,4% пациентов имеют де-
фицит массы тела. При этом грубых лабораторных изменений, таких как гипопротеинемия, гипоальбуми-
немия, снижение уровня гемоглобина, эритроцитов не отмечается. Применение баллонной дилятации по-
зволяет безопасно и эффективно восстановить просвет пищевода, при этом требуется от 1 до 3 процедур с
интервалом в 1-2 дня. При исследовании качества жизни выявлено, что более других страдают показатели:
общего здоровья, ролевого и эмоционального функционирования. А при расчете общих показателей более
страдает «психологический компонент здоровья» – 40,15 балла по сравнению с «физическим компонентом
здоровья», который составил 49,61 балла. Заключение. Основными показателями тяжести состояния пациентов с послеожоговыми стриктурами пи-
щевода являются индекс массы тела и дисфагия. Баллонная дилятация является эффективным и безопас-
ным методом восстановления проходимости пищевода. Снижение качества жизни пациентов с послеожо-
говыми стриктурами происходит в основном за счет психологического компонента здоровья. Ключевые слова: стриктура пищевода, баллонная дилятация пищевода, качество жизни. PETUKHOV A.V. Educational Establishment «Vitebsk State Order of Peoples’ Friendship Medical University», Vitebsk, Republic of Belarus
Vestnik VGMU. 2016;15(2):60-66. Abstract. Objectives. To assess the degree of alimentary inanition and biochemical disturbances as well as the life quality of
patients with esophageal strictures after chemical burns following balloon dilatation. Material and methods. The total of 36 cases with esophageal burns strictures were treated with balloon dilatation. In all patients their body mass index, the level of the main biochemical parameters of the blood, the level of
hemoglobin, erythrocytes as well as the degree of dysphagia were determined. The diagnosis of esophageal stricture
was confirmed using both upper endoscopy and contrast radiography of the upper gastrointestinal tract. After the
provided treatment the quality of life was estimated using SF-36 questionnaire. p
q
y
g
q
Results. The third degree dysphagia was registered in 88,9% of patients and 69,4% of them were underweight. There were no gross deviations in blood analysis such as hypoproteinemia, hypoalbuminemia or decrease in the 60 ВЕСТНИК ВГМУ, 2016, ТОМ 15, №2 amount of red blood cells or hemoglobin. Esophageal balloon dilatation allows to safely and effectively restore
luminal diameter of the esophagus requiring only 1 to 3 procedures with 1-2 days interval. The quality of life
analysis has shown that such indices as general health, emotional health and role functioning are affected most of
all. And when calculating general indices the «psychological component of health» suffers more – 40,15 points in
comparison with the «physical component of health», which made up 49,61 points. p
p y
p
p
p
Conclusions. The main indicators of the severity of patients’ condition with post-burn esophageal strictures are
body mass index and dysphagia degree. Esophageal balloon dilatation is a safe and effective way to restore luminal
diameter of the esophagus thus relieving dysphagia. The reduction of the life quality in patients with post-burn
strictures occurs mainly due to the psychological health component. y
p y
g
p
Key words: esophageal stricture, esophageal balloon dilatation, quality of life. В настоящее время в доступной литера-
туре имеется мало данных о частоте развития
рубцовых стриктур пищевода, а также о совре-
менных методах их лечения. Чаще всего в ка-
честве основного метода лечения указывается
бужирование пищевода [1]. Применение других
методов лечения стриктур пищевода, в том чис-
ле баллонной дилятации, в отечественной лите-
ратуре практически не освещено [2]. Так, А.Ф. Черноусов и соавт. [3] упоминают об эндоско-
пической баллонной гидростатической дилята-
ции, однако в основном описывается методика
различных вариантов бужирования. Abstract. В зарубеж-
ной литературе встречаются сообщения о диля-
тации пищевода в качестве дополнительного
метода при паллиативном лечении рака пище-
вода [4]. По данным Галлингер Ю.И., Годжел-
ло Э.А. (1999), при коротких стриктурах пище-
вода (до 5 см.) стойкого выздоровления после
баллонной дилятации удается добиться в 85-90
% случаев [5]. В то же время, количество паци-
ентов с данной патологией из года в год увели-
чивается, что является основанием для более
глубокого изучения проблемы. Материал и методы В исследования включены 36 пациентов
с послеожоговыми стриктурами пищевода,
которым была произведена баллонная диля-
тация. Средний возраст 53,23±17,15 лет. Муж-
чин было 22, женщин – 14 (61% и 39% соответ-
ственно). Из анамнеза известно, что у 80,6% паци-
ентов причиной развития рубцовых стенозов
пищевода явилось употребление прижигаю-
щей жидкости. Длительность заболевания ко-
лебалась от 7 месяцев до 5,5 лет, среднее значе-
ние составило 18,36±15,7 месяцев. Все пациенты отмечали снижение массы
тела в большей или меньшей степени. Для объ-
ективной оценки этого показателя нами иссле-
дован индекс массы тела (ИМТ), который рас-
считывали по формуле 1: считывали по формуле 1: (1) ф р у
ИМТ=М/Р2,
(1)
где М – масса в кг,
Р – рост в метрах. ф р у
ИМТ=М/Р2,
(1)
где М – масса в кг,
Р – рост в метрах. (1) Для оценки использовали общеприня-
тую шкалу (табл. 1). Все пациенты обследованы лаборатор-
ными и инструментальными методами. При
лабораторных исследованиях обращали вни-
мание на уровень гемоглобина, эритроцитов,
а также на уровень основных биохимических Цель – оценить степень алиментарно-
го истощения и биохимических нарушений, а
также результаты применения баллонной ди-
лятации у пациентов со стриктурами пищево-
да, путем оценки качества жизни. Таблица 1 – Индекс массы тела
ИМТ
Оценка
16 и менее
Выраженный дефицит массы тела
16-18,5
Недостаточная (дефицит) масса тела
18,5-24,99
Норма
25-30
Избыточная масса тела (предожирение)
30-35
Ожирение первой степени
35-40
Ожирение второй степени
40 и более
Ожирение третьей степени (морбидное) 61 БАЛЛОННАЯ ДИЛЯТАЦИЯ И КАЧЕСТВО ЖИЗНИ параметров: АЛТ, АСТ, глюкоза, билирубин
общий, билирубин прямой, мочевина, креати-
нин, общий белок, альбумины, глобулины. параметров: АЛТ, АСТ, глюкоза, билирубин
общий, билирубин прямой, мочевина, креати-
нин, общий белок, альбумины, глобулины. индекса массы тела были получены следующие
данные. Пациентов с ожирением 1, 2 и 3 степе-
ни не было. У 3-х (8,33%) пациентов выявлено
наличие избыточной массы тела (ИМТ 25-30). Нормальное значение ИМТ определено у 15
(41,67%) пациентов. 17 (47,2%) пациентов име-
ли дефицит массы тела (ИМТ от 16 до 18), и у 1
(2,8%) пациента диагностирован выраженный
дефицит массы тела (ИМТ 15,37). Наличие па-
циентов с избыточной массой тела и нормаль-
ными значениями ИМТ объясняется коротким
анамнезом заболевания у данной группы, т.е. чем длительнее анамнез, тем более снижаются
показатели ИМТ. Из инструментальных методов обяза-
тельно проводилась фиброэзофагоскопия и
рентгеноскопия пищевода. Исследование качества жизни осущест-
влялось с применением опросника качества
жизни SF-36 [6]. В опроснике выделено 8 шкал,
по которым и оценивается качество жизни. 8. Психологическое здоровье (MH). Оценка результатов производилась пу-
тем суммирования баллов согласно каждой
шкале с последующим расчетом конкретного
показателя по формуле 2: Основные биохимические показатели
крови у мужчин и женщин представлены в та-
блице 2. [ (реальное значение показателя) – (ми-
нимально возможное значение показателя) ] :
(возможный диапазон значений) * 100
(2) Из таблицы следует, что, вопреки ожи-
даниям, грубых биохимических нарушений у
пациентов с рубцовыми стриктурами не зави-
симо от стажа заболевания не было. Это сви-
детельствует о достаточной степени компен-
сации организма в условиях ограниченного
питания. При фиброэзофагоскопии явления
эзофагита выявлены у 14 пациентов (38,9%). (возможный диапазон значений) 100
(2)
Опрос пациентов производился путем
почтовой рассылки анкет, а также путем анке-
тирования пациентов при повторной госпита-
лизации для очередного курса лечения. Всего
разослано 30 анкет, получено 12 ответов, из
них 1 анкета не доставлена адресату вслед-
ствие смены места жительства, по данным еще
одной анкеты пациент скончался, причина
смерти родственниками не указана. Обработ-
ке подверглись 10 анкет, полученных по по-
чте, и 6 анкет, заполненных пациентами при
повторной госпитализации. Таким образом,
ответы получены от 44,4% респондентов. Об-
работка материала проводилась с помощью
пакета программ MSExcel 2007 и Statistica 6.0. Опрос пациентов производился путем
почтовой рассылки анкет, а также путем анке-
тирования пациентов при повторной госпита-
лизации для очередного курса лечения. Всего
разослано 30 анкет, получено 12 ответов, из
них 1 анкета не доставлена адресату вслед-
ствие смены места жительства, по данным еще
одной анкеты пациент скончался, причина
смерти родственниками не указана. Обработ-
ке подверглись 10 анкет, полученных по по-
чте, и 6 анкет, заполненных пациентами при
повторной госпитализации. Таким образом,
ответы получены от 44,4% респондентов. Об-
работка материала проводилась с помощью
пакета программ MSExcel 2007 и Statistica 6.0. При рентгенологическом исследовании
пищевода и желудка был подтвержден топи-
ческий диагноз патологического процесса
(рис. 1), а также у двух пациентов выявлены
признаки рубцовой деформации желудка с на-
рушением эвакуаторной функции, у одного
– признаки аксиальной грыжи пищеводного
отверстия диафрагмы. Следует отметить, что
такую характеристику, как протяженность
стриктуры можно оценить только по данным
рентгеноскопии пищевода. Материал и методы Чем ниже уровень показателя, тем ниже каче-
ство жизни. Опросник SF – 36 включает следу-
ющие шкалы: 1. Физическое функционирование (PF). 2. Ролевое (физическое) функционирова-
ние (RР). При оценке анализов крови выявлено,
что у мужчин показатели количества эритро-
цитов и лейкоцитов были в пределах нормы
(4,62±0,42*1012/л и 8,65±3,1*109/л соответствен-
но), а уровень гемоглобина умеренно снижен
(131,9±19,5 г/л), у женщин картина аналогич-
ная: количество эритроцитов и лейкоцитов
в пределах физиологической нормы, гемо-
глобин – умеренно снижен (4,21±0,69*1012/л,
7,5±2,7*109/л и 108,4±31,6 г/л соответственно). 3. Боль (P). 4. Общее здоровье (GH). 5. Жизнеспособность (VT). 6. Социальное функционирование (SF). 7. Эмоциональное функционирование
(RE). Результаты и обсуждение Кроме локализации стриктуры, оцени-
вали оставшийся просвет пищевода. При этом
выявлено, что при 3 степени дисфагии просвет,
как правило, не превышал 5 мм. При дисфагии 2
степени просвет составлял 5-8 мм. При дисфагии
4 степени просвет пищевода был менее 2 мм. Основной жалобой всех пациентов была
дисфагия. Дисфагия 2 степени выявлена у 3 па-
циентов, 3 степени – у 32 пациентов, 4 степени
– у 1 пациента. При исследовании показателей 62 ВЕСТНИК ВГМУ, 2016, ТОМ 15, №2 Таблица 2 – Биохимические показатели пациентов со стриктурами пищевода. Мужчины (n=22)
M±SD
Женщины (n=14)
M±SD
Норма
АЛТ
35,1±28,3
26,4±15,2
28-178
АСТ
40,4±24,9
35,5±17,2
28-129
Глюкоза, ммоль/л
4,5±0,8
5,2±2,0
3,3-6,1
Билирубин общий, ммоль/л
13,4±4,2
12,9±3,4
8,5-20,5
Билирубин прямой, ммоль/л
2,8±0,6
3,1±1,4
менее 5,0
Мочевина, ммоль/л
4,2±1,9
4,6±1,8
менее 8,33
Креатинин, ммоль/л
0,104±0,14
0,102±0,12
менее 0,106
Общий белок, г/л
65,8±6,1
67,2±8,3
65-85
Альбумин, г/л
39,8±6,1
37,3±6,6
35-50
Глобулин, г/л
25,3±7,1
30,9±6,1
25-45
2
14
18
1
1
верхняя треть
средняя треть
нижняя треть
верхняя + средняя треть
верхняя + нижняя треть
Рисунок 1 – Локализация стриктур. Таблица 2 – Биохимические показатели пациентов со стриктурами пищевода. Мужчины (n=22)
M±SD
Женщины (n=14)
M±SD
Норма
АЛТ
35,1±28,3
26,4±15,2
28-178
АСТ
40,4±24,9
35,5±17,2
28-129
Глюкоза, ммоль/л
4,5±0,8
5,2±2,0
3,3-6,1
Билирубин общий, ммоль/л
13,4±4,2
12,9±3,4
8,5-20,5
Билирубин прямой, ммоль/л
2,8±0,6
3,1±1,4
менее 5,0
Мочевина, ммоль/л
4,2±1,9
4,6±1,8
менее 8,33
Креатинин, ммоль/л
0,104±0,14
0,102±0,12
менее 0,106
Общий белок, г/л
65,8±6,1
67,2±8,3
65-85
Альбумин, г/л
39,8±6,1
37,3±6,6
35-50
Глобулин, г/л
25,3±7,1
30,9±6,1
25-45 Таблица 2 – Биохимические показатели пациентов со стриктурами пищевода. 2
14
18
1
1
верхняя треть
средняя треть
нижняя треть
верхняя + средняя треть
верхняя + нижняя треть
Рисунок 1 – Локализация стриктур. Рисунок 1 – Локализация стриктур. В клинике госпитальной хирургии ВГМУ
на базе торакального отделения с 2010 года в
качестве метода лечения рубцовых стриктур
используется баллонная дилятация пищево-
да. Причем, если в 2010 году таких пациентов
было 4, то в 2011 – 9, в 2012 – 17, в 2013 – 17,
при этом часть из них была госпитализирова-
на повторно для проведения очередного курса
лечения. Баллонная дилятация пищевода про-
водилась под рентгеновским либо под видео-
эндоскопическим контролем. В первом случае
пациент укладывается на спину, под рентген-
контролем в пищевод вводился контрастный
катетер, а затем в просвет пищевода и желуд-
ка вводился проводник. Необходимость при-
менения катетера была продиктована тем,
что проводник с гибким концом цепляется за
структуры гортанно-глотки, загибается и не
проходит в просвет стриктуры. Результаты и обсуждение После того,
как проводник заведен в желудок, по нему производится введение дилятатора. При рент-
геновском контроле баллон заводился ниже
стриктуры, присоединялся шприц высоко-
го давления, заполненный водорастворимым
контрастом, при этом баллон раскрывается без
дополнительного усилия. Затем баллон про-
двигался проксимально до момента появления
упругого сопротивления, т.е. места нахожде-
ния стриктуры. При этом следует уменьшить
наполнение баллона до того уровня, чтобы он
прошел через зону стриктуры. Для профилак-
тики миграции баллона во время процедуры
дистально или проксимально баллон следует
устанавливать так, чтобы стриктура распо-
лагалась на его середине (рис. 2). Следующим
этапом баллон сначала наполнялся мягко (без
дополнительного усилия), затем, убедившись,
что баллон стоит точно в зоне стриктуры, с по-
мощью шприца высокого давления, в баллоне
постепенно давление повышались с шагом 0,5 63 БАЛЛОННАЯ ДИЛЯТАЦИЯ И КАЧЕСТВО ЖИЗНИ Рисунок 2 – Баллон в зоне стриктуры. Рисунок 3 – Баллон полностью раскрыт. Рисунок 2 – Баллон в зоне стриктуры. Рисунок 3 – Баллон полностью раскрыт. При проведении процедуры под видеоэ-
зофагоскопией, пациент укладывался, как при
ФГДС, на левый бок. Под видеоконтролем в
просвет пищевода через канал эндоскопа вво-
дился проводник, а по проводнику баллон,
затем баллон раскрывался в стриктуре. Ди-
лятация проводилась аналогично описанной
ранее. АТМ, между шагами делались паузы в 30-60
секунд. При этом на манометре обычно отме-
чалось плавное снижение давления, что свиде-
тельствует о постепенном разрыве рубцовой
ткани в зоне стриктуры. Давление постепенно
доводилось до максимальных значений, ука-
занных на баллоне, т.к. в противном случае
раскрытие могло быть неполным. Полностью
раскрытый баллон оставляли еще на 5 минут
с целью гемостаза (рис. 3). Баллон извлекался
в расправленном состоянии, что позволяет до-
полнительно диагностировать вышележащие
стриктуры. Резкое снижение давления в балло-
не может говорить о разрыве баллона, разрыве
пищевода или разрыве «толстой» стриктуры. При разрыве баллона при рентген-контроле
наблюдается вытекание контраста за пределы
баллона. После процедуры обязательно про-
водилась контрольная рентгеноскопия пище-
вода с водорастворимым контрастом, которая
позволяет оценить проходимость пищевода
после баллонной дилятации, а также исклю-
чить затекание контраста за пределы пищево-
да. При необходимости производилась виде-
оэзофагоскопия, компьютерная томография
грудной клетки. Проведение баллонной дилятации под
контролем видеоэзофагоскопии имеет как пре-
имущества, так и недостатки. Главное преиму-
щество заключается в более быстром и более
точном проведении проводника по суженому
просвету пищевода в желудок, точная установ-
ка баллона в области стриктуры, возможность
эндоскопического контроля как проведения
самой процедуры, так и непосредственного
результата дилятации. Результаты и обсуждение К недостаткам следу-
ет отнести невозможность одномоментной
дилятации протяженных или множественных
стриктур, вследствие чего лечебный эффект
может наступить не сразу. Курс лечения составлял от 1 до 3 проце-
дур с интервалом в 1-2 дня. Несколько проце-
дур проводилось при протяженных стриктурах
и стриктурах с минимальным изначальным ди- 64 ВЕСТНИК ВГМУ, 2016, ТОМ 15, №2 и дефицит массы тела, а основные биохимиче-
ские показатели крови диагностического зна-
чения не имеют. аметром просвета. В таких случаях при первой
процедуре дилятация проводилась баллоном
меньшего диаметра (6-8 мм), диаметр которо-
го при последующих процедурах постепенно
доводился до 12-15 мм, что было обусловлено
необходимостью видеоэндоскопического кон-
троля как зоны дилятяции, так и осмотра же-
лудка с целью выявления химического ожога
последнего со стенозированием. аметром просвета. В таких случаях при первой
процедуре дилятация проводилась баллоном
меньшего диаметра (6-8 мм), диаметр которо-
го при последующих процедурах постепенно
доводился до 12-15 мм, что было обусловлено
необходимостью видеоэндоскопического кон-
троля как зоны дилятяции, так и осмотра же-
лудка с целью выявления химического ожога
последнего со стенозированием. 2. Наиболее частой причиной развития
стриктуры пищевода у 80,56% пациентов яв-
ляется употребление прижигающей жидкости. 3. Баллонная дилятация является эф-
фективным и безопасным методом восстанов-
ления проходимости пищевода, однако, для
достижения стойкого эффекта необходим ре-
гулярный контроль (не реже 2 раз в год) с про-
ведением повторной баллонной дилятации,
при необходимости. 19 пациентам баллонная дилятация пи-
щевода проводилась в один этап, 13 паци-
ентов были госпитализированы дважды для
проведения баллонной дилятации, 1 пациент –
трижды и 1 пациент за время наблюдения был
госпитализирован 4 раза. 4. У пациентов с послеожоговыми стрик-
турами пищевода, в наибольшей степени стра-
дает психологический компонент здоровья,
менее – физический компонент здоровья. При исследовании качества жизни с по-
мощью опросника SF-36, получены следую-
щие результаты, представленные в таблице 3. 5. Послеожоговые стриктуры пище-
вода являются не только физиологической
проблемой, но и откладывают отпечаток на
социальное и психологическое благополу-
чие пациентов, поэтому лечение их требуют
комплексного подхода – лечения патологии
пищевода и коррекции психологического со-
стояния. р
у
,
р
Из таблицы следует, что меньше всего
страдают такие показатели как физическое
функционирование и показатель боли, что
говорит об удовлетворительной компенсации
питания в результате проводимой баллонной
дилятации. Умеренно снижены показатели
жизнеспособности, социального функциони-
рования и психологического здоровья. Более
всего снижены показатели общего здоровья,
ролевого и эмоционального функционирова-
ния, что является отражением необходимости
соблюдать определенную диету, в первую оче-
редь для компенсации имеющейся дисфагии. Литература 1. Черноусов, А. Ф. Пластика пищевода при раке и до-
брокачественных стриктурах / А. Ф. Черноусов, В. С. Сильвестров, Ф. С. Курбанов. – М. : Медицина,
1990. – 114 с. 2. Сотников, А. В. Вибрационные и эндохирургические
способы расширения рубцовых сужений пищевода /
А. В. Сотников // 2-й Московский Международный
конгрес по эндоскопической хирургии, 23–25 апр. 1997 г. : сб. тез. – М., 1997. – С. 334–335. 3. Черноусов, А. Ф. Хирургия пищевода : рук. для вра-
чей / А. Ф. Черноусов, П. М. Богопольский, Ф. С. Курбанов. – М. : Медицина, 2000. – 352 с. По нашим наблюдениям, даже при хо-
роших результатах баллонной дилятации пи-
щевода, восстановления исходной массы тела
пациентов не происходит на протяжении всего
времени наблюдения. 4. Malignant
esophagogastric
junction
obstruction:
efficacy of balloon dilation combined with chemotherapy
and/or radiation therapy / G.Y. Ko [et al.] // Cardiovasc. Intervent. Radiol. – 2003 Mar-Apr. – Vol. 26, N 2. – P. 141–145. 5. Галлингер, Ю. И. Оперативная эндоскопия пищево-
да / Ю. И. Галлингер, Э. А. Годжелло. – М., 1999. – 273 с. Результаты и обсуждение Эти же данные подтверждаются при расчете
общих показателей «Физический компонент
здоровья» и «Психологический компонент
здоровья» выявлено, что первый составляет
49,61 балла против 40,15 балла. БАЛЛОННАЯ ДИЛЯТАЦИЯ И КАЧЕСТВО ЖИЗНИ БАЛЛОННАЯ ДИЛЯТАЦИЯ И КАЧЕСТВО ЖИЗНИ Заключение 1. Основными показателями тяжести со-
стояния пациентов с послеожоговыми стрик-
турами пищевода являются степень дисфагии 6. Оценка качества жизни больного в медицине / А. А. Новик [и др.] // Клинич. медицина. – 2000. – № 2. – С. 10–13. Поступила 26.02.2016 г. Принята в печать 15.04.2016 г. Поступила 26.02.2016 г. Принята в печать 15.04.2016 г. Поступила 26.02.2016 г. Принята в печать 15.04.2016 г. 65 4.
Ko GY, Song HY, Hong HJ, Sung KB, Seo
TS, Yoon HK. Malignant esophagogastric junction
obstruction: efficacy of balloon dilation combined with
chemotherapy and/or radiation therapy. Cardiovasc
Intervent Radiol. 2003 Mar-Apr;26(2):141-5. References р
4. Ko GY, Song HY, Hong HJ, Sung KB, Seo
TS, Yoon HK. Malignant esophagogastric junction
obstruction: efficacy of balloon dilation combined with
chemotherapy and/or radiation therapy. Cardiovasc
Intervent Radiol. 2003 Mar-Apr;26(2):141-5. 4. Ko GY, Song HY, Hong HJ, Sung KB, Seo
TS, Yoon HK. Malignant esophagogastric junction
obstruction: efficacy of balloon dilation combined with
chemotherapy and/or radiation therapy. Cardiovasc
Intervent Radiol. 2003 Mar-Apr;26(2):141-5. 1. Chernousov AF, Silvestrov VS, Kurbanov FS. Plastika pishchevoda pri rake i dobrokachestvennykh
strikturakh [An esophagoplasty at cancer and good-
quality strictures]. Moscow, RF: Meditsina; 1990. 114 р. 2. Sotnikov AV. Vibratsionnye i endokhirurgicheskie
sposoby rasshireniia rubtsovykh suzhenii pishchevoda
[Vibratory and endosurgical ways of expansion of
cicatrical esophageal stenoses]. V: 2-i Moskovskii
Mezhdunarodnyi
kongres
po
endoskopicheskoi
khirurgii 23–25 apr 1997 g: sb tez. Moskva, RF; 1997. Р. 334-5. p
( )
5. Gallinger YuI, Godzhello EA. Operativnaia endoskopiia
pishchevoda [Operational endoscopy of an esophagus]. Moscow, RF; 1999. 273 р. p
( )
5. Gallinger YuI, Godzhello EA. Operativnaia endoskopiia
pishchevoda [Operational endoscopy of an esophagus]. Moscow, RF; 1999. 273 р. 6. Novik AA, Matveev SA, Ionova TI, Maksimov AG,
Povzun AS, Sukhonos YuA, Tsepkova AA. Otsenka
kachestva zhizni bol'nogo v meditsine [An assessment
of quality of life of the patient in medicine]. Klinich
Meditsina. 2000;(2):10-3. 6. Novik AA, Matveev SA, Ionova TI, Maksimov AG,
Povzun AS, Sukhonos YuA, Tsepkova AA. Otsenka
kachestva zhizni bol'nogo v meditsine [An assessment
of quality of life of the patient in medicine]. Klinich
Meditsina. 2000;(2):10-3. 6. Novik AA, Matveev SA, Ionova TI, Maksimov AG,
Povzun AS, Sukhonos YuA, Tsepkova AA. Otsenka
kachestva zhizni bol'nogo v meditsine [An assessment
of quality of life of the patient in medicine]. Klinich
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Accept 15.04.2016 Сведения об авторах: Сведения об авторах: д
р
Петухов А.В. – к.м.н., доцент кафедры госпитальной хирургии УО «Витебский государственный ордена
Дружбы народов медицинский университет». Адрес для корреспонденции: Республика Беларусь, 210023, г. Витебск, пр. Фрунзе, 27, УО «Витебский госу-
дарственный ордена Дружбы народов медицинский университет», кафедра госпитальной хирургии. E-mail:
alex.v.pet@gmail.com – Петухов Алексей Владимирович. 66
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https://cancer.jmir.org/2021/1/e16785/PDF
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Effects and Implementation of a Mindfulness and Relaxation App for Patients With Cancer: Mixed Methods Feasibility Study
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JMIR cancer
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cc-by
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Abstract Background: Cancer diagnosis and cancer treatment can cause high levels of distress, which is often not sufficiently addressed
in standard medical care. Therefore, a variety of supportive nonpharmacological treatments have been suggested to reduce distress
in patients with cancer. However, not all patients use these interventions because of limited access or lack of awareness. To
overcome these barriers, mobile health may be a promising way to deliver the respective supportive treatments. Objective: The aim of this study is to evaluate the effects and implementation of a mindfulness and relaxation app intervention
for patients with cancer as well as patients’ adherence to such an intervention. Methods: In this observational feasibility study with a mixed methods approach, patients with cancer were recruited through
the web and through hospitals in Switzerland. All enrolled patients received access to a mindfulness and relaxation app. Patients
completed self-reported outcomes (general health, health-related quality of life, anxiety, depression, distress, mindfulness, and
fear of progression) at baseline and at weeks 4, 10, and 20. The frequency of app exercise usage was gathered directly through
the app to assess the adherence of patients. In addition, we conducted interviews with 5 health professionals for their thoughts
on the implementation of the app intervention in standard medical care. We analyzed patients’self-reported outcomes using linear
mixed models (LMMs) and qualitative data with content analysis. Results: A total of 100 patients with cancer (74 female) with a mean age of 53.2 years (SD 11.6) participated in the study, of
which 25 patients used the app regularly until week 20. LMM analyses revealed improvements in anxiety (P=.04), distress
(P<.001), fatigue (P=.01), sleep disturbance (P=.02), quality of life (P=.03), and mindfulness (P<.001) over the course of 20
weeks. Further LMM analyses revealed a larger improvement in distress (P<.001), a moderate improvement in anxiety (P=.001),
and a larger improvement in depression (P=.03) in patients with high levels of symptoms at baseline in the respective domains. The interviews revealed that the health professionals perceived the app as a helpful addition to standard care. They also made
suggestions for improvements, which could facilitate the implementation of and adherence to such an app. Conclusions: This study indicates that a mindfulness and relaxation app for patients with cancer can be a feasible and effective
way to deliver a self-care intervention, especially for highly distressed patients. Abstract Future studies should investigate if the appeal of
the app can be increased with more content, and the effectiveness of such an intervention needs to be tested in a randomized
controlled trial. (JMIR Cancer 2021;7(1):e16785) doi: 10.2196/16785 Effects and Implementation of a Mindfulness and Relaxation App
for Patients With Cancer: Mixed Methods Feasibility Study Michael Mikolasek1, MSc; Claudia Margitta Witt1,2,3, MBA, MD; Jürgen Barth1, PhD
1Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
2Institute for Social Medicine, Epidemiology and Health Economics, Charité, Universitätsmedizin Berlin, Berlin, Germany
3Center for Integrative Medicine, University of Maryland School of Medicine, Baltimore, MD, United States Corresponding Author:
Michael Mikolasek, MSc
Institute for Complementary and Integrative Medicine
University Hospital Zurich and University of Zurich
Sonneggstrasse 6
Zurich, 8091
Switzerland
Phone: 41 44 255 51 49
Fax: 41 44 255 43 94
Email: michael.mikolasek@usz.ch Original Paper
Effects and Implementation of a Mindfulness and Relaxation App
for Patients With Cancer: Mixed Methods Feasibility Study
Michael Mikolasek1, MSc; Claudia Margitta Witt1,2,3, MBA, MD; Jürgen Barth1, PhD
1Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
2Institute for Social Medicine, Epidemiology and Health Economics, Charité, Universitätsmedizin Berlin, Berlin, Germany
3Center for Integrative Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
Corresponding Author:
Mikolasek et al
JMIR CANCER Mikolasek et al JMIR CANCER Original Paper https://cancer.jmir.org/2021/1/e16785 Michael Mikolasek1, MSc; Claudia Margitta Witt1,2,3, MBA, MD; Jürgen Barth1, PhD
1Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of Zurich, Zurich, Switzerland
2Institute for Social Medicine, Epidemiology and Health Economics, Charité, Universitätsmedizin Berlin, Berlin, Germany
3Center for Integrative Medicine, University of Maryland School of Medicine, Baltimore, MD, United States Study Design For this feasibility study, we used a mixed methods approach. For quantitative data, we assessed 4 paper-and-pencil
questionnaires that were sent to patients with cancer at baseline
and at weeks 4, 10, and 20. Demographics and patient
characteristics were assessed at baseline, and health outcomes
(physical, mental, and social health, health-related quality of
life, anxiety, depression, distress, mindfulness, and fear of
progression) were assessed over the 4 time points. Qualitative
data consisted of semistructured interviews with 5 health
professionals. In those interviews, we inquired about health
professionals’
perspectives
on
a
mindfulness-
and
relaxation-based mHealth intervention for patients with cancer
and its implementation in standard medical care. To receive
feedback from different health professionals, we conducted 2
face-to-face group interviews (1 interview with 2 nursing experts
and the second interview with 2 psychologists providing MBM
treatment for patients with cancer) and 1 individual interview
with an oncologist. All interviewees received access to the app
before the interview and could test the app. The interviewer
also demonstrated the app and its content to the interviewees
before the interview started. However, the uptake of supportive treatments in distressed
patients with cancer is moderate [17]. Barriers for the uptake
of such treatments include stigmatization, unawareness of such
interventions, or limited access [18,19]. This is problematic
because untreated, elevated levels of distress can lead to
additional negative effects, such as reduced quality of life, daily
functioning, and lower adherence to medical treatment [20,21]. Access can be restricted, for instance, because of geographical
distance, lack of treatment providers or knowledge thereof, and
financial constraints [22-24]. To overcome these limitations in
access, eHealth and mobile health (mHealth) interventions have
been proposed. eHealth is defined more broadly as the delivery
of health services or information through the internet and related
technologies [25], whereas mHealth uses mobile technologies
such as smartphones for the delivery of health services [26]. So
far, research indicates that eHealth interventions with
mindfulness or relaxation components can have beneficial
effects on health outcomes in various patient populations
[27-29]. However, eHealth studies focusing on patients with
cancer have shown inconsistent results [30,31]. Nonetheless,
eHealth interventions seem promising because they can have
positive effects on the well-being of patients with cancer [31]. To assess the feasibility of our mHealth intervention, we used
the RE-AIM implementation science framework [37]. Ethical
approval for the study was granted in April 2016 by the cantonal
ethics committee Zurich (BASEC-Nr. Introduction The aim of this study is to assess the feasibility of this mHealth
intervention using the Reach, Effectiveness, Adoption,
Implementation, and Maintenance (RE-AIM) evaluation
framework, which was developed for the evaluation of public
health interventions [37]. Although the results for the reach of
the dimensions, adoption over the course of 10 weeks, and
maintenance were published elsewhere [36], the present analyses
focus on the 3 dimensions of effectiveness, adoption, and
implementation over the course of 20 weeks to assess the
pre-post effects of the app on a variety of health outcomes and
adherence to the app intervention. In doing so, we investigate
whether such an app may be a beneficial, supportive care tool
for patients with cancer. Background Cancer diagnosis and subsequent medical treatments can cause
high levels of distress [1-4]. However, adequate psychological
support for patients with cancer is often lacking in standard
medical care [5,6]. Therefore, a variety of supportive treatments
have been suggested to reduce distress in patients with cancer,
such as mind-body medicine (MBM) [7]. MBM combines
various effective treatments such as mindfulness meditation,
relaxation, yoga, and tai chi [7,8]. Such MBM treatments can
have beneficial effects on cancer-related symptoms, such as
pain, fatigue, and sleep disturbance [9-11]. Furthermore, MBM
treatments can have beneficial effects on the quality of life of
patients with cancer [12-14]. These treatments can be provided
through guided MBM programs for patients with cancer, where
the patients learn various exercises (eg, physical exercises,
relaxation, and stress reduction) and are encouraged to practice
these newly learned exercises at home [15,16]. KEYWORDS mobile app; mobile phone; mindfulness; relaxation; cancer; qualitative research; implementation science; mHealth; evaluation
study; patient compliance; patient participation; patient preference JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 1
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RenderX JMIR CANCER Mikolasek et al Mikolasek et al Study Design 2016-00258), and we
registered the study in the German Clinical Trials Register
(DRKS00010481). Although mHealth interventions have some advantages over
web-based eHealth interventions (eg, more flexible access
because of mobility, the possibility of reaching a large number
of patients because of the large popularity of smartphones),
little is known about the best practices for the implementation
of mHealth interventions [32,33]. In addition, mHealth research
so far indicates that the adoption of mHealth interventions by
health professionals and patients can be inhibited by various
factors, such as perceived usefulness and ease of use [34,35]. Furthermore, there is a lack of mHealth studies with mindfulness
or relaxation-based interventions [27]. Therefore, we developed
a research app to conduct a feasibility study of a mindfulness-
and relaxation-based mHealth intervention for patients with
cancer [36]. The app included 3 exercises, namely, mindfulness
meditation, guided imagery, and progressive muscle relaxation. https://cancer.jmir.org/2021/1/e16785 JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 2
(page number not for citation purposes) App Intervention All enrolled patients received the mindfulness and relaxation
app, which was specifically developed for this study and only
available for patients participating in the study. The app could
be downloaded in the Apple iTunes store and Google Play Store
for Android devices and accessed with a code, which was
provided to the patients after study inclusion. The app offered
3 exercises: mindfulness meditation, guided imagery, and
progressive muscle relaxation. The exercises were included in
the app as audio files with a duration of approximately 15
minutes each, and the patients could choose between a female
or male narrator. Patients were free to choose which exercises
they wanted to use and how often they wanted to practice. However, we recommended to the patients to use an exercise
of their choice on a daily basis, ideally 5 times per week. To
help patients practice regularly, the app included an optional
notification feature that patients could set up to receive a daily
push notification on the mobile device, reminding them to
practice at an individually set time. Information about the use
of exercises (exercise type, date, and start and end times) was
saved in the backend and was only accessible to the researchers
as an XML log file. More information about the app is presented
in a previously published paper [36]. We measured anxiety and depression using the Hospital Anxiety
and Depression Scale (HADS). The HADS assesses 7 items for
the subscales anxiety (Cronbach α=.79) and depression
(Cronbach α=.67) on a 4-point scale, with a maximum score of
21 for each subscale. A score of up to 7 is considered normal,
a score between 8 and 11 is considered borderline, and a score
above 11 is considered caseness [44]. For the assessment of fear of progression, we administered the
Fear of Progression Questionnaire-Short Form (FoP-Q-SF) [45]. The FoP-Q-SF (Cronbach α=.81) consists of 12 items with a
5-point scale. A higher score indicates a greater fear of
progression. We assessed PROMIS 29, FACT-G, and FMI at baseline and
at weeks 4, 10, and 20 and HADS, FoP-Q-SF, and Distress
Thermometer at baseline and at weeks 10 and 20. We defined
a continuous app user as a patient who regularly used the app
exercises (at least one exercise per week). Effects As we conducted a single-arm study without a control group,
we were not able to assess the effectiveness of the app
intervention. Therefore,
for
the
RE-AIM
dimension
effectiveness, we looked into pre-post effects in a variety of
health outcomes relevant to patients with cancer. We assessed
physical, mental, and social health using the Patient-Reported
Outcomes Measurement Information System (PROMIS 29)
[38]. PROMIS 29 is a 29-item scale assessing 7 health domains:
physical function (Cronbach α=.81), fatigue (Cronbach α=.94),
pain interference (Cronbach α=.96), depressive symptoms
(Cronbach α=.85), anxiety (Cronbach α=.81), ability to
participate in social roles and activities (Cronbach α=.88), and
sleep disturbance (Cronbach α=.86) with 4 items, each on a
5-point scale, and pain intensity with a single item on a 10-point
numeric rating scale. Adoption For the RE-AIM dimension adoption, we looked at the number
of completed app exercises over 20 weeks and app exercise
preferences. We reported the median of completed app exercises
by all enrolled patients per week as well as the median of
completed app exercises by continuous app users. For exercise
preferences, we reported frequencies of used exercises for all
enrolled patients, stratified by gender of the patient and the
narrator. Implementation For the RE-AIM dimension implementation, we reported results
from interviews with health professionals regarding their opinion
on the implementation of the app intervention in addition to
standard medical care. In the interviews, we inquired about the
general impression regarding the app, implementation of the
app as an addition to standard medical care, and suggestions
for improvements. For the assessment of health-related quality of life for patients
with cancer, we administered the Functional Assessment of
Cancer Therapy—General (FACT-G) [39,40]. The FACT-G
consists of 4 subscales: physical well-being (Cronbach α=.85),
social well-being (Cronbach α=.76), emotional well-being
(Cronbach α=.70), and functional well-being (Cronbach α=.79),
measured with 27 items on a 5-point scale. A higher score
indicates a better quality of life. Participants Patients were eligible if they (1) had any cancer diagnosis at
any stage of cancer, (2) were aged 18 years or older, and (3)
owned either an iPhone (Apple Inc). or an Android-based
smartphone with at least a weekly connection to the internet. Patients were excluded if they had suicidal ideation or
insufficient German language skills, if they intended to move
to another country, or if they had insufficient knowledge on
how to use a smartphone. The patient recruitment process is
described in detail elsewhere [36]. For the interviews with health
professionals, we invited experts (an oncologist, nursing experts, JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 2
(page number not for citation purposes) JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 2
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RenderX JMIR CANCER Mikolasek et al and psychologists) from the University Hospital Zurich, who
provide health care for patients with cancer. For the assessment of mindfulness, we administered the short
version of the Freiburg Mindfulness Inventory (FMI) [43]. The
FMI (Cronbach α=.87) assesses mindfulness with 14 items on
a 4-point scale, with a higher score indicating higher
mindfulness. and psychologists) from the University Hospital Zurich, who
provide health care for patients with cancer. https://cancer.jmir.org/2021/1/e16785 App Intervention We counted an
exercise as completed if the patient played the exercise audio
file for at least 10 minutes of the total time of 15 minutes. We
defined an intervention dropout as a patient who stopped using
the exercises for 4 consecutive weeks because regular practice
might be a prerequisite for a beneficial intervention. We defined
the first week when the patient stopped using the exercises as
a dropout week. A patient who never used an app exercise was
counted as a week 1 intervention dropout. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 3
(page number not for citation purposes) Sample Size One aspect evaluated in our feasibility study was the
characteristics and number of patients with cancer who
participated in the study (evaluation dimension reach), which
was reported previously [36]. Therefore, we did not perform an
a priori analysis to determine the required sample size for
adequate power. However, we aimed to recruit at least 100
patients, which is sufficient to achieve 80% power for a For the assessment of distress, we administered the Distress
Thermometer [41]. The Distress Thermometer is a numeric
rating scale, ranging from 0 to 10. A score of 5 or higher is
considered to indicate clinically relevant distress [42]. https://cancer.jmir.org/2021/1/e16785 JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 3
(page number not for citation purposes) XSL•FO
RenderX Mikolasek et al JMIR CANCER two-tailed t test with an α level set at .05 and a small effect size
of Cohen d of 0.28. included as a fixed effect. For group analyses, (continuous app
users vs intervention dropouts), we added group and
time-by-group as fixed effects. Hedge g effect sizes were
calculated as mean differences (baseline and week 20) divided
by pooled SDs for each health outcome of interest. Qualitative Data All printed case report forms were entered by trained researchers
into the electronic database REDCap (Research Electronic Data
Capture), which was hosted at the University Hospital Zurich. All analyses were carried out in SPSS version 25.0 (IBM Corp). For the dimension implementation, we recorded the interviews
and transcribed the interviews verbatim. We used thematic
coding for structuring the interviews using MAXQDA 11
(VERBI Software), and we used content analysis according to
Mayring [46]. For baseline characteristics of patients, we used descriptive
statistics (frequencies and percentages for categorical variables
and mean and SD for continuous variables). For the analyses
of pre-post effects, we used linear mixed models (LMMs) to
analyze changes over time (baseline, week 4, week 10, and week
20) in health outcomes as well as differences between
continuous app users and intervention dropouts in health
outcomes. All patients who provided baseline data were included
in the analyses, and because we used LMMs, patients with
missing data in weeks, 4, 10, and 20 questionnaires were
included. The dependent variables were the 7 PROMIS 29
domains, FACT-G, HADS subscales anxiety and depression,
Distress Thermometer, FMI, and FoP-Q-SF. Furthermore, we
looked at the changes in the respective health outcomes for
subsamples with high distress (Distress Thermometer score ≥5),
high anxiety (HADS anxiety score of ≥8), and high depression
(HADS depression score of ≥8). As a covariance type, we used
an autoregressive covariance structure (AR1). Time was JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 4
(page number not for citation purposes) Patient Characteristics Between June 2016 and December 2018, we were able to recruit
100 patients with cancer, all of whom provided baseline
information. At week 20, 72 (72%) patients completed
questionnaire 4 (Figure 1). Baseline characteristics of all
enrolled patients (N=100) as well as subsamples of patients
with high distress (62/100, 62%), high anxiety (35/100, 26%),
and high depression (20/100, 20%) are summarized in Table 1. Most patients (74/100, 74%) were female. The mean age of all
patients was 53.24 (SD 11.55) years, ranging from 23 to 84
years. Patients predominantly owned an iPhone smartphone
(67/100, 67%), whereas 30 patients (30/100, 30%) owned an
Android smartphone, and a few (3/100, 3%) owned both. Figure 1. Flowchart. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 4
https://cancer.jmir.org/2021/1/e16785
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FO Figure 1. Flowchart. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 4
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(page number not for citation purposes) https://cancer.jmir.org/2021/1/e16785 https://cancer.jmir.org/2021/1/e16785 JMIR CANCER Mikolasek et al Table 1. Demographics for the total sample and high distress, high depression, and high anxiety subsamples. Patient Characteristics High depressionc subsample
(n=20)
High anxietyb subsample
(n=35)
High distressa subsample
(n=62)
Total sample
(N=100)
Patient demographics
Gender, n (%)
15 (75)
26 (74)
48 (77)
74 (74)
Female
5 (25)
9 (26)
14 (23)
26 (26)
Male
51.74 (11.63)
51.22 (10.67)
52.74 (10.67)
53.24 (11.55)
Age (years), mean (SD)
Type of cancer, n (%)
8 (40)
18 (51)
27 (44)
39 (39)
Breast cancer
3 (15)
2 (6)
7 (11)
9 (9)
Colon cancer
0 (0)
2 (6)
3 (5)
6 (6)
Ovarian or cervical cancer
1 (5)
0 (0)
3 (5)
6 (6)
Lung cancer
8 (40)
13 (37)
22 (35)
40 (40)
Others
Status of cancer treatment, n (%)
11 (55)
24 (69)
33 (53)
46 (46)
Total removal
5 (25)
6 (17)
15 (24)
25 (25)
Recurrence or incomplete removal
2 (10)
1 (3)
1 (2)
3 (3)
Uncertain
4 (20)
4 (11)
13 (21)
26 (26)
Other
Highest education, n (%)
0 (0)
2 (6)
2 (3)
3 (3)
Primary school
5 (25)
5 (14)
16 (26)
22 (22)
Apprenticeship
7 (35)
14 (40)
21 (34)
41 (41)
Secondary education
7 (35)
14 (40)
22 (35)
33 (33)
University degree
1 (5)
0 (0)
1 (2)
1 (1)
Unknown
aDistress Thermometer score ≥5. bHospital Anxiety and Depression Scale anxiety score ≥8. cHospital Anxiety and Depression Scale depression score ≥8. Effects
The health outcome values at baseline and at week 20 as well
as effect sizes for the total sample and the high distress, high
anxiety, and high depression subsamples are presented in Table
2. Baseline distress was 5.29 (SD 2.31); therefore, patients were
on average above an assumed clinically relevant threshold of
5, with 62% of patients (62/100) reporting a distress level of 5
or higher. At week 20, distress decreased to an average of 4.1
(SD 2.12; Hedge g=0.53). The mean HADS anxiety score at
baseline was 6.88 (SD 3.50) and dropped to 6.31 (SD 3.78;
Hedge g=0.16) at week 20. Overall, 35% (35/100) of patients
reported an elevated HADS anxiety score (≥8) at baseline (mean
10.71, SD 1.95), which dropped to 8.85 (SD 3.50; Hedge
g=0.68) at week 20. For HADS depression, the mean score at
baseline was 4.96 (SD 2.78) and dropped to 4.55 (SD 3.31;
Hedge g=0.14) at week 20. Patient Characteristics Overall, 20% (20/100) of patients
reported an elevated HADS depression score (≥8) at baseline
(mean 9.00, SD 1.12), which dropped to 8.85 (SD 3.50; Hedge
g=0.61) at week 20. For the remaining measures without a
proposed threshold (PROMIS, FACT-G, FMI, and FoP-Q-SF),
changes from baseline to week 20 were small, with Hedges g
effect sizes ranging from 0.04 to 0.33. ble 1. Demographics for the total sample and high distress, high depression, and high anxiety subsamples. aDistress Thermometer score ≥5. reported an elevated HADS anxiety score (≥8) at baseline (mean
10.71, SD 1.95), which dropped to 8.85 (SD 3.50; Hedge
g=0.68) at week 20. For HADS depression, the mean score at
baseline was 4.96 (SD 2.78) and dropped to 4.55 (SD 3.31;
Hedge g=0.14) at week 20. Overall, 20% (20/100) of patients
reported an elevated HADS depression score (≥8) at baseline
(mean 9.00, SD 1.12), which dropped to 8.85 (SD 3.50; Hedge
g=0.61) at week 20. For the remaining measures without a
proposed threshold (PROMIS, FACT-G, FMI, and FoP-Q-SF),
changes from baseline to week 20 were small, with Hedges g
effect sizes ranging from 0.04 to 0.33. reported an elevated HADS anxiety score (≥8) at baseline (mean
10.71, SD 1.95), which dropped to 8.85 (SD 3.50; Hedge
g=0.68) at week 20. For HADS depression, the mean score at
baseline was 4.96 (SD 2.78) and dropped to 4.55 (SD 3.31;
Hedge g=0.14) at week 20. Overall, 20% (20/100) of patients
reported an elevated HADS depression score (≥8) at baseline
(mean 9.00, SD 1.12), which dropped to 8.85 (SD 3.50; Hedge
g=0.61) at week 20. For the remaining measures without a
proposed threshold (PROMIS, FACT-G, FMI, and FoP-Q-SF),
changes from baseline to week 20 were small, with Hedges g
effect sizes ranging from 0.04 to 0.33. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 5
(page number not for citation purposes) Effects Mean values of health outcomes at baseline and week 20, response rate (n), and effect sizes (N=100). Week 20
Baseline
Sample and outcome aHADS: Hospital Anxiety Depression Scale; negative effect=improvement. bPROMIS physfunct: Patient-Reported Outcomes Measurement Information System Physical Function; positive effect=improvement. cPROMIS anxiety: Patient-Reported Outcomes Measurement Information System Anxiety; negative effect=improvement. dPROMIS depression: Patient-Reported Outcomes Measurement Information System Depression; negative effect=improvement. ePROMIS fatigue: Patient-Reported Outcomes Measurement Information System Fatigue; negative effect=improvement. fPROMIS sleep: Patient-Reported Outcomes Measurement Information System Sleep Disturbance; negative effect=improvement. gPROMIS social: Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities; positive
effect=improvement. hPROMIS pain: Patient-Reported Outcomes Measurement Information System Pain Interference; negative effect=improvement. iFACT-G: Functional Assessment of Cancer Therapy—General; positive effect=improvement. jFMI: Freiburg Mindfulness Inventory; positive effect=improvement. kFoP: Fear of Progression; negative effect=improvement. lDistress Thermometer score ≥5; negative effect=improvement; n=62. mHADS anxiety score ≥8; negative effect=improvement; n=35. nHADS depression score ≥8; negative effect=improvement; n=20. The results for effects over time are presented in Table 3. LMM
analyses revealed that there was a significant decrease over time
and fear of progression. LMM analyses for the subsamples
revealed that distress decreased significantly in the high distress aHADS: Hospital Anxiety Depression Scale; negative effect=improvement. HADS: Hospital Anxiety Depression Scale; negative effect=improvement. bPROMIS physfunct: Patient-Reported Outcomes Measurement Information System Physical Function; positive effect=improvement. cPROMIS anxiety: Patient-Reported Outcomes Measurement Information System Anxiety; negative effect=improvement. dPROMIS depression: Patient-Reported Outcomes Measurement Information System Depression; negative effect=improvement. ePROMIS fatigue: Patient-Reported Outcomes Measurement Information System Fatigue; negative effect=improvement. fPROMIS sleep: Patient-Reported Outcomes Measurement Information System Sleep Disturbance; negative effect=improvement. gPROMIS social: Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities; positive
effect=improvement. h gPROMIS social: Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities; positive
effect=improvement. iFACT-G: Functional Assessment of Cancer Therapy—General; positive effect=improvement. jFMI: Freiburg Mindfulness Inventory; positive effect=improvement. kFoP: Fear of Progression; negative effect=improvement. lDistress Thermometer score ≥5; negative effect=improvement; n=62. HADS anxiety score ≥8; negative effect=improvement; n=35. The results for effects over time are presented in Table 3. LMM
analyses revealed that there was a significant decrease over time
in distress (P<.001), fatigue (P=.01), sleep disturbance (P=.02),
and anxiety (P=.04) measured with the HADS. Furthermore,
there was a significant increase in quality of life (P=.03) and
mindfulness (P<.001). Effects The health outcome values at baseline and at week 20 as well
as effect sizes for the total sample and the high distress, high
anxiety, and high depression subsamples are presented in Table
2. Baseline distress was 5.29 (SD 2.31); therefore, patients were
on average above an assumed clinically relevant threshold of
5, with 62% of patients (62/100) reporting a distress level of 5
or higher. At week 20, distress decreased to an average of 4.1
(SD 2.12; Hedge g=0.53). The mean HADS anxiety score at
baseline was 6.88 (SD 3.50) and dropped to 6.31 (SD 3.78;
Hedge g=0.16) at week 20. Overall, 35% (35/100) of patients JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 5
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RenderX Mikolasek et al Mikolasek et al JMIR CANCER Table 2. Mean values of health outcomes at baseline and week 20, response rate (n), and effect sizes (N=100). Hedges g (95% CI)
Week 20
Baseline
Sample and outcome
n
Mean (SD)
n
Mean (SD)
Total sample
−0.16 (−0.46 to 0.15)
71
6.31 (3.78)
99
6.88 (3.50)
HADSa anxiety
−0.14 (−0.44 to 0.17)
71
4.55 (3.31)
100
4.96 (2.78)
HADS depression
−0.53 (−0.84 to 0.22)
71
4.10 (2.12)
99
5.29 (2.31)
Distress
−0.04 (−0.34 to 0.27)
71
46.30 (7.32)
99
46.55 (6.54)
PROMIS physfunctb
−0.15 (−0.45 to −0.16)
70
55.01 (6.83)
99
55.97 (6.46)
PROMIS anxietyc
−0.18 (−0.49 to 0.12)
71
53.88 (7.81)
100
55.20 (6.81)
PROMIS depressiond
−0.38 (−0.69 to −0.07)
70
52.40 (10.31)
99
56.11 (9.23)
PROMIS fatiguee
−0.23 (−0.53 to 0.08)
70
49.52 (8.02)
100
51.44 (8.85)
PROMIS sleepf
0.18 (−0.12 to 0.49)
71
49.84 (7.87)
99
48.42 (7.64)
PROMIS socialg
0.10 (−0.41 to 0.21)
70
51.96 (9.38)
97
52.88 (9.10)
PROMIS painh
0.29 (−0.02 to 0.59)
70
79.62 (14.81)
99
75.54 (13.85)
FACT-Gi
0.51 (−0.20 to 0.83)
69
41.80 (6.42)
96
38.46 (6.62)
FMIj
−0.13 (−0.45 to 0.19)
64
30.28 (7.99)
93
31.33 (7.83)
FoPk
High distressl
−1.36 (−1.79 to −0.94)
46
4.39 (2.19)
62
6.79 (1.36)
Distress
High anxietym
−0.69 (−1.20 to −0.16)
26
8.85 (3.50)
35
10.71 (1.95)
HADS anxiety
High depressionn
−0.61 (−1.27 to 0.05)
17
7.47 (3.52)
20
9.00 (1.12)
HADS depression
aHADS: Hospital Anxiety Depression Scale; negative effect=improvement Table 2. Mean values of health outcomes at baseline and week 20, response rate (n), and effect sizes (N=100). Table 2. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 6
(page number not for citation purposes) https://cancer.jmir.org/2021/1/e16785 Effects bPROMIS physfunct: Patient-Reported Outcomes Measurement Information System Physical Function. bPROMIS physfunct: Patient-Reported Outcomes Measurement Information System Physical Function. cPROMIS anxiety: Patient-Reported Outcomes Measurement Information System Anxiety. dPROMIS depression: Patient-Reported Outcomes Measurement Information System Depression. ePROMIS fatigue: Patient-Reported Outcomes Measurement Information System Fatigue. fPROMIS sleep: Patient-Reported Outcomes Measurement Information System Sleep Disturbance. gPROMIS social: Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities. hPROMIS pain: Patient-Reported Outcomes Measurement Information System Pain Interference. iFACT-G: Functional Assessment of Cancer Therapy—General. jFMI: Freiburg Mindfulness Inventory PROMIS depression: Patient-Reported Outcomes Measurement Information System Depression. ePROMIS fatigue: Patient-Reported Outcomes Measurement Information System Fatigue. fPROMIS sleep: Patient-Reported Outcomes Measurement Information System Sleep Disturbance. gPROMIS social: Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities. hPROMIS pain: Patient-Reported Outcomes Measurement Information System Pain Interference. iFACT-G: Functional Assessment of Cancer Therapy—General jFMI: Freiburg Mindfulness Inventory. kFoP: Fear of Progression. kFoP: Fear of Progression. lDistress Thermometer score ≥5. lDistress Thermometer score ≥5. mHADS anxiety score ≥8. nHADS depression score ≥8. nHADS depression score ≥8. to 0 at week 9. For continuous app users, who completed an
app exercise at least once per week until week 20, the median
of completed exercises at week 1 was 6. For the subsequent
weeks up to week 20, the median of completed exercises varied
between a median of 3 and 5 for the continuous app users. https://cancer.jmir.org/2021/1/e16785 Effects No significant effects were found for
physical functioning, anxiety measured with PROMIS,
depression, ability to participate in social roles and activities, and fear of progression. LMM analyses for the subsamples
revealed that distress decreased significantly in the high distress
subsample (P<.001), anxiety decreased significantly in the high
anxiety subsample (P=.001), and depression decreased
significantly in the high depression subsample (P=.03). Dose-response analyses using LMMs with group-by-time
revealed no significant results. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 6
(page number not for citation purposes) JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 6
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RenderX Mikolasek et al JMIR CANCER Table 3. Linear mixed models: estimates of fixed effect of time on health outcomes from baseline to week 20. Estimates of fixed effects (time)
Sample and dependent variable
P value
t test (df)
Estimate (95% CI)
Total sample (N=100)
.04
−2.04 (201.95)
−0.40 (−0.79 to −0.01)
HADSa anxiety
.09
−1.71 (206.42)
−0.29 (−0.62 to 0.04)
HADS depression
<.001
−3.96 (325.86)
−0.41 (−0.62 to −0.21)
Distress
.66
−.45 (318.35)
−0.13 (−0.68 to 0.43)
PROMIS physfunctb
.16
−1.42 (325.74)
−0.46 (−1.09 to 0.18)
PROMIS anxietyc
.09
−1.72 (324.81)
−0.52 (−1.11 to 0.07)
PROMIS depressiond
.01
−2.61 (324.73)
−1.15 (−2.02 to −0.28)
PROMIS fatiguee
.02
−2.39 (322.65)
−0.85 (−1.55 to −0.15)
PROMIS sleepf
.15
1.45 (314.63)
0.43 (−0.15 to 1.01)
PROMIS socialg
.74
−.34 (322.51)
−0.14 (−0.94 to 0.66)
PROMIS painh
.03
2.16 (307.58)
1.13 (0.10 to 2.15)
FACT-Gi
<.001
4.46 (300.46)
1.11 (0.62 to 1.59)
FMIj
.13
−1.52 (180.05)
−0.68 (−1.56 to .20)
FoPk
High distressl (n=62)
<.001
−6.64 (200.45)
−0.81 (−1.05 to −0.57)
Distress
High anxietym (n=35)
.001
−3.47 (81.69)
−1.13 (−1.77 to −0.48)
HADS anxiety
High depressionn (n=20)
.03
−2.23 (47.99)
−0.87 (−1.65 to −0.09)
HADS depression inear mixed models: estimates of fixed effect of time on health outcomes from baseline to week 20. Table 3. Linear mixed models: estimates of fixed effect of time on health outcomes from baseline to week 20. Estimates of fixed effects (time)
Sample and dependent variable Table 3. Linear mixed models: estimates of fixed effect of time on health outcomes from baseline to week 20. Estimates of fixed effects (time)
Sample and dependent variable
t test (df)
Estimate (95% CI) .03 aHADS: Hospital Anxiety Depression Scale. aHADS: Hospital Anxiety Depression Scale. Adoption According to our definition, 25% (25/100) of all enrolled
patients used the app continuously (ie, at least one completed
exercise per week) at week 20 of the intervention. The average
number (median) of completed exercises during the 20-week
intervention for all patients as well as continuous app users is
presented in Figure 2. Across all patients, the median of
completed exercises was 2 during the first week and dropped The percentage of completed exercises is presented in Figure
3. All patients together completed 3526 exercises. Mindfulness
meditation was used most often, with a total of 1633 completed JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 7
(page number not for citation purposes) https://cancer.jmir.org/2021/1/e16785 XSL•FO
RenderX JMIR CANCER Mikolasek et al exercises (46.31%), followed by guided imagery with 1077
completed exercises (30.55%). Progressive muscle relaxation
was used least frequently, with 816 completed exercises
(23.14%). In both mindfulness meditation and guided imagery,
the female narrator voice was preferred. narrator vs 1031 completed exercises with a male narrator). However, male patients preferred exercises with a male narrator
(389 completed exercises with a male narrator vs 171 completed
exercises with a female narrator). The probability of choosing
the same sex in audio files is therefore increased for women by
87% and for men by 127%, which corresponds to a 2-fold higher
preference for the same sex as the narrator. Furthermore, female patients showed a preference for exercises
with a female narrator (1935 completed exercises with a female Furthermore, female patients showed a preference for exercises
with a female narrator (1935 completed exercises with a female
y
,
p
g
preference for the same sex as the narrator. Figure 2. Completed app exercises by all enrolled patients (N=100) and by continuous app users (n=25) per week (median). Figure 3. Completed exercises (3526) of all patients (N=100) over 20 weeks by type (mindfulness meditation, guided imagery, and progressive muscle
relaxation), gender of patient (male and female), and sex of narrator (male and female). Percentages refer to the total number of exercises per gender. JMIR C
2021 |
l 7 | i
1 | 16785 |
8
htt
//
j i
/2021/1/ 16785 Figure 2. Completed app exercises by all enrolled patients (N=100) and by continuous app users (n=25) per week (median). gure 2. Completed app exercises by all enrolled patients (N=100) and by continuous app users (n=25) per week (median). Implementation [...] And
you can’t just hand out the flyer. You also need to say
a few words [about the app] and that’s why I
sometimes forgot [to mention the app]. Due to
shortage of time. All health professionals perceived the app as appealing, clearly
structured, and as a helpful supportive tool. In addition, the
MBM psychologists liked the app as an addition to the 10-week
face-to-face MBM course and appreciated the app as a good
self-help tool complementing the course. The oncologist also
stated that many patients with cancer look for something they
can use to add to standard care and an app can provide a low
threshold aid. As a negative aspect, a nursing expert stated that
a smartphone is required and not every patient possesses such
a device. The nursing experts also mentioned that the nurses oftentimes
forgot about the app because it is not part of standard care. Therefore, the nursing experts stated that it might be helpful to
better inform the nurses about the app and setting up standards
regarding the communication about the app, for example, when
to inform the patients and how. In addition, the nursing experts
stated that it might be helpful if they had a demonstration device
at the oncology unit so that they could better explain the app to
the patients. All interviewed health professionals further
mentioned that patients with cancer are very diverse and that
although some patients are very eager to try out various
treatments, others are not. One MBM therapist also stated that
not all patients perceive relaxation as important and that those
patients might need some additional information which indicates
why relaxation is good for them. All health professionals also
stated that implementing such an app does not result in a lot of
additional work for them and they appreciate the app, which
they could recommend to suitable patients. All health experts made various suggestions for improving the
app. A shared opinion was that the content of the app (ie,
number and variety of exercises) could be increased, as over an
extended period, patients might get bored with a choice limited
to 3 exercises. A nursing expert suggested that a new exercise
could, for instance, be unlocked after completing the same
exercise several times. Implementation A total of 5 health professionals took part in an interview: 2
female nursing experts (one from an inpatient unit and the other
from an outpatient oncology unit), 2 female MBM psychologists,
and 1 male oncologist. Interviews were conducted between
January and March 2018 and lasted for an average of 45 minutes
(SD 9.54). The qualitative analysis of the interviews yielded 4
themes: (1) general impression of the app, (2) suggestions for
improvement, (3) implementation in standard care, and (4)
experience with recommending the app to patients. The interviewees mentioned several factors that could influence
the implementation of a mindfulness- and relaxation-based app
into standard care. Both nursing experts and one of the MBM
psychologists stated that the time point when the information
of the app is delivered to the patient might be important. These
health professionals mentioned that the patients were bombarded
with information during the first consultation or during the first
day when a patient enters the hospital and additional information
about the app might overwhelm some patients. The outpatient
nursing expert also mentioned that they are often limited because
of time constraints during consultation hours: Overall, the general impression of the app was positive. For
instance, the oncologist summarized his impression of the app
as follows: I think [the app] is a very helpful thing because it is
relatively easy [to use]. You can test it. You can try
it and if you like it, you can integrate it relatively easy
into everyday life. I think it is very practical. It is a
practical thing and if patients are interested, I also
see that they take it up willingly. On the one hand there are the concerns of the
patients, which you have to discuss. But you also have
a little bit of pressure, [to tell them] all relevant
information. [...] And sometimes it’s already two
minutes before the end [of the consultation]. [...] And
you can’t just hand out the flyer. You also need to say
a few words [about the app] and that’s why I
sometimes forgot [to mention the app]. Due to
shortage of time. On the one hand there are the concerns of the
patients, which you have to discuss. But you also have
a little bit of pressure, [to tell them] all relevant
information. [...] And sometimes it’s already two
minutes before the end [of the consultation]. Adoption Figure 3. Completed exercises (3526) of all patients (N=100) over 20 weeks by type (mindfulness meditation, guided imagery, and progressive muscle
relaxation), gender of patient (male and female), and sex of narrator (male and female). Percentages refer to the total number of exercises per gender. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 8
https://cancer.jmir.org/2021/1/e16785
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FO Figure 3. Completed exercises (3526) of all patients (N=100) over 20 weeks by type (mindfulness meditation, guided imagery, and progressive musc
relaxation), gender of patient (male and female), and sex of narrator (male and female). Percentages refer to the total number of exercises per gende JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 8
(page number not for citation purposes) https://cancer.jmir.org/2021/1/e16785 JMIR CANCER Mikolasek et al If I could make a wish, then I would say, it would be
totally cool to have an accompanying Mind Body
Medicine app. That is to say that a lot of
exercises—not all of them—but a lot of exercises we
do [could be added to the app]. Possibly also guided
body exercises. That would be totally cool. https://cancer.jmir.org/2021/1/e16785 JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 9
(page number not for citation purposes) Principal Findings In this study, we explored the feasibility of a mindfulness- and
relaxation-based self-help app for patients with cancer. To
evaluate the feasibility, we used the RE-AIM framework [37],
and in this analysis, we focused on the framework dimensions
effectiveness, adoption, and implementation. Our findings
support the feasibility of this mHealth intervention. The results
indicate that the intervention might have beneficial effects on
patients’ distress and quality of life. Furthermore, the mHealth
intervention is accepted by the target population as well as by
health professionals. The results from the interviews with health professionals provide
some insights into the implementation of a mindfulness and
relaxation mHealth intervention into standard care. In general,
all interviewed health professionals perceived the app as a
helpful addition to standard care. The health professionals also
suggested some improvements, which might increase the
acceptance and long-term use of such mHealth interventions
by patients. A suggested improvement shared by all health
professionals is the increase in the content of the app, such as
additional exercises or variations of the exercises. A statement
about the implementation of the mHealth intervention given by
several health professionals was the adequate provision of
information. One of the interviewed MBM psychologists as
well as the nursing experts stated that patients with cancer are,
on the one hand, flooded with information, especially when
they start their treatment. However, the provision of some
information to the patients about a mHealth intervention is
necessary, at least to let the patients know about the existing
intervention. On the other hand, nursing experts also mentioned
that nurses often forgot about the intervention, although they
approve this kind of intervention. Therefore, a standardized
procedure for informing patients about the mHealth intervention
might facilitate the implementation of the intervention. In
addition, health professionals such as nurses might have to be
informed regularly about such interventions because it is not
part of their standard treatment; therefore, they might forget
about it, as seen in this study. Regarding the recruitment process,
the health professionals made the observation that female
patients were more interested in this mHealth intervention. This
is also reflected by the gender ratio in this study’s sample, with
76 female and 24 male patients with cancer, which is typical
for complementary and alternative treatments [51-53]. This
gender difference raises the question of whether an effort should
be made to better recruit male patients with cancer for such an
intervention. JMIR CANCER I was surprised that so many older patients had the
app on their phone and also used the app regularly
[...]. I had the impression, that it appeals to the young. [...]. But oftentimes, the older people have more time,
because they don’t work anymore. recommendation of 5 exercises per week. We consider this a
good adoption of the mHealth intervention because the
intervention was set up as a self-care intervention without the
involvement of a therapist or health professional. Mindfulness
was the preferred exercise, followed by guided imagery and
progressive muscle relaxation. However, mindfulness meditation
exercises were also presented as the first choice in the app,
whereas guided imagery was placed at the second position, and
progressive muscle relaxation was placed at the third position. Therefore, the preference for mindfulness meditation could also
be caused by the placement of the exercises in the app. These
results regarding adoption are comparable with those of a study
conducted by Kubo et al [48], in which patients with cancer
received access to the commercially available mindfulness app
Headspace (TM). In this study, 40 of 54 patients with cancer
allocated to the intervention group completed the 8-week study,
and 20 patients with cancer used the app on at least 50% of the
days [48]. Principal Findings A nursing expert, for instance, mentioned during
the interview that a focus on more technical aspects or facts
could be more appealing to male patients. For the dimension effectiveness, we looked into pre-post effects. Our results suggest that the app might have the potential to
reduce distress, fatigue, sleep disturbance, and anxiety as well
as improve health-related quality of life and mindfulness. This
is in line with a recent pilot study [47], in which a mobile
mindfulness-based stress reduction program improved, among
others, stress, anxiety, depression, sleep quality, quality of life,
and mindfulness in patients with breast cancer with small to
large effects. Furthermore, a recent randomized controlled trial
conducted by Kubo et al [48] assessed the feasibility of a
commercially available mindfulness program in which they
targeted patients with cancer and their caregivers. This program
leads to an increase in quality of life in patients with cancer
with a medium effect size [48]. Similar to these findings, Rosen
et al [49] reported that the quality of life of patients with breast
cancer improved with a small effect size using a commercially
available mindfulness course when compared with a control
group. As depressive symptoms and anxiety were not significantly
reduced in the total sample in our study, we also looked at
subsamples with higher HADS scores. In the high anxiety and
high depression subsamples, anxiety and depression,
respectively, decreased significantly over time. This might
indicate that a mindfulness and relaxation mHealth intervention
is especially beneficial for patients with cancer with higher
emotional distress. This is also in line with a study by Barth et
al [50], where highly distressed patients benefited most from
psycho-oncological interventions. However, we did not find
any group effects when comparing continuous app users with
intervention dropouts. This might indicate that our definition
of users and dropouts is not precise enough or that another
variable than time spent practicing is responsible for changes
in outcomes. For adoption, our results showed that at week 20 of the
intervention, 25 of 100 patients were using the app continuously. With 54 of 100 continuous app users at week 10 [36], this leads
to a dropout rate of approximately 50% every 10 weeks. The
25 continuous app users practiced on average 3 to 5 times per
week (median), which comes close to our initially stated Strengths, Limitations, and Future Directions Implementation An MBM psychologist suggested that
every week, a different selection of exercises could be activated
with alternating topics such as meditation, relaxation,
self-compassion, or body exercises. In addition, the inclusion
of exercises with different degrees of complexity was suggested. An MBM psychologist stated that exercises for beginners (eg,
more detailed instructions, fewer moments of silence) as well
as exercises for patients experienced in mindfulness and
relaxation could be added. MBM psychologists and nursing
experts also recommended that some exercises should be
accompanied by soothing background music because longer
periods of silence might be uncomfortable for some patients. They also recommended exercises with various lengths of time
so that patients had more flexibility if they were facing time
constraints or if they were too impatient for longer exercises. The oncologist mentioned that adding exercises specifically for
sleep disorders might be a good addition to the app, especially
for inpatients, because poor sleep in hospitals is very common. As an additional topic that could be added, he mentioned body
exercises such as yoga. An MBM psychologist mentioned that
an app mirroring the MBM course more closely would be great: Regarding their experience with recommending the app to
patients, health professionals shared the opinion that female
patients are more drawn to mindfulness and relaxation exercises. Furthermore, the MBM therapists stated that patients who
already practiced some form of relaxation or meditation often
did not participate in the study. The MBM therapists also noticed
that the composition of the MBM group had an influence on
how many patients were willing to try out the app. For instance,
if one patient was very motivated and expressed interest in the
app, hesitant patients sometimes followed suit and were willing
to try the app as well. One MBM therapist also noticed that
many older people were willing to use the app: JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 9
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RenderX XSL•FO
RenderX Mikolasek et al JMIR CANCER https://cancer.jmir.org/2021/1/e16785 JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 10
(page number not for citation purposes) Acknowledgments This study was funded by the Swiss Cancer League (KLS-3564-02-2015). This study was funded by the Swiss Cancer League (KLS-3564-02-2015). Conflicts of Interest None declared. Strengths, Limitations, and Future Directions This study has several strengths and limitations. A strength of
the study is the collection of objective data in the form of https://cancer.jmir.org/2021/1/e16785 JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 10
(page number not for citation purposes) XSL•FO
RenderX Mikolasek et al JMIR CANCER logging the exercise use for each patient over the course of 20
weeks. Therefore, data on using the app exercises were not
biased through self-report. Another advantage of this study was
the use of a mixed methods approach, which is recommended
for the development of digital interventions [54]. helpful addition to standard care, but as described earlier, they
also stated barriers to the implementation of such an
intervention, which should be investigated in future studies. Future studies could also investigate an mHealth intervention
with more content than in this study app, as suggested during
the interviews by health professionals. For instance, audio files
with background music or exercises with variations in their
duration could be added. In addition to mindfulness and
relaxation exercises, physical exercise programs could be added. Physical exercise can have beneficial effects on symptoms of
patients with cancer [56], and physical exercise has already
been implemented in mHealth apps for patients with cancer
[57]. A limitation of the study is that we did not have a control group. Therefore, the effectiveness of the app cannot be determined in
this study because regression to the mean could have an impact
on the improvement of well-being. Furthermore, we used
paper-and-pencil questionnaires, which might have led to more
missing data compared with web-based questionnaires [55]. However, this was compensated by using LMM analyses, which
take into account all patients who provided baseline data. Another limitation is that we did not assess whether patients
were practicing mindfulness and relaxation exercises without
the app, which could have an effect on the assessed outcomes. Conclusions The results of this observational feasibility study indicate that
a mindfulness and relaxation app can be a feasible and an
effective way to deliver a self-care intervention for patients with
cancer. Our results indicate that such an intervention might be
especially beneficial for highly distressed patients with cancer. The appeal of such an app could be increased with more diverse
content, which might also positively affect the adherence of
patients to such an intervention. The effectiveness and further
aspects regarding the implementation of such an mHealth
intervention should be investigated in a future randomized
controlled trial. Therefore, future studies should investigate this topic with a
randomized controlled trial to determine the effectiveness of a
mindfulness and relaxation mHealth intervention. Our study
provides some insights regarding the effects that might be
expected in a similar study, which will be helpful to power
future studies sufficiently. We also looked at aspects of
implementing an mHealth intervention. All interviewed health
professionals perceived such an mHealth intervention as a JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 11
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received 13.03.20; accepted 18.11.20; published 13.01.21 Please cite as:
Mikolasek M, Witt CM, Barth J
Effects and Implementation of a Mindfulness and Relaxation App for Patients With Cancer: Mixed Methods Feasibility Study
JMIR Cancer 2021;7(1):e16785
URL: https://cancer.jmir.org/2021/1/e16785
doi: 10.2196/16785
PMID: 33439132 ©Michael Mikolasek, Claudia Margitta Witt, Jürgen Barth. Originally published in JMIR Cancer (http://cancer.jmir.org),
13.01.2021. This is an open-access article distributed under the terms of the Creative Commons Attribution License
(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work, first published in JMIR Cancer, is properly cited. The complete bibliographic information, a link to
the original publication on http://cancer.jmir.org/, as well as this copyright and license information must be included. JMIR Cancer 2021 | vol. 7 | iss. 1 | e16785 | p. 14
(page number not for citation purposes) https://cancer.jmir.org/2021/1/e16785 https://cancer.jmir.org/2021/1/e16785 XSL•FO
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Anti-Inflammatory Action of Dietary Wild Olive (Acebuche) Oil in the Retina of Hypertensive Mice
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Article
Anti-Inflammatory Action of Dietary Wild Olive (Acebuche) Oil
in the Retina of Hypertensive Mice Álvaro Santana-Garrido 1,2
, Claudia Reyes-Goya 1, Santiago Milla-Navarro 3
, Pedro de la Villa 3,4,
Helder André 5
, Carmen M. Vázquez 1,2
and Alfonso Mate 1,2,* ntana-Garrido 1,2
, Claudia Reyes-Goya 1, Santiago Milla-Navarro 3
, Pedro de la Villa 3,4,
ndré 5
, Carmen M. Vázquez 1,2
and Alfonso Mate 1,2,* 1
Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain;
asgarrido@us.es (Á.S.-G.); crgoya@us.es (C.R.-G.); vazquez@us.es (C.M.V.) g
g y
q
2
Epidemiología Clínica y Riesgo Cardiovascular, Instituto de Biomedicina de Sevilla (IBIS),
Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/
Universidad de Sevilla, 41013 Sevilla, Spain p
3
Department of Systems Biology, University of Alcalá, 28871 Madrid, Spain;
santiago milla@edu uah es (S M N ); pedro villa@uah es (Pd l V) p
3
Department of Systems Biology, University of Alcalá, 28871 Madrid, Spain;
santiago.milla@edu.uah.es (S.M.-N.); pedro.villa@uah.es (P.d.l.V.) g
(
) p
(
)
4
Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28034 Madrid, Spain 4
Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), 28034 Madrid, Spain
5
D
f Cli i
l N
i
S
E ik E
H
i
l K
li
k I
i
11282 S
kh l
S
d 5
Department of Clinical Neuroscience, St. Erik Eye Hospital, Karolinska Institutet, 11282 Stockholm, Sweden;
helder.andre@ki.se 5
Department of Clinical Neuroscience, St. Erik Eye Hospital, Karolinska Institutet, 11282 Stockholm, Sweden
helder.andre@ki.se *
Correspondence: mate@us.es Abstract: Inflammation plays a crucial role in the course of eye diseases, including many vascular
retinopathies. Although olive oil is known to have beneficial effects against inflammatory processes,
there is no information available on the anti-inflammatory potential of the wild olive tree (namely,
acebuche (ACE) for the primitive Spanish lineages). Here we investigate the anti-inflammatory
effects of ACE oil in the retina of a mouse model of arterial hypertension, which was experimentally
induced by administration of L-NAME (NG-nitro-L-arginine-methyl-ester). The animals were fed
supplements of ACE oil or extra virgin olive oil (EVOO, for comparative purposes). Retinal function
was assessed by electroretinography (ERG), and different inflammation-related parameters were
measured in the retina and choroid. Besides significant prevention of retinal dysfunction shown in
ERG recordings, ACE oil-enriched diet upregulated the expression of the anti-inflammatory markers
PPARγ, PPARα and IL-10, while reducing that of major proinflammatory biomarkers, IL-1β, IL-6,
TNF-α and COX-2.
Citation: Santana-Garrido, Á.;
Reyes-Goya, C.; Milla-Navarro, S.; de
la Villa, P.; André, H.; Vázquez, C.M.;
Mate, A. Anti-Inflammatory Action of
Dietary Wild Olive (Acebuche) Oil in
the Retina of Hypertensive Mice. Foods 2021, 10, 1993. https://doi.org/
10.3390/foods10091993 Academic Editors: Ruth Hornedo-
Ortega and Ana B. Cerezo Keywords: acebuche; arterial hypertension; inflammation; olive oil; retina; wild olive tree Received: 26 July 2021
Accepted: 23 August 2021
Published: 25 August 2021 foods foods Article
Anti-Inflammatory Action of Dietary Wild Olive (Acebuche) Oil
in the Retina of Hypertensive Mice This is the first report to highlight the anti-inflammatory properties of an ACE
oil-enriched diet against hypertension-related retinal damage. Noteworthy, dietary supplementation
with ACE oil yielded better results compared to a reference EVOO. 1. Introduction Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations. Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations. Numerous authors have recognized the pivotal role of extra virgin olive oil (EVOO)
(Olea europaea L.) in the context of the well-known Mediterranean diet, and the potential
benefits of its multiple bioactive compounds [1,2]. In this sense, EVOO has been identified
as a key to reducing the risk of various diseases [3–5]. The beneficial health outcomes
derived from the regular consumption of olive oil rely on its nutritional components to
which antioxidant, anti-inflammatory and antitumoral properties are ascribed. y
p
p
The major constituents of EVOO include acyclglycerols, free fatty acids, pigments and
phosphatides, among others. A high proportion of monounsaturated fats also defines its
distinctive biochemical profile [6], of which oleic acid (C18:1) is probably the most studied [7]. Polyunsaturated fatty acids (PUFAs) include linoleic (C18:2) and α-linolenic (C18:3) acids,
whereas saturated fatty acids (SFA) account only for 8–14% [8]. Interestingly, EVOO also
contains a wide range of minor components including sterols, tocopherols, triterpenic and
phenolic compounds, which are involved in a profusion of pathways involved in homeostasis,
inflammation and redox state [9–12]. Consequently, regular consumption of EVOO has been Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article
distributed
under
the
terms
and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/). https://www.mdpi.com/journal/foods Foods 2021, 10, 1993. https://doi.org/10.3390/foods10091993 Foods 2021, 10, 1993 2 of 18 2 of 18 proposed as a powerful nutraceutical tool to avert and mitigate cancer and cardiovascular
or degenerative diseases [13,14], where noticeable contributions of hydroxytyrosol and its
derivates (tyrosol, oleuropein and oleocanthal) have been reported [15]. Nonetheless, some
authors have claimed the need to discover additional minor bioactive components of EVOO
that might help understand its beneficial properties. g
p
p
p
Unlike the renowned reports concerning the consumption of fruits and oil obtained
from the common olive tree (Olea europaea var. europaea) in the setting of the Mediterranean
diet, the information available on the wild olive tree (Olea europaea var. sylvestris)—namely,
acebuche (ACE) for the primitive Spanish lineages—is very limited. 1. Introduction Thus, although different
studies have addressed the composition and therapeutic effects of EVOO, very little is known
specifically about ACE oil, a product of growing interest in specific regions such as Andalusia,
Spain. The conservation of genuine wild olive lineages is desirable from an environmental
point of view; however, these olive varieties have remained largely under-exploited, because
the fruit of the wild olive yields little oil compared to cultivated olives. Therefore, the small
amounts of commercially available ACE oil are typically consumed as “gourmet” products
that are generally recognized as spicier, more bitter and fruitier than standard EVOOs, possibly
due to slight differences in minor compounds [16,17]. Some of the first evidences have
attributed a higher content of tocopherols (e.g., vitamin E), sterols and triterpene acids in
ACE oil than in EVOO, and also a higher amount of secoiridoid compounds relative to
ortodiphenols in the former [18,19]. Moreover, ACE oil has been reported to have lower
antigenic and allergenic capacities compared to cultivated olive trees [20]. g
g
p
p
Despite the importance of EVOO in protecting against cardiovascular diseases (CV),
its potential role as a bioactive supplement able to counteract the development/progression
of ocular diseases is not well established yet. Previous population studies have suggested
that EVOO might be useful to delay the occurrence of age-related macular degenera-
tion (AMD) [21–23], while in vivo and in vitro experiments described neuronal protec-
tion of EVOO components (e.g., hydroxytyrosol and oleuropein) in diabetic retinopathy
(DR) [24–27]. In this regard, we have recently demonstrated a retinoprotective action of
EVOO- and ACE oil-enriched diets, showing better results in the latter case, in a context
of arterial hypertension (AH). The beneficial actions of these oils were ascribed to their
capacity to counteract the progression of hypertensive eye disease by reducing superoxide
anions (O2·−) and by modulating the enzymes NADPH oxidase and nitric oxide synthase,
among others [19]. Therefore, ACE oil and EVOO-based diets could represent a strategical
tool to reduce AH-related ocular damage in pathologies such AMD, DR or hypertensive
retinopathy, among others. However, knowing the precise mechanisms responsible for the
beneficial properties of olive oil consumption at the ocular level requires further research. p
p
p
q
Along with oxidative stress, inflammation has been extensively studied as a key mech-
anism in the pathogenesis of hypertension, especially in the context of persistent AH [28,29]. 1. Introduction The expression of major inflammatory biomarkers, including tumor necrosis factor-alpha
(TNF-α) [30], cyclooxygenase-2 (COX-2) [31] and interleukin (IL) isoforms [32], is known
to be modulated during the course of AH. In addition, it is well known that low-grade
inflammation in AH is associated with several pathways involved in the development and
progression of different ocular pathologies [33,34], including DR [35], glaucoma [36] and
AMD [37], among others. While it is also noteworthy that the literature on the interplay
between inflammation and AH supports the involvement of the former in hypertensive
retinopathy [38] and DR [39], how hypertension contributes to inflammation and its rel-
evance in the development/progression of major retinopathies has not been previously
studied. Some of the components of EVOO mentioned above have been postulated as
possible contributors to reduce the inflammation process in different diseases, including
hydroxytyrosol [40], oleocanthal [41] or triterpenes such as ursolic and oleanolic acids [42],
among others. Novel dietary and/or therapeutic strategies could help reduce retinal in-
flammation (whether or not related to AH) and describe the possible implication of AH in
this regard, thus contributing to unveil hypertension-associated target organ damage. Foods 2021, 10, 1993 3 of 18 3 of 18 The purpose of the current study was to test the ability of an ACE oil-enriched diet to
counteract retinal inflammation, based on a plausible anti-inflammatory effect, in a rodent
model of AH triggered by chronic administration of L-NAME (NG-nitro-L-arginine-methyl-
ester). Visual function was estimated by electroretinography in unconscious hypertensive
mice after a 6-week period of ACE oil administration. Moreover, the expression of peroxi-
some proliferator-activated receptors (PPARs) and that of inflammation-related biomarkers
(namely, interleukin isoforms (IL-1β, IL-6 and IL-10), TNF-α and COX-2) was assayed
by immunohistofluorescence in retinal/choroid layers, and by Western blotting and real-
time PCR in retinal homogenates. Additional experiments were carried out in parallel
substituting EVOO for ACE oil, for comparative analysis. 2.3. Animal Characteristics Systolic and diastolic blood pressure values (SBP, DBP) were recorded every week
throughout treatment by the non-invasive, tail-cuff occlusion method in conscious animals
by means of a pressure recorder (NIPREM 645, CIBERTEC S.A., Madrid, Spain). Blood
pressure values were pooled and averaged from three to four consecutive measurements. 2. Materials and Methods
2.1. Study Design The present study complies with the European Union (EU) Directive 2010/63/EU and
the National (RD 53/2013) guidelines for the care and use of Laboratory animals and was
approved by the relevant Institutional Animal Care and Use Committee (Dirección General
de Producción Agrícola y Ganadería, Junta de Andalucía, reference #13/03/2019/031). 10–12-week-old male C57B/6J mice were supplied by the Center for Animal Production and
Experimentation (University of Seville, Spain). The animals were randomly distributed into
six groups: (1) Control (standard pellet diet), (2) ACE (standard pellet diet supplemented
with 12% (w/w) of wild olive oil), (3) EVOO (standard pellet diet supplemented with 12%
of extra virgin olive oil), (4) L-NAME (mice made hypertensive following treatment with
45 mg L-NAME/kg/day), (5) LN + ACE (L-NAME-treated hypertensive mice fed the same
diet as in group 2; and (6) LN + EVOO group (L-NAME-treated hypertensive mice fed
the same diet as in group 3). All treatments lasted 6 weeks under continuous monitoring
of solid and liquid intake. Animals were housed under standard regulated conditions
(23 ± 1 ◦C, 12 h/12 h light/dark cycles). 2.2. Dietary Supplementation A commercial rodent chow (ROD14IRR, Sodispan Research, Altromin, Germany)
was supplemented with 12% of ACE oil (groups 2 and 5) or EVOO (groups 3 and 6), as
mentioned above. The specifications for the preparation of the diets and the chemical
composition of ACE oil and EVOO were previously reported [19]. The oil-powder pellets
were kept cool and protected from light until daily use. Both oils were produced in Sierra de las Nieves (Málaga, Spain) using exactly the
same extraction methods, in accordance with standard protocols to comply with extra
virgin olive oil definition. Briefly, oils were obtained by a process of grinding, mixing and
extraction at room temperature by centrifugation in a two-phase system. Then, they were
kept in an insulated cellar with controlled temperature, protected from light and away
from any source of external flavors. The oils were analyzed prior to their use in animal
experiments [19]. The required amount of L-NAME in the water bottles was adjusted every
week after monitoring each animal’s body weight and water intake; the specific dose was
chosen from prior studies performed routinely in our laboratory. 2.5. Sample Harvesting Animals were anesthetized with intraperitoneal injections of ketamine (75 mg/Kg)
plus diazepam (10 mg mg/Kg), then subjected to cervical dislocation. The retinas were
immediately isolated under a binocular stereo microscope, immersed in liquid nitrogen and
maintained at −80 ◦C until use for gene/protein expression analyses. For immunodetection
of proteins of interest in retinal/choroidal tissue, eyes were processed as described below
(Section 2.8). 2.4. Electroretinography (ERG) Dark-adapted mice (12 h) were anaesthetized, under dim red light, with an intraperi-
toneal injection of a mix of ketamine (Ketamidor, Richter Pharma AG, Wels, Austria;
100 mg/mL) and xylazine (Xilagesic, CALIER, Barcelona, Spain; 20 mg/mL) in saline Foods 2021, 10, 1993 4 of 18 solution (NaCl 0.9%), at a final concentration of 0.5 mL/150 g body weight. The animals’
temperature was kept at 37 ◦C with a water-content heating pad, to avoid electric noise
during the recording. Pupil dilation was achieved with 1% tropicamide (Alcon Cusí S.A.,
El Masnou, Barcelona, Spain). A needle was located at the base of the tail for grounding
and a reference electrode was placed on the tongue. A gold band electrode was used to
record ERGs from the right eye. The electrode was placed on the cornea, and a drop of 2%
methyl-cellulose (Methocel 2%, Omnivision, Neuhausen, Switzerland) was placed between
the cornea and the electrode to assure electrical conductivity and to protect the eye. y
p
y
Full-field flash ERG was performed with a Ganzfeld dome. Initially, a first scotopic
phase was performed with flashes of increasing intensity (−4.0, −3.0, −2.0, −1.5, −1.0,
−0.5, −0.0, 0.5, 1.0, and 1.5 log cd·s−1·m−2). The interval between flashes in scotopic
conditions ranged from 1.2 s for dim flashes to 15 s for the highest intensity stimuli. ERG signals were amplified and filtered between 0.3 and 1000 Hz with a Grass amplifier
(CP511 AC amplifier, Grass Instruments, Quincy, MA, USA, EE.UU.). In general, scotopic
b-wave (b-scot) informs about rod-driven circuitry, mixed waves (mixed) indicate rod and
cone photoreceptors (a-mix) and their postsynaptic circuitry (b-mix) activity, and photopic
b-wave (b-photo) test how photopic conditions affect cone-driven circuitry through rod-
saturating light stimulation. Moreover, oscillatory potentials (OP) were isolated using a
bright flash (1.5 log cd·s−1·m−2) and band pass filter between 30 and 10,000 Hz. Cone-
mediated responses were recorded on a rod-saturating background of 30 cd/m2, after
5 min of adaptation, with flashes of increasing intensity (−1.0, −0.5, −0.0, 0.5, 1.0 and
1.5 log cd·s−1·m−2). Under photopic conditions, the interval between light flashes was
fixed at 1.2 s. Flicker (FL) response was recorded at different frequencies (20, 30 and
50 Hz) and an intensity of 1.5 log cd·s−1·m−2. ERG wave components were measured
manually using the commercial software LabChart Pro v.8.1.13 (ADInstruments Ltd.,
Oxfordshire, UK). 2.6. Western Blotting Analyses Retinal homogenates were prepared in protease inhibitor-containing phosphate buffer
saline (50 mM PBS, Sigma Aldrich-Roche, Madrid, Spain) using a Potter-Elvehjem tissue
grinder. Homogenized samples were centrifuged for 10 min at 10,000× g and aliquots of the
corresponding supernatants were set aside to estimate the protein concentration according
to the method described by Bradford [43]. Western blotting analyses were performed in
retinal homogenates containing 40–50 µg of proteins, as previously described [19]. Specific
primary and secondary antibodies are listed in Table 1. Blot signals were quantified by
optical densitometry (Cytiva Europe GmbH, Barcelona, Spain), and constitutive β-actin
was used as the loading control in all blots. Foods 2021, 10, 1993 5 of 18 Table 1. Antibodies used for Western blotting analysis. SCB = Santa Cruz Biotechnology (Santa Cruz, CA, USA). Primary Antibody
Origin
Dilution
Secondary
Antibody
Dilution
Reference
Anti-PPARγ
Mouse monoclonal
1:2000
Goat Anti-Mouse
1:4000
SCB
Anti-PPARα
Mouse monoclonal
1:2000
Goat Anti-Mouse
1:4000
SCB
Anti-IL-6
Mouse monoclonal
1:1000
Goat Anti-Rabbit
1:2000
SCB
Anti-IL-1β
Mouse monoclonal
1:1000
Goat Anti-Mouse
1:2000
SCB
Anti-IL-10
Mouse monoclonal
1:1000
Goat Anti-Mouse
1:2000
SCB
Anti-TNF-α
Mouse monoclonal
1:1000
Goat Anti-Mouse
1:2000
SCB
Anti-COX2
Mouse monoclonal
1:1000
Goat Anti-Mouse
1:2000
SCB
Anti-β-Actin
Mouse monoclonal
1:20,000
Goat Anti-Mouse
1:30,000
SCB dies used for Western blotting analysis. SCB = Santa Cruz Biotechnology (Santa Cruz, CA, USA). 2.7. Real-Time PCR 2.8. Immunohistofluorescence Paraffin-embedded sections (5 µm thick) were obtained following intravitreal admin-
istration of 4% paraformaldehyde (PFA) in PBS; eyes were then post-fixed in 4% PFA for
24 h. The localization of PPAR isoforms (PPARγ and PPARα) in the retina and choroid
was evaluated by immunohistofluorescence staining after deparaffination of the sections. A heat retrieval solution (Diva Decloaker, Biocare Medical, LLC, Pacheco, CA, USA) was
used prior to incubation with specific primary antibodies (Table 3). Goat anti-mouse
Alexa Fluor® 647 (Cat. No. CSA3808) or Goat anti-rabbit Alexa Fluor® 488 (Cat. No. CSA3211), where appropriate, were chosen as fluorescent secondary antibodies, and DAPI
Fluoromount-G® was used as a nuclear/chromosomal counterstain. Table 3. Primary antibodies used for immunofluorescence studies. Table 3. Primary antibodies used for immunofluorescence studies. Primary Antibody
Origin
Dilution
Reference
Anti-PPARγ
Mouse monoclonal
1:200
Santa Cruz Biotechnology, Santa
Cruz, CA, USA
Anti-PPARα
Mouse monoclonal
1:200
Santa Cruz Biotechnology
Anti-CD31
Rabbit monoclonal
1:200
Rockland Immunochemicals,
Limerick, PA, USA 2.7. Real-Time PCR Total RNA from each retina sample was isolated with TRIzol® (Thermo Fisher Scientific,
Madrid, Spain); then, reverse transcription reactions were carried out as described else-
where [44]. Specific primers are listed in Table 2. Gene products were amplified in a CFX96
real-time PCR system (Bio-Rad, Madrid, Spain), and relative mRNA expression was quan-
tified by the standard 2−∆∆Ct method, using glyceraldehyde-3-phosphate dehydrogenase
(GAPDH) as the housekeeping gene. Table 2. Primers used for real-time PCR. Gene
Forward Primer (5′→3′)
Reverse Primer (5′→3′)
IL-6
CTCTGCAAGAGACTTCCATCC
TTCTGCAAGTGCATCATCGT
IL-1β
CCGTGGACCTTCCAGGATGA
GGGAAGGTCACACACCAGCA
IL-10
CTGGACAACATACTGCTAACCG
GGGCATCACTTCTACCAGGTAA
TNF-α
CCACGCTCTTCTGTCTACTG
ACTTGGTGGTTTGCTACGAC
GAPDH
GCCAAAAGGGTCATCATCTCCGC
GGATGACCTTGCCCACAGCCTTG
2 8 I
hi t fl Table 2. Primers used for real-time PCR. 2.9. Statistical Analyses Results are expressed as means ± standard error of the mean (SEM). GraphPad
InStat Software (v. 3.10, San Diego, CA, USA) was used to run one-way analysis of
variance (ANOVA) followed by post-hoc Tukey’s multiple comparison test, and p < 0.05
was considered statistically different. Foods 2021, 10, 1993 6 of 18 3.1. Validation of the Experimental Approach At the end of the 6-week experimental period, SBP/DBP values showed a significant
(p < 0.05) rise of both parameters in the L-NAME group (189/110 mmHg, respectively),
in comparison with all other animal groups (Figure 1A). Dietary supplementation with
ACE oil counteracted the typical effect of L-NAME, such that the values recorded in the
LN + ACE group fell slightly below the hypertensive threshold (136/85 mmHg). On the
other hand, the blood pressure lowering effect of EVOO was milder than that of ACE oil
(161/97 mmHg for LN + EVOO group). As shown in Figure 1A, the intake of either oil had
no effect in normotensive (L-NAME-free) mice (126/83 and 134/89 mmHg for ACE and
EVOO groups, respectively) when compared with the Control group (123/80 mmHg). In
addition, no differences were observed among any of the study groups in terms of weight
gain (Figure 1B) or solid/liquid intake (Figure 1C). Figure 1. General parameters. (A) Final blood pressure, (B) weight gain and (C) liquid and solid diet
intake in the six experimental animal groups. Values are expressed as mean ± SEM of seven animals
per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE. 3.2. Retinal Function Analyzed by Full-Field ERG Figure 1. General parameters. (A) Final blood pressure, (B) weight gain and (C) liquid and solid diet
intake in the six experimental animal groups. Values are expressed as mean ± SEM of seven animals
per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE. 3 2 Retinal Function Analyzed by Full Field ERG 3. Results 3.1. Validation of the Experimental Approach 3.1. Validation of the Experimental Approach 3.3. PPARs Expression in Retina Layers 3.3. PPARs Expression in Retina Layers Peroxisome proliferator-activated receptor (PPAR) γ and PPARα expression and
localization were quantified by Western blotting and by immunofluorescence. The hyper-
tensive L-NAME group showed a significant (p < 0.05) decrease of both PPARγ (36%) and
PPARα (42%) expression compared to the Control group (Figure 3A,B). Although normoten-
sive animal groups fed ACE oil displayed upregulation of PPAR isoforms (1.6-fold), the
LN + ACE group showed even higher overexpression of these receptors (2.4- and 2-fold
for PPARγ and PPARα, respectively). PPARγ and PPARα were also upregulated in EVOO
(1.5- and 1.3-fold, respectively) and in LN + EVOO (1.6- and 1.5-fold, respectively) groups
relative to normotensive animals. However, when comparing the global effects of ACE oil
and EVOO, a significantly (p < 0.05) greater capacity to upregulate PPARs was observed in
the former. Quantification of immunofluorescence signal of PPARs in the retinal layers yielded
similar results to those obtained from Western blotting analysis (Figure 3C,D). As shown in
Figure 3E, PPARγ and PPARα expression was localized at the ganglion cell layer (GCL),
inner plexiform layer (IPL), outer plexiform layer (OPL), outer segments (OS) and reti-
nal pigment epithelium/choroid (RPE/CH). Fluorescence signals dropped drastically
for both PPARγ (19%, 25%, 30%, 67% and 31% in RPE/CH, OS, OPL, IPL and GCL, re-
spectively) and PPARα (47%, 72%, 91%, 79% and 72% in the same respective layers) in
retinal sections obtained from L-NAME-treated animals, in comparison with the Control
group. Oil-supplemented groups displayed a clearly visible increase in the retinal ex-
pression of PPARs, with a more prominent effect in the case of ACE oil-fed hypertensive
animals (PPARγ: 1.5-, 1.3-, 4.6-, 3.2- and 4.7-fold increase; PPARα: 2.5-, 1.3- 6.9-, 6.5- and
7.4-fold increase in RPE/CH, OS, OPL, IPL and GCL, respectively, in comparison to Con-
trol group). In turn, upregulation of PPARs (relative to Control group) was only noted
in some retinal layers in hypertensive mice fed EVOO (e.g., PPARγ expression increased
3.6-, 2.3- and 3.4-fold, and PPARα increased 5.3-, 6.5- and 2.44-fold, in OPL, IPL and GCL,
respectively). Interestingly, PPARα immunofluorescence signal was generally higher than
that of PPARγ in the different animal groups. In addition, PPARγ seems to yield higher
signals in GCL and OPL, whereas PPARα signal was more abundant in IPL and OPL. Since
the endothelial marker (anti-CD31) co-localized with PPAR immunofluorescence signals,
these experiments confirmed the relevance of endothelial retinal cells in PPAR release. 3.2. Retinal Function Analyzed by Full-Field ERG Waveforms of the different recording conditions are depicted in Figure 2A–E. The
analyses of these responses to light recorded after overnight dark-adaptation showed a
significant (p < 0.05) reduction in amplitudes of scotopic waves b-scot (rods), a-mix and
b-mix (mixed), and oscillatory potentials (OP), in the L-NAME group in comparison with
Control animals (Figure 2F). Although no significant differences were observed in the b-
phot amplitude, indicating no modifications in retinal activity of cones, and flickers (FL), a
decreasing trend in its amplitude secondary to treatment with L-NAME could be extracted
from our results. Regarding the groups fed with oil-enriched diets, no disturbances were
found in LN + ACE and LN + EVOO animals, thus demonstrating the efficacy of both
oil diets to prevent the negative effects of L-NAME on retinal function. In addition, no
differences were found between any of the oil-supplemented groups (with or without the
hypertensive phenotype), which means that no better efficacy is displayed between the
ACE oil and EVOO diets in terms of visual retinal function. 7 of 18 Foods 2021, 10, 1993 ure 2. Electroretinogram (ERG) responses. Waveforms of representative ERG recordings: (A) b-scot (rods), (B) a-
mix (mixed), (C) b-phot (cones), (D) oscillatory potentials (OP) and (E) flickers of each experimental group are represen
Mean amplitude of all waves from the different experimental groups. Values are expressed as mean ± SEM of
mals per group: a p < 0.05 vs. Control; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE; f p < 0.0
+ ACE. Figure 2. Electroretinogram (ERG) responses. Waveforms of representative ERG recordings: (A) b-scot (rods), (B) a-mix,
b-mix (mixed), (C) b-phot (cones), (D) oscillatory potentials (OP) and (E) flickers of each experimental group are represented. (F) Mean amplitude of all waves from the different experimental groups. Values are expressed as mean ± SEM of ten
animals per group: a p < 0.05 vs. Control; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE; f p < 0.05 vs. LN + ACE. Foods 2021, 10, 1993 8 of 18 3.3. PPARs Expression in Retina Layers Figure 3. Cont. Figure 3. Cont. 9 of 18 Foods 2021, 10, 1993 Figure 3. Cont. Figure 3. Cont. Figure 3. Cont. 10 of 18 10 of 18 Foods 2021, 10, 1993 Figure 3. Protein expression of (A) PPARγ and (B) PPARα in retina homogenates. Quantitative analyses of fluorescence
signal of (C) PPARγ and (D) PPARα in the retinal layers and choroid, and (E) representative fluorescence signal of PPARγ
(left) and PPARα (right), as indicated. Panels show PPAR expression (red) and double staining with CD-31 (green) in the
different retinal layers, with the merge visible in yellow color. Nuclei staining with DAPI (blue color) was used to identify
the different retinal layers in each experimental group. Magnification: 10×. Values are expressed as mean ± SEM of five
animals per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05
vs. ACE. GCL: ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL,
outer nuclear layer; OS, outer segments; RPE/CH, retinal pigmentary epithelium/choroid. Figure 3. Protein expression of (A) PPARγ and (B) PPARα in retina homogenates. Quantitative analyses of fluorescence
signal of (C) PPARγ and (D) PPARα in the retinal layers and choroid, and (E) representative fluorescence signal of PPARγ
(left) and PPARα (right), as indicated. Panels show PPAR expression (red) and double staining with CD-31 (green) in the
different retinal layers, with the merge visible in yellow color. Nuclei staining with DAPI (blue color) was used to identify
the different retinal layers in each experimental group. Magnification: 10×. Values are expressed as mean ± SEM of five
animals per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05
vs. ACE. GCL: ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL,
outer nuclear layer; OS, outer segments; RPE/CH, retinal pigmentary epithelium/choroid. 3.4. Inflammatory Biomarkers in the Retina In retinal homogenates, L-NAME-treated mice presented with upregulation of pro-
tein/gene expression of IL-6 (2.2- and 2.7-fold for protein and mRNA levels, respectively),
IL-1β (1.8- and 2.1-fold, respectively), TNF-α (2.3- and 3.3-fold, respectively), and COX2
(2.6-fold), when compared to the Control group (Figure 4A–D,G–I). 4. Discussion The model of L-NAME-treated rodents has been widely used for in vivo induced
experimental arterial hypertension (AH). SBP and DBP values obtained at the end of the
treatment indicate the presence of severe hypertension in our study design, according to
current guidelines on AH [45]. As previously reported, no significant (p > 0.05) effects on
feeding behavior or weight gain were observed between normotensive and hypertensive
mice after a 6-week period of feeding oil-enriched diets [19]. Our research group was
pioneer in describing a blood pressure lowering effect of ACE oil in mice treated with
L-NAME, showing a preferential action of this “wild origin” oil compared to a parallel
EVOO-enriched diet. Our former analyses showed that ACE oil presented higher content
in sterol, tocopherols, triterpene acids, alcohols, and secoiridoids than an EVOO of similar
origin/characteristics. Therefore, the reduction of SBP and DBP could be partly mediated by
these minor compounds with known antioxidant properties [46–49]. Specifically, the high
content of secoiridoid compounds observed in ACE oil led us to think that these compounds
might be responsible for the greater hypotensive effect observed in hypertensive animals
fed this particular oil. The importance of AH as a risk factor for many pathologies, including neurological
disorders [50] and regrettably widespread hypertensive retinopathy, warrants exploring
how retinal function is affected in L-NAME-induced arterial hypertension. In that exper-
imental group, our ERG recordings exhibited a remarkable reduction in amplitudes of
b-scot (rod functionality), b-mix and a-mix waves, and a sightly reduction in OP, but no dif-
ferences were attributable to AH in b-phot (cone activity) and FL waves. These findings are
in agreement with previous assessment of visual function in spontaneously hypertensive
rats (SHR), where b-scot amplitude was also reduced [51]. Our diminished OP amplitudes
are also in line with Negretto et al. [52], who reported smaller OP in hypertensive patients,
thus suggesting that the inner retina might be affected by AH. Previous morphometric
analysis in the retina of L-NAME-treated animals showed thinner GCL, OS and RPE/CH
layers [19,53], which might be associated with arterial sclerosis and vascular contraction in
choroid [54], as well as with the reduction of retinal blood flow described in hypertensive
patients [55]. 3.3. PPARs Expression in Retina Layers Despite no significant
changes seen in IL-10 protein expression between Control and L-NAME groups, the gene
expression was significantly lower (29% reduction; p < 0.05) in the latter (Figure 4E,F). Foods 2021, 10, 1993 11 of 18 Figure 4. Protein and gene expression of inflammation-related biomarkers IL-6 (A,B), IL-1β (C,D),
IL-10 (E,F), TNF-α (G,H) and COX2 (I) in retina homogenates. Gene expression was quantified
as relative to GAPDH in each corresponding group. Values are expressed as mean ± SEM of five
animals per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE; f p < 0.05 vs. LN + ACE. Figure 4. Protein and gene expression of inflammation-related biomarkers IL-6 (A,B), IL-1β (C,D),
IL-10 (E,F), TNF-α (G,H) and COX2 (I) in retina homogenates. Gene expression was quantified
as relative to GAPDH in each corresponding group. Values are expressed as mean ± SEM of five
animals per group: a p < 0.05 vs. Control; b p < 0.05 vs. L-NAME; c p < 0.05 vs. EVOO; d p < 0.05 vs. LN + EVOO; e p < 0.05 vs. ACE; f p < 0.05 vs. LN + ACE. Foods 2021, 10, 1993 12 of 18 Focusing on olive oil-enriched diets, ACE oil and EVOO-fed hypertensive animals
benefited from reduced IL-6 gene and protein expression up to values similar or even lower
than those found in control normotensive animals, which supports the competence of both
oils to reduce the levels of this cytokine locally in the retina. Similar results were obtained
regarding the expression of IL-1β (Figure 4C,D), and no differences were found between
LN + ACE and LN + EVOO groups with respect to these two pro-inflammatory cytokines,
except for IL-6 protein expression that was significantly lower in the former (Figure 4A). In contrast, ACE oil induced substantial upregulation of anti-inflammatory IL-10 in both
L-NAME-free (2.5- and 2.7-fold for protein/mRNA expression, respectively) and L-NAME
co-administered mice (2.9-/2.2-fold), an effect that was not observed either in EVOO or in
LN + EVOO groups (Figure 4E,F). g
g
The similar expression of TNF-α found in Control, ACE, EVOO, LN + ACE and
LN + EVOO groups was much lower than the values of the L-NAME group (Figure 4G,H). 3.3. PPARs Expression in Retina Layers Concerning COX2, the two oil diets downregulated its expression in hypertensive mice, but
the reduction was greater in LN + ACE than in LN + EVOO group (200% vs. 111% relative
to L-NAME, respectively). No significant changes were found in this regard between
oil-free (Control) and oil-fed (ACE, EVOO) normotensive animals. 4. Discussion In this regard,
PPARs have been shown to downregulate the expression of pro-inflammatory biomarkers
in retinopathy microvascular dysfunction, as well as to regulate endothelial cell function
by targeting angiogenesis [62,63]. In the current study, the clear reduction of PPARγ and PPARα expression found in
the L-NAME group indicates that the retinal inflammatory profile could be affected in
arterial hypertension via PPAR inhibition, an alteration that could be prevented with ACE
oil and with EVOO-enriched diets (thus supporting a beneficial anti-inflammatory strategy
via PPAR upregulation), with better performance in the case of ACE oil. In addition, the
colocalized expression of both PPAR isoforms with CD-31 in GCL, IPL, OPL, OS retinal
layer and in RPE/CH confirms the relationship between PPARs and endothelial cells. Preliminary studies carried out in our laboratory also confer beneficial effects to ACE
oil in terms of improving endothelial dysfunction in aortas from L-NAME treated rats
(unpublished data); interestingly, vascular reactivity in the aorta recovered in parallel with
a reduction of endothelial inflammatory biomarkers, supporting the idea that ACE oil
could also modulate retinal/choroidal endothelial cell function. Both olive oil and some
of its minor components, such as polyphenols, have been described as useful regulators
of PPAR expression [64,65], although regulation of PPAR expression in the hypertensive
retina has not previously been reported in animal studies or in humans. In view of this interesting regulation on PPAR isoforms, and to further characterize
the anti-inflammatory capacity of olive oils in the retina, we postulated that the profile
of major inflammation-related biomarkers would be unbalanced in our experimental
AH setting. Indeed, pro-inflammatory biomarkers (IL-6, IL-1β, TNF-α and COX2) were
all abnormally elevated in hypertensive animals, a situation that was reversed after the
simultaneous administration of oil-enriched diets. On the other hand, the protein and gene
expression of anti-inflammatory IL-10 was highly upregulated by the oil diets, especially
after ACE oil consumption. Interventions to reduce inflammation have been used in many
retinopathies as a way to prevent and/or to treat retinal damage. Thus, some components of
EVOO, such as omega-3 fatty acids, have been explored against retinopathy of prematurity
(ROP) [66], as have polyphenols and flavonoids in DR [67]. In the current study, the
slight differences found between ACE oil and EVOO in this regard might be ascribed to a
different proportion of minor components. 4. Discussion Since b-scot wave and OP responses inform about inner retinal cell layers,
mainly the activity of amacrine and bipolar cells, while a-wave reflects the activity of
photoreceptors, specific modifications of the ERG-pattern in L-NAME-administered mice
could be explained by the presence of retinal vascular dysfunction due to AH, which, in
turn, would affect both the inner retina and OS layer. Moreover, since modifications of
a-wave amplitude have been related to loss of photoreceptors [56], the reduction in the
thickness of the OS and RPE/CH layers found in L-NAME-induced hypertensive animals Foods 2021, 10, 1993 13 of 18 suggests the existence of damaged photoreceptors with compromised retinal function in
our animal model of AH. Interestingly, both ACE oil and EVOO diets were able to reverse
the ERG alterations seen in the L-NAME group, reaching patterns like those found in the
Control group. This supports the notion that diets containing ACE oil- and EVOO could be
postulated as nutraceutical tools to counteract AH-related retinal dysfunction. p
y
As mentioned above, there is a great deal of evidence concerning the healthy properties
of olive oil components based on the modulation of oxidative stress and inflammation;
unfortunately, the literature about specific effects of EVOO on hypertensive retinas is
very limited, and studies on the general properties and healthy potential of ACE oil
are even scarcer. After evaluating the antioxidant properties of ACE oil in hypertensive
retinas [19], we decided to analyze the possible anti-inflammatory properties derived from
the daily consumption of this oily product. In this sense, we first focused on the role
of nuclear receptors PPARs. PPARs are involved in the control of metabolic activities
through differential regulation of glucose and lipid metabolism following activation by
fatty acids [57], which makes them attractive targets for oil-mediated regulation. Moreover,
PPARs can reduce excess inflammation by transcriptional regulation of a wide variety
of genes, not only those related to inflammation but also those involved in metabolism,
proliferation and differentiation pathways [58], and they can even regulate neurotoxic
activities related to microglia activation [58]. PPAR expression and activation provides
clear beneficial effects on different retinopathies of vascular origin [58]. These pleiotropic
effects have prompted the use of different PPAR agonists to treat various inflammatory
retinopathies, including DR, oxygen-induced retinopathy and AMD [59–61]. 4. Discussion As mentioned above, tocopherols, triterpene
acids and polyphenols, mainly secoiridoids, are found in higher proportion in ACE oil, Foods 2021, 10, 1993 14 of 18 14 of 18 and these components have been attributed important anti-inflammatory properties. For
instance, oleocanthal, one of the major secoiridoids found in ACE oil, has antioxidant and
anti-inflammatory properties that could help reduce glial activation and inflammatory
biomarkers [68,69]. Triterpene acids might also account for a preferential anti-inflammatory
effect in ACE oil compared to EVOO. Oleanolic acid seem to have neuroprotective effects
through modulation of inflammatory biomarkers (e.g., IL-6, IL-1β, TNF-α) and nitric oxide
(NO) bioavailability [70,71]; and, together with ursolic acid, they were postulated as a
promising anti-inflammatory compounds [42]. In the same way, maslinic acid reduced
the inflammatory response through regulation of IL-1β [72] and COX-2 reduction, among
other inflammatory biomarkers [73]. Moreover, not only did these compounds reduce
pro-inflammatory biomarkers, but they also increased IL-10 levels [74–76]. In summary, ACE oil and EVOO exerted a retinoprotective effect in hypertensive mice
based upon their anti-inflammatory properties, which adds value to their antioxidant effect
recently demonstrated [19]. Our study offers a broad vision of how these extra-virgin olive
oils can regulate inflammatory events in L-NAME-treated animals, counteracting the retinal
dysfunction observed in ERG recordings in a hypertensive context. Although ACE oil
tends to show better results than EVOO due to a higher content of some minor components,
further experiments with specific molecules contained in olive oil are necessary to clarify
these healthy effects on hypertensive retinas. 5. Conclusions The present work describes changes on retinal function and inflammatory events in
the retina and choroid of a mouse model of L-NAME-induced hypertension. A greater
anti-inflammatory effect seems to be attributable to ACE (wild olive) oil in hypertension-
related ocular diseases in comparison with a reference EVOO of similar geographic origin
and extraction method. A different profile between ACE oil and EVOO regarding minor
components might explain the better outcomes in favor of the former. We postulate ACE oil-
enriched diets as a novel nutraceutical tool to abolish AH-related retinal anti-inflammatory
damage. Considering also its demonstrated antioxidant capacity, ACE oil could represent a
promising therapeutical approach to prevent and/or to treat retinal pathologies, including
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advanced macular degeneration: A prospective cohort study. Am. J. Clin. Nutr. 2015, 102, 1196–1206. [CrossRef] 6. Patents The retinoprotective effect of acebuche oil was previously applied for patent by the
authors (application number P202030625) on 23 June 2020, at the Oficina Española de
Patentes y Marcas (OEPM), Ministerio de Industria, Comercio y Turismo. Author Contributions: Study design: A.M., C.M.V. and Á.S.-G.; data management: A.M., Á.S.-G. and C.M.V.; data acquisition: Á.S.-G. and S.M.-N.; draft of the article: Á.S.-G.; revision of the article:
Á.S.-G., C.R.-G., H.A., S.M.-N., P.d.l.V., A.M. and C.M.V. All authors have read and agreed to the
published version of the manuscript. Funding: This research and the APC were funded by Agencia Estatal de Investigación, Ministerio de
Ciencia e Innovación, Gobierno de España (PID2019-109002RB-I00/AEI/10.13039/501100011033);
Consejería de Economía, Conocimiento, Empresas y Universidad, Junta de Andalucía (2020/275
and 2021/188; CTS-584); and VI PPIT Universidad de Sevilla (IV.7 Ayuda Suplementaria a Grupos
de Investigación por captación de fondos en las convocatorias de proyectos de investigación del
Plan Estatal, 2020/1163). AS is recipient of an FPU predoctoral fellowship from Ministerio de
Universidades (FPU17/03465). CR-G was supported by Ministerio de Ciencia e Innovación, Ayudas
para la Promoción de Empleo Joven e Implantación de la Garantía Juvenil en I + D+i 2017–2020
(PEJ2018-004474-A). Institutional Review Board Statement: The study was conducted according to the guidelines of
the Declaration of Helsinki, and approved by the relevant Institutional Animal Care and Use Com-
mittee: Dirección General de Producción Agrícola y Ganadería, Junta de Andalucía (protocol code
13/03/2019/031, date of approval 20 March 2019). 15 of 18 Foods 2021, 10, 1993 15 of 18 ta Availability Statement: The data presented in this study are available in the article. Acknowledgments: We are thankful for the technical support from Centro de Innovación, Tecnología
e Innovación de la Universidad de Sevilla (CITIUS, Servicio de Biología, Servicio de Microscopía). The authors are also grateful to Alcazarín Reunidos FP, S.L. (Monda, Málaga, Spain) for providing
the extra virgin olive (wild/cultivated) oils used in this study. Acknowledgments: We are thankful for the technical support from Centro de Innovación, Tecnología
e Innovación de la Universidad de Sevilla (CITIUS, Servicio de Biología, Servicio de Microscopía). The authors are also grateful to Alcazarín Reunidos FP, S.L. (Monda, Málaga, Spain) for providing
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Comfort experience in palliative care: a phenomenological study
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© 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Coelho et al. BMC Palliative Care (2016) 15:71
DOI 10.1186/s12904-016-0145-0 Coelho et al. BMC Palliative Care (2016) 15:71
DOI 10.1186/s12904-016-0145-0 Abstract Background: Palliative care aims to provide maximum comfort to the patient. However it is unknown what factors
facilitate or hinder the experience of comfort, from the perspective of inpatients of palliative care units. This lack of
knowledge hinders the development of comfort interventions adjusted to these patients. The aim of this research is
to describe the comfort and discomfort experienced by inpatients at palliative care units. Methods: A phenomenological descriptive study was undertaken. Ten inpatients were recruited from a Spanish
palliative care unit and seven from a Portuguese palliative care unit. Data were collected using individual interviews
and analysed following the method of Giorgi. Results: Four themes reflect the essence of the lived experience: The Palliative Care as a response to the patient’s
needs with advanced disease, attempt to naturalize advanced disease, confrontation with their own vulnerability,
openness to the spiritual dimension. Conclusions: Informants revealed that they experience comfort through humanized care, differentiated
environment, symptomatic control, hope and relationships. The discomfort emerges from the losses and
powerlessness against their situation. Even if such findings may seem intuitive, documenting them is essential
because it invites us to reflect on our convictions about what it means to be comfortable for these patients, and
allows incorporating this information in the design of focused interventions to maximize the comfort experience. Keywords: Palliative care, End of life care, Inpatients, Qualitative research, Phenomenology, Comfor Comfort experience in palliative care: a
phenomenological study Adriana Coelho1*
, Vitor Parola1, Miguel Escobar-Bravo2 and João Apóstolo3 prehension of the phenomenon. However, in the cont
of Palliative Care (PC), such investigations are scarce [
* Correspondence: adriananevescoelho@esenfc.pt
1Nursing School of Coimbra, Coimbra, Portugal
Full list of author information is available at the end of the article
© 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Background beyond physical symptoms management [5]. Nevertheless
the literature continues to give more attention to the
physical comfort [6–8], and little attention is given to
other aspects of comfort commonly observed among
these patients [9]. The development of science and technology is expressed
in an increase in life expectancy [1]. Therefore the popu-
lation’s aging in a society in which death may be delayed
ever more, allows us to predict a gradual increase in the
prevalence of degenerative and disabling diseases. Also
in recent years the process of dying was displaced from
the home environment for the hospital context [2]. Indeed, Kolcaba [10], defines comfort as the immediate
experience of being strengthened by having the needs for
three types of comfort (relief, ease, or renewal) met in four
contexts of human experience (physical, psychospiritual,
environmental, and social). In this sense, there has been an increment of palliative
care units (PCUs) with the aim of provide the greatest
comfort and dignity possible to patients and their families
facing the problem associated with life-threatening illness
[1, 3]. In this sense, knowing the experiences of comfort and
discomfort of patients are a relevant aspect for the prac-
tice of care, guiding the care provided for the patients’
needs and maximizing the effect of comfort interventions. However, patients with advanced disease still experi-
ence discomfort [4]. This could be explained by the fact
that these patients often have comfort needs that extend Some researchers have sought to understand the com-
fort experience in the view of patients in other contexts
[11–14]. These studies are important efforts to the com-
prehension of the phenomenon. However, in the context
of Palliative Care (PC), such investigations are scarce [8]. * Correspondence: adriananevescoelho@esenfc.pt
1Nursing School of Coimbra, Coimbra, Portugal
Full list of author information is available at the end of the article Coelho et al. BMC Palliative Care (2016) 15:71 Coelho et al. BMC Palliative Care (2016) 15:71 Page 2 of 8 Table 1 Inclusion and exclusion criteria
Inclusion criteria
Exclusion criteria
- Adult patients with incurable and
advanced disease;
- Patients with cognitive
alterations;
- Able to consent;
- Dying patients. - Able to speak Spanish or Portuguese;
- In health conditions that allow them
to tolerate an interview of at least
20 min;
- Stay period in the PCU equal or superior
to 3 days. Background Table 1 Inclusion and exclusion criteria There are only studies that describe this experience, in
some of the contexts of comfort, but from the professional
[15–18], or families perspective [19, 20]. However, it is
important to note that both family and health profes-
sionals tend to describe the physical [21–24], and emo-
tional symptoms [21, 25–27], differently to the patient. Therefore it is not clarified what is the patient comfort
experience, and known that the patient’s comfort is an
important objective of PC, their comfort experience
should be taken into account. Furthermore, the analysis of the literature evidence
that the comfort interventions in PC are intuitive or
based on medical principles [28]. of being hospitalized in this unit?, with the intention of
the significant experience of comfort and discomfort to
emerge freely. Therefore being comfort/discomfort subjective states
that can only be understood in the light of the patient’s
experiences, starting from a concrete reality [29], and
with the conviction that intervention processes must
take into account the complexity and subjectivity of the
patient experience, it was conducted this study in order
to describe the comfort and discomfort experienced by
inpatients at PCUs. Follow-up questions in order to deepen understanding
of the experience of the informants were also carried,
such as: How would you describe this in more detail? What does that mean to you? A pilot test with two patients was conducted in order
to adjust the interview question. These interviews were
not included. Study design The present study is a secondary aim of a larger project
about confort interventions. This study was conducted using a qualitative phenom-
enological descriptive design. A descriptive phenomenology
was chosen, in order to study the complex phenomenon of
human experience, giving emphasis to how the life-world is
described by the participants voices [30]. It was assumed that saturation had been reached after
the 10 Spanish PCU and 7 Portuguese PCU interview. Non-participants refused to participate in the study or
dropped out during the interview. Data collection was carried exclusively by one of the in-
vestigators (AC) in order to avoid significant differences in
conduction the interview. Transcripts were reviewed by
the interviewer (AC) to verify their accuracy. This study conforms to Consolidated Criteria for
Reporting Qualitative Research (COREQ) guidelines (see
Additional file 1). The findings were not returned to participants for
confirmation because of participants’ declining health. Participants and setting Study participants were recruited from a Portuguese and
Spanish PCUs, between March and May 2015. Table 2 Participants
Spanish
PCU
Portuguese
PCU
Total
Gender
Male
5
3
8
Female
5
4
9
Age
Range:
58–90 years
Range:
56–78 years
Mean:
70.5
Mean:
74 years
Mean:
67 years
Hospitalization
time
Range:
4–44 days
Range:
9–76 days
Mean:
22.5
Mean:
14 days
Mean:
31 days
Diagnoses
Oncologic
7
7
14
Non-oncologic
3
0
3 The heads nurses, invited face-to-face those who were
eligible to participate (Table 1). A purposive sampling strategy was performed to ensure
a sample that included a wide spectrum of participant
gender, ages, hospitalization time, and diagnoses [31]. A total of 17 inpatients participated (Table 2). Methods
Study design Interviews were individual, mean duration was 32 min,
and were held in a location of the participants’ choice
(their room or an intimate space in the PCU). They were
digitally audio-recorded and transcribed verbatim. The PC as a response to patient’s needs with advanced
disease Informants acknowledge that, to find responses to
their health care needs, they need to be hospitalized in
a PCU: In third step the delineated meaning units identified in
the previous step were transformed in appropriate lan-
guage to the phenomenon under study and grouped into
common themes and sub-themes that represent the es-
sence of comfort experiences. In this step, the researchers
performed imaginative variation by changing qualities of
the object under analyzed so as to determine which data
are essential. The imaginative variation permitted to deter-
mine the essence of the phenomenal structure of the
experience. P16 “(…) the pain and the shortness of breath, that is
the thing I was not able to control, and that was
creating some fearful respect. At the hospital I am
well, arriving home, I stay there for a little longer and
that’s it…loss of control.” The PCU is perceived as a relief space of physical
discomfort, but also a space of comfort by the human
competence, by the surrounding environment and by
rapidly attention to the patient’s needs: The fourth analysis step consisted in synthesize all of
the transformed meaning units into a consistent and
descriptive statement regarding the subject’s experience
of confort. P12 “If you need a nurse, a nurse will come
immediately. If you need anything, just call them and
they will come here straightaway. It is the comfort of
knowing that if I need to call the nurses, they come
here immediately.” According to Giorgi [30, 34, 35], how or where the
meaning units are delineated is not absolute, different
researchers may delineate the meaning units in different
places in the same data. To ensure rigour, each authors
performed individual analyses. Every step of analysis
were compared and discussed to strengthen the validity
of analysis. By making reference to these comfort factors, the infor-
mants establish constant comparison with the experience
lived in other services in which they were previously
hospitalized: To manage the data was used the QSR NVivo version
10 software. P10 “I had never been in a facility with such
human quality as this one. Here the staffs are
attentive to everything, I mean everything. And
always smiling”. Results The analysis of the findings allowed the access to a com-
prehensive scheme (Fig. 1) organized in an interactive
structure. Data collection Data were collected through non-structured inter-
views. Interviews were chosen taking into account
the vulnerability of participants [32]. Furthermore
this technique facilitates a personal narrative by the
participant [33]. Non-structured interviews were conducted, supported
by the original question: How did you live the experience Page 3 of 8 Coelho et al. BMC Palliative Care (2016) 15:71 Page 3 of 8 Page 3 of 8 The patient’s vulnerable conditions constituted a limita-
tion to the rigor of the study, since it was not possible to
confirm the findings with the interviewees. Thus, during
the interviews were performed cross-checks to clarify
and confirm the coherence of the mentioned for patients
in their reports. PCU. Participants were not acquainted to the researchers
prior to the study commencements. They were made
aware of the aim of the study, place of work and role of
interviewer to inform their decision-making. Participation was voluntary and they were informed
of their right to withdraw from the study at any time. Complete confidentiality was guaranteed and a written
consent was obtained by the main researcher before
each interview. Data analysis Consistent with Giorgi method [30, 34, 35], analysis
involved four steps. The first step was a reading of
transcripts, several times, to get a sense of the whole
experience. This was done without a critical reflection
on the experience. Posteriorly, in the second step,
was performed a subsequent readings of the tran-
scripts with the purpose of identify the meaning units
(seccions of the collected data that could reveals po-
tentials aspects of the phenomenon under investiga-
tion). Each meaning unit is delimited by a change in
the thematic content. Ethical considerations Ethical approval was obtained by the Research Ethics
Committees of the Fundació d’Osona per a la Recerca i
l’Educació Sanitària (reference 2015873), Arcebispo
João Crisóstomo Hospital (04 February 2015) and
Health Sciences Research Unit: Nursing (reference
228–10/2014). Participating organisations’ ethical re-
quirements were met. P9 “It is a fact that here I have practically the same
things as in the other hospital, my blood pressure is
assessed, my medication is given to me. Nevertheless,
here, besides it, there is a place where I can go down
and go for a walk.” The interviewer works in the Spanish Center; however
during the data collection period did not work in the Coelho et al. BMC Palliative Care (2016) 15:71 Page 4 of 8 Fig. 1 Conceptual representation of the sub-themes and themes based on the findings Fig. 1 Conceptual representation of the sub-themes and themes based on the findings P3 “The problem that I now have is a breathing one…
I have difficulty even speaking…my body has given all
it has got” P3 “The problem that I now have is a breathing one…
I have difficulty even speaking…my body has given all
it has got” P17 “This means a jail. It’s a prison to be locked here,
a prison.” P17 “This means a jail. It’s a prison to be locked here,
a prison.” P17 “This means a jail. It’s a prison to be locked here,
a prison.” P14 “By saying: I am fine! The disease goes away
quicker … “ P14 “By saying: I am fine! The disease goes away
quicker … “ In the Spanish context, the loss of freedom, for some
informants it relates to the fact that they have to share a
room with another patient. quicker … “ Attempt to naturalize advanced disease Symptomatic control obtained through the hospitalization
in PCU leads to some informants naturalized the ad-
vanced disease, denying the proximity of death: P1 “Always the bedpan…I feel dependant. I am always
waiting for someone to do everything for me.” P1 “(…) this is a temporary situation of one or two
months which will end. This situation does not worry
me, everyday I improve greatly and I am very
positive.” P17 “(…) watch the land, listen to the birdies and
look at the things I have…the yards, the trees…
until this got to me in a stronger way and
everything ended. To be comfortable is not to have
anything, not to have any problem, it is to be at
my home.” In this sense, they described a sense of hope regarding
recovery and return home. P15 “My hope is to recover the least independence
which I know is possible, so I can go home to my little
dog and to my kittens.(…) I believe that there is always
a tomorrow, that there is hope.” Informants of Portuguese PCU even describe as
uncomfortable experience the loss of freedom, which
corresponds with the lack of an exterior space intended
for patients (this space exists in Spanish PCU and was
described as comfort proportioning) The informant reports also reveal the conviction that
it is possible to interfere with the course of the disease
by the optimism: Openness to spiritual dimension The confrontation with their own vulnerability raises in
some patients the opening to the relationship intraper-
sonal, to the need to do a review of his personal history. The findings suggest that although some comfort in-
terventions seem simple and of little technological com-
plexity (such as availability, fondness, support), they had
the ability to significantly affect the state of comfort. P14 “I believe I have not affected anybody…here we
think about everything, we weigh everything, and here
some things are left to be concluded and others left
halfway.” Informants also make a clearly positive assessment of
care received in PCU compared to other units in which
they have already been admitted, stating that the PCU
is a different human and environmental structure. Kolcaba
[38, 39], to define environmental comfort makes reference
to the environment and to internal and external conditions
such as noise, light, temperature or natural elements. This time dedicated to the life review allows the re-
valuation of what is really important. P10 “I lost too much time scolding my family…and
today I can only think of that everything we lived was
wonderful… We don’t regard things until they are lost.” Previous researches report the environment of the PCU
[40, 41]. However, this study brings new data since pa-
tients emphasize the PCU environment as evidence of the
comfort experience through the external environment ad-
justed (Spanish context) and reduced noise (Portuguese
context). The setting was also described as a comfort fac-
tor in the study of Hamilton [42], reported however to the
presence of homelike elements to patients. During this process the world of relations contains a spe-
cial importance. Thus, from the speech of the participants
emerges comfort that comes from affection with peers, with
friends, with family and with the professionals themselves. The satisfaction of needs that required hospitalization,
leads to some patients try to naturalize advanced disease
and make a denial of the proximity of death. P6 “I have a perfect partner. That means I can share
with him my problems, that I can trust him as if he
was my family.” According to Kubler-Ross “denial is usually a tempor-
ary defence and will soon be replaced by partial accept-
ance” [43] (p.39). The patient does not want to believe
in what is happening, there is a threat that it is necessary
to deny to continue living. Discussion In previous research under the comfort in PC, comfort
often appears associated with the physical dimension of
the person [7, 36, 37]. However, this study showed that
in addition to physical symptoms, there are other fac-
tors that promote significantly comfort and discomfort
experiences of inpatients in PCU that should be taken
into account. Due to those experienced losses and powerlessness that
they generate, some informants sense the imminence of
the end of life: P17 “That was why I was sent here… perhaps it was so
that I could end my days in here… “ Therefore, informants recognize as comfort sources,
technical competence and human competence with
which they feel care in PCU. Confrontation with their own vulnerability P3 “I have a neighbour who wants the blinds always
closed…I like to read the newspaper and because of
that I can’t read and that also makes me feel
uncomfortable.” Even if the PCU be recognized as an area that provide
comfort, it is also seen as a discomfort space, where phys-
ical and social losses, the feeling of helplessness, confronts
informants with their vulnerability and finitude. Coelho et al. BMC Palliative Care (2016) 15:71 Page 5 of 8 Page 5 of 8 P9 “To be able to go outside for a walk is to inflate an
internal joy which makes me feel alive.” The experience of all these losses generates impotence
and devaluation feelings on the informants: P9 “To be able to go outside for a walk is to inflate an
internal joy which makes me feel alive.” P17 “It is him (God) who comforts me, he is my saviour.” P14 “I feel inferior… I wanted to go alone (to the toilet)
but I can’t. Asking for help means wanting and not
being able to.” P17 “It is him (God) who comforts me, he is my saviour.” Conclusion The experience of comfort, in the patient’s perspective,
has been ignored by the literature on PC. These findings indicate that experienced losses and the
feeling of powerlessness to solve them are the main
source of discomfort experienced by the informants. This study demonstrated that the PCU can be perceived
as a space of comfort where the patient finds a suitable
therapeutic context to their needs, but also as a place of
discomfort where the patient is confronted with its vulner-
ability. It can be a space where there is a process of de-
nial or openness to spirituality. The discomfort has
underlying the experienced losses and the inability to
transcend. The patient feels comfortable through the
symptomatic control, compassionate care, the PCU dif-
ferentiated environment, hope, interpersonal, transper-
sonal and intrapersonal relationships. Indeed, according Kolcaba [10], one dimension of com-
fort is transcendence, defined as the state in which the
person feels it has the potential to control their destiny,
solve their problems. The discomfort allows informants to intuit their fini-
tude, which could lead them to the denial but also to a
personal growth. There is no social or biological restric-
tion that is so powerful that can overcome the freedom
to take a stand, the freedom to choose what attitude to
adopt in the face of suffering [51]. Even if such findings may seem intuitive, documenting
them is crucial because it invites the reader to reflect on
their beliefs about what it means to be comfortable for
these patients, and allows the incorporation of this infor-
mation in the design of focused interventions to maximize
the comfort experience. Unless one offers patients the
opportunity to be heard on their experience, their per-
spective will remain hidden and you could hardly provide
comfort to them. Thus, some informants choose to open up to spiritu-
ality, through intensification of the relationships and
affections. Previous research in PC states that interper-
sonal relationships are strengthened at the end of life
[52]. Nevertheless this study provides a new under-
standing by suggesting as comfort factors the intraper-
sonal relationships (making a recapitulation of his life
and an evaluation of what is really important), inter-
personal (with professional, family and friends) but
also transpersonal relationships (with God and nature),
since these relationships generate love towards them-
selves, others and the transcendent. Openness to spiritual dimension Thus, the informants speak
about a future recovery. P15 “It is to feel loved, to feel nurtured, to feel spoiled.”
(have friends visit) P17 “There is a moment which is special, which is my
wife’s visit who comes here everyday.” This experiencing is congruent with findings obtained
by Quill et al. [44], according to which one of the most
important aspects to reach to the patient with advanced
disease, would be the ability to change the trajectory of
their illness. P9 “This team that cares us so well, with such
kindness… I think that for a patient it is as important
a good medication or treatment as it is a humanised
and nurtured care.” The findings suggest that hope is a comfort factor,
since patients trust that they still have some control over
their health situation. Or even that it is possible to inter-
fere with the course of the disease, as was also reported
by other studies [45, 46]. The speech of patients also points to the comfort that
comes from the relationship with the transcendent – with
Nature and with God. Coelho et al. BMC Palliative Care (2016) 15:71 Page 6 of 8 Page 6 of 8 According to Broggy [47], sometimes denial is so
intense that resists victoriously to the reason evidence,
under surprising hopes. Nevertheless, the body, through
physical losses that are becoming more evident, restrictive
and generators of impotence, indicates every day more
clearly what will be the end. itself, but also a sense of life that must be met or some-
one to love. This study supports the experience of comfort and
discomfort as a balanced process, in which there is an
oscillation between the losses and the valorisation of re-
lationships. If in a sense discomfort prevails, in other
the intensification of the affections predominates. under surprising hopes. Nevertheless, the body, through
physical losses that are becoming more evident, restrictive
and generators of impotence, indicates every day more
clearly what will be the end. As mentioned by Charmaz [48], there is a loss of iden-
tity, a loss of the “self”. Likewise, Cassel [49], described
suffering as the state of discomfort induced by the person
disintegration threat. Even we mentioned the patient’s perspective, the major-
ity of the interviewed (82 %) had cancer-related diagnoses,
so the focus of the study was almost on palliative cancer
patients. Openness to spiritual dimension As pointed out in our introduction, ageing popu-
lations will lead to an increase in chronic conditions. Data
indicates that these conditions could have a different
dying trajectory than cancer [53]. Physical losses and lack of autonomy favor the experi-
ences of psycho-spiritual discomfort, since the self-esteem
of the patient is affected. Besides somatic vulnerability, informants are confronted
with social vulnerability. The disease traps the patient and
is a source of profound limitations, as the impossibility to
return home. So, grouping the experience of all PC patients together
(cancer/non-cancer) does not take these differences in
comfort experience into account. We believe that our data covers the comfort experi-
ences, but of course, the inclusion of more patients,
with non-cancer diagnoses, and do the data analysis by
separate in future research, might reveal additional
relevant experiences. The fact of sharing a room represents, for some
patients, social comfort, letting them share their ex-
perience with other patients. For others, this is a dis-
comfort factor since sharing a room deprives them of
their freedom. These findings are consistent with the study of Williams
y Gardiner [50], which states that PCU should have col-
lective and single rooms since the choice between these
two types of room is not unanimous among patients. Conclusion In addition, the findings provide useful information that
leads us to two major future research lines: the need to de-
velop and implement comfort interventions adapted and
adjusted to these patients’ comfort needs; and the need to
validate cross-culturally, to the contexts in study, an
instrument for evaluating comfort, in order to assess the
comfort interventions implemented. Indeed, Viktor Frankl [51], states that the core of the
human being is the spirit, that is, the existence is always
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Latitudinal changes of euphausiid assemblages related to the morphological variability of the sound scattering layer along Baja California, October 1994
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Scientia marina
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Latitudinal changes of euphausiid assemblages related
to the morphological variability of the sound scattering
layer along Baja California, October 1994* J. GÓMEZ-GUTIÉRREZ1, G. GONZÁLEZ-CHÁVEZ2, C.J. ROBINSON2, and V. ARENAS-FUENTES2 1Departamento de Plancton y Ecología Marina, Centro Interdisciplinario de Ciencias Marinas Apartado Postal 592,
C.P. 23000 La Paz, Baja California Sur, México
1Current address: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 Ocean. Admin. Building. Corvallis, OR 97331-5503, USA
2Laboratorio de Ecología de Pesquerías, Instituto de Ciencias del Mar y Limnología, UNAM Apartado Postal 70-305,
C.P. 04510. México, D.F., México 1Departamento de Plancton y Ecología Marina, Centro Interdisciplinario de Ciencias Marinas Apartado Postal 592,
C.P. 23000 La Paz, Baja California Sur, México
1Current address: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 Ocean. Admin. Building. Corvallis, OR 97331-5503, USA
2Laboratorio de Ecología de Pesquerías, Instituto de Ciencias del Mar y Limnología, UNAM Apartado Postal 70-305,
C.P. 04510. México, D.F., México SUMMARY: Latitudinal changes in the euphausiid assemblages were compared to the morphological structure (size and
compactness) of the sound scattering layer (SSL) during ten 24-h surveys made in October 1994 along the west coast of
Baja California, México. During October, upwelling was found in the northern area from Punta Eugenia (28°N) to Ensena-
da (30°N) dominated by temperate species from the California Current System. In the southern sector of the peninsula, a
northward movement of tropical waters transports a tropical zooplankton assemblage near Bahia Magdalena (24°N). The
aggregation and the dispersion of the whole SSL (plankton and nekton) were investigated using a single beam vertical
echosounder, Simrad EY-200, working at 200 kHz and the Hydro Acoustic Data Acquisition System (HADAS) that esti-
mates patch variables of density and compactness. The size and shape of the SSL were obtained from the echogram visual-
ization. The euphausiid species composition was obtained using an Isaacs-Kidd midwater trawl, bongo nets, and opening-
closing nets. At Ensenada and Punta Eugenia, an area inhabited by a temperate euphausiid assemblage, large and dense SSLs
were recorded over the continental shelf (mean sizes were 10-km and 7-km long with mean compactness of 15% and 19%). These regions were dominated by the neritic species Nyctiphanes simplex and the temperate species Nematoscelis difficilis,
Euphausia pacifica, and Thysanoessa spinifera. In the southern area, a tropical euphausiid assemblage, dominated by
Euphausia eximia, E tenera, and E. distinguenda, inhabits smaller and dispersed SSLs (mean size 5-km long and 11% com-
pactness) located in the offshore area. The euphausiid biomass of the most abundant species indicated, N. simplex and N. SCIENTIA MARINA SCIENTIA MARINA SCI. MAR., 63 (1): 79-91 1999 Latitudinal changes of euphausiid assemblages related
to the morphological variability of the sound scattering
layer along Baja California, October 1994* difficilis, had their highest standing stock in the north (393 and 643 mg C 1000 m-3), with E. eximia in the southern area (186
mg C 1000 m-3). Euphausiid assemblage development in different biological environments, is evidenced by SSL morphol-
ogy along the west coast of Baja California during autumn, is caused by strong latitudinal changes in physical oceanogra-
phy that affect the biological interactions in each region. Key words: Euphausiids, sound scattering layer, Baja California.. *Received February 18, 1998. Accepted November 12, 1998. 1Departamento de Plancton y Ecología Marina, Centro Interdisciplinario de Ciencias Marinas Apartado Postal 592,
C.P. 23000 La Paz, Baja California Sur, México
1Current address: College of Oceanic and Atmospheric Sciences, Oregon State University, 104 Ocean. Admin. Building.
Corvallis, OR 97331-5503, USA
2Laboratorio de Ecología de Pesquerías, Instituto de Ciencias del Mar y Limnología, UNAM Apartado Postal 70-305,
C.P. 04510. México, D.F., México MATERIAL AND METHODS An insight into the behavior within and between
SSLs is important to understand the function of the
epipelagic ecosystem. The analysis of echograms
provides morphological descriptions of plankton
and fish aggregations together with characteristics
of their habitat. However, most studies have been
made with fish schools (Misund, 1993; Misund et
al., 1995; Petigas and Levenez, 1996; Massé et al.,
1996). Studies of the SSL using nonintrusive tech-
niques (hydroacoustic) may give clues to the link
between euphausiids, the environment, and the rest
of the pelagic community. Data were collected along the west coast of Baja
California, México from October 17 to 30, 1994 on
the RV ‘El Puma’. Ten 18-km transects perpendicu-
lar to the coast, covering three areas, were sampled:
north, from Ensenada to Punta Baja; center, from
Punta Eugenia to Bahia Asuncion; and south, near
Bahia Magdalena (Fig. 1). The transects covered
three zones each approximately 6-km long: neritic,
slope, and oceanic. Along each transect, there were
three oceanographic stations, one at each end and
one in the middle (slope zone) (Fig. 1). Each tran- Along the west coast of Baja California, a strong
latitudinal environmental gradient occurs during
autumn (Gómez-Gutiérrez et al., 1996, Gómez-
Gutiérrez and Robinson, 1997). Because it is known
that zooplankton assemblages have latitudinal
changes along Baja California during this season (i. e. Brinton, 1962, 1979; Gómez-Gutiérrez et al., 1995,
Gómez-Gutiérrez and Robinson, 1997), an interesting
comparative study can be performed of the aggrega-
tion behavior of the SSLs of temperate and tropical
epipelagic assemblages. We hypothesize that temper-
ate and tropical euphausiid community structures
inhabit SSLs with different morphological character-
istics (i.e. shape, size, and compactness). One of the
most important goals of the study of the dynamics of
the SSL is the development of models that include
animal behavior and environmental factors control-
ling this behavior. Field sampling on fine horizontal
(i.e. < 10 km) and vertical scales is important for
understanding patch phenomena. Model studies of
small regions on fine horizontal scales may help
determine how to include the effects of patches in
models with coarser spatial resolution. FIG. 1. – Map of the study area, indicating the sampling stations
covered during October 1994. E = Ensenada; PB = Punta Baja
(northern zone, transects 1 to 4); PE = Punta Eugenia (central zone;
transects 1 to 4); BM = Bahia Magdalena (southern zone, transect
1 and 2). FIG. 1. INTRODUCTION related to euphausiid distribution, abundance, and
community structure have been studied extensively
in the California Current System and Eastern Tropi-
cal Pacific (i.e. Brinton, 1962, 1979; Gómez-Gutiér-
rez, 1995; Gómez-Gutiérrez et al., 1995). However,
little attention has been given to the biological inter-
actions between these assemblages and the rest of
the pelagic community. Euphausiids typically play a major role in the
economy of the pelagic food web in oceanic and
coastal waters. Physical and chemical variables LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 79 LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 79 We designed a sampling program to detect
changes on a circadian time scale over about 18
kilometers of the SSL along the Baja California
peninsula. The aim of this study was to determine if
observed latitudinal changes in the euphausiid com-
munity structure during October 1994 (autumn)
alters according to the physical characteristics of the
SSL along the west coast of Baja California, a
region recognized as a transition zone of the Cali-
fornia Current System. Studies employing both net
sampling and remote techniques could help resolve
the spatial and temporal dependence of species dis-
tribution, particularly vertical, on an ecosystem
scale. In the marine pelagic environment, planktonic
and nektonic organisms form dense aggregations,
hydroacoustically recognized as a Sound Scattering
Layer (SSL). This is defined as the layer where a
large number of pelagic organisms reflect the
hydroacoustic signals. The SSLs are dynamic,
active, and have a particular behavior as a function
of their community structure causing changes in
their vertical distribution, size, and shape over time
and space. These variable structures could imply
different biological interactions among their compo-
nents. Pelagic organisms generally form tight aggre-
gations during the day, often near the seabed, and
break into less dense aggregations that are more
amenable to acoustic observation at night when they
move into midwater (Isaacs and Schwartzlose,
1965; Robinson and Gómez-Gutiérrez, 1998). MATERIAL AND METHODS – Map of the study area, indicating the sampling stations
covered during October 1994. E = Ensenada; PB = Punta Baja
(northern zone, transects 1 to 4); PE = Punta Eugenia (central zone;
transects 1 to 4); BM = Bahia Magdalena (southern zone, transect
1 and 2). 80 J. GÓMEZ-GUTIÉRREZ et al. strengths (MacLennan and Simmonds, 1992), this
echo-strength range was used based on i) results
obtained in more than 400 Isaacs-Kidd mid-water
trawls that we have made along the west coast of
Baja California since 1992, and ii) compared the
catches with echo-analysis obtained using the same
frequency, the same calibrated echosounder, and the
same variables to acquire hydroacoustic data. Accordingly, this target strength corresponds to zoo-
plankton aggregations, mainly euphausiids, which
are common in the area (Gómez-Gutiérrez, 1995,
Gómez-Gutiérrez and Robinson, 1997; Robinson
and Gómez-Gutiérrez, 1998). With this range, we
were able to discriminate fish and other larger nek-
tonic animals. Therefore, the rest of the TS range (-
32 to -52) was neglected in the statistical analyses. When the zooplankton abundance was high enough
to be detected by the echo sounder, the acoustic
technique detected and quantified the backscattering
strength and distribution of the organisms with more
detail than is possible with net sampling. Hydroa-
coustic information, therefore, enabled us to map the
vertical and horizontal zooplankton distribution
continuously during 24 h. sect was monitored for approximately 24 hours,
starting from the neritic station, heading to the
oceanic, returning to the middle station and finish-
ing at the neritic station about 4 h later. The loop was
repeated for a total time of 24 h. About six samples
(Bongo and CTD) per oceanographic station and
about 18 samples per transect were taken. p
p
A continuous hydroacoustic survey of the water
column was obtained along each transect. We used a
single-beam echosounder, Simrad EY-200 (nominal
beam width 7°) with a working frequency of 200
kHz, an average ping rate of 1.7 pulses per second,
and a pulse duration of 0.3 ms was used. The trans-
ducer depth was 4 m and the echo analysis started 1
m from the transducer. Before the cruise, calibration
was done using a standard target, a 13-mm diameter
copper sphere (-45 decibels dB). To analyze the
echosounder information, the Hydro Acoustic Data
Acquisition System (HADAS) was used (Lindem
and Houri, 1988). HADAS processes hydroacoustic
data in several steps. MATERIAL AND METHODS First, data are digitized and
stored in a data file, later they can be displayed as an
echogram and analyzed. This system is an echo-
counting program that transforms the received echo
distribution into area densities and abundance esti-
mates. HADAS uses the Craig and Forbes (1969)
algorithm to remove the beam pattern effect. A modified Isaacs-Kidd mid-water trawl net (a
cod end liner of 500-µm mesh with a 2.5- x 2.5-m
mouth area) was trawled between stations where
dense SSLs occurred to determine the euphausiid
species composition. Along each transect, water
temperature and salinity were recorded at each
oceanographic station using a CTD Inter-Ocean
SO4 (from the surface to 200 m). Zooplankton sam-
ples were collected at each station using Bongo nets
fitted with 300- and 500-µm mesh obliquely towed
from 200 m to the surface (or 10 m from the bottom
in more shallow stations). At selected stations, an
opening-closing net was trawled at three levels
(above, within, and below the thermocline) to detect
if the community structure of the shoal is different at
these layers. The volumes filtered were estimated
using a flowmeter. g
p
The hydroacoustic system is able to detect
echoes between -32 to -57 dB and because a time-
varied gain of 40 was used, an analysis of echo
counts for individuals was done. Results are pre-
sented as individuals per hectare (ind ha-1). More-
over, using HADAS it is possible to obtain the num-
ber of echoes found as single organism and, there-
fore, calculates the degree of compactness of the
scattering layer. The threshold for a single target is
set arbitrarily by the user, but it depends on sound
speed, pulse duration in seconds, and the corre-
sponding length of the pulse in meters. In our case,
the working pulse duration was 0.3 ms and the
sound speed was 1500-m s-1. The pulse length in the
water at any instant was 45 cm. We set ten as the
threshold for single targets. That is, if a target lasted
for less than 10 echoes it was considered to be a sin-
gle organism. If it lasted for more, the target was
considered a group. Results of compactness were
then presented as the percentage of the total number
of grouped echoes that were found. Environmental conditions The temperature-salinity (T-S) diagrams from the
neritic and oceanic zones in the three latitudinal
areas are shown in Figure 2. Strong latitudinal
changes were evident along the west coast of Baja
California. Surface waters of the California Current
dominated the northern area with temperatures <18
°C and salinity < 33.4 ppt in the 50-m surface layer,
the salinity increasing to about 34.3 ppt in deeper
waters. The environmental conditions from the ner-
itic and oceanic stations were quite different with
lower temperature and slightly more saline water
inshore indicating upwelling near shore. The
decrease in minimum subsurface salinity can be
assumed to be caused by the greater influence of
California Current waters. In the center area, the 50-
m layer was warmer (18 to 20 °C) and saltier (about
34.6 ppt) than the northern area. Like the north, in
the center zone a neritic-oceanic gradient was evi-
dent. A body of cool water was present inshore
between 27° and 30°N, a feature perhaps indicative
of recent upwelling. The southern area showed a
marked influence of the Equatorial surface water
mass with warmer surface waters (24-25 °C within FIG 2. – Representative temperature-salinity (T-S) diagrams for dif-
ferent latitudinal zones, North = Ensenada; Center = Punta Eugenia,
and South = Bahia Magdalena during October 1994. At each latitu-
dinal zone, a neritic and an oceanic CTD vertical profile at night and
another two during the day were chosen. the first 25 m) corresponding to surface Equatorial
waters (Fig. 2). MATERIAL AND METHODS The zooplankton biomass was measured as dis-
placement volume and was analyzed using multifac-
tor analysis of variance for latitudinal, cross-shelf,
and day vs. night patterns. All euphausiids from the
500-µm Bongo net were sorted from the samples,
identified to species level, and counted. Numbers
were standardized to individuals per 1000 m-3 and
log-transformed to normalize them. Euphausiid
species were grouped by biogeographic affinities
following the classification of Brinton (1979). A
cluster analysis (1-Pearson r using weighted pair- All the hydroacoustical analyses were made
using target strengths measuring -53 to -57 dB. Although the use of a single beam echosounder is
not the best method to calculate accurate target LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 81 FIG 2. – Representative temperature-salinity (T-S) diagrams for dif-
ferent latitudinal zones, North = Ensenada; Center = Punta Eugenia,
and South = Bahia Magdalena during October 1994. At each latitu-
dinal zone, a neritic and an oceanic CTD vertical profile at night and
another two during the day were chosen. group average) was used to determine the grouping
based on the presence or absence of species using
only samples obtained at night (2000 to 0500)
because euphausiids are known to avoid nets during
the day. Euphausia diomedeae Ortmann was the
only species not included in the analysis because
this was caught only during the day. The total length (from the posterior of the eye to
the end of the telson, not including the spines) of all
stages of the three most abundant euphausiid species
was measured (Nyctiphanes simplex, Nematoscelis
difficilis, and Euphausia eximia). To estimate
euphausiid biomass in each region, the average body
weight by size of these species was estimated as
body carbon weight (mg C 1000 m-3) calculated
from dry-weight equations reported by Gómez-
Gutiérrez and Robinson (1997) (Nyctiphanes sim-
plex DW = 0.005371 (TL)2.31596, Nematoscelis diffi-
cilis DW = 0.001892 (TL)2.87750, and Euphausia
eximia DW = 0.001057 (TL)3.10037, where DW is dry
weight in mg and TL is total length in mm by
assuming a carbon content of 45% (Parsons et al.,
1984). Community structure of the euphausiids difficilis, and
Stylocheiron affine, the euphausiid composition in
the three latitudinal regions showed strong latitudi-
nal differences (Table 1). Nineteen euphausiid species were caught in the
Bongo trawls, showing a higher diversity than the
Isaacs-Kidd net trawls. However, similar latitudinal
trends in community structure of the euphausiids
were observed. Changes in the species list were
noted between latitudinal regions, and the relative
abundance of species varied (Table 2). For example,
Nyctiphanes simplex had its highest abundance when
caught with a Bongo net in the north area, decreasing
toward the south. Whereas, the catch using the
Isaacs-Kidd net had its highest abundance in the cen-
ter area. Nematoscelis difficilis abundance peaked in
the north area using the bongo nets, but it was pre-
sent only in the center area when caught in the LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 83
TABLE 2. – Average of sea surface temperature (°C), zooplankton biomass (ml 1000-3), and abundance (ind 1000 m-3) of the euphausiids
obtained by Bongo net trawls along the west coast of Baja California, México. Relative abundance is shown in parentheses. * = abundance
< 0.005 ind 1000 m-3. Community structure of the euphausiids Zooplankton samples from the Isaacs-Kidd
midwater net trawls were dominated by seven
euphausiid species (Table 1). All the other four
euphausiid species were less than 8% of the total
euphausiid abundance and, therefore, were
grouped. Nyctiphanes simplex was the most abun-
dant euphausiid collected with net gear in the north
and central area and the second most abundant in
the southern area, after Euphausia eximia. Using
biogeographical affinities proposed by Brinton
(1979), we found the north and central zones dom- 82 J. GÓMEZ-GUTIÉRREZ et al. TABLE 1. – Average density (ind dm-3) of the euphausiid species obtained by Isaacs-Kidd net trawls along the west coast of Baja California,
México during October 1994. Relative abundance (%) is shown in parentheses, n = number of Isaacs-Kidd trawls analyzed, and * = species
found in only one sample. TABLE 1. – Average density (ind dm-3) of the euphausiid species obtained by Isaacs-Kidd net trawls along the west coast of Baja California,
México during October 1994. Relative abundance (%) is shown in parentheses, n = number of Isaacs-Kidd trawls analyzed, and * = species
found in only one sample. TABLE 1. – Average density (ind dm-3) of the euphausiid species obtained by Isaacs-Kidd net trawls along the west coast of Baja California,
México during October 1994. Relative abundance (%) is shown in parentheses, n = number of Isaacs-Kidd trawls analyzed, and * = species
found in only one sample. Species
North (n = 5)
Center (n = 5)
South (n = 6)
Average
SD
Average
SD
Average
SD
Nyctiphanes simplex
4049 (84.57)
1844
7625 (60.02)
13603
4206 (40.65)
6626
Thysanoessa spinifera
333 (6.95)
*
Nematoscelis difficilis
266 (2.09)
*
Nematobrachion flexipes
66 (0.51)
*
Euphausia pacifica
3730 (29.36)
4804
Euphausia eximia
266 (2.09)
*
5183 (50.08)
7477
Euphausia tenera
466 (4.51)
*
Others species (four)
406 (8.48)
409
753 (5.93)
879
493 (4.76)
445 inated by the marginal eastern tropical Pacific pro-
liferator (ETP) N. simplex; three temperate Califor-
nia Current terminus species, (Nematoscelis diffi-
cilis, Thysanoessa spinifera, and Euphausia pacifi-
ca) and several species of the offshore section of
the California Current. In the southern zone, N. simplex and Euphausia eximia, another marginal
ETP proliferator species, dominated, followed by
two tropical and equatorial endemic ETP-adapted
species (Euphausia tenera and Euphausia dis-
tinguenda). Excluding N. simplex, N. TABLE 2. – Average of sea surface temperature (°C), zooplankton biomass (ml 1000-3), and abundance (ind 1000 m-3) of the euphausiids
obtained by Bongo net trawls along the west coast of Baja California, México. Relative abundance is shown in parentheses. * = abundance
< 0.005 ind 1000 m-3. Community structure of the euphausiids Abundance is expressed as individuals per hectare using a target strength range between - 53 to -57 dB. n = number of echograms
analyzed. Zone and Transect
Day
Night
Day and Night
Relative
ind ha-1
ind ha-1
ind ha-1
abundance (%)
North 1 (n=6)
916
1910
2826
1.3
North 2 (n=7)
11416
18800
30216
14.1
North 3 (n=7)
95521
91852
187373
84.6
Mean
35951
37521
73472
55.4
Center 1 (n=6)
7969
18058
26027
15.5
Center 2 (n=6)
16966
13580
30546
18.3
Center 3 (n=7)
8744
17084
25828
15.5
Center 4 (n=6)
40030
44949
84979
50.7
Mean
18427
23418
41845
31.5
South 1 (n=7)
7428
8414
13846
43.3
South 2 (n=5)
2654
16219
18118
56.7
Mean
5041
12317
17358
13.1 Isaacs-Kidd net. This indicates the different catch
efficiency of the different nets (Table 1 and 2). How-
ever, these nets were not used in the same areas. The
Bongo nets were used at each of the oceanographic
stations, and the Isaacs-Kidd mid-water net was used
between the oceanographic stations. Cluster analysis,
using data only obtained during the night (2000 to
0500), showed three groups related to the three lati-
tudinal sampling areas. Two groups, the center
(except one northerly station) and southern areas,
were independent. The third group was dominated
by all the stations of the northern zone and the nine
stations of the center zone (these last were located in
transects C1 and C2 near the coast), suggesting an Isaacs-Kidd net. This indicates the different catch
efficiency of the different nets (Table 1 and 2). How-
ever, these nets were not used in the same areas. The
Bongo nets were used at each of the oceanographic
stations, and the Isaacs-Kidd mid-water net was used
between the oceanographic stations. Cluster analysis,
using data only obtained during the night (2000 to
0500), showed three groups related to the three lati-
tudinal sampling areas. Two groups, the center
(except one northerly station) and southern areas,
were independent. The third group was dominated
by all the stations of the northern zone and the nine
stations of the center zone (these last were located in
transects C1 and C2 near the coast), suggesting an overlapping of species from both areas (Fig. 3). A
temperate California Current terminus assemblage
dominated in the northern area, and a marginal ETP
proliferator and an endemic ETP-adapted species
dominated in the southern zone. Community structure of the euphausiids Zone
North (29-31°N)
Center (26-28° N)
South (24-25°N)
Day (n = 41)
Night (n = 27)
Day (n = 44)
Night (n = 33)
Day (n = 20)
Night (n = 17)
SST
18.12
17.83
20.32
19.99
25.34
25.21
Biomass 500 µm
40.33
47.00
63.35
74.02
19.98
29.87
Biomass 300 µm
59.80
84.59
80.27
74.34
25.35
28.50
Nyctiphanes simplex
43.82(92.21)
24.49 (77.72)
23.78 (96.76)
29.73 (94.32)
1.22 (18.96)
0.54 ( 3.47)
Nematoscelis difficilis
2.58 ( 5.43)
4.61 (14.63)
0.18 ( 0.73)
0.66 ( 2.09)
0.05 ( 0.81)
0.04 ( 0.24)
Stylocheiron affine
0.19 ( 0.40)
0.16 ( 0.50)
0.27 ( 1.10)
0.48 ( 1.54)
0.36 ( 5.59)
0.82 ( 5.24)
Stylocheiron longicorne
0.03 ( 0.03)
0.03 ( 0.10)
Stylocheiron maximun
* ( 0.01)
* ( 0.01)
Euphausia hemigibba
* ( 0.01)
Euphausia pacifica
0.50 ( 1.05)
0.99 ( 3.14)
* ( 0.01)
Euphausia gibboides
0.27 ( 0.57)
0.91 ( 2.90)
* ( 0.02)
0.04 ( 0.12)
Euphausia recurva
0.01 ( 0.01)
0.01 ( 0.02)
Stylocheiron abbreviatum
0.03 ( 0.06)
0.03 ( 0.09)
* ( 0.01)
Thysanoessa gregaria
0.08 ( 0.17)
0.09 ( 0.28)
* ( 0.01)
0.03 ( 0.11)
Thysanoessa spinifera
0.16 ( 0.52)
* ( 0.01)
Nematobrachion flexipes
0.01 ( 0.03)
* ( 0.01)
0.02 ( 0.06)
0.01 ( 0.09)
Euphausia eximia
0.01 ( 0.02)
0.02 ( 0.07)
0.33 ( 1.35)
0.54 ( 1.73)
4.34 (67.65)
12.58 (80.14)
Nematoscelis tenella
* ( 0.01)
Nematoscelis gracilis
* ( 0.01)
0.18 ( 2.85)
0.62 ( 3.92)
Euphausia distinguenda
0.05 ( 0.84)
0.26 ( 1.64)
Euphausia tenera
0.20 ( 3.14)
0.83 ( 5.27)
Euphausia diomedeae
0.01 ( 0.16)
Total
47.52
31.52
24.58
31.52
6.41
15.70 TABLE 2. – Average of sea surface temperature (°C), zooplankton biomass (ml 1000-3), and abundance (ind 1000 m-3) of the euphausiids
obtained by Bongo net trawls along the west coast of Baja California, México. Relative abundance is shown in parentheses. * = abundance
< 0.005 ind 1000 m-3. TABLE 3. – Mean abundance of the scattering layer recorded hydroacoustically by an echosounder, Simrad EY-200, (200 kHz), by latitudi-
nal zone. Abundance is expressed as individuals per hectare using a target strength range between - 53 to -57 dB. n = number of echograms
analyzed. TABLE 3. – Mean abundance of the scattering layer recorded hydroacoustically by an echosounder, Simrad EY-200, (200 kHz), by latitudi-
nal zone. Community structure of the euphausiids The euphausiid
community structure, and probably all the zooplank-
ton community, showed strong latitudinal changes
(Table 1 and 2). Nyctiphanes simplex was about two
times more abundant during the day than at night at
Ensenada (north) and Bahia Magdalena (south). At
Punta Eugenia, this euphausiid had almost the same
abundance, day or night. The rest of the species
showed their highest abundance at night, suggesting
night vertical migration to the surface (Table 2). FIG. 3. – Cluster analysis (1-Pearson r using weighted pair-group average) of the euphausiid species obtained
with the Bongo net using samples (59 stations) obtained during the night (2000 to 0500) sorted by sampling
stations (regional analysis). These groups were estimated considering a similarity level of about 2.1 (dashed
line). Euphausia diomedeae was not included in the analysis because it was caught only during the day. Black
points on the y-axis indicate the northern area stations. FIG. 3. – Cluster analysis (1-Pearson r using weighted pair-group average) of the euphausiid species obtained
with the Bongo net using samples (59 stations) obtained during the night (2000 to 0500) sorted by sampling
stations (regional analysis). These groups were estimated considering a similarity level of about 2.1 (dashed
line). Euphausia diomedeae was not included in the analysis because it was caught only during the day. Black
points on the y-axis indicate the northern area stations. 84 J. GÓMEZ-GUTIÉRREZ et al. and only zooplankton of 500 µm showed day-night
difference, suggesting an active diel vertical migra-
tion or net avoidance during daytime. The zooplankton biomass from the 300-µm mesh
net trawls showed significant latitudinal changes
(three-way ANOVA P < 0.05) but no significant dif-
ferences between offshore-inshore regions and day-
night (three-way ANOVA P > 0.05), indicating fac-
tors, such as patchiness and vertical distribution of
the individual species during day and night tend to
balance each other out. The zooplankton biomass
obtained using the 500-µm mesh net showed signif-
icant latitudinal changes and day-night biomass
changes (three-way ANOVA P < 0.05). These did
not show significant differences among the off-
shore-inshore regions (Three-way ANOVA P >
0.05). Thus, two different-size zooplankton had
strong latitudinal changes probably related to
changes in the zooplankton community structure, At particular SSLs, opening-closing net trawls
were made to determine the euphausiid composition
species above, within, and below the SSL. Nine
euphausiid species were caught using this gear. Nyc-
tiphanes simplex (96%) and E. Community structure of the euphausiids White bars are samples obtaining during the day
(0600 to 1900) and black bars are samples taken during the night (2000 to 0500). FIG. 5. – Average body weight by size of the three most abundant euphausiid species (Nyctiphanes simplex, Nematoscelis difficilis, and
Euphausia eximia), in the three latitudinal regions expressed as body carbon weight (mg C 1000 m-3) calculated from dry-weight equations
reported by Gómez-Gutiérrez and Robinson (1997) by assuming a carbon content of 45%. White bars are samples obtaining during the day
(0600 to 1900) and black bars are samples taken during the night (2000 to 0500). erentially above 20 m (15 to 17 °C). Whereas, in the
southern area, both species were found below the
thermocline at about 35 m with a similar range of
temperature (15 to 17 °C) (Fig. 4). These patterns
are similar to the vertical distribution of the zoo-
plankton biomass estimated by the Bongo samples
(volume displaced) and the abundance of echoes
related to zooplankton shoals (-53 to -57 dB) esti-
mated in layers 5-m thick (Fig. 4). individuals observed mainly during the night (<10-
mm total length and an integrated biomass of 35-mg
C 1000 m-3). Nematoscelis difficilis had an impor-
tant standing stock only in the north during the night
with an integrated standing stock of 643-mg C 1000
m-3. In the center and southern areas, its biomass
was almost negligible with less than 6 mg C 1000 m-
3. Euphausia eximia had an opposite trend showing
its highest standing stock in the southern area (186
mg C 1000 m-3) during the day, decreasing north-
ward (center area 39 mg C 1000 m-3 and north area
< 0.5 mg C 1000 m-3). In terms of carbon, the center
area was the least productive of the three in
euphausiid biomass partially caused by populations
composed of relatively smaller individuals. Each latitudinal region showed a different stand-
ing stock of the euphausiids expressed as mg C 1000
m-3 estimated for the three most abundant species
(Fig. 5). Nyctiphanes simplex showed its highest
biomass in the north with an integrated standing
stock (the sum of the biomass of all the classes of
sizes) of 393 mg C 1000 m-3, and the center area (76
mg C 1000 m-3) contributed to mainly by juveniles
and adults. Relatively similar abundances were
recorded during both day and night. Community structure of the euphausiids eximia (3%) (most of
them in calyptope and furciliae stages) were the
dominant species in most of these samples. The rest
of the species contributed only 1% to the total abun-
dance (E. tenera, S. affine, E. distinguenda, N. diffi-
cilis, N. tenella, N. gracilis, and E. pacifica, in
decreasing abundance). In the north and center, a
thermocline was not evident, however, the dominant
species (N. simplex and E. eximia) were found pref- FIG. 4. – Vertical distribution of zooplankton biomass estimated by Bongo net (bars expressed in percentage, the italic number is the biomass
expressed as mL 1000 m-3), zooplankton abundance measured by the echosounder (continuous line; echoes between -53 and -57 dB expressed
as ind ha-1), and vertical distribution of two of the most abundant euphausiid species Nyctiphanes simplex and Euphausia eximia in the three
latitudinal regions expressed as relative abundance. White bars are day samples and black bars are night samples. The italic numbers are the
total abundance integrated over all strata expressed as ind 1000 m-3. In the north and central areas, coastal stations are shown. In the
southern area, the offshore stations where the SSL and these species were more abundant are shown. FIG. 4. – Vertical distribution of zooplankton biomass estimated by Bongo net (bars expressed in percentage, the italic number is the biomass
expressed as mL 1000 m-3), zooplankton abundance measured by the echosounder (continuous line; echoes between -53 and -57 dB expressed
as ind ha-1), and vertical distribution of two of the most abundant euphausiid species Nyctiphanes simplex and Euphausia eximia in the three
latitudinal regions expressed as relative abundance. White bars are day samples and black bars are night samples. The italic numbers are the
total abundance integrated over all strata expressed as ind 1000 m-3. In the north and central areas, coastal stations are shown. In the
southern area, the offshore stations where the SSL and these species were more abundant are shown. LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 85 DINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGE FIG. 5. – Average body weight by size of the three most abundant euphausiid species (Nyctiphanes simplex, Nematoscelis difficilis, and
Euphausia eximia), in the three latitudinal regions expressed as body carbon weight (mg C 1000 m-3) calculated from dry-weight equations
reported by Gómez-Gutiérrez and Robinson (1997) by assuming a carbon content of 45%. Community structure of the euphausiids A clear latitudi-
nal cline of total length was observed with the larg-
er animals in the north and the smaller animals in the
south. This latter area had a population of smaller TABLE 4. – Frequency of records of the zooplankton patches per inshore-offshore regions. Average of the variables (length, depth, and elon-
gation) of the scattering layer recorded hydroacoustically (200 kHz) by latitudinal zone using all target strength range (-32 to -57 dB). The
standard deviation is show in parentheses. Echograms showed that no animal aggregations were neglected. Sound scattering layer characteristics recorded
by the echosounder The northern transects had the highest concentra-
tions of the SSL over the continental shelf; howev-
er, in the south, a tropical assemblage had smaller 86 J. GÓMEZ-GUTIÉRREZ et al. FIG. 6. – Box-and-whisker plot of the abundance (ind ha-1) and percentage of sound scattering layer compactness of zooplankton and nekton
(echoes -53 to -57 dB) at 0-50 m over time of the north (Ensenada) (A and B), center (Punta Eugenia) (C and D), and in the south (Bahia
Magdalena) (E and F). FIG. 6. – Box-and-whisker plot of the abundance (ind ha-1) and percentage of sound scattering layer compactness of zooplankton and nekton
(echoes -53 to -57 dB) at 0-50 m over time of the north (Ensenada) (A and B), center (Punta Eugenia) (C and D), and in the south (Bahia
Magdalena) (E and F). shoals offshore. Ensenada (north) accounted for
55%, and Punta Eugenia (center) accounted for 32%
of the total echoes recorded. Only about 13% were
recorded in the southern area (Bahia Magdalena)
(Table 3). Diel zooplankton backscatter showed
Ensenada and Punta Eugenia to be the regions with
the highest abundance in the 0- to 50-m layers (Fig. 6 a and c). The southern sector (Bahia Magdalena)
had very low abundance with its highest abundance
occurring during the night (Fig. 6 e). No significant
differences were found between day and night
backscattering recorded hydroacoustically in the
three latitudinal regions (Kruskal-Wallis test; P >
0.001). The daily variation of percentage of com-
pactness indicated that in the Ensenada region very
concentrated SSLs were found during the night in
the 0- to 50-m layer (Fig. 6 b). At Punta Eugenia, the SSLs were very compact during both day and night,
particularly between 1100 and 2100 (Fig 6 d). At
Bahia Magdalena, we found the lowest percentage
of compactness (< 50%) of the SSL. Within the 0- to
50-m depth, the highest compactness was found dur-
ing the night. SSL distribution in this region was
extremely patchy, resulting in a skewed frequency
distribution of density (Fig. 6 f) shoals offshore. Ensenada (north) accounted for
55%, and Punta Eugenia (center) accounted for 32%
of the total echoes recorded. Only about 13% were
recorded in the southern area (Bahia Magdalena)
(Table 3). Diel zooplankton backscatter showed
Ensenada and Punta Eugenia to be the regions with
the highest abundance in the 0- to 50-m layers (Fig. 6 a and c). Sound scattering layer characteristics recorded
by the echosounder The southern sector (Bahia Magdalena)
had very low abundance with its highest abundance
occurring during the night (Fig. 6 e). No significant
differences were found between day and night
backscattering recorded hydroacoustically in the
three latitudinal regions (Kruskal-Wallis test; P >
0.001). The daily variation of percentage of com-
pactness indicated that in the Ensenada region very
concentrated SSLs were found during the night in
the 0- to 50-m layer (Fig. 6 b). At Punta Eugenia, the The size and shape (elongation = length/depth)
of the SSL was obtained from the echogram visual-
ization. The size was estimated from each echogram
based on the ship’s speed (11 knots) and time spent
along the transect. In the northern region (Ensenada-
Punta Baja) and the center region (Punta Eugenia-
Bahia Asuncion), the zooplankton shoals hydroa-
coustically recorded were large and dense (mean
sizes were 10- and 7-km long with a mean compact- TABLE 4. – Frequency of records of the zooplankton patches per inshore-offshore regions. Average of the variables (length, depth, and elon-
gation) of the scattering layer recorded hydroacoustically (200 kHz) by latitudinal zone using all target strength range (-32 to -57 dB). The
standard deviation is show in parentheses. Echograms showed that no animal aggregations were neglected. LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 87
Zone and transects
Time
Frequency of positive SSLs
Length of the
Depth of m
Elongation
analyzed
per region
SSL m
the SSL
Length/Depth
Neritic
Slope
Oceanic
North 2 and 3
0800-1400
5
1
4
6663 (4425)
24 (15)
282
North 2 and 3
2200-0700
6
4
5
10100 (4588)
35 (17)
287
44%
20%
36%
Center 1 to 4
0800-1900
7
2
3
4084 (3788)
33 (20)
124
Center 1 to 4
2000-0700
13
7
5
7148 (4087)
42 (22)
170
37%
33%
30%
South 1 and 2
0800-1900
1
1
6
5139 (2684)
30 (15)
174
South 1 and 2
0000-0500
2
0
4
5012 (2480)
37 (13)
136
21%
7%
72% LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 87 FIG. 7. – Comparison of three typical scattering layers recorded hydroacoustically in the three latitudinal regions along the west coast of Baja
California during the day and night and superimposed over sea temperature profiles. Echograms included all target strength ranges (-32 to -
56 dB). Sound scattering layer characteristics recorded
by the echosounder North (transect N3) in day, 1006 (A) and night, 2310 (B); center (transect C4) in day, 0648 (C) and night, 0019 (D), and south
(transect S2) in day, 1225 (E) and night, 0010 (F). The x-axis shows the length of the transect expressed as kilometers. FIG. 7. – Comparison of three typical scattering layers recorded hydroacoustically in the three latitudinal regions along the west coast of Baja
California during the day and night and superimposed over sea temperature profiles. Echograms included all target strength ranges (-32 to -
56 dB). North (transect N3) in day, 1006 (A) and night, 2310 (B); center (transect C4) in day, 0648 (C) and night, 0019 (D), and south
(transect S2) in day, 1225 (E) and night, 0010 (F). The x-axis shows the length of the transect expressed as kilometers. ness of 15% and 19%). The shoals were found to be
mainly of the neritic species Nyctiphanes simplex
and the temperate species Nematoscelis difficilis,
Euphausia pacifica, and Thysanoessa spinifera. In
the southern area, in the smaller and dispersed
patches (mean size 5-km long and 11% compact-
ness), we recorded tropical species, Euphausia
eximia, E tenera, and E. distinguenda, which pre-
sumably did not form swarms, with N. simplex in
lower abundance (data from Bongo nets), found at
night (Table 2). mid-water samples) and compactness over the
coastal shelf both day and night (Fig. 7 c, d). A high
acoustic intensity in the zooplankton-red crab
inshore patches suggests this layer is not homoge-
neous, probably as a result of the presence of fish
schools within the zooplankton patches. In the
southern area, the smallest patches were found in the
offshore area with lower compactness (Fig. 6 e, f). North to south changes in patch structure was
caused by strong latitudinal changes in physical
oceanography that affect the species success at each
region. Representative echograms (all target-strength
ranges included) during the day and night along the
three latitudinal zones are shown in Figure 7. Target-
strength analysis indicated that pelagic fish were
present within the zooplankton layer. The northern
zone had long patches over the coastal shelf during
the day, increasing in size and density during the
night in the inshore and offshore areas (Fig. 7 a, b). In the center area, a dense shoal dominated by the
decapod red crab (Pleuroncodes planipes) had
extraordinary abundance (evidenced by Isaacs-Kidd DISCUSSION Sound-scattering-layer dynamics and euphausiid
community structure obtained via the Isaacs-Kidd
and Bongo nets showed a strong latitudinal cline
during the autumn. According to Gómez-Gutiérrez
and Robinson (1997), the euphausiid abundance and
the biomass of macrozooplankton (> 1000 µm) were 88 J. GÓMEZ-GUTIÉRREZ et al. more important in the northern area than in the south
during December 1993 along the west coast of Baja
California, suggesting a recurrent latitudinal trend
found during the second part of the year. Our data
showed a 300- and 500-µm zooplankton biomass
also had a significant latitudinal cline in its abun-
dance and in the carbon content for three of the most
abundant euphausiid species. This work tests the
hypothesis that euphausiid community structure
changes are parallel to morphological characteristics
of the scattering layer where they live. The temper-
ate euphausiid assemblages inhabit larger and more
concentrated SSLs found mainly over the coastal
shelf in the northern and central area. In these
regions, the neritic euphausiid Nyctiphanes simplex,
which frequently forms dense surface swarms, had
its highest abundance over the continental shelf in
the upper 25 meters (within and above a weak ther-
mocline). Hydroacoustic measurements made for
each five-meter depth also showed the highest abun-
dance near the surface. In the southern region, the
dispersed-offshore SSLs were dominated by a trop-
ical pelagic assemblage of species like Euphausia
eximia, E. distinguenda, and E. tenera. Euphausia
eximia demonstrated its highest abundance below a
strong thermocline > 30-m deep, and the rest of the
zooplankton and nekton (recorded hydroacoustical-
ly) remained also in deeper layers. These latitudinal
trends are reasonably constant unlike the diel vari-
ability observed in the SSLs appearance caused by
the 24-h vertical migration reported by Robinson
and Gómez-Gutiérrez (1998). Latitudinal changes in
N. simplex growth production was reported by
Gómez-Gutiérrez et al. (1996), supporting the idea
that the southern region is less productive than
northern ones, and the SSLs are less dense and
smaller along the southern part of Baja California. Estimations of the standing stock expressed as the
carbon content of three of the most abundant
euphausiid species indicate that the northern area is
at least four times more productive than the southern
area, showing different productivity between these
two environments. Petigas and Levenez (1996) made an echogram acoustic density of the layer decreased with increas-
ing thermocline gradients. DISCUSSION Thus, the patchiness of
whole zooplankton and nekton was less intense
where vertical gradients were strong. This is con-
trary to the results of Barange (1994) where a strong
degree of physical forcing and cross-shelf activity
along a frontal zone affected the intensity of patchi-
ness in the Benguela upwelling system. Robinson et
al. (1997) reported a similar dispersed offshore SSL
in the southern region (Bahia Magdalena) in Decem-
ber 1993, dominated by E. eximia, the red crab Pleu-
roncodes planipes, and the mesopelagic fish Vin-
ciguerria lucetia, indicating that this is a recurrent
feature of the SSL dynamics in this southern area
during the autumn. more important in the northern area than in the south
during December 1993 along the west coast of Baja
California, suggesting a recurrent latitudinal trend
found during the second part of the year. Our data
showed a 300- and 500-µm zooplankton biomass
also had a significant latitudinal cline in its abun-
dance and in the carbon content for three of the most
abundant euphausiid species. This work tests the
hypothesis that euphausiid community structure
changes are parallel to morphological characteristics
of the scattering layer where they live. The temper-
ate euphausiid assemblages inhabit larger and more
concentrated SSLs found mainly over the coastal
shelf in the northern and central area. In these
regions, the neritic euphausiid Nyctiphanes simplex,
which frequently forms dense surface swarms, had
its highest abundance over the continental shelf in
the upper 25 meters (within and above a weak ther-
mocline). Hydroacoustic measurements made for
each five-meter depth also showed the highest abun-
dance near the surface. In the southern region, the
dispersed-offshore SSLs were dominated by a trop-
ical pelagic assemblage of species like Euphausia
eximia, E. distinguenda, and E. tenera. Euphausia
eximia demonstrated its highest abundance below a
strong thermocline > 30-m deep, and the rest of the
zooplankton and nekton (recorded hydroacoustical-
ly) remained also in deeper layers. These latitudinal
trends are reasonably constant unlike the diel vari-
ability observed in the SSLs appearance caused by
the 24-h vertical migration reported by Robinson
and Gómez-Gutiérrez (1998). Latitudinal changes in
N. simplex growth production was reported by
Gómez-Gutiérrez et al. (1996), supporting the idea
that the southern region is less productive than
northern ones, and the SSLs are less dense and
smaller along the southern part of Baja California. DISCUSSION For example, Barange (1994), using a Sim-
rad EK-400 38-kHz echo sounder at the Agulhas
bank (South Africa), estimated that zooplankton
patches are relatively long (71 m) and thin (5 m),
and they are slightly larger than horse-mackerel
patches. that other physicochemical variables or behavior
can have an important role in the vertical distribu-
tion of the SSL. Most euphausiids were caught with
different net gear during the night in the 5- to 50-m
layer where acoustic records were also more fre-
quent. They migrated to deeper layers during the
day crossing the thermocline and halocline. This
suggests a typical vertical migration to the surface
during the night (as found in the north and center
areas) with little relation to the physicochemical
variables. A relation between the appearance of a
SSL and environmental variables alone may not pro-
duce any new insight. Our estimations of the zooplankton-nekton
shoaling (no patchiness sensu Ritz, 1994) are cur-
rently too coarse; however, they are good enough to
prove that the SSL morphological variability is a
function of the community structure. Schoenherr
(1991), although his main goal was to shown a rela-
tion between the blue whale (Balaenoptera muscu-
lus) and the temperate euphausiid (Thysanoessa
spinifera) distribution, describes the deep scattering
layer in the Monterey submarine canyon (37°N),
reporting that the deep scattering layers were 1- to 2-
km wide with the thickest patches concentrated at
depths of 130-150 m located near the shelf break. His echograms (echosounder working with a fre-
quency of 100-200 kHz) showed a similar SSL-mor-
phological appearance similar to the SSL recorded
at our north and center area and those reported by
Robinson and Gómez-Gutiérrez (1998) near Ense-
nada (30°N) during July 1995, where SSLs were
dominated by the euphausiids Nyctiphanes simplex
and Euphausia pacifica. According to Bongo net samples, Nyctiphanes
simplex was found to be about two times more abun-
dant during the day than at night at Ensenada (north)
and Bahia Magdalena (south), probably because this
species tended to form dense surface swarms during
the day in environments favorable to reproduction
and feeding. In the center area, there was a similar
abundance during the day and night. DISCUSSION Dense
euphausiid swarms were detected and showed high-
ly concentrated swarms near the seabed during the
night (Robinson and Gómez-Gutiérrez, 1998) sug-
gesting that this species displays very different diel
vertical patterns as a function, possibly, of the sea-
son and local environmental conditions. Regions
that were dominated by omnivorous temperate
species like E. pacifica and N. difficilis along with
N. simplex (these species have highly setose maxil-
lae, nearly equal length periopods, disproportionate-
ly large pars molaris on the mandible, and a feeding
basket displaying mainly omnivorous feeding
habits) were associated with SSLs with the highest
values of compactness in the 0- to 50- m layer, sug-
gesting that these temperate species form dense
swarms (Robinson and Gómez-Gutiérrez, 1998). A
tropical assemblage dominated by carnivorous
species (the first and second pair of periopods elon-
gated to form grasping legs, a small par molaris rel-
ative to the incisor, and a coarser setose feeding bas-
ket) like E. eximia, E. distinguenda, and E. tenera,
was found within a relatively small SSL 4-km). Our findings represent a different SSL dynamic
pattern to that described for offshore regions, which
were done in regions of water depths of about 1,000
to 4,000 m. In offshore regions, depth distributions,
vertical and horizontal dimensions of the aggrega-
tions, and gaps between aggregations are relatively
consistent (Smith et al., 1989). Our data over the
continental shelf suggest a more variable SSL patch-
iness dynamic than in the oceanic environment. Hydroacoustical records were, in fact, from all zoo-
plankton and nekton assemblages, but we only ana-
lyzed the euphausiid component. Therefore part of
the echoes recorded could be animals detected with
different patchiness behavior and vertical migration
than that of the euphausiids. Probably this was the
cause of several mismatches in the horizontal distri-
bution of the biomass estimated via Bongo nets and
Isaacs Kidd midwater nets, and recorded using the
echosounder. The primary instrumental shortcomings originate
in HADAS’ ability as an echo-counter and the lack
of resolution of our echosounder (200 kHz) to
record animals smaller than 7 mm, which includes
most of the meso- and macrozooplankton communi-
ty structure. In addition, because this device uses a
single-beam, it was not possible to estimate the sin-
gle target strength. Nevertheless, with new methods
like dual-beam or split-beam for acoustical process- The Spearman rank correlation between abun-
dance of zooplankton recorded by the echosounder
vs. DISCUSSION Estimations of the standing stock expressed as the
carbon content of three of the most abundant
euphausiid species indicate that the northern area is
at least four times more productive than the southern
area, showing different productivity between these
two environments. Gómez-Gutiérrez (1995) demonstrated that N. simplex and E. eximia have different inshore-off-
shore life maintenance strategies showing their core
distribution to be inshore (N. simplex) and offshore
(E. eximia). Hydroacoustic results obtained in the
present work suggest that other zooplanktonic and
nektonic species have similar inshore-offshore dis-
tribution preferences. The shape and patchiness
properties of zooplankton can vary widely in differ-
ent community structures, and as a result, the
acoustic scattering properties vary accordingly. Sig-
nificant inshore-offshore differences were found in
the community structure and abundance estimated
by Bongo net samples and hydroacoustic measure-
ments along the peninsula, suggesting behavioral
maintenance strategies of some dominant zooplank-
ton and nekton species. The vertical migratory
behavior of several zooplankton species (i.e. the
euphausiids E. pacifica and N. simplex, clupeidae
fish larvae, and other neritic species) may help them
avoid offshore flow on the surface like other zoo-
plankton species in areas dominated by coastal
upwelling and complex advective processes in the
California Current System. Using conventional nets, Wiebe (1970) provided
one of the first direct estimates of zooplankton patch
size, estimating a median patch length of between
23 and 27 m during daylight and between 66 and
110 m during the night and concluded that aggrega-
tions were physically induced. Previous studies
using sophisticated hydroacoustic devices (307-kHz
acoustic Doppler current profiler ADCP and a Sim-
rad EK-500 split-beam echosounder 120 kHz)
reported wide gaps between zooplankton patches
(Smith et al., 1989) suggest that the capacity and
frequency of the echosounder used are critical to an
adequate interpretation of the patch formation Petigas and Levenez (1996) made an echogram
coding of fish schools according to the morphology
of the echo traces, describing nine types. In this
study, because we are describing whole SSLs with
multispecies clusters instead of monospecies fish
schools, we were unable to do a detailed description
of these structures. However, we were able to dis-
cern the difference in the SSL in a temperate and a
tropical assemblage. Horizontal length and relative LATITUDINAL CHANGES OF EUPHAUSIIDS ASSEMBLAGES 89 process. ACKNOWLEDGEMENTS Isaacs, J.D. and R.A. Schwartzlose. – 1965. Migrant sound scatters:
interaction with the sea floor. Science. 150: 1810-1813. Thanks are extended to the students from the
Laboratory of Fisheries Ecology UNAM, to the RV
‘El Puma’ crew for assistance and comradeship at
sea, and to Dr. Ellis Glazier, CIBNOR, for his edito-
rial help with the English text. We thank Dr. Torfinn
Lindem for comments and advice about the abilities
of HADAS software. This research was supported
by funds provided by the Dirección de Estudios de
Posgrado e Investigación (DEPI 966584, 970123,
and 988002) and by the Consejo Nacional de Cien-
cia y Tecnología (CONACyT 940511, N511-
N9108). The authors J.G.-G., C.J.R., and V.A.-F. are
supported by Sistema Nacional de Investigadores
(SNI), and the first author also is supported by a
Comisión de Operación y Fomento Actividades
Acádemicas del Instituto Politécnico Nacional
(COFAA) fellowship. Lindem, T. and H.A. Houri. – 1988. Hydro Acoustic Data Acquisi-
tion System HADAS. Department of Physics, University of
Oslo, P. Box 0316. Oslo Norway, 4 pp. y
pp
MacLennan,D.N. and E.J., Simmonds. – 1992. Fisheries Acoustics. Chapman & Hall, Fish and Fisheries Series, London. Massé, J., C. Koutsikopoulos and W. Patty. – 1996. The structure
and spatial distribution of pelagic fish schools in multispecies
clusters: an acoustic study. ICES J. Mar. Sci., 53: 155-160. clusters: an acoustic study. ICES J. Mar. Sci., 53: 155- y
Misund, O.V. – 1993. Dynamics of moving masses: variability in
packing density, shape, and size among herring, sprat, and
saithe schools. ICES J. Mar. Sci., 50: 145-160. Misund, O.V., A. Anglen and E. Frfnaes. – 1995. Mapping the
shape, size, and density of fish schools by echo integration and
a high-resolution sonar. ICES J. Mar. Sci., 52: 11-20. g
Parsons,T.R., Y. Maita, and C.M. Lalli. – 1984. A manual of chem-
ical and biological methods for sea water analysis. Pergamon
Press, Oxford. Petigas, P. and J.J. Levenez. – 1996. Spatial organization of pelag-
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mass in Senegalense waters. ICES J. Mar. Sci., 53: 147-153. i
A
1994 S
i l
i
i
l
i i
b
Ad Ritz, D.A. – 1994. Social aggregation in pelagic invertebrates. Adv. Mar. Biol. 30: 155-216. Robinson C.J. and J. Gómez-Gutiérrez. – 1998. Daily vertical
migration of dense scattering layers related to shelf-break area
in the northwest coast of Baja California, México. J. Plankt. Res., 20(9): 1679-1697. DISCUSSION temperature and salinity obtained via the CTD in
the column water showed, in general, no significant
correlation, P > 0.001; rs = -0.6190 (north), rs = -
0.7714 (center), and rs = -0.800 (south), suggesting 90 J. GÓMEZ-GUTIÉRREZ et al. Craig, R.E. and S.T., Forbes. – 1969. A sonar for fishing counting. FiskDir. Skr., Ser. Havunders., 15: 210-219. es at work in the ocean’s interior, ecologists can
begin to gain insights into the processes associated
with zooplankton and nekton patch dynamics. These
types of studies should be made in different seasons
to test our hypothesis concerning the importance of
community structure on SSL dynamics and the
probable homogeneity of SSL dynamics during
spring-early summer in the southern portion of the
California Current System. Gómez-Gutiérrez, J. – 1995. Distribution patterns, abundance and
population dynamics of the euphausiids Nyctiphanes simplex
and Euphausia eximia in the west coast of Baja California,
México. Mar. Ecol. Prog. Ser., 119: 63-76. g
Gómez-Gutiérrez, J. and C.J. Robinson. – 1997. Circadian biomass
and abundance changes of five euphausiids along the west coast
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west coast of Baja California, México during the weak ENSO
1986-87. Mar. Ecol. Prog. Ser., 120: 41-51. Gómez-Gutiérrez, J., De Silva-Dávila, R, Lavaniegos, E.B. – 1996. Growth production of the euphausiid Nyctiphanes simplex at
the coastal shelf off Magdalena Bay, Baja California Sur, Méx-
ico. Mar. Ecol. Progr. Ser. ,138: 309-314. ACKNOWLEDGEMENTS ( )
Robinson, C.M., J. Gómez-Gutiérrez and F.V. Arenas - 1997. On
the structure of a scattering layer in the southwest coast of Baja
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Qeios · Definition, February 2, 2020 Open Peer Review on Qeios Open Peer Review on Qeios Specify IDH Family Mutation National Cancer Institute National Cancer Institute Qeios ID: 06O0XB · https://doi.org/10.32388/06O0XB Source National Cancer Institute. Specify IDH Family Mutation. NCI Thesaurus. Code C160578. National Cancer Institute. Specify IDH Family Mutation. NCI Thesaurus. Code C160578. A request to enter the specific IDH family mutations that were identified in the study. Qeios ID: 06O0XB · https://doi.org/10.32388/06O0XB 1/1
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https://openalex.org/W2089184781
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https://europepmc.org/articles/pmc3930762?pdf=render
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English
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A modular computational framework for automated peak extraction from ion mobility spectra
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BMC bioinformatics
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cc-by
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METHODOLOGY ARTICLE Open Access *Correspondence: Sven.Rahmann@uni-due.de
†Equal contributors
1Collaborative Research Center SFB 876, TU Dortmund University, Dortmund, Germany
3Genome Informatics, Institute of Human Genetics, Faculty of Medicine,
University of Duisburg-Essen, Essen, Germany
Full list of author information is available at the end of the article © 2014 D’Addario et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 A modular computational framework
for automated peak extraction from ion
mobility spectra arianna D’Addario1†, Dominik Kopczynski1†, Jörg Ingo Baumbach2 and Sven Rahmann1,3* Background consider Koczulla et al. [1] and Armenta et al. [2]. The
analytes, metabolites present within exhaled breath, are
pre-separated using the MCC, analogously to gas chro-
matography (GC) before mass spectrometry (MS). While ion mobility (IM) spectrometry (IMS) is an estab-
lished technology to detect volatile organic compounds
(VOCs) in the air or exhaled breath, the more recent
combination with multi-capillary columns (MCCs) has
opened new applications in biotechnology and medicine, VOCs from the human metabolism in exhaled breath
may hint at certain diseases. Applications to diagnosis
of lung cancer, chronic obstructive pulmonary disease
(COPD) or sarcoidosis have already been reported [3-7]. *Correspondence: Sven.Rahmann@uni-due.de
†Equal contributors
1Collaborative Research Center SFB 876, TU Dortmund University, Dortmund, Germany
3Genome Informatics, Institute of Human Genetics, Faculty of Medicine,
University of Duisburg-Essen, Essen, Germany
Full list of author information is available at the end of the article Abstract Background: An ion mobility (IM) spectrometer coupled with a multi-capillary column (MCC) measures volatile
organic compounds (VOCs) in the air or in exhaled breath. This technique is utilized in several biotechnological and
medical applications. Each peak in an MCC/IM measurement represents a certain compound, which may be known or
unknown. For clustering and classification of measurements, the raw data matrix must be reduced to a set of peaks. Each peak is described by its coordinates (retention time in the MCC and reduced inverse ion mobility) and shape
(signal intensity, further shape parameters). This fundamental step is referred to as peak extraction. It is the basis for
identifying discriminating peaks, and hence putative biomarkers, between two classes of measurements, such as a
healthy control group and a group of patients with a confirmed disease. Current state-of-the-art peak extraction
methods require human interaction, such as hand-picking approximate peak locations, assisted by a visualization of
the data matrix. In a high-throughput context, however, it is preferable to have robust methods for fully automated
peak extraction. Results: We introduce PEAX, a modular framework for automated peak extraction. The framework consists of several
steps in a pipeline architecture. Each step performs a specific sub-task and can be instantiated by different methods
implemented as modules. We provide open-source software for the framework and several modules for each step. Additionally, an interface that allows easy extension by a new module is provided. Combining the modules in all
reasonable ways leads to a large number of peak extraction methods. We evaluate all combinations using intrinsic
error measures and by comparing the resulting peak sets with an expert-picked one. Conclusions: Our software PEAX is able to automatically extract peaks from MCC/IM measurements within a few
seconds. The automatically obtained results keep up with the results provided by current state-of-the-art peak
extraction methods. This opens a high-throughput context for the MCC/IM application field. Our software is available
at http://www.rahmannlab.de/research/ims. Keywords: Ion mobility spectrometry, Peak detection, Signal processing, Automated pipeline © 2014 D’Addario et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 For a sample pre-separated by an MCC, an IM spectrum is
captured periodically at several different retention times,
e.g. each 100 ms for up to 10 minutes. The retention time r
is the time a compound needs to pass the MCC. are its coordinates (r, t) and signal intensity s (for exam-
ple s = Sr,t). Additional parameters may describe the
peak shape or alternative signal values. For typical anal-
ysis algorithms, a triple (r, t, s) suffices, where we use s
as shorthand for any signal at or around (r, t), how ever
computed. The drift time t′ is the time a compound needs to drift
through the IM spectrometer and is influenced by param-
eters such as drift tube length, intensity of electric field
as well as temperature or ambient pressure. Figure 1 illus-
trates a schematic cross section of an IM spectrometer. It is thus advantageous to consider a normalized quan-
tity: the reduced inverse mobility t in Vs/cm2. Each IM
spectrum (at a specific MCC retention time r) provides a
signal intensity (ion count, measured as voltage change on
a Faraday plate; for technical details see [8]) for each value
of t. The position and intensity of peaks indicates the pres-
ence and concentration of certain VOCs. Peaks behaving
differentially (presence vs. absence or quantitative differ-
ence) in two classes of measurements (i.e., patients vs. controls) may represent potential biomarkers that can hint
at specific diseases. The need for automated peak extraction: our contributions
The fundamental step of peak extraction from a raw
IMSC is the basis for all subsequent data mining classifi-
cation steps [9]. Given a set of measurements, a domain
expert assisted by visualization software (such as Visual-
Now from B&S Analytik, Dortmund, Germany) is able to
interactively pinpoint peak locations within a few minutes. An experienced expert can often distinguish weak signals
from noise. We obtain a two-dimensional IM spectrum-chroma-
togram (IMSC) S: R × T
→Z with retention times
r ∈R, inverse mobilities t ∈T, and signal intensities
S(r, t) ∈Z (measured as unsigned 12-bit values). In prac-
tice, we have equidistant points on both retention time
and inverse mobility axes; therefore we may assume that
R = {1, . . . , m} and T = {1, . . . MCC/IM measurements and peaks A single measurement with an IM spectrometer takes
about 100 ms, using nitrogen or synthetic air as drift gas. Page 2 of 12 Page 2 of 12 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 , n}, where these index
values correspond to actual times and reduced inverse
mobilities. MCC/IMS technology has matured to a point where
it is applied to automated monitoring [10] and moves
towards a high-throughput domain. Here, interactive
expert-driven and computer-assisted peak extraction is
no longer possible. To a lesser extent, the same situ-
ation holds true in exploratory medical studies, where
the amount of available measurements increases beyond
human analysis capabilities. Therefore, automated peak
extraction methods are urgently required. As another
advantage, they offer better reproducibility and increased
speed. However, they may make certain assumptions
about the data and lack in adaptability. We call a single row or spectrum Sr at a retention time r
an IM spectrum. A single column S·,t at a certain t is
called IM chromatogram. The whole matrix S is the IMSC. Regions of S with a high signal intensity are called peaks. An IMSC can be visualized as a heat map (Figure 2). In
every IMSC, the reactant ion peak (RIP) produced by the
ionisation of the drift gas is visible as a high-intensity
chromatogram at a reduced inverse mobility of approx-
imately t = 0.48 Vs/cm2. When additional analyte ions
occur, the RIP is reduced and may even disappear if the
analyte concentrations are extremely high. We describe
each peak with a set of (at least three) descriptors, which We here provide a modular automated peak extrac-
tion framework. The task of peak extraction is divided Figure 1 Schematic cross section of an IM spectrometer. Analyte compounds pre-separated by the MCC are ionized in the ionization chamber. The ions are accelerated by an electric field and move through the drift tube. They cause a voltage change when colliding with the Faraday plate;
this is the measured signal. Figure 1 Schematic cross section of an IM spectrometer. Analyte compounds pre-separated by the MCC are ionized in the ionization chamber. The ions are accelerated by an electric field and move through the drift tube. They cause a voltage change when colliding with the Faraday plate;
this is the measured signal. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 3 of 12 Page 3 of 12 Figure 2 IMSC visualized before and after preprocessing. Top:
Heat map of a raw IMSC. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 X-axis: reduced inverse mobility t in Vs/cm2;
Y-axis: retention time r in seconds; signal: white (lowest) < blue <
purple < red < yellow (highest), reactant ion peak (RIP) at t=0.48
Vs/cm2. Bottom: IMSC after preprocessing using bc-dn-s (see text). The peak extraction process is divided into four steps
(Figure 3). Each step can be implemented by differ-
ent modules represented by the yellow boxes containing
an abbreviation for each module name. Each resulting
pipeline requires a single IMSC as input and outputs a list
of peaks. Each peak is represented at least by the following
information: name of the measurement, an automatically
given peak ID, reduced inverse mobility, retention time,
signal value, reduced inverse mobility index and reten-
tion time index. Knowing the name of measurement for
each peak is convenient when comparing several peak lists
from different measurements. We now discuss the four
distinct steps. Preprocessing transforms a (raw) IMSC into another
(processed) IMSC, i.e., no data reduction or peak extrac-
tion takes place. Raw IMSCs are noisy and include the
confounding RIP. To remove both noise and the RIP,
we describe three modules: Baseline Correction (bc),
De-Noising (dn) and Smoothing (s); every module’s input
and output is an IMSC. Baseline Correction (bc) han-
dles the RIP (and the baseline in general), removes it, and
uncovers underlying peaks. De-Noising (dn) estimates the
probability of a data point belonging to noise in order to
remove the noise. Smoothing (s) applies a smoothing filter. The order of execution is commutable, but none of these
modules can be omitted. Figure 2 shows a measurement
before and after preprocessing. Figure 2 IMSC visualized before and after preprocessing. Top:
Heat map of a raw IMSC. X-axis: reduced inverse mobility t in Vs/cm2;
Y-axis: retention time r in seconds; signal: white (lowest) < blue <
purple < red < yellow (highest), reactant ion peak (RIP) at t=0.48
Vs/cm2. Bottom: IMSC after preprocessing using bc-dn-s (see text). Figure 2 IMSC visualized before and after preprocessing. Top:
Heat map of a raw IMSC. X-axis: reduced inverse mobility t in Vs/cm2;
Y-axis: retention time r in seconds; signal: white (lowest) < blue <
purple < red < yellow (highest), reactant ion peak (RIP) at t=0.48
Vs/cm2. Bottom: IMSC after preprocessing using bc-dn-s (see text). ure 2 IMSC visualized before and after preprocessing. Top: e 2 IMSC visualized before and after preprocessing. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Top: Peak candidate detection finds a list of potential peaks
within the preprocessed IMSC. We implemented two
alternative modules called Local Maxima (lm) and Cross
Finding (cf). The input of either module is a processed
IMSC, and the output is a list of candidate peaks, which is
further refined in the next step. Local Maxima finds local
maxima within the two-dimensional IMSC, while Cross
Finding searches for zeros in the first partial derivatives
with respect to both retention time and reduced inverse
mobility. into four steps that are performed in sequence. Each step
allows us to use different specific methods, implemented
as separate modules. Each (reasonable) combination of
modules, together with individual module parameters,
specifies a concrete peak extraction pipeline and trans-
forms an IMSC into a list of peaks. In Section ‘Methods’ we introduce the peak extraction
framework, enumerating briefly all pipeline steps. The
next three sections (Sections ‘Modules for preprocessing,
Modules for peak candidate detection, Modules for peak
picking, A module for peak modeling (pme)’) explain the
available modules for each step in detail. Information on
the software architecture and implementation is given in
Section ‘Architecture and implementation’. Results on a
complete dataset are provided in Section ‘Results’, where
we compare the different combinations with each other
and to manual peak extraction. Section ‘Discussion and
conclusion’ concludes. Peak picking examines the proposed candidates and
generates the final list of extracted peaks. We have so
far implemented three modules. All three methods cal-
culate a representative peak for a set of peaks whose
positions are too close to be considered distinct. Merging
by signal intensity (ms) is a basic method considering the
distance between two candidates; it picks highest signal
peak from a set of close peaks within a surrounding box of
given size. Cluster editing (ce) discovers peak clusters by
solving the cluster editing problem and returns the peak
with highest intensity of each cluster as representative. EM Clustering (emc) works similarly, but discovers peak
clusters using the EM algorithm. Methods Peak modeling is an optional final step that can be
used to estimate additional peak parameters, describing
the shape and position more precisely. A module called
Peak model estimation (pme) has been implemented. In Baseline correction (bc) Intuitively and informally, a baseline spectrum B
=
(Bt)t∈T is defined such that Bt is a typical or insignificantly
high value at reduced inverse mobility t when consider-
ing the whole measurement. Formally, for each reduced
inverse mobility t, we consider a histogram Ht with bin
size 1 of the chromatogram S·,t, i.e., Ht,i is the number of
data points with intensity i in the chromatogram. Bader
[13] presented a method that assumes a log-normal model
as baseline and estimate its parameters before subtracting
from spectrum. We developed a new method since Baders
method does not erase the whole RIP. In a typical chro-
matogram (mostly noise, one or a few peak(s), no RIP),
most intensities are at noise level, so the most prominent
peak in the histogram indicates that level. In a RIP chro-
matogram, the most prominent peak corresponds to the
RIP level (Figure 4). In both cases and in the intermedi-
ate ones as well, we model the most prominent peak of the
histogram by a Gaussian distribution and the remainder
by the uniform distribution between lowest and highest
observed intensity. Framework overview We present a framework for automatic processing of an
MCC/IM measurement (ion mobility spectrum-chroma-
togram, IMSC) to discover and quantify all present peaks. D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 4 of 12 Figure 3 Steps and modules of the peak extraction framework PEAX. Figure 3 Steps and modules of the peak extraction framework PEAX. time-critical applications this step is generally omitted by
using the “empty module” ε. to our previous work on peak modeling (contained herein
as the module Peak Model Estimation (pme)), where we
describe how to apply the EM algorithm to a mixture
of Inverse Gaussian distributions to infer peak shape
parameters [12]. The Peak Modeling step can be exchanged with the
Peak Picking step, meaning that each candidate peak is
modeled, and picking is done on the modeled candidate
peaks. In the following section we discuss all modules in
detail and introduce several parameters, remark that user
adjustable parameters are emphasized. Mixture models and expectation maximization Several of our modules use mixture modeling, i.e., the data
is viewed as a realization of a mixture distribution f (x | θ) =
C
c=1
ωc fc(x | θc), f (x | θ) =
C
c=1
ωc fc(x | θc), where c indexes the C different components, θc denotes
all parameters of distribution fc, and θ = (θ1, . . . , θc) is
the collection of all parameters. We allow that the dis-
tributions fc are of different types, e.g., a uniform and a
Gaussian one. The mixture coefficients ωc satisfy ωc ≥0
for all c, and
c ωc = 1. c
The goal of mixture model analysis is to estimate
the mixture coefficients ω = (ωc) and the individual
model parameters θc (whose number and interpretation
depends on the parametric distribution fc). Since this
maximum likelihood problem is non-convex, iterative
locally optimizing methods such as the Expectation Max-
imization (EM) algorithm [11] are frequently used. The
EM algorithm consists of two repeated steps: The E-step
(expectation) estimates the expected membership of each
data point x in each component and then ω, given the
current model parameters θ. The M-step (maximization)
estimates maximum likelihood parameters θc for each
parametric component fc individually, using the expected
memberships as hidden variables that decouple the
model. As the EM algorithm converges towards a local
optimum of the likelihood function, it is crucial to choose
reasonable starting parameters for θ. For details, we refer Thus, we describe the histogram Ht by a heterogeneous
two-component mixture model (Gaussian plus uniform)
and estimate its parameters (μ, σ 2 for the Gaussian, ωG
for the Gaussian mixture coefficient) by the EM algo-
rithm, as outlined above. To start the EM iteration, we set
μ to the location of the maximum of Ht and σ 2 := 1,
while ωG is immediately estimated in the E-step. After
convergence, having estimated μ and σ, we say that all
intensities up to μ + 2σ belong to the baseline and adjust
the chromatogram as follows: S′
r,t := max{Sr,t −(μ +
2σ), 0} for all r ∈R. After repeating this step for every t D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 5 of 12 Figure 4 Histograms (y-axis: frequency) of signal intensities
(x-axis) of two chromatograms, a typical one (top) and a RIP
chromatogram (bottom). Modules for peak candidate detection We discuss two modules to find peak candidates. Both
use parameter I (intensity_threshold) as signal
intensity threshold. The method is not applied to S directly, but to the locally
averaged Ar,t :=
1
(2ρ + 1)2 ·
r+ρ
r′=r−ρ
t+ρ
t′=t−ρ
Sr′,t′, Ar,t :=
1
(2ρ + 1)2 ·
r+ρ
r′=r−ρ
t+ρ
t′=t−ρ
Sr′,t′, Smoothing (s) The smoothing module consists of two consecutive meth-
ods. The first method is a lowpass filter. The IMSC is
transformed from the time/signal domain into the fre-
quency/signal domain by a two-dimensional fast Fourier
transform (2DFFT). All frequencies above a given fre-
quency threshold (parameter fftcutoff) are removed,
i.e., set to zero intensity. The inverse transformation of the
filtered matrix is done using the inverse two-dimensional
fast Fourier transform (I2DFFT). Figure 4 Histograms (y-axis: frequency) of signal intensities
(x-axis) of two chromatograms, a typical one (top) and a RIP
chromatogram (bottom). The prominent intensity peak is modeled
by a Gaussian distribution. with individually estimated μ(t), σ(t), the baseline Bt =
μ(t) + 2σ(t) has been removed. The result is smoothed by a Savitzky-Golay filter (SGF)
[14] on local windows using smoothing_radius ρ = 4
(i.e., 9 × 9 data points) around each data point. To handle
the boundaries of the measurement, we expand the data
matrix with a margin containing only zero values. Since
the data at the boundary of the measurement does not
contain important data, this procedure is uncritical. The
SGF computes a weighted average across the window. Mixture models and expectation maximization The prominent intensity peak is modeled
by a Gaussian distribution. points with a maximum reduced inverse mobility of
t = 1.45 Vs/cm2. With respect to tolerance t
:=
0.003 Vs/cm2
(value explained in Section ‘Modules
for peak picking’) we obtain a tolerance of (2500 ·
0.003)/1.45 ≈5 index units. We chose ρ = 4 to avoid
taking noise into consideration for smoothing. Considering a histogram of all A-values also with bin
size 1 (see Additional file 1: Supplement E), we iden-
tify three components: the noise component (the one of
interest and to be removed) is modeled as a Gaussian dis-
tribution, the signal component (to be kept) is modeled as
an Inverse Gaussian distribution and a background com-
ponent (that explains every intensity not well explained
by the other components) is modeled as a uniform distri-
bution over all measured intensities. This yields a three-
component heterogeneous mixture model (Gaussian plus
Inverse Gaussian plus uniform), whose parameters are
again estimated by the EM algorithm. After convergence and a final E-step, we obtain the
expected membership values Wr,t (which are a weighted
normalized values of every probability computed by the
probability models) of each data point (r, t) in the noise
component. We adjust the original IMSC such that only
the non-noise fraction remains, i.e., S′
r,t := Sr,t · (1 −Wr,t)
for all r ∈R, t ∈T. De-noising (dn) The goal of de-noising is to subtract a substantial amount
of noise from the IMSC S(r, t) by estimating whether
the intensity S(r, t) at coordinates (r, t) belongs to a
peak region or can be explained by background noise. In
previous work on de-noising Bader [13] uses a wavelet
transform but applies it only spectrum wise. Our novel
approach is similar to the Baseline Correction (bc) module
in the sense that the EM algorithm is used, but the model
is more complex and the subtraction works differently. Cross finding (cf) -1
0
1
2
3
4
5
0
2
4
6
8
10 The basic idea of Cross Finding is to find maxima based on
the ideas by Fong et al. [15]. To avoid overlooking peaks at
the borders, the matrix’s borders are temporarily padded
by zeros. We construct two auxiliary matrices DR and DT, both
with the same dimensions |R|×|T|. In DT, discrete deriva-
tives of spectra are stored (partial derivatives with respect
to reduced inverse mobility), DT
r,t := Sr,t+1 −Sr,t; analo-
gously derivatives of chromatograms are stored in DR. We
describe how DT is analysed. 10 In each derived spectrum (for fixed retention time r), we
mark downward zero crossings; these are indices t with
DT
r,t−1 ≥0 and DT
r,t < 0. The resulting indices t are called
active positions for retention time r. Figure 5 Cross finding: Active positions (marking potential peak
maxima) are initially unaligned (top) and then connected by
alignment across spectra (bottom; shown as red + and blue x). The same procedure is repeated over all chromatograms giving
horizontal bands instead of vertical bands. Intersecting the results
from both dimensions results in peak candidates. While we scan through the spectra, we maintain two
data structures. The first one is an active set containing
lists of active positions connected across several spectra. The second one is a finalized set, where lists from the
active sets are moved when they have been processed. Initially both sets are empty. (2) If A+[j] is aligned to some A[i], the corresponding
list containing A[i] is already in the active set and
extended by A+[j]. (2) If A+[j] is aligned to some A[i], the corresponding
list containing A[i] is already in the active set and
extended by A+[j]. We want to connect active positions between consecu-
tive retention times, i.e., we want to find active positions
for spectrum r + 1 corresponding to active positions in
spectrum r (see Figure 5(left)). To find the correspon-
dences, we use a variant of global alignment between the
two sorted integer lists A and A+ containing the active
positions. The score of aligning A[i] to A+[j] depends on
the distance between A[i] and A+[j]. We use the follow-
ing score function: score(i, j) := (1+|A[i] −A+[j] |)−1 ∈
[0, 1]. To prevent that two positions with a high distance
are aligned, we introduce a gap score γ = 0.1. Cross finding (cf) As we will
thus never align positions A[i] and A+[j] with distance
larger than 9 index units, we can solve the alignment
problem very efficiently by only considering (i, j) with
|A[i] −A+[j] | ≤9. (3) Each A[i] that is not aligned to any A+[j] finalizes its
corresponding active list, and the list is moved into
the finalized set. After processing all spectra and finalizing each remain-
ing list, we obtain several position lists pointing out
consecutive maxima throughout each spectrum; see
Figure 5(right). The same procedure is analogously performed with
matrix DR. We report the intersection of positions found
from both matrices (which can be visualised as crosses;
hence the name “Cross Finding”). If more than one posi-
tion overlap is found between two lists, the position with
the highest signal is reported. Each reported point whose
signal exceeds I is a candidate for a peak location. Three scenarios are possible between the aligned
position pairs: Local maxima (lm) This module reports a peak candidate for every local
intensity maximum with intensity at least I
in a
surrounding area. To report a point (r, t), we require (1.) where ρ is the smoothing_radius parameter. The
spectra in our measurements consist of 2500 data where ρ is the smoothing_radius parameter. The
spectra in our measurements consist of 2500 data D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 6 of 12 -1
0
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5
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2
4
6
8
10
-1
0
1
2
3
4
5
0
2
4
6
8
10
Figure 5 Cross finding: Active positions (marking potential peak
maxima) are initially unaligned (top) and then connected by
alignment across spectra (bottom; shown as red + and blue x). The same procedure is repeated over all chromatograms giving
horizontal bands instead of vertical bands. Intersecting the results
from both dimensions results in peak candidates. that (r, t) is a local maximum in the sense the each of its
eight direct neighbors has a lower or equal signal inten-
sity than Sr,t but of at least I, and (2.) that the contiguous
area around (r, t) with signal intensity at least I is of suf-
ficient size. In other words, we discard points where the
surrounding high-intensity area size consists of too few
points. The required number of points is controlled by
a parameter A ≥9 (area_size). (By the first condi-
tion, (r, t) and its eight neighbors always account for nine
points; the parameter A can be used to impose stricter
conditions.) -1
0
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5
0
2
4
6
8
10 Modules for peak picking (1) If A+[j] is not aligned to any A[i], it is a “new” active
position, and a new list, containing only A+[j] is
inserted into the active set. The previous step, peak candidate detection, consid-
ers each potential peak location separately. Two peak D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 7 of 12 w(u, v) :=
2b(1−d2(u,v)) −1
if d2(u, v) ≤1,
1 −d2(u, v)
otherwise. w(u, v) :=
2b(1−d2(u,v)) −1
if d2(u, v) ≤1,
1 −d2(u, v)
otherwise. candidates may be called close to each other, e.g., by
detecting two local maxima of the same underlying peak
that arise because of noise in the data. The range for w(u, v) is therefore [−∞, 2b −1]. If the
distance between the two candidates u and v is zero, then
the edge (u, v) has the maximum weight 2b −1. If the
t- and r-distances of u and v are equal to t and r,
respectively, then d2(u, v) = 1 and w(u, v) = 0. For larger
distances, the weights are negative. Parameter b called
ce_weight_exponent can be set by the user. Thus, not every peak candidate corresponds to a VOC
from the breath sample, and the purpose of peak picking
is to thin out the candidate list. Bödeker [16] introduced a minimum distance in reten-
tion time and in reduced inverse mobility such that
two peaks exceeding those distances belong to distinct
compounds. We write t for the necessary distance in
reduced inverse mobility and r for that in retention
time. We use a constant t := 0.003 Vs/cm2 (tol_rim)
for the reduced inverse mobility. In retention time we
use an affine-linear r := p · r + c for a peak at posi-
tion (r, t), where c
:=
3 s (tol_rt) and p
:=
0.1
(tol_percent_rt), as suggested by Hauschild et al. [9]. We now describe three modules for peak picking. The weighted cluster editing problem is solved with the
yoshiko 2.0 software (http://www.cwi.nl/research/planet-
lisa). Merging by signal intensity (ms) Each component is a two-dimensional Gaussian distri-
bution with independent dimensions, i.e., diagonal covari-
ance matrix. Initially, the mean of every component is the
(r, t) location of the corresponding peak candidate. The
standard deviation on the r- and t-axis is set to r/3 and
t/3, respectively, since 6σ covers most of a Gaussian bell
curve. In the E-step, the hidden membership coefficients
of each peak to each component are estimated. When a
peak candidate is close to another one, the probability that
the first model also (partially) describes the second candi-
date is comparatively high. In the maximization phase, the
parameters of each component are re-estimated based on
candidate membership using maximum likelihood esti-
mators. In the case of two close candidates, the mean of
both components moves towards their middle. When the
distance between the means of two components drops
below a given threshold, the components are merged: The
component of the candidate with lower signal is removed,
and its weight is added to the remaining model. The E-
and M-steps are repeated until convergence. We sort the n peak candidates by descending signal inten-
sity into a list [(ri, ti, si)]i=1,...,n with s1 ≥s2 ≥· · · ≥sn,
resolving ties arbitrarily. First we mark each candidate
as unmerged. Iterating the list, we skip merged candi-
dates and report each unmerged candidate we encounter. When this happens for candidate (ri, ti, si), we find which
peaks fall into the box (ri ± r) × (ti ± t) and mark
them as merged, and continue iterating through the list. In this way, we greedily pick peaks with highest signal as
representative for all peaks in the surrounding box. This
method [16] was used by Hauschild et al. [9]. EM clustering (emc) This module uses the EM algorithm once again. Initially,
each peak candidate represents a component. During the
course of the algorithm, components can be merged. The
remaining components will represent the picked peaks. Cluster editing (ce) We find clusters of peaks, from which we pick a repre-
sentative (peak with highest signal), by solving an instance
of the weighted cluster editing problem [17,18]: Let G =
(V, E) be a weighted, undirected graph without loops with
a symmetric similarity weight function w:
V
2
→R, such
that E = {{u, v} : w(u, v) ≥0}. The graph can be modi-
fied by adding a non-existing or removing an existing edge
{u, v}, which incurs a cost of |w(u, v)|. The costs for several
modifications are added to yield the total cost. The objec-
tive is to find a set of edge modifications with minimum
cost such that the resulting graph consists of disjoints
cliques (i.e., is transitive). When updating the variance by maximum likelihood
estimation, we must be aware that the variance of a com-
ponent described by only one peak tends to zero, which
leads to a singularity in the Gaussian density function. Therefore, we restrict the estimated standard deviation to
values above the threshold τ := 10−5 Vs/cm2. Every candidate peak is a vertex u = (ru, tu). The
similarity w(u, v) between two vertices u, v depends on
their distances on the r- and t-axis. We use the distance
measure Function interfaces Using unified function interfaces for each step ensures
the modularity of the pipeline. A preprocessing function
takes an IMSMeasurement and a parameter_map
manipulating the provided matrix. A module for peak modeling (pme) Peak modeling is an optional step that estimates a para-
metric model of a peak shape. We have so far imple-
mented one module (simply called Peak Model Estimation
(pme)) using shifted Inverse Gaussian distributions, con-
sider [12]. If it is not desired to model the peaks, the empty
ε module (e) can be used instead. It outputs the peak list
without any modification. d2(u, v) := 1
2
tu −tv
t
2
+
ru −rv
r
2 and the similarity weight function (with a constant scaling
factor b) D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 8 of 12 IMSMatrix that represents an IMSC (Sr,t), i.e., it
contains the raw intensity values as a matrix. IMSMatrix that represents an IMSC (Sr,t), i.e., it
contains the raw intensity values as a matrix. A whole IMSC is interpreted as a sample from a mix-
ture model of different shifted Inverse Gaussians plus
a uniform background noise model. Each component
(peak) can then be described by seven parameters (three
for both shifted Inverse Gaussians in both r- and t-
dimension, plus one mixture coefficient). The challenge
is to estimate the parameters correctly, especially when
peaks overlap. Again, the EM algorithm is utilized for this
purpose. Output The class IMSPeak describes a single peak. It stores
the name of the originating measurement, its peak name
(ID), retention time and reduced inverse mobility of the
peaks mode, the signal intensity and the volume (if not
calculated, equal to the intensity). The indices of both
retention time and reduced inverse mobility are also
stored. A map peak_parameters may store additional
parameters, e.g., parameters estimated for inverse Gaussian
distributions, as described in Section ‘A module for peak
modeling (pme)’. For efficiency, each component model is evaluated
only in a surrounding box enclosing the peak. Starting
from the picked peak location, the box borders are
expanded in all four main directions until the signal
intensity drops to zero in each direction. The parame-
ter expansion_size determines how much the box
around the peak is expanded additionally. The class IMSPeakList stores the resulting list of such
peaks found by the candidate detection, picking and mod-
eling steps. Every IMSPeakList contains a list named
parameter_names, which stores the names of addi-
tional parameters for every peak. These are the keys for
the above mentioned peak_parameters map. When two boxes intersect, both boxes are merged into
their convex hull. After that process we have a set of
boxes containing at least one peak. Now we can apply
EM to each box independently, with the advantage of
processing smaller boxes in contrast to the whole signal
matrix. Starting parameters for each component are esti-
mated from the locations of picked peaks and additional
assumptions: The parameters are chosen such that their
modes correspond to the known (r, t) values, the mean
is set slightly higher (μ = mode + 10−3 index units),
and the standard deviation is set to 1 index unit in both
dimensions. As the model parameters have a rather tech-
nical interpretation, they are translated back into mode,
mean and standard deviation of the distribution, which
are conveniently compared and interpreted. The output format is a .csv file with one line per peak
containing the peak’s measurement name, peak name,
retention time, reduced inverse mobility, signal, volume,
retention time index, reduced inverse mobility index and
additional parameters. Module parameters A map called parameter_map stores all peak extraction
parameters (Table 1). Architecture and implementation The framework consists of a number of classes represent-
ing input, output and parameters and, importantly, four
function interfaces, one for each major step of a pipeline. The steps have unified interfaces to guarantee the mod-
ularity of the framework and the exchangeability of the
modules with future ones. A candidate detection method requires an IMS-
Measurement and a parameter_map and returns an
IMSPeakList. The picking functions take those results
as input and return an IMSPeakList that contain Dataset We tested the framework on a dataset of 69 measure-
ments, of which 39 are from different patients suffering
from the same disease and 30 from a control group not
showing corresponding symptoms. The disease is known
but irrelevant with respect to this article and cannot be
disclosed due to confidentiality agreements within the
clinical study approved by the state ethics committee. Our
dataset has been anonymized and serves as an illustration
of the framework. For every of the 69 measurements, a
manually annotated peak list was provided by an expert
annotator. Input Table 1 Parameters used for evaluation
Modules
Parameter name
Value
s
fftcutoff
500
s, dn
smoothing_radius
4
lm
area_size
9
lm, cf
intensity_threshold
{5, 10, 15}
ce
ce_weight_exponent
26
All picking
tol_rt
3
All picking
tol_rt_percent
0.1
All picking
tol_rim
0.003
pme
expansion_size
10
All computations were repeated for three different values of intensity_threshold. Table 1 Parameters used for evaluation
Modules
Parameter name
Value
s
fftcutoff
500
s, dn
smoothing_radius
4
lm
area_size
9
lm, cf
intensity_threshold
{5, 10, 15}
ce
ce_weight_exponent
26
All picking
tol_rt
3
All picking
tol_rt_percent
0.1
All picking
tol_rim
0.003
pme
expansion_size
10
All computations were repeated for three different values of intensity_threshold. The standardized .csv format for MCC/IMS measure-
ments is described by Vautz et al. [19,20]. A more efficient
binary format (.ims) has also been developed inter-
nally. An abstract class IMSFile provides the interface
for loading and storing those formats, and the classes
IMSFileCSV and IMSFileIMS instantiate the interface
for the respective format. The class IMSMeasurement stores a sequence of
retention time points R, a sequence of drift time points
and (proportionally) reduced inverse mobilities T. Addi-
tionally, a measurement_parameters map stores all
meta information e.g. date, time, name or various sam-
ple information of a measurement. It also stores an D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 9 of 12 http://www.biomedcentral.com/1471-2105/15/25 a subset of the input list. Finally the modeling step
requires again the IMSMeasurement in addition to
an IMSPeakList and the parameter_map. This step
returns an IMSPeakList of the same size as the input
one. To augment a particular step with a new module,
these interfaces must be used. Figure 6 Comparing the results of all pipelines with the
manually picked peaks according to sensitivity and PPV. The
green crosses indicate the Pareto front. Top, middle and bottom
figure correspond to signal intensity thresholds I = 5, 10, 15,
respectively. The dashed lines separate two clusters of pipelines. Evaluation of pipelines BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 10 of 12 Table 3 Pipelines of the Pareto front for signal threshold
I = 10
Pipeline
G
d
Pipeline
dn-s -bc-cf-ce
0.741
0.776
dn-s -bc-cf-ce
dn-bc-s -cf-ce
0.736
0.783
s -dn-bc-cf-ce
bc-dn-s -cf-ce
0.733
0.785
s -bc-dn-cf-ce
dn-bc-s -cf-emc
0.732
0.811
dn-bc-s -cf-ce
bc-dn-s -cf-emc
0.729
0.822
bc-dn-s -cf-ce
s -bc-dn-cf-emc
0.728
0.825
dn-bc-s -cf-emc
s -dn-bc-cf-emc
0.727
0.827
bc-s -dn-cf-ce
dn-bc-s -lm-ce
0.720
0.836
bc-dn-s -cf-emc
dn-bc-s -cf-mi
0.717
0.838
s -bc-dn-cf-emc
s -dn-bc-cf-mi
0.709
0.839
s -dn-bc-cf-emc Table 3 Pipelines of the Pareto front for signal threshold
I
10 the sensitivity SENS := TP/(TP + FN) and the positive
predictive value PPV := TP/(TP + FP). Their geomet-
ric mean G :=
√
SENS · PPV summarizes both measures,
which is referred to as Fowlkes-Mallows index [21]. Fur-
ther, the Jaccard index between two peak lists is J := TP /
(FN + TP + FP) ∈[0, 1]. From this, we derive a distance
measure d := 1/J −1 ∈[0, ∞]. The distance and geomet-
ric mean are calculated separately for each combination of
pipeline and measurement. To determine these quantities
for a particular pipeline, we average over all measure-
ments of the dataset. It remains to define what it means
that “the same” peak has been detected by both methods,
since the location parameters (r, t) may differ slightly. All
peak picking modules can be used for this decision, and
we chose “Merging by Signal Intensity” (ms). Imagine a
box around every manually annotated peak (r, t) of widths
2r and 2t, respectively. Then we successively count
each box containing at least one automatically found peak
and delete it. In case of two or more peaks within the box
we count the closest one. groups. The first group has both relatively low sensitivity
and low positive predictive value, while the second one has
high values for both measures. We note that the pipelines
of the first group are characterized by the utilization of
the pme module (see Additional file 1: Supplements A, B
and C). By modeling, the peak coordinate moves slightly,
yielding larger average differences to the manual anno-
tation based on grid coordinates. So module pme seems
to be unnecessary. However, the volume of a peak may
contain important information (not evaluated here), and
we cannot infer it only from the position and intensity at
those coordinates alone. Evaluation of pipelines Concerning the threshold I, the
choice of 10 yields the best results. For both I = 10 and
15, the best pipeline is dn-s-bc-cf-ce. The top values
in Table 3 range around 0.70 for the geometric mean. We note that individual measurement properties (high
or low noise, characteristic VOCs, etc.) were not taken
into consideration for choosing the module parameters. An additional step of parameter estimation from global
measurement properties would likely improve the results. Evaluation of pipelines By combining the implemented modules, we obtain 108
individual pipelines. We name the pipelines by concate-
nating the shortcuts of the used modules in order. For
example, the pipeline using (in that order) the mod-
ules Smoothing, De-Noising, Baseline Correction, Local
Maxima, EM Clustering and No Modeling is named
s-dn-bc-lm-emc-e. There are not 144 pipelines
because of redundancy between pipelines using the empty
module as fourth step and those using it as third one
(consider the example before and s-dn-bc-lm-e-emc,
which is the same computational pipeline). We used the
parameters shown in Table 1. To evaluate each pipeline, we compare the final obtained
peak list with one that was manually annotated by an
expert MCC/IMS development engineer. For the com-
parison, we considered only peaks with a retention
time above 5 s and an inverse reduced mobility above
0.48 Vs/cm2, as is standard practice. Agreement of an automatically obtained peak list with
that obtained by a domain expert is generally considered
favourable. However, one should be aware that manu-
ally annotated list may also be incomplete or contain
extraneous peaks. Nevertheless considering the manually
annotated peaks ground truth, we compute the follow-
ing quantities. Peaks detected by both methods, manual
and automatic, within one measurement are true posi-
tives (TP). (Below, we address the question when peaks
with slightly different location parameters should be con-
sidered the same.) Accordingly, manually annotated peaks
that are not detected by the pipeline are false negatives
(FN) and automatically detected peaks not found in the
manual annotation are false positives (FP). We compute Figure 6 Comparing the results of all pipelines with the
manually picked peaks according to sensitivity and PPV. The
green crosses indicate the Pareto front. Top, middle and bottom
figure correspond to signal intensity thresholds I = 5, 10, 15,
respectively. The dashed lines separate two clusters of pipelines. D’Addario et al. Ranking the pipelines Figure 6 shows a plot of SENS against PPV for each
pipeline for different parameter values of the signal inten-
sity threshold I. The Pareto front is visualized in each
plot. Considering only pipelines that are Pareto-optimal,
we rank the ten best ones by their geometric mean and
distance separately. The results of the rankings are pre-
sented in Tables 2, 3 and 4 for signal intensity thresholds
I ∈{5, 10, 15}, respectively. Note that each of these tables
reports two rankings, the first two columns for the geo-
metric mean G and the both remaining columns for the
distance d. We find that, for the candidate detection step, almost
all Pareto-optimal pipelines use Cross Finding (cf). The
picking step is best done by Cluster Editing (ce). For every
signal intensity threshold I, the pipelines split into two Table 4 Pipelines of the Pareto front for signal threshold
I = 15 Table 2 Pipelines of the Pareto front for signal threshold
I = 5
Pipeline
G
d
Pipeline
bc-s -dn-cf-ce
0.729
0.850
bc-s -dn-cf-ce
bc-s -dn-lm-ce
0.726
0.853
bc-s -dn-lm-ce
dn-bc-s -cf-ce
0.725
0.855
bc-dn-s -cf-ce
dn-bc-s -lm-ce
0.725
0.861
dn-bc-s -lm-ce
bc-s -dn-cf-emc
0.697
0.862
bc-dn-s -lm-ce
bc-dn-s -cf-emc
0.697
0.868
dn-bc-s -cf-ce
dn-bc-s -cf-emc
0.693
1.012
bc-s -dn-cf-emc
dn-bc-s -cf-mi
0.671
1.016
bc-s -dn-lm-emc
s -dn-bc-lm-ce
0.658
1.018
bc-dn-s -cf-emc
dn-s -bc-lm-ce
0.658
1.021
bc-dn-s -lm-emc Table 4 Pipelines of the Pareto front for signal threshold
I = 15
Pipeline
G
d
Pipeline
dn-s -bc-cf-ce
0.718
0.916
dn-s -bc-cf-ce
s -dn-bc-cf-ce
0.718
0.916
s -dn-bc-cf-emc
s -dn-bc-cf-emc
0.718
0.916
s -bc-dn-cf-emc
dn-s -bc-cf-emc
0.716
0.921
dn-s -bc-cf-emc
s -dn-bc-cf-mi
0.707
0.923
s -dn-bc-cf-ce
dn-s -bc-cf-mi
0.706
0.923
s -bc-dn-cf-ce
dn-bc-s -cf-emc
0.697
0.959
s -dn-bc-cf-mi
dn-bc-s -cf-ce
0.696
0.959
s -bc-dn-cf-mi
bc-dn-s -cf-emc
0.695
0.962
dn-s -bc-cf-mi
bc-dn-s -cf-ce
0.693
1.045
dn-bc-s -cf-emc Table 2 Pipelines of the Pareto front for signal threshold
I
5 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Page 11 of 12 D’Addario et al. BMC Bioinformatics 2014, 15:25
http://www.biomedcentral.com/1471-2105/15/25 Discussion and conclusion The framework with the modules described in this arti-
cle are available at http://www.rahmannlab.de/research/
ims, as well as the anonymized datasets and Additional
file 1: Supplement. We presented the first framework for fully automatic pro-
cessing of MCC/IM measurements, consisting of different
modules for four distinct computational steps. The pre-
sented framework processes a single IM measurement
and outputs a peak list within a few seconds. A domain
expert, who before had the time consuming task of peak
annotation, may now quickly verify the resulting auto-
matically generated peak list and manually reject a few
potential false positives. In practice, higher sensitivity of
the automated pipeline (at the cost of more false positive
predictions) may be desirable, as this type of error can be
better compensated by statistical learning methods during
classification than a false negative rate. Competing interests
d
l
h
h We declare that we have no competing financial interests. We do declare that
JIB is chairman of a company, B & S Analytik GmbH that builds and sells ion
mobility spectrometers. However, our algorithms are general-purpose and not
restricted to their instruments. References 1. Koczulla R, Hattesohl A, Schmid S, Bödeker B, Maddula S, Baumbach JI:
MCC/IMS as potential noninvasive technique in the diagnosis of
patients with COPD with and without alpha 1-antitrypsin
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a feasibility study using an automated peak finding procedure. J Breath Res 2009, 3(4):046001. Authors’ contributions The best pipeline achieves a geometric mean of sensitiv-
ity and positive predictive value of 0.741 when compared
to a manual expert manual annotation, without tuning
the parameters for the single modules. Since the manu-
ally extracted peaks are annotated by one single expert,
one cannot be certain whether that solution is fully cor-
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the data for evaluation. All authors read and approved the final manuscript. Received: 29 August 2013 Accepted: 17 January 2014
Published: 22 January 2014 Received: 29 August 2013 Accepted: 17 January 2014
Published: 22 January 2014 The state of the art today is that every expert has his own
“manual procedure” for peak extraction, based on certain
human-observable features of the visualized data matrix. We observed two experts and attempted to infer their
“internal algorithm” and express this knowledge as our
parameters. The most significant parameter values were
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own experience. These last parameters do not influence
the results as much as the previously mentioned ones. Acknowledgements MDA, DK, JIBB, SR are supported by the Collaborative Research Center
(Sonderforschungsbereich, SFB) 876 “Providing Information by Resource-
Constrained Data Analysis” within project TB1 (http://sfb876.tu-dortmund.de). We thank Benjamin Yip and Henning Funke for preliminary work. Additional file 1: Supplement. Additional file 1: Supplement. Author details
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Cite this article as: D’Addario etal.: A modular computational framework for
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A review of the genomics of neonatal abstinence syndrome
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1 Background From 2010 to 2017, the number of pregnant women with opioid-related diagnoses [e.g.,
opioid use disorder (OUD)] increased from 3.5 to 8.2 per 1000 delivery hospitalizations
(Hirai et al., 2021). This resulted in a concomitant increase in the number of neonates with
neonatal abstinence syndrome (NAS) or neonatal opioid withdrawal syndrome (NOWS),
from 4.0 to 7.3 per 1000 births1. This translated to a healthcare cost of $2.5 billion between
2004 and 2014 (Winkelman et al., 2018). Despite this substantial socioeconomic burden,
there remains great variation in the diagnosis and management of NAS, highlighting an
urgent need for objective and validated measures to address this challenge. KEYWORDS
neonatal abstinence syndrome (NAS), genetics, epigenetics, inflammation, biomarker KEYWORDS
neonatal abstinence syndrome (NAS), genetics, epigenetics, inflammation, biomarker OPEN ACCESS OPEN ACCESS
EDITED BY
Funda Tuzun,
Dokuz Eylül University, Türkiye
REVIEWED BY
David J. Vandenbergh,
The Pennsylvania State University (PSU),
United States
*CORRESPONDENCE
Elizabeth Yen,
Elizabeth.Yen2@tuftsmedicine.org
SPECIALTY SECTION
This article was submitted to
Pharmacogenetics and
Pharmacogenomics,
a section of the journal
Frontiers in Genetics
RECEIVED 09 January 2023
ACCEPTED 01 February 2023
PUBLISHED 10 February 2023
CITATION
Yen E, Gaddis N, Jantzie L and Davis JM
(2023), A review of the genomics of
neonatal abstinence syndrome. Front. Genet. 14:1140400. doi: 10 3389/fgene 2023 1140400 OPEN ACCESS
EDITED BY
Funda Tuzun,
Dokuz Eylül University, Türkiye
REVIEWED BY
David J. Vandenbergh,
The Pennsylvania State University (PSU),
United States
*CORRESPONDENCE
Elizabeth Yen,
Elizabeth.Yen2@tuftsmedicine.org
SPECIALTY SECTION
This article was submitted to
Pharmacogenetics and
Pharmacogenomics,
a section of the journal
Frontiers in Genetics Elizabeth Yen1,2,3*, Nathan Gaddis4, Lauren Jantzie5 and
Jonathan M. Davis1,3,6 1Department of Pediatrics, Tufts Medical Center, Boston, MA, United States, 2Mother Infant Research
Institute, Tufts Medical Center, Boston, MA, United States, 3Tufts University School of Medicine, Boston,
MA, United States, 4Research Triangle Institute International, Research Triangle Park, Durham, NC,
United States, 5Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD,
United States, 6Tufts Clinical and Translational Sciences Institute, Boston, MA, United States Neonatal abstinence syndrome (NAS) is a constellation of signs of withdrawal
occurring after birth following in utero exposure to licit or illicit opioids. Despite
significant research and public health efforts, NAS remains challenging to
diagnose, predict, and manage due to highly variable expression. Biomarker
discovery in the field of NAS is crucial for stratifying risk, allocating resources,
monitoring longitudinal outcomes, and identifying novel therapeutics. There is
considerable interest in identifying important genetic and epigenetic markers of
NAS severity and outcome that can guide medical decision making, research
efforts, and public policy. A number of recent studies have suggested that genetic
and epigenetic changes are associated with NAS severity, including evidence of
neurodevelopmental instability. This review will provide an overview of the role of
genetics and epigenetics in short and longer-term NAS outcomes. We will also
describe novel research efforts using polygenic risk scores for NAS risk
stratification and salivary gene expression to understand neurobehavioral
modulation. Finally, emerging research focused on neuroinflammation from
prenatal opioid exposure may elucidate novel mechanisms that could lead to
development of future novel therapeutics. OPEN ACCESS RECEIVED 09 January 2023
ACCEPTED 01 February 2023
PUBLISHED 10 February 2023 CITATION
Yen E, Gaddis N, Jantzie L and Davis JM
(2023), A review of the genomics of
neonatal abstinence syndrome. Front. Genet. 14:1140400. doi: 10.3389/fgene.2023.1140400 COPYRIGHT
© 2023 Yen, Gaddis, Jantzie and Davis. This is an open-access article distributed
under the terms of the Creative
Commons Attribution License (CC BY). The use, distribution or reproduction in
other forums is permitted, provided the
original author(s) and the copyright
owner(s) are credited and that the original
publication in this journal is cited, in
accordance with accepted academic
practice. No use, distribution or
reproduction is permitted which does not
comply with these terms. TYPE Mini Review
PUBLISHED 10 February 2023
DOI 10.3389/fgene.2023.1140400 TYPE Mini Review
PUBLISHED 10 February 2023
DOI 10.3389/fgene.2023.1140400 TYPE Mini Review
PUBLISHED 10 February 2023
DOI 10.3389/fgene.2023.1140400 frontiersin.org 4.1.1 Single nucleotide polymorphism (SNP) Our knowledge of genetic risk factors underlying NAS severity is
in its infancy, mainly due to the difficulty of providing sufficient
statistical power for genetic analyses. More is known about the
genetics of OUD in adults, for which an estimated ~60% of the
population variability is attributable to genetic factors based on twin
and family studies (Kendler et al., 2003; Goldman et al., 2005). Early
studies of the genetics of NAS consisted primarily of candidate SNP
analyses of loci identified in studies of adult opioid dependence or
loci associated with opioid and stress pathways, with inconsistent
results (Oei et al., 2012; Wachman et al., 2013; Wachman et al., 2015;
Mactier et al., 2017; Wachman et al., 2017). In opioid-exposed neonates, the need for pharmacotherapy was
associated with SNPs in cytochrome P450 family 2 subfamily B
member 6 (CYP2B6). Hypermethylation in the opioid receptor mu 1
(OPRM1) promoter was linked to worse NAS outcomes, defined by
the need for ≥2 medications (Wachman et al., 2014). Another study
reported that SNPs in prepronociceptin (PNOC), opioid receptor
kappa 1 (OPRK1), or opioid receptor delta 1 (OPRD1) were linked to
the need for ≥2 medications and longer length of hospital stay
(Mactier et al., 2017). A recent review provides a comprehensive
synopsis of candidate SNP studies and the loci they identified as
potentially being associated with NAS severity (Wachman and
Farrer, 2019). The results of the candidate SNP studies in are
seen in Table 1 and provide an update on the replication status
of the identified loci (discussed below). The loci include OPRM1,
OPRK1, and OPRD1, the endogenous opioid peptide PNOC, the
dopamine-metabolizing
enzyme
catechol-O-methyltransferase
(COMT), and the methadone-metabolizing enzyme CYP2B6. The
majority of these associations with NAS severity were point-wise
significant but failed to reach experiment-wise significance when
applying multiple-testing correction. 2 Current practice: Clinical evaluation and
management of NAS Multiple factors contribute to the challenge of a diagnosis and management of NAS. These include maternal characteristics (type of opioid used during pregnancy, comorbid Frontiers in Genetics 01 frontiersin.org Yen et al. 10.3389/fgene.2023.1140400 4.1.2 Genome-wide association study (GWAS) y
For OUD and related phenotypes, GWAS have identified a small
number of genome-wide association signals and few replicable
findings (Gelernter et al., 2014; Nelson et al., 2016; Polimanti
et al., 2020; Song et al., 2020; Zhou et al., 2020; Sanchez-Roige
et al., 2021; Gaddis et al., 2022; Kember et al., 2022). Several recent
large-scale GWAS of OUD have yielded promising loci with greater
statistical support and consistency across multiple cohorts which
could provide insight into the genetics of NAS (Zhou et al., 2020;
Sanchez-Roige et al., 2021; Gaddis et al., 2022; Kember et al., 2022). A recent NAS GWAS allowed the development of a polygenic risk
score (PRS) model that demonstrated the potential of using PRS for
predicting NAS severity (Bibi et al., 2022); further model
development based on larger sample sizes is needed. These scoring systems also do not account for sex of the
neonates. While some studies have suggested that male sex is
associated with worse NAS, others have not (Jansson et al., 2010;
Unger et al., 2011; Charles et al., 2017). Sex is an important biological
variable that contributes to the fundamental differences seen in
many diseases and pharmacologic responses (Bartz et al., 2020;
Kantarci et al., 2020; Zucker and Prendergast, 2020; Sharifiet al.,
2021). An urgent need exists to incorporate sex in the evaluation and
management of NAS. Based on the current one-size-fits-all model,
the field needs molecular and other approaches to arrive at an
objective method that considers an individual’s characteristics and
enables personalized evaluation and management of NAS. The first ever GWAS examining the need for pharmacotherapy
as a measure of NAS severity consisted of 476 in-utero opioid-
exposed term neonates; 94 were of African ancestry (AA) and
382 European ancestry (EA) (Table 1) (Bibi et al., 2022). Although the sample was small for a GWAS due to the challenge
of enrolling in-utero opioid-exposed neonates, obtaining consent,
and performing genetic testing, this study did identify one genome-
wide significant signal on chromosome 7 upstream of the G protein
regulator and sorting nexin-13 gene (SNX13), which has been 4.1 Genetics in NAS physical/mental
health
conditions),
neonatal
characteristics
(gestational age, sex), and hospital-based practice variation (e.g.,
location of care, breastmilk, supportive care) (Bogen et al., 2017;
Minozzi et al., 2020; Jansson et al., 2017; Favara et al., 2019; Yen
et al., 2021; O’Connor et al., 2017; Krans et al., 2021). Clinicians
assign the diagnosis of NAS using varying criteria: 1) antenatal
opioid exposure, 2) presence of any withdrawal signs following
birth, and/or 3) use of pharmacotherapy (Jilani et al., 2021). In an
effort to address the lack of a standardized clinical definition of NAS,
the US Department of Health and Human Services convened a panel
that proposed two key elements to diagnose NAS; prenatal exposure
of opioids (with/without other substances) and presence of 2 of
5 most common clinical signs of NAS (high-pitched cry, poor sleep,
tremors, hypertonia, gastrointestinal issues) (Jilani et al., 2022a;
Jilani et al., 2022b). Frontiers in Genetics 3 Knowledge gaps surrounding NAS Compounding this diagnostic challenge is lack of objective
diagnostic tools. The most commonly used scoring system is the
Finnegan
Neonatal
Abstinence
Scoring
System
(FNASS)
(Finnegan et al., 1975). Given the intricacies of the FNASS,
attempts have been made to simplify the system with the
introduction
of
multiple
approaches
including
Eat,
Sleep,
Console (Gomez Pomar et al., 2017; Grossman et al., 2018;
Devlin et al., 2020; Kocherlakota et al., 2020). Utilizing other
systems such as the NICU Network Neurobehavioral Scale
(NNNS) that incorporates neurologic and behavioral measures
and signs of stress may provide improved diagnostic information
(Lester et al., 2004). Despite the simplification, all scoring systems
are subjective and require education/training to minimize inter-
rater variability (Timpson et al., 2018; Chin Foo et al., 2021). Scoring systems are tools that may be biased by subjective factors,
resulting in over- and under-medication which could actually
increase long-term risks. frontiersin.org 4 Emerging biomarker research in NAS Researchers have examined molecular mechanisms, genetic and
epigenetic alterations that may increase the risk of more severe NAS
and the need for pharmacotherapy (which prolongs hospitalizations
and increases costs). Several of these approaches are quite promising
and have contributed to a better understanding of the pathogenesis
of NAS. 02 frontiersin.org Yen et al. 10.3389/fgene.2023.1140400 LE 1 Variants with evidence of association with NAS phenotypes. TABLE 1 Variants with evidence of association with NAS phenotypes. SNP
Gene
Phenotype
Ancestry
N
Study
type
Candidate SNP
replication (EA**, N =
113) [Oei et al. (2012)]
GWAS replication (AA +
EA, N = 476) [Bibi et al. (2022)]
rs1799971 [Wachman et al. (2013); Wachman et al. (2015)]
OPRM1
LOS
EA**
86
Candidate
SNP
ND
No
NAS
Treatment
rs204076 [Wachman et al. (2015)]*
OPRD1
LOS
EA**
86
Candidate
SNP
ND
No
≥2 Meds
rs2614095 [Wachman et al. (2015)]*
PNOC
LOS
EA**
86
Candidate
SNP
No
No*
≥2 Meds
rs351776 [Wachman et al. (2015)]*
PNOC
LOS
EA**
86
Candidate
SNP
No
No
≥2 Meds
rs4732636 [Wachman et al. (2015)]*
PNOC
LOS
EA**
86
Candidate
SNP
No
No
NAS
Treatment
≥2 Meds
rs702764 [Wachman et al. (2015)]*
OPRK1
≥2 Meds
EA**
86
Candidate
SNP
ND
No
rs4680 [Wachman et al. (2013)]
COMT
LOS
EA**
86
Candidate
SNP
No
No
NAS
Treatment
≥2 Meds
rs740603 [Wachman et al. (2015)]*
COMT
LOS
EA**
86
Candidate
SNP
No
No
NAS
Treatment
rs3745274 [Mactier et al. (2017)]
CYP2B6
NAS
Treatment
NR
21
Candidate
SNP
ND
No
rs2279343 [Mactier et al. (2017)]
CYP2B6
NAS
Treatment
NR
21
Candidate
SNP
ND
ND
rs73313786 [Bibi et al. (2022)]
SNX13
NAS
Treatment
AA + EA
476
GWAS
ND
ND
NAS, neonatal abstinence syndrome; LOS, length of hospital stay; EA, European ancestry; AA, African ancestry; ND, not done; NR, not reported. *Associations demonstrated point-wise significance at α = 0.05, but not experiment-wise significance. **Cohorts were predominantly EA (98% in the candidate gene discovery cohort (Wachman et al., 2013, Wachman et al., 2015), 88% in the candidate SNP, replication cohort (Wachman et al., NAS, neonatal abstinence syndrome; LOS, length of hospital stay; EA, European ancestry; AA, African ancestry; ND, not done; NR, not reported. *Associations demonstrated point-wise significance at α = 0.05, but not experiment-wise significance. **Cohorts were predominantly EA (98% in the candidate gene discovery cohort (Wachman et al., 2013, Wachman et al., 2015), 88% in the candidate SNP,
2017)). Frontiers in Genetics frontiersin.org 4 Emerging biomarker research in NAS affecting individual variation in responses to opioids (Table 2). These adult studies have identified 25 independent loci and it
will be important to determine whether any of these loci are also
associated with NAS severity. Only one locus (OPRM1) has been
associated with NAS severity, but this finding was not replicated in
the NAS GWAS. Of the 25 loci identified in adults, the ones with
greatest association with NAS severity in the gene-based analysis
performed for the GWAS study are: 1) potassium calcium-activated
channel subfamily N member 1 (KCNN1) which regulates neuronal
excitability and potassium ion trafficking (p = 0.00024) (Kember
et al., 2022); 2) solute carrier family 2 member 9 (SLC2A9) from
which is a member of the facilitative glucose transporter family (p =
0.035) (Song et al., 2020); and 3) cornichon family AMPA receptor
auxiliary protein 3 (CNIH3) which has channel regulator activity in associated with heart failure, neutrophil counts, high density
lipoprotein cholesterol level, apolipoprotein A1 level, and mean
platelet volume (Willer et al., 2013; Li et al., 2014; Chen et al., 2020;
Richardson et al., 2020; Vuckovic et al., 2020). SNX13 has not
previously been associated with addiction, but the related SNX27
has been implicated in attenuating response to cocaine in mice
(Munoz and Slesinger, 2014; Rifkin et al., 2018). Given the sample
size, it will be important to replicate these findings in an independent
dataset. The GWAS failed to replicate any of the associations
identified in the candidate SNP studies (Table 1). However, in a
gene-based analysis of the GWAS results, OPRD1 demonstrated
some association (p = 0.014) as did PNOC (p = 0.073). Large-scale adult GWAS of phenotypes related to opioid abuse/
dependence have provided greater insight into the genetic loci 03 frontiersin.org Yen et al. 10.3389/fgene.2023.1140400 TABLE 2 Summary of genome-wide significant loci identified in studies of opioid use disorder and related phenotypes in adults. Study
Phenotype
Ancestry
(N)
Variant-based loci
Gene-based loci
Gelernter et al. (2014)
DSM-IV OD
AA (5,432)
KCNG2
NR
EA (6,877)
Nelson et al. (2016)
OD
EA (2,637)
CNIH3
NR
Polimanti et al. (2020)
DSM-IV OD
AA (7,138)
C18orf32
C18orf32
Song et al. (2020)
ICD-9/10 OUD
EA (21,310)
DEFB131/SLC2A9/RP11–1396O13.13/ZNF518B*
NR
Zhou et al. (2020)
ICD-9/10 OUD
EA (82,707)
OPRM1
NR
DSM-IV OD
Sanchez-Roige et al. (2021)
POU
EA (132,113)
KDM4A/PTPRF*; LRRIQ3
KDM4A; PTPRF; ARTN
Gaddis et al. 4 Emerging biomarker research in NAS (2022)
OA (DSM-IV OD or FOU-
based)
EA (88,114**)
OPRM1
OPRM1; PPP6C; FURIN
Kember et al. (2022)
ICD-9/10 OUD
AA (88,498)
NNT; CDKAL1/SOX4*; BTNL2; OPRM1; MRS2; TSNARE1; SCAI/
RABEPK*; FBXW4; NCAM1; FURIN; KCNN1; RNF114;
chromosome 10 locus
CHRM2; OPRM1; FTO;
DRD2
EA (302,585)
HA (34,861)
ICD, international classification of diseases; DSM, diagnostic and statistical manual of mental disorders; OUD, opioid use disorder; OD, opioid dependence; EA, European ancestry; AA, African
ancestry; NR, none reported; POU, problematic prescription opioid use; OA, opioid addiction; FOU, frequency of use). *Gene mapping indeterminate. **Effective sample size. ICD, international classification of diseases; DSM, diagnostic and statistical manual of mental disorders; OUD, opioid use disorder; OD, opioid dependence; EA, European ancestry; AA, African
ancestry; NR, none reported; POU, problematic prescription opioid use; OA, opioid addiction; FOU, frequency of use). *Gene mapping indeterminate. **Effective sample size. 5p, and miR-421 predicted the need for pharmacotherapy (area
under the curve/AUC of 0.85) and length of hospital stay (AUC
0.90). Adding a few more miRNAs enhanced predictive validity
of both models. the dendritic shaft and postsynaptic membrane and has been
associated with schizophrenia (p = 0.061) (Drummond et al.,
2012; Nelson et al., 2016). Like KCNN1, sorting nexins related to
SNX13 (e.g., SNX14, SNX27) seem to have a role in regulating
neuronal excitability which may cause an attenuated response to
cocaine in mice (Huang et al., 2014; Munoz and Slesinger, 2014;
Rifkin et al., 2018). Although dopamine receptor type (DRD2) is a key reward gene
in OUD and has been extensively studied in adults, its role in NAS is
not well elucidated. Oei et al. (2012) demonstrated that DRD2
polymorphisms
were
detectable
in
stored
blood
spots. Furthermore, the ins variant of the −141C Del/Ins polymorphism
(located in the promoter region) was more prevalent in non-exposed
compared to opioid-exposed neonates who did not require
pharmacotherapy. The role of dopamine in NAS is also evident
in neonatal salivary transcriptomic studies by Yen et al. (2019). Neonates with NAS have aberrant feeding behavior, especially those
with more severe withdrawal. Using drops of saliva, Yen et al. demonstrated that DRD2 expression was significantly higher in
opioid-exposed males than females, evidence of the sex-specific
impact of prenatal opioids. Furthermore, a positive correlation
was
found
between
DRD2
expression
and
feeding
volume
suggesting that excessive and dysregulated feeding in NAS may
be a compensatory mechanism responding to the abrupt end of the
opioid supply at birth. 4.1.3 Other genetic research in NAS g
In a study of 67 neonates (half opioid-exposed), plasma
brain-derived neurotrophic factor (BDNF) was significantly
elevated in opioid-exposed neonates compared to non-exposed
neonates, suggesting that plasma BDNF might correlate with
NAS severity (Subedi et al., 2017). Mahnke et al. (2022)
demonstrated that three extracellular microRNAs (miRNAs)
in the umbilical cord plasma of opioid-exposed neonates were
predictive of NAS severity. In particular, miR-128-3p, miR-30c- Frontiers in Genetics 4 Emerging biomarker research in NAS The implication of this upregulated reward
signaling on future reward-seeking behavior is yet unknown. Based on the results of our GWAS on NAS severity, we were able
to develop a preliminary set of variants for calculating a PRS for
predicting need for NAS treatment (Bibi et al., 2022). The PRS was
developed in a training set of 290 EA neonates from the GWAS and
it was confirmed to have good predictive ability in independent
validation sets of 92 EA and 94 AA neonates when using effect sizes
calculated in the validation sets. However, to predict need for NAS
treatment in the clinical setting, it is necessary to calculate PRS using
the effect sizes from previous analyses, not the neonate being
assessed. In this scenario, the PRS did not effectively predict
whether a neonate required NAS treatment. While these results
demonstrate the potential of PRS for clinical assessment of NAS
severity, larger sample sizes are needed to develop more effective
PRS models. frontiersin.org 4.2 Epigenetics of NAS Although several studies have demonstrated that genetic factors
may explain the variability of expression seen in NAS, epigenetic
variation in the OPRM1 gene has also been linked to NAS severity. Cytosine methylation of DNA is a known epigenetic mechanism 04 frontiersin.org Yen et al. 10.3389/fgene.2023.1140400 central immune response by binding TLR4 and an accessory protein
known as myeloid differentiation protein 2 (MD-2), inducing
TLR4 oligomerization
and nuclear factor
kappa
B (NFκB)
activation (Wang et al., 2012). This increases the major pro-
inflammatory
cytokines
interleukin
1-beta
(IL-1β),
tumor
necrosis alpha (TNFα), interleukin 6 (IL-6), and monocyte
chemoattractant
protein-1
(MCP-1/CCL2)
and
C-X-C motif
ligand 1 (CXCL1) (Coller and Hutchinson, 2012). Methadone
induces many of these cytokines in the peripheral circulation and
brain at P10, approximately human term equivalent (Jantzie et al.,
2020). Opioids also activate NFκB, which promotes transcription of
opioid
receptors
and
peptides,
propagating
a
detrimental
intracellular signaling cascade (Wang et al., 2004; Chen et al.,
2007; Rehni et al., 2008; Sawaya et al., 2009; Seney et al., 2021). In adults, microglia have been implicated as a driver for opioid-
induced neuroplasticity, catalyzing changes in extracellular matrix,
synaptic and dendritic structures, and are proposed to be a cellular
bridge connecting opioids to the neural-immune system (Zhang
et al., 2020b; Ryu et al., 2021; Seney et al., 2021). Opioid-induced
glial activation may serve as an important mechanism underlying
drug addiction by opposing opioid analgesia in the mature CNS and
enhancing opioid tolerance, dependence, and reward (Hutchinson
et al., 2008; Watkins et al., 2009). that results in the addition of a methyl group to cytosine residues of
cytosine:guanine (CpG) dinucleotides. Chronic in utero opioid
exposure may increase methylation at specific CpG sites within
promoter regions of a gene, potentially increasing or decreasing gene
expression (Nielsen et al., 2012; Doehring et al., 2013). Wachman
et
al. (2014)
obtained
DNA
from
86
neonates
receiving
pharmacotherapy for NAS and measured methylation levels at
16 OPRM1 CpG sites. Increased methylation was detected in
multiple areas within the OPRM1 promoter, with the highest
levels in neonates with the most severe NAS, consistent with
gene silencing. In a follow-up study, OPRM1 methylation was
measured in 68 neonates who were exposed to antenatal opioids
and their mothers (Wachman et al., 2018). 4.2 Epigenetics of NAS While higher levels at
the −18, −14, and +23 CpG sites were associated with receipt of
pharmacotherapy in neonates, elevations in mothers were associated
with an increased length of neonatal hospital stay, confirming prior
findings. In contrast, when placental methylation of the OPRM1
promoter was analyzed in opioid exposed and non-exposed
placentas, no significant associations with neonatal outcome was
noted (Wachman et al., 2020). While these studies suggested that increased methylation of
OPRM1 is associated with more severe NAS, Camerota et al. (2022)
hypothesized that pharmacotherapy for NAS would result in
decreased DNA methylation and improvements in neonatal
neurobehavior. They collected DNA from 37 neonates with NAS
before and after treatment and examined methylation at 4 CpG sites
within the OPRM1 gene. Path analysis was used to examine
associations
with
pharmacotherapy,
DNA
methylation,
and
NNNS summary scores. DNA methylation did decrease in 1 of
4 CpG sites and was accompanied by less excitability, hypertonia,
lethargy, signs of stress and abstinence, and abnormal movement
after
treatment
was
completed. Greater
decreases
in
DNA
methylation were associated with the most significant decreases
in excitability and hypertonia on the NNNS. This study is the first to
suggest that pharmacologic treatment in NAS may directly influence
epigenetics and neonatal neurobehavior. Further studies are needed
in treated and untreated neonates in order to establish a more
definitive association. Jantzie et al. (2020) demonstrated that opioid-induced brain
injuries shared many features of a profound neuroinflammatory
disease characterized by the white matter loss and axonal injury seen
in non-opioid brain injuries (Newville et al., 2020; Vasan et al., 2021;
Madurai et al., 2022). Antenatal opioids primed the immune system
with baseline elevations in cytokines/chemokines as well as
exaggerated
inflammatory
responses
in
peripheral
blood
mononuclear cells after stimulation with lipopolysaccharide. At
term equivalent age, antenatal opioids increased TLR4 and
myeloid differentiation primary response 88 (MyD88) mRNA in
the fetal brain in conjunction with glial activation, evidenced by
increased expression of ionized-calcium binding adaptor molecule 1
(Iba1) and changes in microglial morphology and activation. The
peripheral
inflammation,
immune
priming,
and
sustained
peripheral immune reactivity (SPIHR) extended beyond the
neonatal period (Jantzie et al., 2020; Newville et al., 2020). Even
as markers of serum inflammation and SPIHR normalized in
adulthood, opioid-induced increases in cerebral immune cell
populations
(neutrophils
and
regulatory
T-cells)
remained
(Madurai et al., 2022). 4.2 Epigenetics of NAS Maturing rats with prenatal opioid
exposure also had reduced fractional anisotropy (FA) in major
white
matter
tracts,
as
well
as
marked
loss
in
cerebral
microstructure and abnormalities in directional diffusion. Such
robust systemic inflammatory response and immune dysfunction
were accompanied by cognitive deficits well into adulthood,
evidence of lasting inflammatory impact of antenatal opioids
(Jantzie et al., 2020; Madurai et al., 2022). 4.3.2 Neonatal studies While the impact of prenatal opioids on the developing brain
and neurodevelopmental outcomes has been studied in neonates
(Yuan et al., 2014; Monnelly et al., 2017; Oei et al., 2017; Sirnes et al.,
2017; Merhar et al., 2019; Yeoh et al., 2019; Lowe et al., 2022;
Radhakrishnan et al., 2022), the role of inflammation is unknown. Based on the emerging animal data demonstrating the pro- 4.3 Genetic evidence of inflammation as a
potential mechanism for NAS Emerging animal data highlight the role of inflammation in
potentiating the effects of opioids in drug addiction. Opioids bind
with
toll-like
receptor
type
4
(TLR4)
and
propagate
the
inflammatory cascade through the release of cytokines and
chemokines which precipitate opioid tolerance and dependency
(Hutchinson et al., 2012; Wang et al., 2012; Zhang et al., 2020a). There is an urgent need to better understand the impact of
inflammation in NAS as it may contribute to the immediate
signs of withdrawal and provide the genetic underpinning of the
long-term neurodevelopmental effects of antenatal opioids. Frontiers in Genetics frontiersin.org 4.3.1 Animal studies TLR4 signaling in the mature central nervous system occurs in
response to many types of opioids (e.g., methadone, morphine,
buprenorphine, oxycodone) (Jacobsen et al., 2014). Opioids induce a 05 frontiersin.org Yen et al. 10.3389/fgene.2023.1140400 genetic and epigenetic changes resulting from antenatal opioid
exposure. Such
advancement
is
key
to
the
systematic
understanding and prediction of NAS severity and the discovery
of predictive biomarkers that are readily validated. Emerging animal
and human data point to the crucial role of antenatal opioids on
inflammatory pathways/gene expression in a sex-specific manner. This highlights the potential of non-opioid therapeutics targeting
anti-inflammatory pathways. It is important to consider biological
variables such as sex and carefully account and adjust for the
confounding factors inherent to this type of research. There is
also an urgent need to generate larger datasets that validate
findings from smaller studies to arrive at robust genetic and
epigenetic biomarkers that can be linked to brain structure and
function in order to improve neurodevelopmental outcomes of these
high-risk neonates. inflammatory effects of antenatal opioids on the offspring, Yen et al. (2022) conducted a novel pilot study to understand the role of
inflammation in NAS. Neonatal salivary transcriptomic and brain
magnetic resonance imaging (MRI) data demonstrate that opioid-
exposed females, regardless of the need for pharmacotherapy, had
greater expression of C-C motif chemokine ligand 2 (CCL2) and
CXCL1 than males. MRI showed a higher incidence of punctate
white matter hyperintensity in opioid-exposed compared to non-
exposed
neonates,
with
female
predominance. Salivary
transcriptomics also showed significantly higher expression of
IL1β, IL6, TNFα, and IL10 in opioid-exposed neonates with
white matter hyperintensity than in those without it. While this
pilot study replicated the findings of punctate white matter injury by
Merhar et al. (2019), salivary transcriptomic data from this study
were the first to suggest the genetic mechanisms by which
inflammation may underlie sex-specific white matter injury in
opioid-exposed neonates. In a small subset of neonates, opioid-
exposed neonates had smaller head circumference and qualitatively
reduced FA in major white matter tracts compared to non-exposed
neonates (Sikka et al., 2022). This novel research highlights the sex-
specific and pro-inflammatory effects of antenatal opioid exposure
and supports prior human and animal studies demonstrating the
adverse effects of antenatal opioid exposure on brain development at
both macro- and micro-structural levels (Monnelly et al., 2017;
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dna methylation and neurobehavior: A prospective cohort study. J. Pediatr. 243, 21–26. doi:10.1016/j.jpeds.2021.12.057 Devlin, L. A., Breeze, J. L., Terrin, N., Gomez Pomar, E., Bada, H., Finnegan, L. P., et al. (2020). Conflict of interest The authors declare that the research was conducted in the
absence of any commercial or financial relationships that could be
construed as a potential conflict of interest. Publisher’s note Technology advancement in the last decade has enabled more
sophisticated and objective platforms for the diagnosis of NAS, in
particular in predicting withdrawal severity and the need for
pharmacotherapy. Using cord blood, serum samples, buccal
swabs, and drops of saliva, the field progressed rapidly using
SNPs, DNA methylation, GWAS, and PRS models that highlights All claims expressed in this article are solely those of the authors
and
do
not
necessarily
represent
those
of
their
affiliated
organizations, or those of the publisher, the editors and the
reviewers. Any product that may be evaluated in this article, or
claim that may be made by its manufacturer, is not guaranteed or
endorsed by the publisher. Author contributions EY and JD: paper concept, manuscript writing and editing. NG
and LJ: manuscript writing and editing. All authors contributed to
the article and approved the final/submitted version. 4.3.1 Animal studies Genetic underpinning that confirms the role of
inflammation in NAS may provide exciting opportunities for non-
opioid replacement therapy in neonates most severely affected by
the opioid epidemic. Larger sample sizes are needed to validate these
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Alcohol Depend. 155, 253–259. doi:10.1016/j.drugalcdep.2015.07.001 08 Frontiers in Genetics 08 frontiersin.org
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Evaluation of susceptibility to injuries resulting from falls of children with visual impairment
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EVALUATION OF SUSCEPTIBILITY TO INJURIES RESULTING FROM FALLS
OF CHILDREN WITH VISUAL IMPAIRMENT Dariusz Boguszewski1, Martyna Zabłocka2, Jakub Grzegorz Adamczyk1,3
Katarzyna Boguszewska4, Dariusz Białoszewski1
1. Rehabilitation Department. Medical University of Warsaw, Poland
2. Students Science Club of Physiotherapy. Medical University of Warsaw, Poland
3. Theory of Sport Department. University of Physical Education in Warsaw, Poland
4. Piotr Skarga Catholic Educational Center in Warsaw, Poland The main purpose of the study was the analysis of safe falling skills visually impaired children. An
attempt has been made to examine the relationship between ability of safe falls and occurrence injuries
from the effect of falls. 103 children (10-16 years old) were in research and control groups. In the
research group (Group I) was 39 visually impaired pupils, in control group (Group II) 64 sighted in a
proper manner. Test of Susceptibility to Injury During the Falls (TSIDF) by Kalina and interview
directed to determine the number and frequency of falls and their consequences were used as a
research tools. There were 578 falls and 176 injuries resulting from them (7.33 falls per person in
Group I and 4.96 in Group II; 2.51 injuries per person in Group I and 1.18 in Group II). Visually
impaired people made more mistakes in test (TSIDF) than their non-disabled peers (p=0.007). This
may prove that a high susceptibility to injury of the children from the research group (p=0.001). However visual impairment people had more injuries after the falls. Study confirmed positive effect of
physical activity on the level of safe falls skills. The ability to fall down in a safe way in children
suffering from visual impairment is more improperly developed when compared it to healthy children. Physical activity and especially exercises of safe falls skills can be important element of prevention of
falls. European Journal of Adapted Physical Activity, 6(1), 7-16
© European Federation of Adapted Physical Activity, 2013 European Journal of Adapted Physical Activity, 6(1), 7-16
© European Federation of Adapted Physical Activity, 2013 INTRODUCTION large extent they are the primary causes of
serious injuries, or even death. It is therefore
vital to create a set of principles helping the
avoid situations which may potentially result in
falls and to implement a prophylactic study of
body movements which could minimize the
harmful effects of collapsing to the ground or
hitting a vertical obstacle (Kalina, Kalina &
Klukowski, 1998). Sense organs are our “primary channels” in
receiving stimuli from the environment. Sight
is seemingly the most important sense for
every human being. However, it is particularly
important for children who learn the world
through knowing the objects and phenomena
surrounding it (Gruszczyński & Rutkowska,
2003). Therefore, considerable impairment or
complete loss of sight has great impact on the
child’s cognitive abilities, even though it does
not change the child’s potential developmental
possibilities
(Rutkowska,
Morgulec-
Adamowicz, Skowroński, 2009). Scientific research has proven that a
falling persons have not the skills to secure
themselves. This was the reason to develop the
safe fall theory (Czerwiński et al., 2006;
Kalina et al., 2003, 2011). The safe fall theory
states the measures to be taken in order to
completely avoid or mitigate the effects of
injuries resulting from threatening situations. It
should be noted that specialists in dangerous
professions, affecting the falls and injuries
(such as stuntmen, athletes or soldiers of the
special units) the ability to the safe falling
down use in everyday real life. Hence, the
people who tend to fall down and suffer from Similarly to people undergoing limb
amputation, suffering from osteoporosis or
musculoskeletal system conditions, children
suffering from visual impairment (VI) are a
group which is particularly prone to injuries
resulting from falls (Kalina, Kalina &
Klukowski, 1998). In this case, falls are
considered to be social problems, since to a EUJAPA, Vol. 6, No. 1 7 Susceptibility to injuries of children with VI Boguszewski at al. 2. Determine
the
relationship
between
physical activity and susceptibility to
injury during falls. 2. Determine
the
relationship
between
physical activity and susceptibility to
injury during falls. severe injuries resulting from the falls
(occurring in the street, at home, on stairs, etc.)
are usually those who do not possess the ability
or knowledge of falling down safely (Kalina,
Kalina & Klukowski, 1998; Boguszewski &
Kerbaum, 2011). METHODS ,
)
Therefore, in order to reduce the risk
of suffering from post-fall injuries, one should
develop the habit of falling down in a safe
way. Motor coordination, the ability to protect
one’s head, the ability to loosen one’s muscles
all contribute to preventing body injuries
during falls. Such elements could reduce the
risk entailed by falls or resulting personal
injuries
(Kalina
et
al.,
2003,
2011;
Boguszewski & Kerbaum, 2011). People with
visual impairment are particularly prone to
injuries resulting from falls (Coleman et al.;
2004, Black & Wood, 2005; Patino et al.,
2010;
Manduchi
&
Kurniawan,
2011). Therefore, a special preventive program
dedicated entirely to the visually impaired
could reduce the risk of life-threatening
injuries. Similar solutions have been used with
positive results among different groups (e.g. the elderly) (Rubenstein, et al., 2000; Barnett,
et al., 2003; Li, et al., 2005; Rose, 2008; Groen
et al., 2010). Participants p
The research covered a group of 103
children between the age of 10 and 16
(including 43 girls and 60 boys). The children
participating in the research were divided into
two groups – the researched group (n=39)
comprised children with visual impairment
(VI) – Group I, and the control group (n=64) of
children without visual impairment – Group II
(table 1). The average age of children
participating in the research was 13.1. There
were not significant differences between
groups in age, body mass and height. The
WHO classification was applied in reference to
the researched group. According to the WHO
classification, the children were diagnosed
with visual impairment – best corrected visual
acuity was from 0.3 to 0.005 in the better eye. Additionally, only children without any other
dysfunctions (e.g. neurological dysfunctions)
which could potentially inhibit their motor
abilities have been qualified for the research. The aim of the study was the diagnosis of
safe falling skills visually impaired children
and their healthy peers. An attempt has been
made to: The research was carried out in the
2010/2011 school year in the Educational
Center for Children with Visual Impairment in
Warsaw (Group I) and in the public school in
Warsaw (Group II). 1. Establish the relationship between the
skills to safely falling down and the
occurrence of injuries resulting from falls. TABLE 1 TABLE 1
Characteristics of research groups (mean value ± standard deviation)
groups
gender
n
age [years]
body mass [kg]
height [cm]
physically
active [n]
Group I
(visual impaired)
girls
15
12.4 ± 1.5
45.8 ± 9.9
154.9 ± 10.3
5
boys
24
13.8 ± 2.1
60.2 ± 12.1
168.5 ± 11.1
13
Group II (control)
girls
28
12.4 ± 2.1
46.6 ± 10.3
156.1 ± 8.9
14
boys
36
13.4 ± 2.1
54.4 ± 12.1
163.6 ± 12.5
24 Characteristics of research groups (mean value ± standard deviation) EUJAPA, Vol. 6, No. 1 EUJAPA, Vol. 6, No. 1 8 8 Susceptibility to injuries of children with VI Boguszewski at al. Test of Susceptibility to Injury During the
Falls Children from Group I got significantly
higher results in the Test of Susceptibility to
Injury During the Falls (p=0.007), which
means that they committed a larger number of
errors performing the motor activities. The
biggest disparities (p=0.004) occurred in the
last activity, which was theoretically the most
difficult one. The majority of errors committed
by children from both groups concerned
applying improper support with the hands. The
biggest disparities between the two groups
were recorded in this respect. The smallest
disparities (statistically insignificant) were
recorded with respect to protection of the head
(fig. 1 and 2). The results of the Test of
Susceptibility to Injury During the Falls
acquired by boys and girls were quite similar. y
y
g
In Group I almost 82% of the children were
characterized by high or very high proneness
to injuries resulting from falls. In comparison,
nearly 67% of children from the control group
were similarly classified. In opposition to non-
active children, physically active children
committed fewer errors while performing the
assigned motor activities, although significant
disparities (p=0.000) were recorded only in
Group II. Only 5 (9%) of physically active
children acquired a result standing for very
high proneness to post-fall injuries. 17 (37%)
non-active children acquired the same result. 23 (41%) of physically active children and 5
(11%) non-active children were characterized
by low or medium proneness to post-fall
injuries (tab. 2). The research was accompanied by an
investigation of the types of falls (number of
falls, circumstances of occurrence), the injuries
incurred during falls (with the exception of
sports-related injuries), and the types of
physical activities performed (type, frequency). Information from the last three years was
included in the investigation. MEASURES AND PROCEDURES minimum three times a week outside their
school classes were classified as active (table
1). The second division into sub-groups
referred to the age of the researched children –
younger (10-13 years old) and older children
(14-16 years old). One of the tools used in the research was
Kalina’s Test of Susceptibility to Injury During
the Falls (TSIDF). Reliability of the test was
confirmed by the author (for groups of healthy
young people) (Kalina et al., 2011). The test
was based on performing three motor activities
as fast as possible. The first motor activity was
proceeding from the basic position to lying
down on the back (on a mattress). In the
second motor activity, apart from the above
mentioned process, the child had to hold a
small bag between the chin and the sternum
and to clap its knees. In the third motor
activity, apart from the above mentioned, basic
movement, the child was to make a leap before
proceeding to lying down on the back. However, children were not specifically
instructed how to make the exercises. Each
attempt was evaluated for errors – deviations
from the correct mode of safe falling. The
results were entered to the observation sheet. The sum of errors for particular body parts
(head, legs, hips, arms) collected from all three
activities serves as the Susceptibility to Injury
During the Falls Index (SIDF). The higher the
result, the higher was the proneness to injuries. The sum of points collected after all three
activities serves as the Susceptibility to Injury
During the Falls Index, in which 0 points
stands for low proneness, 1 to 3 points stand
for medium proneness, 4 to 9 points stand for
high proneness, and 10 to 14 points stand for
very high proneness (Kalina et al., 2011). All
children were assessed by two specialists in
physical
education
and
physiotherapy
(specializing in teaching safe falling down). Standard statistical tools, such as arithmetic
mean and standard deviation, were applied in
the research. The relations between particular
variables (number of injuries and results of
SIDF Test) were established with the Pearson’s
correlation
coefficient. The
differences
between particular data were calculated with
independent t-test. The minimal significance
level was established at p<0.05. Data Analysis For comparative purposes, two additional
divisions into sub-groups have been isolated as
part of the above mentioned groups. In the first
division into sub-groups, undertaking or non-
undertaking regular physical activity was the
essential criterion. Children who participated
in organized sports or recreational classes EUJAPA, Vol. 6, No. 1 9 9 Susceptibility to injuries of children with VI Boguszewski at al. FIGURE 2 Results of Test of Susceptibility to Injury During the Falls among the boys
1,63
1,75
2,83
1,00
1,11
1,44
1,61
1,17
0
0,5
1
1,5
2
2,5
3
lower limbs
hips
upper limbs
head
GROUP I
GROUP II
NS
NS
p=0,029
p=0,011
[SIDF] FIGURE 1 FIGURE 1
Results of Test of Susceptibility to Injury During the Falls among the girls
FIGURE 2
Results of Test of Susceptibility to Injury During the Falls among the boys
TABLE 2
Level of susceptibility to injury during a fall of girls and boys
groups
gender
susceptibility to injury during a fall
low
average
high
very high
Group I
active
girls
0
0
3
2
boys
1
3
6
3
non-active
girls
0
2
4
4
boys
0
1
6
4
Group II
active
girls
1
4
9
0
boys
1
13
10
0
ti
girls
0
1
10
3
1,80
1,60
3,13
2,00
1,32
1,14
1,93
1,57
0
0,5
1
1,5
2
2,5
3
3,5
lower limbs
hips
upper limbs
head
GROUP I
GROUP II
p=0,044
NS
p=0,038
NS
[SIDF]
1,63
1,75
2,83
1,00
1,11
1,44
1,61
1,17
0
0,5
1
1,5
2
2,5
3
lower limbs
hips
upper limbs
head
GROUP I
GROUP II
NS
NS
p=0,029
p=0,011
[SIDF] FIGURE 1
Results of Test of Susceptibility to Injury During the Falls among the girls
FIGURE 2
1,80
1,60
3,13
2,00
1,32
1,14
1,93
1,57
0
0,5
1
1,5
2
2,5
3
3,5
lower limbs
hips
upper limbs
head
GROUP I
GROUP II
p=0,044
NS
p=0,038
NS
[SIDF] Results of Test of Susceptibility to Injury During the Falls among the girls Falls and injuries The majority of children participating in the
research (88%) claimed to have fallen at least
once in the last three years, 35 (90%) children
from group one and 57 (89%) children from
group two fell down at least once. In total, the
research children declared 578 falls and 176
personal injuries (resulting from the falls). The
average number of falls per person in Group I
was 7.33, and 4.96 in Group II. Boys tended to
fall down more often (in average 7.58 – Group
I
and
5.64
–
Group
II)
than
girls
(correspondingly 6.93 and 4.11). The average
number of personal injuries was 2.51 with
respect to handicapped children and 1.18 with
respect to healthy children. Girls tended to
suffer from personal injuries more often (in
average 2.97 – Group I and 1.21 – Group II)
than boys (correspondingly 2.41 and 1.16). Comparison of the number of falls and
injuries of children physically active and
inactive, and younger and older children Children with visual impairment staying
physically active usually suffered from injuries
of the lower limbs (in average 1.2 per person)
and of the upper limbs (in average – 1 per
person). On the other hand, physically active
children from Group II usually suffered from
injuries of the lower limbs (0.5). Injuries of the
head and spine area were rather rare (0.28 –
Group I, 0.08 – Group II). Non-active children
indicated more injuries of all aforementioned
body parts (head and spine: in average 0.43 –
Group I and 0.19 – Group II; upper limbs: 0.91
and 0.61; lower limbs: 1.38 and 0.81). Physically
active
children
rarely
suffered from post-fall injuries (in average
2.39 per person – Group I and 0.89 – Group II)
in
comparison
to
non-active
children
(correspondingly 2.62 and 1.62). Injuries
incurred usually concerned the lower limbs (in
average 1.06 per person in reference to non-
active children and 0.62 in reference to active
children). )
Younger children (10-13 years old) suffered
from falls and resulting injuries slightly more
often than older children. No significant
disparities in the number of falls and resulting
injuries were recorded between Groups I and Boguszewski at al. Younger children (between the age of 10-
13) from both groups acquired a higher result
in the Test of Susceptibility to Injury During
the Falls, which means that they committed
more errors. Bigger disparities concerned boys
rather than girls. When it comes to the sub-
group of younger children, children with visual
impairment committed more errors in all of
three assigned motor activities. However,
considerable disparities were recorded only in
the “arm” category in girls (p=0.047) and in
the “head” category in boys (p=0.014). When
it comes to the sub-group of older children (14-
16
years
old),
the
disparity
between
handicapped and healthy children were bigger. In particular, boys from Group I displayed a
significantly lower level of motor skills in
comparison to their peers from Group II. Statistically
significant
differences
were
recorded in the “legs” category (p=0.000), the
“arms” category (p=0.003) and the “head”
category (p=0.016). Visually impaired children suffered from
more injuries resulting from collapsing to the
ground (p=0.001). The most common injuries
in group one were wounds and abrasions (in
average – 1.15 per person), however, in group
two – these were mainly contusions (0.67). The most severe injuries, such as bone
fractures usually occurred in children suffering
from visual impairment (in average 0.33 –
Group I, 0.06 – Group II). Both physically
active
and
non-active
children
suffered
primarily from minor injuries – wounds,
abrasions and contusions (slightly more
incidents in the non-active group). Bone
fractures occurred rarely in both groups. Still
the number of fractures was bigger in the non-
active group. The average number personal
injuries was nearly identical with girls (1.72)
and boys (1.67). When it comes to children with visual
impairment, the injuries were generally located
around the lower limb area (in average 1.15
per person) and, slightly rarer, in the upper
limb area (1.07). Injuries of the head area or of
the spinal area were rather rare (0.36), since
these are the body parts which should be
particularly protected during a fall. Similar
tendency was recorded in the control group,
where the majority of injuries concerned the
lower limb area (0.62), and the upper limb area
(0.41). Head and spine injuries were rare
(0.12), even rarer than in the case of the first
group (fig. 3 and 4). Level of susceptibility to injury during a fall of girls and boys groups
gender
susceptibility to injury during a fall
low
average
high
very high
Group I
active
girls
0
0
3
2
boys
1
3
6
3
non-active
girls
0
2
4
4
boys
0
1
6
4
Group II
active
girls
1
4
9
0
boys
1
13
10
0
non-active
girls
0
1
10
3
boys
0
1
5
6 10 EUJAPA, Vol. 6, No. 1 EUJAPA, Vol. 6, No. 1 10 The type and location of injuries EUJAPA, Vol. 6, No. 1 11 Susceptibility to injuries of children with VI Boguszewski at al. Visually impaired girls suffered from post-fall
injuries more often (p=0.048), whereas in the
case of boys, the result was close to the
significance level (p=0.077) (tab. 4). Visually impaired girls suffered from post-fall
injuries more often (p=0.048), whereas in the
case of boys, the result was close to the
significance level (p=0.077) (tab. 4). II. The above mentioned events referred to
children suffering from visual impairment only
(tab. 3). When it comes to older children (14-
16 years old), the disparities (particularly in the
number of injuries) were more significant. TABLE 4 F indicator value, the number of falls and injuries among the children aged 14-16 years SIDF indicator value, the number of falls and injuries among the children aged 14-16 years
Girls
Boys
Group I
(n=7)
Group II
(n=8)
p
Group I
(n=17)
Group II
(n=17)
p
mean
value
SD
mean
value
SD
mean
value
SD
mean
value
SD
SIDF
6.25
4.35
3.75
3.54
0.364
7.41
3.82
2.76
2.31
0.000
falls
12.5
8.69
5.5
4.84
0.209
9.12
7.86
5.12
3.87
0.072
injuries
2.5
1.29
0.5
0.53
0.048
2.29
2.66
1
1.06
0.077 & Ocetkiewicz, 2003; Czerwiński et al., 2008). FIGURE 3 FIGURE 3
Number of injuries resulting from the fall of the girls
FIGURE 4
Number of injuries resulting from the fall of the boys
Children who acquired lower results in the
Test of Susceptibility to Injury During the
Falls declared to have suffered from post-fall
injuries more often. The correlation between
the Test result and the number of injuries was
r=0.58 (p=0.000). To a great extent, t
tendency concerned children with vis
impairment (r=0.6 p=0.000) rather than heal
children (r=0.53 p=0.000). 1,33
0,80
0,60
0,68
0,32
0,18
0
0,2
0,4
0,6
0,8
1
1,2
1,4
lower limb
upper limb
head, spine
GROUP I
GROUP II
p=0,041
p=0,049
NS
[n/person]
1,04
1,25
0,21
0,58
0,47
0,08
0
0,2
0,4
0,6
0,8
1
1,2
1,4
lower limb
upper limb
head, spine
GROUP I
GROUP II
NS
p=0,044
NS
[n/person] Number of injuries resulting from the fall of the girls
1,33
0,80
0,60
0,68
0,32
0,18
0
0,2
0,4
0,6
0,8
1
1,2
1,4
lower limb
upper limb
head, spine
GROUP I
GROUP II
p=0,041
p=0,049
NS
[n/person] Number of injuries resulting from the fall of the girls FIGURE 4 FIGURE 4 Number of injuries resulting from the fall of the boys
1,04
1,25
0,21
0,58
0,47
0,08
0
0,2
0,4
0,6
0,8
1
1,2
1,4
lower limb
upper limb
head, spine
GROUP I
GROUP II
NS
p=0,044
NS
[n/person] Children who acquired lower results in the
Test of Susceptibility to Injury During the
Falls declared to have suffered from post-fall
injuries more often. The correlation between
the Test result and the number of injuries was Children who acquired lower results in the
Test of Susceptibility to Injury During the
Falls declared to have suffered from post-fall
injuries more often. The correlation between
the Test result and the number of injuries was r=0.58 (p=0.000). To a great extent, this
tendency concerned children with visual
impairment (r=0.6 p=0.000) rather than healthy
children (r=0.53 p=0.000). r=0.58 (p=0.000). To a great extent, this
tendency concerned children with visual
impairment (r=0.6 p=0.000) rather than healthy
children (r=0.53 p=0.000). EUJAPA, Vol. 6, No. 1 12 Susceptibility to injuries of children with VI Boguszewski at al. TABLE 3 TABLE 3
SIDF indicator value, the number of falls and injuries among the children aged 10-13 years TABLE 3
SIDF indicator value, the number of falls and injuries among the children aged 10-13 years
Girls
Boys
Group I
(n=11)
Group II
(n=20)
p
Group I
(n=4)
Group II
(n=19)
p
mean
value
SD
mean
value
SD
mean
value
SD
mean
value
SD
SIDF
8.81
3.97
6.85
2.43
0.156
6.43
2.28
7.73
3.19
0.332
falls
5.09
3.27
3.55
3.3
0.225
3.86
3.02
5.21
3.49
0.351
injuries
2.73
2.05
1.5
0.83
0.082
2.71
2.29
1.32
1.11
0.164
TABLE 4
SIDF indicator value, the number of falls and injuries among the children aged 14-16 years
Girls
Boys
Group I
(n=7)
Group II
(n=8)
p
Group I
(n=17)
Group II
(n=17)
p
mean
value
SD
mean
value
SD
mean
value
SD
mean
value
SD
SIDF
6.25
4.35
3.75
3.54
0.364
7.41
3.82
2.76
2.31
0.000
falls
12.5
8.69
5.5
4.84
0.209
9.12
7.86
5.12
3.87
0.072
injuries
2.5
1.29
0.5
0.53
0.048
2.29
2.66
1
1.06
0.077
DISCUSSION
People of all ages have and will fall down. This is considered one of the major problems
of senior age, and the main cause of injuries in
seniors. Nearly 20% of all causes of death of
people over the age of 65 include post-fall
injuries (Skalska, Walczewska & Ocetkiewicz,
& Ocetkiewicz, 2003; Czerwiński et al., 2008). People who underwent lower limb amputation,
people suffering from diabetes, people using
wheelchairs, seniors, people suffering from
osteoporosis, as well as people suffering from
visual impairment are particularly prone to
falling (Capella-McDonnal, 2007; Patino et al.,
2010; Manduchi & Kurniawan, 2011; Odom, SIDF indicator value, the number of falls and injuries among the children aged 10-13 years
Girls
Boys
Group I
(n=11)
Group II
(n=20)
p
Group I
(n=4)
Group II
(n=19)
p
mean
value
SD
mean
value
SD
mean
value
SD
mean
value
SD
SIDF
8.81
3.97
6.85
2.43
0.156
6.43
2.28
7.73
3.19
0.332
falls
5.09
3.27
3.55
3.3
0.225
3.86
3.02
5.21
3.49
0.351
injuries
2.73
2.05
1.5
0.83
0.082
2.71
2.29
1.32
1.11
0.164 SIDF indicator value, the number of falls and injuries among the children aged 10-13 years F indicator value, the number of falls and injuries among the children aged 10-13 years DISCUSSION ,
;
,
)
People who underwent lower limb amputation,
people suffering from diabetes, people using
wheelchairs, seniors, people suffering from
osteoporosis, as well as people suffering from
visual impairment are particularly prone to
falling (Capella-McDonnal, 2007; Patino et al.,
2010; Manduchi & Kurniawan, 2011; Odom,
Odom, Leys, 2011). People of all ages have and will fall down. This is considered one of the major problems
of senior age, and the main cause of injuries in
seniors. Nearly 20% of all causes of death of
people over the age of 65 include post-fall
injuries (Skalska, Walczewska & Ocetkiewicz,
2003;
Bączkowicz,
Szczegielniak
&
Proszkowiec, 2008; Czerwiński et al., 2008). The causes of falls include internal conditions
(illness,
senile
conditions)
and
external
conditions
(environmental,
situational
conditions). Preventing falls is thus an
essential, but expensive issue. Research clearly
shows that it is possible to lower the risk of
falls even by 40% if the patient is treated by a
multidisciplinary team (Skalska, Walczewska Evaluations
of
proneness
to
injuries
resulting from falls in people with visual
impairment have been carried out very rarely. People suffering from complete blindness or
partial
visual
impairment
are
examined
primarily for their physical fitness and posture
(Bolach et al., 2007, Bolach, Bolach &
Józefowski, 2009; Patel et al., 2009; Jessup,
Cornel
&
Bundy,
2010;
Rutkowska, EUJAPA, Vol. 6, No. 1 13 Susceptibility to injuries of children with VI Boguszewski at al. Bednarczuk,
Skowroński,
2010). The
occurrence of injuries resulting from falls is
generally evaluated in seniors or healthy
children, without comparing their results with
the results acquired by children suffering from
various conditions and dysfunctions (Tinetti &
Williams, 1997; Kalina, Kalina & Klukowski,
1998; Czerwiński et al. 2008). Bednarczuk,
Skowroński,
2010). The
occurrence of injuries resulting from falls is
generally evaluated in seniors or healthy
children, without comparing their results with
the results acquired by children suffering from
various conditions and dysfunctions (Tinetti &
Williams, 1997; Kalina, Kalina & Klukowski,
1998; Czerwiński et al. 2008). of proneness to personal injuries resulting from
falls after having undergone intense safe-
falling training, for instance in the form of
program based on the propaedeutics of combat
sports (Kalina et al., 2008; Gąsienica-Walczak
et al., 2010; Boguszewski & Kerbaum, 2011),
in order to claim to what extent the abilities
taught are acquired by the trainees and how
they could be applied in everyday life. CONCLUSIONS 1. The ability to fall down in a safe way
in children suffering from visual impairment is
more improperly developed when compared it
to healthy children. Therefore, children with
visual impairment may be more prone to
personal injuries resulting from situations
ending with falls. 2. Visually impaired children often have
injuries from falls. This may be a result of a
lower level of special coordination and
inability to safe falling. The risk of falls and
injuries that may occur can be minimized by
learning specific skills (safe fall). Epidemiological data indicates that the
majority of effects of falls in the form of
fractures were recorded in two age groups:
from 8 to 15 and above 60 (Czerwiński,
Borowy & Jasiak, 2006). However, there is no
statistical data defining the types and locations
of injuries in people suffering from visual
impairment (Kalina, Kalina & Klukowski,
1998). The results of this research allow us to
claim that children between the age of 10 and
16 may be prone to personal injuries resulting
from falls, which is proven by high results of
the Test of Susceptibility to Injury During the
Falls carried out. 3. The results of research prove the
beneficial effect of physical activity on the
occurrence of defensive reflexes, protecting the
body from being harmed. Children spending
their time actively suffered from fewer injuries
after falling down than non-active children. DISCUSSION Physical fitness may serve as the basis for
fall
prevention,
since
it
contributes
to
improving bone structure, influences the
operation of the respiratory and circulatory
systems, and results in increasing the muscular
structure as well as the scope of movement of
the
joints
(Tinetti
&
Williams,
1997;
Boguszewski & Kerbaum, 2011). Physical
fitness helps us to properly position our bodies
in order to fall in a safe manner. Therefore,
thanks to physical fitness, we not only become
fitter, but we also become less liable to fall
down randomly – hence we are less prone to
injuries resulting from a fall (Tinetti &
Williams, 1997; Skalska, Walczewska &
Ocetkiewicz, 2003; Skelton, Kennedy &
Rutherford, 2004). REFERENCES Bączkowicz,
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480. The natural direction for further research
would be to expand the groups of people
covered and to include the cause of the loss of
sight as a valid criterion. Due to frequent
occurrence of posture defects, it would be
justified to include an evaluation of postures in
researched groups (Bolach et al., 2007; Bolach,
Bolach & Józefowski, 2009). Additional
elements to be diagnosed may be the ability to
fall down in a safe manner in all variants of
falls occurring in everyday lives – falls to the
back, falls to the front and falls to the side). This would help to establish and evaluate self-
protection movements to be applied in all
possible situations. Yet another direction for
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influence of ballroom dance upon the
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M. (2006). Divergent
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Kruszewski,
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Przeździecki,
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Harasymowicz, J., Syska, J. & Szamotulska
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0500/3/111 ( )
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https://openalex.org/W2075120299
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English
| null |
Construction of Environmental Knowledge: Experiences from India
|
Journal of sustainable development
| 2,009
|
cc-by
| 6,189
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1. Background Despite the existence of international guidelines such as Principle 10 of the Rio Declaration passed in the 'Earth
Summit' of 1992 (UNCED 1992), it is not still clear how and whether the issues of environment are integrated into the
policy process. Positioned amidst ambiguity, are the tensions in how knowledge about the environment is constructed
and by whom (Guha 1989). The significance of knowledge of the environment in the policy process is of great concern
in the developing world which is rapidly exploiting natural resources to meet the rising demands of its population. A
key aspect of this knowledge construction is in conceptualizing who should be involved in making decisions on the
environment and how. Particularly in developing countries with a federal structure of government (where multiple
levels of government including central, regional and/or local are involved in decision making), construction of the
knowledge on the environment and the design of appropriate policy interventions is problematic. For instance, in the
India, environment is a subject in the central list (exclusive authority of central government to legislate), land and water
are subjects in the state list (exclusive authority of state government to legislate), and forest is a subject in the
concurrent list (where both central and state governments have authority to legislate). More recently, the multiplicity of
institutions has become particularly posed challenges with the inclusion of multinational enterprises (or corporate actors)
in the policy arena. Thus, on one hand, the competing role of multiple institutions has created ambiguity in who should
decide and why. While on the other hand, there are arguments to involve individual citizens in environmental governance (DoE 1994;
DETR 1999; Barr 2003). Following on this path, Environment Canada (the federal ministry of the environment) coined
the phrase ‘environmental citizenship’ as a broad concept to help different actors to think through their rights and duties
as inhabitants of planet Earth (Szerzynski 2006). However, such a conceptualization has been vague and brings on
board competing sets of arguments. The first is the inherent rights of different stakeholders on matters concerning their
environment, such as rights to clean air, a safe environment, or a right to be involved in decision making. The second
relates to the values and practices used to nudge citizens to be environmentally aware and responsible in their everyday
practices, such as conserving water, switching off lights and so forth (Horton 2006). Abstract This paper explored key issues in how knowledge of the environment is constructed in the Third World. Drawing on
which, it showed that there are both explicit and implicit ways in which this knowledge is contested. Particularly, it
discussed how implicit forms of contestation are problematic in Third World economies because they are exclusionary
and also where such issues become ‘headlines’ only after environmental damage and accompanying social injustices
have resulted. It concludes by raising crucial questions for environmental research in the Third World where there is
limited role of governments and communities in protecting their environment. words: Environment, Knowledge construction, Roles of actors, Ski Village project, India, Third Worl Construction of Environmental Knowledge: Experiences from India Deepak Gopinath
Department of Town and Regional Planning, University of Sheffield
Winter Street, Sheffield, S10 2TN, United Kingdom
Tel: 44-114-2226913 E-mail: d.gopinath@sheffield.ac.uk
Manik D Gopinath
Former Research Associate, School of Planning and Architecture, Delhi, India
Sheffield, United Kingdom
Tel: 44-7733402251 E-mail: manik.gopinath@gmail.com Deepak Gopinath
Department of Town and Regional Planning, University of Sheffield
Winter Street, Sheffield, S10 2TN, United Kingdom
Tel: 44-114-2226913 E-mail: d.gopinath@sheffield.ac.uk
Manik D Gopinath
Former Research Associate, School of Planning and Architecture, Delhi, India
Sheffield, United Kingdom
Tel: 44-7733402251 E-mail: manik.gopinath@gmail.com 1 le Development le
evelopment Construction of Environmental Knowledge: Experiences from 1.1 Different forms of contestations Due to a lack of clear understanding on how to decide on the environment particularly in developing economies,
competing arguments of ‘who should construct knowledge of the environment’ have broadly resulted in two forms of
contestations. In some cases, competing arguments of who should construct knowledge of the environment are not
explicitly stated. Such forms of ‘implicit’ contestation become particularly problematic in Third World economies
where such environmental issues become ‘headlines’ only after the occurrence of environmental damage and
accompanying social injustices. With the advent of global players in making decisions of local environments, this has in
different ways shaped the roles of governments and communities in the Third World. This has raised concerns about
when, how and why actors beyond the local communities should become involved in the decision-making process. Some of these encounters have produced ‘implicit’ contestations within the Indian context (as in the Himalayan Ski
Village project). The contestations are ‘implicit’ since such concerns have not reached the attention of the academic and
research community, which Smith (2003) rightly notes is partly due to limited awareness of where to look for emerging
environmental debates and conflicts. This is also to a certain extent due to the insistence in academic scholarship of
‘reporting after something has happened’ and as a result there is hardly an academic paper that discusses the Ski Village
project. On matters relating to the environment and particularly in sensitive eco-systems, opportunities for facilitating
basis research to inform policy and applied research appear to be severely limited. In this regard, Hinchliffe and
Blowers (2003) argue that environmental disasters are not chance events and that the context should be examined at
various levels including an exploration of the socio-political context. Such an approach seems to imply of the need to
research the environment starting with the possibility of involving more stakeholders in the decision making process so
that there might be limited ecological damage and minimal social impacts. But ‘implicit’ forms of contestation present
challenges for environmental research in knowing how such issues can be studied. In this regard, this paper first
examines ‘explicit’ contestations, and through an example, brings out a set of questions that can be used as a framework
to explore ‘implicit’ forms. More commonly, contestations are explicitly played out through different modes of ‘head-on’ confrontation among
different stakeholders supplemented by media publicity (Bingham 2003). 1.1 Different forms of contestations For instance in the Indian context, and
particularly with respect to the environment, water management practices in north-western India provide a useful
insight into the nature of ‘explicit’ contestations. It was reported in the local media that following the ineffective
intervention of multiple institutions in providing water supply to drought-prone areas in north-western India (Mago
2000), communities had explicitly contested the notion ‘that they were living in a water scarce environment’. Particularly, in the states of Gujarat (Das 2000) and Rajasthan (Nanda 2000), the traditional systems of water supply
including large tanks, canals and aqueducts were cleaned up so that rainwater in the form of surface run-off could be
collected and used for domestic consumption. This then provides one of the possibilities to unpack the tensions in how
knowledge of the environment is being constructed – how did the state engage with the local context in constructing
knowledge of the environment? Drawing on this inquiry, detailed studies were carried out in the desert city of Jodhpur
in western Rajasthan (Gopinath 2001a). During the fieldwork however, it started to emerge that such forms of head-on
confrontation and social action started to wither away particularly when quantities of public water supply became more
readily available. Such tensions were generally treated as mere ‘cause and effect’- that individuals challenge notions
‘that they are living in a water scare environment’ on the basis of self-interest, i.e. to survive. And when the right to
survive is not threatened, then they do not contest. However, such explanations appeared simplistic and did not in any
way provide an understanding of the socio-political context. Detailed semi-structured interviews were then carried out
with different stakeholders including state actors and community members. Discussions with state actors revealed how
knowledge of the environment (that they were living in a water scarce environment) was constructed independent of
understanding the local context (Gopinath 2001a). State actors were more concerned in using ‘scientific’ approaches in
managing water – including pricing policy, augmenting water supply from neighboring states. More importantly, the
state actors did not find the relevance of creating a platform for engaging with communities for whom water
management measures were being designed. On the other hand, through the discussions with community members, it was learnt that there are underlying forces
(such as the caste system) that were not visible even within ‘explicit’ forms (Gopinath 2001a). 1. Background These theorizations of
environmental citizenship seem to suggest a rights-based as well as a responsibility-based approach, and this reflects the
two broad traditions underpinning the notion of citizenship: a liberal notion, based on citizen rights, and a republican
notion based on citizen responsibilities (Dobson and Bell 2006). However, such approaches are problematic in the Third
World, where communities plagued by poverty and unemployment are more concerned on the different means for
livelihood, and are to a lesser degree aware of their environmental rights – rights to clean air or the right to be involved
in decision making. Also, responsible behavior to the environment is usually nudged through environmental regulations 2 Journal of Sustainable Development March, 2008 March, 2008 that are generally weak and prone to corrupt practices in developing economies. This has in many ways created
ambiguity in what the roles of different stakeholders might be in engaging with the environment. that are generally weak and prone to corrupt practices in developing economies. This has in many ways created
ambiguity in what the roles of different stakeholders might be in engaging with the environment. 2.1 Under-development in the Third World: tourism as a solution? Amidst the lack of sound institutional arrangements in developing countries, there has been the surge in multinational
investments particularly within the tourism industry. This has been supported by claims that tourism investment is a
means to reduce poverty and inequality (Cater 1995; Ashley, Boyd, and Goodwin 2000; Erb 2000) – through increased
foreign exchange revenues and enhanced employment opportunities for the local population. The range of advantages
suggests that the logic of tourism investment is linked to notions of ‘development’. The notion of ‘development’ was
initially argued as a path to be traversed by ‘backward societies along the road to civilization’ (Rist 2002). Then with
the advent of the ‘new development age’, agendas of ‘development’ as ‘modernization’, was reinforced by leading
development models, including Walt Rostow’s ‘unilinear’ model (1960). The Rostovian Take-off model (as it
sometimes called) is a linear theory of development which categorizes economies into primary, secondary and tertiary
sectors by observing the patterns of change in the history of developed nations (Rostow 1960). This model was based
on the premise that ‘development’ is a defining feature of advanced industrial economies and that regions in the Third
World can progress toward development only by treading the same path, earlier traversed by advanced industrial
economies. This was later followed by the Lewis model which regarded industrialization as the essence of development
(Ranis 2004). It however accepted the classical British roadmap to development – of going through a phase of
agricultural revolution first (and thus raising agricultural surplus) and then moving into a phase of industrial revolution
(Figueroa 2004). Further it also assumed that for overpopulated nations a strategy of industrialization could help
transform the subsistence (primary) sector through a process of labor transfer and growth of employment in the
industrial sector (Figueroa 2004; Todaro 2000). These linear models of development attempted to reinforce the notion
that there were no alternative paths to ‘development’ other than ‘modernization’ and by integrating into the world
system. These had influences in the constitution of new international development agencies including the World Bank,
and how development was normatively constructed by them. But ‘development’ as ‘modernization’ has been confronted by the ‘dependency school’ – which argues that
‘modernization’ in an unequal international system would not create autonomous entities but rather will force backward
regions (the ‘periphery’) into a state of great dependence on advanced industrial nations (the ‘centre’) (Rist 2002). Vol. 1, No. 1 Journal of Sustainable Development it emerged from the rain-fed canals. After which, the water drained to further tanks on the plains where lower castes
could access water. But in contemporary Jodhpur and especially in times of severe water shortage, such caste
differentiations have been ignored and people come together to challenge notions ‘that they are living in a water scare
environment’. But when more quantities of public water supply became available, then traditional water systems are no
longer maintained and as a result precious rainwater is lost. At this point, caste differentiations deter communities from
making collective action. This then suggested the possibility that underlying factors might be embedded within
‘explicit’ forms of contestation. Thus, this provides a second possibility to unpack the tensions in how knowledge of the
environment is being constructed - whether and how the views of communities within their local socio-political context
have been taken into consideration while constructing knowledge of the environment? it emerged from the rain-fed canals. After which, the water drained to further tanks on the plains where lower castes
could access water. But in contemporary Jodhpur and especially in times of severe water shortage, such caste
differentiations have been ignored and people come together to challenge notions ‘that they are living in a water scare
environment’. But when more quantities of public water supply became available, then traditional water systems are no
longer maintained and as a result precious rainwater is lost. At this point, caste differentiations deter communities from
making collective action. This then suggested the possibility that underlying factors might be embedded within
‘explicit’ forms of contestation. Thus, this provides a second possibility to unpack the tensions in how knowledge of the
environment is being constructed - whether and how the views of communities within their local socio-political context
have been taken into consideration while constructing knowledge of the environment? This section brought out two questions that explored the challenges in constructing knowledge of the local environment. Drawing on these two questions, the following section will build an understanding of the range of ch allenges within
‘implicit’ forms of contestation through the example of the Himalayan Ski Village project in northern India. Such an
inquiry has particularly become problematic in Third World where there is the lack of a guiding framework for
environmental research. 2. Himalayan Ski Village and ‘implicit’ forms of contestation This section first provides a backdrop to the influence of global forces on developing economies and discusses how
tourism investment has been used by multinational enterprises to engage with the environment. The ‘implicit’ form of
contestation that has largely been under-researched is then discussed by examining the Himalayan Ski Village project in
northern India. Vol. 1, No. 1 More significantly, ‘implicit’ contestations become ‘headlines’ only after the occurrence of
environmental damage and accompanying social injustices. 1.1 Different forms of contestations The caste system is a
form of social organization drawing on the ‘Brahmanic’ traditions and has existed for many centuries in many parts of
India. At the top of the caste hierarchy, are the upper castes consisting of Brahmins (priests), Rajputs (kings) who have
historically controlled the land. The middle stratum consists of peasant castes. And, at the bottom, are the landless
communities including the group of Untouchables. The respondents revealed how ‘access to water’ was shaped by an
individual’s caste identity. Prior to the introduction of public water supply, residents in Jodhpur relied on traditional
systems of water supply. However at that time, settlements were designed in such a way that upper caste households
were located on higher ground. This design consideration ensured that water was first consumed by the upper-castes as 3 3 Vol. 1, No. 1 2.2 The Himalayan Ski Village Project 2.2 The Himalayan Ski Village Project The northern state of Himachal Pradesh in India is an environmentally sensitive region where more than two-thirds of
land area comes under forest land (Winrock International India 2004). Over the last decade, there has been a rampant
sanction of projects in Himachal Pradesh ranging from dam constructions to the recent ski-village project. In this regard,
Although the extent of the Himalayan environmental degradation received scholarly attention in the early 1980s (Ives
and Messerli 1989), recent studies reveal an alarming situation with dwindling fuel wood supplies, and more frequent
occurrence of landslides (Sharma, Goel, and Minhas 1991). Of particular concern has been the increased soil erosion:
this has lead to increased sediment load in the rivers and has reduced the efficiency and lifespan of the many
hydroelectric projects in Himachal Pradesh that provide power not only to the mountain communities but also to the
neighboring states (Sharma and Minhas 1993). Of the total potential of hydroelectric power of 97000 MW in India,
21229 MW comes from Himachal Pradesh (Winrock International India 2004). Such large scale projects in sensitive
environmental regions have also affected the lives of local communities who are dependent on natural resources for
their subsistence. In this regard, many have advocated ‘sustainable livelihoods’ approach in mitigating the effects of
such projects on the livelihoods of local communities (Chambers and Conway 1992; Stonich 1998; Scoones 1998). However, amidst such alarming concerns in how large-scale projects have started to affect the livelihoods of local
communities, one of the biggest tourism projects in India was sanctioned in Himachal Pradesh in 2006 – the Himalayan
Ski Village project. The Himalayan Ski Village project was set up at Kullu valley in the state of Himachal Pradesh by
Alfred Ford, the great-grandson of Henry Ford (founder of Ford motors) who is keen on holding international ski
tournaments including the Winter Olympic Games. Drawing on his company’s success in running a ski resort at Vedli
in Colorado (USA), the Himachal Pradesh state cabinet approved the Preliminary Project Report (PPR) for the setting
up of the Rs.3500 Crore (700 million USD) Himalayan Ski Village in November 2005. 2.2 The Himalayan Ski Village Project This tourism project, also called
the ‘Fort’ is considered to be one of the biggest FDI (foreign direct investment) in India (The scale of the investment is
interesting as according to 2006-07 budget estimates, the HP state annual income is around Rs.8000 Crore or 1.6 billion
USD). In addition, the ski village project has been presented as ‘very local-friendly’, by promising to provide over 70
percent employment to the local population. The marketing schedule of the project has been spread over a period of five
years starting in 2006. The first phase of the project started early in 2007 with the establishment of the training institute
for winter sports. By early 2008, the presale of chalets and condo hotel rooms is expected to commence. The ski village
is expected to be fully ready for commercial operations by early 2011 including the development of 700 hotel rooms,
restaurants along with an 'Indian Village' shopping experience, twenty thousand square feet of convention facility and
an entertainment/performing arts centre. 2.1 Under-development in the Third World: tourism as a solution? While ‘development as modernization’ has been used by multinational enterprises as a guiding principle for tourism
investment in the developing economies, dependency theory has been used to explain how Third World countries can
assume only a passive role in deciding the nature of tourism projects implemented within their borders (Mowforth and
Munt 2003; Britton 1982). But the modernization school of thought has been criticized for adopting technocratic
approaches such as cost-benefit analysis; rather than taking into consideration the needs and priorities of local
communities (de Kadt 1979). Drawing on these arguments, many have cautioned on the perceived advantages of
tourism in addressing persistent poverty and rising inequalities in the developing world (Britton 1982). In addition,
based on the experience of past decades, such claims appear to be more of rhetoric than reality. For instance, studies
have brought out far-reaching social and environmental impacts caused by tourism projects on local communities
(Mathieson and Wall 1987; Wheeller 1997). The debates linking notions of ‘development’ to the environment raises
crucial questions as to what the role of governments and communities in the Third World might be in protecting their 4 Journal of Sustainable Development March, 2008 environment and as a result, how they can and should engage with the activities of multinational enterprises (MNE), or
enterprises that carry out its commercial operations outside its home or ‘parent’ economy (Bull 1991). To understand
the implication of MNE activity and the resultant contestations, the next section takes up the case of the Himalayan Ski
Village that is being developed by a multinational enterprise, the Himalayan Ski Village Project Company headed by
Alfred Ford. environment and as a result, how they can and should engage with the activities of multinational enterprises (MNE), or
enterprises that carry out its commercial operations outside its home or ‘parent’ economy (Bull 1991). To understand
the implication of MNE activity and the resultant contestations, the next section takes up the case of the Himalayan Ski
Village that is being developed by a multinational enterprise, the Himalayan Ski Village Project Company headed by
Alfred Ford. Vol. 1, No. 1 Vol. 1, No. 1 Secondly, of whether the views of communities within their local socio-political context were taken into consideration? Based on the Memorandum of Understanding signed in 2006, the Ski Village project excludes local/indigenous
knowledge of the environment from the policy process (Sethi 2006). In this regard, Gardner and Dekens (2007) have
shown how local/indigenous knowledge has been used to protect communities from devastating floods in the Kullu
valley – by locating the settlements at regular intervals on the hill slopes and surrounding them with areas of cultivated
land. But more recently, the value of such local/indigenous knowledge has been ignored, and where rapid deforestation
and intensification of human activities have increased the frequency and impact of floods and the damage they cause to
the fragile eco-system (Gardner 2002). So on one hand, while the local communities conceive ‘a safe and protected
environment’, the advocates of the Ski village project conceptualize the environment as synonymous with ‘rapid
deforestation’ and ‘intensification of human activities’. It becomes further problematic when local communities are
excluded from the policy process and do not have voice over ‘common property resources’. For instance, Section VII of
the MoU gives the Ski Village company “irrevocable license for the use of ski trails and making of snow and ice on
such trails for the duration of the [land] lease and for the construction of trail markers, retention ponds, underground
water lines and water pumps...”(Sethi 2006). These contradictory understandings of engaging with the environment are
seldom made explicit and where local communities remain passive players in the policy process. In addition, previous
research seems to suggest the existence of implicit forms of knowledge construction prior to implementation of the Ski
Village project – varied infrastructure provisions for different types of villages (highway villages, remote villages etc.),
cultural differences between host and tourist populations etc. (Gopinath 2001b). Thus, being positioned in a culture that
does not explicitly challenge notions of ‘environment’ conceptualized by powerful stakeholders, presents problems for
protecting the fragile eco-system. Moreover, the exploitation of natural resources through large-scale tourism investments raises questions of whether it
has compromised the livelihood opportunities of rural communities (Ellis-Jones 1999). Vol. 1, No. 1 Based on fieldwork carried out
in 2000, rural populations of the Kullu valley have sustained a traditional way of engaging with members outside their
community – through a form of community tourism – and have relied on a defined rural economic base for their
survival (Gopinath 2001b). The rural households engaging in tourist activities have traditionally welcomed tourists into
their ‘personal space’ in the form of family owned guest houses. Further, tourists are largely considered as members of
rural community and not as a community beyond the rural population. By segregating the new, elite tourists from the
host rural community, would in some ways create the notion of a ‘gated community’. However in literature, emergence
of gated communities is generally viewed as an urban phenomenon where communities (mostly upper-class families) by
virtue of their ability to pay, demand a homogenous social culture, a sense of privacy and security from an outside,
seemingly alien world (Roitman 2003). And also justification for creation of such communities has been based on
prevalence of urban violence and crime (Blakely and Snyder 1997; Caldeira 2000). The debates on ‘gated communities’
becomes interesting in the context of Himalayan Ski Village Project in Kullu valley where the residential development
is neither in an urban context nor based on a need for security. But, the notion of development here in Kullu valley, is
one of restricted access where public spaces are being privatized (Blakely and Snyder 1997; Goolbar 2002) and new
lines are being drawn between an emerging, elite tourists and the host rural community. The sustainability of
community tourism now appears threatened especially with the introduction of large scale projects like the Himalayan
Ski village project. Thus, there are also concerns that the Ski Village project will bring about greater inequality in the
region; particularly through the emergence of an elite-driven, tourism agendum (and for private use) as opposed to a
traditional, community-based tourism. 2.3 Unpacking ‘implicit’ contestations This section examines the Ski Village Project through the two questions developed earlier in this paper. Firstly, of how
the state had engaged with the local context in constructing knowledge of the environment .The role of the Himachal
Pradesh state government appears to be caught between a social objective of providing welfare support to rural areas
and to protect the environment, and an economic objective of responding to challenges and constraint of a global market
(Mathew 2005). It is true that the role of the state has been quite pronounced in Himachal Pradesh with the National
Institute of Rural Development placing the state government’s effort in first position with respect to indicators on
human development and infrastructure provision in rural areas across the country (Sanan 2004). However, the
upcoming investment opportunities in Himachal Pradesh owing to its tourism potential have in different ways put
pressure on the state government to respond adequately. This is clearly reflected in the Memorandum of Understanding
(MoU) signed by the state government and the Himalayan Ski Village (HSV) project company in 2006 (Sethi 2006). For instance, the opportunities for investment in property by the elites as well as the commencement of new chartered
flights to the region, in contrast to the development of rural roads and infrastructure, seem to suggest that role of the
state has become rather insignificant. Also, Section VII of the MoU gives the Ski Village company “water rights in the
Project Area, including the tapping of unused nallas /ground water and for building retention ponds for snowmaking
and supply to the resort village” (Sethi 2006). In addition, the sheer scale of the investment in the Ski Village project
(700 million USD) in relation to the state government’s annual budget (1.6 billion USD) point to the state in the Third
World as being a ‘passive player’ in development. Thus, rather than engaging with the local context in constructing
knowledge of the environment, the state seems to have accepted the notion of ‘environment’ as conceived by the
multinational enterprise promoting the Ski Village project – ‘that tourism investment as a means to reduce poverty and
inequality, will result in a sustainable development of the local environment’. 5 5 Journal of Sustainable Development Vol. 1, No. 1 3. Conclusion This paper explored key issues in how knowledge of the environment is developed in the Third World. Cutting across
the different aspects of such arguments, the paper showed that there are both explicit and implicit ways in which
knowledge is contested. In particular, since implicit forms are under-researched, this paper brought out key challenges
by discussing the Ski Village project. Firstly, the paper raises concerns that environmental degradation and
accompanying social impacts caused by the Ski Village project are not explicitly revealed. Such concerns point to the
influence of competing interest groups within the Kullu valley. Particularly, powerful stakeholders including those who
wish to cater for an ‘elite’ tourist population at the Ski Village project seem to be shaping the notion of ‘environment’ in
Kullu valley. That the less powerful, local communities are not involved in decisions shaping the environment seems to
downplayed in the policy process. This seems to suggest why constructions of the ‘environment’ are implicit and
exclusionary. However, such implicit forms of contestations will not prevent environmental degradation and
accompanying social impacts. But after such damage has been done, it will provide material for a range of impact
studies. Thus, the implementation of a large-scale tourism project such as the Himalayan Ski Village project in rural
areas in the developing world raises many concerns particularly in who gets to decide on the nature of such projects. In addition, the paper also raises more general concerns. It brings out challenges in the context of a developing nation
where the livelihoods of communities are greatly connected to their immediate environment. Closely linked to this are
concerns that existing approaches to environmental planning and management do not adequately make provisions for 6 Journal of Sustainable Development March, 2008 March, 2008 stakeholder involvement in making policy decisions (Oduwaye 2006). This is particularly important because
environmental projects that have been implemented without the involvement of intended beneficiaries have had limited
success (Sharp 1992). These wider understandings are hoped to inform policy in re-examining the basis for creating
knowledge of the environment particularly in the Third World particularly where such issues become ‘headlines’ only
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Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
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to Salinity: Implications for Estuarine Distribution and Invasion
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David M. Hudson1,2*, D. Joseph Sexton2,3,4, Dinsdale Wint2,5, Connor Capizzano6, and Joseph F.
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Crivello2
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1 Department of Research and Conservation, The Maritime Aquarium at Norwalk, Norwalk,
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Connecticut, United States of AmericaThe Maritime Aquarium at Norwalk, 10 N. Water Street,
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Norwalk, CT 06854
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2 Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut,
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United States of AmericaUniversity of Connecticut, Dept. of Physiology and Neurobiology, 75 N.
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Eagleville Rd. U-3156, Storrs, CT 06269-3156 USA
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3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
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USA
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4 Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
14
Mycotic Disease Branch, Atlanta, Georgia, United States of America Mycotic Disease Branch,
15
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
16
Atlanta, GA USA
17
5 Momenta Pharmaceuticals, Cambridge, Massachusetts, United States of AmericaA USA
18
6 University of Massachusetts Boston, School for the Environment, 100 William T. Morrissey
19
Blvd., Boston, MA 02125 USASchool for the Environment, University of Massachusetts at
20
Boston, Boston, Massachusetts, United States of America
21
22
*Corresponding Author: dmhudson@gmail.com
23 Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
1
to Salinity: Implications for Estuarine Distribution and Invasion
2
3
David M. Hudson1,2*, D. Joseph Sexton2,3,4, Dinsdale Wint2,5, Connor Capizzano6, and Joseph F. 4
Crivello2
5
1 Department of Research and Conservation, The Maritime Aquarium at Norwalk, Norwalk,
6
Connecticut, United States of AmericaThe Maritime Aquarium at Norwalk, 10 N. Water Street,
7
Norwalk, CT 06854
8
2 Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut,
9
United States of AmericaUniversity of Connecticut, Dept. of Physiology and Neurobiology, 75 N. 10
Eagleville Rd. U-3156, Storrs, CT 06269-3156 USA
11
3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13
4 Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
14
Mycotic Disease Branch, Atlanta, Georgia, United States of America Mycotic Disease Branch,
15
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
16
Atlanta, GA USA
17
5 Momenta Pharmaceuticals, Cambridge, Massachusetts, United States of AmericaA USA
18
6 University of Massachusetts Boston, School for the Environment, 100 William T. Morrissey
19
Blvd., Boston, MA 02125 USASchool for the Environment, University of Massachusetts at
20
Boston, Boston, Massachusetts, United States of America
21
22
*Corresponding Author: dmhudson@gmail.com
23 Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
1
to Salinity: Implications for Estuarine Distribution and Invasion
2
3
David M. Hudson1,2*, D. Joseph Sexton2,3,4, Dinsdale Wint2,5, Connor Capizzano6, and Joseph F. 4
Crivello2
5
1 Department of Research and Conservation, The Maritime Aquarium at Norwalk, Norwalk,
6
Connecticut, United States of AmericaThe Maritime Aquarium at Norwalk, 10 N. Water Street,
7
Norwalk, CT 06854
8
2 Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut,
9
United States of AmericaUniversity of Connecticut, Dept. of Physiology and Neurobiology, 75 N. 10
Eagleville Rd. U-3156, Storrs, CT 06269-3156 USA
11
3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13 Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
1
to Salinity: Implications for Estuarine Distribution and Invasion
2
3
David M. Hudson1,2*, D. Joseph Sexton2,3,4, Dinsdale Wint2,5, Connor Capizzano6, and Joseph F. 4
Crivello2
5
1 Department of Research and Conservation, The Maritime Aquarium at Norwalk, Norwalk,
6
Connecticut, United States of AmericaThe Maritime Aquarium at Norwalk, 10 N. Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
1 Physiological and Behavioral Response of the Asian Shore Crab, Hemigrapsus sanguineus,
1
to Salinity: Implications for Estuarine Distribution and Invasion
2
3
David M. Hudson1,2*, D. Joseph Sexton2,3,4, Dinsdale Wint2,5, Connor Capizzano6, and Joseph F.
4
Crivello2
5
1 Department of Research and Conservation, The Maritime Aquarium at Norwalk, Norwalk,
6
Connecticut, United States of AmericaThe Maritime Aquarium at Norwalk, 10 N. Water Street,
7
Norwalk, CT 06854
8
2 Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut,
9
United States of AmericaUniversity of Connecticut, Dept. of Physiology and Neurobiology, 75 N.
10
Eagleville Rd. U-3156, Storrs, CT 06269-3156 USA
11
3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13
4 Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
14
Mycotic Disease Branch, Atlanta, Georgia, United States of America Mycotic Disease Branch,
15
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
16
Atlanta, GA USA
17
5 Momenta Pharmaceuticals, Cambridge, Massachusetts, United States of AmericaA USA
18
6 University of Massachusetts Boston, School for the Environment, 100 William T. Morrissey
19
Blvd., Boston, MA 02125 USASchool for the Environment, University of Massachusetts at
20
Boston, Boston, Massachusetts, United States of America
21
22
*Corresponding Author: dmhudson@gmail.com
23 Water Street,
7
Norwalk, CT 06854
8
2 Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut,
9
United States of AmericaUniversity of Connecticut, Dept. of Physiology and Neurobiology, 75 N. 10
Eagleville Rd. U-3156, Storrs, CT 06269-3156 USA
11
3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13
4 Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
14
Mycotic Disease Branch, Atlanta, Georgia, United States of America Mycotic Disease Branch,
15
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
16
Atlanta, GA USA
17
5 Momenta Pharmaceuticals, Cambridge, Massachusetts, United States of AmericaA USA
18
6 University of Massachusetts Boston, School for the Environment, 100 William T. Morrissey
19
Blvd., Boston, MA 02125 USASchool for the Environment, University of Massachusetts at
20
Boston, Boston, Massachusetts, United States of America
21
22
*Corresponding Author: dmhudson@gmail.com
23 3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13 3 Department of Biology, Georgia State University, Atlanta, Georgia, United States of AmericaA
12
USA
13
4 Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
14
Mycotic Disease Branch, Atlanta, Georgia, United States of America Mycotic Disease Branch,
15
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control,
16
Atlanta, GA USA
17
5 Momenta Pharmaceuticals, Cambridge, Massachusetts, United States of AmericaA USA
18
6 University of Massachusetts Boston, School for the Environment, 100 William T. Morrissey
19
Blvd., Boston, MA 02125 USASchool for the Environment, University of Massachusetts at
20
Boston, Boston, Massachusetts, United States of America
21
22
*Corresponding Author: dmhudson@gmail.com
23 Abstract
9 The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky
10
intertidal zone of the western north North Atlantic. A likely contributor to this colonization is that
11
H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through
12
a greater geographic area of estuariesadequately defend shelter from competitors within the mid
13
and upper intertidal zone. This studyWe investigatused an effective approached the salinity effects
14
on this animal question by observing survival across a range of salinities, and also running trials
15
to determine the maintenance of hemolymph osmolality under different salinities, and behavioral
16
preference for and avoidance of salinities. We find that H. sanguineus showeds high survival
17
across a broad range of salinities, has had little change in hemolymph osmolality over a short-term
18
salinity shock, and behaviorally distinguishes distinguished between salinities when presented
19
with a choice, regardless ounder both f acclimation salinitiesy of 5 PSU or 35 PSU. Such results
20
suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal
21
zone, yet ishas a capable of willingness to physically movinge to a more optimal salinity. This
22
enhances their competitiveness as an invader, particularly in survivingal of lower salinities that
23 present PSU water strategies in ballast waterchallenges during high-precipitation events in rocky
1
intertidal areas, and partially explains this species’ dominance in this habitat type. 2
3
4
5
6
7
8
9
10
The invasive Asian shore crab, Hemigrapsus sanguineus, is aA particularly successful
11
invasive decapod crustacean species is the invasive Asian shore crab, Hemigrapsus sanguineus,
12
which is now found in estuaries and open coasts in areas along the western Nnorth Atlantic coast
13
(Lohrer et al., 2000; Brousseau et al., 2002) and western Europe, displacing resident species
14
(Lohrer et al., 2000; Brousseau et al., 2002; van den Brink, Wijnhoven & McLay, 2012;
15
Landschoff et al., 2013; Gothland et al., 2013; Gothland et al., 2014). The species has become the
16
most abundant crab in the rocky intertidal in New England (McDermott, 1998; Lohrer &
17
Whitlatch, 2002; Kraemer et al., 2007) since it was first found in New Jersey in 1988 ((McDermott,
18
1998; Williams & McDermott, 1990; Lohrer & Whitlatch, 2002; Kraemer et al., 2007; O’Connor,
19
2014)Williams & McDermott, 1990). Abstract
9 Previous work in this lab and by others investigated the
20
behavioral response of the intertidal and subtidal community to this species’ presence (Hudson et
21
al., 2016) to test the effect of this new member of the community on its neighbors(Epifanio, 2013;
22
Hudson et al., 2016). Conspecific tolerance also enhances its success in overcoming resistance to
23 behavioral response of the intertidal and subtidal community to this species’ presence (Hudson et
21 system by a particular species by incorporating a community component. This is similar to the
4 biologically-based system with five overlapping zones defined for fishes and invertebrates by
5 Bulger et al. (1993), in which zones include: 1) freshwater to 4 PSU; 2) 2 PSU to 14 PSU; 3) 11
16 PSU to 18 PSU; 4) 16 PSU to 27 PSU; and 5) 24 PSU to fully marine. Of these, H. sanguineus
17
would likely reside in zones 4 and 5. This idea has been visited beforeS (Gunter, 1961; Kneib,
18
1984), so this paradigmalinity tolerance may benefitcould therefore be used in the management of
19 PSU to 18 PSU; 4) 16 PSU to 27 PSU; and 5) 24 PSU to fully marine. Of these, H. sanguineus
17 PSU to 18 PSU; 4) 16 PSU to 27 PSU; and 5) 24 PSU to fully marine. Of these, H. sanguineus
17 would likely reside in zones 4 and 5. This idea has been visited beforeS (Gunter, 1961; Kneib,
18
1984), so this paradigmalinity tolerance may benefitcould therefore be used in the management of
19
resources in the context of locational risk for invasion by a particular species. 20 maenas (Towle & Kays, 1986; Cieluch et al., 2004). Crabs osmoregulate utilizing the posterior
12 maenas (Towle & Kays, 1986; Cieluch et al., 2004). Crabs osmoregulate utilizing the posterior
12 (
y
)
g
g
p
gill filaments (Koch, 1954; Burnett & Towle, 1990; Lucu & Towle, 2003), with far greater Na+/K+
13 gill filaments (Koch, 1954; Burnett & Towle, 1990; Lucu & Towle, 2003), with far greater Na+/K+
13 ATPase transport proteins expressed in the posterior gill than in the anterior gill (Burnett & Towle,
14 1990; Koch, 1954). Abstract
9 This transporter’s role is implicated in osmoregulation in crabs and other
15 crustacean species is well-establishedas well (Reviewed in Callinectes sapidus, Neufeld et al.,
16 1980; Uca pugilator, D’Orazio & Holliday, 1985; Uca pugnax, Holliday, 1985; Pacifasticus
17 leniusculus, Henry & Wheatly, 1988; Artemia salina, Holliday et al., 1990; Callinectes sapidus
18 leniusculus, Henry & Wheatly, 1988; Artemia salina, Holliday et al., 1990; Callinectes sapidus
18
and Callinectes similis, Piller et al., 1995; Hemigrapsus nudus, Corotto & Holliday, 1996;
19
Carcinus maenas, Henry et al., 2002 [Reviewed in Lucu & Towle 2003]; Scylla paramamosain,
20
Macrophthalmus banzai, Macrophthalmus abbreviates, Uca lactea, Uca formosensis, Ocypode
21
stimpsoni, Chasmagnathus convexus, Helice formosensis, Eriocheir sinensis, Hemigrapsus
22
sanguineus, Hemigrapsus penicillatus, Perisesarma bidens, Chiromantes dehaani, Tsai & Lin,
23 )
g
g
y p
y
p
y
time of exposure, along with behavior, can therefore be a useful determinant of the implications
2
of salinity change in the whole animal. 3
Salinity stress for H. sanguineus experiences salinity stress belowseems to begin at 15 PSU
4
regardless of acclimation seawater, indicated by increased heart rate and activity level (Depledge,
5
1984). The congener Hemigrapsus crenulatus shows increased oxygen consumption as salinity
6
stress increases (as salinity decreases), strong hyper regulation at low salinities, with increases in
7
regulatory capacity as crab size increases (Urzúa & Urbina, 2017). However, this species is easily
8
exposed to this level of salinities below 15 PSUy during a freshwater event (i.e., rain, snow) in the
9
intertidal zone. Tsai & Lin (2007) noticed little decrease in Na+/K+ ATPase activity in H. 10
sanguineus between 5 PSU and 35 PSU treatments, while optima studies of congeners
11
Hemigrapsus H. crenulatus (Urbina et al., 2010) and Hemigrapsus takanoi (Shinji et al., 2009)
12
determined a 21 PSU optimum and 24.4 PSU optimum, respectively. Similarly, our previous initial
13
gill work found no significant change in Na+/K+ ATPase activity in posterior gill of H. sanguineus
14
when exposed to 35 PSU, 15 PSU, or 5 PSU seawater for 7 days, but did see observe a short-term
15
increase in activity at 2 and 4 hours post-treatment for 15 PSU treatments (Hudson, 2011). 16
Therefore, H. sanguineus has similar osmoregulatory ability with this transporter regardless of
17
treatment, but may be able to increase its activity in the short term. 18 Salinity stress for H. Abstract
9 As cChange in salinity is one of the most common
3
forms of stress in the intertidal zone in estuaries, and several invasive crab species are known to
4
be euryhaline in response (and therefore have the ability to osmoregulate well (Reisser & Forward, 1991; Henry et al., 2006; Roche et al., 2009; Fowler
5
et al., 2011)., Tthis underscores the value here is of a need to investigate how broad salinity tolerancesunderstanding how physiological capacity is related to
6
behavioral choice or avoidance, since both contribute to t are implicated in the invasiveness of a species, i.e., how
7
well a species reproduces and extends its range from its introduction point and starts populations
8
in new places ( (as defined by Rejmánek, 2011). 9
To investigate this interaction between physiology and behavior, the work reported here
10
includes physiological tolerance (i.e., maintenance of hemolymph ion concentration) and survival,
11
but also incorporates the behavioral preference of the animalH. sanguineus as an indicator of true risk of exposurhow well they
12
can avoid riske, mainly utilizing three methods: survival, maintenance of internal ion concentration, and behavioral choice of salinity. With the apparent advantage of H. sanguineus in surviving stressful changes in salinity during ocean crossings, it may arrive with more founding members and be more likely to establish in new areas. Since little change was detectable in gill physiology in previous work, we took a behavioral
13
approach for this work to look atinvestigated sublethal effects by quantifying behavioral avoidance and
14
hemolymph osmolality change, along with investigating differences in overall survivorship over
15
time. This tests the idea that H. sanguineus has an ability to tolerate wide salinity changes for a
16
significant amount of time, and can also behaviorally avoid maladaptive stressful salinities at small spatial
17
scales, as have other species (Teal, 1958; Lagerspetz & Mattila, 1961; Jansson, 1962; Thomas et
18
al., 1981; Ameyaw-Akumfi & Naylor, 1987; McGaw & Naylor, 1992a; McGaw & Naylor, 1992b). 19
This salinity-tolerance character is clearly important in determining invasiveness, particularly in
20
decapods, and sheds light on potential areas they can invade and environments they can alter. 21
Particularly, this research area provides information on the effectiveness of ballast exchange
22
methods, as this is an a major vector for invasive species introduction (Hulme, 2009). 23 Commented [DH1]: Moved to conclusions and edited. Abstract
9 sanguineus experiences salinity stress belowseems to begin at 15 PSU
4
regardless of acclimation seawater, indicated by increased heart rate and activity level (Depledge,
5
1984). The congener Hemigrapsus crenulatus shows increased oxygen consumption as salinity
6
stress increases (as salinity decreases), strong hyper regulation at low salinities, with increases in
7
regulatory capacity as crab size increases (Urzúa & Urbina, 2017). However, this species is easily
8
exposed to this level of salinities below 15 PSUy during a freshwater event (i.e., rain, snow) in the
9
intertidal zone. Tsai & Lin (2007) noticed little decrease in Na+/K+ ATPase activity in H. 10
sanguineus between 5 PSU and 35 PSU treatments, while optima studies of congeners
11
Hemigrapsus H. crenulatus (Urbina et al., 2010) and Hemigrapsus takanoi (Shinji et al., 2009)
12
determined a 21 PSU optimum and 24.4 PSU optimum, respectively. Similarly, our previous initial
13
gill work found no significant change in Na+/K+ ATPase activity in posterior gill of H. sanguineus
14
when exposed to 35 PSU, 15 PSU, or 5 PSU seawater for 7 days, but did see observe a short-term
15
increase in activity at 2 and 4 hours post-treatment for 15 PSU treatments (Hudson, 2011). 16
Therefore, H. sanguineus has similar osmoregulatory ability with this transporter regardless of
17
treatment, but may be able to increase its activity in the short term. 18 Species’ responses to gradients are particularly important in determining where they will
19
fall within a physical range (Case & Taper, 2000), so a wider tolerance will mean a wider
20
geographic footprint is possible. Specifically, salinity tolerance levels can greatly alter distribution
21
of species along a coast (Teal, 1958; Barnes, 1967; Engel, 1977; Felder, 1978; Young, 1978;
22
Young, 1979; Rabalais & Cameron, 1985; Hulathduwa et al., 2007; Fowler et al., 2011; DMH
23 pers. obs.). Freshwater events are common in spring and fall along the eastern coast of the United States, butestuarine areas, and salinity can also change on an
1
hourly timescale with the tides, meaning that organisms living there must rapidly manage these
2
challenges behaviorally and/or physiologically. Abstract
9 approach for this work to look atinvestigated sublethal effects by quantifying behavioral avoidance and
14 hemolymph osmolality change, along with investigating differences in overall survivorship over
15 time. This tests the idea that H. sanguineus has an ability to tolerate wide salinity changes for a
16 1
2
Methods
3
Crabs Adult crabs with carapace widths between 15 mm and 34 mm were collected by
4
hand off Avery Point in Groton, Connecticut, USA under Connecticut Department of
5
Environmental Protection Scientific Collector’s Permits # SC-06040 and # SC-09015. Crabs Crabs
6
were acclimated for at least 14 days in holding tanks at 35 PSU before use. 7
8
Survival
9
A lab-based holding study was performed to evaluate the survival of H. sanguineus
10
immersed into a broad range of salinity treatments typical for euryhaline species. Specifically,
11
cCrabs were exposed to salinity treatments of 1 PSU, 5 PSU, 10 PSU, 15 PSU, and or 35 PSU over
12
for 14 days, given the observed ability of members of the genus Hemigrapsus genus to tolerate
13
low salinities for extended periods of time (McGaw, 2001; Tsai & Lin, 2007). In addition to this
14
typical range of salinities, aThe treatment of 1 PSU treatment, in particular, was included to
15
simulate the use of nearly freshwater surface conditions during precipitation events in estuaries
16
and tide poolsballast in transoceanic shipping as an invasive species control measure. Specimens
17
were kept in tanks at room temperature (~20 °C ) that corresponded with spring and fall
18
environmental conditions from the original capture location, Long Island Sound, including a 12-
19
hour light/dark cycle. Crabs were held in groups, and cannibalism was accounted for as a cause of
20
mortality if it occurred upon observation of mortality events, as were molt failures. Each salinity
21
treatment consisted of 20 males and 20 females, which were fed with shrimp pellets every day to
22 Methods
3 satiety. Crab survival was monitored daily over the course of the 14-day experimental trial where
1
dead specimens were removed upon confirmation. 2
H. sanguineus survivorship over time (i.e., the survival function) was evaluated using
3
methods traditionally used in the context of longitudinal survival analyses. In contrast to “cross-
4
sectional” data, which yield numbers of alive and dead specimens at a specific point in time,L
5
“longitudinal” data provide information on the time animals either died or were last observed alive
6
due to ongoing monitoring of survival (Cox & Oakes, 1984; Benoit et al., 2015). Such longitudinal
7
data for H. sanguineus consist of records for each crab specimen, which include information about
8
the occurrence and timing of an event as well as salinity treatment values and sex that might affect
9
survival (i.e., covariates). Crabs that were still alive when last observed or at the end of the
10
experiment were treated as “right-censored” observations, for which where their time of death wais
11
unknown either because mortality did not occur or was not observed during the holding period the
12
event was not achieved or data collection was too short (Singer & Willett, 2003). 13
A set of non- and semi-parametric longitudinal analyses were first employed to select and
14
evaluate the effect of salinity treatment and sex on a parsimonious set of covariates that best
15
describe the H. sanguineus survival function. The semi-parametric Cox proportional-hazards
16
regression model was initially used given its ability to simultaneously evaluate the additive effect
17
of multiple covariates (Cox, 1972). Preliminary regression model results suggested that the
18
survival function was only dependent upon salinity (Table S1). Consequently, the non-parametric
19
Kaplan-Meier estimator of survival was used to preliminarily identify if each salinity treatment
20
produced distinct survival functions (Kaplan & Meier, 1958; Cox & Oakes, 1984; Fig. S1). The
21
Kaplan-Meier estimator follows the proportion of individuals alive as a function of time in the
22 Commented [DH2]: Comments from CC, other marked-up
document. Commented [DH2]: Comments from CC, other marked-up
document. Commented [DH3]: Comments from CC, other marked-up
document. Commented [DH3]: Comments from CC, other marked-up
document. absence of censored observations and is well-suited for univariate analyses with multiple factor
1
levels. 2 absence of censored observations and is well-suited for univariate analyses with multiple factor
1
levels. Methods
3 2 The Peto & Peto modification of the Gehan-Wilcoxon was then used to accept or reject the
3
null hypothesis that there was no statistical difference between survival functions (Harrington &
4
Fleming, 1982). Multiple pairwise comparisons using the Peto & Peto test with Benjamini-
5
Hochberg corrections to adjust for significance value inflation were subsequently applied to
6
determine if and which salinity-dependent survival functions were statistically distinct from one
7
another. Salinity-dependent survival functions that failed to reject the null hypothesis were
8
subsequently combined. Preliminary results indicated survival was only significantly different
9
between the 1 PSU and the 10 PSU, 15 PSU, and 35 PSU treatments (p < 0.01), and also between
10
5 PSU and 35 PSU (p < 0.05) (Table S2). However, due to inconsistent significance values between
11
salinity treatments (Table S2, Figure S1), no objective procedure could be performed to combine
12
the survival functions with confidence given inconsistencies between pairwise comparison
13
significance values (Table S2). For instance, while survival was not statistically different between
14
the 1 PSU and 5 PSU as well as the 5 PSU and 10 PSU groups (p>0.05), they could not be
15
combined since survival between the 1 PSU and 10 PSU groups was statistically significant (p <
16
0.01). Coarser salinity categories were therefore examined and presented for easier interpretation
17
of results, specifically fresh (1 PSU), estuarine (5 – 15 PSU), and seawater (35 PSU) salinity
18
groups. 19
All survival-related analyses were performed using the statistical computing software R
20
(version 3.4.2; R Core Team, 2017) with added functionality from the associated package
21
“survival” (version 2.38; Therneau, 2015) and “survminer” (version 0.4.0; Kassambara &
22
Kosinski, 2017). Statistical significance was accepted at a level of p < 0.05. 23 Commented [DH4]: Comments from CC, other marked-up
document. All survival-related analyses were performed using the statistical computing software R
20
(version 3.4.2; R Core Team, 2017) with added functionality from the associated package
21
“survival” (version 2.38; Therneau, 2015) and “survminer” (version 0.4.0; Kassambara &
22
Kosinski, 2017). Statistical significance was accepted at a level of p < 0.05. 23 1 Salinity Preference
2 Individual crabs were presented with Salinity comparisons were varied
7
between pairwise choices between 5, 15, orand 35 PSU for a period of 12 hours, with final location
8
at 12 hoursdata recordedanalyzed, for 25 replicates for each sex and acclimation at two acclimation
9
temperatures (total of ~100 per salinity comparison). Due to the initial high activity of this crab
10
species, final location at 12 hours was considered the “chosen” condition. 11
Behavioral choice of salinity data were analyzed for binary choice by Chi-Square test, and
12
then the probability of leaving starting salinity was analyzed by one-way ANOVA for each of
13
starting salinity, sex, acclimation salinity, and temperature. In order to test interactive effects
14
Interaction between those four factors, multiple two-way was tested by a multi-way ANOVAs
15
were completed with the addition of multiple pairwise comparisons, in the statistical computing
16
software R (version 3.4.2; R Core Team, 2017). 17
18
19
Hemolymph Response to Salinity Change:
20
To quantify hemolymph osmolality response to salinity shock, crabs were acclimated to
21
full-strength seawater salinity (32 PSU) for 14 daystwo weeks to normalize gene expression (Tsai
22
& Lin, 2007), then 40 specimens were exposed for seven days (168 hours) to each of the following
23 a ballast tank, unlike the rapid changes (i.e., ~6 hours) that occur in the littoral zone. Given acclimation
1
conditions have been shown to modify preference behavior in other crustacean species
2
(Hernández, 2006; Gross, 1957), we investigated whether acclimation conditions (temperature and
3
salinity) affected the level of impact this original acclimation period had upon salinity preference. 4
We determinedSubsequent tests were performed to determine whether specimens had any
5
preference for a lower or higher salinity based upon the salinity and temperature during their
6
acclimation period. Individual crabs were presented with Salinity comparisons were varied
7
between pairwise choices between 5, 15, orand 35 PSU for a period of 12 hours, with final location
8
at 12 hoursdata recordedanalyzed, for 25 replicates for each sex and acclimation at two acclimation
9
temperatures (total of ~100 per salinity comparison). Due to the initial high activity of this crab
10
species, final location at 12 hours was considered the “chosen” condition. Salinity Preference
2 Given acclimation
1
conditions have been shown to modify preference behavior in other crustacean species
2
(Hernández, 2006; Gross, 1957), we investigated whether acclimation conditions (temperature and
3
salinity) affected the level of impact this original acclimation period had upon salinity preference. 4
We determinedSubsequent tests were performed to determine whether specimens had any
5
preference for a lower or higher salinity based upon the salinity and temperature during their
6
acclimation period. Individual crabs were presented with Salinity comparisons were varied
7
between pairwise choices between 5, 15, orand 35 PSU for a period of 12 hours, with final location
8
at 12 hoursdata recordedanalyzed, for 25 replicates for each sex and acclimation at two acclimation
9
temperatures (total of ~100 per salinity comparison). Due to the initial high activity of this crab
10
species, final location at 12 hours was considered the “chosen” condition. 11
Behavioral choice of salinity data were analyzed for binary choice by Chi-Square test, and
12
then the probability of leaving starting salinity was analyzed by one-way ANOVA for each of
13
starting salinity, sex, acclimation salinity, and temperature. In order to test interactive effects
14
Interaction between those four factors, multiple two-way was tested by a multi-way ANOVAs
15
were completed with the addition of multiple pairwise comparisons, in the statistical computing
16
software R (version 3.4.2; R Core Team, 2017). 17
18
19
Hemolymph Response to Salinity Change:
20
To quantify hemolymph osmolality response to salinity shock, crabs were acclimated to
21
full-strength seawater salinity (32 PSU) for 14 daystwo weeks to normalize gene expression (Tsai
22
& Lin, 2007), then 40 specimens were exposed for seven days (168 hours) to each of the following
23 a ballast tank, unlike the rapid changes (i.e., ~6 hours) that occur in the littoral zone. Given acclimation
1
conditions have been shown to modify preference behavior in other crustacean species
2
(Hernández, 2006; Gross, 1957), we investigated whether acclimation conditions (temperature and
3
salinity) affected the level of impact this original acclimation period had upon salinity preference. 4
We determinedSubsequent tests were performed to determine whether specimens had any
5
preference for a lower or higher salinity based upon the salinity and temperature during their
6
acclimation period. Salinity Preference
2 The behavioral preference of H. sanguineus to varying for specific salinities was evaluated
3
through a separate lab-based experimental trial with new specimens. This study utilizedSince past
4
literature primarily offered choice between only two salinities, (Teal, 1958; Lagerspetz & Mattila,
5
1961; Jansson, 1962; Thomas et al., 1981; Ameyaw-Akumfi & Naylor, 1987; McGaw & Naylor,
6
1992a, McGaw & Naylor, 1992b), we designed an arena that contained two 10 cm x 10 cm
7
chambers, each with a different salinity and bubbled with an airstone, connected by an above-
8
water bridge to offer a binary choice, consistent with past studies (Teal, 1958; Lagerspetz &
9
Mattila, 1961; Jansson, 1962; Thomas et al., 1981; Ameyaw-Akumfi & Naylor, 1987; McGaw &
10
Naylor, 1992a, McGaw & Naylor, 1992b). H. sanguineus is a highly mobile crab that in initial
11
trials actively ran back and forth between the chambers over the bridge, meaning that it was able
12
to effectively sample the conditions of both chambers. Therefore, individual crabs could chose to
13
either 1) stay in the initial chamber, 2) relocate to the second chamber by using the connecting
14
bridge, or 3) remain on the bridge since these are intertidal crabs. Because this species exists in
15
estuaries in the field and therefore along a broad salinity gradient, individual H. sanguineus were
16
acclimated to either 5 PSU or 35 PSU for a period of at least 14 days prior to the experiment to
17
test the effects of acclimation. Since these are poikilothermic animals, activity increases with
18
temperature. As such, tTemperature effects on preference were quantified by acclimating
19
specimens at either 10 °C or 20 °C at those same salinities to simulate seasonal water temperature
20
differences and gauge the general capacity of the animals to behaviorally regulate during different
21
seasons. An eExtended acclimation times up toof two weeks 14 days wasere used to account for
22
longer exposure to lower salinities further up an estuary and during freshwater influx eventsor in
23 trials actively ran back and forth between the chambers over the bridge, meaning that it was able
12 a ballast tank, unlike the rapid changes (i.e., ~6 hours) that occur in the littoral zone. Salinity Preference
2 11
Behavioral choice of salinity data were analyzed for binary choice by Chi-Square test, and
12
then the probability of leaving starting salinity was analyzed by one-way ANOVA for each of
13
starting salinity, sex, acclimation salinity, and temperature. In order to test interactive effects
14
Interaction between those four factors, multiple two-way was tested by a multi-way ANOVAs
15
were completed with the addition of multiple pairwise comparisons, in the statistical computing
16
software R (version 3.4.2; R Core Team, 2017). 17
18
19
Hemolymph Response to Salinity Change:
20
To quantify hemolymph osmolality response to salinity shock, crabs were acclimated to
21
full-strength seawater salinity (32 PSU) for 14 daystwo weeks to normalize gene expression (Tsai
22
& Lin, 2007), then 40 specimens were exposed for seven days (168 hours) to each of the following
23 salinity treatments: 32 PSU (control), 17.5 PSU, 10 PSU, and 5 PSU. Five animals were taken out
1
of the 32 PSU seawater after the 14-day acclimation period and used as the initial time point A
2
shared “time zero” was used for all treatments from five animals collected after the two-week
3
acclimation. A salinity of 32 PSU was used for the full-strength seawater treatment and salinity of
4
17.5 PSU for the middle salinity treatment, along with low salinity exposures at 10 PSU and 5
5
PSU. Due to high mortality in the survival study for some of the lowest salinities (Figs. 1, S1), the
6
experiment was only run for 7 days. Crab hemolymph was sampled from 5 new animals at each
7
post-exposure time points of 1, 2, 4, 8, 24, 48 and, 72, and 168 hours, and at (7 days (168 hours)
8
and frozen at -80 °C. The early time points were chosen to compare with results for other crabs,
9
as work in another euryhaline crab, Callinectes sapidus, supports little change in observed
10
hemolymph osmolality values within 12 hours (Sommer & Mantel, 1988; Towle, 1997; Henry et
11
al., 2002) of salinity shock. Hemolymph samples were taken with the use of a 21 gauge syringe
12
inserted into the crab’s branchial cavity, and stored at -80 °C in 1.5 mL centrifuge tubes. Samples’
13
were quantified for hemolymph osmolality was measured after removal from thaw, centrifuged
14
for 1 minute at 10,000 rpm, and run in duplicate on a Wescor 5100C vapor pressure osmometer. Salinity Preference
2 15
Samples were run in duplicate, with the average of the two taken as the value for that sample. 16
These results were then analyzed by two-way ANOVA for effects of exposure time and treatment,
17
along with interactive effects between the two. A repeated measures ANOVA would be
18
inappropriate to analyze hemolymph data, as the individuals were sacrificed at each time point for
19
a separate study of the upregulation of proteins in posterior gill tissue. Each time point was
20
analyzed for differences between the four salinity treatments by a one-way ANOVA with Tukey
21
post-hoc analysis. Time zero was left out of analysis since it was the same for all four treatments. 22 of the 32 PSU seawater after the 14-day acclimation period and used as the initial time point A
2 shared “time zero” was used for all treatments from five animals collected after the two-week
3 acclimation. A salinity of 32 PSU was used for the full-strength seawater treatment and salinity of
4 All statistics were completed in in R statistical computing software (version 3.4.2; R Core Team,
1
2017). 2
3
4
Results
5
6
Survival
7
The semi-parametric Cox proportional hazards regression model indicated that the H. 8
sanguineus survival function was only dependent on salinity treatment with no effect from the sex
9
covariate (Table S1). When survival data were grouped into broader salinity designations for ease
10
of interpretation and applicability to representative scenarios, tThe non-parametric Kaplan-Meier
11
estimator suggested indicated that H. sanguineus survival functions for differed between the fresh,
12
estuarine, and seawater salinity groups were distinct (Fig. 1), which was reaffirmed by the Peto &
13
Peto test against all three survival functions (χ2 = 26.8, d.f. = 2, p <<0.001). No effect of sex was
14
seen on survival as previously mentioned (Table S1). Moreover, multiple pairwise comparisons
15
between all broader salinity survival functions were statistically different, thereby confirming
16
survival was distinct between groupings (Table S3). For instance, tAll multiple pairwise
17
comparisons between broad salinity survival functions failed to reject the null hypothesis and
18
consequently remained separate from one another (Table S3). he difference in survival between
19
the 35 PSU (highest survival) and pooled 5 PSU/10 PSU/15 PSU treatments (high survival but
20
some mortality) was significant (p < 0.05). Commented [CC5]: Dave; not entirely sure this is
necessary since it was mentioned as preliminary information
in the methods. All statistics were completed in in R statistical computing software (version 3.4.2; R Core Team,
1 All statistics were completed in in R statistical computing software (version 3.4.2; R Core Team,
1
2017).
2 Salinity Preference
2 There were also significant survival differences
21
between the 35 PSU treatment and the 1 PSU treatment (lowest survival rate) (p < 0.001), and
22
between 1 PSU (lowest survival) and the pooled 5 PSU/10 PSU/ 15 PSU treatments (high survival
23 Peto test against all three survival functions (χ2 = 26.8, d.f. = 2, p <<0.001). No effect of sex was
14 between all broader salinity survival functions were statistically different, thereby confirming
16 survival was distinct between groupings (Table S3). For instance, tAll multiple pairwise
7 but some mortality) (p < 0.001) (Table S3). So, it seems that while there is clearly a difference
1
between the highest and lowest salinity treatments, the middle three salinity treatments have a
2
moderate survival rate that is significantly different from both the upper and lower salinity
3
treatments. Interestingly, survival did not differ significantly among the three salinity groups over
4
the first 7 days of observation (p = 0.421). 5
6 Salinity Preference
7 Behavioral preference experiments indicated a significant preference (χ2 = 5.88, d.f. = 1, p
8
< 0.05, n = 75) of H. sanguineus for 35 PSU over 5 PSU seawater at 20 °C regardless of acclimation
9
(Fig. 2D), but no significant preference was exhibited when individuals were given a choice
10
between 35 PSU and 15 PSU (χ2 = 0.653, d.f. = 1, p > 0.05, n = 75), nor for 5 PSU and 15 PSU
11
PSU (χ2 = 1.174, d.f. = 1, p > 0.05, n = 69). This significance appears to come from two sources. 12
Males at 20 °C (Fig. 2B) showed a significant preference for 35 PSU over 5 PSU (χ2 = 9.52, d.f. =
13
1, p < 0.01, n = 42), and also have had a significant difference in preference towards 35 PSU when
14
first acclimated to 35 PSU (χ2 = 7.2, d.f. = 1, p < 0.01, n = 20). Crabs that were acclimated to 5
15
PSU prior to the experiment significantly chose 35 PSU over 5 PSU (χ2 = 4.8, d.f. = 1, p < 0.05, n
16
= 30). Aside from these, there are no other no significant effects of acclimation on final salinity
17
choice in this instance. 18 These data were also analyzed by whether the crab left the starting salinity in any
19
experiments (5 PSU, 15 PSU, or 35 PSU). There was a significant effect of starting salinity on
20
whether crabs where more or less likely to leave (one-way ANOVA, F = 32.55, d.f. = 2, p <<
21
0.001, n = 635). Interactions between factors were not significant in the two-way ANOVAs used
22
to determine interactive effects between acclimation salinity and starting salinity nor between
23 These data were also analyzed by whether the crab left the starting salinity in any
19
experiments (5 PSU, 15 PSU, or 35 PSU). There was a significant effect of starting salinity on
20
whether crabs where more or less likely to leave (one-way ANOVA, F = 32.55, d.f. = 2, p <<
21
0.001, n = 635). Salinity Preference
7 Interactions between factors were not significant in the two-way ANOVAs used
22
to determine interactive effects between acclimation salinity and starting salinity nor between
23 acclimation salinity and sex (Tables S4 and S5, respectively), but the interaction between starting
1 salinity and temperature was significant (Table S6), and a trend exists for an interaction between
2 sex and temperature (Table S7). Crabs that started in 5 PSU (at both temperatures), whether for 5
3 PSU x 35 PSU or 5 PSU x 15 PSU experiments, were more likely to leave that salinity (move to
4 There was a significant effect of salinity exposure to 32 PSU, 17.5 PSU, 10 PSU and 5
19
PSU seawater (n = 160 total) on hemolymph osmolality for H. sanguineus (Fig. 4) over the course
20
of seven days, by two-way ANOVA, for time of exposure (F = 4.6371, d.f. = 7, p < 0.001),
21
depending on salinity treatment (F = 12.0486, d.f. = 3, p << 0.001), and interaction between time
22
of exposure and treatment (F = 2.9242, d.f. = 21, p < 0.001). Time zero was left out of analysis
23 since it was the same for all four treatments. Salinity treatments were quite variable in hemolymph osmolality under 8 hours of exposure, bu
1
did not significantly vary differ from one another for the 8-hour, 24-hour, and 48-hour treatments, as analyzed by Tukey multiple pairwise comparisons after a one-way ANOVA for each time point. A
2
72 hours, hemolymph osmolality was significantly higher (one-way ANOVA, F = 7.055, d.f. = 3,
3
p < 0.01, n = 20) in the 32 PSU treatment than both the 5 PSU (Tukey’s post-hoc test, = 0.05, p
4
<0.01) and the 17.5 PSU (Tukey’s post-hoc test, = 0.05, p < 0.05) treatments. At 168 hours (7
5
days), hemolymph osmolality was significantly different across the four treatments (one-way
6
ANOVA, F = 9.383, d.f. = 3, p < 0.001, n = 20) and the 5 PSU treatment was significantly lower
7
in osmolality than all others (Tukey’s post-hoc test, = 0.05, vs. 32 PSU p < 0.01, vs. 17.5 PSU p < 0.01, vs. 10 PSU p < 0.01)
8
9
10
Discussion
11
That survival declines for H. sanguineus over time for the 1 PSU treatment (Fig. 1)5 PSU
12
and 1 PSU treatments (Fig. 1, Fig. Commented [CC6]: Dave; attempting to remove confusion
by removing the 5 PSU group. At this point, we should be
remain consistent with the three groups we used in the main
results. This may conflict with some data you have a few
sentences later in this paragraph. Salinity Preference
7 S1) is noteworthy, but even prolonged periods of changeover
13
of ballast water to purely freshwater influx may not be effective in keeping out H. sanguineus from
14
surviving to establish a population, since the lowest survival rate after two weeks (ocean crossing
15
time) for these animals is still 65% at 1 PSU. Maintenance of internal hemolymph osmolality over
16
7 days (Fig. 4) by this species is consistent with its ability to survive during the survival trials. The
17
point at which deaths mortality began to occur more oftenincrease in the 1 PSU treatment, (~about
18
day 5), is consistent with the significantly lower internal hemolymph osmolality for the 5 PSU
19
treatment of the hemolymph data only after 7 days of exposure. Work with other euryhaline crabs,
20
like Callinectes sapidus, supports that this ability to maintain hemolymph osmolality values within
21
12 hours (Sommer & Mantel, 1988; Towle, 1997; Henry et al., 2002) helps the animal deal with
22
estuarine osmotic stress. Since the work with This study of H. sanguineus here seesobserved no
23 since it was the same for all four treatments. Salinity treatments were quite variable in hemolymph osmolality under 8 hours of exposure, but
1 Commented [CC6]: Dave; attempting to remove confusion
by removing the 5 PSU group. At this point, we should be
remain consistent with the three groups we used in the main
results. This may conflict with some data you have a few
sentences later in this paragraph. If you disagree, feel free to remove. Commented [CC6]: Dave; attempting to remove confusion
by removing the 5 PSU group. At this point, we should be
remain consistent with the three groups we used in the main
results. This may conflict with some data you have a few
sentences later in this paragraph. If you disagree, feel free to remove. change in hemolymph osmolality for 48 hours72 hours (three days), this underscoringes the survival ability of this crab and
1
therefore its ability to invade new continentsareas. This finding adds to earlier work whichthat merely indicated
2
that stress is induced at 15 PSU seawater for H. sanguineus (Depledge, 1984). 3
However, survival of in a particular salinity is likely different from avoidance of suboptimal
4
salinities. H. Salinity Preference
7 sanguineusIt individuals maintains a functional amount of Na+/K+ ATPase (Tsai & Lin,
5
2007; Hudson, 2011) to help themit navigate this constantly changing environment, and likely uses
6
behavioral strategies to avoid suboptimal salinities. There could be a major difference with one of
7
these physiological characters and the physiological characters of the previously dominant
8
intertidal crab, Carcinus maenas, which still has a depressed hemolymph osmolality at 7 days in
9
low salinity (Siebers et al., 1982; Henry et al., 2006), that may have impacted its competitive
10
interaction with H. sanguineus and facilitated the latter’s invasiontroduction. As H. sanguineus maintains
11
internal osmolality regardless of salinity treatment over short exposures, it may be more suited
12
than competitors to the varying conditions of the intertidal zone. Therefore, it and may be able to
13
behaviorally maintain its shelter against competitors that leave under suboptimal salinity
14
conditions, much like its congener Hemigrapsus nudus (McGaw, 2001). In the littoral zone, a
15
change in salinity can occur during each tidal cycle and during a period of prolonged precipitation
16
or spring melting, allowing these species to maintain territory if they are not behaviorally affected. 17
In the behavioral salinity choice data, a true choice of salinity was a far lesser signal (Fig. 18
2), and less informative, than the analysis of crabs leaving the starting level of salinity (Fig. 3). 19
The decrease in likelihood of leaving as salinity increased is expected for optimal behavioral
20
moderation of osmotic stress, but even the level of 51.3% of crabs leaving 5 PSU after 12 hours
21
still is far less than the tidal cycle. This means that a large portion of crabs would remain in
22
intertidal areas affected by regular salinity changes. This is an important finding with respect to
23 It is likely that theA large proportion of H. sanguineus individuals stayed in stressful
17 starting salinities of 5 PSU (48.7% of the time did not leave) and 15 PSU (69.1% of the time did
18 common trait to the genus, like their congener H. nudus (McGaw, 2001), and could result in faster
1 Hemigrapsus genus by decreasing species could be successful invaders as well as this probably
3 allows for these crabs to maintain higher quality shelters at low tide while other species move
4 vertically with the changing tides. Salinity Preference
7 sanguineus in the Gulf of Maine (Delaney et al., 2012) with small-
5
scale estuarine behavior will offer a far higher resolution to spatial prediction. As invasions often
6
gain a foothold on a small scale, the overall picture must include how the species in question
7
interacts with these parameters on that the local scale, in order to more accurately predict invasion
8
success. 9
10
Conclusions
11
As survival is high in this crab under low salinity conditions, the effectiveness of ballast
12
water exchange at mid-ocean or with freshwater would likely be ineffective. Additionally, seasonal
13
freshwater input into an estuary , unless it causes particularly low salinity for a long period of time,
14
will probably not greatly affect survival of populations of this species. The findings here indicate
15
an advantage of H. sanguineus in surviving stressful changes in salinity during those periods, so
16
more founding members should survive and therefore be more likely to establish in areas where it
17
is introduced. The level at which H. sanguineus maintains its internal hemolymph osmolality,
18
along with its high survival rate in a broad salinity range in this study, highlight itssome of its
19
particularly adept osmotic regulatoryion characters. However, as the energetic demands of this
20
animal do varybecome more variable as temperature increases (Jungblut, 2017), it is important to
21
investigate the interactive effect of seasonal salinity change on likely distribution. 22 As survival is high in this crab under low salinity conditions, the effectiveness of ballast
12
water exchange at mid-ocean or with freshwater would likely be ineffective. Additionally, seasonal
13
freshwater input into an estuary , unless it causes particularly low salinity for a long period of time,
14
will probably not greatly affect survival of populations of this species. The findings here indicate
15
an advantage of H. sanguineus in surviving stressful changes in salinity during those periods, so
16
more founding members should survive and therefore be more likely to establish in areas where it
17
is introduced. The level at which H. sanguineus maintains its internal hemolymph osmolality,
18
along with its high survival rate in a broad salinity range in this study, highlight itssome of its
19
particularly adept osmotic regulatoryion characters. Salinity Preference
7 When these other species migrate into the intertidal to feed at
5 high tide, there are fewer shelters available, and thus more exposure to predators (Jones &
6 Shulman, 2008) and, at low tide, avian and terrestrial predators. These behavioral differences is
7 may be part of what is responsible for the more subtidal than intertidal distribution of C. maenas
8 we observed in other previous work (Hudson et al., 2016), not seen in the intertidal zone in
9 estuarine areas where it does not overlap with H. sanguineus (Behrens Yamada & Gillespie, 2008;
10 Amaral et al., 2009). , D. Additionally, ecreased desiccation of the smaller size of H. sanguineus
11 may make it able to usinge of microhabitats in intertidal cobble fields that cause it to experience
12 lesser desiccationwhen compared to than the larger C. maenas (Altieri et al., 2010) may also have
13 contributed to this intertidal dominance. This is also, as is true for the mud crab Eurypanopeus
14 depressus in intertidal oyster reefs (Grant & McDonald, 1979). This is particularly evident in the
15 large quantity of C. maenas found in the intertidal zone in areas where it does not overlap with H. 6
sanguineus (Behrens Yamada & Gillespie, 2008; Amaral et al., 2009), whereas H. sanguineus does
7 large quantity of C. maenas found in the intertidal zone in areas where it does not overlap with H. 16
sanguineus (Behrens Yamada & Gillespie, 2008; Amaral et al., 2009), whereas H. sanguineus does
17
not seem to have high densities in the subtidal (Hudson et al., 2016). 18 large quantity of C. maenas found in the intertidal zone in areas where it does not overlap with H. 16 g q
y
p
sanguineus (Behrens Yamada & Gillespie, 2008; Amaral et al., 2009), whereas H. sanguineus does
17
not seem to have high densities in the subtidal (Hudson et al 2016)
18 characters synthesized with ecological and biogeographical theory will help facilitate our
1
understanding of these processes. Behavior is becoming more prevalent as an explanation for
2
invasionves’ success (Weis, 2010), and this study adds to our understanding of how this invader’s
3
distribution and use pattern arises from its physiology and behavior. Combiningation of large-scale
4
physical models as done for H. Salinity Preference
7 However, as the energetic demands of this
20
animal do varybecome more variable as temperature increases (Jungblut, 2017), it is important to
21
investigate the interactive effect of seasonal salinity change on likely distribution. 22 The genus Hemigrapsus includes two prominent invaders in Europe and North America,
1
as H. takanoi demonstrates a wide salinity tolerance (Shinji et al., 2009) and invaded Europe
2
(originally misidentified as H. penicillatus) (Gollasch, 1999; Asakura & Watanabe, 2005) shortly
3
followed by H. sanguineus (d’Udekem d’Acoz & Fasse, 2002). The combination of the effects of
4
the behavioral dominance of H. sanguineus for shelter (Hudson et al., 2016) with its ability to
5
withstand salinity changes give it a unique ability to maintain valuable intertidal shelter from
6
predators and competitors during changes in tides and freshwater events. In the end, H. sanguineus
7
is a hardy, effective invasive species This in combination with broad salinity tolerances and
8
preferences , which provide it the opportunity for it to outlast competitors for shelter and food
9
when exposed to maladaptive suboptimal salinities, and allows it to survive ballast water changes. 10
11
12
Acknowledgements
13
The authors thank Stephen McCormick, Mike O’Dea, Amy Bataille and Dr. Larry Renfro
14
for advice and equipment, Igor Gurevich and the Aneskievich lab for use of imaging equipment,
15
and to Adriana Hudson, Kurt Schwenk, Courtney McGinnis, and Mike Gilman, and Barrett
16
Christie. Additional thanks to Hugues Benoît for his input and programming assistance with
17
survival modeling. 18
19
20
References
21
22
23 Altieri AH, van Wesenbeeck BK, Bertness MD, Silliman BR. 2010. Facilitation cascade drives
1
positive relationship between native biodiversity and invasion success. Ecology 91:1269–1275. 2
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1
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Amaral V, Cabral HN, Jenkins S, Hawkins S, Paula J. 2009. Comparing quality of estuarine and
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Ameyaw-Akumfi C, Naylor E. 1987. Spontaneous and induced components of salinity preference
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behaviour in Carcinus maenas. Salinity Preference
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Asakura A, Watanabe S. 2005. Hemigrapsus takanoi, new species, a sibling species of the common
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Japanese intertidal crab H. penicillatus (Decapoda: Brachyura: Grapsoidea). Journal of
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Behrens Yamada S, Gillespie G. 2008. Will the European green crab (Carcinus maenas) persist in
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5
nearshore intertidal habitats for Carcinus maenas. Estuarine, Coastal and Shelf Science 83:219–
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226. DOI: 10.1016/j.ecss.2009.03.029. 7
8
Ameyaw-Akumfi C, Naylor E. 1987. Spontaneous and induced components of salinity preference
9
behaviour in Carcinus maenas. Marine Ecology Progress Series 37:153–158. 10
11
Asakura A, Watanabe S. 2005. Hemigrapsus takanoi, new species, a sibling species of the common
12
Japanese intertidal crab H. penicillatus (Decapoda: Brachyura: Grapsoidea). Journal of
13
Crustacean Biology 25:279–292. DOI: 10.1651/C-2514. 14
15
Barnes R. 1967. The osmotic behaviour of a number of grapsoid crabs with respect to their
16 Amaral V, Cabral HN, Jenkins S, Hawkins S, Paula J. 2009. Comparing quality of estuarine and
5
nearshore intertidal habitats for Carcinus maenas. Estuarine, Coastal and Shelf Science 83:219–
6
226. DOI: 10.1016/j.ecss.2009.03.029. 7 Ameyaw-Akumfi C, Naylor E. 1987. Spontaneous and induced components of salinity preference
9
behaviour in Carcinus maenas. Marine Ecology Progress Series 37:153–158. 10 Asakura A, Watanabe S. 2005. Hemigrapsus takanoi, new species, a sibling species of the common
12
Japanese intertidal crab H. penicillatus (Decapoda: Brachyura: Grapsoidea). Journal of
13
Crustacean Biology 25:279–292. DOI: 10.1651/C-2514. 14 Asakura A, Watanabe S. 2005. Hemigrapsus takanoi, new species, a sibling species of the common
12
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Following Mixed Tree Nut Biscuit Challenge, Are the Nuts Still Included in the Diet?
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| ERROR: type should be string, got "https://doi.org/10.1007/s42399-020-00484-w\nSN Comprehensive Clinical Medicine (2020) 2:2208–2213 MEDICINE MEDICINE To the Editor Undiagnosed food allergy without known reaction to the\navoided food could result in elimination of the suspected food\nfrom a child’s diet [1]. Performing OFC to individual tree nuts\nis time consuming and impractical. Following a negative OFC\nchildren need to regularly include that food in their diet with\nevidence showing this may help to maintain tolerance to that\nfood [2]. The patients in this study are from a retrospective review of\npatients with a negative OFC to mixed tree nut biscuit per-\nformed at Princess Margaret Hospital (PMH), Western\nAustralia between 2016 and 2018. The tree nuts used in the OFC are almond, Brazil nut,\nmacadamia, cashew, pistachio, walnut, pecan, hazel nut, pine\nnut, and coconut. Mixed tree nut biscuit OFC included at least\n2 of the above nuts. The cohort of patients had predominantly negative or low\npositive skin prick test (< 6-mm mean skin prick test weal\ndiameter). Although most of the patients had a negative skin\nprick test (SPT), the challenge was done in hospital as families\nwere anxious or reluctant to introduce the nuts at home. Abstract We studied the introduction rate after a negative challenge to mixed tree nut biscuit. This is a retrospective review of patients who\nunderwent and passed mixed tree nut biscuit challenges performed at Princess Margaret Hospital (PMH) between 2016 and 2018. Follow-up phone calls were made to families to ascertain if the tree nuts included in the tree nut biscuit were still included in the\nchild’s diet 1 to 3 years following negative oral food challenge (OFC). A total of 162 children underwent mixed tree nut biscuit\nchallenge between 2016 and 2018 at Princess Margaret Hospital, Perth, Western Australia. A total of 141 (87%) passed mixed\ntree nut biscuit challenge. Of the 133 children that were contacted (8 children could not be contacted), 104 children still included\nsome or all of the challenge nuts in the child’s diet; with 24 children completely eliminating the challenge nuts (18%), 5 children\neliminated some of the challenge nuts (3.5%). We found a high introduction rate (82%); however, some families may require\nmore support to maintain the tree nuts in the child’s diet following a negative OFC. Keywords Mixed tree nut challenge Following Mixed Tree Nut Biscuit Challenge, Are the Nuts Still\nIncluded in the Diet? Benedicta Itotoh1\n& Ingrid Roche1 & Catherine Power1 Accepted: 24 August 2020\n# The Author(s) 2020\n/ Published online: 7 September 2020 1\nDepartment of Immunology, Perth Children’s Hospital,\nNedlands, Western Australia, Australia Introduction We studied the dietary introduction rate of tree nuts following\na negative OFC. Most of the children avoided tree nuts be-\ncause they were allergic to other foods or sensitized to tree\nnuts with no known clinical reaction. Some were avoiding tree\nnuts because another family member has a nut allergy. The SPT was performed and read as per the published\nguidelines of the Australasian Society of Clinical\nImmunology and Allergy [3]. The SPT size on the day of\nthe challenge was recorded. This article is part of the Topical Collection on Medicine\n* Benedicta Itotoh\nbenedicta.itotoh@health.wa.gov.au\n1\nDepartment of Immunology, Perth Children’s Hospital,\nNedlands, Western Australia, Australia The treating physician decides what nuts were included in\nthe biscuit, and the patient’s family baked and provided the\nmixed tree nut biscuit according to the recipe provided by the\nPMH Immunology Department. The biscuit was then admin-\nistered in a 5-step procedure starting with 1/16, 1/8, 1/4, 1/2,\nand the reminder of the biscuit given at 15-min intervals if\nchallenge was performed in the outpatient department * Benedicta Itotoh\nbenedicta.itotoh@health.wa.gov.au Materials and Methods To the Editor This article is part of the Topical Collection on Medicine This article is part of the Topical Collection on Medicine * Benedicta Itotoh\nbenedicta.itotoh@health.wa.gov.au SN Compr. Clin. Med. (2020) 2:2208–2213 2209 Table 1\nPossible factors associated with failed introduction following\nnegative OFC to three nuts\nSuccessful\n(eating all nuts\nPartial (eating\nsome nuts)\nUnsuccessful\n(not eating any\nof the nuts)\nTotal\n104\n5\n24\nGender\nMale\n65\n3\n8\nFemale\n39\n2\n16\nAge range\n1 year\n5 months to\n17 years\n7 months\n1 year\n8 months to\n10 years\n4 months\n1 year\n8 months to\n16 years\nSymptoms to\nchallenged nuts\nfollowing\nsuccessful OFC\n0\n1\nHives to hazel\nnut\n1\nRespiratory\nsymptoms Table 1\nPossible factors associated with failed introduction following\nnegative OFC to three nuts Data was obtained from electronic patient records as well\nas patient charts and used in strictly anonymous form, accord-\ning to the code of conduct for medical research approved by\nthe hospital’s Medical Ethical Committee (Child and\nAdolescent Health Service Safety and Quality Committee). Results A total of 162 children underwent mixed tree nut biscuit OFC\nbetween 2016 and 2018 at PMH. A total of 141 passed mixed\ntree nut biscuit challenge (87%). The majority of OFCs were\nconducted in the OPD (70.4%). All 141 patient charts were\nexamined with follow-up phone calls made to families to as-\ncertain if the nuts were still included in the child’s diet 1–\n3 years following the OFC. Eight families could not be\ncontacted. The majority were male (55%). Median age at chal-\nlenge was 8 years and 5 months (range 1 year and 7 months to\n17 years and 7 months). Twenty-seven children were admin-\nistered six nut challenge, 40 underwent 5 nut challenge, 38\nhad 4 nut challenge, 23 had 3 nut challenge, and 13 patients\nhad 2 nut challenge. (OPD) or as a 7-step procedure starting with 1/64, 1/32, 1/16,\n1/8, 1/4, 1/2, and reminder of the biscuit given at 20-min\nintervals if challenge was performed in the day procedure unit\n(DPU). The decision to either perform the challenge in the\nOPD or DPU was determined by the treating physician based\non the clinical risk of allergic reaction. Eight grams of each\nchallenge nut were included in the biscuit. Of the 133 families that were contacted, 104 families still\nincluded some or all of the challenge nuts in the child’s diet. Twenty-four patients completely eliminated the challenge\nnuts (18%) and 5 patients eliminated some of the challenge\nnuts (3.5%). Signed consent for the challenge was obtained from the\nparents prior to the challenge. Patients were recorded as a positive OFC if there were\nobjective signs of an IgE-mediated reaction as follows: angio-\nedema, generalized skin erythema, stridor, cough, wheeze, at\nleast 3 or more noncontact urticaria persisting for 5 min or\nmore, rhinoconjunctivitis, abdominal pain, vomiting, and hy-\npotension [4]. All patients had follow-up phone contact 2–\n4 weeks following the OFC. The patients were termed tolerant\nif they had a negative OFC and were tolerating the nuts at their\n2–4-week follow-up phone calls. Patients that passed the chal-\nlenge were advised to continue eating the nuts included in the\nbiscuit regularly (at least weekly). Discussion Possible factors influencing the introduction of the challenge\nnuts in the diet are shown in Table 1. Other patient character-\nistics with successful, partial, and unsuccessful challenge nut\ndietary introduction are shown in Table 1. There are no statis-\ntically relevant differences between the three groups. Fig. 1 Reasons for eliminating\nnuts from diet Fig. 1 Reasons for eliminating\nnuts from diet 2210 SN Compr. Clin. Med. (2020) 2:2208–2213 Table 2\nTree nuts included in biscuit, rate of introduction, and\nelimination from diet\nNuts included in\nmixed tree nut\nbiscuit\nNuts eliminated\nfrom diet following\nOFC\nNuts maintained\nin diet following\nOFC\nAlmond\n97\n21\n77\nBrazil nut\n97\n21\n76\nMacadamia 114\n21\n76\nHazel nut\n66\n13\n53\nPecan\n17\n1\n16\nWalnut\n76\n17\n59\nCashew\n50\n9\n41\nPistachio\n6\n1\n5\nPine nut\n23\n5\n18\nCoconut Table 2\nTree nuts included in biscuit, rate of introduction, and\nelimination from diet The other family describes exacerbation of the child’s asthma\nto all nuts. However, there was no clinical correlation between\nexposure to nuts and exacerbation of asthma with the elimination\nof nuts having no impact on the asthma symptoms. This patient\nwas challenged to almond, Brazil nut, walnut (negative SPT),\nhazel nut (2 × 2 mm SPT), and macadamia nut (1 × 1mm SPT). Of the 5 children whose families partially introduced the\ntree nuts, we note the following: The first child is the same child that excluded hazel nut\nbecause she had hives to hazel nut. She retained almond,\nBrazil, macadamia, and pine nuts in her diet. Two children ate almond only for no defined reason. One\nchild had challenge to almond, Brazil nut, walnut, and\nmacadamia, while the other child had challenge to almond,\nmacadamia, Brazil, hazel, and pine nuts. One child retained 2 of the 4 nuts included in their biscuit\nchallenge (hazel and macadamia nuts) with the remaining nuts\n(brazil and cashew nuts) excluded as this child is reported to\nbe a “fussy eater” by parents. The reasons for the 24 families who completely eliminated\nthe challenge nuts from the child’s diet, in spite of a negative\nOFC, are depicted in Fig. 1. The last child retained 3 of the 5 nuts included in their biscuit\nchallenge (almond, hazel, and macadamia nuts) with the re-\nmaining nuts (brazil and walnut) excluded based on taste. Review of Fig. Fig. 2 SPT prior to OFC Discussion 1 shows 3 children being scared to continue\neating the challenge nuts; 4 children being diagnosed with\nanother nut allergy that was not included in the OFC so the\nfamily choose to avoid all nuts; 1 child being busy with final\nyear of high school; and another child having general poor\nhealth. Average number of tree nuts in challenges was four. Macadamia was the most frequently included tree nut in the\nOFC. Table 2 is a representation of the tree nuts included in\nthe biscuit and tree nuts eliminated or maintained in the diet\nfollowing OFC. Just as macadamia, almond, and Brazil nuts\nwere most likely to be maintained in the diet, they also had\nhigh rates of elimination from diet which may be a reflection\nof the frequency these nuts were included in the OFC. More boys (90%) than girls (83%) had partially or success-\nfully introduced the nuts. Of those that continued to eat the\nnuts, all but 2 families reported there was no reactions to any\nof the nuts. One family reported that the child developed hives\nsecondary to hazel nut exposure. This child had OFC per-\nformed which included almond, hazel nut, Brazil nut,\nmacadamia, and pine nut with the following SPTs: Almond,\nBrazil nut, and macadamia are all negative SPT. Hazel nut\nSPT was 4 × 4 mm. Pine nut SPT was 3 × 3 mm. SPT ranged from negative to 7 × 5 mm prior to the test. SPT was done for all nuts included in the biscuit. Figure 2 is a\nrepresentation of the SPT performed prior to the challenge. Previous reaction to tree nuts included in the biscuit range\nfrom none (sensitized only with no previous exposure) to ob-\njective symptoms as well as nonobjective symptoms. Fig. 2 SPT prior to OFC Fig. 2 SPT prior to OFC 2211 SN Compr. Clin. Med. Discussion (2020) 2:2208–2213 Table 3\nSymptoms to nuts included in biscuits prior to OFC, SPT on day, and outcome on follow-up\nPatients (age and gender)\nSymptoms to nuts in biscuits\nprior to OFC\nNuts included in biscuits\nSPT to nuts on the\nday of OFC\nOutcome on follow-up\nMale\n8 years 6 months\nUpper respiratory symptoms\nAlmond, pine nut, macadamia\nNegative to all\nAll nuts maintained in diet\nMale\n2 years 10 months\nGeneralized rash\nAlmond, Brazil nut, cashew\nNegative to all\nAll nuts maintained in diet\nFemale 12 years 1 month\nThroat tightness\nAlmond, hazel nut, Brazil nut,\ncashew, macadamia\nNegative to all\nNone of the nuts maintained\nin diet, no reason given\nFemale 13 years 6 months\nUrticaria to products labeled\nmay contain traces\nAlmond, Brazil nut, walnut,\nMacadamia\nAlmond (3 × 4 mm)\nBrazil nut (2 × 4 mm)\nwalnut negative\nMacadamia(3 × 3 mm)\nAll nuts maintained in diet\nFemale 3 years 2 months\nFacial rash, itchy tongue\nAlmond, Brazil nut, cashew,\nwalnut, macadamia\nNegative to all\nAll nuts maintained in diet\nMale\n13 years 10 months\nFacial erythema to pine nuts\nBrazil nut, pine nut, macadamia\nBrazil nut 4 × 5 mm\nMacadamia 2 × 3 mm\nPine nut negative\nAll nuts maintained in diet 3\nSymptoms to nuts included in biscuits prior to OFC, SPT on day, and outcome on follow-up Of all the 139 who had negative OFC, 6 describe symp-\ntoms to the challenge nuts prior to the challenge. Characteristics of this group are reflected in Table 3. Our study reveals that there is a high success rate of passing\nthe mixed tree nut OFC with the majority of families continu-\ning to eat the nuts. Recurrence of tree nut allergy following\nOFC has not been reported to date. The presence of asthma, eczema, allergic rhinitis, and other\nfood allergies was determined in out-patient clinic consulta-\ntion before the OFC. This information is detailed in Table 4. It will be interesting to follow up children that failed the\nintroduction of the challenge nuts to note if immunologic tol-\nerance is maintained. Most of the patients that passed the challenge had multiple\nfood allergies. There were 256 cases of documented single or\nmultiple food allergies. Conclusion There are some limitations to our study. It is a retrospective\nstudy which relied on the documentation of the treating physi-\ncian. We also note the majority of patients had negative or low\npositive SPT which is not representative of patients with true tree\nnut allergy. The families prepared the tree nut biscuit as per our\nguidelines though this is not standardized with all tested tree nuts. Our data show that open mixed tree nut OFC is useful in\nexcluding multiple tree nut allergies in children with low sus-\npicion of clinical allergy. Some families will require more\nsupport to maintain the challenge nuts in the child’s diet fol-\nlowing a negative OFC. Table 4\nPatient characteristics for successful, partially successful, and\nunsuccessful introduction of tree nuts\nSuccessful\nPartially successful\nUnsuccessful\nEczema\n25\n1\n7\nAsthma\n25\n0\n5\nAllergic rhinitis\n21\n1\n4\nOther tree nut allergy\n50\n3\n5\nPeanut allergy\n53\n3\n8\nOther food allergy\n111\n2\n21 Table 4\nPatient characteristics for successful, partially successful, and\nunsuccessful introduction of tree nuts Authors’ Contribution Authors 1, 2, and 3 contributed to the conception\nand design of the work and acquisition, analysis, and interpretation of\ndata and also contributed to drafting the work and revising it critically for\nimportant intellectual content as well as final approval of the version to be\npublished. All authors agree to be accountable for all aspects of the work\nin ensuring that questions related to the accuracy or integrity of any part of\nthe work are appropriately investigated and resolved. Discussion Of these 64 are allergic to peanuts, 58\nallergic to other tree nuts not included in the OFC, 47 allergic\nto egg, 18 allergic to cow’s milk, and 69 allergic to other foods\n(wheat, other legumes, sesame, sea food, and kiwi fruit). To further improve rates of introduction of the tree nuts\nfollowing negative OFC, we should encourage families to\nmaintain the nuts in the child’s diet. Contact between families\nand the Immunology Department should be streamlined to\nallow contemporaneous contact at the time of a possible reac-\ntion to the challenge nuts. Previous study by Van Der Valk et al. looked at introduc-\ntion of cashew nut following a negative OFC at 6 months with\na successful introduction rate of 43.3% [5]. Our study found a\ncombined total of successful and partial introduction rate of\n82% for all challenge nuts. Compliance with Ethical Standards Conflict of Interest\nThe authors declare that they have no conflict of\ninterest. 2212 SN Compr. Clin. Med. (2020) 2:2208–2213 patient records as well as patient charts and used in strictly anonymous\nform. Verbal consent was obtained from the parent prior to commencing\nthe phone interview. Ethical Approval\nData was obtained from electronic patient records as\nwell as patient charts and used in strictly anonymous form, according to\nthe code of conduct for medical research approved by the hospital’s\nMedical Ethical Committee (Child and Adolescent Health Service\nSafety and Quality Committee). patient records as well as patient charts and used in strictly anonymous\nform. Verbal consent was obtained from the parent prior to commencing\nthe phone interview. Appendix Informed Consent\nSigned consent for the challenge was obtained from\nthe parents prior to the challenge. In accordance with the hospital’s guide-\nlines for use of patient’s records, data was obtained from electronic Recipe for mixed tree nut biscuit. 1.\nDiagnosing and managing food allergy in children Holloway,\nEdward; Fox, Adam, Fitzsimons, Roisin. Practitioner; London Vol.\n255, Iss. 1741. 2213 SN Compr. Clin. Med. (2020) 2:2208–2213 Open Access This article is licensed under a Creative Commons\nAttribution 4.0 International License, which permits use, sharing, adap-\ntation, distribution and reproduction in any medium or format, as long as\nyou give appropriate credit to the original author(s) and the source, pro-\nvide a link to the Creative Commons licence, and indicate if changes were\nmade. The images or other third party material in this article are included\nin the article's Creative Commons licence, unless indicated otherwise in a\ncredit line to the material. If material is not included in the article's\nCreative Commons licence and your intended use is not permitted by\nstatutory regulation or exceeds the permitted use, you will need to obtain\npermission directly from the copyright holder. To view a copy of this\nlicence, visit http://creativecommons.org/licenses/by/4.0/. 2. Fleischer DM, Conover-Walker MK, Christie L, Burks AW, Wood\nRA. The natural progression of peanut allergy: resolution and the\npossibility of recurrence. J Allergy Clin Immunol St Louis. 2003;112(1):183–9. https://doi.org/10.1067/mai.2003.1517. 3. Australasian Society of Clinical Immunology and Allergy. Skin\nPrick Testing Working Party. Skin Prick testing for the diagnosis\nof allergic disease. Updated 2020. Available at https://\nwww.allergy.org.au/ASCIA_HP_SPT_Guide_2020 4. Thalayasingam M, Noble V, Franzmann A, O’Sullivan M. Outcome\nof mixed nut biscuit challenge in low risk patients who are on tree nut\nexclusion diet. Paediatr Allergy Immunol. 2015. https://doi.org/10. 1111/pai.12437. 5. van der Valk JPM, van Wijk RG, Dubois AEJ, de Groot H, de Jong\nNW. Failure of introduction of cashew nut after a negative oral food\nchallenge test in children. Paediatr Allergy Immunol. 2016. https://\ndoi.org/10.1111/PAI.12591. References Publisher’s Note\nSpringer Nature remains neutral with regard to juris-\ndictional claims in published maps and institutional affiliations."
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Introducere Biofilmele microbiene constituie în prezent o problemă de sănătate publică care afectează populația din toate
țările, indiferent de gradul de dezvoltare al acestora. Biofilmele microbiene constituie în prezent o problemă de sănătate publică care afectează populația din toate
țările, indiferent de gradul de dezvoltare al acestora. ț
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Conceptul de biofilm reprezintă o nouă paradigmă în microbiologie: 99% din bacteriile de pe Terra trăiesc
asociate în consorţii complexe, ataşate suprafeţelor, iar abordarea lor indică noi perspective de cercetare [1,2]. Studiul biofilmelor devine astfel un domeniu interdisciplinar şi multidisciplinar, antrenând microbiologi,
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i Conceptul de biofilm reprezintă o nouă paradigmă în microbiologie: 99% din bacteriile de pe Terra trăiesc
asociate în consorţii complexe, ataşate suprafeţelor, iar abordarea lor indică noi perspective de cercetare [1,2]. Conceptul de biofilm reprezintă o nouă paradigmă în microbiologie: 99% din bacteriile de pe Terra trăiesc
asociate în consorţii complexe, ataşate suprafeţelor, iar abordarea lor indică noi perspective de cercetare [1,2]. Studiul biofilmelor devine astfel un domeniu interdisciplinar şi multidisciplinar, antrenând microbiologi,
ingineri, medici, ecologi, specialiști în evoluționism, microscopie, geneticieni, chimiști, fizicieni, matematicieni,
igienişti, toxicologi din întreaga lume [3,4]. Studiul biofilmelor devine astfel un domeniu interdisciplinar şi multidisciplinar, antrenând microbiologi,
ingineri, medici, ecologi, specialiști în evoluționism, microscopie, geneticieni, chimiști, fizicieni, matematicieni,
igienişti, toxicologi din întreaga lume [3,4]. Biofilmele au subminat graniţa biologică între eucariote şi procariote [5]. Aceste consorții reprezintă niște
structuri complexe de microorganisme legate în mod ireversibil de suprafeţe solide inerte sau vii şi înconjurate
de o matrice polimerică organică amorfă, fiind o secreție extracelulară a microorganismelor – substanțe poli-
merice extracelulare. Autorii studiilor definesc biofilmul microbian ca o structură tridimensională care aderă
atât la suprafețele vii, cât și la cele inerte, fiind constituită din agregate de celule microbiene (proteine şi ADN)
încorporate într-o matrice polimerică, extracelulară, exopolizaharidică, autosecretată [6,7]. Aderarea microorganismelor la o suprafaţă şi dezvoltarea biofilmului reprezintă una dintre „strategiile” de
supravieţuire a acestora la acțiunea factorilor de mediu. În natură biofilmele sunt răspândite pretutindeni fiind
constituite din bacterii, protozoare, actinomicete, ciuperci și alge microscopice aflate în relaţii de mutualism
şi comensalism, care se exprimă prin cooperarea reciproc avantajoasă pentru consorţi, cu referire la hrană, apă,
protecţie, transport etc. [8]. CZU: 579.61
BIOFILMELE FUNGICE – PROVOCARE ACTUALĂ LA NIVEL MONDIAL Olga BURDUNIUC Olga BURDUNIUC
Agenţia Naţională pentru Sănătate Publică,
Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu” g
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Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu” În prezenta lucrare sunt analizate cele mai relevante publicații din literatura medicală selectate printr-o cercetare utili-
zând bazele de date PubMed, EMBASE, HINARI și site-urile web ale OMS, CDC privind unul dintre factorii de viru-
lenţă a fungilor precum formarea biofilmelor. Scopul acestui review este de a furniza informație științifică actuală refe-
ritore la acest subiect. Au fost revizuite un șir de studii și s-a constatat că ambele tipuri de fungi – atît levuriformi, cât și
filamentoși – pot adera la suprafețe biotice și abiotice, dezvoltându-se în comunități extrem de organizate, rezistente la
preparatele antimicotice și la factorii de mediu. p p
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Cuvinte-cheie: fungi, biofilme, persistenţă, rezistență la antimicotice. FUNGAL BIOFILMS – CURRENT CHALLENGE WORLDWIDE This paper is a literature review that analyzes the most relevant publications in the medical literature, selected through a
search in databases such as PubMed EMBASE, HINARI, WHO and CDC websites regarding one of the fungal virulence
factors - biofilm formation. The purpose of this review is to provide up-to-date scientific information on this topic. In
carrying out these objectives, a series of studies were reviewed and it was found that both yeasts and filamentous fungi
can adhere to biotic and abiotic surfaces, developing in highly organized communities, resistant to antifungal drugs and
environmental factors. Keywords: fungi, biofilms, persistence, resistance to antifungals. S T U D I A U N I V E R S I T A T I S M O L D A V I A E S T U D I A U N I V E R S I T A T I S M O L D A V I A E S T U D I A U N I V E R S I T A T I S M O L D A V I A E Revist= [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) CZU: 579.61
BIOFILMELE FUNGICE – PROVOCARE ACTUALĂ LA NIVEL MONDIAL CZU: 579.61 Introducere Natura prezintă biofilmele, adesea multispecifice, de aceea această formă de existență a fost studiată pe
larg în ultimul timp. Cercetătorii au evidențiat în structura biofilmelor agenți microbieni cu expresie genetică
și fenotipică și rată de multiplicare diferită de ale celor aflați în stare planctonică. Biofilmele sunt considerate
ca un stil de viață universal pentru supraviețuirea microbilor în acțiunea preparatelor antimicotice și predomină
în natură comparativ cu celulele planctonice [9,10]. Biofilmele au fost studiate pe larg în ultimul timp și s-a demonstrat implicarea acestora în dezvoltarea unui
spectru larg de maladii infecțioase, inclusiv fungice. Totodată, biofilmelor le datorăm atât rezistenţa la antimi-
crobiene, mecanisme de apărare a organismului, precum și persistenţa portajului [10]. 100 Seria “{tiin\e reale [i ale naturii” {tiin\e Biologice ISSN 1814-3237 Implicarea biofilmelor microbiene în apariția infecțiilor persistente și evoluția microorganismelor rezistente
la antimicrobiene este astăzi o certitudine. Biofilmele fungice au fost raportate a fi de până la 1000 de ori mai
rezistente la antifungice decât celulele planctonice, dar mecanismul acestei rezistențe rămâne neclar [10–12]. Studiile recente subliniază că o bună parte din patologia infecțioasă este generată și/sau întreținută de bio-
filme acestea fiind implicate în cel puțin 60% din totalul cazurilor de infecții cronice sau recurente [12] Implicarea biofilmelor microbiene în apariția infecțiilor persistente și evoluția microorganismelor rezistente
la antimicrobiene este astăzi o certitudine. Biofilmele fungice au fost raportate a fi de până la 1000 de ori mai
rezistente la antifungice decât celulele planctonice, dar mecanismul acestei rezistențe rămâne neclar [10–12]. rezistente la antifungice decât celulele planctonice, dar mecanismul acestei rezistențe rămâne neclar [10–12]. Studiile recente subliniază că o bună parte din patologia infecțioasă este generată și/sau întreținută de bio-
filme, acestea fiind implicate în cel puțin 60% din totalul cazurilor de infecții cronice sau recurente [12]. Studiile recente subliniază că o bună parte din patologia infecțioasă este generată și/sau întreținută de bio-
filme, acestea fiind implicate în cel puțin 60% din totalul cazurilor de infecții cronice sau recurente [12]. Celulele persistente din biofilme formează cel puțin 1% din populație. Acestea sunt celule latente, care asi-
gură supraviețuirea chiar și după un curs extensiv și pe termen lung de terapie antifungică, acest aspect şi duce
la recurență și recidivă [14]. Fungii formează biofilme pentru cooperare metabolică, dobândirea de noi trăsături genetice și creșterea re-
zistenței la factorii de mediu. Actualmente se atestă creșterea ponderii infecțiilor fungice. Introducere Medicina modernă
a furnizat fungilor multe nișe, cum ar fi catetere, șunturi, tuburi, implanturi, lentile de contact, proteze și dis-
pozitive protetice. Dispozitivele sunt colonizate de fungi și formează biofilme pe suprafețele abiotice [12,15]. Biofilmele au fost în atenția multor savanți renumiți, care descriu procesul de formare a acestora într-o
manieră secvențială: (a) aderența și adsorbția. Fixarea iniţială: începe cu o ataşare reversibilă de o suprafaţă
a microorganismelor. Aceşti primi colonişti aderă slab la suprafaţă, legându-se prin forţe Van der Waals. Ataşarea ireversibilă: dacă coloniştii nu sunt îndepărtaţi imediat de pe suprafaţă, ei se pot ancora mai ferm,
folosindu-se de structurile de adeziune celulară, cum sunt pilii; (b) stadiul intermediar (maturizarea I) are o
activitate metabolică maximă. Matricea polimerică extracelulară (PME) fiind îmbunătățită, reprezintă sursa
de nutrienți și protejează comunitatea biofilmelor de desicare, radiații ultraviolete, celulele imune și antimicro-
biene; (c) stadiul de maturizare (I, II). Primii colonişti facilitează sosirea altor celule prin furnizarea diverselor
situsuri de adeziune, prin începerea construcţiei matricei care ţine unit biofilmul. Câteva specii nu sunt capa-
bile să se ataşeze prin suprafeţele lor, dar adesea sunt capabile să se ancoreze la matrice sau direct la primii
colonişti. În timpul colonizării aceste celule sunt capabile să comunice prin „molecule semnalˮ – quorum sensing
sau folosind produşi ca lactonele homoserin acilate. În a doua faza de maturizare, biofilmul creşte prin com-
binaţia dintre diviziunea celulară şi recrutarea de noi celule, procesul de formare a biofilmulului este stabil şi
se poate modifică numai în formă şi dimensiune; d) etapa de eliberare și diseminare de celule din colonia
biofilmului. Aceasta etapă permite biofilmelor să se răspândească şi să colonizeze noi suprafeţe, constituind
o etapă esenţială a ciclului de viaţă al biofilmelor [16–18]. Formarea biofilmului nu este un factor clasic de virulență. Cu toate acestea, biofilmele conduc la creșterea
patogenității, deoarece comunitatea celulelor devine prea mare pentru a fi fagocitată. Fungii din biofilme sunt
mai rezistenți la stres oxidativ, iar PME afectează recunoașterea epitopilor fungici de suprafață de către celu-
lele imune [17]. Biofilmele formate de fungi sunt subiectul unui șir de cercetări demonstrând implicarea celor mai importanți
fungi din punct de vedere medical în formarea biofilmelor, precum Candida, Aspergillus, Cryptococcus, Trichos-
poron, Coccidioides, Pneumocystis. Biofilmele fungice au implicații notabile din punct de vedere clinic și re-
prezintă o formă specifică de creștere microbiană și veriga principală în dezvoltarea infecțiilor fungice [19–24]. Introducere p
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Studiile realizate în ultimul deceniu au listat principalele caracteristici ale biofilmelor fungice importante
pentru evoluția infecțiilor invazive: desprinderea agregatelor de biofilme, care pot genera infecții de flux sangvin
sau embolii, schimbul intercelular de plasmide ce este implicat direct în transmiterea rezistenței antimicrobiene,
microbii din biofilm sunt protejați de acțiunea antimicrobiană, biofilmele nu sunt afectate de clearance-ul sis-
temului imun al gazdei [25]. Formarea biofilmelor de către tulpinile relevante clinic pe endoproteze, catetere, suprafața dispozitivelor medi-
cale, ventilatoarelor mecanice, precum și măsurile de combatere a formării acestora au fost descrise într-un
şir de cercetări din ultima perioadă. Alţi cercetători descriu consecinţele clinice semnificative ale infecţiei
asociate cu biofilmele mature. Astfel, tratamentul antimicrobian de durată este adesea necesar pentru eradica-
rea acestor infecţii (osteomielita, endocardita etc.); din păcate, chiar şi această strategie de multe ori eşuează,
necesitând excizia chirurgicală a biofilmului contaminant [25–27]. Savanți din diferite țări cu puternic potențial de cercetare au semnalat necesitatea şi urgența studiilor privind
elucidarea aprofundată a biofilmelor şi a celor de dezvoltare a strategiilor eficiente de prevenire a formării
biofilmelor și/sau de tratamente pentru infecțiile cauzate. S T U D I A U N I V E R S I T A T I S M O L D A V I A E S T U D I A U N I V E R S I T A T I S M O L D A V I A E Revist= [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) nizațiilor internaționale în domeniu. Pentru elicidarea acestui subiect au fost revizuite şi sistematizate 98 de
surse bibliografice, informaţiile publicate în ultimele decenii. În procesul de analiză au fost excluse 5 articole
vechi care nu s-au găsit a fi sugestive. Astfel, în final au fost selectate 87 de publicații actuale și relevante, 6
articole mai vechi dar foarte demonstrative (în total 93 de lucrări stiintifice) privind structura, compoziția, me-
canismele de formare, factorii ce influențează formarea și înlăturarea biofilmului. nizațiilor internaționale în domeniu. Pentru elicidarea acestui subiect au fost revizuite şi sistematizate 98 de
surse bibliografice, informaţiile publicate în ultimele decenii. În procesul de analiză au fost excluse 5 articole
vechi care nu s-au găsit a fi sugestive. Astfel, în final au fost selectate 87 de publicații actuale și relevante, 6
articole mai vechi dar foarte demonstrative (în total 93 de lucrări stiintifice) privind structura, compoziția, me-
canismele de formare, factorii ce influențează formarea și înlăturarea biofilmului. Material şi metode Lucrarea analizează cele mai relevante publicații din literatura medicală din țară și de peste hotarele ei
utilizând bazele de date PubMed, EMBASE, Scopus, HINARI, Google Academic și site-urile web ale orga- 101 Rezultate şi discuţii
Istoricul biofilmelor și gradul de investigare a problemei la momentul actual Microorganismele au fost descrise sub formă planctonică și caracterizate pe baza proprietăților lor culturale,
percepția clasică a microorganismelor unicelulare. Van Leewenhoek a fost primul savant care a descris feno-
menul prin care aceste microorganisme aderă și se multiplică pe majoritatea suprafețelor, atât cele exterioare,
cât și în organism, dând naștere biofilmului [2]. Termenul „biofilm” a fost introdus de Costerton în 1985. Autorul a definit biofilmul drept „o comunitate
sesilă microbiană caracterizată prin celule care sunt atașate ireversibil de un substrat sau una de cealaltă, într-
o matrice de substanță polimerică extracelulară și prezintă un fenotip modificat în raport cu rata de creștere și
transcripția genelor” [28]. Primele biofilme au fost descrise în secolul al XIX-lea pe plăci dentare, apoi fibroza chistică a oferit modele
de biofilme viabile, cu status sesil, fixat permanent sau temporar de substrat, constituind comunităţi celulare,
comparative cu cele planctonice ce nu aderau la suprafaţă [11, 29]. Î p
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În alte studii se subliniază că biofilmele au devenit un domeniu de studiu începând cu sfârșitul anilor șaptezeci,
când aceste structuri au fost aduse în atenția publicului de Bill Costerton și colaboratorii în 1978 [30]. Din acea perioadă până în prezent au apărut numeroase articole științifice, monografii ce abordează prob-
lema privind formarea biofilmelor şi o parte din ele vor fi prezentate în prezenta lucrare. Interesul sporit al
cercetătorilor faţă de biofilme se explică prin semnificaţia medicală, ecologică, biotehnologică şi teoretică a
fenomenelor de aderenţă şi agregare microbiană. ţ ş
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Unele particularități ale biofilmelor formate de fungi din genul Candida g g
Unele particularități ale biofilmelor formate de fungi din genul Candida Evidențele publicate privind biofilmelor fungice atestă o predominare a speciilor din genul Candida în etio-
logia patologiei infecțioase de origine micotică. Speciile genului Candida, reprezențanț ai microflorei comen-
sale, frecvent sunt implicate și în patologia infecțioasă. Dispozitive de tip: stent, șunt, proteze, implante sonde
endotraheale, catetere etc., sunt frecvent colonizate de aceste tulpini și reprezintă surse pentru dezvoltarea de
biofilme candidozice. Practic ultimul deceniu a cunoscut o creștere exponențială a infecțiilor de flux sangvin
cauzate de Candida spp. (predominant Candida albicans), în paralel cu utilizarea pe scară tot mai largă a dis-
pozitivelor mai sus amintite, astfel încât în acest moment fungii (și în special Candida albicans) reprezintă
cea de-a treia cauză de infecții de cateter, soldate cu rată înaltă de mortalitate [12]. Î În colonizarea suprafețelor celulele fungice trebuie să adere la o suprafața hidrofobă a unui biomaterial, aspect
mediat de forțele electrostatice, dar și adezine fungice, ce recunosc liganzi din suprafața de aderat (fibrinogen,
fibronectină) etc. [53,56]. Biofilmele C. albicans sunt formate pe diverse suprafețe abiotice și biotice [31–33,43]. Alte specii de Candida,
incluzând C. tropicalis, C. parapsiloză și C. glabrata, formează biofilme care conțin ECM, dar nu produc o
hifă adevărată. Totodată, aceste specii pot coagrega bacterii, cu formarea de biofilme polimicrobiene: bacte-
riene și fungice. Aderarea celulelor la un substrat este urmată de diviziune celulară, proliferare și dezvoltarea
biofilmului, structură tridimensională complexă, cu aranjament spațial optim pentru transportul nutrienților și
eliminarea deșeurilor [35]. Studiile analizate demonstrează implicarea biofilmelor formate de microorganismele din genul Candida
la bolnavi cu dispozitive implantabile (proteze valvulare, endovasculare, articulare, dar, mai ales, catetere ve-
noase centrale). Autorii subliniază că pătrunderea acestora în circulația sistemică constituie adesea puncte de
plecare pentru infecții micotice invasive [12, 33, 43]. Cercetările evidențiază în dezvoltarea biofilmelor de Candida spp. unele particularități, aderarea celulelor
fungice fiind urmată la 3-6 ore de formarea structurilor tubulare. După o incubație de 24-48 ore biofilmele ma-
turate de Candida albicans dispun de o rețea densă de celule fungice, hife și pseudohife și matrice polimerică
extracelulară. Dat fiind faptul că filamentarea nu a fost descrisă la formele planctonice, este posibil ca acest
aspect să fie favorizat de formarea biofilmului. Microscopia electronică a permis vizualizarea de canale hi-
drice ramificate în biofilm, cu dimensiuni de 25-450 µm [36]. 102 Seria “{tiin\e reale [i ale naturii” {tiin\e Biologice ISSN 1814-3237 Capacitatea de a se transforma reversibil din celule fungice în filamente a celulelor de C. g g
Unele particularități ale biofilmelor formate de fungi din genul Candida albicans (conversia
morfogenetică) are rol decisiv în dezvoltarea biofilmului. Autorii studiilor axate inclusiv pe conversia morfo-
genetică denotă că hifele constituie elemente esențiale pentru integritatea structurală, arhitectura multistratificată
ce caracterizează biofilme maturate [37]. Ramage și col. au demonstrat că substratul molecular al filamentării celulelor de Candida și dezvoltării bio-
filmelor mature, înalt structurate, este asigurat de prezența proteinei Efg1 [38]. Majoritatea studiilor analizate subliniază rolul decesiv al comunicării intercelulare (quorum sensing-QS)
în procesul de formare a biofilmului. QS controlat de proteina de transducție Chk1p asigură monitorizarea
multiplicării celulare pentru a evita suprapopularea, dar și competiția pentru nutrienți, cu implicații serioase
pentru procesul infecțios, în special în diseminarea infecției și apariția de emboli septici la distanță. Un exemplu
interesant de comunicare intercelulară în biofilm este dat de interacțiunea Candida albicans și Pseudomonas
aeruginosa. Celulele de Pseudomonas formează un biofilm extrem de dens pe filamentele de Candida și distruge
fungii, dar bacteriile nu distrug formele celulare de Candida. Totodată, celulele de Candida spp. pot stopa
filamentarea ca răspuns la expunerea contactului cu molecule de comunicare cu Pseudomonas de tip 3-oxo-
C12homoserin lactonă. Studiile demonstrează că morfogeneza Candidei albicans se află sub controlul mediului
înconjurător al biofilmului [39–41]. j
[
]
Arhitectura biofilmului fungic pathogen Dezvoltarea arhitecturii biofilmelor este în mare măsură legată de producerea matricei polimerice extracelu-
lare (MPE) de către microorganisme. MPE reține apa și nutrienții obținuți din materialele matricei hidrolizate
de enzimele produse de microorganisme [12,42]. Prin urmare, matricea include toate elementele biofilmului şi este compusă în principal din apă (până la
97%), polimeri polizaharidici secretaţi de microorganisme și produse de degradare a substanțelor din mediul
extern și alte componente, cum ar fi ADN, ARN și lipide. Spre deosebire de culturile clasice de microorga-
nisme din mediile lichide agitate, biofilmul nu este un mediu omogen, deoarece prezintă zone cu conţinut va-
riabil de oxigen şi nutrienţi, pH diferit [42–44]. Regiunile din centrul agregatelor bacteriene sunt în general anaerobe şi sărace în nutrimente, în timp ce
cele situate în vecinătatea canalelor sau la interfaţa dintre biofilm şi lichid sunt mai bine oxigenate şi mai bo-
gate în nutrienţi [45]. Biofilmul este acoperit în întregime de MPE, astfel protejează și oferă o structură ideală pentru coeziunea
și adeziunea celulelor [42]. Cea mai relevantă funcție din punct de vedere medical a matricei extracelulare este
capacitatea sa de a oferi o barieră fizică între celulele de biofilm și sistemul imunitar și adesea medicamentele
utilizate pentru tratament [46]. MPE este autoprodusă și poate conține proteine, polizaharide, lipide, acizi nucleici și alte molecule care pot
interacționa între ele și cu suprafața celulei pentru a forma o rețea rigidă de protecție [47]. Compoziția MPE
variază în funcție de specii și chiar de condiții de creștere; cu toate acestea, pentru multe biofilme compoziția
MPE rămâne necunoscută [42,48]. Funcțional, MPE poate servi drept barieră protectoare împotriva agenților antimicrobieni, chimici și biologici,
inclusiv către preparate antimicotice prescrise [48,49]. Biofilmele, fiind populații complexe de celule asociate suprafeței înglobate într-un MPE, posedă fenotipuri
distincte în comparație cu omologii lor celulari planctonici. Elementele nutritive, moleculele sensibile la cvorum și
contactul cu suprafața sunt factori favorizanți. Biofilmele de C. albicans sunt constituite în principal din celule
sub formă de levuri și hife, ambele fiind necesare pentru formarea biofilmului [19]. MPE se acumulează pe măsură ce biofilmul se maturizează și contribuie la coeziune [50]. Biofilmele de
Aspergillus se pot forma atât pe suprafețele abiotice, cât și pe cele biotice. Celulele inițiale colonizatoare care
aderă la substrat sunt conidii. Micelia (forma hifală) se dezvoltă pe măsură ce biofilmul se maturizează [51]. MPE care încheagă biofilmul a fost observat in vitro și în vivo. Revist= [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) C. neoformans formează biofilme constând din celule de drojdie pe multe substraturi abiotice, iar poliza-
haridul capsular sintetizat formează ECM. Cu toate că C. neoformans formează hifa în cursul grupării, până
în prezent nu s-au observat hife în biofilmele de C. neoformans [21]. Î p
f
În mod similar, speciile Pneumocystis nu produc structuri hifale ca parte a biofilmelor lor. Astfel, formarea
hifală nu este o caracteristică uniformă a biofilmelor fungice [24]. g
Comunicarea intercelulară prin semnale (quorum sensing - QS)
Î Comunicarea intercelulară prin semnale (quorum sensing - QS)
Î În biofilme QS este gândit să joace un rol în producţia de biofilme sănătoase şi pe deplin dezvoltate. Aceste
complexe microbiene definesc structuri multistratificate arhitectural formând comunităţi bacteriene relativ
stabile ce trăiesc în sesile într-un mediu protejat [28, 56–59]. Comunicarea intercelulară, este legată de mecanismul prin care microorganismele comunică și își coordo-
nează comportamentul prin secreția de molecule de semnalizare [60,61]. Sistemele QS par să fie implicate în toate etapele de formare a biofilmelor. Ele reglează densitatea populaţiei şi
activitatea metabolică în biofilmul matur pentru a se potrivi cu cerinţele nutriţionale şi resursele disponibile. Bacteriile care locuiesc în biofilme au programe semnificativ diferite de transcripţie faţă de bacteriile plancto-
nice vii libere ale aceleiaşi tulpini. Dovezi recente privind Streptococcus pneumoniae indică faptul că orga-
nismele existente într-o stare sesilă în biofilm sunt mai în măsură să stabilească infecţii localizate (de exemplu,
în ţesutul pulmonar) decât microorganismele izogenice într-o stare planctonică fiziologic [62–65]. QS joacă rol în mai multe mecanisme, inclusiv dezvoltarea biofilmului, morfogeneza, limitarea populației
celulare și, în special, pentru diseminarea procesului infecțios [61,63]. Detectarea QS este de o importanță funda-
mentală și este datorată rolului specific ce îl determină în fiziologia biofilmului. Celulele persistente reprezintă
o mică subpopulație de celule care intră spontan într-o stare latentă ce nu divizează. Atunci când o populație
este tratată cu antimicrobiane, celulele normale pier, în timp ce cele persistente supraviețuiesc. În cazul în care
terapia este întreruptă, celule persistente pot reface biofilmele, inducând recurența infecțiilor [66]. Mecanismele moleculare care promovează rezistența antifungică în biofilmele fungice nu sunt complet elu-
cidate. Unele studii au arătat că pompele de eflux contribuie la dezvoltarea rezistenței față de azoli numai în
faza inițială a formării biofilmului. În plus, conținutul de sterol în membrană contribuie la rezistența anti-azoli,
ce apare în timpul fazelor intermediare și mature [67]. Revist= [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) Conform Soto și col., reglarea pompelor de eflux medicamentos determină, de asemenea, rezistența la anti-
microbiene la majoritatea microorganisme ce formează biofilm [68]. Aceste pompe sunt împărțite în două grupuri: primul este legat de transportoarele- casetă ATP-ligande co-
dificate de genele CDR, în timp ce al doilea este compus din facilitatorul principal codificat de genele MDR
[49]. Activarea pompelor de eflux are loc prin „expulzarea” preparatelor antifungice după contactul cu biofilmul. Totodată, crește expresia genelor CDR1 și MDR1, care a fost corelată cu rezistența fungilor la azoli. Unele
studii privind rezistența la biofilm demonstrează expresia înaltă a genelor pompei de eflux în primele ore de
formare a biofilmului [49]. Semnificația biofilmelor în dezvoltarea rezistenței antifungice j
[
]
Arhitectura biofilmului fungic pathogen Organizarea hifală este diferită în cele două
forme ale infecției cu biofilm de A fumigatus: infecțiile cu aspergillom prezintă o minge de hife interconectate; MPE se acumulează pe măsură ce biofilmul se maturizează și contribuie la coeziune [50]. Biofilmele de
Aspergillus se pot forma atât pe suprafețele abiotice, cât și pe cele biotice. Celulele inițiale colonizatoare care
aderă la substrat sunt conidii. Micelia (forma hifală) se dezvoltă pe măsură ce biofilmul se maturizează [51]. MPE care încheagă biofilmul a fost observat in vitro și în vivo. Organizarea hifală este diferită în cele două
forme ale infecției cu biofilm de A. fumigatus: infecțiile cu aspergillom prezintă o minge de hife interconectate;
infecțiile cu aspergiloză prezintă hife separate individuale [42,51,52]. Hifele C. albicans și A. fumigatus pot forma pori sau canale pe suprafețe biotice [43,75]. Patogenul fungic
emergent T. asahii formează biofilme compuse din levuri și celule hifale încorporate în matrice, la fel ca cele
ale Coccidioides immitis [22,53–55]. 103 S T U D I A U N I V E R S I T A T I S M O L D A V I A E Semnificația biofilmelor în dezvoltarea rezistenței antifungice Majoritatea cercetărilor descriu rezistența antifungică a biofilmelor ca un fenomen complex
cu multe aspecte neelucidate. Microorganismele din structura biofilmelor își încetinesc rata de multiplicare, ceea ce face mai greu de distrus
de antimicrobiene. Prezența microorganismelor facilitează dezvoltarea matricei polimerice care protejează
microbii din fluxul sangvin de actiunea preparatelor antifungice. În același timp, se atestă modificări de com-
portament microbian tipice germenilor din biofilm și faptul că majoritatea acestora suferă de modificări la ni-
velul genelor (de tip up- sau down-regulation) caracteristice fiecărei clase în parte, evidențiază că biofilmele
reprezintă o modalitate de creștere a rezistenței antimicrobiene și se conturează ca o problemă de sănătate pub-
lică, mai ales pentru bolnavul critic și pentru cel cu imunodepresie severă de diverse cauze [69]. Î În biofilm, este facilitat transferul de ADN extracromozomial (plasmide) între celule, element care de asemenea
favorizează apariția și răspândirea rezistenței antimicrobiene. Agregatele de biofilm se pot desprinde și celu-
lele microbiene își pot relua rapid proprietățile planctonice sau de aderare la alte suprafețe. În ambele situații,
aceste structuri posedă potențial de a transfera la distanță și genele de rezistență antimicrobiană. Astfel, după
cum a fost evidențiat și de alți savanți, microorganismele din structura biofilmului sunt o populație cu metabo-
lism diferit de al celor în stare planctonică și pot declanșa infecții grave [70]. 104 Seria “{tiin\e reale [i ale naturii” {tiin\e Biologice ISSN 1814-3237 Totodată, aglomerările de celule ce formează biofilme sunt mult mai rezistente la preparatele antifungice
decât celulele planctonice. Factorii care contribuie la acest fenomen includ complexitatea structurală a biofil-
mului, prezența matricei extracelulare (ECM), heterogenitatea metabolică intrinsecă a biofilmelor și reglarea
asociată genelor generatoare de biofilm cu efect asupra pompei de eflux. Nivelul de rezistență variază în de-
pendență de preparatul antifungic și specia de micete [70–72]. Evidențele în acest domeniu subliniază că modificările sau supraexpresia moleculelor țintă, extruzarea activă
prin pompe de eflux, difuzia limitată, rezistența și comunicarea intercelulară (quorum sensing) și matricea
polimerică extracelulară sunt mecanisme caracteristice fungilor pentru combaterea efectelor tratamentului
antimicotic [72, 73]. MPE este produsă de celulele aderente, constituind o barieră în difuziunea antifungicelor. Studiile denotă că,
în unele cazuri, MPE poate contribui la rezistența antifungică prin legarea la antifungice, împiedicând astfel
accesul la suprafața țintei dorite sau la celulele fungice [74]. Actualmente o provocare aparte reprezintă dovezile științifice insuficiente privind rezistența la antifungice a
acestor biofilme. Semnificația biofilmelor în dezvoltarea rezistenței antifungice Majoritatea standardelor internaționale existente permit testarea formelor planctonice, dar
nu și estimarea sensibilității antifungice pentru celulele din biofilme. Acest aspect ar putea fi o explicație pentru
discrepanța dintre investigațiile de laborator și evoluția clinică a acestor infecții [75]. Actualmente există puține
studii ce descriu astfel de metodologii, iar în unul dintre ele se propune folosirea microplăcilor pe care se for-
mează biofilme, ce sunt expuse ulterior la diverse antifungice. Biofilmele de Candida spp. sunt descrise de
un șir de autori ca una dintre cauzele evoluției rezistenței antifungice. Este îmbucurător faptul că antifungice
noi, cum ar fi echinocandinele și forma liposomală a Amfotericinei B, au dovedit acțiunea fungicidă pentru
microorganismele din biofilme [76]. Celulele planctonice depind de modificări genetice ireversibile pentru a menține un fenotip rezistent, în
timp ce biofilmele persistă din cauza prezenței lor fizice și a densității populației, oferind un fenotip rezistent
aproape indus, indiferent de modificările genetice definite [77,78]. Mai mulți factori ai mediului, inclusiv pH-ul, temperatura, disponibilitatea oxigenului și alții, modifică arhi-
tectura biofilmului și susceptibilitatea antifungică [79]. Rezistența intrinsecă a biofilmelor de Candida presupune diferite mecanisme: densitatea celulară mare a
biofilmului, reducerea ratei multiplicării și limitarea nutrienților, activitatea matrice polimerice extracelulare,
expresia genelor responsabile de rezistență (în special a celor care codifică pompele de eflux) etc. [80]. Chandra și col. au demonstrat că intensitatea ratei metabolice a biofilmului este corelată cu creșterea rezis-
tenței antifungice. Reducerea semnificativă a cantității de ergosterol din biofilme în fazele intermediară și de
maturitate, face ca majoritatea antifungicelor care au mecanism fungicid (interferența cu metabolismul stero-
lilor) să reducă eficiența acestora [81]. Candida parapsilosis este relativ rezistentă la fluconazol, amfotericină B, nistatină, voriconazol și altele. Biofilmele Aspergillus fumigatus sunt relativ rezistente la itraconazol și, într-o oarecare măsură, la caspofungină. Biofilmele criptococice nu sunt afectate de fluconazol și voriconazol, iar biofilmele de Trichosporon asahii
prezintă o rezistență crescută la amfotericină B, caspofungin, voriconazol și fluconazol. Terapiile cu azoli și
amfotericină B sunt ineficiente împotriva biofilmelor de Pneumocystis carinii. Mecanismele de rezistență
asociate biofilmului au fost caracterizate pentru C. albicans și A. fumigatus și includ legarea medicamentelor
prin MPE și producerea de celule persistente. Aceste mecanisme se pot referi și la alți fungi [20,82–84]. Antifungicele nu reușesc să acționeze eficient, deoarece există un gradient de mediu (heterogenitate) în
cadrul biofilmelor. Revist= [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) [tiin\ific= a Universit=\ii de Stat din Moldova, 2020, nr.1(131) Noi strategii alternative de control al biofilmelor Majoritatea studiilor analizate propun noi strategii alternative de control al biofilmelor microbiene, precum
sunt compușii biologici cu proprietăți antibacteriene și antibiofilme. Există foarte puţine preparate antimicotice
ca opţiuni împotriva formelor de fungi încadrate în biofilm; printre ele se enumeră amfotericina B și echino-
candinele. Prin urmare, este nevoie de mai mulți agenți, care pot inhiba aderența la biofilm sau pot elimina
sau perturba biofilmul deja format [87]. Civilizaţiile antice au lăsat informaţii scrise legate de utilizarea produselor naturale în terapia maladiilor
infecțioase. Cel mai vechi document scris datează de acum 4000 de ani, acesta conţine informaţii ce prevăd
remedierea diverselor boli. Totodată, cercetarea metaboliţilor biologici activi secundari pentru aplicaţii folo-
sitoare este departe de a fi considerată nouă [88, 89, 90]. La moment au fost identificate mai multe ținte noi sub formă de componente ale MPE. Multe extracte ve-
getale, nanoparticule de argint, oxid nitric, chitosan etc. au fost încercate pentru a preveni formarea biofilmului
pe suprafețele cateterelor și dispozitivelor intravasculare [91]. Avantajul produselor naturale este dezvoltarea şi perfecţionarea continuă, de-a lungul milioanelor de ani
de presiune evolutivă, pentru a ajunge puternice din punct de vedere biologic. Substanțele obținute natural,
comparativ cu cele artificiale, posedă potențial de biodegradare mult mai înalt şi rapid, fiind acceptate pe piață
mult mai usor din punct de vedere ecologic [88]. Produsele naturale sunt remarcabile prin diversitatea structurii şi activităţii biologice, în contrast cu substan-
ţele produse de industria farmaceutică, ce utilizează metode sintetice, care rareori prezintă o activitate puternică
și diversificată biologic [92]. ș
g
Aceste ipoteze se bazează pe diversitatea şi capacitatea microorganismelor de a se adapta și, prin urmare,
acestea reuşesc să degradeze majoritatea substanţelor naturale. Istoric de mii de ani, produsele naturale au ju-
cat un rol foarte important în fortificarea sănătății și prevenirea maladiilor infecțioase [93]. Î Aceste ipoteze se bazează pe diversitatea şi capacitatea microorganismelor de a se adapta și, prin urmare,
acestea reuşesc să degradeze majoritatea substanţelor naturale. Istoric de mii de ani, produsele naturale au ju-
cat un rol foarte important în fortificarea sănătății și prevenirea maladiilor infecțioase [93]. Î În pofida faptului că până la moment există multe studii ce țin de activitatea antimicrobiană a extractelor
vegetale asupra microorganismelor rezistente, totodată relativ puţine din ele s-au dovedit a fi suficient de active
și inofensive pentru organismul uman. S T U D I A U N I V E R S I T A T I S M O L D A V I A E S T U D I A U N I V E R S I T A T I S M O L D A V I A E Concluzii Concluzii 1. Biofilmele sunt omniprezente, aproape fiecare specie de microorganisme are mecanismele prin care acestea
pot adera la suprafeţe vii sau non-vii; ele pot fi răspândite pretutindeni în natură. 1. Biofilmele sunt omniprezente, aproape fiecare specie de microorganisme are mecanismele prin care acestea
pot adera la suprafeţe vii sau non-vii; ele pot fi răspândite pretutindeni în natură. p
p
p
p
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2. Majoritatea biofilmelor fungice sunt responsabile de infecții foarte rezistente la antimicrobiene, constituind
o preocupare serioasă a serviciilor de sănătate publică, prin creșterea duratei de spitalizare, ratei de morta-
litate și a impactului asupra economiei naționale și globale. 2. Majoritatea biofilmelor fungice sunt responsabile de infecții foarte rezistente la antimicrobiene, constituind
o preocupare serioasă a serviciilor de sănătate publică, prin creșterea duratei de spitalizare, ratei de morta-
litate și a impactului asupra economiei naționale și globale. 3. Actualmente, pe plan mondial sunt disponibile noi strategii alternative de control al biofilmelor, cum ar fi:
substanțe biologic active de origine vegetală, enzime și bacteriofagi. Aceste studii sunt la etapa inițială, de
cercetare in vitro, și necesită studii clinice aprofundate. transmitem recomandări cercetătorilor privind necesitatea studiilor ce țin de identificarea soluțiil
pentru prevenirea și controlul infecțiilor cauzate de biofilm. 4. În final transmitem recomandări cercetătorilor privind necesitatea studiilor ce țin de identificarea soluțiilor
eficiente pentru prevenirea și controlul infecțiilor cauzate de biofilm. Noi strategii alternative de control al biofilmelor În pofida faptului că până la moment există multe studii ce țin de activitatea antimicrobiană a extractelor
vegetale asupra microorganismelor rezistente, totodată relativ puţine din ele s-au dovedit a fi suficient de active
și inofensive pentru organismul uman. ș
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Autorii acestui rewiu subliniază necesitatea studiilor suplimentare privind metodele alternative de obținere a
preparatelor cu acțiune antifungică, naturale, ecologic standardizate, inofensive. ș
p
g
Autorii acestui rewiu subliniază necesitatea studiilor suplimentare privind metodele alternative de obținere a
preparatelor cu acțiune antifungică, naturale, ecologic standardizate, inofensive. Semnificația biofilmelor în dezvoltarea rezistenței antifungice Aceste biofilme fiind după structură asemănătoare cu fungii duc la formarea gradientului
de concentrație sub formă de gradient de oxigen chimic, pH sau gradient de nutrienți. Diferite concentrații de
antimicrobiene ating diverse celule individuale în diferite straturi de biofilme. Această concentrație suboptimă
acționează ca stimul pentru formarea suplimentară a biofilmului și, de asemenea, duce la dezvoltarea rezistenței
la antimicrobiene [85]. Alte mecanisme implicate în rezistența la antimicrobiene sunt: densitatea celulară crescută, modificarea
țintelor medicamentoase și reglarea pompelor de eflux pe măsură ce biofilmele se maturizează. MPE se ma-
nifestă ca o barieră fizică și împiedică pătrunderea preparatelor antifungice în interiorul biofilmului. Există o
concentrație crescută de substanțe, cum ar fi beta-glucanii și mananele, în MPE, care acționează ca „bureți
medicamentoși” și sechestrează azolii, pirimidinele sau polienele. MPE conține ADN extracelular. Dacă se
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ISSN (Online) 1875-6018 Date despre autor: Date despre autor:
Olga BURDUNIUC, doctor în ştiinţe medicale, conferenţiar universitar, USMF „Nicolae Testemiţanu”; șef laborator
Microbiologie, Agenţia Naţională pentru Sănătate Publică. E-mail: olgaburduniuc3@gmail.com
ORCID: 0000-0002-6944-0800 E-mail: olgaburduniuc3@gmail.com
ORCID: 0000-0002-6944-0800 E-mail: olgaburduniuc3@gmail.com
ORCID: 0000-0002-6944-0800 Prezentat la 29.06.2020 110
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COMPORTAMENTO E EFEITO DO TITÂNIO DURANTE O PROCESSAMENTO DE UM MINÉRIO DE FERRO
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Holos
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cc-by
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TURRER ET AL. (2014) DOI: http://dx.doi.org/10.15628/holos.2014.1761 DOI: http://dx.doi.org/10.15628/holos.2014.1761 RESUMO realização de testes em laboratório que simulassem o
processo produtivo industrial. Testes de flotação
mostraram que a recuperação desse elemento é
proporcional a do ferro, indicando associação da
hematita com o titânio. As análises em microscópio ótico
não foram capazes de identificar minerais portadores de
titânio, reforçando a hipótese anterior. Por fim, os teores
de dióxido de titânio obtidos no concentrado foram
usados para estimar a qualidade esperada do pellet feed. Os resultados mostraram que o teor de dióxido de titânio
no concentrado ficou abaixo dos limites exigidos pelo
mercado. O minério de ferro da Serra do Sapo possui características
diferentes daqueles oriundos dos mais importantes polos
produtores brasileiros, uma vez que foi formado em
condições geológicas distintas. Uma característica que o
difere é o seu teor de titânio, que alcança valores pouco
usuais em algumas regiões do depósito. Este trabalho
objetivou verificar o comportamento desse elemento no
tratamento de minérios e seu possível efeito nos
processos subsequentes da cadeia produtiva do aço. Inicialmente, foi realizada uma revisão bibliográfica sobre
o assunto. Em seguida, foram coletadas amostras da
região de maior concentração desse elemento para PALAVRAS-CHAVE: minério de ferro, flotação, pellet feed, titânio. KEYWORDS: iron ore, flotation, pellet feed, titanium. H. D. G. TURRER1, K. B. MENEZES, C. R. MAGALHÃES, F. H. P. GONZAGA, J. C. SILVA, J. A. ALMEIDA e C. M.
NASCIMENTO
¹Gerência de Controle de Qualidade e Desenvolvimento de Processos do Minas-Rio - Anglo American
henrique.turrer@angloamerican.com Artigo submetido em novembro/2013 e aceito em janeiro/2014 Artigo submetido em novembro/2013 e aceito em janeiro/2014 1 INTRODUÇÃO O depósito da Serra do Sapo, localizado no município de Conceição do Mato Dentro, MG,
possui, até o momento, aproximadamente 5 bilhões de toneladas de recursos geológicos. A partir
desse minério serão produzidos 26,5 milhões de toneladas naturais de pellet feed por ano. O
processo produtivo contemplará a extração do minério por escavadeiras e caminhões,
fragmentação por britadores de mandíbulas e cônicos, prensas de rolos e moinhos de bolas,
seguido por deslamagem, flotação, remoagem em moinhos verticais, espessamento,
bombeamento por 525 km de mineroduto e separação sólido-liquido para embarque. A reserva, com mais de 1 bilhão de toneladas de minério de ferro, formará uma cava que
se estenderá por mais de 12 quilômetros na direção norte-sul. Foi observado que em algumas
regiões do depósito, onde a operação de lavra foi planejada para ter início, a concentração de
titânio é pouco usual comparado à média dos minérios de ferro brasileiros. Por isso, este trabalhou objetivou verificar o comportamento desse elemento no
tratamento do minério e seu possível efeito nos processos subsequentes da cadeia produtiva do
aço. Inicialmente foi feita uma revisão bibliográfica em busca de informações que pudessem guiar
e suportar as avaliações experimentais. Em seguida, foram realizados testes em escala de
laboratório que simulassem o processo produtivo para prever o comportamento do óxido de
titânio durante seu futuro processamento industrial. TURRER ET AL. (2014) HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT ABSTRACT were collected to perform laboratory tests to simulate
the industrial process. Flotation tests showed that
titanium recovery is proportional to iron recovery,
indicating association with hematite. Optical microscopy
analysis could not identify titanium minerals, reinforcing
the previous hypothesis. Lastly, the titanium dioxide
amount in the concentrates was used to estimate the
pellet feed quality. The results showed that concentrate
titanium dioxide content will be below the usual limits
requested by the market. Iron ore from Serra do Sapo’s deposit has distinct
characteristics from the ones exploited in the main
Brazilian iron ore production poles since it was formed in
different
geological
conditions. One
of
these
characteristics is the titanium amount, which presents
unusual values in some regions of the deposit. This work
aimed verifies this element behavior during the mineral
processing and its effect in the steelmaking following
process. Initially, a bibliographic revision about the
subject was performed. Subsequently, ore samples from
the region where this element concentration is higher 203 HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT TURRER ET AL. (2014) para que isso ocorra, é de 0,112 e 0,196% em 1.400 e 1.500 °C, respectivamente [5]. Contudo, a
presença do mesmo apresenta um efeito positivo ao processo, pois promove a formação de uma
camada protetora no refratário, elevando sua vida útil. Estudos mostram que adições de 15 até 20
kg/t de gusa são necessários para que porções de carbonidretos de titânio sejam mantidos no
forno e atuem na proteção dos refratários, uma vez que boa parte do cristais de titânio,
precipitados no gusa líquido, são arrastados em direção aos canais de corrida durante o vazamento
[6]. Entretanto, essa quantidade pode variar em função da estrutura mineralógica do portador do
titânio, pois menores quantidades do mesmo são necessárias quando este se encontra em
condições termodinamicamente mais favoráveis [7]. No aço, o titânio eleva a resistência e a dureza, mas diminuiu a ductibilidade. Essas
propriedades apresentam uma repentina mudança de comportamento quando o teor de titânio é
maior que 0,115% no gusa, fato atribuído à precipitação do mesmo [8]. Poucos estudos são encontrados sobre o efeito de minerais portadores de titânio no
processamento mineral. Em um deles, a concentração de várias amostras provenientes de dois
depósitos de minério de ferro na Suécia foi avaliada. Ao todo, 172 amostras foram tratadas,
produzindo concentrados com TiO2 variando de 0,002 até 0,399% com média de 0,059%. Isso
permitiu determinar a média dos concentrados oriundos dos dois depósitos como sendo igual a
0,054 e 0,096%. O autor atribui a presença de titânio a diferentes minerais, já que a relação entre
TiO2 e Al2O3 nas amostras antes do tratamento não era constante. Foi ainda afirmado que os
valores de TiO2 das amostras de concentrado estão bem abaixo dos limites máximos exigidos para
pelotas de redução direta, que são fornecidas pela empresa exploradora do depósito, com exceção
de pequenas partes onde outras técnicas de processamento poderiam ser necessárias [9]. Em se tratando de minérios brasileiros, foi possível obter alguns indicativos do
comportamento do óxido de titânio em trabalhos que não tinham esse tópico como um dos
objetivos, mas reportaram resultados dos teores de TiO2 nos produtos, possibilitando essa
avaliação. Os minerais portadores de titânio tiveram uma maior recuperação no concentrado da
etapa de flotação da usina de Brucutu, de propriedade da Vale S.A. 2 REVISÃO BIBLIOGRÁFICA A apresentação das referências encontradas será feita na ordem inversa do processamento
do minério. Iniciará com questões relativas ao titânio na siderurgia, passando pelo tratamento de
minério e, por fim, abordará sua forma de ocorrência em alguns depósitos. A presença de elevadas quantidades de titânio no pellet feed pode ser prejudicial para os
processos de redução do óxido de ferro à ferro metálico. Grande parte dos estudos sobre esse
assunto é relativa a depósitos de minério de ferro com origem completamente diferente daquele
da Serra do Sapo, que possuem titanomagnetita, apresentando um teor de titânio na ordem de 7%
[1,2]. Durante o processo de pelotização, o titânio pode alterar as propriedades da pelota através
da difusão na rede da hematita, com geração de trincas ao longo da matriz do aglomerado. Em
solução sólida, o titânio também promove uma aceleração da taxa de oxidação da magnetita para
hematita [3]. Fornecedores de módulo de redução direta associam o teor de titânio da pelota ao
inchamento da mesma. Por isso, sugerem adoção de limites máximos de especificação para evitar
a ocorrência de cachos, que diminuem a permeabilidade do leito [4]. No alto forno, o óxido de titânio é reduzido gerando compostos estáveis, chamados de
carbonidretos de titânio, ou Ti(N,C), com pontos de fusão muito elevados, que aumentam a
viscosidade das fases em que se encontram. Dependendo da temperatura e da quantidade de
titânio, esses compostos podem se precipitar na forma sólida. Com isso, o vazamento da escoria e
do gusa se tornam muito mais complexos. A concentração mínima de óxido de titânio no gusa, HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 204 Nos resultados apresentados,
o teor de titânio na alimentação dessa etapa foi, em dois momentos distintos, de 0,047 e 0,039%,
enquanto no concentrado o teor foi de, respectivamente, 0,131 e 0,122% [10]. Minério de ferro
hematítico, com elevado grau de hidratação, abaixo de 0,15 mm e contendo elevado teor de ferro,
58,7%, apresentou teor de titânio igual a 0,139% [11]. Testes de concentração de flotação em
bancada com minério anfibolítico também resultaram numa elevada concentração do titânio no
concentrado. O TiO2 dessa amostra subiu de 0,01% na alimentação da concentração para 0,10%
no concentrado de duas flotações, catiônica reversa e aniônica direta [12]. Testes de concentração
magnética com materiais abaixo de 1,0 mm, provenientes de barragem de rejeitos da usina de
Córrego do Feijão, no Quadrilátero Ferrífero, resultaram em concentrados com TiO2 de 0,063 e
0,054%. Nesses testes, a recuperação de titânio no concentrado foi perto de 30% [13]. Minérios
provenientes das minas de Jangada, João Pereira, Fábrica Nova e Serra Serpentina, todas
localizadas no Quadrilátero Ferrífero, apresentaram TiO2 de, respectivamente, 0,016, 0,033, 0,023
e 0,036% no ROM. Contudo, os teores no concentrado não foram reportados [14]. Titânio foi identificado em finas lamelas, de 5 até 0,2 μm, dispostas em planos cristalinos
da estrutura dos óxidos de ferro em concentrados magnéticos brasileiros com teor de TiO2 de 3,16
e 2,51%. Apesar da difração de raios X não ter detectado nenhum mineral de titânio, a análise em HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 205 TURRER ET AL. (2014) microscópio de luz refletida permitiu a identificação de três formas de ocorrência de ilmenita:
exsolução com magnetita, cristais em contato com magnetita e cristais individuais [15]. microscópio de luz refletida permitiu a identificação de três formas de ocorrência de ilmenita:
exsolução com magnetita, cristais em contato com magnetita e cristais individuais [15]. A caracterização de um minério intemperizado, proveniente da mina de Alegria no
Quadrilátero ferrífero, mostrou que o titânio encontrado nas amostras de goethita apresentava
teores diversos, independente de sua textura e seu grau de cristalinidade, e estaria alojado dentro
da estrutura cristalográfica da goethita. Também foi identificada a presença de fases
intermediárias da solução sólida hematita-ilmenita [16]. Cinquenta e nove amostras de granulados provenientes de diferentes minas do
Quadrilátero foram caracterizadas. O teor médio de TiO2 foi de 0,050%, variando numa ampla
faixa, de 0,010 até 0,201%. O autor identificou poros preenchidos por um plasma goethítico-
hematítico nas amostras mais superficiais com altos valores de alumínio e titânio. Além disso, a
proximidade com os cristais de magnetita permitiu concluir que esses plasmas goethítico-
hematíticos possuíam uma origem supergênica. O teor de 0,201% de TiO2 em uma amostra foi
atribuído a associação com rochas básicas e a alteração supergênica concentrou o elemento no
minério mais superficial. Por fim, concluiu-se que o titânio é mais elevado nas tipologias associadas
à canga e, secundariamente, nas tipologias porosas, itabiríticas e protominério, relacionado aos
eventos genéticos de alteração supergênica [17]. O teor de titânio não é um item contratual de especificação usual para o pellet feed. O
pellet feed produzido a partir de minérios do Quadrilátero Ferrífero, e exportado, não apresentam
teores de titânio em sua especificação, porém, pelotas produzidas a partir do mesmo minério
apresentam um teor máximo de TiO2 que pode variar de 0,038 a 0,045% [18]. O teor máximo de
óxido de titânio máximo da especificação de sinter feed produzidos a partir de três diferentes
minas australianas varia de 0,08 a 0,09% [19]. 3 MATERIAL E MÉTODOS As amostras de minério de ferro foram obtidas através de sondagem de circulação reversa,
com broca de diâmetro igual a 50,5 ou 63,5 mm. Ao todo foram realizados 27 furos, totalizando
1.478 metros. A amostra foi dividida em quarteador rotativo, de forma que um quarto de cada
amostra foi usado para compor as amostras de teste. As amostras foram compostas em intervalos
de 15 m aproximadamente. A moagem do material foi realizada segundo procedimentos internos até obtenção de 90%
passante na malha de 0,150 mm, o que permitiu a determinação do consumo energético da
moagem primária. O produto da moagem foi deslamado em ciclone piloto com diâmetro de 2”,
apex e vortex de 4,8 e 13 mm, respectivamente,. Na deslamagem, solução de soda cáustica foi
adicionada até que a polpa, com 17% de sólidos em peso, atingisse o pH de 11. A velocidade de
bombeamento foi ajustada até a produção de um underflow com 50% de sólidos em peso. Os
testes de flotação foram realizados em cuba de 4,5 l com percentual de sólidos no
condicionamento e na flotação ajustados em 60 e 40%, respectivamente,. Foram utilizadas
soluções a 1% de amina EDA-C da Clariant e amido de milho da Kowaslki. Amido foi gelatinizado
com soda cáustica na relação de 5:1 e dosado em somente um nível. O pH da polpa foi ajustado
para 10,5 com soda cáustica. O amido foi condicionado por 5 minutos antes da adição da amina,
que foi condicionada por 1 minuto. A agitação foi controlada em 1.300 e 1.500 rpm, no HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 206 TURRER ET AL. (2014) condicionamento e na flotação, respectivamente. A coleta do material flotado aconteceu por 6
minutos após inicio da aeração. Os resultados foram reconciliados com programa de balanço de
massas Bilco. condicionamento e na flotação, respectivamente. A coleta do material flotado aconteceu por 6
minutos após inicio da aeração. Os resultados foram reconciliados com programa de balanço de
massas Bilco. Ensaios granulométricos à úmido foram realizados em vibrador suspenso com peneiras da
série Tyler. Os ensaios para determinação da composição química das amostras foram realizados
por fluorescência de raios X de pó prensado ou, em alguns casos, de pastilha fundida com
equipamento Axios da Panalytical. A perda ao fogo foi determinada por calcinação em mufla, a
1.100 °C. 3 MATERIAL E MÉTODOS Análise mineralógica foi conduzida em microscópio ótico Olympus BX51TRF com
magnificação máxima de 200 vezes. TURRER ET AL. (2014) TURRER ET AL. (2014) Não foram observadas, Figura 3, altas correlações entre o teor de óxido de titânio no
minério e seu desempenho na flotação, indicando que esse fator não tem forte efeito no
desempenho dessa etapa. Figura 2 - Comportamento do titânio durante o processamento do minério: recuperações em função da tipologia
(a) e correlação de teor no minério e no concentrado (b). Litotipo
Concentrado
Lama
QF
IFX
IF
HM
CGM
QF
IFX
IF
HM
CGM
100
80
60
40
20
0
%RTiO2
6,0
6,5
6,8
8,3
18,3
6,0
6,5
6,8
8,3
18,3
6,0
6,5
6,8
8,3
18,3
75,9
55,4
78,8
89,5
63,0
75,9
55,4
78,8
89,5
63,0
75,9
55,4
78,8
89,5
63,0
0,30
0,25
0,20
0,15
0,10
0,05
0,00
0,4
0,3
0,2
0,1
0,0
%TiO2_rom
%TiO2_concentrado
S
0,0352399
R-Sq
76,3%
R-Sq(adj)
76,0%
Regression
95% CI
TiO2_c70 = 0,03307 + 1,059 TiO2_rom
Fitted Line Plot
%SiO2_c70 = - 0,0598 + 7,893 TiO2_rom
Fitted Line Plot
%RM = 42,44 + 51,79 TiO2_rom
Fitted Line Plot
%RFe = 81,05 - 76,49 TiO2_rom
a)
b) Litotipo
Concentrado
Lama
QF
IFX
IF
HM
CGM
QF
IFX
IF
HM
CGM
100
80
60
40
20
0
%RTiO2
6,0
6,5
6,8
8,3
18,3
6,0
6,5
6,8
8,3
18,3
6,0
6,5
6,8
8,3
18,3
75,9
55,4
78,8
89,5
63,0
75,9
55,4
78,8
89,5
63,0
75,9
55,4
78,8
89,5
63,0
Fitted Line Plot
%SiO2_c70 = - 0,0598 + 7,893 TiO2_rom
Fitted Line Plot
%RM = 42,44 + 51,79 TiO2_ro
a) 0,30
0,25
0,20
0,15
0,10
0,05
0,00
0,4
0,3
0,2
0,1
0,0
%TiO2_rom
%TiO2_concentrado
S
0,0352399
R-Sq
76,3%
R-Sq(adj)
76,0%
Regression
95% CI
TiO2_c70 = 0,03307 + 1,059 TiO2_rom
m
Fitted Line Plot
%RFe = 81,05 - 76,49 TiO2_rom
b) Figura 2 - Comportamento do titânio durante o processamento do minério: recuperações em função da tipologia
(a) e correlação de teor no minério e no concentrado (b). Figura 3 - Efeito do teor de titânio no ROM no desempenho (sílica no concentrado, recuperação mássica e
metalúrgica) no processamento do minério. 4 RESULTADOS E DISCUSSÕES As amostras foram classificadas tipologicamente segundo os teores de ferro, fósforo e
alumina, além da descrição visual do testemunho. Grande parte das amostras foi classificada como
itabirito friável (IF), com pequena participação de cangas mineralizadas (CGM), localizadas nas
porções superficiais dos furos, seguido de quartzito ferruginoso (QF), itabirito friável com alta
alumina (IFX) e hematita (HM). As amostras de IFX e CGM apresentaram teores de óxido de titânio maior que as demais,
com exceção de algumas poucas classificadas como IF, Figura 1a. Além disso, foi observada uma
nítida correlação entre o teor de alumina e de óxido de titânio nas amostras de minério, Figura 1b. Suspeita-se que o titânio esteja presente em minerais associados a intrusões do manto de rochas
meta-diabásicas ricas em alumina e titânio durante os eventos de formação do depósito. Figura 1 - Teores de óxido de titânio das amostras avaliadas, classificadas em função da litologia (a) e em função
do teor de alumínio das mesmas (b). QF
IFX
IF
HM
CGM
0,30
0,25
0,20
0,15
0,10
0,05
0,00
Litotipo
%TiO2_rom
0,046
0,246
0,052
0,059
0,158
10
8
6
4
2
0
0,35
0,30
0,25
0,20
0,15
0,10
0,05
0,00
%Al2O3_rom
%TiO2_rom
CGM
HM
IF
IFX
QF
Litologia
R2 = 77,4
%TiO 2_rom = 0,008972 + 0,03415 x %A l2O 3_rom
a)
b) 10
8
6
4
2
0
0,35
0,30
0,25
0,20
0,15
0,10
0,05
0,00
%Al2O3_rom
%TiO2_rom
CGM
HM
IF
IFX
QF
Litologia
R2 = 77,4
%TiO 2_rom = 0,008972 + 0,03415 x %A l2O 3_rom
b) Figura 1 - Teores de óxido de titânio das amostras avaliadas, classificadas em função da litologia (a) e em função
do teor de alumínio das mesmas (b). Grande parte do titânio alimentado foi recuperado no concentrado, Figura 2a. Somente a
canga apresentou uma maior recuperação desse elemento nas lamas. Contudo, essa tipologia foi
a que apresentou uma maior perda de massa nas lamas também. Foi comprovado, através de análise de variância e pela correlação da Figura 2b, que o teor
de titânio no minério tem um grande efeito no seu teor no concentrado. HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 207 TURRER ET AL. (2014) 0,30
0,15
0,00
6
5
4
3
2
1
0
-1
-2
TiO2_rom
%SiO2_c70
S
0,677308
R-Sq
32,6%
R-Sq(adj)
31,8%
Regression
95% CI
95% PI
0,30
0,15
0,00
90
80
70
60
50
40
30
20
10
TiO2_rom
%RM
S
13,5570
R-Sq
4,9%
R-Sq(adj)
3,8%
0,30
0,15
0,00
100
90
80
70
60
50
40
30
TiO2_rom
%RFe
S
10,2564
R-Sq
16,5%
R-Sq(adj)
15,6% 0,30
0,15
0,00
6
5
4
3
2
1
0
-1
-2
TiO2_rom
%SiO2_c70
S
0,677308
R-Sq
32,6%
R-Sq(adj)
31,8%
Regression
95% CI
95% PI 0,30
0,15
0,00
90
80
70
60
50
40
30
20
10
TiO2_rom
%RM
S
13,5570
R-Sq
4,9%
R-Sq(adj)
3,8% 0,30
0,15
0,00
100
90
80
70
60
50
40
30
TiO2_rom
%RFe
S
10,2564
R-Sq
16,5%
R-Sq(adj)
15,6% Figura 3 - Efeito do teor de titânio no ROM no desempenho (sílica no concentrado, recuperação mássica e
metalúrgica) no processamento do minério. Algumas das amostras testadas sequer seriam consideradas minérios, por exibirem teores
de alumina elevados, maior que 8%, e baixo teor de ferro, menor que 25%. Por isso, as mesmas
não seriam direcionadas para usina de tratamento, mesmo em pequenas proporções. Ainda assim, a média das amostras restantes não representa a média de toda a região de
onde elas foram extraídas. Para a determinação desse valor, as massas representativas de cada
amostra no depósito deveriam ser consideradas para determinação da média ponderada, como
feito por Abongwa [9]. Uma vez que ainda não é possível determinar as massas representativas, é
aconselhável que somente as amostras de IF, que serão alimentadas em grandes proporções na
usina, sejam consideradas para projeção da qualidade média do concentrado. As amostras de IF
apresentaram qualidade média do ROM e do concentrado muito próxima do planejado. Contudo,
observa-se que algumas poucas amostras, 25% do total, estão com valores mais elevados. Em casos HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 208 TURRER ET AL. (2014) como esse, em que a variabilidade das amostras é elevada, valores extremos podem influenciar
muito a média. Nesses casos, a mediana se torna uma medida descritiva mais adequada para as
amostras [20]. Uma forma de quantificar a variabilidade é através do coeficiente de variação, razão
entre o desvio padrão e média. Quando o mesmo for superior a 20%, é aconselhável que a mediana
seja usada para representar a população. TURRER ET AL. (2014) As amostras apresentaram um coeficiente de variação
de 57% para o TiO2 no concentrado e uma mediana de 0,077%. como esse, em que a variabilidade das amostras é elevada, valores extremos podem influenciar
muito a média. Nesses casos, a mediana se torna uma medida descritiva mais adequada para as
amostras [20]. Uma forma de quantificar a variabilidade é através do coeficiente de variação, razão
entre o desvio padrão e média. Quando o mesmo for superior a 20%, é aconselhável que a mediana
seja usada para representar a população. As amostras apresentaram um coeficiente de variação
de 57% para o TiO2 no concentrado e uma mediana de 0,077%. Por fim, foram realizadas análises mineralógicas em busca da identificação do mineral
portador de titânio em duas amostras, uma de IF e outra de IFX, que apresentaram elevado teor
de titânio no ROM e no concentrado com morfologia distinta, Tabela I. Tabela I - Composição química das amostras analisadas em microscópio
Tipologia
Composição do minério (%)
Composição do concentrado (%)
Fe
Al2O3
SiO2
P
TiO2
Fe
Al2O3
SiO2
P
TiO2
IFX
53,5
8,01
14,2
0,111 0,287
67,2
1,07
0,7
0,044 0,282
IF
45,3
3,52
29,3
0,067 0,204
67,2
0,49
2,4
0,054 0,308 A análise das imagens geradas por microscópio eletrônico não permitiu a identificação de
nenhum mineral portador de titânio, como titanita ou ilmenita, indicando que o titânio poderia
estar presente na estrutura cristalina do mineral de ferro. Essa hipótese só poderá ser comprovada
com a utilização de outras técnicas de caracterização, como microscopia eletrônica de varredura
aliada a espectroscopia de energia dispersiva, como realizado por Rocha [16]. Contudo, optou-se
por não prosseguir com uma caracterização mais detalhada, uma vez que o objetivo principal do
estudo não era a caracterização da fonte de titânio e o mesmo não apresentou efeito significativo
no desempenho do processamento mineral e nem na qualidade final do concentrado. Na Figura 4, um exemplo das imagens obtidas, é possível identificar uma série de óxidos de
ferro e quartzo, mas nenhum mineral de titânio. Figura 4 - Imagem obtida em microscópio de concentrado (IF) com elevado teor de titânio. Figura 4 - Imagem obtida em microscópio de concentrado (IF) com elevado teor de titânio. 6 AGRADECIMENTOS Os autores gostariam de registrar o agradecimento aos colegas de Anglo American
Aguinaldo Pereira Sander, Junio Simões Pereira, Marcelo de Castro, Naldio da Silva Vertelo, Rodrigo
Faustino Gomes pela dedicação, esforço e comprometimento na realização dos testes e análises. 7 REFERÊNCIAS BIBLIOGRÁFICAS 1. PARK, P.; OSTROVSKI, O. Reduction of Titania–Ferrous Ore by Carbon Monoxide. ISIJ
International, v. 43, n.9, p.1316-1325, 2003. 1. PARK, P.; OSTROVSKI, O. Reduction of Titania–Ferrous Ore by Carbon Monoxide. ISIJ
International, v. 43, n.9, p.1316-1325, 2003. 2. PARK, P.; OSTROVSKI, O. Reduction of Titania–Ferrous Ore by Hydrogen. ISIJ International,
v.44, n.6, p.999-1005, 2004. 2. PARK, P.; OSTROVSKI, O. Reduction of Titania–Ferrous Ore by Hydrogen. ISIJ International,
v.44, n.6, p.999-1005, 2004. 3. BUDZIK, R. The balance of titanium and vanadium in the blast furnace with the use of sinter
containing a titanium-vanadium-magnetite concentrate. Metalurgia, v. 46, n. 2, p.145-147,
2007 apud Domingues, A. L. A.; Scudeller, L. A. M.; Pereira, A. S. G. Caracterização mineralógica
de concentrado magnetítico com presença de titânio e bário. In: Anais do 41º Seminário de
Redução de Minério de Ferro e Matérias-primas e 12º Seminário Brasileiro de Minério de
Ferro. p.928-939, 2011. 3. BUDZIK, R. The balance of titanium and vanadium in the blast furnace with the use of sinter
containing a titanium-vanadium-magnetite concentrate. Metalurgia, v. 46, n. 2, p.145-147,
2007 apud Domingues, A. L. A.; Scudeller, L. A. M.; Pereira, A. S. G. Caracterização mineralógica
de concentrado magnetítico com presença de titânio e bário. In: Anais do 41º Seminário de
Redução de Minério de Ferro e Matérias-primas e 12º Seminário Brasileiro de Minério de
Ferro. p.928-939, 2011. 4. HYL. Disponível em <http://www.energiron.com/Tour/HYL%20DR-Minimill%20QTVR%20tour
/start.html> Acessado em: 08/01/2013. 5. WU, J.Y.; HO, C.K. Investigation of Titanium Compound Formation in the Blast Furnace Hearth. China Steel Technical Report, n.22, p.23-28, 2009. 6. PEREIRA, J.L.G.; CAMPANHOLO, B.A.; SILVA, M.B.L.; SILVA, A.L.; SILVA, R.B.L. Titanium Goiás –
Decades of experience in marketing of ilmenite for blast furnaces in Brazil. In: Proceedings of
6th International Congress on the Science and Technology of Ironmaking, 42nd International
Meeting on Ironmaking and 13th International Symposium on Iron Ore, p.642-657, 2012. 7. MANSO, G.A.C.; SANTOS, G.S.; OLIVEIRA, M.A.G.; FERNANDES, M.V.; AMIRZADEH-ASL, D.;
FÜNDERS, D. Preservação do cadinho do alto forno 3 da Usiminas com injeção de titânio
sintético. In: Anais do 41º Seminário de Redução de Minério de Ferro e Matérias-primas e 12º
Seminário Brasileiro de Minério de Ferro, p.533-543, 2011. 8. OKANO, A.N. Influência do titânio na microestrutura e propriedades mecânicas de um aço C-
Mn microligado com 0,08 a 0,16% de titânio produzindo em tiras laminadas a quente. 5 CONCLUSÕES O teor de dióxido de titânio no ROM é diretamente proporcional ao teor de alumina. A
média de TiO2 das amostras analisadas é igual a 0,069%. O titânio é recuperado preferencialmente HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 209 TURRER ET AL. (2014) no concentrado, ou, em outras palavras, 76% do TiO2 alimentado foi, em média, recuperado no
concentrado. O teor de titânio no ROM não afetou o desempenho do processamento mineral. Foi
possível estimar o teor médio de TiO2 no concentrado do minério extraído da região como sendo
igual a 0,077%. Não foram identificados minerais portadores de titânio. no concentrado, ou, em outras palavras, 76% do TiO2 alimentado foi, em média, recuperado no
concentrado. O teor de titânio no ROM não afetou o desempenho do processamento mineral. Foi
possível estimar o teor médio de TiO2 no concentrado do minério extraído da região como sendo
igual a 0,077%. Não foram identificados minerais portadores de titânio. TURRER ET AL. (2014) 126p., 2009. 126p., 2009. 10. SALES, C. G.;LIPPER, G.;PAULA, N. N.;PEREIRA, J. M.;ROBERTO, J. B.; FONSECA, A.;MACHADO,
B. H. Otimização do circuito de flotação reversa de minério de ferro da usina de concentração
de Brucutu. In: Anais do 40º Seminário de Redução de Minério de Ferro e Matérias-primas e
11º Seminário Brasileiro de Minério de Ferro, p.111-118, 2010. 11. TOTOU, A.R. Efeito da dispersão em polpas de minérios hematíticos com elevado grau de
hidratação. In: Anais do 40º Seminário de Redução de Minério de Ferro e Matérias-primas e
11º Seminário Brasileiro de Minério de Ferro, p.186-194, 2010. 11. TOTOU, A.R. Efeito da dispersão em polpas de minérios hematíticos com elevado grau de
hidratação. In: Anais do 40º Seminário de Redução de Minério de Ferro e Matérias-primas e
11º Seminário Brasileiro de Minério de Ferro, p.186-194, 2010. 12. SANTOS; D.F.; VIANA, P.R.M.; ARAUJO, A.C.; SANTOS, J.G.; TEIXEIRA, H.G. Flotação de minérios
de ferro anfibolíticos – uma revisão. In: Anais do 39º Seminário de Redução de Minério de
Ferro e Matérias-primas e 10º Seminário Brasileiro de Minério de Ferro, 10p., 2009. 13. ZAPPAROLI, A.C.; GUIMARÃES, N.C.; PIRET, W.; CALIXTO, M.; PAULA, C.J.; BENTO, P.; SIMÕES,
H.G. Reaproveitamento de depósitos de rejeitos de minério de ferro nos sistemas sul e sudeste
da vale: exemplo da barragem de córrego do feijão. Anais do 39º Seminário de Redução de
Minério de Ferro e Matérias-primas e 10º Seminário Brasileiro de Minério de Ferro, 12p., 2009. 14. LIMA, R.M.F.; LOPES, G.M.; GONTIJO, C.F. Flotação inversa de minérios de ferro de baixos
teores do quadrilátero ferrífero – MG. In: Anais do 40º Seminário de Redução de Minério de
Ferro e Matérias-primas e 11º Seminário Brasileiro de Minério de Ferro, p.155-164, 2010. 15. DOMINGUES, A.L.A.; SCUDELLER, L.A.M.; PEREIRA, A.S.G. Caracterização mineralógica de
concentrado magnetítico com presença de titânio e bário. In: Anais do 41º Seminário de
Redução de Minério de Ferro e Matérias-primas e 12º Seminário Brasileiro de Minério de
Ferro, p.928-939, 2011. 16. ROCHA, J.M.P. Caracterização Mineralógica de minérios goethíticos-limoníticos da mina de
Alegria, MG. Dissertação de Mestrado em Engenharia Metalúrgica e de Minas da Escola de
Engenharia da UFMG, 263p., 1997. 17. FERNANDES, E.Z. Caracterização física, química, mineralógica e metalúrgica dos produtos
granulados de minério de ferro. Tese de Doutorado em Engenharia Metalúrgica e de Minas da
Escola de Engenharia da UFMG, 299p., 2008. 18. SAMARCO. Disponível em <http://www.samarco.com/uploads/xgccbf.pdf> Acessado em:
08/01/2013. 19. HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 7 REFERÊNCIAS BIBLIOGRÁFICAS Dissertação de Mestrado em Engenharia Metalúrgica e de Minas da Escola de Engenharia da
UFMG, 80p., 1985. 8. OKANO, A.N. Influência do titânio na microestrutura e propriedades mecânicas de um aço C-
Mn microligado com 0,08 a 0,16% de titânio produzindo em tiras laminadas a quente. Dissertação de Mestrado em Engenharia Metalúrgica e de Minas da Escola de Engenharia da
UFMG, 80p., 1985. 9. ABONGWA, P.W. Mineral texture and composition of magnetite in the sahavaara IOCG
deposit, Pajala área – A mineral processing approach. Master’s thesis presented to the
Departmant of Chemincal Engineering and Geosciences of Lulea University of Technology, 9. ABONGWA, P.W. Mineral texture and composition of magnetite in the sahavaara IOCG
deposit, Pajala área – A mineral processing approach. Master’s thesis presented to the
Departmant of Chemincal Engineering and Geosciences of Lulea University of Technology, HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 210 20. STEVENSON, W.J. Estatística aplicada à administração. Harper & Row do Brasil, p.23, 1981. BHP. Disponível em <http://www.google.com.br/url?sa=t&rct=j&q=bhp%20billiton%20pro
duct%20specifications_march%202012&source=web&cd=1&cad=rja&ved=0CDQQFjAA&url=
http%3A%2F%2Fwww.bhpbilliton.com%2Fhome%2Fbusinesses%2FDocuments%2FBHP%252
0Billiiton%2520Product%2520Specifications%2520June%25202011.pdf&ei=k1rsULLUHtSY1A
WjloGgDQ&usg=AFQjCNFcS3-WmfSYIrxwj07hxY_ur72RkA&bvm=bv.1357316858,d.d2k>
Acessado em: 08/01/2013. HOLOS, Ano 30, Vol. 3 - Edição Especial - XXV ENTMME / VII MSHNT 211
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English
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Archaeologia Polona
| 2,022
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cc-by
| 947
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SPECIAL THEME:
THE LORDS OF FLINT – 100TH ANNIVERSARY OF THE DISCOVERY
OF THE PREHISTORIC STRIPED FLINT MINES IN KRZEMIONKI The Centenary of the Discovery of the Prehistoric Striped Flint Mines in Krzemionki
Andrzej Przychodni and Artur Jedynak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Krzemionki in the Literature Published in the Years 1923–1939
Magdalena Malak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Non-invasive Investigation of Segment C of the Krzemionki Exploitation Field. Initial Research Results
Artur Jedynak and Piotr Wroniecki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Re-working the Past: Evidence for Late Neolithic and Early Bronze Age Flint Extraction
at the Early Neolithic Mines of Sussex
Jon Bączkowski . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
At the Turn: Flint Mining as an Element of Social Changes in the Second Half
of the Fifth Millennium BC in Western Lesser Poland
Elżbieta Trela-Kieferling and Damian Stefański . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Workshop Places at Chessy (Seine-et-Marne Dpt., France): Contextual and Technological Aspects
Anne Hauzeur, Gilles Monin, Harold Lethrosne, Paul Fernandes and Vincent Delvigne . . . . . . . . . . SPECIAL THEME:
THE LORDS OF FLINT – 100TH ANNIVERSARY OF THE DISCOVERY
OF THE PREHISTORIC STRIPED FLINT MINES IN KRZEMIONKI 109
The Flint Quarry of Pozarrate (Treviño, Spain) in the Context of Iberian and Early European
Neolithic Mining
Antonio Tarriño, Irantzu Elorrietab, Diego Alonso-Herrero, Cristina López-Tascón,
Hugo Hernández-Hernández, Nuria Castañeda, David Larreina, Mikel Aguirre
and José Antonio Mujika . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Mapping Natural Exposures of Siliceous Marls and Cherts as Potential Zones of Raw Material
Acquisition. The Case of the Eastern Polish Carpathian Foothills and the Rzeszów
Settlement Region (SE Poland) in the Neolithic and Bronze Age. Preliminary Results
Andrzej Pelisiak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Striped Flint in Archaeological Materials Around the Outcrops of the Kraków-Częstochowa
Striped Flint Variety
Magdalena Sudoł-Procyk, Magdalena Malak, Hubert Binnebesel and Maciej T. Krajcarz . . . . . . . . 163
Prehistoric Stone Raw Materials from the Bükk Mountains in Northeastern Hungary
Norbert Faragó, Réka Katalin Péter, Orsolya Viktorik, László Máté and Zsolt Mester . . . . . . . . . . . . 187 Online access to previous volumes of Archaeologia Polona is available at the address:
https://journals.iaepan.pl/apolona
Archaeologia Polona is regularly indexed in the International Bibliography of the Social
Sciences; in IBZ – International Bibliography of Periodical Literature; IBZ – CD-ROM;
IBR – International Bibliography of Book Reviews of Scholarly Literature; IBR – CD-ROM.
Archaeologia Polona is included within the database of the Anthropological Index Online of the
Royal Anthropological Institute of Great Britain and Ireland (http://www.aio.anthropology.org.uk). BOOK REVIEWS Wojciech Brzeziński (ed.), Kopalnie krzemienia na stanowisku „Za garncarzami” w Ożarowie
[Flint mines at the “Za garncarzami” site in Ożarów], Warsaw 2020
Hubert Binnebesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Elżbieta Trela-Kieferling (ed.), Nakopalniane pracownie krzemieniarskie z okresu neolitu w Bęble,
stan. 4, woj. małopolskie [Neolithic Flint Workshops at the Mine in Bębło, Site 4,
Małopolska]. Kraków 2021
Dagmara H. Werra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
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NFAT5-mediated expression of S100A4 contributes to proliferation and migration of renal carcinoma cells
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Frontiers in physiology
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cc-by
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Christoph Küper 1*, Franz-Xaver Beck 1 and Wolfgang Neuhofer 2 Christoph Küper 1*, Franz-Xaver Beck 1 and Wolfgang Neuhofer 2 Christoph Küper 1*, Franz-Xaver Beck 1 and Wolfgang Neuhofer 2 1 Department of Physiology, University of Munich, Munich, Germany
2 Department of Internal Medicine, Medical Faculty of Mannheim, Medical Clinic V, University of Heidelberg, Mannheim, Germany 1 Department of Physiology, University of Munich, Munich, Germany
2 Department of Internal Medicine, Medical Faculty of Mannheim, Medical Clinic V, University of Heidelberg, Mannheim, Germany The osmosensitive transcription factor nuclear factor of activated T-cells (NFAT) 5, also
known as tonicity enhancer binding protein (TonEBP), has been associated with the
development of a variety of tumor entities, among them breast cancer, colon carcinoma,
and melanoma. The aim of the present study was to determine whether NFAT5 is also
involved in the development of renal cell carcinoma (RCC). The most common type of
RCC, the clear cell RCC, originates from the proximal convoluted tubule. We tested
our hypothesis in the clear cell RCC cell line CaKi-1 and the non-cancerous proximal
tubule cell line HK-2, as control. Basal expression of NFAT5 and NFAT5 activity in CaKi-1
cells was several times higher than in HK-2 cells. Osmotic stress induced an increased
NFAT5 activity in both CaKi-1 and HK-2 cells, again with significantly higher activities
in CaKi-1 cells. Analysis of NFAT5-regulating signaling pathways in CaKi-1 cells revealed
that inhibition of the MAP kinases p38, c-Jun-terminal kinase (JNK) and extracellular
regulated kinase (ERK) and of the focal adhesion kinase (FAK) partially blunted NFAT5
activity. FAK and ERK were both constitutively active, even under isotonic conditions,
which may contribute to the high basal expression and activity of NFAT5 in CaKi-1 cells. In contrast, the MAP kinases p38 and JNK were inactive under isotonic conditions and
became activated under osmotic stress conditions, indicating that p38 and JNK mediate
upregulation of NFAT5 activity under these conditions. siRNA-mediated knockdown of
NFAT5 in CaKi-1 cells reduced the expression of S100A4, a member of the S100 family
of proteins, which promotes metastasis. Knockdown of NFAT5 was accompanied by a
significant decrease in proliferation and migration activity. Taken together, our results
indicate that NFAT5 induces S100A4 expression in CaKi-1 cells, thereby playing an
important role in RCC proliferation and migration. Edited by: Edited by:
Hyug Moo Kwon, Ulsan National
Institute of Science and Technology,
South Korea Edited by:
Hyug Moo Kwon, Ulsan National
Institute of Science and Technology,
South Korea Reviewed by:
Sang Do Lee, Chungnam National
University School of Medicine,
South Korea
Soo Youn Choi, Ulsan National
Institute of Science and Technology,
South Korea *Correspondence:
Christoph Küper, Department of
Physiology, University of Munich,
Pettenkoferstrasse 12,
80336 Munich, Germany
e-mail: christoph.kueper@
lrz.uni-muenchen.de *Correspondence:
Christoph Küper, Department of
Physiology, University of Munich,
Pettenkoferstrasse 12,
80336 Munich, Germany
e-mail: christoph.kueper@
lrz.uni-muenchen.de ORIGINAL RESEARCH ARTICL
published: 08 August 201
doi: 10.3389/fphys.2014.0029
NFAT5-mediated expression of S100A4 contributes to
proliferation and migration of renal carcinoma cells ORIGINAL RESEARCH ARTICLE
bli h d 08 A
t 2014 ORIGINAL RESEARCH ARTICLE
bli h d 08 A
t 2014 published: 08 August 2014
doi: 10.3389/fphys.2014.00293 Keywords: NFAT5, S100A4, renal cell carcinoma, CaKi-1, cell proliferation, cell migration www.frontiersin.org INTRODUCTION involved signaling pathways have been approved in recent years
(Motzer, 2011). Although these agents increase the therapeutic
options in the treatment of metastatic RCC, continuous research
is necessary to gain a better insight to the biological basis of car-
cinogenesis and metastasis of renal tubular cells and to identify
potential targets for new therapeutic strategies. Renal cell carcinoma (RCC) was the sixth and eighth most com-
mon malignancy among men and women, respectively, in 2012,
contributing to almost 14,000 deaths in the US (Siegel et al.,
2012). The most common type of RCC, the clear cell RCC orig-
inates from the proximal convoluted tubule. Metastatic RCC in
particular has a very poor prognosis due to the high resistance of
the tumors to conventional radiation-, immune-, and chemother-
apies. To develop new therapeutic strategies, significant efforts
have been made in the last two decades to identify the genetic
basis of clear cell RCC. In most cases of sporadic RCC, deletion
or mutation of the tumor suppressor gene Von-Hippel-Lindau
(VHL) can be detected (Linehan et al., 2003). Under normoxic
conditions, VHL catalyzes ubiquitination and, hence, degradation
of the transcription factor hypoxia-inducible factor α (HIF-α). Loss of VHL results in accumulation of HIF-α even under nor-
moxic conditions and downstream induction of diverse growth
and angiogenic factors that contribute to malignant transforma-
tion of tubular epithelial cells (Patel et al., 2006). Based on these
observations, several new pharmaceutical agents that target the The aim of the present study was to determine whether the
osmosensitive transcription factor nuclear factor of activated T-
cells (NFAT) 5, also known as tonicity enhancer binding protein
(TonEBP), is involved in the development of RCC. The NFAT
protein family consists of five members (NFAT1-5) that con-
tain a DNA-binding domain with structural similarity to the
Rel-homology-region of NF-κB (Muller and Rao, 2010). While
activity of NFAT1-4 is regulated by calcineurin, NFAT5 activity
is modulated under hyperosmotic conditions at various lev-
els: increased expression, increased transcriptional activity, and
increased nuclear localization. Upon activation, NFAT5 binds to
tonicity enhancer (TonE) elements in the regulatory region of
target genes to stimulate transcription (Cheung and Ko, 2013). NFAT5 was discovered originally in the renal medulla, where it August 2014 | Volume 5 | Article 293 | 1 www.frontiersin.org www.frontiersin.org NFAT5 and renal cell carcinoma Küper et al. METHODS
MATERIALS Pharmacological inhibitors SB202190, SP600125, U0126, SrcI-
1, and PF-228 were obtained from Sigma (Deisenhofen,
Germany). Anti-NFAT5 antibody, anti-Src antibody, anti-FAK
antibody, and anti-phospho-FAK antibody were from Santa Cruz
Biotechnology (Santa Cruz, CA, USA); anti-actin antibody was
from Sigma; anti-p38, anti-phospho-p38, anti-ERK1/2, anti-
phospho-ERK1/2, anti-JNK, anti-phospho-JNK, and horseradish
peroxidase-conjugated anti-rabbit IgG were purchased from Cell
Signaling (Beverly, MA, USA); anti-phospho–Src antibody was
from Abgent (Suzhou, China); anti-S100A4 antibody was from
Spring Bioscience (Pleasanton, CA, USA). Accell SMARTpool
siRNA constructs for knockdown of NFAT5 or S100A4, and qRT-PCR ANALYSIS
d For determination of NFAT5, S100A4, AR, and β-Actin mRNA
expression levels, the total RNA from HK-2 or CaKi-1 cells
was prepared by adding TRIFAST Reagent (Peqlab, Erlangen,
Germany). The primers (Metabion, Martinsried, Germany) used
in this experiment are: NFAT5_fw: 5′- AAT CGC CCA AGT CCC TCT AC -3′;
NFAT5_rev: 5′- GGT GGT AAA GGA GCT GCA AG -3′;
Actin_fw: 5′- CCA ACC GCG AGA AGA TGA -3′;
Actin_rev: 5′- CCA GAG GCG TAC AGG GAT AG -3′;
S100A4_fw: 5′-CGC TTC TTC TTT CTT GGT TTG-3′;
S100A4_rev: 5′-GAG TAC TTG TGG AAG GTG GAC A-3′;
AR_fw: 5′ATC CGA GCC AAG CAC AAT AA -3′;
AR_rev: 5′-AGC AAT GCG TTC TGG TGT CA -3′ Experiments were caried out on a Roche LightCycler 480
using the SensiMix SYBR One-Step Kit (Bioline, Luckenwalde,
Germany) according to the manufacturer’s recommendations. Specificity of PCR product formation was confirmed by melting
point analysis and by agarose gel electrophoresis. In the present study, we provide evidence that NFAT5
and S100A4 are expressed abundantly in RCC cells, proba-
bly due to the constitutive activation of the extracellular reg-
ulated kinase (ERK). Under hyperosmotic conditions, NFAT5
is upregulated and, in turn, induces enhanced expression
of S100A4. Knockdown of NFAT5 blunts S100A4 expression
and also decreased proliferation and migration activity of the
cells. CELL CULTURE Immortalized human proximal tubule cells HK-2 (ATCC
CRL-2190) and clear cell renal carcinoma cells CaKi-1 (ATCC
HTB-46) were cultured in RPMI 1640 supplemented with 10%
fetal bovine serum (FBS; Biochrom, Berlin, Germany), 100
units/ml penicillin, and 100 μg/ml streptomycin (Invitrogen,
Karlsruhe, Germany). Cells were grown at 37◦C in a humidified
atmosphere (95% air/5% CO2). For experiments involving
pharmacological inhibitors, cells were preincubated for 30 min
with the appropriate inhibitor; medium osmolality was increased
by addition of NaCl. p
Various reports have also suggested involvement of NFAT5 in
the pathogenesis of various tumor entities, such as non-small cell
lung cancer (Zhong et al., 2004; Mijatovic et al., 2006), melanoma
(Levy et al., 2010), leiomyoma (McCarthy-Keith et al., 2011),
breast cancer (Jauliac et al., 2002; Chen et al., 2009; Germann
et al., 2012), or colon carcinoma (Chen et al., 2011; Slattery
et al., 2011; Alvarez-Diaz et al., 2012). In colon and breast car-
cinoma cells NFAT5 drives the expression of the pro-metastatic
factor S100A4, also known as metastasin (Chen et al., 2009, 2011). S100A4 belongs to the family of S100 proteins that consists of
at least 21 calcium-binding, low-molecular-weight (10–12 kDa)
proteins with no known enzymatic activity. S100 proteins form
homo- or heterodimers that bind to various target proteins,
thereby modulating their activities. Many studies indicated a
pathophysiological role for S100A4 in the development of can-
cer by promoting proliferation, angiogenesis, cell motility and
invasiveness (Garrett et al., 2006). S100A4 binds to several target
proteins, among them the tumor suppressor p53 and the non-
muscle myosin IIa. Recent studies suggest that S100A4 also plays
a role in the development of RCC and may be useful as prognostic
marker (Bandiera et al., 2009; Lopez-Lago et al., 2010; Wang et al.,
2012; Yang et al., 2012). INTRODUCTION drives the expression of osmoprotective genes such as betaine-
GABA-transporter-1 (BGT-1) (Miyakawa et al., 1998), aldose
reductase (AR) (Miyakawa et al., 1999), sodium-myo-inositol
transporter (Smit) (Miyakawa et al., 1999), taurine transporter
(TauT) (Zhang et al., 2003) or heat shock protein (HSP) 70 (Woo
et al., 2002), as well as genes that are part of the urinary con-
centrating mechanism, such as aquaporin-2 (AQP-2) and urea
transporter-A (UT-A) (Han et al., 2004). Besides this function in
the kidney, NFAT5 also plays important roles in other cells and
tissues, partly in a tonicity-independent manner, during embry-
onic development, cell differentiation, inflammatory processes,
and cellular stress response (Halterman et al., 2012). Accell non-targeting siRNA (#2) were obtained from Thermo
Fisher Scientific (Epsom, UK). Unless otherwise indicated, other
reagents were purchased from Biomol (Hamburg, Germany),
Biozol (Eching, Germany), Carl Roth (Karlsruhe, Germany), or
Sigma. IMMUNOBLOT ANALYSIS Aliquots (10–30 μg protein) were subjected to sodium dode-
cylsulphate polyacrylamide gelelectrophoresis (SDS-PAGE) and
blotted onto nitrocellulose membranes (Amersham Pharmacia
Biotech, Buckinghamshire, UK). Non-specific binding sites were
blocked with 5% non-fat dry milk in PBS containing 0.1%
Tween-20 (PBS-T) at room temperature for 1 h. Samples were
incubated with primary antibodies in PBS-T containing 5%
non-fat dry milk over night at 4◦C. Subsequently, the blots were
washed 3 times with PBS-T for 5 min each and the membranes
then incubated with appropriate secondary antibody at room
temperature for 1 h in PBS-T containing 5% non-fat dry milk. After washing with PBS-T 3 times for 5 min each, immunocom-
plexes were visualized by enhanced chemiluminescence (Pierce,
Rockford, IL, USA). NFAT5 AND NFAT5 TARGET GENES ARE EXPRESSED ABUNDANTLY IN
RENAL CARCINOMA CELLS The cell line CaKi-1 was used as model for metastatic clear cell
RCC. As non-cancerous control cells, the proximal tubule cell
line HK-2 was used. Expression of NFAT5 in CaKi-1 and HK-2
cells was determined at both the mRNA (Figure 1A) and pro-
tein (Figure 1B) levels. NFAT5 levels were significantly higher in
CaKi-1 cells compared to HK-2 cells. In both cell lines, NFAT5
expression increased during hyperosmotic stress (Figures 1A,B),
whilst again expression levels were significantly higher in CaKi-
1 cells. Expression of S100A4 was almost completely absent in
HK-2 cells, while substantial amounts were present in CaKi-1
cells. Under hyperosmotic stress conditions, S100A4 expression
in CaKi-1 cells increased further. As control, we also evalu-
ated expression levels of the well-defined NFAT5 target gene
AR. In accordance with the results above, expression levels of
AR were also enhanced in CaKi-1 cells, presumably due to
increased NFAT5 activity. Cellular activity of NFAT5 in CaKi-
1 and HK-2 cells was assayed using a TonE-driven reporter
vector. Cells, transiently transfected with the reporter con-
struct, were incubated for 24 h in iso- or hyperosmotic medium. Basal NFAT5 activities under isoosmotic conditions were sig-
nificantly higher in CaKi-1 cells (Figure 1C). Under hyperos-
motic conditions, NFAT5 activity increased approximately 10
times in both cell types, and hence was significantly higher in
CaKi-1 cells, which is in accordance with the higher expres-
sion levels of the NFAT5 target genes S100A4 and AR in these
cells. REPORTER GENE ASSAYS Activation of NFAT5 in response to hyperosmolality was assessed
using the secreted alkaline phosphatase system (SEAP), with August 2014 | Volume 5 | Article 293 | 2 Frontiers in Physiology | Integrative Physiology NFAT5 and renal cell carcinoma Küper et al. a reporter construct, in which the SEAP open reading frame
is under control of two TonE sites (Neuhofer et al., 2007). As transfection control, the vector pcDNA3-lacZ, expressing β-
galactosidase under the control of the constitutive active CMV
promoter, was co-transfected. For transfection, CaKi-1 or HK-
2 cells were grown to ∼80% confluency, trypsinated, washed
in PBS and ∼106 cells were finally resuspended in 200 μl
modified HBS electroporation buffer (0.5% HEPES, 1% glu-
cose, 0.5% Ficoll, 5 mM NaCl, 135 mM KCl, 2 mM MgCl2,
pH 7.4) together with 10 μg reporter vector. Electroporation
was carried out with a Gene Pulser Xcell Electroporation
System (Biorad, Hercules, CA, USA) at 140 V and 1000 μF
(exponential decay pulse) in a 2-mm cuvette and the cells
seeded immediately thereafter in 96-well plates. After growing
to confluency, the cells were treated as indicated and SEAP
activity in the medium determined as described in detail else-
where (Neuhofer et al., 2007). SEAP activity was normalized
to β-galactosidase activity to adjust for uneven transfection of
cells. confluency. Subsequently, Accell delivery medium was replaced
by RPMI 1640 medium + 10% FCS and the cell momolayer
was “scratched” with a 10 μl pipette tip. Cell migration to
close the scratch was monitored by capturing images in regular
intervals. KNOCKDOWN OF NFAT5 AND S100A4 CaKi-1 cells were grown to ∼80% confluency, trypsinated,
washed in PBS and finally resuspended in 100 μl modified
HBS electroporation buffer (see above) containing 2 μM of
NFAT5 siRNA, S100A4 siRNA or unspecific Accell non-targeting
siRNA (#2), as control. Electroporation was carried out as
described above. Cells were incubated for 5 days, and knock-
down efficiency was determined by qRT-PCR or by Western blot
analysis. PROLIFERATION AND SURVIVAL ASSAY For proliferation assays, CaKi-1 cells were transfected with
NFAT5-specific, S100A4-specific, or unspecific (control)-siRNA
constructs by electroporation as described above. After the elec-
tric pulse, cells were seeded immediately in 96-well plates at a den-
sity of ∼104 cells/well. After 4 days, viable cells were determined
using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bro-
mide (MTT) assay. For this purpose, cells were incubated with
MTT (final concentration 0.5 mg/ml in growth medium) for
2 h at 37◦C. Thereafter, growth medium was removed and for-
mazan crystals were solubilized in 200 μl acidified isopropanol
and absorption was rmeasured at 570 nm. For cell survival
assays, cells were treated as described above, but after 4 days
the medium osmolality was raised to 600 mosmol/kg H2O by
addition of NaCl, and cells were incubated for an additional
24 h. Thereafter, viable cells were determined by MTT assay as
described. KNOCKDOWN OF NFAT5 BLUNTS S100A4 EXPRESSION IN CaKi-1 CELLS
To confirm that NFAT5 regulates the expression of S100A4
in CaKi-1 cells, we knocked down NFAT5 in CaKi-1 cells. Transfection of the cells with a NFAT5-specific siRNA construct
resulted in an approximately 80% reduction of NFAT5 expres-
sion compared with cells transfected with an unspecific control
siRNA (Figure 2). NFAT5 knockdown was accompanied by sig-
nificantly reduced S100A4 expression, both under isosmotic and
hyperosmotic conditions (Figure 2). Accordingly, the expression
of the designated NFAT5 target gene AR was also significantly
decreased in NFAT5-knockdown cells. We also performed siRNA-
mediated knockdown of S100A4; as expected, this maneuver had
no significant effect on expression of NFAT5 or AR. These results
suggest strongly that S100A4 expression in CaKi-1 cells is under
the control of NFAT5. STATISTICAL ANALYSES Data are expressed as means ± s.e.m. The significance of differ-
ences between the means was assessed by Student’s t-test. P < 0.05
was regarded as significant. All experiments were performed at
least 3 times and representative results are shown. SCRATCH ASSAY (B) Cells were incubated for 24 h and subsequently
processed for immunoblotting to determine expression of NFAT5, S100A4,
and AR as described in Methods. To demonstrate comparable protein
loading, the blots were also probed for β-actin. Representative blots from 4
independent experiments are shown. (C) Cells were transfected transiently
with a reporter construct in which the SEAP gene is under control of two
TonE sites. After 24 h incubation in iso- or hyperosmotic medium, SEAP
activity was measured as described in Methods. Data are means ± s.e.m. for
n = 4 per point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. FIGURE 1 | Expression of NFAT5 and NFAT5 target genes in CaKi-1 and
HK-2 cells. CaKi-1 cells, as model for clear cell renal cell carcinoma, or HK-2
cells, as proximal tubular control cells, were kept in isoosmotic medium (■; p
p
300 mosm/kg H2O) or were exposed to hyperosmotic medium (■;
500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A)
Cells were incubated for 6 h (for determination of NFAT5 transcription) or 16 h
(for determination of S100A4 and AR transcription). Thereafter, RNA was
extracted and the abundance of NFAT5, S100A4, AR, and β-actin mRNA
transcripts determined by qRT-PCR as described in Methods. Relative mRNA
abundance of NFAT5, S100A4, or AR was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per p
p
300 mosm/kg H2O) or were exposed to hyperosmotic medium (■;
500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A)
Cells were incubated for 6 h (for determination of NFAT5 transcription) or 16 h
(for determination of S100A4 and AR transcription). Thereafter, RNA was
extracted and the abundance of NFAT5, S100A4, AR, and β-actin mRNA
transcripts determined by qRT-PCR as described in Methods. Relative mRNA
abundance of NFAT5, S100A4, or AR was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per SCRATCH ASSAY To demonstrate comparable protein
loading, the blots were also probed for β-actin. Representative blots from 4
independent experiments are shown. (C) Cells were transfected transiently
with a reporter construct in which the SEAP gene is under control of two
TonE sites. After 24 h incubation in iso- or hyperosmotic medium, SEAP
activity was measured as described in Methods. Data are means ± s.e.m. for
n = 4 per point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. FIGURE 1 | Expression of NFAT5 and NFAT5 target genes in CaKi-1 and
HK-2 cells. CaKi-1 cells, as model for clear cell renal cell carcinoma, or HK-2
cells, as proximal tubular control cells, were kept in isoosmotic medium (■;
300 mosm/kg H2O) or were exposed to hyperosmotic medium (■;
500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A)
Cells were incubated for 6 h (for determination of NFAT5 transcription) or 16 h
(for determination of S100A4 and AR transcription). Thereafter, RNA was
extracted and the abundance of NFAT5, S100A4, AR, and β-actin mRNA
transcripts determined by qRT-PCR as described in Methods. Relative mRNA
abundance of NFAT5, S100A4, or AR was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per FIGURE 1 | Expression of NFAT5 and NFAT5 target genes in CaKi-1 and
HK-2 cells. CaKi-1 cells, as model for clear cell renal cell carcinoma, or HK-2
ll
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k
i
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i
di
(■ point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. (B) Cells were incubated for 24 h and subsequently
processed for immunoblotting to determine expression of NFAT5, S100A4,
and AR as described in Methods. To demonstrate comparable protein
loading, the blots were also probed for β-actin. Representative blots from 4
independent experiments are shown. (C) Cells were transfected transiently
with a reporter construct in which the SEAP gene is under control of two
TonE sites. After 24 h incubation in iso- or hyperosmotic medium, SEAP
activity was measured as described in Methods. Data are means ± s.e.m. for
n = 4 per point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. KNOCKDOWN OF NFAT5 AND S100A4 DECREASES PROLIFERATION
AND MIGRATION OF CaKi-1 CELLS were exposed to hyperosmotic conditions (600 mosm/kg H2O)
for 24 h and cell survival determined by MTT assay. Compared
with control cells incubated under isosmotic conditions, ∼80%
of CaKi-1 cells transfected with a control or S100A4-siRNA con-
struct survived hyperosmotic stress conditions (Figure 3C), while
only ∼65% of NFAT5-knockdown cells survived under these
conditions. S100A4 is known to stimulate proliferation and metastasis in
renal carcinoma cells (Yang et al., 2013). In the knockdown exper-
iments described above, we noticed decelerated growth of CaKi-1
cells transfected with NFAT5- or S100A4-specific siRNA, presum-
ably due to downregulation of S100A4. To quantify this effect,
we transfected CaKi-1 cells with NFAT5-specific siRNA, S100A4-
specific siRNA or unspecific control siRNA, let the cells grow
for 96 h in a 96-well plate and determined the number of viable
cells by MTT assay. As shown in Figure 3A, NFAT5 siRNA and
S100A4 siRNA had significant inhibitory effects on CaKi-1 cell
proliferation. These results clearly indicate that both NFAT5 and S100A4 are
important for proliferation and migration ability of CaKi-1 cells. NFAT5 is also important for survival during hyperosmotic stress,
while S100A4 is probably not essential under these conditions. Frontiers in Physiology | Integrative Physiology SCRATCH ASSAY Cell migration was analyzed using the in vitro scratch assay (Liang
et al., 2007), also known as the wound healing assay. CaKi-1
cells at ∼80% confluency were treated for 5 days with Accell
SMARTpool NFAT5 siRNA, Accell SMARTpool S100A4 siRNA,
or unspecific Accell non-targeting siRNA (#2), as control, with a
final concentration of 1000 nM in Accell delivery medium, con-
taining 2% FCS, in accordance with the manufacturer’s recom-
mendations. During the 5-days incubation period, cells reached August 2014 | Volume 5 | Article 293 | 3 www.frontiersin.org www.frontiersin.org NFAT5 and renal cell carcinoma Küper et al. FIGURE 1 | Expression of NFAT5 and NFAT5 target genes in CaKi-1 and
HK-2 cells. CaKi-1 cells, as model for clear cell renal cell carcinoma, or HK-2
cells, as proximal tubular control cells, were kept in isoosmotic medium (■;
300 mosm/kg H2O) or were exposed to hyperosmotic medium (■;
500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A)
Cells were incubated for 6 h (for determination of NFAT5 transcription) or 16 h
(for determination of S100A4 and AR transcription). Thereafter, RNA was
extracted and the abundance of NFAT5, S100A4, AR, and β-actin mRNA
transcripts determined by qRT-PCR as described in Methods. Relative mRNA
abundance of NFAT5, S100A4, or AR was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per
point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. (B) Cells were incubated for 24 h and subsequently
processed for immunoblotting to determine expression of NFAT5, S100A4,
and AR as described in Methods. To demonstrate comparable protein
loading, the blots were also probed for β-actin. Representative blots from 4
independent experiments are shown. (C) Cells were transfected transiently
with a reporter construct in which the SEAP gene is under control of two
TonE sites. After 24 h incubation in iso- or hyperosmotic medium, SEAP
activity was measured as described in Methods. Data are means ± s.e.m. for
n = 4 per point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. point; #P < 0.05 vs. HK-2 isoosmotic medium; ∗P < 0.05 vs. HK-2
hyperosmotic medium. (B) Cells were incubated for 24 h and subsequently
processed for immunoblotting to determine expression of NFAT5, S100A4,
and AR as described in Methods. SIGNAL TRANSDUCTION PATHWAYS INVOLVED IN NFAT5 REGULATION CaKi-1 cells were transfected with siRNA constructs for NFAT5
(siNFAT5), S100A4 (siS100A4) or with non-targeting siRNA (siControl) as
indicated. Cells were kept in isoosmotic medium (■; 300 mosm/kg H2O)
or were exposed to hyperosmotic medium (■; 500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A) Cells were
incubated for 6 h (for NFAT5 determination) or 16 h (for S100A4 and AR
determination). Thereafter, RNA was extracted and the abundance of
NFAT5, S100A4, AR, and β-actin mRNA transcripts determined by qRT-PCR as described in Methods. Relative mRNA abundance of NFAT5,
S100A4, or AR was normalized to that of β-actin to correct for differences
in RNA input. Data are means ± s.e.m. for n = 4 per point; #P < 0.05 vs. siControl isoosmotic medium; ∗P < 0.05 vs. siControl hyperosmotic
medium. (B) Cells were incubated for 24 h and subsequently processed
for immunoblotting to determine expression of NFAT5, S100A4, and AR
as described in Methods. To demonstrate comparable protein loading, the
blots were also probed for β-actin. Representative blot from 4
independent experiments is shown. FIGURE 2 | NFAT5-knockdown attenuates S100A4 expression in CaKi-1
cells. CaKi-1 cells were transfected with siRNA constructs for NFAT5
(siNFAT5), S100A4 (siS100A4) or with non-targeting siRNA (siControl) as
indicated. Cells were kept in isoosmotic medium (■; 300 mosm/kg H2O)
or were exposed to hyperosmotic medium (■; 500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A) Cells were
incubated for 6 h (for NFAT5 determination) or 16 h (for S100A4 and AR
determination). Thereafter, RNA was extracted and the abundance of
NFAT5, S100A4, AR, and β-actin mRNA transcripts determined by FIGURE 2 | NFAT5-knockdown attenuates S100A4 expression in CaKi-1
cells. CaKi-1 cells were transfected with siRNA constructs for NFAT5
(siNFAT5), S100A4 (siS100A4) or with non-targeting siRNA (siControl) as
indicated. Cells were kept in isoosmotic medium (■; 300 mosm/kg H2O)
or were exposed to hyperosmotic medium (■; 500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A) Cells were
incubated for 6 h (for NFAT5 determination) or 16 h (for S100A4 and AR
determination). Thereafter, RNA was extracted and the abundance of
NFAT5, S100A4, AR, and β-actin mRNA transcripts determined by evidence that NFAT5 is also involved in the development and pro-
gression of clear cell RCC. We found increased expression and
activity of NFAT5 in the RCC cell line CaKi-1 compared with
non-cancerous proximal tubule cells. SIGNAL TRANSDUCTION PATHWAYS INVOLVED IN NFAT5 REGULATION Moreover, the metastasis-
associated protein S100A4, which has been previously identified
in colon cancer cells as an NFAT5 target gene, is very strongly
upregulated in CaKi-1 cells. Accordingly, knockdown of NFAT5
also decreased S100A4 expression. In control HK-2 cells, sub-
stantial NFAT5 expression and activity can be observed especially
during hyperosmotic stress, but S100A4 expression is still almost
undetectable under these conditions. This indicates that, in addi-
tion to regulation by NFAT5 activity, one or more further mecha-
nisms control S100A4 expression. The most probable mechanism
is methylation of the S100A4 promoter in normal cells, which effi-
ciently prevents S100A4 expression, while the promoter is often
hypomethylated in cancer cells, as has been observed in colon
cancer cells (Chen et al., 2011). Accordingly, hypomethylation
of the S100A4 promoter has also been reported in RCC cells
(Lopez-Lago et al., 2010). kinases decreased NFAT5 activity and expression in CaKi-1 cells
(Figure 5). However, FAK and Src kinase are also constitutively
active in HK-2 cells (Figure 4), indicating that FAK and Src are
necessary, but alone not sufficient to account for the high NFAT5
activity in CaKi-1 cells. The MAP kinases p38, ERK1/2 (p44/42),
and c-jun-terminal kinase (JNK or p54/46) also regulate NFAT5
activity. p38 and JNK are inactive under isosmotic conditions and
are activated under hyperosmotic conditions in both CaKi-1 and
HK-2 cells. In contrast, ERK1/2 is constitutively active in CaKi-
1 cells, even under isosmotic conditions, but not in HK-2 cells. Inhibition of ERK1/2, but not of p38 or JNK, decreased NFAT5
activity and expression under isosmotic conditions in CaKi-1
cells (Figures 5A,C), while inhibition of p38 and JNK impaired
osmolality-induced upregulation of NFAT5 activity and expres-
sion (Figures 5B,D). Accordingly, osmolality induced enhance-
ment of S100A4 was attenuated by pharmacological inhibition
of Src, FAK, ERK1/2, and p38 (Figure 5F). Surprisingly, JNK
inhibition attenuated hyperosmolality-induced S100A4 expres-
sion only slightly, the reason for this is unclear. Taken together,
these results indicate that constitutive activation of FAK and Src is
a prerequisite for NFAT5 expression, osmolality-induced activa-
tion of p38 and possibly JNK stimulate NFAT5 activation under
hyperosmotic conditions, and constitutive activation of ERK1/2
in CaKi-1 cells is probably responsible for the higher basal activity
and expression of NFAT5 in these cells compared with HK-2 cells. The role of S100A4 in RCC has not yet been studied in detail. SIGNAL TRANSDUCTION PATHWAYS INVOLVED IN NFAT5 REGULATION However, in the last years three clinical studies provided evidence
that high expression of S100A4 in primary tumors correlates
with metastasis and poor prognosis in RCC (Bandiera et al.,
2009; Wang et al., 2012; Yang et al., 2012). It has been proposed
that upregulation of S100A4 mediates epithelial-to-mesenchymal
transition, an initial step in the development of metastasis. Accordingly, S100A4 is highly expressed in the metastatic RCC
cell line LM2, whilst knockdown decreases metastatic activity
(Lopez-Lago et al., 2010). In another study on RCC cells S100A4 SIGNAL TRANSDUCTION PATHWAYS INVOLVED IN NFAT5 REGULATION We next analyzed the activation of signal transduction path-
ways to elucidate the molecular basis for the high basal NFAT5
activity in CaKi-1 cells, compared to HK-2 cells. Various signal-
ing molecules are believed to mediate NFAT5 activity, among
them focal adhesion kinase (FAK) (Neuhofer et al., 2014), the
SRC kinase (Chen et al., 2011), often associated with FAK, and
the MAP kinases p38, ERK1/2, and JNK (Tsai et al., 2007). We found that FAK and Src kinase are constitutively active in
CaKi-1 cells (Figure 4), and pharmacological inhibition of these Next, the effect of NFAT5- and S100A4-knockdown on the
migratory capacity of cells was evaluated using the in vitro scratch
assay (Liang et al., 2007). For this purpose, a scratch was created
in a confluent monolayer and cell migration to close the scratch
was observed under the microscope. As can be seen in Figure 3B,
knockdown of NFAT5 or S100A4 clearly decreased the migration
ability of CaKi-1 cells. Finally, the effect of NFAT5- and S100A4-knockdown on cell
survival during osmotic stress was examined. Confluent cells August 2014 | Volume 5 | Article 293 | 4 Frontiers in Physiology | Integrative Physiology NFAT5 and renal cell carcinoma Küper et al. FIGURE 2 | NFAT5-knockdown attenuates S100A4 expression in CaKi-1
cells. CaKi-1 cells were transfected with siRNA constructs for NFAT5
(siNFAT5), S100A4 (siS100A4) or with non-targeting siRNA (siControl) as
indicated. Cells were kept in isoosmotic medium (■; 300 mosm/kg H2O)
or were exposed to hyperosmotic medium (■; 500 mosm/kg H2O). Medium osmolality was elevated by addition of NaCl. (A) Cells were
incubated for 6 h (for NFAT5 determination) or 16 h (for S100A4 and AR
determination). Thereafter, RNA was extracted and the abundance of
NFAT5, S100A4, AR, and β-actin mRNA transcripts determined by
qRT-PCR as described in Methods. Relative mRNA abundance of NFAT5,
S100A4, or AR was normalized to that of β-actin to correct for differences
in RNA input. Data are means ± s.e.m. for n = 4 per point; #P < 0.05 vs. siControl isoosmotic medium; ∗P < 0.05 vs. siControl hyperosmotic
medium. (B) Cells were incubated for 24 h and subsequently processed
for immunoblotting to determine expression of NFAT5, S100A4, and AR
as described in Methods. To demonstrate comparable protein loading, the
blots were also probed for β-actin. Representative blot from 4
independent experiments is shown. FIGURE 2 | NFAT5-knockdown attenuates S100A4 expression in CaKi-1
cells. DISCUSSION Data are means ± s.e.m. for n = 6; ∗P < 0.05 vs. siControl hyperosmotic medium. FIGURE 3 | Effect of NFAT5 and S100A4 knockdown on proliferation, FIGURE 3 | Effect of NFAT5 and S100A4 knockdown on proliferation,
migration and survival of CaKi-1 cells. (A) Proliferation. CaKi-1 cells
(104 per case) were transfected with NFAT5-specific (siNFAT5),
S100A4-specific (siS100A4), or unspecific control (siControl) siRNA
constructs as described in Methods and seeded into one well of a
96-well plate. After 96 h, the cell number in each well was determined
by MTT assay. The number of viable cells treated with control siRNA
was defined as 100%. Data are means ± s.e.m. for n = 6; ∗P < 0.05 vs. siControl. (B) Migration. CaKi-1 cells were treated with NFAT5-specific
(siNFAT5), S100A4-specific (siS100A4), or unspecific control (siControl)
siRNA constructs as described in Methods. After reaching confluency, the stimulates the expression of Bcl-2, thereby attenuating apoptosis,
and MMP-2, which may also stimulate metastatic activity (Yang
et al., 2013). conditions. The absence of this osmoadaptive response in NFAT5-
knockdown cells is probably the reason for the observed decreased
resistance to hyperosmotic conditions in these cells. CaKi-1 cells,
as a model for clear cell RCC, originate from the cortical proximal
tubule. Since this region is not exposed to hyperosmotic stress,
even during antidiuresis, osmolality-induced increase of cellular
NFAT5 activity may be not relevant as long as tumor cells remain
in the cortex. However, if cells of a growing tumor invade the renal
medullary region, these cells are exposed to hyperosmotic condi-
tions, which means that NFAT5 activity is increased. On the one
hand, this probably facilitates survival of tumor cells by elevating
the expression of S100A4 and other osmoadaptive genes like AR,
HSP70, or BGT-1; on the other, the elevated S100A4 expression
may also increase the metastatic activity of the tumor cells. Interestingly, S100A4 is expressed in the normal (i.e., non-
cancerous) kidney under physiological conditions (Rivard et al.,
2007). While it is not expressed in the isosmotic renal cortex,
S100A4 can be detected in the hyperosmotic renal medulla, where
its expression is even more stimulated during antidiuresis. In the
same study, the authors showed that S100A4 is strongly induced
under hyperosmotic conditions in inner medullary collecting
duct cells and that knockdown of S100A4 results in a 48 h-delay
in the onset of adaptation to hypertonic stress. DISCUSSION The osmosensitive transcription factor NFAT5 has been associ-
ated with a variety of cancers. Here we present for the first time August 2014 | Volume 5 | Article 293 | 5 www.frontiersin.org www.frontiersin.org NFAT5 and renal cell carcinoma Küper et al. FIGURE 3 | Effect of NFAT5 and S100A4 knockdown on proliferation,
migration and survival of CaKi-1 cells. (A) Proliferation. CaKi-1 cells
(104 per case) were transfected with NFAT5-specific (siNFAT5),
S100A4-specific (siS100A4), or unspecific control (siControl) siRNA
constructs as described in Methods and seeded into one well of a
96-well plate. After 96 h, the cell number in each well was determined
by MTT assay. The number of viable cells treated with control siRNA
was defined as 100%. Data are means ± s.e.m. for n = 6; ∗P < 0.05 vs. siControl. (B) Migration. CaKi-1 cells were treated with NFAT5-specific
(siNFAT5), S100A4-specific (siS100A4), or unspecific control (siControl)
siRNA constructs as described in Methods. After reaching confluency, the
cell layer was scratched with a 10 μl pipette tip. Shown are
representative phase-contrast images of cells migrating into the wounded
area, immediately after scratching (0 h) and after an incubation time of
24 h. (C) Cell survival. CaKi-1 cells were treated with NFAT5-specific
(siNFAT5), S100A4-specific (siS100A4), or unspecific control (siControl)
siRNA constructs as described in Methods. Confluent cells were kept in
isoosmotic medium (■; 300 mosm/kg H2O) or were exposed to
hyperosmotic medium (■; 600 mosm/kg H2O) for 24 h. Thereafter, the
cell number in each well was determined by MTT assay. Cell numbers in
isosmotic controls (■) were defined as 100%. Data are means ± s.e.m. for n = 6; ∗P < 0.05 vs. siControl hyperosmotic medium. FIGURE 3 | Effect of NFAT5 and S100A4 knockdown on proliferation,
migration and survival of CaKi-1 cells (A) Proliferation CaKi-1 cells cell layer was scratched with a 10 μl pipette tip. Shown are
representative phase-contrast images of cells migrating into the wounded
area, immediately after scratching (0 h) and after an incubation time of
24 h. (C) Cell survival. CaKi-1 cells were treated with NFAT5-specific
(siNFAT5), S100A4-specific (siS100A4), or unspecific control (siControl)
siRNA constructs as described in Methods. Confluent cells were kept in
isoosmotic medium (■; 300 mosm/kg H2O) or were exposed to
hyperosmotic medium (■; 600 mosm/kg H2O) for 24 h. Thereafter, the
cell number in each well was determined by MTT assay. Cell numbers in
isosmotic controls (■) were defined as 100%. DISCUSSION Inhibiton of JNK decreased NFAT5 activity, but expression
of S100A4 was only slightly and non-significantly decreased. The
reason for this discrepancy is not clear. Most reports in the lit-
erature deny an involvement of JNK in NFAT5 activation (Kultz
et al., 1997; Kojima et al., 2010; Roth et al., 2010). In colon cancer cells NFAT5-mediated upregulation of S100A4
has been shown to be stimulated by Integrins and Src kinase
(Chen et al., 2011). Integrins are transmembrane receptors that
link the extracellular matrix to the intracellular actin cytoskele-
ton. Integrins can also initiate intracellular signaling events by
co-clustering with receptor- and non-receptor protein tyrosine
kinases (PTK). The non-receptor PTK Src often forms a dual
kinase complex with the non-receptor PTK FAK. Activated FAK-
Src complex promotes cell cycle progression, cell motility and
cell survival and is therefore often associated with the develop-
ment of cancer and metastasis (Mitra and Schlaepfer, 2006). It
was reported recently that Src and FAK are also expressed and
activated in patients with clear cell RCC (Qayyum et al., 2012). Our own studies suggest that FAK is a positive regulator of NFAT5
expression in HEK 293 cells (Neuhofer et al., 2014). Accordingly,
the data of the present study provide evidence that NFAT5 expres-
sion and activity in CaKi-1 cells is positive regulated by Src and
FAK. Pharmacological inhibition of these kinases decreased cellu-
lar NFAT5 activity and expression of S100A4, and both kinases are
constitutively active in CaKi-1 cells. Since Src and FAK were also
constitutively active in HK-2 cells it is doubtful whether patho-
physiological upregulation of FAK-Src activity is responsible for
the elevated NFAT5 activity in RCC cells. In contrast, the MAP
kinase ERK1/2 was constitutively active in CaKi-1 cells, but not
in HK-2 cells. The role of ERK in NFAT5 activation is currently
controversial and may depend on the cell type (Tsai et al., 2007;
Morancho et al., 2008). In the present study, inhibition of ERK
in CaKi-1 cells attenuated both NFAT5 activation and expression
and also S100A4 expression, indicating that constitutive activa-
tion of this kinase is at least partly responsible for the high NFAT5
activity in RCC cells. Constitutive activation of the Ras-Raf-
MEK-ERK pathway, which mediates cellular responses to growth
signals under physiological conditions, has been observed in a
wide variety of cancers (Roberts and Der, 2007), but the molec-
ular mechanisms underlying this constitutive activation vary. DISCUSSION These data sug-
gest that S100A4 is under physiological conditions part of the
osmoadaptive response that allows cells to tolerate the harsh con-
ditions in the renal inner medulla, however, in the present study
knockdown of S100A4 had no significant effect on CaKi-1 cell
survival during hyperosmotic stress. Whether S100A4 expression
in medullary collecting duct cells is driven by NFAT5 has not
been studied extensively, but the present results and other stud-
ies (Chen et al., 2009, 2011) strongly suggest that this is so. In
the present study, we also observed an “intact” osmoadaptive
response in CaKi-1 cells, meaning that NFAT5 mediates upreg-
ulation of osmoadaptive genes such as AR under hyperosmotic We observed also that NFAT5 knockdown decreases prolifera-
tion and migration of CaKi-1 cells. This is probably due, at least
in part, to the decreased S100A4 expression, since it has been
shown before that S100A4 promotes proliferation and migration
in renal carcinoma cells (Yang et al., 2013). However, it cannot
be ruled out that other NFAT5 target genes also stimulate tumor
development and metastasis. Especially the designated NFAT5
target gene HSP70 has been implicated in tumor cell prolifera-
tion, differentiation, and metastasis in a wide variety of cancers August 2014 | Volume 5 | Article 293 | 6 Frontiers in Physiology | Integrative Physiology Küper et al. NFAT5 and renal cell carcinoma FIGURE 4 | Activation of signaling molecules in CaKi-1 and HK-2 cells. CaKi-1 cells or HK-2 cells were incubated in isoosmotic medium (300
mosm/kg H2O) or hyperosmotic medium (500 mosm/kg H2O). Medium
osmolality was elevated by addition of NaCl. Cells were incubated for 1 h
and subsequently lysed and abundance and phosphorylation status of FAK,
Src, JNK, ERK1/2, and p38 determined by immunoblotting as described in
Methods. Representative blots from 4 independent experiments are
shown. FIGURE 4 | Activation of signaling molecules in CaKi-1 and HK-2 cells We investigated osmolality-related signal transduction pro-
cesses and observed activation of the MAP kinases p38 and JNK
in both CaKi-1 and HK-2 cells in response to hyperosmotic
conditions. Our results indicate clearly that p38 is involved in
upregulation of NFAT5 activity and expression of the NFAT5 tar-
get gene S100A4 in CaKi-1 cells under these conditions, consistent
with previous reports (Lee et al., 2008; Roth et al., 2010). The
role of JNK for NFAT5 activation in CaKi-1 cells is more uncer-
tain. DISCUSSION An
important mechanism that has been identified in various tumor
entities is mutation of the BRAF gene, which results in expression
of a constitutive active B-Raf kinase and hence constitutive acti-
vation of ERK (Davies et al., 2002). However, since CaKi-1 cells
harbor a wildtype BRAF gene (Friday et al., 2008), this mecha-
nism can be excluded. A possible mechanism for constitutive ERK
activation in RCC cells is increased expression of transforming
growth factor-α (TGF-α), a ligand of the epidermal growth factor
receptor (EGFR). We have previously found in (non-cancerous) FIGURE 4 | Activation of signaling molecules in CaKi-1 and HK-2 cells. FIGURE 4 | Activation of signaling molecules in CaKi-1 and HK-2 cells. CaKi-1 cells or HK-2 cells were incubated in isoosmotic medium (300
mosm/kg H2O) or hyperosmotic medium (500 mosm/kg H2O). Medium
osmolality was elevated by addition of NaCl. Cells were incubated for 1 h
and subsequently lysed and abundance and phosphorylation status of FAK,
Src, JNK, ERK1/2, and p38 determined by immunoblotting as described in
Methods. Representative blots from 4 independent experiments are
shown. CaKi-1 cells or HK-2 cells were incubated in isoosmotic medium (300
mosm/kg H2O) or hyperosmotic medium (500 mosm/kg H2O). Medium
osmolality was elevated by addition of NaCl. Cells were incubated for 1 h
and subsequently lysed and abundance and phosphorylation status of FAK,
Src, JNK, ERK1/2, and p38 determined by immunoblotting as described in
Methods. Representative blots from 4 independent experiments are
shown. (Ciocca and Calderwood, 2005). In non-small cell lung cancer,
NFAT5-mediated upregulation of HSP70 confers enhanced resis-
tance against apoptosis on tumor cells by inhibition of lysosomal
membrane permeabilization (Zhong et al., 2004; Mijatovic et al.,
2006). High expression of HSP70 has also been observed in RCC,
however, it is not clear whether HSP70-mediated inhibition of
apoptosis plays an important role in carcinogenesis and tumor
progression in RCC (Ramp et al., 2007). Other proposed NFAT5
target genes reportedly upregulated in RCC are Cyr61 (O’Connor
et al., 2007; Chintalapudi et al., 2008), and COX-2 (Chen et al.,
2004; Favale et al., 2009), whether NFAT5 is responsible for this
upregulation remains to be established. (Ciocca and Calderwood, 2005). In non-small cell lung cancer,
NFAT5-mediated upregulation of HSP70 confers enhanced resis-
tance against apoptosis on tumor cells by inhibition of lysosomal
membrane permeabilization (Zhong et al., 2004; Mijatovic et al.,
2006). DISCUSSION High expression of HSP70 has also been observed in RCC,
however, it is not clear whether HSP70-mediated inhibition of
apoptosis plays an important role in carcinogenesis and tumor
progression in RCC (Ramp et al., 2007). Other proposed NFAT5
target genes reportedly upregulated in RCC are Cyr61 (O’Connor
et al., 2007; Chintalapudi et al., 2008), and COX-2 (Chen et al.,
2004; Favale et al., 2009), whether NFAT5 is responsible for this
upregulation remains to be established. August 2014 | Volume 5 | Article 293 | 7 www.frontiersin.org NFAT5 and renal cell carcinoma Küper et al. FIGURE 5 | Inhibition of FAK, Src, and MAP kinases attenuates NFAT5
activity in CaKi-1 cells. CaKi-1 cells were preincubated with the ERK1/2
inhibitor U0126 (U0; 10 μM), the p38 inhibitor SB202190 (SB; 10 μM), the JNK
inhibitor SP600125 (SP; 10 μM), the FAK inhibitor PF-228 (PF; 5 μM), the Src
inhibitor SrcI-1 (SrcI; 10 μM), or vehicle DMSO (Veh) for 30 min. Subsequently,
cells were incubated at 300 or 500 mosm/kg H2O as indicated. (A,B) CaKi-1
cells were transfected transiently with a reporter construct in which the SEAP
gene is under control of two TonE sites. After preincubation, the transfected
cells were incubated for 24 h at 300 or 500 mosm/kg H2O, as indicated. Subsequently, SEAP activity was measured as described in Methods. Data
are means ± s.e.m. for n = 4 per point; ∗P < 0.05 vs. vehicle; #P < 0.05 vs. vehicle hyperosmotic medium. (C–F) After preincubation, CaKi-1 cells were
incubated for 16 h at 300 or 500 mosm/kg H2O, as indicated. Subsequently,
RNA was extracted and the abundance of NFAT5, S100A4 and β-actin mRNA
transcripts was determined by qRT-PCR as described in Methods. Relative
mRNA abundance of NFAT5 and S100A4 was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per
point; *P < 0.05 vs. vehicle; #P < 0.05 vs. vehicle hyperosmotic medium. FIGURE 5 | Inhibition of FAK, Src, and MAP kinases attenuates NFAT5
activity in CaKi-1 cells. CaKi-1 cells were preincubated with the ERK1/2
inhibitor U0126 (U0; 10 μM), the p38 inhibitor SB202190 (SB; 10 μM), the JNK
inhibitor SP600125 (SP; 10 μM), the FAK inhibitor PF-228 (PF; 5 μM), the Src
inhibitor SrcI-1 (SrcI; 10 μM), or vehicle DMSO (Veh) for 30 min. Subsequently,
cells were incubated at 300 or 500 mosm/kg H2O as indicated. DISCUSSION (A,B) CaKi-1
cells were transfected transiently with a reporter construct in which the SEAP
gene is under control of two TonE sites. After preincubation, the transfected
cells were incubated for 24 h at 300 or 500 mosm/kg H2O, as indicated. Subsequently, SEAP activity was measured as described in Methods. Data
are means ± s.e.m. for n = 4 per point; ∗P < 0.05 vs. vehicle; #P < 0.05 vs. vehicle hyperosmotic medium. (C–F) After preincubation, CaKi-1 cells were
incubated for 16 h at 300 or 500 mosm/kg H2O, as indicated. Subsequently,
RNA was extracted and the abundance of NFAT5, S100A4 and β-actin mRNA
transcripts was determined by qRT-PCR as described in Methods. Relative
mRNA abundance of NFAT5 and S100A4 was normalized to that of β-actin to
correct for differences in RNA input. Data are means ± s.e.m. for n = 4 per
point; *P < 0.05 vs. vehicle; #P < 0.05 vs. vehicle hyperosmotic medium. FIGURE 5 | Inhibition of FAK, Src, and MAP kinases attenuates NFAT5 ACKNOWLEDGMENTS renal collecting duct cells that maximal NFAT5 activation requires
TGF-α-mediated activation of the EGFR and the downstream
ERK kinase (Küper et al., 2009). Furthermore, overexpression of
TGF-α has long been known as a characteristic feature and has
been implicated with proliferation and vascularization of RCC
(Gomella et al., 1989; Gunaratnam et al., 2003; Pelletier et al.,
2009). We plan to investigate this potential mechanism for ERK
activation in RCC cells in future studies. Work in the authors’ laboratory was supported by grants from the
Deutsche Forschungsgemeinschaft, the Deutsche Nierenstiftung,
the Münchener Medizinische Wochenschrift, and by the Friedrich
Baur Stiftung, Munich. We thank Dr. John Davies for critical
reading of the manuscript. The help of Maria-Luisa Fraek is
gratefully acknowledged. Work in the authors’ laboratory was supported by grants from the
Deutsche Forschungsgemeinschaft, the Deutsche Nierenstiftung,
the Münchener Medizinische Wochenschrift, and by the Friedrich
Baur Stiftung, Munich. We thank Dr. John Davies for critical
reading of the manuscript. The help of Maria-Luisa Fraek is
gratefully acknowledged. CONCLUSIONS NFAT5 in cellular adaptation to hyper-
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10.1113/jphysiol.2007.135178 O’Connor, R. S., Mills, S. T., Jones, K. A., Ho, S. N., and Pavlath, G. K. (2007). A combinatorial role for NFAT5 in both myoblast migration and differ-
entiation during skeletal muscle myogenesis. CONCLUSIONS Alvarez-Diaz, S., Valle, N., Ferrer-Mayorga, G., Lombardia, L., Herrera, M.,
Dominguez, O., et al. (2012). MicroRNA-22 is induced by vitamin D and con-
tributes to its antiproliferative, antimigratory and gene regulatory effects in
colon cancer cells. Hum. Mol. Genet. 21, 2157–2165. doi: 10.1093/hmg/dds031 Taken together, the present study shows that the osmosensitive
transcription factor NFAT5 is expressed abundantly and is highly
active in the RCC cell line CaKi-1. NFAT5 stimulates the expres-
sion of the S100A4 metastasis factor in these cells, thereby regu-
lating proliferation and migration activity. These results indicate
that NFAT5 may contribute to the development and progression
of RCC. Bandiera, A., Melloni, G., Freschi, M., Giovanardi, M., Carretta, A., Borri, A.,
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binding protein S100A4 is markedly up-regulated by osmotic stress and is August 2014 | Volume 5 | Article 293 | 9 www.frontiersin.org NFAT5 and renal cell carcinoma Küper et al. involved in the renal osmoadaptive response. J. Biol. Chem. August 2014 | Volume 5 | Article 293 | 10 Frontiers in Physiology | Integrative Physiology CONCLUSIONS Mol. Morphol. 20, 71–76. doi: 10.1097/PAI.0b013e31821
fc8b7 of S100A4 contributes to proliferation and migration of renal carcinoma cells. Front. Physiol. 5:293. doi: 10.3389/fphys.2014.00293 This article was submitted to Integrative Physiology, a section of the journal Frontiers
in Physiology. Woo, S. K., Lee, S. D., Na, K. Y., Park, W. K., and Kwon, H. M. (2002). TonEBP/NFAT5 stimulates transcription of HSP70 in response to hypertonicity. Mol. Cell. Biol. 22, 5753–5760. doi: 10.1128/MCB.22.16.5753-5760.2002 Copyright © 2014 Küper, Beck and Neuhofer. This is an open-access article dis-
tributed under the terms of the Creative Commons Attribution License (CC BY). The
use, distribution or reproduction in other forums is permitted, provided the original
author(s) or licensor are credited and that the original publication in this jour-
nal is cited, in accordance with accepted academic practice. No use, distribution or
reproduction is permitted which does not comply with these terms. Copyright © 2014 Küper, Beck and Neuhofer. This is an open-access article dis-
tributed under the terms of the Creative Commons Attribution License (CC BY). The
use, distribution or reproduction in other forums is permitted, provided the original
author(s) or licensor are credited and that the original publication in this jour-
nal is cited, in accordance with accepted academic practice. No use, distribution or
reproduction is permitted which does not comply with these terms. Yang, H., Zhao, K., Yu, Q., Wang, X., Song, Y., and Li, R. (2012). Evaluation of
plasma and tissue S100A4 protein and mRNA levels as potential markers of
metastasis and prognosis in clear cell renal cell carcinoma. J. Int. Med. Res. 40,
475–485. doi: 10.1177/147323001204000209 August 2014 | Volume 5 | Article 293 | 10 Frontiers in Physiology | Integrative Physiology Frontiers in Physiology | Integrative Physiology
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Preferences and Perceptions in Provision and Maintenance Public Goods
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Social Science Research Network
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cc-by
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a b s t r a c t Article history:
Received 28 October 2021
Available online 15 July 2022
JEL classification:
C92
H41
Keywords:
Maintenance and provision social dilemmas
Conditional cooperation
Kindness
Misperceptions
Experiments
Framing We study two generic versions of public goods problems: in Provision problems, the public
good does not exist initially and needs to be provided; in Maintenance problems, the public
good already exists and needs to be maintained. In four lab and online experiments (n =
2,105), we document a robust asymmetry in preferences and perceptions in two incentive-
equivalent versions of these public good problems. We find fewer conditional cooperators
and more free riders in Maintenance than Provision, a difference that is replicable, stable,
and reflected in perceptions of kindness. Incentivized control questions administered
before gameplay reveal dilemma-specific misperceptions but controlling for them neither
eliminates game-dependent conditional cooperation, nor differences in perceived kindness
of others’ cooperation. Thus, even when sharing the same game form, Maintenance and
Provision are different social dilemmas that require separate behavioral analyses. © 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the
CC BY license (http://creativecommons.org/licenses/by/4.0/). Simon Gächter a,b,c,∗, Felix Kölle d,∗, Simone Quercia e,∗ a University of Nottingham, Nottingham NG7 1BW, United Kingdom
b CESifo, 81679 Munich, Germany
c IZA, 53113 Bonn. Germany
d University of Cologne, 50923 Cologne, Germany
e University of Verona, 37129 Verona, Italy https://doi.org/10.1016/j.geb.2022.06.009
0899-8256/© 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Games and Economic Behavior 135 (2022) 338–355 Games and Economic Behavior 135 (2022) 338–355 * Corresponding authors.
E-mail addresses: simon.gaechter@nottingham.ac.uk (S. Gächter), felix.koelle@uni-koeln.de (F. Kölle), simone.quercia@univr.it (S. Quercia). Preferences and perceptions in Provision and Maintenance
public goods Simon Gächter a,b,c,∗, Felix Kölle d,∗, Simone Quercia e,∗ * Corresponding authors.
E-mail addresses: simon.gaechter@nottingham.ac.uk (S. Gächter), felix.koelle@uni-koeln.de (F. Kölle), simone.quercia@univr.it (S. Quercia).
https://doi.org/10.1016/j.geb.2022.06.009
0899 8256/© 2022 Th
A th
( ) P bli h d b
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ti l
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th
CC BY li 1. Introduction In this paper, we study two generic forms of voluntary cooperation: providing initially inexistent public goods and main-
taining existing ones. Contributing to charities, volunteering, being a team player, or participating in collective action, are
examples of voluntary cooperation that provides public goods. Shared natural resources, known as “common-pool resources”
(e.g., Ostrom, 1990), but also biodiversity and a stable climate, are important public goods that nature has provided but peo-
ple need to limit extraction or environmentally damaging emissions if they want to maintain them. Similarly, public goods
that previous generations created, such as democracy and the rule of law, only continue existing if people limit rule-bending,
rent-seeking, and corruption. As the examples illustrate, “provision” and “maintenance” public goods differ along many dimensions. Crucially, however,
for selfish players, they are all social dilemmas: providing or maintaining the public good is often collectively beneficial, but
individual incentives are to hold back on provision and to exploit rather than to maintain the public good – the “tragedy of
the commons” (Hardin, 1968). Although the comparison between these two problems has been studied both in economics
and psychology (see, e.g., Sell and Son, 1997 and Dufwenberg et al., 2011), until recently, most studies only investigated S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 cooperative behavior, and less the psychological mechanisms that produce cooperation.1 Here, we ask whether, from the
perspective of social preferences and perceptions, maintenance and provision dilemmas are psychologically different social
dilemmas. cooperative behavior, and less the psychological mechanisms that produce cooperation.1 Here, we ask whether, from the
perspective of social preferences and perceptions, maintenance and provision dilemmas are psychologically different social
dilemmas. Studying preferences and perceptions as drivers of cooperation and understanding whether their impact on cooperative
behavior differs across maintenance and provision dilemmas is important from both a theoretical and practical point of
view. 1. Introduction From a theoretical viewpoint, studying preferences and perceptions is interesting because it can help explain why
people often cooperate even in anonymous one-shot games without communication, where mechanisms that can support
cooperation, such as reputation or repeated interactions (e.g., Dal Bó and Fréchette, 2018; Rand and Nowak, 2013) do not
apply (see, e.g., Fischbacher and Gächter, 2010; and Gächter et al., 2017 for evidence from the lab; and, e.g., Frey and Meier,
2004; Alpizar et al., 2008; Rustagi et al., 2010; Fehr and Leibbrandt, 2011 for evidence from the field). Do people cooperate
because they misperceive their incentives in a social dilemma, or do they have a ‘genuine’ preference for cooperation? If
people misunderstand their incentives, they may implement choices they otherwise would not. Thus, observing cooperation
without controlling for perception of incentives may not be a conclusive revelation of a preference for cooperation (for
related arguments see, e.g., Koszegi and Rabin, 2008 and Cason and Plott, 2014). Apart from potential differences in the
understanding of the incentive structure, maintenance and provision might also differ in the way people perceive others’
actions, e.g., in terms of kindness. Perceptions of the kindness of other players’ actions are important because, in social
dilemmas, they can explain why some people cooperate in the first place (e.g., Falk and Fischbacher, 2006). The practical relevance of our research question comes from the fact that any policy intervention aimed at fostering
cooperation must rest on accurate behavioral mechanisms. If these mechanisms are dilemma-specific, this would imply that
maintenance and provision might require different approaches to overcome the tragedy of the commons. To answer these questions, and to provide a comprehensive understanding of the fundamental nature of cooperation
in maintenance and provision dilemmas, we present the results from four experiments, in which we study preferences
and perceptions in conjunction. We compare two versions of a linear public good game that share the same game form:
A Provision game and a Maintenance game. In Provision, the public good initially does not exist; four players in a group
are endowed with 20 tokens each and decide simultaneously how many of them to contribute to the public good. In
Maintenance, players have no endowment, but the public good already exists because 80 tokens are invested at the outset in
the public good. Players decide simultaneously how many (up to 20) tokens to withdraw from the public good. 1. Introduction Any token
contributed to the public good (in Provision) or not withdrawn from the public good (in Maintenance) is worth 1.6 money
units to the group, which is then shared equally between group members; any token not contributed to the public good or
withdrawn from the public good is worth 1 money unit.2 of preferences and perceptions in influencing cooperation in these two dilemmas, we proceed in
marize in Table 1. To ascertain the role of preferences and perceptions in influencing cooperation in these two
four steps that we summarize in Table 1. Our first step is to ensure that what we study is a replicable phenomenon (Drazen et al., 2021). This is the purpose of
Experiment 1. In this experiment, we replicate the one-shot results of Gächter et al. (2017) using a diverse online subject
pool (MTurk). We find that in a simultaneous one-shot game, people contribute 52% of their endowment in Provision com-
pared to 39% in Maintenance, a difference that is highly statistically significant. Furthermore, using the Fischbacher et al. (2001) strategy-method experiment to separate beliefs from preferences, we replicate that there are systematically fewer
conditional cooperators and more free riders in Maintenance than Provision. In two additional experiments (Experiments
2a and 2b in Table 1), we collect new evidence to test whether, within-participants, our measure of cooperation prefer-
ences is stable over time and, together with beliefs, predicts contribution or withdrawal decisions in one-shot games played
immediately or five months after preferences were elicited. In Steps 2 and 3 we turn to our central question of how people perceive others’ behavior (Step 2) and the incentives
in the dilemmas (Step 3). Our second step measures people’s perceptions about the kindness of others’ behavior. While
differences in kindness perceptions could support a preference interpretation, it is possible that some people misperceive
the game form because they do not understand the material incentives of the public good game. Such “confusion” is likely
because of previous evidence (e.g., Andreoni, 1995a; Houser and Kurzban, 2002; Ferraro and Vossler, 2010; Bayer et al.,
2013). Moreover, irrespective of the game form, cooperation preferences as measured by the strategy method might be
influenced by misperceptions (Burton-Chellew et al., 2016). Testing for misperception of incentives is our third step. 1 The behavioral evidence about cooperation in maintenance and provision dilemmas comes from largely separate literatures. For cooperation in main-
tenance (common-pool resource) problems, see, e.g., the surveys by Ostrom (1990) and Ostrom (2006). Evidence on cooperation in public goods provision
problems is surveyed in, e.g., Ledyard (1995); Gächter and Herrmann (2009); Chaudhuri (2011) and Fehr and Schurtenberger (2018).
2 We focus sharply on the social dilemma dimension of provision and maintenance public goods, and abstract from technological features (e.g., resource
rivalry in common-pool resources vs. non-rivalrous public goods) and institutional details (rules and regulations) that define real-world social dilemmas
(e.g., Ostrom, 1990; Cornes and Sandler, 1996; Poppe, 2005; Apesteguía and Maier-Rigaud, 2006; Levin, 2014). 1 The behavioral evidence about cooperation in maintenance and provision dilemmas comes from largely separate literatures. For cooperation in main-
tenance (common-pool resource) problems, see, e.g., the surveys by Ostrom (1990) and Ostrom (2006). Evidence on cooperation in public goods provision
problems is surveyed in, e.g., Ledyard (1995); Gächter and Herrmann (2009); Chaudhuri (2011) and Fehr and Schurtenberger (2018). 2 We focus sharply on the social dilemma dimension of provision and maintenance public goods, and abstract from technological features (e.g., resource
rivalry in common-pool resources vs. non-rivalrous public goods) and institutional details (rules and regulations) that define real-world social dilemmas
(e.g., Ostrom, 1990; Cornes and Sandler, 1996; Poppe, 2005; Apesteguía and Maier-Rigaud, 2006; Levin, 2014). Table 1 Table 1
Four steps to test whether Maintenance and Provision are different dilemmas. Measure how kind or unkind people perceive a certain
cooperation level to be. Measured on a scale of -100 (=very
unkind) to +100 (= very kind) Measure with 8 incentivized questions about payoffs and goals
how people perceive the incentives in the public good game. Control for misperceptions to test for potential differences in
cooperative preferences * Data taken from https://doi .org /10 .5061 /dryad .8d9t2. ences using the strategy method by Fischbacher et al. (2001).3 Controlling for people’s misunderstanding will then allow us
to test whether cooperation preferences continue to differ statistically significantly between Maintenance and Provision. Our
fourth step is to discuss how various theories of social preferences can explain our results. ences using the strategy method by Fischbacher et al. (2001).3 Controlling for people’s misunderstanding will then allow us
to test whether cooperation preferences continue to differ statistically significantly between Maintenance and Provision. Our
fourth step is to discuss how various theories of social preferences can explain our results. Our paper offers several contributions to the literature. Our methodology of holding the nature of the social dilemma
constant relates us to literatures on framing and context effects in other-regarding behavior.4 More specifically, our focus on
provision/maintenance of public goods leads us naturally to a design that is a version of what psychologists (Dawes, 1980)
have called “take-some” vs. “give-some” dilemmas (e.g., Sell and Son, 1997; van Dijk and Wilke, 1997; Sonnemans et al.,
1998; Messer et al., 2007; Cubitt et al., 2011a; Dufwenberg et al., 2011; Cox, 2015; Cox and Stoddard, 2015; Fosgaard et
al., 2014; Fosgaard et al., 2017; Khadjavi and Lange, 2015; Isler et al., 2021). Our maintenance/provision design differs from
designs that manipulate whether the positive externality of contributing to the public good or the negative externality of
not contributing is emphasized. Papers in this line of research are Andreoni (1995b); Park (2000); and Fujimoto and Park
(2010). For a comparative discussion of give/take or positive/negative externality framing effects and an overview of studies
see Cartwright (2016).5 Different from most early literature on give-some and take-some games, our analysis consists of separating preferences
and perceptions as determinants of cooperation rather than focusing only on cooperation decisions. 3 To measure confusion, previous studies used various experimental designs, like changed incentive structures (Andreoni, 1995a), information conditions
(Bayer et al., 2013), or computerized players (Houser and Kurzban, 2002; Ferraro and Vossler, 2010; Burton-Chellew et al., 2016). Fosgaard et al. (2017)
used an incentivized post-experimental questionnaire.
4 Our focus is on public goods games, but also relates to the importance of context effects. For instance, previous evidence from dictator games reveals
that people are less willing to give if the choice set also includes the option to take away money (List, 2007; Bardsley, 2008; Cappelen et al., 2013; Dreber
et al., 2013; Korenok et al., 2014; Bicchieri et al., 2022). Also, the approval of egoistic behavior seems to be context-dependent too, e.g., in markets vs.
non-market settings (Bartling et al., 2021).
5 Another dimension of framing effects is due to attaching labels to games (e.g., “Wallstreet vs Community game”; e.g., Ellingsen et al., 2012 and
Dufwenberg et al., 2011). In this paper we use neutral labels.
6 Our focus on social preferences and (mis-)perception does not deny the possibility that cognitive ability, risk preferences and loss aversion might matter
too (e.g., De Dreu and McCusker, 1997; Iturbe-Ormaetxe et al., 2011), but we leave this for future research, not least to keep this paper manageable. ming effects is due to attaching labels to games (e.g., “Wallstreet vs Community game”; e.g., Ellingsen et al., 2012 an
his paper we use neutral labels. 1. Introduction To this end, we designed a set of eight incentivized control ques-
tions that people answered after they had correctly solved ten standard understanding questions covering payoffs in the
public good game. We administered the incentivized control questions before we measured participants’ cooperation prefer- 339 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Table 1
Four steps to test whether Maintenance and Provision are different dilemmas. Table 1
Four steps to test whether Maintenance and Provision are different dilemmas. Exp. Experiment
Number of participants
Subject pool
Purpose
Step 1: Establishing the replicability and stability of cooperative preferences (Section 3)
0
Gächter et al. (2017)*
(n = 703)
Students (UoN)
These data provide a previous benchmark result, which we
replicate in Experiment 1
1
Replication study
n = 704
US citizens (MTurk)
Assess whether Experiment 0 with students can be replicated
in a non-student subject pool
2a
Temporal stability
(5 months delay)
n = 119
Students (UoN, sampled
from experiment 0)
Assess the role of stability of conditionally cooperative
preferences over time
2b
Predictive power of
cooperation
attitudes
n = 116
Students (UoN, sampled
from experiment 4)
Assess the predictive power of conditionally cooperative
preferences plus beliefs to explain actual cooperation levels
Step 2: Measuring perceptions of kindness (Section 4)
3
Kindness survey
n = 185
Students (UoN, new
participants)
Measure how kind or unkind people perceive a certain
cooperation level to be. Measured on a scale of -100 (=very
unkind) to +100 (= very kind)
n = 401
US citizens (MTurk,
new participants)
Step 3: Measuring game form misperceptions and controlling for them (Section 5)
4
Dilemma-specific
game-form
misperceptions
n = 696
Students (UoN, new
participants)
Measure with 8 incentivized questions about payoffs and goals
how people perceive the incentives in the public good game. Control for misperceptions to test for potential differences in
cooperative preferences
Step 4: Assessing theoretical explanations (Section 6)
* Data taken from https://doi .org /10 .5061 /dryad .8d9t2. 5 Another dimension of framing effects is due to attaching labels to games (e.g., “Wallstreet vs Community game”; e.g., Ellingsen et al., 2012 and
Dufwenberg et al., 2011). In this paper we use neutral labels.
6 Our focus on social preferences and (mis-)perception does not deny the possibility that cognitive ability, risk preferences and loss aversion might matter
too (e.g., De Dreu and McCusker, 1997; Iturbe-Ormaetxe et al., 2011), but we leave this for future research, not least to keep this paper manageable. 6 Our focus on social preferences and (mis-)perception does not deny the possibility that cognitive ability, risk preferences and loss aversion might matter
too (e.g., De Dreu and McCusker, 1997; Iturbe-Ormaetxe et al., 2011), but we leave this for future research, not least to keep this paper manageable. 3 To measure confusion, previous studies used various experimental designs, like changed incentive structures (Andreoni, 1995a), information conditions
(Bayer et al., 2013), or computerized players (Houser and Kurzban, 2002; Ferraro and Vossler, 2010; Burton-Chellew et al., 2016). Fosgaard et al. (2017)
used an incentivized post-experimental questionnaire.
4 s and (mis-)perception does not deny the possibility that cognitive ability, risk preferences and loss aversion might matter
997; Iturbe-Ormaetxe et al., 2011), but we leave this for future research, not least to keep this paper manageable. 2. The basic setup and the proxy for cooperation preferences Our setup consists of the two social dilemmas described above, Provision and Maintenance. In both conditions, partici-
pants are randomly assigned to groups of n = 4. In Provision, each group member i is endowed with 20 tokens, which they
can either keep or (partly or fully) contribute (ci) to a “group project”. Contributions to the group project are summed up,
multiplied by a factor of 1.6, and distributed equally among the four members. Equation (1) describes the material incentives
of individual i: πi = 20 −ci + 1.6
4
4
j=1
c j. (1) In Maintenance, 80 tokens are initially placed in a “group project”. Each group member i decides about the allocation
of 20 tokens, which they can either leave or (partially or fully) withdraw (wi) from the project. Material incentives are
described by equation (2): πi = wi + 1.6
4 (80 −
4
j=1
w j). (2) πi = wi + 1.6
4 (80 −
4
j=1
w j). (2) If people are only motivated by material incentives, (1) and (2) are incentive-equivalent social dilemmas because ci = 20
– wi. Furthermore, because the material costs of cooperation outweigh its benefits, both the Maintenance and Provision
dilemma have full free-riding (ci = 0; wi = 20) as the unique Nash equilibrium in dominant strategies, no matter what
other members of their group (are believed to) do. All experiments were based on these two incentive-equivalent social dilemmas and consisted of several parts. In the
first part of each experiment, participants were introduced to the basic decision situation explaining either the Maintenance
or the Provision dilemma and its incentive structure, that is, each participant only faced one of the two social dilemmas
(between-subjects design). To ensure understanding, participants then had to complete a set of ten computerized control
questions. Only after correctly answering all of them, participants could proceed with the experiment. The exact design of the remaining parts differed across our experiments.7 In most of our experiments, in the second part
we implemented a strategy-method public goods game (described below) through which we measure cooperation attitudes,
our main proxy for cooperation preferences. Some of the sessions in these experiments included a third part in which
participants played a direct-response game in which they simultaneously had to state their contribution decision and belief
about others’ contributions. 7 At the beginning of the experiment, participants were told that the experiment consists of several parts, but that the details about later parts would be
disclosed only after they had completed the respective parts. The different designs of the later parts could therefore not affect behavior in previous parts.
8 As a robustness check, we used an alternative classification method by Thöni and Volk (2018), who proposed a refinement of the criteria of Fischbacher
et al. (2001). All results are qualitatively and quantitatively in line with those reported below. Table 1 With regard to prefer-
ences, our paper joins the small literature that elicits preferences for conditional cooperation in maintenance or provision
problems (e.g., Frackenpohl et al., 2016; Gächter et al., 2017; Fosgaard et al., 2014; Fosgaard et al., 2017; Isler et al., 2021). Our experiments also measure the perception of incentives before we elicit preferences for cooperation. This heeds argu-
ments by Koszegi and Rabin (2008) and Cason and Plott (2014) that measuring preferences requires controlling for the
perception of incentives.6 Our goals relate us to Fosgaard et al. (2017). They also measure preferences for conditional cooperation and misper-
ceptions albeit after the elicitation of preferences and with fewer questions. Theirs is a representative subject pool from
Denmark (n = 2, 042), whereas we present evidence from a student subject pool in the UK and online workers (MTurk)
from the general population in the US (total n = 2, 105). More importantly, unlike Fosgaard et al. (2017), we report evi-
dence on the temporal stability of preferences, perceptions of kindness and guilt, and link our results to theories of social
preferences. Our four-step analysis that combines lab and online experiments, replications, between and within-subject sta- 340 S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 bility tests, measurement of perceptions of kindness as well as of the incentives in the games, establishes that Maintenance
and Provision are different social dilemmas even when sharing the same game form and when controlling for possible
misperceptions of incentives. bility tests, measurement of perceptions of kindness as well as of the incentives in the games, establishes that Maintenance
and Provision are different social dilemmas even when sharing the same game form and when controlling for possible
misperceptions of incentives. 2. The basic setup and the proxy for cooperation preferences In the experiments in which we elicited game-form misperceptions, the strategy-method game
in part 2 was preceded by a set of incentivized control questions. In the following, we explain how we elicited cooperation
attitudes, which is our main variable of interest. All instructions and control questions are in Online Appendix A. To elicit a proxy for cooperation preferences we used the design introduced by Fischbacher et al. (2001), which employs
a variant of the strategy method (Selten, 1967). This design elicits an individual’s willingness to cooperate as a function
of other group members’ cooperation. Participants played a one-shot version of the game and were asked to make an un-
conditional and a conditional contribution (or withdrawal) decision. In the unconditional decision, participants chose one
contribution or withdrawal level. In the conditional decision, participants were asked to fill in a table in which they had
to indicate their contribution (or withdrawal) decision for each possible (rounded) average contribution (or withdrawal) of
the other three group members. To guarantee incentive compatibility, in each group a random mechanism selected three
members for whom the unconditional decision was payoff-relevant and one member for whom the conditional decision
was payoff-relevant. For this participant, the conditional decision was calculated according to the (rounded) average uncon-
ditional decision of the other three group members. The incentive-compatibly elicited attitudes are a proxy for cooperation
preferences in the sense that they measure people’s willingness to pay for conditional cooperation. Following Fischbacher et al. (2001), we classify a participant as a (i) conditional cooperator if their contribution/withdrawal
schedule exhibits a (weakly) monotonically increasing pattern, or if the Spearman correlation coefficient between their
schedule and the others’ average contribution (or withdrawal) is positive and significant at p < 0.01; (ii) a free rider if they
never contribute anything or withdraw everything irrespective of how much the others contribute (or withdraw); and (iii)
as other if none of the criteria in (i) & (ii) apply.8 341 S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 Our data come from four experiments and three main sources: the CeDEx lab at the University of Nottingham; the online
labor market platform Amazon Mechanical Turk (MTurk); and online experiments conducted with students at the University
of Nottingham (see Table 1 for an overview of our experiments). We used z-Tree (Fischbacher, 2007) for conducting the
laboratory sessions. 2. The basic setup and the proxy for cooperation preferences For the online experiments on MTurk and the University of Nottingham, we used the survey software
Qualtrics. For the lab and online experiments at Nottingham, we recruited student participants (average age 20.2 years;
58% female) from various disciplines at the University of Nottingham using the software ORSEE (Greiner, 2015). Students
were only allowed to participate in one lab or online session. On MTurk, participants (all US residents) were 31.9 years old
and 41% were female.9 Average payments were £20.60 for lab sessions, and $2.60 for MTurk sessions (corresponding to an
hourly wage of $13.00). 3. Step 1: replicability and stability of preferences in Maintenance and Provision We start by summarizing the findings from our previous study (Gächter et al., 2017). We then compare these results
with an online replication study conducted on MTurk. Being able to replicate the basic phenomenon we want to study is an
important first step in our analysis.10 After that, we show that cooperation preferences are not only stable between different
subject pools but are also stable over time within participants. Finally, we investigate the predictive power of the elicited
cooperation preferences for simultaneous gameplay and compare it across Maintenance and Provision. All procedural details
and further supporting evidence are in Online Appendix B1. 11 The category ‘others’ contains “unconditional cooperators” who contribute a constant positive amount irrespective of what other group members
contribute, “anti-conditional cooperators” whose cooperation depends negatively on the cooperation of other group members, “triangle cooperators” who
are conditionally cooperative up to a certain level when they turn into anti-conditional and the rest. See Online Appendix B1 for further details and the
relative frequencies of these subtypes. 9 See Horton et al. (2011) and Arechar et al. (2018) for a detailed description of MTurk, and a comparison of MTurk versus lab experiments. Both studies
as well as Snowberg and Yariv (2021) demonstrate that behavior in a variety of games is similar on MTurk and the lab.
10 See Maniadis et al. (2014), Camerer et al. (2016), Camerer et al. (2019), and Drazen et al. (2021) on the importance of replicability in experimental
economics.
11 The category ‘others’ contains “unconditional cooperators” who contribute a constant positive amount irrespective of what other group members
contribute, “anti-conditional cooperators” whose cooperation depends negatively on the cooperation of other group members, “triangle cooperators” who
are conditionally cooperative up to a certain level when they turn into anti-conditional and the rest. See Online Appendix B1 for further details and the
relative frequencies of these subtypes.
12 We decided to replicate the findings of Gächter et al. (2017) with a planned sample size of n = 700 because we were interested in the robustness of
our lab results with undergraduates in a much more diverse subject pool. Based on the differences in the type distributions in the left panel of Fig. 1, a
sample size of n = 215 would have sufficed to detect the same effect size with a power of 0.99 at α = 0.001 (calculations based on G*Power 3.1, Faul et al.,
2007). However, given the different socio-demographic characteristics of the subject pool and the online nature of the experiment in MTurk, we decided to
increase the sample to n = 700.
13 The different levels of the frequency of types across our two studies is not surprising given the different cultural and sociodemographic background of
the participants. We note, however, that the results from our MTurk study are very similar to Kocher et al. (2008) who elicited cooperation types among
US students using a Provision public goods game: When comparing their results to ours, we find a remarkably similar distribution of types (χ 2(2) = 0.02;
p = 0.992): 81% vs. 80% conditional cooperators, 8% vs. 8% free riders, and 11% vs. 12% others. We thank M. Kocher for providing the data. Disaggregating
the category ‘others’ in our MTurk data shows similar results than in Gächter et al. (2017). See Table B1 (Panel B) in Online Appendix B.
14 We note that the differences across Maintenance and Provision are somewhat less pronounced in the MTurk sample compared to the student sample:
the difference in the share of conditional cooperators amounts to 13 and 20 percentage points, respectively; the difference in the share of free riders is
8 and 11 percentage points, resp.; and the difference in the share of others is 4 and 11 percentage points, resp.. To test whether these differences across
the two samples are significant, we run logistic regressions in which we use the different types as dependent variable, a treatment dummy, a MTurk
dummy, and an interaction between the latter two as independent variables. The results, reported in Table B2 in Online Appendix B, confirm that there are
significantly more conditional cooperators and significantly less free riders and others in Provision than Maintenance and on MTurk, but that there are no
significant interaction effects (Provision × MTurk). 9 See Horton et al. (2011) and Arechar et al. (2018) for a detailed description of MTurk, and a comparison of MTurk versus lab experiments. Both studies
as well as Snowberg and Yariv (2021) demonstrate that behavior in a variety of games is similar on MTurk and the lab. 10 See Maniadis et al. (2014), Camerer et al. (2016), Camerer et al. (2019), and Drazen et al. (2021) on the importance of replicability in experimental
economics. increase the sample to n = 700.
13 The different levels of the frequency of types across our two studies is not surprising given the different cultural and sociodemographic background of
the participants. We note, however, that the results from our MTurk study are very similar to Kocher et al. (2008) who elicited cooperation types among
US students using a Provision public goods game: When comparing their results to ours, we find a remarkably similar distribution of types (χ 2(2) = 0.02;
p = 0.992): 81% vs. 80% conditional cooperators, 8% vs. 8% free riders, and 11% vs. 12% others. We thank M. Kocher for providing the data. Disaggregating
the category ‘others’ in our MTurk data shows similar results than in Gächter et al. (2017). See Table B1 (Panel B) in Online Appendix B.
14 We note that the differences across Maintenance and Provision are somewhat less pronounced in the MTurk sample compared to the student sample:
the difference in the share of conditional cooperators amounts to 13 and 20 percentage points, respectively; the difference in the share of free riders is
8 and 11 percentage points, resp.; and the difference in the share of others is 4 and 11 percentage points, resp.. To test whether these differences across
the two samples are significant, we run logistic regressions in which we use the different types as dependent variable, a treatment dummy, a MTurk
dummy, and an interaction between the latter two as independent variables. The results, reported in Table B2 in Online Appendix B, confirm that there are
significantly more conditional cooperators and significantly less free riders and others in Provision than Maintenance and on MTurk, but that there are no
significant interaction effects (Provision × MTurk). 0 See Maniadis et al. (2014), Camerer et al. (2016), Camerer et al. (2019), and Drazen et al. (2021) on the importance o
conomics.
1
h
h
d
l
h
b are conditionally cooperative up to a certain level when they turn into anti conditional and the rest. See Online Appendix B1 for further details and the
relative frequencies of these subtypes.
12 We decided to replicate the findings of Gächter et al. (2017) with a planned sample size of n = 700 because we were interested in the robustness of
our lab results with undergraduates in a much more diverse subject pool. Based on the differences in the type distributions in the left panel of Fig. 1, a
sample size of n = 215 would have sufficed to detect the same effect size with a power of 0.99 at α = 0.001 (calculations based on G*Power 3.1, Faul et al.,
2007). However, given the different socio-demographic characteristics of the subject pool and the online nature of the experiment in MTurk, we decided to
increase the sample to n = 700.
13 The different levels of the frequency of types across our two studies is not surprising given the different cultural and sociodemographic background of
the participants. We note, however, that the results from our MTurk study are very similar to Kocher et al. (2008) who elicited cooperation types among
US students using a Provision public goods game: When comparing their results to ours, we find a remarkably similar distribution of types (χ 2(2) = 0.02;
p = 0.992): 81% vs. 80% conditional cooperators, 8% vs. 8% free riders, and 11% vs. 12% others. We thank M. Kocher for providing the data. Disaggregating
the category ‘others’ in our MTurk data shows similar results than in Gächter et al. (2017). See Table B1 (Panel B) in Online Appendix B.
14 We note that the differences across Maintenance and Provision are somewhat less pronounced in the MTurk sample compared to the student sample:
the difference in the share of conditional cooperators amounts to 13 and 20 percentage points, respectively; the difference in the share of free riders is
8 and 11 percentage points, resp.; and the difference in the share of others is 4 and 11 percentage points, resp.. To test whether these differences across
the two samples are significant, we run logistic regressions in which we use the different types as dependent variable, a treatment dummy, a MTurk
dummy, and an interaction between the latter two as independent variables. The results, reported in Table B2 in Online Appendix B, confirm that there are
significantly more conditional cooperators and significantly less free riders and others in Provision than Maintenance and on MTurk, but that there are no
significant interaction effects (Provision × MTurk). 9 See Horton et al. (2011) and Arechar et al. (2018) for a detailed description of MTurk, and a comparison of MTurk ve
as well as Snowberg and Yariv (2021) demonstrate that behavior in a variety of games is similar on MTurk and the lab. 12 We decided to replicate the findings of Gächter et al. (2017) with a planned sample size of n = 700 because we were interested in the robustness of
our lab results with undergraduates in a much more diverse subject pool. Based on the differences in the type distributions in the left panel of Fig. 1, a
sample size of n = 215 would have sufficed to detect the same effect size with a power of 0.99 at α = 0.001 (calculations based on G*Power 3.1, Faul et al.,
2007). However, given the different socio-demographic characteristics of the subject pool and the online nature of the experiment in MTurk, we decided to
increase the sample to n = 700. See Horton et al. (2011) and Arechar et al. (2018) for a detailed description of MTurk, and a comparison of MTurk versus lab experiments. Both studies
as well as Snowberg and Yariv (2021) demonstrate that behavior in a variety of games is similar on MTurk and the lab.
10 See Maniadis et al. (2014), Camerer et al. (2016), Camerer et al. (2019), and Drazen et al. (2021) on the importance of replicability in experimental
economics. 12 We decided to replicate the findings of Gächter et al. (2017) with a planned sample size of n = 700 because we were interested in the robustness of
our lab results with undergraduates in a much more diverse subject pool. Based on the differences in the type distributions in the left panel of Fig. 1, a
sample size of n = 215 would have sufficed to detect the same effect size with a power of 0.99 at α = 0.001 (calculations based on G*Power 3.1, Faul et al.,
2007). However, given the different socio-demographic characteristics of the subject pool and the online nature of the experiment in MTurk, we decided to
increase the sample to n = 700.
13 The different levels of the frequency of types across our two studies is not surprising given the different cultural and sociodemographic background of
the participants. We note, however, that the results from our MTurk study are very similar to Kocher et al. (2008) who elicited cooperation types among
US students using a Provision public goods game: When comparing their results to ours, we find a remarkably similar distribution of types (χ 2(2) = 0.02; 3.1. Gächter et al. (2017) and a replication on MTurk 3.1. Gächter et al. (2017) and a replication on MTurk The left panel of Fig. 1 summarizes the main relevant finding for our paper from Gächter et al. (2017), which was
based on a one-shot strategy method experiment as described in Section 3. Participants were significantly more likely to be
conditional cooperators (χ 2(1) = 31.03; p < 0.001) and significantly less likely to be free riders (χ 2(1) = 10.46; p = 0.001)
and others (χ 2(1) = 11.08; p = 0.001) in Provision than in Maintenance.11 In a one-shot direct response game played after
the type elicitation, Gächter et al. (2017) further found that cooperation rates were significantly higher in Provision than in
Maintenance (41% vs. 30%; two-sided t-test: p = 0.007). Our replication for the purposes of this paper was conducted on MTurk with n = 703 US participants (instructions are
in Online Appendix A).12 The results match our previous findings. While the levels in the frequency of types are different
compared to our UK student sample – we observe more conditional cooperators (73% vs. 53%, χ 2(1) = 62.21; p < 0.001)
and less free riders (13% vs. 22%, χ 2(1) = 23.26; p < 0.001) and others (14% vs. 24%, χ 2(1) = 24.97; p < 0.001) on MTurk
- treatment differences are highly significant.13 Specifically, as shown in the right panel of Fig. 1, in line with Gächter et
al. (2017), we find a significantly different distribution of types across treatments (χ 2(2) = 15.96, p < 0.001) with a larger
fraction of conditional cooperators (80% vs. 67%, χ 2(1) = 14.75; p < 0.001), and a lower fraction of free riders (8% vs. 17%,
χ 2(1) = 10.75; p = 0.001) and others (12% vs. 16%, χ 2(1) = 3.07; p = 0.080) in Provision compared to Maintenance.14 Like in our previous study, we also find that effective cooperation rates (after contributions/withdrawals), measured in
a one-shot direct-response game played after the type elicitation, are significantly higher in Provision than in Maintenance
(52% vs. 39%, two-sided t-test: p < 0.001). In both samples, we also find unconditional contributions in the strategy method 342 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Fig. 1. Distribution of cooperation types. Left panel: n = 704 students from the UK (source: Gächter et al. (2017)). 3.2. Temporal stability To test whether the observed difference in the distribution of types is also stable within participants, we ran an additional
experiment in which we re-invited a subset of participants from the Gächter et al. (2017) sample (left panel of Fig. 1) four
months after their first participation. Without knowing in advance, participants took part in sessions that were identical to
the ones in which they participated before. We report results from n = 119 participants (n = 65 in Provision and n = 54 in
Maintenance) who showed up in both waves. At the aggregate level, cooperation preferences are remarkably stable over a period of four months; the distribution of
types within treatments is very similar and does not significantly change between waves, neither in Maintenance (χ 2(2)
= 0.51, p = 0.776) nor Provision (χ 2(2) = 1.57, p = 0.456). Consequently, when comparing the distribution of types across
treatments, we find a significantly different distribution across Maintenance and Provision for both Wave 1 and Wave 2 (χ 2(2)
= 10.32, p = 0.006 and χ 2(2) = 11.87, p = 0.003, respectively; see also Table B3 in Online Appendix B). Regarding individual-level stability of cooperation preferences, we find that in Provision 66% of participants are classified
as the same type in both waves, compared to 59% in Maintenance, a difference that is not statistically significant (χ 2(1)
= 0.60, p = 0.438). While these numbers indicate that the stability of types across waves is clearly not perfect, for both
treatments we find it to be significantly higher than chance (which amounts to 46% and 35%, in Provision and Maintenance,
resp.; t-tests, both p < 0.001; see Table B4 in Online Appendix B). The stability rate in Provision is similar to Volk et al. (2012) who, using a similar setup and a gap of 2.5 months between waves, find a stability rate of 64%. No such comparison
is possible for Maintenance because, as far as we are aware of, no previous study has investigated the stability of cooperation
preferences using a maintenance dilemma. 3.1. Gächter et al. (2017) and a replication on MTurk Right panel: n = 703 US participants from
MTurk (source: new experiments). p-values from χ 2-tests. Fig. 1. Distribution of cooperation types. Left panel: n = 704 students from the UK (source: Gächter et al. (2017)). Right panel: n = 703 US participants from
MTurk (source: new experiments). p-values from χ 2-tests. to differ significantly across both dilemmas (Lab: Provision: 42%, Maintenance: 34%, two-sided t-test: p = 0.003; MTurk:
Provision: 53%, Maintenance: 38%, two-sided t-test: p < 0.001). to differ significantly across both dilemmas (Lab: Provision: 42%, Maintenance: 34%, two-sided t-test: p = 0.003; MTurk:
Provision: 53%, Maintenance: 38%, two-sided t-test: p < 0.001). 3.2. Temporal stability 3.3. Predictive power of cooperation preferences If our proxy for cooperation preferences measures something fundamental about people’s attitude towards cooperation,
it should be predictive of actual behavior in another comparable environment. To test this, we rely on the third part of
our experiment in which a subset of participants took part in a one-shot direct-response public goods game in which
they made a single contribution decision. We also elicited incentivized beliefs about the average contribution of the other
group members. Following Fischbacher et al. (2012), by combining elicited cooperation attitudes with stated beliefs we can 343 S. Gächter, F. Kölle and S. Quercia
Games and Economic Behavior 135 (2022) 338–355
Fig. 2. Deviations from predicted choices in Maintenance and Provision. Left panel: Students (n = 288). Middle panel: MTurk (n = 703). Right panel: Students
who participated in the direct-response experiment five months after the preference elicitation experiment (n = 116). Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Fig. 2. Deviations from predicted choices in Maintenance and Provision. Left panel: Students (n = 288). Middle panel: MTurk (n = 703). Right panel: Students
who participated in the direct-response experiment five months after the preference elicitation experiment (n = 116). make a point prediction about the contribution decision, ˆci. We then compare ˆci with ci (i’s actual contribution in the
direct-response game), delivering an individual-level measure of consistency. In total, we have (1) n = 288 observations from our Gächter et al. (2017) sample, and (2) n = 703 observations from our
MTurk experiment.15 We further report data from (3) a set of n = 116 participants, for which the elicitation of cooperation
preferences and the direct-response game took place in two separate sessions that lay five months apart. To our knowledge,
this is the first paper that undertakes such a test of temporal stability. Our results are shown in Fig. 2, depicting the
distribution of individual deviations from predicted choices, ci −ˆci, separately for Maintenance and Provision and for each of
the three samples. Fig. 2 reveals that in all cases the modal and the median deviation is zero, that is, participants’ contribution decision in
the direct-response game is perfectly consistent with their predicted contribution from the strategy-method, even after a
delay of 5 months. 15 The remaining participants from Gächter et al. (2017) played a repeated game. The results on the predicted power for the first-period contributions are
similar to the one reported here (see Gächter et al., 2017). 3.3. Predictive power of cooperation preferences While not all participants are completely consistent (see Online Appendix B for further details), for none
of the three samples the distribution of deviations is significantly different across Maintenance and Provision (Kolmogorov
Smirnov tests; Lab: p = 0.195; MTurk: p = 0.532; Lab (5 months): p = 0.472). Overall, this demonstrates that the elicited
attitudes are, together with elicited beliefs, an equally good predictor of actual cooperation behavior in both Maintenance
and Provision. 16 Since we asked participants for their personal perceptions, answers were not incentivized. However, we did incentivize participation. Student partici-
pants were offered three randomly drawn prizes of £50 each. MTurkers received a flat payment of $2. According to Cubitt et al. (2011b) who studied moral
judgments in social dilemmas, incentivizing participation does not affect moral judgments, making it unlikely that it affects kindness evaluations. 3.4. Discussion Consistent with the evidence from Frackenpohl et al. (2016) and Fosgaard et al. (2017), in Gächter et al. (2017) we
have shown that Maintenance and Provision dilemmas elicit systematically different cooperation attitudes with significantly
fewer participants behaving conditionally cooperative in the former than in the latter. In Gächter et al. (2017) we have
further shown that together with differences in the beliefs about others’ cooperation, this translates into different levels
of cooperation in both one-shot and repeated games. We extend this prior evidence by showing that (i) differences in
cooperation attitudes across Maintenance and Provision are replicable across different subject pools, (ii) elicited attitudes in
both dilemmas are equally stable within participants over a period of four months, and (iii) elicited attitudes are (jointly
with beliefs) an equally good predictor of actual cooperation decision in both dilemmas, even after a delay of five months. We summarize these findings in our first result: 344 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Gächter, F. Kölle and S. Quercia
Games and Economic Behavior 135 (2022) 338–3
Fig. 3. Kindness perceptions in Provision and Maintenance of others’ effective contributions (±1 s.e.m). Fig. 3. Kindness perceptions in Provision and Maintenance of others’ effective contributions (±1 s.e.m). Result 1: Maintenance and Provision evoke systematically different cooperation attitudes. Most importantly, conditional coop-
eration is more frequent in Provision than Maintenance. The elicited attitudes are stable within individuals and, jointly with beliefs,
predictive of actual cooperation decisions. Result 1: Maintenance and Provision evoke systematically different cooperation attitudes. Most importantly, conditional coop-
eration is more frequent in Provision than Maintenance. The elicited attitudes are stable within individuals and, jointly with beliefs,
predictive of actual cooperation decisions. While replicability, stability, and predictive power are necessary conditions to interpret the effects as differences in
underlying social preferences, they are not sufficient. An alternative interpretation of the observed differences is that they
are due to stable and systematic misperceptions of the game form. In the next two steps (and sections), we disentangle
the relative importance of social preferences and misperceptions. We start in the next section by investigating whether the
differences between Provision and Maintenance can be related to different social perceptions across the two contexts. 5.1. Conceptualization of game form misperceptions 5.1. Conceptualization of game form misperceptions 5.1. Conceptualization of game form misperceptions Our conceptualization of game-form misperceptions draws on Cason and Plott (2014). They analyze the tension between
standard theory, which assumes that preferences are only influenced by elements of the game form (i.e., the set of actions,
the set of material consequences, and the links between actions and consequences), and non-standard theories, which
postulate that preferences may depend on elements outside the game form such as how the game form is described. In their example, Cason and Plott investigate anomalous bidding behavior in the Becker et al. (1964) mechanism. While
observed bids are consistent with frame-dependent preferences, Cason and Plott show that this effect is driven by a subset
of participants who mistakenly perceive the situation as a first-price auction rather than a second-price auction. They
conclude that in their case, the description of the decision situation affected participants’ perception of the game form,
which, in turn, led them to implement ‘wrong’ behavioral responses given their underlying preferences. Cason and Plott’s
general conclusion is that researchers should be careful when interpreting choices as revealed preferences, an issue that
Koszegi and Rabin (2008) also point out. The implication of Cason and Plott’s argument for our context is that interpreting differences in behavioral responses
across treatments as evidence for dilemma-dependent preferences might be erroneous because such differences can be
due to dilemma-dependent misperceptions of the game form. If failure of correct game-form recognition is also at work
in our setup, which is possible given previous evidence on confusion (see Introduction), then the observed distribution of
cooperation types might not reflect participants’ true cooperation preferences as some of the participants might have mis-
takenly implemented behavior different from their preferred one. For example, if some participants erroneously believe that
to maximize their individual income, they should increase their contribution if the contributions of other group members
increase, this might lead to an inflated rate of conditional cooperation. Moreover, if this type of game-form misperception
is more frequent in Provision than in Maintenance, this could explain the observed treatment effect of a higher frequency of
conditional cooperation and a lower frequency of free riding in the former than the latter. Some evidence for this possibility
comes from Fosgaard et al. 5.1. Conceptualization of game form misperceptions (2017) who find that many participants fail to recognize the dominant strategy of full free-riding
and that this type of mistake occurs more frequently in Provision than in Maintenance. In the next subsection, we describe
the details of a new experiment that was specifically designed to examine the role of misperceptions in our context. 4. Step 2: perceptions of kindness in Maintenance and Provision In these cases, payoff equivalent actions are
considered as unkinder in Maintenance compared to Provision (two-sided t-tests, average others’ contribution = 10, p = 0.045
and p = 0.001 for students and MTurkers, respectively; average others’ contribution = 20, p = 0.007 and p = 0.062 for
students and MTurkers, respectively). pattern for medium and high effective contributions of 10 and 20, respectively. In these cases, payoff equivalent actions are
considered as unkinder in Maintenance compared to Provision (two-sided t-tests, average others’ contribution = 10, p = 0.045
and p = 0.001 for students and MTurkers, respectively; average others’ contribution = 20, p = 0.007 and p = 0.062 for
students and MTurkers, respectively). Further support comes from OLS regressions in which we use kindness evaluations as the dependent variable, others’
average contributions, a dummy for Provision, and an interaction term of the last two as independent variables. We run this
regression separately for each subject pool. The results are in Table B5 in Online Appendix B. In line with Fig. 3, we find
a positive and significant coefficient for the interaction term, indicating greater responsiveness of kindness evaluations to
others’ contributions in Provision than in Maintenance. We summarize these findings in our second result: Result 2: Maintenance and Provision evoke systematically different perceptions of kindness: Complete free-riding is perceived to
be unkinder in Provision than in Maintenance, while positive contributions (of 10 and 20) are perceived as more kind in Provision than
in Maintenance. Overall, Result 2 suggests that both with respect to kindness and unkindness, individuals have stronger reactions in their
perception of others’ contributions when contributing to, rather than withdrawing from, a public good. Result 2 is also con-
sistent with Cubitt et al. (2011b) who found a similar pattern for moral judgments: Failing to contribute to the public good
was perceived as morally worse than withdrawing everything. These stronger reactions likely trigger a stronger need to re-
ciprocate and, hence, can explain the higher frequency of conditional cooperators in Provision compared to Maintenance. The
result from our kindness survey thus favors the explanation that the differences in cooperation attitudes across treatments
are rooted in differences in the underlying preferences. 4. Step 2: perceptions of kindness in Maintenance and Provision A prominent psychological explanation for the existence of conditional cooperation is that individuals are reciprocal, that
is, they have a desire to reward kind intentions with kindness and punish unkind intentions with unkindness (see Fehr
and Schurtenberger, 2018 for a review). Hence, as reciprocity is the behavioral response to perceived kindness or unkind-
ness (Rabin, 1993; Dufwenberg and Kirchsteiger, 2004; Falk and Fischbacher, 2006), a crucial question is how participants
evaluate actions of others in terms of (un)kindness, and whether these evaluations differ across games. If people perceive
payoff-equivalent actions differently in terms of kindness across Maintenance and Provision, this could trigger game-specific
reciprocal responses which, in turn, could explain the observed differences in conditional cooperation across the two setups. p
p
p
p
p
To test this conjecture, we conducted two online studies in which we elicited kindness perceptions about other people’s
contribution behavior for both types of social dilemmas (see Falk and Fischbacher, 2006 for a related exercise and Wilson,
2012 for a cautionary note). In the questionnaire, we explained to participants either a Maintenance or a Provision dilemma
and then asked them to evaluate the kindness of average effective contributions of three other group members on a scale
from -100 to +100 (where -100 corresponds to ‘very unkind’ and +100 corresponds to ‘very kind’). We asked participants to
evaluate the kindness of a low, an intermediate, and a high effective contribution of 0, 10, and 20, respectively (see Online
Appendix A3). We recruited n = 185 students from the University of Nottingham and n = 401 participants from MTurk. No
participant was involved in any of our experimental sessions before.16 Fig. 3 reports the average kindness evaluation of others’ average effective contributions. The results from the two samples
are remarkably similar. While low effective contributions of 0 are considered as significantly less kind in Provision than in
Maintenance (two-sided t-tests, p < 0.001 and p < 0.001 for students and MTurkers, respectively), we observe the reverse 345 S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 pattern for medium and high effective contributions of 10 and 20, respectively. 5. Step 3: measuring and controlling for game form misperceptions One alternative explanation for our results is that participants may have systematic misperceptions of the game form
and that these misperceptions may be dilemma specific. If this were the case, differences in conditional cooperation may
not be due to different social preferences but due to differences in the understanding of the incentives of the game. In this
section, we assess to what extent game-form misperceptions can explain our results. Table 2
i i Table 2 Table 2
Incentivized misperception questions and percentage of correct answers across Maintenance (M, n = 320) and Provision (P, n = 376). % Correct answers
M
P
χ 2 – test
Payoff questions:
Q1: Assume that you contribute 20 tokens to the project and the other three group members contribute
nothing to the project. What will your total income be? 95.3
95.5
p = 0.917(q = 0.917)
Q2: Assume that you contribute 20 tokens to the project and the other three group members contribute
nothing to the project. What will the total income of each of the other group members be? 90.9
84.3
p = 0.009 (q = 0.035)
Q3: Assume that you contribute 0 tokens to the project and each of the other three group members
contributes 20 tokens to the project. What will your total income be? 94.4
92.8
p = 0.405 (q = 0.649)
Q4: Assume that you contribute 0 tokens to the project and each of the other three group members
contributes 20 tokens to the project. What will the total income of each of the other group members be? 95.9
93.1
p = 0.103 (q = 0.275)
Goal questions:
Q5: Suppose the other group members contribute on average 0 tokens to the project. How much should a
person who wants to make as much money as possible for him/herself contribute to the project? 92.8
95.0
p = 0.239 (q = 0.478)
Q6: Suppose the other group members contribute on average 20 tokens to the project. How much should a
person who wants to make as much money as possible for him/herself contribute to the project? 93.8
85.6
p = 0.001 (q = 0.004)
Q7: Suppose the other group members contribute on average 0 tokens to the project. How much should a
person who wants that the group as a whole makes as much money as possible contribute to the project? 79.1
77.1
p = 0.539 (q = 0.664)
Q8: Suppose the other group members contribute on average 20 tokens to the project. How much should a
person who wants that the group as a whole makes as much money as possible contribute to the project? 93.1
92.0
p = 0.581 (q = 0.664)
Total
91.9
89.4
p = 0.030
Notes: Shown are the questions in Provision. The questions for Maintenance were formulated equivalently. Payoff questions: Notes: Shown are the questions in Provision. The questions for Maintenance were formulated equivalently. q-values correspond to p-values corrected for
multiple comparisons using the Benjamini and Hochberg (1995) false discovery rate procedure. For testing the total effect (last row) we use logistic
regressions with standard errors clustered at the individual level. correct answer.17 After that, the experiment proceeded with the elicitation of cooperation preferences using the strategy
method. We asked the incentivized questions before we elicited participants’ preferences to ensure maximal understanding
of the situation and incentives.18 correct answer.17 After that, the experiment proceeded with the elicitation of cooperation preferences using the strategy
method. We asked the incentivized questions before we elicited participants’ preferences to ensure maximal understanding
of the situation and incentives.18 The first four questions, which we label payoff questions, are akin to standard control questions in which participants have
to calculate earnings for various contribution scenarios. We asked participants to determine their own and others’ monetary
earnings in case (i) they would contribute their whole endowment, but the other group members would contribute nothing,
and (ii) they would contribute nothing but each of the other group members would contribute their whole endowment
(20 tokens) (see Q1 – Q4 in Table 2 for the exact wording of questions). Our first measure of game-form misperception
classifies a participant as misperceiving if they make at least one mistake in the payoff questions (see Bartling et al., 2015
for a similar approach in a value elicitation task). In the other four questions (compare Q5 – Q8 in Table 2), which we label goal questions, we follow a similar strategy
as Fosgaard et al. (2017) and ask participants what a person who wants to implement a specific goal should do. The first
goal was individual payoff maximization; participants were asked how much a person who “wants to make as much money
as possible for him/herself” should contribute given the other group members contribute either 0 or 20. The second goal
was group payoff maximization: we asked participants how much a person who “wants that the group as a whole makes
as much money as possible” should contribute given the other group members contribute either 0 or 20. We classify a
participant as misperceiving if they make at least one mistake in the goal questions. This constitutes our second measure
of game-form misperception. 18 In this methodological aspect, our approach is akin to Plott and Zeiler (2005) who used a battery of experimental tools designed to maximize under-
standing before eliciting WTA-WTP valuations. Payoff questions: Compared to the payoff questions, which require an understanding of the incentive structure
as well as sufficient calculation skills, the goal questions require the ability to put oneself into the shoes of another person
that might have different objectives than oneself, a task that is arguably more difficult than just calculating payoffs. Finally, our third measure checks whether a participant is a mistaken conditional cooperator, that is, whether they think
that maximizing their own income requires increasing own contribution if others’ contributions increase (from 0 to 20),
that is if their response to Q6 is strictly higher than their response to Q5. Such a mistake could lead participants to believe
that they face incentives akin to a coordination game rather than a social dilemma game. As a result, participants may then
implement ‘wrong’ behavioral responses given their underlying preferences. That is, while the behavioral response of such a
misperceiving participant in the strategy method might look like evidence of prosocial, reciprocal preferences, such behavior
is also consistent with a model in which a purely selfish participant maximizes their misperceived payoffs. 5.3. Misperceptions are dilemma specific To avoid any income effects when eliciting cooperation preferences, incentives were modest, and participants were informed about the number of
questions they answered correctly only at the very end of the experiment.
18 In this methodological aspect, our approach is akin to Plott and Zeiler (2005) who used a battery of experimental tools designed to maximize under-
standing before eliciting WTA-WTP valuations. 17 To avoid any income effects when eliciting cooperation preferences, incentives were modest, and participants wer
questions they answered correctly only at the very end of the experiment. Table 2
i i q-values correspond to p-values corrected for
multiple comparisons using the Benjamini and Hochberg (1995) false discovery rate procedure. For testing the total effect (last row) we use logistic
regressions with standard errors clustered at the individual level. 5.2. Measurement of game form misperceptions 5.2. Measurement of game form misperceptions We measure game-form misperceptions in a new experiment with n = 696 Nottingham students who had not partici-
pated in any of our experiments before. The experiment followed the structure presented in Section 2, except that there
was no direct-response experiment after the strategy-method experiment. Instead, after participants answered the standard
set of ten control questions, we asked them two additional sets of four incentivized questions (see Table 2), paying £0.1 per 346 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia 5.4. Misperceptions and cooperation attitudes In the following, we analyze the connection between misperceptions and the elicited cooperation attitudes. If there was
none, i.e., if mistakes were randomly distributed across types, then the different degrees in the level of misperception across
Maintenance and Provision should not affect the distribution of types. If, instead, the likelihood of game-form misperception
is correlated with displaying a certain cooperation type, this could explain the differences in conditional cooperation we
observed across our two treatments. Table 4 reports the fraction of misperceiving participants conditional on type classification. We report these numbers
separately for Maintenance and Provision and our three measures of misperception. Table 4 reveals that the null hypothe-
sis of no relationship between types and misperceptions can be rejected for both Maintenance and Provision according to
Measure 2 (goal questions, χ 2 – tests, both p < 0.007) and Measure 3 (mistaken conditional cooperation, χ 2 – tests, both
p < 0.003), but not for Measure 1 (payoff questions, χ 2 – tests, both p > 0.065). On top of that, our results reveal that
the way misperceptions interact with the elicited attitudes is treatment-specific. In Maintenance we observe mainly the
participants classified as others who display some form of misperceptions; compared to free riders their odds of displaying
misperceptions (calculated as the ratio between misperceiving and non-misperceiving participants) are increased by a factor
of 2.3 (Measure 1) up to 5.9 (Measure 3). In Provision, in contrast, we find that mainly the group of conditional cooperators
exhibiting misperceptions; compared to free riders their odds of displaying misperceptions is increased by a factor of 1.6
(Measure 1) up to 8.3 (Measure 3). These results show that the two types of dilemmas not only affect the overall level of misperception but also how
perceptions interfere with preferences. This provides a strong case for the need of controlling for misperceptions before in-
terpreting behavioral differences as dilemma-dependent preferences. In the following, we therefore test whether accounting
for the different types of misperceptions can explain the observed treatment differences in the distribution of cooperation
preferences. We report this analysis in Table 5. Panel A of Table 5 shows the distribution of types in the full sample (without controlling for misperceptions). 19 The relative frequency of types is somewhat different compared to the one found in our initial student sample as reported in Section 3.1. Specifically,
we find a significant change in the distribution of types in both Provision (χ2(2) = 14.26, p = 0.001) and Maintenance (χ2(2) = 11.01, p = 0.004), with
more free riders (Provision: 27% vs. 17%, χ2(1) = 10.43, p = 0.001, Maintenance 39% vs. 28%, χ2(1) = 10.44, p = 0.001) and fewer conditional cooperators 5.3. Misperceptions are dilemma specific When comparing the
fraction of correct answers between Maintenance and Provision for each question separately, we find significant differences
for two out of the eight questions, Q2 (p = 0.009) and Q6 (p = 0.001). Next, we turn to an individual-level analysis of mistakes by applying our three measures of game-form misperceptions
as described above. As shown in Table 3, for all measures, we find that misperceptions are significantly more frequent in
Provision than in Maintenance; the number of people misperceiving is between 8 and 9 percentage points higher in Provision
than in Maintenance (χ 2 – tests, all p < 0.023). (χ
p
)
We summarize these findings in our third result: Result 3: Provision dilemmas cause significantly higher levels of misperceptions of the game form tha 5.4. Misperceptions and cooperation attitudes 5.3. Misperceptions are dilemma specific Table 2 summarizes the percentages of correct answers separately for each question and for Maintenance and Provision. It reveals that, at the aggregate level, in both treatments there is an overall very low level of misperception. With a few 347 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Table 3
Percent of participants classified as misperceiving in Maintenance and Provision. Maintenance [n = 320]
Provision [n = 376]
χ 2 - test
Measure 1 – At least one mistake in the payoff questions Q1-Q4
13% [n = 40]
22% [n = 84]
p = 0.001
Measure 2 – At least one mistake in the goal questions Q5-Q8
29% [n = 93]
37% [n = 140]
p = 0.023
Measure 3 – Mistaken conditional cooperation
5% [n = 17]
13% [n = 47]
p = 0.001 Table 4
Fraction of misperceiving participants in Maintenance and Provision by type. Maintenance
Provision
Measure 1
Measure 2
Measure 3
Measure 1
Measure 2
Measure 3
Conditional Cooperators
0.103
0.252
0.028
0.247
0.447
0.200
Free Riders
0.095
0.230
0.024
0.165
0.262
0.029
Others
0.195
0.425
0.126
0.241
0.337
0.072
χ 2 - tests
p = 0.066
p = 0.005
p = 0.002
p = 0.247
p = 0.006
p < 0.001 Table 4
Fraction of misperceiving participants in Maintenance and Provision by type. exceptions, the percentage of correct answers is above 90% for every single question and treatment. On average, participants
answer 91% of the questions correctly, 92% in Maintenance (7.35 out of 8) and 89% in Provision (7.15 out of 8). Despite the
overall treatment differences being small, they are statistically significant at the 5% level (p = 0.030). When comparing the
fraction of correct answers between Maintenance and Provision for each question separately, we find significant differences
for two out of the eight questions, Q2 (p = 0.009) and Q6 (p = 0.001). exceptions, the percentage of correct answers is above 90% for every single question and treatment. On average, participants
answer 91% of the questions correctly, 92% in Maintenance (7.35 out of 8) and 89% in Provision (7.15 out of 8). Despite the
overall treatment differences being small, they are statistically significant at the 5% level (p = 0.030). Table 5 Table 5
Distribution of cooperation preferences in Maintenance and Provision after controlling for different types of misperceptions. Panel A: Full sample
Panel B: No mistake in payoff questions
Type
Maintenance (n = 320)
Provision (n = 376)
χ 2-test
Maintenance (n = 280)
Provision (n = 292)
χ 2-test
Conditional Cooperators
34%
51%
p < 0.001
34%
49%
p < 0.001
Free Riders
39%
27%
p = 0.001
41%
29%
p = 0.005
Others
27%
22%
p = 0.118
25%
22%
p = 0.332
χ 2-test
p < 0.001
p = 0.001
Panel C: No mistake in goal questions
Panel D: No mistaken conditional cooperation
Type
Maintenance (n = 227)
Provision (n = 236)
χ 2-test
Maintenance (n = 303)
Provision (n = 329)
χ 2-test
Conditional Cooperators
35%
45%
p = 0.042
34%
46%
p = 0.002
Free Riders
43%
32%
p = 0.019
41%
31%
p = 0.007
Others
22%
23%
p = 0.743
25%
23%
p = 0.623
χ 2-test
p = 0.050
p = 0.006 ation preferences in Maintenance and Provision after controlling for different types of misperceptions. In panels B, C, and D, we compare the distribution of types across Maintenance and Provision after dropping participants
who are classified as misperceiving according to Measures 1, 2, and 3, respectively. The results reveal that our main result of
different distributions of cooperation preferences across Maintenance and Provision is robust to the exclusion of participants
who do not fully understand the game form. That is, the distribution of types is significantly different across Maintenance
and Provision across all subsamples of non-confused participants (χ 2 – tests, all p ≤0.05). χ
Regarding the distribution of types, we observe significantly more conditional cooperators (χ 2 – tests, all p < 0.05) and
significantly fewer free riders (χ 2 – tests, all p < 0.02) in Provision than in Maintenance (the difference in others is never
significant, χ 2 – tests, all p > 0.117; see also Table B7 in Online Appendix B). Notably, however, we find that once we control
for misperceptions, the differences in the distribution of types become smaller compared to the full sample. The percentage
difference in conditional cooperators decreases from 17 percentage points in the full sample to 10 to 15 percentage points
depending on the misperception measure. (Provision: 63% vs. 51%, χ2(1) = 12.50, p < 0.001, Maintenance 33% vs. 43%, χ2(1) = 5.84, p = 0.016) in the new experiment. We believe that the reason for
this result is that we administered the incentivized control questions before the elicitation of cooperation attitudes. This might have made the incentive
structure of the social dilemma situation even clearer, which, in turn, might have corrected some ‘mistaken’ conditional cooperation. Alternatively, it could
be that the incentivized questions increased the salience of material incentives, thereby priming participants to be more self-interested. While we cannot
rule out neither of these channels, we can ascertain whether the shifts in the distribution of types had any effect on the differences across treatments. To
this end, similar to our analysis in which we compared our student with the MTurk sample, we run logistic regressions in which we use the different types
as dependent variable, a treatment dummy, a sample dummy, and an interaction between the latter two as independent variables. The results, reported
in Table B6 in Online Appendix B, show that there are no significant interaction effects between the treatment and the sample, indicating that adding the
additional questions at the beginning of the experiment had no systematic effect on our treatment comparison. Table 5 The difference in the fraction of free riders, in contrast, remains stable, varying
between 10 and 12 percentage points. This demonstrates that while misperceptions can account for some of the observed
differences across treatments, even after controlling for misperceptions, we observe substantial and significantly different
degrees of conditional cooperation in Maintenance and Provision. We summarize these findings in our fourth result: g
p
g
Result 4: Even after accounting for the different degrees of misperceptions across Maintenance and Provision, we find significantly
more conditional cooperators and fewer free riders in Provision than in Maintenance. 5.5. Misperceptions do not affect perceptions of kindness 5.4. Misperceptions and cooperation attitudes In line with
our results from Section 3, we find again a highly significant difference in the distribution of preferences across treatments
(χ 2(2) = 21.23, p < 0.001), with significantly fewer conditional cooperators (χ 2(1) = 20.65, p < 0.001) and significantly
more free riders (χ 2(1) = 11.24, p = 0.001) in Maintenance than in Provision.19 348 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia 5.5. Misperceptions do not affect perceptions of kindness The results above already strongly suggest that the observed differences in cooperation types across Maintenance and
Provision are rooted in differences in the underlying social preferences. As we have argued above, these differences can be
explained by differences in the perceived kindness of others’ actions across the two treatments. As a final test of this argu-
ment, we provide evidence that the different perceptions of kindness that we presented in Section 4 are not a consequence
of game-form misperceptions. This is important because if differences in kindness perceptions are indeed the main trigger
of differences in conditional cooperation across the two social dilemmas, we should observe that perceptions of kindness
still differ when controlling for misperceptions. If, instead, the different kindness perceptions across Maintenance and Provi-
sion disappear when controlling for misperceptions, then the elicited kindness perceptions may not be considered a relevant
explanation for the differences in conditional cooperation across the two dilemmas. To test this, in some sessions of the misperception experiment reported in the previous two subsections, we included
the kindness questionnaire at the end of the experiment before participants received feedback about the outcome of the
game. Hence, while the kindness results reported in Section 4 (see Fig. 3) were elicited using non-involved participants,
we can now test whether the results hold when participants have experienced the decision situation. Furthermore, we
can test whether the differences in kindness perceptions across Maintenance and Provision are robust to the exclusions
of participants who exhibit some misperception. Our sample comprises n = 200 participants, n = 80 in Maintenance and
n = 120 in Provision. The results are shown in Fig. 4. 349 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia Fig. 4. Kindness perceptions in Provision and Maintenance of participants who experienced the decision situation (±1 s.e.m). Fig. 4. Kindness perceptions in Provision and Maintenance of participants who experienced the decision situation (±1 s.e.m). The first (upper left) panel of Fig. 4 depicts the comparison between the kindness schedules between Maintenance and
Provision for the full sample. The second, third, and fourth panel show the same data for the subset of participants without
misperceptions according to our three measures. Fig. 4 shows that the differences in kindness schedules across Maintenance
and Provision are not only similar across the four panels but also similar to the ones reported in Fig. 3. 20 Parametric estimates further corroborate these results. Using regression analyses in which we regress kindness evaluations on others’ average contri-
butions, a Provision dummy, and an interaction term between the last two, we find that the Provision dummy is significantly negative and the interaction
term between the Provision dummy and others’ average contributions is positive and significant. The size of these effects, which we report in Table B8 in
Online Appendix B, is similar to the ones reported in Section 4 where we analyze the kindness evaluations of uninvolved participants (compare also Table
B5). 5.5. Misperceptions do not affect perceptions of kindness This indicates that the
differences in kindness perceptions across Maintenance and Provision are robust to having experienced the decision situation
beforehand and, more importantly, to the exclusion of participants who exhibit some form of game-form misperception.20
We summarize these findings in our fifth result: We summarize these findings in our fifth result: Result 5: Even after accounting for the different degrees of misperceptions across Maintenance and Provision, we find that the
two dilemmas evoke systematically different perceptions of kindness that can explain why there are more conditional cooperators and
fewer free riders in Provision than in Maintenance. 6.1. Explaining dilemma-specific conditional cooperation 6.1. Explaining dilemma-specific conditional cooperation We start our discussion with theories of distributional preferences (Fehr and Schmidt, 1999; Bolton and Ockenfels, 2000;
Charness and Rabin, 2002). While all these theories can explain conditional cooperation, e.g., if advantageous inequity
aversion is strong enough, they do not predict any dilemma-specific conditional cooperation. The reason is that these the-
ories are only based on payoff consequences, which are identical across the two incentive-equivalent social dilemmas of
Maintenance and Provision.21 Note that this prediction hinges on the original assumption of these theories that individual
preference parameters are game-independent. If one would be willing to relax this assumption by allowing preference pa-
rameters to differ across contexts, then these models could potentially rationalize our findings. For example, if one assumes,
using Fehr and Schmidt (1999) preferences, that agents are more advantageous inequity-averse when facing a Provision
rather than a Maintenance dilemma, then this could explain why we observe more conditional cooperators and fewer free
riders in the former than in the latter. We note, however, that while such shifts in advantageous inequity aversion might
be empirically relevant, there is no psychological mechanism in the formal assumptions of Fehr and Schmidt (1999) that
postulate such shifts. Next, we consider theories of reciprocity (Rabin, 1993; Dufwenberg and Kirchsteiger, 2004; Falk and Fischbacher, 2006),
in which agents’ motivations derive from their material payoff as well as a psychological payoff that depends on their
first-order beliefs about others’ actions. These theories can also explain conditional cooperation (Dufwenberg et al., 2011)
because agents want to reward kind actions with kindness and punish hostile actions with unkindness. Kindness is thereby
assumed to be evaluated relative to a reference point that is the midpoint between the maximum and minimum possible
payoff (see Online Appendix C, and Dufwenberg and Kirchsteiger, 2019 for a recent discussion). Because the payoff sets
are the same in Maintenance and Provision, the reference point must be the same. Therefore, beliefs are the only channel
through which simultaneous gameplay may differ in Maintenance and Provision. Since in our strategy-method experiment
(i) first-order beliefs are fixed because participants condition their contributions on all possible average contributions of
others, and (ii) as argued by Dufwenberg et al. (2011), in a linear public goods game the evaluation of others’ kindness only
depends on first-order beliefs, these models do not predict dilemma-dependent conditional cooperation. 6.1. Explaining dilemma-specific conditional cooperation This prediction
also hinges on the assumption that the concern for reciprocity as measured by a reciprocity parameter does not vary
across dilemmas. If one would be willing to relax this assumption to allow that the reciprocity parameter is stronger under
Provision than Maintenance, then reciprocity theory could also rationalize our finding that conditional cooperation is more
frequent in Provision than Maintenance. Note, however, that also in this theory there is no psychological mechanism in the
formal assumptions that postulates such a shift. The next theory we discuss is guilt aversion. We rely on a model of guilt by Battigalli and Dufwenberg (2007) that assumes
that an agent’s utility depends on her material payoff as well as her second-order beliefs, that is, what she believes the other
players believe she will do. Applied to the context of a public goods game (see also Dufwenberg et al., 2011), guilt aversion
predicts that player i will suffer guilt if i contributes less than what i thinks the other three group members expect i to
contribute (on average). If the disutility from guilt becomes large enough, player i has an incentive to contribute whatever
she thinks others expect her to contribute (that is, her second-order beliefs). Given that in our strategy-method experiment
first-order beliefs are fixed, differences in cooperation attitudes could be reconciled via dilemma-dependent second-order
beliefs: If more participants in Provision than in Maintenance would have second-order beliefs that others expect them to
reciprocate their contributions, the perceived guilt from not matching others’ contributions would be stronger, which, in
turn, could lead to a higher fraction of conditional cooperators in Provision than in Maintenance. However, guilt aversion
theory does not explicitly model any mechanism for why there should be any difference in second-order beliefs between
Maintenance and Provision. Similarly, the guilt-sensitivity parameter is also assumed to be the same across dilemmas and
there is no psychological mechanism in the formal assumptions that would suggest dilemma-specific guilt sensitivity.22 In sum, all standard theories of social preferences discussed so far can explain conditional cooperation. However, to
be able to explain dilemma-specific conditional cooperation they all require some adjustments not present in the original
formulations of these theories, such as modeling mechanisms of dilemma-dependent beliefs or preference parameters. One theory that has the potential to predict a difference between Maintenance and Provision is revealed altruism by Cox
et al. (2008). 6. Step 4: which theory of social preferences can explain our results? In our fourth step, we investigate which of the existing models of social preferences, using their original formulations, can
reconcile the observation of a higher share of conditional cooperators and fewer free riders in Provision than in Maintenance
as found in our experiments as well as in some previous research (Fosgaard et al., 2014; Frackenpohl et al., 2016; Gächter
et al., 2017; Isler et al., 2021). We emphasize that our aim here is not to conduct a horse race between different models of
social preferences (see, e.g., Miettinen et al., 2020, for such an analysis in a sequential PD), but to provide a discussion about
whether, and under which assumptions, existing theories of social preferences can explain dilemma-dependent conditional
cooperation (note that all theories we discuss here can explain conditional cooperation in a given social dilemma). In the
following, we only describe the main arguments, more details and formal analyses are in Online Appendix C. In Section 6.1.,
we discuss how theories of social preferences might explain dilemma-specific conditional cooperation. In Section 6.2., we
discuss the models also in relation to our results on kindness perceptions (Results 2 and 5). 350 Games and Economic Behavior 135 (2022) 338–355 Games and Economic Behavior 135 (2022) 338–355 S. Gächter, F. Kölle and S. Quercia A similar argument holds for models of altruism and fairness such as Levine (1998) and Cox et al. (2007).
22 Evidence from two online surveys in which we elicited ex post feelings of guilt further reveal that participants do not feel more guilty when free riding
on others’ contributions in Provision than in Maintenance, indicating that ex post feelings of guilt cannot explain the observed differences in conditional
cooperation across the two dilemmas (see Online Appendix D for further details). 21 A similar argument holds for models of altruism and fairness such as Levine (1998) and Cox et al. (2007). Evidence from two online surveys in which we elicited ex post feelings of guilt further reveal that participants do n
on others’ contributions in Provision than in Maintenance, indicating that ex post feelings of guilt cannot explain the
cooperation across the two dilemmas (see Online Appendix D for further details). 6.1. Explaining dilemma-specific conditional cooperation This theory is governed by two axioms, the reciprocity Axiom R, and Axiom S, which allows for status quo
effects. Applying Cox et al.’s Axiom R to our public goods games, the model predicts that participants will perceive higher
contributions by the other group members as more generous towards them, and, therefore, they will be more altruistic
towards the others. In our strategy-method experiment, this will be manifested in a positive slope of the contribution
schedule (see Cox et al., 2013 for a related analysis). In Axiom S, Cox et al. (2008) assume that, based on the psychological asymmetry behind omission and commission (see,
e.g., Spranca et al., 1991), generous actions that change the status quo trigger stronger reciprocity than generous actions
that just uphold the status quo. That is, Axiom S strengthens or weakens the effect of Axiom R depending on the status
quo. If one assumes that players perceive the original allocation to the public good before decision making (0 in Provision and 351 S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 80 in Maintenance) as the status quo (as in Cox et al., 2013), then, applying Axiom S to our strategy-method experiment,
the theory predicts that second movers will be less altruistic towards first movers in Maintenance than in Provision. The
reason is that in Provision any positive contribution by the other three group members increases the payoff opportunities of
the second mover compared to the status quo where nothing is contributed to the public good. In Maintenance, in contrast,
where all resources are initially allocated to the public good, any withdrawal by the other three group members reduces
the payoff opportunities for the second mover. This asymmetry triggers a stronger preference for reciprocity in Provision
than Maintenance, which can explain our finding of more conditional cooperators and fewer free riders in Provision than in
Maintenance (see Online Appendix C for further details).23 80 in Maintenance) as the status quo (as in Cox et al., 2013), then, applying Axiom S to our strategy-method experiment,
the theory predicts that second movers will be less altruistic towards first movers in Maintenance than in Provision. The
reason is that in Provision any positive contribution by the other three group members increases the payoff opportunities of
the second mover compared to the status quo where nothing is contributed to the public good. 23 Here we have assumed that, as in Cox et al. (2013), the initial resource allocation is taken as the status quo. We acknowledge, however, that different
assumptions on the status quo could be plausible. For example, the status quo could be the wealth level of participants before entering the lab. In this
case, the Cox et al. (2008) theory would predict no differences between Maintenance and Provision.
24 Formally, Axiom S would need to be modified to allow the status quo allocation to affect not only the MAT (more altruistic than) partial ordering but
also the MGT (more generous than) partial ordering (see Online Appendix C for further details). 6.2. Explaining dilemma-specific kindness perceptions As a next step, we discuss which of the above theories can reconcile the robust and replicable evidence on different
perceptions of kindness between Maintenance and Provision (Results 2 and 5). First, notice that models of distributional
preferences are only based on payoff consequences and therefore do not incorporate any evaluation of others’ actions. Guilt
aversion is also mute with respect to others’ kindness as players evaluate their own action with respect to the distance from
their second-order belief but make no evaluation about others’ actions. Reciprocity models such as those by Dufwenberg and
Kirchsteiger (2004) and Falk and Fischbacher (2006) are natural candidates to explain our kindness results: these theories
incorporate the perception of other’s (un)kindness as a central element into their models and the positive and negative
kindness evaluations we observe are consistent with typical modeling assumptions. In these models, kindness is evaluated
with respect to a reference point that is only based on material payoffs. Because material payoffs are identical in Maintenance
and Provision, for a given effective contribution perceived kindness is predicted to be the same across Maintenance and
Provision. Finally, we consider the revealed altruism model by Cox et al. (2008) that also incorporates kindness. However, like the
reciprocity models, this model also does not predict any differences in kindness perceptions across the dilemmas. Instead,
it postulates that the different status-quo allocation in Maintenance and Provision directly affect the reciprocity parameter
(see Axiom S). If one would be willing to adjust the model by allowing Axiom S to also affect perceptions of kindness, then
every effective contribution in Provision should be perceived as more generous than the corresponding effective contribution
in Maintenance.24 The results from our kindness survey reveal, however, that while this is indeed true for average effective
contributions of 10 and 20, for effective contributions of 0 we find the opposite as contributing 0 in Provision is perceived
as unkinder than withdrawing everything in Maintenance. Hence, although Cox et al. (2008) comes closest to explaining
our results as it is the only theory that postulates an explicit mechanism for why one could expect stronger conditional
cooperation in Provision than in Maintenance, some discrepancies between the theory and our data remain as we have seen
in our results on kindness perceptions (Results 2 and 5). 6.1. Explaining dilemma-specific conditional cooperation In Maintenance, in contrast,
where all resources are initially allocated to the public good, any withdrawal by the other three group members reduces
the payoff opportunities for the second mover. This asymmetry triggers a stronger preference for reciprocity in Provision
than Maintenance, which can explain our finding of more conditional cooperators and fewer free riders in Provision than in
Maintenance (see Online Appendix C for further details).23 7. Discussion and conclusion In this paper, we provided a comprehensive behavioral analysis of two generic and incentive-equivalent social dilemmas
of voluntary cooperation: providing and maintaining public goods. We first established a lower fraction of conditional co-
operators (and higher fraction of free riders) in Maintenance than Provision (Result 1). We then focused on two fundamental
dimensions: social preferences and (mis)perceptions of others’ intentions and the game form. We reported two important
asymmetries. First, regarding perceptions, we found that perceptions of the kindness of others’ actions differ between Main-
tenance and Provision because withdrawing everything from the public good is seen as less unkind than failing to contribute
to the public good; and contributing everything is considered kinder in Provision than in Maintenance (Result 2). Regard-
ing perceptions of the game form, we found that misperceptions are game-specific: misunderstandings are more likely in
Provision than Maintenance (Result 3). Second, even after controlling for misperceptions, we observe substantial and signifi-
cantly different degrees of conditional cooperation in Maintenance and Provision (Result 4); perceptions of kindness remain
unaffected by misperceptions (Result 5). Hence, conditional cooperation is not just mistaken cooperation (as argued, e.g., by
Burton-Chellew et al., 2016), but a true preference that is less frequently found in Maintenance than in Provision dilemmas. )
p
q
y
Our Result 4 somewhat differs from the results by Fosgaard et al. (2017). Like them, we find that the differences in
conditional cooperation across dilemmas become smaller once accounting for misperceptions. Unlike us, in their case the
differences become statistically insignificant while in ours they remain economically and statistically significant. One pos-
sible explanation for the different findings is that Fosgaard et al. (2017) asked their misperception questions, which are
similar to our Measure 2, only at the end of the experiment rather than before the elicitation of cooperation preferences as
we do. Another reason could be the different subject pools used across the two studies – our results are based on a UK
student sample while theirs is based on a representative sample of the Danish population – which could also explain why 352 S. Gächter, F. Kölle and S. Quercia Games and Economic Behavior 135 (2022) 338–355 the overall level of misperceptions is much higher in Fosgaard et al.: In their sample, 41% and 51% of participants exhibit
some form of misperception in Maintenance and Provision, respectively, compared to 29% and 37% in our case. Data availability The data and analysis code of this paper are available at https://osf .io /3jpgh/ Acknowledgments This work was supported by the European Research Council [grant numbers ERC-AdG 295707 COOPERATION and ERC-
AdG 101020453 PRINCIPLES] and the Economic and Social Research Council [grant number ES/K002201/1]. The research
reported in this paper was approved by the Research Ethics Committee of the Nottingham School of Economics. The au-
thors declare they have no relevant or material financial interests that relate to the research described in this paper. We
thank Ben Beranek for excellent research support and Abigail Barr, Tim Cason, Gary Charness, Jim Cox, Robin Cubitt, Mar-
tin Dufwenberg, Urs Fischbacher, Maria Garcia-Vega, Werner Güth, Georg Kirchsteiger, Friederike Mengel, Charles Noussair,
Elena Manzoni, Vjollca Sadiraj, Maroš Servátka, Chris Starmer, Robert Sugden, and referees and participants from various
seminars and conferences for helpful comments. 7. Discussion and conclusion Our finding
that kindness perceptions remain different across dilemmas also after removing misperceiving subjects reinforces further a
preference explanation for the difference between Maintenance and Provision. Our Results 1 – 5 also suggest an important general lesson: the revealed preference approach, that is, using choices
to infer social preferences and/or dilemma-specific effects, requires controlling for perceptions.25 This includes potential
misperceptions of the game form to ensure measurement of preferences over clearly understood alternatives. Administering
simple understanding questions at the beginning of experiments is nowadays quite common in experimental economics. However, it might not be enough. Our evidence on the existence of misperceived conditional cooperation is a point in case. Our results also have implications for future literature. Hitherto, behavioral investigations of public goods provision and
common pool resource problems have largely been conducted in independent literatures, in particular regarding conditional
cooperation, which was mostly studied in the context of linear public goods provision games (see, e.g., Chaudhuri, 2011;
Fehr and Schurtenberger, 2018; and Thöni and Volk, 2018). Our comparative analysis of preferences and perceptions in
maintenance and provision problems with identical social dilemma incentives is only a first step in bringing these two
literatures closer together. Finally, our results are not only of theoretical significance but have some potential policy implications. If many people are
conditional cooperators, any factor that shifts beliefs about others’ cooperativeness will shift cooperation – a fact that can be
used for policy interventions (e.g., Gächter, 2007). The observation that conditional cooperation, even after being corrected
for misperceptions, is weaker in Maintenance than Provision suggests that policy proposals that reckon with conditional
cooperation (e.g., MacKay et al., 2015) need to take into account that the extent of it is dilemma-specific. Some of the
pressing challenges for mankind such as global warming and sustaining natural resources and biodiversity concern mainly
Maintenance dilemmas (e.g., Fehr-Duda and Fehr, 2016). Our results suggest that the power of conditional cooperation may
be limited in maintenance problems, at least in comparison with provision dilemmas. Other solutions such as punishment
(Gächter et al., 2017; Ramalingam et al., 2019) or incentives may instead be needed. Supplementary material related to this article can be found online at https://doi .org /10 .1016 /j .geb .2022 .06 .009. Supplementary material related to this article can be found online at https://doi .org /10 .1016 /j .geb .2022 .06 .009. 25 Alternatively, when it is not possible to measure misperceptions directly (e.g., in representative surveys), econometric techniques such as those proposed
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https://www.nature.com/articles/s41467-019-10614-1.pdf
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Targeting a therapeutic LIF transgene to muscle via the immune system ameliorates muscular dystrophy
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Nature communications
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ARTICLE 1 Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095-1606, USA. 2 Molecular, Cellular & Integrative
Physiology Program, University of California, Los Angeles, CA 90095-1606, USA. 3 Department of Neurology, David Geffen School of Medicine at UCLA,
University of California, Los Angeles, CA 90095, USA. 4 Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA,
University of California, Los Angeles, CA 90095, USA. 5These authors contributed equally: Steven S. Welc, Ivan Flores. Correspondence and requests for
materials should be addressed to J.G.T. (email: jtidball@physci.ucla.edu) Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy Coinciding with
the unpredictable ebb and flow of pathology in muscular dys-
trophy, inflammatory cells invade in numbers that coincide with
the magnitude of muscle pathology. Although the immune cell
infiltrate in dystrophin-deficient muscle is complex7–12, macro-
phages comprise the vast majority and they can reach con-
centrations that exceed 107 cells per pound of muscle at the peak
of mdx pathology7. They are also rich sources of regulatory
molecules that can amplify muscle damage but also promote
muscle repair and regeneration in muscular dystrophy7,13,14. Thus, the introduction of therapeutic transgenes that are
expressed at elevated levels in activated macrophages or other
immune cells could provide a strategy for intrinsically-regulated
targeting of therapeutic molecules specifically to dystrophic
muscles at the time of active pathology and at levels that were
commensurate with the extent of pathology. We assessed effects of the transgene on mdx pathology over the
course of the disease, sampling at the acute onset of pathology (1-
month-old), the period of successful regeneration (3-months-
old), and the late, progressive stage of pathology (12-months-old)
in TA muscles. Diaphragm muscles show a progressive pathology
following disease onset. The CD11b/LIF transgene reduced
numbers of macrophages expressing the pan-macrophage marker
F4/80 at the stages of pathology characterized by extensive,
muscle inflammation (1-month-old in TA; 12-months-old in
diaphragm) (Fig. 2e–g). The transgene also reduced numbers of
CD163+ macrophages at the acute onset of pathology in both TA
and diaphragm (Fig. 2h–j) but did not affect numbers of CD68+
macrophages in either muscle at any stage of the disease that we
tested (Supplementary Fig. 2). In this investigation, we test whether transplantation of bone
marrow cells (BMCs) into which we have introduced a leukemia
inhibitory factor (LIF) transgene controlled by the human CD11b
promoter reduces the pathology of mdx dystrophy. Although mdx
pathology is less severe than DMD pathology, they share the
pathological features of muscle inflammation and progressive
fibrosis that persist over the entire lifespan and impair muscle
function, reduce health and increase mortality. The CD11b pro-
moter was chosen to drive the therapeutic transgene because
CD11b is expressed at low or undetectable levels in myeloid
precursors, but at increasingly elevated levels during myeloid cell
differentiation and activation15–17. LIF was selected as a ther-
apeutic molecule to test this system because it is expressed by
macrophages and can influence muscle growth, fibrosis, and
inflammation during disease or following injury18–21. Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy Per-
haps more valuable, the findings indicate that inflammatory cells
can be exploited as natural vectors to deliver therapeutic trans-
genes for the treatment of chronic diseases in which there is a
significant inflammatory component. marrow-derived macrophages
isolated bone marrow mononucl
genic mice had a ~2.8-fold high
wild-type (WT). After 9 days of
fold higher in transgenic BMDM
transgene expression increased w
activation as monocytes differen
Upon becoming fully-differentiat
transgene had an autocrine eff
increasing expression of Cd68 by
arginase-1 (Arg1) by 47% and 42%
present at high levels in macrop
inflammatory phenotype (M1-bi
present in macrophages that are
reparative phenotype (M2-biased
CD11b/LIF transgene reduces m
fibrosis. We assayed whether th
transgene affected mdx patholo
muscle inflammation and fibr
expression of Lif in the tibialis
muscles of transgenic mice (CD1
observed that cells in inflammat
mice showed higher levels of L
mice (Fig. 2b–d). However, sera f
elevation in LIF protein assayed b
19.25 ± 1.85 and LIF/mdx 26.19 ±
P = 0.25; two-tailed t-test). We
ences in the concentrations of cy
influencing the pathology of mus
4, and IL-10) in the serum of tra
transgenic mice (Supplementary
We assessed effects of the trans
course of the disease, sampling at
month-old), the period of succ
old), and the late, progressive stag
in TA muscles. Diaphragm musc
following disease onset. The
numbers of macrophages express
F4/80 at the stages of patholo
muscle inflammation (1-month
diaphragm) (Fig. 2e–g). The tran
CD163+ macrophages at the acu
and diaphragm (Fig. 2h–j) but di
macrophages in either muscle at
tested (Supplementary Fig. 2). We tested whether the CD11b
accumulation in mdx muscles, w
reduction in numbers or activit
promote fibrosis of dystrophic
diaphragm showed significant red
acute onset of pathology, and the
collagen type 1 accumulation in
months-old (Fig. 2k–m). The CD
accumulation of collagen type 1
reduced accumulation of collagen
late stages of pathology and redu marrow-derived macrophages (BMDMs) (Fig. 1a). Freshly-
isolated bone marrow mononuclear cells (BMMCs) from trans-
genic mice had a ~2.8-fold higher Lif expression compared to
wild-type (WT). After 9 days of culture, Lif expression was ~10-
fold higher in transgenic BMDMs than WT (Fig. 1b). Thus, LIF
transgene expression increased with increased CD11b promoter
activation as monocytes differentiate into mature macrophages. Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy Our find-
ings show that this intervention significantly modifies intramus-
cular macrophage phenotype and reduces inflammation and
fibrosis of dystrophic muscle, thereby reducing pathology. Per-
haps more valuable, the findings indicate that inflammatory cells
can be exploited as natural vectors to deliver therapeutic trans-
genes for the treatment of chronic diseases in which there is a
significant inflammatory component. pp
y
g
We tested whether the CD11b/LIF transgene reduced collagen
accumulation in mdx muscles, which would be consistent with a
reduction in numbers or activity of CD163 macrophages that
promote fibrosis of dystrophic muscle23. Both the TA and
diaphragm showed significant reductions in collagen type 1 at the
acute onset of pathology, and the transgene completely abrogated
collagen type 1 accumulation in the TA muscle, at least until 12-
months-old (Fig. 2k–m). The CD11b/LIF transgene also reduced
accumulation of collagen type 1 in diaphragms (Fig. 2n–p) and
reduced accumulation of collagen types 3 and 5 in diaphragms at
late stages of pathology and reduced collagen type 5 in 3-month-
old TA muscles (Supplementary Fig. 3). pp
y
g
Because the CD11b/LIF transgene prevented collagen type 1
accumulation in TA muscles and collagen type 1 is primarily
responsible for increased muscle stiffness caused by fibrosis, we
assayed for changes in the passive mechanical properties of TA
muscles in CD11b/LIF transgenic mdx mice. We subjected TA
muscles to cyclic, dynamic loading using 20% strains at a 0.6/s
strain rate, which is within the physiological range. Lissajous Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy Upon becoming fully-differentiated macrophages, the CD11b/LIF
transgene had an autocrine effect on macrophage phenotype,
increasing expression of Cd68 by ~31% and reducing Cd163 and
arginase-1 (Arg1) by 47% and 42%, respectively (Fig. 1c). CD68 is
present at high levels in macrophages that are biased to a pro-
inflammatory phenotype (M1-biased). Arginase and CD163 are
present in macrophages that are biased toward a pro-fibrotic and
reparative phenotype (M2-biased)22. O
ver recent years, investigators have identified numerous,
potentially-therapeutic molecules for the treatment of
Duchenne muscular dystrophy (DMD), a lethal and
incurable muscle-wasting disease. For example, systemic delivery
of therapeutic agents that can inhibit fibrosis (e.g., block TGFβ
function1–3), inhibit muscle wasting (e.g., myostatin blocking
molecules4), and increase numbers of muscle stem cells called
satellite cells (e.g., Klotho5) all reduce pathology in the mdx
mouse model of DMD. However, systemic delivery of any of these
molecules presents risks of unintended off-target effects which
provide an obstacle to their clinical application for the treatment
of DMD. In addition, the occurrence of muscle pathology is not
synchronized in DMD patients. The unpredictable timing and
severity of disease vary between muscles in a single individual at
any given time, and also vary between locations in a single
muscle6. Even if a therapeutic agent were specifically targeted to
dystrophic muscle, achieving delivery only when pathology is
active presents an additional challenge. CD11b/LIF transgene reduces mdx muscle inflammation and
fibrosis. We assayed whether the expression of the CD11b/LIF
transgene affected mdx pathology, focusing on influences on
muscle inflammation and fibrosis. We confirmed elevated
expression of Lif in the tibialis anterior (TA) and diaphragm
muscles of transgenic mice (CD11b/LIF mdx mice) (Fig. 2a) and
observed that cells in inflammatory lesions in CD11b/LIF mdx
mice showed higher levels of LIF protein than non-transgenic
mice (Fig. 2b–d). However, sera from transgenic mice showed no
elevation in LIF protein assayed by ELISA (mean ± sem: WT/mdx
19.25 ± 1.85 and LIF/mdx 26.19 ± 4.86 pg/ml , n = 3 per data set,
P = 0.25; two-tailed t-test). We also found no significant differ-
ences in the concentrations of cytokines previously implicated in
influencing the pathology of muscular dystrophy (IFNγ, TNF, IL-
4, and IL-10) in the serum of transgenic mice, compared to non-
transgenic mice (Supplementary Fig. 1). Nature has provided a naturally-occurring system for targeted
delivery of potentially-therapeutic molecules to dystrophic muscle
at stages of the disease when pathology is active. NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy Steven S. Welc
1,5, Ivan Flores2,5, Michelle Wehling-Henricks1, Julian Ramos1, Ying Wang2, Carmen Bertoni3 &
James G. Tidball
1,2,4 Steven S. Welc
1,5, Ivan Flores2,5, Michelle Wehling-Henricks1, Julian Ramos1, Ying Wang2, Carmen Bertoni3 &
James G. Tidball
1,2,4 Many potentially therapeutic molecules have been identified for treating Duchenne muscular
dystrophy. However, targeting those molecules only to sites of active pathology is an obstacle
to their clinical use. Because dystrophic muscles become extensively inflamed, we tested
whether expressing a therapeutic transgene in leukocyte progenitors that invade muscle
would provide selective, timely delivery to diseased muscle. We designed a transgene in
which leukemia inhibitory factor (LIF) is under control of a leukocyte-specific promoter and
transplanted transgenic cells into dystrophic mice. Transplantation diminishes pathology,
reduces Th2 cytokines in muscle and biases macrophages away from a CD163+/CD206+
phenotype that promotes fibrosis. Transgenic cells also abrogate TGFβ signaling, reduce
fibro/adipogenic progenitor cells and reduce fibrogenesis of muscle cells. These findings
indicate that leukocytes expressing a LIF transgene reduce fibrosis by suppressing type 2
immunity and highlight a novel application by which immune cells can be genetically modified
as potential therapeutics to treat muscle disease. 1 Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095-1606, USA. 2 Molecular, Cellular & Integrative
Physiology Program, University of California, Los Angeles, CA 90095-1606, USA. 3 Department of Neurology, David Geffen School of Medicine at UCLA,
University of California, Los Angeles, CA 90095, USA. 4 Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA,
University of California, Los Angeles, CA 90095, USA. 5These authors contributed equally: Steven S. Welc, Ivan Flores. Correspondence and requests for
materials should be addressed to J.G.T. (email: jtidball@physci.ucla.edu) 1 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 O
ver recent years, investigators have identified numerous,
potentially-therapeutic molecules for the treatment of
Duchenne muscular dystrophy (DMD), a lethal and
incurable muscle-wasting disease. For example, systemic delivery
of therapeutic agents that can inhibit fibrosis (e.g., block TGFβ
function1–3), inhibit muscle wasting (e.g., myostatin blocking
molecules4), and increase numbers of muscle stem cells called
satellite cells (e.g., Klotho5) all reduce pathology in the mdx
mouse model of DMD. However, systemic delivery of any of these
molecules presents risks of unintended off-target effects which
provide an obstacle to their clinical application for the treatment
of DMD. Targeting a therapeutic LIF transgene to muscle via
the immune system ameliorates muscular
dystrophy In addition, the occurrence of muscle pathology is not
synchronized in DMD patients. The unpredictable timing and
severity of disease vary between muscles in a single individual at
any given time, and also vary between locations in a single
muscle6. Even if a therapeutic agent were specifically targeted to
dystrophic muscle, achieving delivery only when pathology is
active presents an additional challenge. Nature has provided a naturally-occurring system for targeted
delivery of potentially-therapeutic molecules to dystrophic muscle
at stages of the disease when pathology is active. Coinciding with
the unpredictable ebb and flow of pathology in muscular dys-
trophy, inflammatory cells invade in numbers that coincide with
the magnitude of muscle pathology. Although the immune cell
infiltrate in dystrophin-deficient muscle is complex7–12, macro-
phages comprise the vast majority and they can reach con-
centrations that exceed 107 cells per pound of muscle at the peak
of mdx pathology7. They are also rich sources of regulatory
molecules that can amplify muscle damage but also promote
muscle repair and regeneration in muscular dystrophy7,13,14. Thus, the introduction of therapeutic transgenes that are
expressed at elevated levels in activated macrophages or other
immune cells could provide a strategy for intrinsically-regulated
targeting of therapeutic molecules specifically to dystrophic
muscles at the time of active pathology and at levels that were
commensurate with the extent of pathology. In this investigation, we test whether transplantation of bone
marrow cells (BMCs) into which we have introduced a leukemia
inhibitory factor (LIF) transgene controlled by the human CD11b
promoter reduces the pathology of mdx dystrophy. Although mdx
pathology is less severe than DMD pathology, they share the
pathological features of muscle inflammation and progressive
fibrosis that persist over the entire lifespan and impair muscle
function, reduce health and increase mortality. The CD11b pro-
moter was chosen to drive the therapeutic transgene because
CD11b is expressed at low or undetectable levels in myeloid
precursors, but at increasingly elevated levels during myeloid cell
differentiation and activation15–17. LIF was selected as a ther-
apeutic molecule to test this system because it is expressed by
macrophages and can influence muscle growth, fibrosis, and
inflammation during disease or following injury18–21. Our find-
ings show that this intervention significantly modifies intramus-
cular macrophage phenotype and reduces inflammation and
fibrosis of dystrophic muscle, thereby reducing pathology. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Significant findings
were verified with biological replicates of experiments from independent donors. * Indicates significantly different from WT BMDMs at P < 0.05. P-values
based on two-tailed t-test. F-test Cd206 (P = 0.0258) and Il10 (P = 0.0311). Source data are provided as a Source Data file Cs into macrophages increases CD11b/LIF transgene expression, causing suppression of M2-biased macrophage ma
ences in the level of Cd11b expression in C57BL6 BMCs stimulated with MCSF and differentiated to macrophages for 3 macrophages increases CD11b/LIF transgene expression, causing suppression of M2-biased macrophage markers. the proportions of dMHC+ fibers in 3-months-old and 12-
months-old diaphragms were increased by the transgene (Sup-
plementary Fig. 4C). Collectively, these observations indicate that
the CD11b/LIF transgene does not impair muscle growth or
regeneration, despite the reduction of CD163+ cells. figures obtained by measuring force–strain relationships showed
that muscle stiffness (indicated by the slope of the tangent to the
loading phase of each cycle) was significantly less in CD11b/LIF
transgenic mdx mice (Fig. 2q, r). In addition, the transgenic mdx
muscles showed less energy dissipation during each cycle of
loading (proportional to the area inside each hysteresis loop
during a cycle of loading/unloading) (Fig. 2q, s), indicating higher
mechanical efficiency in the CD11b/LIF transgenic muscles. Transplanted CD11b/LIF cells reduce inflammation. Our ana-
lyses of CD11b/LIF transgenic mdx mice showed that the trans-
gene
reduces
muscle
inflammation
and
fibrosis,
thereby
validating the transgene as a therapeutic molecule for muscular
dystrophy. However, our primary goal in the investigation was to
determine whether transplanted bone marrow derived cells
(BMDCs) could serve as vehicles to deliver therapeutic molecules
to dystrophic muscle through a clinically-relevant approach; in
particular, we questioned whether transplantation of genetically-
modified BMCs into dystrophic animals provides a strategy for
targeted delivery of therapeutic cargo to diseased muscle. We
assayed treatment effects in 6-months-old mdx mice at 4 months
post-bone marrow transplantation (BMT) for scientific and
technical reasons. First, we anticipated that a likely, beneficial
outcome of leukocyte delivery of a LIF transgene to muscle would
be reductions in fibrosis. Our previous work5 showed that 6-
months-old
mdx
muscles
show
significantly
elevated CD11b/LIF
transgene
does
not
impair
muscle
growth. Although previous investigations showed that M2-biased mac-
rophages
promote
muscle
fibrosis,
they
also
promote
regeneration23,24. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Source data are provided as a Source Data file 4
20
15
10
5
0
BMMCs
BMDMs
WT
CD11b/
LIF
WT
CD11b/
LIF
3
2
1
Relative expression
Relative expression
0
3 days
5 days
7 days
9 days
CD11b
#
LIF
a
b 4
20
15
10
5
0
2.0
2.5
1.5
1.0
0.5
0.0
M1
M2
Th1
Th2
n.d. BMMCs
BMDMs
WT
WT BMDMs
CD11b/LIF BMDMs
CD11b/
LIF
WT
CD11b/
LIF
3
2
1
Relative expression
Relative expression
Relative expression
0
3 days
CD68
iNOS
CD163
CD206
ARG1
ARG2
TNF
IFNγ
IL-1β
TGFβ1
SOCS3
IL-6
IL-12
IL-4
IL-10
5 days
7 days
9 days
CD11b
#
LIF
a
b
c b 2.0
2.5
1.5
1.0
0.5
0.0
M1
M2
Th1
Th2
n.d. WT BMDMs
CD11b/LIF BMDMs
Relative expression
CD68
iNOS
CD163
CD206
ARG1
ARG2
TNF
IFNγ
IL-1β
TGFβ1
SOCS3
IL-6
IL-12
IL-4
IL-10
c Th2 M1 Fig. 1 Differentiation of BMCs into macrophages increases CD11b/LIF transgene expression, causing suppression of M2-biased macrophage markers. a QPCR data showing differences in the level of Cd11b expression in C57BL6 BMCs stimulated with MCSF and differentiated to macrophages for 3–9 days. Values are normalized to 3-day cultures, n = 4 for each data set; * indicates significantly different from 3-day data set and # indicates significantly different
from 5- and 7-day data sets at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. For all histograms in the figure, the bars indicate
mean ± sem. b QPCR data showing increased Lif expression in freshly-isolated BMMCs and BMDMs cultured for 9 days from CD11b/LIF transgenic mice
compared to transgene negative littermate controls (WT). Data are presented as mean ± sem. BMCs were isolated from three independent donors, n = 3
per data set. * Indicates significantly different from WT at P < 0.05. P-values based on two-tailed t-test. F-test BMDMs day 9 (P = 0.0038). c QPCR
analysis shows that CD11b/LIF BMDMs have increased the expression of Cd68 and reduced the expression of Cd163 and Arg1. Data are presented as mean
± sem, n = 5 for each data set, n = 4 for WT BMDMs Inos, and CD11b/LIF BMDMs Arg1 data sets (P < 0.05). n.d. indicates that no expression was detected. Data presented for BMDMs (b, c) were isolated from a single donor animal of each genotype and cultured as n = 5 technical replicates. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 4
20
15
10
5
0
2.0
2.5
1.5
1.0
0.5
0.0
M1
M2
Th1
Th2
n.d. BMMCs
BMDMs
WT
WT BMDMs
CD11b/LIF BMDMs
CD11b/
LIF
WT
CD11b/
LIF
3
2
1
Relative expression
Relative expression
Relative expression
0
3 days
CD68
iNOS
CD163
CD206
ARG1
ARG2
TNF
IFNγ
IL-1β
TGFβ1
SOCS3
IL-6
IL-12
IL-4
IL-10
5 days
7 days
9 days
CD11b
#
LIF
a
b
c
Fig. 1 Differentiation of BMCs into macrophages increases CD11b/LIF transgene expression, causing suppression of M2-biased macrophage markers. a QPCR data showing differences in the level of Cd11b expression in C57BL6 BMCs stimulated with MCSF and differentiated to macrophages for 3–9 days. Values are normalized to 3-day cultures, n = 4 for each data set; * indicates significantly different from 3-day data set and # indicates significantly different
from 5- and 7-day data sets at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. For all histograms in the figure, the bars indicate
mean ± sem. b QPCR data showing increased Lif expression in freshly-isolated BMMCs and BMDMs cultured for 9 days from CD11b/LIF transgenic mice
compared to transgene negative littermate controls (WT). Data are presented as mean ± sem. BMCs were isolated from three independent donors, n = 3
per data set. * Indicates significantly different from WT at P < 0.05. P-values based on two-tailed t-test. F-test BMDMs day 9 (P = 0.0038). c QPCR
analysis shows that CD11b/LIF BMDMs have increased the expression of Cd68 and reduced the expression of Cd163 and Arg1. Data are presented as mean
± sem, n = 5 for each data set, n = 4 for WT BMDMs Inos, and CD11b/LIF BMDMs Arg1 data sets (P < 0.05). n.d. indicates that no expression was detected. Data presented for BMDMs (b, c) were isolated from a single donor animal of each genotype and cultured as n = 5 technical replicates. Significant findings
were verified with biological replicates of experiments from independent donors. * Indicates significantly different from WT BMDMs at P < 0.05. P-values
based on two-tailed t-test. F-test Cd206 (P = 0.0258) and Il10 (P = 0.0311). Results A CD11b regulated LIF transgene suppresses M2-biased mar-
kers. We generated mice with a LIF transgene under control of
the CD11b promoter (CD11b/LIF transgenic mice). Quantitative
PCR (QPCR) analysis of Cd11b mRNA levels confirmed that
Cd11b expression increased as BMCs differentiate into bone 2 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 We tested this possibility by assaying for effects
of the transgene on TA muscle fiber cross-sectional area as an
index of regeneration and found no difference in TA fiber size
between transgenic and non-transgenic mdx mice at any age
sampled (Supplementary Fig. 4A). We also assayed for the pro-
portion of muscle fibers that expressed developmental myosin
heavy chain (dMHC), which is upregulated in regenerating fibers. We observed a higher proportion of dMHC+ fibers in TAs of
CD11b/LIF transgenic mdx mice at 3-months-old and a trend for
more dMHC+ fibers at 1-month and 12-months-old, compared
to non-transgenic mdx mice (Supplementary Fig. 4B). Similarly, TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications 3 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 umulation of type I and type III collagen. We also showed that
-months-old, mdx limb muscles contain elevated numbers of
biased macrophages that contribute to muscle fibrosis5. The
nical rationale for sampling at 6 months is that engraftment
l
d
ll
k
i
d
li
i
i
showed that high levels of engraftment could be achieved
4 months post-BMT. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 At the time of tissue collection from transplant recipie
circulating leukocytes were 86.6% donor-derived (sem = 1
25) QPCR
f
l
h
d
h
CD11b/LIF
i i
3
2
1
0
TA
Diaphragm
1
month
3
months
12
months
1
month
3
months
12
months
1
month
3
months
12
months
1
month
3
months
12
months
1
month
3
months
12
months
1
month
3
months
12
months
WT/mdx
LIF/mdx
LIF
LIF
Relative expression
60
40
20
0
30,000
20,000
10,000
0
0
2000
4000
6000
8000
MFI (arbitrary units)
F4/80+ cells/mm3
CD163+ cells/mm3
0
2000
4000
6000
8000
CD163+ cells/mm3
25
50
40
30
20
10
0
600
25,000
20,000
15,000
10,000
5000
0
500
Energy
dissipation
Collagen 1: diaphragm
# #
#φ
#φ
#φ
#
#
#
#
#
#
#
#
#
#
#
#φ
Collagen 1: TA
CD163+ cells: diaphragm
CD163+ cells: TA
F4/80+ cells: TA
F4/80+ cells: diaphragm
Stiffness
400
300
200
100
0
20
15
10
5
0
Collagen 1
(% section area)
Collagen 1
(% section area)
Work-loop area
Stiffness (mN)
30,000
20,000
10,000
0
F4/80+ cells/mm3
1
2
3
4
5
4000
3000
2000
1000
0
0
Strain (%)
Force (mN)
15
5
10
20
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
RTICLE
NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-106 LIF
60
40
20
0
MFI (arbitrary units)
d MFI (arbitrary units)
d 3
2
1
0
TA
Diaphragm
WT/mdx
LIF/mdx
LIF
Relative expression
a d c a b c 1
month
3
months
12
months
30,000
20,000
10,000
0
F4/80+ cells/mm3
#φ #
F4/80+ cells: TA
f 1
month
3
months
12
months
#
#
#
#
F4/80+ cells: diaphragm
30,000
20,000
10,000
0
F4/80+ cells/mm3
g 3
f f e g month months months
1
month
3
months
12
months
0
2000
4000
6000
8000
CD163+ cells/mm3
#
#
#
#
CD163+ cells: TA
i 3
j 1
month
3
months
12
months
0
2000
4000
6000
8000
CD163+ cells/mm3
#
#
CD163+ cells: diaphragm
j i h i CD163+ cells/mm3 1
month
3
months
12
months
25
#φ
Collagen 1: TA
20
15
10
5
0
Collagen 1
(% section area)
m k m l l 1
month
3
months
12
months
50
40
30
20
10
0
Collagen 1: diaphragm
# #
#φ
#φ
Collagen 1
(% section area)
p n o p o 1
2
3
4
5
4000
3000
2000
1000
0
0
Strain (%)
Force (mN)
15
5
10
20
q q 25,000
20,000
15,000
10,000
5000
0
Stiffness
Stiffness (mN)
r month months months
600
500
Energy
dissipation
400
300
200
100
0
Work-loop area
s Strain (%) accumulation of type I and type III collagen. NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE Additionally, the transgene affected the
expression of Th2 cytokines associated with M2-biased macro-
phage activation, IL-4 (Il4) and IL-10 (Il10), which were reduced
by ~79% and ~84%, respectively (Fig. 3a). Reduced cytokine
expression was accompanied by a ~2.8-fold increase in the
expression of suppressor of cytokine signaling 3 (Socs3) in
CD11b/LIF BMT recipients (Fig. 3a). Socs3 expression is activated
by LIF25 and its elevation in muscles of CD11b/LIF BMT
recipients verifies an increase in LIF signaling in muscle. that expressed detectible CCR2 but found that the proportion of
CD68+ or CD206+ macrophages that expressed CCR2 was not
influenced by the transgene (Fig. 4c, d). This indicates that
reductions in macrophage-derived CCR2 in muscles reflect
reductions in macrophage numbers, rather than ablating the
expression of CCR2 in macrophages in CD11b/LIF BMT
recipients. However, stimulation of BMDMs with LIF reduced
Ccl2 expression and CCL2 protein secretion (Fig. 4e, f), indicating
that LIF acts directly on macrophages to negatively regulate Ccl2. In addition, F4/80+ macrophages were prominent sources of
CCL2 in mdx muscle (Fig. 4g), and transplantation of CD11b/LIF
BMCs reduced the proportion of F4/80+ macrophages that
expressed detectible CCL2 by 15% (Fig. 4h). p
g
g
We tested the effect of CD11b/LIF BMT on macrophage
numbers and phenotype because changes in macrophages have
profound effects on dystrophic muscle pathology7,13,14,26. We
performed immunohistochemistry using anti-F4/80, to identify
total macrophage populations, or anti-CD68 (M1-biased macro-
phages), anti-CD163 (M2-biased), or anti-CD206 (M2-biased). Mdx mice that received CD11b/LIF BMCs had 37% fewer F4/80+
cells compared to mice receiving WT BMCs (Fig. 3b). Quantita-
tion of CD68+, CD163+ and CD206+ macrophages showed no
difference in CD68+ cells (mean ± sem: WT BMT/mdx 17,525 ±
1502 and LIF BMT/mdx 16,377 ± 1440 cells/mm3, n = 5 per data
set, P = 0.60; two-tailed t-test), a 32% reduction of CD163+ cells
(Fig. 3e) and 46% fewer CD206+ cells (Fig. 3h) in the dystrophic
muscle. However, numbers of CD4+ T-cells and neutrophils in
mdx muscles were unaffected by transplantation of CD11b/LIF
BMCs (Fig. 3k, l), indicating a selective reduction of M2-biased
macrophages caused by transgenic BMDCs. Transplanted CD11b/LIF cells reduce muscle fibrosis. Fibrosis
of dystrophin-deficient muscle is largely driven by arginine
metabolism by arginase expressed by M2-biased macrophages23. Arginine hydrolysis by arginase produces metabolites that are
utilized to generate substrate molecules necessary for connective
tissue production28. ARTICLE Fig. 2 CD11b/LIF transgene expression modulates inflammation and reduces fibrosis. a QPCR data showing Lif expression in muscles of CD11b/LIF
transgenic mdx mice (LIF/mdx) and non-transgenic littermates (WT/mdx), normalized to WT/mdx. TA muscles: n = 10. Diaphragm muscles: n = 8 or 7 for
WT/mdx and LIF/mdx data sets, respectively. * Indicates significant difference versus WT/mdx (P < 0.05). For all histograms, bars indicate mean ± sem. b,
c Cross-sections of WT/mdx (b) and LIF/mdx (c) TA muscles labeled with anti-LIF. Bars = 50 μm. d Mean fluorescence intensity (MFI) of inflammatory
lesions in sections immunolabeled for LIF. * Indicates significant difference from WT/mdx (n = 4; P < 0.05). e–j Cross-sections of muscles from WT/mdx
and LIF/mdx mice were immunolabeled with antibodies to F4/80 (e) and CD163 (h). Numbers of F4/80+ (f, g) and CD163+ (i, j) cells were normalized to
muscle volume. Labeling of F4/80+ (e) and CD163+ (h) cells in TA muscle from 1-month-old WT/mdx muscle. Bars = 100 μm. N = 5 for each group,
except n = 4 for F4/80 WT/mdx 1- and 12-month TA, LIF/mdx 12-month TA, WT/mdx 1- and 3-month diaphragm, and CD163 WT/mdx 12-month TA data
sets. k–p Cross-sections of TA (k, i) and diaphragm (n, o) muscles from 12-month-old WT/mdx (k, n) and LIF/mdx (l, o) mice were immunolabeled with
anti-collagen type 1. Bars = 50 μm. The volume fraction of muscle occupied by collagen type 1 (m, p). N = 5 for each group, except n = 4 for 3-month TA. *
Indicates significant difference versus age-matched WT/mdx mice (P < 0.05). # and Φ indicate significant difference versus 1- and 3-months-old,
genotype-matched mice, respectively (P < 0.05). P-values based on two-tailed t-test. q–s The passive mechanical properties of TA muscles of WT/mdx
(curves 1 and 2) and LIF/mdx (curves 3–5) mice were measured in-situ. Lissajous curves (q) show passive stiffness (r) and energy dissipation (s) of TAs. N = 2 and 3 for WT/mdx and LIF/mdx groups, respectively. * Indicates significant difference versus WT/mdx mice. P-values based on two-tailed t-test. Source data are provided as a Source Data file (LIF BMT/mdx mice) had reduced expression of the M2-biased
markers Cd163, CD206 (Mrc1), and arginase-2 (Arg2) expression
by 51%, 49%, and 43%, respectively (Fig. 3a). This effect
resembles the autocrine effect of CD11b/LIF on macrophages
in vitro (Fig. 1c). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 We also showed that
at 6-months-old, mdx limb muscles contain elevated numbers of
M2-biased macrophages that contribute to muscle fibrosis5. The
technical rationale for sampling at 6 months is that engraftment
of transplanted cells takes time and our preliminary experiments showed that high levels of engraftment could be achieved by
4 months post-BMT. showed that high levels of engraftment could be achieved by
4 months post-BMT. At the time of tissue collection from transplant recipients,
circulating leukocytes were 86.6% donor-derived (sem = 1.14;
n = 25). QPCR of muscles showed that CD11b/LIF recipients NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunicatio 4 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE Because we observed reductions in M2-
biased macrophages in muscles of mdx mice that were recipients
of CD11b/LIF BMT and lower levels of expression of Arg2, we
assayed whether fibrosis was affected. Transplantation of CD11b/
LIF BMCs reduced collagen types 1, 3, and 5 in mdx muscle by
~41%, 22%, and 25%, respectively, compared to WT BMT reci-
pients (Fig. 5a–i). However, the anti-fibrotic effect of CD11b/LIF
BMT cannot be solely attributed to reductions of arginine
metabolism by M2-biased macrophages. QPCR data showed that
mRNA levels of collagen types 1 alpha 1 (Col1a1), 3 alpha 1
(Col3a1), and 5 alpha 3 (Col5a3) were reduced by ~57%, 51%,
and 30%, respectively, in CD11b/LIF BMC recipients (Fig. 5j),
indicating treatment effects on fibrogenic cells, in addition to
effects on macrophages that provide substrate for fibrogenesis. LIF reduces Ccl2 expression in muscle and macrophages. The
large reductions of M2-biased macrophages in dystrophic muscle
of mice transplanted with CD11b/LIF BMCs (Fig. 3) suggest that
LIF
inhibits
their
recruitment. Because
abrogation
of
CCR2 signaling reduces macrophage accumulation in dystrophic
muscle27, we tested whether CCR2 signaling was affected by LIF. QPCR assays showed reduced expression of Ccr2 and its ligands
Ccl2, Ccl8 and Ccl12 in muscles of CD11b/LIF BMT recipients,
and a strong trend for lower levels of Ccl7 expression (P = 0.06)
(Fig. 4a). M2-biased macrophages can act directly on fibrogenic cells
through TGFβ which activates fibro/adipogenic progenitor cells
(FAPs) into fibroblasts and stimulates fibroblasts to produce
collagen29–32. TGFβ can also activate Wnt-signaling, which
increases myogenic-to-fibrogenic conversion of muscle stem cells,
further contributing to dystrophic muscle fibrosis33. We tested
whether the CD11b/LIF BMT affected key transcripts of the Wnt
and TGFβ pro-fibrotic pathways. Although there was no effect on
the expression of Tgfb1 or Axin2, a Wnt-target gene (Fig. 5k), the
expression of downstream TGFβ target genes connective tissue
growth factor (Ctgf), fibronectin (Fn1), and snail family zinc
finger 1 (Snai1)34–37 were reduced by ~33%, 43%, and 33%,
respectively (Fig. 5k). We next tested the possibility that LIF acts directly on
macrophages to inhibit CCR2 signaling in vitro. Unexpectedly,
brief periods of macrophage stimulation with LIF had no effect on
Ccr2 expression and extended periods significantly increased Ccr2
expression (Fig. 4b). We assayed whether the CD11b/LIF
transgene affected the numbers of intramuscular macrophages 5 5 TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 6
WT BMT/mdx
LIF BMT/mdx
WT BMT/mdx
LIF BMT/mdx
5
4
3
2.0
1.5
1.0
0.5
0.0
20,000
F4/80+
15,000
10,000
5000
0
6000
5000
4000
3000
2000
1000
30,000
20,000
10,000
CD206+
CD4+
CD163+
0
0
10
20
30
40
150
100
50
0
Neutrophils
0
M1
M2
Th1
Th2
CD68
iNOS
CD163
CD206
ARG1
ARG2
TNF
IFNγ
IL-1β
IL-6
IL-12
IL-4
IL-10
SOCS3
Relative expression
F4/80+ cells/mm3
CD163+ cells/mm3
CD206+ cells/mm3
CD4+ cells/mm3
Ly6B.2+ cells/mm3
a
b
c
d
e
f
g
h
i
j
k
l
splantation of CD11b/LIF transgenic BMCs into mdx mice reduces inflammation in dystrophic muscle. a QPCR analysis s
ion of CD11b/LIF transgenic BMCs into mdx recipients (LIF BMT/mdx) reduced expression of transcripts associated wit 6
WT BMT/mdx
LIF BMT/mdx
5
4
3
2.0
1.5
1.0
0.5
0.0
M1
M2
Th1
Th2
CD68
iNOS
CD163
CD206
ARG1
ARG2
TNF
IFNγ
IL-1β
IL-6
IL-12
IL-4
IL-10
SOCS3
Relative expression
a a Th2 20,000
F4/80+
15,000
10,000
5000
0
F4/80+ cells/mm3
b b d c d 6000
5000
4000
3000
2000
1000
CD163+
0
CD163+ cells/mm3
e e g f g 30,000
20,000
10,000
CD206+
0
CD206+ cells/mm3
h h j i j i WT BMT/mdx
LIF BMT/mdx
150
100
50
0
Neutrophils
Ly6B.2+ cells/mm3
l CD4+
0
10
20
30
40
CD4+ cells/mm3
k l 3
l k Fig. 3 Transplantation of CD11b/LIF transgenic BMCs into mdx mice reduces inflammation in dystrophic muscle. a QPCR analysis shows that the
transplantation of CD11b/LIF transgenic BMCs into mdx recipients (LIF BMT/mdx) reduced expression of transcripts associated with M2-biased
macrophages (Cd163, Cd206, and Arg2), Th2 cytokines (Il4 and Il10), and increased expression of the negative regulator of cytokine signaling (Socs3)
compared to WT BMT mdx recipients (WT BMT/mdx) 4 months post-transplantation. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets,
respectively, except n = 7 for LIF BMT/mdx Arg1 data set. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. F-test Ifng (P =
0.0145), Il6 (P < 0.0001), Il4 (P = 0.0015), Il10 (P < 0.0001), and Socs3 (P = 0.0061). For all histograms in the figure, the bars indicate mean ± sem. b–j
Cross-sections of TA muscles from WT BMT/mdx (c, f, i) or LIF BMT/mdx (d, g, j) mice were immunolabeled with antibodies to F4/80 (c, d), CD163 (f, g),
and CD206 (i, j). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 3
WT BMT/mdx
CCR2
Vehicle
LIF
Vehicle
LIF
LIF BMT/mdx
WT BMT/mdx
LIF BMT/mdx
WT BMT/mdx
LIF BMT/mdx
WT BMT/mdx
LIF BMT/mdx
2
Relative expression
Relative expression
Relative expression
1
0
100
50
2.0
1.5
1.0
0.5
0.0
40
30
20
10
0
(CCR2+/CD68+) × 100
(CCR2+/CD206+) × 100
80
60
40
20
250
60
(CCL2+/F4/80+) × 100
50
40
30
20
10
0
200
150
CCL2 (pg/ml)
100
50
0
0
3
2
1
0
3 h
24 h
3 h
24 h
6 h
24 h
CCR2
CCL2
CCL7
CCL8
CCL12
CCL2
Vehicle
LIF
CCL2
a
b
c
d
e
f
g
h
Fig. 4 Transplantation of CD11b/LIF transgenic BMCs disrupts Ccl2 expression in dystrophic muscles by inhibiting macrophage expression of CCL2. a QPCR
analysis shows that TA muscles from LIF BMT/mdx recipients have reduced expression of Ccr2 and its ligands Ccl2, Ccl7 (P = 0.06), Ccl8, and Ccl12. N = 7
or 8 for WT BMT/mdx and LIF BMT/mdx data sets, respectively, except n = 7 for LIF BMT/mdx Ccl8 data set. * Indicates significantly different from WT
BMT/mdx recipients at P < 0.05. F-test Ccr2 (P = 0.0087), Ccl2 (P < 0.0001), Ccl7 (P = 0.0001), Ccl8 (P = 0.001), and Ccl12 (P = 0.001). For all histograms
in the figure, the bars indicate mean ± sem. b QPCR analysis for Ccr2 gene expression of BMDMs treated with recombinant LIF (10 ng/ml) for 3- and 24-h. c, d Muscle sections co-labeled with antibodies to CD68 (c) or CD206 (d) and CCR2 show no change in the proportions of cells co-expressing CCR2
between transplant recipient groups. N = 5 for each data set. e QPCR analysis shows reduced Ccl2 gene expression in BMDMs stimulated with LIF as
described in (b). f ELISA of conditioned media showed less CCL2 secreted into the media of BMDMs stimulated with LIF for 6- and 24-h compared to
control cultures. For cell culture experiments, N = 5 technical replicates for each data set, cells for each time point were isolated from independent donors. Significant findings were verified with biological replicates of experiments from independent donors. P-values based on two-tailed t-test. F-test CCL2
protein 24 h (P = 0.0337). g, h Cross-sections of TA muscles from WT BMT/mdx or LIF BMT/mdx mice were immunolabeled with antibodies to F4/80
(green) and CCL2 (red) show that F4/80+ cells express CCL2 (g). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 f ELISA of conditioned media showed less CCL2 secreted into the media of BMDMs stimulated with LIF for 6- and 24-h compared to
control cultures. For cell culture experiments, N = 5 technical replicates for each data set, cells for each time point were isolated from independent donors. Significant findings were verified with biological replicates of experiments from independent donors. P-values based on two-tailed t-test. F-test CCL2
protein 24 h (P = 0.0337). g, h Cross-sections of TA muscles from WT BMT/mdx or LIF BMT/mdx mice were immunolabeled with antibodies to F4/80
(green) and CCL2 (red) show that F4/80+ cells express CCL2 (g). Nuclei are stained blue with DAPI. Bar = 10 μm. h The proportion of F4/80+ cells co-
expressing CCL2 was reduced in LIF BMT/mdx recipients. N = 5 for each data set, * indicates significantly different from WT BMT/mdx recipients at P <
0.05. P-values based on two-tailed t-test. Source data are provided as a Source Data file a negative regulator of TGFβ1 expression in macrophages. However, Tgfb1 gene expression was not reduced after 3 h of
LIF stimulation, suggesting that LIF-mediated inhibition of Tgfb1
could be a secondary effect. LIF reduces macrophage TGFβ1 expression. Although we
observed no effect of CD11b/LIF BMT on Tgfb1 mRNA in whole
muscle homogenates, we assayed more specifically for effects on
TGFβ expression in intramuscular macrophages by assaying the
proportion of macrophages that expressed TGFβ. We found that
there were 17.7% fewer intramuscular macrophages that expres-
sed detectible TGFβ in CD11b/LIF recipients, compared to WT
recipients (Fig. 6a). Interestingly, the greatest reduction of TGFβ
expressing macrophages was seen in inflammatory lesions of
CD11b/LIF recipients (Fig. 6c) compared to WT recipients
(Fig. 6b). LIF reduces fibrogenesis and Ctgf mRNA in muscle cells. TGFβ
signaling promotes the fibrogenic conversion of myogenic cells in
dystrophic muscle, thereby contributing to fibrosis33. Because
transplantation of CD11b/LIF BMCs into mdx mice reduces
fibrosis, we tested whether LIF reduces the proportion of myo-
genic cells acquiring a fibrogenic phenotype. Muscle sections that
were double-labeled with anti-Pax7, a marker of satellite cells, and
anti-HSP47, a collagen-specific molecular chaperone38,39 showed
that the proportion of Pax7+ cells that expressed HSP47 was
reduced by 27.8% in CD11b/LIF recipients (Fig. 7a–c); this We tested whether reduced TGFβ1 expression in CD11b/LIF
BMT recipients reflected direct actions of LIF on macrophages to
inhibit TGFβ1 expression. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Nuclei are stained blue with DAPI. Bar = 10 μm. h The proportion of F4/80+ cells co-
expressing CCL2 was reduced in LIF BMT/mdx recipients. N = 5 for each data set, * indicates significantly different from WT BMT/mdx recipients at P <
0.05. P-values based on two-tailed t-test. Source data are provided as a Source Data file 3
WT BMT/mdx
CCR2
Vehicle
LIF
LIF BMT/mdx
2
Relative expression
Relative expression
1
0
3
2
1
0
3 h
24 h
CCR2
CCL2
CCL7
CCL8
CCL12
a
b CCR2
Vehicle
LIF
Relative expression
3
2
1
0
3 h
24 h
b 3
WT BMT/mdx
LIF BMT/mdx
2
Relative expression
1
0
CCR2
CCL2
CCL7
CCL8
CCL12
a b a WT BMT/mdx
LIF BMT/mdx
50
40
30
20
10
0
(CCR2+/CD206+) × 100
d WT BMT/mdx
LIF BMT/mdx
100
(CCR2+/CD68+) × 100
80
60
40
20
0
c d Vehicle
LIF
Relative expression
2.0
1.5
1.0
0.5
0.0
3 h
24 h
CCL2
e WT BMT/mdx
LIF BMT/mdx
60
(CCL2+/F4/80+) × 100
50
40
30
20
10
0
h 250
200
150
CCL2 (pg/ml)
100
50
0
6 h
24 h
Vehicle
LIF
CCL2
f g g Fig. 4 Transplantation of CD11b/LIF transgenic BMCs disrupts Ccl2 expression in dystrophic muscles by inhibiting macrophage expression of CCL2. a QPCR
analysis shows that TA muscles from LIF BMT/mdx recipients have reduced expression of Ccr2 and its ligands Ccl2, Ccl7 (P = 0.06), Ccl8, and Ccl12. N = 7
or 8 for WT BMT/mdx and LIF BMT/mdx data sets, respectively, except n = 7 for LIF BMT/mdx Ccl8 data set. * Indicates significantly different from WT
BMT/mdx recipients at P < 0.05. F-test Ccr2 (P = 0.0087), Ccl2 (P < 0.0001), Ccl7 (P = 0.0001), Ccl8 (P = 0.001), and Ccl12 (P = 0.001). For all histograms
in the figure, the bars indicate mean ± sem. b QPCR analysis for Ccr2 gene expression of BMDMs treated with recombinant LIF (10 ng/ml) for 3- and 24-h. c, d Muscle sections co-labeled with antibodies to CD68 (c) or CD206 (d) and CCR2 show no change in the proportions of cells co-expressing CCR2
between transplant recipient groups. N = 5 for each data set. e QPCR analysis shows reduced Ccl2 gene expression in BMDMs stimulated with LIF as
described in (b). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Bars = 50 μm. The numbers of F4/80+ (b), CD163+ (e), and CD206+ (h) cells normalized to muscle volume were reduced in LIF BMT/
mdx recipients. Similarly, cross-sections were immunolabeled with antibodies to CD4 and Ly-6B.2 (neutrophils) to test for changes in the concentrations of
other populations of immune cells. There was no change in the concentrations of CD4+ (k) and Ly-6B.2+ (l) cells. N = 5 for each data set, except n = 4 for
CD206 LIF BMT/mdx data set. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. All P-values based on two-tailed t-test. Source
data are provided as a Source Data file Fig. 3 Transplantation of CD11b/LIF transgenic BMCs into mdx mice reduces inflammation in dystrophic muscle. a QPCR analysis shows that the
transplantation of CD11b/LIF transgenic BMCs into mdx recipients (LIF BMT/mdx) reduced expression of transcripts associated with M2-biased
macrophages (Cd163, Cd206, and Arg2), Th2 cytokines (Il4 and Il10), and increased expression of the negative regulator of cytokine signaling (Socs3)
compared to WT BMT mdx recipients (WT BMT/mdx) 4 months post-transplantation. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets,
respectively, except n = 7 for LIF BMT/mdx Arg1 data set. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. F-test Ifng (P =
0.0145), Il6 (P < 0.0001), Il4 (P = 0.0015), Il10 (P < 0.0001), and Socs3 (P = 0.0061). For all histograms in the figure, the bars indicate mean ± sem. b–j
Cross-sections of TA muscles from WT BMT/mdx (c, f, i) or LIF BMT/mdx (d, g, j) mice were immunolabeled with antibodies to F4/80 (c, d), CD163 (f, g),
and CD206 (i, j). Bars = 50 μm. The numbers of F4/80+ (b), CD163+ (e), and CD206+ (h) cells normalized to muscle volume were reduced in LIF BMT/
mdx recipients. Similarly, cross-sections were immunolabeled with antibodies to CD4 and Ly-6B.2 (neutrophils) to test for changes in the concentrations of
other populations of immune cells. There was no change in the concentrations of CD4+ (k) and Ly-6B.2+ (l) cells. N = 5 for each data set, except n = 4 for
CD206 LIF BMT/mdx data set. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. All P-values based on two-tailed t-test. Source
data are provided as a Source Data file NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunicatio 6 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Source data are provided as a Source Data file 50
40
30
20
2.0
Relative expression
Relative expression
1.5
1.0
0.5
Col 1
Col 3
Col 5
0.0
2.0
WT BMT/mdx
LIF BMT/mdx
1.5
1.0
0.5
0.0
n2
β1
GF
FN
AI1
10
0
Collagen 5
Collagen 5
(% section area)
g
h
i
j
k i g h Relative expression
2.0
WT BMT/mdx
LIF BMT/mdx
1.5
1.0
0.5
0.0
Axin2
TGFβ1
CTGF
FN
SNAI1
k 2.0
Relative expression
1.5
1.0
0.5
Col 1
Col 3
Col 5
0.0
j k Fig. 5 Transplantation of CD11b/LIF transgenic BMCs into mdx mice reduces muscle fibrosis. a–i TA muscles from WT BMT/mdx (b, e, h) and LIF BMT/
mdx transplant recipients (c, f, i) were immunolabeled for collagen types 1 (a–c), 3 (d–f), and 5 (g–i). Bars = 50 µm. The volume fraction of muscle
occupied by collagen types 1 (a), 3 (d), and 5 (g) was reduced in LIF BMT/mdx recipients. N = 5 for WT BMT/mdx and LIF BMT/mdx data sets, except n =
4 WT BMT/mdx collagen type 3 and LIF BMT/mdx collagen type 1. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. F-test
collagen type 3 (P = 0.0055) and type 5 (P = 0.0155). For all histograms in the figure, the bars indicate mean ± sem. j QPCR data presented as mean ± sem
shows that LIF BMT/mdx recipients also had reduced expression of transcripts encoding Col1a1, Col3a1, and Col5a3. N = 7 or 8 for WT BMT/mdx and LIF
BMT/mdx data sets, respectively, except n = 5 for Col5a3 data sets. k QPCR analysis of transcripts associated with the pro-fibrotic Wnt- (Axin2) and
TGFβ1-signaling (Tgfb1, Ctgf, Fn1, and Snai1) pathways showed reduced expression of Ctgf, Fn1, and Snai1 in LIF BMT/mdx recipients. N = 7 or 8 for WT
BMT/mdx and LIF BMT/mdx data sets, respectively, except n = 7 for LIF BMT/mdx Axin2 group. * Indicates significantly different from WT BMT/mdx
recipients at P < 0.05. P-values based on two-tailed t-test. F-test Col1a1 (P = 0.0250). Source data are provided as a Source Data file shifted away from a myogenic phenotype, toward a fibrogenic
phenotype40,41. Our data show that the transgene reduced the
proportion of satellite cells that expressed ERTR7 in mdx muscle
in vivo, similar to the reduction of satellite cells expressing HSP47
(Fig. 7c, d). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Source data are provided as a Source Data file 25
Collagen 1
20
Collagen 1
(% section area)
15
10
5
0
a b b c c 60
50
40
30
20
10
0
Collagen 3
Collagen 3
(% section area)
d d f e
f f e 50
40
30
20
2.0
Relative expression
Relative expression
1.5
1.0
0.5
Col 1
Col 3
Col 5
0.0
2.0
WT BMT/mdx
LIF BMT/mdx
1.5
1.0
0.5
0.0
Axin2
TGFβ1
CTGF
FN
SNAI1
10
0
Collagen 5
Collagen 5
(% section area)
g
h
i
j
k
Fig. 5 Transplantation of CD11b/LIF transgenic BMCs into mdx mice reduces muscle fibrosis. a–i TA muscles from WT BMT/mdx (b, e, h) and LIF BMT/
mdx transplant recipients (c, f, i) were immunolabeled for collagen types 1 (a–c), 3 (d–f), and 5 (g–i). Bars = 50 µm. The volume fraction of muscle
occupied by collagen types 1 (a), 3 (d), and 5 (g) was reduced in LIF BMT/mdx recipients. N = 5 for WT BMT/mdx and LIF BMT/mdx data sets, except n =
4 WT BMT/mdx collagen type 3 and LIF BMT/mdx collagen type 1. * Indicates significantly different from WT BMT/mdx recipients at P < 0.05. F-test
collagen type 3 (P = 0.0055) and type 5 (P = 0.0155). For all histograms in the figure, the bars indicate mean ± sem. j QPCR data presented as mean ± sem
shows that LIF BMT/mdx recipients also had reduced expression of transcripts encoding Col1a1, Col3a1, and Col5a3. N = 7 or 8 for WT BMT/mdx and LIF
BMT/mdx data sets, respectively, except n = 5 for Col5a3 data sets. k QPCR analysis of transcripts associated with the pro-fibrotic Wnt- (Axin2) and
TGFβ1-signaling (Tgfb1, Ctgf, Fn1, and Snai1) pathways showed reduced expression of Ctgf, Fn1, and Snai1 in LIF BMT/mdx recipients. N = 7 or 8 for WT
BMT/mdx and LIF BMT/mdx data sets, respectively, except n = 7 for LIF BMT/mdx Axin2 group. * Indicates significantly different from WT BMT/mdx
recipients at P < 0.05. P-values based on two-tailed t-test. F-test Col1a1 (P = 0.0250). NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 When we treated BMDMs with LIF for
24 h, Tgfb1 gene expression was reduced by 47% and secreted
TGFβ protein expression by 29% (Fig. 6d, e), showing that LIF is 7 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 25
60
50
40
30
20
10
0
50
40
30
20
2.0
Relative expression
Relative expression
1.5
1.0
0.5
Col 1
Col 3
Col 5
0.0
2.0
WT BMT/mdx
LIF BMT/mdx
1.5
1.0
0.5
0.0
Axin2
TGFβ1
CTGF
FN
SNAI1
10
0
Collagen 1
Collagen 3
Collagen 5
20
Collagen 1
(% section area)
Collagen 3
(% section area)
Collagen 5
(% section area)
15
10
5
0
a
b
c
d
e
f
g
h
i
j
k
5 Transplantation of CD11b/LIF transgenic BMCs into mdx mice reduces muscle fibrosis. a–i TA muscles from WT BMT/mdx (b, e, h
ransplant recipients (c, f, i) were immunolabeled for collagen types 1 (a–c), 3 (d–f), and 5 (g–i). Bars = 50 µm. The volume fractio
pied by collagen types 1 (a), 3 (d), and 5 (g) was reduced in LIF BMT/mdx recipients. N = 5 for WT BMT/mdx and LIF BMT/mdx data s
T BMT/mdx collagen type 3 and LIF BMT/mdx collagen type 1. * Indicates significantly different from WT BMT/mdx recipients at P
gen type 3 (P = 0.0055) and type 5 (P = 0.0155). For all histograms in the figure, the bars indicate mean ± sem. j QPCR data presented
s that LIF BMT/mdx recipients also had reduced expression of transcripts encoding Col1a1, Col3a1, and Col5a3. N = 7 or 8 for WT BM
/mdx data sets, respectively, except n = 5 for Col5a3 data sets. k QPCR analysis of transcripts associated with the pro-fibrotic Wnt
1-signaling (Tgfb1, Ctgf, Fn1, and Snai1) pathways showed reduced expression of Ctgf, Fn1, and Snai1 in LIF BMT/mdx recipients. N =
/mdx and LIF BMT/mdx data sets, respectively, except n = 7 for LIF BMT/mdx Axin2 group. * Indicates significantly different from W
ents at P < 0.05. P-values based on two-tailed t-test. F-test Col1a1 (P = 0.0250). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 d QPCR analysis of BMDMs treated with recombinant LIF
(10 ng/ml) for 3- or 24-h shows that Tgfb1 expression is inhibited by LIF after 24 h of stimulation. e The concentration of secreted TGFβ was also reduced
in BMDMs stimulated with LIF for 24 h, analyzed by ELISA. N = 5 technical replicates for each data set. Significant findings were verified with biological
replicates of experiments from independent donors. * Indicates significantly different from control at P < 0.05. Source data are provided as a Source
Data file PDGFRα+ cells that expressed HSP47 was unaffected by the
transgene (Fig. 8d). The findings indicate that reductions in
numbers of FAPs in the muscles of mdx mice receiving CD11b/
LIF BMT may contribute to reduced muscle fibrosis. integrin+ cells) from CD11b/LIF transgenic mdx mice showed
lower expression levels of Fn1 and Col3a1 compared to non-
transgenic mice (Supplementary Fig. 5). In addition, we observed
strong trends for the reduction in expression of Serpinh1 (HSP47)
and Col1a1 in freshly-isolated MPCs. y
We then tested whether LIF influenced the fibrogenic activity
of FAP-derived fibroblasts in vitro. We sorted FAPs (CD11b/31/
45- PDGFRα+) from WT muscles (Fig. 8e) and subcultured them
prior to stimulation with TGFβ1, LIF, or TGFβ1 + LIF41,42. We
used fibroblasts derived from FAPs rather than freshly-isolated
FAPs because fibroblasts differentiated from FAPs are the
primary source of connective tissue proteins in muscle32. We
tested if LIF affected Pdgfra expression in fibroblasts in vitro
because enhanced PDGFRα signaling can cause pathological
fibrosis43. However, LIF did not affect Pdgfra expression in
fibroblasts (mean ± sem: control cells 1 ± 0.04 and LIF-treated
cells 1.13 ± 0.23, n = 4 per data set, P = 0.61; two-tailed t-test). Treatments for 3 h with TGFβ1-induced Ctgf expression in
fibroblasts, but LIF had no effect on basal or TGFβ1-induced Ctgf
(Fig. 8f). The magnitude of TGFβ1-induced Ctgf expression in
fibroblasts (1.9-fold) was less than in myoblasts (~11.6-fold) and
myotubes (~7.1-fold) (Fig. 7e). TGFβ1, LIF or TGFβ1 + LIF had
no effect on Fn1 or Col1a1 expression in fibroblasts (Fig. 8g, h). We then tested whether prolonged stimulation of fibroblasts with
TGFβ1, LIF, or TGFβ1 + LIF affected Ctgf, Fn1, or Col1a1
expression. Similar to effects of brief stimulations, Ctgf expression
was induced ~2.0-fold by TGFβ1 but the induction was not
affected by LIF. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 80
WT BMT/mdx
LIF BMT/mdx
60
(TGFβ1+/F4/80+) × 100
40
20
1.5
150
100
50
0
TGFβ1
TGFβ1
Vehicle
LIF
TGFβ1 (pg/ml)
1.0
Relative expression
0.5
0.0
3 h
24 h
24 h
0
a
b
c
d
e
Fig. 6 LIF inhibits macrophage TGFβ1 expression. a–c Muscle sections were co-labeled with antibodies to pro-fibrotic TGFβ (red) and the pan macrophage
marker F4/80 (green) to test for changes in macrophage expression of TGFβ. Nuclei appear blue (DAPI). Bars = 25 μm. a The proportion of F4/80+ cells
co-expressing TGFβ was reduced in LIF BMT/mdx recipients. The greatest reduction in the number of F4/80+ cells positive for TGFβ (orange) was in
inflammatory lesions of LIF BMT/mdx (c) compared to WT BMT/mdx recipients (b). N = 5 for each data set, * indicates significantly different from WT
BMT/mdx recipients at P < 0.05. For all histograms in the figure, the bars indicate mean ± sem. d QPCR analysis of BMDMs treated with recombinant LIF
(10 ng/ml) for 3- or 24-h shows that Tgfb1 expression is inhibited by LIF after 24 h of stimulation. e The concentration of secreted TGFβ was also reduced
in BMDMs stimulated with LIF for 24 h, analyzed by ELISA. N = 5 technical replicates for each data set. Significant findings were verified with biological
replicates of experiments from independent donors. * Indicates significantly different from control at P < 0.05. Source data are provided as a Source
Data file 80
WT BMT/mdx
LIF BMT/mdx
60
(TGFβ1+/F4/80+) × 100
40
20
0
a b c b a c 1.5
TGFβ1
1.0
Relative expression
0.5
0.0
3 h
24 h
d 150
100
50
0
TGFβ1
Vehicle
LIF
TGFβ1 (pg/ml)
24 h
e e Fig. 6 LIF inhibits macrophage TGFβ1 expression. a–c Muscle sections were co-labeled with antibodies to pro-fibrotic TGFβ (red) and the pan macrophage
marker F4/80 (green) to test for changes in macrophage expression of TGFβ. Nuclei appear blue (DAPI). Bars = 25 μm. a The proportion of F4/80+ cells
co-expressing TGFβ was reduced in LIF BMT/mdx recipients. The greatest reduction in the number of F4/80+ cells positive for TGFβ (orange) was in
inflammatory lesions of LIF BMT/mdx (c) compared to WT BMT/mdx recipients (b). N = 5 for each data set, * indicates significantly different from WT
BMT/mdx recipients at P < 0.05. For all histograms in the figure, the bars indicate mean ± sem. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 indicates that satellite cells had a less fibrogenic phenotype in
CD11b/LIF recipients. Expression of Serpinh1, the gene that
encodes HSP47, was also reduced 24% in the whole muscle lysate
of CD11b/LIF recipients (mean ± sem: WT BMT/mdx 1 ± 0.08
and LIF BMT/mdx 0.76 ± 0.06, n = 7 and 8 per data set, respec-
tively, P = 0.03; two-tailed t-test). We also assayed whether
transplantation of CD11b/LIF BMCs affected the proportion of
satellite cells that expressed ERTR7 in vivo. ERTR7 was chosen in
addition to HSP47 because satellite cells in injured and aging
muscle that display elevated levels of ERTR7 expression have g
We also tested whether the CD11b/LIF transgene affected the
phenotype of myogenic progenitor cells (MPCs) in later stages of
mdx pathology by assaying for changes in the expression of
fibrogenic genes in MPCs that were freshly-isolated from muscles
of 14-months-old mice. MPCs (CD11b-CD31-CD45-Sca1-α7 TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications 8 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 There was also no effect of prolonged stimulation
with TGFβ1 on the expression of Fn1 or Col1a1 (Fig. 8i–k). y
We also examined the effects of LIF on TGFβ1-induced muscle
cell fibrogenesis in vitro. We assayed myoblasts and myotubes
treated with TGFβ1 and/or LIF for changes in expression of
fibrogenic genes downregulated in CD11b/LIF BMT recipients
(Ctgf, Fn1, and Col1a1; Fig. 5j, k). Co-stimulation with TGFβ1
and LIF inhibited Ctgf expression, compared to cells treated with
TGFβ1 only (Fig. 7e, h). LIF also reduced basal Ctgf expression
after 24 h of stimulation in myotubes. Fn1 expression was stable
in myoblasts treated with TGFβ1, LIF, or TGFβ1 + LIF for 3 h
(Fig. 7f). After 24 h, TGFβ1-induced Fn1 expression, but co-
stimulation with LIF had no effect (Fig. 7i). TGFβ1 stimulation
for 3 h induced the expression of Col1a1 in myotubes, and LIF
attenuated TGFβ1-induced expression of Col1a1 in myotubes
(Fig. 7g). LIF stimulation for 24 h reduced basal Col1a1
expression in myoblasts, but not TGFβ1-induced expression of
Col1a1 (Fig. 7j). LIF reduces the prevalence of FAPs in dystrophic muscle. Because FAP-derived fibroblasts are important sources of con-
nective tissue proteins, we assayed whether CD11b/LIF BMT
affected FAP numbers in vivo or whether LIF affected the
expression of fibrogenic proteins by FAP-derived fibroblasts
in vitro. QPCR analysis showed that CD11b/LIF BMT recipients
had a 47% reduction in Pdgfra expression (Fig. 8a) which could
reflect fewer FAPs. Recipients of CD11b/LIF BMT had fewer cells
that expressed PDGFRα and were double-negative for CD31 and
CD45, which are FAPs42 (Fig. 8b, c), although the proportion of Transplanted CD11b/LIF cells do not affect muscle growth. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Because changes in macrophage phenotype and numbers influ-
ence muscle regeneration and myogenesis14,44–47, we assayed TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications 9 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 40
40
60
80
100
15
CTGF
FN
COL1
CTGF
FN
COL1
#φ
#φ
#φ
φ
φ φ
#φ
#
#
#
#
#
#
#
#
10
5
1.5
Relative expression
Relative expression
1.0
0.5
0.0
Veh TGFβ1
LIF TGFβ1+
LIF
Veh TGFβ1
LIF TGFβ1+
LIF
Veh TGFβ1
LIF TGFβ1+
LIF
1.5
1.0
0.5
0.0
Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
30
20
10
2.0
1.5
Relative expression
Relative expression
1.0
0.5
0.0
Veh TGFβ1
LIF TGFβ1+
LIF
Veh TGFβ1
LIF TGFβ1+
LIF
Veh TGFβ1
LIF TGFβ1+
LIF
2
1
0
Relative expression
1.5
2.0
1.0
0.5
0.0
30
20
20
10
0
0
(HSP47+/Pax7+) × 100
(ERTR7+/Pax7+) × 100
WT BMT/mdx
LIF BMT/mdx
Myoblasts
Myotubes
a
b
c
d
e
f
g
h
j
i
Fig. 7 LIF inhibits fibrogenesis and TGFβ1-induced Ctgf expression in muscle cells. a TA muscle sections were co-labeled with antibodies to Pax7 (red) and
HSP47 (green) in WT BMT/mdx (a) and LIF BMT/mdx (b) recipients. Nuclei appear blue (DAPI). Bars = 5 μm. c Fewer Pax7+ cells co-expressed HSP47 in
LIF BMT/mdx recipients (green symbols) compared to WT BMT/mdx recipients (black symbols). d Muscle sections were also co-labeled with antibodies
to Pax7 and fibrogenic marker Ertr7 to confirm that fewer Pax7+ cell acquired a fibrogenic phenotype in LIF BMT/mdx recipients. N = 5 for each data set,
except n = 4 for WT BMT/mdx Pax7/HSP47 data set, * indicates significantly different from WT BMT/mdx at P < 0.05. P-values based on two-tailed t-test. For all histograms in the figure, the bars indicate mean ± sem. e–j Myoblasts (black symbols) and myotubes (green symbols) were stimulated with LIF (10
ng/ml) and TGFβ1 (10 ng/ml) for 3- (e–g) or 24-h (h–j). e, h LIF inhibited TGFβ1-induced Ctgf mRNA in myoblasts and myotubes after 3- and 24-h of
stimulation. LIF inhibited basal Ctgf expression in myotubes at 24 h (h). f, i LIF did not affect Fn1 expression in myoblasts or myotubes after 3- or 24-h. Additionally, LIF attenuated TGFβ1-induced Col1a1 expression in myotubes, but not myoblasts after 3 h of stimulation (g). Myoblasts stimulated with LIF for
24 h had reduced Col1a1 expression (j). N = 4 technical replicates per group. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Additionally, LIF attenuated TGFβ1-induced Col1a1 expression in myotubes, but not myoblasts after 3 h of stimulation (g). Myoblasts stimulated with LIF for
24 h had reduced Col1a1 expression (j). N = 4 technical replicates per group. Significant findings were verified with biological replicates of experiments from
independent cultures. * Indicates significantly different from control, # indicates significantly different from TGFβ1-stimulated, and Φ indicates significantly
different from LIF-stimulated at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. Source data are provided as a Source Data file Fig. 7 LIF inhibits fibrogenesis and TGFβ1-induced Ctgf expression in muscle cells. a TA muscle sections were co-labeled with antibodies to Pax7 (red) and
HSP47 (green) in WT BMT/mdx (a) and LIF BMT/mdx (b) recipients. Nuclei appear blue (DAPI). Bars = 5 μm. c Fewer Pax7+ cells co-expressed HSP47 in
LIF BMT/mdx recipients (green symbols) compared to WT BMT/mdx recipients (black symbols). d Muscle sections were also co-labeled with antibodies
to Pax7 and fibrogenic marker Ertr7 to confirm that fewer Pax7+ cell acquired a fibrogenic phenotype in LIF BMT/mdx recipients. N = 5 for each data set,
except n = 4 for WT BMT/mdx Pax7/HSP47 data set, * indicates significantly different from WT BMT/mdx at P < 0.05. P-values based on two-tailed t-test. For all histograms in the figure, the bars indicate mean ± sem. e–j Myoblasts (black symbols) and myotubes (green symbols) were stimulated with LIF (10
ng/ml) and TGFβ1 (10 ng/ml) for 3- (e–g) or 24-h (h–j). e, h LIF inhibited TGFβ1-induced Ctgf mRNA in myoblasts and myotubes after 3- and 24-h of
stimulation. LIF inhibited basal Ctgf expression in myotubes at 24 h (h). f, i LIF did not affect Fn1 expression in myoblasts or myotubes after 3- or 24-h. Additionally, LIF attenuated TGFβ1-induced Col1a1 expression in myotubes, but not myoblasts after 3 h of stimulation (g). Myoblasts stimulated with LIF for
24 h had reduced Col1a1 expression (j). N = 4 technical replicates per group. Significant findings were verified with biological replicates of experiments from
independent cultures. * Indicates significantly different from control, # indicates significantly different from TGFβ1-stimulated, and Φ indicates significantly
different from LIF-stimulated at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. Source data are provided as a Source Data file whether regeneration was affected in CD11b/LIF BMT recipients. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 There were no significant differences in TA muscle weight, total
muscle fiber number, proportions of regenerating fibers or muscle
fiber size (Fig. 9a–d). No muscle fibers expressed dMHC in WT
BMT/mdx or LIF BMT/mdx mice. Additionally, QPCR assays
showed no effect of CD11b/LIF on expression of the myogenic
transcription factors: Pax7, Myod1, Myog, or Mrf4 (Fig. 9e). These
data indicate that the CD11b/LIF transgene did not influence
processes through which immune cells modulate regeneration in
mdx muscle. whether regeneration was affected in CD11b/LIF BMT recipients. There were no significant differences in TA muscle weight, total
muscle fiber number, proportions of regenerating fibers or muscle
fiber size (Fig. 9a–d). No muscle fibers expressed dMHC in WT
BMT/mdx or LIF BMT/mdx mice. Additionally, QPCR assays
showed no effect of CD11b/LIF on expression of the myogenic
transcription factors: Pax7, Myod1, Myog, or Mrf4 (Fig. 9e). These
data indicate that the CD11b/LIF transgene did not influence
processes through which immune cells modulate regeneration in
mdx muscle. recipients that is responsive to the magnitude and site of
inflammation. This system also permits long-term delivery of
therapeutic molecules following a single therapeutic intervention. Although tissues were analyzed 4 months following transplanta-
tion in the present investigation, at that time circulating leukocyte
populations were nearly 87% donor-derived. However, in humans
experiencing BMT, stable mixed chimerism can persist for years
in peripheral blood cell populations48,49, showing that long-term
benefits to humans can result from a single transplantation. The potential therapeutic advantage of targeting therapeutic
molecules to diseased tissue by using transgenes under control of
the CD11b promoter is emphasized by comparing our findings
with the outcomes of previous strategies to deliver LIF via
hematopoietic cell transplantation. Transplantation of a hema-
topoietic cell line in which the cells were multiply-transduced
with a retroviral construct containing cDNA encoding LIF pro-
duced high systemic levels of LIF and killed the recipient
mice50,51. In those experiments the retrovirus-transplant reci-
pients reached serum LIF concentrations at 1400 units/ml,
although serum LIF was undetectable in mice transplanted with
cells that did not contain the LIF expressing retrovirus50,51. This NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Significant findings were verified with biological replicates of experiments from
independent cultures. * Indicates significantly different from control, # indicates significantly different from TGFβ1-stimulated, and Φ indicates significantly
different from LIF-stimulated at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. Source data are provided as a Source Data file a b c d FN
Relative expression
Veh TGFβ1
LIF TGFβ1+
LIF
1.5
1.0
0.5
0.0
f 15
CTGF
#φ
#φ
#
#
10
5
1.5
Relative expression
1.0
0.5
0.0
Veh TGFβ1
LIF TGFβ1+
LIF
e COL1
#
Veh TGFβ1
LIF TGFβ1+
LIF
Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
Myoblasts
Myotubes
g e g FN
φ
#
Relative expression
Veh TGFβ1
LIF TGFβ1+
LIF
2
1
0
i CTGF
#φ
#φ
#
#
30
20
10
2.0
1.5
Relative expression
1.0
0.5
0.0
Veh TGFβ1
LIF TGFβ1+
LIF
h COL1
φ φ
#
#
Veh TGFβ1
LIF TGFβ1+
LIF
Relative expression
1.5
2.0
1.0
0.5
0.0
j Fig. 7 LIF inhibits fibrogenesis and TGFβ1-induced Ctgf expression in muscle cells. a TA muscle sections were co-labele Fig. 7 LIF inhibits fibrogenesis and TGFβ1-induced Ctgf expression in muscle cells. a TA muscle sections were co-labeled with antibodies to Pax7 (red) and
HSP47 (green) in WT BMT/mdx (a) and LIF BMT/mdx (b) recipients. Nuclei appear blue (DAPI). Bars = 5 μm. c Fewer Pax7+ cells co-expressed HSP47 in
LIF BMT/mdx recipients (green symbols) compared to WT BMT/mdx recipients (black symbols). d Muscle sections were also co-labeled with antibodies
to Pax7 and fibrogenic marker Ertr7 to confirm that fewer Pax7+ cell acquired a fibrogenic phenotype in LIF BMT/mdx recipients. N = 5 for each data set,
except n = 4 for WT BMT/mdx Pax7/HSP47 data set, * indicates significantly different from WT BMT/mdx at P < 0.05. P-values based on two-tailed t-test. For all histograms in the figure, the bars indicate mean ± sem. e–j Myoblasts (black symbols) and myotubes (green symbols) were stimulated with LIF (10
ng/ml) and TGFβ1 (10 ng/ml) for 3- (e–g) or 24-h (h–j). e, h LIF inhibited TGFβ1-induced Ctgf mRNA in myoblasts and myotubes after 3- and 24-h of
stimulation. LIF inhibited basal Ctgf expression in myotubes at 24 h (h). f, i LIF did not affect Fn1 expression in myoblasts or myotubes after 3- or 24-h. Discussion
h
l a QPCR analysis
shows that TA muscles from LIF BMT/mdx recipients have reduced Pdgfra gene expression. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets,
respectively, * indicates significantly different from WT BMT/mdx recipients at P < 0.05. P-values based on two-tailed t-test. For all histograms in the
figure, the bars indicate mean ± sem. b To quantify the number of FAPs, muscle sections were co-labeled with antibodies to PDGFRα (red) and CD31, CD45
(green). Arrowheads indicate FAPs (CD31-CD45-PDGFRα+). Bar = 50 μm. c Fewer FAPs (CD31-CD45-PDGFRα+) in TA cross-sections of LIF BMT/mdx
recipients compared to WT BMT/mdx recipients. N = 5 for each data set. d There was no detectible change in phenotype of PDGFRα+ cells assayed for
co-expression of the fibrogenic marker HSP47. e FACS plots demonstrating strategy for sorting FAPs (Hoechst + CD11b-CD31-CD45-PDGFRα+). Fibroblasts derived from FAPs were stimulated with LIF (10 ng/ml) and/or TGFβ1 (10 ng/ml) for 3 h (f–h) or 3 days (i–k) and assayed by QPCR for Ctgf
(f, i), Fn1 (g, j), and Col1a1 (h, k). N = 4 technical replicates for each data set. Significant findings were verified with biological replicates of cells sorted from
independent donors. * Indicates significantly different from control cultures, # indicates significantly different from TGFβ1 treated cultures, and Φ indicates
significantly different from LIF-treated cultures at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. Discussion
h
l Source data are provided as
a Source Data file 40
20
0
(HSP47+/PDGFRα+)
×100
WT BMT/mdx
LIF BMT/mdx
d FAPs
5000
4000
3000
2000
1000
0
CD31–/CD45–/PDGFRα+
(cells/mm3)
c b Relative expression
1.5
2.0
1.0
0.5
0.0
PDGFRα
a d b c SSC-A
105
104
103
102
–102
–403
0
102
103
104
105
M
Hoechst CD11b/31/45 FITC
105
104
103
–1173
0
102
103
FAPs (lin- PDGFRα+)
PDGFRα PeCy7
104
105
M SSC-A
105
104
103
102
–102
50
100
150
200
250
(×1000)
–403
0
M
e
FSC-A e e CD11b/31/45 FITC Relative expression
1.5
1.0
0.5
0.0
Veh
TGFβ1
LIF
Fβ1+LIF
COL1
h Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
Veh
TGFβ1
LIF
GFβ1+LIF
FN
g Relative expression
Veh
TGFβ1
LIF
Fβ1+LIF
3
2
1
0
CTGF
#
φ
f h f h g Relative expression
1.5
1.0
0.5
0.0
Veh
TGFβ1
LIF
TGFβ1+LIF
T
COL1
k Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
Relative expression
1.5
1.0
0.5
0.0
Relative expression
1.5
1.0
0.5
0.0
T
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
T
T
CTGF
FN
COL1
#
φ
i
j
k k Fig. 8 Transplantation of CD11b/LIF transgenic BMCs reduces the numbers of FAPs in dystrophic muscle but does not affect phenotype. a QPCR analysis
shows that TA muscles from LIF BMT/mdx recipients have reduced Pdgfra gene expression. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets,
respectively, * indicates significantly different from WT BMT/mdx recipients at P < 0.05. P-values based on two-tailed t-test. For all histograms in the
figure, the bars indicate mean ± sem. b To quantify the number of FAPs, muscle sections were co-labeled with antibodies to PDGFRα (red) and CD31, CD45
(green). Arrowheads indicate FAPs (CD31-CD45-PDGFRα+). Bar = 50 μm. c Fewer FAPs (CD31-CD45-PDGFRα+) in TA cross-sections of LIF BMT/mdx
recipients compared to WT BMT/mdx recipients. N = 5 for each data set. d There was no detectible change in phenotype of PDGFRα+ cells assayed for
co-expression of the fibrogenic marker HSP47. e FACS plots demonstrating strategy for sorting FAPs (Hoechst + CD11b-CD31-CD45-PDGFRα+). Fibroblasts derived from FAPs were stimulated with LIF (10 ng/ml) and/or TGFβ1 (10 ng/ml) for 3 h (f–h) or 3 days (i–k) and assayed by QPCR for Ctgf
(f, i), Fn1 (g, j), and Col1a1 (h, k). Discussion
h
l The results of our investigation demonstrate that transplantation
of genetically-modified BMCs provides a means to deliver ther-
apeutic molecules to dystrophic muscle. In addition, by regulating
the expression of the therapeutic transgene with the CD11b
promoter, LIF delivery can be modified by the stages of
maturation and activation of innate immune cells that differ-
entiate from BMCs. This strategy provides a mechanism for the
endogenous regulation of transgene expression by the transplant NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications 10 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Relative expression
SSC-A
1.5
2.0
1.0
0.5
0.0
105
40
FAPs
5000
4000
3000
2000
1000
0
20
0
(HSP47+/PDGFRα+)
×100
CD31–/CD45–/PDGFRα+
(cells/mm3)
WT BMT/mdx
LIF BMT/mdx
PDGFRα
Relative expression
Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
ession
2.5
2.0
Relative expression
1.5
1.0
0.5
0.0
ession
1.5
1.0
ession
1.5
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
3
2
1
0
CTGF
FN
COL1
CTGF
FN
COL1
#
φ
φ
104
103
102
–102
50
100
150
200
250
(×1000)
–403
0
SSC-A
105
104
103
102
–102
–403
0
CD11b/31/45 FITC
105
104
103
–1173
0
M
102
103
104
105
102
103
FAPs (lin- PDGFRα+)
PDGFRα PeCy7
104
105
M
M
a
e
f
g
h
i
j
k
b
c
d
FSC-A
Hoechst Relative expression
SSC-A
1.5
2.0
1.0
0.5
0.0
105
40
FAPs
5000
4000
3000
2000
1000
0
20
0
(HSP47+/PDGFRα+)
×100
CD31–/CD45–/PDGFRα+
(cells/mm3)
WT BMT/mdx
LIF BMT/mdx
PDGFRα
Relative expression
Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
Relative expression
2.5
1.5
2.0
1.0
0.5
0.0
Relative expression
1.5
1.0
0.5
0.0
Relative expression
1.5
1.0
0.5
0.0
Relative expression
1.5
1.0
0.5
0.0
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
Veh
TGFβ1
LIF
TGFβ1+LIF
3
2
1
0
CTGF
FN
COL1
CTGF
FN
COL1
#
#
φ
φ
104
103
102
–102
50
100
150
200
250
(×1000)
–403
0
SSC-A
105
104
103
102
–102
–403
0
CD11b/31/45 FITC
105
104
103
–1173
0
M
102
103
104
105
102
103
FAPs (lin- PDGFRα+)
PDGFRα PeCy7
104
105
M
M
a
e
f
g
h
i
j
k
b
c
d
FSC-A
Hoechst
Fig. 8 Transplantation of CD11b/LIF transgenic BMCs reduces the numbers of FAPs in dystrophic muscle but does not affect phenotype. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Source data are provided as a Source Data file stages of the disease1,2,29. In addition to increasing the production
of connective tissue proteins, TGFβ can also influence muscle
fibrosis by promoting the differentiation of myofibroblasts from
muscle55,56 and by increasing the expression of other profibrotic
growth factors, especially CTGF53,54. Our finding that LIF
reduced or prevented the TGFβ-mediated induction of Ctgf
expression in muscle cells may be particularly significant in mdx
pathology because reductions in Ctgf expression can significantly
slow pathology57. Thus, our in vitro and in vivo data collectively
indicate that increases in LIF diminish fibrosis of dystrophic
muscle by opposing the profibrotic influence of TGFβ on
muscle cells. contrasts with the delivery system we employ, in which elevated
LIF production was detectible within inflammatory lesions in
dystrophic muscle and pathology was reduced, but LIF remained
undetectable in the sera. This indicates that more precise tem-
poral and spatial delivery of LIF is necessary for safe and bene-
ficial therapeutic application. p
pp
Exogenous LIF has been reported previously to increase the
growth of dystrophic muscle fibers19,20, but we did not observe an
effect of the CD11b/LIF transgene on muscle mass or fiber size in
transgenic mice or in CD11b/LIF BMT recipients. These differ-
ences in outcome may reflect the different modes of LIF delivery,
in which increased fiber size resulted from continuous delivery of
high concentrations of exogenous LIF19,20. However, we found
that transplantation of CD11b/LIF transgenic BMCs affected mdx
muscle by decreasing muscle fibrosis, consistent with the treat-
ment effect achieved by delivery of exogenous LIF19,20,52. In part,
the anti-fibrotic influences of the CD11b/LIF transgene were
attributable to modifying the phenotype of satellite cells, reflected
in the reduced proportion of satellite cells that expressed detec-
tible levels of the collagen chaperone, HSP47, and expressed
ERTR7, a connective tissue protein expressed by pro-fibrotic
satellite cells40. This is functionally important in the context of
DMD pathology because the transition of satellite cells from an
HSP47−/ERTR7−to an HSP47+/ERTR7+ phenotype reflects a
reduction in their myogenic capacity and an increase in their
production of connective tissue proteins that may exacerbate the
pathology of muscular dystrophy33 and lead to a reduction in the
regenerative capacity of muscle over time40. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Mass ratio
Total fibers
Regen fibers
WT BMT/mdx
LIF BMT/mdx
2
4000
60
40
20
0
3000
2000
2000
2500
CSA
3
2
1
0
Pax7
MyoD Myogenin
Mrf4
1000
1000
1500
500
0
0
Muscle mass/
body mass
Fiber X-se area (μm2)
Relative expression
Fiber number
Central nucleated fibers
(% total)
1
0
WT BMT/mdx
LIF BMT/mdx
a
b
c
d
e
Fig. 9 Transplantation of CD11b/LIF transgenic BMCs does not affect muscle growth or regeneration. Assays of muscle mass to body mass ratio (a), fiber
number (b), proportion of centrally-nucleated regenerating fibers (c), and muscle fiber cross-sectional area (d) indicate no difference in muscle growth or
regeneration between WT BMT/mdx and LIF BMT/mdx recipients. N = 5 per group. For all histograms in the figure, the bars indicate mean ± sem. e QPCR
analysis shows no difference in the expression of myogenic transcription factors (Pax7, Myod1, Myog, and Mrf4) in WT BMT/mdx versus LIF BMT/mdx
recipients. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets, respectively. No significant differences were identified between groups at P < 0.05,
determined by two-tailed t-test. Source data are provided as a Source Data file Mass ratio
2
Muscle mass/
body mass
1
0
a Total fibers
4000
3000
2000
1000
0
Fiber number
b Regen fibers
WT BMT/mdx
LIF BMT/mdx
60
40
20
0
Central nucleated fibers
(% total)
c b a c 2000
2500
CSA
1000
1500
500
0
Fiber X-se area (μm2)
d 3
2
1
0
Pax7
MyoD Myogenin
Mrf4
Relative expression
WT BMT/mdx
LIF BMT/mdx
e d e Fig. 9 Transplantation of CD11b/LIF transgenic BMCs does not affect muscle growth or regeneration. Assays of muscle mass to body mass ratio (a), fiber
number (b), proportion of centrally-nucleated regenerating fibers (c), and muscle fiber cross-sectional area (d) indicate no difference in muscle growth or
regeneration between WT BMT/mdx and LIF BMT/mdx recipients. N = 5 per group. For all histograms in the figure, the bars indicate mean ± sem. e QPCR
analysis shows no difference in the expression of myogenic transcription factors (Pax7, Myod1, Myog, and Mrf4) in WT BMT/mdx versus LIF BMT/mdx
recipients. N = 7 or 8 for WT BMT/mdx and LIF BMT/mdx data sets, respectively. No significant differences were identified between groups at P < 0.05,
determined by two-tailed t-test. Discussion
h
l N = 4 technical replicates for each data set. Significant findings were verified with biological replicates of cells sorted from
independent donors. * Indicates significantly different from control cultures, # indicates significantly different from TGFβ1 treated cultures, and Φ indicates
significantly different from LIF-treated cultures at P < 0.05. P-values based on ANOVA with Tukey’s multiple comparison test. Source data are provided as
a Source Data file 11 11 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Some of the immunomodulatory effects achieved by trans-
plantation of CD11b/LIF transgenic cells reflect the effects of
transgene expression within the diseased muscle. For example,
Socs3 expression was significantly elevated in muscles of mice that
received CD11b/LIF BMT, although expression of the transgene
in macrophages in vitro did not affect the expression of Socs3. LIF
can increase Socs3 expression in multiple cell types62 and elevated
expression or activity of Socs3 in macrophages can strongly
influence their phenotype and cytokine production. In vivo
models of inflammation show that siRNA-silencing of SOCS3 or
targeted deletion of SOCS3 in macrophages can either promote63
or oppose64 the M1-biased phenotype. In experimental perito-
nitis, SOCS3 mRNA silencing in macrophages caused elevated
expression of the M2 phenotypic markers Il10, Mrc1, and Arg164,
which is consistent with the inverse relationship we observed
between elevated Socs3 expression in CD11b/LIF BMT recipients
and reduced expression of Il10, Arg2, and Mrc1. Together, these
observations suggest that the shift of CD11b/LIF macrophages
away from an M2-biased phenotype in mdx BMT recipients may
result, in part, from LIF induction of Socs3 after the transgenic
macrophages enter the diseased muscle. However, some of the
treatment effects that we observed may have resulted from
immunomodulatory roles of the transgene that occurred before
their invasion into the pathological muscle. Our finding that
isolated BMCs from CD11b/LIF mice showed greatly reduced
levels of Cd163 and Arg1 expression as they differentiated to
macrophages in vitro shows that some autocrine influences of the
transgene on macrophage gene expression do not require locali-
zation of the cells in the dystrophic muscle. This contrasts with
the reduced expression of TGFβ in intramuscular macrophages of
CD11b/LIF BMT recipients that did not occur in transgenic
macrophages in vitro. The reduction in arginase expression in
CD11b/LIF transgenic macrophages may be particularly impor-
tant in the pathophysiology of muscular dystrophy because
arginine metabolism by arginase increases proline production
which is necessary for collagen synthesis and contributes sig-
nificantly to increased fibrosis in mdx muscles during progressive
stages of pathology23. p
p
yp
Collectively, our findings show that expression of a CD11b/LIF
transgene in BMDCs can disrupt multiple processes that con-
tribute to fibrosis of dystrophic muscle, including affecting
macrophage recruitment, phenotype and production of pro-
fibrotic cytokines and enzymes, in addition to preventing the
fibrogenic conversion of satellite cells and reducing numbers of
FAPs (Fig. 10). NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Monocytes/
macrophages
LIF
LIF
LIF
LIF
FAPs
Intramuscular
macrophages
Pro-fibrotic
macrophages
2
1
3
4
Increased arginase expression
Increased TGFβ expression
Myogenic
muscle cells
Fibrogenic
muscle cells
Fibrosis
Fibrosis
Fibrosis
Fig. 10 Potential immunomodulatory and anti-fibrotic actions of LIF expressed by the CD11b/LIF transgene in muscular dystrophy. (1) LIF can serve an
immunomodulatory role by reducing the expression of Ccl2 in macrophages, which is associated with reduced recruitment of monocytes/macrophages into
dystrophic muscle. (2) LIF can serve an immunomodulatory role by reducing the activation of monocytes/macrophages to a CD163+, M2-biased
phenotype that can increase fibrosis of dystrophic muscle. (3) LIF can reduce the expression of the pro-fibrotic molecules Arg1 and Tgfb1 in macrophages. (4) LIF can reduce the TGFβ1-mediated induction of pro-fibrotic genes in muscle cells, including Ctgf and Col1a1 Monocytes/
macrophages Increased TGFβ expression Fig. 10 Potential immunomodulatory and anti-fibrotic actions of LIF expressed by the CD11b/LIF transgene in muscular dystrophy. (1) LIF can serve an
immunomodulatory role by reducing the expression of Ccl2 in macrophages, which is associated with reduced recruitment of monocytes/macrophages into
dystrophic muscle. (2) LIF can serve an immunomodulatory role by reducing the activation of monocytes/macrophages to a CD163+, M2-biased
phenotype that can increase fibrosis of dystrophic muscle. (3) LIF can reduce the expression of the pro-fibrotic molecules Arg1 and Tgfb1 in macrophages. (4) LIF can reduce the TGFβ1-mediated induction of pro-fibrotic genes in muscle cells, including Ctgf and Col1a1 characteristic of type 2 immunity; much of the lethality of DMD
is attributable to fibrosis of cardiac and respiratory muscles. Thus,
by modulating the numbers and phenotype of macrophages in
dystrophic muscle, LIF can produce broad effects on muscle
pathology. established that signaling through CCR2 is a primary mechanism
for recruiting macrophages to diseased or injured muscle by
showing that blockade or deletion of CCR2 greatly reduces
macrophage entry into injured muscle27,45,47. We found that
CD11b/LIF BMT decreased expression of CCR2 ligands in muscle
and reduced the numbers of macrophages that expressed CCL2. Those reductions were also associated with large reductions in
total numbers of F4/80+ intramuscular macrophages, including
CD206+ and CD163+ macrophages. Thus, much of the anti-
inflammatory effect of the transgene may occur through disrup-
tion of CCR2-mediated signaling, leading to reduced numbers of
intramuscular macrophages and impairing their activation to a
pro-fibrotic, M2-biased phenotype. NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 The observation that the CD11b/LIF BMT reduced TGFβ1
expression
in
intramuscular
macrophages
without
causing
reductions in total TGFβ1 expression in whole muscle also
indicates the specificity of targeting treatment effects that are
achieved by the CD11b/LIF transgene. This may provide advan-
tages over other experimental and therapeutic approaches that
have been explored previously to reduce fibrosis of dystrophic
muscle by inhibiting TGFβ1 expression or activity through
pharmacological approaches1,3,58,59. While those pharmacologi-
cal approaches are technically straight-forward and effective at
reducing fibrosis in dystrophic muscle, their systemic adminis-
tration does not provide delivery specifically to sites of inflam-
mation, and increases the risks of off-target effects. Although CD11b/LIF BMT reduced pathological changes in
satellite cells, we found that some beneficial effects of CD11b/LIF
transgenic cells are attributable to modulation of the inflamma-
tory response, rather than direct actions on muscle (Fig. 10). Despite the fact that DMD and mdx dystrophy result from
mutations that cause loss of the membrane-associated structural
protein, dystrophin, and lead to a mechanically-weaker muscle
cell membrane60,61, most muscle fiber damage results from lysis
caused by myeloid cells, especially macrophages expressing
inducible nitric oxide synthase (iNOS) that are biased toward the
M1, pro-inflammatory phenotype7,26. However, as the disease
progresses, macrophages in dystrophic muscle shift to a CD163
+/CD206+ phenotype that increases muscle fibrosis23 and is g
p
y
Although the CD11b/LIF transgene reduced the expression of
pro-fibrotic molecules by muscle cells in CD11b/LIF BMT reci-
pients in vivo, LIF did not reduce the basal level of expression of
genes encoding connective tissue proteins by muscle cells in vitro. Instead, we found that LIF reduced the activation of pro-fibrotic
genes in myoblasts that was induced by the cytokine TGFβ. TGFβ
has broad, profibrotic effects by increasing the expression of
major,
connective
tissue
proteins,
including
collagen
and
fibronectin53,54,
and
reductions
in
TGFβ
can
significantly
decrease fibrosis of dystrophin-deficient muscle, at least at early TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications 12 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 However, we believe that the more broadly-
significant finding in our investigation is that our data show that
genetically-modified BMCs can be used as vectors to deliver
therapeutic genes to dystrophic muscle. This approach is
applicable not only to LIF, but may provide a more specific tar-
geting strategy for the numerous gene products that have been
previously identified as potentially-useful, therapeutic molecules
for DMD. ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 488 (1:200, 30 min at RT, Abcam, #ab102260) and horse anti-rabbit IgG Dylight
594 (1:200, 30 min at RT, Vector, #DI-1094) or horse anti-goat IgG Dylight 594
(1:200, 30 min at RT, Vector, #DI-3094). Sections were then washed with PBS and
mounted with Prolong Gold mounting media (Invitrogen). line is maintained as hemizygous to produce transgenic mice and wild-type,
littermate controls for experimentation. Mice were randomly allocated to
experimental groups. WT or CD11b/LIF BMCs were transplanted into mdx mice
assigned non-sequential identification numbers. Investigators collecting data and
performing analysis were aware of animal numbers only and were blinded to
treatment groups. g
g
g
For identification of CCR2+ macrophages, sections were fixed with 4% PFA for
10 min and then incubated with blocking buffer for 1 h. Sections were then labeled
with rabbit anti-mouse CCR2 (1:50, Abcam, clone E68) and rat anti-mouse CD68
or rat anti-mouse CD206 at 4 °C overnight. Sections were washed with PBS and
then incubated with donkey anti-rat IgG Dylight 594 (1:200, 30 min at RT, Abcam,
#ab102262) and horse anti-rabbit IgG Dylight 488 (1:200, 30 min at RT, Vector,
#DI-1088). CD11b/LIF mdx transgenic mice were produced by crossing CD11b/LIF
hemizygous males with mdx females to generate CD11b/LIF hemizygous,
transgenic mice that were also dystrophin-deficient (CD11b/LIF mdx). Dystrophin-
deficient status was verified by ARMS PCR screening65 and presence of the
hCD11b/LIF construct was determined as described above. The CD11b/LIF mdx
mice were backcrossed with wild-type mdx mice for 7 generations to produce
CD11b/LIF mdx mice that were dystrophin-deficient and either hemizygous or
wild-type controls for the CD11b/LIF transgene. For identification of fibrogenic satellite cells, sections were fixed in 2%
paraformaldehyde for 10 min. Slides were then immersed in antigen retrieval buffer
(10 mM sodium citrate, 0.05% Tween-20, pH 6) at 95–100 °C for 40 min, except for
sections undergoing Pax7/Ertr7 co-labeling this step was omitted. Sections were
then treated with blocking buffer from a mouse-on-mouse immunohistochemistry
kit (M.O.M. kit; Vector) for 1 h and immunolabeled with mouse anti-Pax7 and
rabbit anti-HSP47 (1:200, Abcam, #77609) or anti-Ertr7 (1:1000, SCBT, #SC-
73355) overnight at 4 °C. Anti-Pax7 was purified from hybridoma cell supernatant
(Developmental Studies Hybridoma Bank, Iowa City, Iowa)68. Sections were
washed with PBS and then incubated with horse anti-mouse IgG Dylight 594
(1:200, 30 min at RT, Vector, DI-2594) and horse anti-rabbit IgG Dylight 488
(1:200, 30 min at RT). ARTICLE The number of cells per volume of muscle was determined by mea-
suring the total volume of each section using a stereological, point-counting
technique to determine section area and then multiplying that value by the section
thickness (10 μm)7. The numbers of immunolabeled cells in each section were
counted and expressed as the number of cells per unit volume of each section. RNA was isolated from FACS sorted cells by first sorting cells directly into
Buffer RLT RNA lysis buffer (Qiagen). RNA was isolated using a Qiagen RNeasy
Micro Kit according to the manufacturer’s protocol. RNA yield was quantified
using a BioDrop μLite. RNA (50 ng/reaction) was reverse transcribed using a
qScript XLT cDNA Supermix (QuantaBio). QPCR experiments were performed on
a QuantStudio 5 Real-Time PCR System (Thermo Fisher) with PerfeCTa SYBR
Green Supermix, Low Rox (QuantaBio)13. Assays for fiber number, central nucleation, and size. TA muscles were sec-
tioned at the midbelly of muscles and used for fiber cross-sectional area mea-
surements5. The proportion of fibers containing central nuclei, an indicator of fiber
regeneration, was also determined. Central-nucleation was expressed as the ratio of
central nucleated fibers relative to the entire population of fibers sampled for each
muscle. The cross-sectional areas of >300 muscle fibers were measured using a
digital imaging system (BioQuant). Immunohistochemistry. Muscles dissected from euthanized mice were frozen in
liquid nitrogen-cooled isopentane. Cross-sections 10-µm thick were taken from the
mid-belly of muscles and fixed in ice-cold acetone or 2% paraformaldehyde for 10
min. Endogenous peroxidase activity in the sections was quenched by immersion in
0.3% H2O2. Most sections were blocked for 1 h with blocking buffer (3% bovine
serum albumin (BSA), 2% gelatin, and 0.05% Tween-20 in 50 mM Tris–HCl pH 7.6
containing 150 mM NaCl). Alternatively, sections were incubated with 10% horse
serum in PBS with 0.1% Tween-20 or mouse-on-mouse blocking reagent (M.O.M. kit; Vector) for sections to be incubated with primary antibodies from goat or
mouse origin, respectively. ARTICLE Sections were then incubated with: rat anti-mouse F4/80
(1:100, overnight at 4 °C, eBioscience, clone BM8), rat anti-mouse CD68 (1:100, 3 h
at room temperature (RT), AbD Serotec, clone FA-11), rabbit anti-mouse CD163
(1:100, 3 h at RT, Santa Cruz Biotech, clone M-96), rat anti-mouse CD206 (1:50, 3
h at RT, AbD Serotec, clone MR5D3), rat anti-CD4 (1:25, overnight at 4 °C,
Biolegend, clone GK1.5), rat anti-Ly-6B.2 (1:25, 2 h at RT, Bio-Rad, clone 7/4),
rabbit anti-collagen type 1 (1:50, 3 h at RT, Chemicon, #AB745), goat anti-collagen
type 3 (1:50, 3 h at RT, Southern Biotech #1330-01), goat anti-collagen type 5 (1:50,
overnight at 4 °C, Southern Biotech, #1350-01), goat anti-LIF (1:66, overnight at 4 °
C, R&D Systems, #AB-449), and mouse anti-developmental myosin heavy chain
(1:100, overnight at 4 °C, Novacastra, #106304). The sections were washed with
phosphate buffered saline (PBS) and probed with biotin-conjugated secondary
antibodies (1:200, 30 min at RT, Vector Laboratories). Sections were then washed
with PBS and incubated with avidin D-conjugated HRP (1:1000, 30 min at RT,
Vector). Staining was visualized with the peroxidase substrate, 3-amino-9-
ethylcarbazole (Vector). Assay of muscle connective tissue content. The volume fraction of muscle that
was occupied by collagen types 1, 3, and 5 was determined by overlaying a 10 × 10
eye-piece grid on microscopic images of cross-sections of entire muscle that were
immunolabeled with antibodies to collagen types 1, 3, or 5. Assay of muscle connective tissue content. The volume fraction of muscle that
was occupied by collagen types 1, 3, and 5 was determined by overlaying a 10 × 10
eye-piece grid on microscopic images of cross-sections of entire muscle that were
immunolabeled with antibodies to collagen types 1, 3, or 5. Preparation of BMMCs and BMDMs. BMMCs were separated from whole BMC
preparations flushed from WT or CD11b/LIF femurs and tibiae and separated
using a histopaque-1077 gradient (Sigma). The freshly-isolated BMMCs were then
used for RNA isolation and analysis. For preparation of BMDMs, BMCs were
aseptically flushed from WT or CD11b/LIF femurs and tibiae and differentiated
in vitro to BMDMs24. BMDMs were stimulated for 24 h with activation media
consisting of Dulbecco’s Modified Eagle Medium (DMEM) with 0.25% heat-
inactivated fetal bovine serum (FBS; Omega), 100 U/ml penicillin, 100 µg/ml
streptomycin (1% P/S), and 10 ng/ml macrophage colony stimulating factor
(MCSF; R&D). ELISA analysis of BMDM conditioned media. ARTICLE Bone marrow transplantation. Beginning 1 week prior to BMT, mouse drinking
water was supplemented with trimethoprim/sulfamethoxazole (80 μg/ml tri-
methoprim and 400 μg/ml sulfamethoxazole) and continued for 3 weeks. Two-
month-old female mdx mice underwent myeloablative preconditioning via intra-
peritoneal injections of 1,4-butanediol dimethanesulfonate (Sigma-Aldrich) (20
mg/kg body weight) 72-, 48-, and 24-h prior to BMT. On the day of transplan-
tation, male WT and CD11b/LIF donor mice were euthanized and their femur and
tibia bones were sterilely dissected and flushed of BMCs. BMCs were isolated and
recipient mice received 107 donor BMCs by tail-vein injection. At 4 months post-
BMT, tissues and BMCs were collected from recipient mice. BMCs were used for
chimerism analysis by fluorescent in situ hybridization of the Y-chromosome
(Kreatech FISH Probes). For identification of FAPs, sections were fixed in ice-cold acetone for 10 min
and then incubated with blocking buffer for 1 h. Sections were then labeled with rat
anti-mouse CD31 conjugated with FITC (1:50, eBioscience, clone 390), rat anti-
mouse CD45 conjugated with FITC (1:100, eBioscience, clone 30-F11), and goat
anti-PDGFRα (1:100, R&D Systems, #AF1062) at 4 °C overnight. Sections were
washed with PBS and then incubated with horse anti-goat IgG Dylight 594 (1:200,
30 min at RT, Vector). RNA isolation and QPCR. RNA was isolated from muscle homogenates and
reverse transcribed to produce cDNA24. QPCR experiments were designed using
established guidelines for experimental design, data normalization and data ana-
lysis to maximize the rigor of quantifying the relative levels of mRNA13,66,67. The
expression for each gene in control samples was set to 1 and the other expression
values were then scaled to that value. PCR primers are listed in Supplementary
Table 1. For identification of fibrogenic PDGFRα+ cells, sections were fixed in ice-cold
acetone for 10 min and then incubated with blocking buffer for 1 h. Sections were
then labeled with rabbit anti-mouse HSP47 (1:100, ABcam, clone EPR4217) and
goat anti-PDGFRα at 4 °C overnight. Sections were washed with PBS and then
incubated with horse anti-goat IgG Dylight 594 (1:200, 30 min at RT) and horse
anti-rabbit IgG Dylight 488 (1:200, 30 min at RT). Cultured cells were washed twice with ice-cold DPBS and collected in Trizol
(Invitrogen). RNA was extracted and isolated with chloroform extraction and
isopropyl alcohol precipitation, followed by clean-up with an RNA Clean and
Concentrator Kit (Zymo Research). Total RNA was quantified, reverse transcribed,
and used for QPCR13. Stereology. Methods
Mi
ll Mice. All experimentation complied with all relevant ethical regulations for animal
testing and research, and the study protocol was approved by the Chancellor’s
Animal Research Committee at the University of California, Los Angeles. C57BL/
10ScSn-Dmdmdx/J mice (mdx mice) were purchased from The Jackson Laboratory
(Bar Harbor, ME) and bred in pathogen-free vivaria. Mdx mice were selected for
use in these experiments instead of more rapidly progressive models of DMD
because the goal of our investigation is to test our hypothesis that transplantation
of genetically-modified BMCs provides a novel therapeutic strategy for muscular
dystrophy. If we used a rapidly, progressive mouse model, such as the mdx/utr−
mouse line in which the mice die at 2–3 months of age, we would be unable to
assay for treatment effects achieved by bone marrow transplantation because the
mice would die before enough time passed for sufficient BMC engraftment and
then for the transplanted cells to mediate their therapeutic effects. In preparation for generating CD11b/LIF mice, the complete Mus musculus LIF
cDNA sequence (611-bp; NM_008501) was amplified by PCR and ligated into a
pGL3-Basic vector (Promega) at the Nco I/Xba I sites. The pGL3-Basic vector
contained a 550-bp fragment of the human CD11b promoter at the Hind III site,
upstream of the LIF insertion site. The 1215-bp, hCD11b/LIF fragment was isolated
from pGL3-Basic by restriction endonuclease digestion with Xho I/Xba I and used
for pronuclear injection into CB6F1 eggs to generate transgenic mice. Positive
founders were identified by PCR screening for presence of the hCD11b/LIF
construct and backcrossed with C57BL/6J mice for 7 generations. The hCD11b/LIF g
p
gy
The immunomodulatory influences of the transgene extend
beyond autocrine effects on macrophage phenotype, because the
muscles of CD11b/LIF BMC recipients showed large reductions
in the expression of ligands for CCR2. Previous investigators 13 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications ARTICLE ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 concentration of each cytokine was determined by comparing the optical density of
the samples to the standard curve. concentration of each cytokine was determined by comparing the optical density of
the samples to the standard curve. fiber length (Lf). To measure elasticity, the muscle was left unstimulated while the
lever arm oscillated at ±20% of the Lf for 20 s. Muscles were allowed to rest for 60 s
before subsequent oscillation series. Muscles were allowed to rest for 60 s before a
series of oscillations at 3 Hz, which provides a physiological strain and strain rate70. Dynamic Muscle Control and Dynamic Muscle Analysis (Aurora Scientific) soft-
ware was used to conduct experiments and record data. Force measurements were
normalized to muscle cross-sectional area, and position measurements were nor-
malized to percent of Lf. fiber length (Lf). To measure elasticity, the muscle was left unstimulated while the
lever arm oscillated at ±20% of the Lf for 20 s. Muscles were allowed to rest for 60 s
before subsequent oscillation series. Muscles were allowed to rest for 60 s before a
series of oscillations at 3 Hz, which provides a physiological strain and strain rate70. Dynamic Muscle Control and Dynamic Muscle Analysis (Aurora Scientific) soft-
ware was used to conduct experiments and record data. Force measurements were
normalized to muscle cross-sectional area, and position measurements were nor-
malized to percent of Lf. ELISA analysis of serum. Whole blood was collected from the femoral artery and
allowed to clot on ice for at least 30 min. The whole blood was spun for 10 min at
2000×g at 4 °C. The serum was collected and stored in liquid nitrogen until ana-
lyzed for circulating LIF, TNFα, IFNγ, IL-4, and IL-10 by ELISA, according to
manufacturer’s instructions (R&D Systems, Quantikine ELISAs, #MLF00,
MTA00B, MIF00, M4000B, and M1000B). Each group contained 3 replicates. Statistical analyses. All data are presented as mean ± sem. Statistical significance
was calculated using unpaired Student’s t-tests or ordinary one-way ANOVA with
Tukey’s multiple comparison test to determine differences among multiple groups. Differences with a P-value < 0.05 were considered statistically significant. The
equality of variance between the groups that are being compared was tested with an
F test, experiments with a P-value < 0.05 are denoted in the figure legend. Addi-
tionally, for immunohistochemistry and immunofluorescence experiments, slides
were only included if concurrently immunolabeled. References 1. Nelson, C. A. et al. Inhibiting TGF-β activity improves respiratory function in
mdx mice. Am. J. Pathol. 178, 2611–2621 (2011). 2. Andreetta, F. et al. Immunomodulation of TGF-beta 1 in mdx mouse inhibits
connective tissue proliferation in diaphragm but increases inflammatory
response: implications for antifibrotic therapy. J. Neuroimmunol. 175, 77–86
(2006). MPCs were isolated from 14-months-old CD11b/LIF mdx mice and littermate
controls. Hindlimb and forelimb muscles were dissected and digested as described
for FAPs isolation. Isolated cells were resuspended in staining buffer with CD16/32
for 10 min to block Fc receptor binding. Cells were labeled with cell impermeant
dye DAPI (Sigma) to distinguish live cells and antibodies against CD11b, CD31,
and CD45 conjugated with FITC and Sca-1 conjugated with PE-Cy5 (eBioscience
#15-5981; 0.2 µg/test), integrin α7 conjugated with PE (Medical and Biological
Laboratories #K0046-5; 15 µl/test). Live MPCs (DAPI-CD11b/31/45-Sca1-α7int+)
were sorted into Buffer RLT RNA lysis buffer (Qiagen) using a FACSAriaIII high
speed cell sorter. 3. Taniguti, A. P. T., Pertille, A., Matsumura, C. Y., Santo Neto, H. & Marques,
M. J. Prevention of muscle fibrosis and myonecrosis in mdx mice by suramin,
a TGF-β1 blocker. Muscle Nerve 43, 82–87 (2011). 4. Bogdanovich, S. et al. Functional improvement of dystrophic muscle by
myostatin blockade. Nature 420, 418–421 (2002). myostatin blockade. Nature 420, 418–421 (2002). 5. Wehling-Henricks, M. et al. Klotho gene silencing promotes pathology in the
mdx mouse model of Duchenne muscular dystrophy. Hum. Mol. Genet. 25,
2465–2482 (2016). 6. Straub, V., Rafael, J. A., Chamberlain, J. S. & Campbell, K. P. Animal models
for muscular dystrophy show different patterns of sarcolemmal disruption. J. Cell Biol. 139, 375–385 (1997). Primary fibroblast cell culture. Sorted FAPs were cultured in growth medium
(DMEM, 20% FBS, 10% heat-inactivated horse serum, 1% P/S and 2.5 ng/ml bFGF)
on tissue culture plates coated with Matrigel41. After plating, cells were cultured for
3 days and half the medium was changed. Cells were expanded and subcultured. Prior to stimulation, cells were cultured in reduced serum media overnight
(DMEM, 2% FBS, 1% P/S, and 2.5 ng/ml bFGF). Fibrogenic cell cultures were
stimulated with vehicle, TGFβ1 (10 ng/ml), LIF (10 ng/ml), or TGFβ1 + LIF for 3 h
or 3 days (with media changes at 24- and 48-h). 7. Wehling, M., Spencer, M. J. & Tidball, J. G. A nitric oxide synthase transgene
ameliorates muscular dystrophy in mdx mice. J. Cell Biol. 155, 123–131
(2001). 8. Spencer, M. Data availability
Th
h
d
l
h The authors declare that the data supporting the findings of this study are available
within the paper and its Supplementary Information files. The source data pertaining to
Figs. 1a–c, 2a, d, f, g, i, j, m, p–r, 3a, b, e, h, k, l, 4a–f, h, 5g, j, k, 6a, d, e, 7c–f, 9a–d, f and
Supplementary Figs. 1a, 1b, 1c, 1d, 2a, 2b, 3a, 3b, 3c, 3d, 4a, 4b, 4c, 5b, 5c, 5d, 5e, and 5f
are provided as a Source Data file. Received: 22 June 2018 Accepted: 22 May 2019 ARTICLE Statistical analysis was per-
formed using GraphPad Prism. Assays for LIF effects on muscle cell fibrogenesis. The C2C12 cell line was
purchased from American Type Culture Collection (ATCC CRL-1772 cell line). The cells were authenticated as myoblasts by confirming their differentiation into
contractile myotubes that express characteristic muscle proteins. Cells were seeded
in six-well plates at 6 × 104 cells per well and cultured in DMEM containing 10%
FBS, 1% P/S at 37 °C in 5% CO2 for 24 h and then serum-starved overnight prior to
stimulation. To generate myotubes, myoblasts were grown to 90% confluence and
then differentiated in serum-free DMEM for 24 h. The cells were then returned to
DMEM containing 10% FBS for 5 days. Myoblast and myotube cultures were
stimulated with vehicle, TGFβ1 (10 ng/ml), LIF (10 ng/ml), or TGFβ1 + LIF for 3-
or 24-h. Reporting summary. Further information on research design is available in
the Nature Research Reporting Summary linked to this article. FAPs and myogenic progenitor cell preparation and isolation. FAPs were iso-
lated from 6-month-old WT mice. Hindlimb and forelimb muscles were dissected
and rinsed in DMEM. Muscles were minced and digested in 5 ml of enzyme buffer
(DMEM, 25 mM HEPES (Sigma), 5 mM MgCl2 (Fisher), 2% P/S, 12.5 U dispase,
type II, 12.5 U collagenase B, and 20 μg/ml DNase I (Roche)) for 60 min at 37 °C
with gentle trituration. The digestion was neutralized with 2 volumes of staining
buffer (DMEM, 10 mM NaHCO3 (EMD Millipore), 25 mM HEPES, 5 mM EDTA,
5 mM MgCl2, 1 mM L-glutamine, 2% BSA, and 2% P/S). The digestate was passed
through 100 μm mesh filters and cells were pelleted at 350g for 5 min. Cells were
resuspended in ACK lysis buffer (Lonza) for 5 min followed by the addition of an
equal volume of staining buffer and cells were pelleted at 350g for 5 min. Cells were
resuspended in staining buffer with CD16/32 (eBioscience #14-0161-85; 0.5 µg/test)
for 10 min to block Fc receptor binding. Cells were labeled with Hoechst (Sigma
#14533) and antibodies against CD11b (eBioscience #11-0112; 0.25 µg/test), CD31
(eBioscience #11-0311; 0.5 µg/test) and CD45 (eBioscience #11-0451; 0.1 µg/test)
conjugated with FITC and PDGFRα conjugated with PE-Cy7 (eBioscience #25-
1401; 0.2 µg/test). FAPs (Hoechst + CD11b/31/45-PDGFRα+) were sorted into
collection buffer (DMEM, 10 mM NaHCO3 and 20% FBS) using a BD SORP
FACSAriaII cell sorter. References J., Walsh, C. M., Dorshkind, K. A., Rodriguez, E. M. & Tidball, J. G. Myonuclear apoptosis in dystrophic mdx muscle occurs by perforin-
mediated cytotoxicity. J. Clin. Invest. 99, 2745–2751 (1997). 9. Spencer, M. J., Montecino-Rodriguez, E., Dorshkind, K. & Tidball, J. G. Helper
(CD4(+)) and cytotoxic (CD8(+)) T cells promote the pathology of
dystrophin-deficient muscle. Clin. Immunol. 98, 235–243 (2001). Physiological analysis. We assayed muscle stiffness and viscoelasticity at
14 months of age because connective tissue accumulation in mdx muscle is pro-
gressive between 3 and 24 months of age. We expected that if we sampled for
effects of the transgene on muscle stiffness during the late, progressive stage of the
disease, the magnitude of the effect would be greater, which would enable us to
address more definitively the question of whether the transgene influenced muscle
stiffness. Male WT/mdx and LIF/mdx mice were anesthetized by the intraper-
itoneal (i.p.) injection of ketamine (40 mg/kg body weight). Anesthesia was checked
by testing mice for a positive reflex response to a hind foot pinch and by mon-
itoring respiration. Additional i.p. injections of ketamine were given throughout
the study, as needed. For in-situ analysis of the TA muscle the knee was immo-
bilized to the heated (37 °C) platform of an 809C in-situ mouse apparatus (Aurora
Scientific). Silk sutures (5-0; Ethicon) were knotted to the distal, severed tendon
and then secured to the lever arm of a dual-mode force transducer-servomotor
(Aurora Scientific, Model 305C-5N). After placing platinum-tipped electrodes into
the leg above the knee, flanking the sciatic nerve, the TA muscle was stimulated by
pulses and manipulated on three axes to find the optimal muscle length (Lo). Lo
was multiplied by the pennation of 0.6 for the TA muscle69 to determine optimal 10. Cai, B., Spencer, M. J., Nakamura, G., Tseng-Ong, L. & Tidball, J. G. Eosinophilia of dystrophin-deficient muscle is promoted by perforin-mediated
cytotoxicity by T cell effectors. Am. J. Pathol. 156, 1789–1796 (2000). 11. Hodgetts, S., Radley, H., Davies, M. & Grounds, M. D. Reduced necrosis of
dystrophic muscle by depletion of host neutrophils, or blocking TNFalpha
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muscle after mild damage J Neurol Sci 135 10 17 (1996) 11. Hodgetts, S., Radley, H., Davies, M. & Grounds, M. D. NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunicatio ARTICLE Cultures of BMDM from WT mice
were established as described above. On the 6th day of culture, the BMDMs were
switched to DMEM containing 1% P/S, 0.25% heat-inactivated FBS, and M-CSF or
media containing 10 ng/ml recombinant mouse LIF (eBioscience) (stimulation
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dystrophic muscle by depletion of host neutrophils, or blocking TNFalpha
function with Etanercept in mdx mice. Neuromuscul. Disord. 16, 591–602 (2006). function with Etanercept in mdx mice. Neuromuscul. Disord. 16, 591–602 (2006). 12. Gorospe, J. R., Nishikawa, B. K. & Hoffman, E. P. Recruitment of mast cells to
muscle after mild damage. J. Neurol. Sci. 135, 10–17 (1996). 12. Gorospe, J. R., Nishikawa, B. K. & Hoffman, E. P. Recruitment of mast cells to
muscle after mild damage. J. Neurol. Sci. 135, 10–17 (1996). 13. Villalta, S. A., Deng, B., Rinaldi, C., Wehling-Henricks, M. & Tidball, J. G. IFN-γ promotes muscle damage in the mdx mouse model of Duchenne
muscular dystrophy by suppressing M2 macrophage activation and inhibiting
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dystrophy by deactivating M1 macrophages and modulating macrophage
phenotype. Hum. Mol. Genet. 20, 790–805 (2011). 15 TURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications Acknowledgements Hybridoma Bank, created by the NICHD of the NIH and maintained at The University of
Iowa, Department of Biology, Iowa City, IA 52242, USA. ARTICLE 12, 143–152 (2010). 16 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunicatio ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-019-10614-1 Additional information 70. Bellardita, C. & Kiehn, O. Phenotypic characterization of speed-associated gait
changes in mice reveals modular organization of locomotor networks. Curr. Biol. 25, 1426–1436 (2015). Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-
019-10614-1. Acknowledgements Reprints and permission information is available online at http://npg.nature.com/
reprintsandpermissions/ g
Research reported in this publication was supported by the National Institute of Arthritis and
Musculoskeletal and Skin Diseases of the National Institutes of Health under Award
Numbers F32AR065845 (to S.S.W.), F31AR071783 (to I.F.), F32AR071233 (to J.R.), and
RO1AR066036, RO1AR062579, and R21AR066817 (to J.G.T.). The content is solely the
responsibility of the authors and does not necessarily represent the official views of the
National Institutes of Health. Flow cytometry was performed in the UCLA Jonsson Com-
prehensive Cancer Center (JCCC) and Center for AIDS Research Flow Cytometry Core
Facility that is supported by National Institutes of Health awards P30 CA016042 and 5P30
AI028697, and by the JCCC, the UCLA AIDS Institute, the David Geffen School of Medicine
at UCLA, the UCLA Chancellor’s Office, and the UCLA Vice Chancellor’s Office of
Research. Confocal laser scanning microscopy was performed at the California NanoSystems
Institute Advanced Light Microscopy/Spectroscopy Shared Resource Facility at UCLA. DNA
microinjections for the production of the CD11b/LIF transgenic mice were performed at the
University of California, Irvine Transgenic Mouse Facility. The Pax7 hybridoma developed
by T.M. Jessell, Columbia University, was obtained from the Developmental Studies
Hybridoma Bank, created by the NICHD of the NIH and maintained at The University of
Iowa, Department of Biology, Iowa City, IA 52242, USA. Peer review information: Nature Communications thanks the anonymous reviewers for
their contribution to the peer review of this work. Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations. Open Access This article is licensed under a Creative Commons
Attribution 4.0 International License, which permits use, sharing,
adaptation, distribution and reproduction in any medium or format, as long as you give
appropriate credit to the original author(s) and the source, provide a link to the Creative
Commons license, and indicate if changes were made. The images or other third party
material in this article are included in the article’s Creative Commons license, unless
indicated otherwise in a credit line to the material. If material is not included in the
article’s Creative Commons license and your intended use is not permitted by statutory
regulation or exceeds the permitted use, you will need to obtain permission directly from
the copyright holder. To view a copy of this license, visit http://creativecommons.org/
licenses/by/4.0/. Author contributions S.S.W., M.W.-H., I.F., and J.G.T. conceived and designed the experiments. S.S.W.,
M.W.-H., I.F., C.B., J.R., and Y.W. performed the experiments. S.S.W., I.F., and J.G.T. analyzed the data and wrote the manuscript. © The Author(s) 2019 © The Author(s) 2019 17 NATURE COMMUNICATIONS | (2019) 10:2788 | https://doi.org/10.1038/s41467-019-10614-1 | www.nature.com/naturecommunications
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Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size
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Chen Song1,2,3, Kristian Sandberg1,4,5, Lau Møller Andersen4,6, Jakob Udby Blicher4 and Geraint Rees1,2 Chen Song1,2,3, Kristian Sandberg1,4,5, Lau Møller Andersen4,6, Jakob Udby Blicher4 and Geraint Rees1,2 1Institute of Cognitive Neuroscience, University College London, London WC1N 3AR, UK
2Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK
3Department of Psychiatry, University of Wisconsin - Madison, Madison 53719 WI, USA
4Center of Functionally Integrative Neuroscience, Aarhus University, 8000 Aarhus C, Denmark
5Hammel Neurorehabilitation and Research Centre, Aarhus University Hospital, 8450 Hammel, Denmark
6NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden Author contributions: C.S., K.S., and G.R. designed research; C.S., K.S., L.M.A., and J.B. performed
research; C.S., K.S., L.M.A., and J.B. contributed unpublished reagents/analytic tools; C.S., K.S., L.M.A., and
J.B. analyzed data; C.S., K.S., L.M.A., J.B., and G.R. wrote the paper. his Accepted Manuscript has not been copyedited and formatted. The final version may differ from this version. his Accepted Manuscript has not been copyedited and formatted. The final version may differ from this version. This Accepted Manuscript has not been copyedited and formatted. The final version may differ from this version. Research Articles: Behavioral/Cognitive DOI: 10.1523/JNEUROSCI.3945-16.2017 Department of Psychiatry, University of Wisconsin - Madison, Madison
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4. Center of Functionally Integrative Neuroscience, Aarhus University, 80
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5. Hammel Neurorehabilitation and Research Centre, Aarhus University H
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6. NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, 1
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* These two authors contributed equally. 19
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Correspondence:
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Chen Song
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Institute of Cognitive Neuroscience
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University College London
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London WC1N 3AR
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UK
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chen.song.09@ucl.ac.uk
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OR
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Kristian Sandberg
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Center of Functionally Integrative Neuroscience
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Aarhus University
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8000 Aarhus C
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Denmark
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krissand@rm.dk
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Abbreviated title: Selective influence of GABA on visual perception
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Number of pages: 17
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Number of figures: 5
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Number of words for Abstract: 230
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Number of words for Introduction: 529
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Number of words for Discussion: 1003
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Conflict of interest: None
51
52
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Acknowledgements: We thank Dr. Jamie Near and Dr. Peter Jezzard at FM
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providing the Magnetic Resonance Spectroscopy (MRS) sequence used in
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supported by the Brain Research Trust (CS), the Danish Ministry of Scien
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UNIK program (KS), and the Wellcome Trust (GR). 57 DOI: 10.1523/JNEUROSCI.3945-16.2017 Received: 23 December 2016
Revised: 27 April 2017
Accepted: 3 May 2017 Published: 21 August 2017 Author contributions: C.S., K.S., and G.R. designed research; C.S., K.S., L.M.A., and J.B. performed
research; C.S., K.S., L.M.A., and J.B. contributed unpublished reagents/analytic tools; C.S., K.S., L.M.A., and
J.B. analyzed data; C.S., K.S., L.M.A., J.B., and G.R. wrote the paper. Conflict of Interest: The authors declare no competing financial interests. We thank Dr. Jamie Near and Dr. Peter Jezzard at FMRIB, Oxford University, UK for providing the Magnetic
Resonance Spectroscopy (MRS) sequence used in the current study. The study was supported by the Brain
Research Trust (CS), the Danish Ministry of Science, Technology and Innovation's UNIK program (KS), and the
Wellcome Trust (GR). We thank Dr. Jamie Near and Dr. Peter Jezzard at FMRIB, Oxford University, UK for providing the Magnetic
Resonance Spectroscopy (MRS) sequence used in the current study. The study was supported by the Brain
Research Trust (CS), the Danish Ministry of Science, Technology and Innovation's UNIK program (KS), and the
Wellcome Trust (GR). Correspondence: Chen Song, Institute of Cognitive Neuroscience, University College London, London WC1N
3AR, UK, chen.song.09@ucl.ac.uk, OR Kristian Sandberg, Center of Functionally Integrative Neuroscience,
Aarhus University, 8000 Aarhus C, Denmark, krissand@rm.dk Correspondence: Chen Song, Institute of Cognitive Neuroscience, University College London, London WC1N
3AR, UK, chen.song.09@ucl.ac.uk, OR Kristian Sandberg, Center of Functionally Integrative Neuroscience,
Aarhus University, 8000 Aarhus C, Denmark, krissand@rm.dk Cite as: J. Neurosci ; 10.1523/JNEUROSCI.3945-16.2017 Cite as: J. Neurosci ; 10.1523/JNEUROSCI.3945-16.2017 Alerts: Sign up at www.jneurosci.org/cgi/alerts to receive customized email alerts when the fully formatted
version of this article is published. Alerts: Sign up at www.jneurosci.org/cgi/alerts to receive customized email alerts when the fully formatted
version of this article is published. Accepted manuscripts are peer-reviewed but have not been through the copyediting, formatting, or proofreading
process. Copyright © 2017 Song et al. Copyright © 2017 Song et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license, which
permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed. Human occipital and parietal GABA selectivel
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perception of orientation and size
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Chen Song1,2,3,*, Kristian Sandberg1,4,5,*, Lau Møller Andersen4,6, Jakob Ud
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1. Institute of Cognitive Neuroscience, University College London, Londo
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2. Wellcome Trust Centre for Neuroimaging, University College London,
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3. Human occipital and parietal GABA selectively influence visual
1
perception of orientation and size
2
3 perception of orientation and size
2
3
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Chen Song1,2,3,*, Kristian Sandberg1,4,5,*, Lau Møller Andersen4,6, Jakob Udb
5
6
1. Institute of Cognitive Neuroscience, University College London, London
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2. Wellcome Trust Centre for Neuroimaging, University College London, L
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3. Department of Psychiatry, University of Wisconsin - Madison, Madison
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4. Center of Functionally Integrative Neuroscience, Aarhus University, 800
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5. Hammel Neurorehabilitation and Research Centre, Aarhus University Ho
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6. NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, 17
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* These two authors contributed equally. 19
20
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Correspondence:
22
23
Chen Song
24
Institute of Cognitive Neuroscience
25
University College London
26
London WC1N 3AR
27
UK
28
chen.song.09@ucl.ac.uk
29
30
OR
31
32
Kristian Sandberg
33
Center of Functionally Integrative Neuroscience
34
Aarhus University
35
8000 Aarhus C
36
Denmark
37
krissand@rm.dk
38
39
40
Abbreviated title: Selective influence of GABA on visual perception
41
42
43
Number of pages: 17
44
Number of figures: 5
45
Number of words for Abstract: 230
46
Number of words for Introduction: 529
47
Number of words for Discussion: 1003
48
49
50
Conflict of interest: None
51
52
53
Acknowledgements: We thank Dr. Jamie Near and Dr. Peter Jezzard at FMR
54
providing the Magnetic Resonance Spectroscopy (MRS) sequence used in t
55
supported by the Brain Research Trust (CS), the Danish Ministry of Science
56
UNIK program (KS), and the Wellcome Trust (GR). 57 Acknowledgements: We thank Dr. Jamie Near and Dr. Peter Jezzard at FMRIB, Oxford University, UK for
54
providing the Magnetic Resonance Spectroscopy (MRS) sequence used in the current study. The study was
55
supported by the Brain Research Trust (CS), the Danish Ministry of Science, Technology and Innovation's
56
UNIK program (KS), and the Wellcome Trust (GR). 57 1 ABSTRACT
58 Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in human brain. GABA level
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varies substantially across individuals and this variability is associated with inter-individual differences in visual
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perception. However, it remains unclear whether the association between GABA level and visual perception
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reflects a general influence of visual inhibition, or whether GABA level of different cortical regions selectively
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influences perception of different visual features. To address this, we studied how GABA level in parietal and
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occipital cortices related to inter-individual differences in size, orientation, and brightness perception, in a group
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of healthy young male participants. We used visual contextual illusion as a perceptual assay, since it dissociates
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perceptual content from stimulus content and its magnitude reflects the effect of visual inhibition. Across
66
individuals, we observed selective correlations between GABA level and the magnitude of contextual illusion. 67
Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness
68
illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with
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size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA
70
level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size
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and orientation preference in which neural responses to sizes or orientations are modualted by intra-regional
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lateral connections. We propose that these lateral connections may underlie the selective influence of GABA
73
level on visual feature perception. 74 SIGNIFICANCE STATEMENT
75 Gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in human visual system, varies
76
substantially across individuals and this variability is linked to inter-individual differences in many aspects of
77
visual perception. The widespread influence of GABA raises the question of whether inter-individual variability
78
in GABA reflects an overall variability in visual inhibition and has a general influence on visual perception, or
79
whether GABA level of different cortical regions has selective influence on perception of different visual
80
features. Here we report a region- and feature-dependent influence of GABA level on human visual perception. 81
Our findings suggest that GABA level of a cortical region selectively influences perception of visual features
82
that are topographically mapped in this region through intra-regional lateral connections. 83 Gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in human visual system, varies
76
substantially across individuals and this variability is linked to inter-individual differences in many aspects of
77
visual perception. The widespread influence of GABA raises the question of whether inter-individual variability
78
in GABA reflects an overall variability in visual inhibition and has a general influence on visual perception, or
79
whether GABA level of different cortical regions has selective influence on perception of different visual
80
features. Here we report a region- and feature-dependent influence of GABA level on human visual perception. 81
Our findings suggest that GABA level of a cortical region selectively influences perception of visual features
82
that are topographically mapped in this region through intra-regional lateral connections. 83 2 The inhibitory neurotransmitter Gamma-aminobutyric acid (GABA) plays a central role in visual processing
85
ranging from neural selectivity and neural response gain control, to synaptic plasticity and network oscillation
86
(Katzner et al., 2011; Lehmann et al., 2012; Priebe et al., 2008). GABA level (measured using Magnetic
87
Resonance Spectroscopy) varies substantially across human individuals and this variability may contribute to
88
inter-individual differences in visual processing and visual perception. Indeed, a higher GABA level is
89
associated with higher visual discrimination ability, lower susceptibility to distraction, stronger surround
90
suppression and stronger interocular suppression (Edden et al., 2009; Lunghi et al., 2015; Sandberg et al., 2014;
91
Sandberg et al., 2016; Vanloon et al., 2013; Yoon et al., 2010). This wide range of observations raises the question of whether inter-individual variability in GABA reflects an
95
overall variability in visual inhibition and has a general influence on visual perception, or whether GABA level
96
of different cortical regions has selective influence on perception of different visual features. One hypothesis is
97
that, GABA level of each cortical region is uniquely determined in each individual, possibly by a combination
98
of genetic and environmental factors (Bachtiar et al., 2015; Lunghi et al., 2015; Marenco et al., 2010; Taniguchi
99
et al., 2011). As such, GABA level of different cortical regions may exhibit dissociable inter-individual
100
variability and influence perception of different visual features separately. An alternative hypothesis is that,
101
GABA level of different cortical regions may co-vary as a result of common embryonic origins or shared
102
subcortical GABAergic projections (Caputi et al., 2013; Chen et al., 2015; Dammerman et al., 2000; Jinno et al.,
103
2007; Picardo et al., 2011), and may influence perception of different visual features concurrently. 104 This wide range of observations raises the question of whether inter-individual variability in GABA reflects an
95
overall variability in visual inhibition and has a general influence on visual perception, or whether GABA level
96
of different cortical regions has selective influence on perception of different visual features. One hypothesis is
97
that, GABA level of each cortical region is uniquely determined in each individual, possibly by a combination
98
of genetic and environmental factors (Bachtiar et al., 2015; Lunghi et al., 2015; Marenco et al., 2010; Taniguchi
99
et al., 2011). As such, GABA level of different cortical regions may exhibit dissociable inter-individual
100
variability and influence perception of different visual features separately. An alternative hypothesis is that,
101
GABA level of different cortical regions may co-vary as a result of common embryonic origins or shared
102
subcortical GABAergic projections (Caputi et al., 2013; Chen et al., 2015; Dammerman et al., 2000; Jinno et al.,
103
2007; Picardo et al., 2011), and may influence perception of different visual features concurrently. 104 To test these two alternative hypotheses, we studied how GABA level of parietal and occipital cortices related to
105
inter-individual differences in size, orientation, and brightness perception. SIGNIFICANCE STATEMENT
75 Moreover, in neurological disorders such as
92
attention-deficit / hyperactivity disorder and schizophrenia, both an abnormal level of GABA and an abnormal
93
performance in perceptual tasks are observed (Edden et al., 2012; Moult, 2009; Yoon et al., 2010). 94 Participants
120 Thirty-seven healthy volunteers (aged 20 to 40, all males, females ineligible due to menstrual cycle) gave
121
written informed consent to participate in this study that was approved by the local ethics committee, De
122
Videnskabsetiske Komitéer for Region Midtjylland, Denmark. All participants had normal or corrected-to-
123
normal vision, and no neurological or psychiatric history. The Magnetic Resonance Spectroscopy data of four
124
participants were contaminated by signal from lipids and the psychophysics data of three participants were
125
outliers of the normal distribution (Shapiro-Wilk test). These data were therefore excluded from further analysis. 126 Magnetic resonance spectroscopy measure of GABA
127 Neuroimaging took place in a Siemens Trio 3T MRI scanner. Structural MRI data were acquired using a T1-
128
weighted MPRAGE sequence (TR: 2420 msec; TE: 3.7 msec; resolution: 1 mm isotropic; scanning time: 5.5
129
min) and were used to guide the voxel placement in Magnetic Resonance Spectroscopy (MRS). Resting GABA
130
measures were acquired from a 2 cm isotropic voxel in the parietal lobe (TR: 2500 msec; TE: 68 msec; 240 edit
131
on and edit off averages; scan time: 20 min) and a 3 cm isotropic voxel in the occipital lobe (TR: 2500 msec; TE:
132
68 msec; 96 edit on and edit off averages; scan time: 8 min), using MEGA-PRESS method (Edden et al., 2007;
133
Mescher et al., 1998). To compensate for the size differences between the two voxels, the parietal voxel had a
134
longer scan time (20 min) than the occipital voxel (8 min). An even longer scan time (40 min) could lead to a
135
better compensation, however the subject motion would be a drawback. 136 Neuroimaging took place in a Siemens Trio 3T MRI scanner. Structural MRI data were acquired using a T1-
128
weighted MPRAGE sequence (TR: 2420 msec; TE: 3.7 msec; resolution: 1 mm isotropic; scanning time: 5.5
129
min) and were used to guide the voxel placement in Magnetic Resonance Spectroscopy (MRS). Resting GABA
130
measures were acquired from a 2 cm isotropic voxel in the parietal lobe (TR: 2500 msec; TE: 68 msec; 240 edit
131
on and edit off averages; scan time: 20 min) and a 3 cm isotropic voxel in the occipital lobe (TR: 2500 msec; TE:
132
68 msec; 96 edit on and edit off averages; scan time: 8 min), using MEGA-PRESS method (Edden et al., 2007;
133
Mescher et al., 1998). To compensate for the size differences between the two voxels, the parietal voxel had a
134
longer scan time (20 min) than the occipital voxel (8 min). An even longer scan time (40 min) could lead to a
135
better compensation, however the subject motion would be a drawback. 136 We used a standard resting state protocol where participants had their eyes open and faced the insider of the
137
scanner with no mirrors attached or no visual stimuli presented (Edden et al., 2009; Ogorman et al., 2011). Occipital cortex contains a map of
106
orientation preference in which individual neurons respond preferentially to specific orientation and neighboring
107
neurons to adjacent orientations; by contrast, parietal cortex contains a map of size preference in which
108
individual neuronal populations respond preferentially to specific size of a visually presented object and
109
neighboring neurons to adjacent sizes (Harvey et al., 2015; Yacoub et al., 2007). Since neurotransmitters are
110
contained in and released at synapses, GABA level of a cortical region may influence visual feature perception
111
through lateral connections within the region. These lateral connections link neighboring neurons with similar
112
feature preferences, and underlie contextual illusions where the perceived feature (e.g., orientation, size) of a
113 3 visual stimulus is modulated by the stimulus surrounding it (Bosten et al., 2010; Cannon et al., 1996; Kapadia et
114
al., 1999; Stettler et al., 2002; Song et al., 2013). We therefore used contextual illusion as a perceptual assay,
115
hypothesizing that selective correlation may be observed between GABA level of a cortical region and
116
contextual illusion for visual features topographically mapped in this region. Specifically, parietal and occipital
117
GABA level may correlate selectively with the magnitude of size and orientation illusion. 118 visual stimulus is modulated by the stimulus surrounding it (Bosten et al., 2010; Cannon et al., 1996; Kapadia et
114
al., 1999; Stettler et al., 2002; Song et al., 2013). We therefore used contextual illusion as a perceptual assay,
115
hypothesizing that selective correlation may be observed between GABA level of a cortical region and
116
contextual illusion for visual features topographically mapped in this region. Specifically, parietal and occipital
117
GABA level may correlate selectively with the magnitude of size and orientation illusion. 118 A theoretical model has been proposed to subtract MM
152
contribution post-hoc (Murdoch et al, 2011). Nevertheless, this technique could introduce additional variability
153
into the estimated GABA values, and is thus rarely used (see discussion in Mullins et al., 2014). Newer
154
sequences such as MEGA-SPECIAL (Near et al., 2011) and SPECIAL (Near et al., 2013) aims to remove MM
155
contribution by editing and modelling, respectively. However, both sequences have other drawbacks such as the
156
imperfect lipid suppression. The raw GABA value is subject to bias from day-to-day scanner-related variation. 157
For an unbiased estimate of GABA, a normalization of raw GABA value to Cr is typically applied (Mullins et
158
al., 2012), since Cr resonates around the same frequency (3 ppm) as GABA and is not affected by disturbances
159
that depend on the resonance frequency. The ratio GABA+/Cr was calculated to quantify GABA level. 160 The analysis of MRS data was performed by author JUB who was blind to the psychophysics data, and
161
constituted part of a database that have been reported in previous studies (Near et al., 2014; Sandberg et al.,
162
2014; Sandberg et al., 2016). The MRS data were first preprocessed in MATLAB with FID-A software for
163
motion corruption removal, drift correction and phasing, and then analyzed in jMRUI software with AMARES
164
package (Edden et al., 2007; Mescher et al., 1998; Simpson et al., 2015). Data were visually inspected for noise,
165
line broadening, voxel misplacement and lipid contamination. Four participants who had spectra with large lipid
166
contamination failed to pass the visual inspection and were excluded from further analysis. The quality of the
167
included spectra was evaluated by calculating signal-to-noise ratio (SNR), line width and fit uncertainty. 168 The analysis of MRS data was performed by author JUB who was blind to the psychophysics data, and
161
constituted part of a database that have been reported in previous studies (Near et al., 2014; Sandberg et al.,
162
2014; Sandberg et al., 2016). The MRS data were first preprocessed in MATLAB with FID-A software for
163
motion corruption removal, drift correction and phasing, and then analyzed in jMRUI software with AMARES
164
package (Edden et al., 2007; Mescher et al., 1998; Simpson et al., 2015). Data were visually inspected for noise,
165
line broadening, voxel misplacement and lipid contamination. The MEGA-PRESS method measures GABA concentrations through the acquisition of two spectra: one with an
146
editing pulse targeting the C3-GABA peak at 1.9 ppm (edit on), and one with an editing pulse targeting the
147
water peak on the symmetrical side at 7.5 ppm (edit off). By averaging the two spectra, the Creatine (Cr) peak at
148
3.0 ppm was quantified. By subtracting the two spectra, the C4-GABA peak at 3 ppm was quantified. This C4-
149
GABA peak is often referred to as GABA+, since a coupled macromolecule (MM) resonance at 3 ppm is co-
150
edited and contributes to the measured signal. Due to the limitation of the MEGA-PRESS sequence, the exact
151
MM contribution is difficult to estimate or remove. A theoretical model has been proposed to subtract MM
152
contribution post-hoc (Murdoch et al, 2011). Nevertheless, this technique could introduce additional variability
153
into the estimated GABA values, and is thus rarely used (see discussion in Mullins et al., 2014). Newer
154
sequences such as MEGA-SPECIAL (Near et al., 2011) and SPECIAL (Near et al., 2013) aims to remove MM
155
contribution by editing and modelling, respectively. However, both sequences have other drawbacks such as the
156
imperfect lipid suppression. The raw GABA value is subject to bias from day-to-day scanner-related variation. 157
For an unbiased estimate of GABA, a normalization of raw GABA value to Cr is typically applied (Mullins et
158
al., 2012), since Cr resonates around the same frequency (3 ppm) as GABA and is not affected by disturbances
159
that depend on the resonance frequency. The ratio GABA+/Cr was calculated to quantify GABA level. 160 The MEGA-PRESS method measures GABA concentrations through the acquisition of two spectra: one with an
146
editing pulse targeting the C3-GABA peak at 1.9 ppm (edit on), and one with an editing pulse targeting the
147
water peak on the symmetrical side at 7.5 ppm (edit off). By averaging the two spectra, the Creatine (Cr) peak at
148
3.0 ppm was quantified. By subtracting the two spectra, the C4-GABA peak at 3 ppm was quantified. This C4-
149
GABA peak is often referred to as GABA+, since a coupled macromolecule (MM) resonance at 3 ppm is co-
150
edited and contributes to the measured signal. Due to the limitation of the MEGA-PRESS sequence, the exact
151
MM contribution is difficult to estimate or remove. Magnetic resonance spectroscopy measure of GABA
127 MRS
138
measure of resting GABA varies little across day or even months (Evans et al., 2010; Near et al., 2014). The
139 We used a standard resting state protocol where participants had their eyes open and faced the insider of the
137
scanner with no mirrors attached or no visual stimuli presented (Edden et al., 2009; Ogorman et al., 2011). MRS
138
measure of resting GABA varies little across day or even months (Evans et al., 2010; Near et al., 2014). The
139 We used a standard resting state protocol where participants had their eyes open and faced the insider of the
137
scanner with no mirrors attached or no visual stimuli presented (Edden et al., 2009; Ogorman et al., 2011). MRS
138
measure of resting GABA varies little across day or even months (Evans et al., 2010; Near et al., 2014). The
139 4 high test-retest reliability suggests that the scanning order will not bias the measures. Nevertheless, to minimize
140
the between-subject variance of no interest, we kept the scanning order identical for all participants, collecting
141
data for the occipital voxel first and the parietal voxel second. The parietal voxel was placed on the anterior part
142
of the superior parietal lobe with its anterior border in parallel to the postcentral gyrus. The occipital voxel was
143
placed to cover the calcarine sulcus bilaterally with its anterior border in alignment with the parietal-occipital
144
sulcus. Care was taken to avoid the inclusion of the scalp and/or the tentorium cerebelli in the voxels. 145 Psychophysics measure of contextual illusion
178 The size illusion stimulus comprised two white circles
182
(1° diameter), a reference one surrounded by sixteen small white circles (0.2° diameter) and a test one by seven
183
large white circles (2° diameter), presented simultaneously for 500 msec on two sides of the fixation (3.85°
184
eccentricity) with randomized spatial order. The orientation illusion stimulus comprised two circular gratings
185
(45° orientation, 1.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast), a reference one surrounded by an
186
annular grating (60° orientation, 4.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast) and a test one
187
with no surround. The brightness illusion stimulus comprised two gray circles (50% luminance, 1.5° diameter),
188
a reference one surrounded by white annulus (4.5° diameter) and a test one by black annulus (4.5° diameter). 189 Psychophysics took place in a dark room. Visual stimuli were presented on a 17-inch LCD monitor (spatial
179
resolution: 1024 x 768 pixels; temporal resolution: 60 Hz) and viewed through a chin rest. The magnitudes of
180
size illusion (Ebbinghaus illusion), orientation illusion (tilt illusion), and brightness illusion (simultaneous
181
contrast illusion) were measured in separate experiments. The size illusion stimulus comprised two white circles
182
(1° diameter), a reference one surrounded by sixteen small white circles (0.2° diameter) and a test one by seven
183
large white circles (2° diameter), presented simultaneously for 500 msec on two sides of the fixation (3.85°
184
eccentricity) with randomized spatial order. The orientation illusion stimulus comprised two circular gratings
185
(45° orientation, 1.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast), a reference one surrounded by an
186
annular grating (60° orientation, 4.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast) and a test one
187
with no surround. The brightness illusion stimulus comprised two gray circles (50% luminance, 1.5° diameter),
188
a reference one surrounded by white annulus (4.5° diameter) and a test one by black annulus (4.5° diameter). 189 To minimize the confounding factors such as decision factors (Gold et al., 2012; Vogels et al., 1986), we kept
190
the psychophysical procedures identical for all three illusions. Psychophysics measure of contextual illusion
178 Psychophysics took place in a dark room. Visual stimuli were presented on a 17-inch LCD monitor (spatial
179
resolution: 1024 x 768 pixels; temporal resolution: 60 Hz) and viewed through a chin rest. The magnitudes of
180
size illusion (Ebbinghaus illusion), orientation illusion (tilt illusion), and brightness illusion (simultaneous
181
contrast illusion) were measured in separate experiments. The size illusion stimulus comprised two white circles
182
(1° diameter), a reference one surrounded by sixteen small white circles (0.2° diameter) and a test one by seven
183
large white circles (2° diameter), presented simultaneously for 500 msec on two sides of the fixation (3.85°
184
eccentricity) with randomized spatial order. The orientation illusion stimulus comprised two circular gratings
185
(45° orientation, 1.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast), a reference one surrounded by an
186
annular grating (60° orientation, 4.5° diameter, 2.5 cycles/° spatial frequency, 100% contrast) and a test one
187
with no surround. The brightness illusion stimulus comprised two gray circles (50% luminance, 1.5° diameter),
188
a reference one surrounded by white annulus (4.5° diameter) and a test one by black annulus (4.5° diameter). 189
To minimize the confounding factors such as decision factors (Gold et al., 2012; Vogels et al., 1986), we kept
190
the psychophysical procedures identical for all three illusions. Participants first performed a match-to-standard
191
session in which they manually adjusted the size, orientation, or luminance of the test stimulus till it matched
192
the perceived size, orientation, or luminance of the reference stimulus, and a visual discrimination session in
193
which the size, orientation, and luminance discrimination threshold was measured through a standard 2-up-1-
194
down staircase. The point of subjective equality measured from the match-to-standard session and the visual
195
discrimination threshold measured from the staircase session were used to guide the choices of stimulus
196 Psychophysics took place in a dark room. Visual stimuli were presented on a 17-inch LCD monitor (spatial
179
resolution: 1024 x 768 pixels; temporal resolution: 60 Hz) and viewed through a chin rest. The magnitudes of
180
size illusion (Ebbinghaus illusion), orientation illusion (tilt illusion), and brightness illusion (simultaneous
181
contrast illusion) were measured in separate experiments. Four participants who had spectra with large lipid
166
contamination failed to pass the visual inspection and were excluded from further analysis. The quality of the
167
included spectra was evaluated by calculating signal-to-noise ratio (SNR), line width and fit uncertainty. 168 5 Examples of typical spectra are shown in Fig. 1. SNR was calculated using the difference spectrum following
169
the phase adjustment such that the N-acetylaspartate (NAA) peak was upright with a phase of 0 degree. Signal
170
was calculated as the maximal intensity of the NAA peak in the difference spectrum; noise was calculated as the
171
standard deviation of the noise in the signal-free spectrum, following a baseline correction to remove any 1st
172
and 2nd order baseline variations. SNR was 108 for the parietal voxel and 226 for the occipital voxel. Line
173
width was calculated by measuring the full width at half maximum of the NAA peak in the difference spectrum. 174
Mean line width was 4.8 Hz for the parietal voxel and 5.4 Hz for the occipital voxel. Fit uncertainty was
175
measured as the SD/amplitude ratio output by jMRUI. Mean SD/amplitude ratio was 0.04 for the parietal voxel
176
and 0.03 for the occipital voxel. 177 The data from the two-alternative-forced choice session were fitted with psychometric function to measure the
202
50% threshold point where the two central stimuli appeared perceptually equal despite their physical difference. 203
The goodness-of-fitting (R-square) was 0.963 ± 0.033 for orientation illusion, 0.956 ± 0.041 for size illusion,
204
and 0.960 ± 0.033 for brightness illusion. It did not differ significantly between illusions (size illusion versus
205
orientation illusion: T(29) = 1.03, p = 0.313; size illusion versus brightness illusion: T(29) = 0.47, p = 0.640;
206
orientation illusion versus brightness illusion: T(29) = 0.28, p = 0.785), or correlate significantly with GABA
207
(size illusion and parietal GABA: r = -0.194, p = 0.304; size illusion and occipital GABA: r = 0.143, p = 0.451;
208
orientation illusion and parietal GABA: r = 0.244, p = 0.194; orientation illusion and occipital GABA: r = 0.142,
209
p = 0.456; brightness illusion and parietal GABA: r = -0.224, p = 0.234; brightness illusion and occipital GABA:
210
r = 0.174, p = 0.359). The physical difference between the two central stimuli at the 50% threshold point was
211
calculated to quantify the illusion magnitude. 212 The data from the two-alternative-forced choice session were fitted with psychometric function to measure the
202
50% threshold point where the two central stimuli appeared perceptually equal despite their physical difference. 203
The goodness-of-fitting (R-square) was 0.963 ± 0.033 for orientation illusion, 0.956 ± 0.041 for size illusion,
204
and 0.960 ± 0.033 for brightness illusion. It did not differ significantly between illusions (size illusion versus
205
orientation illusion: T(29) = 1.03, p = 0.313; size illusion versus brightness illusion: T(29) = 0.47, p = 0.640;
206
orientation illusion versus brightness illusion: T(29) = 0.28, p = 0.785), or correlate significantly with GABA
207
(size illusion and parietal GABA: r = -0.194, p = 0.304; size illusion and occipital GABA: r = 0.143, p = 0.451;
208
orientation illusion and parietal GABA: r = 0.244, p = 0.194; orientation illusion and occipital GABA: r = 0.142,
209
p = 0.456; brightness illusion and parietal GABA: r = -0.224, p = 0.234; brightness illusion and occipital GABA:
210
r = 0.174, p = 0.359). The physical difference between the two central stimuli at the 50% threshold point was
211
calculated to quantify the illusion magnitude. Psychophysics measure of contextual illusion
178 Participants first performed a match-to-standard
191
session in which they manually adjusted the size, orientation, or luminance of the test stimulus till it matched
192
the perceived size, orientation, or luminance of the reference stimulus, and a visual discrimination session in
193
which the size, orientation, and luminance discrimination threshold was measured through a standard 2-up-1-
194
down staircase. The point of subjective equality measured from the match-to-standard session and the visual
195
discrimination threshold measured from the staircase session were used to guide the choices of stimulus
196 6 parameters in the subsequent two-alternative-forced choice session. There, participants were asked on 112 trials
197
to judge which central stimulus was larger (for size illusion), more tilted (for orientation illusion), or brighter
198
(for brightness illusion). The size, orientation, or luminance of the reference stimulus was kept constant; that of
199
the test stimulus was varied between seven values (16 trials per value) around the point of subjective equality
200
acquired from match-to-standard session, with a step size equal to visual discrimination threshold. 201 212 7
To account for the influence of Weber’s law (Shen, 2013), we used the log transform of the illusion magnitude
213
and the semi-log plots (Fig. 3~5) to assess inter-individual differences. Since the magnitude of orientation
214
illusion is subject to oblique effect (Clifford, 2014), we performed additional control experiments in a group of
215
twenty healthy volunteers (aged 21 to 35, 11 females) to test the influence of stimulus orientation (cardinal
216
versus oblique) on the measure of inter-individual differences. We found that although the illusion magnitude
217
was weaker for cardinal condition than oblique condition (t(19) = 20.362, p < 10-13), the illusion magnitude were
218
highly correlated between the two conditions (r = 0.866, p < 10-6). This observation suggested that inter-
219
individual differences in orientation illusion magnitude were not biased by oblique effect. 220
Statistics
221
Pearson’s correlation can capture the linearity in the relation between two variables, whereas Spearman’s rank
222
correlation can only reflect whether two variables are monotonically related or not. For example, Spearman’s
223 To account for the influence of Weber’s law (Shen, 2013), we used the log transform of the illusion magnitude
213
and the semi-log plots (Fig. 3~5) to assess inter-individual differences. Since the magnitude of orientation
214
illusion is subject to oblique effect (Clifford, 2014), we performed additional control experiments in a group of
215
twenty healthy volunteers (aged 21 to 35, 11 females) to test the influence of stimulus orientation (cardinal
216
versus oblique) on the measure of inter-individual differences. We found that although the illusion magnitude
217
was weaker for cardinal condition than oblique condition (t(19) = 20.362, p < 10-13), the illusion magnitude were
218
highly correlated between the two conditions (r = 0.866, p < 10-6). This observation suggested that inter-
219 Pearson’s correlation can capture the linearity in the relation between two variables, whereas Spearman’s rank
222
correlation can only reflect whether two variables are monotonically related or not. For example, Spearman’s
223 Pearson’s correlation can capture the linearity in the relation between two variables, whereas Spearman’s rank
222
correlation can only reflect whether two variables are monotonically related or not. RESULTS
234 We found that GABA level in parietal cortex (0.252 ± 0.035) and GABA level in occipital cortex (0.299 ± 0.042)
235
exhibited dissociable inter-individual variability (Fig. 2; r = -0.066, 95% C.I. of r = [-0.372, 0.250], p = 0.730, N
236
= 30). Subsequently, we studied how parietal GABA level versus occipital GABA level contributed to inter-
237
individual differences in size illusion (Ebbinghaus illusion), orientation illusion (tilt illusion), and brightness
238
illusion (simultaneous contrast illusion). 239 We found that GABA level in parietal cortex (0.252 ± 0.035) and GABA level in occipital cortex (0.299 ± 0.042)
235
exhibited dissociable inter-individual variability (Fig. 2; r = -0.066, 95% C.I. of r = [-0.372, 0.250], p = 0.730, N
236
= 30). Subsequently, we studied how parietal GABA level versus occipital GABA level contributed to inter-
237
individual differences in size illusion (Ebbinghaus illusion), orientation illusion (tilt illusion), and brightness
238
illusion (simultaneous contrast illusion). 239 Across individuals, we observed a positive correlation between the magnitude of size illusion and parietal
240
GABA level (Fig. 3; r = 0.395, 95% C.I. of r = [0.117, 0.610], p = 0.031, N = 30). By contrast, we did not
241
observe any significant correlation between the magnitude of size illusion and occipital GABA level (Fig. 3; r =
242
-0.038, 95% C.I. of r = [-0.317, 0.250], p = 0.841, N = 30). Moreover, compared to occipital GABA level,
243
parietal GABA level showed a significantly higher correlation with size illusion magnitude (t(27) = 2.369, p =
244
0.018). These results suggest a selective correlation between size illusion and parietal GABA. 245 Across individuals, we observed a positive correlation between the magnitude of size illusion and parietal
240
GABA level (Fig. 3; r = 0.395, 95% C.I. of r = [0.117, 0.610], p = 0.031, N = 30). By contrast, we did not
241
observe any significant correlation between the magnitude of size illusion and occipital GABA level (Fig. 3; r =
242
-0.038, 95% C.I. of r = [-0.317, 0.250], p = 0.841, N = 30). Moreover, compared to occipital GABA level,
243
parietal GABA level showed a significantly higher correlation with size illusion magnitude (t(27) = 2.369, p =
244
0.018). These results suggest a selective correlation between size illusion and parietal GABA. For example, Spearman’s
223 7 correlation coefficient will return the same result of 1 for two variables that both monotonically increase,
224
regardless of whether their rates of increase are linearly or non-linearly correlated; by contrast, Pearson’s
225
correlation coefficient can capture the difference between these two conditions. As such, Pearson’s correlation
226
coefficient is a more suitable test for studying the difference in correlation coefficient between conditions (e.g.,
227
between size illusion and parietal versus occipital GABA). Application of Pearson’s correlation requires the
228
data to satisfy normal distribution. Shapiro-Wilk test failed to refute the assumption of normality for parietal
229
GABA level (W = 0.952, p = 0.187), occipital GABA level (W = 0.962, p = 0.295), size illusion magnitude (W
230
= 0.937, p = 0.072), orientation illusion magnitude (W = 0.985, p = 0.942), or brightness illusion magnitude (W
231
= 0.960, p = 0.314). Therefore, Pearson’s correlation was used throughout the study to test the relations between
232
variables, with age regressed out. 233 RESULTS
234 255
These results suggest that GABA level does not influence all types of contextual illusion, and its correlation
256
with size or orientation illusion may relate with the way how stimulus size or orientation is cortically processed. 257 For the brightness illusion, we did not observe any significant correlation across individuals between the illusion
251
magnitude and parietal GABA level (Fig. 5; r = -0.149, 95% C.I. of r = [-0.456, 0.163], p = 0.431, N = 30) or
252
occipital GABA level (Fig. 5; r = -0.017, 95% C.I. of r = [-0.377, 0.391], p = 0.927, N = 30). Accordingly, the
253
correlation between parietal GABA level and brightness illusion magnitude was not significantly different from
254
the correlation between occipital GABA level and brightness illusion magnitude (t(27) = 0.690, p = 0.490). 255
These results suggest that GABA level does not influence all types of contextual illusion, and its correlation
256
with size or orientation illusion may relate with the way how stimulus size or orientation is cortically processed. 257 RESULTS
234 245 Conversely, across individuals, the magnitude of orientation illusion exhibited a positive correlation with
246
occipital GABA level (Fig. 4; r = 0.367, 95% C.I. of r = [0.042, 0.599], p = 0.046, N = 30), but not with parietal
247
GABA level (Fig. 4; r = 0.002, 95% C.I. of r = [-0.363, 0.355], p = 0.990, N = 30). Moreover, occipital GABA
248
level correlated with orientation illusion magnitude significantly higher than parietal GABA level did (t(27) =
249
1.990, p = 0.047). These results suggest a selective correlation between orientation illusion and occipital GABA. 250 Conversely, across individuals, the magnitude of orientation illusion exhibited a positive correlation with
246
occipital GABA level (Fig. 4; r = 0.367, 95% C.I. of r = [0.042, 0.599], p = 0.046, N = 30), but not with parietal
247
GABA level (Fig. 4; r = 0.002, 95% C.I. of r = [-0.363, 0.355], p = 0.990, N = 30). Moreover, occipital GABA
248
level correlated with orientation illusion magnitude significantly higher than parietal GABA level did (t(27) =
249
1.990, p = 0.047). These results suggest a selective correlation between orientation illusion and occipital GABA. 250 Conversely, across individuals, the magnitude of orientation illusion exhibited a positive correlation with
246
occipital GABA level (Fig. 4; r = 0.367, 95% C.I. of r = [0.042, 0.599], p = 0.046, N = 30), but not with parietal
247
GABA level (Fig. 4; r = 0.002, 95% C.I. of r = [-0.363, 0.355], p = 0.990, N = 30). Moreover, occipital GABA
248
level correlated with orientation illusion magnitude significantly higher than parietal GABA level did (t(27) =
249
1.990, p = 0.047). These results suggest a selective correlation between orientation illusion and occipital GABA. 250 8 For the brightness illusion, we did not observe any significant correlation across individuals between the illusion
251
magnitude and parietal GABA level (Fig. 5; r = -0.149, 95% C.I. of r = [-0.456, 0.163], p = 0.431, N = 30) or
252
occipital GABA level (Fig. 5; r = -0.017, 95% C.I. of r = [-0.377, 0.391], p = 0.927, N = 30). Accordingly, the
253
correlation between parietal GABA level and brightness illusion magnitude was not significantly different from
254
the correlation between occipital GABA level and brightness illusion magnitude (t(27) = 0.690, p = 0.490). DISCUSSION
258 Taken together, our study reveals a region- and feature-dependent influence of neurotransmitter level on human
259
visual perception. We show that inter-individual variability in parietal GABA level correlated with size illusion
260
magnitude but not with orientation or brightness illusion magnitude; in contrast, inter-individual variability in
261
occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion
262
magnitude. Our findings suggest that inter-individual variability in GABA does not reflect a general variability
263
in visual inhibition; instead, GABA level of different cortical regions has selective influence on perception of
264
different visual features. This influence is likely to be exerted through lateral connections within the cortical
265
region and is observed specifically for visual features mediated by such connections. 266 In occipital cortex, neurons exhibit orientation preference such that their response is the strongest for a preferred
267
orientation and gradually decays as the stimulus orientation deviates from this preferred orientation (Ringach et
268
al., 2002). Neurons preferring adjacent orientations are cortically adjacent to one another and are connected by
269
intra-regional lateral connections (Bock et al., 2011; Li et al., 2012; Yacoub et al., 2007). This topographical
270
organization of lateral connections allows the orientation preference of neurons to be modulated by the activity
271
of their adjacent neurons, and the level of occipital GABA to affect the degree of modulation (Burr et al., 1981;
272
Chavane et al., 2011; Eysel et al., 1990; Fitzpatrick, 2000; Gilbert et al., 1996; Morrone et al., 1987; Smith et al.,
273
2006; Stettler et al., 2002). This neural-level modulation may then give rise to perceptual-level modulation,
274
where the perceived orientation of a stimulus is modulated by the orientation of the stimulus surrounding it
275
(Schwartz et al., 2007; Song et al., 2013). If so, the correlation between orientation illusion magnitude and
276
occipital GABA level could be a perceptual reflection of the link between neural-level modulation and GABA. 277 9 9 Whereas orientation preference is topographically mapped in occipital cortex with neurons preferring more
278
similar orientations being more highly connected, there is no topographic map of size preference in occipital
279
cortex (Chklovskii et al., 2004; Swindale, 2000). As such, a local GABA influence, exerted through lateral
280
connections within occipital cortex, is likely to be specific to orientation illusion and not generalizable to size
281
illusion. DISCUSSION
258 Just as the topographic map of orientation preference is prominent in occipital cortex (Kaschube et al.,
282
2010; Wolf et al., 1998; Yacoub et al., 2007), a topographic map of size preference exists in parietal cortex
283
where individual neuronal populations respond preferentially to specific size and adjacent neurons to adjacent
284
sizes (Harvey et al., 2015). By contrast, there is no map of orientation preference in parietal cortex. Therefore, a
285
local GABA influence, exerted through lateral connections within parietal cortex, would be specific to size
286
illusion and not generalizable to orientation illusion. Similar to the topogrpahical maps of orientation preference
287
and size preference in visual cortices, neurons in the retina exhibit preference for stimulus luminance and are
288
topographically connected by their luminance preference. Possibly, the inter-individual differences in brightness
289
illusions may associate with inter-individual variability in retinal GABA (Lukasiewicz et al., 1998; Wu, 2010). 290
Moreover, since neural responses to visual features are modulated not only by intra-regional lateral connections
291
but also by inter-regional feedback connections (Fitzpatrick, 2000; Smith et al., 2006), the lack of correlation
292
between brightness illusion and occipital or parietal GABA could also indicate a predominant contribution of
293
inter-regional (as opposed to intra-regional) modulation to this illusion (Kinoshita, 2001; Perna et al., 2005). 294 Whereas orientation preference is topographically mapped in occipital cortex with neurons preferring more
278
similar orientations being more highly connected, there is no topographic map of size preference in occipital
279
cortex (Chklovskii et al., 2004; Swindale, 2000). As such, a local GABA influence, exerted through lateral
280
connections within occipital cortex, is likely to be specific to orientation illusion and not generalizable to size
281
illusion. Just as the topographic map of orientation preference is prominent in occipital cortex (Kaschube et al.,
282
2010; Wolf et al., 1998; Yacoub et al., 2007), a topographic map of size preference exists in parietal cortex
283
where individual neuronal populations respond preferentially to specific size and adjacent neurons to adjacent
284
sizes (Harvey et al., 2015). By contrast, there is no map of orientation preference in parietal cortex. Therefore, a
285
local GABA influence, exerted through lateral connections within parietal cortex, would be specific to size
286
illusion and not generalizable to orientation illusion. DISCUSSION
258 Similar to the topogrpahical maps of orientation preference
287
and size preference in visual cortices, neurons in the retina exhibit preference for stimulus luminance and are
288
topographically connected by their luminance preference. Possibly, the inter-individual differences in brightness
289
illusions may associate with inter-individual variability in retinal GABA (Lukasiewicz et al., 1998; Wu, 2010). 290
Moreover, since neural responses to visual features are modulated not only by intra-regional lateral connections
291
but also by inter-regional feedback connections (Fitzpatrick, 2000; Smith et al., 2006), the lack of correlation
292
between brightness illusion and occipital or parietal GABA could also indicate a predominant contribution of
293
inter-regional (as opposed to intra-regional) modulation to this illusion (Kinoshita, 2001; Perna et al., 2005). 294 This account, that GABA level of a cortical region influences perception of visual features topographically
295
mapped in this region, would be able to explain the reported correlations between occipital GABA level and
296
orientation discrimination threshold (Edden et al., 2009). The intra-regional modulation exerted through lateral
297
connections may not only shift the orientation preference of neurons, and give rise perceptual shifts in
298
orientation illusion, but also sharpen the orientation tuning of neurons, and give rise perceptual sharpenings in
299
orientation discrimination (Benyishiai et al., 1995; Orban et al., 1998; Somers et al., 1995; Song et al., 2013;
300
Song et al., 2015). As such, the influence of occipital GABA level on orientation illusion could be mirrored in
301
orientation discrimination (Song et al., 2013). In addition to orientation preference, ocular preference is also
302
topographically mapped in occipital cortex, where individual neurons respond preferentially to stimulus from a
303
specific eye, and adjacent neurons to opposite eyes (Adams et al., 2007; Dechent et al., 2000; Menon et al.,
304
1997). There, lateral connections would link neurons with opposite ocular preference, allowing the influence of
305
occipital GABA on orientation perception to generalize to binocular perception. This would explain the reported
306
decrease in both occipital GABA and interocular suppression after monocular deprivation (Lunghi et al., 2015). 307 10 This account, that GABA level of a cortical region influences perception of visual features topographically
308
mapped in this region, further predicts a correlation between parietal GABA level and numerosity perception. 309
Just as occipital cortex is crucial for processing low-level visual features and contains maps of orientation
310
preference and ocular preference, parietal cortex is important for processing high-level visual features and
311
contains maps of size preference and numerosity preference (Bueti et al., 2009; Chklovskii et al., 2004; Dehaene
312
et al., 2007; Dormal et al., 2008; Harvey et al., 2013; Harvey et al., 2015; Kadosh et al., 2009; Nieder et al.,
313
2009; Pinel et al., 2004; Roitman et al., 2007; Roitman et al., 2012; Walsh, 2003). The lateral connections in
314
parietal cortex are likely to link neighboring neurons with similar numerosity preference, which would allow
315
parietal GABA to influence numerosity discrimination and numerosity illusion (Almeida et al., 2007; Bosten et
316
al., 2010; Dormal et al., 2008; Pinel et al., 2004). Almeida, A., Arantes, J., & Machado, A. (2007). Numerosity discrimination in preschool children. Journal of
327
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functional connectivity by transcranial direct current stimulation. Elife, 4, e08789. 330 Ben-Yishai, R., Bar-Or, R. L., & Sompolinsky, H. (1995). Theory of orientation tuning in visual cortex. 331
Proceedings of the National Academy of Sciences, 92(9), 3844-3848. 332 Ben-Yishai, R., Bar-Or, R. L., & Sompolinsky, H. (1995). Theory of orientation tuning in visual cortex. 331
Proceedings of the National Academy of Sciences 92(9) 3844-3848
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333
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335
research, 50(17), 1656-1664. 336 Bueti, D., & Walsh, V. (2009). The parietal cortex and the representation of time, space, number and other
337
magnitudes. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 364(1525),
338
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340
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342
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344
opinion in neurobiology, 23(2), 179-186. 345 Chavane, F., Sharon, D., Jancke, D., Marre, O., Frégnac, Y., & Grinvald, A. (2011). Lateral spread of
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orientation selectivity in V1 is controlled by intracortical cooperativity. Frontiers in Systems Neuroscience, 5, 4. 347 Chen, J., & Kriegstein, A. R. (2015). A GABAergic projection from the zona incerta to cortex promotes cortical
348
neuron development. Science, 350(6260), 554-558. 349 Chklovskii, D. B., & Koulakov, A. A. (2004). Maps in the brain: what can we learn from them? Annu. Rev. 350
Neurosci., 27, 369-392. 351 Clifford, C. W. (2014). The tilt illusion: Phenomenology and functional implications. Vision research, 104, 3-11. 352 Constantinescu, A. O., O’Reilly, J. X., & Behrens, T. E. (2016). Organizing conceptual knowledge in humans
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317
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318
cortex, suggesting a potential role of frontal GABA in conceptual categorization (Constantinescu et al., 2016). It
319
would be of interest for future studies to test the links between parietal GABA and numerosity perception, as
320
well as between frontal GABA and conceptual categorization. 321 322 11 323
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(2010). GABA concentration is reduced in visual cortex in schizophrenia and correlates with orientation-
487
specific surround suppression. The Journal of Neuroscience, 30(10), 3777-3781. 488 Yoon, J. H., Maddock, R. J., Rokem, A., Silver, M. A., Minzenberg, M. J., Ragland, J. D., & Carter, C. S. 486
(2010). 459 15 15 Somers, D. C., Nelson, S. B., & Sur, M. (1995). An emergent model of orientation selectivity in cat visual
460
cortical simple cells. The Journal of neuroscience, 15(8), 5448-5465. 461 Somers, D. C., Nelson, S. B., & Sur, M. (1995). An emergent model of orientation selectivity in cat visu
460
ti
l i
l
ll
Th J
l f
i
15(8) 5448 5465
461 Song, C., Schwarzkopf, D. S., Lutti, A., Li, B., Kanai, R., & Rees, G. (2013). Effective connectivity within
462
human primary visual cortex predicts interindividual diversity in illusory perception. The Journal of
463
Neuroscience, 33(48), 18781-18791. 464 Song, C., Schwarzkopf, D. S., Lutti, A., Li, B., Kanai, R., & Rees, G. (2013). Effective connectivity within
462
human primary visual cortex predicts interindividual diversity in illusory perception. The Journal of
463
Neuroscience 33(48) 18781-18791
464 Figure 2. Parietal and occipital GABA. Parietal and occipital GABA levels were plotted against each other,
496
illustrating a lack of inter-individual correlation between these two variables. Each data point represents a
497
participant. Statistics are Pearson’s correlation and bootstrap results. 498 Figure 2. Parietal and occipital GABA. Parietal and occipital GABA levels were plotted against each other,
496
illustrating a lack of inter-individual correlation between these two variables. Each data point represents a
497
participant. Statistics are Pearson’s correlation and bootstrap results. 498 Figure 2. Parietal and occipital GABA. Parietal and occipital GABA levels were plotted against each other,
496
illustrating a lack of inter-individual correlation between these two variables. Each data point represents a
497
participant. Statistics are Pearson’s correlation and bootstrap results. 498 Figure 3. GABA and size illusion. In the Ebbinghaus illusion, two physically identical central circles appear to
499
have different perceived size as a result of the surrounding context of either smaller or larger circles. The
500
magnitude of Ebbinghaus illusion for each participant was plotted in semi-log graph against their parietal or
501
occipital GABA level, illustrating a positive correlation between size illusion magnitude and parietal GABA
502
level, as well as a lack of significant correlation between size illusion magnitude and occipital GABA level. 503
Each data point represents a participant. Statistics are Pearson’s correlation and bootstrap results. 504 Figure 3. GABA and size illusion. In the Ebbinghaus illusion, two physically identical central circles appear to
499
have different perceived size as a result of the surrounding context of either smaller or larger circles. The
500
magnitude of Ebbinghaus illusion for each participant was plotted in semi-log graph against their parietal or
501
occipital GABA level, illustrating a positive correlation between size illusion magnitude and parietal GABA
502
level, as well as a lack of significant correlation between size illusion magnitude and occipital GABA level. 503
Each data point represents a participant. Statistics are Pearson’s correlation and bootstrap results. 504 Figure 4. GABA and orientation illusion. In the tilt illusion, two physically identical central gratings appear to
505
have different perceived orientation as a result of their immediate surroundings. GABA concentration is reduced in visual cortex in schizophrenia and correlates with orientation-
487
specific surround suppression The Journal of Neuroscience 30(10) 3777 3781
488 489 16 16 FIGURE LEGENDS
490 Figure 1. MRS Spectra. MRS measure of resting GABA was acquired in separate experiment runs, from a
491
parietal voxel (blue) placed on the anterior part of the superior parietal lobe with its anterior border parallel to
492
the postcentral gyrus, and a occipital voxel (red) placed to cover the calcarine sulcus bilaterally with its anterior
493
border in alignment with the parietal-occipital sulcus. Examples of MRS spectra from ten randomly selected
494
participants are shown. The GABA peak is seen at 3 ppm and the inverted NAA peak at around 2 ppm. 495 Figure 1. MRS Spectra. MRS measure of resting GABA was acquired in separate experiment runs, from a
491
parietal voxel (blue) placed on the anterior part of the superior parietal lobe with its anterior border parallel to
492
the postcentral gyrus, and a occipital voxel (red) placed to cover the calcarine sulcus bilaterally with its anterior
493
border in alignment with the parietal-occipital sulcus. Examples of MRS spectra from ten randomly selected
494
participants are shown. The GABA peak is seen at 3 ppm and the inverted NAA peak at around 2 ppm. 495 The magnitude of tilt illusion
506
for each participant was plotted in semi-log graph against their parietal or occipital GABA level, illustrating a
507
positive correlation between orientation illusion magnitude and occipital GABA level, as well as a lack of
508
significant correlation between orientation illusion magnitude and parietal GABA level. Each data point
509
represents a participant. Statistics are Pearson’s correlation and bootstrap results. 510 Figure 4. GABA and orientation illusion. In the tilt illusion, two physically identical central gratings appear to
505
have different perceived orientation as a result of their immediate surroundings. The magnitude of tilt illusion
506
for each participant was plotted in semi-log graph against their parietal or occipital GABA level, illustrating a
507
positive correlation between orientation illusion magnitude and occipital GABA level, as well as a lack of
508
significant correlation between orientation illusion magnitude and parietal GABA level. Each data point
509
represents a participant. Statistics are Pearson’s correlation and bootstrap results. 510 Figure 4. GABA and orientation illusion. In the tilt illusion, two physically identical central gratings appear to
505
have different perceived orientation as a result of their immediate surroundings. The magnitude of tilt illusion
506
for each participant was plotted in semi-log graph against their parietal or occipital GABA level, illustrating a
507
positive correlation between orientation illusion magnitude and occipital GABA level, as well as a lack of
508
significant correlation between orientation illusion magnitude and parietal GABA level. Each data point
509
represents a participant. Statistics are Pearson’s correlation and bootstrap results. 510 Figure 5. GABA and brightness illusion. In the simultaneous contrast illusion, two physically identical central
511
circles appear to have different brightness as a result of their immediate surroundings. The magnitude of
512
simultaneous contrast illusion for each participant was plotted in semi-log graph against their parietal or
513
occipital GABA level, illustrating a lack of significant correlation between brightness illusion magnitude and
514
either parietal or occipital GABA level. Each data point represents a participant. Statistics are Pearson’s
515
correlation and bootstrap results. 516 17 17 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 1
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 2
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 3
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 4
GABA
NAA
Participant 5
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 6
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 7
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 8
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 9
GABA
NAA
Participant 10
Parietal Voxel
Occipital Voxel
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 1
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 2
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 3
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 4
GABA
NAA
Participant 5
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 6
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 7
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 8
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 9
GABA
NAA
Participant 10 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 1
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 2
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 3
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 6
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 7
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 8
Parietal Voxel
Occipital Voxel
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 1
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 2
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 3
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 6
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 7
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 8 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 1
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 6 Participant 6 Participant 2 Participant 7 Participant 7 1
2
3
4
5
Frequency (ppm)
GABA
NAA
p
1
2
3
4
5
Frequency (ppm)
GABA
NAA
p Participant 8 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 4
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 9 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 4
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 9 Participant 9 1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 5
1
2
3
4
5
Frequency (ppm)
GABA
NAA
Participant 10 r = -0.066 [-0.372 0.250], p = 0.730, N = 30
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32 r = -0.066 [-0.372 0.250], p = 0.730, N = 30
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32 r = -0.066 [-0.372 0.250], p = 0.730, N = 30 Parietal GABA (GABA+/Cr Ratio) diameter: 1.0 deg of visual angle
Size Illusion Magnitude (deg)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = 0.395 [0.117 0.610], p = 0.031, N = 30
0.13
0.21
0.34
0.55
Size Illusion Magnitude (deg)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.038 [-0.317 0.250], p = 0.841, N = 30
0.13
0.21
0.34
0.55
diameter: 2.0 deg of visual angle
diameter: 0.2 deg of visual angle diameter: 1.0 deg of visual angle
diameter: 2.0 deg of visual angle
diameter: 0.2 deg of visual angle Size Illusion Magnitude (deg)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = 0.395 [0.117 0.610], p = 0.031, N = 30
0.13
0.21
0.34
0.55
Size Illusion Magnitude (deg)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.038 [-0.317 0.250], p = 0.841, N = 30
0.13
0.21
0.34
0.55 Size Illusion Magnitude (deg)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.038 [-0.317 0.250], p = 0.841, N = 30
0.13
0.21
0.34
0.55 Size Illusion Magnitude (deg)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = 0.395 [0.117 0.610], p = 0.031, N = 30
0.13
0.21
0.34
0.55 Brightness Illusion Magnitude (%)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = -0.149 [-0.456 0.163], p = 0.431, N = 30
1.76
4.66
12.3
32.7
Brightness Illusion Magnitude (%)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.017 [-0.377 0.391], p = 0.927, N = 30
1.76
4.66
12.3
32.7
luminance: 100%
luminance: 0%
luminance: 50% luminance: 100%
luminance: 0%
luminance: 50% 456 0.163], p = 0.431, N = 30
r = -0.017 [-0.377 0.391
luminance: 100%
luminance: 0%
luminance: 50% Brightness Illusion Magnitude (%)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = -0.149 [-0.456 0.163], p = 0.431, N = 30
1.76
4.66
12.3
32.7
Brightness Illusion Magnitude (%)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.017 [-0.377 0.391], p = 0.927, N = 30
1.76
4.66
12.3
32.7 Brightness Illusion Magnitude (%)
Occipital GABA (GABA+/Cr Ratio)
0.22
0.28
0.34
0.40
r = -0.017 [-0.377 0.391], p = 0.927, N = 30
1.76
4.66
12.3
32.7 Brightness Illusion Magnitude (%)
Parietal GABA (GABA+/Cr Ratio)
0.20
0.24
0.28
0.32
r = -0.149 [-0.456 0.163], p = 0.431, N = 30
1.76
4.66
12.3
32.7 r = -0.017 [-0.377 0.391], p = 0.927, N = 30 r = -0.149 [-0.456 0.163], p = 0.431, N = 30
|
https://openalex.org/W2903480700
|
https://www.frontiersin.org/articles/10.3389/fmicb.2018.02877/pdf
|
English
| null |
Dual RNA-Seq Uncovers Metabolic Amino Acids Dependency of the Intracellular Bacterium Piscirickettsia salmonis Infecting Atlantic Salmon
|
Frontiers in microbiology
| 2,018
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cc-by
| 8,313
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ORIGINAL RESEARCH
published: 27 November 2018
doi: 10.3389/fmicb.2018.02877 Citation: Valenzuela-Miranda D and
Gallardo-Escárate C (2018) Dual
RNA-Seq Uncovers Metabolic Amino
Acids Dependency of the Intracellular
Bacterium Piscirickettsia salmonis
Infecting Atlantic Salmon. Front. Microbiol. 9:2877. doi: 10.3389/fmicb.2018.02877 Dual RNA-Seq Uncovers Metabolic
Amino Acids Dependency of the
Intracellular Bacterium
Piscirickettsia salmonis Infecting
Atlantic Salmon Diego Valenzuela-Miranda and Cristian Gallardo-Escárate* Diego Valenzuela-Miranda and Cristian Gallardo-Escárate* Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research, University
of Concepción, Concepción, Chile High-throughput sequencing technologies have offered the possibility to understand
the complexity of the transcriptomic responses of an organism during a wide variety
of biological scenarios, such as the case of pathogenic infections. Recently, the
simultaneous sequencing of both pathogen and host transcriptomes (dual RNA-seq)
during the infection has become a promising approach to uncover the complexity of the
host–pathogen interactions. In this study, through a double rRNA depletion and RNA
sequencing protocols, we simultaneously analyzed the transcriptome of the intracellular
bacterium Piscirickettsia salmonis and its host the Atlantic salmon (Salmo salar) during
the course of the infection. Beyond canonical host immune-related response and
pathogen virulent factors, both bacteria and host displayed a large number of genes
associated with metabolism and particularly related with the amino acid metabolism. Notably, genome-wide comparison among P. salmonis genomes and different fish
pathogens genomes revealed a lack of the biosynthetic pathway for several amino acids
such as valine, leucine, and isoleucine. To support this finding, in vitro experiments
evidenced that when these amino acids are restricted the bacterial growth dynamics
is significantly affected. However, this condition is phenotypically reversed when the
amino acids are supplemented in the bacterial growth medium. Based on our results, a
metabolic dependency of P. salmonis on S. salar amino acids is suggested, which could
imply novel mechanisms of pathogenesis based on the capacity to uptake nutrients
from the host. Overall, dual transcriptome sequencing leads to the understanding of
host–pathogen interactions from a different perspective, beyond biological processes
related to immunity. Valenzuela-Miranda D and
Gallardo-Escárate C (2018) Dual
RNA-Seq Uncovers Metabolic Amino
Acids Dependency of the Intracellular
Bacterium Piscirickettsia salmonis
Infecting Atlantic Salmon.
Front. Microbiol. 9:2877.
doi: 10.3389/fmicb.2018.02877 Keywords: dual RNA-seq, Piscirickettsia salmonis, Atlantic salmon, nutritional immunity, metabolic dependency,
amino acids Edited by: Edited by:
Suhelen Egan,
University of New South Wales,
Australia Reviewed by:
Weiming Sun,
Yantai University, China
Chang Chen,
University of Illinois at Chicago,
United States
Khalil Eslamloo,
Memorial University of Newfoundland,
Canada *Correspondence:
Cristian Gallardo-Escárate
crisgallardo@udec.cl;
crisgallardo@oceanografia.udec.cl Specialty section:
This article was submitted to
Microbial Symbioses,
a section of the journal
Frontiers in Microbiology Received: 07 August 2018
Accepted: 09 November 2018
Published: 27 November 2018 Keywords: dual RNA-seq, Piscirickettsia salmonis, Atlantic salmon, nutritional immunity, metabolic dependency,
amino acids INTRODUCTION High-throughput sequencing technologies applied to transcriptomic studies (RNA-Seq) have
offered the possibility to understand complex molecular responses under different biological
scenarios. Among them, a pathogenic infection entails a deep transcriptomic remodeling of the
host to promote the pathogenic clearance; in turn, pathogens display the expression of different November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate pathogen can evade host immune response are still unclear. Due
to the high prevalence, negative impact and scientific interest
on this pathogen, different efforts have tried to understand
salmonids defensive mechanism against P. salmonis and how
the bacteria overcome this response. Host transcriptomic
response has been mainly associated with a regulation of
genes involved in the innate immunity, apoptosis, different
signaling pathways, endocytosis, non-coding RNAs and iron
metabolism among others (Rise et al., 2004; Tacchi et al., 2011;
Pulgar et al., 2015; Valenzuela-Miranda and Gallardo-Escarate,
2016; Valenzuela-Miranda et al., 2017). On the other hand,
P. salmonis transcriptomic response has been assessed after
the in vitro infection in Sf21 cell lines (Machuca and Martinez,
2016). Although different genes associated with the type IV
secretion and iron acquisition system were identified, it remains
unexplored how P. salmonis transcriptome is modulated during
the infection. Due to this, we explore a dual RNA-Seq approach
to unravel novel mechanisms of interactions during the infection
of P. salmonis on the Atlantic salmon. A special emphasis
was placed in bacterial gene expression, since transcriptional
response of the Atlantic salmon against P. salmonis have
been widely described previously (Tacchi et al., 2011; Pulgar
et al., 2015; Valenzuela-Miranda and Gallardo-Escarate, 2016;
Tarifeno-Saldivia et al., 2017). Beyond canonical pathogenic
and immune related-genes, our results evidenced a common
transcriptomic response between host and pathogen associated
with the amino acid metabolism. Further analyses revealed a
lack of P. salmonis genes associated with different amino acids
biosynthetic pathways and the importance of the availability
of some amino acids for the bacterial growth medium. We
hypothesize metabolic amino acids dependency of P. salmonis on
S. salar, which could imply novel mechanisms of pathogenesis
based on the capacity to uptake nutrients from the host and
capacity of the host to regulate the availability of free amino
acids. genes to grant their survival and replicate within the host. INTRODUCTION In
this context, the simultaneous analysis of host and pathogen
transcriptomes (dual RNA-Seq) during their interaction can
reveal novel aspects of the infective process (Westermann
et al., 2017). Initially, this approach was limited to viral, fungal
and parasitic infections, where the pathogen resembles host
transcripts (Tierney et al., 2012; Strong et al., 2013; Choi et al.,
2014; Pittman et al., 2014) and scarcely reported in bacterial
models (Westermann et al., 2012). However, the improvement of
high-throughput sequencing and the development of novel RNA
capture/depletion methods offer a promising opportunity to also
expand this approach to bacterial infections (Westermann et al.,
2016). Although most dual RNA-seq approaches applied in bacterial
infections have been exploratory, some of them have unraveled
novel mechanisms of host–pathogen interaction. For instance,
a dual RNA-seq was used to discover a possible strategy
employed by Chlamydia trachomatis for the in vitro infection
of human epithelial cells based on an early iron acquisition
and a host immune depletion strategy (Humphrys et al., 2013). Furthermore, the simultaneous transcriptome analysis of the
Gram-negative bacterium Haemophilus influenza during the
infection of mucosal epithelial cells revealed the importance
of the host oxidative response and the mechanisms employed
by the bacteria to overcome this adverse environment (Baddal
et al., 2016). Likewise, the co-transcriptomic analysis of the
uropathogenic Escherichia coli (UPEC) and its host evidenced
that while host transcriptomic response was similar to different
bacterial strains, different expression patterns were identified in
UPEC strains with contrasting pathogenic effects (Mavromatis
et al., 2015). These results were used to reveal novel insights
into the mechanisms employed by the bacteria for the
intra-macrophage survival. Moreover, a dual RNA-Seq was used
to characterize the regulatory role of small RNAs (sRNAs)
in Salmonella enterica infection. Here, researchers identified
bacterial sRNA involved in the regulation of both host and
pathogenic genes, revealing the hidden roles of S. enterica
transcripts during the pathogenesis (Westermann et al., 2016). Simultaneous profiling of host-pathogen transcriptomes has
become a powerful approach tool to unravel key aspects during
the infection process. In the present study, we apply a dual
RNA-Seq approach to reveal novel aspects of the infective process
of the intracellular bacterium Piscirickettsia salmonis during the
infection on the Atlantic salmon (Salmo salar). Frontiers in Microbiology | www.frontiersin.org Experimental Design Experimental Design
Atlantic salmons (154.7 ± 13.5g) were obtained from a
commercial farm located at Puerto Montt, Chile and transferred
to the Marine Biology Station of the University of Concepción
(Dichato, Chile). Here, individuals were randomly screened
to discard the presence of different pathogens commonly
present salmonid aquaculture. After quarantine, individuals were
randomly divided into two independent marine water-based
recirculating lines, each containing five 370 L tanks. For each
line, three tanks were used for sampling (six in total), one tank
was used to record mortality (two in total) and the remaining
tank was not considered in this experiment. A total of 50
individuals per tank were maintained during an acclimation
period of 14 days before the challenge. After this period, each
individual was anesthetized and intraperitoneally injected with
0.2 ml of P. salmonis (EM-90 strain) containing 1 × 106
bacteria per dose, as previously standardized. Later, samples were
collected from infected individuals at 3, 7, and 14 days post Piscirickettsia
salmonis
is
a
facultative
intracellular
gram-negative bacterium that causes the salmonid rickettsial
septicemia (SRS), a severe systemic disease responsible for up
to 85% of the infectious moralities in farmed salmons in Chile. Just in this country, the economic losses associated with this
pathogen has been estimated in around US$100 million per year
(Smith et al., 1997; Bravo and Midtlyng, 2007; Pulgar et al., 2015),
becoming one of the main concerns for the industry (Mauel
and Miller, 2002). Beyond this negative impact, perhaps one
of the most remarkable features of P. salmonis is its capability
to infect and replicate within host immune cells, such as in
macrophages (McCarthy et al., 2008; Rajas et al., 2009; Ramirez
et al., 2015). In this context, the mechanism whereby this November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 2 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate infection (dpi). Head kidney and spleen tissues were collected
from two individuals of each sampling tank (12 individuals per
point) and stored in RNA later solution (Ambion, United States)
at −80◦C. In the remaining tanks, mortalities were daily
recorded (Supplementary Figure S1), clinically and molecularly
confirmed as a result of SRS. All animal procedures were carried
out under the guidelines approved by the Ethics Committee of
University of Concepción. were used as baseline for gene expression comparison. RNA Isolation and Sequencing Strategy RNA Isolation and Sequencing Strategy
Infected tissues stored at −80◦C in RNA later solution
were thawed at room temperature and total RNA (host and
pathogen) was isolated from 10 different individuals using the
TRIzol reagent kit (Thermo Fisher Scientific) according to
manufactures instructions. RNA integrity was verified using the
R6K screen tape 2200 on the TapeStation (Agilent Technologies,
United States) platform. Thus, isolated RNAs with RNA Integrity
Numbers (RIN) above 8 were considered for further analysis. Based on RNA quality, 3 different pools of RNA were prepared
from 3 distinct individuals for each tissue and time (biological
replicates). RNA pools were precipitated in absolute ethanol and
shipped in dry ice to Macrogen Inc. (Korea). Here, two Ribo-Zero
rRNA Removal Kit (Illumina, San Diego, CA, United States)
were used to remove both bacterial and host rRNAs. Remaining
RNA containing both P. salmonis and S. salar transcripts were
used to prepare high-throughput sequencing libraries using the
TrueSeq RNA sample preparation kit (Illumina, San Diego, CA,
United States). Each library was sequenced on a HiSeq platform at
100 bp paired-end reads (Macrogen, Korea). All sequencing data
will be available under the SRA accession number SUB4576220. Sequencing statistics for each RNA-seq data are presented in
Supplementary Table S1. Molecular annotation of the differentially expressed transcripts
for both P. salmonis and S. salar was carried out to identify the
most representative biological processes. For this purpose, the
Gene Ontology (GO) annotation was conducted through
the BLAST2GO software V 4.1.9 (Conesa et al., 2005) and
the enrichment analysis was performed using as reference the
genomes of P. salmonis and S. salar. Further, resulting GO
enrichment analysis was visualized in REVIGO platform (Supek
et al., 2011). Finally, KEGG pathway annotation analysis
was also conducted using the KEGG automatic annotation
server (Moriya et al., 2007) through the bidirectional best-hit
assignment method. Furthermore, RT-qPCR were used to
validate sequencing results. To do this, 10 genes from the bacteria
and 10 genes from the fish were randomly selected and used to
RT-qPCR primer design (Supplementary Table S2). After primer
validation, each RT-qPCR was conducted in a thermocycler
StepOne plus (Applied Biosystems, United States) using the
Maxima SYBR Green/ROX kit according to manufactures
instructions. Amplification cycles were used as following 95◦C
for 10 min, 40 cycles at 95◦C for 30 s, 60◦C for 30 s, and 72◦C for
30 s. RNA Isolation and Sequencing Strategy All qPCRs were carried on five biological and three technical
replicates and expression values were estimated through the 21
Ct method using 16s and elongation factor 1a as normalizer genes
for P. salmonis and S. salar, respectively. Significant differences
between 7 and 14 dpi regarding 3 dpi were estimated with the
Student’s t-test (p < 0.05). A comparison between fold-changes
obtained through RT-qPCR and RNA-seq evidence a r2 value
above 0.8, evidencing a high correlation between the fold changes
obtained by RT-qPCR and RNA-seq (Supplementary Figure S2). Individual fold changes were included as Supplementary
Figure S3. Dual RNA-Seq and Differential
Expression Analysis Raw sequencing reads were filtered by quality and adapter/index
were identified and removed from remaining reads using CLC
Genomics Workbench (V10, CLC Bio, Denmark). In order
to discriminate pathogen and host transcriptomes, cleaned
reads were mapped against the last available version of the
Atlantic salmon (S. salar)1 and against P. salmonis available
genomes2. Mapping parameters included a mismatch cost of 2,
insertion/deletion cost of 3 and a similarity/length fraction of 0.8. Effectively mapped reads against both genomes were separated in
different files and used for further RNA-Seq analysis. RNA-Seq
analysis was conducted using CLC Genomics Workbench (V10,
CLC Bio, Denmark). Previously discriminated reads from host
and pathogen were used to perform RNA-Seq analysis using
all coding sequences annotated in the Atlantic salmon and
P. salmonis genomes. For RNA-Seq analyses, similarity/length
fraction was set as 0.9 in order to minimize the probability to
include misassigned reads for each species. Expression values
were estimated as transcripts per million (TPM) and normalized
by totals per million read. Expression values obtained at 3 dpi Experimental Design We
decided to use this dataset as reference because we needed
transcriptomic data that contained reads from the pathogen to
compare, since pathogenic reads in any type of control would not
be present. Further, statistical differences were identified through
a Baggerly’s test adjusting p-values through a false discovery
rate (FDR) correction. Genes with a fold change > 4 and FDR
p-values < 0.01 were considered as differentially expressed. 1https://www.ncbi.nlm.nih.gov/assembly/GCF_000233375.1/
2https://www.ncbi.nlm.nih.gov/genome/genomes/11769 3https://www.ncbi.nlm.nih.gov/genome/genomes/511
4https://www.ncbi.nlm.nih.gov/genome/genomes/540 Exploring the Amino Acid Metabolism of
P. salmonis Dual RNA-Seq analysis revealed a large number of genes
differentially expressed associated with amino acid metabolism
during the infection process. Due to this, we further explored the
importance of amino acids in P. salmonis metabolism. First, a
genome-scale comparison was conducted between P. salmonis,
a second salmonid pathogen such as Aeromonas salmonicida
and a closely related bacterium as Francisella tularensis. For
this purpose, coding genes were obtained from NCBI for
P. salmonis (see text footnote 2), F. tularensis3 and A. salmonicida4 3https://www.ncbi.nlm.nih.gov/genome/genomes/511
4https://www.ncbi.nlm.nih.gov/genome/genomes/540 November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 3 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate FIGURE 1 | (A) Global transcriptome analysis of Piscirickettsia salmonis (blue) and S. salar (red) at 3, 7, and 14 days post-infection (dpi) in spleen and head kidney
tissues. Expression values were estimated as transcripts per million reads (TPM) and Log2 transformed for heat map clustering. (B) Differentially expressed genes in
spleen and head kidney at 7 and 14 dpi using as control the expression values at 3 dpi. Three days post-infection were used as baseline gene expression since no
bacterial reads would be present in any type of control group. FIGURE 1 | (A) Global transcriptome analysis of Piscirickettsia salmonis (blue) and S. salar (red) at 3, 7, and 14 days post-infection (dpi) in spleen and head kidney
tissues. Expression values were estimated as transcripts per million reads (TPM) and Log2 transformed for heat map clustering. (B) Differentially expressed genes in
spleen and head kidney at 7 and 14 dpi using as control the expression values at 3 dpi. Three days post-infection were used as baseline gene expression since no
bacterial reads would be present in any type of control group. material for the growth of P. salmonis in CM medium. When the
exponential phase was reached, 300 µL from the liquid culture
was used to inoculate 2.7 ml of liquid culture containing the
different experimental mediums. All cultures were carried on
triplicates and maintained at 20◦C with a constant agitation of
100 rpm. Bacterial growth was daily based monitored through
the change in the optical density at an absorbance of 600 nm. A multiple t-test was carried out to identify statistically significant
differences (p < 0.01) between treatments. genomes. RESULTS Exploring Host and Pathogen
Transcriptome During Pathogenesis
Dual RNA-Seq analysis evidenced the modulation of P. salmonis
and S. salar transcriptomes during the infection. This modulation
is represented in two heat maps, one for the fish host (red) and
another one for the pathogen (blue), where different clusters Exploring the Amino Acid Metabolism of
P. salmonis All coding sequences were annotated through KAAS
annotation server as described above, focusing our attention
in Histidine metabolism (00340), valine, leucine and isoleucine
degradation/biosynthesis (00280 and 00290), Arginine and
proline metabolism (00330), Lysine biosynthesis/degradation
(00300 and 00310), Cysteine and methionine metabolism
(00270), Glycine, serine and threonine metabolism (00260),
Phenylalanine, tyrosine and tryptophan biosynthesis (00400)
and Alanine, aspartate and glutamate metabolism (00250). Furthermore, liquid cultures of P. salmonis were conducted
considering different experimental culture media with distinct
amino acid composition. A basal medium (BM) was prepared
with Eugon (30.4 g/l) supplemented with FeCl3 (2 mM),
a complete medium (CM) prepared with Eugon (30.4 g/l)
supplemented with FeCl3 (2 mM) and Casamino acid (1%)
and experimental cultures medias were prepared with BM +
1% of the desired amino acid (Valine, leucine, and Isoleucine). A bacterial inoculum previously obtained from CHSE-214 cells
infected with P. salmonis at 90% of lysis was used as starting Frontiers in Microbiology | www.frontiersin.org Exploring Host and Pathogen
Transcriptome During Pathogenesis Dual RNA-Seq analysis evidenced the modulation of P. salmonis
and S. salar transcriptomes during the infection. This modulation
is represented in two heat maps, one for the fish host (red) and
another one for the pathogen (blue), where different clusters November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 4 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate FIGURE 2 | Venn diagram showing the number of exclusive and shared genes in the transcriptome of P. salmonis during the infection in spleen (blue) and head
kidney (red) tissues of Atlantic salar. The heat maps show a subset of exclusive and shared genes expressed by P. salmonis in both tissues. FIGURE 2 | Venn diagram showing the number of exclusive and shared genes in the transcriptome of P. salmonis during the infection in spleen (blue) and head
kidney (red) tissues of Atlantic salar. The heat maps show a subset of exclusive and shared genes expressed by P. salmonis in both tissues. the genes exclusively regulated in head kidney included a MATE
efflux family protein, DNA repair protein RecN, chaperone protein
HtpG and membrane proteins among others (Figure 2). Among
shared genes, different Protein phosphatase 1, ribosomal protein,
chaperones and Asn/Gln aminotransferase subunits were also
found (Figure 2). The complete list of differentially expressed
genes for the Atlantic salmon and P. salmonis is included as
Supplementary Table S3. of expression profiles were identified (Figure 1A). Regarding
S. salar transcriptome, 771 and 829 genes were differentially
expressed in spleen at 7 and 14 dpi, respectively (Figure 1B). Meanwhile, 412 and 467 genes were differentially modulated
in the head kidney at the same time-points (Figure 1B). On
the other hand, 68 and 79 P. salmonis genes were differentially
expressed in the spleen at 7 and 14 days, respectively, while
14 and 44 were identified in the head kidney (Figure 1B). Thus, the number of bacterial genes differentially expressed
were increased together with the course of the infection. Since
transcriptional responses for the host have been previously
reported, a special focus was placed on bacterial gene expression. Herein, a Venn diagram analysis revealed that 31 P. salmonis
genes were differentially regulated in both spleen and head
kidney, while 101 and 15 transcripts were exclusively regulated in
spleen and head kidney, respectively. Exploring Host and Pathogen
Transcriptome During Pathogenesis Genes exclusively regulated
in spleen included a ferritin-like domain protein, genes associated
with the type IV secretion system (VirB9, IcmL, and IcmW) and
several outer membrane proteins (Figure 2). On the other hand, Frontiers in Microbiology | www.frontiersin.org Amino Acid Metabolism: A Common
Response Between P. salmonis and
S. salar A functional annotation of the different differentially expressed
genes for both S. salar and P. salmonis was conducted in
order to identify key molecular pathways regulated during the
infective process. GO enrichment analysis evidenced that a
large percent of differentially expressed genes in P. salmonis
belonged to biological processes related with the metabolism of November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 5 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate FIGURE 3 | Gene ontology annotation (A) and KEGG pathway annotation (B) of the differentially expressed genes in Salmo salar and P. salmonis during the infection. The size of each circle represents the frequency of the GO term in the underlying GO database (larger circles represent more general terms) and the color represents
the number of genes in each term (value). Both host and pathogen displayed a large number of genes associated to amino acid biosynthesis and degradation. FIGURE 3 | Gene ontology annotation (A) and KEGG pathway annotation (B) of the differentially expressed genes in Salmo salar and P. salmonis during the infection. The size of each circle represents the frequency of the GO term in the underlying GO database (larger circles represent more general terms) and the color represents
the number of genes in each term (value). Both host and pathogen displayed a large number of genes associated to amino acid biosynthesis and degradation. signaling pathways (Supplementary Table S4), but also with
key metabolic pathways, including the “biosynthesis of amino
acids” (Figure 3B). Overall, the results evidenced that although
the metabolism of amino acids was not the predominant
transcriptomic response in the host, both P. salmonis and S. salar
displayed a large number of genes involved with biosynthesis
and degradation of amino acids. Due to this common response,
we further investigate the role of amino acids in P. salmonis
metabolism. proteins and nitrogen compounds, such as the terms “protein
metabolism,”
“cellular
protein
metabolism”
and
“cellular
nitrogen compound biosynthesis” among others (Figure 3A). On the other hand, a more complex transcriptomic response
was found in Atlantic salmon. Here, multiple biological
processes were represented, such as organic acid metabolic
process, oxidation-reduction process, response to external
stimulus, chemotaxis among others (Supplementary Table S2). However, terms related to the metabolism of amino acids was
also represented within differentially expressed transcripts,
such as the “cellular amino acid metabolism” (Figure 3A). Amino Acid Metabolism: A Common
Response Between P. salmonis and
S. salar Enrichment of genes associated with protein metabolism was
also found through KEGG annotation. Furthermore, one of
the most represented pathways among differentially regulated
genes in P. salmonis transcriptome included different metabolic
pathways, among them, the “biosynthesis and degradation
of amino acids” (Figure 3B). Regarding host transcriptome,
the response of the Atlantic salmon was associated not
just associated with endocytosis, cytokine-cytokine receptor
interaction,
apoptosis,
phagosome
and
Nod-like
receptor Frontiers in Microbiology | www.frontiersin.org DISCUSSION involved in biosynthesis/degradation of amino acids (Figure 4). However, a significant lack of genes related with valine, leucine,
and isoleucine metabolism was found in P. salmonis compared
with F. tularensis and A. salmonicida, where over 60% of all
possible genes were found (Figure 4A). However, a deeper look
into this metabolic pathway evidenced that although P. salmonis
lacks the majority of the genetic background for the biosynthesis
of this amino acids, it was possible to found the gene that encodes
for the primary degradation of valine, leucine, and isoleucine
(Figure 4B). These results suggest that the bacterium is not able
to biosynthesize these amino acids and therefore a metabolic
dependency of P. salmonis on environmental host amino acid
availability can be expected. To further explore the importance
of amino acid availability to the bacteria, P. salmonis was growth
in different liquid culture mediums with different amino acidic
availability. A control medium (CM) fully supplemented with
amino acids, a basal medium (BM) with no supplementation
of amino acids and basal mediums supplemented with 1% of
either valine (BM + V), leucine (BM + I) or isoleucine (BM + L)
were used as experimental mediums. The results evidence
that the bacteria are not able to grow when no amino acid is
supplemented. However, when BM is supplemented with either
valine, leucine or isoleucine, the growth kinetics of P. salmonis
resembles the one observed in a fully amino acidic supplemented
condition (Figure 5). involved in biosynthesis/degradation of amino acids (Figure 4). However, a significant lack of genes related with valine, leucine,
and isoleucine metabolism was found in P. salmonis compared
with F. tularensis and A. salmonicida, where over 60% of all
possible genes were found (Figure 4A). However, a deeper look
into this metabolic pathway evidenced that although P. salmonis
lacks the majority of the genetic background for the biosynthesis
of this amino acids, it was possible to found the gene that encodes
for the primary degradation of valine, leucine, and isoleucine
(Figure 4B). These results suggest that the bacterium is not able
to biosynthesize these amino acids and therefore a metabolic
dependency of P. salmonis on environmental host amino acid
availability can be expected. To further explore the importance
of amino acid availability to the bacteria, P. salmonis was growth
in different liquid culture mediums with different amino acidic
availability. Role of Amino Acids in P. salmonis
Metabolism To explore the importance of amino acids in P. salmonis
metabolism, a genome-scale comparison was used to identify
the
presence/absence
of
genes
directly
involved
in
the
degradation/biosynthesis
of
different
bacterial
pathogens. Thus, P. salmonis genome was compared with F. tularensis and
A. salmonicida available genomes. Results showed that all three
pathogens dispose of a similar genetic background of genes November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 6 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate FIGURE 4 | (A) Genomic-wide comparison of genes involved in the biosynthesis and degradation of amino acid in P. salmonis, a close related bacterium
(F. tularensis) and another fish Gram negative bacterium (A. salmonicida). Bars represent the percentage of genes identified for each pathogen underlying all the
possible genes for the pathway in KEGG pathway database. (B) Subset of the biosynthesis and degradation pathway for valine, leucine, and isoleucine in
P. salmonis, F. tularensis, and A. salmonicida. Circles represent intermediate molecules and arrows the genes catalyzing each reaction. Thus, a green arrow
represents a gene that was found in the genome of each pathogen and gray ones for those absent. Thus, P. salmonis evidenced a smaller number of genes involved
in valine, leucine, and isoleucine biosynthesis/degradation. FIGURE 4 | (A) Genomic-wide comparison of genes involved in the biosynthesis and degradation of amino acid in P. salmonis, a close related bacterium
(F. tularensis) and another fish Gram negative bacterium (A. salmonicida). Bars represent the percentage of genes identified for each pathogen underlying all the
possible genes for the pathway in KEGG pathway database. (B) Subset of the biosynthesis and degradation pathway for valine, leucine, and isoleucine in
P. salmonis, F. tularensis, and A. salmonicida. Circles represent intermediate molecules and arrows the genes catalyzing each reaction. Thus, a green arrow
represents a gene that was found in the genome of each pathogen and gray ones for those absent. Thus, P. salmonis evidenced a smaller number of genes involved
in valine, leucine, and isoleucine biosynthesis/degradation. DISCUSSION th
t
i ti
l
d l ti
f
th of several members of the type IV secretion system, including
VirB9, IcmL, and IcmW. The type IV secretion system it has
been described as a conserved mechanism for the delivery
of virulent factors from host to pathogen (Thanassi and
Hultgren, 2000). This system has been previously described
in P. salmonis (Gomez et al., 2013) and even the directed
mutagenesis of this locus has resulted in the attenuation of
the pathogenesis of P. salmonis (Mancilla et al., 2018). On the
other hand, the repertory of genes displayed by the Atlantic
salmon in response to infection was classified into different
molecular pathways. These processes included endocytosis,
cytokine-cytokine receptor interaction, apoptosis, phagosome
and Nod-like receptor signaling pathways, which has been
previously described as key responses triggered during the
infection of P. salmonis in S. salar tissues (Valenzuela-Miranda
and Gallardo-Escarate, 2016). However, beyond the canonical pathogenic genes commonly
associated with bacterial pathogenesis and the Atlantic salmon
immunity
(Valenzuela-Miranda
and
Gallardo-Escarate,
2016; Tarifeno-Saldivia et al., 2017), a common response
associated
with
protein
metabolism
and
particularly
the
biosynthesis/degradation of amino acids was present in both
S. salar and P. salmonis transcriptomic response during the
infection process. Due to this, a genome-scale comparison
was performed in order to evidence the genetic background of
genes involved in biosynthesis degradation of amino acids in
P. salmonis, a close related bacterium F. tularensis and another
salmonid bacterial pathogen A. salmonicida. The genomic
background has been previously used to predict essential and
non-essential amino acids in different pathogens (Meibom
and Charbit, 2010). Based on our results, we found a lack of
biosynthetic genes associated with the metabolism of valine,
leucine, and isoleucine for P. salmonis when compared with
F. tularensis and A. salmonicida genomes. Therefore, the
availability of these amino acids for P. salmonis might rely
upon the presence of these resources in the host intracellular
environment. During infection, intracellular pathogens must overcome
different adverse condition, such as the entrance to host
cells, host immune response, free radicals and also nutrient
deprivation. Although host cytosol was previously considered
as an abundant source of nutrients for invading pathogens
(Ray et al., 2009), recent evidence suggests that hosts can
reduce
the
intracellular
availability
of
certain
nutrients
as a protective response against the invading pathogens
(Abu
Kwaik
and
Bumann,
2013;
Barel
and
Charbit,
2013). DISCUSSION A control medium (CM) fully supplemented with
amino acids, a basal medium (BM) with no supplementation
of amino acids and basal mediums supplemented with 1% of
either valine (BM + V), leucine (BM + I) or isoleucine (BM + L)
were used as experimental mediums. The results evidence
that the bacteria are not able to grow when no amino acid is
supplemented. However, when BM is supplemented with either
valine, leucine or isoleucine, the growth kinetics of P. salmonis
resembles the one observed in a fully amino acidic supplemented
condition (Figure 5). Dual RNA-Seq has emerged as a promising approach to
elucidate host–pathogen interaction. Although this approach was
previously limited to pathogens that resembles host transcripts
(Westermann et al., 2017), the development of high-throughput
sequencing technologies has allowed to expand this approach to
bacterial infections. In this context, we applied a dual RNA-Seq
approach to explore novel means of interaction between the
intracellular bacterium P. salmonis and its main host the
Atlantic salmon (S. salar). In addition to being the main
threat to Chilean salmonid aquaculture (Rozas and Enriquez,
2014), the intracellular nature of this pathogen makes it an
interesting model to study host immune evasion strategies
and intracellular survival mechanisms employed by intracellular
pathogens. The
dual
RNA-Seq
analysis
revealed
the
presence
of
different bacterial genes among the spleen and head kidney
transcriptome. Thus, the spleen showed the largest number
of bacterial genes regarding the ones found in head kidney
data. This can be attributable due to when IP injection is
used as infection method in previous IP challenges with
P. salmonis, the spleen is one of the first tissues to be
infected, followed by head kidney (Valenzuela-Miranda and
Gallardo-Escarate, 2016). Therefore, the differences between November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 7 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate FIGURE 5 | Growth kinetics of P. salmonis in liquid culture media
supplemented with different amino acids. Bacteria was growth in a control
medium (CM), a basal medium without amino acids (BM) and in basal mediu
supplemented with valine (BM + V), leucine (BM + L), and isoleucine (BM + I)
amino acids at 1%. ∗Represents statistically significant differences (p < 0.01
between the supplemented medium (Val, Leu, or Ile) regarding control group
(no amino acids). Frontiers in Microbiology | www.frontiersin.org DISCUSSION This deprivation results in a struggle between host
and pathogen for the limited nutrient availability, which
commonly
known
as
nutritional
immunity
(Hood
and
Skaar, 2012). Thus, it has been suggested that part of the
immune response of the Atlantic salmon to P. salmonis
infection relies on the nutritional immunity. This has been
exclusively explored due to the struggle for iron availability. From P. salmonis perspective, it has been suggested the
importance of a siderophore-based mechanism to capture
iron from different host sources (Calquin et al., 2018). On the other hand, the infection of P. salmonis induces a FIGURE 5 | Growth kinetics of P. salmonis in liquid culture media
supplemented with different amino acids. Bacteria was growth in a control
medium (CM), a basal medium without amino acids (BM) and in basal medium
supplemented with valine (BM + V), leucine (BM + L), and isoleucine (BM + I)
amino acids at 1%. ∗Represents statistically significant differences (p < 0.01)
between the supplemented medium (Val, Leu, or Ile) regarding control group
(no amino acids). FIGURE 5 | Growth kinetics of P. salmonis in liquid culture media
supplemented with different amino acids. Bacteria was growth in a control
medium (CM), a basal medium without amino acids (BM) and in basal medium
supplemented with valine (BM + V), leucine (BM + L), and isoleucine (BM + I)
amino acids at 1%. ∗Represents statistically significant differences (p < 0.01)
between the supplemented medium (Val, Leu, or Ile) regarding control group
(no amino acids). the transcriptional modulation of pathogen genes among
this tissue could be as a result of different infection stages
rather than a tissue-specific transcriptomic response of the
pathogen. Nevertheless, different classical pathogenic related
genes were identified in transcriptomic data. Such as the case November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 8 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate strong transcriptomic modulation of genes involved in iron
availability
in
S. salar
(Pulgar
et
al.,
2015;
Valenzuela-
Miranda and Gallardo-Escarate, 2016). In this context, our
results evidence that both host and pathogen display a large
number of genes involved in the biosynthesis/degradation of
amino acids. Considering the lack of biosynthetic pathways
in leucine, valine and isoleucine in P. DISCUSSION salmonis and that
these same amino acids are defined as essential amino
acids
for
salmonids
(Helland
et
al.,
2010),
we
suggest
that this transcriptional modulation can be reflecting an
amino acid-based nutritional immunity triggered by S. salar
to overcome P. salmonis infection. In turn, P. salmonis
displayed a transcriptional modulation of different genes
associated with amino acid metabolism to deal with host
response. acid sources could become an advantage in a resource-
limited scenario. This metabolic plasticity has been reported
in other intracellular pathogens like F. tularensis, where
the intracellular survival of this bacteria relies on their
availability to exploit multiple host amino acids (Meibom
and Charbit, 2010; Barel et al., 2015). Based in our results,
and considering the recently proposed metabolic models for
P. salmonis (Cortes et al., 2017; Fuentealba et al., 2017),
we can hypothesize that this bacteria is capable to use
different amino acids as a carbon an energy resource. This
strategy has been adopted by others intracellular bacterium,
where this capability has been described as a crucial factor
for virulence development (Eisenreich et al., 2010; Meibom
and Charbit, 2010; Barel et al., 2015). In this scenario, the
implications of a metabolic plasticity in P. salmonis and its
link to virulence of different bacterial strains must be further
explored. Intracellular pathogens have developed different strategies
to overcome amino acids starvation triggered by the host
during infection. Some of these adaptations include the growth
arrest and differentiation, an amino acid self-sufficiency and
to exploit host machinery to obtain amino acids form host
cell (Zhang and Rubin, 2013). Based on our results and
considering the recent reconstruction of metabolic models
for the bacteria (Cortes et al., 2017), the self-sufficiency
strategy for amino acids in the P. salmonis can be rejected. Regarding growth arrest and differentiation, it has been reported
that during an amino acid restricted scenario C. trachomatis
morphologically changes into an aberrant form that is unable to
grow but protects them from a nutrient restricted environment
(Leonhardt et al., 2007). However, the addition of tryptophan
or isoleucine can restore these aberrant forms and reactivate
bacterial growth (Hatch, 1975; Ibana et al., 2011). Previously,
it has been reported the existence of morphological small
variants of P. salmonis, which were suggested as a survival
mechanism employed by the bacteria to overcome adverse
scenarios (Veronica Rojas et al., 2008). FUNDING This work was supported by the CONICYT-PCHA/Doctorado
Nacional (Grant 2015-21150728), FONDECYT (1180867), and
FONDAP (1510027). ACKNOWLEDGMENTS The authors are grateful for the support provided by the Ph.D. Program in Renewable Resource Management of the University
of Concepción, Chile. DISCUSSION However, the role of
these variants during an amino acid restricted scenario and
its relation with virulence remains unexplored. On the other
hand, pathogens like Legionella pneumophila have devolved
mechanism that grants the access to host nutrients by promoting
the expression of host amino acid transporters and taking
advantage of proteasomes of infected cells to generate free
amino acids for bacterial growth (Wieland et al., 2005;
Price et al., 2011). In this context, it has been suggested
that one of the mechanisms employed by P. salmonis to
evade immune response can be related with the regulation
of host transcriptional response through non-coding RNAs
(Valenzuela-Miranda and Gallardo-Escarate, 2016; Valenzuela-
Miranda et al., 2017), therefore, the idea that P. salmonis is able
to hijack host machinery to obtain amino acids should also be
explored. Overall, our results showed how a dual RNA-Seq approach
can
lead
us
to
the
understanding
of
novel
means
of
interaction
between
host
and
pathogens. However,
the
importance of an amino acid-based nutritional immunity
of S. salar in response to P. salmonis infection must be
further investigated. This information will not just lead us
to the development of novel treatments for the pathogen,
but also to the understanding of the pathogenesis process
from a different perspective, beyond canonical immunological
mechanisms. AUTHOR CONTRIBUTIONS DV-M and CG-E conceived the study and drafted the manuscript. DV-M performed the experiments and analyzed the data under
CG-E extensive supervision. Frontiers in Microbiology | www.frontiersin.org REFERENCES Mancilla, M., Saavedra, J., Grandon, M., Tapia, E., Navas, E., Grothusen, H., et al. (2018). The mutagenesis of a type IV secretion system locus of Piscirickettsia
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W. S., and Koop, B. F. (2004). SUPPLEMENTARY MATERIAL The importance of amino acids in pathogenic cell cycle
has not only be associated as a primary resource for the
biogenesis of proteins, but also as alternative sources of carbon
and nitrogen (Steeb et al., 2013). Therefore, a metabolic
plasticity to obtain carbon and energy from multiple amino The Supplementary Material for this article can be found
online
at:
https://www.frontiersin.org/articles/10.3389/fmicb. 2018.02877/full#supplementary-material November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 9 Dual RNA-Seq of P. salmonis Infecting S. salar Valenzuela-Miranda and Gallardo-Escárate REFERENCES Severe
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of coding genes and lncRNAs during bacterial infection. Fish Shellfish Immunol. 59, 427–438. doi: 10.1016/j.fsi.2016.11.001 Zhang, Y. J., and Rubin, E. J. (2013). Feast or famine: the host-pathogen battle over
amino acids. Cell Microbiol. 15, 1079–1087. doi: 10.1111/cmi.12140 Conflict of Interest Statement: The authors declare that the research was
conducted in the absence of any commercial or financial relationships that could
be construed as a potential conflict of interest. Valenzuela-Miranda, D., Valenzuela-Munoz, V., Farlora, R., and Gallardo-
Escarate, C. (2017). MicroRNA-based transcriptomic responses of atlantic
salmon during infection by the intracellular bacterium Piscirickettsia salmonis. Dev. Comp. Immunol. 77, 287–296. doi: 10.1016/j.dci.2017.08.016 ev. Comp. Immunol. 77, 287–296. doi: 10.1016/j.dci.2017.08.016 Copyright © 2018 Valenzuela-Miranda and Gallardo-Escárate. Frontiers in Microbiology | www.frontiersin.org November 2018 | Volume 9 | Article 2877 REFERENCES This is an open-
access article distributed under the terms of the Creative Commons Attribution
License (CC BY). The use, distribution or reproduction in other forums is permitted,
provided the original author(s) and the copyright owner(s) are credited and that the
original publication in this journal is cited, in accordance with accepted academic
practice. No use, distribution or reproduction is permitted which does not comply
with these terms. Copyright © 2018 Valenzuela-Miranda and Gallardo-Escárate. This is an open-
access article distributed under the terms of the Creative Commons Attribution
License (CC BY). The use, distribution or reproduction in other forums is permitted,
provided the original author(s) and the copyright owner(s) are credited and that the
original publication in this journal is cited, in accordance with accepted academic
practice. No use, distribution or reproduction is permitted which does not comply
with these terms. Veronica Rojas, M., Olivares, P. J., del Rio, R., and Marshall, S. H. (2008). Characterization of a novel and genetically different small infective variant of
Piscirickettsia salmonis. Microb. Pathog. 44, 370–378. doi: 10.1016/j.micpath. 2007.10.012 Westermann, A. J., Barquist, L., and Vogel, J. (2017). Resolving host-pathogen
interactions by dual RNA-seq. PLoS Pathog. 13:e1006033. doi: 10.1371/journal. ppat.1006033 November 2018 | Volume 9 | Article 2877 Frontiers in Microbiology | www.frontiersin.org 11
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https://openalex.org/W2018562790
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https://www.nature.com/articles/cddis2013105.pdf
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English
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Gap junctional communication promotes apoptosis in a connexin-type-dependent manner
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Cell death and disease
| 2,013
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cc-by
| 10,328
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1Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universita¨t Mu¨nchen and Munich University Hospital, Munich, Germany; 2DZHK (German Centre
for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany and 3Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
*Corresponding author: P Kameritsch, Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universita¨t Mu¨nchen and Munich University Hospital,
Marchioninistrasse 27, Mu¨nchen 81377, Germany. Tel: þ 49 89 2180 76536; Fax: þ 49 89 2180 76532; E-mail: Kameritsch@lmu.de
Received 10.8.12; revised 31.1.13; accepted 21.2.13; Edited by Y Shi
Keywords: gap junction; connexin; apoptosis; streptonigrin; Fas; Ca2 þ; IP3
Abbreviations: GJ, gap junction; Cx, connexin/s; NT, N-terminal part; CT, C-terminal part; SN, streptonigrin; Ca2 þ
i, intracellular free calcium; FITC, fluorescein
isothiocyanate; PI, propidium iodide; aa, amino acids; IP3, inositol triphosphate; a, anti Gap junctional communication promotes apoptosis in
a connexin-type-dependent manner P Kameritsch*,1, N Khandoga1, U Pohl1,2,3 and K Pogoda1 Gap junctions (GJs) have been described to modulate cell death and survival. It still remains unclear whether this effect requires
functional GJ channels or depends on channel-independent effects of connexins (Cx), the constituents of GJs. Therefore, we
analysed the apoptotic response to streptonigrin (SN, intrinsic apoptotic pathway) or to a-Fas (extrinsic apoptotic pathway) in
HeLa cells expressing Cx43 as compared with empty vector-transfected (CTL) cells. Apoptosis assessed by annexin
V-fluorescein isothiocyanate/propidium iodide staining was significantly higher in HeLa-Cx43 compared with HeLa-CTL cells. Moreover, the cleavage of caspase-7 or Parp occurred earlier in HeLa-Cx43 than in HeLa-CTL cells. Comparative analysis of the
effect of two further (endothelial) Cx (Cx37 and Cx40) on apoptosis revealed that apoptosis was highest in HeLa-Cx43 and lowest
in HeLa-Cx37 cells, and correlated with the GJ permeability (assessed by spreading of a GJ-permeable dye and locally induced
Ca2 þ signals). Pharmacologic inhibition of GJ formation in HeLa-Cx43 cells reduced apoptosis significantly. The role of GJ
communication was further analysed by the expression of truncated Cx43 proteins with and without channel-forming capacity. Activation of caspases was higher in cells expressing the channel-building part (HeLa-Cx43NT-GFP) than in cells expressing the
channel-incompetent C-terminal part of Cx43 (HeLa-Cx43CT-GFP) only. A hemichannel-dependent release and, hence, paracrine
effect of proapoptotic signals could be excluded since the addition of a peptide (Pep)-blocking Cx43-dependent hemichannels
(but not GJs) did not reduce apoptosis in HeLa-Cx43 cells. Treatment with SN resulted in a significant higher increase of the
intracellular free Ca2 þ concentration in HeLa-Cx43 and HeLa-Cx43NT-GFP cells compared with HeLa-CTL or HeLa-Cx43CT-GFP
cells, suggesting that Ca2 þ or a Ca2 þ-releasing agent could play a signalling role. Blocking of inositol triphosphate receptors
reduced the SN-induced Ca2 þ increase as well as the increase in apoptosis. Our observations suggest that Cx43 and Cx40 but
not Cx37 promote apoptosis via gap junctional transfer of pro-apoptotic signals between cells. Cell Death and Disease (2013) 4, e584; doi:10.1038/cddis.2013.105; published online 11 April 2013
Subject Category: Experimental Medicine decreased expression of bcl-2 has been described, and a
suppression of Src activity was observed in Cx43-expressing
malignant mesothelioma cells.14,15 Moreover, the intracellular
localisation of Cx43 at the mitochondrial16–19 or nuclear20
membranes has been shown to have a role in this context. Other reports refer to a distinct role of gap junctional
communication in promoting apoptosis. Citation: Cell Death and Disease (2013) 4, e584; doi:10.1038/cddis.2013.105
& 2013 Macmillan Publishers Limited
All rights reserved 2041-4889/13 Citation: Cell Death and Disease (2013) 4, e584; doi:10.1038/cddis.2013.105
& 2013 Macmillan Publishers Limited
All rights reserved 2041-4889/13 Results The fluorescence intensity
(red
fluorescence
units
(RFUs)),
indicating
activated
caspases, was significantly higher in the channel-forming
HeLa-Cx43-GFP
(mean±S.E.M.:
21 422±1494)
and
HeLa-Cx43NT-GFP
cells
(22 546±2031)
as
compared
with
the
channel-incompetent
HeLa-Cx43CT-GFP
cells
(14 543±758; Figure 4). The Cx effect on apoptosis varies with the Cx type and
correlates with gap junctional dye or calcium transfer. To elucidate the effect of other Cx proteins and their channel
properties on the development of apoptosis, HeLa cells
expressing either Cx37 or Cx40 or Cx43 were compared. The expression of the different Cx proteins was analysed by
western blot (Figure 2a). Immunocytochemically, the cells
showed the typical expression pattern with an increased
localisation at cell–cell contacts (Figure 2b). Cx-deficient
HeLa-CTL cells were used as controls. Apoptosis was
induced with SN (1 mM, 3 h) and measured by annexin
V-FITC/PI staining. The increase of apoptotic cells after
stimulation
with
SN
was
lowest
in
HeLa-CTL
cells
and highest in Cx43-expressing cells (Figure 2c). The
SN-induced increase in apoptotic cells was significantly higher
in Cx43-expressing cells compared with HeLa-Cx37 cells. p
g
p
To figure out whether the differences in the increase of
SN-induced apoptotic cells were associated with different GJ
channel permeabilities, we assessed cell coupling by inter-
cellular spreading of a GJ-permeable fluorescent dye after
injection of a single cell (Figure 2d). HeLa-CTL cells showed
no (n stained cells, mean±S.E.M.: 0.1±0.1) and HeLa-Cx37
only little dye transfer (2±1). In contrast, cell coupling of
Cx40- and Cx43-expressing HeLa cells (Cx40: 9±1; Cx43:
17±2) was significantly elevated as compared with HeLa-
CTL cells. Thus, the highest number of stained neighbouring
cells was observed in HeLa-Cx43 cells. In addition, we
analysed the intercellular spreading of a Ca2 þ signal after
mechanical stimulation of a single cell. Again, the signal
spread wider in HeLa-Cx43 cells compared with HeLa-Cx37
and HeLa-CTL cells (n cells with elevated Ca2 þ; mean±
S.E.M. – Cx43: 21±3; Cx37: 12±2; CTL: 0±0; Po0.05; two
different cell cultures, n ¼ 10–14). Hemichannels are not involved in augmented apoptosis
of Cx43-expressing cells. Gap junctional communication promotes apoptosis in
a connexin-type-dependent manner For example, experi-
ments performed with heavy ions21 or cytochrome C22,23 as
inducers of apoptosis demonstrated cell death in untreated
neighbouring cells, which points towards a role of GJs in
modulating apoptosis. Not only death signals but also cell
survival factors have been proposed to be transferred via
GJs.24–26 However, in most cases, it has not been studied
whether GJ channels or channel-independent effects were
important. Thus, it remains unclear which of the two potential
Cx-related pathways is quantitatively more important and
whether the modulatory effect of Cx on apoptosis depends on
the type of Cx expressed. It is also unclear which signals or
small molecules, which are able to pass GJs, could be
involved in promotion of apoptosis. A growing body of evidence shows that connexins (Cx) are
able to modulate essential cellular processes such as
proliferation, differentiation and migration. Likewise, survival
and apoptosis have been shown to be partially Cx-dependent
processes.1–3 However, it remains unclear whether Cx exert
their functions in a manner which is dependent on their ability
to form gap junction (GJ) channels or whether channel-
independent properties of Cx play a role such as that
observed in cell migration and proliferation.4–7 This question
is still controversially discussed. There are a few studies
suggesting that Cx, and in particular Cx43, have effects on cell
death and survival by mechanisms independent of gap
junctional communication. Most of these effects have been
related to the potential role of hemichannels that may allow the
passage of proapoptotic or survival factors from the intracel-
lular to the extracellular space or vice versa.8–12 Alternatively,
regulatory effects of Cx were found to play a role in pro- and
antiapoptotic genes.1 DNA arrays of Cx43-null and wild-type
mice indeed showed clear differences in gene expression.13
For example, in Cx43-expressing glioblastoma cells, a Gap junctions promote apoptosis
P Kameritsch et al 2 2 To
clarify
these
questions,
we
studied
apoptosis
in
Cx-transfected HeLa cells with no background expression of
Cx in the wild-type state. Our results show that the Cx-dependent
enhancement of apoptosis requires gap junctional communica-
tion and that this effect varies with the type of Cx expressed. We further investigated whether the treatment with SN has
an influence on the gap junctional coupling. Dye transfer via
GJs was measured in HeLa-Cx43 cells, the cell population
with the highest amount of apoptosis. Results Expression of Cx43 enhances the rate of apoptosis. To
examine the effect of Cx43 expression on apoptosis, we
used HeLa cells stably transfected with Cx43 or Cx-deficient
empty vector-transfected HeLa cells (CTL) as controls. Apoptosis was either induced by streptonigrin (SN; intrinsic
pathway) or a-Fas (extrinsic receptor-stimulated pathway). Treatment with SN (1, 10 mM) or a-Fas (10, 100 ng/ml) lasted
for 5 h and the rate of apoptosis was determined by annexin
V-fluorescein isothiocyanate (FITC)/propidium iodide (PI)
staining. Under both conditions, the apoptosis was signifi-
cantly higher in HeLa-Cx43 cells compared with HeLa-CTL
cells (Figure 1b). Likewise, treatment with SN (10 mM)
resulted in a higher and earlier increase of cleavage products
of Parp (cl. Parp) and caspase-7 (cl. Cas7) when Cx43 was
present (Figure 1c). Similarly, stimulation with a-Fas (100ng/ml)
resulted in cleaved Parp and caspase-7 already after 2h in
HeLa-Cx43 cells, whereas in HeLa-CTL cells, it started only
after 4h (Figure 1c). Gap junctional communication is required for enhance-
ment of apoptosis. The role of GJ communications for the
enhanced apoptosis was firstly investigated by using the GJ
blockers meclofenamic acid (M; 100 mM) and heptanol
(H, 0.25 mM). The amount of SN- or a-Fas-induced apoptotic
HeLa-Cx43 cells (mean±S.E.M. – 1 mM SN: 15.5±4.7%;
100 ng/ml Fas: 24.1±3.6%) was significantly reduced under
treatment with GJ blockers (1 mM SN þ MH: 7.1±0.4%;
100 ng/ml Fas þ MH: 11.8±1.1%; Figure 3). GJ blockers
alone did not affect the basal rate of apoptosis (untreated
cells: 6.4±0.6%; cells treated with the GJ blockers only –
MH: 6.0±0.7%). To further analyse whether an intact channel function
between cells was necessary for the enhanced apoptosis in
Cx43-expressing cells, we compared apoptosis in HeLa cells
expressing the N-terminal channel-building part of Cx43
(Cx43NT-GFP) with cells expressing the cytoplasmic C-term-
inal part (CT) of Cx43 (Cx43CT-GFP), which cannot form GJs
or hemichannels but exerts channel-independent functions of
Cx43.5 As controls, we used HeLa cells expressing full-length
Cx43 (Cx43-GFP). To determine the rate of SN-induced
apoptosis in these cells, the amount of activated caspases
(caspase-1, -3, -4, -5, -6, -7, -8 and -9) was measured (binding
of a red fluorescent-labelled inhibitor to active caspases),
as the expression of GFP interfered with the annexin
V-FITC/PI assay otherwise used. Gap junctional communication promotes apoptosis in
a connexin-type-dependent manner After treatment with SN
for 1 or 3 h, the cells were still able to form functional GJs,
although the rate of coupling decreased over time (n stained
cells; mean±S.E.M. – untreated cells: 17±2; 1 mM SN for 1 h:
11±2; 1 mM SN for 3 h: 6±1; nZ7 in three different cell
cultures). Results Cas) (induced by 10 mM SN and 100 ng/ml a-Fas)
is time-dependent and earlier detectable in HeLa-Cx43 cells compared with HeLa-CTL cells 20
15
10
5
25
30
untreated
1
10
100
200
SN (M)
-FAS (ng/ml)
apoptotic cells (%)
CTL
Cx43
*
#
*
#
*
#
*
#
untreated
+ -Fas
HeLa-Cx43
HeLa-Cx43
PI
annexin V-FITC
annexin V-FITC
104
104
103
103
102
102
101
101
100
100
104
103
102
101
100
104
103
102
101
100
FL2-H
FL2-H
FL1-H
FL1-H 20
15
10
5
25
30
untreated
1
10
100
200
SN (M)
-FAS (ng/ml)
apoptotic cells (%)
CTL
Cx43
*
#
*
#
*
#
*
#
4 untreated
HeLa-Cx43
PI
annexin V-FITC
104
104
103
103
102
102
101
101
100
100
FL2-H
FL1-H Cx43
h
SN (10 M)
0
8
16
6
CTL
0
8
16
6 -FAS (100 ng/ml)
0
4
6
2
0
4
6
2
CTL
Cx43
h
-cl. Parp
-GAPDH
-cl. Cas7 Figure 1
Cx43 expression enhances apoptosis of HeLa cells. (a) Representative contour plots of untreated and a-Fas (100 ng/ml, 5 h)-treated HeLa-Cx43 cells. The
amount of apoptotic cells was determined by annexin V-FITC/PI staining and is displayed in the lower right quadrant (grey). (b) SN- or a-Fas-induced apoptotic cell death of
HeLa cells is significantly increased by the expression of Cx43. Apoptosis of HeLa-Cx43 and HeLa-CTL cells untreated or treated with increasing concentrations of SN or
a-Fas for 5 h was detected by annexin V-FITC/PI labelling. Mean±S.E.M., *Po0.05 versus untreated (NG); #Po0.05 versus CTL cells (NG); nZ8 in at least three different
cell cultures. (c) Representative western blots show that apoptotic cleavage of Parp (cl. Parp) and clevage of caspase-7 (cl. Cas) (induced by 10 mM SN and 100 ng/ml a-Fas)
is time-dependent and earlier detectable in HeLa-Cx43 cells compared with HeLa-CTL cells untreated and SN-treated cells (10 mM) showed a low basal PI
uptake, which was significantly increased in the presence of
the hemichannel opener ATP (Figure 5b). This ATP-induced
enhancement was abolished after pretreatment with the
inhibitory Pep (50 mM). The ConPep did not reduce the
ATP-induced PI uptake in HeLa-Cx43 cells (mean fluores-
cence
of
single
cells
(mean
grey)
untreated:
149±1;
SN: 155±1; ATP: 194±3; ATP þ Pep: 155±1; ATP þ
ConPep: 207±2; in three different cultures, nZ80–160;
Po0.001 ATP/ATP þ ConPep versus untreated and SN). Results corresponds well with the amount of GJ-deficient cells
responding with a Ca2 þ
i increase to stimulation with SN
(Figure 6b). The inhibition of IP3 receptors by xestospongin C
reduced the rate of SN-induced apoptosis only in HeLa-Cx43
but not in HeLa-CTL cells (Figure 6c). untreated and SN-treated cells (10 mM) showed a low basal PI
uptake, which was significantly increased in the presence of
the hemichannel opener ATP (Figure 5b). This ATP-induced
enhancement was abolished after pretreatment with the
inhibitory Pep (50 mM). The ConPep did not reduce the
ATP-induced PI uptake in HeLa-Cx43 cells (mean fluores-
cence
of
single
cells
(mean
grey)
untreated:
149±1;
SN: 155±1; ATP: 194±3; ATP þ Pep: 155±1; ATP þ
ConPep: 207±2; in three different cultures, nZ80–160;
Po0.001 ATP/ATP þ ConPep versus untreated and SN). Discussion In this study, we have shown that the enhancing effect
of Cx expression on apoptosis in HeLa cells is dependent on
their channel-forming capacity and their influence on channel
permeability. In
contrast,
channel-independent
effects,
such as that observed to have a role in migration in the same
type of cells5 or in cell proliferation as shown in Neuro2a
cells,28 could not be observed. Thus, our study confirms and
extends previous reports on a decisive role of gap junctional
communication on augmentation of apoptosis in tumour
cell lines such as BC31 (a rat bladder carcinoma cell line)29
or C6 glioma cells,30 as well as in neuronal cells, for example,
astrocytes31 and Neuro2a cells.32 GJ channels enhance the amount of cells responding to
SN with a Ca2 þ
i increase. Ca2 þ and inositol triphosphate
(IP3) are known to represent potential proapoptotic signal
molecules, which are small enough to pass through GJs. We,
therefore, analysed changes of intracellular free calcium
(Ca2 þ
i) in cells without GJs (CTL and Cx43CT-GFP) and in
cells with functional GJs (Cx43, Cx43NT-GFP) after treat-
ment with SN. SN (10 mM) increased Ca2 þ
i in 84±5% of
cells expressing full-length Cx43 and 59±8% of cells
expressing the N-terminal channel-building part of Cx43
(Cx43NT-GFP; Figure 6a). In contrast, only 27±7% of HeLa
cells expressing no Cx (CTL) or 28±7% of HeLa cells
expressing the channel-incompetent cytoplasmic CT of Cx43
(Cx43CT-GFP) reacted to SN with an increase of Ca2 þ
i. Our conclusion of gap junctional communication being a
prerequisite for the augmented apoptosis is based on several
lines of evidence. Firstly, the pharmacologic inhibition of GJs
decreased the extent of SN- or a-Fas-induced apoptosis. In
agreement with an inhibitory action of meclofenamic acid and
heptanol on GJ coupling,33 we have shown that GJs remain
open during the development of apoptosis and this concurs
with results from other groups.30,34 Although the inhibitors
used, meclofenamic acid and heptanol, may have unspecific
effects, they did not directly interfere with apoptotic signalling
processes since they did not affect the rate of apoptosis in
untreated cells. Second, the decisive role of gap junctional
communication but not of channel-independent effects of Inhibition of IP3 receptor-mediated Ca2 þ release dimin-
ish apoptosis in GJ-coupled HeLa-Cx43 cells. Results The potential release of proa-
poptotic signals via Cx hemichannels, which may act in a
paracrine manner, was investigated by specific blockade of
Cx43 hemichannels using an inhibitory Pep (50 mM),27 which
does not affect gap junctional communication (HeLa-Cx43
cells;
Ca2 þ
spreading
due
to
mechanical
stimulation;
untreated: 25±2 cells; control peptide (ConPep): 28±3
cells; Pep: 27±2 cells; n ¼ 9 in three different cell culture
wells). The amount of apoptosis of HeLa-Cx43 cells with SN
(10 mM)
or
a-Fas
(100 ng/ml)
was
not
changed
under
treatment with the hemichannel-blocking Pep (SN þ Pep;
Fasþ Pep; Figure 5a). Apoptosis of cells incubated with the
inhibitory Pep alone was as low as that of untreated cells or of
cells incubated with the ConPep (Figure 5a). The efficiency of
the hemichannel-blocking Pep was tested by measuring the
uptake of PI via hemichannels in HeLa-Cx43 cells. Both Cell Death and Disease Gap junctions promote apoptosis
P Kameritsch et al 3 3 -FAS (100 ng/ml)
0
4
6
2
0
4
6
2
CTL
Cx43
h
-cl. Parp
-GAPDH
-cl. Cas7
20
15
10
5
25
30
untreated
1
10
100
200
SN (M)
-FAS (ng/ml)
apoptotic cells (%)
CTL
Cx43
*
#
*
#
*
#
*
#
untreated
+ -Fas
HeLa-Cx43
HeLa-Cx43
PI
annexin V-FITC
annexin V-FITC
Cx43
h
SN (10 M)
0
8
16
6
CTL
0
8
16
6
104
104
103
103
102
102
101
101
100
100
104
103
102
101
100
104
103
102
101
100
FL2-H
FL2-H
FL1-H
FL1-H
Figure 1
Cx43 expression enhances apoptosis of HeLa cells. (a) Representative contour plots of untreated and a-Fas (100 ng/ml, 5 h)-treated HeLa-Cx43 cells. The
amount of apoptotic cells was determined by annexin V-FITC/PI staining and is displayed in the lower right quadrant (grey). (b) SN- or a-Fas-induced apoptotic cell death of
HeLa cells is significantly increased by the expression of Cx43. Apoptosis of HeLa-Cx43 and HeLa-CTL cells untreated or treated with increasing concentrations of SN or
a-Fas for 5 h was detected by annexin V-FITC/PI labelling. Mean±S.E.M., *Po0.05 versus untreated (NG); #Po0.05 versus CTL cells (NG); nZ8 in at least three different
cell cultures. (c) Representative western blots show that apoptotic cleavage of Parp (cl. Parp) and clevage of caspase-7 (cl. Discussion GAPDH, glyceraldehyde 3-phosphate dehydrogenase -GAPDH
Cx43
-Cx43
CTL
CTL Cx37
-Cx37
Cx40
CTL
-Cx40 Cx37
Cx43
CTL
Cx40 CTL
Cx37
Cx40
Cx43
fold increase
of apoptotic cells
0
1
2
3
4
5
6
*
#
*
*
apoptosis cell coupling
stained cells
CTL
Cx37
Cx40
Cx43
0
5
10
15
20
*
#
*
# Figure 2
The rate of apoptosis is dependent on the Cx type expressed and correlates to the GJ permeability. (a) Western blot analysis for the expression of Cx37, Cx40
and Cx43 in stably transfected HeLa cells compared with empty vector-transfected HeLa (CTL). (b) Immunofluorescence stainings of Cx proteins in stably transfected HeLa
cells demonstrate typical localisation at the membrane of adjacent cells. HeLa-CTL cells were used as controls and showed no Cx43 expression by staining for Cx43. (c) Apoptosis (induced by 1 mM SN, 3 h) of stably transfected HeLa cells is dependent on the Cx type expressed and significantly increased by expression of Cx40 or Cx43
compared with HeLa-CTL. Apoptosis was determined by annexin V-FITC/PI labelling and fold increase of apoptotic cells is expressed as mean±S.E.M.; *Po0.05 versus
CTL; #Po0.05 versus Cx37; nZ5 in at least three different cell cultures. (d) Gap junctional cell coupling of HeLa cells varies with the Cx type expressed and correlates with
the rate of apoptosis. Cell coupling was measured by dye spreading (Alexa Fluor 488). The number of dye-stained cells is displayed as mean±S.E.M. (nZ18 dye injections in
Z3 different cell cultures; *Po0.05 versus CTL; #Po0.05 versus Cx37; NG). GAPDH, glyceraldehyde 3-phosphate dehydrogenase untreated
0
5
10
15
20
25
30
MH
SN+MH
SN
Fas
Fas+MH
apoptotic cells (%)
*
*
Figure 3
Impact of gap junctional communication on apoptosis of HeLa cells. Apoptosis induced by SN (1 mM, 5 h) or a-Fas (100 ng/ml, 5 h) in HeLa-Cx43 cells is
significantly reduced by blocking the GJ channels with meclofenamic acid
(M, 100 mM) and heptanol (H, 0.25 mM). Apoptosis was measured by annexin
V-FITC/PI staining and quantified using flow cytometry. The percentage of apoptotic
cells from the total cell number is expressed as mean±S.E.M. *Po0.05; NG; nZ3
in at least three different cell cultures untreated
0
5
10
15
20
25
30
MH
SN+MH
SN
Fas
Fas+MH
apoptotic cells (%)
*
* apoptosis was only augmented in cells expressing the
N-terminal channel-building part but not in cells expressing
the C-terminal cytoplasmic part of Cx43. Discussion In another
set of experiments (Figure 6b), preincubation (15 min) with
the IP3 receptor blocker xestospongin C (Sigma Aldrich,
Taufkirchen, Germany; 40 mM) restricted the SN-induced
Ca2 þ increase to 36±12% of the cells (Cx43 þ SN: 99±1,
Po0.001, n ¼ 8, in 3–4 different cultures). This number Inhibition of IP3 receptor-mediated Ca2 þ release dimin-
ish apoptosis in GJ-coupled HeLa-Cx43 cells. In another
set of experiments (Figure 6b), preincubation (15 min) with
the IP3 receptor blocker xestospongin C (Sigma Aldrich,
Taufkirchen, Germany; 40 mM) restricted the SN-induced
Ca2 þ increase to 36±12% of the cells (Cx43 þ SN: 99±1,
Po0.001, n ¼ 8, in 3–4 different cultures). This number Cell Death and Disease Gap junctions promote apoptosis
P Kameritsch et al 4 4 Cx37
Cx43
CTL
Cx40
-GAPDH
Cx43
-Cx43
CTL
CTL Cx37
-Cx37
Cx40
CTL
-Cx40
cell coupling
stained cells
CTL
Cx37
Cx40
Cx43
0
5
10
15
20
*
#
*
#
CTL
Cx37
Cx40
Cx43
fold increase
of apoptotic cells
0
1
2
3
4
5
6
*
#
*
*
apoptosis
Figure 2
The rate of apoptosis is dependent on the Cx type expressed and correlates to the GJ permeability. (a) Western blot analysis for the expression of Cx37, Cx40
and Cx43 in stably transfected HeLa cells compared with empty vector-transfected HeLa (CTL). (b) Immunofluorescence stainings of Cx proteins in stably transfected HeLa
cells demonstrate typical localisation at the membrane of adjacent cells. HeLa-CTL cells were used as controls and showed no Cx43 expression by staining for Cx43. (c) Apoptosis (induced by 1 mM SN, 3 h) of stably transfected HeLa cells is dependent on the Cx type expressed and significantly increased by expression of Cx40 or Cx43
compared with HeLa-CTL. Apoptosis was determined by annexin V-FITC/PI labelling and fold increase of apoptotic cells is expressed as mean±S.E.M.; *Po0.05 versus
CTL; #Po0.05 versus Cx37; nZ5 in at least three different cell cultures. (d) Gap junctional cell coupling of HeLa cells varies with the Cx type expressed and correlates with
the rate of apoptosis. Cell coupling was measured by dye spreading (Alexa Fluor 488). The number of dye-stained cells is displayed as mean±S.E.M. (nZ18 dye injections in
Z3 different cell cultures; *Po0.05 versus CTL; #Po0.05 versus Cx37; NG). Discussion We conclude that the
expression of functional Cx43 GJ channels is required for
enhancement of apoptosis. A further piece of evidence that gap junctional communica-
tion enhances apoptosis can be deducted from the observa-
tion that the rate of apoptosis was clearly dependent on the
permeability of the gap junctions as determined by the Cx s
studied here: Cx43ZCx40ZCx374Cx-deficient controls. These Cx-dependent differences in GJ permeabilities are in
agreement with own previous observations35 and another
recently published study, showing the highest dye transfer for
Cx43-composed channels, followed by Cx40 channels and
lowest transfer for Cx37 channels.36 Of note, our results are
based on the use of the GJ-permeant dye Alexa Fluor 488. Although the cellular exchange of GJ-permeant dyes between
cells can differ with respect to their size and surface charge
and may not represent the permeability of any potential
proapoptotic molecule,36,37 it underpins a close connection
between gap junctional permeability and augmentation of
apoptosis in the experiments reported here. However, the
finding that the spreading of Ca2 þ signals through GJs
showed a similar behaviour than Alexa Fluor 488 suggests
that the different permeabilities are not unique for this dye. Figure 3
Impact of gap junctional communication on apoptosis of HeLa cells. Apoptosis induced by SN (1 mM, 5 h) or a-Fas (100 ng/ml, 5 h) in HeLa-Cx43 cells is
significantly reduced by blocking the GJ channels with meclofenamic acid
(M, 100 mM) and heptanol (H, 0.25 mM). Apoptosis was measured by annexin
V-FITC/PI staining and quantified using flow cytometry. The percentage of apoptotic
cells from the total cell number is expressed as mean±S.E.M. *Po0.05; NG; nZ3
in at least three different cell cultures Cx43 could be confirmed by our results obtained in HeLa cells
expressing truncated variants of Cx43. We have shown
before that cells expressing the N-terminal part (NT) of Cx43
are able to form functional GJs, whereas cells expressing the
C terminus of Cx43 did not.5 Accordingly, SN-induced Cell Death and Disease Gap junctions promote apoptosis
P Kameritsch et al 5 5 for
such
a
mechanism
in
our
experimental
setting. A hemichannel-blockingPep,27 which did not affect gap
junctional coupling could not decrease SN- or a-Fas-induced
apoptosis in Cx43-expressing HeLa cells. The fact that the
cellular uptake of PI in the presence of ATP as reported
elsewhere40 could be blocked by preincubation with the
hemichannel-blocking Pep confirmed its expected inhibitory
action in our experimental setting. Discussion Our study shows a role of gap junctional communication on
apoptosis for both the exogenous and endogenous pathway
as induced by two different stimuli. Although our study does
not allow to conclude that there is a general role of gap
junctional communication in the control of apoptosis, it is not
limited to a single stimulus. Furthermore, a more general role
of gap junctional communication is suggested by the
observation that cells in a cluster are more susceptible to
the induction of apoptosis than single cells.29,31 However, our
experiments also clearly show that gap junctional commu-
nication is not an essential prerequisite for the development of
apoptosis but rather enhances its development. p
g
Obviously, the requirement of functional GJs for the
augmentation of apoptosis suggests that some proapoptotic
signals may be exchanged between apoptotic cells and their
neighbours. Such signals cannot comprise caspases or
proapoptotic regulator proteins like bad or bax, as these
molecules are too large to pass GJs, which allow passage
only for molecules up to 1.8 kDa.41 Small-molecule candi-
dates that have been suggested to be potential death
mediators when transferred via GJs are Ca2 þ, IP3 and
cAMP.1,42 Several apoptosis-inducing stimuli are known to
affect Ca2 þ
i. Ca2 þ signals in turn can lead to the activation of
caspases, the mainstream apoptosis executioners and open-
ing of mitochondrial permeability transition pores (PTPs). PTP
formation and opening result in the release of cytochrome C,
which in turn has a role in the activation of the caspase
cascade, and other proapoptotic proteins.1,43 The impact of
the GJ-permeable molecule IP3 on apoptosis is related to
IP3-triggered Ca2 þ release, whereby it contributes to the
induction of apoptotic cell events.1,42 The importance of
Ca2 þ as a proapoptotic signal has been shown by the
treatment of cells with the calcium ionophore ionomycin
or with thapsigargin. Such induced sustained elevation of
Ca2 þ was sufficient to trigger apoptosis without any other
apoptosis-inducing stimuli.44,45 Several studies have implicated a role of hemichannels in
cell survival and death.8,10,38,39 Although Cx s can form
hemichannels that could enable the release of pro-apoptotic
signals independent of gap junctions, we found no evidence SN-induced increase
in RFUs
25000
20000
15000
10000
5000
0
Cx43-GFP
Cx43NT-
GFP
Cx43CT-
GFP
*
*
Figure 4
The channel-building part of Cx43 mediates enhanced apoptosis. Discussion SN-induced apoptosis (1 mM, 16 h) of HeLa cells expressing green fluorescent
protein (GFP)-labelled Cx43 or truncated Cx43 proteins was determined by caspase
activation. SN-induced apoptosis of HeLa cells expressing full-length Cx43 (Cx43-
GFP) or the channel-building part of Cx43 (Cx43NT-GFP) was significantly
enhanced compared with cells expressing the cytoplasmic part of Cx43 (Cx43CT-
GFP). RFUs indicating activation of caspases in apoptotic cells are depicted as
mean±S.E.M.; *Po0.05 versus Cx43CT-GFP, NG; nZ3 in different cell cultures SN-induced increase
in RFUs
25000
20000
15000
10000
5000
0
Cx43-GFP
Cx43NT-
GFP
Cx43CT-
GFP
*
* Figure 4
The channel-building part of Cx43 mediates enhanced apoptosis. SN-induced apoptosis (1 mM, 16 h) of HeLa cells expressing green fluorescent
protein (GFP)-labelled Cx43 or truncated Cx43 proteins was determined by caspase
activation. SN-induced apoptosis of HeLa cells expressing full-length Cx43 (Cx43-
GFP) or the channel-building part of Cx43 (Cx43NT-GFP) was significantly
enhanced compared with cells expressing the cytoplasmic part of Cx43 (Cx43CT-
GFP). RFUs indicating activation of caspases in apoptotic cells are depicted as
mean±S.E.M.; *Po0.05 versus Cx43CT-GFP, NG; nZ3 in different cell cultures g
We analysed whether changes of Ca2 þ
i could be involved
into the enhanced rate of apoptosis observed in cells coupled
by gap junctions. Indeed, treatment with SN resulted in a fast
increase of Ca2 þ
i. An increase of Ca2 þ
i upon treatment with
SN has been described previously in lymphoblastoid cells.46
However in cells without gap junctional coupling only a minor However, in cells without gap junctional coupling, only a minor PIuptake (meang rey)
untreated
SN
ATP
ATP+Pep
ATP+ConPep
0
100
120
140
160
180
200
220
*
*
apoptotic cells (%)
a
b
untreated
0
5
10
15
20
25
30
ConPep
SN+ConPep
SN
Fas
Fas+ConPep
Pep
SN+Pep
Fas+Pep
Figure 5
Effect of hemichannels on apoptosis. (a) The inhibition of Cx43 hemichannels with a blocking Pep (50 mM, Pep) does not affect the rate of apoptosis induced by
SN (10 mM, 5 h) or a-Fas (100 ng/ml, 5 h) in HeLa-Cx43 cells. A non-inhibitory ConPep (50 mM) was used as a control. Apoptosis was measured by annexin V-FITC/PI staining
and quantified using flow cytometry. The percentage of apoptotic cells from the total cell number is expressed as mean±S.E.M.; nZ6 in at least three different cell cultures. Discussion (b) The uptake of PI (mean red fluorescence of single cells) by HeLa-Cx43 cells from the culture medium could be stimulated by opening the hemichannels with ATP (50 mM)
and was efficiently blocked by preincubation with a hemichannel-blocking Pep (50 mM). Treatment with SN (10 mM) did not affect the PI uptake. A non-inhibitory Pep (ConPep)
was used as a control. PI uptake of single cells is displayed as mean±S.E.M.; nZ80–160 cells in at least three different cell cultures *Po0.001 versus untreated, SN and
ATP þ ConPep, NG
Cell Death and D PIuptake (meang rey)
untreated
SN
ATP
ATP+Pep
ATP+ConPep
0
100
120
140
160
180
200
220
*
*
apoptotic cells (%)
a
b
untreated
0
5
10
15
20
25
30
ConPep
SN+ConPep
SN
Fas
Fas+ConPep
Pep
SN+Pep
Fas+Pep a Figure 5
Effect of hemichannels on apoptosis. (a) The inhibition of Cx43 hemichannels with a blocking Pep (50 mM, Pep) does not affect the rate of apoptosis induced by
SN (10 mM, 5 h) or a-Fas (100 ng/ml, 5 h) in HeLa-Cx43 cells. A non-inhibitory ConPep (50 mM) was used as a control. Apoptosis was measured by annexin V-FITC/PI staining
and quantified using flow cytometry. The percentage of apoptotic cells from the total cell number is expressed as mean±S.E.M.; nZ6 in at least three different cell cultures. (b) The uptake of PI (mean red fluorescence of single cells) by HeLa-Cx43 cells from the culture medium could be stimulated by opening the hemichannels with ATP (50 mM)
and was efficiently blocked by preincubation with a hemichannel-blocking Pep (50 mM). Treatment with SN (10 mM) did not affect the PI uptake. A non-inhibitory Pep (ConPep)
was used as a control. PI uptake of single cells is displayed as mean±S.E.M.; nZ80–160 cells in at least three different cell cultures *Po0.001 versus untreated, SN and
ATP þ ConPep, NG Cell Death and Disease 0
20
40
60
80
100
Cx43NT-
GFP
Cx43
Cx43CT-
GFP
CTL
cells with elevated Ca2+
i (%)
Cx43+SN
Cx43+SN
xesto
0
20
40
60
80
100
cells with elevated Ca2+
i (%)
*
*
*
0
3
1
2
4
CTL
Cx43
untreated
SN
SN+xesto
fold increase of apoptosis
*
*
*
*
#
Figure 6
The immediate Ca2 þ
i response is increased in cells expressing functional Cx43 channels. Discussion (a) The number of cells responding within 3 min with a Ca2 þ
i increase
due to SN treatment (10 mM) was significantly enhanced in Cx43- and Cx43NT-expressing HeLa cells compared with HeLa-CTL or HeLa-Cx43CT cells. The percentage of
cells with a Ca2 þ
i increase from the total cell number is expressed as mean±S.E.M.; *Po0.05 versus CTL/Cx43CT, nZ8 in at least three different cell cultures. In another
series of experiments (b), the Ca2 þ increase induced by SN (10 mM) was blocked by preincubation (15 min) with xestospongin C (xesto, 40 mM). The percentage of cells with
a Ca2 þ
i increase from the total cell number is expressed as mean±S.E.M.; *Po0.05, NG; n ¼ 8 in three different cell cultures. (c) Inhibition of IP3-mediated Ca2 þ release
(by xesto, 40 mM) reduces significantly SN (10 mM, 5 h)-induced apoptosis of HeLa-Cx43 cells but does not affect Cx-deficient control cells. Apoptosis was determined by
annexin V-FITC/PI labelling and fold increase of apoptotic cells is expressed as mean±S.E.M.; *Po0.05 versus corresponding untreated; #Po0.05 versus Cx43 SN; n ¼ 6
in three different cell cultures
Gap junctions promote apoptosis
P Kameritsch et al Gap junctions promote apoptosis
P Kameritsch et al 6 6 0
20
40
60
80
100
Cx43NT-
GFP
Cx43
Cx43CT-
GFP
CTL
cells with elevated Ca2+
i (%)
Cx43+SN
Cx43+SN
xesto
0
20
40
60
80
100
cells with elevated Ca2+
i (%)
*
*
*
P Kameritsch et al 6 0
3
1
2
4
CTL
Cx43
untreated
SN
SN+xesto
fold increase of apoptosis
*
*
*
*
# SN+xesto Figure 6
The immediate Ca2 þ
i response is increased in cells expressing functional Cx43 channels. (a) The number of cells responding within 3 min with a Ca2 þ
i increase
due to SN treatment (10 mM) was significantly enhanced in Cx43- and Cx43NT-expressing HeLa cells compared with HeLa-CTL or HeLa-Cx43CT cells. The percentage of
cells with a Ca2 þ
i increase from the total cell number is expressed as mean±S.E.M.; *Po0.05 versus CTL/Cx43CT, nZ8 in at least three different cell cultures. In another
series of experiments (b), the Ca2 þ increase induced by SN (10 mM) was blocked by preincubation (15 min) with xestospongin C (xesto, 40 mM). Discussion The percentage of cells with
a Ca2 þ
i increase from the total cell number is expressed as mean±S.E.M.; *Po0.05, NG; n ¼ 8 in three different cell cultures. (c) Inhibition of IP3-mediated Ca2 þ release
(by xesto, 40 mM) reduces significantly SN (10 mM, 5 h)-induced apoptosis of HeLa-Cx43 cells but does not affect Cx-deficient control cells. Apoptosis was determined by
annexin V-FITC/PI labelling and fold increase of apoptotic cells is expressed as mean±S.E.M.; *Po0.05 versus corresponding untreated; #Po0.05 versus Cx43 SN; n ¼ 6
in three different cell cultures part responded with a Ca2 þ
i increase, whereas virtually all
cells responded when the cells were coupled. Interestingly,
pretreatment with the IP3 receptor inhibitor xestospongin C47
limited the calcium response to a fraction of cells, which was
numerically identical with the fraction of cells that responded
in the absence of gap junctions. We have shown before that
xestospongin
C
reliably
abolished
IP3-mediated
Ca2 þ
responses.33 Therefore, our findings are consistent with the
view that SN induced an IP3-independent increase of Ca2 þ
i in
SN-sensitive cells. This Ca2 þ signal could have spread to
neighbouring cells via GJs, which is also consistent with our
findings that part of the cells responded with a delayed Ca2 þ
i
increase (up to 30 s) upon SN treatment (data not shown). As
shown before, an increase of Ca2 þ
i can induce a secondary
release of calcium via IP3 receptors,48 which in our setting
may have spread via GJs to non-SN-responsive neighbouring
cells to induce increases of Ca2 þ
i as well. Thus, both absence
of gap junctional communication and inhibition of IP3
receptors may restrict apoptosis by the same amount as
observed here. Discussion We have recently described that a similar
mechanism plays a pivotal role in the Ca2 þ response of
endothelial cells to stimulation with histamine or ATP.49 Ca2 þ
i
increases were also reported for Fas-initiated apoptosis with a
sustained increase in Ca2 þ
i commencing between 1 and 2 h
after treatment.50,51 granulosa cells52 or astrocytes.53 A so-called bystander death
induced by gap junctional spreading of cell-killing signals from
cells undergoing apoptosis to healthy surrounding cells has
been
described
for
several
apoptosis-inducing
condi-
tions.21,22 Although the physiologic role of a spread of
apoptosis signals to potentially healthy neighbouring cells
remains a matter of debate, the passage of ‘death signals’, for
example, from lethally irradiated cells to their neighbours via
GJs54,55 seems to be very promising for cancer therapies.56
GJ-mediated bystander effects are described also for a few
diseases, for example, retinitis pigmentosa57 or HIV-1
infection,58
and
may
represent
a
potentially
important
therapeutic principle in these disease states. part responded with a Ca2 þ
i increase, whereas virtually all
cells responded when the cells were coupled. Interestingly,
pretreatment with the IP3 receptor inhibitor xestospongin C47
limited the calcium response to a fraction of cells, which was
numerically identical with the fraction of cells that responded
in the absence of gap junctions. We have shown before that
xestospongin
C
reliably
abolished
IP3-mediated
Ca2 þ
responses.33 Therefore, our findings are consistent with the
view that SN induced an IP3-independent increase of Ca2 þ
i in
SN-sensitive cells. This Ca2 þ signal could have spread to
neighbouring cells via GJs, which is also consistent with our
findings that part of the cells responded with a delayed Ca2 þ
i
increase (up to 30 s) upon SN treatment (data not shown). As
shown before, an increase of Ca2 þ
i can induce a secondary
release of calcium via IP3 receptors,48 which in our setting
may have spread via GJs to non-SN-responsive neighbouring
cells to induce increases of Ca2 þ
i as well. Thus, both absence
of gap junctional communication and inhibition of IP3
receptors may restrict apoptosis by the same amount as
observed here. Discussion Apoptosis was measured with the sulforhodamine FLICA
apoptosis detection kit (Immunochemistry Technologies, Biomol, Hamburg,
Germany). The red fluorescent inhibitor of caspases SR-VAD-FMK detects
activated caspases (caspase-1, -3, -4, -5, -6, -7, -8 and -9) of apoptotic cells. Untreated or SN-treated (1 mM, 16 h) HeLa cells expressing full-length Cx43-GFP,
Cx43NT-GFP or Cx43CT-GFP were detached with trypsin-EDTA (Sigma Aldrich)
and 300 ml cell suspension (5 106 cells per ml) were stained with FLICA reagent
according to the manufacturer’s instructions. After staining, the cells were washed
three times with 1 wash buffer and cell concentrations of untreated and
SN-treated cells were determined again. After equilibration of the cell
concentrations, the cells were resuspended in PBS and the red fluorescence
intensity of sulforhodamine (RFU) was measured in a fluorescence plate reader at
excitation/emission wavelengths of 550/595 nm. Annexin V-FITC/PI staining. The annexin V-FITC apoptosis detection kit
(BD Biosciences, Heidelberg, Germany) was used according to the manufacturer’s
recommendations. The cells were treated as indicated, detached with Accutase
(PAA Laboratories, Coelbe, Germany) and collected by centrifugation (1500 r.p.m.,
5 min). Cell pellets were washed with phosphate-buffered saline (PBS),
resuspended in 1 binding buffer (0.01 M HEPES/NaOH, pH 7.4, 140 mM NaCl
and 2.5 mM CaCl2), and stained with annexin V-FITC and PI for 15 min at room
temperature in the dark. A total of 10 000 cells of each sample were analysed by
fluorescence-activated cell sorting (FACSort; BD Bioscience). Apoptotic cells were
defined as annexin V-FITC-positive and PI-negative cells. Analysis of GJ-independent transfer of proapoptotic signals via
hemichannels. The effect of hemichannels on the rate of apoptosis was
analysed with a hemichannel-blocking Pep. HeLa-Cx43 cells were incubated with
a Cx43-specific Pep (H-Val-Asp-Cys-Phe-Leu-Ser-Arg-Pro-Thr-Glu-Lys-Thr-OH;
50 mM; Biosyntan, Berlin, Germany), which reportedly inhibits hemichannels at a
concentration of 50 mM by affecting the extracellular loop of Cx43.27 For control
experiments, cells were incubated with 50 mM ConPep (H-Gly-Asp-Glu-Gln-Ser-
Ala-Phe-Arg-Cys-Asn-Thr-Gln-OH). Apoptosis was induced by the addition of SN
(10 mM) or a-Fas (100 ng/ml) for 5 h and the amount of apoptotic cells was
measured by annexin V-FITC/PI staining. Western blot analysis. Empty vector-transfected HeLa cells (CTL) or HeLa
cells stably expressing Cx37, Cx40 or Cx43 were seeded in 6-well plates and
lysed in Laemmli buffer59 the next day. The samples were boiled for 5 min and
size-separated by SDS-PAGE using 8–16% Tris-glycine gels (Thermo Scientific,
Bonn, Germany). Discussion On the
next day, the cells were treated with 10 mM SN (Sigma Aldrich) or 100 ng/ml a-Fas
(Millipore) for the indicated time points and lysed in Laemmli buffer.59 For detection
of cleaved Parp, an a-Parp antibody (1 : 500; Cell Signaling, NEB, Frankfurt am
Main, Germany), and for cleaved caspase-7, an a-caspase-7 antibody (1 : 500; Cell
Signaling), was used. Detection of GAPDH (a-GAPDH, 1 : 10000; Chemicon, Merck
Chemicals, Schwalbach, Germany) was used to demonstrate equal loading. The Ca2þ-sensitive dye was alternatively excited at 340 and 380 nm and the
signal was detected at 505 nm with a computerised system (Till Photonics). Frames at 340 and 380nm of the analysed areas (640nm 480nm) were stored
every 500ms for 3 min and the signal ratio corrected for the background was
determined for each pixel after the experiment. Based on changes of the mean ratio of
single cells over time, the percentage of cells showing a Ca2 þ
i increase due to
stimulation (reacting cells per cells in the visible area) was calculated. No attempt was
made to calculate the exact Ca2 þ
i concentration from the ratio. Immunofluorescence staining. HeLa cells expressing Cx37, Cx40 or
Cx43 or HeLa-CTL cells were seeded on glass coverslips. On the next day, the cells
were fixed with 3.7% formaldehyde in PBS for 20min at room temperature. After
rinsing with PBS, cells were permeabilised with 0.1% Triton X-100 (AppliChem) in PBS
for 4min. Unspecific antibody binding was blocked with PBS containing 0.5% BSA for
1h. Cells were incubated with rabbit a-Cx37 (Alpha Diagnostic; 1:100), rabbit a-Cx40
(Alpha Diagnostic; 1:100) or rabbit a-Cx43 (Sigma Aldrich; 1:100) overnight at 41C. The cells were washed and incubated with a secondary antibody (1:200) coupled to
the fluorochrome Alexa Fluor 488 (Invitrogen) for 1h at room temperature. Coverslips
were mounted and expression and localisation of the Cx proteins were analysed using
confocal microscopy (Leica, Wetzlar, Germany). Cells were stimulated mechanically or by the addition of SN (10 mM). Mechanical
stimulation of single cells by touching with glass pipettes (tip diameter 1 mm)
increased the Ca2 þ
i of the stimulated cell. In the presence of apyrase (Sigma
Aldrich; 50 U/ml), which degraded the ATP released due to the stimulation, the
Ca2 þ signal spread to neighbouring cells via gap junctions. The number of cells
showing an elevated Ca2 þ level (except of the stimulated cell) was counted. Discussion The proteins were electrophoretically transferred to a Hybond-P
membrane (Amersham, GE Healthcare, Freiburg, Germany) at 0.8 mA/cm2 for 1 h
and unspecific antibody binding was blocked by 5% skimmed milk powder
(AppliChem, Darmstadt, Germany) in PBS solution containing 0.1% Tween-20
(Sigma Aldrich) for 1 h at room temperature. The membranes were incubated with
rabbit a-Cx37 (1 : 1000; Alpha Diagnostic, Biotrend, Koeln, Germany), rabbit
a-Cx40 (1 : 1000; Alpha Diagnostic) or rabbit a-Cx43 (1 : 1000; Sigma Aldrich)
overnight at 4 1C. After washing with PBS–0.1% Tween, the blots were incubated
for 2 h with the secondary antibody coupled to horseradish peroxidase (1 : 1000;
Calbiochem, Merck, Darmstadt, Germany). Primary antibodies were diluted in 5%
bovine serum albumin (BSA; AppliChem) in PBS–0.1% Tween and secondary
antibodies in 5% skimmed milk powder in PBS–0.1% Tween. The blots were
washed four times for 10 min each and bound antibodies were detected using a
chemiluminescence detection kit for horseradish peroxidase (AppliChem). PI uptake via hemichannels. To analyse the activity of hemichannels,
HeLa-Cx43 cells were incubated with PI (20 mg/ml, 10 min) and fluorescence
images (excitation: 546 nm; emission: 570 nm; exposure time 1000 ms; experi-
mental set-up: see calcium measurements) were taken immediately after washout
of PI. The mean fluorescence (mean grey value) of single cells was calculated by
the the Till Vision software (Till Photonics, Gra¨felfing, Germany). To verify that the
PI uptake is not due to cell death, the cells were stained with Trypan blue
afterwards and blue stained cells were excluded from calculations. Hemichannels
were activated by ATP (50 mM). Measurement of the Ca2 þ
i. Intracellular changes of free Ca2 þ were
detected with the Ca2 þ-sensitive dye Fura2 (Invitrogen). After incubation with
4 mM Fura2 solved in DMEM (30 min at 37 1C and 5% CO2), HeLa cells (grown on
coverslips) were washed two times, transferred to the experimental chamber
(which had a wide opening on the top) and incubated in HEPES (pH 7.4; 125 mM
NaCl, 3 mM KCl, 1.25 mM NaH2PO4, 2.5 mM CaCl2, 1.5 mM MgCl, 10 mM
glucose). The chamber filled with 200 ml HEPES was mounted on an inverted
microscope (Axiovert S100; Zeiss, Go¨ttingen, Germany). To analyse the apoptotic cleavage of caspase-7 and Parp in HeLa-Cx43 and
HeLa-CTL cells, the cells were seeded in 6-well-plates to 80% confluence. Discussion We have recently described that a similar
mechanism plays a pivotal role in the Ca2 þ response of
endothelial cells to stimulation with histamine or ATP.49 Ca2 þ
i
increases were also reported for Fas-initiated apoptosis with a
sustained increase in Ca2 þ
i commencing between 1 and 2 h
after treatment.50,51 In conclusion, our study has shown that Cx expression
enhances apoptosis induction. This is not a class effect but
varies considerably dependent on the type of the Cx as
studied here for Cx being expressed in vascular tissue. Our
results suggest that this effect is due to the transfer of
proapoptotic signals, among which IP3 may play a significant
role. Thus, gap junctional communication and the control of
gap junctional permeability by variation of Cx expression may
be a potential target for therapeutic control of apoptosis. Materials and Methods
Cell cultures. HeLa cells stably transfected with murine Cx37, murine Cx40 or
rat Cx43 were kindly provided by Dr. Klaus Willecke (University of Bonn, Bonn,
Germany). HeLa cells transfected with the empty vector pBEHpac18 (CTL; kindly
provided by Dr. Willecke, Bonn, Germany) using SuperFect (Qiagen, Hilden, In agreement with our study, it has been reported that the
blockade of intercellular communication via GJs attenuated
the extent of apoptosis, for example, in BC31 cells,29 Cell Death and Disease 7 Gap junctions promote apoptosis
P Kameritsch et al amount of apoptotic cells was quantified by flow cytometry with annexin V-FITC
staining as described above. amount of apoptotic cells was quantified by flow cytometry with annexin V-FITC
staining as described above. amount of apoptotic cells was quantified by flow cytometry with annexin V-FITC
staining as described above. Germany), which served as controls. Generation of stably transfected HeLa cells
expressing the NT (amino acids (aa) 1–257, Cx43NT-GFP) or the CT of
Cx43 (aa 257–382, Cx43CT-GFP) was described previously.5 Cells were cultured
in Dulbecco’s modified Eagle’s medium (DMEM; Invitrogen, Life Technologies,
Darmstadt, Germany) with 10% new born calf serum (Biochrom, Berlin,
Germany), penicillin (100 U/ml; Sigma Aldrich) and streptomycin (100 mg/ml;
Sigma Aldrich) at 37 1C and 5% CO2. Growth medium of stably transfected HeLa-
CTL, HeLa-Cx37, HeLa-Cx40 and HeLa-Cx43 was supplemented with puromycin
(1 mg/ml; Sigma Aldrich) and of HeLa-Cx43NT-GFP and HeLa-Cx43CT-GFP with
zeocin (200 mg/ml; Invitrogen, Life Technologies). Apoptosis was induced with SN
(Sigma Aldrich) or a-Fas antibody (Millipore Merck, Schwalbach, Germany) as
indicated. FLICA staining. Discussion The dye was injected using a dye-filled
borosilicate micropipette (at a tip pressure of 60 mm Hg for 0.6 s, tip diameter
o1 mm) connected to an injecting system (FemtoJet; Eppendorf, Wesseling-
Berzdorf, Germany). The fluorescent dye was excited at 488 nm and fluorescence
signals were detected using a long-pass emission filter lemZ515 nm. Following
dye injection, images were captured using a digital camera (Imago; Till Photonics)
that was mounted on the inverted microscope (Axiovert S100; Zeiss). To assess
cellular coupling, the total number of dye-stained cells at the 5-min postinjection
timepoint was counted. 17. Halestrap AP. Mitochondria and preconditioning: a connexin connection? Circ Res 2006;
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through the heat shock protein 90-dependent TOM pathway and its importance for
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phenotype of human glioblastoma cells by connexin 43 (cx43). Cancer Res 1998; 58:
5089–5096. Statistics. Gaussian distributed data were analysed for statistically significant
differences by the Student’s t-test (two groups, unpaired data). Differences
between more than two groups were determined by one-way ANOVA, followed by
Student–Newman–Keuls method for multiple comparisons. Error probabilities of
Pr0.05 were considered significant. All values are expressed as means±S.E.M. Non-Gaussian distributed data (indicated as ‘NG’ in the figure legends) were
analysed by the non-parametric Mann–Whitney rank-sum test. For multiple
comparisons, the Kruskal–Wallis test on ranks followed by pairwise multiple
comparisons with Dunn’s method was used. Although these tests do not allow
analysing differences of mean values, for descriptive reasons mean values are
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Development and Field Validation of Lidocaine-Loaded Castration Bands for Bovine Pain Mitigation
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UVicSPACE: Research & Learning Repository Faculty of Science
Faculty Publications Faculty of Science
Faculty Publications Development and Field Validation of Lidocaine-Loaded Castration Bands for Bovine
Pain Mitigation
James W. Saville, Joseph A. Ross, Tyler Trefz, Crystal Schatz, Heather Matheson-
Bird, Brenda Ralston, … & Merle Olson
December 2020 © 2020 James W. Saville et al. This is an open access article distributed under the terms of
the Creative Commons Attribution License. https://creativecommons.org/licenses/by/4.0/ s W. Saville et al. This is an open access article distributed under the terms of
Commons Attribution License. https://creativecommons.org/licenses/by/4.0/ This article was originally published at:
https://doi.org/10.3390/ani10122363 Development and Field Validation of Lidocaine-Loaded Castration Bands for Bovine
Pain Mitigation
James W. Saville, Joseph A. Ross, Tyler Trefz, Crystal Schatz, Heather Matheson-
Bird, Brenda Ralston, … & Merle Olson
December 2020 Received: 6 November 2020; Accepted: 8 December 2020; Published: 10 December 2020 Simple Summary: Castration is among the most common management procedures performed in
the dairy and beef cattle industries. Despite the widely accepted benefits of castration, all castration
methods produce pain and distress. While slower than other approaches, castration by banding is
simple, inexpensive, and produces fewer complications. We have therefore focused the present study
on developing herd-level pain mitigation during banded castration. Because lidocaine is effective
at reducing pain and can be delivered topically, we have formulated lidocaine-loaded castration
bands (LLBs) to deliver local pain relief to calves and bulls during banded castration. Laboratory
results indicated a rapid release of lidocaine for the first 30 min, followed by a slow release for at
least 48 h. Field studies indicated that, for both lidocaine delivery into tissues and pain mitigation,
LLBs performed at least as well as standard lidocaine injections in the short term and outperformed
lidocaine injections in the long term. LLBs delivered therapeutic quantities of lidocaine into scrotal
tissues over a period of at least seven days in cattle. This approach would provide long-term pain
mitigation to the animals and, by avoiding surgery or the administration of injections, would also
decrease the time and handling costs for the producer. Abstract: Castration is among the most common management procedures performed in the dairy
and beef cattle industries and is mainly performed by surgery or elastic banding. Despite the various
benefits of castration, all methods produce pain and distress. Castration by banding is simple,
inexpensive, produces fewer complications, and can be performed in a high-throughput manner. Because lidocaine, a local anesthetic, can be delivered to trauma sites topically, we have formulated
lidocaine-loaded castration bands (LLBs) to deliver local pain relief to calves during banded castration. The initial lidocaine content of three band types developed was between 80 and 200 mg per band. The transfer kinetics of lidocaine into tissue was determined in vitro, indicating a rapid release for
the first 30 min, followed by a slow release lasting at least 48 h. Furthermore, the lidocaine delivery
and pain mitigation effects of these LLBs were compared to standard lidocaine injections in vivo. Field studies indicated that LLBs performed at least as well as lidocaine injections for short-term
lidocaine delivery into tissues and pain mitigation. Moreover, LLBs significantly outperformed
lidocaine injections for long-term delivery and pain mitigation. animals animals animals Development and Field Validation of
Lidocaine-Loaded Castration Bands for Bovine
Pain Mitigation James W. Saville 1, Joseph A. Ross 2
, Tyler Trefz 1, Crystal Schatz 2, Heather Matheson-Bird 2,
Brenda Ralston 3
, Ori Granot 1, Karin Schmid 4, Richard Terry 5, Nicholas D. Allan 2,*
,
Jeremy E. Wulff1,* and Merle Olson 6 1
Department of Chemistry, University of Victoria, Victoria, BC V8W 3V6, Canada;
jameswsaville@gmail.com (J.W.S.); ttrefz@uvic.ca (T.T.); origuvic@gmail.com (O.G.) 1
Department of Chemistry, University of Victoria, Victoria, BC V8W 3V6, Canada;
jameswsaville@gmail.com (J.W.S.); ttrefz@uvic.ca (T.T.); origuvic@gmail.com (O.G.)
2
Chinook Contract Research Inc., Airdrie, AB T4A 0C3, Canada; joe.ross@ccr01.com (J.A.R.);
crystal.schatz@ccr01.com (C.S.); heather@ccr01.com (H.M.-B.)
3
Alberta Agriculture and Forestry, Airdrie, AB T4A 0C3, Canada; Brenda.Ralston@gov.ab.ca
4
Alberta Beef Producers, Calgary, AB T2E 7H7, Canada; KarinS@albertabeef.org
5
Richard Terry Innovations, LLC, Conyers, GA 30094, USA; rt33@bellsouth.net
6
Alberta Veterinary Laboratories, Calgary, AB T2C 5N6, Canada; merle.olson@avetlabs.com
*
Correspondence: nick.allan@ccr01.com (N.D.A.); wulff@uvic.ca (J.E.W.) www.mdpi.com/journal/animals Animals 2020, 10, 2363; doi:10.3390/ani10122363 This article was originally published at:
https://doi.org/10.3390/ani10122363 Saville, J. W., Ross, J. A., Trefz, T., Schatz, C., Matheson-Bird, H., Ralston, B., … Olson,
M. (2020). Development and Field Validation of Lidocaine-Loaded Castration Bands for
Bovine Pain Mitigation. Animals, 10(12), 1-16. https://doi.org/10.3390/ani10122363. animals 1. Introduction Castration is one of the most common management procedures performed in the dairy and beef
cattle industries. In the United States alone, an estimated 15 million bovine castration procedures are
performed each year [1]. In modern agriculture, castration is undertaken to: (i) decrease aggression,
enhancing safety for handlers and animals; (ii) selectively control livestock populations; and (iii) produce
higher-quality meats that command higher market prices [1–3]. Despite the widely accepted benefits of
castration, all methods of castration result in physiological, neuroendocrine, and behavioural changes
indicative of distress and pain [1–6]. The Canadian Code of Practice for the Care and Handling of
Beef Cattle has recently been updated, advising that pain control be used for castration of bulls older
than 6 months, and it is expected that pain management will be advised for all castrations in the near
future [7]. Pain management is important for the well-being of the animal and castration recovery
time [3,4]. Existing techniques (i.e., ring blocking the scrotum or spermatic cord injection) to deliver
anesthesia during castration are not practical at the herd level [7]. Currently, only one pain control product (Meloxicam) is labeled for alleviating the pain associated
with castration. This product’s label claim is for up to 56 h of pain relief, requiring approximately 2.5 h
to reach maximal plasma concentration [5]; however, given the practicalities of cattle handling, and the
desire of producers to mitigate the stress of handling, it is often administered at the time of castration. This means that pain control does not begin until sometime after the initial castration procedure and
wears offwell before the wounds have healed. Accordingly, producers, scientists, and agriculture
ministries are seeking practical solutions to the challenge of herd-level pain mitigation for castration. Many methods of castration are employed by the cattle industry, each with inherent advantages,
disadvantages, and unique considerations. Surgical testicle removal is a common means of castration
but is losing popularity [1]. Surgical castration is rapid and effective; however, in certain jurisdictions,
a licensed veterinarian may be required on site to perform this procedure [8]. Complications are
not uncommon and include hemorrhage, infection, and myiasis. Castration by banding (Figure 1)
is an alternative technique and the second-most common method applied [1]. Banded castration
takes 3–6 weeks before the testes are sloughed off, making it the slowest means of castration [1,9]. Received: 6 November 2020; Accepted: 8 December 2020; Published: 10 December 2020 The concentrations of lidocaine in the
LLB-treated tissue samples were generally in the range of 0.5–3.5 mg of lidocaine per gram of tissue www.mdpi.com/journal/animals Animals 2020, 10, 2363; doi:10.3390/ani10122363 2 of 16 Animals 2020, 10, 2363 and were overall highest after 6 h. Lidocaine-loaded elastration bands deliver therapeutic quantities
of lidocaine into scrotal tissues over a period of at least seven days in cattle. This approach would
provide long-term pain mitigation to the animals and, by avoiding surgery or the administration of
injections, would also decrease the time and handling costs for the producer. Keywords: animal welfare; bovine; castration; elastration; lidocaine; pain mitigation 1. Introduction Although there are fewer complications with banded castration, it produces chronic pain that can last
at least 42 days [10]. Additionally, castration band application is simple and may be performed in a
high-throughput manner [1,9]. We have therefore focused this study on developing herd-level pain
mitigation for banded bovine castrations of different ages and body weights. Local anesthetics are used to numb acute, chronic, and surgical pain across all species. Anesthetics decrease pain sensation by preventing the transmission of nerve impulses from the
site of trauma to the brain. Lidocaine is an archetypal local anesthetic, characterized by its rapid
onset and prolonged duration of effect [11]. Meléndez et al. (2018) found that injected lidocaine was
effective at reducing physiological and behavioural indicators of pain (measured by salivary cortisol,
white blood cell counts, scrotal circumference, leg movement, head distance, and escape response) [5]. Additionally, Stafford et al. (2002) showed that lidocaine injected into the scrotum virtually abolished
the cortisol response to banded castration [12]. Lidocaine may be effectively delivered to trauma sites
non-invasively, through simple topical application [11]. 3 of 16
3 of 17 Animals 2020, 10, 2363
Animals 2020 10 x FOR Figure 1. Castration procedure using elastic castration bands. Figure 1. Castration procedure using elastic castration bands. Figure 1. Castration procedure using elastic castration bands
Figure 1. Castration procedure using elastic castration bands. Local anesthetics are used to numb acute, chronic, and surgical pain across all species. Anesthetics decrease pain sensation by preventing the transmission of nerve impulses from the site
of trauma to the brain. Lidocaine is an archetypal local anesthetic, characterized by its rapid onset
and prolonged duration of effect [11]. Meléndez et al. (2018) found that injected lidocaine was
effective at reducing physiological and behavioural indicators of pain (measured by salivary cortisol,
white blood cell counts, scrotal circumference, leg movement, head distance, and escape response)
[5]. Additionally, Stafford et al. (2002) showed that lidocaine injected into the scrotum virtually
abolished the cortisol response to banded castration [12] Lidocaine may be effectively delivered to
Motivated by the results available in the literature, we have formulated castration bands containing
therapeutic amounts of lidocaine, to deliver local pain relief to calves during banded castration. Based on
industry stakeholder inputs, three different sized bands were developed for evaluation and field
trialing in staggered parallel development streams to optimize resources and development timelines. medium (beige bands) for b
The band material was ma
2. Materials and Methods The band material was made of latex, which is sufficiently permeable to permit the release of local
anesthetic from the lumen of the band to exterior surfaces, where it can then penetrate the scrotal
tissue. The objective of this study was to evaluate the lidocaine content, tissue transfer, and release
kinetics of these lidocaine-loaded bands in vitro. Furthermore, the lidocaine delivery and pain
mitigation effects of these lidocaine castration bands were determined in vivo through field trials. Manufacturing and release of lidocaine formulations for each device subtype was evaluated in a
matrix-driven design. This development testing also evaluated occupational health and safety
considerations, human factors, animal application factors, environmental durability, shelf life, and
simulated use case stresses. 2. Materials and Methods
Three types of latex elastrator band—small (green), medium (beige), and large (CallicrateTM)—
were loaded with free-base lidocaine (no epinephrine) according to a proprietary process that
Three types of latex elastrator band—small (green), medium (beige), and large (CallicrateTM)—were
loaded with free-base lidocaine (no epinephrine) according to a proprietary process that impregnates
lidocaine and a skin permeation enhancer into the material of the band using a solvent carrier to
produce LLBs, which were evaluated in this study. The first LLB was developed for small (4.3 cm
circumference, 0.5 g) green elastrator bands recommended to be used in calves less than 90 Kg. These small bands had an average of 100 mg of lidocaine per band. The second LLB for the larger
beige (5.3 cm circumference, 1.4 g) Tri-bander bands contained an average of 250 mg of lidocaine per
band. The CallicrateTM band, recommended for use in animals 180 Kg or greater, is much larger and
forms a loop, so only the lower portion of the loop that would be in contact with tissue once applied
was loaded with lidocaine. This lidocaine formulation had a blue dye added to help determine where
the formulation was placed on the band and had an average of 86.4 mg of lidocaine per gram of band
material. Under the conditions of our pilot manufacturing, this was found to be the maximum amount
of lidocaine the bands were able to consistently retain. 1. Introduction The size categories include large (CallicrateTM) bands for bulls > 180 Kg, medium (beige bands) for
bulls between 90 and 180 Kg, and small (green bands) for calves < 90 Kg. The band material was made
of latex, which is sufficiently permeable to permit the release of local anesthetic from the lumen of the
band to exterior surfaces, where it can then penetrate the scrotal tissue. abolished the cortisol response to banded castration [12]. Lidocaine may be effectively delivered to
trauma sites non-invasively, through simple topical application [11]. Motivated by the results available in the literature, we have formulated castration bands
containing therapeutic amounts of lidocaine, to deliver local pain relief to calves during banded
castration. Based on industry stakeholder inputs, three different sized bands were developed for
evaluation and field trialing in staggered parallel development streams to optimize resources and
development timelines. The size categories include large (CallicrateTM) bands for bulls >180 Kg,
The objective of this study was to evaluate the lidocaine content, tissue transfer, and release kinetics
of these lidocaine-loaded bands in vitro. Furthermore, the lidocaine delivery and pain mitigation
effects of these lidocaine castration bands were determined in vivo through field trials. Manufacturing
and release of lidocaine formulations for each device subtype was evaluated in a matrix-driven design. This development testing also evaluated occupational health and safety considerations, human factors,
animal application factors, environmental durability, shelf life, and simulated use case stresses. (
p
p
)
impregnates lidocaine and a skin permeation enhancer into the
i
t
d
LLB
hi h
l
t d i
thi
t d
T
2.1. In Vitro Measurement of Initial Lidocaine Content in the Bands carrier to produce LLBs, which were evaluated in this study. The first LLB was developed for small
(4.3 cm circumference, 0.5 g) green elastrator bands recommended to be used in calves less than 90
Kg. These small bands had an average of 100 mg of lidocaine per band. The second LLB for the larger
The lidocaine from several castration bands was extracted in 100 mL tetrahydrofuran (THF) for 2 h
at 37 ◦C. The extraction solution was diluted 12.5 times with acetone (in duplicate) and filtered through 4 of 16 Animals 2020, 10, 2363 a 0.2 µm syringe filter prior to injection (in duplicate) onto a gas chromatography–mass spectrometry
(GC–MS) instrument (see Table 1 for specifications and run conditions). A standard curve was obtained
using solutions of 0.05, 0.1, 0.2, 0.4, 0.8 mg/mL of lidocaine prepared in the same solvent composition
as the samples. The standards were injected (in duplicate) onto the same instrument, and the resulting
data were used for quantitation. Table 1. GC–MS specifications and run conditions. Table 1. GC–MS specifications and run conditions. Instrument or Parameter
Details
GC–MS
PerkinElmer Clarus 680-AxION iQT
Column
Elite-5MS, 30 m × 0.25 mm, 0.25 µm
Carrier Gas
Nitrogen
Analysis Time
15 min
Flow Rate
1 mL/min
Injection Volume
0.5 µL
Injection Temperature
250 ◦C
Split Ratio
20:1
Oven Program
60 ◦C →300 ◦C over 15 min
Detection
MS Scan 50—1045 m/z
GC–MS
PerkinElmer Clarus 680-AxION iQT
Column
Elite-5MS, 30 m × 0.25 mm, 0.25 µm
2.2. In Vitro Measurement of Lidocaine Transfer into Steak Tissue over Time Table 1. GC–MS specifications and run conditions. Instrument or Parameter
Details
GC–MS
PerkinElmer Clarus 680-AxION iQT
Column
Elite-5MS, 30 m × 0.25 mm, 0.25 µm
Carrier Gas
Nitrogen
Analysis Time
15 min
Flow Rate
1 mL/min
Injection Volume
0.5 µL
Injection Temperature
250 ◦C
Split Ratio
20:1
Oven Program
60 ◦C →300 ◦C over 15 min
Detection
MS Scan 50—1045 m/z
GC–MS
PerkinElmer Clarus 680-AxION iQT
Column
Elite-5MS, 30 m × 0.25 mm, 0.25 µm
2.2. In Vitro Measurement of Lidocaine Transfer into Steak Tissue over Time 2.2. 2.3. Field Study Overview The protocols were reviewed and approved by Chinook Contract Research’s Institutional Animal
Care and Use Committee (OLAW #F19-00433, Application #14026-002-2,3,7) and the animals were
cared for in accordance with Canadian Council on Animal Care (CACC) guidelines [13]. We developed
and conducted a series of field studies to evaluate lidocaine release kinetics and pain mitigation
effects in vivo for each band type. The three studies reported here first examined the green bands
in May 2018, then the beige bands in July 2018, followed by the CallicrateTM bands in October 2018. Each study was conducted at the same commercial veal operation and feedlot in southern Alberta. For each study, animals were weighed, ranked by weight, and allocated to treatment (LLB) or control
(lidocaine injection) groups using random numbers. The animal was the experimental unit. All calves
were intact male Holstein calves which were brought to the facility from multiple dairy farms in
Southern Alberta. For study number 1 (green band) or 2 (beige band): Forty-eight calves (each study), weaned at
birth and 3–4 weeks of age (53 ± 4.0 kg of body weight for study 1, 56.0 ± 8.0 kg of body weight
for study 2), were used in an 8 day trial. Upon arrival at the farm (at approximately 4–5 days of
age), calves were placed into individual pens (2.1 m × 0.76 m) with a partially slatted floor for waste
removal. All animals were housed in the same room of a barn with forced air ventilation. Calves were
vaccinated with an 8-way clostridial vaccine (Tasvax 8, Merck Animal Health, Kirkland, QC, Canada),
respiratory disease vaccine (Inforce 3, Intranasal vaccine Zoetis Canada Inc., Kirkland, QC, Canada),
topical parasiticide (Solmectin Pour-On for Cattle, Alberta Veterinary Laboratories Ltd., Calgary, AB,
Canada), and allowed a minimum of two week adaptation period prior to the start of the trial. Calves
were fed twice daily (morning and afternoon) via 7.6 L buckets attached to the front gate of each
calf’s individual pen. One bucket contained milk replacer, 5 L per day (Mapleview Express Start +
Deccox, Mapleview Agri Ltd., Drayton, ON, Canada) and the second bucket a dry pelleted complete
feed (21% Protein Calf Starter, Landmark Feeds, Strathmore, AB, Canada). On the days of castration,
biopsy, and biometrics collection, calves were manually restrained within their individual pen by a
staffmember utilizing proper restraining methods for young calves. (
p
p
)
impregnates lidocaine and a skin permeation enhancer into the
i
t
d
LLB
hi h
l
t d i
thi
t d
T
2.1. In Vitro Measurement of Initial Lidocaine Content in the Bands In Vitro Measurement of Lidocaine Transfer into Steak Tissue over Time The transfer kinetics of lidocaine into steak tissue (shown schematically in Figure 2) was determined
for the small green bands as follows: A bovine sterling silver inside round steak was cut into 1 cm3
portions, and a LLB was placed around the steak and incubated for 0, 0.5, 5, 24, and 48 h at 37 ◦C,
5% CO2 (in triplicate for each time point). The LLB was removed from the steak cube following the
prescribed incubation time, and both band and steak were stored in separate sealed containers at 4 ◦C. Steak cubes were cut into 10 uniformly sized pieces and extracted (twice) with 100 mL THF for 2 h at
37 ◦C. The extraction solution was diluted 2 times with acetone and filtered through a 0.2 µm syringe
filter prior to injection (in duplicate) onto a GC–MS instrument. The LLBs from each time point were
also extracted (three times) in 100 mL THF, and the extraction solution was diluted and analyzed as
described above. Animals 2020, 10, x FOR PEER REVIEW
5 of 17 Figure 2. Schematic overview of lidocaine quantitation in steak tissue. Figure 2. Schematic overview of lidocaine quantitation in steak tissue. Figure 2. Schematic overview of lidocaine quantitation in steak tissue. Figure 2. Schematic overview of lidocaine quantitation in steak tissue. 5 of 16 Animals 2020, 10, 2363 2.4.1. Infrared Imaging of Scrotal Temperature Images of the scrotal neck were captured above and below the placement of the elastration
band using a thermal imaging camera (Model E75 1.1, lense 42◦; FLIR Systems, Made in Estonia and
Distributed by ITM Instruments Inc., Calgary, AB, Canada) from a distance of approximately 1 m
(Emissivity = 0.95). The temperatures were registered and recorded at a single point (indicated by cross
hairs in the thermographs) of the target scrotal areas approximately 2 cm above or below the castration
band for each band type. Temperatures were also measured for the under belly of the animal, with the
center of the scrotum targeted (beige and CallicrateTM bands only; under belly temperatures were only
considered and introduced at the conclusion of the green band field trial). Note also that the timing of
the temperature measurements was updated between the green band trial (1, 1.5, 24, 48, and 144 h)
and the later field trials (2, 6, 24, 48, and 168 h). 2.4. Measuring Lidocaine Release Kinetics and Pain-Associated Behaviour In Vivo The amount of lidocaine was determined from two tissue biopsies taken at each time point (2, 6,
24, 48, and 168 h after band placement) to determine in vivo lidocaine release rates. After removing
the bands, two tissue biopsy samples (punch biopsy comprising both skin and subcutaneous tissue,
4 mm) were collected from the area that was in direct contact with the band. Each biopsy sample was
placed in a microtube and stored at −80 ◦C. Tissue lidocaine extraction was initiated by chemically
homogenizing the skin and subcutaneous tissue with 1 M Sodium Hydroxide and then neutralizing
the dissolved solution with hydrochloric acid. A liquid–liquid extraction was performed with ethyl
ether to separate and allow the removal of the organic layer. The remaining ether-lidocaine solution
was evaporated to dryness and the residue re-dissolved with 1 mL of high-performance liquid
chromatography (HPLC)-grade methyl alcohol. Lidocaine concentrations were measured by HPLC to
determine lidocaine release (see Table 2 for specifications and run conditions). Table 2. HPLC specifications and run conditions. Instrument or Parameter
Details
HPLC
Hewlett Packard 1100 Series
Column
Kinetex 2.6 µm C18 (100A, 150 × 4.6 mm)
Mobile Phase
40:60 (Acetonitrile: 0.05 M Sodium Phosphate Buffer Solution), 0.05%
Diethylamine
Analysis Time
6 min
Flow Rate
1 mL/min
Injection Volume
10 µL
Column Temperature
28 ◦C
Detector
Variable Wavelength Detector (VWD)
Wavelength
210 nm
Bandwidth
10 nm Table 2. HPLC specifications and run conditions. Table 2. HPLC specifications and run conditions. At each time point, prior to punch biopsies, the animals were monitored for inflammation and
pain-associated behaviour as follows: 2.3. Field Study Overview 2.4. Measuring Lidocaine Release Kinetics and Pain-Associated Behaviour In Vivo 2.4. Measuring Lidocaine Release Kinetics and Pain-Associated Behaviour In Vivo 2.3. Field Study Overview For study number 3 (CallicrateTM band): Thirty calves, weaned at birth and 5 months of age
(225 ± 20.0 kg of body weight), were used in an 8 day trial. Calves were comingled in a rectangular
open-air pen (37 m × 55 m) with a wind break fence, a feed bunk along the front of the pen, straw bedding,
and ad libitum well water supplied via an automatic watering system. Calves were vaccinated with
an 8-way clostridial vaccine (Tasvax, Merck Animal Health, Kirkland, QC, Canada), respiratory
disease vaccine (Inforce 3, Intranasal vaccine Zoetis Canada Inc., Kirkland, QC, Canada), and topical
parasiticide (Solmectin Pour-On for Cattle, Alberta Veterinary Laboratories Ltd., Calgary, AB, Canada)
at 1–2 weeks of age, and an 8-way clostridial vaccine again at castration. Calves also received an
implant at Castration (Component E-S, Elanco Animal Health, Guelph, ON, Canada). Calves were
adapted on farm for a minimum of four months prior to the start of the trial. Calves were fed once daily,
approximately 3.5% of their body weight: 7.7–8.2 kg total mixed ration (TMR) comprising 30% barley
silage, 15% corn dried distillers grain, 2.5% Premix containing mineral and vitamins (Landmark Feeds,
Strathmore, AB, Canada), and 52.5% barley grain. On the days of castration, biopsy, and biometrics
collection, calves were restrained in a manual squeeze chute (Lakeland, Stonewall, MB, Canada). Animals in each study were randomly assigned to either experimental group 1 (control: lidocaine
injection and castration with plain castration band) or 2 (treatment: castration using lidocaine-loaded
band). Each experimental group contained 5 sampling time points (2, 6, 24, 48, and 168 h
post-elastration), yielding 3 animals per treatment per time point (n = 3 per treatment per time
point). A 20 mg/mL solution of lidocaine hydrochloride with 0.01 mg/mL epinephrine [5] (LIDO-2,
Rafter 8 products, Calgary, AB, Canada; 1 mL for the Green- or Beige-banded small calves, 3 mL for the
CallicrateTM-banded, larger calves) was injected subcutaneously into each of the spermatic cords in the
neck of the scrotum of control animals before application of the plain castration band. LLBs and plain
castration bands were administered to the treatment and control groups, respectively, at t = 0 h. All of Animals 2020, 10, 2363 6 of 16 the animals were weighed individually using a Jorvet scale (model J825PM, Jorgensen Laboratories,
CO, USA) on day 0 and day 7 to calculate an average daily gain (ADG) for each experimental condition. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro GC–MS was employed to measure lidocaine concentrations in vitro (shown schematically in
Figure 2). The amount of lidocaine in the LLBs was quantified by comparison to a standard curve
(Figure 3A), indicating an initial content of approximately 80–210 mg of lidocaine per band (Figure 3B)
for the three different LLBs developed. As an initial proof of concept, the transfer kinetics of lidocaine
into ex vivo tissue (steak) was determined for the small green castration bands (Figure 4). The amount
of lidocaine released from the bands was rapid for the first 30 min, followed by a slower release lasting
at least 48 h (Figure 4A). Similarly, the amount of lidocaine transferred into the tissue was initially
rapid, reaching approximately 7 mg in the first 30 min before plateauing at approximately 13.5 mg at
5 h, which was sustained for at least 48 h after band placement (Figure 4B). Taken together, these data
suggest that LLBs are capable of delivering significant concentrations of lidocaine into tissue for at
least 48 h. Animals 2020, 10, x FOR PEER REVIEW
8 of 17 Figure 3. Calibration curve and lidocaine quantitation by GC–MS. (A) Standard curve for various
lidocaine concentrations quantified (in duplicate) by GC–MS. (B) Quantitation of lidocaine extracted
from each type of lidocaine-loaded castration band (LLB). Note that, for the Callicrate bands, only a
section of the band (corresponding with the surface that would contact the animal’s scrotum) was
analyzed. Bars represent the mean ± standard deviation for 6 (green), 3 (beige), or 4 (Callicrate)
independent replicates. Figure 3. Calibration curve and lidocaine quantitation by GC–MS. (A) Standard curve for various
lidocaine concentrations quantified (in duplicate) by GC–MS. (B) Quantitation of lidocaine extracted
from each type of lidocaine-loaded castration band (LLB). Note that, for the Callicrate bands, only a
section of the band (corresponding with the surface that would contact the animal’s scrotum) was
analyzed. Bars represent the mean ± standard deviation for 6 (green), 3 (beige), or 4 (Callicrate)
independent replicates. Figure 3. Calibration curve and lidocaine quantitation by GC–MS. (A) Standard curve for various
lidocaine concentrations quantified (in duplicate) by GC–MS. (B) Quantitation of lidocaine extracted
from each type of lidocaine-loaded castration band (LLB). Note that, for the Callicrate bands, only a
section of the band (corresponding with the surface that would contact the animal’s scrotum) was
analyzed. 2.5. Statistical Analyses Statistical significance was determined using an unpaired, two-tailed t-test. Data were assessed
for normality using a Shapiro–Wilk test. The cutofffor significance was p < 0.05. The experimental unit
was defined as each individual animal. Statistical analyses were carried out in Prism v 8.4.3 (GraphPad
Software, San Diego, CA, USA). 2.4.2. Electrostimulation After infrared imaging, cutaneous stimulation was performed according to the procedure of
Fierheller et al. [14] for the beige and CallicrateTM banded experimental groups. This procedure was
not performed for the animals castrated with green bands, as the evaluation methodology was not
developed at the time of the green band field trial. A peripheral variable output nerve stimulator with
the provided extension lead wires (one positive and one negative) and infant monitoring electrodes
(8-1053-60; SunStim Peripheral Nerve Stimulator; Distributed by SunMed, Largo, FL, USA) was 7 of 16 Animals 2020, 10, 2363 used to stimulate the skin over the banded area of the calf’s scrotum (after removing the band). Measurements were made at t = 2, 6, 24, 48, 168 h post-elastration. The uniformly effective stimulus
setting was established to be 90 mAmp. The response of the animals to electrostimulation was
graded [14] by a blinded large-animal veterinarian, using the following scale: 0 = no reaction, 1 = slight
reaction (e.g., muscle tightening, twitch in the hind area, stiffening of stance), 2 = moderate reaction
(e.g., flinch, slight jump with hind, tightening and stiffer stance), and 3 = severe reaction (e.g., severe
flinch, obvious jump, abrupt stiffening). Reactions (if any) were immediate. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak tissue Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak
tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs)
following various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine
extracted from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was
quantified by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs) following
various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine extracted
from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was quantified
by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. 3.2. LLBs Deliver Therapeutic Quantities of Lidocaine into Scrotal Tissue In Vivo In order to confirm the efficacy of LLBs for lidocaine delivery into scrotal tissue during band
castration, three field studies were performed to evaluate lidocaine release kinetics and pain mitigation
effects in vivo. For each of the three band types (green, beige, and CallicrateTM), animals were castrated
with either LLBs or with plain bands; the latter (control) group were injected with lidocaine immediately
prior to band application for pain mitigation (in compliance with Institutional Animal Use and Care
Committee recommendations). Scrotal tissue from the banding site was sampled, and the concentration
of lidocaine therein was measured by HPLC over the course of a one-week study period (Figure 5). For the green bands (small calf bands for bulls < 90 Kg), LLBs generally delivered quantities of lidocaine
that were similar to those of the lidocaine-injected control samples, although the 24 h tissue sample
contained significantly more lidocaine in the LLB group than in the injected group (Figure 5A). In the
case of the beige bands (medium bands for bulls < 180 Kg), LLBs generally delivered higher lidocaine
concentrations relative to the injected controls, with statistically significant increases at 6, 24, and 168 h
(Figure 5B). Similarly, LLB-treated tissue samples generally contained more lidocaine than their injected
counterparts for CallicrateTM bands (large bands for bulls > 180 Kg), with significant differences at all
but the 2 and 24 h time points (Figure 5C). 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro Bars represent the mean ± standard deviation for 6 (green), 3 (beige), or 4 (Callicrate)
independent replicates. Figure 3. Calibration curve and lidocaine quantitation by GC–MS. (A) Standard curve for various
lidocaine concentrations quantified (in duplicate) by GC–MS. (B) Quantitation of lidocaine extracted
from each type of lidocaine-loaded castration band (LLB). Note that, for the Callicrate bands, only a
section of the band (corresponding with the surface that would contact the animal’s scrotum) was
analyzed. Bars represent the mean ± standard deviation for 6 (green), 3 (beige), or 4 (Callicrate)
independent replicates. 8 of 16
te) Animals 2020, 10, 2363
analyzed. Bars
independent re Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak
tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs)
following various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine
extracted from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was
quantified by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs) following
various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine extracted
from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was quantified
by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. LLB D li
Th
i Q
i i
f Lid
i
i
S
l Ti
I
Vi Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak
tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs)
following various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine
extracted from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was
quantified by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak tissue. (A) The amount of lidocaine recovered from lidocaine-loaded green castration bands (LLBs) following
various periods of incubation wrapped around steak tissue. (B) The amount of lidocaine extracted
from steak tissue following various incubation periods wrapped with LLBs. Lidocaine was quantified
by GC–MS. Bars represent the mean ± standard deviation for three independent replicates. Figure 4. Lidocaine transfer kinetics between lidocaine-loaded, green castration bands and steak
Figure 4. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro The concentrations of lidocaine in the LLB-treated tissue
samples were generally in the range of 0.5–3.5 mg of lidocaine per gram of tissue and were generally
highest after 6 h (Figure 5). Taken together, the results indicate that, over the short term, LLBs deliver
at least as much lidocaine into scrotal tissue as injections into the spermatic cords. Over the long term
(i.e., upwards of 6 h), LLBs can deliver significantly higher levels of lidocaine than injections. 9 of 16
deliver Animals 2020, 10, 2363
as injections into t
significantly highe Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
(A), beige (B), or CallicrateTM (C) bands (LLB), or their corresponding controls (lidocaine injection),
were homogenized, extracted, and the lidocaine content measured by HPLC. Bars represent the mean
± standard error of the mean (SEM) for three independent replicates per time point. Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
(A), beige (B), or CallicrateTM (C) bands (LLB), or their corresponding controls (lidocaine injection),
were homogenized, extracted, and the lidocaine content measured by HPLC. Bars represent the mean
± standard error of the mean (SEM) for three independent replicates per time point. Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
Figure 5. Lidocaine concentrations from scrotal biopsy samples collected over time. Time indicates
the duration the band was on the animal prior to biopsy. Biopsies from animals treated with green
(A), beige (B), or CallicrateTM (C) bands (LLB), or their corresponding controls (lidocaine injection),
were homogenized, extracted, and the lidocaine content measured by HPLC. Bars represent the mean
± standard error of the mean (SEM) for three independent replicates per time point. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro As an indicator of overall performance, the animals were weighed on induction to this study (day 0)
and on day 7 to calculate an average daily gain (ADG) for each experimental condition. ADG was
comparable for LLB-treated versus lidocaine-injected animals, indicating similar performance between
these groups (Table 3). No statistically significant differences in ADG were observed between
the LLB-treated and injected animals (statistical significance was determined using an unpaired,
two-tailed t-Test). Infrared thermography is a non-invasive means of measuring tissue inflammation [15,16]. Accordingly, we used thermal imaging to assess the temperature of different scrotal regions,
and
representative images are presented in Figure 6, with the results quantitated in Figure 7. As expected, scrotal temperatures were generally lower below the banding site over time, consistent with
the restriction of blood flow imposed by the bands (Figure 7). No significant differences in scrotal
temperature were observed for LLBs relative to their injected counterparts, indicating similar levels
of inflammation (Figure 7). However, at 168 h, the under-belly temperature was significantly lower
for CallicrateTM LLBs relative to their injected controls, suggesting decreased inflammation for the
LLB-treated animals at this time point (Figure 7C). The number of tail flicks and average heart rate were
also measured, and indicated no significant differences between LLB-treated and lidocaine-injected
animals (Supplemental Figures S1 and S2). 10 of 16 Animals 2020, 10, 2363 Table 3. Average daily gain for control versus treatment animals. Average Animal Size at Banding
Band Type
Treatment Group
ADG a
(Kg/Day)
± SD b
225 ± 20 Kg
CallicrateTM
Injection (n = 14)
0.43
0.52
LLB (n = 15)
0.80
0.67
56 ± 8 Kg
Beige
Injection (n = 21)
0.93
0.33
LLB (n = 20)
0.99
0.23
53 ± 4 Kg
Green
Injection (n = 3)
0.73
0.27
LLB (n = 3)
0.89
0.65
a ADG: average daily gain, calculated 7 days post-castration. b SD: standard deviation. nimals 2020, 10, x FOR PEER REVIEW
11 of 17 Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the
band, and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which
the temperature was registered. Orange arrows (right-most images) indicate the bands. The
temperatures were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the band,
and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which the
temperature was registered. Orange arrows (right-most images) indicate the bands. The temperatures
were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the
band, and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which
the temperature was registered. Orange arrows (right-most images) indicate the bands. The
temperatures were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the band,
and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which the
temperature was registered. Orange arrows (right-most images) indicate the bands. The temperatures
were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the
band, and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which
the temperature was registered. Orange arrows (right-most images) indicate the bands. The
temperatures were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the band,
and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which the
temperature was registered. Orange arrows (right-most images) indicate the bands. The temperatures
were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the
band, and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which
the temperature was registered. Orange arrows (right-most images) indicate the bands. The
temperatures were quantitated and are presented in Figure 7. Figure 6. Infrared imaging of animals with castration bands. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro Representative infrared images (left) and
corresponding photographs (right) are presented for (A) above the castration band, (B) below the band,
and (C) the underbelly of the animal. Cross hairs (left-most images) indicate the point at which the
temperature was registered. Orange arrows (right-most images) indicate the bands. The temperatures
were quantitated and are presented in Figure 7. 11 of 16
12 of 17 Animals 2020, 10, 2363
Animals 2020 10 x FOR Figure 7. Scrotal temperatures of control and treatment calves above and below castration band
placement over time. Scrotal temperature above and below the green (A), beige (B), and CallicrateTM
(C) castration bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. The temperature of the animal’s belly was also measured for the animals treated
with beige (B) and CallicrateTM (C) bands. Bars represent the mean ± standard error of the mean (SEM)
for three independent replicates per time point. Statistical significance was determined using an
unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutoff for
significance was p < 0.05. Figure 7. Scrotal temperatures of control and treatment calves above and below castration band
placement over time. Scrotal temperature above and below the green (A), beige (B), and CallicrateTM
(C) castration bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. The temperature of the animal’s belly was also measured for the animals treated
with beige (B) and CallicrateTM (C) bands. Bars represent the mean ± standard error of the mean
(SEM) for three independent replicates per time point. Statistical significance was determined using an
unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutofffor
significance was p < 0.05. Fi
ll
f
t l
b
t th
t
ti
it
l
t
ti
l ti
d Figure 7 Scrotal temperatures of control and treatment calves above and below castration band
Figure 7. Scrotal temperatures of control and treatment calves above and below castration band Figure 7. Scrotal temperatures of control and treatment calves above and below castration band
placement over time. Scrotal temperature above and below the green (A), beige (B), and CallicrateTM
(C) castration bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro The temperature of the animal’s belly was also measured for the animals treated
with beige (B) and CallicrateTM (C) bands. Bars represent the mean ± standard error of the mean (SEM)
for three independent replicates per time point. Statistical significance was determined using an
unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutoff for
significance was p < 0 05
Figure 7. Scrotal temperatures of control and treatment calves above and below castration band
placement over time. Scrotal temperature above and below the green (A), beige (B), and CallicrateTM
(C) castration bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. The temperature of the animal’s belly was also measured for the animals treated
with beige (B) and CallicrateTM (C) bands. Bars represent the mean ± standard error of the mean
(SEM) for three independent replicates per time point. Statistical significance was determined using an
unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutofffor
significance was p < 0.05. Finally, as a measure of scrotal numbness at the castration sites, electrostimulation was used to
elicit a pain response, which was graded according to the scale detailed in Materials and Methods. For both the beige and CallicrateTM bands, LLBs gave comparable pain responses to their injected
controls up to 48 h (Figure 8). However, at 168 h, LLBs gave significantly decreased pain responses
relative to the injected controls, indicating that LLBs are more effective at inducing long-term
numbness in the relevant tissue (Figure 8)
Finally, as a measure of scrotal numbness at the castration sites, electrostimulation was used to
elicit a pain response, which was graded according to the scale detailed in Materials and Methods. For both the beige and CallicrateTM bands, LLBs gave comparable pain responses to their injected
controls up to 48 h (Figure 8). However, at 168 h, LLBs gave significantly decreased pain responses
relative to the injected controls, indicating that LLBs are more effective at inducing long-term numbness
in the relevant tissue (Figure 8). 12 of 16
13 of 17 Animals 2020, 10, 2363
Animals 2020, 10, x FOR Figure 8. Response of control and treatment calves to electrostimulation at the castration site. Animals
were treated with electrostimulation at the banding site and their pain response measured according
to a graded scale as described in Materials and Methods. 4. Discussion
4. Discussion The main goal of this study was to establish whether lidocaine could be topically delivered from
elastration bands into tissue for pain mitigation during banded castration. As an initial proof of
concept, the transfer kinetics of lidocaine into ex vivo tissue (steak) was successfully determined. These data suggest that lidocaine delivery by LLBs into tissue is initially fast, followed by a sustained
delivery lasting at least 48 h (Figure 4). Similar results were obtained in a study that evaluated
lidocaine permeation across rabbit ear skin from a transdermal patch [17]. We note that the transfer
kinetics of lidocaine into steak tissue was only determined for the small green bands; given the
conserved latex composition of the three different band types and the similar amount of lidocaine in
each band (Figure 3), it is reasonable to expect similar results for both the beige and CallicrateTM
bands. We acknowledge that steak and scrotal tissue have different characteristics that could affect
lidocaine release and diffusion. Accordingly, we have moved future in vitro lidocaine transfer
experiments into tissue models incorporating epidermal and dermal tissues to better replicate bovine
scrotal tissue. However, at the inception of this study, these tissue models were not yet in place and
therefore steak tissue was used to provide a rough approximation of lidocaine transfer kinetics prior
The main goal of this study was to establish whether lidocaine could be topically delivered from
elastration bands into tissue for pain mitigation during banded castration. As an initial proof of
concept, the transfer kinetics of lidocaine into ex vivo tissue (steak) was successfully determined. These data suggest that lidocaine delivery by LLBs into tissue is initially fast, followed by a sustained
delivery lasting at least 48 h (Figure 4). Similar results were obtained in a study that evaluated
lidocaine permeation across rabbit ear skin from a transdermal patch [17]. We note that the transfer
kinetics of lidocaine into steak tissue was only determined for the small green bands; given the
conserved latex composition of the three different band types and the similar amount of lidocaine in
each band (Figure 3), it is reasonable to expect similar results for both the beige and CallicrateTM bands. We acknowledge that steak and scrotal tissue have different characteristics that could affect lidocaine
release and diffusion. 3.1. Transfer Kinetics for Lidocaine-Loaded Castration Bands (LLBs) In Vitro Graded responses for the beige (A) and
CallicrateTM (B) bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. Bars represent the mean ± standard error of the mean (SEM) for three independent
replicates per time point. Statistical significance was determined using an unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutoff for significance was p < 0.05. Figure 8. Response of control and treatment calves to electrostimulation at the castration site. Animals were treated with electrostimulation at the banding site and their pain response measured
according to a graded scale as described in Materials and Methods. Graded responses for the beige
(A) and CallicrateTM (B) bands were plotted against the duration of band placement for test (LLB)
and control (injection) animals. Bars represent the mean ± standard error of the mean (SEM) for three
independent replicates per time point. Statistical significance was determined using an unpaired,
two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutofffor significance
was p < 0.05. Figure 8. Response of control and treatment calves to electrostimulation at the castration site. Animals
were treated with electrostimulation at the banding site and their pain response measured according
to a graded scale as described in Materials and Methods. Graded responses for the beige (A) and
CallicrateTM (B) bands were plotted against the duration of band placement for test (LLB) and control
(injection) animals. Bars represent the mean ± standard error of the mean (SEM) for three independent
replicates per time point. Statistical significance was determined using an unpaired, two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutoff for significance was p < 0.05. Figure 8. Response of control and treatment calves to electrostimulation at the castration site. Animals were treated with electrostimulation at the banding site and their pain response measured
according to a graded scale as described in Materials and Methods. Graded responses for the beige
(A) and CallicrateTM (B) bands were plotted against the duration of band placement for test (LLB)
and control (injection) animals. Bars represent the mean ± standard error of the mean (SEM) for three
independent replicates per time point. Statistical significance was determined using an unpaired,
two-tailed t-test. Data were assessed for normality using a Shapiro–Wilk test. The cutofffor significance
was p < 0.05. 4. Discussion
4. Discussion Accordingly, we have moved future in vitro lidocaine transfer experiments into
tissue models incorporating epidermal and dermal tissues to better replicate bovine scrotal tissue. However, at the inception of this study, these tissue models were not yet in place and therefore steak
tissue was used to provide a rough approximation of lidocaine transfer kinetics prior to field studies. therefore steak tissue was used to provide a rough approximation of lidocaine transfer kinetics prior
to field studies. The in vitro observations were generally corroborated by the in vivo data (in which all three
band types were assessed): tissue concentrations of lidocaine were similar over the short term (i.e.,
up to 6 h), but higher over the longer term (i.e., up to 7 days) for LLBs relative to injected control
animals (Figure 5). These results confirm that lidocaine absorption is initially similar for the two
routes of administration (i.e., transdermal vs subcutaneous injection), despite the difference between
The in vitro observations were generally corroborated by the in vivo data (in which all three band
types were assessed): tissue concentrations of lidocaine were similar over the short term (i.e., up to
6 h), but higher over the longer term (i.e., up to 7 days) for LLBs relative to injected control animals
(Figure 5). These results confirm that lidocaine absorption is initially similar for the two routes of
administration (i.e., transdermal vs subcutaneous injection), despite the difference between the two
tissue types. However, lidocaine tends to be significantly higher in LLB-treated vs injected samples 13 of 16 Animals 2020, 10, 2363 13 of 16 starting at approximately the 6 h time point, likely reflecting the fact that lidocaine injection is a
one-offtreatment at Time 0, while LLBs were shown continue to deliver lidocaine for at least 7 days. This would have obvious benefits for both acute and chronic pain management during castration,
with immediate pain relief at the time of band application and sustained pain-relief over the course of
at least 7 days. In order to confirm whether LLBs continue to deliver therapeutic quantities of lidocaine
beyond 7 days, it will be necessary to conduct a longer-term study. The concentrations of lidocaine in the LLB-treated tissue samples were generally in the range of
0.15–3.5 mg of lidocaine per gram of tissue. 4. Discussion
4. Discussion In contrast, lidocaine levels were generally lower for injected
tissue samples—in fact, beyond the 6 h time point, they were generally either undetectable or around
0.1 mg of lidocaine per gram of tissue (100 µg/g of tissue). For reference, tissue concentrations below
100 µg/g are not considered therapeutic [18]. It thus appears that lidocaine injection is often—but not
always—sufficient to achieve therapeutic levels of lidocaine in the scrotal tissue, while LLBs consistently
yield levels well above this threshold. Accordingly, with regard to the performance metrics evaluated in
this study, LLBs often perform similarly to lidocaine injection. For instance, LLBs yielded no statistically
significant differences in ADG versus lidocaine injection (Table 3), suggesting that LLB-treated animals
gained at least as much weight as the lidocaine-injected animals. ADG is a common indicator for
post-operative performance in livestock [19–21]. The lack of statistically significant differences in ADG
could also reflect the high variability in this data due, at least in part, to the low n value (especially for
the green bands). The green-banded ADG sampling is especially low (n = 3) because measuring ADG
was only considered and introduced at the conclusion of the green band trial. Based on this pilot
work, it would be interesting to measure ADG in a future trial involving a larger number of animals. Additionally, scrotal and underbelly temperatures were generally similar for LLB-treated versus injected
animals according to infrared thermography (Figures 6 and 7), with only one statistically significant
difference: for Callicrate™bands, at 168 h, the under-belly temperature was significantly lower for
LLB-treated vs injected animals (Figure 7C). In this context, lower temperature indicates reduced
blood flow and/or decreased inflammation [15,16]. This difference might reflect the fact that lidocaine
levels were significantly higher in the LLB-treated tissues at this time point; in fact, lidocaine was
undetectable in the injected samples (Figure 5C). Finally, LLB-treated animals had similar responses
to electrostimulation relative to lidocaine-injected animals (Figure 8), with significantly reduced
responses only at the 168 h time points of the Callicrate™and Beige-banded animals. This might reflect
the significantly reduced levels of lidocaine in the injected animals at this time point (Figure 5B,C),
even though the injected levels were above the therapeutic threshold for the Beige-banded cohort
(Figure 5B). 4. Discussion
4. Discussion Moreover, the average heart rate and number of tail flicks were not significantly different
between LLB-treated and lidocaine-injected animals (Supplemental Figures S1 and S2), suggesting a
similar performance of these two methods of pain mitigation. From a safety perspective, no adverse
events or mortalities were observed in either the treatment or control groups over the course of the
in vivo field studies. Taken together, these results indicate that LLBs perform at least as well as
lidocaine injections for short-term lidocaine delivery and pain mitigation (up to approximately 6 h). Moreover, LLBs generally outperform lidocaine injections for long-term delivery and pain mitigation
(up to at least 7 days). Of note, we elected to compare the performance of the LLBs to injections of lidocaine into
the spermatic cord rather than a ring block delivery because the LLB technology incorporates
a skin permeation enhancer which is designed to deliver anesthetic deep into the scrotal tissue. Therefore, the cord injection was chosen over the ring block to facilitate a more accurate comparison to
the LLB delivery profile. We acknowledge that future studies could also include a ring block control
group to make an evaluation of deep versus surface anesthesia. The relatively short duration of lidocaine delivery and pain mitigation reported here for lidocaine
injection at the time of castration is in keeping with other published studies. For instance, in a study
of the effect of lidocaine on indicators of pain and distress during and after knife castration in beef
calves, Melendez et al. (2018) noted that salivary cortisol concentrations were only significantly lower Animals 2020, 10, 2363 14 of 16 14 of 16 in lidocaine-injected versus untreated animals at 0.5 and 1 h after castration [5]. Stafford et al. (2002)
found that lidocaine injection significantly reduced mean plasma cortisol concentrations in calves in
response to band castration over a similar time period (0.5 to 3 h post-banding) [12]. Generally, this pilot work facilitated the prototype development and field validation of
lidocaine-loaded castration bands for bovine pain mitigation. Due to the complex, multi-faceted nature
of accurately assessing and reporting pain in animal studies [3,4], a robust, unambiguous measurement
protocol should be employed. 4. Discussion
4. Discussion To evaluate the effectiveness of the LLB compared to lidocaine injection,
the methods presented here combined the measurement of two behavioural responses (tail flicks and
response to electrocutaneous stimulation) with the quantitation of one performance indicator (ADG),
two physiological indicators (tissue inflammation and average heart rate), and tissue lidocaine levels. In future studies, it might be advantageous to include additional physiological indicators of pain and
inflammation, such as substance P and salivary cortisol levels. While the field studies presented here
lasted 7 days, future work should increase the study duration to approximately 3–6 weeks to reflect
the actual duration of banded castration. A secondary objective of this work was to develop an objective assessment tool that generated
more consistent results between different observers and different instruments [19] for the specific
application of evaluating topical lidocaine delivery to generate an effective local anesthetic effect. To this
aim, we took cues from the work of Melendez et al. (2018) [5], Musk et al. (2017) [19], and Winder et al. (2017) [22], and developed an evaluation protocol that incorporated a combination of physiological and
behavioural metrics to evaluate pain response over the course of our field trials. Moreover, we adopted
the use of an electrocutaneous nerve stimulation protocol (a standard of practice in guiding and
monitoring peripheral nerve blocks) [23,24] to evaluate the loss of sensation in the animals’ scrotums
over acute and chronic observation periods. For the purposes of this study, we define ‘acute’ and
‘chronic’ as the first several hours (up to approximately 6 h) and the first several days (up to at least
one week) post-castration, respectively. Our method also incorporated the use of precision analytical
HPLC to detect and quantify the lidocaine directly in the sampled tissue of interest. This analysis
was originally incorporated into the trial design to better understand the LLB device performance;
however, the addition of this analytical step provided this protocol with the means to attain comparable
objective measurements between instruments (electrocutaneous stimulation results assessed against
physiologically relevant levels of lidocaine in the tissue). The ultimate goal of this work is to provide producers with a practical and effective tool to
provide long-term pain control for banded castration. 4. Discussion
4. Discussion The benefits to the industry include a simplified
banding procedure (eliminating the need for lidocaine injection), reduced costs, societal and animal
welfare benefits associated with improved pain control, and a potentially improved castration device
(i.e., through increased ADG and enhanced recovery). Finally, as pain management is important for
the well-being of the animal and castration recovery time [3,4], this work has obvious benefits for
animal welfare. Author Contributions: Conceptualization, N.D.A., C.S., H.M.-B., B.R., K.S. and M.O.; methodology, N.D.A., C.S.,
H.M.-B., B.R., K.S., M.O., T.T., O.G., J.E.W. and R.T.; formal analysis, J.W.S., J.A.R., C.S., N.D.A., H.M.-B., B.R.
and M.O.; investigation, J.W.S., N.D.A., C.S., H.M.-B., B.R., K.S. and M.O.; writing—original draft preparation,
J.A.R. and J.W.S.; writing—review and editing, J.A.R., J.W.S., C.S., N.D.A. and J.E.W.; visualization, J.A.R. and Supplementary Materials: The following are available online at http://www.mdpi.com/2076-2615/10/12/2363/s1,
Figure S1: Number of tail flicks for control (lidocaine injection) or treated (LLB) animals over time. Figure S2:
Average heart rate for control (lidocaine injection) or treated (LLB) animals over time. References 1. Coetzee, J.F.; Nutsch, A.L.; Barbur, L.A.; Bradburn, R.M. A survey of castration methods and associated
livestock management practices performed by bovine veterinarians in the United States. BMC Vet. Res. 2010,
6, 12. [CrossRef] [PubMed] 1. Coetzee, J.F.; Nutsch, A.L.; Barbur, L.A.; Bradburn, R.M. A survey of castration methods and associated
livestock management practices performed by bovine veterinarians in the United States. BMC Vet. Res. 2010,
6, 12. [CrossRef] [PubMed] 2. AVMA. Literature Review on the Welfare Implications of Castration of Cattle. Am. Vet. Med. Assoc. 2014. Available online: https://www.avma.org/sites/default/files/resources/castration-cattle-bgnd.pdf (accessed on
8 December 2020). 2. AVMA. Literature Review on the Welfare Implications of Castration of Cattle. Am. Vet. Med. Assoc. 2014. Available online: https://www.avma.org/sites/default/files/resources/castration-cattle-bgnd.pdf (accessed on
8 December 2020). 3. Coetzee, J.F. A review of pain assessment techniques and pharmacological approaches to pain relief after
bovine castration: Practical implications for cattle production within the United States. Appl. Anim. Behav. Sci. 2011, 135, 192–213. [CrossRef] 3. Coetzee, J.F. A review of pain assessment techniques and pharmacological approaches to pain relief after
bovine castration: Practical implications for cattle production within the United States. Appl. Anim. Behav. Sci. 2011, 135, 192–213. [CrossRef] 4. Fajt, V.R.; Wagner, S.A.; Norby, B. Analgesic drug administration and attitudes about analgesia in cattle
among bovine practitioners in the United States. J. Am. Vet. Med. Assoc. 2011, 238, 755–767. [CrossRef]
[PubMed] 4. Fajt, V.R.; Wagner, S.A.; Norby, B. Analgesic drug administration and attitudes about analgesia in cattle
among bovine practitioners in the United States. J. Am. Vet. Med. Assoc. 2011, 238, 755–767. [CrossRef]
[PubMed] 5. Melendez, D.M.; Marti, S.; Pajor, E.A.; Sidhu, P.K.; Gellatly, D.; Moya, D.; Janzen, E.D.; Coetzee, J.F.;
Schwartzkopf-Genswein, K.S. Effect of meloxicam and lidocaine administered alone or in combination on
indicators of pain and distress during and after knife castration in weaned beef calves. PLoS ONE 2018,
13, e0207289. [CrossRef] [PubMed] 6. Olson, M.E.; Ralston, B.; Burwash, L.; Matheson-Bird, H.; Allan, N.D. Efficacy of oral meloxicam suspension
for prevention of pain and inflammation following band and surgical castration in calves. BMC Vet. Res. 2016, 12, 102. [CrossRef] [PubMed] 7. NFACC. Code of Practice for the Care and Handling of Beef Cattle; National Farm Animal Care Council: Lacombe,
AB, Canada, 2013; Available online: https://www.nfacc.ca/pdfs/codes/beef_code_of_practice.pdf (accessed on
8 December 2020). 8. Anderson, N. Castration of Calves; Ontario Ministry of Agriculture, Food and Rural Affairs: Guelph,
ON, Canada, 2015. Available online: http://www.omafra.gov.on.ca/english/livestock/beef/facts/07-029.htm
(accessed on 8 December 2020). 5. Conclusions Lidocaine-loaded elastration bands are capable of delivering significant quantities of lidocaine
into scrotal tissues over at least seven days. This approach could provide long-term pain mitigation to
the animals and, by avoiding surgery or the administration of injections, decrease time and handling
costs for the producer. Supplementary Materials: The following are available online at http://www.mdpi.com/2076-2615/10/12/2363/s1,
Figure S1: Number of tail flicks for control (lidocaine injection) or treated (LLB) animals over time. Figure S2:
Average heart rate for control (lidocaine injection) or treated (LLB) animals over time. Author Contributions: Conceptualization, N.D.A., C.S., H.M.-B., B.R., K.S. and M.O.; methodology, N.D.A., C.S.,
H.M.-B., B.R., K.S., M.O., T.T., O.G., J.E.W. and R.T.; formal analysis, J.W.S., J.A.R., C.S., N.D.A., H.M.-B., B.R. and M.O.; investigation, J.W.S., N.D.A., C.S., H.M.-B., B.R., K.S. and M.O.; writing—original draft preparation,
J.A.R. and J.W.S.; writing—review and editing, J.A.R., J.W.S., C.S., N.D.A. and J.E.W.; visualization, J.A.R. and 15 of 16 15 of 16 Animals 2020, 10, 2363 J.W.S.; supervision, N.D.A., J.E.W. and M.O.; project administration, C.S., H.M.-B. and N.D.A.; funding acquisition,
J.E.W., N.D.A. and M.O. All authors have read and agreed to the published version of the manuscript. J.W.S.; supervision, N.D.A., J.E.W. and M.O.; project administration, C.S., H.M.-B. and N.D.A.; funding acquisition,
J.E.W., N.D.A. and M.O. All authors have read and agreed to the published version of the manuscript. Funding: Partial salary support for J.W.S. came from an NSERC USRA, while laboratory studies were funded
in part by NSERC Engage and Engage Plus grants to J.W. (award #531133-18 and 538474-19). CCR funded the
field studies and additional support came from the Canada Research Chairs program and the University of
Victoria. Development work and field trial work was supported in part by Canadian Advancing Agriculture
Grant P074 (held by Alberta Beef Producers) and AAF Strategic Research and Develop Program Grant 2018R033R
(held by CCR). Acknowledgments: The authors wish to acknowledge the study design inputs from Karen Schwartzkopf-Genswein
and Daniela Meledez Suarez. The authors also wish to acknowledge the excellent technical assistance of
Denis Nagel, Les Burwash, Andrea Hanson, Karen Wickerson and Patty Manum (animal handling and data
collection), Henry Van Huigenbos, Wei (Ruth) Wei, Peri Donaghy, Tong Li, and Rebecca Hof. Finally, the authors
wish to acknowledge the critical input from the Canadian cattle industry for design inputs and feedback,
particularly Alberta Beef Producers, Alberta Farm Animal Care, and Mary-Anne Schwengler of the Calgary
Central Feeders Association. 5. Conclusions Conflicts of Interest: J.A.R., C.S., N.D.A., and H.M.-B. receive a salary from Chinook Contract Research Inc. (CCR);
M.O. and N.D.A. own shares of CCR, which has applied for patents relating to the contents of this manuscript. R.T. has patent interests. R.T. has patent interests. References 9. Carter, B.; Mathis, C.P.; Löest, C.; Wenzel, J. Castrating Beef Calves: Age and Method; New Mexico State
University: College of Agricultural, Consumer, and Environmental Sciences: Las Cruces, NM, USA, 2011;
Available online: https://aces.nmsu.edu/pubs/_b/B227.pdf (accessed on 8 December 2020). 10. Molony, V.; Kent, J.E.; Robertson, I.S. Assessment of acute and chronic pain after different methods of
castration of calves. Appl. Anim. Behav. Sci. 1995, 46, 33–48. [CrossRef] 11. Golzari, S.E.; Soleimanpour, H.; Mahmoodpoor, A.; Safari, S.; Ala, A. Lidocaine and pain management in the
emergency department: A review article. Anesth. Pain Med. 2014, 4, e15444. [CrossRef] [PubMed] 16 of 16 Animals 2020, 10, 2363 16 of 16 12. Stafford, K.J.; Mellor, D.J.; Todd, S.E.; Bruce, R.A.; Ward, R.N. Effects of local anaesthesia or local anaesthesia
plus a non-steroidal anti-inflammatory drug on the acute cortisol response of calves to five different methods
of castration. Res. Vet. Sci. 2002, 73, 61–70. [CrossRef] 13. Tennessen, T.; Connor, L.; Passillé, A.M.D.; Duncan, I.; Feddes, J.; Keaney, M.; Kochhar, H.; MacDonald, S.;
Rushen, J.; Silversides, F.; et al. CCAC Guidelines on: The Care and Use of Farm Animals in Research,
Teaching and Testing; Canadian Council on Animal Care: Ottawa, ON, Canada, 2009; Available online:
https://www.ccac.ca/Documents/Standards/Guidelines/Farm_Animals.pdf (accessed on 8 December 2020). Rushen, J.; Silversides, F.; et al. CCAC Guidelines on: The Care and Use of Farm Animals in Research,
Teaching and Testing; Canadian Council on Animal Care: Ottawa, ON, Canada, 2009; Available online:
https://www.ccac.ca/Documents/Standards/Guidelines/Farm Animals.pdf (accessed on 8 December 2020). 14. Fierheller, E.E.; Caulkett, N.A.; Haley, D.B.; Florence, D.; Doepel, L. Onset, duration and efficacy of four
methods of local anesthesia of the horn bud in calves. Vet. Anaesth. Analg. 2012, 39, 431–435. [CrossRef]
[PubMed] 15. Alsaaod, M.; Schaefer, A.L.; Büscher, W.; Steiner, A. The Role of Infrared Thermography as a Non-Invasive
Tool for the Detection of Lameness in Cattle. Sensors 2015, 15, 14513–14525. [CrossRef] [PubMed] 16. Purohit, R.C.; Hudson, R.S.; Riddell, M.G.; Carson, R.L.; Wolfe, D.F.; Walker, D.F. Thermography of the
bovine scrotum. Am. J. Vet. Res. 1985, 46, 2388–2392. [PubMed] 7. Padula, C.; Colombo, G.; Nicoli, S.; Catellani, P.L.; Massimo, G.; Santi, P. Bioadhesive film for the transder
delivery of lidocaine: In vitro and in vivo behavior. J. Control. Release 2003, 88, 277–285. [CrossRef] 17. Padula, C.; Colombo, G.; Nicoli, S.; Catellani, P.L.; Massimo, G.; Santi, P. Bioadhesive film for the transdermal
delivery of lidocaine: In vitro and in vivo behavior. J. Control. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/). References Release 2003, 88, 277–285. [CrossRef]
18. Tanaka, E.; Yoshida, K.; Kawaai, H.; Yamazaki, S. Lidocaine Concentration in Oral Tissue by the Addition of 8. Tanaka, E.; Yoshida, K.; Kawaai, H.; Yamazaki, S. Lidocaine Concentration in Oral Tissue by the Additio
Epinephrine. Anesth. Prog. 2016, 63, 17–24. [CrossRef] [PubMed] 19. Musk, G.C.; Jacobsen, S.; Hyndman, T.H.; Lehmann, H.S.; Tuke, S.J.; Collins, T.; Gleerup, K.B.; Johnson, C.B.;
Laurence, M. Objective Measures for the Assessment of Post-Operative Pain in Bos indicus Bull Calves
Following Castration. Animals 2017, 7, 76. [CrossRef] [PubMed] 20. Canozzi, M.E.A.; Mederos, A.; Manteca, X.; Turner, S.; McManus, C.; Zago, D.; Barcellos, J.O.J. A meta-analysis
of cortisol concentration, vocalization, and average daily gain associated with castration in beef cattle. Res. Vet. Sci. 2017, 114, 430–443. [CrossRef] [PubMed] 21. Van der Saag, D.; Lomax, S.; Windsor, P.A.; Taylor, C.; Thomson, P.; Hall, E.; White, P.J. Effects of topical
anaesthetic and buccal meloxicam on average daily gain, behaviour and inflammation of unweaned beef
calves following surgical castration. Animal 2018, 12, 2373–2381. [CrossRef] [PubMed] 22. Winder, C.B.; LeBlanc, S.J.; Haley, D.B.; Lissemore, K.D.; Godkin, M.A.; Duffield, T.F. Clinical trial of local
anesthetic protocols for acute pain associated with caustic paste disbudding in dairy calves. J. Dairy Sci. 2017, 100, 6429–6441. [CrossRef] [PubMed] 23. Bomberg, H.; Wetjen, L.; Wagenpfeil, S.; Schöpe, J.; Kessler, P.; Wulf, H.; Wiesmann, T.; Standl, T.; Gottschalk, A.;
Döffert, J.; et al. Risks and Benefits of Ultrasound, Nerve Stimulation, and Their Combination for Guiding
Peripheral Nerve Blocks: A Retrospective Registry Analysis. Anesth. Analg. 2018, 127, 1035–1043. [CrossRef]
[PubMed] 24. Warren, V.T.; Fisher, A.G.; Rivera, E.M.; Saha, P.T.; Turner, B.; Reside, G.; Phillips, C.; White, R.P., Jr. Buffered 1% Lidocaine with Epinephrine Is as Effective as Non-Buffered 2% Lidocaine With Epinephrine for
Mandibular Nerve Block. J. Oral Maxillofac. Surg. 2017, 75, 1363–1366. [CrossRef] [PubMed] Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional
affiliations. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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Geological education scenario in India and role of open educational resources in the light of COVID-19 pandemic
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El escenario de la educación geológica en India y el rol de los recursos
pedagógicos abiertos a las luces de la pandemia del covid-19 El escenario de la educación geológica en India y el rol de los recursos
pedagógicos abiertos a las luces de la pandemia del covid-19 resources in the light of COVID-19 pandemic Omkar Vermaa*, Manthena Prashantha, Roberto Grecob, Ashu Khoslac, Kulwant Singhd
a. Geology Discipline Group, School of Sciences, Indira Gandhi National Open University, New Delhi, India. E-mail: omkarverma@ignou.ac.in
b Instituto de Geociências, Universidade Estadual de Campinas, Rua Carlos Gomes, 250, Campinas, SP, Brazil. c. Department of Geology, Panjab University, Chandigarh, India. d. Department of Geology, GGM Science College, Jammu Tawi, India. d. Department of Geology, GGM Science College, Jammu Tawi, India. Palabras clave: Educación geológica; datos
de inscripciones; educación superior; recursos
educativos abiertos; covid-19; trabajo de campo
geológico; India. ABSTRACT Keywords: Geological education; Enrolment data;
Higher education; OER; COVID-19; Geological
fieldwork; India. Geological education plays a major role in the social, economic, and cultural growth and development of any coun-
try. India is a vast diversified country with wide-ranging geological features, consisting of rocks of all geological ages
with well-developed physiographic divisions. The Indian lithospheric plate is a storehouse of vast georesources and
also serves as a natural field laboratory for developing and testing numerous geological principles. The exploration of
Indian georesources began in the past; with the organized exploration began way back in the 1830s. The number of
institutions offering geological education is, however, comparatively low. Thus, Geology as a science discipline is less
popular in comparison with other science subjects such as Physics, Chemistry, Zoology, Botany, and Environmental
science, based on enrolment data of the learners enrolled in academic sessions from 2011-2012 to 2018-2019 of the
Master’s degree programs. Analysis indicates that teaching-learning resources of foreign origin are dominantly being
adopted as learning resources in the teaching-learning pedagogy of degree programs in Geology, and are over-riding
those of Indian origin. The COVID-19 pandemic is affecting geological education in two ways namely, the disruption
of conventional (face-to-face) teaching together with not allowing learners of Geology programs to complete their
compulsory out-door geological fieldwork assignments. The analysis of data gathered by an online questionnaire survey
shows that the use of indigenous open educational resources in Geology appears as a plausible solution to overcome the
learning barriers created by the COVID-19 pandemic, and also to enrich teaching-learning resources of Indian origin. This article provides an up-to-date detailed account of the necessity and evolution of geological education, the current
popularity of Geology as a science discipline, the nature of available geological teaching-learning resources, the impact
of the COVID-19 on geological education, and the role of open educational resources in providing quality and equita-
ble geological education, whilst removing educational barriers created by COVID-19 in India. How to cite item:
Verma, O., Prashanth, M., Greco, R., Khosla, A.,
& Singh, K. (2022). Geological education scenario
in India and role of open educational resources in
the light of COVID-19 pandemic. Earth Sciences
Research Journal, 26(3), 239-254. https://doi.
org/10.15446/esrj.v26n3.96209 Geological education scenario in India and role of open educational
resources in the light of COVID-19 pandemic Geological education scenario in India and role of open educational EARTH SCIENCES
RESEARCH JOURNAL
Earth Sci. Res. J. Vol. 26, No. 2 (September, 2022): 239 - 254 EARTH SCIENCES
RESEARCH JOURNAL
Earth Sci. Res. J. Vol. 26, No. 2 (September, 2022): 239 - 254 GEOLOGY EARTH SCIENCES
RESEARCH JOURNAL
Earth Sci. Res. J. Vol. 26, No. 2 (September, 2022): 239 - 254 ISSN 1794-6190 e-ISSN 2339-3459
https://doi.org/10.15446/esrj.v26n3.96209 RESUMEN La educación geológica juega un papel importante en el desarrollo y en el crecimiento social, económico y cultural de
cualquier país. La India es un país vasto y diverso y con un amplio rango de características geológicas que consiste en
rocas de todas las edades geológicas y divisiones fisiográficas bien desarrolladas. La placa litosférica india es un depósito
de grandes georecursos y también sirve como un laboratorio de campo para el desarrollo y evaluación de numerosos
principios geológicos. La exploración organizada de los georrecursos indios comenzó en la década de 1830. El número
de instituciones que ofrecen educación geológica es, sin embargo, comparativamente bajo. De este modo, la geología
es una ciencia disciplinar menos popular en comparación con otras materias de estudio como la física, la química,
la zoología, la botánica y la ciencia ambiental, con base en la información de inscripciones de los estudiantes en los
programas de maestría para los períodos de 2011-2012 hasta 2018-2019. El análisis indica que los recursos foráneos de
enseñanza-aprendizaje son adoptados dominantemente como los recursos de aprendizaje en la pedagogía de los progra-
mas de pregrado en Geología y superan aquellas de origen indio. La pandemia del covid-19 está afectando la educación
geológica en dos vías especificamente: la disrupción de la enseñanza convencional (presencial) junto con no permitir a
los estudiantes de los programas de geología completar sus tareas obligatorias de trabajo de campo. El análisis de la in-
formación recopilada por una encuesta digital muestra que el uso de recursos educativos nativos abiertos en geología es
una solución posible para superar las barreras de aprendizaje creadas por la pandemia, y también enriquecen los recur-
sos de enseñanza-aprendizaje de origen indio. Este artículo provee un recuento detallado y actualizado de la necesidad
y evolución de la educación geológica, la actual popularidad de la geología como una ciencia disciplinar, la naturaleza de
los recursos disponibles de enseñanza-aprendizaje, el impacto de la pandemia del covid-19 en la educación geológica,
y el rol de los recursos pedagógicos para proveer educación geológica equitativa y de calidad mientras se remueven las
barreras educativas creadas por la pandemia en India. Record
Manuscript received: 28/05/2021
Accepted for publication: 17/08/2022 Record
Manuscript received: 28/05/2021
Accepted for publication: 17/08/2022 2. Methodology y
Geology plays a significant role in the overall growth and development
of society. In support of geological education, an International Geoscience
Education Organization (IGEO) was formally established in 2000 (King,
2019). The main objectives of the IGEO are to promote geoscience education
at the global level, enhance its quality and equity, and increase its awareness
in all sectors of society at all levels (http://www.igeoscied.org/about-
the-igeo/). In this context, eight international conferences on geoscience
education have been organized worldwide so far by the IGEO since 1993
(http://www.igeoscied.org/activities/geoscied/). The IGEO is also promoting
open online teaching geological resources encompassing Earth learning
ideas, complete teaching units, and geoscience textbooks for the use of the
global teaching-learning community in various international languages
(King, 2008; http://www.igeoscied.org/teaching-resources/). Apart from
this, the IGEO has been conducting International Earth Science Olympiad
since 2007 for popularizing geoscience education among school kids
(http://www.igeoscied.org/activities/ieso-2/). Two methodological approaches were adopted for this study. The first
approach involved the collection and analysis of literature to evaluate the
importance of imparting geological education, trace the development of
geological education from 1851 to the present in India, evaluate the status of
geological education in comparison with other sciences at the level of Master’s
degree programs, and finally, know the nature of geological TLR in India. It
was found that almost all research dealing with the historical development
of geological education in India was undertaken by historians. To date, no
researcher with a geological background had investigated evolutionary
development and the future of geological education in India. The data dealing with the enrolment and successful completion of
Master’s degree programs in Geology, Physics, Chemistry, Botany, Zoology,
and Environmental science for academic sessions from 2011-2012 to 2018-
2019 was obtained from the annual reports of the Ministry of Human Resources
and Development (now renamed as the Ministry of Education), GOI within
the ‘all India survey on higher education’ available on its website (http://aishe. nic.in/aishe/reports); this allowed comparative analysis between Geology and
other science disciplines. The data dealing with learners’ enrolment and their
successful completion in the Bachelor’s degree programs are not available;
therefore, Bachelor’s degree programs were not included in this study. 1. Introduction media platforms like youtube. It has been shown that course-based-specific
OER (including virtual labs, virtual field experiences, and Google Earth-based
laboratory/field manuals) for Bachelor’s and Master’s degree programs in
Geology are the need of the hour (Verma, 2021a). The use of OER in teaching-
learning practice offers an opportunity to narrow down the gap of the TLR of
Indian origin. OER provide off-campus specific-course-based learning during
any pandemic like COVID-19, and also can, to an extent, facilitate the learners
to complete their geological field-based assignments using Google Earth-based
virtual field manuals. Research focusing on the past, present, and future of
geological education is a major concern and is being carried out in the Western
Hemisphere particularly, in the US and UK (King, 2008, 2018; GSA Position
Statement, 2016; Dolphin et al., 2019). As a consequence, a journal has been
launched, the “Journal of Geoscience Education” for publishing geological
education research. To date, substantial research on geological education has
not taken place in India, and probably, this article may be first of its kind in
India. The primary objectives of this paper are threefold: first, to evaluate why
geological education is necessary for the country and review its historical
development; second, to assess the current popularity of Geology as a science
discipline, the nature of available geological TLR, and impact of COVID-19
on higher geological education; and third, to evaluate OER role in providing
high quality and equitable geological education, and in removing some of the
educational barriers created by COVID-19. The usage of the word “Geology” in the scientific literature can
be traced to the beginning of the eighteenth century (Howarth, 2020). In
the late nineteenth century, the scope of the discipline of Geology was
massively broadened in the Western World (King, 2008). As a result, different
terminologies for the discipline of Geology came into existence. The new
terms “Earth sciences” emerged in 1852; “Geoscience” appeared in 1929 and
later, “Geological sciences” in 1938, in the geological literature (Wilson, 1883;
Adams, 1938; Field, 1941; Howarth, 2020). All these words are synonymous
with each other and broadly, involved in the study of the whole Earth and other
planetary systems (Manduca & Kastens, 2012). Geology has been described as
a historical and descriptive science, where processes and conditions of Earth,
atmosphere, and oceans are investigated to understand Earth for the well-being
of the society (Frodeman, 1995; Manduca & Kastens, 2012). 2. Methodology Both, geological education and research are essential in India, because
the Indian subcontinent is endowed with significant amounts of georesources,
whilst research on its geological settings has proved to be valuable in unraveling
various mechanisms of the Earth system and generation of the georesources of
the subcontinent (Wadia, 1964; Tandon et al., 1991; Naqvi, 2005; Radhakrishna,
2005; Santosh, 2012; Valdiya, 2016; Searle & Treloar, 2019; Kumari et
al., 2020). Geological research in India began in 1836 (Oldham, 1856), but,
Geology as an independent educational science discipline first appeared in a
few Indian universities in the 1890s (Murty, 1982). An analysis of the enrolment
data for the Master’s degree program in Geology shows that Geology is still
a less popular science discipline in India. It also indicates that a majority of
Teaching-Learning Resources (TLR) consisting of reading material used in
higher geological education, are more of foreign origin, and may or may not be
accessible to the teaching-learning community in India. Two types of negative
impacts are visualized in the light of the current pandemic (i.e. COVID-19)
on geological education, firstly, temporary suspension of classroom/face-to-
face teaching, and secondly, the creation of an unfavorable environment for
completing geological field-based compulsory assignments for Bachelor’s and
Master’s degree programs. We downloaded two curricula of Bachelor’s degree programs in Geology
from the website of the University Grant Commission and the curricula of
Master’s degree programs from 25 universities (including Central Universities
and State/Union Territory Universities) from their websites to discover the
nature of existing TLR. The number of TLR of foreign and Indian origin
recommended in the above-mentioned curricula were counted and analyzed. We had not disclosed the names of 25 universities and presented them as
anonymous because the purpose of the research was to evaluate the nature of
TLR available or used in India. The second method followed was a structured
online survey. A Google-based questionnaire dealing with the current use of the
OER for geological teaching-learning practices in India, their role in overcoming
the learning restrictions imposed by the prevailing COVID-19 pandemic, and
enriching teaching-learning resources of Indian origin were prepared and sent
by email to numerous academicians and researchers covering almost all parts of
the country. The responses received were evaluated and interpreted. 1. Introduction It is a scientific
discipline of societal relevance in meeting many of its needs notably, natural
resources, environmental quality, and resilience to natural hazards (King,
2019). Geoscientists use current natural phenomenon data to understand Earth’s
past data to evaluate Earth’s present conditions and together, predict how Earth
will likely behave in the future. Thus, geological education is the backbone
of the socio-economic development of any country, and the dissemination of
its knowledge to the different individuals (learners, public, and policymakers),
is crucial in the decision-making processes, and for the long-term survival of
humanity on the Mother Earth.i How to cite item: ISSN 1794-6190 e-ISSN 2339-3459
https://doi.org/10.15446/esrj.v26n3.96209 240 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh 2. Methodology Recently, Open Education Resources (OER) are becoming popular
among science disciplines and the global teaching-learning community has
been using them extensively in day-to-day teaching-learning practices (Smith,
2009; Henderson & Ostashewski, 2018; y Verma, 2021a). OER are also gaining
importance in India and currently, there are a few OER in Geology, which are
available on online platforms of the Government of India (GOI), for example,
the e-pgpathshala portal of the University Grant Commission (UGC) and
Swayam of the Ministry of Human Resources Development (MHRD) (https://
epgp.inflibnet.ac.in/; https://swayam.gov.in/), and a few available on social Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh Geological education: why it is important in India? DC stands for
Dharwar craton, BC Bastar craton, SC Singhbhum craton, BKC Bundelkhand
craton, AC Aravalli craton, MC Meghalaya craton; PMB Pandyan mobile belt,
EGMB Eastern Ghat mobile belt, SMB Satpura mobile belt, ADMB Aravalli-Delhi
mobile belt; CKB Cuddapah- Kurnool basin, CGB Chhattisgarh basin, KB Kaladgi
basin, BB Bhima basin, PB Pakhal basin, VB Vindhyan basin, GB Gwalior basin,
MB Marwar basin; PGV Pranhita-Godavari valley, MV Mahanadi valley, DV
Damodar valley, SV Satpura valley; DT Deccan traps, and RT Rajmahal traps. Figure 1. Map of India showing the main physiographic divisions and geological
units (modified after Kumar, 2010; Valdiya, 2016; Shah, 2018). DC stands for
Dharwar craton, BC Bastar craton, SC Singhbhum craton, BKC Bundelkhand
craton, AC Aravalli craton, MC Meghalaya craton; PMB Pandyan mobile belt,
EGMB Eastern Ghat mobile belt, SMB Satpura mobile belt, ADMB Aravalli-Delhi
mobile belt; CKB Cuddapah- Kurnool basin, CGB Chhattisgarh basin, KB Kaladgi
basin, BB Bhima basin, PB Pakhal basin, VB Vindhyan basin, GB Gwalior basin,
MB Marwar basin; PGV Pranhita-Godavari valley, MV Mahanadi valley, DV
Damodar valley, SV Satpura valley; DT Deccan traps, and RT Rajmahal traps. Prominent rift valleys such as Pranhita-Godavari, Satpura, Mahanadi, and
Damodar (Fig. 1) probably developed during Proterozoic times, where thick
sedimentary covers developed within these valleys that are termed Gondwana
basins containing huge deposits of coal and a wealth of animal and plant fossils
over Upper Palaeozoic to Mesozoic time intervals (Naqvi, 2005; Valdiya, 2016;
Fareeduddin et al., 2020). The fossils of Gondwana deposits have provided
data enabling the reconstruction of land ecosystems of Upper Palaeozoic to
Mesozoic of peninsular India, together with their interrelations with ecosystems
of continents that were adjacent at the time (Valdiya, 2016). The prominent
Cretaceous volcanic traps (Rajmahal and Deccan) offer opportunities to study
the interior of the Earth, the role of mantle plumes in the rifting and drifting of
the former Gondwanan continents, the movement rate of the Indian plate, and
the environmental impacts of volcanic eruption on contemporary biota (Beane
et al., 1986; Courtillot, 1990; Verma, 2015; Verma et al., 2016, Mukherjee et
al., 2016; Verma & Khosla, 2019; Kania et al., 2022; Khosla et al., 2022). Geological education: why it is important in India? Indian geological education has many strategies for meeting the varied
needs of society, addressing the economic growth of the country using natural
resources, and refining basic and applied principles of Geology (Sharma, 1998;
Radhakrishna, 2005; Sheth, 2007; Jain et al., 2016; Mandal, 2016; Mukherjee
et al., 2016; Mazumder et al., 2019; Parsons et al., 2020). Since geological 241 Geological education scenario in India and role of open educational resources in the light of COVID-19 pandemic and industrial materials, gemstones, and decorative stones, and are excellent
sites for investigating Precambrian tectonism. The Proterozoic sedimentary
successions have yielded much biotic evidence, which is useful in studying
the early evolution of Earth’s life and atmosphere (Naqvi, 2005; Kumar, 2010;
Santosh, 2012; Mohanty, 2015; Valdiya, 2016; Shah, 2018; Mazumder et al.,
2019; Fareeduddin et al., 2020). education includes the whole Earth system, geoscientists study where we get
most of the things that we use in everyday life, such as minerals, soils, oil and
natural gas, energy, air, water, and food (Radhakrishna, 2005; Press, 2008). Geo-
professionals also play a critical role in numerous other societal services like the
management of waste (sewage, water pollution, landfills, non-biodegradable,
nuclear, and recycling), site selection for the construction of mega-projects
(dams, tunnels, reservoirs, roads, rail tracks, and buildings) together with
providing remedial measures for various environment-related problems. Geoscientists study natural hazards (earthquakes, tsunamis, volcanoes,
landslides, subsidence, floods, heat waves, droughts, natural contaminations,
cyclones, and severe storms) to determine the magnitude of their risks and to
develop resilient societies where life and property losses are minimized and
preparedness, mitigation and recovery are initiated (Shalley, 1971; Chakraborti
et al., 2011; Mora, 2013; Mukherjee, 2019; Valdiya, 2016; Fareeduddin et al.,
2020; Ali et al., 2021; Verma, 2021b; Prashanth & Verma, 2022). In today’s
world, due to the rapid increase in population and unsustainable practices in
the use of natural resources, there is tremendous stress on Earth’s resources,
causing many problems such as climate change, global warming, fossil fuels
scarcity, natural resources depletion, biodiversity loss, extreme weather events,
water contamination, and air pollution. Thus, nowadays, geo-professionals have
been working to resolve various Earth and environment-related issues whilst
ensuring sustainability in the use of natural resources, and their protection for
future generations (Häggquist & Söderholm, 2015; Valdiya, 2016). Geological education: why it is important in India? Additionally,
geological education has important societal implications in improving human
health standards and the environment by suggesting key remedial measures
to reduce the impact of geogenic elements and anthropogenic interventions in
the Earth’s natural environment. The geogenic contaminants of groundwater,
especially fluoride and arsenic, pose a serious threat to human health in India
(Ali et al., 2016; Ali et al., 2021). The endemic fluorosis caused due to high
concentration of fluoride in groundwater was recognized in 1937 and arsenic
contaminated health effects in the year 1976. However, groundwater was not
properly investigated for these contaminants until the late 1990s, resulting in the
poor health of millions of people in India (Chakraborti et al., 2011; Raju, 2017;
Ali et al., 2019; Saha et al., 2021). Figure 1. Map of India showing the main physiographic divisions and geological
units (modified after Kumar, 2010; Valdiya, 2016; Shah, 2018). DC stands for
Dharwar craton, BC Bastar craton, SC Singhbhum craton, BKC Bundelkhand
craton, AC Aravalli craton, MC Meghalaya craton; PMB Pandyan mobile belt,
EGMB Eastern Ghat mobile belt, SMB Satpura mobile belt, ADMB Aravalli-Delhi
mobile belt; CKB Cuddapah- Kurnool basin, CGB Chhattisgarh basin, KB Kaladgi
basin, BB Bhima basin, PB Pakhal basin, VB Vindhyan basin, GB Gwalior basin,
MB Marwar basin; PGV Pranhita-Godavari valley, MV Mahanadi valley, DV
Damodar valley, SV Satpura valley; DT Deccan traps, and RT Rajmahal traps. The awareness of geological time, the evolution of life, and Earth’s past
environments through the deep time is critically useful for society in view of
the alternative perspectives of myths and religions that help us to understand
how to live in harmony with the Earth (Ayala, 2008; Kölbl-Ebert, 2009). Overall, geological education, information, and guidance play key roles in
the decision-making process in numerous societal services such as sustainable
natural resources management, mega-structures construction, natural hazards
mitigation and management, local and regional planning, and environmental
impact assessments (Häggquist & Söderholm, 2015). Geological education is
also critical in meeting some of the sustainable development goals of the United
Nations (UN) such as zero hunger, good health and well-being, clean water and
environment, infrastructure, sustainable cities, climate action, and sustainable
marine resources (UN, 2015; Stewart & Gill, 2017). Figure 1. Map of India showing the main physiographic divisions and geological
units (modified after Kumar, 2010; Valdiya, 2016; Shah, 2018). Geological education: why it is important in India? The GSI has
recognized 26 geological sites as National Geological Monuments of India
that are located in various geologically rich states such as Andhra Pradesh,
Telangana, Chhattisgarh, Gujarat, Himachal Pradesh, Karnataka, Kerala,
Odisha, Rajasthan, Maharashtra, and Tamil Nadu (INTACH, 2016). However,
there are numerous geoheritage sites are in India, which are yet to be recognized
(Fig. 2). The Himalayan mountains belt, which is a product of the India-Asia
collision that took place in Eocene times, created a unique monsoon system,
and provided numerous natural resources, together with increased risks of
natural hazards across the Indian subcontinent (Sharma, 1998; Valdiya, 2016;
Searle & Treloar, 2019; Parsons et al., 2020). The monsoon system is a boon for
the agro-economic sector of the subcontinent. There are opportunities to study
the monsoon system to understand its mechanisms and the influence of the
El Niño-Southern Oscillation cycle on it (Das, 2015; Dimri et al., 2016). The
complex geological framework of the Himalayan makes it as an astonishing
natural laboratory to investigate pre-, post-, and syn-collisional and depositional
events associated with geodynamics of the Indian lithospheric plates and their
influence on the environment. The rich fossiliferous Palaeozoic-Mesozoic
successions of the north-western Himalaya provide excellent rock outcrops
for investigating the biological evolution of invertebrates (corals, mollusks,
brachiopods, echinoderms). The Himalayan Cenozoic successions contain
well-preserved vertebrate fossils (particularly of mammals), which are useful
for reconstructing mammalian diversity and their bearing on paleoecology,
paleoenvironment, and paleobiogeography of the Indian subcontinent (Naqvi,
2005; Valdiya, 2016). The Himalayan contains large regions of glaciers, snow,
and ice that serve as a significant freshwater reserve in Asia and provide
uninterrupted water supply to the nine river systems of Asia, and these give a
lifeline for nearly one-third of humanity. Climate change is seriously impacting
the snow and ice cover of the Himalayan ecosystem, which needs to be
investigated (Bisht et al. 2019; Sabin et al., 2020). The Himalaya is divided
into five tectonic belts from north to south: Trans, Tethys, Greater, Lesser, and
Outer Himalaya (Fig. 1). Each belt is bounded by prominent tectonic features
such as Tethyan, Main Central, Main Boundary, and Himalayan Frontal Thrusts
(Naqvi, 2005; Valdiya, 2016). These thrusts are seismically active zones and
any tectonic movement along these thrusts can cause serious natural hazards
such as slope instability, landslides, and earthquakes (Rajendran et al., 2017;
Prashanth et al., 2021). Geological education: why it is important in India? A vast majority, around 75%, of total global landslides
occur in the Asian continent alone, with a significant number of landslide
events occurring along the Himalaya mountain belts (Froude & Petley, 2018). Thus, the Himalayan region provides unique opportunities for studying plate
movements, plate boundaries, seismicity, neotectonics, slope stabilization,
soil erosion proneness, climate change, glacial melting, harnessing geological
resources, and mountain building processes (Jain & Sinha, 2005; Rajendran
et al., 2017; Prashanth et al., 2021, 2022; Kouser et al., 2022; Tandon, 2022). 2a 2a 2b
Figure 2. Photographs showing potential geoheritage sites in India. a. Huge granite
batholith, situated nearly 50 km from Hyderabad along the Hyderabad-Warangal
national highway at Bhongir town, Telangana, South India. This batholith is a
part of the Eastern Dharwar Craton and around 2.7 to 2.5 billion years old. b. Quaternary fluvio-lacustrine deposits at Lamayuru, Union Territory of Ladakh,
Northern India. These deposits are 105 m thick, dominantly composed of clay and
sand layers, which develop a lunar landscape at Lamayuru. These deposits are
popularly known as “moonland” of the Lamayuru. Both these geosites are places
of tourist’s attraction
(Courtesy: Naveen Kumar, Geologist, Geological Survey of India for b). 2b 2b The vast Indo-Gangetic plains of northern India comprise recent
sediments, which were brought down from the rising Himalayan by its various
rivers (Tandon et al., 1991; Tandon, 2022). These plains contain enormous
water resources and their sediments have made the soil cover of the plains very
fertile and so suitable for agriculture and industrial activities. As a result, nearly
50% of the total food grain production to feed 40% population of India comes
from these plains (Pal et al., 2009). These plains are currently facing alarming
amounts of soil degradation and water contamination (Mythili & Goedecke,
2016). The Great Thar Desert of Western India is an active area for exploring
mineral resources and for harnessing renewable energy such as solar and wind. Thus, geoscientific research plays an influential role in studying the availability
and spatial distribution of natural resources, regions of natural hazards,
environment-related issues, and sustainable natural resources management,
which are of direct concern to the society. Historically, the importance of the geological richness of the country
was understood in earlier times by the Mughal Empire, and as a result, they
ruled the subcontinent for 332 years from 1526 to 1858 (Babu & Nautiyal,
2013). Meanwhile, Britishers (i.e. Geological education: why it is important in India? The coastal regions of India contain a considerable cover of sedimentary
successions such as Bombay high (Maharashtra), Cambay basin (Gujarat),
Assam shelf (Assam), and Krishna-Cauvery basins (south India) largely formed
in response to marine transgression and regression during Cenozoic time, and
have provided valuable sources of lignite, coal, oil and natural gas (Biswas,
1982, 1987; Nagendra et al., 2011; Shah, 2018). These allow us to study the
phenomenon of the past sea level changes concerning changes in paleoclimate
(Naqvi, 2005; Kundal & Humane, 2007; Valdiya, 2016; Fareeduddin et al., 2020
y Verma, 2021b). Apart from education, geological research on the Indian lithospheric
plate provides a platform for generating new geological ideas and offers many
opportunities to study the geodynamics of the Earth on the global scale (Tandon
et al., 1991; Radhakrishna, 2005; Naqvi, 2005; Jain et al., 2016; Santosh, 2012;
Mandal, 2016; Mukherjee et al., 2016; Valdiya, 2016; Searle & Treloar, 2019;
Parsons et al., 2020). The Indian subcontinent has a distinctive topography
with the Indian Ocean lying to the south and the snow-covered Himalayan
mountains belt to the north. It includes three main physiographic divisions
(Fig. 1): peninsular India to the south, extra-peninsular India (i.e., Himalayan
division) to the north, and the Indo-Gangetic plains sandwiched between them
(Shah, 2018). The Indian lithospheric plate preserves the vast history of the
Earth from Archean to Holocene (4.6 billion years to the present) in its rock
record (Naqvi, 2005; Santosh, 2012; Mohanty, 2015; Valdiya, 2016; Shah,
2018). The peninsular region of India is dominantly composed of rocks of the
Precambrian age and is an amalgamation of Archean cratons (Dharwar, Bastar,
Singhbhum, Bundelkhand, Aravalli, and Meghalaya), and Proterozoic mobile
belts (Eastern Ghat, Pandyan, Satpura, and Aravalli-Delhi) and sedimentary
basins (Vindhyan, Kurnool-Cuddapah, Chhattisgarh, Gwalior, Pakhal, Marwar,
Bhima, and Kaladgi) (Fig. 1; Valdiya, 2016; Shah, 2018). The cratons and
mobile belts suffered various phases of Archean tectonic activity and as a
consequence, they are a rich storehouse of varied economic minerals, building 242 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh “geosites of significant educational, cultural, scientific, and aesthetic value”
(https://www.americasgeoheritage.com/geoheritage/). India has numerous rich
and diversified geocultural heritage sites and thus, provides ample opportunities
to promote education, research, and tourism related to geoheritage (Shekhar
et al., 2019; Biswas & Chauhan, 2021; Chauhan et al., 2021). Development of Indian higher geological education Development of Indian higher geological education The study of geological phenomena in India had been recorded from time
immemorial when Indians started to observe and record the behavior of Earth’s natural
processes. The Bronze Age and Iron Age, which were associated with the growth
and development of human civilizations and their presence in the country,
clearly indicate the exploration and utilization of mineral resources by ancient
Indians. There are several references for using basic concepts of Geology and
Metallurgy in the ancient literature of the country. However, reliable evidence
of the early existence of geological information and its utilization for the
development of society comes from an old Treatise “Arthashastra”, composed
by an ancient Indian statesman and philosopher, Kautilya, around 321-296
BC (Chakraborty, 1970; Murty, 1979). This Treatise provides an account of
geological knowledge, which is used to discover and extract metals from
various ores (GOI, 2012). The growth of Geology as an independent science
discipline emerged in the eighteenth century (Chakraborty, 1971; Rajendran,
2019). The initial phase of realization of the importance of Geology in India
was seen with the establishment of the Survey of India in 1767 and the Asiatic
Society of Bengal in 1784 by the East India Company. The main objective of
the Survey of India was to map the country and produce maps at different scales
for discovering natural resources and Society had as its objective “enquiry into
the history and antiquities, arts, science and literature of Asia” (Chakraborty,
1971). The results of the survey and society together later played a profound
role in the growth of geological studies in India. The opening of a museum in
Calcutta (now Kolkata) in 1840 by the East India Company was considered
a step towards the beginning of geological education (Stubblefield, 1970). Indeed, the East India Company understood the importance of the geological
richness of India, especially the coal resources before 1835. As a consequence,
they established a Coal Committee in 1836 for discovering the coal and mineral
resources of the country (Kumar, 1982). Figure 3. Map of India showing the distribution of higher learning institutes
offering geological education in India.f Based on the rich and varied geology of the subcontinent, with its huge
resource potential, the East India Company formally established the world’s
second-largest organization, the Geological Survey of India (GSI) in 1851,
to undertake geological mapping and exploration of mineral resources of the
country (Oldham, 1856). Development of Indian higher geological education In 1858, the East India Company developed into
the British Raj (i.e. Government of colonial India). But before the 1850s, the
colleges of the East India Company taught Geology and Mineralogy, but there
was no separate department of Geology (Larwood, 1958; Tolman, 2016). p
p
gy (
)
The opening of the GSI marked the informal beginning of geological
higher education in India (Kumar, 1982; Murty, 1982; Palit, 2013). Shortly
after its establishment, Henry B. Medlicott, an Irish geologist, came to India
in 1854 to become a Professor of Geology at the Thomson College of Civil
Engineering, Roorkee (now Indian Institute of Technology, Roorkee) founded
in 1847. He was probably the first teacher of Geology in India. For a long period,
British geologists undertook all activities of the GSI and they were of the view
that Indians were not capable of doing any kind of sophisticated teaching and
research in Geology, and no Indian university was properly equipped to impart
higher geological education. In fact, they were not much interested to open
geological education in the higher learning institutes of India (Kumar, 1982;
Tolman, 2016). As a consequence, geological education did not become part of
higher education in Indian universities until the 1870s (Kumar, 1982; Tolman,
2016). Over time, the British Raj found difficulties in recruiting geologists from
Europe because they rejected the offer of British Raj to join GSI due to limited
financial benefits and serious health problems in India; particularly, unfavorable
climatic conditions, which often caused their death within a few years of joining
the GSI (Grout, 1995; Kumar, 1995). This led to a shortage of geologists in the
GSI and to fill this gap, the British Raj decided to recruit Indian geologists. In
1886, the British Raj constituted two positions exclusively for Indian geologists
within the GSI and also felt the need to establish a sound education system to
teach Geology (Kumar, 1995).i Figure 3. Map of India showing the distribution of higher learning institutes
offering geological education in India. There were around 14 universities in the country that offered geological
education before1952 (Stubblefield, 1970). Following one and a half decades
of independence, out of a total of 35 universities, around 20 had departments
of Geology (Wadia, 1964). Later, geological education witnessed a substantial
expansion, thus, many Geology departments were opened in various colleges
and universities across the country. Geological education: why it is important in India? Over time, many Geology departments were opened in other universities
namely, Banaras Hindu University, Varanasi in 1923; Indian School of Mines
(now Indian Institute of Technology), Dhanbad in 1926; Andhra University,
Visakhapatnam in 1941; Lucknow University, Lucknow in 1942; Aligarh
Muslim University, Aligarh in 1946; Patna University, Patna in 1946, and
Rashtrasant Tukadoji Maharaj University, Nagpur in 1946 (Stubblefield, 1970;
Bhattacharya, 2016). Thus, the development of geological education was seen
as a by-product of the GSI growth and rich georesources of the country. (now Chennai), and Bombay University in the 1890s (Murty, 1982). Geology
as an optional subject was introduced at Bombay University in 1879. In 1892,
a separate department of Geology was opened at the Presidency College
(now Presidency University), Kolkata. Another Presidency College (now
Madras University) at Chennai already had Geology as an auxiliary subject,
but an independent department of Geology was started in 1910 (Murty, 1982). Meanwhile, the spread of geological education also reached northern India with
the visit of the Prince of Wales to Jammu in 1906. To commemorate his visit,
His Highness, the Maharaja (i.e. ruler) Sir Pratap Singh of Jammu and Kashmir,
built the Prince of Wales College (now Government Gandhi Memorial Science
College and is a part of the Cluster University of Jammu) on the banks of the
River Tawi. In this college, Geology education commenced in 1907, under the
stewardship of the renowned Indian geologist, Dr. D. N. Wadia (Stubblefield,
1970). Over time, many Geology departments were opened in other universities
namely, Banaras Hindu University, Varanasi in 1923; Indian School of Mines
(now Indian Institute of Technology), Dhanbad in 1926; Andhra University,
Visakhapatnam in 1941; Lucknow University, Lucknow in 1942; Aligarh
Muslim University, Aligarh in 1946; Patna University, Patna in 1946, and
Rashtrasant Tukadoji Maharaj University, Nagpur in 1946 (Stubblefield, 1970;
Bhattacharya, 2016). Thus, the development of geological education was seen
as a by-product of the GSI growth and rich georesources of the country. Given this wide geological background, geological education is crucial
for India to refine existing geological principles, establish geoheritage
sites, explore georesources and ensure their sustainability, and resolve geo-
environment-related problems across the country. Geological education: why it is important in India? East India Company) invaded the country in
1757, and later, expanded their imperialism, and ruled the country from 1858 to
1947 (Wagh, 2018). They understood mineral resource richness, especially the
coal resources of the country, and extensively mined several mineral resources
during their rule (Fox, 1947). The country still has many georesources. Some
world-famous diamonds namely, Kohinoor, Great Moghul, and Regent were
discovered from gravels of the Krishna valley that were derived from the Krishna
lamproite (ultramafic igneous rock) field, near the north-eastern margin of the
Cuddapah Basin, southern India (GSI, 2011). Recently, geoheritage emerged
as an important field of public and scientific interest that promotes geoscience
education, research, geotourism, and sustainable development. Geoheritage
is an essential part of the natural (geocultural) heritage and encompasses 2b 2b Figure 2. Photographs showing potential geoheritage sites in India. a. Huge granite
batholith, situated nearly 50 km from Hyderabad along the Hyderabad-Warangal
national highway at Bhongir town, Telangana, South India. This batholith is a
part of the Eastern Dharwar Craton and around 2.7 to 2.5 billion years old. b. Quaternary fluvio-lacustrine deposits at Lamayuru, Union Territory of Ladakh,
Northern India. These deposits are 105 m thick, dominantly composed of clay and
sand layers, which develop a lunar landscape at Lamayuru. These deposits are
popularly known as “moonland” of the Lamayuru. Both these geosites are places
of tourist’s attraction 243 (now Chennai), and Bombay University in the 1890s (Murty, 1982). Geology
as an optional subject was introduced at Bombay University in 1879. In 1892,
a separate department of Geology was opened at the Presidency College
(now Presidency University), Kolkata. Another Presidency College (now
Madras University) at Chennai already had Geology as an auxiliary subject,
but an independent department of Geology was started in 1910 (Murty, 1982). Meanwhile, the spread of geological education also reached northern India with
the visit of the Prince of Wales to Jammu in 1906. To commemorate his visit,
His Highness, the Maharaja (i.e. ruler) Sir Pratap Singh of Jammu and Kashmir,
built the Prince of Wales College (now Government Gandhi Memorial Science
College and is a part of the Cluster University of Jammu) on the banks of the
River Tawi. In this college, Geology education commenced in 1907, under the
stewardship of the renowned Indian geologist, Dr. D. N. Wadia (Stubblefield,
1970). Development of Indian higher geological education At present, there are more than 153
higher learning institutes that host Geology departments imparting geological
education in India up to a Master’s degree level (excluding colleges). These
institutes include various universities (state/union territory, central and
private), Indian Institutes of Technology, Indian Institute of Science, Indian
Statistical Institute, and Indian Institutes of Science Education and Research
(Fig. 3). Apart from conventional learning systems, geological education is
also offered through open and distance modes of learning in India, with the
opening of departments at Dr. B. R. Ambedkar Open University in 1991, and
Indira Gandhi National Open University in 2010. Currently, higher education
in Geology is being offered at three-degree levels across the country viz., To fill the shortage gaps of geologists and associated skilled manpower
needed in the GSI and through continuous struggle by the Indian educationists,
a more systematic effort was made by the British Raj and GSI for opening
the Geology departments at the Presidency Colleges of Kolkata and Madras 244 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh Bachelor’s degree programs of three-year duration, Master’s degree programs
of two-year duration, and integrated Bachelor’s-Master’s degree programs of
five-year duration. Apart from this, Ph.D. in Geology is a common research
degree program in Indian universities.i Bachelor’s degree programs of three-year duration, Master’s degree programs
of two-year duration, and integrated Bachelor’s-Master’s degree programs of
five-year duration. Apart from this, Ph.D. in Geology is a common research
degree program in Indian universities.i the performance of Master’s degree programs in Geology, in terms of the
successful completion of the program by learners and to make comparisons
between the Master’s degree programs in Geology and other science disciplines
to evaluate the percentage of their success rate and to ascertain awareness
of Geology among the learners. For this analysis, five science disciplines
comprising Physics, Chemistry, Botany, Zoology, and Environmental science
were selected. The data about the learners’ enrolment and their successful pass
rates (i.e. completion of programs) for the academic sessions from 2011-2012
to 2018-2019 of Master’s degree programs in Geology, Physics, Chemistry,
Botany, Zoology, and Environmental science was obtained from reports of the
MHRD, GOI on “all India survey on higher education” (Table 1). Status of Geology education among other sciences: a comparative analysis Numerous public and private sectors including non-governmental
organizations in India offer job opportunities to those who had qualified with
a Master’s degree in Geology. Thus, an analysis was carried out to evaluate Table 1. Learner’s enrolment and successful completion data of Master’s degree programs in Geology, Physics, Chemistry, Botany, Zoology, and Environmental science
(complied after MHRD Reports, 2014, 2015a, b, 2016a, b, 2017, 2018, 2019). Academic
sessions
Master’s programs in
Geology
Physics
Chemistry
Botany
Zoology
Environmental science
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Qualified
2011-2012
3564
1801
36954
16585
73984
34588
22850
10288
27581
12606
4520
3335
2012-2013
4028
1962
42898
17202
77858
35495
24896
11140
31965
14008
5100
2549
2013-2014
4749
1786
52496
18829
90101
35142
29680
12276
36559
15184
5395
3129
2014-2015
5179
2008
56824
20558
95295
37142
32619
12140
38850
15703
5797
2528
2015-2016
5597
2076
60889
20759
99888
34639
36736
12473
41025
13899
5393
2462
2016-2017
6039
2133
69754
24211
114328
38216
42542
14625
48774
17453
6252
2484
2017-2018
6281
2469
75114
26915
125805
44027
43967
17131
51672
19134
6766
2553
2018-2019
7134
2843
72797
28737
124526
46925
43036
19208
50904
20903
7281
3243
Total
42571
17078
467726
173796
801785
306174
276326
109281
327330
128890
46504
22283
Average
completion
percentage
40.11
37.15
38.18
39.54
39.37
47.91
Figure 4. a. Pie-chart showing relative enrolment data percentage for Master’s degree programs in six science disciplines of academic sessions from 2011-2012 to 2018-
2019. b. Bar-chart showing average successful completion percentage of learners in Master’s programs in six science disciplines of academic sessions from 2011-2012 to
2018-2019. Refer to Table 1 for enrolment data. Env sci stands for Environmental science. 40.86%
23.84%
16.68%
14.09%
2.37%
2.16%
Chemistry
Physics
Zoology
Botany
Envi sci
Geology
4b
Env sci
Geology
Botany
Zoology
Chemistry
Physics
47.91
40.11
39.54
39.37
38.18
31.15
Successful compleƟon percentage Table 1. Learner’s enrolment and successful completion data of Master’s degree programs in Geology, Physics, Chemistry, Botany, Zoology, and Environmental science
(complied after MHRD Reports, 2014, 2015a, b, 2016a, b, 2017, 2018, 2019). Development of Indian higher geological education the performance of Master’s degree programs in Geology, in terms of the
successful completion of the program by learners and to make comparisons
between the Master’s degree programs in Geology and other science disciplines
to evaluate the percentage of their success rate and to ascertain awareness
of Geology among the learners. For this analysis, five science disciplines
comprising Physics, Chemistry, Botany, Zoology, and Environmental science
were selected. The data about the learners’ enrolment and their successful pass
rates (i.e. completion of programs) for the academic sessions from 2011-2012
to 2018-2019 of Master’s degree programs in Geology, Physics, Chemistry,
Botany, Zoology, and Environmental science was obtained from reports of the
MHRD, GOI on “all India survey on higher education” (Table 1). The need for geology education at the school level in India was first
highlighted by Wadia in 1964 (Stubblefield, 1970). So far, the picture of
geology education offered at the school level is very sparse; it is largely
neglected in comparison with other science disciplines: Physics, Chemistry,
Mathematics, Biology, Engineering, and Computer science (Tandon, 2005). From kindergarten to 10th grade of high school level (pupils with age range 4
to 16 years), geology education is taught as a part of either general studies or
social sciences (Paliwal, 2005). In 11th and 12th grade higher school education
(pupils with age range 16 to 18 years), there are very few school boards of
Indian states/union territories offering Geology as an independent subject in
their science or arts streams. The states/union territories that do so are Kerala,
Rajasthan, Jammu and Kashmir, Jharkhand, Karnataka, Maharashtra, and
Manipur (Paliwal, 2005; Padmanabhan, 2018). Analysis of the data shows that there was an increasing trend in
enrolment numbers of learners in the Master’s degree programs of all
six science disciplines in the academic sessions 2011-2012 to 2018-2019
(Table 1). Nearly 40.86% of learners were enrolled in the Master’s degree
program in Chemistry whilst a minimum of learners, at 2.16%, were enrolled
in the Master’s degree program in Geology (Fig. 4a). Surprisingly that the
importance of Geology in India was realized in 1851 with the establishment
of the GSI, but the enrolment percentage of the Master’s degree program in
Geology indicates that Geology had the lowest popularity as a science subject
among these six science disciplines (Fig. 4a). Geology education among other sciences: a comparative ana Status of Geology education among other sciences: a comparative analysis Academic
sessions
Master’s programs in
Geology
Physics
Chemistry
Botany
Zoology
Environmental science
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Quali-
fied
Enrol-
ment
Qualified
2011-2012
3564
1801
36954
16585
73984
34588
22850
10288
27581
12606
4520
3335
2012-2013
4028
1962
42898
17202
77858
35495
24896
11140
31965
14008
5100
2549
2013-2014
4749
1786
52496
18829
90101
35142
29680
12276
36559
15184
5395
3129
2014-2015
5179
2008
56824
20558
95295
37142
32619
12140
38850
15703
5797
2528
2015-2016
5597
2076
60889
20759
99888
34639
36736
12473
41025
13899
5393
2462
2016-2017
6039
2133
69754
24211
114328
38216
42542
14625
48774
17453
6252
2484
2017-2018
6281
2469
75114
26915
125805
44027
43967
17131
51672
19134
6766
2553
2018-2019
7134
2843
72797
28737
124526
46925
43036
19208
50904
20903
7281
3243
Total
42571
17078
467726
173796
801785
306174
276326
109281
327330
128890
46504
22283
Average
completion
percentage
40.11
37.15
38.18
39.54
39.37
47.91
Figure 4. a. Pie-chart showing relative enrolment data percentage for Master’s degree programs in six science disciplines of academic sessions from 2011-2012 to 2018-
2019. b. Bar-chart showing average successful completion percentage of learners in Master’s programs in six science disciplines of academic sessions from 2011-2012 to
2018-2019. Refer to Table 1 for enrolment data. Env sci stands for Environmental science. 40.86%
23.84%
16.68%
14.09%
2.37%
2.16%
Chemistry
Physics
Zoology
Botany
Envi sci
Geology
4b
Env sci
Geology
Botany
Zoology
Chemistry
Physics
47.91
40.11
39.54
39.37
38.18
31.15
Successful compleƟon percentage Figure 4. a. Pie-chart showing relative enrolment data percentage for Master’s degree programs in six science disciplines of academic sessions from 2011-2012 to 2018-
2019. b. Bar-chart showing average successful completion percentage of learners in Master’s programs in six science disciplines of academic sessions from 2011-2012 to
2018-2019. Refer to Table 1 for enrolment data. Env sci stands for Environmental science. 245 The analysis of recommended TLR by the UGC for Bachelor’s degree
program in Geology under its CBCS and LOCF schemes shows that 75.69%
of the TLR listed in the syllabi are of foreign origin, and only 24.31% are of
Indian origin (Table 2; Fig. 5a). Status of Geology education among other sciences: a comparative analysis Similarly, the analysis of recommended TLR
in the syllabi of Master’s degree programs in Geology of 25 universities of five
Indian regions namely, northern, western, southern, eastern, and central shows
that these regions contain 81.36%, 81.05%, 78.30%, 80.20%, 76.29%, and
18.64%, 18.95%, 21.70%, 19.80%, 23.71% TRL of foreign and Indian origin,
respectively (Table 3; Fig. 5b). As a whole, the recommended TRL of these
25 universities include 79.68% of foreign origin, and only 20.32% of Indian
origin (Table 3; Fig. 5b). A few of the MOOCs in Geology such as Physical
and Structural Geology, Stratigraphy and Palaeontology, Crystallography and
Mineralogy, Photogeology and Remote Sensing, Metamorphic Petrology and
Thermodynamics, Metamorphic Petrology, and Environmental Geology are
on offer through the UGC-MOOCs portal (http://ugcmoocs.inflibnet.ac.in/
ugcmoocs/moocs_courses.php). In addition, some modules related to geological
courses namely, Igneous and Metamorphic Petrology, Sedimentology and
Petroleum Geology, Crystallography and Mineralogy, Economic Geology
and Mineral Resources of India, Hydrogeology and Engineering Geology,
Remote Sensing and Geographic Information System are available as open
TLR at e-pgpathshala portal of the UGC (https://epgp.inflibnet.ac.in/Home/
ViewSubject?catid=448). Further data analysis of learner’s enrolment and their successful
completion in Master’s programs in all six science disciplines from 2011-
2012 to 2018-2019 had given quite interesting results (Fig. 4b). The results
indicate that the Master’s degree program in Geology had a very good
learner’s average completion rate i.e. 40.11%, and stands second, after average
program completion rate of Environmental science, which is 47.91% (Fig. 4b). The average successful program completion rate for Botany, Zoology,
and Chemistry was 39.59%, 39.37%, and 38.18%, respectively. Physics had
the lowest average completion rate, which is 31.15% (Fig. 4b). This may
indicate that better quality education was available to the qualified learners of
the Master’s program in Geology, and alternatively, reflects a higher quality
of qualified postgraduates of Geology. The Union Public Service Commission
(UPSC) of the GOI recruits candidates who had Master’s degrees in Geology
as geologists for the GSI almost every year. The applicants from all over the
country appear for the UPSC written examination to obtain geologist positions
in the GSI after completing their Master’s degree in Geology. Thus, the
performance of applicants in the UPSC geologists’ written examination can
provide a means of checking the quality of masters-level geological education
in India. Nature of Teaching-Learning Resources in Geology Over the past few years, several reforms in the country’s higher educational
system had been made by the UGC and Department of Higher Education of
the MHRD of the GOI. Recently, the UGC implemented a minimum course
curriculum under, the Choice-Based Credit System (CBCS) and Learning
Outcomes-Based Curriculum Framework (LOCF) for Bachelor’s degree
programs in India to provide high-quality and equitable education (UGC, 2015a,
2019). Under the CBCS and LOCF, the UGC issued a national curriculum in
Geology for implementation in Bachelor’s (both general and honors) degree
programs for all higher education institutes in India (UGC, 2015b, c, 2019). The MHRD had taken several remarkable steps in enhancing the quality
and providing equity with extensive use of Information and Communication
Technology (ICT) in higher education. Nowadays, online higher education is
also being offered to learners through Massive Open Online Courses (MOOCs)
through various online platforms (http://www.sakshat.ac.in). In addition, TLR
in the form of the OER in various disciplines for the use of teachers and learners
have also been provided by the GOI (e.g., https://epgp.inflibnet.ac.in/). CBCS
LOCF
CBCS-LOCF
79.08
72.23
75.69
20.92
27.77
24.31
5a 5a To know the nature of the TLR in Geology for its Bachelor’s and Master’s
degree programs, the TLR recommended for all the courses of these programs
were evaluated. For Bachelor’s degree programs, the TLR mentioned in UGC-
CBCS and LOCF in Geology, in the form of recommended books/texts, were
evaluated (Table 2). For Master’s degree programs, the Master’s curricula of 25
universities (including five universities each from northern, western, southern,
eastern, and central regions of India) were downloaded from their respective
websites, and the TLR were recommended for all courses of programs were
evaluated (Table 3). Northen
Western
Southern
Eastern
Central
Total TRL
81.36
81.05
78.3
80.2
76.29
79.68
18.64
18.95
21.7
19.8
23.71
20.32
TRL percentage of foreign origin
TRL percentage of Indian origin
5b Table 2. Statistics of the TLR recommended for Bachelor’s program in Geology by
the UGC. Curricula
types
of the UGC
Total
TLR
recom-
mended
TLR of
foreign
origin
TLR of Indian origin
No. %
No. %
CBCS
curriculum
239
189
79.08
50
20.92
LOCF
curriculum
234
169
72.23
65
27.77
Total
TLRs
recommended
473
358
75.69
115
24.31 Table 2. Statistics of the TLR recommended for Bachelor’s program in Geology by
the UGC. 5b Figure 5. a. Status of Geology education among other sciences: a comparative analysis In the past few years of the UPSC recruitment process for geologists
had shown that the subject-specific knowledge of the applicants was a little low
and applicants were securing average marks in the written examination, i.e. 30
to 40% (Saha, 2016, 2018). j
)
CBCS
LOCF
CBCS-LOCF
79.08
72.23
75.69
20.92
27.77
24.31
TRL percentage of foreign origin
TRL percentage of Indian origin
5a
Northen
Western
Southern
Eastern
Central
Total TRL
81.36
81.05
78.3
80.2
76.29
79.68
18.64
18.95
21.7
19.8
23.71
20.32
TRL percentage of foreign origin
TRL percentage of Indian origin
5b
Figure 5. a. Bar-chart showing percentage of the TLR recommended in the
curricula issued by the UGC under its CBCS and LOCF schemes for Bachelor’s
degree programs in Geology. b. Bar-chart showing the percentage of TLR
recommended in the curricula of 25 universities across India for their Master’s
degree programs in Geology. Refer to Table 2 for the TLR data. TRL percentage of foreign origin
TRL percentage of Indian origin Nature of Teaching-Learning Resources in Geology Bar-chart showing percentage of the TLR recommended in the
curricula issued by the UGC under its CBCS and LOCF schemes for Bachelor’s
degree programs in Geology. b. Bar-chart showing the percentage of TLR
recommended in the curricula of 25 universities across India for their Master’s
degree programs in Geology. Refer to Table 2 for the TLR data. 246 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh Table 3. Statistics of the TLR recommended for Master’s program in Geology covering all parts of India. The letters A to Y have been sequentially assigned to these
universities within parentheses for identification purposes as their names have been kept anonymous. S. No. University selected for accessing
curricula /
syllabi
Total TRL rec-
ommended
TLR of foreign origin
TLR of Indian or-
igin
Region of India
No. %
No. %
1. Union Territory University (A)
274
218
79.56
56
20.44
Northern
2. Union Territory University (B)
151
128
84.76
23
15.24
3. State University (C)
185
139
75.14
46
24.86
4. State University (D)
240
197
82.10
43
17.90
5. Central University (E)
202
174
86.14
28
13.86
Subtotal of TRL
1052
856
81.36
196
18.64
6. State University (F)
222
191
86.10
31
13.90
Western
7. State University (G)
275
221
80.36
54
19.64
8. State University (H)
123
97
78.86
26
21.14
9. State University (I)
200
164
82.00
36
18.00
10. State University (J)
394
311
78.94
83
21.06
Subtotal of TRL
1214
984
81.05
230
18.95
11. Central University (K)
150
122
81.34
28
18.66
Southern
12. State University (L)
187
150
80.21
37
19.79
13. State University (M)
287
210
73.17
77
26.83
14. State University (N)
156
131
83.97
25
16.03
15. State University (O)
192
148
77.08
44
22.92
Subtotal of TRL
972
761
78.30
211
21.70
16. State University (P)
148
114
77.03
34
22.97
Eastern
17. Central University (Q)
182
149
81.87
33
18.13
18. Central University (R)
267
210
78.65
57
21.35
19. Central University (S)
249
206
82.73
43
17.27
20. State University (T)
169
135
79.88
34
20.12
Subtotal of TRL
1015
814
80.20
201
19.80
21. State University (U)
121
96
79.34
25
20.66
Central
22. Central University (V)
172
139
80.82
33
19.18
23. State University (W)
145
114
78.62
31
21.38
24. Central University (X)
167
109
65.27
58
34.73
25. OER and their role in geological higher education OER and their role in geological higher education The global teaching-learning community has come to understand the real
value of the OER at a time when COVID-19 has led to the sudden closure
of educational institutions (Huang et al., 2020). In order to meet educational
challenges posed by the COVID-19 outbreak, many countries, including India,
advised institutions to adopt a policy of undisrupted learning by offering online,
remote, and distance teaching (Huang et al., 2020; UGC, 2020). In this context,
OER emerged as ideal educational resources because they are in digital format,
freely accessible at anytime, anywhere, and easy to incorporate into the existing
learning system of any educational institution (Smith, 2009). The OER had
been a part of the education system since the advent of computer and internet
technology around the 1990s. OER are “teaching, learning, and research
materials in any medium – digital or otherwise – that reside in the public domain
or have been released under an open license that permits no-cost access, use,
adaptation, and redistribution by others with no or limited restrictions” (https://
hewlett.org/strategy/open-educational-resources/). There are numerous types
of OER comprising course materials, full courses, modules, encyclopedias,
text-books, games, lesson plans, syllabi, quizzes, instructional modules, model
tests, assignments, practical modules, educational audios/videos, virtual field
trips, virtual field experiences, and virtual science laboratories (Smith, 2009;
Waldrop, 2013). In addition, the OER also contain rich teaching resources,
including methods and tools of teaching that led to improved pedagogical skills,
growth, and professional development of teachers. COVID-19 has had at least two impacts on higher geological education,
firstly, the suspension of regular classroom teaching, and secondly, not allowing
learners to undertake geological fieldwork in out-door environments because it
involves moving learners between sites and use of public transport in groups. The loss of classroom teaching can be substituted by the use of online TLR,
although the value of online TLR for particular courses or programs needs
to be considered. However, geological fieldwork is one of the distinctive and
compulsory components of both Bachelor’s and Master’s degree programs
in Geology. It involves out-door visits of learners where they study rock
outcrops exposed in their natural settings, for example, in quarries or mines,
road cuttings, hilly and mountainous terrains, and along the river valleys. In
the field, the learners carefully observe, record, and measure various geological
features. Nature of Teaching-Learning Resources in Geology State University (Y)
171
134
78.36
37
21.64
Subtotal of TRL
776
592
76.29
184
23.71
Total of TRL
5029
4007
79.68
1022
20.32 COVID-19 pandemic and geological higher education:
Challenges and opportunities COVID-19 pandemic and geological higher education:
Challenges and opportunities Overall, data indicate that a majority of the TLR for higher education
programs in Geology in India are of foreign origin. These resources are costly
for learners and may or may not be sufficient to meet all content requirements
of the various courses in the programs. Geology is a distinctive and field-based
science discipline so a majority of its courses are based on the geological setting
of the country. Therefore, the teaching-learning practice of such courses usually
demands TLR of Indian origin (Wadia, 1916; Krishnan, 1949; Kumar, 2010;
Mishra, 2016; Shah, 2018). The need to develop TLR of Indian origin taking
the Indian geological setting into account has been highlighted by various
workers (Wadia, 1919; Mishra, 2016; Kumar, 2010; Verma, 2017, 2018, 2019,
2021; Shah, 2018). The recent development of TLR in the form of MOOCs
and modules of e-pgpathshala of the UGC are progressive steps taken to enrich
TLR of the Indian origin for some Geology courses, but these resources are still
meagre and need to be added extensively. The Corona virus disease 2019 (COVID-19) was declared a global
pandemic by the World Health Organisation (WHO) in March 2020 (WHO,
2020) and recognized as a health, economic, and social crisis. It can be viewed
as both a challenge and opportunity as far as geological education and research
are concerned. Due to the COVID-19 outbreak, all educational institutions
including schools, colleges, and universities in India were closed from 24th
March 2020 due to lockdown implementation across the country by the GOI,
which opened later on in a phased manner (https://www.mohfw.gov.in/). The
months-long closure of educational institutions in 2020-2021 had stopped
classroom teaching and thus, badly hampered teaching-learning processes whilst 247 Geological education scenario in India and role of open educational resources in the light of COVID-19 pandemic disengaging learners from active learning. It impacted the mental health of both
learners and teachers. In order to provide uninterrupted learning to learners,
the UGC and MHRD advised higher learning institutes to make extensive use
of the ICT to deliver online higher education to learners (UGC, 2020). Nature of Teaching-Learning Resources in Geology It also
advised learners to use the OER available on various online platforms such as
Swayam online courses, e-pgpathshala, etc. to continue their learning. (b) if, it becomes impossible to arrange geological fieldwork in the coming two
years due to travel restrictions because of the extended COVID-19 infection,
what would be the best possible solution to the problem might be. OER and their role in geological higher education They learn to identify various rock-types, fossils, structural features
(fold, faults, joints, unconformities), and techniques for collecting samples in
the field (Lisle et al., 2011). In addition, they also learn how to measure dip,
strike, and thickness of rock units and structural features, and how to document
field data in field diaries. The overall purpose of geological fieldwork is to
develop field-based geological skills and understanding in the learners (Lisle
et al., 2011). As Geology is a field-based science, a degree without having
field-related skills is of no value to learners. Therefore, learners of degree
programs in Geology in one region of the country normally visit other regions
to undertake geological fieldwork and develop sound field-based geological
skills, often traveling distances of hundreds of kilometers. To summarize, the
major challenges posed by COVID-19 to the geological teaching community
are: (a) to evaluate whether the currently available online TLR are sufficient to
meet the current and future demands or whether more TLRs are required, and There are several higher education organizations/societies around the
world that have been developing OER in geological education and offering
them free online in various formats like PDF, HTML, videos, etc. for the benefit
of the global teaching-learning community (Table 4). Table 4. Name and web link of educational institutions and societies offering geological OER
S.No. Name educational institution /society/
organization
Web link of geological OER
1. Humboldt State University
https://libguides.humboldt.edu/openedu/geol
2. University of Houston-Victoria
https://library.uhv.edu/oer/geology
3. Washtenaw Community College
https://libguides.wccnet.edu/oer-subjects/geology
4. Mt San Antonio College
https://mtsac.libguides.com/oer/earth-science
5. University of Kentucky
https://libguides.uky.edu/c.php?g=222941&p=6722485
6. Austin Community College
https://researchguides.austincc.edu/c.php?g=434670&p=5818520
7. East Tennessee State University
https://libraries.etsu.edu/research/guides/geosciences/oer
8. Salt Lake Community College
https://opengeology.org/textbook/
9. San Bernardino Valley College
https://www.valleycollege.edu/open-education-resources/faculty/geology.php,
10. Creative Commons
https://www.oercommons.org/browse?f.search=Geology
11. The Open University
https://www.open.edu/openlearn/science-maths-technology/science/geology
12. University of Edinburgh
https://open.ed.ac.uk/tag/geoscience/
13. International Geoscience Education Organization
http://www.igeoscied.org/teaching-resources/
14. Geological Society
https://www.geolsoc.org.uk/heresources
15. British Geological Survey
https://www.bgs.ac.uk/discoveringGeology/newsAndEvents/links.html
16. US Geological Survey
https://www.usgs.gov/science-support/osqi/yes/resources-teachers
17. Society of Vertebrate Palaeontology
http://vertpaleo.org/What-is-Vertebrate-Paleontology/Resources-for-
Educators-and-Students.aspx Table 4. Name and web link of educational institutions and societies offering geological OER 248 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh Many higher learning institutes in India had both typed and handwritten
specific-course-based study material uploaded on their websites to provide
continuity of learning to their learners during the COVID-19 crisis. The GOI
has previously noted the potential of OER to offer high-quality and equitable
education across the country (GOI, 2009). Data collection and interpretation Data collection and interpretation A structured questionnaire was prepared to investigate the value of OER
in higher geological education in India and their role in the COVID-19 response
efforts. The questionnaire was divided into three parts: personal data, educational
resources in geological education, and, the use and need of OER in the higher
Indian geological education system. All questions of the questionnaire were
simple, easy to understand, and consisted mainly of multiple-choice options
with a few short answer types. Part A: Personal Data provided information
regarding age, gender, educational qualification, profession, affiliation, teaching
experience, and mode of teaching before the COVID-19 pandemic of the
respondents. Part B: Use of Educational Resources in Geological Education
was designed to get information from respondents about the TLR of Indian and
foreign origin that they had been using before and during the COVID-19. Part
C: OER contained questions related to familiarity of the OER to the faculty,
changes in their use before and during the COVID-19, and their potential to
meet the requirement of compulsory components (fieldwork and laboratory) of
higher degree programs. Figure 6. Map of India showing the distribution of places and response numbers in
parenthesis from where the completed questionnaires were received. OER and their role in geological higher education The COVID-19 crisis prompted the
Geology teaching-learning community to appreciate the potential of OER in
higher education. As a consequence, a few OER in Geology are available at
the e-pgpathshala portal of the UGC (https://epgp.inflibnet.ac.in/). Laboratory
experiments and fieldwork are very important components in the successful
completion of any degree program of higher geological education. In this regard,
OER consisting of laboratory experiments, virtual geological laboratories,
virtual field experiences, and geological field modules can offer hands-on
training to learners in geological education. For example, Google Earth images
have been extensively used as resources for teaching geological principles
as well as for mapping, identifying, and interpreting geological features
since 2005 (Lisle, 2006; Monet & Greene, 2012). The Indian lithospheric
plate contains numerous geological features notably; geomorphic, tectonic,
structural, stratigraphic, and petrologic that can be examined by utilizing freely
downloadable high-resolution satellite images from the Google Earth program
(http://earth.google.com). OER consisting of geological virtual fieldwork and
modules of field-specific problems based on Indian outcrops using images of
Google Earth were being developed, through which learners of Bachelor’s
and Master’s degree programs in Geology may complete their compulsory
fieldwork-based assignments in the light of the COVID-19 outbreak. Figure 6. Map of India showing the distribution of places and response numbers in
parenthesis from where the completed questionnaires were received. OER usefulness in higher geological education: OER usefulness in higher geological education: Part A: Personal Data The analyzed sample shows that out of the total sample number (n = 63),
the majority (i.e. 81%) of respondents hold doctorate degrees (Ph.D.) and a
small group of just 17% holds master’s degrees. 83% (52) of respondents were
males and only 17% (11) were females. The mean age of respondents was 44
years. They had a wide range of teaching experience and had been working at
various positions viz., assistant professors (51%), professors (19%), associate
professors (6%), researchers (5%), and geoscientists (5%) in descending order. A majority of respondents were at the beginning or in the middle of their
teaching career, as is apparent from their teaching experience statistics: 0-5
years (28%), 5-10 years (23%), 10-15 years (15%) and 15-20 years (15%). Two
(3%) respondents were not involved in teaching and the remaining 61 (97%)
were directly involved in Bachelor’s and/or Master’s level teaching. The consolidated list of all Indian universities was obtained from the
website of the UGC (https://www.ugc.ac.in/#) and one by one, the websites
of all the universities were visited to find whether or not the university had a
Department of Geology/Applied Geology/Earth Science/Geological Sciences,
and further e-mail addresses of the existing teaching faculty of the departments
were collected. The questionnaire was prepared using the Google Forms service
of Google Docs (https://www.google.com/forms/about/) and sent online to the
collected e-mail addresses of almost all universities faculty of Geology in the
entire country. Additionally, the questionnaire was also sent to the geological
teaching faculty of Indian Institutes of Technology, Indian Institutes of Science
Education and Research, a few geologists of the GSI, and the Indian Statistical
Institute. The questionnaire was sent to a total of 790 people, from which, 63
responses were received covering almost all parts of the country (Fig. 6). The
data was collected between July and October 2020. A majority of responses
were complete and usable for interpretation. Part B: Educational resources in geological education, use of TLR of Indian
and foreign origin before and during the COVID-19 Trends in use of Indian and foreign OER before
and during the COVID-19
OER types
Indian OER
Foreign OER
Before
COVID-19
During
COVID-19
Before
COVID-19
During
COVID-19
Open
textbooks
79%
56%
66%
48%
Online videos
67%
77%
69%
83%
Online audios
12%
28%
26%
31%
Online lesson
plans
34%
30%
19%
26%
Modules
24%
28%
24%
19%
Complete
courses
24%
16%
17%
12%
MOOCs
29%
37%
22%
24%
Practical
modules
24%
16%
12%
17%
Virtual science
laboratory
16%
7%
12%
14%
Virtual field
trips
16%
8%
10%
10%
Assignment
for students
38%
38%
25%
21% Table 6. Trends in use of Indian and foreign OER before
and during the COVID-19 The questionnaire tested the change in the usage of TLR for teaching
before and during COVID-19 (Table 5). The data showed a significant decrease
in the use of hand-written content, followed by real field trips and real science
laboratory work. However, typed learning content continued to be used almost
in the same way as it was used before and during COVID-19. During the
pandemic, the use of online platforms increased significantly from 26% to 66%. Table 5. Kind and percentage of TLR used before and after the COVID-19
Kind of TLR
Before COVID-19
During
COVID-19
Hand written contents
61%
29%
Typed contents
65%
66%
Typed containing all
learning requirements and
plagiarism free with no
copyright issue
47%
42%
Real science laboratory
activities
55%
6%
Real field trips
69%
3%
Online platforms like
SWAYAM, e-pgpathshala,
and other online platforms
26%
66% Table 5. Kind and percentage of TLR used before and after the COVID-19 Thematic analysis indicates that the respondents thought that virtual open
laboratory and field-based manuals could enhance the practical and field skills
of learners to a reasonable extent. In fact, they (35%) were also of the view
that virtual field trips based on Google Earth programs and, identification and
measurement of various geological features by using high-resolution images,
was a good alternative for completing compulsory geological fieldwork
assignment for learners during the COVID-19 pandemic; 48% believed this
at least to some extent. As far as practical components of the curriculum of
programs are concerned, 35% of respondents realized that open laboratory
manuals and virtual open labs were a good alternative, whilst nearly 48%
thought this alternative was useful to a certain extent only. Part B: Educational resources in geological education, use of TLR of Indian
and foreign origin before and during the COVID-19 Part B: Educational resources in geological education, use of TLR of Indian
and foreign origin before and during the COVID-19 Before the COVID-19 pandemic, a majority of respondents (84%) were
involved in face-to-face teaching and a minor proportion was also involved
in online teaching (16%). It is inferred that out of the 61 respondents who
responded to this item, the institutes/universities of almost one-third of the
respondents (27%) did not provide any support and training in shifting from
face-to-face to online modes of teaching. However, the institutes/universities
of the remaining respondents, who were involved in face-to-face teaching
before the pandemic, did provide support and training in moving to online
modes of teaching. Such institutions had the advantage of being able to provide
undisrupted learning during the pandemic. We followed Braun & Clarke’s (2006) six-step approach for undertaking
thematic analysis of questionnaires received that involves becoming familiar
with data, generating initial codes, searching themes, reviewing themes,
defining themes, and, finally, undertaking interpretation. 249 eological education scenario in India and role of open educational resources in the light of COVID-19 pandemic to 28% (Table 6). The use of online lesson plans and assignments for students
remained almost the same. It was anticipated that there might have been an
increase in the use of virtual field trips or virtual science lab OER, but this is not
the case, at least not according to the data so far collected. This may reflect the
non-availability of virtual field trips or virtual science lab OER of Indian origin. The respondents, in assessing the quality of the TLR, showed more
positivity towards the foreign origin resources (62%) in terms of cost,
quality and availability, in comparison to the Indian origin resources (38%). However, they were of the view that the TLR of Indian origin are slightly more
comprehensible than that of foreign origin. They thought that more preference
should be given to the TLR of Indian origin (75%) in comparison to those of
foreign origin (67%). Moreover, the majority (77%) declared that they found
some shortage in the TLR of Indian origin and almost all the respondents (94%)
thought that more courses-based TLR incorporating Indian geological context
are needed. Almost one-third (28%) of the respondents commented that the
TLR of Indian origin are not up-to-date. Table 6. Part B: Educational resources in geological education, use of TLR of Indian
and foreign origin before and during the COVID-19 A small group
consisting of 11% of respondents were quite negative about the potential use
of virtual open laboratory, open field-based manuals, and open virtual field
trips based on Google Earth. Overall, 20% of respondents were enthusiastic
about exploring all the possibilities of the OER related to field and laboratory
components. Meanwhile, more than one-third of the respondents (37%) were
positive about the availability of Indian origin OER for teaching Geology. 4. Conclusions They can play a critical role in offering high-quality and equitable education. The availability of these resources in higher geological education is poor and
not sufficient to meet the current demands of the teaching-learning community
of the country. The questionnaire data show that there is an urgent need for
open educational resources in all branches of Geology especially focused on
course-specific modules, open lab manuals, open field-based manuals, virtual
field experiences, and virtual field trips based on the Google Earth program. The latter should be based on Indian geological contexts to provide effective
teaching-learning practices in Geological education. Therefore, it is critical to
design and develops more open educational resources in Geology to meet the
current demand of the country in terms of indigenous learning as well as to face
any future COVID-19-like challenges. COVID-19 has hit geological higher education badly by disrupting face-
to-face teaching-learning processes and preventing learners from undertaking
compulsory geological fieldwork assignments in their programs. In this context,
Open Educational Resources, which are course-based or chapter-specific free
digital resources available in various downloadable formats (like PDF), have
provided a suitable option for providing undisrupted, online, and remote
learning, in overcoming many of the educational challenges posed by the
COVID-19 pandemic. Open educational resources policies are valued by the
Government of India and many educational institutions are implementing them. f Beane, J. E., Turner, C. A., Hooper, P. R., Subbarao, K. V., & Walsh, J. N. (1986). Stratigraphy, composition and form of the Deccan basalts, Western
Ghats, India. Bulletin of Volcanology, 48, 61–83. https://doi.org/10.1007/
BF01073513 They can play a critical role in offering high-quality and equitable education. The availability of these resources in higher geological education is poor and
not sufficient to meet the current demands of the teaching-learning community
of the country. The questionnaire data show that there is an urgent need for
open educational resources in all branches of Geology especially focused on
course-specific modules, open lab manuals, open field-based manuals, virtual
field experiences, and virtual field trips based on the Google Earth program. The latter should be based on Indian geological contexts to provide effective
teaching-learning practices in Geological education. Therefore, it is critical to
design and develops more open educational resources in Geology to meet the
current demand of the country in terms of indigenous learning as well as to face
any future COVID-19-like challenges. Bhattacharya, B. B. (2016). 4. Conclusions Geological education and research are the basic building blocks of the
socio-economic growth and development of any country. Geologically, India
is a unique country, because of the huge amount of georesources it contains. The mineral resource richness of the country was first fully understood by the
British East India Company in 1835. They established the world’s second-
largest organization, the GSI, in 1851 in India, to prospect for mineral resources. After a long time gap, Geology emerged as an independent science education
discipline in the 1890s as a by-product of the GSI development. In the early
nineteenth century, only a few universities offered higher education degree
programs in Geology. Then, the number of institutes offering higher education
programs in Geology substantially expanded in the late nineteenth to the early
twentieth century. However, Geology as a science discipline within higher
education is still less popular than other science disciplines in India. Further,
Indian higher education in Geology still relies on costly and less accessible
teaching-learning resources. Ali, S., Shekhar, S., Chandrasekhar, T., Yadav, A. K., Arora, N. K., Kashyap, C. A.,
Bhattacharya, P., Rai, S. P., Pande, P., & Chandrasekharam, D. (2021). Influence of the water–sediment interaction on the major ions chemis-
try and fluoride pollution in groundwater of the Older Alluvial Plains of
Delhi, India. Journal of Earth System Science, 130(2), 1–16. https://doi. org/10.1007/s12040-021-01585-3 Ali, S., Thakur, S. K., Sarkar, A., & Shekhar, S. (2016). Worldwide contamination
of water by fluoride. Environmental chemistry letters, 14(3), 291–315. https://doi.org/10.1007/s10311-016-0563-5 Ayala, F. J. (2008) Science, evolution, and creationism. Proceedings of the National
Academy of Sciences of the United States of America, 105(1), 3–4. https://
doi.org/10.1073/pnas.0711608105 Babu, M. S. U., & Nautiyal, S. (2015). Historical issues and perspectives of land re-
source management in India: a review. The Institute for Social and Eco-
nomic Change, Bangalore. http://www.isec.ac.in/WP%20309%20-%20
Umesh%20Babu%20and%20Sunil%20 Nautiyal_final.pdf (last accessed
April 2021) COVID-19 has hit geological higher education badly by disrupting face-
to-face teaching-learning processes and preventing learners from undertaking
compulsory geological fieldwork assignments in their programs. In this context,
Open Educational Resources, which are course-based or chapter-specific free
digital resources available in various downloadable formats (like PDF), have
provided a suitable option for providing undisrupted, online, and remote
learning, in overcoming many of the educational challenges posed by the
COVID-19 pandemic. Open educational resources policies are valued by the
Government of India and many educational institutions are implementing them. Part C: OER use before and during the COVID-19 The respondents reported that they were quite well informed about
OER. Around 81% had heard about OER before the survey, and nearly 61%
had previously used them in the teaching-learning process. They (79%) had
informed their students about the existence of the OER, and more than half
(65%) were familiar with the appropriate geological OER, while 63% were
acquainted with the OER of Indian origin. A majority of respondents reported
that they were aware of Indian OER offering online platforms such as Nptel
(https://nptel.ac.in/), Swayam (https://swayam.gov.in/), e-pgpathshala (https://
epgp.inflibnet.ac.in/), and others. Additionally, they were also aware of several
foreign geological OER offering online platforms. The data also revealed
that respondents were using various types of OER such as open textbooks,
educational audios and videos, lesson plans, modules, and practical modules
both before and during the COVID-19 pandemic. The majority of respondents
were of the view that OER could work well for learners pursuing Bachelor’s
(70%) and even more, for Master’s (78%) degree programs in Geology. The majority of respondents (75%) thought that it is quite important
to use OER of either Indian or foreign origin, where content is enriched with
Indian geological examples. Almost two-thirds (65%) feel that learners would
benefit through the use of OER and that they have great potential to contribute to
equitable and high-quality geological education across the country. When they
were asked through the questionnaire what they had planned for the completion
of compulsory geological fieldwork assignment during the COVID-19
pandemic, almost one-third (31%) hoped to be able to carry out the fieldwork Even before the COVID-19 pandemic, there was a quite wide variety of
OER that had been used in teaching-learning practice; the most commonly used
were open textbooks and videos available online (Table 6). There was a slight
decrease in the use of open textbooks during COVID-19 and an increase in the
use of online audio and videos, especially of Indian origin increasing from 12% 250 Omkar Verma, Manthena Prashanth, Roberto Greco, Ashu Khosla, Kulwant Singh after the end of the COVID-19 pandemic, around 20% had no plan, and 10%
would like to wait until the end of the pandemic, and in the meantime, they
will use online resources. The remaining one-third (39%) planned to use the
online training and virtual field geology programs available from professional
organizations and webinars for this purpose. valuable views. We are highly thankful to Late Prof. C. Dedication To complete the laboratory component of the curriculum during the
COVID-19 pandemic, around one-third (34%) plan to complete it after the end
of the COVID-19 pandemic, almost another third (24%) plan to complete the
laboratory component of the curriculum by maintaining social distancing, using
precautionary measures, and calling students in small groups to the laboratory,
15% had no plan, and the remaining 27% will think about the use of OERs and
online video demonstrations for completing the activity. The authors are pleased to dedicate this paper to Late Prof. Chris King. He
was a Professor and Director of Earth Science Education Unit, Keele University,
United Kingdom. Prof. King was deeply involved in the establishment and
development of the International Geoscience Organization and in organizing
the first International Conference in Geoscience Education. He was a great
promoter of geological education across the globe and immensely contributed
to the field of geological education by designing and developing several
teaching-learning resources till his last breath. Finally, in the comment section of the questionnaire, respondents were
of the view that Geology is a field-based science and geological fieldwork is
therefore vital for imparting real field skills to the learners. However, OER,
particularly course-specific, open lab manuals, open field-based manuals,
virtual field experiences, and virtual field trips based on the Google Earth
program related to the Indian geological context, should be developed in almost
all branches of Geology. Overall, the questionnaire data indicates that OER
will enhance understanding of Geology and increase the skill of the learners,
which will reduce the paucity of TLR. Further, they will help in providing
equitable and high-quality higher geological education and make geological
education more flexible by providing a new teaching-learning experience with
the potential to tackle any future COVID-19-like situation. Part C: OER use before and during the COVID-19 King for offering initial
comments on the manuscript. The authors also sincerely thank five anonymous
reviewers, Prof. M.A. Malik, and Prof. Alexander Caneva (Editor-in-Chief) for
constructive criticism. 4. Conclusions Geoscience education – experiences and future pers-
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Design and Performance Investigation of a New Distributed Amplifier Architecture for 40 and 100 Gb/s Optical Receivers
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International journal of computer and technology
| 2,015
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cc-by
| 7,788
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ISSN 2277-3061
Design and Performance Investigation of a New Distributed Amplifier
Architecture for 40 and 100 Gb/s Optical Receivers
Essra E. Al-Bayati, R. S. Fyath
Department of Electronic and Communications Engineering, Al-Nahrain University, Baghdad, Iraq.
Email: eema_87@yahoo.com
Department of Computer Engineering, Al-Nahrain University, Baghdad, Iraq.
Email: rsfyath@yahoo.com
ABSTRACT
The design of distributed amplifiers (DAs) is one of the challenging aspects in emerging ultra high bit rate optical
communication systems. This is especially important when implementation in submicron silicon complementary metal
oxide semiconductor (CMOS) process is considered. This work presents a novel design scheme for DAs suitable for frontend amplification in 40 and 100 Gb/s optical receivers. The goal is to achieve high flat gain and low noise figure (NF) over
the ultra wideband operating bandwidth (BW). The design scheme combines shifted second tire (SST) matrix configuration
with cascode amplification cell configuration and uses m-derived technique. Performance investigation of the proposed DA
architecture is carried out and the results are compared with that of other DA architectures reported in the literature. The
investigation covers the gain and NF spectra when the DAs are implemented in 180, 130, 90, 65 and 45 CMOS
standards.The simulation results reveal that the proposed DA architecture offers the highest gain with highest degree of
flatness and low NF when compared with other DA configurations. Gain-BW products of 42772 and 21137 GHz are
achieved when the amplifier is designed for 40 and 100 Gb/s operation, respectively, using 45 nm CMOS standard. The
simulation is performed using AWR Microwave Office (version 10).
Indexing terms/Keywords
Distributed Amplifier; 40Gb/s Distributed amplifier; 100Gb/s Distributed amplifier
Academic Discipline And Sub-Disciplines
Electronics and Commun iocation Engineering- Optical Communications
TYPE (METHOD/APPROACH)
Anaylisis and Simulation
Council for Innovative Research
Peer Review Research Publishing System
Journal: INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY
Vol 14 . No. 5
www.ijctonline.com , editorijctonline@gmail.com
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Februarury 28, 2015
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1- INTRODUCTION
Everybody wants to benefit from the evaluation in the field of communication especially through internet. Due to the
expanding demand of communication services, the volume of data exchanged in the communication systems has
increased. This leads to increase data rate of the global communication systems from tens of Gb/s to Tb/s. BW
requirements will increase by more than 100 times and applications such as virtual reality require data rate that are 10,000
times higher than currently available. To transport such data rate, a media with low loss and high BW is required [1, 2].
Among the available medium to transfer the data, optical fibers have the best performance. Optical fibers are very
common these days to transport very high rate digital data. Such high speed data rates can be transported over kilometers
of optical fiber and without significant loss. Normally loss is very low when the signal is transmitted using light rather than
electrical signal. These fibers also have the advantage of being low cost in addition to improvement of performance. Fiber
optic devices and systems are evidently employed to realize very high data rates. Fiber optic communication is a solution
because high data rates can be transmitted through this high capacity cable with high performance [3].
The exponential growth of Internet traffic is fueling the research and development of wavelength division
multiplexed passive optical network technology in the access network segment [4]. Driven by the continues increase in
BW demand and number of subscribers, future access networks will require 40 Gb/s high speed service per wavelength
channel [5, 6] on a 50 GHz dense wavelength grid. The realization of high-speed analog-to-digital conversation and digital
signal processing have enabled a bit rate of 100 Gb/s in long-haul coherent optical communication system [7]. However,
for short-reach 100 Gb/s applications, solutions that use intensity modulation and direction detection are seen as more
practical [8]. With the advances in semiconductor technologies, integrated circuits operating at 40 Gb/s have been realized
in standard CMOS process [9]. Among all kinds of high speed circuits, the broadband amplifier is a key building block at
both the transmitting and receiving ends, see Fig. 1. In fact there is demand for wideband CMOS amplifiers in the frontend section of the optical receivers. Distributed amplification is one of the well-known methods to provide such
performance by absorbing the parasitic capacitances of parallel gain distributed cell into an artificial transmission line,
which in return, guarantees the gain uniformity and input/output matching within the BW of operation. However, design DA
for 40 Gb/s (and above) optical receivers needs careful consideration related to the gain, frequency spectrum and NF.This
paper addresses the design issues and performance investigation of CMOS DA for the front-end amplification stage in 40
and 100 Gb/s optical receivers.
Figure 1: Optical communication system [10].
2- RELATED WORK
In 2005, Wolf et al [11] demonstrated an eight-stage DA with 12.5 dB ± 0.45 dB gain and 50 GHz BW in a commercially
available 0.1 μm metamorphic GaAs HEMT technology. The amplifier has a minimum NF lower than 2.5 dB in the BW.
The group delay variation from 9 to 40 GHz is ± 7.5 ps and circuit power consumption is 0.4 W. Such amplifier packaged
with a high responsively PD into a fiber pig-tailed module. Eye diagrams measurements demonstrate the successful highspeed operation of the photoreceiver.
In 2007, Chien and Lu [12] presented a novel circuit topology for high-gain 40 Gb/s DAs. Based on the conventional
distributed architecture, the gain cells were realized by cascading cascode stages for gain enhancement. In addition, the
stagger-tuning technique was extensively utilized in the design of the cascode stages as well as the cascaded stages,
leading to significant improvement in terms of the operating BW and the gain flatness. With the proposed circuit
architecture, two amplifiers were implemented in a standard 180 nm CMOS technology. The amplifier with a 3 x3
configuration exhibits a gain of 16.2 dB and a 3 dB BW of 33.4 GHz, while the one in a form of 2x4 demonstrates a gain of
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20 dB and a BW of 39.4 GHz. Consuming a DC power of 260 mW from a 2.8-V supply voltage, both circuits provide clear
eye-opening with a pseudorandom bit sequence at 40 Gb/s.
In 2009, Moez and Elmasry [13] presented a circuit technique to compensate for the metal and substrate loss of the onchip transmission lines, and, consequently, to improve the gain flatness and BW of CMOS DAs for optical receivers. An
eight-stage DA suitable for 40 Gb/s optical communication was devised and implemented in a 130 nm CMOS process.
The DA achieves a flat gain of 10 dB from DC to 44 GHz with an input and output matching better than −8 dB. The
measured NF varies from 2.5 to 7.5 dB with the amplifier‟s band. The proposed DA dissipates 103mW from two 1-V and
1.2-V DC supplies.
In 2009, Entesari et al [14] presented a state-of-the-art DA with coupled inductors in the gate line. The proposed coupled
inductors, in conjunction with series-peaking inductors in cascode gain stages, provide BW extension with flat gain
response for the amplifier without any additional power consumption. On the other hand, gate-inductor coupling improves
the input matching of the amplifier considerably. The detailed analysis and design methodology for the proposed DA were
presented. The new four-stage DA, fabricated using an IBM 0.18- m CMOS process, achieves a power gain of around 10
dB, input and output return losses better than 16 and 18 dB, respectively, a NF of 3.6–4.9 dB, and a power consumption of
21mW over a 16-GHz flat 1-dB BW. is between 0.1 and 3.75 dBm across the entire band.
In 2010, Ghadiri and Moez [15] presented a new high-gain structure for DA. Negative capacitance cells were exploited to
ameliorate the loading effects of parasitic capacitors of gain cells in order to improve the gain of the DA while keeping the
desired BW. In addition, the negative capacitance circuit creates a negative resistance that can be used to increase the
amplifier BW. Implemented in 130 nm IBM‟s CMRF8SF CMOS, the proposed six-stage DA presents an average gain of
13.2 dB over a BW of 29.4 GHz. The measured input return loss is less than 9 dB and the output return loss is less than
9.5 dB over the entire BW. With a chip area of 1.5 mm X 0.8 mm, the amplifier consumes 136 mW from a 1.5-V DC power
supply.
In 2010, Chien et al [16] presented a transimpedance amplifier (TIA) with a tunable BW for optical communications. The
proposed TIA is composed of two cascaded stages in which an input network with inductive peaking elements is employed
in the first stage for broadband operations while a modified DA is utilized as the second stage for enhanced
transimpedance gain. In addition, a feedback loop is incorporated as the bandwidth-tuning mechanism. By tuning the BW
of the TIA, optimum circuit operation with lowest bit error rate (BER) can be achieved in the receiver front end for highspeed data transmission. The proposed circuit was implemented in a 180 nm CMOS process. Consuming a DC power of
33.3 mW from a 1.8-V supply, the fabricated TIA exhibits a transimpedance gain of 47.8 dB and a variable 3-dB BW from
6.2 to 10.5 GHz. Providing a
-1 pseudorandombit sequence at 9-15 Gb/s, a BER less than
was demonstrated
experimentally by the TIA with the BW tuning mechanism.
In 2011, KimandBuckwalter [17] demonstrated a low-power cascode DA in a 45 nm silicon-on-insulator (SOI) CMOS
process. The amplifier achieves a 3 dB BW of 92 GHz. The peak gain is 9 dB with a gain-ripple of less 1.5 dB over the
BW. The group-delay variation is under ± 4.7ps over the 3 dB BW. The amplifier consumes 73.5mW from a 1.2V supply
and results in a GBW efficiency figure of merit of 3.53 GHz/mW. The chip occupies an area of 0.45
including the
pads.
In 2012, Jahanian and Heydari [18] presented a CMOS DA with distributed active input balun that achieves a GBW
product of 818 GHz, while improving linearity. Each cell within the DA employs dual-output two-stage topology that
improves gain and linearity without adversely affecting BW and power. Comprehensive analysis and simulations were
carried out to investigate gain, BW, linearity, noise, and stability of the proposed cell, and compare them with conventional
cells. Fabricated in a 65-nm low-power CMOS process, the 0.9-mm DA achieves 22 dB of gain and a P1dB of 10 dBm,
while consuming DC power of 97 mW from a 1.3-V supply. A distributed balun, designed and fabricated in the same
process, using the same topology achieves a BW larger than 70 GHz and a gain of 4 dB with 19.5-mW power
consumption from 1.3-V supply.
In 2013, Feng et al [19] realized compact self-biased wideband low noise amplifier (LNA) in Global Foundries 65 nm
CMOS technology. Wideband input matching characteristic is achieved by placing a series gate inductor and a parallel
tuning capacitor in the resistive-feedback network. Combined with the inductive-series peaking technique which further
extends the BW, the proposed cascaded three-stage resistive-feedback amplifier obtains a large operating BW which is
comparable with the DA. Measurement shows that the proposed amplifier achieves a power gain of with input and output
return losses better than 8 dB and NF ranging from 4.5 to 6.8 dB between 2.1–39 GHz. The fabricated low LNA occupies
a silicon area of 0.16 including all testing pads and draws 17 mA from a 1.5 V power supply.
In 2013, Kao et al. [20] proposed a new DA topology which is a combination of the conventional DA and the cascaded
single-stage DA. This DA topology can provide wide BW with considerations of the gain, NF, and output power
simultaneously, and requires reasonable DC power consumption. Two termination methods of this combination were
investigated. From the measurements, the first DA has a small-signal gain of 20.5 dB, a 3-dB BW of 35 GHz, and a GBW
product of 371 GHz. The maximum output power at 1-dB output compression point is 8.6 dBm and the NF is between 6.8–
8 dB at frequencies lower than 18 GHz. The chip size, including testing pads, is only 0.78 mm, and the ratio of the GBW to
chip size is 476GHz/mm. The second DA has a small-signal gain of 24dB, a 3-dB BW of 33 GHz, and a GBW product of
523 GHz. The maximum output power is 9 dBm and the NF is between 6.5-7.5 dB at frequencies lower than 18 GHz. The
chip size including testing pads is only 0.83 mm, and the ratio of the GBW to chip size is 630 GHz mm.
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In 2013, Cho et al. [21] proposed a wideband switchless bi-directional DA in a commercial 130 nm CMOS technology,
which realizes multi-octave BW with high gain and low NF using DA technique and cascode amplifier pair. The measured
gain is over 10 dB and measured NF is 3.2-6.5 dB. The input and output return losses are better than 9 dB at 3–20 GHz.
The measured output power 1dB and output input power (OIP3) is larger than 8 dBm and 17 dBm at 4–15 GHz. The chip
sizeis 0.96 x 0.85
including pads. The proposed switchless bi-directional amplifier has almost the same chip size
compared to the conventional uni-directional DA.
In 2014, Kim and Nguyen [22] presented a new tri-band power amplifier on a 180 nm SiGeBiCMOS process, operating
concurrently in Ku/K/Ka and -band, is presented. The concurrent tri-band PA design is based on the DA structure with
capacitive coupling to enable large device size, while maintaining wide BW, gain cells with the enhanced-gain peaking
inductor, and negative-resistance active notch filters for improved tri-band gain response. The concurrent tri-band PA
exhibits measured small-signal gain around 15.4, 14.7 and 12.3 dB in the low band (10–19 GHz), midband (23–29 GHz),
and high band (33–40 GHz), respectively.
It is clear from the above survey that the reported designs of DAs suitable for high bit rate optical receiver don‟t
achieves simultaneously wide BW, high flat gain and low NF. This issue is addressed in this thesis where a modified DA
topology is introduced to reach these goals.
3- PROPOSED DA ARCITECTURE AND DESIGN CONCEPTS
In the literature, different DA architectures have been discussed. Each one has its own design topology and uses different
techniques to enhance one of the design requirements: wide BW, high flat gain and low NF. In this section, a new DA
architecture is proposed to achieve ultrawide band operation under high amplification gain and low NF conditions. The
proposed architecture collects the main features behind different topologies and techniques adopted in previous DA
designs such as shifted second stage (SST) topology, matrix configuration, cascode cell amplifier configuration, and mderived matching technique. Design issues based on deep submicron CMOS technology are discussed toward achieving
efficient front-end amplification in 40 Gb/s and 100 Gb/s optical receivers.
3.1 - Architecture of the Proposed Distributed Amplifier
The main idea behind the proposed DA is to combine high-feature topologies and techniques adopted by other DA
designs. The task in this work is primarily to design CMOS-based DA with ultrawide BW, high flat gain and low NF suitable
for high bit rate optical receivers ( 40 Gb/s). The proposed DA uses the following techniques and topologies
a- m-derived technique
m-derived techniques is used at the input and output of constant-k filter sections in order to obtain flat BW and
constant impedance matching.
b- Shifted-Second Tire Matrix Configuration
This type of DA uses additive and multiplicative technique to achieve high flat gain. The configuration uses M
stages and N distributed cells (N tires). Simulation results show that design the DA with two stages and four
distributed cells is sufficient to get the require design target. Using M>2 and N>4 will increase the complexity of
the design without offering reasonable performance improvement.
c- Cascode Amplification Cell Configuration
Cascode DA is obtained by adding common-gate amplifier section to the drain line of common-source amplifier
stage. Using cascode amplification cells in DA configuration will decrease the variation of the capacitance seen
by the transmission line and offer a nearly flat gain over wider BW as compared with the simple common-source
amplifier.
The cascode amplifier can be considered as a two-stage amplifier composed of a transconductance amplifier
followed by a current buffer [23]. Compared to a single amplifier stage, this combination may have one or more of the
following characteristics: higher input-output isolation, higher input impedance, higher output impedance, higher gain or
higher BW. Thus cascade configuration can be designed to improve input-output isolation (or reverse transmission) as
there is no direct coupling from the output to the input.
Fig. 2a shows a MOSFET cascode amplifier. If one make a small-signal analysis for this amplifier using the
simplified small-signal equivalent circuit shown in Fig. 2b, the following results are obtained [23]. The voltage gain
=-(
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(1.a)
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(a)
(b)
Figure 2: a- Cascode MOSFET amplifier b- Simplified small-signal equivalent circuit of MOSFET [23].
≈
when
>>1
(1.b)
Note that the cascode amplifier behaves as a common-source amplifier with higher gain. If identical transistor is used, the
≈
. The input resistance of the cascode amplifier tends to infinitely since the input signal source is applied to the
high impedance gate terminal.
The output resistance of the cascode amplifier is given by
(2.a)
For identical transistors
(2.b)
≈
when
>>2.
This yields higher output impedance compared with conventional common-source amplifier.
Fig. 3 shows a block diagram for the proposed DA configuration. The structure contains two amplification stages
each with four amplification cells. The corresponding circuit-level description of the proposed DA is illustrated in Fig. 4.
Figure 3: Block diagram of the proposed shifted second tier with m-derived DA.
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3.2- Design Concepts
The gate and drain transmission lines are designed with equal inductance and capacitance to ensure equal wave
propagation velocities along both lines. The cutoff frequency and characteristic impedance
of the transmission lines
are given by
=
=
=
=
=
(3.a)
=
(3.b)
where L and C stand, respectively, to the inductance and capacitance of the transmission line, while the subscripts g and
d denote gate and drain, respectively. For given values of and , the transmission line elements can be calculated as
follows
=
=
(4.a)
=
=
(4.b)
Figure 4: Circuit-level description of the proposed DA having two stages each with four amplifications cells with m-drive
techniques.
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Note that both capacitance and inductance are inversely proportional to the cutoff frequency . This is illustrated in Figs. 5
a and b which show respectively, the dependence of =
and = on the transmission line cutoff frequency when
=50 Ω. At
nH for
=10 GHz,
=
= 0.63 pF and
=
nH. These values are to be compared with 0.08 pF and 0.19
=80 GHz.
(a)
(b)
Figure 5: Dependence of the transmission line capacitance (a) and inductance (b) on the cutoff frequency.
The next step is to determine transistor gate width for different submicron CMOS standards. The gate length
(channel length) L is set equal to the used CMOS standard [24].The gate width is estimated using the following relation.
= WL
(5)
W=
(6.a)
W=
(6.b)
where
is the oxide capacitance per unit area. Unfortunately, values of
for submicron CMOS standards used in this
thesis <180 nm are not reported in the literature. For example, Ref. [25] gives
for CMOS standards 800, 500, 250 and
180 nm (see Table 1). These data are curve fitted to the flowing equation
=
where
+
+
(7)
is the CMOS standard in nm. The values of the fitting coefficients are
= 0.017188
= -25.876
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= 12084
Fig. 6 shows the variation of
with CMOS standard. The marks are the data taken for Ref. [25] while the solid
line denotes curve fitting. The curve fitting is used to extract
for CMOS standards 130, 90, 65 and 45 nm (see Table 1
and Fig. 7).
Table 1: Oxide Capacitance
CMOSStandard (nm)
800
(
for various CMOS standards.
OxideCapacitance
2300 )
Referenc
es [25]
500
3800
[25]
250
5800
[25]
180
8600
[25]
130
9001
This work
90
9089
This work
65
45
10005
11000
This work
This work
Figure 6: Variation of oxide capacitance with CMOS standard (>180 nm)
Figure 7: Extracted values of oxide capacitance for 130, 90, 65 and 45 nm standards
It is clear from Table 1 and Figs. 6 and 7 that
increases as CMOS standard increases. This result can be
explained by treating the gate capacitance simply as a two-parallel plate capacitance arises from the dioxide layer.
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=
(8.a)
=
=
(8.b)
=3.9
=3.45 x
F/m
where
is the gate area and
is the permittivity of the sillicon oxide which has
decreases,
thickness decreases too and leading to higher values for
.
thickness. As CMOS standard
The dependence of the gate width on the cutoff frequency of the transmission line is reflected in Equ. 6b. For a
given CMOS standard, the gate width is inversely proportional to the cutoff frequency. This relation is illustrated
graphically in Fig. 8 where the gate width is plotted versus cutoff frequency for different values of CMOS standards.
According to Equ. 6b, W Increases as CMOS standard decreases.
Figure 8: Dependence of gate width on transmission line cutoff frequency for different CMOS standards.
The next design step is to calculate the transistor transconductance
as a function of transmission line cutoff
frequency for different values of CMOS standards. Recall that
=(
)
when the transistor operates in the
saturation region. Here
is the electron mobility in the channel (assuming NMOS structure) and
is the over drive
voltage which is set to 0.2V in the simulation. With the aid of Equ. 6b one can arrive to the following expression for the
transconductance
=
(9)
Investigating Equ. 9 reveals the following findings
I.
is independent of oxide capacitance
and gate width
II.
is inversely proportion to both cutoff frequency
.
and the square of the gate length.
The electron mobility for NMOS transistors fabricated with standards 180 nm and above are reported in Ref. [25] and
listed in Table 2. These data is curve fitted to the following polynomial in order to extract the values of
for standards
below 180 nm (see Fig. 9)
=
where
+
in
+
/
/
b2= 1.7265 x
/
b1= 0.14487
b0= 423.09
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The extracted values of
for standards 130, 90, 65 and 45 nm are listed in Table 2.
Table 2: Electron mobility for various CMOS standards.
CMOS Standard (nm)
Electron Mobility (
Reference
)
800
550
[25]
500
500
[25]
250
460
[25]
180
450
[25]
130
442
This work
90
436
This work
65
433
This work
45
430
This work
Figure 9: Variation of electron mobility with CMOS standard.
Figs. 10 a-e show the variation of transconductance with transmission line cutoff frequency for different CMOS
standards 180, 130, 90, 65 and 45 nm, respectively. Note that
increases rapidly as the fabrication process goes to a
smaller standard. This result is expected since
is inversely proportional to
and the gate length L decreases as one
dopted deeper submicron standards. For example, the values of
at = 40 GHz are 0.053S, 0.124S, 0.256S, 0.488S
and 1.012S for 180, 130, 90, 65 and 45 nm standards, respectively.
Table 3 lists the required transistor design parameters (L, W and
) for NMOS transistor fabricated using deep
submicron standards and operates at a specific value of cutoff frequency .
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Figuer 10: Dependence of NMOS transconductance with transmission line cutoff frequency for different standards. (a)
180 nm, (b) 130 nm, (c) 90 nm, (d) 65 nm, (e) 45 nm.
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Table 3: NMOS transistor parameters for different values of cutoff frequency and fabrication standards.
Standard (nm)
180
Transistor
Parameter
80
180
180
W (µm)
270
138
87
69
0.104
0.053
0.033
0.026
L (nm)
130
130
130
130
W (µm)
396
203
128
101
0.243
0.124
0.078
0.062
L (nm)
90
90
90
90
W (µm)
522
267
168
134
0.500
0.256
0.161
0.128
L (nm)
65
65
65
65
W (µm)
681
349
219
174
0.953
0.488
0.307
0.244
L (nm)
45
45
45
45
W (µm)
939
481
303
241
1.974
1.012
0.637
0.507
(S)
45
60
180
(S)
65
40
180
(S)
90
20
L (nm)
(S)
130
Cutoff frequency ( GHz)
(S)
4- PERFORMANCE SIMULATION RESULTS
4.1- Introduction
This section presents simulation results characterizing the gain, NF and BW of the proposed distributed amplifier for 40
and 100 Gb/s operation. The results are compared with the performance of five DA architectures, namely
I.
Conventional DA which uses common-source amplification cells.
II.
Cascode DA which uses cascode configuration for the amplification.
III.
m-derived DA which is a conventional DA supported with both input and output m-derived stages.
IV.
Matrix DA where the amplification cells are arranged in matrix-form topology.
V.
Shifted second tier (SST) DA.
All the DAs considered here are designed with four amplification cells per stage. The proposed DA, matrix and SST
distributed amplifiers have two stages.
Simulation results related to DA characteristic are obtained using AWR Microwave Office (version 10). The
results are then used to design the proposed DA for 40 and 100 Gb/s optical receivers.
4.2- Gain and Noise Figure Spectra
The aim of this section is to investigate the gain and NF spectra when the proposed DA is designed using different nano
scale CMOS technologies. The results are to be compared with other DA architectures to assess the main features behind
the proposed DA.
Figs. 11 a-e illustrates the variation of the DA gains with frequency when the amplifiers are designed with 35 GHz
cutoff frequency. This value of cutoff frequency is found to be suitable for operation around 40 Gb/s. Parts a-e of this figure
are related to 180, 130, 90, 65 and 45 nm standards, respectively. Investigating these figures highlights the following
finding. The proposed DA offers the highest gain with almost flat characteristic in the passband region compared with
other DAs. Tables 4 and 5 list, respectively, the DC gain and BW of various DAs under investigation and taking the CMOS
standard as independent parameter.
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130 nm
180 nm
(a)
(b)
65 nm
90 nm
(c)
(d)
45 nm
(e)
Figure 11: Gain spectra of various DA configurations designed with 35 GHz cutoff frequency using (a) 180 nm standard,
(b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard, (e) 45 nm standard.
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Table 4: DC gain of various DAs designed with 35 GHz cutoff frequency.
DC Gain (dB)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
13 dB
19 dB
17 dB
20 dB
20 dB
Cascode
9 dB
15 dB
23 dB
23 dB
24 dB
m-derived
12 dB
19 dB
17 dB
19 dB
20 dB
Matrix
22 dB
27 dB
29 dB
29 dB
35 dB
Shifted second tier
21 dB
29 dB
33 dB
33 dB
39 dB
This work
24 dB
42 dB
47 dB
56 dB
62 dB
Table 5: Bandwidth of various DAs designed with 35 GHz cutoff frequency.
Bandwidth ( GHz)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
1.2 GHz
3 GHz
6 GHz
5 GHz
6 GHz
Cascode
30 GHz
32 GHz
26 GHz
28 GHz
29 GHz
m-derived
7 GHz
8 GHz
11 GHz
10 GHz
19 GHz
Matrix
3.7 GHz
4 GHz
5 GHz
5.5 GHz
7 GHz
Shifted second tier
9.7 GHz
20 GHz
13 GHz
16 GHz
18 GHz
This work
31 GHz
31 GHz
34 GHz
32 GHz
34 GHz
From the results illustrated in Fig. 11 and Tables 4 and 5 one can find out that the proposed DA the best results
(highest gain and BW) when compared with other DAs. Conventional DA gives medium gain but not flat with low BW.
Cascode DA gives low gain with BW range close to this work. M-derived DA gives flat medium gain with low BW. Matrix
DA gives high gain but not flat with low BW. SST gives flat high gain with low BW.
The simulation is repeated to investigate the characteristics of 80 GHz-cut off frequency DAs suitable for around
100 Gb/s operation. The results are presented in Fig. 12 to highlight the gain spectrum and summarised in Tables 6 and 7
to assess the DC gain and BW, respectively, of various DAs synthesized with nanoscale CMOS standards.
130 nm
180 nm
(a)
(b)
Figure12: Gain spectra of various DA configurations designed with 80 GHz cut off frequency using (a) 180 nm standard,
(b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard, (e) 45 nm standard.
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90 nm
65 nm
(c)
(d)
45 nm
(e)
Figure12: (Continued)
Table 6: DC gain of various DAs designed with 80 GHz cutoff frequency.
DC Gain (dB)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
3 dB
9 dB
9 dB
9 dB
11 dB
Cascode
2 dB
8 dB
12 dB
15 dB
17 dB
m-derived
3 dB
8 dB
8 dB
10 dB
12 dB
Matrix
6 dB
15 dB
15 dB
15 dB
19 dB
Shifted second tier
9 dB
12 dB
14 dB
15 dB
20 dB
This work
10 dB
23 dB
34 dB
42 dB
49 dB
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Table 7: Bandwidth of various DAs designed with 80 GHz cutoff frequency.
Bandwidth ( GHz)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
19 GHz
20 GHz
16 GHz
17 GHz
12 GHz
Cascode
50 GHz
52 GHz
59 GHz
63 GHz
68 GHz
m-derived
27 GHz
28 GHz
25 GHz
29 GHz
35 GHz
Matrix
10 GHz
10 GHz
9 GHz
9 GHz
13 GHz
Shifted second tier
27 GHz
31 GHz
32 GHz
30 GHz
58 GHz
This work
70 GHz
75 GHz
74 GHz
71 GHz
75 GHz
Investigating the results in Fig 12 and Tables 6 and 7 reveals that the same conclusions drawn from the 35 GHz
cutoff frequency DAs are also applied.
The results also show that when the cutoff frequency increases, the gain decreases for all DAs. However, the
proposed DA gives the highest gain. One can apply these results to all standards (180, 130, 90, 65 and 45 nm).
The simulation is carried further to assess the NF spectrum of 35 GHz – and 80 GHz cut off frequency DAs and
the results are displayed in Figs. 13 and 4.4, respectively. Tables 8 and 9 summarises the dependants of low frequency
NF on CMOS standard for various DA configurations.
180 nm
(a)
130 nm
(b)
Figure13: Noise figure spectra of various DA configurations designed with 35 GHz cutoff frequency using (a) 180 nm
standard, (b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard, (e) 45 nm standard.
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90 nm
(c)
65 nm
(d)
45 nm
(e)
Figure13: (Continued)
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180 nm
130 nm
(a)
(b)
90 nm
65 nm
(c)
(d)
45 nm
(e)
Figure14: Noise figure spectra of various DA configurations designed with 80 GHz cutoff frequency using (a) 180 nm
standard, (b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard, (e) 45 nm standard.
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Table 8: Noise figure of various DAs designed with 35 GHz cutoff frequency.
DC Noise figure (dB)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
3 dB
4 dB
16 dB
30 dB
3 dB
Cascode
15 dB
25 dB
14 dB
10 dB
9 dB
m-derived
5.1 dB
4.5 dB
8 dB
18 dB
1.7 dB
Matrix
2.4 dB
2.2 dB
3.7 dB
2.2 dB
4 dB
Shifted second tier
3 dB
3.6 dB
10 dB
5 dB
2 dB
This work
4 dB
1.5 dB
5 dB
1.7 dB
2 dB
Table 9: Noise figure of various DAs designed with 80 GHz cutoff frequency.
DC Noise figure (dB)
Distributed Amplifier
180 nm
130 nm
90 nm
65 nm
45 nm
Conventional
18 dB
12 dB
26 dB
30 dB
36 dB
Cascode
7 dB
7.3 dB
10.1 dB
8 dB
5 dB
m-derived
18 dB
5 dB
0.8 dB
1 dB
0.3 dB
Matrix
2.5 dB
2.5 dB
1.5 dB
4 dB
2 dB
Shifted second tier
2 dB
3 dB
3 dB
4.5 dB
4 dB
This work
6 dB
1.7 dB
3 dB
3.5 dB
3.5 dB
From the results illustrated in Figs. 5 and 6 and Tables 8 and 9 one can find out that proposed DA gives low NF
with almost flat spectrum when compared with other DAs. The value of the NF of this DA doesn‟t exceed 6 dB for all
standards (180, 130, 90, 65 and 45 nm).
4.3- Effect of Transmission Line Cutoff Frequency
The cutoff frequency of drain and gate transmission lines is usually used as one of the main entry design parameters for
DAs. This section illustrates the depends of DA characteristic on the cutoff frequency. The results are reported for various
DA architectures and various CMOS standards. The investigation is focused on low-frequency gain, low-frequency NF,
and 3 dB BW.
Figs. 15 a-e shows the dependence of the low-frequency gain on the line cutoff frequency for CMOS standards
180, 130, 90, 65 and 45 nm, respectively. Note that the proposed DA has the highest gain among the DAs considered
here and this conclusion holds true for all cutoff frequency and CMOS standards. Note further that the amplifier gain
decreases as the cutoff frequency increases.
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180 nm
130 nm
(a)
(b)
90 nm
65 nm
(c)
(d)
45 nm
(e)
Figure15: Dependence ofgain on cutoff frequency for various DAs designed using CMOS technology of (a) 180 nm
standard, (b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard and (e) 45 nm standard.
Variation of low-frequency NF with cutoff frequency is given in Fig. 16. The results are reported for various DA
configuration and CMOS standards. Investigation the results in this figure highlights the following findings. The proposed
DA is characterized by relatively low NF over all values of cutoff frequency and CMOs standards.
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180 nm
130 nm
(a)
(b)
65 nm
90 nm
(c)
(d)
45 nm
(e)
Figure16: Dependence ofnoise figure on cutoff frequency for various DAs designed using CMOS technology of (a) 180
nm standard, (b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard and (e) 45 nm standard.
The calculation is carried further to estimate the 3 dB BW of the DAs and the results are displayed in Fig. 17 for
various CMOS standards. The main conclusions drawn from this figure are
I.
For a given cutoff frequency, the proposed DA generally offers the highest BW compared with other DAs and this
effect is more pronounced for high CMOS standards. For example, at 35 GHz cutoff frequency and 180 nm
standard, the BWs of the proposed, cascode, SST, m-derived, matrix and conventional DAs are 31, 30, 9.7, 7,
3.7 and 1.2 GHz, respectively. These values are to be compared with 31, 31, 10, 8, 4 and 3 GHz for 130 nm
DAs designed with 35 GHz cutoff frequency.
II.
In general, the BW of all DAs increases with cutoff frequency and this effect is more pronounced with the
proposed DA. For example, if the DAs are designed with
= 80 GHz and 180 nm standard, then the BW are
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enhanced by 2.25, 1.66, 2.7, 3.85, 2.70 and 15.83 for the proposed, cascode, SST, m-derived, matrix and
conventional DAs when compared with 35 GHz cutoff frequency counterparts.
130 nm
180 nm
(a)
(b)
90 nm
65 nm
(c)
(d)
Figure17: Dependence ofbandwidth on cutoff frequency for various DAs designed using CMOS technology of (a) 180 nm
standard, (b) 130 nm standard, (c) 90 nm standard, (d) 65 nm standard and (e) 45 nm standard.
45 nm
(e)
Figure17: (Continued)
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4.4- Designing the Proposed DAs for 40 and 100 Gb/s Operation
The results reported in the previous sections can be used as a guideline to design the proposed DA for front-end
amplification in 40 Gb/s and 100 Gb/s optical receivers. The BW of the optical receiver is usually set equal to 0.7x bit rate
as a hand of thumb estimate.
From Fig. 17, one can deduced the cutoff frequencies for various CMOs standards that can be used as a design
parameter to achieve BWs corresponding to 40 and 100 Gb/s. This design parameter is used to deduce both geometric
and characteristics parameters of the DAs. Tables 10 and 11 list the obtained results, for both 40 and 100 Gb/s DAs,
respectively. Again various CMOS standards are used to estimate the DA parameters for both operating bit rates. The
thickness of the oxide layer
is calculated from the gate capacitance using a simple model based on parallel-plate
capacitance,
=
=3.9
(11.a)
=3.45 x
F/m
(11.b)
Figs. 18a and 18b show the gain and NF spectra for 40 Gb/s DAs designed with different CMOS standards. The
calculations are repeated in Figs. 19a and 19b for the designed 100 Gb/s DAs.
(a)
(b)
Figure 18: Gain and noise figure spectra for the proposed 40 Gb/s DA designed using different CMOS standards.
(a)
(b)
Figure 19: Gain and noise figure spectra for the proposed 100 Gb/s DA designed using different CMOS standards.
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Table 10: Design and characteristics parameters of the proposed DA for 40 Gb/s operation. Cutoff frequency of 35 GHz is
used in the design.
Value
Parameter
180 nm
130 nm
90 nm
65 nm
45 nm
Gate length (nm)
180
130
90
65
45
Gate width (µm)
158
233
306
399
551
Oxide thickness (nm)
4
3.8
3.7
3.4
3.1
Transconductance (S)
0.061
0.142
0.293
0.559
1.159
Gain (dB)
25
42
47
59
62
Noise figure (dB)
3
1.5
3.5
1.7
2
Gain - BandwidthProduct ( GHz)
551
3902
7611
28512
42772
Table 11: Design and characteristics parameters of the proposed DA for 100 Gb/s operation. Cutoff frequency of 80 GHz
is used in the design.
Value
Parameter
180 nm
130 nm
90 nm
65 nm
45 nm
Gate length (nm)
180
130
90
65
45
Gate width (µm)
69
101
134
174
241
Oxide thickness (nm)
4
3.8
3.7
3.4
3.1
Transconductance (S)
0.026
0.062
0.128
0.244
0.507
Gain (dB)
10
23
34
42
49
Noise figure (dB)
6
1.2
3
3.5
3.5
Gain x Bandwidth
221
1059
3708
8938
21137
Product ( GHz)
From the results illustrated in graphs and tables above, one can find that the gain is increased by increasing the
standard values, this can applied at both 35 and 80 GHz cutoff frequency, and the value of NF remains low. Gate width
also increased by increasing the standard values, oxide thickens decrease by increasing the standard value, while
transconductance increase by increasing standard value.
5- CONCLUSIONS
A new distributed amplifier architecture has been introduced to achieve high flat gain and low noise figure over ultra
wideband bandwidth. Investigation has been carried out to assess the performance of the proposed DA when it is
implemented in various submicron CMOS standards process. The results have been used to design DAs for front-end
amplification in 40 and 100 Gb/s optical receivers. The main conclusions drawn from this work are
I.
The proposed DA offers the highest gain among various DAs investigated in this work.
II.
The proposed DA offers a nearly flat gain over the wide bandwidth. The degree of gain flatness is the highest
among the investigated DAs.
III.
Designing the DAs with high cutoff frequency leads to gain reduction.
IV.
The noise figure of the proposed DA does not exceed 6 dB for various CMOS standards.
6- REFERENCES
[1] B. Razavil, „„Integrated circuit for optical communication‟‟, Second edition, Johenwiely and Sons Inc, 2012.
[2] K. Kurokawa, „„Optical fiber for high power optical communication‟‟, Journal of Crystals, Vol. 2, No. 2, PP. 1382-1392,
2012.
[3] V.S. Bagad, „„Optical fiber communication‟‟, First edition, MC. Grow. Hill, 2009.
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[4] R. Zhou, M. Anandarujah, R. Maher, M. Paskov, D. Lavery, B.C. Thomsen, S. J. Savory and L.P. Barry, „„80 -km
coherent DWDM-PON on 20-GHz grid with injected gain switched comb source”, IEEE Photonics Technology Letters,
Vol. 26, No. 4, PP. 364-366, 2014.
[5] G. Cossu, F. Bottoni, R. Corsini, M. Presi, and E. Ciaramella, „„40 Gb/s single R-SOA transmission by optical
equalization and adaptive of DM‟‟, IEEE Photonics Technology Letters, Vol. 25, No. 21, PP. 2119 - 2122, 2013.
[6] Q. Guo and V. Tran, „„Demonstration of a 40 Gb/s wave length reused WDM – PON using coding and equalization‟‟,
IEEE Journal of Optical Communication and Networking, Vol. 5, No. 10, PP. 119 – 124, 2013.
[7] J. Yu, and X. Zhou, „„Ultra–high–capacity DWDM transmission systems for 100 G and beyond‟‟, IEEE Communication
Magazine, PP. 556 – 563, 2010.
[8] J.C. Cartledge and A.S. karar, „„100 Gb/s intensity modulation and direct detection‟‟, Journal of Lightwave Technology,
Vol. 32, No. 16, PP. 2809-2813, 2014.
[9] N.A. Quadir, P.D. Townsend and P. Ossieur, „„An inductorless linear optical receiver for Gbaud/s (40Gb/s) PAM-4
modulation using 28nm CMOS‟‟, IEEE International Symposium on Circuits and Systems, Melbourne, PP. 2473-247,
2014.
[10] J.M. Gene Bernaus, “Fiber-optic communication”, Departament de Teoria del Senyal i Comunicacions,
UniversitatPolitecnica
de
Catalunya,
2010.
(http://ocw.upc.edu/sites/default/files/materials/15011956/oc_chapter_i_100224-2804.pdf)
[11] G. Wolf, S. Demichel, R. Leblanc, F. Bdache, R. Lefevre, G. Dambrine and H. Happy, “A metamorphic GaAS HEMT
Distribut Amplifier with 50 GHZ bandwidth and low noise for 40 Gb/s optical receivers‟‟ , InstitutElectronique de
Microelectronique de Nanotechnologie (IEMN), DepartementHyperfrequences et semiconductors, PP. 93-94, 2005.
[12] J. C. Chien and L. –H. Lu, “40-Gb/s high-gain distributed amplifiers with cascaded gain stages in 0.18-µm CMOS”,
IEEE Journal of Solid-State Circuits, Vol. 42, No. 12, PP. 2715-2724, 2007.
[13] K. Moez and M. Elmusry, “A new loss compensation technique for CMOS distributed amplifiers‟‟, IEEE Transactions
on Crcuits and Systems, Vol. 56, No. 3, PP. 185-188, 2009.
[14] K. Entesari, A.R. Tavakoli and A. Helmy, “CMOS distributed amplifier with extended flat bandwidth and improved
input matching using gate line with coupled inductors‟‟, IEEE Transactions on Microwave Theory and Techniques,
Vol. 57, No. 12, PP. 2862 – 2870, 2009.
[15] A. Ghadiri and K. Moez, “Gain-Enhanced distributed amplifier using negative capacitance‟‟, IEEE Transactions on
Circuit and Systems, Vol. 57, No. 11, PP. 2834 – 2841, 2010.
[16] C. K. Chien, H. H. Hsich, H. S. Chen and L. H. Lu, “A transimpedance amplifier with tunable bandwidth in 0.18 µm
CMOS‟‟, IEEE Transactions on Microwave Theory and Techniques, Vol. 58, No. 3, PP. 498-504, 2010.
[17] J. Kim and J. F. Buckwalter, „„A 92 GHz bandwidth distributed amplifier in 45nm SOI CMOS Technology‟‟, IEEE
Microwave and Wireless Components Letters, Vol. 21, No. 6, PP. 329 – 331, 2011.
[18] A. Jahanian and P. Heydari, „„A CMOS distributed amplifier with distributed active input balun using GBW and linearity
enhancing techniques‟‟, IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 5, PP. 1331 – 1340,
2012.
[19] C. Feng, W. M. Lim and K. S. Yeo, „„A compact 2.1 – 39 GHz self – biased low – niose amplifier in 65nm CMOS
technology‟‟, IEEE Microwave and Wireless Components Letters, Vol. 23, No. 12, PP. 662 – 669, 2013.
[20] J. C. Kao, P. C. Huang and H. W. fellow, „„A novel distributed amplifier with high gain, Low noise, and high output
power in 0.18 m CMOS technology‟‟, IEEE Transactions on Microwave Theory and Techniques, Vol. 61, No. 4, PP.
1533 – 1541, 2013.
[21] M. K. Cho, J. G. Kim and D. Baek, “A switch less CMOS Bi- Directional distributed gain amplifier with multi – octave
bandwidth‟‟ , IEEE Microwave and Wireless Component Letters, Vol. 23, No. 11, PP. 611 – 613, 2013.
[22] K. Kim and C. N. Fellow, “A concurrent Ku / K / Ka Tri-band distributed power amplifier with negative – resistance
active notch using SiGeBiCMOS process” , IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 1,
PP. 125-135, 2014.
[23] J. Kim, J.F.Buckwalter, “A 92 GHz bandwidth distributed amplifier in 45 nm SOI CMOS technology” ,IEEE Microwave
and Wireless Component Letters, Vol.21, No.6,June 2011.
[24] Y. Cao, “Predictive technology model for robust nanoelectronic design”, 1
2011.
st
Edition, Predictive Process Design Kids,
th
[25] S. Serdar and C. Smith, “Microelectronic circuits”, 6 Edition, Oxford University Press, 2010.
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ISSN 2277-3061
Author’s biography
EsraaEhsan Al-Bayati was born in London, UK, in 1987. She received the B.Sc. degree
in Electronic and Communications Engineering from Al-Nahrain University, Iraq in 2009.
Currently, she is an M.Sc. student in the Electronic and Communications Engineering
Department at Al-Nahrain University. Her research interests include Optical and wireless
communications, Distributed
microwave amplifiers and receivers, CMOS and
Communication systems.
Raad Sami Fyathwas born in Maysan, Iraq, in 1954. He received the B.Sc. degree in
Electrical Engineering from the University of Basrah, Iraq, in 1976, the M.Sc. degree in
Electronics and Communications Engineering from the University of Baghdad, Iraq, in
1987, and the PhD degree in Electronics Engineering from University of Wales-Bangor,
UK, in 1990. Currently, he is a professor of electronics and communications engineering at
the College of Engineering, Al-Nahrain University, Baghdad, Iraq. His research interests
include Optical and wireless communications, Optoelectronics, and Nanophotonics. He
published more than 100 papers in different scientific journals and conference
proceedings.
5686 | P a g e
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|
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https://openalex.org/W4389670551
|
https://www.nature.com/articles/s41598-023-47860-9.pdf
|
English
| null |
Biophosphorescence in fluorescent millipedes (Diplopoda: Xystodesmidae) and its relationships with bioluminescence
|
Scientific reports
| 2,023
|
cc-by
| 6,640
|
Biophosphorescence in fluorescent
millipedes (Diplopoda:
Xystodesmidae) and its
relationships with bioluminescence
OPEN Vadim R. Viviani Three types of luminescence have been reported in living organisms: bioluminescence (BL), ultraweak
chemiluminescence and biofluorescence (FL). In millipedes, both BL and FL have been reported in
Motyxia sequoiae and related Xystodesmidae species. Noteworthy, when walking at night with a UV
lantern at the Biological Station of Highlands, I found three blue-fluorescent millipedes (Deltotaria
brimleii, Deltotoria sp and Euryus orestes) that also displayed phosphorescence after turning off
the UV source. The phosphorescence of the cuticle was in the green region (λmax = 525 nm). The
phosphorescence remained associated with cuticle and pellets, but frozen fluorescent supernatants,
also displayed phosphorescence. The fluorescent compounds extracted from the cuticles in water
and methanol and separated by TLC, displayed fluorescence spectra similar to that of 6-pteridine
carboxylic acid. In contrast to Motyxia sequoiae cuticle extracts, no bioluminescence was found in
Deltatoria and Euryus extracts in the presence of MgATP, but weak green chemiluminescence was
detected with H2O2 and superoxide. The spectral overlapping of phosphorescence of these millipedes
with the bioluminescence of Motyxia (~ 507 nm) and the intimate association of both types of
luminescence with the cuticles, raises the possibility that bioluminescence in Motyxia may arise from
chemiluminescence reactions preferentially generating triplet excited states instead of singlet states. In living organisms, three types of luminescence have been reported: (1) bioluminescence, a special case of
enzymatically catalyzed chemiluminescence for communicative purposes1, (2) ultraweak chemiluminescence
resulting from side-reactions of the oxidative metabolism2 and (3) fluorescence, also referred as biofluorescence,
a kind of photoluminescence which depends on excitation by light. Biofluorescence, has been reported for several
classes of organisms, including mainly marine organisms with fluorescent proteins (FPs), arthropods, amphib-
ians, reptiles, birds and even mammals3–6. In marine organisms such as jellyfishes, GFPs participate in modula-
tion of bioluminescence spectrum through energy transfer (BRET)7, and possibly as fluorescent light dissipators
of damaging UV light in some corals. In some cases, such in the case of bird´s plumage, in which fluorescence
enhances the plumage color effect for sexual attraction purposes8,9, the biological function of fluorescence is
evident. In some insects and amphibians, fluorescence may also display an amplification effect on visual clues. In other cases, such as the scorpion´s cuticle, fluorescence does not have any apparent function, being just a side
effect of production of cuticle fluorescent compounds10. fl
Bioluminescence occurs in several organisms, both marine and terrestrial. www.nature.com/scientificreports www.nature.com/scientificreports www.nature.com/scientificreports Department of Physics, Chemistry and Mathematics, Center for Sustainable Sciences and Technologies (CCTS),
UFSCar, Sorocaba, SP, Brazil. email: viviani@ufscar.br Results and discussion
Field observations of millipede fluorescence and phosphorescence Field observations of millipede fluorescence and phosphorescence pl
p
p
When walking at night in the late April and beginning of May spring at HBS, 3 strongly fluorescent millipedes
were readily observed upon turning an UV LED lantern. These species were identified as Deltotaria bremleii,
Deltotaria sp and Euryus orestes (Fig. 1). During the day, these millipedes were found in the woods hidden
under the litter and near and under decayed logs in the forest. At night they were easily found by their strong
bluish fluorescence upon turning on a LED UV lantern. Upon touching them, they release from lateral glands
a defensive cyanide secretion with characteristic almond fragrance. In Deltoria sp, only the legs and antennae
fluoresced, whereas in D. bremleii and Euryurus orestes the dorsal cuticle exhibited strong fluorescence. The
fluorescence of wandering millipedes at night could also be filmed with a cell phone video camera (Video-1). Noteworthy, I observed that after turning off the UV lantern, the millipedes still phosphoresced for less than 1 s. www.nature.com/scientificreports/ Besides bioluminescent species, the Xystodesmidae family also includes a diversity of colorful millipedes which
release hydrogen cyanide and benzaldeyde from lateral glands for defensive purposes, being especially repre-
sented in Eastern United States16,17.i Noteworthy, bioluminescence in Motyxia spp is cuticular, does not involve a defined light organ, and involves
a still poorly investigated photoprotein system which is dependent on ATP and Ca2+ or Mg2+11,18,19. The photo-
protein, which was partially isolated by Shimomura, has ~ 100 kDa and it may involve a porphyrin chromophore
being very unstable in solution11,19. Furthermore, besides the cuticular bioluminescence, Motyxia also displays
strong cuticular blue-green fluorescence under UV light, but it is not clear whether there is or not a relationship
between bioluminescence and fluorescence in these millipedes. Similar fluorescence has also been reported in
the non-bioluminescent xystodesmid train millipede, Parafrontaria laminate, from Japan20. The fluorescent
compounds isolated from the cuticles of Motyxia sequoiae and Parafrontaria millipedes were identified as pterin-
6´carboxylic and 7,8-dihydropterin carboxylic acids20,21. The authors suggested that these compounds could be
the putative emitters of Motyxia bioluminescence based on the fluorescence, and also on chemiluminescent
properties in the presence of hydrogen peroxide, but no conclusive experiment has been shown yet regarding
chemiluminescence of such compounds. Furthermore, the spectral properties of the bioluminescence (green)
and of the fluorescence (blue-green) in Motyxia do not match, which would be expected if these compounds
functioned as the bioluminescence emitters. Thus, whether there is a relationship between the blue fluorescence
these pteridin carboxylic acids and the greenish bioluminescence in millipedes remains unclear. p
y
g
p
Very recently, when walking in the woods at night at the Biological Station of Highlands (HBS) in North-
Carolina with a LED UV lantern, I found 3 species of Xystodesmidae millipedes that are strongly fluorescent,
emitting a blue-green fluorescence (Fig. 1). To my surprise, after turning off the UV light source, these millipedes
also displayed a rapidly vanishing phosphorescence (Fig. 1). In this note, I report the first characterization of this
phosphorescence and also of the fluorescence of these millipedes, and compare these photophysical properties
with the bioluminescence properties of the xystodesmid millipede relative, Motyxia sequoiae, kindly provided
by J.W Hastings† in 2005. To our knowledge, this is the first report of occurrence of phosphorescence in animals. Anatomical location of fluorescence and phosphorescencel l
p
p
Back in the lab, I could photograph the fluorescence (Fig. 1) and phosphorescence. The fluorescence is bluish and
arises from both the dorsal and ventral cuticles of the body in these millipedes. However, in the black-reddish
specimens of Deltoria bremleii the blue fluorescence was more intense in the reddish/yellowish parts of the dorsal
segments (Fig. 1A, B), and less intense in the dark parts. In of Deltotoria sp, only the legs and antennae displayed
intense fluorescence (Fig. 1D, E). In Euryurus orestes the fluorescence was intense in most of the dorsal cuticle,
and weaker in the reddish marks (Fig. 1G, H). The blue fluorescence could be more easily seen from the whitish
areas, especially the legs and ventral tegument (Fig. 1F).h y
g
g
g
The phosphorescence of these millipedes was usually more intense in the whitish intersegmental and ventral
areas, and in the legs. In Deltatoria bremleii, the more intense phosphorescence was usually detected in the
intersegmental parts and legs, whereas in Euryurus orestes it was detected over all ventral area and almost all the
dorsal part of the segments, with the exception of the reddish spots (Fig. 1I). Therefore, there was a good match
between the anatomical location of fluorescence and phosphorescence in the dorsal part of the segments as well
as the legs (Fig. 1H and I), an indication that the compounds responsible for fluorescence and phosphorescence
could be the same. Fluorescence and phosphorescence spectrah The phosphorescence decay is very fast: it visually decays completely in less than 1 s. By using a spectrofluorom-
eter and also a very sensitive CCD based spectroluminometer, we were able to scan the emission spectrum of
the rapidly vanishing phosphorescence of the cuticle after UV light irradiation. The emission was in the green
region, with a peak at 525–530 nm (Fig. 2; Table 1). Therefore, the emission spectrum of this luminescence after
turning off the UV light source was red-shifted in relation to the fluorescence spectrum, indicating that this
luminescence is indeed phosphorescence. Delayed fluorescence is unlikely considering the red-shifted spectrum
in relation to fluorescence. Biophosphorescence in fluorescent
millipedes (Diplopoda:
Xystodesmidae) and its
relationships with bioluminescence
OPEN It arises from exothermic oxidative
reactions in which compounds generally called luciferins are oxidized by molecular oxygen in the presence of
enzymes called luciferases or photoproteins, producing peroxidic intermediates, whose spontaneous cleavage
preferentially yield singlet (fluorescent state) excited products that decay, emitting light1. Among arthropods, it
occurs in marine crustaceans, millipedes and mainly insects11. Despite some confusion in the old literature regarding the use of the term phosphorescence for biolumines-
cence, until recently phosphorescence was not known to occur among living organisms or biological materials. Recently, phosphorescence has been reported in rice, starch and frozen serum albumin solutions12. An image of
phosphorescence has been published in millipedes of Xystodermidae family, but no detailed characterization of
this phosphorescence has been carried out yet13. p
p
y
In millipedes, bioluminescence was originally reported in Motyxia sequoiae from the Xystodesmidae family,
which occurs in California14. More recently, weak bioluminescence was also reported in other Motyxia species15. Scientific Reports | (2023) 13:22171 | https://doi.org/10.1038/s41598-023-47860-9 www.nature.com/scientificreports/ Fluorescence and phosphorescence properties of extracted material Upon extraction of Deltatoria bremleii and Euryus orestes cuticles and centrifugation, intense bluish fluorescence
was recovered in both aqueous and acidic methanol supernatants (Fig. 3). The fluorescence spectra of aqueous
extracts had excitation peaks at 251 and 364 nm, and emission at 468 nm (Fig. 4; Table 1). In methanol, although
the extracted pigments displayed similar excitation spectra of the aqueous extracts, the emission spectrum was https://doi.org/10.1038/s41598-023-47860-9 Scientific Reports | (2023) 13:22171 | www.nature.com/scientificreports/ /scientificreports/
slightly blue-shifted peaking at 450 nm. The fluorescent pigments were highly soluble in water and
Figure 1. Highlands Biological station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria brem
displaying dorsal fluorescence upon UV irradiation; (C) Deltatoria bremleii lateral body phosphoresc
Deltatoria sp fluorescence; (E) Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G)
orestes displaying blue fluorescence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus oreste
phosphorescence. al station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria bremleii
upon UV irradiation; (C) Deltatoria bremleii lateral body phosphorescence; (D)
Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G) Euryurus
ence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus orestes dorsal Figure 1. Highlands Biological station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria bremleii
displaying dorsal fluorescence upon UV irradiation; (C) Deltatoria bremleii lateral body phosphorescence;
Deltatoria sp fluorescence; (E) Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G) Euryu
orestes displaying blue fluorescence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus orestes dors
phosphorescence. Figure 1. Highlands Biological station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria bremleii
displaying dorsal fluorescence upon UV irradiation; (C) Deltatoria bremleii lateral body phosphorescence; (D)
Deltatoria sp fluorescence; (E) Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G) Euryurus
orestes displaying blue fluorescence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus orestes dorsal
phosphorescence. Figure 1. Highlands Biological station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria bremleii
displaying dorsal fluorescence upon UV irradiation; (C) Deltatoria bremleii lateral body phosphorescence; (D)
Deltatoria sp fluorescence; (E) Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G) Euryurus
orestes displaying blue fluorescence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus orestes dorsal
phosphorescence. Figure 1. Fluorescence and phosphorescence properties of extracted material Highlands Biological station (HBS) millipedes: (A) Deltatoria bremleii; (B) Deltatoria bremleii
displaying dorsal fluorescence upon UV irradiation; (C) Deltatoria bremleii lateral body phosphorescence; (D)
Deltatoria sp fluorescence; (E) Deltatoria sp showing only legs fluorescence; (F) Euryurus orestes; (G) Euryurus
orestes displaying blue fluorescence; (H) Euryurus orestes dorsal blue fluorescence; (I) Euryurus orestes dorsal
phosphorescence. slightly blue-shifted peaking at 450 nm. The fluorescent pigments were highly soluble in water and methanol,
but could not be efficiently acid extracted in ethyl acetate, indicating that such compounds are highly polar. The
residue obtained upon solvent evaporation of methanol extracts was whitish for the ventral cuticle and reddish
for the dorsal cuticle, and in both cases displayed strong blue fluorescence. https://doi.org/10.1038/s41598-023-47860-9 Scientific Reports | (2023) 13:22171 | www.nature.com/scientificreports/ Figure 2. Phosphorescence spectrum of Deltatoria bremleii ventral cuticle and pellet of extracted material. The phosphorescence was obtained by short irradiation with UV LED lantern (370 nm), and shortly after
luminescence spectra scanning. Figure 2. Phosphorescence spectrum of Deltatoria bremleii ventral cuticle and pellet of extracted material. The phosphorescence was obtained by short irradiation with UV LED lantern (370 nm), and shortly after
luminescence spectra scanning. Luminescence/λmax (nm)
Motyxia sequoiae*
Deltatoria bremleii
Euryus orestes
Phosphorescence (λPh )
Cuticle
–
525
520
Pellet
–
525
525
Frozen supernatant
498
–
507
Fluorescence
λEX
–
251/364
251/364
λFL (H2O)
467
453 (467)
459
λFL (metanol)
454
447
450
Chemiluminescence (λCL )†
–
513
–
Bioluminescence (λBL )‡
507
–
– Luminescence/λmax (nm)
Motyxia sequoiae*
Deltatoria bremleii
Euryus orestes
Phosphorescence (λPh )
Cuticle
–
525
520
Pellet
–
525
525
Frozen supernatant
498
–
507
Fluorescence
λEX
–
251/364
251/364
λFL (H2O)
467
453 (467)
459
λFL (metanol)
454
447
450
Chemiluminescence (λCL )†
–
513
–
Bioluminescence (λBL )‡
507
–
– Table 1. Comparative photoluminescence and chemi- and bioluminescence spectral properties of millipedes. *We did not test Motyxia cuticle for phosphorescence. † Chemiluminescence of concentrated methanol extracts
in DMSO with potassium superoxide. ‡ Bioluminescence of crude extracts in the presence of MgSO4 and ATP. Table 1. Comparative photoluminescence and chemi- and bioluminescence spectral properties of millipedes. *We did not test Motyxia cuticle for phosphorescence. † Chemiluminescence of concentrated methanol extracts
in DMSO with potassium superoxide. ‡ Bioluminescence of crude extracts in the presence of MgSO4 and ATP. Table 1. Comparative photoluminescence and chemi- and bioluminescence spectral properties of millipedes. *We did not test Motyxia cuticle for phosphorescence. Fluorescence and phosphorescence properties of extracted material † Chemiluminescence of concentrated methanol extracts
in DMSO with potassium superoxide. ‡ Bioluminescence of crude extracts in the presence of MgSO4 and ATP. Table 1. Comparative photoluminescence and chemi- and bioluminescence spectral properties of millipedes. *We did not test Motyxia cuticle for phosphorescence. † Chemiluminescence of concentrated methanol extracts
in DMSO with potassium superoxide. ‡ Bioluminescence of crude extracts in the presence of MgSO4 and ATP. Figure 3. Phosphorescence and fluorescence of Deltatoria bremleii extracted material upon UV light
irradiation: (A) fluorescence; (B) phosphorescence of pelleted material and debris after UV light irradiation; (C)
phosphorescence of frozen supernatant. Figure 3. Phosphorescence and fluorescence of Deltatoria bremleii extracted material upon UV light
irradiation: (A) fluorescence; (B) phosphorescence of pelleted material and debris after UV light irradiation; (C)
phosphorescence of frozen supernatant. Scientific Reports | (2023) 13:22171 | https://doi.org/10.1038/s41598-023-47860-9 www.nature.com/scientificreports/ p
Figure 4. Fluorescence spectra of Deltatoria bremleii millipedes cuticle extracts: (A) excitation spectrum; (B)
fluorescence spectra excited at 364 nm: (a) methanol extract of ventral cuticle; (b) methanol extract of dorsal
cuticle; (c) aqueous extract of dorsal cuticle; (d) aqueous extract of ventral cuticle. Figure 4. Fluorescence spectra of Deltatoria bremleii millipedes cuticle extracts: (A) excitation spectrum; (B)
fluorescence spectra excited at 364 nm: (a) methanol extract of ventral cuticle; (b) methanol extract of dorsal
cuticle; (c) aqueous extract of dorsal cuticle; (d) aqueous extract of ventral cuticle. On the other hand, phosphorescence always remained in the pelleted material and decanted debris (Fig. 3). As expected, both aqueous and methanol extracts did not display any visually observable phosphorescence,
even when oxygen was removed by slight vacuum made inside a blood collecting type vessel, using a hypoder-
mic syringe. However, the fluorescent aqueous extracts of these millipedes, once frozen in dry ice, displayed
intense phosphorescence in the green region (Table 1). Under such conditions we could also measure the life
time of phosphorescence of frozen extracts, which averaged ~75 ms. Once again, these results confirm that the
delayed light emission is true phosphorescence and not delayed fluorescence and the possibility that the pigment
responsible for the fluorescence and phosphorescence could be the same compound, however phosphorescence
is displayed only in the solid state of the cuticle or frozen crystals. Pigment partial isolation and propertiesh g
The methanol extracts and aqueous extracts were submitted to TLC to separate the compounds in the fluorescent
spots. Under Ethyl acetate/ethanol/H2O as mobile phase, the Deltatoria bremleii dorsal cuticle extracts displayed
at least 4 fluorescent spots, two with higher migration coefficients displaying blue fluorescence, and two almost
merging bands with lower Rf displaying blue-green fluorescence spectra upon excitation at 364 nm (Fig. 5). The ventral cuticle displayed mainly a pigment with blue-green fluorescence with lower Rf. On the other hand,
when using 60% methanol as a mobile phase, the TLC of both ventral and dorsal cuticle extracts displayed a
main blue fluorescent spot with very high Rf, and a smear with the same Rf of commercial 6-pteridinic acid
(Table 2). It is also noteworthy that a considerable amount of the blue fluorescent material was retained at the
origin of TLC. Previously, Kuse et al. isolated from the bioluminescent millipede Motyxia sequoiae20 and from
the Japanese fluorescent train millipede Parafrontaria laminate21 two main fluorescent compounds with similar
fluorescence spectral properties and structures, 7,8-dihydropterin-6-carboxylic acid and pterin-6-carboxylic acid. The fluorescence properties of the eluted compounds from the blue fluorescent spots from Deltatoria bremleii
and Euryus orestes millipedes, are similar to those of 7,8-dihydropterin-6-carboxylic acid and pterin-6-carboxylic
acid, suggesting that these compounds could be similar to pteridine compounds. Comparison of photoluminescence and bioluminescence in millipedes extracts §Peak of
fluorescence spectra of water eluted compounds. Table 2. Migration (Rf) and Fluorescence properties of TLC partially isolated compounds from millipede
cuticles. *Solvent system I: Methanol 60%. **Solvent system II: Ethyl acetate/Ethanol/H2O (5:3:2). §Peak of
fluorescence spectra of water eluted compounds. were phosphorescent too. However, similarly to Deltatoria and Euryus aqueous extracts, stored frozen Motyxia
sequoiae cuticle aqueous extracts were also phosphorescent upon UV light irradiation. As expected, the crude
extracts of Motyxia sequoiae cuticle produced weak greenish bioluminescence in the presence of ATP and mag-
nesium or calcium ions (Table 1). The peak of the in vitro bioluminescence spectrum of Motyxia sequoiae was
507 nm (Fig. 6), just in the green region. No light emission, however, could be luminometrically detected using
non-bioluminescent Deltatoria and Euryus millipedes cuticle extracts under the same conditions, indicating
that these millipedes do not have an active photoprotein. Furthermore, the cross-reaction between Motyxia
sequoiae photoprotein active cold extracts and Deltotaria cuticle hot extracts were negative for the biolumines-
cence reaction. Comparison of photoluminescence and bioluminescence in millipedes extracts The fluorescence and bioluminescence of Motyxia have been already studied11. The thawed millipedes pro-
duced weak bioluminescence and also displayed fluorescence when irradiated with UV. Unfortunately, at the
time we investigated the phosphorescence of the millipedes Deltotaria and Euryus, we had already run out
of Motyxia sequoiae millipedes, which hampered the possibility to further investigate whether their cuticles https://doi.org/10.1038/s41598-023-47860-9 Scientific Reports | (2023) 13:22171 | www.nature.com/scientificreports/ www.nature.com/scientificreports/ Figure 5. TLC of fluorescent pigments on silica-gel plates after UV light irradiation: (A) Ethyl acetate/Ethanol/
H2O (5:2:3); (B) Methanol 60%. (1) 6´-pteridinic carboxylic acid; (2) methanol/TFA extract of Deltatoria
ventral cuticle; (3) methanol/TFA extract of Deltatoria bremleii dorsal cuticle; (4) aqueous extract of Deltatoria
bremleii ventral cuticle; (5) aqueous extract of Deltatoria bremleii dorsal cuticle; (6) aqueous extract of Euryus
orestes cuticle. Figure 5. TLC of fluorescent pigments on silica-gel plates after UV light irradiation: (A) Ethyl acetate/Ethanol/
H2O (5:2:3); (B) Methanol 60%. (1) 6´-pteridinic carboxylic acid; (2) methanol/TFA extract of Deltatoria
ventral cuticle; (3) methanol/TFA extract of Deltatoria bremleii dorsal cuticle; (4) aqueous extract of Deltatoria
bremleii ventral cuticle; (5) aqueous extract of Deltatoria bremleii dorsal cuticle; (6) aqueous extract of Euryus
orestes cuticle. Table 2. Migration (Rf) and Fluorescence properties of TLC partially isolated compounds from millipede
cuticles. *Solvent system I: Methanol 60%. **Solvent system II: Ethyl acetate/Ethanol/H2O (5:3:2). §Peak of
fluorescence spectra of water eluted compounds. Solvent System/Fluorescent
spots
Deltatoria bremleii
Euryus orestes
Motyxia sequoiae
Rf
λFL (nm)§
Rf
Rf
λFL (nm)§
Solvent I*
Spot 1
0.69
449
0.69
0.72
443
Spot 2
0.57
456
0.57
Solvent II**
Spot 3
0.57
449
0.57
–
–
Spot 2
0.52
456
0.52
–
–
Spot 1
0.42
465
0.42
–
– Table 2. Migration (Rf) and Fluorescence properties of TLC partially isolated compounds from millipede
cuticles. *Solvent system I: Methanol 60%. **Solvent system II: Ethyl acetate/Ethanol/H2O (5:3:2). §Peak of
fluorescence spectra of water eluted compounds. Solvent System/Fluorescent
spots
Deltatoria bremleii
Euryus orestes
Motyxia sequoiae
Rf
λFL (nm)§
Rf
Rf
λFL (nm)§
Solvent I*
Spot 1
0.69
449
0.69
0.72
443
Spot 2
0.57
456
0.57
Solvent II**
Spot 3
0.57
449
0.57
–
–
Spot 2
0.52
456
0.52
–
–
Spot 1
0.42
465
0.42
–
– Table 2. Migration (Rf) and Fluorescence properties of TLC partially isolated compounds from millipede
cuticles. *Solvent system I: Methanol 60%. **Solvent system II: Ethyl acetate/Ethanol/H2O (5:3:2). Chemiluminescence properties of millipedes cuticles Despite being non-bioluminescent, the Deltatoria bremleii and Euryus orestes millipedes cuticle extracts, simi-
larly to the Japanese millipede Parafrontaria laminate21, produced a very weak chemiluminescence, just above
the detection limit of the luminometer (Table 1), in the presence of 0.1–3% H2O2, indicating the presence of
chemiluminescent compounds, similarly to the report of Kuse et al.21. The pelleted material also displayed chemi-
luminescence upon addition of 0.1–1% H2O2 or potassium superoxide, which could be detected using a highly
sensitive CCD camera (Fig. 7). The concentrated methanolic extracts, once dissolved in DMSO in the presence
of potassium superoxide, produced weak chemiluminescence which was intense enough to allow the measure-
ment of the emission spectrum using a sensitive spectroluminometer, displaying an emission peak at 507 nm. Although the chemiluminescence under such harsh circumstances could not be easily attributed to a specific
reaction of the isolated pigments yet, the chemiluminescence spectrum (507 nm) considerably overlaps with
the phosphorescence and bioluminescence spectra of these millipedes, suggesting that this chemiluminescence
may arise from the oxidation of the same compounds responsible for phosphorescence and bioluminescence. Further studies are undergoing to better understand the origin of such chemiluminescence. Scientific Reports | (2023) 13:22171 | https://doi.org/10.1038/s41598-023-47860-9 www.nature.com/scientificreports/ www.nature.com/scientificreports/ Figure 6. In vitro bioluminescence spectrum of Motyxia sequoiae crude extracts. Figure 6. In vitro bioluminescence spectrum of Motyxia sequoiae crude ext Figure 6. In vitro bioluminescence spectrum of Motyxia sequoiae crude extracts. Figure 7. Chemiluminescence of Deltatoria bremleii millipedes cuticles precipitated debris: (A) upon addition
of H2O2 and (B) upon addition of potassium superoxide. Figure 7. Chemiluminescence of Deltatoria bremleii millipedes cuticles precipitated debris: (A) upon addition
of H2O2 and (B) upon addition of potassium superoxide. www.nature.com/scientificreports/ of the relatively close relatives Motyxia spp of the Xystodesmidae family. It is noteworthy that the phosphores-
cent spectra of Deltatoria and Euryus cuticles, as well as Motyxia sequoiae frozen extracts, in the green region,
considerably overlap with the bioluminescent spectrum of Motyxia sequoiae. of the relatively close relatives Motyxia spp of the Xystodesmidae family. It is noteworthy that the phosphores-
cent spectra of Deltatoria and Euryus cuticles, as well as Motyxia sequoiae frozen extracts, in the green region,
considerably overlap with the bioluminescent spectrum of Motyxia sequoiae. y
p
p
y
q
It is generally considered that all known bioluminescence examples arise from chemiluminescent reactions
that yield mainly excited singlet species (fluorescent state). This is valid and expected for liquid state solvent
environments, such as the cytoplasm of many photocytes where most luciferin-luciferase enzymatic reactions
occur, in which the lifetime of the excited state shall be extremely short to be emissive. On the other hand, triplet
excited species, with the exception of ultraweak chemiluminescence2,22, have not been usually considered reason-
able candidates for the highly efficient bioluminescent reactions, because of their long life-times that makes them
easily quenched by oxygen and other molecules in solution rather than decaying emitting light. Similarly to the Deltatoria and Euryues phosphorescence, Motyxia sequoiae bioluminescence is also strictly
associated with the cuticle which is an almost solid-state tissue, and not with soft tissues. In such case, triplet spe-
cies may have a chance to be emissive, giving off phosphorescence instead of being quenched, as we have shown
for the first time in the cuticles of the non-bioluminescent related species Deltatoria spp and Euryus orestes from
the same subfamily. It is likely that Motyxia sequoiae cuticle is also phosphorescent, as indicated by their frozen
extracts, although this property may have been overlooked in live millipedes.h g
p
p
y
y
p
Therefore, here I raise the possibility that, in the case of millipedes of the Xystodesmidae family, biolumi-
nescence could be associated with the generation of triplet excited species and that the emissive process of such
chemiluminescence could be phosphorescence instead of fluorescence. Alternatives could be delayed fluorescence
or sensitized triplet-singlet luminescence. Concluding remarksi Here I report for the first time the occurrence of phosphorescence in the cuticles of fluorescent millipedes,
Deltoria spp and Euryus orestes occurring in North Carolina forests, being also the first report characterizing
phosphorescence in arthropods and animals. The phosphorescence of these millipedes arises from the cuticle,
has a short life time and its emission spectrum in the green region is red-shifted as compared with the spectrum
of its fluorescence. This phosphorescence may arise from pteridine acid derivatives in the cuticle that may also
be responsible for the fluorescence. Remarkably, the considerable overlapping of the phosphorescence spectrum
of these millipedes cuticles and frozen extracts with the bioluminescence spectrum of the close relative Motyxia
sequoiae and its extracts raises the possibility, for the first time, that bioluminescence in millipedes could be
generated by a chemiluminescent reaction generating preferentially triplet excited states (phosphorescent state)
instead of singlet states (fluorescent state). www.nature.com/scientificreports/ However, such possibilities are unlikely, considering the red-shifted
spectrum of phosphorescence that argues against delayed fluorescence, and the closely matching of the biolumi-
nescence spectrum of Motyxia with the phosphorescence spectrum of the related Deltatoria bremleii and Euryus
orestes, that argues against an energy transfer process which requires a higher energy phosphorescence spectrum
donor to sensitize the fluorescent emitter.h l
The photoprotein responsible for the bioluminescence reaction in Motyxia sequoiae has been isolated in the
active form in solution, but is very unstable, indicating that it is more likely an insoluble protein which could
be incorporated in the cuticle during the sclerotization process. In arthropods, the process of sclerotization and
hardening of cuticles involve oxidation by reactive pigment intermediates, such as quinones and pteridines,
that may react with proteins, thereby generating excited species. Although the active photoprotein has been
partially isolated in the soluble fraction, which in principle argues against the participation of emissive triplet
excited states, the definition of photoprotein itself does not exclude such possibility. The photoprotein is a pro-
tein that oxidizes the substrate, stabilizing a peroxide intermediate, which in the presence of triggering agents
such as calcium, undergoes conformational changes promoting its breakdown and generating an excited prod-
uct that decays emitting light just once, without apparent turnover like a typical luciferase1. Furthermore, the
relatively efficient enzyme generation of triplet species chemiluminescence is not an unlikely possibility, it has
been already demonstrated in vitro for the HRP/Isobutanal system which produces triplet acetone by Cilento
and coworkers22. In such a circumstance, a triplet excited product generated inside a closed, relatively rigid and
protective environment against solvent quenching of a protein associated to the cuticle could be in principle
emissive. Studies are awaited to investigate this interesting possibility. Material and methods
Millipedes p
Frozen Motyxia sequoiae millipedes, previously obtained from California, were graciously provided by J. W. Hastings† at Harvard University in 2005 and used in our laboratory for biochemical studies. Fluorescent mil-
lipedes Deltatoria brimleii, Deltotaria sp and Euryus orestes were collected during May of 2019 and 2023 at the
Highland Biological Station (Highlands, NC) and were kindly identified by Derek Merret (Virginia Technology
Natural History Museum). sible biological function for fluorescence and phosphorescence in millipedes
l b fl
h
b
d
l
l
l
l
l Possible biological function for fluorescence and phosphorescence in millipedes
Recently, biofluorescence has been suggested to play important signaling ecological role in crepuscular-nocturnal
mammals23. In nocturnal millipedes, both fluorescence and phosphorescence may have not a readily recognizable
biological function, considering they are blind, ruling out an inter-specific function such as sexual attraction,
and because they are active just at night, when there is not strong illumination to excite the fluorescence and
phosphorescence. Similarly, the coloration may not have an apparent biological function for the same reasons. However, in the case of Motyxia spp millipedes, it was recently demonstrated that bioluminescence has an
aposematic function since that millipedes turned dark upon artificial painting their cuticles with black ink were
much less prone to predation24. Thus a strong pigmentation could be also indicative of an aposematic defensive
function, and a biological function could be hypothesized for coloration and fluorescence during the day or
twilight, whenever the millipede is exposed to sunlight by a predator, showing an aposematic coloration which
could be amplified by fluorescence, similarly to some bird´s plumage. Another possibility that would be worth
investigating is whether there is a function during moonlit nights. Are those millipedes more active during
such nights? Is moonlight, especially during a full moon, bright enough to excite this fluorescence and phos-
phorescence? The moonlit emission spectrum certainly has a considerable proportion of near-UV light that can
potentially excite both fluorescence and phosphorescence in these millipedes. In such cases both fluorescence
and phosphorescence could amplify visual warning aposematic signals that may deter a predator: after all these
millipedes produce and secrete cyanide whenever disturbed, giving off their characteristic and pleasant, albeit
dangerous, and sweet almond smell! Relationship between phosphorescence, fluorescence and bioluminescence in millipedes Relationship between phosphorescence, fluorescence and bioluminescence in millipedes
Independently of whether or not there is a biological function for the observed phosphorescence in millipedes,
such photophysical processes are interesting and may have a relationship with the bioluminescence mechanism https://doi.org/10.1038/s41598-023-47860-9 Scientific Reports | (2023) 13:22171 | www.nature.com/scientificreports/ Fluorescence and phosphorescence spectra
l
d
h
h
b Fluorescence and phosphorescence spectra were obtained using mainly a Hitachi F4500 spectrofluorometer
(Japan). Fluorescence spectra were obtained upon excitation at 364 nm with an excitation window of 2.5–5.0 nm
and an emission window of 10 nm. Phosphorescence spectra were scanned from 400 to 700 nm with excitation at
364 nm, excitation window at 10 nm and speed 240 nm/min, using the phosphorescence mode. Bioluminescence
and phosphorescence spectra were also obtained with a refrigerated CCD camera provided spectroluminometer
LumiSpectra (ATTO, Japan). Phosphorescence spectra in this latter equipment were measured in the high sen-
sitivity mode upon pre-irradiation with a SouthWalker lantern provided with Nichia UV LED (Japan) followed
by turning off the UV light source. Phosphorescence life‑timeh The phosphorescence life-time was measured using a Hitachi F4500 spectrofluorometer in the module Time
scan (Phosphorescence), upon excitation at 364 nm and emission at 525 nm. Photography
Ph
hi i Photographic images and videos of millipede fluorescence were obtained using a Galaxy S10Plus camera. Images
of millipede phosphorescence were obtained using a Canon Ti5 camera with a 100 mm macro lens, and 10 s
exposure at 12,200 ISO after UV irradiation using a SouthWalker lantern provided with Nichia UV LED (Japan)
during 10 s. Scientific Reports | (2023) 13:22171 | https://doi.org/10.1038/s41598-023-47860-9 www.nature.com/scientificreports/ Supplemental information pp
Link for Video-1. Fluorescent Deltatoria bremleii millipede: https://drive.google.com/file/d/1TT_Pajh6MGCc8
a9Q6csaWjDWFHAq-Ok_/view?usp=drive_link Fluorescent compound extraction Bioluminescence and Chemiluminescence spectra Thin Layer Chromatography (TLC)h h
Thin Layer Chromatography (TLC) was performed using pre-coated silica-gel 60 sheets (Alugram XtraSIL G,
Germany) using methanol 60% in water or ethyl acetate/ethanol/water (5:3:2) as mobile phases at room tem-
perature. Fluorescence was revealed using UV irradiation at 370 nm. Fluorescent compound extraction Fluorescent compound extractionl To obtain fluorescent pigments, frozen Deltatoria millipides were allowed to partially thaw, and then laterally
opened with a scissor. After removing the still frozen digestive tube, the remaining dorsal (pigmented) and
ventral (whitish) cuticles, including legs, were separately ground with a mortar on ice using methanol/1% TFA. The suspension was then centrifuged at 15,000 g during 15 min at 4 °C, and the supernatant used to measure
fluorescence spectra and for Thin Layer Chromatography (TLC) analysis. The cuticles were also ground in
50 mM sodium acetate buffer pH 5.8 supplemented with 10 mM EGTA and 0.20 M NaCl, centrifuged and the
supernatants used for fluorescence and phosphorescence analysis. Bioluminescence system extraction y
In the case of photoprotein extraction from either Motyxia or other fluorescent millipedes, we followed the pro-
tocol of Shimomura11. The cuticles of 1 or 2 of these frozen millipedes were also excised with scissors using the
procedure described above, and grounded in an ice-cold mortar, with an ice-cold extraction buffer consisting of
10 mM sodium acetate buffer pH 5.8, containing 0.2 M NaCl, 10 mM EDTA supplemented with an antiprotease
cocktail (Merck). The homogenates were then centrifuged at 15,000 g for 15 min at 4 °C, and the supernatants
used for photoprotein in vitro bioluminescence and chemiluminescence luminometric assays and spectra. Bioluminescence and chemiluminescence assaysh y
The in vitro bioluminescence was assayed using an adaptation of the protocol described by Shimomura11. Inside
a luminometer tube, 10–20 µl of crude extract were mixed with a solution consisting of 80–90 µl of 0.10 M
Tris–HCL buffer pH 8.5, 2 mM ATP and 4 mM MgSO4. The luminescence output was measured in counts per
second (cps) using an ATTO AB220 luminometer (Tokyo, Japan). Chemiluminescence assays were performed
by mixing crude and methanolic millipede cuticle extracts with hydrogen peroxide 0.1–3% in buffer and light
intensities were measured using an ATTO luminometer. Bioluminescence and Chemiluminescence spectra
Bioluminescence and chemiluminescence spectra were measured using a LumiSpectra spectroluminometer
(ATTO, Japan). For bioluminescence spectra 10–20 µl of Millipede crude extracts were mixed with a solu-
tion consisting of 80–90 µl of 0.10 M Tris–HCL buffer pH 8.5, 2 mM ATP and 4 mM MgSO4 inside a lumi-
nometer tube. Chemiluminescence spectra were measured upon mixing 2–10 µl of concentrated methanolic
cuticle extracts with 100 µl of a solution of potassium superoxide (8 mg/mL) dissolved in anhydrous DMSO
(SIGMA-Aldrich). Data availabilityh & Moore, W. Discovery of a glowing millipede in California and the gradual evolution of bioluminescence in Diplopoda
PNAS. 112, 6419–6424 (2015). 6. Blum, M. S. & Woodring, J. P. Secretion of benzaldehyde and hydrogen cyanide by the millipede Pachydesmus crassicutis (Wood)
Science 138, 512–513 (1962). 7. Means, J. C., Hennen, D. A., Tanabe, T. & Marek, P. E. Phylogenetic systematics of the millipede family Xystodesmidae. Insect Syst
Divers. 5, 1–26 (2021). 18. Shimomura, O. A new type of ATP-activated bioluminescent system in the millipede Luminodesmus sequoiae. FEBS Lett. 128,
242 244 (1981) 18. Shimomura, O. A new type of ATP-activated bioluminescent system in the millipede Luminodesmus sequoiae. FEBS Lett. 128,
242–244 (1981). (
)
19. Shimomura, O. Porphyrin chromophore in Luminodesmus photoprotein. Comp. Biochem. Physiol. 79B, 565–567 (1984). 20. Kuse, M. et al. 7,8-dihydropterin-6-carboxylic acid as light emitter of luminous millipede. Luminodesmus sequeiae. Bioorg. Med. Chem. Lett. 11, 1037–1040 (2001).il 1. Kuse, M., Yanagi, M., Tanaka, E., Tani, N. & Nishikawa, T. Identification of a fluorescent compound in the cuticle of the train
millipede Parafrontaria laminate armigera. Biosci. Biotechnol. Biochem. 11, 2307–2309 (2010). 2. Ramos, L. D., Gomes, T. M. V., Stevani, C. V. & Bechara, E. J. H. Mining reactive triplet carbonyls in biological systems. J. Photo
chem. Photobiol. B. 243, 112712 (2023).l 23. Olson, E. R. et al. Vivid biofluorescence discovered in the nocturnal Springhare (Pedetidae). Sci. Rep 11, 4125 (2021). 23. Olson, E. R. et al. Vivid biofluorescence discovered in the nocturnal Springhare (Pedetidae). Sci. Rep 11, 4125 (2021). l
24. Marek, P., Papaj, D., Yeager, J., Molina, S. & Moore, W. Bioluminescent aposematism in millipedes. Current Biol. 21, Data availabilityh y
The datasets used and/or analysed during the current study are available from the corresponding autho
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5. Marek, P. Acknowledgements g
I am grateful to Prof. James Costa for allowing my visit to the Highlands Biological Station and discussions, Dr. Derek Hennen from Virginia Tech for kind identification of the millipede specimens and especially Prof. Carl
H. Johnson (Vanderbilt University) for his kind support and helpful comments on the manuscript. This work
was supported by grants from FAPESP 2010/05426-8 and 2022/04800-0, and CNPq. Author contributionsh The author discovered phosphorescence in millipedes, made the experimental work and wrote the manuscript Competing interests h p
g
The author declares no competing interests. The author declares no competing interests. © The Author(s) 2023 Additional informationh Supplementary Information The online version contains supplementary material available at https://doi.org/
10.1038/s41598-023-47860-9. Supplementary Information The online version contains supplementary material available at https://doi.org/
10.1038/s41598-023-47860-9. Correspondence and requests for materials should be addressed to V.R.V. Correspondence and requests for materials should be addressed to V.R.V. Reprints and permissions information is available at www.nature.com/reprints. Reprints and permissions information is available at www.nature.com/reprints. Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and
nstitutional affiliations. Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and
institutional affiliations. Open Access This article is licensed under a Creative Commons Attribution 4.0 International
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permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from
the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. © The Author(s) 2023 https://doi.org/10.1038/s41598-023-47860-9 Scientific Reports | (2023) 13:22171 |
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The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping
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bioRxiv (Cold Spring Harbor Laboratory)
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cc-by
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The amplitude in periodic neural state
trajectories underlies the tempo of rhythmic
tapping Jorge Ga´mezID, Germa´n MendozaID, Luis Prado, Abraham BetancourtID
H
M
h Jorge Ga´mezID, Germa´n MendozaID, Luis Prado, Abraham BetancourtID
Hugo MerchantID* Jorge Ga´mezID, Germa´n MendozaID, Luis Prado, Abraham BetancourtID,
Hugo MerchantID*
Instituto de Neurobiologı´a, Universidad Nacional Auto´noma de Me´xico, Campus Juriquilla, Quere´taro, Me´xico Hugo MerchantID*
Instituto de Neurobiologı´a, Universidad Nacional Auto´noma de Me´xico, Campus Juriquilla, Quere´taro, Me´xico Instituto de Neurobiologı´a, Universidad Nacional Auto´noma de Me´xico, Campus Juriquilla, Quere´taro, Me´xico * hugomerchant@unam.mx a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 RESEARCH ARTICLE Academic Editor: Robert Zatorre, McGill
University, CANADA Academic Editor: Robert Zatorre, McGill
University, CANADA
Received: September 13, 2018
Accepted: March 19, 2019
Published: April 8, 2019
Copyright: © 2019 Ga´mez et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. Received: September 13, 2018
Accepted: March 19, 2019
Published: April 8, 2019 Copyright: © 2019 Ga´mez et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. Data Availability Statement: All underlying
experimental data used in this study have been
deposited in G-Node (https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/). Abstract Our motor commands can be exquisitely timed according to the demands of the environ-
ment, and the ability to generate rhythms of different tempos is a hallmark of musical cogni-
tion. Yet, the neuronal underpinnings behind rhythmic tapping remain elusive. Here, we
found that the activity of hundreds of primate medial premotor cortices (MPCs; pre-supple-
mentary motor area [preSMA] and supplementary motor area [SMA]) neurons show a
strong periodic pattern that becomes evident when their responses are projected into a
state space using dimensionality reduction analysis. We show that different tapping tempos
are encoded by circular trajectories that travelled at a constant speed but with different radii,
and that this neuronal code is highly resilient to the number of participating neurons. Cru-
cially, the changes in the amplitude of the oscillatory dynamics in neuronal state space are a
signature of duration encoding during rhythmic timing, regardless of whether it is guided by
an external metronome or is internally controlled and is not the result of repetitive motor
commands. This dynamic state signal predicted the duration of the rhythmically produced
intervals on a trial-by-trial basis. Furthermore, the increase in variability of the neural trajec-
tories accounted for the scalar property, a hallmark feature of temporal processing across
tasks and species. Finally, we found that the interval-dependent increments in the radius of
periodic neural trajectories are the result of a larger number of neurons engaged in the pro-
duction of longer intervals. Our results support the notion that rhythmic timing during tapping
behaviors is encoded in the radial curvature of periodic MPC neural population trajectories. Citation: Ga´mez J, Mendoza G, Prado L,
Betancourt A, Merchant H (2019) The amplitude in
periodic neural state trajectories underlies the
tempo of rhythmic tapping. PLoS Biol 17(4):
e3000054. https://doi.org/10.1371/journal.
pbio.3000054 OPEN ACCESS Citation: Ga´mez J, Mendoza G, Prado L,
Betancourt A, Merchant H (2019) The amplitude in
periodic neural state trajectories underlies the
tempo of rhythmic tapping. PLoS Biol 17(4):
e3000054. https://doi.org/10.1371/journal. pbio.3000054 Academic Editor: Robert Zatorre, McGill
University, CANADA Introduction Precise timing is a fundamental requisite for a select group of complex actions such as the exe-
cution and appreciation of music and dance [1]. In these behaviors, the perception of time
intervals is facilitated by the presence of a regular beat in the rhythmic sequence, and individ-
ual intervals are encoded relative to this pulse or beat. This is called beat-based timing and
serves as a framework for rhythmic entrainment, in which subjects perform movements syn-
chronized to music [2–4]. Most of occidental music is organized by a quasi-isochronous pulse
and frequently also in a metrical hierarchy, in which the beats of one level are typically spaced
at two or three times those of a faster level (i.e., the tempo of one level is 1/2 [march meter] or
1/3 [waltz meter] that of the other), and humans can typically synchronize at more than one
level of the metrical hierarchy [5,6]. Rhythmic tapping to an isochronous metronome is the
simplest case of beat entrainment [7] and has been thoroughly studied in humans [8,9]. In
contrast to the large human flexibility to perceive and entrain to complex beats in music, non-
human primates can perceive [10–13] and synchronize to simple isochronous beats [14–16]. On the other hand, other sets of behaviors, such as the interception of a moving target or the
production of a single interval, seem to depend on a duration-based timing mechanism, in
which the absolute duration of individual time intervals is encoded discretely, like a stopwatch
[2,17]. Functional imaging and behavioral studies have suggested the existence of a partially
segregated timing neural substrate, with the cerebellum as a key structure for duration-based
timing, the basal ganglia as main nuclei for beat-based timing, and medial premotor cortices
(MPCs; which include the pre-supplementary motor area [preSMA] and supplementary
motor area [SMA]) as a potential master clock for both timing mechanisms [7,18–20]. Yet, the
neural substrate for absolute timing, and especially for beat perception and rhythmic entrain-
ment, is still largely unknown. Recent advances on the neurophysiology of absolute timing during single interval repro-
duction tasks suggest that time is represented in the structured patterns of activation of cell
populations in timing areas such as the MPC and the neostriatum [21–24]. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping data collection and analysis, decision to publish, or
preparation of the manuscript. metronome. Using principal component analysis, we projected the time-varying activity
of hundreds of neurons into a low-dimensional space. The projected activity of the neural
population generated a circular trajectory for every interval produced in the sequence,
which travelled at a constant speed but with different radii for different tapping tempos. In addition, the increase in amplitude and variability of the neural trajectories accounted
for the scalar property of timing, a generalized feature of temporal processing across tasks
and species and which defines a linear relationship between the variability of temporal
performance and interval duration. Competing interests: The authors have declared
that no competing interests exist. Abbreviations: a.u., arbitrary unit; CC, continuation
condition; DAT, Dynamic Attending Theory; dPCA,
demixed PCA; EEG, electroencephalogram; MPC,
medial premotor cortex; MSE, mean square error;
PC, principal component; PCA, principal
component analysis; preSMA, pre-supplementary
motor area; SC, synchronization condition; SCT,
synchronization-continuation task; SI, surprise
index; SMA, supplementary motor area; SRTT,
serial reaction time task; ST, synchronization task;
SVM, support vector machine; TDNN, time-delay
neural network; TIND, target interval normalized
data; UTND, unit time normalized data. Author summary The ability to extract the regular pulse in music and to respond in synchrony to this pulse
is called beat synchronization and is a natural human behavior exhibited during dancing
and musical ensemble playing. A part of the brain called the medial premotor cortex has
been associated with rhythmic entrainment, and yet the neural basis of this complex
behavior is still far from known. In this work, we recorded the neuronal activity from the
medial premotor cortices of macaques trained to tap rhythmically to the frequency of a Funding: This work was funded by Consejo
Nacional de Ciencia y Tecnologia #236836 and
#196, https://www.conacyt.gob.mx/, and
Programa de Apoyo a Proyectos de Investigacio´n e
Innovacio´n Tecnolo´gica #IN202317, http://dgapa. unam.mx/index.php/impulso-a-la-investigacion/
papiit. The funders had no role in study design, 1 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping produced interval. The moving bump repeats itself on each produced interval of the tapping
sequence [4,21,28]. Nevertheless, single MPC cells multiplex the interval, the serial order, and
task phase of the SCT, showing complex and heterogenous time-varying profiles of activation
that make it difficult to understand the neural population mechanisms behind rhythmic tap-
ping. A successful approach to determine the latent task variables in cell populations is to proj-
ect high-dimensional individual neural activity into a low-dimensional topological space, in
order to generate a robust and stable manifold [29]. Recent studies have reconstructed key hid-
den task parameters in the neural state population dynamics [30–32]. Thus, the combined use
of high-density single unit recordings with dimensional reduction methods have revealed
basic organizing principles at the level of the population dynamics, which seem to be extremely
complex at the level of individual neurons [29,33]. p
Here, we investigated the population dynamics of hundreds of MPC neurons in monkeys
performing two isochronous tapping tasks, testing whether low-dimensional state network tra-
jectories can act as a neural clock during rhythmic tapping. Using dimensional reduction anal-
ysis, we found highly stereotyped neural trajectories that had two main properties during the
SCT. First, the three first principal components showed a periodic path for each produced
interval. Notably, these oscillatory state trajectories did not overlap across durations, a signa-
ture of temporal scaling; instead, they showed a linear increase in their radius and a constant
linear speed as a function of the target interval during metronome guidance (synchronization
condition [SC]), as well as during internally controlled rhythmic tapping (continuation condi-
tion [CC]). Second, the intertrial variability of the trajectories’ radial magnitude also increased
as a function of the interval, accounting for a key feature of timing behavior: the scalar prop-
erty, which states that the variability of produced or estimated intervals increases linearly as a
function of interval duration. These properties were highly resilient to the number of partici-
pating neurons and were replicated using simultaneously recorded cells during synchronized
tapping, but not during a serial reaction time-control task that precluded rhythmic prediction. Finally, we found a tight correlation between the interval-associated changes in trajectory
amplitude and variability during SCT, the number of neurons involved in the sequential tran-
sient activation patterns, and the duration of the neural activation periods within these moving
bumps. Indeed, moving bumps simulations revealed that scaling the duration of the transient
period of activity and increasing the number of neurons participating in the evolving patterns
produced an increase in the radius and the variability of the corresponding neural trajectories,
replicating the empirical findings. These results suggest that rhythmic timing depends on the
radial amplitude of periodic state population trajectories in MPC, which in turn depend on the
number of neurons involved and the duration of these cells’ activation periods within moving
bumps. Introduction Rather than being
quantified in the instantaneous activity of single cells that accumulate elapsed time or encode
the time remaining for an action [25–27], the duration of produced intervals depends on the
speed at which the neural population response changes. This implies that the activation pro-
files are compressed for short and elongated for long intervals due to temporal scaling on the
activity of the same population of cells [23,24]. On the other hand, MPC neurons are tuned to the duration and ordinal sequence of rhyth-
mic movements produced either in synchrony with a metronome or guided by an endogenous
tempo (synchronization-continuation task [SCT]) [4,21]. Remarkably, the time-varying profile
of activation of these interval-specific neural circuits forms a moving bump, which is defined
as a sequential pattern of responses in which the cells are activated consecutively within a PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 2 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Rhythmic tapping behavior We trained two monkeys (M01 and M02) in the SCT. M01 was also trained in two additional
tapping tasks: the synchronization task (ST) and the serial reaction time task (SRTT). During
SCT, the animals tapped on a push button in synchronization with a rhythmic metronome for
four times, thus producing three intervals (SC phase), followed by three internally generated
intervals (CC phase; Fig 1A). In the ST, the monkey produced five intervals guided by a metro-
nome, similarly to the SC of SCT (Fig 1B). During the SRTT, the animal pressed the button in
response to five brief visual stimuli presented in a sequence but separated by a random inter-
stimulus interval, precluding the prediction of the next stimulus-response loop (Fig 1C). Thus,
during SCT and ST, the animals entrained their rhythmic movements to a sensory 3 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 1. Tasks. A. SCT. The trial started when the monkey placed his hand on a lever for a variable delay. Then, a visual metronome was
presented, and the monkey tapped on a button to produce three intervals of a specific duration following the isochronous stimuli
(synchronization phase), after which the animal had to maintain the tapping rate to produce three additional intervals without the
metronome (continuation phase). Correct trials were rewarded with an amount of juice that was proportional to the trial length. The
instructed target intervals were 450, 550, 650, 850, and 1,000 ms. B. ST. Similar to the synchronization phase of the SCT, the animal
had to produce five intervals guided by a visual metronome. The instructed intervals were 450, 550, 650, 750, 850, and 950 ms. C. SRTT. As in ST, the trial started when the monkey placed its hand on a lever for a variable delay. However, in this task, the monkey
tapped the button after six stimuli separated by a random interstimulus interval, precluding the temporalization of the tapping
behavior. D. Rhythmic tapping behavior Constant error (mean ± SD/2) as a function of target interval during the SC (orange) and CC (red) of the SCT (ANOVA
main effect interval, F(4, 1,112) = 61.01, p < 0.0001; main effect task condition, F(1, 1,112) = 43.16, p < 0.0001; interval × condition
interaction, F(4, 1,112) = 17.66, p < 0.0001), and the ST (purple) as a function of target interval (ANOVA for 450, 550, 650, and 850
target intervals between SC of the SCT and the ST, main effect interval, F(3, 631) = 4.18, p < 0.01; main effect condition, F(1, 631) =
202.16, p < 0.0001; nonsignificant interval × condition interaction, F(3, 631) = 2.46, p = 0.06). Underlying data are available in https://
doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; SC, synchronization condition; SCT,
synchronization-continuation task; SRTT, serial reaction time task; ST, synchronization task. Fig 1. Tasks. A. SCT. The trial started when the monkey placed his hand on a lever for a variable delay. Then, a visual metronome was
presented and the monkey tapped on a button to produce three intervals of a specific duration following the isochronous stimuli Fig 1. Tasks. A. SCT. The trial started when the monkey placed his hand on a lever for a variable delay. Then, a visual metronome was
presented, and the monkey tapped on a button to produce three intervals of a specific duration following the isochronous stimuli
(synchronization phase), after which the animal had to maintain the tapping rate to produce three additional intervals without the
metronome (continuation phase). Correct trials were rewarded with an amount of juice that was proportional to the trial length. The
instructed target intervals were 450, 550, 650, 850, and 1,000 ms. B. ST. Similar to the synchronization phase of the SCT, the animal
had to produce five intervals guided by a visual metronome. The instructed intervals were 450, 550, 650, 750, 850, and 950 ms. C. SRTT. As in ST, the trial started when the monkey placed its hand on a lever for a variable delay. However, in this task, the monkey
tapped the button after six stimuli separated by a random interstimulus interval, precluding the temporalization of the tapping
behavior. D. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Neural state trajectories We characterized the dynamics of the evolving response patterns using the projection of the
neural population time-varying activity onto a low-dimensional state space using principal
component analysis (PCA) on a population of 1,477 MPC cells recorded during SCT (see
Materials and methods, recording locations in S1 Fig). The results showed highly stereotyped
trajectories with a strong periodicity in the first three principal components (PCs) (Fig 2A–
2D). Indeed, PC2 and PC3 showed together a cyclic path for each produced interval (Fig 2C
and 2D). Each loop in the trajectory corresponded to the periodic network state variation dur-
ing the production of the rhythmic tapping sequence of the SCT. The circular trajectories in
the plane exhibited the tendency to start at the same position in the phase-space after each tap,
suggesting the existence of a movement-triggering point at a particular location in the popula-
tion trajectory across durations (see below). Crucially, from this common phase-space loca-
tion, longer intervals produced larger state trajectory loops, with a monotonic increase in the
trajectory radius as a function of target interval during both the SC and CC (Fig 2E). However,
the observed interval-dependent modulations in curvilinear amplitude were not accompanied
by modulations of the linear speeds of the periodic neural trajectories, as these remained con-
stant across durations (Fig 2F). The same properties were observed in PC1 and when the PCA
is computed from a subpopulation of neurons whose activity was task related (see S2 Fig). Hence, contrary to a prototypical temporal scaling, in which there is a decrease in linear speed
as a function of interval and similar trajectory paths and traversed distances for different dura-
tions [24,34], the present results show that rhythmic timing during the SCT is represented as
an increase in curvature radii in the neural network state dynamics. To test the relationship between the radius of the curvature in the neural-state trajectories
and the monkeys’ behavior during SC and CC, we split the produced intervals into two groups:
those in which the monkeys produced an inter-tap time that was below the 20th percentile,
and those with inter-tap times above the 80th percentile [21]. Strikingly, on those intervals in
which the monkeys tended to produce shorter inter-tap durations, the state trajectory radius
was smaller, and vice versa (Fig 2G). The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping target durations (Fig 1D). Finally, the temporal variability (a measure of timing precision) dur-
ing the SCT and ST are depicted in Fig 2H and Fig 4E, respectively. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Rhythmic tapping behavior Constant error (mean ± SD/2) as a function of target interval during the SC (orange) and CC (red) of the SCT (ANOVA
main effect interval, F(4, 1,112) = 61.01, p < 0.0001; main effect task condition, F(1, 1,112) = 43.16, p < 0.0001; interval × condition
interaction, F(4, 1,112) = 17.66, p < 0.0001), and the ST (purple) as a function of target interval (ANOVA for 450, 550, 650, and 850
target intervals between SC of the SCT and the ST, main effect interval, F(3, 631) = 4.18, p < 0.01; main effect condition, F(1, 631) =
202.16, p < 0.0001; nonsignificant interval × condition interaction, F(3, 631) = 2.46, p = 0.06). Underlying data are available in https://
doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; SC, synchronization condition; SCT,
synchronization-continuation task; SRTT, serial reaction time task; ST, synchronization task. https://doi.org/10.1371/journal.pbio.3000054.g001 metronome, while in the CC of SCT, this was done to an internal representation of the same
rhythm. The asynchronies in the SC of SCT were (mean ± SD: 288.7 ± 70 ms). On the other
hand, the SRTT involved similar stimuli, tapping behavior, and sequential structure, but no
predictive rhythmic timing was possible. Expectedly, the reaction times were significantly
larger in the SRTT than the asynchronies in the ST (mean ± SD: 263 ± 37 ms in the ST and
381 ± 46 ms in the SRTT; ANOVA main effect of task: F(1, 718) = 1443.93, p < 0.0001). The
constant error, a measure of timing accuracy that corresponds to the difference between the
produced and the instructed interval, was slightly negative during SCT and ST, indicating that
the monkeys were able to properly produce the intervals with a small underestimation across PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 4 / 32 Neural state trajectories Another important property of the curvilinear radii in the PCA neural trajectories was that
their variability (SD of the trajectory radii) followed the same linear increase as a function of
target interval observed in the monkeys’ behavior (Fig 2H). This linear relation between tem-
poral variability and interval duration, known as scalar property of interval timing, has been
widely reported in the timing literature, and our findings suggest that it depends on the radius
of the rotatory dynamical state of MPC neural populations during both SCT conditions. It is
important to mention that all the described properties in the neural trajectories are resilient on
the methods used to compute the PCs (see S3 Fig). The dynamics in the MPC population activity during the SCT was also characterized using
demixed PCA (dPCA; Fig 3, see Materials and methods). This method not only captures most
of the variance in the neural data but, most importantly, also decomposes the dependencies of
the neural population activity into latent components associated with task parameters [30]. In
contrast, PCA only focuses on the total variance explained using orthogonal decomposition. The first dPCA (dPCA1) showed a strong periodic structure with a minimum value around
the beginning of each produced interval in the SCT sequence, similar to the findings from the
PCA neural trajectories (Fig 2C and 2D). In addition, the dPCA1 showed a strong change in
amplitude with target duration (Fig 3A). Because we used time-normalized neural data as PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 5 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 2. Neural population trajectories during SCT and their oscillatory dynamic properties. A, C. Projection of the neural activity in the MPC
(1,477 neurons) during the SC of the SCT onto the first (A) or second and third PCs (C). The first three PCs explained the 10.7%, 3.8%, and 2.3% of
p
p
j
p
y
pp g Fig 2. Neural population trajectories during SCT and their oscillatory dynamic properties. A, C. Projection of the neural activity in the MPC
(1,477 neurons) during the SC of the SCT onto the first (A) or second and third PCs (C). The first three PCs explained the 10.7%, 3.8%, and 2.3% of Fig 2. Neural population trajectories during SCT and their oscillatory dynamic properties. A, C. Variability (SD) of SCT rotational neural trajectories (orange, mean ± SD,
normalized data slope = 0.0019, constant = −1.02, R2 = 0.94, p = 0.005) and the monkeys’ produced intervals (gray, mean ± SD, normalized data
slope = 0.005, constant = −0.721, R2 = 0.98, p = 0.0008) as a function of target interval. The Weber increase in tapping variability was not statistically
different from the increase in the variability of neural trajectories across target intervals (normalized data, slope t test = 0.86, p = 0.42; constant t
test = 1.36, p = 0.22). Underlying data are available in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; CC,
continuation condition; MPC, medial premotor cortex; PC, principal component; SC, synchronization condition; SCT, synchronization-
continuation task. input to the dPCA, all trials had the same length regardless of the target interval. In this sce-
nario, a scaling mechanism should have produced similar dPCAs across durations. Instead, we
observed a time-dependent modulation in dPCA1 amplitude. In order to compare the two
methods for dimensional reduction, we computed the bin-by-bin distance between the
450-ms and the other four target intervals (Fig 3D) using the PCAs (Fig 3B) and dPCA1 (Fig
3C). The resulting distance profiles are very similar between methods, with a periodic structure
whose amplitude mean and variability increased as a function of the target interval (Fig 3E and
3F). Thus, with a separate set of assumptions, the dPCA corroborates the existence of both the
periodic structure of the neural state dynamics and a beat-based timing mechanism based on
the amplitude modulation of the rotatory population trajectories during SCT. The analyses described above were done on neurons recorded throughout different ses-
sions. Thus, as a next step we determine the neural state trajectories on simultaneously
recorded cells while monkey M01 performed an ST (Fig 1B) and an SRTT (Fig 1C). This strat-
egy not only allows us to validate the data of the SCT on the ST but also permits us to deter-
mine population dynamics on a trial-by-trial basis. As in the SCT, the PCA-projected activity
during the ST showed periodic state dynamics (Fig 4A; S4A Fig), whereas the SRTT neural tra-
jectories were not as periodic (Fig 4B; S4B Fig). The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping the total variance. Each point in the trajectory represents the neural network state at a particular moment. The trajectory completes an oscillatory
cycle on every produced interval during the synchronization and continuation phases of the SCT. Target interval in milliseconds is color coded (450,
green; 650, blue; 1,000, red). Color progression within each target interval corresponds to the elapsed time. A cube indicates the beginning of each
trajectory, while an octahedron indicates the end. B, D. Projection of the neural activity during CC of the SCT onto the first (B) or the second and
third (D) PC. Color code is the same as (A). E. Monotonic increase of the radii in the oscillatory neural trajectories during SC (orange, mean ± SD,
slope = 0.0009, constant = 0.0679, R2 = 0.9, p = 0.01) and CC (red, mean ± SD, slope = 0.0009, constant = −0.0296, R2 = 0.9, p < 0.01) as a function of
target interval. F. Linear speed of neural trajectories during SC (orange, mean ± SD, slope = 0.0001, constant = 7.322, R2 = 0.0007, p = 0.896) and CC
(red, mean ± SD, slope = 0.002, constant = 4.049, R2 = 0.354, p = 0.002) as a function of target interval (ANOVA main effect interval, F(4, 39) =
92.15, p < 0.0001; main effect condition, F(1,39) = 381.46, p < 0.0001; interval × condition interaction, F(4, 39) = 15.15, p < 0.0001). The linear
speed was similar (SC) or showed a slight increase (CC) with the target interval. G. Neural trajectory radii for the top 20% (red, slope = 0.0011,
constant = −0.035, R2 = 0.7, p < 0.0001) and bottom 20% (green, slope = 0.00088, constant = −0.009, R2 = 0.75, p < 0.0001) inter-tap intervals across
target intervals. Note that on those intervals in which the monkeys tended to produce shorter inter-tap durations, the state trajectory radius was
smaller, and vice versa (ANOVA main effect interval, F(4, 40) = 155.7, p < 0.0001; main effect population, F(1, 40) = 33.3, p < 0.0001;
interval × population interaction, F(4, 40) = 3.98, p = 0.008). H. https://doi.org/10.1371/journal.pbio.3000054.g002 Neural state trajectories Projection of the neural activity in the MPC
(1,477 neurons) during the SC of the SCT onto the first (A) or second and third PCs (C). The first three PCs explained the 10.7%, 3.8%, and 2.3% of PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 6 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Linear speed of neural
trajectories during ST (purple, mean ± SD, slope = 0.0001, constant = 7.322, R2 = 0.0007, p = 0.896) and SRTT (green, mean ± SD, slope = 0.002,
constant = 4.049, R2 = 0.354, p = 0.002) did not change as a function of target interval. G. Output of the time-delay neural network (TDNN, in blue) Fig 4. Comparison of ST and SRTT trajectories in simultaneously recorded neurons. A. Neural activity data projected on the PC1 (solid line,
linearly detrended) and the correspondent sinusoidal fit (dotted line) during a trial of ST for the target interval of 650 ms. B. Similar to (A) for SRTT. Note that the strong periodic structure of the ST neural trajectory is lost during SRTT for the same population of cells. C. The MSE of the sinusoidal fits
during ST (purple) is significantly smaller than during SRTT (green; 60 trials, two-sample t test = −6.78, p < 0.0001). D. Radii of the neural trajectories
during ST (purple, slope = 0.000087, constant = 0.055, R2 = 0.619, p < 0.0001) and SRTT (green, nonsignificant linear regression, R2 = 0.0172 and Fig 4. Comparison of ST and SRTT trajectories in simultaneously recorded neurons. A. Neural activity data projected on the PC1 (solid line,
linearly detrended) and the correspondent sinusoidal fit (dotted line) during a trial of ST for the target interval of 650 ms. B. Similar to (A) for SRTT. Note that the strong periodic structure of the ST neural trajectory is lost during SRTT for the same population of cells. C. The MSE of the sinusoidal fits
during ST (purple) is significantly smaller than during SRTT (green; 60 trials, two-sample t test = −6.78, p < 0.0001). D. Radii of the neural trajectories
during ST (purple, slope = 0.000087, constant = 0.055, R2 = 0.619, p < 0.0001) and SRTT (green, nonsignificant linear regression, R2 = 0.0172 and
p = 0.489) as a function of target interval. E. Variability of the neural trajectories during ST (purple, data slope = 0.000037, constant = 0.028, R2 = 0.368,
p < 0.0001), SRTT (green, nonsignificant linear regression, R2 = 0.0005 and p = 0.903), and temporal variability of the monkeys’ produced intervals
(gray, mean ± SD/2, data slope = 0.0009, constant = −0.003, R2 = 0.999, p < 0.0001) across target intervals during ST. F. Radii of the neural trajectories
during ST (purple, slope = 0.000087, constant = 0.055, R2 = 0.619, p < 0.0001) and SRTT (green, nonsignificant linear regression, R2 = 0.0172 and
p = 0.489) as a function of target interval. E. Variability of the neural trajectories during ST (purple, data slope = 0.000037, constant = 0.028, R2 = 0.368,
p < 0.0001), SRTT (green, nonsignificant linear regression, R2 = 0.0005 and p = 0.903), and temporal variability of the monkeys’ produced intervals
(gray, mean ± SD/2, data slope = 0.0009, constant = −0.003, R2 = 0.999, p < 0.0001) across target intervals during ST. F. Linear speed of neural
trajectories during ST (purple, mean ± SD, slope = 0.0001, constant = 7.322, R2 = 0.0007, p = 0.896) and SRTT (green, mean ± SD, slope = 0.002,
constant = 4.049, R2 = 0.354, p = 0.002) did not change as a function of target interval. G. Output of the time-delay neural network (TDNN, in blue)
The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 4. Comparison of ST and SRTT trajectories in simultaneously recorded neurons. A. Neural activity data projected on the PC1 (solid line,
linearly detrended) and the correspondent sinusoidal fit (dotted line) during a trial of ST for the target interval of 650 ms. B. Similar to (A) for SRTT. Note that the strong periodic structure of the ST neural trajectory is lost during SRTT for the same population of cells. C. The MSE of the sinusoidal fits
during ST (purple) is significantly smaller than during SRTT (green; 60 trials, two-sample t test = −6.78, p < 0.0001). D. Radii of the neural trajectories
during ST (purple, slope = 0.000087, constant = 0.055, R2 = 0.619, p < 0.0001) and SRTT (green, nonsignificant linear regression, R2 = 0.0172 and
p = 0.489) as a function of target interval. E. Variability of the neural trajectories during ST (purple, data slope = 0.000037, constant = 0.028, R2 = 0.368,
p < 0.0001), SRTT (green, nonsignificant linear regression, R2 = 0.0005 and p = 0.903), and temporal variability of the monkeys’ produced intervals
(gray, mean ± SD/2, data slope = 0.0009, constant = −0.003, R2 = 0.999, p < 0.0001) across target intervals during ST. F. In fact, the fitting of a normalized sinusoidal
function on the first PC was statistically more robust for ST than SRTT (in terms of mean
square error [MSE]: Fig 4C), even when the length of the inter-tap PCA-projected activity was
matched between different produced intervals (see Materials and methods). Again, the radius
of the neural trajectories during the ST showed a significant increase in both mean radius (Fig
4D, purple) and variability (Fig 4E), but a constant linear speed (Fig 4F), as a function of the
target interval, reproducing the findings in SCT. In contrast, the radius and variability of the
trajectories during SRTT showed small changes across target intervals, with a nonsignificant
linear fit as a function of target interval for the three parameters (Fig 4D, 4E and 4F, green). This phenomenological comparison suggests that rhythmic tapping to a metronome depends
on the amplitude of the cyclic dynamics of population activity and that the shift from a predic-
tive to a reactive behavior during SRTT precludes the organization of periodic population state This phenomenological comparison suggests that rhythmic tapping to a metronome depends
on the amplitude of the cyclic dynamics of population activity and that the shift from a predic-
tive to a reactive behavior during SRTT precludes the organization of periodic population state
trajectories. The simultaneity of the recordings during ST [35] allowed for the decoding of the produced
intervals on a trial-by-trial basis. Using a time-delay neural network (TDNN; see Materials and
methods) (Fig 4G), we found that an ideal reader of the neural trajectories could predict PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 7 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 4. Comparison of ST and SRTT trajectories in simultaneously recorded neurons. A. Neural activity data projected on the PC1 (solid line,
linearly detrended) and the correspondent sinusoidal fit (dotted line) during a trial of ST for the target interval of 650 ms. B. Similar to (A) for SRTT. Note that the strong periodic structure of the ST neural trajectory is lost during SRTT for the same population of cells. C. The MSE of the sinusoidal fits
during ST (purple) is significantly smaller than during SRTT (green; 60 trials, two-sample t test = −6.78, p < 0.0001). D. Mean
inter-tap Euclidean distance (mean ± SD) between the 450-ms and each target interval for the PCA data using PC1–3, (orange) and dPCA using dPC1
(magenta). There was no significant difference between the slopes of PCA and dPCA (slope t test = 1.97, p = 0.0539) F. Variability of the distance between the
450-ms and each target interval for the PCA (orange) and dPCA (magenta). The variability increased monotonically as a function of the target interval for both
analyses. Underlying data are available in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; dPCA, demixed PCA; PC,
principal component; PCA, principal component analysis; SCT, synchronization-continuation task. https://doi.org/10.1371/journal.pbio.3000054.g003 Fig 3. dPCA applied to neural population activity during SCT. A, dPC1 of the dPCA of the neural activity associated with the target interval (explains 7.8% of
the total variance). Target interval in milliseconds is color coded (see inset A). The neural trajectories show oscillatory activity, and their amplitude varies across
target intervals. B,C. Euclidean distance between the first PC of the 450-ms target interval and the first PC of each target interval across time for (B) time-
normalized PCA and (C) dPCA. Target interval is color coded as in (A). Two-sample Kolmogorov–Smirnov test on the distributions of PCA and dPCA
distances showed nonsignificant differences (p < 0.05) across target intervals. D. Distance calculation diagram for PCA data. The inter-tap trajectories for two
target intervals are shown (green, 450 ms; red, 1,000 ms). The 450-ms target interval trajectory is used as the reference for distance calculation. The Euclidean
distance between each sequential bin is calculated among the reference interval and the other target intervals trajectories. Both population analyses, PCA and
dPCA, produced population signals with similar characteristics. Thus, oscillatory activity, modulation of the amplitude with the target interval, and an
intersection close to the tap time are characteristics of the underlying neural population activity, irrespective of the dimension reduction algorithm. E. Mean
inter-tap Euclidean distance (mean ± SD) between the 450-ms and each target interval for the PCA data using PC1–3, (orange) and dPCA using dPC1
(magenta). There was no significant difference between the slopes of PCA and dPCA (slope t test = 1.97, p = 0.0539) F. Variability of the distance between the
450-ms and each target interval for the PCA (orange) and dPCA (magenta). The variability increased monotonically as a function of the target interval for both
analyses. Underlying data are available in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping trained to decode the duration of produced intervals based on the PC1 neural trajectories (orange) during a target interval of 850 ms. Tapping times are
shown in yellow. H. TDNN error, defined as the difference between the produced and the decoded interval, as a function of produced interval. TDNN
predicted accurately the performance of the monkey on a trial-by-trial basis (the decoded mean was not statistically different from 0, t test = −0.5228,
p = 0.6). Underlying data are available in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; MSE, mean square
error; PC, principal component; SRTT, serial reaction time task; ST, synchronization task; TDNN, time-delay neural network. https://doi org/10 1371/journal pbio 3000054 g004 https://doi.org/10.1371/journal.pbio.3000054.g004 accurately the tapping times during ST on 86% of the produced intervals. Indeed, the decoding
accuracy was better than the actual percent of correct trials in this demanding task (Fig 4H),
supporting the notion that the neural trajectories can robustly predict the rhythmic tapping
behavior. Fig 3. dPCA applied to neural population activity during SCT. A, dPC1 of the dPCA of the neural activity associated with the target interval (explains 7.8% of
the total variance). Target interval in milliseconds is color coded (see inset A). The neural trajectories show oscillatory activity, and their amplitude varies across
target intervals. B,C. Euclidean distance between the first PC of the 450-ms target interval and the first PC of each target interval across time for (B) time-
normalized PCA and (C) dPCA. Target interval is color coded as in (A). Two-sample Kolmogorov–Smirnov test on the distributions of PCA and dPCA
distances showed nonsignificant differences (p < 0.05) across target intervals. D. Distance calculation diagram for PCA data. The inter-tap trajectories for two
target intervals are shown (green, 450 ms; red, 1,000 ms). The 450-ms target interval trajectory is used as the reference for distance calculation. The Euclidean
distance between each sequential bin is calculated among the reference interval and the other target intervals trajectories. Both population analyses, PCA and
dPCA, produced population signals with similar characteristics. Thus, oscillatory activity, modulation of the amplitude with the target interval, and an
intersection close to the tap time are characteristics of the underlying neural population activity, irrespective of the dimension reduction algorithm. E. Linear speed of neural
trajectories during ST (purple, mean ± SD, slope = 0.0001, constant = 7.322, R2 = 0.0007, p = 0.896) and SRTT (green, mean ± SD, slope = 0.002,
constant = 4.049, R2 = 0.354, p = 0.002) did not change as a function of target interval. G. Output of the time-delay neural network (TDNN, in blue) PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 8 / 32 Distributed nature of the trajectories’ timing information We determined whether we could extract information about the target interval from the neural
population dynamics, and how this information was modulated by the size of the neural popu-
lation used to compute the trajectories. To this end, we first segregated each segment of the
single-dimension trajectory according to the SCT target interval (450, 550, . . . 1,000 ms; see
insets in Fig 6A). Then, to capture the shape of the trajectory segments as a single three-dimen-
sional coordinate, we applied a second-layer PCA (PCA0) and kept the first three PCs. As a
result, we obtained a dot cloud in 3D, in which each point represents a particular produced
interval trajectory segment (Fig 6A). We trained support vector machines (SVMs) to classify
the cloud of points for the five target intervals of the SCT. We trained the SVM ten times and
used 5-fold cross-validation to evaluate the performance of the classifier. On the other hand,
each neuron was sorted according to the weight magnitude of the original PCAs. The neurons
with the largest PC participation were removed in steps of 10% from the original population
size, and the second-layer PCAs were computed on the new trajectories. Finally, the SVM was
carried out on the second-layer PCAs for different population sizes (see Fig 6). There was an
asymptotic decline in the classifier performance with the removal of a larger percentage of the
neural population (Fig 7A). However, even with very small populations (total cells: 15), the
classifier was able to extract all SCT target intervals above chance. These results are in line with
the idea that the temporal structure of rhythmic behavior depends on a neural population
code that is distributed within MPC. The population state dynamics are not related to the tapping kinematics The cyclic and smooth nature of the neural trajectories during ST and SCT sharply contrast
with the kinematics of movement (Fig 5A, 5C and 5D), which is characterized by stereotypic
tapping movements separated by a dwell period that increased as a function of the target inter-
val (Fig 5E; [16,37]). These observations suggest that during rhythmic tapping, an explicit tim-
ing mechanism in MPC keeps track of the dwell time by setting in motion a continuous and
periodic change in the neural population state. According to this scheme, the tapping com-
mand is triggered once the state trajectories get to a specific position in the phase-space that
corresponds to the intersection point between the tangent circular paths whose radii increase
with the tapping tempo. To test the hypothesis, we computed the distance between a point in
state space and the position of the taps in the neural trajectory and found a similar distance
across target intervals (Fig 5B, see inset). In addition, the distance between the same point and
half inter-tap position increased as a function of target interval (Fig 5B). Therefore, these
results support the idea that the neural trajectories behave as tangent circles and encode the
dwell time between taps in the PC amplitude and trigger the stereotypic tapping movements
once the neural dynamics reach a point in state space (S5 Fig). The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping a.u., arbitrary unit; dPCA, demixed PCA; PC,
principal component; PCA, principal component analysis; SCT, synchronization-continuation task. https://doi org/10 1371/journal pbio 3000054 g003 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 9 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Neural population trajectories and evolving activation patterns The results of the previous section revealed a distributed representation of tapping tempo
across MPC cell populations. However, a critical question is what aspects of the time-varying
activity defined the changes in amplitude in the neural trajectories as a function of the timed
duration [28]. Based on our previous observations [4,21], we hypothesized that the evolving
patterns of neural activity could be directly linked with the time-encoding features of the neu-
ral trajectories during the SCT. Consequently, to test this idea we first characterized the prop-
erties of neuronal moving bumps [21,23,36] during this task. With this information we carried
out simulations to determine whether the key features of the moving bumps were linked to the PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 10 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 5. Neural trajectories do not follow the tapping kinematics. A. Diagram of the rotational trajectory of the SCT neural activity during three
inter-tap intervals: one 450-ms interval (green) and two 1,000-ms intervals (red). Each tap is numbered and projected in the trajectory as a white
circle. A blue triangle marks the beginning, whereas a yellow triangle marks the end of the movement time. The monkeys produced phasic
stereotypic movements whilst timing the dwell between taps during SCT [37]. B. Euclidean distance (dt, see inset) between an anchor point (red)
and the position of each tap (green, mean ± SD, slope = 0.00007, R2 = 0.0633, p = 0.225), or half of the inter-tap interval position on the neural
trajectories (blue, mean ± SD, slope = −0.001, R2 = 0.801, p < 0.0001) across target intervals for SC. A two-way ANOVA detected significant main Fig 5. Neural trajectories do not follow the tapping kinematics. A. Diagram of the rotational trajectory of the SCT neural activity during three
inter-tap intervals: one 450-ms interval (green) and two 1,000-ms intervals (red). Each tap is numbered and projected in the trajectory as a white
circle. A blue triangle marks the beginning, whereas a yellow triangle marks the end of the movement time. The monkeys produced phasic
stereotypic movements whilst timing the dwell between taps during SCT [37]. B. A two-way ANOVA showed significant main effects on kinematic state (movement/dwell
duration, F(1, 228) = 1,850.61, p < 0.0001), target interval (F(5, 228) = 272.72, p < 0.0001), and their interaction (F(5, 228) = 236.18, p < 0.0001). Tukey HSD post hoc test showed that dwell durations across intervals were significantly different (p < 0.05). Therefore, the monkey modulated
the dwell duration to successfully temporalize her behavior, while the down-push-up sequence of the tapping movement was phasic and
stereotypic across target intervals. F. Mean ± SD of the peak speed during the tapping movement as a function of the target interval during ST
(ANOVA main effect interval, F(5, 114) = 5.13, p < 0.001). The Tukey HSD post hoc test showed that only the peak speed of the 450-ms target
interval trials were significantly different from the 650-, 750-, 850-, and 950-ms trials (p < 0.05). Underlying data are available in https://doid.gin. g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; dh, Euclidean distance of the anchor point to the half inter-tap position; dt,
Euclidean distance from the anchor point to the tap position; HSD, honestly significant difference; PC, principal component; SCT,
synchronization-continuation task; ST, synchronization task. https://doi.org/10.1371/journal.pbio.3000054.g005 https://doi.org/10.1371/journal.pbio.3000054.g005 observed changes in curvature radius and variability as a function of duration in the neural
state trajectories. As expected, a substantial proportion of MPC cells during the SCT showed a progressive
pattern of activation in the neuronal population, consisting of a gradual response onset of sin-
gle cells within a produced interval (Fig 8, see Materials and methods). This activation pattern
started before a tap, migrated during the timed interval, and finished after the next tap (Fig 8). In addition, a similar response profile was repeated in a cyclical manner for the three intervals
of SC and the three intervals of CC (Fig 8A and 8B) [4,21]. These findings suggest that rhyth-
mic timing can be encoded in the sequential activation of neural populations [23]. A central
question is what parameters of the neuronal response profiles are encoding the target interval
and the SCT condition. Remarkably, the number of neurons involved in these evolving activa-
tion patterns (Fig 8A and 8B, Fig 9C), as well as the duration of neural activation periods (Fig
9D), increased as a function of the target interval. SC showed a larger number of active cells,
whereas CC showed a longer activation period. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping effects on position (F(1, 40) = 1855.72, p < 0.0001), target interval (F(4, 40) = 77, p < 0.0001) and their interaction (F(4, 40) = 63.68, p < 0.0001). Tukey HSD post hoc test showed that the distances of the anchor point to tap and half inter-tap positions were significantly different (p < 0.05). In contrast, the anchor to tap distances across target intervals were not statistically different. Inset: scheme of the distance calculation; red sphere
marks the anchor point and two-sample inter-tap trajectories for 550 ms (dark gray) and 1,000 ms (light gray) are shown. The green sphere marks
the tap position and the blue sphere marks the half inter-tap position. Thus, the neural trajectories converge on an attractor around the tap time,
to later diverge at half the inter-tap interval. Note that these results suggest the existence of tangent circular trajectories that converge in an
intersection zone close to the tapping moment, although their amplitude changed as a function of interval. C. Speed of the tapping movement
(orange trace) from the second to the sixth tap of ST, and the PC1 projected neural information (cyan) for 26 simultaneously recorded neurons
during a trial with a target interval of 550 ms. Taps were represented as yellow squares and stimuli as red circles. Movement and dwell times are
depicted in green and magenta, respectively. D. Similar to (C) during an 850-ms target interval (PC1 projected neural information as a yellow
trace). E. Mean ± SD of the duration of the movement (green) and the dwell between movements (magenta) across target intervals, computed
from the speed profile of the tapping movements. A two-way ANOVA showed significant main effects on kinematic state (movement/dwell
duration, F(1, 228) = 1,850.61, p < 0.0001), target interval (F(5, 228) = 272.72, p < 0.0001), and their interaction (F(5, 228) = 236.18, p < 0.0001). Tukey HSD post hoc test showed that dwell durations across intervals were significantly different (p < 0.05). Therefore, the monkey modulated
the dwell duration to successfully temporalize her behavior, while the down-push-up sequence of the tapping movement was phasic and
stereotypic across target intervals. F. Neural population trajectories and evolving activation patterns Euclidean distance (dt, see inset) between an anchor point (red)
and the position of each tap (green, mean ± SD, slope = 0.00007, R2 = 0.0633, p = 0.225), or half of the inter-tap interval position on the neural
trajectories (blue, mean ± SD, slope = −0.001, R2 = 0.801, p < 0.0001) across target intervals for SC. A two-way ANOVA detected significant main PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 11 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Mean ± SD of the peak speed during the tapping movement as a function of the target interval during ST
(ANOVA main effect interval, F(5, 114) = 5.13, p < 0.001). The Tukey HSD post hoc test showed that only the peak speed of the 450-ms target
interval trials were significantly different from the 650-, 750-, 850-, and 950-ms trials (p < 0.05). Underlying data are available in https://doid.gin. g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; dh, Euclidean distance of the anchor point to the half inter-tap position; dt,
Euclidean distance from the anchor point to the tap position; HSD, honestly significant difference; PC, principal component; SCT,
synchronization-continuation task; ST, synchronization task. effects on position (F(1, 40) = 1855.72, p < 0.0001), target interval (F(4, 40) = 77, p < 0.0001) and their interaction (F(4, 40) = 63.68, p < 0.0001). Tukey HSD post hoc test showed that the distances of the anchor point to tap and half inter-tap positions were significantly different (p < 0.05). In contrast, the anchor to tap distances across target intervals were not statistically different. Inset: scheme of the distance calculation; red sphere
marks the anchor point and two-sample inter-tap trajectories for 550 ms (dark gray) and 1,000 ms (light gray) are shown. The green sphere marks
the tap position and the blue sphere marks the half inter-tap position. Thus, the neural trajectories converge on an attractor around the tap time,
to later diverge at half the inter-tap interval. Note that these results suggest the existence of tangent circular trajectories that converge in an
intersection zone close to the tapping moment, although their amplitude changed as a function of interval. C. Speed of the tapping movement
(orange trace) from the second to the sixth tap of ST, and the PC1 projected neural information (cyan) for 26 simultaneously recorded neurons
during a trial with a target interval of 550 ms. Taps were represented as yellow squares and stimuli as red circles. Movement and dwell times are
depicted in green and magenta, respectively. D. Similar to (C) during an 850-ms target interval (PC1 projected neural information as a yellow
trace). E. Mean ± SD of the duration of the movement (green) and the dwell between movements (magenta) across target intervals, computed
from the speed profile of the tapping movements. In contrast, the neural recruitment lapse,
namely the time between pairs of consecutively activated cells (Fig 9E), and the cells’ discharge
rate (Fig 9F) did not show statistically significant changes across target intervals and task
phases. These results suggest that both the size of the circuits involved in measuring the pas-
sage of time and the duration of their activation times are core time-encoding signals in MPC,
and suggest the existence of a delicate balance between these two measures to produce the pro-
gressive activation profiles of neurons when tapping to a metronome or an internally gener-
ated rhythmic signal (Fig 9C and 9D). Next, we simulated evolving patterns of population activity with different response profiles
and evaluated their translation onto PCA state space. First, we generated activity patterns on
individual units that were complex, heterogenous, and that scaled in time, producing activa-
tion periods with the same time-varying activity but different durations (Fig 10A, see Materials
and methods) [24]. Then, we simulated population cascade patterns for three consecutive
intervals, emulating two key features on the MPC population responses: a gradual response
onset of single cells that started before, migrated within, and finished after the end of an inter-
val, with a constant overall recruitment of cells over time; and the cyclical repetition of this
response profile for the three intervals (Fig 10C and 10D). In addition, Fig 11A shows that neu-
rons were added randomly in the intermediate portion of the simulated moving bumps when PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 12 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 6. Robustness in the classifier for SCT target interval using segments of the PCA neural trajectory between taps with different neural
population sizes. A-C. Three principal components projection of the second-layer PCA0 applied to each of the six inter-tap neural trajectory segments
and the five trial repetitions (see inset) for (A) 100%, (B) 50%, and (C) 1% of the neural population. Each dot in the second-layer PCA0 corresponds to
ogy | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019
13 / 32 Fig 6. Robustness in the classifier for SCT target interval using segments of the PCA neural trajectory between taps with different neural
population sizes. A-C. Simulations with constant values in both parameters
produced PCA trajectories with similar radii or variability across interval durations, and a
decrease in speed with target interval consistent with the notion of temporal scaling (Fig 10E–
10G, Fig 11B–11E). Furthermore, the scaling of the response duration alone did not reproduce
the observed changes in radii and variability across durations in the state trajectories (Fig
11D–11E). These findings indicate not only a close relation between the properties of the
sequential neural patterns of activation and the neural state trajectories during rhythmic tap-
ping, but also suggest that an increment in the number of neurons engaged in the evolving pat-
terns of population activity is fundamental to reproducing the two critical duration-dependent
features of the PCA neural population trajectories: the increase in the magnitude and variabil-
ity of the radii as a function of target interval. Fig 7. Trajectory classifier robustness across neural population sizes during SCT. A. SVM classifier performance (mean ± SD of percent of correct classifications)
for target interval (five instructed intervals) during the SCT task based on the neural trajectory computed from different population sizes. The total initial population
size was of 1,477 neurons. Dotted lines correspond to random level. The neurons with the largest PC participation were removed in steps of 10% of the original
population size, until reaching 1% of the original population. Inset shows the original time-normalized neural trajectory PC used to generate the second-layer PCA0. B. Point cloud in 3D for the second-layer PCAs’ for target interval. See color code in the inset. Note that the percentage of correct classification decreased as a
function of the population size; however, the classification was above chance even for the trajectories based on small cell ensembles. Underlying data are available in
https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; PC, principal components; PCA, principal component analysis; SCT,
synchronization-continuation task; SVM, support vector machine. https://doi.org/10.1371/journal.pbio.3000054.g007 Fig 7. Trajectory classifier robustness across neural population sizes during SCT. A. SVM classifier performance (mean ± SD of percent of correct classifications)
for target interval (five instructed intervals) during the SCT task based on the neural trajectory computed from different population sizes. The total initial population
size was of 1,477 neurons. Dotted lines correspond to random level. The neurons with the largest PC participation were removed in steps of 10% of the original
population size, until reaching 1% of the original population. Three principal components projection of the second-layer PCA0 applied to each of the six inter-tap neural trajectory segments
and the five trial repetitions (see inset) for (A) 100%, (B) 50%, and (C) 1% of the neural population. Each dot in the second-layer PCA0 corresponds to PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 13 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping an inter-tap trajectory segment. Target interval color in the inset in (A). D-F. Distances between cluster centroids of data projection across target
intervals for (D) 100%, (E) 50%, and (F) 1% of the neural population. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; PC, principal component; PCA, principal component analysis; SCT, synchronization-
continuation task. https://doi.org/10.1371/journal.pbio.3000054.g006 https://doi.org/10.1371/journal.pbio.3000054.g006 increasing the total number of neurons. The projection of the simulated cascades onto PCA
space produced oscillatory trajectories (Fig 10B), whose radii and variability increased but the
linear speed was similar with the target interval, as seen in the actual population responses. Importantly, these properties were only followed when the simulated neural cascades included
an increase in both the number of neurons and the duration of the activation periods as a func-
tion of target interval (Fig 10E and 10F). Simulations with constant values in both parameters
produced PCA trajectories with similar radii or variability across interval durations, and a
decrease in speed with target interval consistent with the notion of temporal scaling (Fig 10E–
10G, Fig 11B–11E). Furthermore, the scaling of the response duration alone did not reproduce
the observed changes in radii and variability across durations in the state trajectories (Fig
11D–11E). These findings indicate not only a close relation between the properties of the
sequential neural patterns of activation and the neural state trajectories during rhythmic tap-
ping, but also suggest that an increment in the number of neurons engaged in the evolving pat-
terns of population activity is fundamental to reproducing the two critical duration-dependent
features of the PCA neural population trajectories: the increase in the magnitude and variabil-
ity of the radii as a function of target interval. increasing the total number of neurons. The projection of the simulated cascades onto PCA
space produced oscillatory trajectories (Fig 10B), whose radii and variability increased but the
linear speed was similar with the target interval, as seen in the actual population responses. Importantly, these properties were only followed when the simulated neural cascades included
an increase in both the number of neurons and the duration of the activation periods as a func-
tion of target interval (Fig 10E and 10F). Inset shows the original time-normalized neural trajectory PC used to generate the second-layer PCA0. B. Point cloud in 3D for the second-layer PCAs’ for target interval. See color code in the inset. Note that the percentage of correct classification decreased as a
function of the population size; however, the classification was above chance even for the trajectories based on small cell ensembles. Underlying data are available in
https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u., arbitrary unit; PC, principal components; PCA, principal component analysis; SCT,
synchronization-continuation task; SVM, support vector machine. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 14 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 8. Overall patterns of activity in cell populations. A,B. Neural activation periods, sorted by their mean peak activation time, during the
SCT task for the target intervals of 450 (A) and 850 (B) ms. Each horizontal line corresponds to the onset and duration of the significant
activation period of a cell according to the Poisson-train analysis (see Materials and methods). The Poisson-train analysis was carried out on
the discharge rate of cells that was warped in relation to the tapping times (seven white vertical lines [4,73]). Note that the number of cells with
significant activation periods is larger for the longer target interval. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. SCT, synchronization-continuation task. Fig 8. Overall patterns of activity in cell populations. A,B. Neural activation periods, sorted by their mean peak activation time, during the
SCT task for the target intervals of 450 (A) and 850 (B) ms. Each horizontal line corresponds to the onset and duration of the significant
activation period of a cell according to the Poisson-train analysis (see Materials and methods). The Poisson-train analysis was carried out on
the discharge rate of cells that was warped in relation to the tapping times (seven white vertical lines [4,73]). Note that the number of cells with
significant activation periods is larger for the longer target interval. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. SCT, synchronization-continuation task. https://doi org/10 1371/journal pbio 3000054 g008 Fig 8. Overall patterns of activity in cell populations. A,B. Neural activation periods, sorted by their mean peak activation time, during the
SCT task for the target intervals of 450 (A) and 850 (B) ms. Discussion The present study supports four conclusions. First, the time-varying discharge rate of MPC
cells shows a strong periodic organization when projected onto a two-dimensional state space,
generating a circular neural trajectory during each produced interval. The amplitude of this
trajectory increases with target duration and is closely related to the rhythmic tapping during
the SCT and ST, but not during the reactive tapping of SRTT. Second, the scalar property, a
hallmark of timing behavior, was accounted for by the variability of the curvilinear radii in the
PCA neural trajectories. Third, the population dynamics for simultaneously recorded MPC
cell populations during ST contained information to accurately decode the tapping times on a
trial-by-trial basis. Last, there is a strong correlation between the interval-associated changes in
radial magnitude and variability of the periodic neural trajectories during SCT and the number
of neurons involved in the sequential activation patterns, as well as the duration of their tran-
sient periods of activation within these moving bumps. Each horizontal line corresponds to the onset and duration of the significant
activation period of a cell according to the Poisson-train analysis (see Materials and methods). The Poisson-train analysis was carried out on
the discharge rate of cells that was warped in relation to the tapping times (seven white vertical lines [4,73]). Note that the number of cells with
significant activation periods is larger for the longer target interval. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. SCT, synchronization-continuation task. In contrast with the temporal scaling model [24], we found
that the neural trajectories do not scale in time, because they present a time-related amplitude
modulation with similar linear speed profiles across durations. In line with our observations,
neural-network simulations of complex sensorimotor patterns showed that temporal scaling
of input stimuli produced curvilinear trajectories that increased in radii for longer intervals
[38]. Hence, amplitude modulations in neural population trajectories can be associated with
rhythmic timing [39] or complex temporal processing [38]. y
g
p
p
p
g
We found a strong correlation between the duration of the produced intervals and the cur-
vilinear amplitude of the MPC neural trajectories during the SCT and ST, and, due to the
simultaneity of the recordings in the latter task, we decoded accurately the produced durations
on a trial-by-trial basis. In addition, the cyclic and smooth nature of the neural trajectories
during ST and SCT sharply contrasts with the tapping kinematics, which are characterized by
stereotypic tapping movements separated by a dwell period that increases with the timed inter-
val [16,37]. Previous studies have demonstrated that cell populations in premotor and motor
cortical areas show rotatory non-muscle-like trajectories that reflect the internal dynamics
needed for controlling reaching and cycling [40,41]. Under this scenario, we found evidence
supporting the notion that the periodic MPC trajectories during rhythmic tapping encode the
dwell between taps in their curvilinear radii and that the tapping command is triggered when-
ever the trajectory reaches a specific phase-space, which corresponds to the intersection point
between the tangent circular paths. This dynamical geometry contrasts with the neural trajec-
tories of medial frontal areas during a single interval reproduction task [34]. In this interval-
based paradigm, the state trajectories not only evolve at different speeds but also generate par-
allel paths for different timed intervals, depending on the initial conditions of the neural popu-
lation dynamics [34]. Thus, the present data are consistent with the notion that timing is
encoded in a neural population clock [28,42–45] and puts forward the hypothesis that tempo-
ral processing during the entrainment to an isochronous metronome depends on the ampli-
tude of tangent circular trajectories in MPC populations. Under this scenario, temporal
processing is governed by MPC neural population clocks that switch from temporal scaling of
their state dynamics during interval timing to amplitude modulation in their tangent circular
trajectories during rhythmic timing. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 9. Evolving patterns of activation. A. Neural activation periods for the second produced interval (second and third taps as white vertical
lines) during SC for the target interval of 850 ms. The horizontal lines of each row correspond to the onset and extent of the activation
periods detected by the Poisson-train analysis. Cells were sorted by their time of peak activity. B. Recruitment lapse as a function of cell
number. The activation lapse was the difference in the time of peak activity between contiguous cells in the neural avalanche. The mean
activation lapse (±SEM) was 2.98 ± 0.08 ms. C. Number of cells with significant activation periods across target intervals for SC (blue) and CC
(red). Avalanches for longer intervals recruited more cells (ANOVA main effect target interval, F(4, 20) = 21.1, p < 0.0001; main effect task
condition, F(1, 20) = 6.2, p < 0.02; interval × condition interaction, F(4, 20) = 0.71, p = 0.594). D. Duration of the activation periods during
the SC (blue) and CC (red) increased as a function of target intervals. (ANOVA main effect target interval, F(4, 20) = 18.9, p < 0.0001; main
effect task condition, F(1, 20) = 26.7, p < 0.0001; interval × condition interaction, F(4, 20) = 1.3, p = 0.268). E. Mean neural recruitment lapse
during SC (blue) and CC (red) did not change as a function of target interval (ANOVA main effect target interval, F(4, 20) = 2.7, p = 0.06;
main effect task condition, F(1, 20) = 3.4, p = 0.08; interval × condition interaction, F(4, 20) = 0.79, p = 0.55). F. The discharge rate during
activation periods in SC (blue) and CC (red) did not vary across target intervals (ANOVA main effect target interval, F(4, 20) = 2.2, p = 0.06;
main effect task condition, F(1, 20) = 0.86, p = 0.35; interval × condition interaction, F(4, 20) = 0.92, p = 0.45). Underlying data are available
in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; SC, synchronization condition. https://doi.org/10.1371/journal.pbio.3000054.g009 https://doi.org/10.1371/journal.pbio.3000054.g009 https://doi.org/10.1371/journal.pbio.3000054.g009 ST. Furthermore, the switch from predictive rhythmic tapping to a reaction time task (SRTT)
produced a profound disorganization in the periodicity of neural trajectories, accompanied by
no changes in radial amplitude. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Rhythmic timing and the amplitude of neural state trajectories The network state trajectories showed the following properties: they were simple, periodic,
exhibited an amplitude modulation according to the timed duration, and were different from
the stereotypic kinematics of the phasic tapping movements and the timing control of the
dwell between movements in this task [16,37]. Notably, the increases in trajectory amplitude
as a function of target interval were observed during the two rhythmic tapping tasks, repro-
duced with dPCA, and closely related with the monkeys’ produced intervals during SCT and PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 15 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping 16 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 10. Simulations of moving bumps and neural trajectories. A. Activity profile of one simulated neuron during its activation period is scaled for
the five simulated durations. B. Neural trajectories generated from the population activity of moving bumps simulations. The number of neurons and
activation periods varied across intervals (see Materials and methods). The simulated interval is color coded. Second and third simulated taps are
marked as white spheres on each trajectory. C,D. Activation profiles of neurons for three consecutive simulated intervals with durations of 450 ms (C)
and 1,000 ms (D). The white vertical lines correspond to the tap events defining the intervals. The activation profiles follow a Gaussian shape of cell
recruitment, with slow activation rates at the tails (close to each tap). The number of neurons and the duration of the activation periods increased as a
function of simulated interval. E,F,G. Radii (E), variability (F), and linear speed (G) of the neural trajectories generated from simulations. Data from
the simulated neural activity with growing numbers of neurons and activation periods (expanding simulation: red), constant duration of activation
periods and constant number of neurons (static simulation: orange), and from the actual recorded population during SCT (blue) across target intervals. Note that a constant was added to both simulation data in graphs. (E) Radii for simulation with expanding parameters (red, mean ± SD, slope = 0.0009,
R2 = 0.811, p < 0.0001), simulation with static parameters (orange, mean ± SD, nonsignificant linear regression, slope = −0.0001, R2 = 0.811, p = 0.214),
and actual neural activity (blue, mean ± SD, slope = 0.0009, R2 = 0.897, p < 0.0001). The slopes of the radius, variability, and linear speed were not
statistically different between the simulations with expanding parameters and the actual neuronal trajectories (radius slope t test = 0.15, p = 0.878;
variability slope t test = 0.25, p = 0.803; linear speed slope t test = 1.8, p = 0.077). However, the slopes between the simulations with constant parameters
and neuronal trajectories showed statistically significant differences (radius slope t test = 9.13, p < 0.0001; variability slope t test = 3.73, p < 0.001;
linear speed slope t test = 17.71, p < 0.0001). Underlying data are available in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. a.u.,
arbitrary unit; PC, principal component; SCT, synchronization-continuation task. htt
//d i
/10 1371/j
l bi 3000054 010 Beat perception in humans is shaped by the temporal structure of extrinsic musical sound
and by the metrical interpretation that defines where a subject hears the beat. Thus, the percep-
tion of a beat and the corresponding movement entrainment depend on a mental interpreta-
tion of the metrics of music. The Dynamic Attending Theory (DAT) is one of the most
successful hypotheses to explain these phenomena. According to DAT, it is possible to match
the tapping movements to a beat during rhythmic entrainment because the periodic dynamics
of music drive our attention [50,51], allowing the prediction of the next pulse in the rhythmic
auditory sequence. The DAT suggests that attention is a dynamic process that can be success-
fully modeled by internal self-sustained oscillations in the auditory system [52,53]. These inter-
nal oscillations generate periodic shifts in attention to the most salient events in the sound
signal (the pulse that constructs an isochronous sequence in the musical stream), so that the
brain generates rhythmic expectations that correspond to the subjective interpretation of the
beat. Indeed, electroencephalogram recordings in auditory areas of humans have shown that
the brain oscillates at both the exogenous frequency of stimuli and at the metric interpretation
of the beat, providing strong support for DAT [54]. In addition, the perception of an inferred
musical beat in humans strongly engages the motor system, including the basal ganglia and
the MPC [55,56], supporting the notion that rhythmic perception and entrainment depend on
a dynamic interaction between the auditory and motor systems in the brain [15,43,57]. Conse-
quently, the present findings add important elements to these ideas, namely, neural popula-
tions in the motor system show cyclic dynamics whose period is tightly associated with the
tempo of the isochronous metronome, even when the metronome is turned off and the mon-
keys continue tapping with the same tempo. Hence, in accordance with DAT, the MPC neural
trajectories act as a neural oscillator, with a period similar to the tapping tempo during both
the sensory cued and the internally driven rhythmic tapping. Importantly, because MPC is part of both the cortico-
basal ganglia and the cortico-cerebellar circuits, it can play an important role in both interval
and rhythmic timing and can act as a synergistic context-dependent element within the two
core timing systems, as suggested previously [46–49]. 17 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 18 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Furthermore, in agreement with
the audiomotor hypothesis for beat perception and entrainment, our data suggest that preSMA
and SMA generate a periodic and predictive neural population signal that not only times the
inter-tap dwell and triggers the rhythmic tapping movement, but also may help the sensory
system to expect a specific temporal structure on the metronome [57,58]. However, a couple of
cautionary notes are in place here. First, monkeys can perceive and predictively synchronize to
isochronous metronomes [11,16,59]. We still do not know what the metrical hierarchy is that
monkeys can perceive and entrain to [11], but, definitively, nonhuman primates do not have
the flexibility to predictively perceive and entrain to a pulse across the range of tempi and
meters observed in humans [6]. Hence, our present data may generalize only to isochronous
rhythmic timing in humans. Second, monkeys show a bias to synchronize to visual rather than PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 19 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Fig 11. Moving bump simulation parameters. A. Temporal positions of the activation periods of the neurons that were included to the
simulation of the 1,000-ms target interval trial (red), in addition to the position of the activation periods of neurons that also participated in the
450-ms simulation (shaded). B,C. Radius (B) and variability (C) of PCA trajectories generated from moving bump simulations when the
number of neurons was modified by a constant number (−100, green; −50, cyan; +50, yellow; and +100, red) from the original number of
(
f
l
f
l
f
l Fig 11. Moving bump simulation parameters. A. Temporal positions of the activation periods of the neurons that were included to the Fig 11. Moving bump simulation parameters. A. Temporal positions of the activation periods of the neurons that were included to the
simulation of the 1,000-ms target interval trial (red), in addition to the position of the activation periods of neurons that also participated in the
450-ms simulation (shaded). B,C. A two-way ANOVA on the radius showed significant main effects for number of neurons (F(4, 100) = 10,544.2, p < 0.0001),
target interval (F(4, 100) = 4,013.12, p < 0.0001), and their interaction (F(16, 100) = 25.8, p < 0.0001). Tukey HSD post hoc test showed
significant differences for the radii of all simulations with different numbers of neurons and for all target intervals (p < 0.05). Additionally, A
two-way ANOVA on the variability showed significant main effects for number of neurons (F(4, 100) = 2,421.8, p < 0.0001), target interval (F
(4, 100) = 3,476.91, p < 0.0001), and their interaction (F(16, 100) = 22.53, p < 0.0001). Tukey HSD post hoc test showed significant differences
for the variability of all simulations with different numbers of neurons (p < 0.05). D,E. Radius (D) and variability (E) of the trajectories
generated from neural moving bumps in which the duration of the activation periods was reduced by 50% (short, green) or increased by 50%
(long, red) of the original scaled duration (197 ms for 450-ms target interval, 205 ms for 550-ms target interval, 213 ms for 650-ms target
interval, 233 ms for 850-ms target interval, and 257 ms for 1,000-ms target interval; blue) while the number of neurons was kept constant at
130 across target intervals. A two-way ANOVA on the variability showed significant main effects for activation duration (F(2, 60) = 3,081.54,
p < 0.0001), target interval (F(4, 60) = 2,801.16, p < 0.0001), and their interaction (F(8, 60) = 211.34, p < 0.0001). Tukey HSD post hoc test
showed significant differences for all simulations with different activation durations (p < 0.05). In addition, a two-way ANOVA on the
variability showed significant main effects for activation duration (F(2, 60) = 1,227.53, p < 0.0001), target interval (F(4, 60) = 257.49,
p < 0.0001), and their interaction (F(8, 60) = 24.87, p < 0.0001). Tukey HSD post hoc test showed significant differences for all simulations
with different activation durations (p < 0.05). Thus, the number of neurons and the activation duration within moving bumps produce large
changes in the radius and variability of the simulated neural trajectories. a.u., arbitrary unit; HSD, honestly significant difference; PCA,
principal component analysis. https://doi.org/10.1371/journal.pbio.3000054.g011 https://doi.org/10.1371/journal.pbio.3000054.g011 auditory metronomes [16], whereas humans have a strong entrainment bias towards auditory
sequences, including music [1,14]. The scalar property of timing and the state dynamics variability The scalar property states that temporal variability increases linearly as a function of timed
duration [60]. This hallmark feature of temporal processing has been documented across
many timing tasks and species [20,60–63]. Several computational models based on neural pop-
ulation time representations have been implemented to describe this property, including drift
diffusion [64,65] and recurrent networks [36,66]. Here, we found that the variability in the
radii of neural trajectories increased as a function of target interval during SCT and ST, but
remained similar during the SRTT, a task that precludes time prediction while preserving the
sensory and tapping components. Therefore, these results suggest that the amplitude of the
MPC state-network trajectories is a feasible neural correlate of the scalar property during
rhythmic tapping. It has been suggested that the connections between the dor-
sal auditory regions and the motor planning areas via parietal cortex are stronger in humans
than in nonhuman primates, conferring the latter their larger ability for beat perception and
entrainment [15,57]. Therefore, it is quite possible that the neural state dynamics in the audio-
motor system of the Homo sapiens are more flexible and complex than what we report here. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping target intervals. A two-way ANOVA on the radius showed significant main effects for number of neurons (F(4, 100) = 10,544.2, p < 0.0001),
target interval (F(4, 100) = 4,013.12, p < 0.0001), and their interaction (F(16, 100) = 25.8, p < 0.0001). Tukey HSD post hoc test showed
significant differences for the radii of all simulations with different numbers of neurons and for all target intervals (p < 0.05). Additionally, A
two-way ANOVA on the variability showed significant main effects for number of neurons (F(4, 100) = 2,421.8, p < 0.0001), target interval (F
(4, 100) = 3,476.91, p < 0.0001), and their interaction (F(16, 100) = 22.53, p < 0.0001). Tukey HSD post hoc test showed significant differences
for the variability of all simulations with different numbers of neurons (p < 0.05). D,E. Radius (D) and variability (E) of the trajectories
generated from neural moving bumps in which the duration of the activation periods was reduced by 50% (short, green) or increased by 50%
(long, red) of the original scaled duration (197 ms for 450-ms target interval, 205 ms for 550-ms target interval, 213 ms for 650-ms target
interval, 233 ms for 850-ms target interval, and 257 ms for 1,000-ms target interval; blue) while the number of neurons was kept constant at
130 across target intervals. A two-way ANOVA on the variability showed significant main effects for activation duration (F(2, 60) = 3,081.54,
p < 0.0001), target interval (F(4, 60) = 2,801.16, p < 0.0001), and their interaction (F(8, 60) = 211.34, p < 0.0001). Tukey HSD post hoc test
showed significant differences for all simulations with different activation durations (p < 0.05). In addition, a two-way ANOVA on the
variability showed significant main effects for activation duration (F(2, 60) = 1,227.53, p < 0.0001), target interval (F(4, 60) = 257.49,
p < 0.0001), and their interaction (F(8, 60) = 24.87, p < 0.0001). Tukey HSD post hoc test showed significant differences for all simulations
with different activation durations (p < 0.05). Thus, the number of neurons and the activation duration within moving bumps produce large
changes in the radius and variability of the simulated neural trajectories. a.u., arbitrary unit; HSD, honestly significant difference; PCA,
principal component analysis. target intervals. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Radius (B) and variability (C) of PCA trajectories generated from moving bump simulations when the
number of neurons was modified by a constant number (−100, green; −50, cyan; +50, yellow; and +100, red) from the original number of
neurons (208 neurons for 450-ms target interval, 220 neurons for 550-ms target interval, 230 neurons for 650-ms target interval, 270 neurons
for 850-ms target interval, and 282 neurons for 1,000-ms target interval; blue) while the activation period was kept constant at 257 ms across PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 20 / 32 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping moving bumps was constant and was accompanied by an increase in the number of neurons
participating in the evolving patterns of population activity. Thus, an optimal reader could
estimate the tempo of rhythmic tapping based on two signals: the location of the activity within
a bump, in which longer intervals engaged moving bumps composed of a larger number of
neurons, and the resetting between consecutive evolving activation patterns [65]. Strikingly,
our simulations revealed a tight relation between the scaling of the duration of the transient
period of activity, the increase in the number of neurons within moving bumps, and the
increase in radius and variability of the corresponding neural trajectories. The simulations also
suggest that neurons have the same relative position within a moving bump independently of
the timed interval, as seen previously in the rat striatum [23]. Consequently, the increase in
neural population size for longer intervals implies incorporation of new cells at intermediate
locations within the moving bump [21]. These results not only replicate our empirical observa-
tions but also support the notion that the properties of moving bumps, especially the number
of participating neurons, can shape the curvilinear amplitude and the corresponding variabil-
ity in neural state trajectories during SCT. Subjects Two monkeys (M01 and M02, Macaca mulatta, both males, 5–7 kg BW) were trained to tap
on a push button in SCT, ST, and SRTT. The monkeys were monitored daily by the research-
ers and the animal care staff to check their conditions of health and welfare. Ethics statement All the animal care, housing, and experimental procedures (protocol 090.A INB) were
approved by the Ethics in Research Committee of the Universidad Nacional Auto´noma de
Me´xico and conformed to the principles outlined in the Guide for Care and Use of Laboratory
Animals (NIH, publication number 85–23, revised 1985). Conclusions Overall, these findings support the notion that the rhythmic timing mechanism is based on the
changes in curvature radii of the neural population state dynamics in MPC, with slower tem-
pos encoded in larger traversed distances in the tangent periodic neural trajectories, and sug-
gest that the variability in these neural trajectories is a feasible neural substrate of the scalar
property during rhythmic tapping. The relation between neural trajectories and moving bumps during
rhythmic tapping The dynamics of coordinated neural population activity define the evolution of the network
state trajectories, which in turn have revealed functional principles in a variety of behaviors
that are not evident at the single cell level [24,30,32,67]. Notably, the tapping tempo is strongly
mapped in the neural trajectories and is encoded in a distributed fashion, not dependent on a
particular response profile of individual neurons. Within this neural population framework,
we found large groups of neurons that showed sequential transient activation patterns that tra-
versed each produced interval during the SCT. Previous studies have reported moving bumps
as a timing mechanism in parietal cortex [68], MPC [4,21], the basal ganglia [23,69,70], and
hippocampus [71,72]. For example, the bump activity in the rat striatum during a peak interval
task moved progressively slower as the timed interval progressed, providing a functional basis
for the decrease in the animals’ timing accuracy as the length of the timed interval increased
[23]. In contrast, during the SCT we found that the rate of engagement of the neurons within PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 21 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Neural recordings For the SCT, the extracellular recordings were obtained from the MPC of the monkeys using a
system with 7 or 16 independently movable microelectrodes (1–3 MO, Uwe Thomas Record-
ing, Germany, S3). Only correct trials were analyzed. All isolated neurons were recorded
regardless of their activity during the task, and the recording sites changed from session to ses-
sion. At each site, raw extracellular membrane potentials were sampled at 40 kHz. Single-unit
activity was extracted from these records using the Plexon offline sorter (Plexon, Dallas, TX). Using the seven-electrode system, the number of simultaneously recorded cells ranged from 5
to 14 cells, whereas with the 16-electrode system the number ranged from 10 to 35 cells during
a recording session. In the present paper we analyzed the activity of 1,477 (1,074 of Monkey 1
and 403 of Monkey 2) MPC neurons in both monkeys. The functional properties of some of
these cells (1,083 neurons) have been reported previously [20,21,25]. In addition, using a semi-
chronic, high-density electrode system [35], 26 and 41 MPC cells were recorded simulta-
neously while Monkey 1 was performing the ST and SRTT tasks. All the isolated neurons were
recorded regardless of their activity during the SCT, ST, and SRTT, and the recording sites
changed from session to session. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping ST. This task was similar to the synchronization phase of the SCT [16]. The subject had to
push a button with a stimulus. Six stimuli with a constant interstimulus were presented (red
square with a side length of 5 cm, shown for 33 ms). Thus, the metronome was always present
during the task. The target intervals were 450, 550, 650, 750, 850, and 950 ms. Five repetitions
were collected for each target interval. SRTT. This task is also described elsewhere [14]. Monkeys were required to push a button
each time a stimulus was presented, but in this case the interstimulus interval within a trial was
random (picking randomly from the same 450, 550, 650, 750, 850, or 950 ms), precluding the
explicit temporalization of tapping (Fig 1B). Monkeys received a reward if the response time to
each of the five stimuli was within a window of 200 to 500 ms. The intertrial interval was as ST. Visual (white square with a side length of 5 cm, presented for 33 ms) stimuli were used, and
five repetitions were collected. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Tasks SCT. The SCT has been described before [14]. Briefly, the monkeys were trained to push a
button each time stimuli with a constant interstimulus interval were presented. This resulted
in a stimulus-movement cycle (Fig 1A). After four consecutive synchronized movements, the
stimuli were eliminated, and the monkeys had to continue tapping with the same interval for
three additional intervals. Monkeys received a reward (drops of juice) if each of the intervals
produced had an error <30% of the target interval. The daily performance of the monkeys was
>70% of correct trials. The amount of juice was proportional to the trial length. Trials were
separated by a variable intertrial interval (1.2–4 s). The target intervals, defined by visual sti-
muli (red square with a side length of 5 cm, presented for 33 ms), were 450, 550, 650, 850, and
1,000 ms. The target intervals were chosen pseudorandomly within a repetition. Five repeti-
tions were collected for each target interval. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 22 / 32 Neural trajectories Event time normalization and binarization. We developed a time-normalization algo-
rithm to align the neural data from different tapping times of different recording sessions in
the same relative time framework. For each neuron, we calculated the produced interval (time
between two taps). Then, we subtracted the time of the second tap of a produced interval in
the task sequence from all spike and stimulus times (eventtimes) and divided them by the pro-
duced interval. The tapping times acquired values of minus one and zero, and all the other
eventtimes were normalized between these two values. Finally, we added the tap sequence num-
ber. Thus, all the normalized values for movement, sensory, and spike events acquired values
between zero and seven in an SCT trial, as follows: time normalized event ¼ ðevent time tap timeÞ
produced interval
þ tap sequence time normalized event ¼ ðevent time tap timeÞ
produced interval
þ tap sequence time normalized event ¼ ðevent time tap timeÞ
produced interval
þ tap sequence Therefore, the time range of events between the first and the last tap of the normalized data
of a trial (unit time normalized data [UTND]) was the same regardless of the target interval. In
addition to the trial relative time framework, we also used the target interval normalized data
(TIND), which corresponds to the UTND multiplied by the target interval. This time-normali-
zation procedure was not necessary for simultaneously recorded data. Trial binarization. For UTND, TIND, and simultaneously recorded data, we divided the
neural data in bins by calculating the discharge rate on consecutive windows of 0.02 units. For
UTND, we always got 50 bins between each pair of taps across target intervals, whereas for
TIND and the simultaneously recorded data, this number depended on the target interval of
the trial. For example, the total number of bins was 23 and 50 for trials with the 450- and
1,000-ms intervals, respectively. The binned data of each neuron were divided by the maxi-
mum discharge rate of that particular neuron across all repetitions and target intervals of the
SCT. We did not use this time-normalization algorithm on the ST and SRTT data. Principal component coefficients matrix. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping period is statistically different from the average discharge rate r, considering that the firing of
the cell is following a nonhomogenous Poisson process (see also [73]). The detection of activa-
tion periods above randomness has been described previously [4,74]. Importantly, the Pois-
son-train analysis provided the response-onset latency and the activation period for each cell
and for each combination of target interval/serial order. Y ¼ PX Y ¼ PX Hence, we first calculated the matrix P using a matrix X that includes all trials and target
interval combinations for the visual SCT of our UTND cell population. Using this P on other
data guarantees that the same transformation is applied to different neural activity sets. There-
fore, using the UTND framework we avoided over- or underrepresentation of the information
for different target intervals, due to the constant total number of bins across conditions. Neural activation periods We used the Poisson-train analysis to identify the cell activation periods within each interval
defined by two subsequent taps. This analysis determines how improbable it is that the number
of action potentials within a specific condition (i.e., target interval and ordinal sequence) was a
chance occurrence. For this purpose, the actual number of spikes within a time window was
compared with the number of spikes predicted by the Poisson distribution derived from the
mean discharge rate during the entire recording of the cell. The measure of improbability was
the surprise index (SI), defined as follows: SI ¼ logP where P was defined by the Poisson equation: P ¼ e rT X
1
i¼n
ðrTÞ
i
i! where P is the probability that, given the average discharge rate r, the spike train for a produced
interval T contains n or more spikes in a trial. Thus, a large SI indicates a low probability that a
specific elevation in activity was a chance occurrence. This analysis assumes that an activation PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 23 / 32 Neural trajectories Given a linear transformation of a matrix X
into a matrix Y, such that each dimension of Y explains variance of the original data X in
descending order, PCA can be described as the search for matrix P that transforms X into Y,
as follows: PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping trial allowed the comparison of trajectories for different trials and tasks. A locally weighted
scatterplot smoothing function was applied to the columns of the Y matrix. The first three
dimensions of Y were used to generate graphical three-dimensional trajectories, while the first
eight dimensions, which explained at least 1% of the variance, were used for the other analysis. Trajectory radius and variability The first three PCs explained 10.7%, 3.8%, and 2.3% of the total variance. These three first PCs
produced highly stereotyped trajectories with a strong periodicity. In addition, the PC2 and
PC3 showed a strong oscillatory structure with a phase difference of π/2 radians during SCT. For these two PCs, we calculated the centroids of the segments of trajectories between adjacent
taps. We measured the radius of the 2D trajectory segment as the mean of the Euclidean dis-
tances between the centroid and each point in the trajectory segment. The variability of the tra-
jectory was calculated as the standard deviation of the Euclidean distances between the
centroid and each point in the trajectory segment across the six serial order elements (three of
the SC and three of the CC) for each target interval. Accordingly, the temporal variability of
the behavior for each target interval was computed as the standard deviation of the produced
intervals within a trial, namely the across-six-serial-order elements of the SCT. Neural trajectory decoder We trained a TDNN [75] to decode the produced intervals from the first PC of the simulta-
neously recorded neural activity during ST. The TDNN architecture had an input layer with
20 time delays and one hidden 10-unit layer. The output layer consisted of a single unit that
was trained to generate a value of 1 when a tap occurred, or 0 otherwise. We trained the net-
work using a Bayesian regularization backpropagation algorithm that minimized the mean
squared error of the output. The tap time was defined as the time of the peak of the neural net-
work output higher than a threshold of 0.12. We considered a correctly decoded interval when
the decoded and the produced taps times’ difference was less than 60 ms. We used 5-fold
cross-validation to evaluate the performance of the neural network. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Generating neural trajectories The TIND information for every trial of all neurons constituted the columns of the X’ matrix. The principal component coefficients matrix P were multiplied by the X’ matrix to transform
the neural data into the space of the original Y. Using the same transformation matrix for each PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 24 / 32 SVM classifier We were interested in studying the relation between the neural trajectory dynamics and the
instructed interval of the SCT (450 ms, 550 ms, . . . 1,000 ms). Therefore, we first normalized
the length of each segment of the first eight PCs of the neural trajectory associated with a pro-
duced interval (the time between two taps) to 30 bins (see inset, Fig 7A). This step was neces-
sary to avoid a bias associated with the length of the segment. Then, we applied a second-layer
PCA0 to each of the original neural trajectory segments for each PC independently. We kept
the first three PCs, as they explained 96% of the variance. As a result, a point in a new three-
dimensional coordinate for each 30-bin trajectory segment was obtained (see Fig 7B). In order
to assess which PC had more information about each of the SCT parameters, we carried out a
classification procedure for each PC using an SVM algorithm [76]. Each classifier was
retrained 10 times, and we used 5-fold cross-validation to evaluate the performance of the clas-
sifier. Thus, we identified the PC with more information for each SCT parameter and called it
best-PC. Additionally, we were interested in studying how the size of the neural population used to
generate the PCA affected the information contained in the trajectory. We sorted each neuron
according to the magnitude of the PCA weights for the best-PC. We iteratively removed the
activity of 10% of the neurons with the largest PCA weights for the best-PC until reaching 1%
(15 total neurons). Finally, for each population size, we computed the second-layer PCAs on
the new trajectories and the corresponding SVM classification. Oscillatory activity analysis To characterize the phase, frequency, and amplitude of the neural trajectories, we calculated a
series of nonlinear regression models over the residuals of linear regressions on the first PC
projected data. Each inter-tap segment of the projected data was resampled to 30 bins and
time normalized to 1 s before calculating the regressions. The general function of the nonlinear
models was as follows: PC ¼ a sineð2p t þ cÞ þ d where t is time. In addition, the parameter a is the amplitude of the oscillatory function, c the
phase offset, and d is a constant. For each trial of both tasks (ST and SRTT), we calculated the
MSE. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 dPCA The dPCA method finds separate decoder (F) and encoder (D) matrices for each task parame-
ter (;) by minimizing the loss function, LdPCA ¼
X
;
kX; F;D;Xk
2 LdPCA ¼
X
;
kX; F;D;Xk
2 where X is a linear decomposition of the data matrix, which contains the instantaneous firing
rate of the recorded neurons, into parameter-specific averages: where X is a linear decomposition of the data matrix, which contains the instantaneous firing
rate of the recorded neurons, into parameter-specific averages: X ¼
X
;
X; þ Xnoise The decoder and encoder axes permit us to reduce the data into a few components captur-
ing the majority of the variance of the data dependent on each task parameter [30]. We used the TIND resampled to 30 bins for all target intervals as the input data to the
dPCA, and the target interval as the marginalization parameter. Therefore, the length of all the
trials for all target intervals was the same. We calculated the bin-by-bin Euclidean distance
between the 450-ms first PC and all the target intervals using the PCA and dPCA analyses. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 25 / 32 Supporting information S1 Fig. Location of the silicon shank for the MPC recordings in Monkey 1 during the ST. MRI cortical surface reconstruction of the macaque brain and the recording position of the
Buszaki-64 silicon shank over MPC. The green line corresponds to the anterior-posterior loca-
tion of the spur of the arcuate sulcus that divides preSMA from SMA. The silicon shank was
implanted according to this landmark, so that four more anterior shanks were located in pre-
SMA and other four posterior shanks in SMA. For the recording locations of MPC in Monkeys
1 and 2 during SCT, see Fig 1B of Merchant and colleagues, 2011. AS, arcuate sulcus; CS, cen-
tral sulcus; IPS, intraparietal sulcus; MPC, medial premotor cortex; preSMA, pre-supplemen-
tary motor cortex; PS, principal sulcus; SMA, presupplementary motor cortex proper; ST,
synchronization task. S2 Fig. Neural population trajectories during SCT from a subpopulation of cells with task-
related activity. The PCA was performed on the time-varying activity of 104 cells that showed
at least 15 activation periods on the Poisson-train analysis across the five target durations and
six serial order elements of the SCT. The first three PCs explained 32.5% of the total variance. A. Projection of the neural activity during the SC and CC of SCT onto the first three PCs. The
trajectory completes an oscillatory cycle on every produced interval during the synchroniza-
tion and continuation phases of the SCT. Target interval in milliseconds is color coded (450,
green; 650, blue; 1,000, red). Color progression within each target interval corresponds to the
elapsed time. A cube indicates the beginning of each trajectory, while an octahedron indicates
the end. B. Linear increase of the radii in the oscillatory neural trajectories during SC and CC
(mean ± SD, slope = 0.0003, constant = 0.2, R2 = 0.7, p < 0.0001) as a function of target inter-
val. C. Linear speed of neural trajectories during SC and CC (mean ± SD, slope = −0.002, con-
stant = 6.3, R2 = 0.42, p = 0.001) as a function of target interval. D. Variability of neural
trajectories (mean ± SD, normalized data slope = 0.0002, constant = −0.05, R2 = 0.87,
p < 0.0001) as a function of target interval. Underlying data are available in https://doid.gin.g-
node.org/d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; PC, principal
component; PCA, principal component analysis; SC, synchronization condition; SCT, syn-
chronization-continuation task. S3 Fig. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Moving bumps simulations In order to investigate how the properties of the pattern of neuronal activation affected the
generation of population neuronal trajectories, we generated five repetitions of simulations of
neuronal activity for each target interval. The individual neuronal activation period was com-
posed of the sum of 20 random gamma functions. The activation period was constant for all
the neurons on one simulation, but varied with the target interval: 197-, 205-, 213-, 233-, and
257-ms activation durations for 450-, 550-, 650-, 850-, 1,000-ms target intervals, respectively. The initial activation time for each neuron was adjusted so that the population activation rate
followed a Gaussian function as to produce a moving bump pattern. The number of neurons
in the simulation was incremented according to the target interval (450 ms, 108 neurons; 550
ms, 120 neurons; 650 ms, 130 neurons; 850 ms, 170 neurons; 1,000 ms, 182 neurons). Fig 11A
shows neurons were added randomly in the intermediate portion of the moving bumps. Movement kinematics We applied the Lucas-Kanade optic flow method to measure the monkey’s arm speed during
the ST. This method calculates a flow field from the intensity changes between two consecutive
video frames. The analyzed video was recorded with a Microsoft Kinect for Windows camera
with a 640 × 480 resolution. The optic flow method was applied to a smaller area of 141 × 141
pixels from the original video that contained the monkey’s arm during the whole trial, and no
other moving objects. The arm’s movement velocity vector was calculated across all frames as
the magnitude of the sum of all the individual flow fields vectors whose magnitude was larger
than a predefined threshold. The velocity vector was calculated from the first to the last tap on
each correct trial. We reported the speed as the magnitude of the velocity vector. Posteriorly,
the kinematic state of the arm was tagged as movement when the velocity vector was larger
than a threshold or dwell otherwise. The tagging algorithm considered a change on the kine-
matic state when the new state lasted longer than three consecutive frames. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 26 / 32 (H) PC2, nonsignificant linear regression, R2 = 0.089, p = 0.145, ANOVA main
effect target interval, F(4, 20) = 8.18, p < 0.001. Underlying data are available in https://doid. gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. PC, principal component; PCA, princi-
pal component analysis; SCT, synchronization-continuation task. (TIF) C,D. Coefficients and trajectories are computed using time-normalized data. (C) PC1, data
slope = 0.0012, constant = −0.651, R2 = 0.902, p < 0.0001, ANOVA main effect target interval,
F(4, 20) = 875.21, p < 0.0001. (D) PC1, data slope = 0.0048, constant = −1.638, R2 = 0.98,
p < 0.0001, ANOVA main effect target interval, F(4, 20) = 390.94, p < 0.0001. E,F. Coefficients
and trajectories are computed using actual time data. (E) PC1, data slope = 0.00084, constant
= −0.225, R2 = 0.899, p < 0.0001, ANOVA main effect target interval, F(4, 20) = 332.76,
p < 0 0001 (F) PC1 data slope
0 0034 constant
0 641 R2
0 686 p < 0 0001 ANOVA C,D. Coefficients and trajectories are computed using time-normalized data. (C) PC1, data
slope = 0.0012, constant = −0.651, R2 = 0.902, p < 0.0001, ANOVA main effect target interval,
F(4, 20) = 875.21, p < 0.0001. (D) PC1, data slope = 0.0048, constant = −1.638, R2 = 0.98,
p < 0.0001, ANOVA main effect target interval, F(4, 20) = 390.94, p < 0.0001. E,F. Coefficients
and trajectories are computed using actual time data. (E) PC1, data slope = 0.00084, constant
= −0.225, R2 = 0.899, p < 0.0001, ANOVA main effect target interval, F(4, 20) = 332.76,
p < 0.0001. (F) PC1, data slope = 0.0034, constant = 0.641, R2 = 0.686, p < 0.0001, ANOVA
main effect target interval, F(4, 20) = 100.04, p < 0.0001. G,H. Same as (A,B) but using non-
normalized firing rate data to calculate the trajectories. (G) PC2, data slope = 0.175, con-
stant = 62.162, R2 = 0.625, p < 0.0001, ANOVA main effect target interval, F(4, 20) = 27.58,
p < 0.0001. (H) PC2, nonsignificant linear regression, R2 = 0.089, p = 0.145, ANOVA main
effect target interval, F(4, 20) = 8.18, p < 0.001. Underlying data are available in https://doid. gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. PC, principal component; PCA, princi-
pal component analysis; SCT, synchronization-continuation task. (TIF) S4 Fig. State trajectories during ST and SRTT using simultaneously recorded neurons. A,
B. Three-dimensional neural dynamics trajectory of 650-ms single ST (A) and SRTT (B) inter-
vals. The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping fitted a sine function on each of the first 10 PCs and measured their amplitude and speed. For
all the possible normalization combinations, we found at least one of the first three PCs that
showed a robust fit of the sine function that was accompanied by a monotonic increase in the
mean and the variability of the trajectory radius and a similar speed across target intervals. Here, we show only one PC for each normalization combination (see A, C, E, G). (A-F) These
were generated using normalized firing rate data to calculate the trajectories. The left row cor-
responds to PC radial amplitude and the right row to the PC linear speed. A,B. Coefficients
computed with time normalized but trajectories calculated on actual time bins, as presented
across this paper for SCT. (A) PC amplitude increased with target interval: PC3, data
slope = 0.00081, constant = 0.011, R2 = 0.899, p < 0.0001, ANOVA main effect target interval,
F(4, 20) = 128.69, p < 0.0001. (B) PC linear speed is similar across target intervals: PC3, non-
significant linear regression, R2 = 0.07, p = 0.201, ANOVA main effect target interval, F(4, 20)
= 22.12, p < 0.0001. C,D. Coefficients and trajectories are computed using time-normalized data. (C) PC1, data
slope = 0.0012, constant = −0.651, R2 = 0.902, p < 0.0001, ANOVA main effect target interval,
F(4, 20) = 875.21, p < 0.0001. (D) PC1, data slope = 0.0048, constant = −1.638, R2 = 0.98,
p < 0.0001, ANOVA main effect target interval, F(4, 20) = 390.94, p < 0.0001. E,F. Coefficients
and trajectories are computed using actual time data. (E) PC1, data slope = 0.00084, constant
= −0.225, R2 = 0.899, p < 0.0001, ANOVA main effect target interval, F(4, 20) = 332.76,
p < 0.0001. (F) PC1, data slope = 0.0034, constant = 0.641, R2 = 0.686, p < 0.0001, ANOVA
main effect target interval, F(4, 20) = 100.04, p < 0.0001. G,H. Same as (A,B) but using non-
normalized firing rate data to calculate the trajectories. (G) PC2, data slope = 0.175, con-
stant = 62.162, R2 = 0.625, p < 0.0001, ANOVA main effect target interval, F(4, 20) = 27.58,
p < 0.0001. Supporting information Effect of timing and firing rate normalization on the amplitude and speed of neural
trajectories. We used different combinations of the time and firing rate normalization of the
neural data in order to calculate the PCA coefficients and then the neural trajectories. We 27 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 The amplitude in periodic neural state trajectories underlies the tempo of rhythmic tapping Conceptualization: Jorge Ga´mez, Hugo Merchant. Conceptualization: Jorge Ga´mez, Hugo Merchant. Conceptualization: Jorge Ga´mez, Hugo Merchant. Data curation: Jorge Ga´mez, Abraham Betancourt, Hugo Merchant. Formal analysis: Jorge Ga´mez, Abraham Betancourt, Hugo Merchant. Funding acquisition: Hugo Merchant. Investigation: Jorge Ga´mez, Germa´n Mendoza, Luis Prado, Hugo Merchant. Methodology: Jorge Ga´mez, Germa´n Mendoza, Luis Prado, Hugo Merchant. Project administration: Luis Prado. Data curation: Jorge Ga´mez, Abraham Betancourt, Hugo Merchant. Data curation: Jorge Ga´mez, Abraham Betancourt, Hugo Merchant. Software: Jorge Ga´mez, Abraham Betancourt, Hugo Merchant. Supervision: Germa´n Mendoza, Luis Prado, Hugo Merchant. Supervision: Germa´n Mendoza, Luis Prado, Hugo Merchant. Validation: Hugo Merchant. Validation: Hugo Merchant. Visualization: Hugo Merchant. Writing – original draft: Jorge Ga´mez, Hugo Merchant. Writing – review & editing: Jorge Ga´mez, Germa´n Mendoza. Acknowledgments We thank Victor de LaFuente, Ranulfo Romo, and Roman Rossi for their fruitful comments
on the manuscript. We also thank Raul Paulı´n for his technical assistance. Jorge Ga´mez is a
doctoral student from Programa de Doctorado en Ciencias Biome´dicas, Universidad Nacional
Auto´noma de Me´xico (UNAM), and received fellowship 339118 from CONACYT. PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
April 8, 2019 Elapsed time is color coded. The previous and the next taps are marked as red and white
spheres, respectively. The stimuli are marked as a white pyramid. Underlying data are available
in https://doid.gin.g-node.org/d315b3db0cee15869b3d9ed164f88cfa/. SRTT, serial reaction
time task; ST, synchronization task. (TIF) S5 Fig. State trajectory progress during SCT. A,B. One trajectory loop for the second pro-
duced interval of the (A) SC and (B) CC, during 450-ms (dark gray) and a 1,000-ms (light
gray) target intervals. Trajectory progression marked as colored spheres is as follows: previous
tap (green), first inter-tap quarter (cyan), second inter-tap quarter/half interval (blue), third
inter-tap quarter (yellow), and next tap (red). Therefore, the neural trajectories follow circular
paths with different radii that increase according to the target interval, but with similar speed
profiles. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; SC, synchronization con-
dition; SCT, synchronization-continuation task. (TIF) S5 Fig. State trajectory progress during SCT. A,B. One trajectory loop for the second pro-
duced interval of the (A) SC and (B) CC, during 450-ms (dark gray) and a 1,000-ms (light
gray) target intervals. Trajectory progression marked as colored spheres is as follows: previous
tap (green), first inter-tap quarter (cyan), second inter-tap quarter/half interval (blue), third
inter-tap quarter (yellow), and next tap (red). Therefore, the neural trajectories follow circular
paths with different radii that increase according to the target interval, but with similar speed
profiles. Underlying data are available in https://doid.gin.g-node.org/
d315b3db0cee15869b3d9ed164f88cfa/. CC, continuation condition; SC, synchronization con-
dition; SCT, synchronization-continuation task. (TIF) 28 / 32 PLOS Biology | https://doi.org/10.1371/journal.pbio.3000054
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Mitochondrial Function in Gilles de la Tourette Syndrome Patients With and Without Intragenic IMMP2L Deletions
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Frontiers in neurology
| 2,020
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cc-by
| 6,411
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BRIEF RESEARCH REPORT
published: 24 March 2020
doi: 10.3389/fneur.2020.00163 Mitochondrial Function in Gilles de la
Tourette Syndrome Patients With and
Without Intragenic IMMP2L Deletions
Victoria A. Bjerregaard 1, Bitten Schönewolf-Greulich 1, Lene Juel Rasmussen 2,
Claus Desler 2† and Zeynep Tümer 1,3*† 1 Department of Clinical Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Denmark, 2 Department
of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark,
3 Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark Background: Gilles de la Tourette syndrome (GTS) is a neurodevelopmental condition
characterized by motor and vocal tics. The underlying etiology remains largely unknown,
and GTS is considered as a complex multifactorial disorder associated with effects
of several genes in combination with environmental factors. The inner mitochondrial
membrane peptidase, subunit 2 (IMMP2L) has been suggested as one of the
susceptibility genes for GTS, and IMMP2L-deficient mouse and human cells show
increased levels of mitochondrial oxidative stress and altered cell fate programming. Hence, a potential involvement of IMMP2L-induced mitochondrial dysfunction in GTS
pathology is yet to be elucidated. To address this, we investigated mitochondrial function
in a group of GTS patients with intragenic IMMP2L deletions and compared with GTS
without IMMP2L deletions and healthy controls. Edited by:
Davide Martino,
University of Calgary, Canada
Reviewed by:
Danielle Cath,
University of Groningen, Netherlands
Thomas V. Fernandez,
Yale University, United States
*Correspondence:
Zeynep Tümer
zeynep.tumer@regionh.dk
†These authors share
senior authorship Edited by:
Davide Martino,
University of Calgary, Canada Reviewed by:
Danielle Cath,
University of Groningen, Netherlands
Thomas V. Fernandez,
Yale University, United States *Correspondence:
Zeynep Tümer
zeynep.tumer@regionh.dk Methods: Mitochondrial function in fibroblasts from GTS patients and non-GTS parents
(with and without IMMP2L deletions) compared to healthy controls were evaluated
by measuring mitochondrial superoxide production, mitochondrial membrane potential,
mitochondrial mass, and mitochondrial respiration. In addition, we evaluated apoptosis
and senescence. Specialty section:
This article was submitted to
Movement Disorders,
a section of the journal
Frontiers in Neurology Specialty section:
This article was submitted to
Movement Disorders,
a section of the journal
Frontiers in Neurology
Received: 21 October 2019
Accepted: 20 February 2020
Published: 24 March 2020 Results: None of the mitochondrial parameters assessed in this study were significantly
distinctive when comparing GTS patients with and without IMMP2L deletions against
healthy controls or parents with or without IMMP2L deletions, and we did not observe
altered cell programming. Received: 21 October 2019
Accepted: 20 February 2020
Published: 24 March 2020 Conclusion: This study suggests that IMMP2L deletions do not lead to a substantial
general mitochondrial dysfunction in GTS fibroblasts. Assessing a large cohort of controls
and patients of similar age and gender would possibly reveal small differences in
mitochondrial function. However, it is possible that IMMP2L variants affect mitochondrial
function during specific instances of stress stimuli or in brain regions suggested to be
affected in GTS. Keywords: Gilles de la Tourette syndrome, GTS, IMMP2L, mitochondria, oxidative stress Citation: Bjerregaard VA,
Schönewolf-Greulich B, Juel
Rasmussen L, Desler C and Tümer Z
(2020) Mitochondrial Function in Gilles
de la Tourette Syndrome Patients With
and Without Intragenic IMMP2L
Deletions. Front. Neurol. 11:163. doi: 10.3389/fneur.2020.00163 Keywords: Gilles de la Tourette syndrome, GTS, IMMP2L, mitochondria, oxidative stress March 2020 | Volume 11 | Article 163 Frontiers in Neurology | www.frontiersin.org 1 Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. INTRODUCTION (7). We hypothesized that impaired mitochondrial function
through a defective cerebellar IMMP2L may contribute to
GTS pathogenesis. To test this hypothesis, we conducted
a series of mitochondrial studies in fibroblasts obtained
from
GTS
patients
with
or
without
IMMP2L
deletions
compared
to
control
fibroblasts
obtained
from
parents
without GTS and with or without deletions, and from
asymptomatic controls. To our knowledge, this is the first
study to evaluate mitochondrial function in fibroblasts from
GTS patients. Gilles de la Tourette syndrome (GTS) is a neurodevelopmental
disorder, characterized by sudden, repetitive, non-rhythmic
movements or sounds, referred to as tics. The GTS diagnosis
is based on several motor and at least one vocal tic that have
persisted for more than a year. There is significant comorbidity
between
GTS
and
other
neurobiological/neuropsychiatric
conditions, especially attention deficit hyperactivity disorder
(ADHD) and obsessive–compulsive disorder (OCD). The disease
etiology is complex and multifactorial, with an evident genetic
component (1). One of the suggested GTS susceptibility genes
is the inner mitochondrial membrane peptidase, subunit 2
(IMMP2L) (2–7), and structural variants involving this gene
are also implicated in other neurobiological/neuropsychiatric
conditions including autism and ADHD (8–11). IMMP2L
transcript is expressed in several brain regions including
the cerebellum (7). Cerebellum is implied to have a role
not only in motor function, but also in cognitive and
emotional
processes,
and
its
dysfunction
is
implicated
both
in
movement
disorders
(e.g.,
ataxia
and
dystonia)
and non-motor neuropsychiatric diseases (e.g., autism and
ADHD) (12). As mitochondrial dysfunction is also linked to
disorders affecting cerebellum (13), IMMP2L is a plausible
susceptibility
factor
for
neurobiological/neuropsychiatric
disorders including GTS. Subjects and Study Design j
y
g
In this study, we analyzed skin fibroblasts available from four
of our previously published GTS patients (P1, P2, P5, P6) and
three non-GTS parents (of P1, P2, P6) with IMMP2L deletions
(7). According to their own descriptions, the three parents had
some behavioral features at subclinical level (Table 1). Three
anonymous GTS patients and four non-GTS controls (including
mothers of P1 and P6) without deletions were also included in the
study. The following considerations were made for the inclusion
of family members: (1) inclusion of two asymptomatic mothers
without deletions (of P1 and P6) in the control group would
ensure similar mitochondrial DNA background when comparing
fibroblasts with and without IMMP2L deletions; (2) inclusion
of the parents with a deletion and without a GTS diagnosis
(of P1, P2, P6) would minimize the effect of the background
variation in the nuclear genome on mitochondrial function, as
half of the genetic material in the nuclear genome is identical
between child–parent. g
Studies in different organisms (yeast, mice, and human cells)
show that substrates processed by IMMP2L include cytochrome
c1, mitochondrial glycerol-3-phosphate dehydrogenase 2 (GPD-
M), and apoptosis inducing factor (AIF) (14–16). Cytochrome
c1 is involved in electron transfer in the mitochondrial
electron transport chain, and GPD-M is a component of the
mitochondrial glycerol phosphate shuttle, which functions in
shuttling of electrons mitochondrial carriers in the oxidative
phosphorylation pathway. Both peptides hence have important
roles in mitochondrial respiratory chain and metabolism (17–
19). AIF triggers apoptosis and promotes removal of damaged
and irreparable cells when activated by IMMP2L under
oxidative stress, while in the absence of IMMP2L, cells are
driven toward a senescent state (16). Thus, IMMP2L has an
important role both in both mitochondrial metabolism and cell-
fate determination. All the experiments investigating mitochondrial dysfunction
were repeated at least three times. Quantitative visual scoring was
performed blinded to avoid bias. Cell Cultures Fibroblasts were cultured in Dulbecco’s modified Eagle’s medium
(DMEM) (Gibco) supplemented with 10% fetal bovine serum
(FBS) (Gibco) and 1% penicillin/streptomycin, at 37◦C in a
humidified atmosphere with 5% CO2. Cells were routinely tested
for mycoplasma. Brain tissue from Immp2l mutant mice show increased
production of reactive oxygen species (ROS), hyperpolarization,
and increased levels of ATP, but seem to have a normal
volume
of
mitochondria
and
bioenergetic
capacity
(15,
20). Phenotypically,
Immp2l
mutant
mice
display
a
series
of
features
including
altered
behavior,
reduced
social
interaction,
early
onset
ataxia,
and
age-dependent
degeneration of cerebellar granule neurons (21–25). The
majority of these phenotypes has been proposed to be a
consequence of cytotoxic insults caused by an increased
superoxide production. Frontiers in Neurology | www.frontiersin.org Superoxide Generation Assay p
y
The level of mitochondrial ROS was quantified by measuring
MitoSOX red (Molecular Probes, Invitrogen) using high-
throughput microscopy (Nucleocounter 3000). Fibroblasts were
incubated with 5 µM MitoSOX for 20 min at 37◦C and
washed once in phosphate-buffered saline (PBS) before harvest. Cells were harvested, resuspended in 10 µg/ml Hoechst 33342
(Tocris), incubated for 10 min at 37◦C, and immediately
analyzed. MitoSOX Red was excited at 530 nm, and data were
collected at 675/75 nm. Hoechst was excited at 365 nm, and
data were collected at 430/20 nm. Only live cells were included,
and the mean fluorescence intensity (MFI) was obtained by
subtracting the fluorescence of the control cells (not stained with
MitoSOX) from the fluorescence of the MitoSOX stained cells. Our group has previously identified intragenic IMMP2L
deletions in a Danish cohort of GTS patients, and these deletions
had an occurrence that was significantly high compared
to Danish controls (frequency, 3.7 vs. 0.9%, respectively) March 2020 | Volume 11 | Article 163 Frontiers in Neurology | www.frontiersin.org 2 Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. TABLE 1 | Subjects investigated in this study and information on fibroblast cultures. Superoxide Generation Assay Fibroblast
Subject identification
Sex
Symptoms
IMMP2L status
(deleted exons)§
IMMP2L status
effected transcript§
Age#
Passage
IMMP2L-1
P1
M
GTS, ADHD
Deletion (1a, 1b, 2, 3,
3a, 3b)
Long/short
23
3
IMMP2L-2
P1 father
M
Dyslexia*, Temper*
Deletion (1a, 1b, 2, 3,
3a, 3b)
Long/short
52
2
IMMP2L-3
P2
M
GTS, ADHD
Deletion (2, 3)
Long
20
3
IMMP2L-4
P2 mother
F
Tics*, OCD*
Deletion (2, 3)
Long
53
3
IMMP2L-5
P5
M
GTS
Deletion (3a, 3b)
Short
23
2
IMMP2L-6
P6
M
GTS, ADHD, OCD
Deletion (3a, 3b)
Short
19
2
IMMP2L-7
P6 father
M
Stubbornness*
Deletion (3a, 3b)
Short
62
3
TS-1
M
GTS
No deletion
–
22
3
TS-2
M
GTS
No deletion
–
24
3
TS-3
M
GTS
No deletion
–
21
3
Control-1
P1 mother
F
No symptoms
No deletion
–
50
2
Control-2
P6 mother
F
No symptoms
No deletion
–
56
2
Control-3
104027
F
No symptoms
No deletion
–
30
3
Control-4
104028
M
No symptoms
No deletion
–
45
3
§IMMP2L has two alternative transcripts differing at the 5′-end: The long transcript has exons 1a, 1b, 2, 3, 5–7 (ATG start codon in exon2) and the short transcript has exons 3a, 3b,
5–7 (ATG start codon in exon 3a) (7). #Age (years) when biopsy was taken. *Subclinical symptoms according to individuals own description. GTS, Gilles de la Tourette syndrome; ADHD, attention deficit hyperactivity disorder; OCB, obsessive–compulsive behavior; OCD, obsessive–compulsive disorder; M, male; F, female. TABLE 1 | Subjects investigated in this study and information on fibroblast cultures. §IMMP2L has two alternative transcripts differing at the 5′-end: The long transcript has exons 1a, 1b, 2, 3, 5–7 (ATG start codon in exon2) and the short transcript has exons 3a, 3b,
5–7 (ATG start codon in exon 3a) (7). #Age (years) when biopsy was taken. *Subclinical symptoms according to individuals own description. GTS, Gilles de la Tourette syndrome; ADHD, attention deficit hyperactivity disorder; OCB, obsessive–compulsive behavior; OCD, obsessive–compulsive disorder; M, male; F, female. Mitochondrial Membrane Potential The mitochondrial membrane potential was determined by
detecting tetramethylrhodamine, ethyl ester (TMRE) (Abcam) by
high-throughput microscopy (Nucleocounter 3000). Fibroblasts
were incubated with 100 nm TMRE for 15 min at 37◦C, briefly
washed in PBS, and harvested by standard procedures. Cells
were resuspended in 10 µg/ml Hoechst 33342 (Tocris), incubated
10 min at 37◦C, and immediately analyzed. TMRE was excited
at 530 nm, and data were collected at 675/75 nm. Hoechst was
excited at 365 nm, and data were collected at 430/20 nm. Only live
cells were included in the MFI, and 20 µM carbonyl cyanide 4-
(trifluoromethoxy) phenylhydrazone (FCCP) (Abcam) was used
as a positive control. For each sample, a minimum of 5,000 cells
were scored. The mitochondrial respiration was measured using an XF-
96 Extracellular Flux Analyzer (Seahorse Bioscience, Agilent). Seeded cells were washed and resuspended in Seahorse assay
media (Seahorse Bioscience, Agilent), supplemented with 1 mM
pyruvate, 2 mM glutamine, and adjusted to pH 7.4. Oxygen
consumption rates (OCRs) were measured to establish a baseline. Subsequently, wells were injected with either 1 µM oligomycin,
to measure ATP turnover from the changes in OCR, or with
0.5 µM carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone
(FCCP) to determine reserve respiratory capacity from change
in OCR. All cells were finally treated with 2 µM antimycin A as
a control. ATP Content and Mitochondrial
Respiration Antimycin A (150 µM) (Sigma-Aldrich) was used as a positive
control. For each sample, a minimum of 5,000 cells were scored. The ATP content was determined using the luciferase-based assay
Vialight MDA Plus kit (Lonza) according to the manufacturer’s
instructions. Levels of luminescence was quantified in a
Microbeta2 scintillation counter (Perkin Elmer). DISCUSSION In this study, we investigated whether mitochondrial dysfunction
was a contributing factor in disease etiology of GTS patients
with and without deletions affecting the mitochondrial peptidase
IMMP2L. Having the highest mitochondrial energy demand of
all organs, the brain in particular is sensitive to mitochondrial
dysfunction, which indeed has been implicated in the etiology of a
wide spectrum of neurobiological and neuropsychiatric disorders
(27, 28). IMMP2L has a dual role in the mitochondria affecting
both the mitochondrial metabolism and the cell fate. IMMP2L
deficiency has been linked to mitochondrial dysfunction in the
form of increased oxidative stress, a pathological feature common
to several central nervous system disorders (29), and increased
occurrence of cellular senescence, a pathological feature of
neurodegeneration (30). In line with this, rare structural variants
affecting IMMP2L were implicated as susceptibility factors in
autism spectrum disorders (31) and ADHD (11). To determine the level of mitochondrial ROS, we measured
mitochondrial levels of superoxide, which represents total
mitochondrial ROS, using mitoSOX in living and unstressed
fibroblasts. In cells from all subjects, the level of ROS was
below that of the stressed positive control (antimycin A), and
we did not observe any significant differences between each
subject or between the IMMP2L deletion, GTS-without deletion,
or control group (Figure 1A). The results did not change when
the non-GTS parents with or without IMMP2L deletions were
omitted from the analysis (statistical analysis not included, raw
data available). Mitochondrial membrane potential was measured using the
fluorophore TMRE that labels mitochondria proportional to the
potential across the inner membrane. Depolarized or inactive
mitochondria fail to sequester TMRE. The membrane potential
of mitochondria is related to its ability to produce ATP by
oxidative phosphorylation, but it is also an indicator of general
apoptosis, as collapse of the mitochondrial membrane triggers
an apoptotic cascade. No significant difference in mitochondrial
membrane potential was demonstrated between fibroblasts of
individual patients or between the three groups (Figure 1B). p
IMMP2L has been suggested as a candidate susceptibility gene
in GTS (3, 6), and we have shown that intragenic IMMP2L
deletions were present at a higher frequency in GTS patients
compared to control population. We hypothesized that the
IMMP2L deletions could exert their effect through impaired
mitochondrial function (7). Apoptosis and Senescence The mitochondrial mass of active mitochondria was quantified
by measuring MitoTracker Green probe (Molecular Probes,
Invitrogen) by high-throughput microscopy (Nucleocounter
3000). Cells were incubated with 100 nM MitoTracker for 20 min
at 37◦C and washed once in PBS before harvest. Cells were
resuspended in 10 µg/ml Hoechst 33342 (Tocris), incubated
10 min at 37◦C, and immediately analyzed. MitoTracker Green
was excited at 475 nm, and data were collected in the 560/35 nm
channel. Hoechst was excited at 365 nm, and data were collected
in the 430/20 nm channel. Only live cells were included. For each
sample, a minimum of 5,000 cells were scored. The apoptotic state of the fibroblasts was evaluated using
the Annexin V-CF488A conjugate (Biotium) following the
instructions of the Nucleocounter NC-3000 Annexin V Assay
(Application note no. 3017 Rev. 1.4). For each sample, a
minimum of 5,000 cells were scored. Senescence
was
analyzed
using
the
SA-β-Gal-based
senescence
detection
kit
(Abcam)
according
to
the
manufacturer’s
instructions. The
percentage
of
senescent
cells were scored after five passages using the EVOS XL Core Cell
Imaging System (Life Technologies) and the cell counter plugin March 2020 | Volume 11 | Article 163 Frontiers in Neurology | www.frontiersin.org 3 Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. ImageJ software (NIH). A minimum of 200 cells were counted
per sample per experimental replica. ImageJ software (NIH). A minimum of 200 cells were counted
per sample per experimental replica. between fibroblasts of individual patients or between different
groups as described above. To evaluate cell fate of the fibroblasts, we quantified the
percentage of cells in apoptosis and senescence. Live apoptotic
cells were stained with the apoptotic marker Annexin V
and distinguished from dead cells by propidium iodine. The
percentage of apoptotic cells were within a normal range for
all fibroblasts, and we did not observe any differences between
individuals or when comparing the two groups of GTS patients
with controls (Figure 3A). To determine the percentage of cells
in senescence, cells were fixed and stained with β-Gal in their
exponential phase. Since the number of cells in senescence
increases with age (26), individuals over 50 years of age were
excluded from this assay (see Table 1). No significant difference
was observed between individuals or between different groups as
described above (Figure 3C). RESULTS The subjects investigated in this study were divided into
three groups: (1) seven individuals with IMMP2L deletions
(IMMP2L1–7), where four of them were clinically diagnosed with
GTS (P1, P2, P5, and P6) and three of them were parents (of
P1, P2, and P6) without a GTS diagnosis; (2) three GTS patients
without IMMP2L deletions (TS 1–3); and (3) four controls
without any GTS symptoms (control 1–4) including mothers of
patients P1 and P6 (Table 1). The subjects investigated in this study were divided into
three groups: (1) seven individuals with IMMP2L deletions
(IMMP2L1–7), where four of them were clinically diagnosed with
GTS (P1, P2, P5, and P6) and three of them were parents (of
P1, P2, and P6) without a GTS diagnosis; (2) three GTS patients
without IMMP2L deletions (TS 1–3); and (3) four controls
without any GTS symptoms (control 1–4) including mothers of
patients P1 and P6 (Table 1). Statistics Results are presented as mean ± SD from at least three
experimental replicas. A one-way analysis of variance (ANOVA)
and Tukey tests were used to compare subjects individually
or as specified groups (Table 1). A p < 0.05 was considered
significant. All statistical analyses were carried out using Prism
software (Graphpad). Frontiers in Neurology | www.frontiersin.org DISCUSSION To test this hypothesis, we conducted
a series of experiments to assess whether fibroblasts from
GTS patients with or without IMMP2L deletions would show
phenotypes of oxidative stress or other signs of mitochondrial
dysfunction compared to controls. As control individuals,
we also included parents without GTS and with IMMP2L
deletions, to ensure a more similar background for the nuclear
genome to minimize any confounding effect of background
variations, and asymptomatic mothers without deletions and
to ensure a similar mitochondrial DNA background (Table 1). This would be an important issue in case we found a
difference in mitochondrial function. However, we found no
evidence for altered mitochondrial ROS, membrane potential,
mass, respiration, or ATP content, suggesting that there is no
substantial mitochondrial dysfunction in fibroblasts of GTS
patients with or without IMMP2L deletions. However, these Determination of mitochondrial mass provides a simplified
overview of mitochondrial dynamics and is one of the signs of
an altered activity of mitochondrial fission, fusion, biogenesis,
or mitophagy. To label mitochondria in live cells, we used a
MitoTracker probe, which passively diffuses across the plasma
membrane and accumulates in active mitochondria. We did not
observe significant difference in mitochondrial mass between
individual subjects or between the three groups (Figure 1C). To evaluate the bioenergetic capacity, we quantified basal
respiration rate, ATP turnover, and reserve respiratory in
live cells by standard protocols using the Seahorse XF
analyzer (Figures 2A–D), and for a total overview of the
energy metabolism, whole-cell count of ATP was determined
(Figure 2E). None of the assays showed a significant difference March 2020 | Volume 11 | Article 163 Frontiers in Neurology | www.frontiersin.org 4 Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. y
RE 1 | Fibroblasts of Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions display no signs of oxidative stress, altered membrane
tial, or abnormal mitochondrial mass. (A) Mitochondrial reactive oxygen species (ROS) levels presented as relative MitoSOX MFI ± SD of each subject (left) and
h group (right). (B) Mitochondrial membrane potential presented as relative TMRE MFI ± SD of each subject (left) and of each group (right). (C) Mitochondrial
presented as MitoTracker MFI ± SD of each subject (left) and of each group (right). All MFI values are normalized to the mean of the healthy control cells within
experimental replica. Each bar represents at least three independent experiments. DISCUSSION Black stars mark non-GTS individuals with IMMP2L deletions. gs do not exclude that processing of known IMMP2L
ates, such as cytochrome c1, GPD-M, and AIF is affected,
IMMP2L has a key role in cell-fate programming during
conditions of increased ROS by either promoting apoptosis FIGURE 1 | Fibroblasts of Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions display no signs of oxidative stress, altered membrane
potential, or abnormal mitochondrial mass. (A) Mitochondrial reactive oxygen species (ROS) levels presented as relative MitoSOX MFI ± SD of each subject (left) and
of each group (right). (B) Mitochondrial membrane potential presented as relative TMRE MFI ± SD of each subject (left) and of each group (right). (C) Mitochondrial
mass presented as MitoTracker MFI ± SD of each subject (left) and of each group (right). All MFI values are normalized to the mean of the healthy control cells within
each experimental replica. Each bar represents at least three independent experiments. Black stars mark non-GTS individuals with IMMP2L deletions. IMMP2L has a key role in cell-fate programming during
conditions of increased ROS by either promoting apoptosis
by AIF activation or being shut down upon the onset of IMMP2L has a key role in cell-fate programming during
conditions of increased ROS by either promoting apoptosis
by AIF activation or being shut down upon the onset of findings do not exclude that processing of known IMMP2L
substrates, such as cytochrome c1, GPD-M, and AIF is affected,
and further studies are necessary to clarify this. March 2020 | Volume 11 | Article 163 Frontiers in Neurology | www.frontiersin.org 5 Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. E 2 | Properties of mitochondrial respiration were unaltered in fibroblasts of Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions. spiration overview of groups. (B) Basal respiration as determined as initial resting consumption of oxygen. (C) ATP turnover as measured as a decrease in
consumption after addition of oligomycin. (D) Reserve respiratory capacity as measured as a percentage of basal respiration, after addition of FCCP. The
y between the groups was also present in whole-cell ATP levels. (E) Mean percentage ± SD of whole-cell ATP presented for each subject (left) and the three
(right). Black stars mark non-GTS individuals with IMMP2L deletions. DISCUSSION All values are normalized to the mean of the healthy control cells within each experimental
Each bar represents at least three independent experiments. FIGURE 2 | Properties of mitochondrial respiration were unaltered in fibroblasts of Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions. (A) Respiration overview of groups. (B) Basal respiration as determined as initial resting consumption of oxygen. (C) ATP turnover as measured as a decrease in
oxygen consumption after addition of oligomycin. (D) Reserve respiratory capacity as measured as a percentage of basal respiration, after addition of FCCP. The
similarity between the groups was also present in whole-cell ATP levels. (E) Mean percentage ± SD of whole-cell ATP presented for each subject (left) and the three
groups (right). Black stars mark non-GTS individuals with IMMP2L deletions. All values are normalized to the mean of the healthy control cells within each experimental
replica. Each bar represents at least three independent experiments. March 2020 | Volume 11 | Article 163 6 Frontiers in Neurology | www.frontiersin.org Mitochondrial Function in Gilles de la Tourette Syndrome Bjerregaard et al. Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions show no signs of increased apoptosis or senescence (A) Mean FIGURE 3 | Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions show no signs of increased apoptosis or senescence. (A) Mean
percentage ± SD of apoptotic cells presented for each subject (left) and the three groups (right). (B) Representatives of dot plot and histogram for Annexin V and
propidium iodine (PI) staining. As indicated on the dot plot, the cell population was divided into apoptotic, late apoptotic/dead, and dead. The apoptotic population
was included in the charts. Black stars mark non-GTS individuals with IMMP2L deletions. (C) Mean percentage ± SD of senescent cells presented for each subject
(left) and the three groups (right). (D) Representative image of a fibroblast culture with a senescent cell positive for β-Gal (arrow). For all charts, each bar represents
three independent experiments. n indicates the number of cells analyzed per replica. FIGURE 3 | Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions show no signs of increased apoptosis or senescence. (A) Mean
percentage ± SD of apoptotic cells presented for each subject (left) and the three groups (right). (B) Representatives of dot plot and histogram for Annexin V and
propidium iodine (PI) staining. REFERENCES 8. Leblond CS, Cliquet F, Carton C, Huguet G, Mathieu A, Kergrohen T, et al. Both rare and common genetic variants contribute to autism in the Faroe
Islands. NPJ Genom Med. (2019) 4:1. doi: 10.1038/s41525-018-0075-2 1. Robertson MM, Eapen V, Singer HS, Martino D, Scharf JM, Paschou
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3:16097. doi: 10.1038/nrdp.2016.97 9. Baldan F, Gnan C, Franzoni A, Ferino L, Allegri L, Passon N, et al. Genomic
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translocation breakpoint at 18q22.3. Am J Hum Genet. (1996) 59:999–1005. 2. Boghosian-Sell L, Comings DE, Overhauser J. Tourette syndrome in a
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K. Candidate region for Gilles de la Tourette syndrome at 7q31. Am J
Med Genet. (2001) 101:259–61. DISCUSSION As indicated on the dot plot, the cell population was divided into apoptotic, late apoptotic/dead, and dead. The apoptotic population
was included in the charts. Black stars mark non-GTS individuals with IMMP2L deletions. (C) Mean percentage ± SD of senescent cells presented for each subject
(left) and the three groups (right). (D) Representative image of a fibroblast culture with a senescent cell positive for β-Gal (arrow). For all charts, each bar represents
three independent experiments. n indicates the number of cells analyzed per replica. FIGURE 3 | Gilles de la Tourette syndrome (GTS) patients with and without IMMP2L deletions show no signs of increased apoptosis or senescence. (A) Mean
percentage ± SD of apoptotic cells presented for each subject (left) and the three groups (right). (B) Representatives of dot plot and histogram for Annexin V and
propidium iodine (PI) staining. As indicated on the dot plot, the cell population was divided into apoptotic, late apoptotic/dead, and dead. The apoptotic population
was included in the charts. Black stars mark non-GTS individuals with IMMP2L deletions. (C) Mean percentage ± SD of senescent cells presented for each subject
(left) and the three groups (right). (D) Representative image of a fibroblast culture with a senescent cell positive for β-Gal (arrow). For all charts, each bar represents
three independent experiments. n indicates the number of cells analyzed per replica. March 2020 | Volume 11 | Article 163 7 Frontiers in Neurology | www.frontiersin.org Bjerregaard et al. Mitochondrial Function in Gilles de la Tourette Syndrome ACKNOWLEDGMENTS We thank all the families for their participation and contribution
to this work. ETHICS STATEMENT This study was approved by the Danish Regional Committee on
Health Research Ethics (H-1-2014-109). All included participants
gave their specific consent to participate and for the publication
of the data. Cerebellum has been implicated in GTS pathophysiology
(32, 33), and our group has previously shown that IMMP2L
transcripts were highly expressed in the granular and Purkinje
cell layer of the cerebellum (7). Abnormal or dysfunctional
cerebellum and Purkinje cells have also been implicated in
other neurodevelopmental and movement disorders, such as
autism spectrum disorders, ataxia, and dystonia, and notably,
mitochondrial dysfunction is linked to these disorders (34–
36). It is thus possible that IMMP2L deletions have a more
pronounced effect in high energy-dependent neurons, such
as the Purkinje cells, which are known to be vulnerable to
mitochondrial dysfunction (36). Notably, Purkinje cells are a
class of GABAergic (γ-aminobutyric acid) neurons, and altered
GABA function has been suggested to contribute to GTS
pathology (37). Further studies using induced pluripotent stem
cell (iPSC)-derived brain cells, including GABAergic neurons,
are necessary to understand the involvement of mitochondrial
dysfunction in brain tissues. FUNDING This study was supported by the Lundbeck Foundation (R100-
2001-933). LJ was supported by Nordea-fonden and Olav Thon
Stiftelsen. CD was supported by Nordea-fonden. This study was supported by the Lundbeck Foundation (R100-
2001-933). LJ was supported by Nordea-fonden and Olav Thon
Stiftelsen. CD was supported by Nordea-fonden. In summary, we could not show a substantial mitochondrial
dysfunction in GTS patients with or without IMMP2L deletions
in fibroblast. However, involvement of IMMP2L in GTS
pathogenesis cannot be completely excluded, and further studies
investigating larger number of patients and using iPSC-derived
neuronal cells are necessary. AUTHOR CONTRIBUTIONS VB designed and carried out the experiments presented in
Figures 1, 3. CD designed and conducted the experiments
presented in Figure 2, with assistance from VB. BS-G collected
the skin biopsies from patients. VB and CD performed the data
analysis and interpretation. ZT conceptualized the project and
guided the experimental design. LJ contributed with equipment
and reagents. The manuscript was written by VB and ZT with the
contribution of CD. DATA AVAILABILITY STATEMENT senescence (16). In GTS fibroblasts, we did not observe
induction of either apoptosis or senescence, but this could
be due to the normal ROS levels that we have measured. It is therefore plausible that in high ROS levels, a defective
IMMP2L may not be able to process AIF to its proapoptotic
active form. Further studies may elucidate how fibroblasts with
IMMP2L deletions would respond to exogenous stimulation
of ROS. All datasets generated for this study are included in the
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Tümer. This is an open-access article distributed under the terms of the Creative
Commons Attribution License (CC BY). The use, distribution or reproduction in
other forums is permitted, provided the original author(s) and the copyright owner(s)
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Acoustic Intervention in a Cultural Heritage:
The Chapel of the Royal Palace in Caserta, Italy Umberto Berardi 1,†, Gino Iannace 2,*,† and Carmine Ianniello 3,† 1
Department of Architectural Science, Ryerson University, Toronto, ON M5B 2K3, Canada;
uberardi@ryerson.ca 1
Department of Architectural Science, Ryerson University, Toronto, ON M5B 2K3, Canada;
uberardi@ryerson.ca 2
Dipartimento di Architettura e Disegno Industriale, Seconda Università di Napoli, Aversa 81031, Italy
3
Dipartimento di Ingegneria Industriale, Università di Napoli “Federico II”, Napoli 80125, Italy;
ianniell@unina2.it 2
Dipartimento di Architettura e Disegno Industriale, Seconda Università di Napoli, Aversa 81031, Italy
3
Dipartimento di Ingegneria Industriale, Università di Napoli “Federico II”, Napoli 80125, Italy;
ianniell@unina2.it *
Correspondence: gino.iannace@unina2.it; Tel.: +39-081-5010845; Fax: +39-081-8149266
h
h
b
d
ll
h
k *
Correspondence: gino.iannace@unina2.it; Tel.: +39-081-5010845; Fax: +39-081-8149266
†
These authors contributed equally to this work. *
Correspondence: gino.iannace@unina2.it; Tel.: +39-081-5010845; Fax: +39-081-8149266
†
These authors contributed equally to this work. Correspondence: gino.iannace@unina2.it; Tel.: +39-081-5010845; Fax: +39-081-8149266
†
These authors contributed equally to this work. †
These authors contributed equally to this work. †
These authors contributed equally to this work. Abstract: The modern use of ancient heritage sites can be, to say the least, challenging from an
acoustical perspective. In fact, modern needs may require acoustical interventions in contrast
with the preservation issues of the cultural heritage. This paper deals with this topic in an
UNESCO designated world heritage site, the Palatine Chapel of the Royal Palace in Caserta,
Italy. Since this chapel is currently being used for meetings and music chamber concerts, the
acoustical characteristics of the chapel, originally used for religious purposes, are investigated. Field
measurements were undertaken to evaluate the acoustical performance of the empty chapel. The
measurements were then used to calibrate and validate a computer simulation model. Different
acoustical treatments are then considered and simulations are used to determine the related
acoustical improvements. Finally, the benefits of different acoustical treatments which are respectful
of the aesthetic and historical value of this cultural heritage are discussed. Keywords: room acoustics; cultural heritage; reverberation; simulations; sound absorption panels Keywords: room acoustics; cultural heritage; reverberation; simulations; sound absorption pane Buildings 2016, 6, 1; doi:10.3390/buildings6010001 1. Introduction Italy, one of the cradles of Western Civilization, has over 100,000 monuments such as
churches, cathedrals, archaeological sites, and historical palaces, and it has the most United Nations
Educational, Scientific and Cultural Organization (UNESCO) designated world heritage sites [1]. Among the 51 sites on the list there is the 18th-Century Royal Palace at Caserta with its park, the
Aqueduct of Vanvitelli, and the San Leucio Complex. This large scale palace was created by the
Bourbon King of Naples Charles III as the Italian response to the Palace of Versailles or the Royal
Palace in Madrid [2]. The building exemplifies the Italian way of bringing together a magnificent
palace with its park and gardens, as well as natural woodland, hunting lodges, and a silk factory. In
fact, the site expresses the beauty of the integration of the architectural masterpiece into the natural
landscape. The Palace, designed and built by the architect Luigi Vanvitelli, was the Bourbon dynasty’s
way to showcase the Kingdom of the Two Sicilies [2]. The Palatine Chapel, the focus of the current study, is located within the Royal Palace and was
opened with a midnight mass on Christmas day, 1784 in the presence of King Ferdinand IV. The
chapel emulates the analogous room of the Palace of Versailles. Originally dedicated to religious
purposes, the magnificent chapel, located on the first floor of the Palace (Figure 1), is currently used
for public events such as meetings and chamber music concerts. The new functions have shown the
inadequacy of the acoustics of this marbled and highly decorated room (Figure 2). www.mdpi.com/journal/buildings 2 of 14 Buildings 2016, 6, 1 Figure 1. Plans of the Royal Palace in Caserta, showing the position of the Palatine Chapel. Figure 1. Plans of the Royal Palace in Caserta, showing the position of the Palatine Chapel. The chapel is rectangular with a semi-circular apse at one end. On the opposite side to the apse
is the entrance portal, above which is the royal tribune used by high dignitaries and the court ladies
during sacral functions. Two galleries run along the side walls with double Corinthian columns that
rise in support of a barrel vault with a richly decorated coffered ceiling. An abundance of colored
marble characterizes most of the surfaces of the chapel. 2.1. Acoustic Parameters of Analysis In room acoustics, the reverberation time is the most common parameter and it can be described
as the persistence of sound after a source has stopped. In particular, the reverberation time is the
time needed to have a reduction of 60 dB in the sound pressure level. In sound diffuse rooms, the
reverberation time has the advantage of being steady throughout the space and predictable using
simple formulas. However, it requires the capability of creating an energy gain of more than 60 dB
over the background noise, before being able to measure the 60 dB sound pressure decay. In this
paper, the early decay time (EDT) which is the slope of the best-fit linear regression line of the initial
10 dB, between 0 and ´10 dB, of the decay was evaluated as it is often shown to correlate better to the
early reverberation effect in the room. Several acoustic parameters defined in the ISO 3382-1 [4] were analyzed. These parameters have
been defined in order to better describe the perception of a sound field, even though their prediction
depends on many factors, such as the relative position of sources and receivers. In particular, this
study focused on the values assumed by the center time, the clarity, and the definition. The center time (Ts) is defined as the time of the center of gravity of the squared impulse response
of the sound energy, and it is related to the balance between early sound and delayed sound respect
to the Ts value. In reverberant rooms such as churches, where late reflections reach listeners with a
long delay, Ts can assume values up to several hundreds of milliseconds. Late sound contributes to
have a long reverberation of the room and although it may improve the perception of the music, it is
generally detrimental for listening to speeches. The clarity measures the balance between the useful and detrimental sound for the listening
perception. It represents the degree to which different reflections arrives and are perceived by the
listener, and it is assessed as an early-to-late arriving sound energy ratio. This ratio can be calculated
for either a 50 ms or an 80 ms early time limit, depending on whether it relates to conditions for
speech or music respectively. 1. Introduction A large icon painted by Giuseppe Bonito
portraying the Immaculate Conception is suspended in the apse, while originally organ pipes are
placed on the two side galleries. The Chapel suffered severe damages during World War II, and was
then restored according to the original design. Figure 2. Views of the Palatine Chapel toward the apse (a) and toward the royal tribune (b). Figure 2. Views of the Palatine Chapel toward the apse (a) and toward the royal tribune (b). Figure 3 shows the floorplan and a cross section of the Palatine Chapel with its main geometrical
dimensions. The total length of the chapel is 37 m, and the transversal width is 15 m, while the vault
has a maximum height of 25 m. The inner volume is about 22,860 m3. It can be seen from Figure 2
that the chapel has highly decorated sound reflective surfaces. The instances of heritage preservation 3 of 14 Buildings 2016, 6, 1 suggest the use of transparent plastic chairs for audience seating, as seen in Figure 2, in order to show
the aesthetic beauty of the marble floor. suggest the use of transparent plastic chairs for audience seating, as seen in Figure 2, in order to show
the aesthetic beauty of the marble floor. Figure 3. Cross section and plan of the Palatine Chapel, with location of the sound source ( ) and of
the receivers ( ). Figure 3. Cross section and plan of the Palatine Chapel, with location of the sound source ( ) and of
the receivers ( ). The present study aims to explore feasible acoustical treatments to obtain better acoustic
conditions for the events planned to be held in the chapel. Acoustical treatments had to consider the
preservation of the heritage site. The study consisted of both field measurements inside the chapel
and computer simulations of different intervention hypothesis with the aid of the software Odeon [3]. 2.1. Acoustic Parameters of Analysis In particular, the C80 is defined as the ratio, expressed in decibels, of the
early energy (from 0 to 80 ms) over the late reverberant energy (from 80 ms to infinite). The definition (D50) considers the early arriving sound energy over the total sound energy and
it is calculated using 50 ms as the early time limit. 4 of 14 Buildings 2016, 6, 1 Finally, the parameter of sound strength (G) was assessed since this is representative of the
subjective level of sound, and it is defined as the gain from the sound pressure level, which is
produced by the same sound source with the same power level in a free field at a distance of 10 m
from the sound source. In order to establish suggested values of the different monaural acoustic parameters considered
in this study different references were used. In this phase, it was important to select the most adequate
function for this room. In order to guarantee a certain flexibility in the use, the room was supposed to
host public meetings with speech comprehension (talks and receptions are common in this room), but
also some baroque chamber music or small orchestra listening. The different requests of the several
sound messages required some compromises in the acoustics goals. Using recent studies about the
typical listening preference in sacred spaces [5–7], the following criteria were finally established: -
The early decay time (EDT) should assume values between 1 s, a value adequate for a clearer
perception of speeches, and 2.5 s, a value adequate for music listening preference. In churches
reverberation time and early decay time values well above 3 s are common and may well fit
for example with organ music. However, since this kind of music is not contemplated in the
programming of the Palatine chapel anymore, a shorter reverberation was considered necessary; -
The center time (Ts) should assume values below 100 ms for a clearer perception of speeches,
while it may assume greater values, up to 200 or 250 ms for music listening preference; -
The clarity (C80) expressing the balance between the early and late arriving energy, should have
an higher value if the goal is to separate the initial sounds from the diffuse ones and making the
discrete sounds stand apart from each other. 2.1. Acoustic Parameters of Analysis For the purposes of good listening conditions of
music, it is generally preferable that C80 should be in the range between ´2 dB and 2 dB, while
it is expected to be above 2 dB if speech perception is a priority; -
The definition (D50) which may assume values from 0 to 1, should be above 0.50 for a good
speech comprehension. -
The definition (D50) which may assume values from 0 to 1, should be above 0.50 for a good
speech comprehension. Obviously, the preferred values for the different parameters refer to fully occupied conditions so
in a room such as the Palatine chapel, were the audience would represent the main sound absorbing
surfaces, it is important to analyze the effect of the presence of the audience. 2.2. Acoustic Measurements The sound source used to perform acoustic measurements consisted of a dodecahedron
loudspeaker Peeker Sound JA12 (Peeker Sound Corportation, Reggio Emilia, Italy). MLS signals
of order 16 with a length of 5 s were generated by a 01 dB Symphonie system. The sound pressure
was recorded with a ½” microphone GRAS 40 connected with a preamplifier 01 dB PRE 12 H. The
floor plan in Figure 3 shows the location of the sound source and of the fifteen receivers. The sound
source was placed at the height of 1.5 m over the floor at the center of the area in front of the altar
where musicians are usually located during concerts. The measurement microphone was placed at
the height of 1.5 m over the floor too. Measurements were done both in the empty conditions of the
chapel or with transparent chairs that are generally used (Figure 2). The recorded impulse responses were then elaborated with the software Dirac 4.0 [5], and several
acoustic parameters defined in the ISO 3382-1 [4], such as the early decay time (EDT), the center time
(Ts), the clarity (C80), and the definition (D50) were analyzed. Figure 4 reports the measured values of EDT, Ts, C80, and D50, averaged among the fifteen
receiver locations together with the intervals of the standard deviation for each octave band from
125 Hz to 4 kHz. All the measurements were done in unoccupied conditions. Obviously, the audience
would have had an absorbing effect with a consequent reduction of the reverberation and hence of the
EDT and Ts. However, the results of the measurements suggested that the hall in the observed state is
clearly over reverberant and it is not well suited neither for chamber music nor for the intelligibility
of speech. This led to study the possibility to introduce in this room some acoustic treatments. 5 of 14 Buildings 2016, 6, 1 Acoustic measurements with the presence of chairs were also realized using the same
measurement equipment and setup described previously. The measurement with the chairs showed
no significant difference in the reverberation parameter (EDT), while other parameters, such as C80
or Ts had more remarkable difference within the room. In fact, the sound scattering realized by the
chairs reduced the clarity while increased the center time. Figure 4. 2.2. Acoustic Measurements Comparison between measured and simulated results averaged among the 15 receiver
positions of four room acoustic parameters, EDT, Ts, C80, and D50, and their standard deviations. Figure 4. Comparison between measured and simulated results averaged among the 15 receiver
positions of four room acoustic parameters, EDT, Ts, C80, and D50, and their standard deviations. 3.1. The Virtual Model To obtain realistic data for the Palatine Chapel in actual use, including the effect of audience,
computer simulations were carried out using the software Odeon [3]. This software model was then
used to study the effect of temporary sound absorbing systems that can be adopted in the respect of
the architectural value of the venue. Odeon uses the principles of the geometrical acoustics and adopts a hybrid calculation method
that combines the image source method and the ray-tracing method. The approach used by the
software merges the best features of both models, since the image source method is used for the
early-scattered rays of the first reflections, while a ray-tracing technique which also considers the
surface scattering according to a Lambert’s cosine law, is used for the more statistically computed
late part of the impulse response [8–10]. Early reflections are generated by point sources for which
the reflection order is less than or equal to the Transition Order (TO). The early reflections take into
account the scattering properties of the surfaces. Every time a ray is reflected at a surface, the position
of an image source is found. In this early part of the impulse response calculation, rays are only
used indirectly to detect image sources that are likely to be valid. The image sources are then split
into a specular contribution and a scattering contribution which consists of secondary sources on the
image-source surfaces, allowing for a realistic calculation of early scattering. All reflections that are
not accounted for by the early reflection method are treated by the late-reflection method. Every Buildings 2016, 6, 1 6 of 14 time a late ray is reflected at a surface, a secondary source is generated, having directivity varying
according to Lambert’s law. The late-reflection process keeps the reflection density constant in order
to reduce the calculation time. Usually, a computer software simulation requires a first step aimed at the development of a
model of the space as it exists and for which acoustic measurements are available. Unavoidable
approximations about the geometry and the acoustic behavior of materials must be faced with. A
second step consists of the comparison between measured and simulated parameters which allows
a suitable calibration of the acoustic model in order to reduce the difference between measured and
simulated acoustical parameters to minimal values or at least to a value below the just noticeable
difference (JND) of each parameter. 3.1. The Virtual Model After having obtained a virtual model that represents adequately
the observed state of a room, desired changes or insertions are considered [11,12]. In situ checks and detailed 3D drawings of the Palatine Chapel allowed the realization of the
reticulated version of the geometry of the room (Figure 5). The number of surfaces in the model was
3849. The estimated inner surface amounted to 15,864 m2. Clearly, many details of the CAD drawings
could not be handled. Based on previous experience and software suggestions for the given volume
of the simulated room, the simulations were performed using the following parameters: TO = 2,
impulse response length = 6 s., resolution = 3 ms, and number of rays = 50,000. Other parameters
were assigned the default values of the software. Figure 5. Palatine Chapel: reticulated geometry (a) and rendering as given by Odeon (b). Figure 5. Palatine Chapel: reticulated geometry (a) and rendering as given by Odeon (b). 3.2. The Calibration of the Virtual Model The results of the difference expressed in
JND as receiver-averaged values and the relevant standard deviation for each octave band showed
satisfactory values (Figure 4). The highest errors were found in the octave band of 4 kHz for the EDT,
and in that of 250 Hz for the Ts, C80, and D50. Overall, results in Figure 4 shows that the calibration
was highly satisfactory. g
y
y
In order to assess the effect of occupancy, the area where chairs are generally located was
simulated as a series of boxes with a height of 0.8 m, with absorption coefficients typical of lightly
upholstered seats, as reported in Table 1 [17–19]. In the virtual model, the area occupied by the public
is 200 m2. Figure 6 shows the plan distribution of the occupancy, which was modeled as boxes. Table 1. Absorption and scattering coefficient used in the simulated model, data taken from [13–17]. Table 1. Absorption and scattering coefficient used in the simulated model, data taken from [13–17]. Material
Absorption (α)
Scattering (s)
125 Hz
250 Hz
500 Hz
1000 Hz
2000 Hz
4000 Hz
Hard
walls
0.048
0.047
0.045
0.05
0.053
0.03
0.05
Ceiling
0.145
0.13
0.14
0.145
0.098
0.06
0.01
Windows
0.35
0.25
0.18
0.12
0.07
0.02
0.05
Audience
0.51
0.64
0.75
0.80
0.82
0.78
0.70 The effect of the occupancy and the exact location of the source in historical churches have
recently received increasing attention due to the highly reflective characteristics of these spaces [17,20]. In previous studies, it was found that the presence of the audience in churches determines a
significant improvement of the monaural acoustical parameters, especially since the reverberation
reduces once the presence of the audience is considered. Reversely, the sound source position has
generally a limited effect over the reverberation time and a more significant impact on other acoustical
parameters, as these strongly depend on the source-receiver position. The results in Figure 7 show that the presence of the public is not sufficient to make the acoustics
of the chapel in line with the goals reported in Section 2. Consequently, some acoustic correction
treatments based on sound-absorbing surfaces were implemented. These treatments are considered
necessary since the early decay time in fully occupied conditions still resulted to be above 3 s at
middle frequencies. Figure 6. 3.2. The Calibration of the Virtual Model Most of the internal surfaces of the Palatine Chapel are constituted by flat marbles, which is
an acoustically reflective material. The vault is made of a thick structure composed of cocciopesto, a
lime mortar with crushed pottery. A relatively small fraction of the inner envelope is constituted of
windows, doors and a few canvases, which could have a more sound absorbing behavior. The initial values of the sound absorption (α) and sound scattering (s) were selected from
literature data [12–17]. Then, in order to validate the acoustic model, measured averaged values of the
different parameters were compared with the corresponding values calculated with the software. An
iterative procedure was used to reduce the difference between the measured and calculated values. This implied little adjustments to the sound absorption and scattering coefficients [13]. In order to
maintain the simplicity of the model together with its practicality, richly decorated surfaces were
modelled as flat ones while the absorption and scattering coefficients were modified accordingly [17]. Figure 4 displays the results of the calibration of the virtual model of the Palatine Chapel, as well
as the measured parameters, and it shows that the virtual model was able to obtain results particularly
close to the measured ones. When measured and simulated are compared, it is a common practice in
room acoustics to evaluate them in terms of the JND, the subjective limen of the specific parameter. This approach follows the common assumption that “what cannot be heard can be neglected” [14–16]. According to the standard ISO 3382 [4], the JND of the EDT is 5% of its value, while that of Ts, 7 of 14 Buildings 2016, 6, 1 C80, and D50 should be 10 ms, 1 dB, and 0.05, respectively. Thus, the precision of the simulated
parameters was assessed in terms of number of JND. The results of the difference expressed in
JND as receiver-averaged values and the relevant standard deviation for each octave band showed
satisfactory values (Figure 4). The highest errors were found in the octave band of 4 kHz for the EDT,
and in that of 250 Hz for the Ts, C80, and D50. Overall, results in Figure 4 shows that the calibration
was highly satisfactory. C80, and D50 should be 10 ms, 1 dB, and 0.05, respectively. Thus, the precision of the simulated
parameters was assessed in terms of number of JND. 3.2. The Calibration of the Virtual Model Plan distribution of the location of the audience (a), and position of banner treatments on
the sides and in the apse (b). Figure 6. Plan distribution of the location of the audience (a), and position of banner treatments on
the sides and in the apse (b). 8 of 14 8 of 14 Buildings 2016, 6, 1 Figure 7. Simulation results obtained considering the presence of the audience (full occupancy), and
with the acoustic absorbing curtains or perforated panels along lateral walls and in the apse. Figure 7. Simulation results obtained considering the presence of the audience (full occupancy), and
with the acoustic absorbing curtains or perforated panels along lateral walls and in the apse. 4. Acoustic Treatments Historic buildings, such as the Palatine Chapel, are heritage buildings whose cultural value
prevents invasive or irreversible interventions. In this case, given the completely marbled nature
of all the surfaces, permanent acoustic treatments to the room surfaces were not allowed. The need to
create acoustic conditions closer to the actual needs led to evaluate removable elements that could be
mounted and dismounted easily for specific events. Among the different acoustic treatment options,
it was considered the possibility to adopt transparent vibrating banners, eventually micro-perforated,
as well as heavy curtains. y
Vibrating panels and perforated (or micro-perforated) ones once mounted at a given distance
from a back rigid wall provide significant absorption at low frequencies. According to the theory,
the largest absorption of vibrating panels occur for a distance from the rear wall of a quarter of the
wavelength [21]. Micro-perforation in glazing or polycarbonate transparent panels were considered
as a solution to get an absorber with a minimal visual presence. These panels being micro-perforated
(with holes as small as 0.1 mm) behave as Helmholtz devices, but without the normal resistive
material. The holes are drilled mechanically and provide absorption through high viscous losses
as air passes through the holes. Micro-perforated transparent absorbers have reached an increasing
attention since they are transparent when looked at from straight on, although at oblique angles the
holes become more apparent although the surface is still translucent [21]. Panels with holes dimeters
ranging between 0.1 and 0.2 mm and with a percentage of holes in the range between 8% and 10% of
the surface were considered. Panels with a surface density of 0.48 kg/m2 and a thickness of 1.41 mm
were then selected. Another category of acoustics treatments that was considered is that of heavy textile materials. The absorption of these surfaces have received increasing attention in room acoustics application [22]. Add curtains sustained by rigid frame next to the base of the lateral walls could guarantee high
absorption especially at high frequency. Moreover, if the curtains were mounted at a given distance
from the back wall, the sound absorption would also be higher at lower frequencies, as a consequence
of the smaller impedance of the sound wave far from the wall. 4. Acoustic Treatments 9 of 14 Buildings 2016, 6, 1 Obviously, the specific effect of the absorption of curtains would depend on their distance from
the back walls, but the typical drapes of curtains determine a significant variation of their distance
from the rigid backing walls. This means that an exact determination of the sound absorption could
not be defined. In order to simulate the effects of curtains, the literature values reported by Cox and
D’Antonio for heavy curtains with a density of 610 g/m2 were used [22]. The absorption coefficient values of the different acoustic treatments considered for the acoustic
intervention are reported in Table 2. Overall, the acoustic treatments consisted of 250 square meter
panels, mainly distributed along the lateral walls each one with a height of 3.5 m from the floor
(Figure 6). The treatments were considered as temporary elements to display in the room in occasion
of specific events. In particular, the transparent vibrating panels, absorbing the low frequency
could guarantee a more tonal balanced acoustics of the room, which would be highly beneficial for
speech listening; reversely, the introduction of heavy curtains would represent an elegant way to
reduce the reverberation of the room, although their acoustic effect would be more appreciable at
higher frequencies. Table 2. Absorption coefficient of the acoustic treatments proposed in the Palatine chapel. Acoustic Treatment
Frequency (Hz)
125
250
500
1000
2000
4000
Transparent
micro-perforated panel
0.15
0.70
0.40
0.30
0.20
0.15
Heavy curtain banner
0.10
0.20
0.40
0.50
0.60
0.70 Table 2. Absorption coefficient of the acoustic treatments proposed in the Palatine chapel. Figure 7 shows the acoustic parameters of the fully occupied room and the effects of the addition
of banners placed on the side walls and in the apse. It can be noticed that the chapel still remains
with an excess of reverberation showing the typical behavior of large churches influenced by air
absorption at high frequencies [23]. Overall, the simulated values showed that the investigated room
with the proposed acoustic corrections has acoustical properties that could be considered adequate
for musical performance. Figures 8 and 9 report the color maps at 1 kHz of the T30, C80, and STI in the configuration
with the audience and with the heavy curtains and vibrating transparent micro-perforated panels
respectively. 4. Acoustic Treatments The figures show that the homogeneity of the sound field through the room also with
the introduction of sound absorbing treatments along the two sides. At middle frequencies, the area
where the audience seats would have a reverberation time equal to 2.6 s with the treatments of the
heavy curtain banners and to 2.8 s with the vibrating micro-perforated panels (Figure 7). The clarity reduces with the distance from the sound source, showing a remarkable behavior
from values up to 8 dB closer to the sound source to values between ´2 dB and ˘2 dB in the rest of
the chapel, both with the heavy curtains as well as with the vibrating panels. Finally, in order to assess the possibility to use this room for meetings, which involve speech
listening, the Speech Transmission Index (STI) was considered. This parameter represents the degree
of amplitude modulation in a speech signal and refers to the distortion in speech signals caused by
reverberation, echoes, and background noise. This index can assume values between 0 and 1, being
greater than 0.5 for favorable speech conditions. Results in Figures 8 and 9 show that the STI would be acceptable in the first half of the audience
area, while the area farther from the sound source (simulated in the apse) would have a STI value
around 0.45. Such a value generally corresponds to a “poor” speech listening condition. However, it
should be stated that these results were obtained with an omnidirectional sound source. This means
that a sound reinforcement system consisting of directive loudspeakers should be used for a better
speech listening in order to have improved STI values even in the back of the Chapel if this has to
host events were highly speech intelligibility is required. 10 of 14 Buildings 2016, 6, 1 gure 8. Color maps at 1 kHz of the T30, C80, and STI in the configuration with the audi
oustic treatments heavy curtain banners (the maps only cover the area where the audi Figure 8. Color maps at 1 kHz of the T30, C80, and STI in the configuration with the audience and the
acoustic treatments heavy curtain banners (the maps only cover the area where the audience seats). 11 of 14 Buildings 2016, 6, 1 e 9. 4. Acoustic Treatments Color maps at 1 kHz of the T30, C80, and STI in the configuration with the audienc
rated transparent banners (the maps only cover the area where the audience seats). Figure 9. Color maps at 1 kHz of the T30, C80, and STI in the configuration with the audience and the
perforated transparent banners (the maps only cover the area where the audience seats). 12 of 14 12 of 14 Buildings 2016, 6, 1 Figure 10. Sound strength (G) at the frequency of 250 Hz and 1 kHz in different configurations. Figure 10. Sound strength (G) at the frequency of 250 Hz and 1 kHz in different configurations. Figure 10. Sound strength (G) at the frequency of 250 Hz and 1 kHz in different configurations. A final evaluation of the acoustic interventions presented in this paper regarded the impact of
the sound absorption materials over the sound strength. The sound strength was evaluated along
the central axes of the Royal Chapel room both at 250 Hz and 1 kHz (Figure 10). The choice to
check the sound absorption at both low and middle frequencies was due to the highly absorptive
behavior of the vibrating panels at low frequencies. In fact, although the acoustics intervention
with micro perforated vibrating panels aimed to absorb the low frequencies and hence to reduce
the frequency unbalanced response of the rom, it was considered important to control the overall
sound strength levels. The sound strength (G) was simulated in different scenarios: in the actual condition, with
and without the audience, and after the introduction of the acoustic treatments of the banners. As
expected, in the empty condition of the hall, the parameter G has higher values than when the
audience and the acoustic treatments are introduced. In particular, in the room before the introduction
of the acoustic treatments, the G decreases almost linearly closer to the sound source, while at a larger
distance the sound field becomes diffuse and the G assumes more stable values. Reversely, after the
introduction of the acoustics treatments the sound field does not become diffuse quickly, while the
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6. Berardi, U. A double synthetic index to evaluate the acoustics of churches. Arch. Acoust. 2012, 37, 521–528. [CrossRef] 6. Berardi, U. A double synthetic index to evaluate the acoustics of churches. Arch. Acoust. 2012, 37, 521–528. [CrossRef] 7. Martellotta, F. Subjective study of preferred listening conditions in italian catholic churches. J. Sound Vib. 2008, 317, 378–399. [CrossRef] 8. Katz, B.F.G. International round robin on room acoustical impulse response analysis software. Acoust. Res. Lett. Online 2004, 5, 158–164. [CrossRef] 9. Krokstad, A.; Strøm, S.; Sørsdal, S. Calculating the acoustical room response by the use of a ray tracing
technique. J. Sound Vib. 1968, 8, 118–125. [CrossRef] 10. Patania, F.; Gagliano, A.; Nocera, F.; Galesi, A. Intervention of acoustic correction to improve speech quality
of two conference halls in a Sicilian historical building (XVI sec.). In Proceedings of the 38th International
Congress on Noise Control Engineering, Ottawa, Canada, 23–26 August 2009. Congress on Noise Control Engineering, Ottawa, Canada, 23–26 August 2009. 11. Bork, I. Report on the 3rd round robin on room acoustical computer simulation—Part I: Measurements. Acta Acust. United Acust. 2005, 91, 740–752. 12. Bork, I. 5. Conclusions This paper has reported a study about the acoustics in a cultural heritage buildings, the Palatine
Chapel in the Royal Palace in Caserta (Italy). Average reverberation times of about 5 s recorded
initially at mid frequencies in unoccupied conditions were deemed inappropriate for the public events
hosted in this room nowadays. This situation requires to propose acoustics treatments that could
modify the acoustics of the room, while respecting the historical and architectonical value of the room. Simulation techniques provided useful information for understanding how to improve the
acoustics of this room. Firstly, simulations were used for to obtain realistic data about the current
acoustics of the room in fully occupied conditions. The study showed that even in fully occupancy
conditions, the reverberation time would still be too long. Hence a study of the effects of temporary
acoustic treatments compatible with the specific nature of the room was carried out. For this
scope, heavy curtains along the lateral walls as well as transparent vibrating panels were considered
opportunities to introduce occasionally high sound absorption with minimal aesthetic or visual
impact respectively. 13 of 14 13 of 14 Buildings 2016, 6, 1 The acoustic treatments that were proposed guaranteed a reduction of the reverberation to about
2.5 s at middle frequencies. The final acoustic characteristics were therefore considered acceptable for
the functions hosted in this chapel while also considering the historical value of this cultural heritage. Author Contributions: Umberto Berardi, Gino Iannace and Carmine Ianniello contributed equally to this work. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest. References Report on the 3rd round robin on room acoustical computer simulation—Part II: Calculations. Acta
Acust. United Acust. 2005, 91, 753–763. 13. Zeng, X.; Christensen, C.L.; Rindel, J.H. Practical methods to define scattering coefficients in a room
acoustics computer model. Appl. Acoust. 2006, 67, 771–786. [CrossRef] 14. Christensen, C.L.; Koutsouris, G.; Rindel, J.H. The ISO 3382 parameters: Can we simulate them? Can we
measure them? In Proceedings of the International Symposium on Room Acoustics, Toronto, ON, Canada,
9–10 June 2013. 15. Galindo, M.; Zamarreno, T.; Girón, S. Acoustic simulations of Mudejar-Gothic churches. J. Acoust. Soc. Am. 2009, 126, 1207–1218. [CrossRef] [PubMed] 16. Vorländer, M. Computer simulations in room acoustics: Concepts and uncertaintie. J. Acoust. Soc. Am. 2013, 133, 1203–1213. [CrossRef] [PubMed] 17. Berardi, U. Simulation of acoustical parameters in rectangular churches. J. Build. Perform. Simul. 2014, 7,
1–16. [CrossRef] 18. Hidaka, T.; Nishihara, N.; Beranek, L.L. Mechanism of sound absorption by seated audiences in concert
halls. J. Acoust. Soc. Am. 1996, 100, 2705–2706. [CrossRef] 19. Beranek, L.L.; Hidaka, T. Sound absorption in concert halls by seats, occupied and unoccupied, and by the
hall’s interior surfaces. J. Acoust. Soc. Am. 1998, 104, 3169–3177. [CrossRef] 20. Alvarez-Morales, L.; Martellotta, F. A geometrical acoustic simulation of the effect of occupancy and source
position in historical churches. Appl. Acoust. 2015, 91, 47–58. [CrossRef] 14 of 14 14 of 14 Buildings 2016, 6, 1 21. Berardi, U.; Cirillo, E.; Martellotta, F. A comparative analysis of energy models in churches. J. Acoust. Soc. Am. 2009, 126, 1838–1849. [CrossRef] [PubMed] 22. Asdrubali, F.; Pispola, G. Properties of transparent sound-absorbing panels for use in noise barriers. J. Acoust. Soc. Am. 2007, 121, 214–221. [CrossRef] 23. D’Antonio, P.;
Cox, T. Technical Bulletin on the Design of Microperforated Transparent Absorbers;
RPG
Diffusor
Systems,
Inc.,
2005. Available
online:
http://www.rpginc.com/docs/
Technology/White%20Papers/Clearsorber%20White%20Paper.pdf (accessed on 21 December 2015). © 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open
access article distributed under the terms and conditions of the Creative Commons by
Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
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Mass and Heat Transfer During Two-Phase Flow in Porous Media - Theory and Modeling
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1
Mass and Heat Transfer During Two-Phase Flow in
Porous Media - Theory and Modeling
Jennifer Niessner1 and S. Majid Hassanizadeh2
1 Institute
2 Department
of Hydraulic Engineering, University of Stuttgart, Stuttgart
of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht
1 Germany
2 The Netherlands
1. Introduction
1.1 Motivation
This chapter focusses on the description and modeling of mass transfer processes occurring
between two fluid phases in a porous medium. The principle underlying physical process
comprises a transport of particles from one phase to the other phase. This process takes
place across fluid–fluid interfaces (see Fig. 1) and may constitute evaporation, dissolution,
or condensation, for example.
Such mass transfer processes are crucial in many applications involving flow and transport in
porous media. Major examples are found in soil science (where the evaporation from soils is
of interest), soil and groundwater remediation (like thermally-enhanced soil vapor extraction
where dissolution, evaporation, and condensation play a role), storage of carbon dioxide in
the subsurface (where the dissolution of carbon dioxide in the surrounding groundwater is a
crucial storage mechanism), CO2 -enhanced oil recovery (where after primary and secondary
recovery, carbon dioxide is injected into the reservoir in order to mobilize an additional 8-20
per cent of oil), and various industrial porous systems (such as certain types of fuel cells).
Let us have a closer look at a few of these applications and identify where interphase mass
transfer is relevant. Four specific examples are shown in Fig. 2 and briefly described.
solid phase
fluid
phase 1
fluid phase 2
Fig. 1. Mass transfer processes (evaporation, dissolution, condensation) imply a transfer of
particles across fluid–fluid interfaces.
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(a) Carbon dioxide storage in the subsurface
(figure from IPCC (2005))
(b) Soil contamination and remediation
precipitation
radiation
infiltration
evaporation
groundwater
(c) Enhanced
www.oxy.com)
oil
recovery
(figure
from
(d) Evaporation from soil
Fig. 2. Four applications of flow and transport in porous media where interphase mass
transfer is important
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(a) Carbon capture and storage (Fig. 2 (a)) is a recent strategy to mitigate the greenhouse
effect by capturing the greenhouse gas carbon dioxide that is emitted e.g. by coal power
plants and inject it directly into the subsurface below an impermeable caprock. Here, three
different storage mechanisms are relevant on different time scales: 1) The capillary barrier
mechanism of the caprock. This geologic layer is meant to keep the carbon dioxide in the
storage reservoir as a separate phase. 2) Dissolution of the carbon dioxide in the surrounding
brine (salty groundwater). This is a longterm storage mechanism and involves a mass
transfer process as carbon dioxide molecules are “transferred” from the gaseous phase to
the brine phase. 3) Geochemical reactions which immobilize the carbon dioxide through
incorporation into the rock matrix.
(b) Shown in Fig. 2 (b) is a cartoon of a light non-aqueous phase liquid (LNAPL)
soil contamination and its clean up by injection of steam at wells located around the
contaminated soil. The idea behind this strategy is to mobilize the initially immobile
(residual) LNAPL by evaporation of LNAPL component at large rates into the gaseous
phase. The soil gas is then extracted by a centrally located extraction well. It means that the
remediation mechanism relies on the evaporation of LNAPL component which represents a
mass transfer from the liquid LNAPL phase into the gaseous phase.
(c) In order to produce an additional 8-20% of oil after primary and secondary recovery,
carbon dioxide may be injected into an oil reservoir, e.g. alternatingly with water, see
Fig. 2 (c). This is called enhanced oil recovery. The advantage of injecting carbon dioxide lies
in the fact that it dissolves in the oil which in turn reduces the oil viscosity, and thus, increases
its mobility. The improved mobility of the oil allows for an extraction of the otherwise
trapped oil. Here, an interphase mass transfer process (dissolution) is responsible for an
improved recovery.
(d) The last example (Fig. 2 (d)) shows the upper part of the soil. The water balance of this part
of the subsurface is extremely important for agriculture or plant growth in general. Plants
do not grow well under too wet or too dry conditions. One of the very important factors
influencing this water balance (besides surface runoff and infiltration) is the evaporation of
water from the soil, which is again an interphase mass transfer process.
1.2 Purpose of this work
Mass transfer processes are essential in a large variety of applications—the presented
examples only show a small selection of systems. A common feature of all these applications is
the fact that the relevant processes occur in relatively large domains such that it is not possible
to resolve the pore structure and the fluid distribution in detail (left hand side of Fig. 3).
Instead, a macro-scale approach is needed where properties and processes are averaged over
a so-called representative elementary volume (right hand side of Fig. 3). This means that the
common challenge in all of the above-mentioned applications is how to describe mass transfer
processes on a macro scale. This transition from the pore scale to the macro scale is illustrated
in Fig. 3 where on the left side, the pore-scale situation is shown (which is impossible to be
resolved in detail) while on the right hand side, the macro-scale situation is shown.
2. Overview of classical mass transfer descriptions
2.1 Pore-scale considerations
In order to better understand the physics of interphase mass transfer, which is essential to
provide a physically-based description of this process, we start our considerations on the pore
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n
w
non−wetting
fluid phase
wetting
fluid phase
s
solid
phase
macro scale
pore scale
Fig. 3. Pore-scale versus macro-scale description of flow and transport in a porous medium.
scale. From there, we try to get a better understanding of the macro-scale physics of mass
transfer, which is our scale of interest.
In Fig. 1 we have seen that interphase mass transfer is inherently a pore-scale process as
it—naturally—takes place across fluid–fluid interfaces. Let us imagine a situation where two
fluid phases, a wetting phase and a non-wetting phase, are brought in contact as shown in
Fig. 4. Commonly, when the two phases are brought in contact (time t = t0 ), equilibrium is
quickly established directly at the interface. With respect to mass transfer, this means that
the concentration of non-wetting phase particles in the wetting phase at the interface as well
as the concentration of wetting-phase particles in the non-wettting phase at the interface are
1 . At t = t , away from the interface, there
2
both at their equilibrium values, C1,eq
and C2,eq
0
is still no presence of α-phase particles in the β-phase. At a later time t = t1 , concentration
profiles develop within the phases. However, within the bulk phases, the concentrations are
still different from the respective equilibrium concentration at the interface. Considering a
still later point of time, t = t2 , the equilibrium concentration is finally reached everywhere in
the bulk phases.
These considerations show that mass transfer on the pore scale is inherently a kinetic process
that is very much related to phase-interfaces. But how is this process represented on the macro
scale, i.e. on a volume-averaged scale? This is what we will focus on in the next section.
t = t0
t = t1
t = t2
solid phase
solid phase
solid phase
fluid
phase 1
fluid
phase 1
fluid phase 2
C
C
2
2
C1,eq
1
C2,eq
1
C2,eq
1
C2,eq
x
Fig. 4. Pore-scale picture of interphase mass transfer.
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fluid phase 2
C
C1,eq
2
C1,eq
fluid
phase 1
fluid phase 2
x
x
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2.2 Current macro-scale descriptions
In Fig. 3, we illustrated the fact that when going from the pore scale to the macro scale,
information about phase-interfaces is lost. The only information present on the macro scale is
related to volume ratios, such as porosity and fluid saturations. But, as mentioned earlier,
mass transfer is strongly linked to the presence of interfaces and interfacial areas and all
the information about phase-interfaces disappears on the macro scale. This means that the
description of mass transfer on the macro scale is not straight forward. Classical approaches
for describing mass transfer generally rely on one of the following two principles:
1. assumption of local chemical equilibrium within an averaging volume or
2. kinetic description based on a fitted (linear) relationship.
These two classical approaches will be discussed in more detail in the following. An
alternative approach which accounts for the phase-interfacial area will be presented later in
Sec. 3.
2.2.1 Local equilibrium assumption
The assumption of local chemical equilibrium within an averaging volume means that the
equilibrium concentrations are reached instantaneously everywhere within an averaging
volume (in both phases). That means it is assumed that everywhere within the averaging
volume, the situation at t = t2 in Fig. 4 is reached from the beginning (t = t0 ). Thus, at each
point in the wetting phase and at each point in the non-wetting phase within the averaging
volume, the equilibrium concentration of the components of the other phase is reached.
This is an assumption which may be good in case of fast mass transfer, but bad in case of
slow mass transfer processes. To be more precise, the assumption that the composition of
a phase is at or close to equilibrium may be good if the characteristic time of mass transfer
is small compared to that of flow. However, if large flow velocities occur as e.g. during air
sparging, the local equilibrium assumption gives completely wrong results, see Falta (2000;
2003) and van Antwerp et al. (2008). We will investigate and quantify this issue later in Sec. 3.3
.
Local equilibrium models for multi-phase systems have been introduced and developed
e.g. by Miller et al. (1990); Powers et al. (1992; 1994); Imhoff et al. (1994); Zhang & Schwartz
(2000) and have been used and advanced ever since. Let us consider a system with a liquid
phase (denoted by subscript l) and a gaseous phase (denoted by subscript g) composed of
air and water components. Then, Henry’s Law is employed to determine the mole fraction
of air in the liquid phase, while the mole fraction of water in the gas phase is determined by
assuming that the vapor pressure in the gas phase is equal to the saturation vapor pressure.
Denoting the water component by superscript w and the air component by superscript a, this
yields
xla
xw
g
=
p ag · Hla− g
(1)
=
pw
sat
(2)
pg
,
where xla [−] is the mole fraction of air in the liquid phase, x w
g [−] is the mole fraction of water
1
a
in the gaseous phase, Hl − g Pa is the Henry constant for the dissolution of air in the liquid
a
phase, pw
sat [ Pa ] is the saturation vapor pressure of water, p g [ Pa ] is the partial pressure of air
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in the gas phase while p g [ Pa] is the gas pressure. The remaining mole fractions result simply
from the condition that mole fractions in each phase have to sum up to one,
xlw
x ga
=
=
1 − xla
1−
xw
g.
(3)
(4)
Note that while for a number of applications the equilibrium mole fractions are constants or
merely a function of temperature, in our case, they will be functions of space and time as
pressure and the composition of the phases changes.
2.2.2 Classical kinetic approach
Kinetic mass transfer approaches are traditionally applied to the dissolution of contaminants
in the subsurface which form a separate phase from water, the so-called non-aqueous phase
liquids (NAPLs). If such a non-aqueous phase liquid is heavier than water, it is called
“dense non-aqueous phase liquid” or DNAPL. When an immobile lense of DNAPL is present
at residual saturation (i.e. at a saturation which is so low that the phase is immobile) and
dissolves into the surrounding groundwater, the kinetics of this mass transfer process usually
plays an important role: the dissolution of DNAPL is a rate-limited process. This is also
the case when a pool of DNAPL is formed on an impermeable layer. In these relatively
simple cases, only the mass transfer of a DNAPL component from the DNAPL phase into
the water phase has to be considered. For these cases, classical models acknowledge the
fact that the rate of mass transfer is highly dependent (proportional to) interfacial area and
assume a first-order rate of kinetic mass transfer between fluid phases in a porous medium
on a macroscopic (i.e. volume-averaged) scale which can be expressed as (see e.g. Mayer &
Hassanizadeh (2005)):
κ
Qκα→ β = kκα→ β aαβ (Cβ,s
− Cβκ ),
(5)
kg
where Qκα→ β m3 s is the interphase mass transfer rate of component κ from phase α to
phase β, kκα→ β ms is the mass transfer rate coefficient, aαβ m1 is the specific interfacial
kg
κ
area separating phases α and β, Cβ,s
is the solubility limit of component κ in phase
m3
kg
β, and finally, Cβκ m3 is the actual concentration of component κ in phase β. The actual
κ . The case C κ = C κ corresponds
concentration is not larger than the solubility limit, Cβκ ≤ Cβ,s
β
β,s
to the local equilibrium case.
In the absence of a physically-based estimate of interfacial area in classical kinetic models, the
mass transfer coefficient kκα→ β and the specific interfacial area aαβ are often lumped into one
single parameter (Miller et al. (1990); Powers et al. (1992; 1994); Imhoff et al. (1994); Zhang &
Schwartz (2000)). This yields, in a simplified notation,
Q = k(Cs − C ).
(6)
Here, Cs is the solubility limit of the DNAPL component
in water and C is its actual
1
concentration. The lumped mass transfer coefficient k s is commonly related to a modified
Sherwood number Sh by
Dm
k = Sh 2 ,
(7)
d50
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2
where Dm ms is the aqueous phase molecular diffusion coefficient, and d50 [m] is the mean
size of the grains. The Sherwood number is then related to Reynold’s number Re and DNAPL
saturation Sn [−] by
Sh = pReq Snr ,
(8)
where p, q, and r are dimensionless fitting parameters. This is a purely empirical relationship.
Although interphase mass transfer is proportional to specific interfacial area in the original
Eq. (5), this dependence cannot explicitly be accounted for as the magnitude of specific
interfacial area is not known.
An alternative classical approach for DNAPL pool dissolution has been proposed by Falta
(2003) who modeled the dissolution of DNAPL component by a dual domain approach
for a case with simple geometry. For this purpose, they divided the contaminated porous
medium into two parts: one that contains DNAPL pools and one without DNAPL. For
their simple case, the dual domain approach combined with an analytical solution for
steady-state advection and dispersion provided a means for modeling rate-limited interphase
mass transfer. While this approach provided good results for the case of simplified geometry,
it might be oversimplified for the modeling of realistic situations.
3. Interfacial-area-based approach for mass transfer description
3.1 Theoretical background
Due to a number of deficiencies of the classical model for two-phase flow in porous media
(one of which is the problem in describing kinetic interphase mass transfer on the macro
scale), several approaches have been developed to describe two-phase flow in an alternative
and thermodynamically-based way. Among these are a rational thermodynamics approach
by Hassanizadeh & Gray (1980; 1990; 1993b;a), a thermodynamically constrained averaging
theory approach by Gray and Miller (e.g. Gray & Miller (2005); Jackson et al. (2009)),
mixture theory (Bowen (1982)) and an approach based on averaging and non-equilibrium
thermodynamics by Marle (1981) and Kalaydjian (1987). While Marle (1981) and Kalaydjian
(1987) developed their set of constitutive relationships phenomenologically, Hassanizadeh &
Gray (1990; 1993b); Jackson et al. (2009), and Bowen (1982) exploited the entropy inequality
to obtain constitutive relationships. To the best of our knowledge, the two-phase flow models
of Marle (1981); Kalaydjian (1987); Hassanizadeh & Gray (1990; 1993b); Jackson et al. (2009)
are the only ones to include interfaces explicitly in their formulation allowing to describe
hysteresis as well as kinetic interphase mass and energy transfer in a physically-based way. In
the following, we follow the approach of Hassanizadeh & Gray (1990; 1993b) as it includes
the spatial and temporal evolution of phase-interfacial areas as parameters which allows
us to model kinetic interphase mass transfer in a much more physically-based way than is
classically done.
It has been conjectured by Hassanizadeh & Gray (1990; 1993b) that problems of the classical
two-phase flow model, like the hysteretic behavior of the constitutive relationship between
capillary pressure and saturation, are due to the absence of interfacial areas in the theory.
Hassanizadeh and Gray showed (Hassanizadeh & Gray (1990; 1993b)) that by formulating
the conservation equations not only for the bulk phases, but additionally for interfaces,
and by exploiting the residual entropy inequality, a relationship between capillary pressure,
saturation, and specific interfacial areas (interfacial area per volume of REV) can be derived.
This relationship has been determined in various experimental works (Brusseau et al. (1997);
Chen & Kibbey (2006); Culligan et al. (2004); Schaefer et al. (2000); Wildenschild et al. (2002);
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Chen et al. (2007)) and computational studies (pore-network models and CFD simulations
on the pore scale, see Reeves & Celia (1996); Held & Celia (2001); Joekar-Niasar et al. (2008;
2009); Porter et al. (2009)). The numerical work of Porter et al. (2009) using Lattice Boltzman
simulations in a glass bead porous medium and experiments of Chen et al. (2007) show
that the relationship between capillary pressure, the specific fluid-fluid interfacial area, and
saturation is the same for drainage and imbibition to within the measurement error. This
allows for the conclusion that the inclusion of fluid–fluid interfacial area into the capillary
pressure–saturation relationship makes hysteresis disappear or, at least, reduces it down
to a very small value. Niessner & Hassanizadeh (2008; 2009a;b) have modeled two-phase
flow—using the thermodynamically-based set of equations developed by Hassanizadeh &
Gray (1990)—and showed that this interfacial-area-based model is indeed able to model
hysteresis as well as kinetic interphase mass and also energy transfer in a physically-based
way.
3.2 Simplified model
After having presented the general background of our interfacial-area-based model, we will
now proceed by discussing the mathematical model. The complete set of balance equations
based on the approach of Hassanizadeh & Gray (1990) is too large to be handled numerically.
In order to do numerical modeling, simplifying assumptions need to be made. In the
following, we present such a simplified equation system as was derived in Niessner &
Hassanizadeh (2009a).
This set of balance equations can be described by six mass and three momentum balance
equations. These numbers result from the fact that mass balances for each component of each
phase and the fluid–fluid interface (that is 2 × 3) while momentum balances are given for the
bulk phases and the interface. Governing equations were derived by Hassanizadeh & Gray
(1979) and Gray & Hassanizadeh (1989; 1998) for the case of flow of two pure fluid phases
with no mass transfer. Extending these equations to the case of two fluid phases, each made
of two components, we obtain the following equations.
mass balance for phase components (κ = w, a):
∂ φSl ρ̄l X̄lκ
κ
+ ∇ · (φSl ρ̄l X̄lκ v̄l ) − ∇ · φSl j̄l
∂t
1
= ρ̄l Qκl +
(9)
ρl Xlκ vlg − vl + jκ · nlg dA
l
V Alg
∂ φSg ρ̄ g X̄gκ
κ
+ ∇ · φSg ρ̄ g X̄gκ v̄ g − ∇ · φSg j̄ g
∂t
1
= ρ̄ g Qκg +
(10)
ρ g Xgκ v g − vlg − jκ · nlg dA
g
V Alg
mass balance for lg-interface components (κ = w, a):
κ a
∂ Γ̄lg X̄lg
lg
κ
κ
+ ∇ · Γ̄lg X̄lg
alg v̄lg − ∇ · j̄ alg −
lg
∂t
1
ρl Xlκ vl − vlg − jκ − ρ g Xgκ v g − vlg + jκ · nlg dA
=
l
g
V Alg
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momentum balance for phases:
=
=
∂ (φSl ρ̄l v̄l )
+ ∇ · (φSl ρ̄l v̄l v̄l ) − ∇ · (φSl T l )
∂t
1
ρl vl vlg − vl + tl · nlg dA
V Alg
∂ φSg ρ̄ g v̄ g
+ ∇ · φSg ρ̄ g v̄ g v̄ g − ∇ · φSg T g
∂t
1
ρ g v g v g − vlg − t g · nlg dA
V Alg
momentum balance for lg-interface:
∂ Γ̄lg v̄lg alg
+ ∇ · Γ̄lg v̄lg alg v̄lg − ∇ · T lg alg
∂t
1
=
ρl vl vl − vlg − tl − ρ g v g v g − vlg + t g · nlg dA,
V Alg
(12)
(13)
(14)
κ
where the overbars denote volume-averaged (macro-scale)
3 quantities. Here, Xα [−] is the
mass fraction of component κ in phase α, t is time, Qκα ms is an external source of component
kg·m4
κ in phase α, jκ
is the diffusive flux of component κ in phase α, V is the magnitude of
s
α
the averaging volume, Alg denotes the interfaces separating the l-phase and the g-phase in an
averaging volume, vlg ms is the velocity of the lg-interface, and nlg is the unit vector normal
κ [−] is the mass fraction of component κ
to Alg and pointing into the g-phase. Furthermore, Xlg
4
kg
kg
·
m
is the diffusive flux of component κ in the lg-interface, tα m·s2
in the lg-interface, jκ
s
lg
kg
is the α-phase micro-scale stress tensor, T α s2 is the α-phase macro-scale stress tensor, and
kg
T lg s2 is the macro-scale lg-interfacial stress tensor.
In the following, we provide a simplified version of Eq. (9) through (14). First, we assume
that the composition of the interface does not change. This is a reasonable assumption as long
as no surfactants are involved. This reduces the number of balance equations to eight, as we
can sum up the mass balance equations for interface components. Furthermore, we assume
that momentum balances can be simplified so far that we end up with Darcy-like equations
for both bulk phases and interface. We further proceed by applying Fick’s law to relate the
micro-scale diffusive fluxes jκ to the local concentration gradient resulting in the following
α
approximation:
κ
ρα Dκ
jκ · nlg = ± κ alg Xα,s
− Xακ ,
(15)
α
d
2
where Dκ ms is the micro-scale Fickian diffusion coefficient for component κ, dκ [m] is the
κ [−] is the solubility limit of component κ in phase α
diffusion length of component κ, Xα,s
(i.e. the mass fraction corresponding to local equilibrium), and Xακ [−] is the micro-scale mass
fraction of component κ in phase α at a distance dκ away from the interface. Niessner &
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Hassanizadeh (2009a) obtained the following determinate set of macro-scale equations:
∂ φSl ρ̄l X̄lw
w
+ ∇ · (ρ̄l X̄lw v̄l ) − ∇ · j̄l
∂t
D w ρ̄ g
w
w
= ρl Qw
l − dw alg X g,s − X g
∂ φSl ρ̄l X̄la
a
+ ∇ · (ρ̄l X̄la v̄l ) − ∇ · j̄l
∂t
D a ρ̄
a
− Xla
= ρl Qla + a l alg Xl,s
d
∂ φSg ρ̄ g X̄gw
+
∂t
=
∂ φSg ρ̄ g X̄ga
+
∂t
=
∂alg
∂t
+ ∇ · alg vlg
=
Elg
v̄l
=
−K
v̄ g
=
v̄lg
+ Xla
+ Xga
=
=
=
=
=
−Klg ∇ alg
p g − pl
1
1
1
alg
=
alg (Sl , pc ),
pc
Sl + S g
Xlw
Xgw
w
∇ · ρ̄ g X̄gw v̄ g − ∇ · j̄ g
D w ρ̄ g
w
ρ g Qw
alg Xg,s
− Xgw
g +
w
d
a
∇ · ρ̄ g X̄ga v̄ g − ∇ · j̄ g
D a ρ̄
a
− Xla
ρ g Q ag − a l alg Xl,s
d
Sl2
∇ pl − ρ̄l g
µl
S2g
−K
∇ p g − ρ̄ g g
µg
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
κ
α
The macro-scale mass fluxes j̄ are given by a Fickian dispersion equation,
κ
α
j̄ = −ρα D̄ακ ∇ ( X̄ακ ) ,
(29)
where D̄ακ is the macro-scale dispersion coefficient. Note that in Eq. (16) through (19), we
have acknowledged the fact that an internal source of a component in one of the phases
must correspond to a sink of that component of equal magnitude in the other phase. The
w and X a are obtained from a local equilibrium assumption at the
solubility limits Xg,s
l,s
fluid–fluid interface. If, for example, we consider a two-phase–two-component air–water
system solubility limits with respect to mole fractions are given by Eqs. (1) and (2).
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3.3 Is a kinetic approach necessary?
Depending on the parameters, initial conditions, and boundary conditions of the system,
kinetics might be important for mass transfer. If so, then it may not be sufficient to use a
classical local equilibrium model instead of the more complex interfacial-area-based model.
To allow for a decision, Niessner & Hassanizadeh (2009a) make the system of equations (16)
through (28) dimensionless and study the dependence of kinetics on Damköhler number and
Peclet number.
To do so, they define dimensionless variables:
t∗
=
a∗lg
=
∗
Elg
=
p∗α
=
tv R
,
φL
alg
a R,lg
∇ ∗ = L ∇,
a R,lg φL
vR
pα
,
pR
D̄ακ ∗ =
,
D̄ακ
,
DR,α
g∗ =
Elg ,
α
p∗c =
v̄∗α =
pc
,
pR
v̄α
,
vR
v∗lg =
ρ̄α gL
pR
Qκα L
κ v ,
Xα,s
R
(30)
φ
v ,
v R lg
∗
Klg
=
,
ρ∗g =
Qκα∗ =
ρ̄ g
ρ̄l
(31)
φKlg
La R,lg v R
µ∗l =
,
(32)
µl
.
µg
(33)
Here, ρ∗g is density ratio, µ∗l is viscosity ratio, v R is a reference velocity, L is a characteristic
length, a R,lg is a reference specific interfacial area, DR,α is a reference dispersion coefficient,
and p R is a reference pressure. We assume that p R and v R can be chosen such that
Also, Peclet number Peα and Damköhler number Daκ are defined by
Peα =
vR L
,
DR,α
Daκ =
Dκ La R,lg
dv R
Kp R
µl v R L
.
= 1.
(34)
These definitions lead to the following dimensionless form of Eq. (16) through (28):
Dlw∗ ∗ w
∇ X̄l
Pel
Dla∗ ∗ a
∂
∗
a ∗
∗
a
−
∇
·
v
+
∇
·
S
∇ X̄l
X̄
X̄
)
)
(
(
l
l
l
l
∂t∗
Pel
Dgw∗ ∗ w
∂
∗
∗
w ∗
w
∇ X̄g
Sg X̄g + ∇ · X̄g v g − ∇ ·
∂t∗
Peg
Dga∗ ∗ a
∂
∗
∗
a ∗
a
Sg X̄g + ∇ · X̄g v g − ∇ ·
∇ X̄g
∂t∗
Peg
∂
(S X̄ w ) + ∇∗ · ( X̄lw v∗l ) − ∇∗ ·
∂t∗ l l
∂a∗lg
∂t∗
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+ ∇∗ · a∗lg v∗lg
=
w
w
∗
w ∗ ∗
Qw
l − Da alg ρ g X g,s − X̄ g (35)
=
a
Qla∗ + Daa a∗lg Xl,s
− X̄la
(36)
=
∗
w ∗
w
w
Qw
g + Da alg X g,s − X̄ g
(37)
=
=
v∗l
=
v∗g
=
1 a
Q ag∗ − Daa a∗lg ∗ Xl,s
− X̄la (38)
ρg
∗
Elg
(39)
−Sl2 ∇∗ p∗l − g∗l
−S2g µ∗l ∇∗ p∗g − g∗g
(40)
(41)
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v∗lg
=
∗ ∗ ∗
−Klg
∇ alg
(42)
p∗c
=
=
=
=
p∗g − p∗l
(43)
1
(44)
1
(45)
1
(46)
=
a∗lg (Sl , p∗c ) .
(47)
Sl + S g
X̄lw + X̄la
X̄gw + X̄ga
a∗lg
In order to investigate the importance of kinetics, we define Pe := Pel = Peg and Da := Daw =
Daa and vary Pe and Da independently over five orders of magnitude. Therefore, we consider
a numerical example where dry air is injected into a horizontal (two-dimensional) porous
medium of size 0.7 m × 0.5 m that is almost saturated with water (initial and boundary water
saturation of 0.9).
a
Fig. 5 shows a comparison of actual mass fractions X̄la and X̄gw to solubility mass fractions Xl,s
w
and Xg,s for five different Damköhler numbers. Therefore, a cut through the domain is shown
and two different time steps are compared.
Da=0.1 Da0
Da=0.01 Da0
4.0E-5
4E−5
Da=Da0
4.0E-5
4E−5
Da=10 Da0
4.0E-5
4E−5
Da=100 Da0
4.0E-5
4E−5
4.0E-5
4E−5
a
Xl [−]
t = 0.0035s
0m
x
0.7m
0.7
00
0.014
0.014
0m
x
0.7m
0.7
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
00
0.014
0.014
0m
x
0.7m
0.7
0m
x
0.7m
0.7
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
00
0.014
0.014
00
0.014
0.014
00m
0
0.014
0.014
x
0.7m
0.7
w
Xg [−]
4.0E-5
4E−5
4.0E-5
4E−5
4.0E-5
4E−5
4.0E-5
4E−5
00m
0
x
0.7m
0.7
4.0E-5
4E−5
a
Xl [−]
00m
0
t = 0.01s
x
0.7m
0.7
0.014
0.014
00m
0
x
0.7m
0.7
0.014
0.014
00m
0
x
0.7m
0.7
0.014
0.014
00m
0
x
0.7m
0.7
0.014
0.014
00m
0
x
0.7m
0.7
0.014
0.014
w
Xg [−]
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
00m
0
x
0.7m
0.7
solubility limit
actual mass fraction
a and X w and actual mass fractions X̄ a and X̄ w for two different
Fig. 5. Solubility limits Xl,s
g
g,s
l
time steps (0.0035 s and 0.01 s) and 5 different Damköhler numbers.
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13
It can be seen that the system is practically instantaneously in equilibrium with respect to the
mass fraction X̄gw (water mass fraction in the gas phase) for the whole range of considered
Damköhler numbers (see the second and forth row of graphs). With respect to the mass
fraction X̄la (air mass fraction in the water phase), for low Damköhler numbers and early times,
the system is far from equilibrium (see the first and third row of graphs). With increasing
time and with increasing Damköhler number, the system approaches equilibrium. As for
high Damköhler numbers mass transfer is very fast, an ”overshoot“ occurs and the system
becomes oversaturated before it reaches equilibrium.
One might argue that the considered time steps are extremely small and not relevant for the
time scale relevant for the whole domain. However, what happens at this very early time has
a large influence on the state of the system at all subsequent times.
It turned out that for different Peclet numbers, there is no difference in results. That means
that kinetic interphase mass transfer is independent of Peclet number, at least within the four
orders of magnitude considered here.
4. Extension to heat transfer
The concept of describing mass transfer based on modeling the evolution of interfacial areas
using the thermodynamically-based approach of Hassanizadeh & Gray (1990; 1993b) can
be extended to describing interphase heat transfer as well. The main difference between
interphase mass and heat transfer is that, in addition to fluid–fluid interfaces, heat can also be
transferred across fluid–solid interfaces, see Fig. 6.
Similarly to mass transfer, classical two-phase flow models describe heat transfer on the
macro scale by either assuming local thermal equilibrium within an averaging volume or
by formulating empirical models to describe the transfer rates. The latter is necessary
as classically, both fluid–fluid and fluid–solid interfacial areas are unknown on the macro
scale. And similiarly to mass transfer, we can use the thermodynamically-based approach
of Hassanizadeh & Gray (1990; 1993b) which includes both fluid–fluid and fluid–solid
interfacial areas in order to describe mass transfer in a physically-based way. We can
(1)
(2)
wetting
non−wetting
mass transfer
wetting
non−wetting
heat transfer
Fig. 6. Mass transfer takes place across fluid–fluid interfaces (left hand side) and heat transfer
across fluid–fluid as well as fluid–solid interfaces (right hand side)
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also perform a dimensional analysis and derive dimensionless numbers that help to decide
whether kinetics of heat transfer needs to be accounted for or whether a local equilibrium
model is sufficiently accurate on the macro scale. For more details on these issues, we refer
to Niessner & Hassanizadeh (2009b).
5. Macro-scale example simulations
For the numerical solution of the system of Eq.s (16) through (28), we use a fully-coupled
vertex-centered finite element method (an in-house code) which not only conserves mass
locally, but is also applicable to unstructured grids. For time discretization, a fully implicit
Eulerian approach is used, see e.g. Bastian et al. (1997); Bastian & Helmig (1999). The nonlinear
system is linearized using a damped inexact Newton-Raphson solver, and the linear system
is subsequently solved using a Bi-Conjugate Gradient Stabilized method (known as BiCGStab
method). Full upwinding is applied to the flux terms of the bulk phase equations, but in the
interfacial area flux term, central weighting is used.
5.1 Evaporator
As a simulation example, we consider a setup which is relevant in many industrial processes
where a product needs to be concentrated (e.g. foods, chemicals, and salvage solvents) or
dried through evaporation of water. The aqueous solution containing the desired product is
fed into the evaporator mostly consisting of micro-channels and then passes a heat source.
Heat converts the water in the solution into vapor and the vapor is subsequently removed
from the solution. We model the heating and evaporation process through a setup as shown
in Fig. 7.
This means we consider a horizontal domain that is closed along the sides (top and bottom
in the figure) and that is subjected to a gradient in wetting phase pressure from left to
right in the undisturbed situation. This system is assumed to be at the following initial
conditions: a temperature of 293 K, gas phase at atmospheric pressure, water saturation of 0.9,
a corresponding capillary pressure based on the primary drainage curve, and mass fractions
that correspond to the local chemical equilibrium conditions as prescribed by Henry’s Law
and Raoult’s Law (Lüdecke & Lüdecke (2000)). The porous medium is heated with a rate of
Qs in a square-shaped part of the domain, causing the evaporation of water (see Fig. 7). Note
that the heat source heats up only the walls of the microchannels (the solid phase) and the
heat is then transferred from the solid phase to the water phase.
Sil = 0.9
pgi = 106875 Pa
pci = pcdr (0.9)
ai
a
Xl = Xl,s (pgi , Til )
w (p i , Ti )
Xwg i = Xg,s
g g
Tli = 293.15 K
i
Tg = 293.15 K
Tsi = 293.15 K
Sil = 0.9
pgi = 101325 Pa
pci = pcdr (0.9)
ai
a
Xl = Xl,s (pgi , Tli )
w
Xwg i = Xg,s
(pgi , Tni )
Tli = 293.15 K
Tgi = 293.15 K
Tsi = 293.15 K
Qs
Sil = 0.9
pgi = 101325 Pa
pci = pcdr (0.9)
a
i
i
Xai
l = Xl,s (pg , Tl )
w
Xwg i = Xg,s
(pgi , Tgi )
Tli = 293.15 K
Tgi = 293.15 K
Tsi = 293.15 K
0.5 m
0.7 m
Fig. 7. Setup of the numerical example: water passes a heat source and is evaporated.
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For comparison, the same setup is used for simulations using a classical two-phase flow
model, where—in the absence of interfacial areas as parameters—local chemical and thermal
equilibrium is assumed. This means that the heat source cannot be defined for the solid phase
only; instead, the applied heat will instantaneously lead to a heating of all three phases.
The distribution of water saturation and water–gas specific interfacial area are shown in Fig. 8
at the time of 17 seconds after the heat source is switched on. The saturation distribution given
by the interfacial area-based model is compared to that of the classical model. Obviously,
water saturation decreases in the heated region due to the evaporation of water. Downstream
of the heated zone, water saturation increases indicating that in the colder regions, water
condenses again. Due to the decrease in water saturation, gas–water interfacial areas are
created. The classical model predicts a much lower decrease in water saturation in the heated
region.
Fig. 9 shows the mass fraction of air dissolved in the liquid phase after 17 seconds. There,
also the equilibrium value (solubility limit) predicted by the interfacial area-based model
is shown. Clearly, chemical non-equilibrium effects occur, but the classical model predicts
approximately the same result as the equilibrium values in the interfacial area-based model.
This is due to the fact that the classical two-phase flow approach always assumes local
equilibrium and can only represent mass fractions corresponding to the equilibrium values.
The analogous comparison is shown in Fig. 10 with respect to the mass fractions of vapor in
the gas phase.
Here, the mass fractions in the interfacial area-based model are very close to the equilibrium
values, but larger differences to the classical model can be detected.
Sl from interfacial area model
Sw:
0.8 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.9 0.91
Sl from classical model
S l Sw:
alg from interfacial area model
awn:
a lg [1/m]
0.8 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.9 0.91
380 400 420 440 460 480 500 520 540 560 580
Fig. 8. Water saturation and water–gas specific interfacial area after 17s.
a
Xl from interfacial area model
a
a
Xl,s from interfacial area model
Xl from classical model
a
Xsw2
2.36E-05
2.34E-05
2.32E-05
2.3E-05
2.28E-05
2.26E-05
2.24E-05
2.22E-05
2.2E-05
2.18E-05
2.16E-05
2.14E-05
Xl
2.36E.6
2.24E−6
Fig. 9. Mass fraction of air in the liquid phase after 17s. Left: results using the interfacial
area-based model, middle: equilibrium values given by the interfacial area-based model,
right: results given by the classical model.
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w
Xw
g from interfacial area model
w
Xg,s from interfacial area model
Xg from classical model
w
X g [−]
Xsn1
XWG
0.75
0.7
0.65
0.6
0.55
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0.75
0.7
0.65
0.6
0.55
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
Fig. 10. Mass fractions of vapor in the gas phase after 17s. Left: results using the interfacial
area-based model, middle: equilibrium values given by the interfacial area-based model,
right: results given by the classical model.
Fig. 11 shows the temperatures of the three phases (liquid l, gas g, solid s) after 17s using the
interfacial area-based model and the classical model. It can be seen that a lower temperature
rise is predicted by the classical model than by the interfacial area-based model.
T l from interfacial area model
T g from interfacial area model
T s from interfacial area model
T from classical model
T[K]Te
Tn
375
370
365
360
355
350
345
340
335
330
325
320
315
310
305
300
295
375
370
365
360
355
350
345
340
335
330
325
320
315
310
305
300
295
Fig. 11. Temperatures of the phases after 17s using the interfacial area-based model (three
pictures on left) and the classical model (right picture).
Fig. 12 shows the temperature differences between the phases using the interfacial area-based
model. We find that there are differences of up to 8 K between the phases. The classical
two-phase model assumes local thermal equilibrium, i.e. Tw = Tn = Ts . In reality, however,
the heat exchange between the phases is restricted by the respective interfacial areas and the
heat equalization does not take place instantaneously.
Tl
− Tg
T[K]
dTwTn
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
-4
-4.5
-5
-5.5
-6
-6.5
-7
-7.5
-8
Tg − Ts
T[K]
dTnTs
0
-0.2
-0.4
-0.6
-0.8
-1
-1.2
-1.4
-1.6
-1.8
-2
-2.2
-2.4
-2.6
-2.8
-3
-3.2
-3.4
Fig. 12. Temperatures differences between wetting and non-wetting phase (left hand side)
and between non-wetting and solid phase (right hand side) after 17s.
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5.2 Drying of a porous medium
As a second example, we consider the drying of an initially almost water-saturated porous
medium through injection of hot dry air (50 ◦ C). This process is relevant in the textile,
construction, and paper industries as well as in medical applications. The setup is shown
in Fig. 13. For comparison, this setup is also simulated using the classical model. Note that
in the classical model, due to the assumption of local chemical and thermal equilibrium,
it is impossible to apply a source of hot dry air. Instead, the air supplied to the system
instantaneously redistributes among the phases in order to yield equilibrium composition.
The temperature of the air source will instantaneously heat up all three phases.
Sil = 0.9
pgi = 101475 Pa
pci = pcdr (0.9)
ai
a
Xl = Xg,s (pgi , Til )
w (p i , Ti )
Xwg i = Xg,s
g g
Tli = 293 K
Tgi = 293 K
Tsi = 293 K
Sil = 0.9
pgi = 101325 Pa
pci = pcdr (0.9)
a
i
i
Xai
l = Xl,s (pg , Tl )
w (pi , Ti )
Xwg i = Xg,s
g
g
Tli = 293 K
Tgi = 293 K
Tsi = 293 K
a
Sil = 0.9
Qn
pgi = 101325 Pa T =
333 K
pci = pcdr (0.9)
ai
a
i
i
Xl = Xl,s (pg, Tl )
w
i , Ti )
Xwi
g = Xg,s (pg
g
Tli = 293 K
i
Tg = 293 K
Tsi = 293 K
0.5 m
0.7 m
Fig. 13. Setup of the numerical example: drying of a porous medium through injection of
warm dry air.
Fig. 14 shows the water saturation and the specific gas–water interfacial area after 12 seconds.
The water saturation decreases due to the gas injection and interfaces are produced. The
saturation distribution is different if the classical model is used. This may be due to the
fact that the source term needs to be specified differently for the two models (see the above
comments on the problem description).
Sl from interfacial area model
Sl from classical model
Sw
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.8
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
SSw
l
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.8
0.79
0.78
0.77
0.76
0.75
0.74
0.73
0.72
alg from interfacial area model
a lg awn[1/m]
600
580
560
540
520
500
480
460
440
420
Fig. 14. Water saturation (using both interfacial area-based and classical model) and specific
fluid–fluid interfacial area using the interfacial area-based model after 12s.
In Fig. 15, the mass fraction of air disolved in the water phase is shown after 12s. The
actual mass fraction distribution using the interfacial-area-based approach is shown in the
left picture. The mass fraction corresponding to local chemical equilibrium is shown in the
middle figure. For comparison, the mass fraction distribution resulting from the classical
model is shown in the right figure. Obviously, significant deviations from equilibrium can be
detected. This implies that chemical non-equilibrium is very important in this example. The
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a
a
a
Xl,s from interfacial area model
Xl from interfacial area model
Xl from classical model
a
XXAW
l
XAW
2.348E-05
2.347E-05
2.346E-05
2.345E-05
2.344E-05
2.343E-05
2.342E-05
2.341E-05
2.348E-05
2.347E-05
2.346E-05
2.345E-05
2.344E-05
2.343E-05
2.342E-05
2.341E-05
Fig. 15. Mass fractions of air in water. Left: interfacial-area-based model, actual mass
fractions; middle: equilibrium mass fractions. Right: classical model.
equilibrium mass fractions of the interfacial area-based model are also very different from that
predicted by the classical model, probably due to the differently specified source.
Fig. 16 shows the same for water vapor in the gas phase. Here, the deviation from chemical
equilibrium is also significant, but the equilibrium mass fractions using the interfacial
area-based model and the classical model are very similar.
Xw
g from interfacial area model
Xwg,s from interfacial area model
w
Xg from classical model
w
XWG
XXWG
g [−]
0.0175
0.017
0.0165
0.016
0.0155
0.015
0.0175
0.017
0.0165
0.016
0.0155
0.015
Fig. 16. Mass fractions of vapor in the gas phase. Left: interfacial-area-based model, actual
mass fractions; middle: equilibrium mass fractions. Right: classical model.
In Fig. 17, the temperatures of the three phases (liquid l, gas g, and solid phase s) resulting
from the interfacial area-based model are shown and compared to the temperature given
by the classical model. Unlike the mass fractions, the temperatures are not very far from
equilibrium (maximum difference in phase temperatures is approximately 0.17 K, see also
Fig. 18). An interesting aspect is that the temperature difference is lower in the middle of the
injection zone than in the surrounding area. This is due to the fact that specific interfacial area
is at a maximum in this middle part leading to higher heat transfer rates in this region and
phase temperature closer to each other and thus, closer to thermal equilibrium.
6. Summary and conclusions
In this chapter, the issue of interphase mass transfer during two-phase flow in a porous
medium has been discussed. Starting from pore-scale considerations, the classical approaches
for describing mass transfer have been presented which—due to the absence of interfacial area
as a parameter—either assume local equilibrium within an averaging volume or use empirical
approaches to describe the kinetics.
www.intechopen.com
19
19
Massand
andHeat
HeatTransfer
TransferDuring
During
Two-Phase
Flow
in Porous
Media
- Theory
and Modeling
Mass
Two-Phase
Flow
in Porous
Media
- Theory
and Modeling
T l from interfacial area model
T g from interfacial area model
T s from interfacial area model
T from classical model
T[K]
Te
Ts
296.4
296.2
296
295.8
295.6
295.4
295.2
295
294.8
294.6
294.4
294.2
294
293.8
293.6
293.4
293.2
296.6
296.4
296.2
296
295.8
295.6
295.4
295.2
295
294.8
294.6
294.4
294.2
294
293.8
293.6
293.4
Fig. 17. Temperatures of the phases using the interfacial area-based model (three pictures on
left hand side) and the classical model (right hand side picture).
Tl − Tg
Tg − Ts
dTnTs
T[K]
T[K]
dTwTn
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
-0.08
-0.09
-0.1
-0.11
-0.12
-0.13
-0.14
-0.15
-0.16
-0.17
0.15
0.14
0.13
0.12
0.11
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Fig. 18. Temperature differences between the phases.
As an alternative, a thermodynamically-based model was presented which explicitly accounts
for the presence of interfaces and describes their evolution in space and time. Due to
the knowledge of interfacial area, kinetic interface mass transfer can be modeled in a
physically-based way. In order to decide whether kinetics of mass transfer needs to be
accounted for or whether an equilibrium model would give sufficiently good results, a
dimensional analysis was carried through. Also, the concept was extended to kinetic
interphase heat transfer where in addition to fluid–fluid interfaces, fluid–solid interfaces are
important. Two examples have illustrated the issues presented: in our results, we could
observe that in the drying example, chemical non-equilibrium is significant. In the evaporator
example, contrarily, thermal non-equilibrium is very pronounced.
In order to advance the description of real life systems, such as those described in Sec. 1.1, an
important future step would be to apply the presented model concept to practical applications
and to verify the results by comparison to experimental data.
7. Acknowledgements
We thank Benjamin Ahrenholz for providing the interfacial - area - capillary pressure saturation relationships from Lattice - Boltzman simulations that entered the numerical
simulations shown in this chapter.
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www.intechopen.com
Mass Transfer in Multiphase Systems and its Applications
Edited by Prof. Mohamed El-Amin
ISBN 978-953-307-215-9
Hard cover, 780 pages
Publisher InTech
Published online 11, February, 2011
Published in print edition February, 2011
This book covers a number of developing topics in mass transfer processes in multiphase systems for a
variety of applications. The book effectively blends theoretical, numerical, modeling and experimental aspects
of mass transfer in multiphase systems that are usually encountered in many research areas such as
chemical, reactor, environmental and petroleum engineering. From biological and chemical reactors to paper
and wood industry and all the way to thin film, the 31 chapters of this book serve as an important reference for
any researcher or engineer working in the field of mass transfer and related topics.
How to reference
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Porous Media - Theory and Modeling, Mass Transfer in Multiphase Systems and its Applications, Prof.
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https://openalex.org/W4312274758
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https://ph.pollub.pl/index.php/acs/article/download/3230/2796
|
English
| null |
AN EFFECTIVE METAHEURISTIC FOR TOURIST TRIP PLANNING IN PUBLIC TRANSPORT NETWORKS
|
Applied Computer Science
| 2,018
|
cc-by
| 5,563
|
Submitted: 2018-05-14
Revised: 2018-06-03
Accepted: 2018-06-21 Submitted: 2018-05-14
Revised: 2018-06-03
Accepted: 2018-06-21 Applied Computer Science, vol. 14, no. 2, pp. 5–19
doi:10.23743/acs-2018-09 time-dependent orienteering problem with time-windows,
evolutionary algorithm, public transport network, tourist trip planning Krzysztof OSTROWSKI* * Faculty of Computer Science, Białystok University of Technology, Wiejska 45A,
15-001 Białystok, Poland, k.ostrowski@pb.edu.pl Abstract ract
The Time-Dependent Orienteering Problem with Time Windows (TDOPTW)
is a combinatorial optimization problem defined on graphs. Its real life
applications are particularly associated with tourist trip planning in trans-
port networks, where travel time between two points depends on the moment
of travel start. In the paper an effective TDOPTW solution (evolutionary
algorithm with local search operators) was presented and applied to gen-
erate attractive tours in real public transport networks of Białystok and Athens. The method achieved very high-quality solutions in a short execution time. 1. INTRODUCTION The Time-Dependent Orienteering Problem with Time Windows (TDOPTW)
belongs to the Orienteering Problem (OP) family. The classic OP is defined on
a weighted graph with nonnegative profits associated to vertices and nonnegative
costs associated to edges. The goal of the OP is to find a path between given two
vertices that maximizes total profit of visited vertices and its total cost does not
exceed a given limit. The OP solution does not have to contain all vertices (usually
it is impossible because of cost limit) and each vertex can be visited only once. The Time-Dependent Orienteering Problem with Time Windows (TDOPTW)
is a generalization of the OP defined for time-dependent graphs. Edge costs are
identified with travel times, which depend on the moment of travel start (edge 5 weights are time-dependent functions). In addition each vertex has a visit time
and a time-window. Arriving too early means waiting for the time-window to open
while arriving too late makes it impossible to visit a given vertex. Transport networks are examples of time-dependent graphs are. Travel time
between two points depends on traffic intensity (i.e. longer during rush hours)
and timetables (in case of public transport networks). Problems from the TDOPTW
family have many practical applications including tourist trip planning (Garcia,
Vansteenwegen, Arbelaitz, Souffriau & Linaza, 2013) and transport logistics. In tourist trip planning each tourist attraction (point of interest – POI) has some
profit (i.e. dependent on its popularity), visit time and opening hours (time-
window). Finding an attractive tour of a limited duration in a time-dependent
transport network is equivalent to solving the TDOPTW. The paper is organized as follows. In section 2 a mathematical formulation
of the TDOPTW is given. In section 3 a literature review is presented. Section 4
describes public transport network as a time-dependent graph. Section 5 describes
methods applied. In section 6 experimental results are given. Section 7 is the con-
clusion of the paper. 2. PROBLEM DEFINITION Let G = (V, E) be a directed, weighted graph. Each vertex i has a nonnegative
profit pi, a nonnegative visit time τi and a time-window <oi, ci>. Travel time
between vertices i and j (i, j ∈ V ) is a nonnegative function wij(t) dependent
on the moment of travel start t. The goal of the TDOPTW is to find a path from
vertex s to vertex e starting at time t0 which maximizes total profit of visited
vertices without exceeding total travel time (Tmax) and without violating time-
windows of visited vertices. TDOPTW can be formulated as a Mixed Integer
Programming (MIP) problem. Let’s introduce three additional variables. Variable
xij is 1 if a path contains a direct travel from vertex i to vertex j and 0 otherwise. Let tai and tdi be a time of arrival at vertex i and a time of departure from it – these
functions are defined only for vertices included in the path. It’s assumed that
vertices s and e have no profit, zero visit time and no time-window. 2. PROBLEM DEFINITION The purpose
of the TDOPTW is to maximize formula 1 without violating constraints 2–8: ,
max
i
ij
i j V
p x
(1)
1
sj
ie
j V
i V
x
x
(2) (1) 1
sj
ie
j V
i V
x
x
(2) (2) 6 6 \{ , }
1
ik
kj
k V
s e
i V
j V
x
x
(3)
0
s
td
t
(4)
(5)
\{ , }
(
max(
,
)
)
i
i
i
i
i V
s e
td
ta o
(6)
0
max
e
ta
t
T
(7)
\{ , }
(
)
i
i
i V
s e
ta
c
(8)
,
1
(
)
ij
j
i
ij
i
i j V
x
ta
td
w td
\{ , }
(
max(
,
)
)
i
i
i
i
i V
s e
td
ta o
(8) Equation 2 guarantees that the solution starts at vertex s and ends at vertex e
while formula 3 means that each vertex can be visited only once. Formula 4 forces
travel to start at time t0 while formulas 5 and 6 defines a relation between arrival
and departure times at subsequent vertices (based on travel times, visit times
and time-windows). Assuming that travel times between different vertices are
positive, formulas 4–6 guarantee that there are no sub-cycles in the path. Constraints 7 and 8 are associated with maximum travel time and time-windows. 3. LITERATURE REVIEW Problems from the Orienteering Problem family are NP-hard (Golden, Levy,
Vohra, 1987) and exact algorithms can be very time-consuming for larger graphs. For this reason most papers are devoted to metaheuristics. Various approaches
for the OP were based i.a. on greedy and randomized construction of solutions
(Campos, Marti, Sanchez-Oro & Duarte, 2014), local search methods (Chao, Golden
& Wasil, 1996; Vensteenwegen, Souffriau, Vanden Berghe & Oudheusden,
2009), tabu search (Gendreau, Laporte & Semet, 1998), ant-colony optimization
(Schilde, Doerner, Hartl & Kiechle, 2009) and genetic algorithms (Tasgetiren, 2001). g
g
g
Most papers about Time-Dependent versions of the Orienteering Problem
were published in recent years and emphasize practical aspects of the problem,
especially tourist trip planning in transport networks. Garcia et al. (2013)
presented the first paper describing its application in POI and public transport
network of San Sebastian. To solve the problem the authors proposed Iterated
Local Search method (ILS). However, they performed computations on average
daily travel times and assumed periodicity of public transport timetables. 7 Gavalas et al. (2015) proposed an approach which uses real time-dependent
travel times in a transport network of Athens. The authors introduced two fast
heuristics (TD_CSCR and TDSlCSCR), which based on ILS and vertex clustering,
and made comparisons of a few methods. Verbeeck at al. (2014) developed new benchmark instances for the TDOP,
which model street traffic. The authors proposed an ant-colony approach, which
achieved high quality results in a short execution time. Gunawan et al. (2014)
modified Verbeeck's benchmarks (discretization of time) and compared a few
approaches (adaptive ILS proved to be the most effective of them). The author's previous papers were devoted to metaheuristics for problems from
the OP family. Methods developed by the author (composition of evolutionary
algorithms and local search heuristics) proved successful on the OP (Ostrowski,
Karbowska-Chilinska, Koszelew & Zabielski, 2017; Ostrowski, 2015) as well as
TDOP benchmark instances (Ostrowski, 2017). The algorithms achieved results
close to optimal and outperformed other methods: GRASP (Campos et al, 2014),
GLS (Vensteenwegen et al., 2009), ACS (Verbeeck at al 2014) and Adaptive ILS
(Gunawan et al, 2014). The purpose of this work was to adapt the TDOP algorithm
to the TDOPTW, apply it for tourist trip planning in real public transport and POI
network and verify quality of its solutions. 4. PUBLIC TRANSPORT AND POI NETWORK
AS A TIME-DEPENDENT GRAPH It’s assumed that a tourist uses means of public transport (buses in the city
of Białystok) when travelling between attractions (POIs). Travel time between
POIs depends on bus timetables. For this reason a network of POIs connected
by public transportation is a time-dependent graph. Here are assumptions made
by the author: y
1. A travel between two POIs can consist of two kinds of edges: walk links
and bus connections. 2. Walk links have a limited length (Dmax) and walk times are determined
by assuming that walking speed is 3 km/h. A tourist can walk directly
between POIs, between POIs and bus stops and between bus stops (during
bus transfers). 3. During a travel between a pair of POIs a tourist can use up to k bus transfers
(k+1 bus connections). 4. To compensate for deviations of bus arrival times from timetables a min-
imum waiting time at a bus stop (3 minutes) was introduced. 5. Each graph weight wij(t) is the duration of the shortest travel from POI i
to POI j starting at time t. To compute weights it’s necessary to execute
shortest path algorithm in multimodal time-dependent graph. 8 6. Time is discrete (resolution of 1 minute), which is consistent with time-
tables. For this reason there are 1440n2 graph weights (n is number of POIs
and there are 1440 minutes in a day). Fig. 1. An exemplary travel between two POIs Fig. 1. An exemplary travel between two POIs In fig. 1. there is an exemplary travel between two POIs consisting of 3 bus
connections (2 transfers) and 3 walk links. A tourist leaves POI 1, walks to bus
stop B1 and gets on a bus (line A). He gets off at bus stop B2 and waits there for
another bus (line B). Afterwards he goes by bus B to bus stop B4. From there he
walks to a nearby bus stop B5, where he gets onto another bus (line C) and travels
to bus stop B7. From there he walks to his destination (POI 2). Computation
of such shortest paths is necessary to get time-dependent weights, which will be
used by the metaheuristic solving the Time-Dependent Orienteering Problem. 5. METHOD DESCRIPTION To realize tourist trip planning in a public transport network of Białystok two
tasks should be done: 1. Computation of time-dependent weights based on bus timetables and POIs
location. 2. Execution of the TDOP algorithm, which operates on time-dependent
weights and generates attractive tours. 9 Shortest travels from a given POI at a given start time to all other POIs In order to compute all weights efficiently the author decided to use modified
Ford-Bellman algorithm and optimize some precomputation steps. The basic
Ford-Bellman procedure computes shortest travels starting at time t0 from a given
start POI s to all other POIs and bus stops. The algorithm has k+1 main iterations
(k – number of bus transfers). It enables to efficiently compute shortest paths
consisted of a limited number of bus connections. During the first iteration bus
connections starting at bus stops not farther than max. walk distance (Dmax) from
s are considered. Only earliest possible buses of given lines are considered. Afterwards all possible bus stops, where a tourist can get off the bus (exit bus
stops), are analysed. From there destination POIs (within walking distance from
exit bus stops) are checked. In this way all shortest travel times (consisting of one
transport connection) are computed. Analogically the second iteration computes
all shortest travels consisted of at most two transport connections (one bus transfer):
when analysing an exit bus stop the algorithm searches for other bus connections
leaving from the current bus stop and from other neighbouring bus stops (transfer
step). The same steps are performed for subsequent iterations. For optimization
purposes the algorithm only analyses those bus stops, for which travel time
improved in the previous iteration. 5.1. Precomputation of weights During its execution the TDOP metaheuristic refers to graph weights millions
of times. Computing shortest path in a time-dependent network so many times can
cause an additional time overhead. For this reason the author decided to precompute
and save all 1440n2 weights. Precomputed weights are stored in a 3-dimensional
array. Thanks to the precomputation step the TDOP algorithm has access to all
weights in constant time. Shortest travels between all POIs for all start times To compute all possible weights for all 1440 start times the above procedures
are executed for all starting POIs. Thanks to the described optimization
precomputation time was significantly reduced. Shortest travels from a given POI for all start times The purpose of precomputation is to compute shortest travels for all 1440 start
times (minutes) in a day. Instead of executing the same shortest path algorithm
(described above) 1440 times an optimization can be done. It arises from a simple
observation (known as FIFO property): t + wij(t) ≤ (t+1) + wij(t+1). The formula
means that earlier travel start implies not later travel finish – in the most
pessimistic case travel starting at time t will use the same bus connections as travel
starting at time t+1 (the only difference is one more minute of waiting at the first
bus stop). Thanks to this property shortest travels for consecutive start times can
be computed much faster. When computing shortest travels starting at time t
the algorithm uses shortest travel times previously computed for start time t+1. The algorithm considers only those bus connections, which were impossible 10 to catch one minute later. This significantly reduces precomputation time,
especially when frequency of bus connections is less than a minute (which is common
in public transport networks – see fig. 2). In the below figure there is an example of
time-dependent arrival times: the function is nondecreasing (and constant
in intervals). Inside these intervals an equality t + wij(t) = (t+1) + wij(t+1) holds, which
usually means that the same set of connections is used and computation time can
be reduced. What is more, the FIFO property in time-dependent networks implies
existence of polynomial time shortest-paths algorithms (Dean, 2004), which made
it possible to develop fast precomputation procedure. Fig. 2. Arrival time at POI j as a function of departure time from POI i Fig. 2. Arrival time at POI j as a function of departure time from POI i 5.2. TDOPTW metaheuristic for tourist trip planning To solve the trip planning problem the author used an evolutionary algorithm,
which is based on the method solving the TDOP (Ostrowski, 2017). The author
adapted the method to the presence of time-windows. It uses both random and
local search operators, 2-point heuristic crossover, disturb operator and deter-
ministic crowding as selection mechanism. What is more, infeasible solutions
(too long paths) are present in the population (penalized by the fitness function). A path representation is used – subsequent genes in a chromosome correspond
to successive vertices in a path. After a random initialization the algorithm
continues computations until a given generations limit (Ng) is achieved or there
was no solution improvement in the last Cg generations. 11 Selection After crossover children compete with their own parents for places in the pop-
ulation – survivor selection in the form of deterministic crowding (Mahfoud,
1992). Distance metric used bases on the length of longest common subsequence
of two solutions. This form of selection preserve population diversity for longer,
which allows a more effective search of the solution space (Ostrowski, 2015). Evaluation Fitness of a feasible solution s is equal to its profit. Otherwise it is described
by the formula: fitness(s) = p(s)[Tmax/t(s)]k, where p(s) and t(s) are profit and
travel time of solution s. Parameter k (penalty severity) is initially equal to 1 but
it is adaptive and increases if more than α percent of paths in the population are
infeasible. Crossover Parent selection is random. Crossover probability determines the fraction of
population chosen for reproduction (selected individuals arranged in random
pairs). The algorithm uses specialized 2-point heuristic crossover. Crossover
procedure exchanges one pair of path fragments between consecutive common
points of both parents. In fig. 3. an example of crossover is illustrated. There are
three possible crossings (varying in exchanged fragments). Heuristic crossover
chooses the option which maximizes fitness of the better child. Mutation Mutation probability determines the fraction of individuals which are selected
(randomly) for mutation. Initially, selected paths undergo 2-opt procedure, which
tries to reverse a path fragment in order to reduce total travel time as much as
possible. Afterwards a vertex insertion or vertex deletion is carried out (each with
a probability of 0.5). Both insert and delete operators have two versions: local
search and random. Local search insert from all options of inserting a new vertex
chooses the one that maximizes profit to travel time increase ratio. Analogically
delete searches for a vertex which minimizes profit to travel time reduction ratio. Random versions choose vertices arbitrary but insertion place is chosen in order
to minimize travel time increase. Probability of local search during mutation
is determined by a parameter (heuristic coefficient). 12 Fig. 3. An example of crossover Fig. 3. An example of crossover Fig. 3. An example of crossover Time-Windows All operators used in the algorithm were modified in order to take into account
time-windows. Given a POI with a time-window <o, c> and arrival time t, arriving
too early (t<o) means that additional waiting time (o-t) was added to the tour
duration. Arriving too late (t>c) made it impossible to visit a vertex and such cases
weren’t allowed by the algorithm operators. Disturb Disturb procedure is another form of mutation, which applies bigger changes
in individuals but is executed rarely. A small fraction of population (determined
by disturb probability) is randomly chosen and a path fragment (no longer than
10 percent of vertices) is removed from each of them. Path fragment is chosen
randomly or in a heuristic way (to minimize profit to travel time reduction ratio). 6. EXPERIMENTAL RESULTS Experiments were conducted on a computer with Intel Core i7 3.5 GHz
processor and the algorithms were implemented in C++. First part of experiments
was devoted to precomputation of travel times between POIs in public transport
network of Białystok and in the second part the TDOPTW metaheuristic was
applied for tourist trip planning in this network (using precomputed weights). 13 6.1. Precomputation and network properties Public transport and POI network of Białystok consists of 74 POIs (museums,
palaces, churches etc), 37 bus lines and 693 bus stops. Thanks to optimizations
(described in the previous section) precomputation time was only a few seconds. Shortest travel times between all pairs of POIs for all start times (1440 minutes
in a day) were stored in a 3-dimensional array (occupying 18 MB of RAM). To find out about interesting features of the network, precomputation was
executed many times for different values of parameters: maximal walk distance
(Dmax) and maximal number of bus transfers (k). Tests were conducted for two
Dmax values (0.3 and 0.6 km) and four k values (0, 1, 2, 3). In fig. 4. a dependency between percentage of connected POIs and pre-
computation parameters is illustrated. It can be seen that large majority of POI
pairs are connected when travel consists of at most one bus transfer (two transport
connections) and there is no connectivity improvement for more than 2 bus
transfers. Connection percentage improves for larger value of Dmax. Longer walk
links enable to reach larger number of bus stops, which naturally implies more
connection options. One can see that for shorter walk links connectivity is always
less than 100 percent (regardless of number of bus transfers). This is due to the fact
that a few POIs were farther than 0.3 km from nearest bus stop. In fig. 5. it can be
seen that most of shortest travels between POIs are very simple (no bus transfer
or one transfer) and almost no paths consist of more than 2 transfers. This is due to the fact that Białystok is a relatively compact city. Larger Dmax
value influences paths simplicity for the same reason as it influenced connections
percentage. Fig. 4. Percentage of connected POI pairs depending on Dmax and k Fig. 4. Percentage of connected POI pairs depending on Dmax and k Fig. 4. Percentage of connected POI pairs depending on Dmax and k 14 14 Fig. 5. Percentage of different types of shortest paths depending on Dmax
Fig. 6. Histogram of travel times between POIs for different Dmax values
(computed for daily hours 6:00–18:00). ig. 6. it can be seen that travel times of 20–40 minutes are most c
9 percent) and the majority of travels last less than an hour. In additio
re short travels and less long travels when increasing Dmax. 6.2. Trip planning in Białystok The tested network included 74 POIs and 2 start/end points. For each attraction
a profit, a visit time and a time-window (opening hours) were assigned (link to
network: http://p.wi.pb.edu.pl/krzysztof-ostrowski/node/1252). Trips were 3, 6 and 9
hours long (Tmax) and started at 6:00, 9:00, 12:00 and 15:00 (t0). Time unit used in
test files as well as during computations was a minute i.e. 9:00 is 540 and 4 hours
are 240 minutes. There were two variants of trips: starting and ending in the city
centre (s = e = 1) and in the western part of the city (s = e = 2). The author tested
two methods: the TDOPTW metaheuristic (evolutionary algorithm with local search
heuristics) as well as an exact algorithm (composition of branch-and-bound and
dynamic programming developed by the author). Thanks to the exact algorithm
optimal solutions are known (up to a few hours of computation time for longest trips)
and it’s possible to access the quality of paths generated by the metaheuristic. p
q
y
p
g
y
Algorithm parameter values were derived from EVO100 in the author’s previous
TDOP article (Ostrowski, 2017) with a small change: mh = 0.8 and ch = 1 instead
of mh = 1 and ch = 0.8 (minor error in the article). For each test case the evolutionary
algorithm was executed 30 times and average result was calculated. Gaps are given
in percent and illustrate relative quality loss to optimal solutions. Execution times are
given in seconds. The author’s metaheuristic is marked as EVO while OPT indicate
profits of optimal tours (expressed as the sum of attractiveness of visited POIs). In tab. 1. results of trip planning are given (trips start and end in the city centre). One can see that EVO achieves optimal results in most cases and average gap
is only 0.02 and 0.19 percent (for Dmax = 0.3 and 0.6 km). High-quality results are
achieved in short execution times (0.3–1.4 s). It can be seen that optimal trips are
a few percent better for larger value of Dmax. This is due to shorter travel times
when using longer walk links (as described in the previous subsection), which
enables to visit more POIs within a given time frame. Tab.1. 6.1. Precomputation and network properties It is ass
e fact that for larger Dmax value travel times are generally shorter (m
ctions are considered when searching for paths) – average daily trav
nd 41 minutes (for Dmax 0.3 and 0.6 accordingly). Fig. 5. Percentage of different types of shortest paths depending on Dmax Fig. 5. Percentage of different types of shortest paths depending on Dmax Fig. 6. Histogram of travel times between POIs for different Dmax values
(computed for daily hours 6:00–18:00). Fig. 6. Histogram of travel times between POIs for different Dmax values
(computed for daily hours 6:00–18:00). In fig. 6. it can be seen that travel times of 20–40 minutes are most common
(46–49 percent) and the majority of travels last less than an hour. In addition, there
are more short travels and less long travels when increasing Dmax. It is associated
with the fact that for larger Dmax value travel times are generally shorter (more bus
connections are considered when searching for paths) – average daily travel time
is 45 and 41 minutes (for Dmax 0.3 and 0.6 accordingly). In fig. 6. it can be seen that travel times of 20–40 minutes are most common
(46–49 percent) and the majority of travels last less than an hour. In addition, there
are more short travels and less long travels when increasing Dmax. It is associated
with the fact that for larger Dmax value travel times are generally shorter (more bus
connections are considered when searching for paths) – average daily travel time
is 45 and 41 minutes (for Dmax 0.3 and 0.6 accordingly). 15 6.2. Trip planning in Białystok Trip planning results for s = e = 1
Dmax = 0.3 km
Dmax = 0.6 km
EVO
EVO
Tmax
t0
Gap
Time
OPT
Tmax
t0
Gap
Time
OPT
3h
6:00
0.0
0.3
327
3 h
6:00
0.0
0.5
342
9:00
0.0
0.4
475
9:00
0.0
0.5
475
12:00
0.0
0.4
475
12:00
0.0
0.5
512
15:00
0.0
0.5
485
15:00
1.6
0.5
506
6 h
6:00
0.0
0.9
741
6 h
6:00
0.1
0.8
769
9:00
0.0
0.8
813
9:00
0.0
0.8
878
12:00
0.1
0.9
850
12:00
0.0
0.7
900
9 h
6:00
0.1
1.4
1089
9 h
6:00
0.0
1.2
1144
9:00
0.0
1.1
1178
9:00
0.0
1.2
1218
Average
0.02
0.75
–
Average
0.19
0.75
– 16 In tab. 2. analogical results are presented for trips starting and ending in the
western part of the city (s = e = 2). Optimal solutions were obtained by EVO for
all but 2 test cases in short execution times. Trips quality is lower than it the
previous table because most attractions are located in the city centre and additional
time is needed to get there. In fig. 7. a trip generated by the algorithm is presented. It is short and all visited
POIs are in the city centre so only one bus connection is needed. It worth noting
that the algorithm usually chooses consecutive POIs which are close to each other
in order to use the time budget effectively. For this reason travels between POIs
found in solutions are usually short (only 5–15 minutes, compared to average
of 40–45 minutes) and simple (a walk link or a single bus connection). Tab. 2. Trip planning results for s = e = 2
Dmax = 0.3 km
Dmax = 0.6 km
EVO
EVO
Tmax
t0
Gap
Time
OPT
Tmax
t0
Gap
Time
OPT
3 h
6:00
0.0
0.3
226
3 h
6:00
0.0
0.4
226
9:00
0.0
0.4
338
9:00
0.0
0.4
350
12:00
0.0
0.4
338
12:00
0.0
0.4
338
15:00
0.0
0.4
358
15:00
0.0
0.4
375
6 h
6:00
0.0
0.7
659
6 h
6:00
0.0
0.6
677
9:00
0.0
0.7
708
9:00
0.5
0.7
721
12:00
0.0
0.8
786
12:00
0.0
0.7
805
9 h
6:00
0.0
1.1
996
9 h
6:00
0.1
1.2
1024
9:00
0.0
1.1
1125
9:00
0.0
1.0
1162
Average
0.0
0.65
–
Average
0.07
0.65
– Tab. 2. 6.2. Trip planning in Białystok Trip planning results for s = e = 2
Dmax = 0.3 km
Dmax = 0.6 km
EVO
EVO
Tmax
t0
Gap
Time
OPT
Tmax
t0
Gap
Time
OPT
3 h
6:00
0.0
0.3
226
3 h
6:00
0.0
0.4
226
9:00
0.0
0.4
338
9:00
0.0
0.4
350
12:00
0.0
0.4
338
12:00
0.0
0.4
338
15:00
0.0
0.4
358
15:00
0.0
0.4
375
6 h
6:00
0.0
0.7
659
6 h
6:00
0.0
0.6
677
9:00
0.0
0.7
708
9:00
0.5
0.7
721
12:00
0.0
0.8
786
12:00
0.0
0.7
805
9 h
6:00
0.0
1.1
996
9 h
6:00
0.1
1.2
1024
9:00
0.0
1.1
1125
9:00
0.0
1.0
1162
Average
0.0
0.65
–
Average
0.07
0.65
–
Fig. 7. A tour generated by the algorithm (Google Maps): walk links in red, bus connections
in blue; icons: camera (POI), bus (bus stop), house (start/end), Tmax = 3h, t0 = 9:00. Tab. 2. Trip planning results for s = e = 2 Fig. 7. A tour generated by the algorithm (Google Maps): walk links in red, bus connections
in blue; icons: camera (POI), bus (bus stop), house (start/end), Tmax = 3h, t0 = 9:00. Fig. 7. A tour generated by the algorithm (Google Maps): walk links in red, bus connections
in blue; icons: camera (POI), bus (bus stop), house (start/end), Tmax = 3h, t0 = 9:00. 17 6.3. Trip planning in the city of Athens Additional tests were performed on public transport and POI network in Athens
(tests created by Gavalas et al, 2015). The authors proposed 2000 different test
cases (varying in topology and tourist preferences) and the presented results are
average of all 2000 algorithm runs. The evolutionary algorithm was compared
with the following heuristics: g
1. Time-dependent heuristics: TD_CSCR, TD_SlCSCR (Gavalas et al, 2015)
and their version working on average travel times (AvgCSCR). 2. ILS algorithm working on average travel times (AvgILS, Garcia et al, 2013)
and its time-dependent version (TD_ILS). 3. Exact algorithm implemented by the author (OPT). Compared methods were very fast (execution times of less than 0.1 s) and in order
to achieve similar execution times the author tested another version of the evolu-
tionary algorithm with reduced population size (EVO30). Population size and gen-
eration parameters were scaled (Psize = 30, Ng = 1500, Cg = 150). In tab. 3. experimental results are presented. It can be seen that the proposed
evolutionary algorithm (in both versions) achieves results very close to optimal. They are 0.6–2.0 percent better than the best of other metaheuristics (TD_SlCSCR
and TD_CSCR). Gaps to other methods are much bigger (3.5–13.5 percent). It confirms effectiveness of the proposed method. Tab. 3. Trip planning results for the city of Athens (Tmax = 5h, t0 = 10:00)
Method
Score
Gap
Method
Score
Gap
EVO100
344.57
0.02
Avg_CSCR
332.01
3.7
EVO30
344.34
0.1
TD_ILS
326.28
5.3
TD_SlCSCR
342.06
0.7
Avg_ILS
298.53
13.4
TD_CSCR
337.78
2.0
OPT
344.6
– REFERENCES Campos, V., Marti, R., Sanchez-Oro, J., & Duarte, A. (2014). Grasp with Path Relinking for the
Orienteering Problem. Journal of the Oper. Res. Society, 65(12), 1800–1813. doi:10.1057/jors.2013.156 Chao, I., Golden, B., & Wasil, E. (1996). Theory and methodology - a fast and effective heuristic
for the orienteering problem. European Journal of Operational Research, 88(3), 475–489. doi:10.1016/0377-2217(95)00035-6 Dean, B.C. (2004). Shortest paths in FIFO time-dependent networks: theory and algorithms. Technical report, MIT Department of Computer Science. Garcia, A., Vansteenwegen, P., Arbelaitz, O., Souffriau, W., & Linaza, M. T. (2013). Integrating
public transportation in personalised electronic tourist guides. Computers and Operations
Research, 40(3), 758–774. doi:10.1016/j.cor.2011.03.020 Gavalas, D., Konstantopoulos, C., Mastakas, K., Pantziou, G., & Vathis, N. (2015). Heuristics for
the time dependent team orienteering problem: Application to tourist route planning. Computers and Operation Research, 62, 36-50. doi:10.1016/j.cor.2015.03.016 Gendreau, M., Laporte, G., & Semet, F. (1998). A tabu search heuristic for the undirected selective
travelling salesman problem. European Journal of Operational Research, 106(2–3), 539–545. doi:10.1016/S0377-2217(97)00289-0 Golden, B., Levy, L., & Vohra, R. (1987). The orienteering problem. Naval Research Logistics, 34,
307-318. doi:10.1002/1520-6750(198706)34:3<307::AID-NAV3220340302>3.0. CO;2-D Gunawan, A., Yuan, Z., & Lau, H. C. (2014). A Mathematical Model and Metaheuristics for Time
Dependent Orienteering Problem. In PATAT 2014: Proceedings of the 10th International
Conference of the Practice and Theory of Automated Timetabling, 26–29 August 2014 (pp. 202–217). Research Collection School Of Information Systems. Mahfoud, S. W. (1992). Crowding and preselection revisited. In Proceedings of the 2nd
International Conference on Parallel Problem Solving from Nature (PPSN II), Brussels,
Belgium, 1992 (pp. 27–36). Amsterdam: Elsevier. Ostrowski, K. (2015). Parameters Tuning of Evolutionary Algorithm for the Orienteering Problem. Advances in Computer Science Research, 12, 53–78. Ostrowski, K., Karbowska-Chilinska, J., Koszelew, J., & Zabielski, P. (2017). Evolution-inspired
local improvement algorithm solving orienteering problem. Annals of Operations Research,
253(1), 519-543. doi:10.1007/s10479-016-2278-1 Ostrowski, K. (2017). Evolutionary Algorithm for the Time-Dependent Orienteering Problem. In K. Saeed, W. Homenda, & R. Chaki (Eds.), Computer Information Systems and Industrial
Management. CISIM 2017, Lecture Notes in Computer Science (10244, pp. 50–62). Cham:
Springer. doi:10.1007/978-3-319-59105-6_5 p
g
Schilde, M., Doerner, K., Hartl, R., & Kiechle, G. (2009). Metaheuristics for the biobjective
orienteering problem. Swarm Intelligence, 3(3), 179–201. doi:10.1007/s11721-009-0029-5 Tasgetiren, M. (2001). A genetic algorithm with an adaptive penalty function for the orienteering
problem. Journal of Economic and Social Research, 4(2), 1–26. Vansteenwegen, P., Souffriau, W., Vanden Berghe, G., & Oudheusden, D.V. (2009). 7. CONCLUSION In this paper a metaheuristic solving the Time-Dependent Orienteering
Problem with Time Windows (TDOPTW) was presented and applied to tourist trip
planning in public transport networks. The algorithm was tested on public transport
and POI networks of Białystok and Athens and in all cases obtained optimal
or close to optimal solutions (tours) in short execution times. The composition
of evolutionary algorithm and local search heuristics confirmed to be effective for
the problems from the Orienteering Problem family (high-quality results were
previously obtained by the author for the OP and TDOP benchmarks). Further re-
search will concentrate on adaptation of the proposed method to the Time-Dependent
Team Orienteering Problem with Time Windows (TDTOPTW). In this version
of the problem m paths are generated (instead of one) and effective TDTOPTW
solutions can be applied to planning multi-day tours. 18 REFERENCES A guided local
search metaheuristic for the team orienteering problem. European Journal of the
Operational Research, 196(1), 118–127. doi:10.1016/j.ejor.2008.02.037 Verbeeck, C., Sörensen, K., Aghezzaf, E.H., & Vansteenwegen, P. (2013). A fast solution method
for the time-dependent orienteering problem. European Journal of Operational Research,
236(2), 419–432. doi:10.1016/j.ejor.2013.11.038 19
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Figure S1. Hydrological systems from this study.
Black dots indicate collecting sites within each of the water bodies, represented by
uppercase letters in coloured circles (A = Lower Conchos River; B = Upper and
Middle Mezquital River; C = Lower Lerma River; D = Zacapu Lake; E = Cuitzeo Lake
F = Pátzcuaro Lake; G = Zirahuén Lake; H = Armería-Ayuquila Rivers; I = Cuzalapa
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Figure S1. Hydrological systems from this study. Black dots indicate collecting sites within each of the water bodies, represented by
uppercase letters in coloured circles (A = Lower Conchos River; B = Upper and
Middle Mezquital River; C = Lower Lerma River; D = Zacapu Lake; E = Cuitzeo Lake
F = Pátzcuaro Lake; G = Zirahuén Lake; H = Armería-Ayuquila Rivers; I = Cuzalapa
River; J = Cotija; K = Lower Balsas River; L = Upper Balsas River. Codes correspond Figure S1. Hydrological systems from this study. Figure S1. Hydrological systems from this study. Black dots indicate collecting sites within each of the water bodies, represented by
uppercase letters in coloured circles (A = Lower Conchos River; B = Upper and
Middle Mezquital River; C = Lower Lerma River; D = Zacapu Lake; E = Cuitzeo Lake;
F = Pátzcuaro Lake; G = Zirahuén Lake; H = Armería-Ayuquila Rivers; I = Cuzalapa
River; J = Cotija; K = Lower Balsas River; L = Upper Balsas River. Codes correspond to
those found in Table 1 of the manuscript.
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Pricing Method of the Flexible Bus Service Based on Cumulative Prospect Theory
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Hindawi
Journal of Advanced Transportation
Volume 2022, Article ID 1785199, 14 pages
https://doi.org/10.1155/2022/1785199
Research Article
Pricing Method of the Flexible Bus Service Based on Cumulative
Prospect Theory
Wanjing Ma ,1 Yuhang Guo ,1 Kun An ,1 and Lei Wang
1
2
1,2
The Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji University, Shanghai 201804, China
College of Transport and Communications, Shanghai Maritime University, Shanghai, China
Correspondence should be addressed to Kun An; kunan@tongji.edu.cn
Received 26 October 2021; Revised 11 January 2022; Accepted 5 February 2022; Published 16 March 2022
Academic Editor: Ren-Yong Guo
Copyright © 2022 Wanjing Ma et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Pricing directly affects the sustainable development of the flexible bus service. This study proposes a profit maximization model
and a social welfare maximization model for the flexible bus operator based on the cumulative prospect theory. Fares and
uncertain travel time due to unforeseen detours in serving passengers jointly affect passengers’ mode choice. On the other hand,
fares and passengers’ probabilistic choices over the flexible bus jointly determine the profits of the flexible bus company and social
welfare. This study explores the relationship between the probability of passengers choosing the flexible bus, trip fares, and
uncertain travel time. Serving more passengers indicates more profits, which also results in longer detour time thus decreasing the
probability of passengers choosing the flexible bus. Considering the interactive influence among passengers, we further calculate
the detour time distribution. Finally, a pricing model is established to compensate for the side effects of the detour. The results
show that heterogeneous fares can help the flexible bus company to obtain higher profits but have negligible influence on social
welfare. In addition, the development of long-distance services and regulations over the detour time can also help to obtain
more profits.
1. Introduction
The flexible bus can be regarded as a bridging mode between
the conventional fixed-route transit and dial-a-ride services.
The flexible bus typically uses small or medium-sized vehicles to provide door-to-door travel services subject to
passenger demand [1]. Since taxies are way more expensive
despite their high level of service, the flexible bus service with
its high flexibility and customization capability is an attractive alternative for high-to-medium income customers
[2]. It is critical for operators to seek an appropriate pricing
method for the flexible bus service. On the one hand, reasonable pricing can affect the behavior of travelers, reduce
the demand for private cars/taxies, and transfer it to public
transit, thereby alleviating urban traffic congestion. On the
other hand, pricing also directly affects the financial sustainability of the flexible bus company.
In recent years, a growing number of studies investigated
the pricing problem for many emerging travel modes such as
flexible bus and customized bus. Li et al. [3] formulated a
competitive game model in which the objective was to
maximize the profits of customized bus services and ridesharing based on passengers’ transport mode choices.
Sayarshad and Gao [4] developed a dynamic pricing scheme
that utilized a balking rule considering socially efficient
levels and revenue-maximizing price. An equilibriumjoining threshold was obtained by imposing a toll on the
customers who joined the on-demand mobility system.
Kaddoura et al. [5] proposed an agent-based transport
simulation to investigate different design concepts for the
demand-responsive transit. The simulation results show that
a small service area and low prices may result in an unwanted mode shift effect from walk and bicycle to Demand
Responsive Transit. Gong et al. [6] constructed a game
theory model between the customized city bus service and
the conventional urban bus transportation to maximize the
profits of the two transportation modes. Wang et al. [2]
integrated the disaggregated trip choice model with the
2
vehicle routing model to determine incentive schemes. They
concluded that passengers’ sensitivity towards incentives is
decisive to the result.
In addition, there are many studies on the pricing for
other on-demand responsive travel modes, such as ridehailing and ride-pooling. Ozkan [7] studied the interrelationship between pricing and matching decisions of a ridesharing firm. He formulated a stylized ride-sharing model that
captured customer and driver behaviors considering the
geospatial nature of the system. The results showed that
optimizing the pricing decisions alone with fixed matching
rules did not increase the number of matchings in general.
Yan et al. [8] designed and implemented a matching and
pricing algorithm at scale to strike a balance between model
complexity and accurate description of the marketplace dynamics. Wang et al. [9] found that if the platform offers the
carpool service option, they can achieve a larger market
coverage and the riders can enjoy more affordable rides
without compromising on service quality. Bai et al. [10]
considered an on-demand service platform using earningsensitive independent providers with heterogeneous reservation prices (for work participation) to serve its time and
price-sensitive customers with the heterogeneous valuation of
the service. Zhong et al. [11] examined how an on-demand
ride-hailing platform in competition with the traditional taxi
industry designs its pricing strategies under unregulated and
regulated pricing scenarios. They found that the monopolistic
on-demand ride-hailing platform’s price rate and profit under
the unregulated pricing scenario are relatively higher than
those under the regulated pricing scenario.
Detours are a problem faced by both the flexible bus and
carpooling companies. However, few studies considered how
the detour time would affect the pricing strategy of the flexible
bus. Ke et al. [12] innovatively established a set of nonlinear
equations to explore the relationships between the platform
decision variables (i.e., trip fare) and endogenous variables
(e.g., actual detour time) in ride-sourcing markets with and
without on-demand ride-pooling services. By considering the
extra detour time experienced by passengers and drivers, they
found that decrease in trip fare not only directly increases
passenger demand due to negative price elasticity, but also
reduces actual detour time, which in turn increases passenger
demand. Zhang and Nie [13] established a market equilibrium
based on a spatial driver–passenger matching model that
determines the passenger wait time for both solo and pooling
rides. They found the system’s benefit diminishes quickly as
the average en-route detour time increases.
Both ride pooling and flexible bus are travel demandresponsive travel modes and how to pricing for both of
them considering the uncertainty of the detour time is a
challenging problem. However, a flexible bus can serve
more passengers at the same time, making possible detours
outcomes more complicated. The uncertainty in detour
time affects passengers’ travel decisions to a greater extent,
thereby affecting demand. Only few pricing studies considered travel decisions under uncertain travel time conditions. Choi et al. [14] applied the mean-risk theory to
analytically explore how the risk attitude of customers
affects the optimal service pricing decision of the on-
Journal of Advanced Transportation
demand platform. Wu et al. [15] proposed a choice-based
framework for modeling the supply/demand interaction in
risky choice contexts. The model allowed the system operator to set an optimal pricing strategy regardless of
whether user risk preferences are risk-seeking or riskaverse.
There are few studies on the relationship between
pricing, detours, and passenger decision-making under
uncertain conditions. Instead, most existing studies considered the relationship between price and demand from a
macro perspective. Flat and homogenous fare is provided to
all passengers [3, 6]. When passengers receive different
service levels in terms of detour level, their fares should be
different.
Cumulative prospect theory (CPT) is widely used to
solve travel decision-making problems and transportation
pricing problems. As a descriptive decision-making model
under uncertainty, the prospect theory was proposed by
Kahneman and Tversky [16] as a critique of the expected
utility theory. In 1992, Kahneman and Tversky [17] extended
their model to CPT. CPT is based on the assumption of
bounded rationality of decision-makers and can describe
decision-makers’ behavior under uncertain conditions more
accurately. Katsikopoulos et al. [18] found that drivers were
risk-averse when choosing among routes in the gain domain
and risk-seeking in the loss domain. It is consistent with the
view of CPT. Sepehr et al. [19] introduced a CPT-based
framework for mode choice modeling using observational
data. The framework utilized CPT for modeling reliability in
the trip-based models. CPT has also been widely applied to
congestion pricing. Liu et al. [20] considered the psychological factors of passengers in the congestion pricing model
and verified the feasibility of the model based on user
equilibrium and CPT. Xu et al. [21] developed an optimal
congestion pricing model in which user equilibrium was
adopted to capture travelers’ response to pricing signals
under risk based on CPT. However, the application of CPT
in the pricing of the flexible bus is limited.
We aim to study the pricing of the flexible bus service
considering the interaction between passenger travel behavior and fares and thus propose a profit-maximization
pricing strategy for the flexible bus system based on CPT.
Considering the travel time of the flexible bus is uncertain
due to its high route flexibility, we can apply CPT to our
pricing model. The relationship of detour time distribution,
fares, and acceptance of detours (choosing to take the
flexible bus) are explored. On this basis, considering the
detour problem of the flexible bus, we build a pricing model
under static demand for the flexible bus company with the
goal of expected profit maximization and social welfare
maximization.
In summary, the aims of this research are as follows:
(1) Under uncertain travel time of trips by the flexible
bus, we explore the influence of fares and uncertain
travel time on passengers’ travel mode choices based
on CPT
(2) We establish two customized pricing models with
the objective of profit maximization for the flexible
Journal of Advanced Transportation
bus company and social welfare, considering the
impacts of trip detours on-demand loss
The remainder of this paper is organized as follows.
Section 2 establishes the mode choice model and the pricing
model. The parameters are calibrated through a stated
preference (SP) survey. Section 3 describes the design of two
case studies and analyzes the results. The last section
summarizes the innovations and conclusions.
2. Methodology
In this section, we first introduce the hypotheses used in the
flexible bus pricing problem. Based on prospect theory, we
calculate the perceived travel time utility of passengers.
Taking the travel time utility and out-of-pocket costs as the
components in the utility function, we can obtain the
probability of passengers taking flexible buses for a given
detour time. In addition, considering the mutual influence
among passengers in each other’s travel time, we develop a
series of equations to obtain the detour time distribution.
Finally, a flexible bus pricing model is constructed, which
aims at maximizing the bus company’s profit and maximizing the social welfare respectively. The model parameters
are calibrated through the SP survey and Maximum Likelihood Estimation (MLE). The main ideas are shown in
Figure 1.
2.1. Problem Description. We consider regional flexible bus
service in this study [22], which allows vehicles to operate in
a demand-responsive way through reservation within the
service area. Passengers can only board or alight in the
predefined service areas. The pick-up region and drop-off
region are connected by a non-stop fast route. It can be
regarded as a variant of customized buses. Figure 2 illustrates
the operation of the regional flexible bus. In this paper, we
aim to investigate the pricing problem for this regional
flexible bus service.
The flexible bus adopts small and medium-sized vehicles
and provides door-to-door services based on reservation. In
the responsive area, the stops and bus routes depend on the
demand of passengers, and the demand of passengers is
elastic which is subject to the utility of the flexible bus.
Compared with the taxi, the flexible bus will detour when
delivering multiple passengers. More passengers to be served
will probably lead to longer detour time. To passengers, a
longer travel time would decrease the utility of the flexible
bus thus affecting his/her mode choice probability. It is
necessary to make reasonable pricing to compensate for the
side effects of detours so as to make flexible buses competitive with taxies. In addition, as flexible buses may adjust
routes dynamically while en-route, the travel time of passengers on-board may be prolonged and thus is uncertain.
Passengers’ risk attitude and personal preference also influence passengers’ decision-making in the case of uncertain
travel time. Therefore, it is necessary to accurately measure
the impact of these factors on passenger decision-making to
obtain the probability of passengers choosing the flexible
bus. The mode choice probability and ticket price jointly
3
affect the expected profit of the flexible bus company and the
social welfare. This section solves the pricing problem
considering the interactions among passengers in the system. The price for each passenger is optimized to maximize
the expected profit and the social welfare respectively.
Due to the similarity of flexible bus and taxi services, we
assume passengers can choose between the flexible bus and
the taxi for their trip. They mainly consider the travel time
and the fare assuming the other influencing factors are the
same. The flexible bus knows the demand of passengers in
advance through the reservation, but it is uncertain whether
passengers will take it in the end. After knowing the passengers’ demand, the flexible bus will plan the route. If the
passenger eventually chooses to get on the bus, the bus will
pick him up. According to the probability of passenger
boarding, the flexible bus can estimate the travel time
through the probability of passengers getting on the bus.
Before boarding, the flexible bus displays passengers the fare,
travel time, possible detour time, and corresponding
probabilities (in this paper, they are captured by the detour
time distribution). Detour time refers to the increased time
for passengers due to picking up other passengers (the time
loss for waiting for boarding, etc.) after boarding compared
with the shortest travel time from the origin to the destination. The shortest travel time is equal to the travel time of a
taxi. The distribution of detour time refers to the detour time
and its corresponding probability.
2.2. Behavior of Passengers. When passengers make mode
choice decisions, they will be affected by many factors such
as travel time, cost, and uncertainty of travel time [5]. In
addition, passengers will also be influenced by their risk
attitudes and preferences [21]. Considering the characteristics of the flexible bus, serving other passengers leads to the
increase of uncertain detour time for the loaded passengers.
The uncertain travel time and fare jointly affect the passengers’ mode choice decisions. This part explores the interrelationship between the distribution of detour time, the
fare, and the acceptance of detours under the condition of
uncertain travel time of the flexible bus.
2.2.1. Perceived Time Utility. Most of the traditional travel
decision-making models are based on the expected utility
theory, assuming that the decision-maker is entirely rational.
In fact, people in the process of making travel decisions are
often affected by the traveler’s habits, attitude towards risk,
preferences, and other factors. Decision-makers often canno’t be entirely rational.
CPT was developed by Kahneman and Tversky [17]
based on prospect theory (PT), which is different from the
traditional expected utility theory (EUT). CPT has three
main observations about an individual’s bounded rationality. (i) People usually consider possible outcomes relative
to a certain reference point (x0 ) rather than to the final state.
The payoffs are defined as the gains or losses relative to x0
before making choices. The payoffs that people perceive can
be described by a concave function for gains and a convex
function for losses which results in diminishing sensitivity.
4
Journal of Advanced Transportation
Mutual Influence among Passengers
Behavior of Passengers
Perceived Time Utility:
Calculate the Time Utility Perceived by the
passengers based on the CPT
Detour Time Distribution:
Calculate the detour time distribution
using the probability of passengers
choosing to take the flexible bus
Calibration of Parameters:
Calibrate the parameters of the
pricing model through
SP survey and MLE
Acceptance of Detours:
Calculate the probability of passengers
choosing to take the flexible bus based on
the utility maximization theory
Pricing Model:
Calculate the fare for each person with the goals of
maximizing profit and maximizing social welfare
Figure 1: Main idea of the method.
can lead to k different outcomes, quantified by x1 , x2 , . . . , xk ,
The outcome i happens with probability Pi . Each alternative
can be seen as a prospect (xi , Pi ). The following value
function proposed by Kahneman and Tversky [17] is used in
this paper:
Region 1
Region 2
Responsive area
Fixed route (between regions)
Responsive route (within regions)
Responsive boarding station
Responsive alighting station
Figure 2: Operation of the regional flexible bus.
(ii) People tend to be loss aversion. People are more sensitive
to losses than gains. (iii) People tend to overweight the
probability of extreme, but rare events, and underweight
more common events. People’s decisions are affected by the
decision weights, not actual probabilities. In conclusion,
CPT argues that decision-makers perceive values v(xi )
(travel time in the case of this paper) differently from the
actual values xi , and probabilities Pi (probability of experiencing a certain travel time for a given trip) are converted
to decision weights w(Pi ).
Although some studies have considered the influence of
detour time, they have not considered the uncertainty of
detour [12]. Due to demand uncertainty, the travel time of
the flexible bus is uncertain. Therefore, the choice between
flexible public transportation and other modes of transportation is a typical travel decision-making problem under
uncertain conditions. Given that CPT provides a well-supported descriptive paradigm for individuals’ decisionmaking under risk or uncertainty, we can apply CPT to
measure travelers’ perceived utility of time.
We assume that a passenger intends to choose between a
flexible bus and a taxi for a trip. Choosing each alternative
α
⎪
⎧
⎨ xi − x 0 , x i ≥ x 0 ,
v xi � ⎪
where 0 < α, β < 1, λ ≥ 1,
⎩ −λ x − x β , x < x ,
0
i
i
0
(1)
where x0 is the reference point; α is the exponent of the value
function over the gain region, and β is the exponent of the
value function over the loss region. v(xi ) is the value
function, reflecting an individual’s perceived value. The
parameters α and β measure the degree of diminishing
sensitivity of the value function. λ is the loss aversion coefficient, indicating that individuals are more sensitive to
losses than gains.
The following probability weighting function by Kahneman and Tversky [17] is used:
c
w Pi �
Pi
c
c 1/c
Pi + 1 − P i
where 0 < c < 1,
(2)
where c is the probability weighting parameter, representing the level of distortion in probability judgment in
the decision-making process. w(Pi ) is the probability
weighting function, reflecting an individual’s perception
of probability. Figures 3 and 4 show the value function and
the weighting function. As shown in Figures 3 and 4, the
value function v(xi ) is S-shaped, concave in the gain
region and convex in the loss region. Besides, individuals
are more sensitive to losses than gains. Furthermore, the
probability weighting function w(Pi ) expands the influence of rare events and shrinks the influence of common
events.
The cumulative prospect value is defined as
Journal of Advanced Transportation
5
v (x)
k
CPV tm � vtm,i πPm,i ,
(10)
i�1
x0
where CPV(tm ) is the perceived time utility of mode m. (6)
calculates the perceived utility v(tm,i ) corresponding to the
travel time tm,i . (7), (8), (9) calculate the decision weight
π(Pm,i ) corresponding to the travel time tm,i . (10) calculates
the total perceived time utility of mode m.
x
Figure 3: Value function.
CPV � v xi π Pi ,
(3)
k
π Pi � w Pi + Pi+1 · · · + Pk − w Pi+1 + Pi+2 · · · + Pk ,
where i � 1, 2, . . . , k − 1,
(4)
π Pk � w Pk ,
β
vtm,i � −λtm,i − t0 , tm,i ≥ t0 ,
(6)
c
Pm,i
c
Vm � θm ym ,
(5)
The decision weight π(Pi ) is calculated based on the
cumulative distribution function. All potential outcomes are
ranked in increasing order in terms of preference. In these
equations, k is the number of all potential outcomes, and i
denotes a generic outcome.
For mode-alternative m, the travel time can be
tm,1 , tm,2 , · · · , tm,k with probabilities Pm,1 , Pm,2 , · · · , Pm,k , respectively. To apply CPT, we need to define the reference point,
the value function, and the weighting function first. In the case
of the flexible bus detour problem, people will pay more attention to the increase in detour time compared with the
shortest travel time when making travel decisions. Therefore,
the shortest travel time t0 (equal to taxi travel time) is selected
as the reference point. (1) is assumed to be the value function.
(2) is assumed to be the probability weighting function. Since
tm,i ≥ t0 , ∀i ∈ k, we only model in the loss domain.
The calculation process of perceived time utility
CPV(tm ) is as follows:
wPm,i �
2.2.2. Acceptance of Detours. We assume that the speeds of
the flexible bus and the taxi are equal. The difference in travel
time between the flexible bus and the taxi is because that the
flexible bus needs to detour to serve multiple passengers in
one trip. Therefore, we define the probability of passengers
choosing a flexible bus as the acceptance of detours.
According to the assumption, the fare will also have an
important impact on passengers’ decision-making.
When travelers make travel decisions, they always
choose the one with a larger utility, which is called the utility
maximization theory. The formula of the utility maximization theory is as follows:
c 1/c
,
Pm,i + 1 − Pm,i
(7)
A
where ym is the characteristic variable and θm is the parameter reflecting travelers’ perceived relative importance
of different attributes. According to the discussion above,
travel time and travel cost are selected as characteristic
variables. Considering that travel time is uncertain, the
utility of travel time is more suitable to be described by
CPT. The travel cost is a deterministic factor. Therefore, the
probability estimation and risk attitude of travelers will not
affect the utility of the travel cost. The modified utility
function is
MVm � β0 σ m + βt CPV tm + βc Cm ,
p�
(8)
where i � 1, 2, . . . , k − 1
(12)
where Cm is the travel cost of mode m; CPV(tm ) is the
perceived travel time utility of mode m; σ m is a dummy
variable indicating whether a particular mode-alternative is
the flexible bus or not; β0 is the mode-specific constant
added to capture the effect of unforeseen variables; βc is the
coefficient of cost, and βt is the coefficient of time. CPT can
be used to calculate the value of the modified utility (MVm )
of each mode (the flexible bus and the taxi) and the mode
decision between the two modes. Acceptance of detours can
be described by a Logit function:
πPm,i � wPm,i + Pm,i+1 · · · + Pm,k
− wPm,i+1 + Pm,i+2 · · · + Pm,k ,
(11)
p�
expMVfb
expMVfb + exp MVtaxi
,
(13)
1
1 + exp−β0 + βt CPV ttaxi − CPVtfb + βc ΔC
,
(14)
πPm,k � wPm,k ,
(9)
ΔC � Ctaxi − Cfb ,
(15)
6
Journal of Advanced Transportation
1.0
w (p)
0.8
0.6
0.4
0.2
0.0
0.0
0.2
0.4
p
0.6
0.8
1.0
Figure 4: Weighting function.
where p is the acceptance of detours; fb refers to the flexible
bus; MVfb is the modified utility of the flexible bus; MVtaxi
is the modified utility of the taxi, and ΔC is the difference
between taxi cost and flexible bus cost. CPV(ttaxi ) is equal to
0 and CPV(tfb ) can be calculated by (6), (7), (8), (9), and
(10). Therefore, passengers’ acceptance of detour can be
simplified as
p�
1
1 + exp−β0 +
Δti � ti − t0 ,
βt λ ki�1
β
Δti π Pi + βc ΔC
,
(16)
(17)
where Δti is the detour time for taking the flexible bus.
2.3. Detour Time Distribution. In (16), the probability of
taking the flexible bus is affected by the perceived time utility
and fare. The perceived time utility is jointly affected by the
detour time and its corresponding probability. Calculating
the perceived time utility of a passenger requires the detour
time distribution. By analyzing the reasons for the detour, we
propose a method to calculate the time distribution of the
detour. For a certain passenger, the detour he/she faced is
caused by serving other passengers during his/her ride.
Generally speaking, the more stations served, the longer the
detour time the passenger suffers. However, the detour does
no’t necessarily happen. It is related to the probability of
passengers choosing to take the flexible bus. Considering
that the passenger demand is usually densely distributed in a
certain area, it can be assumed that, for each passenger, the
detour time increases by T for serving every extra station
(including the boarding station and the alighting station).
To explain the method, we consider a case of five passengers, A-E, and they get on and off at given stations.
Figure 5 shows everyone’s boarding and alighting stations.
Since the flexible bus provides door-to-door service, the
2
B (on)
C (on)
D (on)
4
E (on)
A (off)
A (on)
1
6
B (off)
D (off)
3
5
C (off)
E (off)
The boarding or alighting station of A
The boarding or alighting station of B-E
The route of a taxi
The route of a flexible bus
A (on) : A gets on at this station
A (off) : A gets off at this station
Figure 5: Boarding and alighting stations of A-E.
boarding and alighting stations are also the origin and the
destination respectively. Take A as an example, if B-E choose
to take the flexible bus, A will be affected by the detour
caused by serving B-E. If B-E do no’t take the flexible bus, A
will not suffer a detour. This is related to the probability that
B-E choose to take the flexible bus. The probabilities of B, C,
D, and E taking the flexible bus are pB , pC , pD , and pE
respectively. They further affect the probability of the flexible
bus serving Stations 2–5. The probabilities of serving Stations 2–5 are sp2 , sp3 , sp4 , and sp5 respectively, which can be
calculated as follows:
sp2 � 1 − 1 − pB 1 − pC 1 − pD ,
(18)
sp3 � 1 − 1 − pB 1 − pD ,
(19)
sp4 � pE ,
(20)
Journal of Advanced Transportation
sp5 � 1 − 1 − pC 1 − pE ,
7
(21)
According to the assumption, the detour time increases
by T for serving every extra station. For A, the detour time
can be 0, T, 2T, 3T, and 4T with probabilities P1 , P2 , P3 , P4 ,
and P5 , respectively. By combining Stations 2–5, the corresponding probability of the detour time can be obtained.
Taking the detour time Δt � 0 as an example, the corresponding probability is calculated as follows:
P1 � P(Δt � 0) � 1 − sp2 1 − sp3 1 − sp4 1 − sp5 ,
The operating cost is assumed to be L, which is the
system parameter related to operating distance, the vehicle
types, fuel consumption, and other factors of the flexible bus
system. The calculation of operating cost is similar to the
calculation method of taxi fare. The operating distance is
composed of the operating distance within the region and
the operating distance between regions. The operating
distance between regions is a constant, while operating
distance within the region is related to the spatial distribution of passengers. Besides, detours within the region will
also affect the operation costs. The operating cost L is
(22)
where sp2 , sp3 sp4 , and sp5 can be calculated by (18), (19),
(20), and (21). P2 , P3 , P4 , and P5 can be calculated in the
same way. The possible detour time for A is (0, T, 2T, 3T, 4T,
5T). Then, we can get the detour time distribution of
A. Similarly, we can use this method to calculate the detour
time distribution for customers B-E. This idea of calculating
detour time distribution can then be extended to a flexible
public transport system with Q individuals. In general, for a
passenger, his/her detour time is related to the number of
other stations served by the flexible bus. The probability
corresponding to the detour time is determined by the
probability of passengers choosing to take the flexible bus in
other stations.
2.4. Pricing Model
2.4.1. Service Provider Profit. The profit of flexible buses is
the fare revenue minus the operating cost. The expected fare
revenue of passenger is
(23)
where xj is the fare of the flexible bus for passenger j and pj
is the probability of passenger j taking the flexible bus.
According to (12), (13), (14), (15), (16), and (17), pj is related
to detour time and the difference between taxi fare c and
flexible bus fare xj :
1
β
1 + exp−β0 + βt λ ki�1 Δti,j πPi,j + βc c − xj
,
(26)
where φ is the fare of taxi per kilometer; s is the travel distance
between regions; v is the average speed of the flexible bus and
Δt is the expected detour time. Δt can be calculated by the
distribution of detour time mentioned in Section 2.4.
The profit of the service provider Z1 can be expressed as
Q
Z1 � xj · pj − L,
(27)
j�1
where L is the operating cost; pj is the probability of passenger j taking the flexible bus, and c is the fare of the taxi.
2.4.2. Passenger Surpluses. The passenger surplus is the fare
that a passenger is willing to pay for the flexible bus service
minus the actual out of pocket costs. The fare that a passenger is
willing to pay for the flexible bus service can be expressed as:
W � c − UΔt ,
k
rj � xj · pj ,
pj �
L � φ(s + vΔt),
(28)
β
UΔt � βt λ Δti π Pi ,
(29)
i�1
where W is the fare that a passenger is willing to pay, and UΔt
is the disutility caused by detours.
The passenger surpluses Z2 can be expressed as:
Q
Z2 � Wj − xj ,
(30)
j�1
(24)
Taxi fare c is related to the travel distance of the passenger. The travel distance is composed of the travel distance
within the region and the travel distance between regions.
The travel distance between regions is a constant, while
travel distance within the region is related to the origin and
the destination of the passenger. Considering that the travel
distance between regions accounts for the main part, we
assume that ticket fare and the distance between regions are
positively correlated. The taxi fare c is:
c � μs,
(25)
where μ is the fare of taxi per kilometer and s is the travel
distance between regions.
2.4.3. Optimization Model of Fares. We consider two objectives (profit maximization and social welfare maximization) to optimize the fare of the flexible bus.
(i) Expected profit maximization: compared with the
taxi, the flexible bus will detour, so the fare of the
flexible bus will not exceed the fare of the taxi. The
profit maximization model of the flexible bus can be
expressed as
max Z1
(31)
0 ≤ xj ≤ c,
(32)
s.t. (12)-(27)
8
Journal of Advanced Transportation
(ii) Social welfare maximization: social welfare includes
the profit of the service provider and passenger
surpluses, considering the interests of the flexible bus
operator and the passengers simultaneously. The
profit of the flexible bus operator should not be less
than the threshold θ. The social welfare maximization model of the flexible bus can be expressed as
max Z1 + Z2 ,
(33)
s.t. (12)-(30)
Z1 ≥ θ,
(34)
(12), (13), (14), (15), (16), and (17) calculate the
probability of passenger j taking the flexible bus. (18),
(19), (20), (21), and (22) propose a method of calculating
the time distribution of each passenger. (23) calculates the
expected fare revenue of passenger j. (24) displays the
probability of passenger j taking the flexible bus. (25)
calculates the taxi fare. (26) calculates the operating cost.
(27) calculates the service provider profit. (28) calculates
the fare that a passenger is willing to pay for the flexible
bus service. (29) calculates the disutility caused by detours. (30) calculates the passenger surpluses. The objective function aims at maximizing the expected profits of
the flexible bus and maximizing the social welfare respectively. Constraint (32) ensures that the fare is within a
reasonable range. Constraint (34) ensures that the profit
of the flexible bus operator should not be less than a
certain threshold.
Combined with the calculation of detour time distribution proposed in Section 2.3, we can find that the passengers in the flexible bus system affect each other. Take the
service order as A-B-A-B as an example, the reduction in A’s
fare will increase A’s probability of choosing the flexible bus.
Because of the increase in the probability of A choosing the
flexible bus, the probability of B’s detour also increases,
resulting in a decrease in the probability of B choosing to
take the flexible bus. Therefore, the fare of each passenger
directly affects his probability of taking the flexible bus, and
indirectly affects the probability of other people’s detours,
thereby affecting the probability of other passengers’ taking
the flexible bus. Figure 6 shows the relationship between A
and B. Therefore, a reasonable price should be set for each
passenger in the flexible bus system to maximize the expected profit or the social welfare.
The final output of the pricing model is the optimal fare
that is shown to each reserved passenger before the flexible
bus departs. However, the model is under static demand. The
actual operation of a flexible bus is a dynamic process. When a
passenger refuses service or completes the service, new
passengers will enter the system. This situation will lead to an
increase in detour time. It will reduce the level of service for
loaded passengers who have already received the initial fare
on the bus. Correspondingly, the fare should be reduced.
From the perspective of fairness to passengers, the result
calculated by the profit maximization model should be the
highest price given by the flexible bus in real-world operation.
2.5. Calibration of Parameters. To calibrate the parameters of
our model, we conducted an online stated preference survey.
The SP survey includes three parts: The first part is the individual
socioeconomic attributes of the participants. The second part is
regarding people’s risk attitudes towards time. We design a set of
binary travel plan choices. Each has a different travel time
distribution. The average travel time of the choice is equal, but
the variance is not. Participants need to choose their preferred
travel plan. The third part is related to mode choice between the
flexible bus and the taxi. Finally, 246 questionnaires were
returned in this SP survey. After sorting the questionnaires, 205
valid questionnaires were obtained, with an effective rate of 83%.
Overall, the collected data samples are representative. The model
parameters were calibrated using the data of the SP survey.
In many existing studies on travel decision-making
based on CPT, researchers use the parameters in the value
and weighting functions which are directly estimated by
Kahneman and Tversky. However, parameters in Kahneman
and Tversky are estimated from the results of gambling in
the economic field. In different scenarios, the parameters β
of the value function in the loss domain of different travelers
should be different [21].
The values of β in our model are estimated based on the
experimental results of stated choice questions of the second
part and the CPV parameter values (i.e., λ � 2.25 and
c � 0.69). A logit model and MLE are used to estimate the
value function parameter β. On this basis, the values of
β0 , βt , βc in our model are estimated by using logistic regression. Our estimation results are β � 0.60, β0 � −0.326,
βt � 0.252, and βc � −0.285. The rate of substitution between
CPV(t) and travel cost in our study is 0.252/0.285 � 0.88
RMB/min. For passengers, the detour is essentially a loss.
Compared with taxi fares, the decrease of flexible bus fares is
compensation for detours. Therefore, the results mean that
travelers’ willingness to accept every unit increase in CPV(t)
is about 0.88 RMB per minute in our SP survey.
Passengers’ willingness to accept CPT(t) includes the
willingness to accept detour time and the willingness to accept
the uncertainty of travel time. Most studies on the value of time
or uncertainty addressed users of cars, buses, and taxis, while
few considered ride-sharing or flexible bus passengers [23].
There are mainly three approaches considering reliability in the
utility maximization theory. Small [24] proposed a scheduling
model to analyze travelers’ departure time choices to ensure
on-time arrival. Small and Noland [25] improved Small’s
scheduling model to understand choices under uncertainty by
adding the probability distribution of travel time. The mean
lateness at departure and/or arrival [26] is another approach to
measuring the value of uncertainty. The mean-variance (MV)
model [25] estimates the values of travel time and uncertainty
within the utility maximization framework.
We choose the mean-variance model to compare with
our model based on CPT framework. In the mean-variance
model, the utility of mode i is
Ui � βt E ti + βSD SD ti + βc ci + βσ σ i ,
(35)
where E(ti ) is the expected travel time of mode i, SD(ti ) is
the standard deviation of travel time, ci is the ticket fare, σ i is
Journal of Advanced Transportation
9
(+)
Probability of B
taking the flexible bus
Fare of A
(+)
(+)
(−)
(−)
Expected profit
(−)
(+)
(+)
Probability of A
taking the flexible bus
(−)
Fare of B
(+)
direct effect
indirect effect
Figure 6: The relationship between A and B.
a dummy variable indicating whether a particular modealternative is the flexible bus or not, and βt , βSD , βc and βσ are
the parameters. The value of travel time and value of uncertainty can be defined as βt /βc and βSD /βc . We used the
data based on the experimental results of stated choice
questions to calibrate the parameters in the mean-variance
model. The estimation results are βσ � −0.054, βt � 0.152,
βSD � 0.018, βc � −0.311. The value of travel time is 0.49
RMB/min and the value of time uncertainty is 0.06 RMB/
min. The value of time uncertainty is too small, which is
unreasonable. The rate of substitution between CPV(t) and
travel cost in our model is 0.88 RMB/min, which is bigger
than 0.49 RMB/min. Because our model considers the time
uncertainty when calculating the value of travel time are
shown in Table 1.
In addition, travel time variability generates utility or
disutility depending on the relationship between the reference point. Therefore, the time value and uncertainty
perceived by travelers cannot be estimated separately. And
according to the above analysis, the subjective perception
value of the traveler will affect the utility. Therefore, it is
more reasonable to apply CPT to describe the passengers’
decision-making behavior in this context.
Table 1: Parameter calibration results of the mean-variance model.
3. Case Study
km, v � 30 km/h, Q � 8, T � 2 min, μ � 3 RMB/km, φ � 4
RMB/km, and θ � 100 RMB. λ, c, β are parameters in CPT.
λ, c are obtained by referring to the research of Tversky and
Kahneman. β is calibrated through the SP survey. We set λ �
2.25, c � 0.69, and β � 0.60. β0 , βt , βc are the parameters in
the pricing model, which are also calibrated through the SP
survey. We set β0 � − 0.326, βt � 0.252, and βc � −0.285. In
two cases, we omit the average detour time because the
average detour time is much smaller than the travel time
between regions.
3.1. Case Description and Parameter Settings. We suppose
that there are two small areas, area R is a residential area, and
area S is a commercial area. The distance between the two
areas is 20 km. There are Q passengers going from R to S, and
passengers can choose between flexible bus and taxi. The
flexible bus can obtain the demand of all passengers in
advance and determines the passengers’ boarding and
alighting order at the stops. Two cases are set up in this
section. Table 2 describes the stops where passengers get on
and off the bus. Case 1 adopts the first-on, first-off service
principle. In Case 2, there is no specific service principle
(random service principle).
The parameters of the two cases are set as follows:
s, v, Q, T, μ, φ, and θ are system parameters. We set s � 20
Parameters
Coef.
P-value
βσ
βt
βSD
βc
−0.054
0.712
0.152
0.000
0.018
0.615
−0.311
0.000
Table 2: Passengers’ boarding and alighting stops in Case 1 and
Case 2.
Stop
Passenger
Case 1
1
1 (on)
2
2 (on), 3 (on)
3
4 (on)
4
5 (on)
5
6 (on), 7 (on)
6
8 (on)
Case 2
1
1 (on), 2 (on)
2
3 (on)
3
4 (on), 5 (on), 6 (on)
4
7 (on), 8 (on)
Stop
Passenger
7
8
9
10
11
12
1 (off)
2 (off), 3 (off)
4 (off)
5 (off)
6 (off), 7 (off)
8 (off)
5
6
7
8
3 (off), 6 (off), 7 (off)
2 (off), 4 (off)
5 (off)
1 (off), 8 (off)
Note. 1 (on) means Passenger 1 gets on the flexible bus.
3.2. Results
3.2.1. Case 1. Table 3 shows the fares for each passenger in
profit maximization and social welfare maximization
10
Journal of Advanced Transportation
Table 3: Results of case 1.
Passenger
Detour stops
Profit maximization model
Social welfare maximization model
Fares (RMB)
Maximum profit (RMB)
Fares (RMB)
Maximum social welfare (RMB)
models. In addition, the number of stops that affect each
passenger’s detour is also listed.
In the profit maximization model, the average fare is
43.4, and the std is 0.3. The expected maximum profit is
235.9. The fare of each passenger is almost the same. It is
because that the number of detour stops (referring to the
detour suffered by the passenger due to serving other stops)
is the same. The increase in the fare of passenger 1 will result
in a reduction in the probability of Passengers 2–8 taking the
flexible bus. It is the same for every passenger. When the
individual’s fare is set as the average, the expected profit is
reduced to 235.8 with negligible differences from the
maximum profit.
In the social welfare maximization model, the average
fare is 22.5, and the std is 1.2. The maximum social welfare is
381.9 with the constraint that the service provider profit is at
least 100. The fare of each passenger is slightly different.
When the individual’s fare is set as the average, the social
welfare is also with negligible differences from the maximum
social welfare.
Figure 7 shows that the profit and social welfare (without
the constraint that the service provider profit is at least 100
RMB) change with the fare. Here, we set the fare equal for
each passenger. As the fare increases, the profit first increases
and then decreases, reaching the maximum at around 43
RMB/trip, while the social welfare first remains almost
unchanged and then gradually decreased after around 34
RMB/trip.
3.2.2. Case 2. Table 4 shows the fares for each passenger in
profit maximization and social welfare maximization
models. In addition, the number of stops that affect each
passenger’s detour is also listed.
In the profit maximization model, the average fare is
45.5, and the std is 2.2. The expected maximum profit is
254.8. In the profit maximization model, the average fare is
22.5, and the std � 2.64. The expected maximum profit is
254.8. Since the number of detour stops for each person is
different, the individual fare is also different. Figure 8 shows
the relationship between detour stops and fares in Case 2.
When the travel distance is certain, the more stops you take,
the lower the fare is. It is because the effective distance (the
distance from the origin to the destination) is fixed for
passengers. Detours caused by serving other stops increase
the travel time of the passengers. Therefore, for the flexible
bus system, the more detour stops a passenger travels, the
lower the fare should be. This is consistent with the calculation results of our model. When an equal fare is used, the
expected profit is 249.9, reduced by 1.9% compared to the
1
5
43.6
2
5
43.1
3
5
43.1
23.7
21.0
21.3
4
5
5
5
43.6
43.6
235.9
24.0
23.3
381.9
6
5
43.1
7
5
43.1
8
5
43.6
21.3
21.9
23.4
maximum expected profit, and the social welfare is 388.7. It
shows that it is better to take a different fare for each user
when aimed at gaining more profits. However, taking a
different fare has negligible influence on social welfare.
The travel distance, number of passengers, and other
parameters of Case 1 and Case 2 are all the same except for
the service order. By comparing Case 1 and Case 2, the
maximum profit of Case 2 is 8.0% higher than Case 1, and
the maximum social welfare of Case 2 is 1.8% higher than
Case 1. This is due to the fact there are more detour stops in
Case 1 that affect each passenger than in Case 2. It shows that
the detour time has an important influence on the expected
profit of the system.
3.3. Effects of the Travel Distance. We set the travel distance
to vary from 10 to 40 km while maintaining the other parameters unchanged. Figure 9 shows that as the travel
distance increases, the profit and the social welfare per unit
distance increase, and the magnitude of the increase decreases. Take the maximum profit model as an example,
when the travel distance is 10 km, the maximum profit per
unit distance is 7.1 RMB; when the travel distance is 40 km,
the profit per unit distance is 15.2 RMB. Compared with the
travel distance of 10 km, the profit per unit distance increased by 114.1%, indicating that the flexible bus can
obtain more profit in long-distance transportation. The
trend of social welfare and profit is consistent. Therefore,
the development of long-distance flexible bus services
should be a priority strategy for the company and the whole
society. Focusing on providing long-distance flexible public
transportation services, such as between residential areas,
transportation hubs, large shopping malls, and work areas
can increase profit and social welfare. With the change of
travel distance, the optimal fares per unit distance of the
two objectives range from 1.8 to 2.5 and 1.1 to 1.2 respectively. The variation range is small, which indicates that
the pricing model has good robustness when travel distance
changes.
3.4. Effects of the Average Detour Time. The average detour
time is caused by serving other stops for passenger boarding
and alighting. We set the average detour time to vary from 1
to 9 minutes for serving one extra stop. Figure 10 shows that
as the average detour time increases, the maximum expected
profit and social welfare decrease, and the magnitude decreases. Take the maximum profit model as an example,
when the average detour time is 1 minute, the maximum
profit is 254.2 RMB; when the average detour time is
Journal of Advanced Transportation
11
500
400
300
200
100
0
0
5
10
15
20
25
30
35
40
45
50
55
60
-100
-200
Fares (RMB)
Social welfare (RMB)
Profit (RMB)
Figure 7: The relationship between fares, profit, and social welfare in Case 1.
Table 4: Results of case 2.
Passenger
Detour stops
Profit maximization model
2
4
43.7
3
2
45.8
16.6
21.2
24.5
1
2
51.0
27.0
49.0
25.0
Fares (RMB)
Fares (RMB)
Social welfare maximization model
Fares (RMB)
Maximum profit (RMB)
Fares (RMB)
Maximum social welfare (RMB)
1
6
42.0
47.0
45.0
43.0
41.0
4
5
2
3
45.7
44.7
254.8
22.4
24.3
388.7
6
1
47.1
7
0
50.0
8
3
44.9
23.2
25.9
22.1
23.0
21.0
19.0
17.0
0
1
2
3
4
Detour stops
5
6
(a)
7
15.0
0
3
4
Detour stops
5
6
7
(b)
Figure 8: The relationship between detour stops and fares in Case 2. (a) The profit maximization model, (b) The social welfare maximization
model.
9 minutes, the maximum profit is 161.1 RMB, substantially
reduced by 36.6%. As the average detour time increases, a
lower fare is needed to compensate for the delay suffered by
passengers, resulting in a decrease in the maximum profit
and social welfare. Therefore, the flexible bus company
should pay attention to setting an upper limit for the detour
time in operation. With the change of average detour time,
the optimal fares per unit distance of the two objectives
range from 1.7 to 2.3 and 1.1 to 1.2 respectively. This small
range indicates that the pricing model has good robustness
when average detour time changes.
3.5. Effects of the Value of Time. βt /βc measures the value of
time, which is related to the individual’s attributes. We set
βt /βc to vary from 0.6 to 1.5 RMB/min while maintaining the
other parameters unchanged. Figure 11 shows that as the
value of time increases, the maximum expected profit and
social welfare decreases, and the magnitude decreases. Take
the maximum profit model as an example, when βt /βc is 0.4
RMB/minute, the maximum profit is 265.5 RMB; when βt /βc
is 1.2 RMB/minute, the maximum profit is 217.0 RMB,
substantially reduced by 18.3%. As the value of time increases, the operator needs to compensate more for the same
12
Journal of Advanced Transportation
25.0
20.0
15.0
10.0
5.0
0.0
10
15
20
25
30
Travel distance (km)
35
40
Profit (RMB/km)
Social welfare (RMB/km)
Figure 9: Effects of the travel distance (Case 1).
450.0
400.0
350.0
300.0
250.0
200.0
150.0
100.0
50.0
0.0
1
2
3
4
5
6
Average detour time (min)
7
8
9
Profit (RMB)
Social welfare (RMB)
Figure 10: Effects of the average detour time (Case 1).
500.0
400.0
300.0
200.0
100.0
0.0
0.4
0.6
0.8
Value of time (RMB/min)
1
Profit (RMB)
Social welfare (RMB)
Figure 11: Effects of the value of time.
1.2
Journal of Advanced Transportation
delay suffered by the passenger whose value of time is
higher, resulting in a decrease in the maximum profit and
social welfare. Therefore, the flexible bus company should
determine the scope of target passengers in combination
with the available service level in operation. With the
change of the value of time, the optimal fares per unit
distance of the two objectives range from 2.0 to 2.3 and 1.1
to 1.5, respectively, indicating good robustness when the
value of time changes.
4. Conclusions
With the goals of maximizing the expected profit and
maximizing social welfare, the pricing model is constructed
based on the cumulative prospect theory for the regional
flexible bus service. The parameters of the model were
calibrated through a stated preference survey, and two
flexible bus cases were designed to analyze the performance
of the model. First, we considered the passenger detour in
the flexible bus pricing problem and explored the influence
of uncertain detour time and fare on passengers’ mode
choice probability. Second, we modeled the mutual influence
among passengers and found that the certain passenger’s
mode choice probability would affect the detour probability
of other passengers. Thus, a calculation method for detour
time distribution was proposed.
The results showed that the detour time has a greater
impact on the profit and social welfare of the system. More
detour stops lead to a lower fare. As the travel distance
increases, both the maximum expected profit and social
welfare per unit distance increase. As the average detour
time increases, the maximum expected profit and social
welfare decrease. It is suggested that the flexible bus
company may develop long-distance services and set a
proper upper limit to the detour time to achieve higher
profit. Besides, the passengers’ value of time and uncertainty also has a vital influence on the profit and social
welfare of the system. The flexible bus company should
determine the scope of target passengers in combination
with the available service level in operation. With the
change of the parameters, the optimal fares per unit
distance vary in a small range. The pricing model has good
robustness.
There were some limitations to this study. When the area
is small and the passengers are densely distributed, a detour
time distribution can be calculated. But for few passengers in
a large area, there may not be a specific detour time distribution. In addition, the current pricing model can only be
used to handle static demand. How to dynamically price the
flexible bus needs to be explored further.
Data Availability
The data used to support the findings of this study are
available from the corresponding author upon request.
Conflicts of Interest
The authors declare that they have no conflicts of interest.
13
Acknowledgments
The study was supported by the Shanghai Science and
Technology Innovation Action Plan Project (20DZ1202805
and 21692110900), National Natural Science Foundation of
China (nos. 72101186, 52131204, and 52002280).
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Journal of Advanced Transportation
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English
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Understanding carbon dioxide capture on metal–organic frameworks from first-principles theory: The case of MIL-53(X), with X = Fe3+, Al3+, and Cu2+
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Journal of chemical physics online/The Journal of chemical physics/Journal of chemical physics
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cc-by
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Understanding carbon dioxide capture
on metal–organic frameworks from first-
principles theory: The case of MIL-53(X),
with X = Fe3+, Al3+, and Cu2+ Cite as: J. Chem. Phys. 155, 024701 (2021); https://doi.org/10.1063/5.0054874
Submitted: 22 April 2021 • Accepted: 18 June 2021 • Published Online: 09 July 2021 Cite as: J. Chem. Phys. 155, 024701 (2021); https://doi.org/10.1063/5.0054874
Submitted: 22 April 2021 • Accepted: 18 June 2021 • Published Online: 09 July 2021 Giane B. Damas,
Luciano T. Costa,
Rajeev Ahuja, et al. ABSTRACT Metal–organic frameworks (MOFs) constitute a class of three-dimensional porous materials that have shown applicability for carbon dioxide
capture at low pressures, which is particularly advantageous in dealing with the well-known environmental problem related to the carbon
dioxide emissions into the atmosphere. In this work, the effect of changing the metallic center in the inorganic counterpart of MIL-53 (X),
where X = Fe3+, Al3+, and Cu2+, has been assessed over the ability of the porous material to adsorb carbon dioxide by means of first-principles
theory. In general, the non-spin polarized computational method has led to adsorption energies in fair agreement with the experimental
outcomes, where the carbon dioxide stabilizes at the pore center through long-range interactions via oxygen atoms with the axial hydroxyl
groups in the inorganic counterpart. However, spin-polarization effects in connection with the Hubbard corrections, on Fe 3d and Cu 3d
states, were needed to properly describe the metal orbital occupancy in the open-shell systems (Fe- and Cu-based MOFs). This methodology
gave rise to a coherent high-spin configuration, with five unpaired electrons, for Fe atoms leading to a better agreement with the experimental
results. Within the GGA+U level of theory, the binding energy for the Cu-based MOF is found to be Eb = −35.85 kJ/mol, which is within the
desirable values for gas capture applications. Moreover, it has been verified that the adsorption energetics is dominated by the gas–framework
and internal weak interactions. © 2021 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license
(http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/5.0054874 Understanding carbon dioxide capture
on metal–organic frameworks from first-principles
theory: The case of MIL-53(X), with X = Fe3+, Al3+,
and Cu2+ Cite as: J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
Submitted: 22 April 2021 • Accepted: 18 June 2021 •
Published Online: 9 July 2021 AFFILIATIONS 1 Materials Theory Division, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
2Department of Physics Chemistry and Biology Linköping University 58330 Linköping Sweden 1 Materials Theory Division, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
2Department of Physics, Chemistry and Biology, Linköping University, 58330 Linköping, Sweden
3MolMod-CS- Department of Physical-Chemistry, Campus Valonguinho, Institute of Chemistry,
Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
4Department of Engineering and Physics, Karlstad University, 65188 Karlstad, Sweden Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
4Department of Engineering and Physics, Karlstad University, 65188 Karlstad, Sweden a)Authors to whom correspondence should be addressed: giane.benvinda.damas@liu.se and moyses.araujo@physics.uu.se a)Authors to whom correspondence should be addressed: giane.benvinda.damas@liu. a)Authors to whom correspondence should be addressed: gia a)Authors to whom correspondence should be addressed: giane.benvinda.damas@liu.se and moyses.araujo@physics.uu.se ARTICLES YOU MAY BE INTERESTED IN A consistent and accurate ab initio parametrization of density functional dispersion
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155, 024701
© 2021 Author(s). J. Chem. Phys. 155, 024701 (2021); https://doi.org/10.1063/5.0054874
© 2021 Author(s). © 2021 Author(s). The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp I. INTRODUCTION have found that strong interactions between water
molecules and the framework lead to enhanced water adsorption
that could be beneficial or not for gas capture.24 In another work,
Siegelman et al. have found an improvement in efficiency by an
amine-functionalized Mg-based MOF due to hydrogen-bonding
interactions between water molecules and carbamate nitrogen
atoms, which favor carbon dioxide binding.37 However, it is more
common that trace amounts of water can exert a negative impact on
the adsorption capacity.33 For instance, Liu et al.33 have verified a
decrease in carbon dioxide adsorption from 3.74 to 2.69 mol/kg in
a Ni-based MOF with water traces besides the negative effect on the
CO2/N2 selectivity.l i
In general, the presence of open metal sites with appropri-
ate geometry and pore size in metal–organic frameworks is directly
associated with high adsorption capacity and selectivity.12,28 Addi-
tionally, the material should present high heat or enthalpy of
adsorption for good performance at low pressures.28 This important
macroscopic quantity is directly associated with the gas–framework
interaction strength, which is expected to be strong enough to main-
tain the latter inside the pore through weak interactions at the end
of the process and also provide a suitable post-processing based cat-
alytic reaction where the activated carbon dioxide can be converted
in raw materials.29 On the other hand, the ideal condition of process
reversibility is maintained with intermediate values for this quantity. y
This work aims at understanding the influence of the metal-
lic center from MIL-53 (X), where X = Fe3+, Al3+, or Cu2+, on
the carbon dioxide capture. Such analysis is performed on a ther-
modynamic point of view by means of first-principles calculations
based on density functional theory (DFT). The outcomes suggest
that the organic counterpart of the metal–organic framework also
participates in the adsorption energetics as the oxygen atoms in
this region and hydroxyl groups interact in a different extent in
each material. In general, the non-spin polarized results have shown
consistency to describe the energetics for these systems, but the
open shell configuration exhibited by Fe- and Cu-based MOFs is
better described with inclusion of such effects. Additionally, the
Hubbard corrections have led to a consistent description of the
atomic magnetic moment for the metallic center in these systems,
a property that has been found to affect severely the adsorption
energetics. I. INTRODUCTION It is important to emphasize that further developments in
the field are still made necessary in order to turn these mate-
rials competitive in an industrial point of view. In this context,
different strategies have been proposed to improve the perfor-
mance of metal–organic frameworks for gas capture applications. In analogy with the amine-based solvents that are traditionally
employed in post-combustion methods, the functionalization by
amine groups has been widely considered to increase the storage
capacity and selectivity by improving the interaction strength with
carbon dioxide.13,27,28,30 For instance, Hu et al.13 have evaluated the
effects of anchoring alkylamine groups in unsaturated Cr3+ cen-
ters of MOF-101 at room temperature conditions. In their series,
the diethylenetriamine-functionalized MOF exhibits the best CO2
uptake (3.5 mmol g−1) even with a significant reduction in the sur-
face area. In another work, 2-aminoterephthalic acid has been tested
as an organic linker in an amino-functionalized Cu-based MOF
to increase the gas uptake to 5.85 mmol g−1.15 Methacrylamides
have also been employed to enhance the carbon dioxide capture in
MOFs.31 I. INTRODUCTION capture and storage (CCS) program4–6 has different technologies
to partially deal with the carbon emissions, finding applications in
several industrial installations that include thermodynamic power
plants and steel production. In the post-combustion approach, car-
bon dioxide is captured from the gas stream due to its affinity
to amine-based solutions.7–9 In general, these compounds present
kinetically favored reactivity with carbon dioxide, as well as low
solubility of hydrocarbon compounds that are quite interesting.10
Nonetheless, the low selectivity in the presence of sulfur dioxide
and the high energy necessary for solvent regeneration represent a The World Meteorological Organization (WMO) has pointed
out an expected average temperature of 1.5 ○C higher than the pre-
industrial levels in less than 35 years, as the most abundant green-
house gas, carbon dioxide, has reached an increase in 3.3 ppm
(0.83%) in one year of analysis, which corresponds to an overall
increase of about 145% compared to the pre-industrial levels.1 In
this context, great efforts are necessary from different sectors of our
society for a further change in the current scenario.2,3 The carbon J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-1 155, 024701-1 The Journal
of Chemical Physics The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp major problem for capture-related applications.11 Thus, the devel-
opment and synthesis of new chemical absorbers that can address
these problems without losing the capacity for gas adsorption are
highly desired.6 chloride groups. Although still containing amine groups in the struc-
ture, the extra adsorption sites promote an increase of about ∼20%
in gas uptake by the resulting MOFs when compared to the initial
amine-functionalized material.32 g y
Metal–organic frameworks (MOFs) constitute a class of three-
dimensional porous materials formed by interconnecting inorganic
and organic counterparts, which has found large applicability in
this field.12–16 In particular, the MIL-53 frameworks comprise an
inorganic region formed by the metallic centers connecting oxy-
gen atoms from hydroxyl groups (axial positions) or benzene dicar-
boxylate (BDC) ligands (equatorial positions) in an octahedral con-
figuration.17–19 In recent years, the applicability of this series has
been widely evaluated by means of experimental14,18,20–25 and the-
oretical methods17,26 for gas adsorption, including carbon diox-
ide,14,18,20–23,26,27 methane,18,23,25,26 and hydrogen sulfide.24 Traces of water can also affect the adsorption capacity
and selectivity for carbon dioxide capture in a gas mixture.33–36
Huang et al. II. COMPUTATIONAL METHODS The applicability of metal–organic frameworks to gas capture
at low pressures has direct association with certain macroscopic
properties, such as adsorption capacity and heat/enthalpy of
adsorption.12,28
The
latter
has
a
thermodynamic
definition
that requires the inclusion of thermal corrections to the total
energies for its full assessment, i.e., zero point energies and thermal
effects acting over the internal energy of each system, but the main
contributing term is the total energy itself.17 Hence, variations
in this property prior and posterior to adsorption give a reliable
estimation of the enthalpy of reaction/adsorption that is crucial
to evaluate how good the material is for gas capture. From a
microscopic standpoint, such variations are generally dictated
by the interaction strength between the metal–organic framework
and the guest molecule (carbon dioxide), namely, the binding
energy (Eb). Furthermore, pore functionalization by other chemical groups,
including methyl, hydroxyl, and carboxyl groups, has been
reported.12,27,28 In this sense, Torrisi et al.27 have shown that embed-
ding carboxyl and hydroxyl groups into MIL-53(Al3+) is particu-
larly advantageous for gas capture applications in comparison to
amine functionalities. Nonetheless, anchoring chemical groups in
metal–organic frameworks is not always straightforward in a practi-
cal point of view since the synthesis conditions, given by high pres-
sures and temperatures, do not favor the anchoring process of sev-
eral chemical functionalities.32 To overcome this issue, Yan et al.32
have initially synthesized the template with active amine groups that
were further substituted by the desired acetic acid and trimesoyl Therefore, the heat/enthalpy of adsorption has been assessed by
calculating the binding energy (Eb) of the solid-state system within
the framework of the density functional theory (DFT) as imple-
mented in the Vienna Ab-Initio Simulation Package (VASP).38 Fur-
ther details on the computational methodology for modeling the
metal–organic framework are given in Subsections II A and II B. J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-2 155, 024701-2 The Journal
of Chemical Physics The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp A. Bulk structures Fe, Al, Cu, C, O, and H atoms. As the semi-local generalized gradi-
ent approximation (GGA) functional fails to describe the bandgap of
semiconducting materials, Hubbard corrections have been applied
on Fe 3d and Cu 3d states through spin-polarized static calculations
within the tetrahedron method with Blöchl corrections. The partial
occupancies for each orbital have also been determined by using the
Gaussian smearing for visual analysis of the orbital hybridization. Here, the assessment of the electronic structure is basically intended
to complement the material description. To model the metal–organic frameworks here under consid-
eration, the crystallographic data of MIL-53 (Fe3+) reported by
Millange et al have been used.39 The original structure has been
modified to include hidden hydrogen atoms at the inorganic region,
more specifically at the oxygen atoms that are displaced in axial posi-
tions related to the metallic center.17 Furthermore, it was necessary
to remove the water molecules lying inside the pores in order to
activate the material for gas adsorption (Fig. 1).40 The Perdew–Burke–Ernzerhof (PBE) functional41 was the
functional of choice to treat the exchange-correlation potential in
the initial solid-state calculations, as it has provided good agree-
ment with experimental data obtained for the evaluation of similar
thermodynamic properties in previous reports.42–45 In the current
study, the ionic relaxations were carried out until the total ener-
gies reached the convergence criterion of 1.0 × 10−3 eV. Dispersion
effects and weak interactions were taken into account by including
the D3-Grimme corrections46 in all steps. The plane wave-basis set
was defined with a cutoff energy of 800 eV after convergence tests
in the sampled region (400–1000 eV). The Brillouin zone was sam-
pled by a 2 × 2 × 4 Monkhorst–Pack k-point mesh. Spin-polarization
effects were further considered for the frameworks with an open
shell configuration [MIL-53 (X), where X = Fe3+ and Cu2+]. Alterna-
tively, the lattice parameters have been fully relaxed for these systems
as displayed in Table S1 of the supplementary material. A. Bulk structures In order to evaluate how the metallic center affects the ability
of a non-functionalized metal–organic framework to capture carbon
dioxide, we have considered the bulk structure from MIL-53 (Fe3+)
with a diamond-shape pore, also called the narrow pore form. This
material crystallizes in a P21/c space group with unit cell dimensions
given by a = 19.32 Å, b = 15.04 Å, c = 6.84 Å, and β = 96.3○. Initially,
lattice parameters have been constrained during the relaxation step
in order to maintain the spatial group symmetry of the crystalline
structure. Table S1 shows that the optimization of lattice parameters
leads to a slight decrease of ∼1–2 Å of the b lattice parameter and
variation of <2○in the lattice angles for these systems that are not
expected to affect the adsorption thermodynamics upon expansion
into the 2 × 2 supercell. g
An interesting point is that μ for oxygen atoms is slightly
increased
at
the
hydroxyl
groups
in
the
Cu-based
MOF
(∼0.3
μb/atom)
in
comparison
with
the
Fe-based
system
(<0.2 μb/atom), which is not verified for the oxygen atoms
connected to the BDC ligands. Although the Cu-based MOF does
not exhibit a significant change in the atomic μ for the metallic
centers regarding the level of theory, the iron-based material does
have a significant variation in this property (1.0–4.0 μb) within
the PBE level, which would lead to Fe3+ ions displaying different
electronic configurations along the symmetric crystal environment. Such inaccuracy to describe the Fe-based MOF electronic structure
could affect the thermodynamic properties if this effect is not
propagated upon addition of the carbon dioxide molecule in the
further steps. p
In MIL-53 (Fe3+), the inorganic counterpart formed by the iron
metallic center is linked to the benzene dicarboxylate (BDC) ligands
via oxygen atoms that are located in equatorial positions. In the axial
positions, the hydroxyl groups form a region that can interact with
the guest molecule as the hydrogen atoms are pointed out vertically
to the pore center, while not presenting any steric hindrance. In this
sense, the vertical distance between hydrogen atoms from different
inorganic counterparts has been calculated as dH–H = 5.20–5.40 Å,
with iron atoms from adjacent parts being distanced by 19.32 Å. A. Bulk structures Replacing the metallic center by aluminum or copper in MIL-53 (Al)
and MIL-53 (Cu) does not promote variations in the pore width
(∼19.3 Å), but its size is diminished for the aluminum case (dH–H
= 5.11 Å). Additionally, there is a shortage in the Al–O chemical
bond of about ∼0.2 Å in comparison to Fe–O or Cu–O, which might
be resultant from a stronger interaction between the metallic center
and the oxygen connecting the organic counterpart. At this point,
it is necessary to emphasize that MIL-53 (Al3+) does not present
the same crystal structure as the iron-based material; thus, it is an
approximate model for this study.17 p
For MIL-53 (Fe3+), the optimum value for the Hubbard param-
eter on Fe 3d states was estimated to be U = 7 eV and J = 1 eV
to give a theoretical bandgap (Eg = 2.20 eV) that shows fair agree-
ment with the experimental report.47 As displayed in Fig. 2(a),
this system has the valence band maximum (VBM) mainly com-
posed of O 2p orbitals connecting to the metallic center, which
persists until −2.6 eV. In the valence band, the spin-up contri-
butions from Fe 3d states have a rising contribution from ∼−0.3
to −0.7 eV, but the conduction band minimum (CBM) is basi-
cally determined by the position of the spin-down contributions
from these atoms. Fingerprints from C–H and O–H bonds can
be easily identified in the H 1s plot [Fig. 2(a)- bottom] with four
clear peaks in the interval from −1.8 to −5.7 eV that match well
with C 2p states and O 2p states that are present in the same
interval. In Fig. S1(b), the calculated bandgap for MIL-53 (Al3+) is
Eg = 3.23 eV, which also shows good agreement with the experi-
mental value reported by Guo et al. (Eexp = 3.56 eV).51 In the same
work, the authors have found that this material has an absorption B. Structure model 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-3 155, 024701-3 © Author(s) 2021 The Journal
of Chemical Physics The Journal
of Chemical Physics The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp 0.01 and 0.03 eV/Å for the pore structure and the guest molecule,
respectively. The GGA+U relaxations have been carried out using
U = 7 eV and J = 1 eV as Hubbard parameters on Fe 3d and Cu 3d
states, while employing the same energy convergence criteria for the
electronic/ionic steps. structural parameters that are optimized during the relaxation pro-
cess, i.e., the ionic positions are always considered but the lattice
parameters are usually kept fixed throughout the relaxation. i
MIL-53 (Fe3+) has shown photoactivity in the visible light
region with an experimental optical gap of 2.64 eV, which corre-
sponds to an absorption edge at λ = 470 nm.47 Furthermore, the
authors point out that the maximum absorption at λ = 220 nm
is due to the ligand to metal charge transfer, O (II) →Fe (II).47
Figure 2 and Fig. S1 depict the density of states of MIL-53 (X), where
X = Fe3+, Al3+, and Cu2+, as obtained using the Gaussian smear-
ing and tetrahedron method with Blöchl corrections, respectively. The latter choice is justified by the semiconducting nature of these
materials, which requires such a methodology for an appropriate
description of their intrinsic bandgaps, whereas the Gaussian
smearing facilitates the plot visualization. The binding energy Eb of the adsorbed species to the frame-
work has been calculated by subtracting the total energy prior and
posterior to the adsorption, i.e., Eb = EMOF−gas −(EMOF + Egas),
(1) (1) where EMOF-gas is the total energy of the gas–framework system and
the last terms correspond to the individual total energies before
adsorption. Zero-point energies and thermal corrections are not
considered in this definition. Effects of spin-polarization and Hub-
bard corrections (GGA+U) on Fe 3d and Cu 3d states over the
quantity expressed by Eq. (1) have also been evaluated for the Fe-
and Cu-based metal–organic frameworks. For Fe- and Cu-based metal–organic frameworks, the GGA+U
methodology has been used to deal with the self-interaction prob-
lem from the GGA approximation to density functional theory that
often leads to an underestimated bandgap.48–50 In this sense, these
calculations were performed in a static mode after spin-polarized
ionic relaxation within the PBE level of theory. B. Structure model These open-shell
systems present an octahedral d orbital splitting with the electron
occupancy in Cu d-orbitals expressed as (t3↑↓
2g e2↑,1↓
g
), whereas the
magnetic moment (μ) for Fe3+ (4.5 μb/atom) suggests a high-spin
state with electron occupancy given by (t3↑
2ge2↑
g ). B. Structure model The gas capture process has been evaluated by expanding the
initial bulk structure into a 2 × 2 supercell aiming to avoid adsor-
bate interactions with their respective images in the periodic system. Initially, it has been assumed that the pore structures do not vary
in a significant way upon gas uptake by allowing partial relaxation
of the system, i.e., the ionic positions. This is an oversimplifica-
tion that is expected to describe the gas adsorption process in a
proper way. Nonetheless, we have also considered eventual changes
in the crystal lattice by enabling full relaxation of the system. These
results are briefly discussed in this publication. In the former case,
the partial relaxations were performed within the Γ-point with a
plane-wave cutoff energy of 550 eV. A tighter energy convergence
criterion has been applied for electronic/ionic steps (1.0 × 10−5/1.0
× 10−4 eV) in order to guarantee that the global minimum on the
potential energy surface (PES) has been reached. The final atomic
forces over the metal–organic frameworks are found to be less than The electronic structure has been attained by calculating the
density of states (DOS) and its projected components (pDOS) on FIG. 1. Bulk structure of MIL-53 (Fe3+) after ionic position relaxation at the PBE/800 eV level of theory including spin-polarization effects. In detail, it is possible to observe
the narrow pore structure of this material. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively, whereas the golden sphere is
representative of Fe, Al, or Cu. Code: VASP. FIG. 1. Bulk structure of MIL-53 (Fe3+) after ionic position relaxation at the PBE/800 eV level of theory including spin-polarization effects. In detail, it is possible to observe
the narrow pore structure of this material. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively, whereas the golden sphere is
representative of Fe, Al, or Cu. Code: VASP. FIG. 1. Bulk structure of MIL-53 (Fe3+) after ionic position relaxation at the PBE/800 eV level of theory including spin-polarization effects. In detail, it is possible to observe
the narrow pore structure of this material. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively, whereas the golden sphere is
representative of Fe, Al, or Cu. Code: VASP. J. Chem. Phys. B. Electronic structure edge at λ = 348 nm; therefore, it would not exhibit activity in the
visible region for eventual photocatalytic purposes. Here, it is veri-
fied that the valence band is formed mainly of O 2p and C 2p states
from the top (−0.3 eV) until −2.3 eV. Al 3p states do not participate
in the VBM or CBM composition, which are prominent just in the
range of −2.1 to −7.1 eV with very low density of states (<2.6 den-
sity of states/eV). In the VBM, a very low contribution from Al 3s
states (0.11 DOS/eV) can be seen at −2.9 eV. This is the reason for
the large bandgap shown by this material, since the CBM is formed
by the overlapping of 2p states from carbon and oxygen atoms that
lie much higher in energy than the unoccupied d states from Fe and
Cu atoms. Here, the C–H and O–H bonds are verified upon orbital
overlapping from −1.74 to −10.0 eV with four major peaks that are
shifted in about +0.25 eV compared to the Fe-based MOF. p
As displayed in Fig. 2(c), MIL-53 (Cu2+) has a similar den-
sity of states profile shown by the iron-based system with Cu 3d
unoccupied states lying much lower in energy compared to Fe 3d
states. Therefore, the overlapping with unoccupied states from oxy-
gen atoms is promoted initially at +0.23 eV (1.4 eV lower than
Fe-based MOF) to significantly reduce the bandgap. On the other
hand, carbon unoccupied orbitals will just appear with a higher
intensity at about +3.0 eV. This material has a calculated bandgap
of Eg = 0.83 eV using U = 7 eV and J = 1 eV for Cu 3d states
[see Fig. S1(c)]. p
Mahdipoor et al. have previously determined the absolute
heat of adsorption for MIL-53 (Fe3+) in 58.7 kJ/mol by experi-
mental methods.52 Table I (second column) indicates that Eb lies
between −47.60 and −73.42 kJ/mol for this material, which gives
an overestimation of ∼25% for the most favorable configuration
(site 1). In this system, the final configuration shows a small angular
shift for a better (CO2) O⋅⋅⋅H (MOF) interaction at ∼1.97 Å. Such an interaction does not alter the O–H bond (∼0.98 Å) from the
hydroxyl groups or the C=O bond (1.18 Å), a typical behavior for
weak van der Waals interactions. B. Electronic structure This analysis has been primarily considered to validate the
density functional theory methodology, but also to establish the J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-4 155, 024701-4 © Author(s) 2021 The Journal
of Chemical Physics
ARTICLE
scitation.org/journal/jcp
FIG. 2. Density of states obtained for the metal–organic frameworks under investigation at the level of theory: PBE/800 eV for MIL-53 (Al3+) and GGA+U/800 eV, with
U = 7 eV on Fe 3d or Cu 3d states of MIL-53 (X = Fe3+, Cu2+). Code: VASP /Gaussian smearing method with σ = 0.1. The Journal
of Chemical Physics scitation.org/journal/jcp FIG. 2. Density of states obtained for the metal–organic frameworks under investigation at the level of theory: PBE/800 eV for MIL-53 (Al3+) and GGA+U/800 eV, with
U = 7 eV on Fe 3d or Cu 3d states of MIL-53 (X = Fe3+, Cu2+). Code: VASP /Gaussian smearing method with σ = 0.1. FIG. 2. Density of states obtained for the metal–organic frameworks under investigation at the level of theory: PBE/800 eV for MIL-53 (Al3+) and GGA+U/800 eV, with
U = 7 eV on Fe 3d or Cu 3d states of MIL-53 (X = Fe3+, Cu2+). Code: VASP /Gaussian smearing method with σ = 0.1. FIG. 2. Density of states obtained for the metal–organic frameworks under investigation at the level of theory: PBE/800 eV for MIL-53 (Al3+) and GGA+U/800 eV, with
U = 7 eV on Fe 3d or Cu 3d states of MIL-53 (X = Fe3+, Cu2+). Code: VASP /Gaussian smearing method with σ = 0.1. that are connected to the metallic center in the axial positions. At
site (2), the interaction occurs with the ligand carbon and hydrogen
atoms through the oxygen atom. At site (3), the molecule is expected
to move freely inside the pore to interact via carbon or oxygen atoms. Horizontal interactions with hydrogen from the BDC ligand have
been considered at site (4). Finally, at site (5), the guest molecule
has been placed to interact with both inorganic (via hydroxyl
groups) and organic (via carbon) counterparts. Table I contains
the gas–framework binding energies (Eb) calculated via Eq. (1)
for all configurations (in kJ/mol). Inclusion of spin-polarization
has been considered at the third and fourth columns, in which
the latter column is estimated within the GGA+U level of the-
ory. The experimental values are available in the last column for
comparison. B. Electronic structure Thus, one should not expect any
changes in the electronic structure of this system since there is no
orbital hybridization between O 2p (CO2) and H 1s orbitals (-OH
group). Here, the comparison between experiment/calculation
methods
is
given
with
the
absolute
values
for
heat
of
adsorption. C. Gas capture Figure 3 displays the adsorption sites (labeled by different num-
bers) here under consideration for CO2 capture. At site (1), the
interaction takes place via hydrogen atoms from hydroxyl groups J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-5 155, 024701-5 scitation.org/journal/jcp FIG. 3. Initial configurations for CO2 adsorption inside the MOF structures under investigation: the interaction takes place vertically in 1, 2, and 5, whereas in 3 (in detail) and
4, the carbon dioxide molecule has been placed in a horizontal position. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively,
whereas the golden sphere is representative of Fe, Al or Cu. FIG. 3. Initial configurations for CO2 adsorption inside the MOF structures under investigation: the interaction takes place vertically in 1, 2, and 5, whereas in 3 (in detail) and
4, the carbon dioxide molecule has been placed in a horizontal position. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively,
whereas the golden sphere is representative of Fe, Al or Cu. FIG. 3. Initial configurations for CO2 adsorption inside the MOF structures under investigation: the interaction takes place vertically in 1, 2, and 5, whereas in 3 (in detail) and
4, the carbon dioxide molecule has been placed in a horizontal position. The red, gray, and white spheres correspond to oxygen, carbon, and hydrogen atoms, respectively,
whereas the golden sphere is representative of Fe, Al or Cu. (Eb = −189.58 to −245.43 kJ/mol). In order to investigate the under-
lying reasons for such a discrepancy, the atomic magnetic moment
(μ) at the metallic site has been evaluated for each case (see Table S2). The supercell prior to adsorption has ∼1–3 unpaired electrons at the It is interesting to note that applying spin-polarization effects,
within the DFT/GGA theory level (third column), does not
improve the theory–experiment agreement, instead leading to an
even more significant overestimation in terms of absolute values TABLE I. Binding energies (Eb) for several possible configurations upon carbon dioxide adsorption within the GGA level
without spin-polarized effects (second column, ISPIN = 1), as well as with its inclusion (third column, ISPIN-2). GGA+U
values correspond to spin-polarized calculations with U = 7 eV and J = 1 eV on Fe 3d or Cu 3d states. C. Gas capture S2 (a) and (b) illus-
trate the final structures after ionic relaxation with the experimental
result than that found by previous works.17,27i metallic center (μ = 1.0–2.7 μB), but the introduction of the guest
molecule promotes oscillations in the electron occupancy across the
framework for all sites. As a result, the total magnetization does not
remain constant in the series, even with multiple reoptimizations
being carried out after the convergence is reached. These data clearly
indicate the lack of consistency in the GGA level of theory to describe
the open shell configuration of these frameworks, i.e., to find the
correct minimum energy configuration in the potential energy
surface, since the gas capture does not involve the metallic center
in a direct way to justify the change in its electronic structure. The Cu-based MOF has site (1) as the most favorable config-
uration within the PBE level of theory, with Eb = −39.80 kJ/mol in
the non-spin polarized case. The final geometry can be visualized in
Figs. S3(a) and S3(b), where the guest molecule is also rotated in rela-
tion to site (1) in a similar position to that verified for the Fe-based
MOF. Here, it is remarkable that the inclusion of spin-polarization
effects provides a smoother trend with Eb = −37.49 to −47.36 kJ/mol
in comparison with the Fe-based MOF. This can be associated with
the lower number of unpaired electrons in the Cu-based MOF that
approximates the solution to the non-spin polarized case, but it still
provides a different chemical trend for this framework series. On the other hand, μ remains constant upon addition of car-
bon dioxide within the GGA+U approximation as displayed in the
fourth column in Table S2. In this case, the use of Hubbard cor-
rections has returned Eb = −47.13 kJ/mol, which has an agreement
of 80.3% with the experimental reported value.52 The total magne-
tization determined for this material (mag = 80.00 μB) establishes
a coherent high spin configuration with five unpaired electrons for
each Fe atom. Changes in the U parameter (U = 6 and 8 eV) have
been tested for better tuning of Eb, but no significant improvement
has been observed (<1 kJ/mol) for site (1). C. Gas capture Note that the
comparison between the heat of adsorption and Eb, which is based on the total energy variation prior and posterior to the
adsorption, is held using the absolute values. In the last column, the absolute values of heat of adsorption are taken from the
literature. The boldfaces denote the most favorable Eb for each case. Binding energies (Eb, kJ/mol)
GGA
GGA+U
Heat of adsorption
Configuration
ISPIN-1
ISPIN-2
ISPIN-2
(kJ/mol)
MIL-53 (Fe3+)
1
−73.42
−242.04
−47.13
58.752
2
−69.57
−198.47
−38.19
3
−48.34
−189.58
−21.26
4
−47.60
−215.50
−29.11
5
−51.55
−245.43
−17.71
MIL-53 (Al3+)
1
−36.19
⋅⋅⋅
2
−35.61
⋅⋅⋅
3
−36.73
⋅⋅⋅
35.018
4
−34.17
⋅⋅⋅
5
−19.39
⋅⋅⋅
MIL-53 (Cu2+)
1
−39.80
−42.87
−35.85
2
−28.34
−39.90
−32.19
3
−33.23
−46.97
−33.66
n/a. 4
−30.38
−47.36
−30.97
5
−29.71
−37.49
−34.18 J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874 155, 024701-6 © Author(s) 2021 The Journal
of Chemical Physics
ARTICLE
scitation.org/journal/jcp
FIG. 4. Final configurations for CO2
adsorption inside MIL-53 (Fe3+) after
ionic relaxation. In (a), the most favor-
able configuration at site 1 is shown,
whereas the other systems are rep-
resented in (b). Note: the position of
the hydrogen (from -OH groups) slightly
varies for each case. The red, gray, and
white spheres correspond to oxygen,
carbon, and hydrogen atoms, respec-
tively, whereas the golden sphere is rep-
resentative of Fe. scitation.org/journal/jcp FIG. 4. Final configurations for CO2
adsorption inside MIL-53 (Fe3+) after
ionic relaxation. In (a), the most favor-
able configuration at site 1 is shown,
whereas the other systems are rep-
resented in (b). Note: the position of
the hydrogen (from -OH groups) slightly
varies for each case. The red, gray, and
white spheres correspond to oxygen,
carbon, and hydrogen atoms, respec-
tively, whereas the golden sphere is rep-
resentative of Fe. FIG. 4. Final configurations for CO2
adsorption inside MIL-53 (Fe3+) after
ionic relaxation. In (a), the most favor-
able configuration at site 1 is shown,
whereas the other systems are rep-
resented in (b). Note: the position of
the hydrogen (from -OH groups) slightly
varies for each case. The red, gray, and
white spheres correspond to oxygen,
carbon, and hydrogen atoms, respec-
tively, whereas the golden sphere is rep-
resentative of Fe. functions applied on hydrogen atoms, using a different model for
MIL-53 (Al3+) that is based on its crystallographic data.17 Thus, the
present study shows better agreement, and Fig. C. Gas capture The main H⋅⋅⋅O interactions in
MIL-53 (X), where X = Fe3+, Al3+, or
Cu2+ before the gas adsorption. The red,
gray, and white spheres correspond to
oxygen, carbon, and hydrogen atoms,
respectively, whereas the golden sphere
is representative of Fe, Al, or Cu. Level
of theory: PBE/non-spin polarized. electronic convergence that remains constant in the further steps
until the ionic relaxation is finished. This is not verified for the PBE
method, where the magnetization tuning along with the ionic relax-
ation process could lead to different electronic structure descriptions
for some systems. same final configuration as site (3) for Al and Cu] as the GGA+U
methodology has not been employed for structural relaxation of the
Al-based MOF. All relevant data are reported in Table II. It is noticeable that the vertical distance between hydrogen
atoms from different inorganic counterparts d(H1⋅⋅⋅H2) increases
in the order Fe < Al < Cu as the H–O bond in the hydroxyl group
is bent toward the organic counterpart. Such geometrical distortion
is an overall effect of the electrostatic attraction between hydrogen
(H1) and the surrounding oxygen atoms connected to that
counterpart. In MIL-53 (Cu2+), the attraction is more evident due
to the shorter H1⋅⋅⋅O1 and H1⋅⋅⋅O2 distances (2.55 and 2.62 Å),
while the (O1⋅⋅⋅H1⋅⋅⋅O2) angle is about 26○higher than that in
the other MOFs. Nonetheless, these interactions are weakened upon
gas adsorption, as indicated by the stretching of H1⋅⋅⋅O1 and
H1⋅⋅⋅O2 distances to up to 2.98 Å (an increase of ∼0.4 Å) in MIL-
53 (Cu2+), which is a more significant variation than that observed
for the other frameworks. Furthermore, the decrease of 56.4○in
the a(O1⋅⋅⋅H1⋅⋅⋅O2) angle for this framework upon adsorption
indicates a weakened interaction between the gas and the organic
region. Albeit these frameworks have crystal structures that only dif-
fer by the metallic center, it is noticeable that the Fe-based MOF
has a binding energy (Eb) for carbon dioxide capture that is much
higher than the other frameworks (see Table I). Such disparity is not
explained by the gas–framework interaction strength since the inter-
action distance remains unaltered (1.97–2.04 Å) regardless of the
material. Moreover, the van der Waals nature of these interactions
points out the inactivity of the metallic center in the gas adsorp-
tion. Thus, we should account for other weak interactions inside
the framework that could play a significant role in the adsorption
energetics. C. Gas capture p
In the GGA+U case, Eb = −35.85 kJ/mol is 7.0 kJ/mol lower
than that predicted by the PBE method, suggesting a very simi-
lar heat of adsorption for this material in comparison with MIL-53
(Al3+). The final magnetization in the supercell (mag = 32.00) is
coherent with the presence of one unpaired electron in each metallic
center (∼0.9 μB/atom) and a slight magnetization on O atoms from
the metal–organic framework (∼0.1–0.3 μB). Hence, the presence of
an unpaired electron confirms the Cu d9 electronic configuration
arising from the Cu2+ oxidation state in these systems. Therefore,
this methodology is consistent to determine the electronic config-
uration for these materials prior and posterior to the adsorption,
thus providing total energies that can be compared with each other. The method itself determines the correct magnetization in the first The absolute heat of adsorption measured by Bourrelly et al.18
(35 kJ/mol) is indicative of a much weaker gas–framework inter-
action in MIL-53 (Al3+) in comparison with the Fe-based MOF
(58.7 kJ/mol).52 This property has been properly described by
our calculations, where the most favorable configuration (3) over-
estimates the experimental value by only 1.73 kJ/mol (<5%,
Eb = −36.73 kJ/mol). For matters of comparison, Ramsahye et al. have determined Eb = −41 kJ/mol for MIL-53 (Al3+) within the
PW91 level of theory/double numerical basis set with polarization J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-7 155, 024701-7 The Journal
of Chemical Physics
ARTICLE
scitation.org/journal/jcp
FIG. 5. The main H⋅⋅⋅O interactions in
MIL-53 (X), where X = Fe3+, Al3+, or
Cu2+ before the gas adsorption. The red,
gray, and white spheres correspond to
oxygen, carbon, and hydrogen atoms,
respectively, whereas the golden sphere
is representative of Fe, Al, or Cu. Level
of theory: PBE/non-spin polarized. ARTICLE scitation.org/journal/jcp FIG. 5. The main H⋅⋅⋅O interactions in
MIL-53 (X), where X = Fe3+, Al3+, or
Cu2+ before the gas adsorption. The red,
gray, and white spheres correspond to
oxygen, carbon, and hydrogen atoms,
respectively, whereas the golden sphere
is representative of Fe, Al, or Cu. Level
of theory: PBE/non-spin polarized. FIG. 5. The main H⋅⋅⋅O interactions in
MIL-53 (X), where X = Fe3+, Al3+, or
Cu2+ before the gas adsorption. The red,
gray, and white spheres correspond to
oxygen, carbon, and hydrogen atoms,
respectively, whereas the golden sphere
is representative of Fe, Al, or Cu. Level
of theory: PBE/non-spin polarized. FIG. 5. C. Gas capture Subsection III D will address this point in detail. J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 D. Structural analysis: The non-spin polarized case In the second column, the oxygen atoms (O1–O6) are located either at the organic counterpart (organic) or the gas molecule (CO2). Level of theory: PBE/non-spin
polarized. TABLE II. Structural parameters given by atomic distances (d, in Å) and angle (a, in ○) of the main contributions to the gas adsorption energetics in MIL-53 (X), with X = Fe3+,
Al3+, or Cu2+. In the second column, the oxygen atoms (O1–O6) are located either at the organic counterpart (organic) or the gas molecule (CO2). Level of theory: PBE/non-spin
polarized MIL-53 (Fe3+)
MIL-53 (Al3+)
MIL-53 (Cu2+)
Atomic distance (Å)/Angle(○)
Oxygen
Initial
+CO2
Δd
Initial
+CO2
Δd
Initial
+CO2
Δd
d(O1⋅⋅⋅H1)
Organic
2.87
2.82
−0.05
2.90
2.85
−0.05
2.55
2.69
0.14
d(O2⋅⋅⋅H1)
Organic
2.64
2.64
0.00
2.71
2.69
−0.02
2.62
2.98
0.36
d(O3⋅⋅⋅H1)
Organic
2.71
2.95
0.14
2.68
2.89
0.21
3.12
2.97
−0.15
d(H1⋅⋅⋅H2)
⋅⋅⋅
5.16
5.44
0.28
5.22
5.39
0.17
5.50
5.76
0.26
d(X–X)
⋅⋅⋅
7.50
8.46
1.16
7.52
8.42
0.90
7.52
8.47
0.95
d(H1⋅⋅⋅O4)
CO2
⋅⋅⋅
1.97
⋅⋅⋅
⋅⋅⋅
1.98
⋅⋅⋅
⋅⋅⋅
2.04
⋅⋅⋅
d(H2⋅⋅⋅O5)
CO2
⋅⋅⋅
1.97
⋅⋅⋅
⋅⋅⋅
1.98
⋅⋅⋅
⋅⋅⋅
2.05
⋅⋅⋅
d(C1⋅⋅⋅O6)
⋅⋅⋅
⋅⋅⋅
2.88
⋅⋅⋅
⋅⋅⋅
2.90
⋅⋅⋅
⋅⋅⋅
2.81
⋅⋅⋅
a(O1⋅⋅⋅H1⋅⋅⋅O2)
Organic
114.6
115.1
0.5
112.0
113.2
1.2
138.9
82.5
−56.4
Eb (kJ/mol)
−73.42
−36.73
−39.18 and with a CO2 binding energy of −47.13 kJ/mol in good agreement
with the experimental finding for heat of adsorption. It should be
pointed out that our thermodynamics assessment includes only the
total energy contribution for the reaction enthalpy, i.e., temperature-
dependent contributions to the internal energy, zero-point energy,
and pV term are not included. Therefore, the agreement with the
experimental outcome could be further improved if such contri-
butions are included and specific thermodynamics conditions are
properly simulated. However, it lays beyond the scope of the cur-
rent study. In the case of the Cu-based MOF, we have obtained
a CO2 binding energy of −35.85 kJ/mol. The latter is similar to
the one obtained for the Al-based MOF, viz., −36.73 kJ/mol. These
results indicate that Cu-based MIL-53 is a promising framework for
CO2 capture applications. Concerning the structure, the CO2 guest
molecule is stabilized within the MOF pore center through weak
interactions with the hydroxyl groups of the inorganic counterpart,
which shows the relevance of the coordinating molecule on the metal
site. These results provide insights for future design of suitable MOF
compounds for CO2 capture and storage. IV. CONCLUSIONS In the current study, we have investigated the effect of vary-
ing the metallic center in the inorganic counterpart of MIL-53
(X), where X = Fe3+, Al3+, Cu2+, on the carbon dioxide adsorp-
tion by using first-principles methods. The relevance of applying
spin-polarization and Hubbard corrections (GGA+U method) to
describe the electronic structure and gas adsorption energetics has
been investigated. The Hubbard parameters for Cu- and Fe-based
MOFs have been initially estimated through electronic structure
assessment, in which the values of U = 7 eV and J = 1 eV are found
to be appropriate to treat the Fe d and Cu d states. Within this
theory level, MIL-53 (Cu2+) has a calculated bandgap of 0.83 eV,
whereas MIL-53 (Fe3+) and MIL-53 (Al3+) display bandgaps of
2.20 and 3.23 eV, respectively, in fair agreement with experimental
reports. D. Structural analysis: The non-spin polarized case The process of gas accommodation inside the framework pore
promotes an increase in the distance between metallic centers in
about d(X–X) = 0.9–1.2 Å. As this distance is decreased in the adja-
cent unit cells by ∼0.5 Å, it is suggested that the presence of the
guest molecule slightly opens the pore, whereas the flexibility of
this model is clarified. Thus, the wider space opened between dif-
ferent inorganic regions in MIL-53 (Cu2+) could slightly decrease
the interaction strength with the guest molecule, i.e., the adsorp-
tion enthalpy or heat of adsorption, as the hydrogen atoms are the
main sites contributing to the adsorption. However, the constant
gas–framework interactions suggest that internal interactions inside
the framework involving the hydroxyl group and organic counter-
part have significant contributions to the binding energy of these
materials. SUPPLEMENTARY MATERIAL See the supplementary material for density of states obtained
for the metal–organic frameworks under investigation using the
tetrahedron method with Blöchl corrections and final configura-
tion for gas adsorption inside MIL-53(Al3+) and MIL-53(Cu2+) after
ionic relaxation. The supplementary material is available free of
charge on the ACS Publications website. D. Structural analysis: The non-spin polarized case It has been discussed in Subsection III C that the inactivity of
the metallic center to affect the gas–framework interactions should
lead to more similar values for Eb. In order to address this ques-
tion, the main gas–framework and framework–framework interac-
tions are investigated in this subsection. Figures 5 and 6 highlight
these interactions prior and posterior to the gas adsorption, respec-
tively, where O1–O3 correspond to oxygen atoms from the organic
counterpart. This analysis has been performed using the non-spin
polarized case for the same interaction site [site (1) for Fe has the Other interactions inside the framework after adsorption are
quite constant regardless of the metallic center. For instance,
d(H1⋅⋅⋅O4) and d(H2⋅⋅⋅O5) distances lie in the range 1.97–2.05 Å
for all systems, whereas the interaction between the oxygen
atom from the organic counterpart and the carbon atom, i.e.,
d(C1⋅⋅⋅O6), is about 2.81–2.90 Å. Thus, these interactions are not
dictating the differences seen in the gas adsorption energetics of
these frameworks. FIG. 6. The main interactions after gas adsorption at site (1) inside the MIL-53 (Fe3+). Note that the interactions may vary according to each system. The red, gray, and white
spheres correspond to oxygen, carbon, and hydrogen atoms, respectively, whereas the golden sphere is representative of Fe, Al, and Cu. Level of theory: PBE/non-spin
polarized. FIG. 6. The main interactions after gas adsorption at site (1) inside the MIL-53 (Fe3+). Note that the interactions may vary according to each system. The red, gray, and white
spheres correspond to oxygen, carbon, and hydrogen atoms, respectively, whereas the golden sphere is representative of Fe, Al, and Cu. Level of theory: PBE/non-spin
polarized. r gas adsorption at site (1) inside the MIL-53 (Fe3+). Note that the interactions may vary according to each system. The red, gray, and white
arbon, and hydrogen atoms, respectively, whereas the golden sphere is representative of Fe, Al, and Cu. Level of theory: PBE/non-spin J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874 J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-8 © Author(s) 2021 The Journal
of Chemical Physics The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp TABLE II. Structural parameters given by atomic distances (d, in Å) and angle (a, in ○) of the main contributions to the gas adsorption energetics in MIL-53 (X), with X = Fe3+,
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Effective and selective CO2 adsorption with amino or amide functionality,” Chem. Eng. J. 380, 122496 (2020). 32Q. Yan, Y. Lin, P. Wu, L. Zhao, L. Cao, L. Peng, C. Kong, and L. ACKNOWLEDGMENTS This research project received financial support from the
Swedish Research Council (VR) and STandUP for Energy collab-
oration, with computational resources provided by the Swedish
National Infrastructure for Computing (SNIC) at the PDC Cen-
ter for High Performance Computing and National Supercom-
puter Centre (NSC). G.B.D. acknowledges CAPES (Coordenação
de Aperfeiçoamento de Pessoal de Ensino Superior) for financial In fact, the proper description of the metal orbital occupancy in
the open shell systems is achieved using the spin-polarized GGA+U
calculations. The atomic magnetic moment on the metallic center
is, in this context, an important parameter to be tracked throughout
the adsorption process, as it should remain constant prior and pos-
terior to the adsorption. Here, MIL-53(Fe3+) is found to stabilize on
the high-spin configuration with five unpaired electrons per atom J. Chem. Phys. 155, 024701 (2021); doi: 10.1063/5.0054874
© Author(s) 2021 155, 024701-9 The Journal
of Chemical Physics The Journal
of Chemical Physics ARTICLE scitation.org/journal/jcp frameworks materials MIL-53 (Al, Cr) and MIL-47 (V) by density functional
theory,” J. Phys. Chem. C 112(2), 514–520 (2008). support of her Ph.D. studies. L.T.C. acknowledges support from
CAPES/Print/UFF Grant No. 8881.310460/2018-01 and CAPES- frameworks materials MIL-53 (Al, Cr) and MIL-47 (V) by density functional
theory,” J. Phys. Chem. C 112(2), 514–520 (2008). 18S. Bourrelly, P. L. Llewellyn, C. Serre, F. Millange, T. Loiseau, and G. Férey,
“Different adsorption behaviors of methane and carbon dioxide in the iso-
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Transcriptomic analysis between self- and cross-pollinated pistils of tea plants (Camellia sinensis)
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Ma et al. BMC Genomics (2018) 19:289
https://doi.org/10.1186/s12864-018-4674-1 Ma et al. BMC Genomics (2018) 19:289
https://doi.org/10.1186/s12864-018-4674-1 Open Access © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Transcriptomic analysis between self- and
cross-pollinated pistils of tea plants
(Camellia sinensis) Qingping Ma1, Changsong Chen2, Zhongping Zeng1, Zhongwei Zou3, Huan Li1, Qiongqiong Zhou1, Xuan Chen1,
Kang Sun1 and Xinghui Li1* Abstract Background: Self-incompatibility (SI) is a major barrier that obstructs the breeding process in most horticultural
plants including tea plants (Camellia sinensis). The aim of this study was to elucidate the molecular mechanism of
SI in tea plants through a high throughput transcriptome analysis. Results: In this study, the transcriptomes of self- and cross-pollinated pistils of two tea cultivars ‘Fudingdabai’ and
‘Yulv’ were compared to elucidate the SI mechanism of tea plants. In addition, the ion components and pollen tube
growth in self- and cross-pollinated pistils were investigated. Our results revealed that both cultivars had similar pollen
activities and cross-pollination could promote the pollen tube growth. In tea pistils, the highest ion content was potassium
(K+), followed by calcium (Ca2+), magnesium (Mg2+) and phosphorus (P5+). Ca2+ content increased after self-pollination but
decreased after cross-pollination, while K+ showed reverse trend with Ca2+. A total of 990 and 3 common differentially
expressed genes (DEGs) were identified in un-pollinated vs. pollinated pistils and self- vs. cross-pollinated groups after 48 h,
respectively. Function annotation indicated that three genes encoding UDP-glycosyltransferase 74B1 (UGT74B1),
Mitochondrial calcium uniporter protein 2 (MCU2) and G-type lectin S-receptor-like serine/threonine-protein kinase
(G-type RLK) might play important roles during SI process in tea plants. Conclusion: Ca2+ and K+ are important signal for SI in tea plants, and three genes including UGT74B1, MCU2 and
G-type RLK play essential roles during SI signal transduction. Keywords: Self-incompatibility, Ion components, Pollen tube growth, Transcriptome GSI has been found in many plant species, such as
Solanaceae [3, 4] and Rosaceae [5–7], while SSI is typically
found in Brassicaceae [8]. Both GSI and SSI have male or
female determinate conditions which are regulated by
different prominent genes [9]. In GSI system, S locus-
encoded F-box (SLF/SFB) proteins control the pollen
recognition of S-RNase based SI [10–12]. In SSI systems,
S-locus receptor kinase (SRK) gene and S-locus cysteine-
rich protein (SCR)/S-locus protein-11 (SP11) function as a
receptor-ligand pair to recognize self-pollens at the
surface of stigma epidermal papilla cells [13]. The SRK
is a membrane-spanning receptor protein in stigma
containing an extracellular domain (S-domain) for recogni-
tion of SP11, a transmembrane domain, and an intracellular
serine/threonine kinase domain [14]. S-locus glycoprotein
gene (SLG) and SRK exhibit series characteristics which are Background
lf
b Self-incompatibility (SI) is a common phenomenon in plant
reproduction system, which prevents self-fertilization in
flowering plants. There are two classical known mecha-
nisms for SI, namely, homomorphic gametophytic self-
incompatibility (GSI) and homomorphic sporophytic
self-incompatibility (SSI). In GSI system, the pollen
incompatibility (haploid male gametophyte) is controlled
by the S allele, pollen and pistils bearing the same S allele
trigger an incompatible reaction [1]. While in SSI system,
incompatibility is determined by both S alleles of the
(diploid-sporophyte) pollen parents [2]. * Correspondence: lxh@njau.edu.cn
1Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China
Full list of author information is available at the end of the article Pollen culture in vitro Pollen culture medium was prepared with the following
substances: 0.59 g MES, 0.02 g H3BO3, 0.05 g Ca(NO3)
·4H2O, 5 g sucrose and 5 g polyethylene glycol 4000
(PEG 4000), diluted with distilled water to 100 mL. Pollens
were cultured in the medium in the dark and observed
by Olympus light microscope (Olympus, Tokyo, Japan). Pollen germination rate and mean pollen tube length at 1,
2, and 4 h were calculated based on eight visual fields. Page 2 of 12 Ma et al. BMC Genomics (2018) 19:289 associated with the female determinant of SSI in Brassica
[15]. The S domain of SRK is highly similar to the SLG,
which is the first S-locus gene to be identified and a soluble
glycoprotein secreted to the stigma surface [16, 17]. Besides,
the pollen coat protein SCR/ SP11 controls pollen deter-
minant of SSI in Brassica [8, 18], and many SP11, SRK, and
SLG alleles were inherited together to term different S
haplotypes. Fig. 1 Morphology of flowers from ‘Fudingdabai’ and ‘Yulv’ cultivars Self-incompatibility mechanism remains unclear in tea
plant. Previous studies suggested that tea plant SI might
be in late-acting self-incompatibility system (LSI), in that
self-pollinated pollen tubes elongated through the style
but failed in fertilization [19, 20]. This has made it
almost impossible to obtain fruits in self-pollinated tea
plants (Camellia sinensis); thus, breeding process in tea
plant is not encouraged. LSI is a novel SI system in
plants, but the molecular mechanism of this system is
still unclear. Recently, Zhang et al. [21] found that tea
plant SI might be categorized to GSI through transcrip-
tome analysis. Therefore, the SI mechanism in tea plants
is still controversial and needs further exploration. Fig. 1 Morphology of flowers from ‘Fudingdabai’ and ‘Yulv’ cultivars 8, 24, 48 and 72 h were picked from each combination and
frozen quickly in liquid nitrogen and stored at −80 °C
for RNA extraction. Three biological replicates were
conducted with at least five pistils for each replicate. To understand the mechanism of SI in tea plant, the
ion components and pollen tube growth in self- and
cross-pollinated pistils were investigated. Furthermore,
the transcriptome of self- and cross-pollinated pistils of
two tea cultivars ‘Fudingdabai’ and ‘Yulv’ was compared
to figure out the DEGs which may be involved in SI of
tea plant. ‘Fudingdabai’ is a national superior clone and
cultivated widely in China because of its good quality,
high yield, and excellent stress resistance, while ‘Yulv’ is a
high-quality cultivar selected from the hybrid offsprings of
‘Yabukita’. Both cultivars are self-incompatible and show
high fruiting rates after cross-pollination. This study will
provide reference for understanding SI mechanism of tea
plant. Methods Fig. 2 The flow diagram of the experiment design. Red and green
indicate pollination combination of the two tea cultivars in this
study. The color dots mean pollens from the corresponding cultivars Identification of differentially expressed genes Identification of differentially expressed genes
Fragments per Kilobase of transcript per Million mapped
reads (FPKM) estimates produced by RNA-Seq by
Cuffquant and Cuffnorm of Cufflinks was used to evaluate
the expression of transcripts [29]. The transcriptome com-
parisons of un-pollinated vs. pollinated groups and self-
pollinated vs. cross-pollinated groups were conducted to
find the differentially expressed genes (DEGs). Differential
expression analyses were performed using the DESeq R
package 1.10.1 [30], which provides statistical routines to
determine DEGs based on a negative binomial distribution
model. The P values were adjusted by the Benjamini and
Hochberg’s approach for controlling the false discovery
rate [31]. False discovery rate < 0.01 and fold change > 2
was considered to be significantly differentially expressed. Pearson’s Correlation Coefficient was used to evaluate the
correlation of biological repeats [30]. Genome alignment and gene annotation Raw data of fastq format were processed, and then were
cleaned by trimming the adapter sequences, ploy-A con-
taining reads and low quality reads. The clean reads were
aligned to the reference genome (http://www.plantking-
domgdb.com/tea_tree/) by TopHat2 using the default
parameters [22]. The mapped reads were assembled into
possible transcripts by Cufflinks [23]. The unannotated
transcripts were annotated by BLAST [24] based on the Statistical analysis The statistical analysis was conducted using Excel 2016
and GraphPad Prism 5.0 (San Diego, USA). The signifi-
cance analysis of difference between two samples was
evaluated with Student t-test and multiple comparisons
were analyzed using One-way ANOVA and P < 0.05 was
considered to be statistically significant. The results were
displayed as mean ± standard deviation. Plant materials and treatments Two ten-year-old tea cultivars, namely, C. sinensis cv. Fudingdabai and C. sinensis cv. Yulv, cultivated in tea
germplasm repository of Tea Research Institute of Fujian
Academy of Agricultural Sciences were used in this study. Flowers from both of the two tea cultivars have three
petals and trifid stigmas. The stigmas of ‘Fudingdabai’
divided at the base but ‘Yulv’ at the upper part (Fig. 1). Flower buds of the two tea cultivars were harvested at
4:00 pm for pollens collection. Besides, the remaining
flower buds of two cultivars were emasculated and used
for artificial pollination next morning. A total of four
pollination combinations were conducted: ‘Fudingdabai’
(♂) × ‘Fudingdabai’ (♀),‘Yulv’ (♂) × ‘Yulv’ (♀),‘Fudingdabai’
(♂) × ‘Yulv’ (♀), and Yulv’ (♂) × ‘Fudingdabai’ (♀), as
shown in Fig. 2. The un-pollinated and pollinated pistils at Fig. 2 The flow diagram of the experiment design. Red and green
indicate pollination combination of the two tea cultivars in this
study. The color dots mean pollens from the corresponding cultivars Ma et al. BMC Genomics (2018) 19:289 Page 3 of 12 Quantitative real time PCR verification Quantitative real time PCR verification The first-strand cDNA was synthesized from 1 μg of total
RNA by using the RevertAid™First Strand cDNA Synthesis
Kit (Thermo Scientific, MA, USA) according to the manual. Quantitative real time PCR (QRT-PCR) was performed
using SYBR Premix EX Taq (Takara, Japan) on Roche
LightCycler® 480II (Switzerland) as instruction specified. The qRT-PCR primers (Table 1) were designed by using
Primer Premier 5.0 (Premier Biosoft International, Palo
Alto, CA). The GAPDH (GenBank: GE651107) from tea
plant was used as the reference gene. All of the PCR reac-
tions were conducted in triplicate and the average expres-
sion values were calculated. The relative expression level of
each gene was calculated with the 2-ΔΔCT method [32]. RNA extraction, library construction and sequencing
Total RNA was extracted using Plant RNA extraction kit
(Bioteke, China) according to the manual. RNA quality
and concentration were assessed by 1% agarose gels,
Qubit®2.0 Fluorometer (Invitrogen, Carlsbad, USA), and
Agilent Bioanalyzer 2100 system (Agilent, Palo Alto,
USA). A total of 3 μg RNA per sample was used for
sequencing libraries preparation by NEBNext®Ultra™
RNA Library Prep Kit for Illumina® (NEB, USA) following
manufacturer’s instructions and library quality was
assessed on the Agilent Bioanalyzer 2100 system (Agilent
Technologies, Palo Alto, CA). The clustering of samples
was performed using TruSeq PE Cluster Kit v3-cBot-HS
(Illumina) according to the manufacturer’s instructions. Finally, sequencing analysis was carried out with an
Illumina Hiseq 2500 platform to generate pair-end
reads. Ion components of pistils Un-pollinated and pollinated styles were dried at 80 °C
for 4 h. A total of 0.1 g dried samples (at least 15 pistils)
were ground and digested in 5 ml nitric acid by ETHOS
One high performance microwave digestion system
(Milestone, Bergamo, Italy) for 1 h. The digested samples
were diluted with nitric acid to 25 mL and analyzed by
inductively coupled plasma-optical emission spectrometer
(PerkinElmer Optima 2100DV, Massachusetts, USA). A
total of nine ions were detected, including potassium (K+),
calcium (Ca2+), magnesium (Mg2+), phosphorus (P5+),
zinc (Zn2+), boron (B3+), Ferrous (Fe2+), aluminium (Al3+),
and manganese (Mn2+). The contents of the ions were
quantified by establishing standard curve. Fluorescence activity of pollen tube following databases: NR (NCBI non-redundant protein
sequences) [25], COG (Clusters of Orthologous Groups
of proteins) [26], Swiss-Prot (A manually annotated and
reviewed protein sequence database) [27], KEGG (Kyoto
Encyclopedia of Genes and Genomes) and GO (Gene
Ontology) [28]. following databases: NR (NCBI non-redundant protein
sequences) [25], COG (Clusters of Orthologous Groups
of proteins) [26], Swiss-Prot (A manually annotated and
reviewed protein sequence database) [27], KEGG (Kyoto
Encyclopedia of Genes and Genomes) and GO (Gene
Ontology) [28]. Fresh un-pollinated and pollinated styles were fixed in
FAA fixative buffer (5 mL formalin, 6 mL acetic acid,
and 89 mL 50% ethanol) for 24 h [19]. The styles were
washed with deionized water and then softened by 2 M
NaOH overnight. The softened styles were stained by 0.1%
aniline blue solution dissolved with 0.15 M K2HPO4. Finally, the styles were observed under Leica DM6B
fluorescence microscope (Leica, Bannockburn, USA)
after 15 min staining. At least five styles were observed
for each sample. Results Pollen germination in vitro and fluorescence of pollen tubes
In order to evaluate the pollen vitality, pollen germination
rate and tube growth between ‘Fudingdabai’ and ‘Yulv’
were assessed and compared. As shown in Additional Ma et al. BMC Genomics (2018) 19:289 Page 4 of 12 Table 1 The primers used for qRT-PCR verification
ID
Forward (5′-3′)
Reverse (5′-3′)
CSA006398 GGCGTATCCAACAATCTTATCG CCAAACCCAATCATCATCCA
CSA005891 GAACGTGTGTTGGTCATTGAT
CATAAATTGTCTACTGGCGAG
CSA028406 GAGATTCAGTTGTCGCTTTG
AGAGCCACCATTTCATTAGC
CSA024717 CCACTGCCACTTGTCGTTGTT
GAGTTTGCCACCGTGAATTCG
CSA002728 GTCGTTCCACTGGCTTCCTAC
GGCAGTAGTTGTTCATAGAGA
CSA026098 GGCTCCCTCTTTCTTTATATG
CCACCATCAATTTCTCCCTTG
CSA024379 TCCCATCATTAGCCTGCCAAC
ATCCCATCTCAGCCCATAAC
GAPDH
TTGGCATCGTTGAGGGTCT
CAGTGGGAACACGGAAAGC pistils, respectively. Taken these results together, pollens
from other cultivars would grow faster in pistils than
that from themselves. This result was similar to that by
Zhang et al. [21]. In addition, reciprocal cross-pollination
showed that the pollen tube growth was slower when
‘Fudingdabai’ was used as maternal parent. However,
pollen tubes in all of the self- and cross-pollinated samples
reached the base of styles after 48 h. Ion components in self- and cross-fertilized pistils
Ion components, especially Ca2+, are an indicator of
self-incompatibility [33]. In tea pistils, the highest level
of ion component observed in the tea pistil was K+,
followed by Ca2+, Mg2+ and P5+ in sequence (Fig. 3a). Pistils of ‘Fudingdabai’ contained more K+ but less Ca2+
than those in ‘Yulv’. Ca2+ content in self-pollinated pistils
of ‘Yulv’ (YLS) was higher than that in cross-pollinated
pistils of ‘Yulv’ (YLC), but no apparent difference between
self- (FDS) and cross-pollinated pistils of ‘Fudingdabai’
(FDC). In FDS pistils, the K+ content was higher than in
FDC pistils, suggesting that Ca2+ and K+ may be involved
in potential signal transduction in SI. file 1: Figure S1A, the pollen appearance between two
cultivars has no significant difference. Pollen germination
rate and mean length of pollen tubes of the two cultivars
were similar and increased gradually with prolongation of
the growth time (Additional file 1: Figure S1B). The fluorescence of pollen tube was observed to exam-
ine the growth of pollens in pistils (Additional file 2:
Figure S2). After 8 h self-fertilization of ‘Fudingdabai’, the
pollens germinated at stigma but no fluorescence was seen
in styles. After 24 h, a few pollen tubes entered styles and
the fluorescence on the base of styles was observed firstly
after 48 h. Pollen tubes of ‘Yulv’ (♂) × ‘Fudingdabai’ (♀)
cross-fertilized pistils showed higher growth rate than
‘Fudingdabai’ self-fertilization. Results The pollen tubes arrived at
the base of styles after 24 and 8 h in self-fertilized ‘Yulv’
pistils and ‘Fudingdabai’ (♂) × ‘Yulv’ (♀) cross-fertilized Differentially expressed genes between self- and
cross-pollinated groups Correlation analysis showed that T02 of self-pollinated
‘Fudingdabai’ at 48 h (FDS48) revealed low correlation
to other two FDS48 samples (T07 and T12) with R2 of 0. 33 and 0.43, respectively. T15 of self-pollinated ‘Yulv’
pistil sample at 48 h (YLS48) deviated from other two
replicates (T05 and T10) with R2 of 0.46 and 0.52,
respectively. These two samples (T02 and T15) were
therefore removed in further DEG analysis. All replicates
of remaining samples showed high correlation (Fig. 4). In comparison of self- and cross-pollinated groups, only
three common DEGs were found (Fig. 6a). The 1160
common DEGs identified at least in two comparisons
were therefore considered in further analysis. COG func-
tion classification revealed that ‘General function predic-
tion only’ contained the most common DEGs followed by
‘Replication, recombination and repair’, ‘Transcription’
and ‘Signal transduction’. This result shows that cross-
fertilization caused a series of responses in transcriptional
level. In addition, the three common DEGs in all compari-
sons
were
UDP-glycosyltransferase
74B1
(UGT74B1,
CSA001819), Mitochondrial calcium uniporter protein
2 (MCU2, CSA014152) and G-type lectin S-receptor-
like serine/threonine-protein kinase RLK1 (G-lecRLK,
Camellia_sinensis_newGene_13508). These genes showed
similar expression patterns in un-pollinated and pollinated
pistils. They also expressed at same levels during reciprocal
cross-pollinations, but adversely expressed during self- A total of 1948, 3399, 3927, 3682, 145, 2061, 1343, 600
and 1859 genes were found to be differentially expressed
between each of un-pollinated ‘Fudingdabai’ pistils (FD0)
vs. FDS48, FD0 vs. cross-pollinated ‘Fudingdabai’ (♀) pistils
after 48 h (FDC48), un-pollinated ‘Yulv’ pistils (YL0) vs. YLS48, YL0 vs. cross-pollinated ‘Yulv’ (♀) pistils after 48 h
(YLC48), FDS48 vs. FDC48, FDS48 vs. YLC48, YLS48 vs. FDC48, YLS48 vs. YLC48 and FDC48 vs. YLC48, respect-
ively (Fig. 5a). By comparing the pollinated groups with
un-pollinated groups, 990 common DEGs were found
(Fig. 5b). Transcriptome assembly and function annotation A total of 18 samples were sequenced and 122.75 Gb
clean data were obtained. The percentages of clean reads
having a base quality greater or equal than Q30 were
above 85.01% indicating that the data produced by
sequencing are of high quality. The clean reads from the Fig. 3 Ion components in self- and cross-pollinated pistils of tea plants. a 1 un-pollinated ‘Fudingdabai’ pistils; 2–5 self-pollinated ‘Fudingdabai’
pistils at 8 h, 24 h, 48 h and 72 h; 6–9 ‘Yulv’(♂) × ‘Fudingdabai’(♀) at 8 h, 24 h, 48 h and 72 h; 10 un-pollinated ‘Yulv’ pistils; 11–14 self-pollinated
‘Yulv’ pistils at 8 h, 24 h, 48 h and 72 h; 15–18 ‘Yulv’(♀) × ‘Fudingdabai’(♂) at 8 h, 24 h, 48 h and 72 h. b The Ca2+ and K+ content during self- and
cross-pollinated pistils Fig. 3 Ion components in self- and cross-pollinated pistils of tea pla
pistils at 8 h, 24 h, 48 h and 72 h; 6–9 ‘Yulv’(♂) × ‘Fudingdabai’(♀) a Fig. 3 Ion components in self- and cross-pollinated pistils of tea plants. a 1 un-pollinated ‘Fudingdabai’ pistils; 2–5 self-pollinated ‘Fudingdabai’
pistils at 8 h, 24 h, 48 h and 72 h; 6–9 ‘Yulv’(♂) × ‘Fudingdabai’(♀) at 8 h, 24 h, 48 h and 72 h; 10 un-pollinated ‘Yulv’ pistils; 11–14 self-pollinated
‘Yulv’ pistils at 8 h, 24 h, 48 h and 72 h; 15–18 ‘Yulv’(♀) × ‘Fudingdabai’(♂) at 8 h, 24 h, 48 h and 72 h. b The Ca2+ and K+ content during self- and
cross-pollinated pistils Page 5 of 12 Ma et al. BMC Genomics (2018) 19:289 Page 5 of 12 ‘General function prediction only’ enriched most of DEGs,
followed by ‘Transcription’,‘Signal transduction mechanisms’,
‘Replication, recombination and repair’ and ‘Secondary
metabolites biosynthesis, transport and catabolism’ (Fig. 5c). GO enrichment analysis revealed that metabolic process in
biological process, cell part in cellular component and cata-
lytic activity in molecular function enriched the most DEGs
(Additional file 3: Figure S3). 18 samples showed alignment ratios between 47.77%
and 54.96% (SRA accession: SRP110788, Table 2). Based
on the alignment with the reference genome of tea, 8136
unannotated genes were found, and 6621 of these genes
were annotated after BLAST, with 1481 unigenes in COG
database, 3465 in GO database, 2301 in KEGG database,
4285 in Swissprot database and 6588 in Nr database. Differentially expressed genes between self- and
cross-pollinated groups COG classification of these DEGs showed that Table 2 The alignment of transcriptomic reads on genome
Sample
Total Reads
Mapped Reads (%)
Unique Mapped Reads
Multiple Map Reads
FD0–1
41,191,716
21,483,151 (52.15%)
49.14%
3.01%
FD0–2
47,556,326
22,717,253 (47.77%)
43.74%
4.03%
FD0–3
42,082,490
22,243,075 (52.86%)
49.41%
3.44%
FDS48–1
42,900,034
22,929,028 (53.45%)
49.59%
3.86%
FDS48–2
47,034,306
23,852,770 (50.71%)
46.94%
3.77%
FDS48–3
45,609,388
23,605,185 (51.76%)
48.43%
3.33%
FDC48–1
48,440,032
25,869,526 (53.41%)
50.72%
2.68%
FDC48–2
41,896,840
21,354,194 (50.97%)
47.74%
3.23%
FDC48–3
49,373,892
25,641,271 (51.93%)
49.57%
2.37%
YL0–1
46,464,662
23,481,565 (50.54%)
47.86%
2.68%
YL0–2
43,549,168
23,651,982 (54.31%)
52.27%
2.04%
YL0–3
41,549,084
21,639,699 (52.08%)
49.26%
2.82%
YLS48–1
53,246,958
26,180,870 (49.17%)
46.35%
2.82%
YLS48–2
50,605,784
27,367,119 (54.08%)
51.17%
2.91%
YLS48–3
40,743,908
21,133,266 (51.87%)
45.29%
6.57%
YLC48–1
45,900,260
25,068,461 (54.62%)
51.87%
2.74%
YLC48–2
53,049,730
29,157,364 (54.96%)
52.29%
2.67%
YLC48–3
47,106,846
24,086,169 (51.13%)
48.49%
2.64% Ma et al. BMC Genomics (2018) 19:289 Page 6 of 12 Fig. 4 Correlation analysis of the samples for differential expression analysis. Different sample numbers represent un-pollinated ‘Fudingdabai’ pistils
(FD0), self-pollinated ‘Fudingdabai’ pistils at 48 h (FDS48), ‘Yulv’(♂) × ‘Fudingdabai’(♀) at 48 h (FDC48), un-pollinated ‘Yulv’ pistils (YL0), self-pollinated
‘Yulv’ pistils at 48 h (YLS48) and ‘Yulv’(♀) × ‘Fudingdabai’(♂) at 48 h (YLC48), respectively. Bold values are R2 for replicates of each sample Fig. 4 Correlation analysis of the samples for differential expression analysis. Different sample numbers represent un-pollinated ‘Fudingdabai’ pistils
(FD0), self-pollinated ‘Fudingdabai’ pistils at 48 h (FDS48), ‘Yulv’(♂) × ‘Fudingdabai’(♀) at 48 h (FDC48), un-pollinated ‘Yulv’ pistils (YL0), self-pollinated
‘Yulv’ pistils at 48 h (YLS48) and ‘Yulv’(♀) × ‘Fudingdabai’(♂) at 48 h (YLC48), respectively. Bold values are R2 for replicates of each sample Fig. 4 Correlation analysis of the samples for differential expression analysis. Different sample numbers represent un-pollinated ‘Fudingdabai’ pistils
(FD0), self-pollinated ‘Fudingdabai’ pistils at 48 h (FDS48), ‘Yulv’(♂) × ‘Fudingdabai’(♀) at 48 h (FDC48), un-pollinated ‘Yulv’ pistils (YL0), self-pollinated
‘Yulv’ pistils at 48 h (YLS48) and ‘Yulv’(♀) × ‘Fudingdabai’(♂) at 48 h (YLC48), respectively. Bold values are R2 for replicates of each sample pollinations of the two cultivars (Fig. 6b). Function
annotation found that G-lecRLK was functioned on ‘Signal
transduction mechanisms’. MCU2 worked on ‘Energy pro-
duction and conversion’ and ‘Carbohydrate transport and
metabolism’. Finally, UGT74B1 was annotated to ‘General
function prediction only’. Except for ‘general function prediction only’, the classes
of ‘Replication, recombination and repair’, ‘Transcription’
and ‘Signal transduction’ enriched most of the DEGs. Differentially expressed genes between self- and
cross-pollinated groups In
addition, G-lecRLK, MCU2 and UGT74B1 were found in
these common DEGs, suggesting that these DEGs played
vital roles during SI process. In the five overlapping genes,
MCU2 and UGT74B1 were found. G-lecRLK was only
expressed in the comparisons in our study because it was
annotated by database blast but not genome mapping. In order to compare our results to the previous study
[21], the data from self-pollinated (FDS48–1, SRR3290055)
and cross-pollinated ‘Fudingdabai’ samples (FDC48–1,
SRR3290084) at 48 h were downloaded and re-analyzed
based on genome of tea plants. A total of 4262 DEGs were
identified between FDS48–1 and FDC48–1 comparison. According to the large number of DEGs, we suggested that
‘Fudingdabai’ should be used as the paternal parent in the
study of Zhang et al. [21]. As shown in Fig. 7, in compari-
son of self- and cross-pollinated groups (FDS48 vs. FDC48,
FDS48 vs. YLC48 and FDS48–1 vs. FDC48–1), only five
common DEGs were filtered. Therefore, the common
DEGs identified at least in two comparisons were con-
cerned. COG function classification revealed similar result
to the four groups comparisons in our study (Fig. 7). Verification of differentially expressed genes and resulting in self-recognition. Interactions between
pollen and pistil in the same haplotype triggered a SI
response, which inhibits pollen tube growth and leads to
failure of fertilization [34]. During SI process, a series of
signal changes occurred in plants. The earliest identified
physiological event caused by SI recognition is the
increase of Ca2+ in incompatible pollen tubes or stigma
papilla cells [35, 36]. In the present study, Ca2+ changes
suggest a potential correlation between pollen tube
growth and Ca2+ content. Furthermore, the opposing
trend of Ca2+ ion content of the two cultivars between
self- and cross-pollinated pistils reveals that Ca2+ may
be an important signal for SI in tea plants. DEGs between reciprocal cross-pollinations In the present study, 1859 DEGs were identified in FDC48
vs. YLC48 comparison. Except for ‘General function predic-
tion only’, most of these DEGs were involved in ‘Transcrip-
tion’ and ‘Replication, recombination and repair’ (Fig. 8a). KEGG pathway enrichment analysis showed that ‘Galactose
metabolism’ possessed the highest rich factor and ‘Phe-
nylpropanoid biosynthesis’ had the most DEGs (Fig. 8b). This result suggests different responses between reciprocal
cross-pollinations in tea cultivars. Ma et al. BMC Genomics (2018) 19:289 Page 7 of 12 Fig. 5 Differentially expressed genes identified in different comparisons. a The number of DEGs found in different comparisons. b, c Venn
diagram and COG annotation for DEGs between un-pollinated and pollinated groups Fig. 5 Differentially expressed genes identified in different comparisons. a The number of DEGs found in different comparisons. b, c Venn
diagram and COG annotation for DEGs between un-pollinated and pollinated groups Fig. 5 Differentially expressed genes identified in different comparisons. a The number of DEGs found in different comparisons. b, c Venn
diagram and COG annotation for DEGs between un-pollinated and pollinated groups Verification of differentially expressed genes
In order to verify the reliability of RNA-Seq data, eight
DEGs were selected for qRT-PCR analysis. As shown in
Fig. 9, most of the DEGs showed similar expression
trend compared to the RNA-Seq analysis. Therefore, the
RNA-Seq analysis is credible. Discussion Self-incompatibility is a common phenomenon in angio-
sperm. In order to understand the SI mechanism of tea
plants, we studied the ion components and pollen growth
in self- and cross-pollinated pistils from two tea cultivars. The results showed that pollen tubes grew faster in
cross-pollinated pistils than those in self-pollinated pistils. Furthermore, Ca2+ in pistils increased after self-pollinations
but decreased after cross-pollinations. In addition, compara-
tive transcriptome analysis showed that G-type LecRLK,
UGT74B1 and MCU2 genes might contribute the SI signal
transduction mechanism in tea plant. In the present study, a DEG MCU2 was identified
between self- and cross-pollination, which undertook
the mitochondrial Ca2+ uptake [37]. In animals, Ca2+
uptake could regulate the mitochondrial energy production
that is a stimulation of sperm-induced Ca2+ release [38]. There is evidence that the Ca2+ uptake also occurred at
fertilization in mammalian eggs [39]. Inhibition of the
mitochondrial function also disrupted the sperm-induced
Ca2+ oscillatory pattern and intracellular Ca2+ homeostasis,
and resulted in low developmental competence in mammals Signal transduction during self-incompatibility in tea plants
Self-incompatibility is genetically regulated by a multi-
allelic S-locus which links pollen and pistil S-determinants Ma et al. BMC Genomics (2018) 19:289 Page 8 of 12 Fig. 6 DEGs identified between self- and cross-pollinated groups. a Venn diagram for DEGs between self- and cross-pollinated groups. b The ex-
pression of the three common DEGs between self- and cross-pollinated groups Fig. 6 DEGs identified between self- and cross-pollinated groups. a Venn diagram for DEGs between self- and cross-pollinated groups. b The ex-
pression of the three common DEGs between self- and cross-pollinated groups Ca2+ after pollination (Fig. 3). We can therefore propose
that SI activates a nonspecific ion channel in tea plants. [40]. Unlike in animals, the functional mechanism of
MCU in tea plants has been less studies, and; therefore,
needs verification except for Ca2+, K+ is also sensitive to
SI. In Papaver rhoeas, conductance of some monovalent
cations, such as K+ and NH4
+ were also stimulated by SI
[41]. Interestingly, content of K+ changes was opposite to Role of self-incompatibility related genes in tea plants
LecRLK family has been classified to three subfamilies:
L-type, G-type and C-type LecRLKs. This classification Fig. 7 Venn diagram and COG function classification for DEGs identified between self- and cross-pollinated groups. FDS48–1 and FDC48–1 are
self- and cross pollinated samples from the study by Zhang et al. Fig. Discussion 7 Venn diagram and COG function classification for DEGs identified between self- and cross-pollinated groups. FDS48–1 and FDC48–1 are
self- and cross pollinated samples from the study by Zhang et al. Ma et al. BMC Genomics (2018) 19:289 Page 9 of 12 Fig. 8 The DEGs between reciprocal cross-pollinations. a COG function classification of DEGs between reciprocal cross-pollinations. b KEGG enrichment
analysis of DEGs between reciprocal cross-pollinations Fig. 8 The DEGs between reciprocal cross-pollinations. a COG function classification of DEGs between reciprocal cross-pollinations. b KEGG enrichment
analysis of DEGs between reciprocal cross-pollinations Fig. 8 The DEGs between reciprocal cross-pollinations. a COG function classification of DEGs between reciprocal cross-pollinations. b KEGG enrichment
analysis of DEGs between reciprocal cross-pollinations Fig. 8 The DEGs between reciprocal cross-pollinations. a COG function classification of DEGs between reciprocal cross-pollinations. b KEGG enrichment
analysis of DEGs between reciprocal cross-pollinations is supported by the structure analysis of these proteins. L-type LecRLK contains a legume lectin-like extracellular
domain, and G-type LecRLK has a α-mannose binding bulb
lectin domain, while C-type LecRLKs are characterized
due to the presence of calcium-dependent carbohydrate-
binding domain [42]. G-type LecRLKs were historically
known as SRKs, since they hold the D-mannose binding
lectin (B_lectin) and catalytic domain of the serine/threo-
nine kinases. a similar SRK gene (Camellia_sinensis_newGene_13508)
from tea plant which differently expressed between self- and
cross-pollinated pistils and might contribute to the signal
transduction of SI in tea plant. In general, the SRK genes
function in SI through the diversity of S domain. Therefore,
the S domain of the SRK gene should be identified in
different tea cultivars to explore the role of SRK on SI
process of tea. The previous studies have identified a LSI or an ovarian
sterility (OS) type controlling self-incompatibility in tea
plants [19, 20]. The same phenomenon was also observed
in our study. However, the molecular mechanism of this
SI system remained unclear until Zhang et al. [21, 45] SRK genes have a S domain which is responsible for SI
in Brassicaceae [15, 43]. Recently, these genes were also
reported to confer abiotic stress tolerance and delay
dark-induced leaf senescence in rice [44]. Here, we screened Ma et al. BMC Genomics (2018) 19:289 Page 10 of 12 Fig. 9 The qRT-PCR verification for RNA-Seq analysis. * means different significantly (P < 0.05) proposed a gametophytic SI mechanism based on S-
RNase control in tea plant. Discussion Unexpectedly, S-RNase
gene was not found in tea plant in the present study,
but three DEGs were identified in comparison between
self- and cross-pollinated pistils: G-type LecRLK, MCU2
and UGT74B1. Pollen tube reception, the crosstalk be-
tween the male and female gametophytes when pollen
tubes arrive at the synergid cells of the ovule in flower-
ing plants, mutation of TURAN(TUN) and EVAN(EVN)
genes led to overgrowth of the pollen tubes inside the
female gametophyte and inhibited the rupture of pollen
tubes. TUN encodes a UGT superfamily protein and is
required for pollen tube growth and integrity by affecting
the stability of the pollen-specific FERONIA RLKs [46, 47]. In this work, whether the UGT74B1 and G-type RLK
genes work together on fertilization in tea plant remains unknown. Nevertheless, we can suggest that
both of the genes may codetermine the SI mechanism
in tea plant. It is difficult to explain that G-type LecRLK, MCU2 and
UGT74B1 showed so different expression patterns be-
tween self-pollinations. It may be due to the variety differ-
ence of tea plants. More cultivars should be adopted to
detect the expression of these genes in self- and cross-
pollinations to interpret their roles in SI. Besides, function
analysis through transgenic test to clarify the mechanism
of these two genes in SI will be a good way in the future if
more studies can be conducted to overcome the barriers
in tea plant transformation. Our study suggests a dis-
tinctive mode of action of SI in tea, and the results
therein provide new guidance and reference for exploration
of SI mechanism in tea. Page 11 of 12 Page 11 of 12 Ma et al. BMC Genomics (2018) 19:289 Funding
Thi
k This work was supported by the National Natural Science Foundation of
China (31470690, 31570689) and the China Earmarked Fund for Modern
Agro-industry Technology Research System (CARS-19). The funders had no role
in study design, data collection, analysis and interpretation, or preparation of
the manuscript. This work was supported by the National Natural Science Foundation of
China (31470690, 31570689) and the China Earmarked Fund for Modern
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and observation of pollen tubes fluorescence. HL conducted the ion assay and
edited the figures in the manuscript. QZ carried out qRT-PCR experiment. XC was
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identification. Our study will help understand the SI
mechanism of tea plant further. Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations. Ethics approval and consent to participate Tea plants used in this study were cultivated in tea germplasm repository of
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h 1Tea Research Institute, Nanjing Agricultural University, Nanjing 210095, China. 2Tea Research Institute, Fujian Academy of Agricultural Sciences, Ningde
355015, China. 3Department of Plant Science, University of Manitoba, Winnipeg
R3T 2N2, Canada. 355015, China. 3Department of Plant Science, University of Manitoba, Winnipeg
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Recommended Citation
Recommended Citation Dwiranti, Astari (2020). Foreword from Handling Editor - 7th Edition. ASEAN Journal of Community
Engagement, 4(1). Available at: https://doi.org/10.7454/ajce.v4i1.1097 Available at: https://doi.org/10.7454/ajce.v4i1.1097 Foreword from Handling Editor - 7th Edition
Foreword from Handling Editor - 7th Edition Astari Dwiranti
astari.dwiranti@sci.ui.ac.id Follow this and additional works at: https://scholarhub.ui.ac.id/ajce Part of the Social and Behavioral Sciences Commons Recommended Citation
Recommended Citation This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.
This Front Matter is brought to you for free and open access by the Universitas Indonesia at ASEAN Journal of
Community Engagement. It has been accepted for inclusion in ASEAN Journal of Community Engagement. ASEAN Journal of Community
ASEAN Journal of Community
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Engagement
Volume 4
Number 1 July
Article 1
7-31-2020
Foreword from Handling Editor - 7th Edition
Foreword from Handling Editor - 7th Edition
Astari Dwiranti
astari.dwiranti@sci.ui.ac.id
Follow this and additional works at: https://scholarhub.ui.ac.id/ajce
Part of the Social and Behavioral Sciences Commons
Recommended Citation
Recommended Citation
Dwiranti, Astari (2020). Foreword from Handling Editor - 7th Edition. ASEAN Journal of Community
Engagement, 4(1).
Available at: https://doi.org/10.7454/ajce.v4i1.1097
Creative Commons License ASEAN Journal of Community
ASEAN Journal of Community
Engagement
Engagement
Volume 4
Number 1 July
Article 1
7-31-2020
Foreword from Handling Editor - 7th Edition
Foreword from Handling Editor - 7th Edition
Astari Dwiranti
astari.dwiranti@sci.ui.ac.id ASEAN Journal of Community
ASEAN Journal of Community
Engagement
Engagement
Volume 4
Number 1 July
Article 1
7-31-2020 ASEAN Journal of Community
ASEAN Journal of Community
Engagement
Engagement
Volume 4
Number 1 July
Article 1
7-31-2020 Foreword from Handling Editor - 7th Edition
Foreword from Handling Editor - 7th Edition Dear Readers, It is very happy for us to present this edition, Volume 4 Number 1, July 2020. Amid the concerns
of the Covid-19 pandemic, which influences human life around the globe, we are honor to select
and publish the best submitted-papers in the field of community engagement (5 papers from
Indonesia, 3 Papers from Philippines, 1 Paper from Portugal, 1 Paper from Australia, 1 Paper from
Thailand, and 1 Paper from Malaysia and Vietnam). At the first insight, we present an article with type of Research Paper, Review Articles, and Case-
based Articles. For Research Paper, we have excellent of 8 articles. First article about creative
economy clinic. The authors: Andri Zainal, T. Citra Nisa Farza, Khairunnisa Harahap, and Pasca
Dwi Putra writes, “Developing an on-campus creative economy clinic to elevate the quality of
existing community service program”. The article is to highlights the potential outcomes of
establishing an in-campus creative economy clinic that ensuring the business sustainability of
MSMEs in the disruptive technology era. Initial assessment related to the needs of MSME is
further required as a strategic step for the development of the ecosystem of related creative
economy clinic based on competitive advantage attached to each university Next, we present the paper an enriching creative communities through literature, “Enriching
creative communities through young adult (YA) literature: a content analysis of zines from
Philippine High School for the Arts” written by Reya Mari Soriaga Veloso. This article conclude
that YA zines provide alternative creative community to the youth, are a form of counter-
storytelling, and a means for sociological theorizing—all of which are necessary functions for
enriching creative communities among the youth. On the topic of health, we present articles by the author Hugo Oliveira and Jorge Bonito. with the
title “Health education projects in Portuguese schools: A multicases study”. Authors presents there
is a lack of instruments and methodologies able to record the behavioral changes developed within
the scope of health education, while simultaneously stimulating the reflection on these behavioural
changes and their causes. Next article, still with Research Paper, written by Sri Ismiyati Damayanti, Simparmin Ginting,
Otik Nawansih, and Siti Hudaidah, with the article “Implementation of biogas-based energy
security program and evaluation of its sustainability in Kediri Village, Pringsewu District,
Lampung Province”. Creative Commons License This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License. This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License. This Front Matter is brought to you for free and open access by the Universitas Indonesia at ASEAN Journal of
Community Engagement. It has been accepted for inclusion in ASEAN Journal of Community Engagement. This Front Matter is brought to you for free and open access by the Universitas Indonesia at ASEA
Community Engagement It has been accepted for inclusion in ASEAN Journal of Community Eng Community Engagement. It has been accepted for inclusion in ASEAN Journal of Community Eng Dear Readers, Authors concluded that the Biogas-based Energy Security Program has
succeeded in making the community awareness, accept and apply the technology of processing
cow manure into biogas, where the people whose houses have biogas flow, all the fuel needs for
cooking and electricity off, 100% have been met by biogas. A discussion of current issues about Covid-19 written by Yeni, Najmah, and Sharyn Graham
Davies. The paper “Predicitive modeling, empowering women, and Covid-19 in South Sumatra,
Indonesia” shows modelling indicates that over 1,000 people had Covid-19 by the end of April,
reaching over 150,000 by the end of May, and over a third of South Sumatra’s population is likely to be infected by the end of June. Multiple interventions are needed to reduce cases and flatten the
curve. Women are key to flattening the curve and must be empowered to undertake actions from
a familial base. to be infected by the end of June. Multiple interventions are needed to reduce cases and flatten the
curve. Women are key to flattening the curve and must be empowered to undertake actions from
a familial base. On the topic of kids related to protection, we present a paper “Self protection and stop bullying
campaign for kids at RPTRA Sungai Bambu, Tanjung Priok, Jakarta Utara” written by Suraya
Mansur. The result shown that children who take part in community service activities shown an
increase level of knowledge and awareness of self-protection by following the instructions in the
song “Sentuhan Boleh Sentuhan Tidak Boleh” (What You Can Touch, and What You Can’t
Touch). These approach must be done together with other friends, for more mature children to
guide younger children. On the topic of kids related to protection, we present a paper “Self protection and stop bullying
campaign for kids at RPTRA Sungai Bambu, Tanjung Priok, Jakarta Utara” written by Suraya
Mansur. The result shown that children who take part in community service activities shown an
increase level of knowledge and awareness of self-protection by following the instructions in the
song “Sentuhan Boleh Sentuhan Tidak Boleh” (What You Can Touch, and What You Can’t
Touch). These approach must be done together with other friends, for more mature children to
guide younger children. Another article from health, is written by Artemio Morado Gonzales Jr. The article “Empowering
the lowland indigenous community through child health and nutrition program in Occidental
Mindoro Province, Philippines”. Dear Readers, The common tools used from this article were seating
arrangement, flipcharting, props, social hours, and recreation. In terms of the evaluation of the
program, the child health remains poor despite of the effort of the different blocks that is working
in the health system. Thus, this program could enhance their health knowledge and practice in
other forms of extension modalities. Development of technology for dairy cattle production, is discussed in a paper entitled
“Intensifying forage legumes strata system technology through dairy cattle production” written by
Marcos E. Bollido, Teresa B. Polbos, and Feleciano R. Bejar. These technologies was implemented
in collaboration with the Department of Agriculture and Local Government Unit of San Jorge,
Samar. Beneficiaries were selected based on the set criteria and qualifications. For Review Articles we have 3 selected papers. First, about Social Life Cycle Assessment (S-
LCA) is written in the article “Enhancing the community engagement of Indonesian Palm Oil
Companies through the implementation of the Social Life Cycle Assessment (SLCA)” by Indah
Budiani. The study highlights importance of community stakeholders’ inclusion in decision-
making processes as the means to prevent conflict, and to maintain company reputation. Other
approaches such as capacity building and social economic development can be also effective as
long as there is a thorough assessment in advance and participation of local community in
developing the intervention plan. Next article is from Thailand with the topic of cross-border development in Universities, with the
title “Cross-border development - a long-term role for Universities” by Robert Brian Smith and
Nucharee Nuchkoom Smith. The results showed that there are three issues were identified as
priority areas to be addressed: quality of higher education, complex government bureaucracies and
ineffective on the job training. This will require universities to provide high quality offerings which
are relevant to their community and the wider world market. Third article for Review Article is written by Ma Tin Cho Mar and Pham Huong Trang, with the
title of “Malay minorities in The Tenasserim coast”. This paper discussed Malay Minorities in the Tenasserim Coast and then Tanintharyi Division is an administrative region of Myanmar at
present. This study methodology combined two complementary approaches for identifying,
analyzing and understanding patterns of knowledges sharing within complex social systems. Furthermore, the paper discussed the significance attached to the aspects of human migration in
Southeast Asia. Dear Readers, Last one article for Case-based Articles is written by Hanna Lianti, Novi Kurnia, Kshetra
Rinaldhy, Amanda Safira Aji, M Febriadi Ismet, and Rizky Amaliah. This article about knowledge
regarding Biliary Atresia, with the title of “Analysis of knowledge regarding Biliary Atresia among
healthcare providers and laypersons in East Jakarta after educational intervention”. The result are
there were significant increase in the median value between pre-test and post-test knowledge
scores in both healthcare providers and laypersons groups. We want to express our thanks to the Directorate of Community Engagement and Empowerment,
Universitas Indonesia, and reviewers who gave inputs and contributions to improve the quality of
the articles. Our greatest thanks are also due to Azhar Firdaus for helping us with the publication
process and to the Directorate of Administration, Data, and Management of Research Product and
Innovation (DADPPRI UI) for providing a journal development grant and proofread assistance
through Enago. Finally, we hope that readers enjoy the articles that we present in this edition. We hope that readers enjoy exploring the papers on this edition and keep healthy and safe. Best Regards, https://scholarhub.ui.ac.id/ajce/ Astari Dwiranti, Ph.D. Handling Editor - ASEAN Journal of Community Engagement Handling Editor - ASEAN Journal of Community Engagement https://scholarhub.ui.ac.id/ajce/
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Knowledge, Attitudes and Perceptions towards COVID-19 Vaccinations: A Cross-Sectional Survey in Pakistan
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Article
Knowledge, Attitudes and Perceptions towards COVID-19
Vaccinations: A Cross-Sectional Survey in Pakistan Abbas 1, Saima Mushtaq 2, Atika Mansoor 3, Ivan R. Green 4
, Tauqeer Hussain Mallhi 5
,
and Amjad Khan 1,* Asima Bibi 1, Sameen Abbas 1, Saima Mushtaq 2, Atika Mansoor 3, Ivan R. Green 4
, Tauqeer Hussain Mallhi 5
,
Yusra Habib Khan 5
and Amjad Khan 1,* 1
Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan 1
Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
2
Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences,
National University of Sciences and Technology, Islamabad 44000, Pakistan
3
Institute of Biomedical and Genetic Engineering (IBGE), KRL Hospital, Islamabad 44000, Pakistan
4
Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland,
Stellenbosch 7600, South Africa
5
Department of Clinical Pharmacy, College of Pharmacy, Jouf University, Sakaka 72388, Saudi Arabia
*
Correspondence: amjadkhan@qau.edu.pk 1
Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
2
Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences,
National University of Sciences and Technology, Islamabad 44000, Pakistan
3
Institute of Biomedical and Genetic Engineering (IBGE), KRL Hospital, Islamabad 44000, Pakistan
4
Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland,
Stellenbosch 7600, South Africa
5
Department of Clinical Pharmacy, College of Pharmacy, Jouf University, Sakaka 72388, Saudi Arabia
*
Correspondence: amjadkhan@qau.edu.pk 5
Department of Clinical Pharmacy, College of Pharmacy, Jouf University, Sakaka 72388, Saudi Arabia
*
Correspondence: amjadkhan@qau.edu.pk Abstract: Background and Objectives: Several vaccines have been approved for the prevention of the
coronavirus disease, discovered on 31 December in Wuhan, China. Pakistan procured vaccines
from various countries. However, the lack of knowledge and reluctance of the general population to
embrace the use of the vaccines are considered to be the major determinant of the slow vaccination rate. Hence, it is necessary to evaluate the willingness of the general population about their perception of
the COVID-19 vaccination. Materials and Methods: A cross sectional survey based on a self-structured
questionnaire comprising 18 questions was conducted (from 21 April–21 June) on 400 Pakistani
participants to evaluate their knowledge, attitude, and perception towards the COVID-19 vaccination. Chi-square independent t-test and one-way Anova including a multiple step wise linear regression
were used to draw conclusions about the results. p < 0.05 was considered significant. Results: A
total of 400 participants responded in the knowledge, attitude, and perception (KAP) survey of
which 46.5% were female and 53.5% were male. The mean age of participants was 36.08 years. Academic Editor: Gennaro De
Pascale Keywords: COVID-19; vaccine; knowledge; attitude; perception; survey; questionnaire Received: 29 October 2022
Revised: 14 December 2022
Accepted: 15 December 2022
Published: 31 January 2023 Keywords: COVID-19; vaccine; knowledge; attitude; perception; survey; questionnaire Article
Knowledge, Attitudes and Perceptions towards COVID-19
Vaccinations: A Cross-Sectional Survey in Pakistan This
survey showed a poor knowledge (50.5%), a fair attitude (75.1%) and a poor perception (58.1%)
towards the COVID-19 vaccination. Higher mean knowledge and attitude scores were reported in
the age group 21–40, females, and unmarried urban citizens. Regression analysis showed that age,
education, residence, and employment status influenced the knowledge and perception score to a
considerable extent. Conclusions: The findings reflect an inadequate knowledge and perception on
the one hand, but a better attitude towards the COVID-19 vaccination. This knowledge attitude and
perception (KAP) survey will help in better understanding the opinion of the general population
towards vaccination, and will be useful for policy makers and health care authorities aiming to
increase the vaccination rate. medicina medicina medicina Citation: Bibi, A.; Abbas, S.;
Mushtaq, S.; Mansoor, A.; Green, I.R.;
Mallhi, T.H.; Khan, Y.H.; Khan, A. Knowledge, Attitudes and
Perceptions towards COVID-19
Vaccinations: A Cross-Sectional
Survey in Pakistan. Medicina 2023, 59,
272. https://doi.org/10.3390/
medicina59020272 Citation: Bibi, A.; Abbas, S.;
Mushtaq, S.; Mansoor, A.; Green, I.R.;
Mallhi, T.H.; Khan, Y.H.; Khan, A. Knowledge, Attitudes and
Perceptions towards COVID-19
Vaccinations: A Cross-Sectional
Survey in Pakistan. Medicina 2023, 59,
272. https://doi.org/10.3390/
medicina59020272 Academic Editor: Gennaro De
Pascale 1. Background After the Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory
Syndrome (MERS) outbreak, a new virus was discovered on 31 December in Wuhan, China,
named 2019 n-CoV by the World Health Organization (WHO), and later named SARS-
CoV-2 by the International Committee on the taxonomy of viruses [1]. The WHO declared
COVID-19 to be the sixth Public Health Emergency of International Concern (PHEIC),
and later declared it to be a global pandemic on 11 March 2020 (WHO, 2005). The first
COVID-19 case was reported in Pakistan on 26 February 2020 [2]. Since then, the number
of cases increased rapidly. Copyright:
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article
distributed
under
the
terms
and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/). https://www.mdpi.com/journal/medicina Medicina 2023, 59, 272. https://doi.org/10.3390/medicina59020272 Medicina 2023, 59, 272 2 of 14 Persons infected with COVID-19 develop the common conditions of fever, cough,
shortness of breath, sore throat, nasal congestion, weakness, fatigue, and dyspnea [3–5]. Various risk factors are involved with the complexity of COVID-19. These risk factors are:
old age, respiration distress, and various chronic co-morbid conditions [6,7] Other risk
factors includes respiratory distress, sepsis, metabolic acidosis, arrhythmia heart failure,
kidney failure, and hypoxic encephalopathy [8]. Treatment strategies were initially mainly focused on corticosteroids, blood thinners,
and neutralizing antibodies, due to the lack of a specific cure, such as vaccination [9]. After
an extensive development phase, vaccination became one of the best treatment strategies
recommended by the WHO to generate herd immunity in the general population [10,11]. Despite supply challenges, the Pakistan government acquired 40 million COVID-19 vaccines
from China, the WHO, USA, UK and Germany, in order to be able to vaccinate an estimated
70 million people [12–16]. Statistics shared by the Government of Pakistan showed that
only 18.2% of the Pakistan population is fully vaccinated [17]. Pakistan has a history of a
relatively low vaccination rate for a variety of vaccine preventable diseases, such as HBV and
polio [18]. Unless this COVID-19 low vaccination rate is not seriously addressed, it will take
an unnecessarily longer time for the general population to return a semblance of normalcy
from this pandemic [19]. 2.2. Study Setting The study was conducted on the general population of all the provinces (Punjab,
Sindh, Khyber Pakhtunkhwa, Balochistan) of Pakistan. 2.1. Study Design Cross sectional studies were performed to assess knowledge, attitude, and perception
of the Pakistani population towards the COVID-19 vaccination. 1. Background p
It is well known that, generally, any new medical intervention has its own acceptabil-
ity rate among the general population, and thus the acceptance of the COVID-19 vaccine,
along with its distribution and proper utilization to every member of society, is also very
important. [20]. Previous reported data showed that those reluctant to take the COVID-19
vaccination due to safety concerns totaled, in the USA, 33% of general participants and 50%
of health care workers [21]; in Turkey, 45.3% of general participants and 42.2% of health care
workers; and in Oman, 23% of general respondents and 40% of healthcare workers [22–26]. In
the USA, its acceptance was 50%, in France its acceptance was only 62% [20,27]. While in Italy,
acceptance of the COVID-19 vaccination was 59% [28,29]. Similarly, one of China’s surveys
about COVID-19 vaccination declared that only one half, that is 54% pf the population, was
willing to have vaccination [30]. Several important factors, such as health knowledge, serve as
being important for the participants in increasing their acceptance, as more knowledge by the
general population towards breakouts such as the COVID-19 pandemic, its vaccination and
potential benefits, coupled with its precautionary measures, contributes in a better implemen-
tation of health system facilities [30,31]. Similarly, attitude and perception are the two primary
cognitive factors that play a vital role in the vaccination coverage rate of COVID-19. Knowledge, attitude, and perception (KAP) surveys mostly help to identify knowl-
edge gaps and behavior patterns of the general population on the basis of their socio-
demographics, in order to implement effective public health interventions [32]. This study
aimed to determine the knowledge, acceptance, and perception of the COVID-19 vaccine
among the Pakistani population. 2.7. Questionnaires Development and Validation A self-structured questionnaire was designed based on a previous literature review. After an extensive literature review, the questionnaire was designed in English [33]. The
English version of the questionnaire was translated into Urdu by using a back-to-back
translation procedure [34]. This questionnaire was tested for its reliability and internal
consistency. The internal consistency of the knowledge, attitude, and perception (KAP)
survey questionnaire calculated by Cronbach’s alpha was 0.720 for knowledge, 0.642 for
attitude, and 0.629 for perception, and found to be in an acceptable range. An initial pilot
study was performed among 20 participants to evaluate its acceptability and consistency,
but these results were not included in the final study. 2.8. Scoring Criteria and Statistical Analysis The scoring criteria was based on the original bloom’s cut-off point used in previ-
ous studies conducted on dengue fever anticipation in male people of the Maldives and
Bangkok in 2007, as well as a KAP study performed on COVID-19 among Chronic Dis-
ease Patients in Northwest Ethiopia in 2020 [35,36]. Criteria of bloom’s cut-off point were
80–100% (good), 60.0–79.0% (fair), and ≤59.0% (poor). In statistical analysis categorical
variables were represented in form percentages and frequencies and Chi Square Indepen-
dent was used to analyze significant association between demographics and knowledge,
attitude, and perception. Independent t-test (for two groups) and one-way ANOVA (for
more than two groups) were used to measure association within groups. Similarly, multiple
linear regression model was used to analyze the impact of an independent variable over
a dependent variable. The statistical software package for social sciences (IBM SPSS for
Windows, Version 21.0. SPSS Inc., Chicago, IL, USA) was used to evaluate the data. p-value
less than 0.05 are considered significant. 2.4. Inclusion and Exclusion Criteria Participants were 18 years or older and Pakistani residents, having an easy access to
the Internet and were voluntary participants. People below the targeted age of 18 years
were excluded from this study. 2.3. Study Duration The study was carried out from April–June 2021 through an online questionnaire,
which was distributed on different social media platforms (e.g., Facebook and WhatsApp). During this time duration of April to June (3rd and 4th wave of COVID-19), a community-
based national survey was not possible. So, relying on online social media links, the Medicina 2023, 59, 272 3 of 14 3 of 14 questionnaire was posted/reposted to local people living in different areas of Pakistan. In
this online survey, answers to all questions was mandatory for final submission. questionnaire was posted/reposted to local people living in different areas of Pakistan. In
this online survey, answers to all questions was mandatory for final submission. 2.4. Inclusion and Exclusion Criteria 2.5. Sample Size and Sampling Technique Initially, the convenient sampling technique was used for sample size estimation. In
this survey, thousands of participants could be included, however, due to the limited time
period, sample size was calculated from the estimated current population of Pakistan by
using the Rao-soft calculator to have an idea of the least number of participants that must
be included in this survey. The current population of Pakistan is 213,222,917 as per 2017
Census of Pakistan. With a 95% confidence interval, 50% population representation and 5%
margin of error, a 385 sample size was calculated by using the Rao-soft calculator. However,
data from 400 participants was collected. It was a limited sample size because of the limited
time duration of survey during the 3rd and 4th wave. 2.6. Study Tool A self-structured 18-item questionnaire, along with the appropriate demographics,
was prepared and divided into three sections. In addition to demographics, six questions
explored knowledge about COVID-19 while eight questions focused on attitude and four
questions focused on perception of participants towards the COVID-19 vaccination. 2.9. Ethical Approval This survey was conducted after ethical approval from the institutional research and
ethics forum of Rawalpindi Medical University (Vide letter number: 64/IREF/RMU/2021, Medicina 2023, 59, 272 4 of 14 Dated 23 April 2021). Respondents were clearly informed about the purpose of the study
and privacy of their data was also assured. 3.1. Demographics of Knowledge, Attitude and Perception Study Age, gender, marital status, employment, education status, and residence of partici-
pants are articulated in Table 1. All these were categorical variables to facilitate statistical
analysis in the form of frequencies and percentages to be performed. In all, 400 participants
completed the survey. Both males 53.5% (n = 214) and females 46.5% (n = 186) participated
in the study. The mean age of participants was 36.08 years. (S.D 15.54). The majority of
the respondents were from age group 21–40 years. Most of the participants were urban
281 (70.2%) and married citizens 220 (55.0%). In the educational category, 43.22% (n = 172)
of the participants had a higher education or below, while those with a graduate level of
education were 30.3% (n = 121). Participants having a postgraduate level of education
were 26.7% (n = 107). Participants having government jobs account for 20.3% (n = 81),
non-government employees were 18.9% (n = 75), unemployed 16.9% (n = 67), retired 9.1%
(n = 36), self-employed 8.0% (n = 32) and students 27.3% (n = 109). This classification
illustrates a greater number of government employee participation in the study. Table 1. Demographic characteristics of study participants. Demographics
Frequency (n)
Percentages (%)
Age
<20
39
9.7
21–40
218
54.5
41–60
109
27.2
>61
34
8.5
Gender
Female
186
46.5
Male
214
53.5
Marital status
Unmarried
180
45
Married
220
55.0
Education level
High school or below
172
43.2
Graduate
121
30.3
Postgraduate
107
26.7
Employment status
Gov. employee
81
20.3
Non Gov. employee
75
18.9
Self employed
32
8.0
Student
109
27.3
Retired
36
9.0
Unemployed
67
16.9
Residence
Urban
281
70.2
Rural
119
29.8
Note: number of participants (n); percentages (%) n = 400. Table 1. Demographic characteristics of study participants. Table 1. Demographic characteristics of study participants. 3.2. Frequency of Response to Knowledge Knowledge was evaluated by six questions about several aspects of the COVID-19
vaccination, with a corresponding scale ranging from 0–6. Responses were scored as 0 for
no/don’t know and 1 for yes. Total score was calculated by the sum of six knowledge
scores and ranged from 0–6. This led to the finding that 318 (79.5%) know about the COVID-
19 vaccination, 250 (62.5%) know about the effectiveness of the vaccination, 177 (44.3%)
responded that it is unsafe to use an overdose of vaccination, 302 (75.5%) responded that Medicina 2023, 59, 272 5 of 14
wledge
ut the 5 of 14
wledge
ut the vaccination cannot cause allergic reactions, while 305 (76.2%) don’t know that the vaccine
is recommended for pregnant women and 272 (68.0%) of the participants reported that
vaccination is available in two doses with an additional booster dose becoming available at
a later stage. Figure 1 also shows the response to knowledge. (44.3%) responded that it is unsafe to use an overdose of vaccination, 302 (75.5%) re-
sponded that vaccination cannot cause allergic reactions, while 305 (76.2%) don’t know
that the vaccine is recommended for pregnant women and 272 (68.0%) of the participants
reported that vaccination is available in two doses with an additional booster dose becom-
ing available at a later stage. Figure 1 also shows the response to knowledge. vaccination cannot cause allergic reactions, while 305 (76.2%) don’t know that the vaccine
is recommended for pregnant women and 272 (68.0%) of the participants reported that
vaccination is available in two doses with an additional booster dose becoming available at
a later stage. Figure 1 also shows the response to knowledge. (44.3%) responded that it is unsafe to use an overdose of vaccination, 302 (75.5%) re-
sponded that vaccination cannot cause allergic reactions, while 305 (76.2%) don’t know
that the vaccine is recommended for pregnant women and 272 (68.0%) of the participants
reported that vaccination is available in two doses with an additional booster dose becom-
ing available at a later stage. Figure 1 also shows the response to knowledge. Figure 1. Response to knowledge of the vaccination. Figure 1. Response to knowledge of the vaccination. Figure 1. Response to knowledge of the vaccination. Figure 1. Response to knowledge of the vaccination. Figure 1. Response to knowledge of the vaccination. Figure 1. Response to knowledge of the vaccination. 3.3. Frequency of Response to Attitude
A i
d
l
d b
i h
3.3. Frequency of Response to Attitude Frequency of Response to Perception
Perception was assessed by four questions, which were scored as yes, no, do not
know, and scaled as 0, for no/do not know and 1 was for a yes response. Scoring scale
ranged from 0–4. Responses of participants showed that: 57.0% (n = 228) indicated that
after taking the vaccination they should follow guidelines to combat new variants; 56.0%
(n = 224) believe that COVID-19 can be eradicated by taking preventive measures instead
Figure 2. Response to attitude of the vaccination. 3.4. Frequency of Response to Perception
Perception was assessed by four questions, which were scored as yes, no, do not
know, and scaled as 0, for no/do not know and 1 was for a yes response. Scoring scale
ranged from 0–4. Responses of participants showed that: 57.0% (n = 228) indicated that
after taking the vaccination they should follow guidelines to combat new variants; 56.0%
(n = 224) believe that COVID-19 can be eradicated by taking preventive measures instead
of vaccination; 79.5% (n = 318) indicated that they prefer to have the vaccination even if
h i h
l h i
i
d b
h
il
d 60 0% (
240)
d d h
h (a) Frequency of response to attitude of 5 questions (a) Frequency of response to attitude of 5 questions
(b) Frequency of response to attitude of 3 questions (b) Frequency of response to attitude of 3 questions Figure 2. Response to attitude of the vaccination. (a
tions; (b) Frequency of response to attitude of 3 que
Figure 2. Response to attitude of the vaccination. ; ( )
q
y
p
3 4 F
f R
t P
ti
3.4. Frequency of Response to Perception 3.3. Frequency of Response to Attitude
A i
d
l
d b
i h
3.3. Frequency of Response to Attitude Attitude was evaluated by eight questions. Each question was scored as disagree,
undecided and agree and scaled as 0, 1 and 2 respectively. Scoring scale ranged from 0–
16. In these eight questions of attitude assessment, 400 participants responded, out of
which: 207 (51.8%) agreed that the vaccine is safe; 310 (77.5%) agreed that the vaccine is
essential; 257 (64.3%) agreed that they will take the vaccination when it becomes available
in Pakistan; 301 (75.3%) responded that they will encourage their friends, family, and rel-
atives to get vaccinated; 215 (53.8%) agreed to the response that COVID-19 eradication
without vaccination is impossible; 325 (81.3%) agreed that the vaccine should be circulated
on a priority basis; 206 (51.5%) believed that by taking precautionary measures instead of
vaccination COVID-19 could be eradicated; and 317 (79.3%) agreed that vaccination is
their social responsibility to control the spread of COVID-19. Similarly, Figure 2 also
shows response to attitude. Attitude was evaluated by eight questions. Each question was scored as disagree,
undecided and agree and scaled as 0, 1 and 2 respectively. Scoring scale ranged from
0–16. In these eight questions of attitude assessment, 400 participants responded, out of
which: 207 (51.8%) agreed that the vaccine is safe; 310 (77.5%) agreed that the vaccine is
essential; 257 (64.3%) agreed that they will take the vaccination when it becomes available
in Pakistan; 301 (75.3%) responded that they will encourage their friends, family, and
relatives to get vaccinated; 215 (53.8%) agreed to the response that COVID-19 eradication
without vaccination is impossible; 325 (81.3%) agreed that the vaccine should be circulated
on a priority basis; 206 (51.5%) believed that by taking precautionary measures instead
of vaccination COVID-19 could be eradicated; and 317 (79.3%) agreed that vaccination is
their social responsibility to control the spread of COVID-19. Similarly, Figure 2 also shows
response to attitude. Medicina 2023, 59, 272
Medicina 2022, 58, x FOR 6 of 14
of 14 (a) Frequency of response to attitude of 5 questions
(b) Frequency of response to attitude of 3 questions
Figure 2. Response to attitude of the vaccination. (a) Frequency of response to attitude of 5 ques-
tions; (b) Frequency of response to attitude of 3 questions. 3.4. ; ( )
q
y
p
3 4 F
f R
t P
ti
3.4. Frequency of Response to Perception 3.4. Frequency of Response to Perception
Perception was assessed by four questions, which were scored as yes, no, do not
know, and scaled as 0, for no/do not know and 1 was for a yes response. Scoring scale
ranged from 0–4. Responses of participants showed that: 57.0% (n = 228) indicated that
after taking the vaccination they should follow guidelines to combat new variants; 56.0%
(n = 224) believe that COVID-19 can be eradicated by taking preventive measures instead
of vaccination; 79.5% (n = 318) indicated that they prefer to have the vaccination even if
their health is compromised by any other ailment; and 60.0% (n = 240) responded that they
could not afford vaccination at their own cost if it was not given free of charge by the state. Perception was assessed by four questions, which were scored as yes, no, do not
know, and scaled as 0, for no/do not know and 1 was for a yes response. Scoring scale
ranged from 0–4. Responses of participants showed that: 57.0% (n = 228) indicated that
after taking the vaccination they should follow guidelines to combat new variants; 56.0%
(n = 224) believe that COVID-19 can be eradicated by taking preventive measures instead
of vaccination; 79.5% (n = 318) indicated that they prefer to have the vaccination even if
their health is compromised by any other ailment; and 60.0% (n = 240) responded that they
could not afford vaccination at their own cost if it was not given free of charge by the state. Figure 3 shows response to perception of the participants towards vaccination. Medicina 2023, 59, 272
Medicina 2022, 58, x FO 7 of 14
7 of 14 Figure 3. Response to perception of the vaccination. Figure 3. Response to perception of the vaccination. 3 5 Categorization of Participant’s Score and Their Association with Demographics
3.5. Categorization of Participant’s Score and Their Association with Demographics 3 5 Categorization of Participant’s Score and Their Association with Demographics
3.5. Categorization of Participant’s Score and Their Association with Demographics 3.5. Categorization of Participant s Score and Their Association with Demographics
Characterization of the participants’ response based on blooms’ cut-off points. Crite-
ria of bloom’s cut-off point were 80–100% (good), 60.0–79.0% (fair), and ≤59.0% (poor). Similarly for knowledge, this score was determined from scale 0–6, for attitude score, 0–
16 and for perception score, 0–4. ; ( )
q
y
p
3 4 F
f R
t P
ti
3.4. Frequency of Response to Perception Responses regarding knowledge, age group of partici-
pants and the maximum number of ‘fair knowledge’ was observed in people of the age
group of 21–40 years. In the gender category, both male and female participants had an
equal level of ‘fair knowledge’. In the marital status group, married people had a high rate
of fair knowledge. Students and government employees also had a high rate of fair
knowledge. Chi-square analysis was used to find any significant association between de-
mographics and knowledge related questions about COVID-19 vaccination. A significant
Characterization of the participants’ response based on blooms’ cut-off points. Cri-
teria of bloom’s cut-off point were 80–100% (good), 60.0–79.0% (fair), and ≤59.0% (poor). Similarly for knowledge, this score was determined from scale 0–6, for attitude score, 0–16
and for perception score, 0–4. Responses regarding knowledge, age group of participants
and the maximum number of ‘fair knowledge’ was observed in people of the age group
of 21–40 years. In the gender category, both male and female participants had an equal
level of ‘fair knowledge’. In the marital status group, married people had a high rate of fair
knowledge. Students and government employees also had a high rate of fair knowledge. Chi-square analysis was used to find any significant association between demographics
and knowledge related questions about COVID-19 vaccination. A significant relationship
was found between education, employment, and the residence group. relationship was found between education, employment, and the residence group. In responses regarding attitude, participants in the age group of 21–40 years showed
a good attitude response. In the gender category, female participants had a high level of
‘good attitude score’. In the marital status group, unmarried people had a high rate of
good attitude. Students and urban citizens also had a high rate of good attitude. A signif-
icant relationship was found between age, education, marital status, employment, and the
p
y
g
p
In responses regarding attitude, participants in the age group of 21–40 years showed
a good attitude response. In the gender category, female participants had a high level
of ‘good attitude score’. In the marital status group, unmarried people had a high rate
of good attitude. Students and urban citizens also had a high rate of good attitude. A
significant relationship was found between age, education, marital status, employment,
and the residence group. residence group. ; ( )
q
y
p
3 4 F
f R
t P
ti
3.4. Frequency of Response to Perception In responses about perception, participants in the age group of 21–40 years showed
a fair attitude response. In the gender category, male participants had a high level of ‘fair
perception’. In the marital status group, married people had a high rate of fair perception. Students and urban citizens also had a high rate of fair perception. No significant associ-
ation of perception score was noticed with any demographics’ variable. Table 2 summa-
In responses about perception, participants in the age group of 21–40 years showed
a fair attitude response. In the gender category, male participants had a high level of
‘fair perception’. In the marital status group, married people had a high rate of fair
perception. Students and urban citizens also had a high rate of fair perception. No
significant association of perception score was noticed with any demographics’ variable. Table 2 summarizes the p value obtained. Medicina 2023, 59, 272 8 of 14 Table 2. Categorization of participants and association of demographics with knowledge, attitude and perception. Knowledge
Attitude
Perception
Variables
Good
Fair
Poor
p Value
Good
Fair
Poor
p Value
Good
Fair
Poor
p Value
Age
<20
4
25
7
0.347
20
13
3
0.001
8
10
18
0.064
21–40
43
142
29
132
54
28
39
112
63
41–60
26
64
15
35
44
26
22
54
29
Gender
>61
10
15
5
10
10
10
8
16
5
Female
32
129
25
103
56
27
0.148
31
96
59
0.077
Male
51
129
30
96
74
40
54
100
55
Marital status
Unmarried
40
115
24
0.831
105
49
24
0.005
37
80
62
0.088
Married
44
144
32
94
82
44
49
116
54
Education level
high
school or
below
38
100
34
0.043
66
72
33
0.001
39
82
50
0.577
graduate
27
83
11
67
34
20
28
63
30
postgraduate
19
75
11
66
24
15
19
50
36
Employment
status
Gov. employee
9
62
10
0.030
38
32
11
0.019
21
40
20
0.615
non Gov. Note: for knowledge score 4.8–6 considered (Good) 3.6–4.7 (Fair) and ≤3.5 (Poor); for attitude score 12.8–16 consid
considered good, 2.4–3.16 Fair and ≤2.3 Poor. p value < 0.05 compared within groups. Bold p values showed signifi Note: for knowledge score 4.8–6 considered (Good) 3.6–4.7 (Fair) and ≤3.5 (Poor); for attitude score 12.8–16 considered Good, 9.6–12.7 Fair and ≤9.5 Poor; for perception score 3.2–4
considered good, 2.4–3.16 Fair and ≤2.3 Poor. p value < 0.05 compared within groups. Bold p values showed significant association. 3.6. Analysis of Mean Knowledge, Attitude and Perception To estimate association within groups with mean knowledge, an independent t-test
(for two groups) including one for more than two groups and a one-way ANOVA test was
performed. The mean count of knowledge was considerably higher among participants
aged 21–40 years. Females, unmarried, graduates or below, students, and urban citizens
had a higher mean knowledge score. It was found that the mean knowledge score is
significantly associated with age, gender, marital status, residence, and employment status. The mean score of attitude was appreciably higher among participants in the age
group of 21–40 years. In terms of gender, females had a high mean attitude score. The
educational level of participants also plays a role since a higher mean score of attitude
was found in postgraduates and similarly in unmarried and non-government participants. Urban residents also showed a higher mean score. Mean attitude is significantly related
with age, gender, education level, marital status, residence, and employment status. g
g
p
y
The mean score of perception was considerably higher among participants aged 21–
40 years. In terms of gender, females have a high mean perception score. Educational
level is a factor contributing to a higher mean score of perception in graduates, while
unmarried and student participants also showed a higher mean perception score, as did
urban residents. In this survey, the mean attitude is significantly linked with age, gender,
education level, marital status, residence, and employment status. Table 3 below shows
association within groups with mean knowledge, mean attitude and mean perception score. Table 3. Association within groups with mean knowledge, mean attitude and mean perception score. ; ( )
q
y
p
3 4 F
f R
t P
ti
3.4. Frequency of Response to Perception employee
13
53
9
42
22
11
13
39
23
self
employed
9
17
4
7
15
8
10
13
7
Student
27
63
17
64
25
17
19
55
33
Retired
14
15
7
12
14
10
10
17
8
Unemployed
12
47
8
34
22
11
13
30
24
Residence
Urban
48
187
44
0.015
149
85
44
0.051
58
141
80
0.755
Rural
35
69
13
47
46
24
27
54
35
Note: for knowledge score 4.8–6 considered (Good) 3.6–4.7 (Fair) and ≤3.5 (Poor); for attitude score 12.8–16 considered Good, 9.6–12.7 Fair and ≤9.5 Poor; for perception score 3.2–4
considered good, 2.4–3.16 Fair and ≤2.3 Poor. p value < 0.05 compared within groups. Bold p values showed significant association. gorization of participants and association of demographics with knowledge, attitude and perception. Medicina 2023, 59, 272 9 of 14 3.6. Analysis of Mean Knowledge, Attitude and Perception 3.6. Analysis of Mean Knowledge, Attitude and Perception Mean Knowledge
Mean Attitude
Mean Perception
Variables
Mean (S.D)
p Value
Mean (S.D)
p Value
Mean (S.D)
p Value
Age
0.5602 (0.165)
0.5964 (0.19568)
0.3759 (0.26572)
0.1944 (0.19615)
0.009
1.5556 (0.28730)
1.5736 (0.37016)
1.4029 (0.34624)
1.3375 (0.39000)
0.001
0.6111 (0.24960)
0.6752 (0.21860)
0.4762 (0.29114)
0.3750 (0.29906)
0.001
<20
21–40
41–60
>61
Gender
0.5658 (0.20926)
0.4525 (0.26746)
0.001
1.5390 (0.36552)
1.4705 (0.37266)
0.066
0.6452 (0.23052)
0.5226 (0.30705)
0.017
Female
Male
Marital Status
0.6134 (0.19448)
0.4188 (0.25468)
0.012
1.5475(0.37851)
1.4662(0.36106)
0.029
0.6508 (0.23912)
0.5239 (0.29792)
0.002
Unmarried
Married
Education Level
0.3777 (0.25744)
0.6074 (0.19467)
0.5997 (0.19107)
0.001
1.4523 (0.33256)
1.5289 (0.38587)
1.5560 (0.40541)
0.051
0.4753 (0.29452)
0.6426(0.26581)
0.6810 (0.20655)
0.001
High school or below
Graduate
Postgraduate
Employment Status
0.5251 (0.20190)
0.5431 (0.23216)
0.2889 (0.25496)
0.6184(0.19018)
0.2269 (0.23622)
0.5075 (0.24521)
0.001
1.5231 (0.29981)
1.5724 (0.33364)
1.2750 (0.40921)
1.5339 (0.39624)
1.3819 (0.31756)
1.5037 (0.41342)
0.002
0.5494 (0.30726)
0.5967 (0.25959)
0.5250 (0.33701)
0.6752 (0.21504)
0.3750 (0.29580)
0.5821 (0.26610)
0.001
Gov. employee
Non Gov. employee
Self employed
Student
Retired
Unemployed
Residence
0.5446 (0.21737)
0.4074 (0.29152)
0.019
1.5302 (0.35036)
1.4306 (0.41015)
0.015
0.6246 (0.26132)
0.4722 (0.29503)
0.026
Urban
Rural
Note: S.D is standard deviation. Statistics: one way ANOVA and independent t test; p value < 0.05 compared
within groups. Bold p values showed significant association. Table 3. Association within groups with mean knowledge, mean attitude and mean perception score. Medicina 2023, 59, 272 10 of 14 10 of 14 3.7. Factors Affecting Knowledge, Attitude and Perception Response on the Use of Vaccine A multiple linear regression model was used to analyze the impact of an independent
variable over a dependent variable, as illustrated in Table 4. Age, education, residence,
and employment status influenced the knowledge score to a considerable extent. Gender
and marital status had no significant impact on the knowledge score. Correlation analyses
shows that the relationship between the dependent and independent variable is a reliable
factor for further analysis. Perception score was significantly influenced by age, education,
and residence. Table 4. Analysis of factors affecting knowledge, attitude, and perception score. 3.6. Analysis of Mean Knowledge, Attitude and Perception Independent
Variable
Knowledge
Attitude
Perception
R Square
0.316
R Square
0.063
R Square
0.224
Adjusted
R Square
0.293
Adjusted
R Square
0.031
Adjusted R Square
0.198
Durbin
Watson
1.657
Durbin
Watson
1.938
Durbin Watson
1.718
B
SE
p-Value
B
SE
p-Value
B
SE
p-Value
(Constant)
0.622
0.057
0.000
1.641
0.090
0.000
0.678
0.066
0.000
Age
−0.070
0.028
0.013
−0.073
0.045
0.106
−0.069
0.033
0.036
Gender
0.007
0.040
0.869
0.024
0.063
0.704
−0.033
0.046
0.471
Marital status
0.076
0.047
0.110
−0.053
0.076
0.483
0.054
0.055
0.329
Education level
0.077
0.025
0.002
0.013
0.040
0.751
0.076
0.029
0.009
Employment
status
−0.028
0.010
0.006
−0.015
0.016
0.349
−0.021
0.012
0.067
Residence
−0.075
0.034
0.030
−0.034
0.055
0.533
−0.140
0.040
0.001
Note: B = unstandardized regression coefficient; SE = Standard error; p value < 0.05 considered significant. Bold
p values showed significant association. Statistics: Multiple linear regression model; p value < 0.05 compared
within groups. Table 4. Analysis of factors affecting knowledge, attitude, and perception score. Note: B = unstandardized regression coefficient; SE = Standard error; p value < 0.05 considered significant. Bold
p values showed significant association. Statistics: Multiple linear regression model; p value < 0.05 compared
within groups. 4. Discussion In order to overcome the aftermath of the COVID-19 pandemic, the implementation of
COVID-19 vaccination is the best if not the ideal solution. After an extensive development
phase and positive responses of clinical trials, various countries approved specific vaccines
for further implementation. Although various campaigns have been implemented to
increase knowledge about vaccination and previous studies also suggests that COVID-
19 vaccines are safe and effective in general, based on the billions of doses administered
worldwide and the rare incidence of adverse events only in at-risk group [37]. However, due
to the newness of this disease, it poses a serious question for policy-makers regarding the
knowledge, attitude, and perceptions of the general population about receiving the COVID-
19 vaccination. The present survey has been conducted to assess knowledge, attitude,
and perceptions of participants including large demographics factors that influence the
knowledge and attitude of the general population [38]. This knowledge-based survey suggest that the people of Pakistan that participated in
this study had an average knowledge (50.4%) about the vaccine, its side effects, allergic
reactions, and its effect on autoimmune diseases. Knowledge was considerably linked with
education, employment status, and residence. This finding is in contrast with the knowl-
edge, attitude, and perception survey conducted in Bangladesh, where knowledge was
significantly associated with education, family type, and monthly income of a family [38]. The findings of our survey suggest that the mean knowledge score was found to be
higher for female participants, in respondents of the age group 21–40, among graduates,
and in unmarried participants. These findings concur with two previous surveys conducted
in China and the USA. Data from this survey also indicate that gender and education level Medicina 2023, 59, 272 11 of 14 11 of 14 could have a constructive impact on the knowledge field of participants [39,40]. In our
survey, 76.2% of participants had a lack of knowledge regarding the safety of the COVID-19
vaccination in pregnant women. These findings stress the need to convey effective and
updated information for the general population through various social media platforms. Regarding the attitude domain of this study, a mean attitude score is more associated
with females than males. This finding is in line with the results of the studies conducted
in Indonesia and Bangladesh [41,42]. 4. Discussion We believe this result can be of significant value
by appealing to women with a domestic level of education and an encouragement for
COVID-19 vaccination could strongly suggest the way to a drastic enhancement in the
vaccination program. The findings of a high level of a positive attitude of participants
towards the preventive measure of vaccination is also reported globally [42]. Our findings show that 64.3% of the participants were willing to take the COVID-19
vaccination without any hesitation, and 75.3% advised their family, friends, and relatives
to also take the COVID-19 vaccination. Findings from our study illustrate the wide scale
of variation among countries. A study conducted in France during the pandemic shows
that 77% of their participants would agree to take the vaccination [43]. While comparing
attitude globally in terms of willingness to take the vaccine, studies show that a high
percentage of positive attitude responses come from Panama (87.44%), a lower reaction was
from Russia (51.34%), Australia had the highest response (92.88%), while the very lowest
response was observed in Egypt (43.55%) for taking the COVID-19 vaccination [44]. An average number of participants (51.8%) in our study agreed that the vaccine is
safe. This limited knowledge regarding safety of vaccination may be due to rumors and
misinformation related to safety issues of the vaccine. Since the pandemic is generally
accepted to have started in December 2019, there was only limited knowledge about the
disease, along with rumors and misinformation that affected its perception globally [45]. g
p
p
g
y
In the perception domain, 57% of participants believe that COVID-19 vaccination had
side effects. This apprehension may be due to misinformation regarding fatal and adverse
events associated with the COVID-19 vaccine [46,47]. Overall, in our study, female participants had a better ranking of knowledge, at-
titude, and perception, as compared to males, which is in agreement with findings of
prior studies [48]. Possible reasons identified for this were education and socio-economic
factors [49,50]. Equal participation by both genders is important for any social survey. This is because
both males and females are equally important for forming an opinion about any critical
social issues, such as the COVID-19 vaccination. However, in our study, female participa-
tion was found to be less than males, which agrees with a previous knowledge, attitude,
and perception survey [51]. 4. Discussion These findings suggest that more focused research needs to be
conducted to determine the possible barriers that women might be facing in participating
in such responses. p
In this survey, graduates and postgraduates illustrated high scores towards knowledge,
attitude, and perception. This finding suggests that education plays an important role to
overcome such pandemics since educated citizens had a greater tendency to analyze the
critical situations and consequently behave positively. Various research studies have been conducted to initiate effective strategies in order
to improve the vaccination rate. These studies show that information alone has a limited
impact on enhancing the vaccination rate. Acceptance and a willingness of vaccination
is still an unparalleled challenge. Data of this survey could strengthen the efforts of
health authorities to achieve their targets of high vaccination coverage through effective
communication and updated information. Limitations This survey was conducted over a short time period with incompetence to reach
people residing in far-off, remote locations with no access to the Internet, and therefore the
findings obtained in this survey might not express the perspective of the whole general Medicina 2023, 59, 272 12 of 14 12 of 14 population, and the sample was not generalized to a meaningful population. The general
population who do not have Internet access and were not proficient in working with online
platforms were difficult to connect with. The study used a virtual self-reporting system
that may be exposed to social acceptability and memory biases. There would be a response
biasness, too, about being judged on knowledge or on financial situations, that also resulted
in low responses being one of the drawbacks of online survey. 5. Conclusions Until the development of vaccines, the COVID-19 pandemic was a major global threat. Our survey reflects a poor knowledge (50.6%), fair attitude (75.1%), and poor perception
(58.1%) towards vaccination. These findings suggest that more educational campaigns and
the advertisement of the correct information status could contribute fairly to eradicating the
pandemic. Guiding principle makers can take preliminary steps to ensure the distribution
of positive information about the attitudes and perceptions towards COVID-19 vaccinations
in order to decrease the vaccine timidity and to increase the vaccination rate. However,
research should be performed on participants not included in this study, such as immigrants
and the elderly, who do not have access to social media and technology. Author Contributions: Conceptualization: A.B. and A.K.; data curation: A.K. and A.M.; formal
analysis: S.M.; investigation: A.B. and A.K.; methodology: A.B. and A.K.; project administration:
A.B.; resources: A.M.; supervision: A.K.; visualization: A.M. and Y.H.K.; writing—original draft:
A.B.; writing—review and editing: A.K., S.A., T.H.M., and I.R.G. All authors have read and agreed to
the published version of the manuscript. Funding: This research received no external funding. Funding: This research received no external funding. Institutional Review Board Statement: The study was conducted after ethical approval by the
Institutional Review Board (or Ethics Committee) of RAWALPINDI MEDICAL UNIVERSITY (ref. no. 64/IREF/RMU/2021 and date of approval was 23 April 2021). Informed Consent Statement: Purpose of this survey was clearly explained and written informed
consent has been obtained from the participants to publish this paper. Acknowledgments: We acknowledge all the participants who consented to be a part of this re-
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people or property resulting from any ideas, methods, instructions or products referred to in the content.
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Modelling the emergence of rodent filial huddling from physiological huddling
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Royal Society open science
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Subject Category:
Biology (whole organism) Subject Category:
Biology (whole organism) on November 22, 2017
http://rsos.royalsocietypublishing.org/
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http://rsos.royalsocietypublishing.org/
Downloaded from rsos.royalsocietypublishing.org Research
Cite this article: Wilson SP. 2017 Modelling
the emergence of rodent filial huddling from
physiological huddling. R.Soc.opensci. 4: 170885. http://dx.doi.org/10.1098/rsos.170885 SPW, 0000-0001-8125-5133 SPW, 0000-0001-8125-5133 SPW, 0000-0001-8125-5133 Huddling behaviour in neonatal rodents reduces the metabolic
costs of physiological thermoregulation. However, animals
continue to huddle into adulthood, at ambient temperatures
where they are able to sustain a basal metabolism in isolation
from the huddle. This ‘filial huddling’ in older animals
is known to be guided by olfactory rather than thermal
cues. The present study aimed to test whether thermally
rewarding contacts between young mice, experienced when
thermogenesis in brown adipose fat tissue (BAT) is highest,
could give rise to olfactory preferences that persist as filial
huddling interactions in adults. To this end, a simple model
was constructed to fit existing data on the development
of mouse thermal physiology and behaviour. The form of
the model that emerged yields a remarkable explanation for
filial huddling; associative learning maintains huddling into
adulthood via processes that reduce thermodynamic entropy
from BAT metabolism and increase information about social
ordering among littermates. Received: 11 July 2017
Accepted: 24 October 2017 Received: 11 July 2017
Accepted: 24 October 2017 Research 1Department of Psychology, and 2Sheffield Robotics, The University of Sheffield,
Sheffield, UK 1Department of Psychology, and 2Sheffield Robotics, The University of Sheffield,
Sheffield, UK Cite this article: Wilson SP. 2017 Modelling
the emergence of rodent filial huddling from
physiological huddling. R.Soc.opensci. 4: 170885. rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . p
g
The huddling behaviour of laboratory rodents, in particular rats and mice, has emerged as a model
system for the study of social thermoregulation. This is due to their prevalence as laboratory species,
and to the precision with which the thermal physiology of these species has been investigated [12,13]. A number of agent-based computer models [5,8,14–20] have been formulated to describe how rodent
huddling behaviours at the level of the group emerge from simple rules of interaction between
individuals [5,6,21,22]. The individual behaviour from which rodent huddling emerges has been described formally as
‘homeothermotaxis’; turning in the direction that brings the body temperature closer to a preferred
temperature [18,19]. As such, individuals act like the magnetic spins in an Ising model, or the particles in
a Vicsek model from statistical physics, attracted or repelled by the relative body temperatures of their
littermates [20]. These thermodynamic models have been used to explain a phase transition in mouse
huddling behaviours, from aggregation in cold environments to dispersion at warmer temperatures
[5,18], and by analogy with particle systems they generate new predictions, such as a temperature-
dependent peak in ‘pup flow’, where animals cycle between the cold huddle periphery and its warm
core [6,20]. Central to thermodynamic descriptions of huddling is a role for brown adipose fat tissue (BAT), which
evolved as the organ of thermogenesis in early mammals [23,24], and has been shown to be a requirement
for the emergence of huddling [25–28]. Individual differences in early huddling can be explained in
terms of individual differences in thermal physiology, for example sex differences in rat huddling can
be understood by considering females, who are born with more BAT, as heat sources and males as heat
sinks [29]. Syrian golden hamsters, which start to produce heat by BAT thermogenesis relatively late in
postnatal development, will initiate huddling behaviours when introduced into groups of age-matched
rats, who are generating heat via BAT at this age [26,27]. In turn, early individual differences in huddling
behaviours have been shown to predict metrics of adult social behaviour. For example, rabbit pups that
tend to occupy peripheral versus central positions in the huddle during the first postnatal week are
more likely to jump a gap to attend to the cries of a distressed littermate when tested as adults ([30];
see also [31–33]). 1. Introduction Social thermoregulation has been described in social insects,
reptiles, birds and mammals, including humans. For example,
honeybee swarms cluster to form structures whose surface
density varies with the environment temperature, maintaining the
porous core at thermal homeostasis [1]. Common garter snakes
in Canada have been found to hibernate in dens comprising
8000 animals for up to a third of the year during winter [2]. Emperor penguins aggregate at a density of up to 10 birds
per square metre, adapting the overall shape of the huddle to
weather cold winds [3]. Bats huddle to compensate for poor
insulation in forest roosting sites, and huddling is important for
the initiation and maintenance of group cohesion during collective
roost-switching behaviours [4]. Other rodents, including mice [5],
rats [6], rabbits [7] and degus [8], huddle to insulate from the Author for correspondence:
Stuart P. Wilson
e-mail: s.p.wilson@sheffield.ac.uk Electronic supplementary material is available
online
at
https://doi.org/10.6084/m9. figshare.c.3928318 Electronic supplementary material is available
online
at
https://doi.org/10.6084/m9. figshare.c.3928318 2017 The Authors. Published by the Royal Society under the terms of the Creative Commons
Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted
use, provided the original author and source are credited. 2017 The Authors. Published by the Royal Society under the terms of the Creative Commons
Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted
use, provided the original author and source are credited. on November 22, 2017
http://rsos.royalsocietypublishing.org/
Downloaded from on November 22, 2017
http://rsos.royalsocietypublishing.org/
Downloaded from cold, by collectively reducing the exposed surface-area-to-volume ratio of the group [9,10]. And social
thermoregulation in primates (bamboo lemurs) has recently been shown to be more important for
temperature homeostasis than the choice of resting site [11]. cold, by collectively reducing the exposed surface-area-to-volume ratio of the group [9,10]. And social
thermoregulation in primates (bamboo lemurs) has recently been shown to be more important for
temperature homeostasis than the choice of resting site [11]. 2 2. Models A Monte Carlo algorithm has recently been shown to capture the statistics of huddling behaviour
[20], i.e. the distribution of groups of pups in contact, as predicted by more elaborate models of the
underlying physical interactions between littermates (see [18,19,47]). The idea is to iteratively reconfigure
the distribution of pups between groups by choosing pairs of pups at random from the litter and
either joining together the groups to which they belong, or isolating one from its group. The decision
between these two alternatives is made by comparing a randomly generated number each time to a
value representing the probability that those two pups will remain in contact. If the random number
is less than the probability of remaining in contact, then the groups to which the two pups belong are
joined together to form a larger group; else one pup is isolated to form a new group of size 1. In this way,
a higher probability makes larger huddles more likely to form. More precisely, the huddling algorithm involves iteratively selecting a pup at random, a, then
selecting a second pup at random from a different group, b, and then either joining together the groups
to which pups a and b belong with probability ρa,b, or detaching a from its group to form a new group of
size 1, where ρa,b = (1 + e−T)−1,
(2.1) (2.1) and the threshold T is referred to as the ‘temperature parameter’. Predicting how huddling statistics
change over developmental time thus requires a definition of how T, which determines the likelihood of
two groups joining to form a larger huddle, changes as the thermal physiology matures. Although studies of the developing thermal physiology of mice are numerous, few have quantified
the relationship between the maturing thermal physiology and the development of thermal behaviour
in the same animals and under the same experimental conditions. The basis of the model is therefore
a dataset published by Eedy & Ogilvie [48], which describes, for the same set of mice, how the body
mass, the mass-specific metabolic rate and crucially the preferred ambient temperature of the animals
change across the first 60 postnatal days. In that study, animals were briefly isolated from the huddle on
successive days and placed on a thermocline, i.e. an apparatus in which temperature varies continuously
from hot on one side to cold on the other. rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In rodents,
this may occur during postnatal development, as odour-heat conditioning between huddling littermates on November 22, 2017
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Downloaded from replaces the physiological drive for huddling with a drive based on the strength of association to
olfactory cues. 3
hysiological drive for huddling with a drive based on the strength of association to 3 To make explicit these assumptions about the role of odour-heat conditioning in social
thermoregulation, and to test the idea that social thermoregulation can provide a scaffold for the
development of non-thermal social behaviours, the current study presents a model, based on the
thermodynamic description of rodent huddling by Wilson [20], which predicts how huddling behaviours
should change over time as BAT physiology matures in litters of mice. The model is then extended to ask
how odour-heat conditioning during contact in the huddle shapes the emergent group behaviour. The
model is calibrated to data on the development of thermal physiology and individual thermal behaviour
in mice, and thus it may be used to generate testable predictions about the developmental time course of
the emergence of social behaviour. rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In similar terms, social thermoregulation is thought to confer, in a number of species,
human-like social behaviours [34,35], such as the ‘contact comfort’ offered in consolation to distressed
conspecifics by prairie voles [36], bonobos [37] and chimpanzees [38]. As precocial mammals develop, maximal energy in BAT stores at birth decay, as does the drive
towards huddling based on physiological demands [6,24,26,39,40]. However, rodents continue to huddle
into adulthood, and the transition from physiological huddling to ‘filial huddling’ is characterized
by a preference for (even cool) objects whose odours have been associated with a warm soft touch
[6,39,41–44]. According to Alberts [45]: ‘The olfactory-perceptual preferences that direct and maintain
social contact (huddling) behavior in rat pups are established by the association of olfactory cues with
the thermotactile stimulation present during mother-litter interactions. The induction of odor preferences
that guide affiliative social behaviour are not susceptible to other reinforcers such as suckling rewards.’
Thus, associative learning, and in particular odour-heat conditioning, is thought to play a primary role
in the emergence of rodent social behaviour. Emerging theories of social thermoregulation in primates are beginning to extrapolate from the data
on rodent huddling to explain how complex human psychological concepts, such as the establishment
of distinct attachment styles, and the formation of internal models for social behaviour, may be
supported by the same neural systems that regulate huddling behaviours in rats and mice [34], such
as hypothalamic circuitry and oxytocin regulation [6,35,46]. A central theme in these discussions is
that neural systems which evolved under selection pressure to allow animals to react to thermal
stimuli, to help minimize the energetic costs of physiological thermoregulation, have since been
supplanted by more elaborate (presumably neocortical) circuitry that enables animals to predict the
thermal consequences of contact with conspecifics [34]. The idea has recently been developed further
by Morrison [35], who proposes that ‘[Neural] pathways involved in social thermoregulation may have
evolved to use conspecific touch patterns as shorthand for “warm and close”. [. . .Such] temporal and
contextual shorthand may manifest in regulatory neural shortcuts in which “warm and close” states
can be instigated by social touch alone, rather than requiring a cycle of behaviorally mediated physical
warmth restoration following actual temperature decreases.’ Essentially, the neural substrate of social
thermoregulation may provide a scaffold for the emergence of non-thermal social behaviours. 2. Models The recorded temperature of the location at which the animals
settled is referred to herein as the preferred ambient temperature. The next section shows how, together with existing data describing changes in mouse BAT over a
similar period [49], the preferred ambient temperature of developing mice can be related to the changing
thermal physiology, and thus how the physiological drive towards huddling, T, develops. To investigate
the transition from physiological to filial huddling, the data of [48,49] were first approximated by a series
of simple expressions to estimate the preferred ambient temperature T; then values of T were fed through
the huddling model (equation (2.1)) to predict how group sizes change during postnatal development. Corresponding to a ‘no-learning’ control condition, the algorithm begins with n = 7 pups joined
in a single group, and then evaluates equation (2.1) many thousands of times, comparing ρa,b to a
random number between 0 and 1 each time to determine the reconfiguration of the pups between
subgroups, while T changes according to the fit to the preferred ambient temperature measured by
Eedy & Ogilvie [48]. Corresponding to the main ‘learning’ condition, the same procedure is repeated,
using an associative learning rule to adapt a set of associative strengths between pups, and in turn to
weight T by these associative strengths, on each iteration. This extension is detailed in the final Results
section and represents the ability of animals to learn, by odour-heat conditioning, to predict the outcome
of future contacts. on November 22, 2017
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yp
g g
p
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
0.4
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35
0.6
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brown fat per 100 g
metabolism (cal g–1h–1)
1.0
1.2
(a)
(b)
10
20
30
t (days)
40
50
60
P = 0
P = e–t/k
G = k(1 + S),
S = –kP lnP
P = 1
k
0
10
20
30
t (days)
40
50
60
Figure 1. Development of mouse physiology. Data recorded by Lagerspetz [49] in (a) and Eedy & Ogilvie [48] in (b) are shown as black
dots. Curves show the fit of the model. 3.1. Metabolism as the entropy of brown adipose fat tissue energy consumption The points p plotted in figure 1a show the weights of BAT, as a percentage of the body weight, as
measured in mice at different ages by Lagerspetz [49]. Using the first (p1) and final (p0) measurements to
define p′ = (p −p0)/(p1 −p0), the rescaled points p′ were well approximated by an exponential decay, P = e−t/k,
(3.1) (3.1) with k a time constant describing the rate of depletion of BAT reserv
Fi
1b h
h
ifi
b li
(
d with k a time constant describing the rate of depletion of BAT reserves. Figure 1b shows the mass-specific metabolic rate (converted to calories per gram per hour) reported
by Eedy & Ogilvie [48], and a fit to these data by G, defined as S = −kP ln P
(3.2) S = −kP ln P
(3.2) S = −kP ln P (3.2) and G = k(1 + S),
(3.3) (3.3) where the unit term corresponds to the basal metabolic rate and S is the entropy associated with P. As
such, k is a unit of energy, and the fit obtained using k = 8.31 ascribes particular significance to k as the
universal gas constant [50]. Thus the mass-specific metabolic rate is proposed to be the thermodynamic
entropy generated by the conversion of energy that is stored in BAT at birth. where the unit term corresponds to the basal metabolic rate and S is the entropy associated with P. As
such, k is a unit of energy, and the fit obtained using k = 8.31 ascribes particular significance to k as the
universal gas constant [50]. Thus the mass-specific metabolic rate is proposed to be the thermodynamic
entropy generated by the conversion of energy that is stored in BAT at birth. Entropy is a measure of disorder, describing the number of different configurations of a system that
are possible. Only in open systems can entropy decrease, i.e. in systems that exchange matter with the
surrounding environment. From day 8, figure 1 shows a decrease in the entropy (per unit mass) that
relates the amount of BAT to the rate of metabolism. This suggests that as the mouse uses energy stored
in BAT, and exchanges matter with its environment via respiration, the number of possible states of the
brown fat tissue decreases from day 8. 2. Models (a) The depletion of brown adipose fat reserves was modelled as an exponential decay, P, with a
timeconstantofk = 8.31.(b)Themass-specificmetabolicrate,G,wasmodelledintermsoftheentropy,S,associatedwithP.According
to this model, the mass-specific metabolic rate is predicted to peak at postnatal day k = 8.31. 4
rsos.royalsocietypublishing.org R.Soc. opensci. 4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
5
10
15
20
25
30
35
metabolism (cal g–1h–1)
(b)
G = k(1 + S),
S = –kP lnP
k
0
10
20
30
t (days)
40
50
60 0
0.4
0.6
0.8
brown fat per 100 g
1.0
1.2
(a)
10
20
30
t (days)
40
50
60
P = 0
P = e–t/k
P = 1 4
rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 1. Development of mouse physiology. Data recorded by Lagerspetz [49] in (a) and Eedy & Ogilvie [48] in (b) are shown as black
dots. Curves show the fit of the model. (a) The depletion of brown adipose fat reserves was modelled as an exponential decay, P, with a
timeconstantofk = 8.31.(b)Themass-specificmetabolicrate,G,wasmodelledintermsoftheentropy,S,associatedwithP.According
to this model, the mass-specific metabolic rate is predicted to peak at postnatal day k = 8.31. A full implementation of the model in C++ is included as electronic supplementary material, S1,
together with a script, written in Python, to extract and display the changing huddling statistics, i.e. the
average group size predicted on each postnatal day. A full implementation of the model in C++ is included as electronic supplementary material, S1,
together with a script, written in Python, to extract and display the changing huddling statistics, i.e. the
average group size predicted on each postnatal day. 3.1. Metabolism as the entropy of brown adipose fat tissue energy consumption 0
5
10
weight (g)
15
20
25
30
k
0
10
20
30
t (days)
40
50
60
M = k(1 – P)
W = M + ce–kT1
(a) 5 Figure 2. Development of mouse behavioural thermoregulation. Data recorded by Eedy & Ogilvie [48] are shown as black dots. Curves
show the fit of the model. (a) The growth curve was modelled as a muscle mass M, plus a non-muscle mass that rises as temperature
T1 falls. (b) The environment temperature selected by mice on a thermocline was modelled as a combination of temperatures T1 and
T2, related to the development of muscle and non-muscle masses, respectively. The model suggests that behavioural thermoregulation
(b) is driven by the developing metabolism, defined in terms of the entropy associated with brown adipose fat depletion. 3.1. Metabolism as the entropy of brown adipose fat tissue energy consumption Intuitively, the effect is similar to the way that water molecules
become more ordered when they freeze to create ice. on November 22, 2017
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rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
5
10
weight (g)
15
20
25
30
k
0
32
33
34
preference (°C)
35
36
37
38
39
10
20
30
t (days)
40
50
60
0
10
20
30
t (days)
40
50
60
M = k(1 – P)
W = M + ce–kT1
Tp+ [T1µ P]
Tp– [T2µ G(W – M)]
Tp
(a)
(b)
Figure 2. Development of mouse behavioural thermoregulation. Data recorded by Eedy & Ogilvie [48] are shown as black dots. Curves
show the fit of the model. (a) The growth curve was modelled as a muscle mass M, plus a non-muscle mass that rises as temperature
T1 falls. (b) The environment temperature selected by mice on a thermocline was modelled as a combination of temperatures T1 and
T2, related to the development of muscle and non-muscle masses, respectively. The model suggests that behavioural thermoregulation
(b) is driven by the developing metabolism, defined in terms of the entropy associated with brown adipose fat depletion. 5
rsos.royalsocietypublishing.org R.Soc. opensci. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
33
34
preference (°C)
35
36
37
38
39
0
10
20
30
t (days)
40
50
60
Tp+ [T1µ P]
Tp– [T2µ G(W – M)]
Tp
(b) 5
rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Behavioural thermoregulation as a competition between fat and muscle The growth curves of mice typically display an initial rise (of decreasing magnitude) followed by the
more familiar sigmoidal shape that is often modelled as a logistic/autocatalytic function (e.g. [51–53];
see electronic supplementary material, figure S2). Figure 2a shows that the growth curves measured by
Eedy & Ogilvie [48] are well described as sums of two quantities, M = k(1 −P)
(3.4) (3.4) and and W = M + c e−kT1,
(3.5) (3.5) where c = 19 is a constant (see electronic supplementary material, figure S2) and T1 is a temperature. where c = 19 is a constant (see electronic supplementary material, figure S2) and T1 is a temperature. Viewed in terms of the growth rates, the growth curve comprises a mass M that is driven towards
a saturating value of k by dM/dt = k −M, and a second mass N = W −M, which increases with M at a
rate that decreases as M →k, according to dN/dM ∝N. The initial rise in N occurs at around postnatal
day 15, which for mice coincides with a rapid development of muscle shivering as a response to cold
challenge [49]. The quantity M is thus interpreted to be the muscle mass and the quantity N is therefore
referred to as the non-muscle mass. The temperatures selected by the developing mice (when isolated) on a thermocline, as recorded by
Eedy & Ogilvie [48], are shown in figure 2b. Selected temperatures could also be approximated by a
combination of two curves, when added to a ‘target’ adult body temperature assumed to be Tp ≈36◦C: T1 ∝P
(3.6) (3.6) T1 ∝P and T2 ∝GN,
(3.7) (3.7) T2 ∝GN, where the constants of proportionality were estimated as c1 = 3 and c2 = 0.025, respectively. here the constants of proportionality were estimated as c1 = 3 and c2 = 0.025, respectively. On each postnatal day, the animals appear to select either Tp + T1 or Tp −T2, suggesting that
thermoregulatory systems based on BAT energy metabolism (responsible for T1) and total (non-muscle)
metabolism (responsible for T2) are in competition for behavioural thermoregulation. Compared with
the dominance of BAT in determining the preferred temperature in the first few postnatal days, the later
dominance of other thermoregulatory systems represented by T2 may correspond with increases in e.g. liver, thyroid and adrenal activity [49]. on November 22, 2017
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rsos.royalsocietypublishing.org R.Soc. opensci. 3.2. Behavioural thermoregulation as a competition between fat and muscle In the control condition, the predicted mean group size decreases with T (light trace), but with
associative learning enabled (heavy trace) high huddling levels remain stable into adulthood, with huddling dominated by ‘filial’
preferences(basedonα)ratherthanphysiology(basedonT)fromapproximatelyday15.(b)Developmentoftheassociativestrengthsof
an arbitrary pup to the odours of its littermates in the ‘learning’ condition. Heavier traces highlight the emergent heterogeneity of filial
huddling preferences (litter size; n = 7). 3.2. Behavioural thermoregulation as a competition between fat and muscle 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
1.0
–0.05
0
0.05
0.10
0.15
0.20
0.25
control
learning
a1,2, a1,3
...a1,n
1.5
2.0
2.5
huddle size
association
3.0
3.5
4.0
10
20
30
t (days)
40
50
60
0
10
20
30
t (days)
40
50
60
(a)
(b)
Figure 3. From physiological huddling to filial huddling. (a) Huddling statistics were generated by supplying a Monte Carlo model [20]
with temperatures T = T1 −T2, weighted either by α = 1 to define a ‘physiological huddling’ control condition, or by allowing
associative strengths αa,b to adapt. In the control condition, the predicted mean group size decreases with T (light trace), but with
associative learning enabled (heavy trace) high huddling levels remain stable into adulthood, with huddling dominated by ‘filial’
preferences(basedonα)ratherthanphysiology(basedonT)fromapproximatelyday15.(b)Developmentoftheassociativestrengthsof
an arbitrary pup to the odours of its littermates in the ‘learning’ condition. Heavier traces highlight the emergent heterogeneity of filial
huddling preferences (litter size; n = 7). –0.05
0
0.05
0.10
0.15
0.20
0.25
a1,2, a1,3
...a1,n
association
0
10
20
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t (days)
40
50
60
(b) 6
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
1.0
control
learning
1.5
2.0
2.5
huddle size
3.0
3.5
4.0
10
20
30
t (days)
40
50
60
(a) 6 association rom physiological huddling to filial huddling. (a) Huddling statistics were generated by supplying a Monte Carlo model [20]i Figure 3. From physiological huddling to filial huddling. (a) Huddling statistics were generated by supplying a Monte Carlo model [20]
with temperatures T = T1 −T2, weighted either by α = 1 to define a ‘physiological huddling’ control condition, or by allowing
associative strengths αa,b to adapt. 7
rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The quantities and expressions derived in modelling the data of [48,49] suggest the following about
the development of the thermal physiology and behaviour of the mouse. Mice are born with maximum
BAT stores, which decrease exponentially over time as P = e−t/k, as is the typical profile for a precocial
mammal [23]. From birth, mice accumulate body mass by a process that converts between fat and muscle,
such that muscle mass increases as M = k(1 −P). As such, the unit of energy k may be interpreted as a
conversion factor between the (mass-specific) energy stored in fat tissue and the (absolute) muscle mass. The energy released in the conversion between fat and muscle is reflected by a spike in the entropy of
BAT, measured as a peak in the mass-specific metabolic rate, i.e. the oxygen consumption. This spike
is similar to the fluctuation in entropy (or heat capacity) measured by physicists during a Schottky
anomaly (see [50,55]), or as occurs when an open system undergoes a transition from a low-energy
ground state to a steady state of higher energy [56]. Here, the ground state corresponds to ectothermy,
and the transition is to the higher-energy thermal physiology associated with endothermy. Ectothermy in
the newborn makes it highly resistant to a cold environment, for example neonatal mice can recover from
hypothermia at 0◦C, whereas adults cannot [49]. However, the later transition to endothermy, through a
peak in entropy, is required in order for the adult to sustain a higher energy metabolism; In the words
of Erwin Schrödinger ‘. . .the higher temperature of the warm-blooded animal includes the advantage of
enabling it to get rid of its entropy at a quicker rate, so that it can afford a more intense life process’ [57]. g
g
py
q
p
The results of adding odour-heat conditioning to the model of [20] provides a parsimonious
explanation for the persistence of rodent filial huddling into adulthood, confirming the intuitions
of several researchers (e.g. [34,35,45]). Equation (3.9) makes explicit the distinction between reactive
behaviour (i.e. physiological huddling with all α = 1; figure 3a, ‘control’) and predictive behaviour (i.e. filial huddling based on a learnt distribution of α values among littermates; figure 3a, ‘learning’). More
detailed models of associative learning are expected to yield qualitatively similar results. 7
rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Beyond the a priori prediction that odour-heat conditioning might lead to the persistence of huddling
into adulthood, the additional prediction that associative strengths among the litter can develop to be
increasingly positive or negative was not anticipated, although the effect is simple to understand post
hoc. Once two pups have developed a moderate association, an early contact that by chance results in
a surprising outcome will lead to an adjustment in association that makes that predicted outcome less
likely to result from future encounters. For example, two pups that expect to maintain contact (α > 0) but
do not, will adjust α to predict that future contacts are unlikely to be maintained (α < 0), and in doing so
reduce the probability of maintaining future contacts. Steady increases or steady decreases in associative
strength between pups (figure 3b) thus reflect an amplification of early individual differences between
them and result from closing the loop between behaviour (equation (2.1)) and learning (equation (3.9)). By driving the summation term in equation (3.9) towards binary values of r, the overall associative
strengths among the group remain bounded, thus enforcing a competition where pairwise increases
and decreases in associative strength are balanced. The net effect is a steady state in which the system
remains poised in a critical regime (ρ ≈0.5). These dynamics demonstrate the usefulness of computational modelling as a tool for teasing out the
predictions of how even simple systems behave when learning is allowed to interact with behaviour. The
new prediction in this case is that while associative learning enables huddling to persist into adulthood,
individuals will become increasingly selective in their choice of huddling partners. This prediction could
in principle be tested by measuring the changing preferences of animals, at thermoneutral temperatures,
to huddle with surrogate objects scented with different littermate odours in a forced-choice experimental
set-up. In similar set-ups using artificial odours, rats have been shown to spend more time on postnatal
day 6 exploring odours recently paired with the experience of warmth, whereas on days 7 and 8 rats
spend less time exploring an odour paired with the experience of cold, compared to baseline times spent
exploring the warmer of two odour-neutral locations [44]. Filial huddling preferences can be induced by exposure to novel odours when paired with soft
contacts and/or warm environments (rather than food [58]). 3.3. From physiological huddling to filial huddling The Monte Carlo method developed by Wilson [20] (equation (2.1)) can be used to translate T1 and T2
into a prediction of how the mean group size varies with age as the physiology matures from ectothermy
to endothermy, using T ∝T1 −T2. Figure 3a (light trace) confirms that huddling (average group size) is
predicted to decrease as the preferred temperature falls. To model how pups learn from huddling interactions, each is assumed to maintain a strength of
association α for the odour of each of its littermates. The thermodynamic temperature parameter T is
then weighted at each time step by the strength of association of pup b for the odour of pup a, T = αb,a(T1 −T2)β,
(3.8) (3.8) where β = 0.2 is an arbitrary scaling constant. Note that in the control condition, where huddling
interactions are determined only by the maturing physiology, α = 1 for all strengths of association. The Delta rule from animal learning theory [54] can then be used to modify these associative strengths,
treating each simulated encounter between a and b as a conditioning trial. On each iteration of the
huddling algorithm, the strength of association of pup a for the odour of pup b, αa,b, is updated to better
predict whether future contacts between them will be maintained, αa,b = γ
⎛
⎝r −
i̸=a
αa,i
⎞
⎠,
(3.9) (3.9) where the reward is r ≡1 whenever the groups of a and b are combined, or r ≡0 otherwise, and the
learning rate is set to γ = 0.001. where the reward is r ≡1 whenever the groups of a and b are combined, or r ≡0 otherwise, and the
learning rate is set to γ = 0.001. Figure 3a (heavy trace) shows that when littermates can learn to predict the outcome of huddling
interactions, large huddles persist into adulthood, with larger huddles predicted from around day 15 in
littermates able to learn compared to non-learning controls. Figure 3b shows the associative strengths
learnt by an arbitrary pup, which grow to an early peak for all littermates, but thereafter increasingly
discriminate among the littermates. The development of two associative strengths are highlighted,
showing how littermates can learn strong positive or negative associations to one another. This emergent
heterogeneity of preferences for maintaining contacts with specific littermates may constitute the basis
of a rudimentary social system. on November 22, 2017
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Donati G. 2017 Huddling is more important than rest
site selection for thermoregulation in southern
bamboo lemurs. Anim.Behav. 127, 153–161. (doi:10.1016/j.anbehav.2017.03.019) 2. Gregory PT. 1984 Communal denning in snakes. In
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Knight, L Malaret, NL Zuschlag), pp. 57–75. Lawrence, KS: University of Kansas, Museum of
Natural History. 2. Gregory PT. 1984 Communal denning in snakes. In
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . According to the model, mechanisms of classical conditioning, which presumably involve the pre-
optic region of the hypothalamus [23,24,46,60–62] and the olfactory bulb [39], adjust the relative
strengths of association to the smells of littermates to better predict the thermal consequences of
huddling encounters. As a result, huddling levels are maintained into adulthood, despite a decline in
the immediate energetic benefits to huddling. In the process, the thermodynamic entropy is essentially
converted into an information-theoretic entropy, storing among the relative strengths of association
information about the history of rewarding and non-rewarding thermotactile experiences between
littermates. This information represents a potential template for an adult social system in which animals
prefer to interact with certain others. Data accessibility. The datasets supporting this article have been uploaded as part of the electronic supplementary
material. mpeting interests. I declare I have no competing interests Funding. I received no funding for this study. Funding. I received no funding for this study. Acknowledgements. The author is grateful to Hannes Saal and Tony Prescott at the University of Sheffield and Paul Wilson
at the University of Hull for useful discussions. For Pippa April Wilson. 7
rsos.royalsocietypublishing.org R.Soc. opensci. 4: 170885
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these data, the point at which the two traces in figure 3a intersect defines a transition from physiological
to filial huddling, i.e. at around postnatal day 15. Day 15 represents a landmark in the development of rat social thermoregulation. Preferences
measured in rats on day 15 can be induced by a single 2 h exposure at postnatal day 14 to a scented object
other than the mother, only if it is both warm and soft (consistent with the definition of r), suggesting on November 22, 2017
http://rsos.royalsocietypublishing.org/
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intranasal infusion of zinc sulphate) [39]. An important test of the model will be to establish whether day
15 is also a landmark in the development of mouse social behaviour. 8 9
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A computational model to predict the Diels–Alder reactivity of aryl/alkyl-substituted tetrazines
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Monatshefte für Chemie
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cc-by
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& Hannes Mikula
hannes.mikula@tuwien.ac.at Introduction Abstract The tetrazine ligation is one of the fastest
bioorthogonal ligations and plays a pivotal role in time-
critical in vitro and in vivo applications. However, pre-
diction of the reactivity of tetrazines in inverse electron
demand Diels–Alder-initiated ligation reactions is not
straight-forward. Commonly used tools such as frontier
molecular orbital theory only give qualitative and often
even wrong results. Applying density functional theory, we
have been able to develop a simple computational method
for the prediction of the reactivity of aryl/alkyl-substituted
tetrazines
in
inverse
electron
demand
Diels–Alder
reactions. Tetrazine ligations (TLs) are bioorthogonal inverse elec-
tron demand Diels–Alder (IEDDA) initiated cycloadditions
proceeding with exceptional high second-order rates of up
to 3,300,000 M-1 s-1 [1]. In TLs, an 1,2,4,5-tetrazine (Tz)
reacts with an electron-rich dienophile in an IEDDA
reaction followed by cycloreversion under the loss of
nitrogen (Fig. 1). Strained alkenes such as norbornenes
[2, 3], cyclopropenes [4, 5], and trans-cyclooctenes (TCOs)
[1, 6–8] are commonly used dienophiles, with TCOs pro-
viding the highest reactivity. The rate-determining step is
the Diels–Alder cycloaddition, while the cycloreversion
has only a low energy barrier and is suspected to show
strong non-statistical effects [9]. Graphical Abstract Graphical Abstract Keywords Cycloadditions Computational chemistry
Click chemistry Bioorthogonal chemistry Due to the high reaction rates, these ligations can be
used in time-critical applications such as rapid radiolabel-
ing and pretargeted PET imaging [10–16] and provide high
yields within short reaction times even at low concentra-
tions as usually encountered in radiochemistry and in vivo. Therefore, kinetics is one of the most important charac-
teristics of bioorthogonal reactions. However, prediction of
reactivities using the chemist’s understanding of organic
chemistry, especially of IEDDA reactions, might lead to
wrong predictions [17] and only qualitative estimates. In
addition, synthesis of tetrazines is often low yielding and
involves handling or even requires the production of
anhydrous hydrazine (not commercially available in Eur-
ope), which limits the feasibility of screening for high
Diels–Alder reactivity. Hence, there is the need of reliable
computational tools to predict the reactivity of various
tetrazines in TLs. Keywords Cycloadditions Computational chemistry
Click chemistry Bioorthogonal chemistry Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s00706-017-2110-x) contains supple-
mentary material, which is available to authorized users. Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s00706-017-2110-x) contains supple-
mentary material, which is available to authorized users. 1
Institute of Applied Synthetic Chemistry, TU Wien, Vienna,
Austria Monatsh Chem (2018) 149:833–837
https://doi.org/10.1007/s00706-017-2110-x Monatsh Chem (2018) 149:833–837
https://doi.org/10.1007/s00706-017-2110-x ORIGINAL PAPER A computational model to predict the Diels–Alder reactivity
of aryl/alkyl-substituted tetrazines Dennis Svatunek1 • Christoph Denk1 • Hannes Mikula1 Received: 18 October 2017 / Accepted: 20 November 2017 / Published online: 29 November 2017
The Author(s) 2017. This article is an open access publication Introduction Herein, we introduce a computational model for the
prediction of the reactivity of aryl/alkyl-substituted Tz in
the cycloaddition with trans-cyclooctene (TCO), thus 12 3 834 D. Svatunek et al. Fig. 1 Mechanism of the bioorthogonal ligation of 1,2,4,5-tetrazine (Tz) and trans-cyclooctene (TCO) Fig. 1 Mechanism of the bioorthogonal ligation of 1,2,4,5-tetrazine (Tz) and trans-cyclooctene (TCO) eliminating the need for expensive and even dangerous
synthetic work, finally enabling in silico screening for
tetrazines with desired reactivity. imaging (Fig. 2). While the alkyl substituent is the same
for all eight tetrazines the aryl component shows consid-
erable variation including electron-rich and electron-poor
aryl groups. In addition, Tz 9 and 10 were included to
investigate the influence of the alkyl group and an ortho-
substituted aryl residue, respectively. While 3,6-bisaryl- and 3-aryl-substituted Tz show the
highest reactivity, aryl/alkyl-substituted Tz are commonly
used due to higher stability [18, 19] and show favorable
properties in Tz-triggered bioorthogonal elimination reac-
tions [20, 21]. The second-order rate constants of Tz 1–10 in the
reaction with trans-cyclooctene 11 at 25 C in anhydrous
1,4-dioxane were measured by stopped-flow spectropho-
tometry, which gave rates ranging from 1.00 M-1 s-1 for
electron-rich
trimethoxyphenyl-substituted
Tz
3
to
14.6 M-1 s-1 for Tz 8 bearing an electron withdrawing
2-pyridyl substituent (Fig. 3). A computational model to predict the Diels–Alder reactivity of aryl/alkyl-substituted… 835 a
b
HOMO
HOMO
LUMO+1
LUMO
1
2
3
4
5
6
7
8
9 10 11
-12
-10
-8
0.0
0.5
1.0
1.5
2.0
orbitalenergy / eV
tetrazine
HOMO
LUMO
LUMO+1
c
Fig. 4 a HOMO, LUMO, and
LUMO?1 of 3-methyl-6-
phenyl-Tz (9); b HOMO of
TCO (11); c energy levels of
selected orbitals for tetrazines
1–10 and TCO (11) a
HOMO
LUMO+1
LUMO
Fig. 4 a HOMO, LUMO, and
LUMO?1 of 3-methyl-6-
phenyl-Tz (9); b HOMO of
TCO (11); c energy levels of
selected orbitals for tetrazines
1–10 and TCO (11) a
HOMO
Fig. 4 a HOMO, LUMO, and
LUMO?1 of 3-methyl-6-
phenyl-Tz (9); b HOMO of
TCO (11); c energy levels of
selected orbitals for tetrazines
1–10 and TCO (11) LUMO LUMO+1
LUMO LUMO+1 b
HOMO
1
2
3
4
5
6
7
8
9 10 11
-12
-10
-8
0.0
0.5
1.0
1.5
2.0
orbitalenergy / eV
tetrazine
HOMO
LUMO
LUMO+1
c b
HOMO 1
2
3
4
5
6
7
8
9 10 11
-12
-10
-8
0.0
0.5
1.0
1.5
2.0
orbitalenergy / eV
tetrazine
HOMO
LUMO
LUMO+1
c orbitalenergy / eV tetrazine tetrazine According to the FMO theory, a smaller energy gap
between the interacting orbitals facilitates the reaction. Thus, one might expect that a more electron withdrawing
and thus LUMO?1-lowering substituent accelerates the
reaction, while an electron-rich aryl substituent will
decrease
reactivity. HF/6-311?G(d,p)//M06-2X/6-
311?G(d,p)-calculated orbital energies are shown in
Fig. 4c. Tz 4 and 7 bearing an electron-withdrawing tri-
fluoromethyl or sulfone group, respectively, show the
lowest LUMO and LUMO?1 energies. However, the tet-
razine with the highest reactivity, Tz 8, has one of the
highest LUMO and a rather high LUMO?1 energy within
the series. As shown in Fig. 5, there is no significant correlation between the LUMO?1-energy levels and the
rate constants (R2 = 0.07). This can be rationalized by the
fact that FMO interactions are not the only major con-
tributors to activation energies in such cycloadditions
[17, 27–29]. Therefore, the FMO theory cannot be applied
for the reliable prediction of the Diels–Alder reactivity of
aryl/alkyl-substituted Tz. However, the calculated energies of activation (DE) of
the reactions between tetrazines 1–10 and TCO (11) show
excellent linear correlation with the natural logarithm of
the measured rate constants, as per transition state theory
(Fig. 6). M06-2X/6-311?G(d,p) calculated energies of Fig. Fig. 4 a HOMO, LUMO, and
LUMO?1 of 3-methyl-6-
phenyl-Tz (9); b HOMO of
TCO (11); c energy levels of
selected orbitals for tetrazines
1–10 and TCO (11) Results and discussion Recently, we have investigated the reactivity of several
3-aryl-6-(3-fluoropropyl)-1,2,4,5-tetrazines 1–8 as chemi-
cal probes for rapid radiolabeling and pretargeted PET These experimental results were selected as a basis for
the construction of a predictive computational tool. DFT
was successfully used in the past by our group [16, 22] and
others [7, 17, 23, 24] to predict or explain the reactivity of
dienophiles and tetrazines in the tetrazine ligation. There-
fore,
the
Minnesota
density
functional
M06-2X
in
combination with the 6-311?G(d,p) basis set, was used as
model chemistry. This density functional has been proven
to
produce
accurate
results
for
thermodynamics
of
cycloaddition reactions [25, 26]. was successfully used in the past by our group [16, 22] and
others [7, 17, 23, 24] to predict or explain the reactivity of
dienophiles and tetrazines in the tetrazine ligation. There-
fore,
the
Minnesota
density
functional
M06-2X
in
combination with the 6-311?G(d,p) basis set, was used as
model chemistry. This density functional has been proven
to
produce
accurate
results
for
thermodynamics
of
cycloaddition reactions [25, 26]. Diels–Alder reactions can be described by HOMO/
LUMO interactions using the frontier molecular orbital
(FMO) theory. In case of the IEDDA cycloaddition the
main orbital interaction is between a low-lying unoccupied
orbital of the dienophile, usually being the LUMO?1 for
aryl/alkyl tetrazines (Fig. 4a) [17], and the HOMO of the
electron-rich dienophile (in this case TCO, Fig. 4b). Fig. 2 Investigated aryl/alkyl substituted 1,2,4,5-tetrazines in the
IEDDA reaction with trans-cyclooctene (11)
Fig. 3 Second-order rate constants of tetrazines 1–10 with trans-
cyclooctene (11) in 1,4-dioxane at 25 C Fig. 2 Investigated aryl/alkyl substituted 1,2,4,5-tetrazines in the
IEDDA reaction with trans-cyclooctene (11) Diels–Alder reactions can be described by HOMO/
LUMO interactions using the frontier molecular orbital
(FMO) theory. In case of the IEDDA cycloaddition the
main orbital interaction is between a low-lying unoccupied
orbital of the dienophile, usually being the LUMO?1 for
aryl/alkyl tetrazines (Fig. 4a) [17], and the HOMO of the
electron-rich dienophile (in this case TCO, Fig. 4b). Fig. 3 Second-order rate constants of tetrazines 1–10 with trans-
cyclooctene (11) in 1,4-dioxane at 25 C Fig. 3 Second-order rate constants of tetrazines 1–10 with trans-
cyclooctene (11) in 1,4-dioxane at 25 C Fig. 2 Investigated aryl/alkyl substituted 1,2,4,5-tetrazines in the
IEDDA reaction with trans-cyclooctene (11) 123 123 A computational model to predict the Diels–Alder reactivity of aryl/alkyl-substituted… Experimental Table 2 Observed rate constants, concentrations of TCO (11) and the
corresponding Tz, and calculated second-order rate constants of the
IEDDA reaction between Tz 1–10 and 11 Table 2 Observed rate constants, concentrations of TCO (11) and the
corresponding Tz, and calculated second-order rate constants of the
IEDDA reaction between Tz 1–10 and 11
Reaction
kobs/s-1
cTCO/M
ctetrazine/M
k/M-1 s-1
1 ? 11
0.003278
0.002081
0.000064
1.58
2 ? 11
0.002652
0.002096
0.00005
1.27
3 ? 11
0.00205
0.002051
0.000049
1.00
4 ? 11
0.007801
0.002015
0.00005
3.87
5 ? 11
0.002703
0.002081
0.000034
1.30
6 ? 11
0.005811
0.00196
0.000046
2.96
7 ? 11
0.009894
0.001933
0.000103
5.12
8 ? 11
0.03064
0.002096
0.00005
14.6
9 ? 11
0.00461
0.002813
0.000058
1.64
10 ? 11
0.004514
0.002224
0.000061
2.03 Kinetic measurements Kinetic measurements were performed on a SX20 stopped-
flow spectrophotometer (Applied Photophysics, UK) using
a 535 nm LED light source. A 4 mM solution of 11 and
approximately 0.1 mM solutions of Tz 1–10 were prepared
in anhydrous 1,4-dioxane (note: for correct measurements
it is of utmost importance to use anhydrous 1,4-dioxane, A computational model to predict the Diels–Alder reactivity of aryl/alkyl-substituted… 6 Correlation between natural logarithm of second-order rate
constants
and
M06-2X/6-311?G(d,p)
calculated
energies
of
activation Fig. 5 Second-order
rate
constants
plotted
against
HF/6-
311?G(d,p)//M06-2X/6-311?G(d,p) calculated LUMO?1 energies
of the corresponding tetrazine
Fig. 6 Correlation between natural logarithm of second-order rate
constants
and
M06-2X/6-311?G(d,p)
calculated
energies
of
activation Fig. 5 Second-order
rate
constants
plotted
against
HF/6-
311?G(d,p)//M06-2X/6-311?G(d,p) calculated LUMO?1 energies
of the corresponding tetrazine Fig. 6 Correlation between natural logarithm of second-order rate
constants
and
M06-2X/6-311?G(d,p)
calculated
energies
of
activation Fig. 6 Correlation between natural logarithm of second-order rate
constants
and
M06-2X/6-311?G(d,p)
calculated
energies
of
activation Fig. 5 Second-order
rate
constants
plotted
against
HF/6-
311?G(d,p)//M06-2X/6-311?G(d,p) calculated LUMO?1 energies
of the corresponding tetrazine 12 3 836 D. Svatunek et al. Table 1 Calculated total electronic energies of compounds 1–11 and
transition states for the reaction between 1–10 and 11, and calculated
energies of activation (DE) activation can, therefore, be used to reliably predict the
reactivity of aryl/alkyl-Tz in IEDDA reactions with trans-
cyclooctenes. Table 1 Calculated total electronic energies of compounds 1–11 and
transition states for the reaction between 1–10 and 11, and calculated
energies of activation (DE) Table 1 Calculated total electronic energies of compounds 1 11 and
transition states for the reaction between 1–10 and 11, and calculated
energies of activation (DE)
Compound
E(Tz)/hartree
E(TS)/hartree
DE/kJ mol-1
1
- 744.464487
- 1057.63536
4.74
2
- 783.771996
- 1096.942379
6.02
3
- 1087.994366
- 1401.164459
6.78
4
- 1081.515706
- 1394.687804
1.52
5
- 1181.953194
- 1495.123556
6.08
6
- 1257.12132
- 1570.293123
2.29
7
- 1332.328085
- 1645.501028
- 0.70
8
- 760.498963
- 1073.674144
- 6.57
9
- 566.619295
- 879.789737
5.87
10
- 641.851471
- 955.023032
2.93
TCO (11)
- 313.172677
–
– Compound
E(Tz)/hartree
E(TS)/hartree
DE/kJ mol-1 Using the linear correlation between ln(k) and calculated
DE, Eq. (1) can be constructed which allows the predic-
tion of the rate constant of new aryl/alkyl-Tz for the
reaction with TCO (11) in anhydrous 1,4-dioxane at 25 C. k ¼ e0:1963DEzþ1:460
ð1Þ k ¼ e0:1963DEzþ1:460 ð1Þ energies for Tz 1–10 and the respective transition states (for
the reaction with TCO) are shown in Table 1. energies for Tz 1–10 and the respective transition states (for
the reaction with TCO) are shown in Table 1. energies for Tz 1–10 and the respective transition states (for
the reaction with TCO) are shown in Table 1. Synthesis Trans-cyclooctene (11) and tetrazines 9 and 10 were pre-
pared following known procedures [31, 32]. The synthesis
of compounds 1–8 will be published elsewhere (manuscript
in preparation). We are convinced that our method will aid the devel-
opment of new aryl/alkyl tetrazines for bioorthogonal
applications, and represents a step forward to the devel-
opment of a universal computational tool being able to
predict the reactivity of tetrazines with various substitution
patterns. Conclusion Prediction of the reactivity of Tz in bioorthogonal ligation
reactions is essential to reduce synthetic work, the resulting
costs and associated risks. However, the chemist’s pre-
diction of these reactivities, mainly based on frontier
molecular orbital theory, can only yield qualitative or even
wrong results as shown in this work. We were able to
develop a computational method for the prediction of
reactivities of aryl/alkyl-substituted 1,2,4,5-tetrazines in
the reaction with trans-cyclooctene based on M06-2X-
calculated energies of activation. This method is compu-
tationally cheap as it requires only the optimization of the
tetrazine and the corresponding transition state with trans-
cyclooctene at the M06-2X/6-311?G(d,p) level of theory,
which can even be done on an average desktop PC within
hours. Computational methods Calculations were performed at the M06-2X/6-311?G(d,p)
level of theory in the gas phase using the Gaussian 09 Rev. D.01 software package [30]. Vibrational analysis was per-
formed to confirm stationary points are energetic minima or
transition states, respectively. Orbital energies were calcu-
lated by performing a HF/6-311?G(d,p) single-point
calculation on M06-2X/6-311?G(d,p) optimized structures. DE was determined by calculating the difference in ener-
gies between transition state and reactants. Data analysis
was preformed using Gaussview 5 and Chemcraft. XYZ
coordinate files of all reactants and transition states are
available as electronic supplementary material. Calculated 12 123 123 A computational model to predict the Diels–Alder reactivity of aryl/alkyl-substituted… 837 since even small amounts of water will accelerate the
reaction, leading to irreproducible data). These solutions
were loaded into the driver syringes and equal volumes of
TCO and Tz solution were mixed, resulting in concentra-
tions of 2 and 0.05 mM, respectively. The reaction
progress was followed by measuring the absorption around
535 nm. All measurements were performed in triplicates. Observed reaction constants (kobs) were determined by
non-linear regression (one-phase-decay) using Prism 6
(Graphpad) and second-order rate constants (k) were cal-
culated from kobs. Table 2 lists kobs, cTCO, cTz and k for all
reactions. 12. Rossin R, van Duijnhoven SMJ, van den Bosch SM, Robillard
MS (2014) Nucl Med Biol 41:630 13. Li Z, Cai H, Hassink M, Blackman ML, Brown RCD, Conti PS,
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This article is distributed under the terms of the
Creative Commons Attribution 4.0 International License (http://
creativecommons.org/licenses/by/4.0/), which permits unrestricted
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Clinical influence of conversion of laparoscopic sleeve gastrectomy to one anastomosis gastric bypass on gastroesophageal reflux disease
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Langenbeck's archives of surgery
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cc-by
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Does Conversion of Sleeve Gastrectomy to One-
Anastomosis Gastric Bypass induce Gastro-
Esophageal Reflux Disease?
Shlomi Rayman
(
shlomirayman@gmail.com
)
Assuta Ashdod Public Hospital, Ben-Gurion University
Maor Staierman
Assuta Ashdod Public Hospital, Ben-Gurion University
Dan Assaf
Chaim Sheba Medical Center
Jacob Rachmuth
Assuta Ashdod Public Hospital, Ben-Gurion University
Idan Carmeli
Assuta Ashdod Public Hospital, Ben-Gurion University
Andrei Keidar
Assuta Ashdod Public Hospital, Ben-Gurion University
Research Article
Keywords: Revisional surgery, sleeve gastrectomy, one-anastomosis gastric bypass, GERD, bariatric
surgery
Posted Date: September 27th, 2022
DOI: https://doi.org/10.21203/rs.3.rs-2081268/v1
License:
This work is licensed under a Creative Commons Attribution 4.0 International
License.
Read Full License
Additional Declarations: No competing interests reported.
Version of Record: A version of this preprint was published at Langenbeck's Archives of Surgery on April
27th, 2023. See the published version at https://doi.org/10.1007/s00423-023-02892-7. Does Conversion of Sleeve Gastrectomy to One-
Anastomosis Gastric Bypass induce Gastro-
Esophageal Reflux Disease? Shlomi Rayman
(
shlomirayman@gmail.com
)
Assuta Ashdod Public Hospital, Ben-Gurion University
Maor Staierman
Assuta Ashdod Public Hospital, Ben-Gurion University
Dan Assaf
Chaim Sheba Medical Center
Jacob Rachmuth
Assuta Ashdod Public Hospital, Ben-Gurion University
Idan Carmeli
Assuta Ashdod Public Hospital, Ben-Gurion University
Andrei Keidar
Assuta Ashdod Public Hospital, Ben-Gurion University
Research Article
Keywords: Revisional surgery, sleeve gastrectomy, one-anastomosis gastric bypass, GERD, bariatric
surgery
Posted Date: September 27th, 2022
DOI: https://doi.org/10.21203/rs.3.rs-2081268/v1
License:
This work is licensed under a Creative Commons Attribution 4.0 International
License. Read Full License
Additional Declarations: No competing interests reported. Version of Record: A version of this preprint was published at Langenbeck's Archives of Surgery on April
27th, 2023. See the published version at https://doi.org/10.1007/s00423-023-02892-7. Does Conversion of Sleeve Gastrectomy to One-
Anastomosis Gastric Bypass induce Gastro-
Esophageal Reflux Disease? Shlomi Rayman
(
shlomirayman@gmail.com
)
Assuta Ashdod Public Hospital, Ben-Gurion University
Maor Staierman
Assuta Ashdod Public Hospital, Ben-Gurion University
Dan Assaf
Chaim Sheba Medical Center
Jacob Rachmuth
Assuta Ashdod Public Hospital, Ben-Gurion University
Idan Carmeli
Assuta Ashdod Public Hospital, Ben-Gurion University
Andrei Keidar
Assuta Ashdod Public Hospital, Ben-Gurion University
Research Article
Keywords: Revisional surgery, sleeve gastrectomy, one-anastomosis gastric bypass, GERD, bariatric
surgery
Posted Date: September 27th, 2022
DOI: https://doi.org/10.21203/rs.3.rs-2081268/v1
License:
This work is licensed under a Creative Commons Attribution 4.0 International
License. Read Full License
Additional Declarations: No competing interests reported. Results During the study period, 37 patients underwent revision from LSG to OAGB. Mean age at LSG and pre-
OAGB were 38 ± 11.74 and 46 ± 12.75, respectively. Median follow-up time was 21.5 months (range 3–
65). DRQ and GERD-HRQL scores were obtained at a median of 14 months (range 3–51) between pre-
and post-OAGB. Median RDQ score pre-OAGB vs post-OAGB was significantly reduced [30 (range 12–72)
vs 14 (range 12–60), p = 0.007]. All 3 parts of the GERD- HRQL questionnaires were significantly reduced
between pre-OAGB and post-OAGB: Symptoms (20; 62.5% vs 10; 31.3%, p = 0.012), overall score [15(0–
39) vs 7(0–28), p = 0.04] and subjective improvement [10; 31% vs 20; 62.5%, p = 0.025). Purpose Assess the subjective impact of GERD symptoms on patients undergoing revision from LSG to OAGB
using the Diagnostic Questionnaire for GERD (DRQ) and the GERD-health related quality of life score
(GERD-HRQL), prior to- and following conversion. Conversion of LSG to OAGB does not induce subjective GERD symptoms in a short-term follow up. Conversion of LSG to OAGB does not induce subjective GERD symptoms in a short-term follow up. Methods Patients undergoing revision from LSG to OAGB were prospectively followed between May 2015 and
December 2020. Data retrieved included demographics, anthropometrics, previous bariatric history, time
interval between LSG and OAGB, weight loss and co-morbidities. Pre- and post-OAGB DRQ and GERD-
HRQL questionnaires were obtained. In case of sleeve dilatation, a partial gastrectomy was performed. Research Article Additional Declarations: No competing interests reported. Version of Record: A version of this preprint was published at Langenbeck's Archives of Surgery on April
27th, 2023. See the published version at https://doi.org/10.1007/s00423-023-02892-7. Page 1/13 Page 1/13 Introduction Over the last two decades Laparoscopic sleeve gastrectomy (LSG) has become the most popular bariatric
operation performed worldwide [1]. Although LSG is frequently performed, up to 20% of patients undergo
conversional operations [2–4]. Conversion of LSG to other bariatric operations is safe, feasible and
effective, for multiple indications, which include inadequate weight loss, weight recidivism, gastro-
esophageal reflux disease (GERD), staple line leak, sleeve stenosis and dysphagia[5–8]. Although LSG is
utilized extensively, a systematic review by Laffin et al. showed that there is an indeterminate rate of post-
LSG de novo GERD, with a wide diversity of reports ranging from 2.1–34.9% of post-LSG patients
suffering from GERD [9–11]. The one-anastomosis gastric bypass (OAGB) has gained popularity in
recent years as a primary bariatric operation and as an acceptable conversional option following LSG [8, Page 2/13 12–16]. While OAGB is being increasingly utilized as a primary and revisional bariatric operation, it
remains under scrutiny for potentially inducing GERD symptoms or bile reflux [14, 17, 18]. Our aim was to assess the results of conversion of LSG to OAGB, emphasizing evaluation of the reflux
symptoms with the Diagnostic Questionnaire for Gastroesophageal Reflux Disease (DRQ)[19] and the
GERD-Health Related Quality of Life Questionnaire (GERD-HRQL)[20]. Our hypothesis was that conversion
of LSG to OAGB does not induce or worsens GERD. Materials And Methods Following an institutional review board (IRB) approval, patients undergoing conversion of LSG to OAGB
from May 2015 to December 2020 were prospectively followed and consented. Inclusion criteria included
patients aged 18 years and above who previously underwent a LSG and sought revisional operative
management due to weight-related indications (weight regain or insufficient weight-loss), complication-
related indications (dysphagia or GERD), or both. Patients were presented with data regarding expected
weight-loss and risks of complications (specifically GERD) following conversion options suitable for LSG
failure which included Roux-en-Y Gastric Bypass (RYGB), Biliopancreatic Diversion with Duodenal Switch
(BPD/DS), Single Anastomosis Duodeno-Ileal Bypass (SADI) and the aforementioned OAGB. Exclusion
criteria included patients who opted to undergo a conversion operation other than OAGB. Data collected included demographics, anthropometrics, previous operative & bariatric history, time
interval between LSG and conversion, medications and co-morbidities. All patients underwent endoscopic
& fluoroscopic studies prior to undergoing conversion. The diagnostic questionnaires for GERD
symptoms were compared between prior to- and following the conversion to OAGB. Weight results are
expressed in change in Body Mass Index (BMI) & percent Total Weight Loss (%TWL) from the pre-LSG
weight to the post-OAGB nadir weight. Perioperative complications were logged according the Clavien-
Dindo Classification [21]. Patients were routinely followed up at 1, 3, 6 & 12 months post-operatively. Patients that haven’t showed up to clinic in over 12 months or have not answered a telephone, email or
virtual communication were considered lost to follow up. Post-operative course Patients were allowed a clear liquid diet on day 1, discharged on day 2 and allowed a pureed diet after 2
weeks following their first office visit post-op. The drain was removed prior to discharge. All patients
underwent a nutritionist consult prior to discharge with a routine diet and supplement education. All
patients received daily physiotherapy care and enoxaparin injections (40-60mg od) for 1 week along with
an oral PPI od for 3 months. Patients with lack of oral diet advancement underwent an UGI prior to
discharge, the findings of which did not change the expected post-op course. Pre-operative Assessment All patients underwent a multidisciplinary assessment prior to approval of conversional bariatric surgery
which included psychosocial, nutritional, radiological and gastroenterological assessment. Smokers were
counseled for smoking cessation. An esophago-gastro-duodenoscopy (EGD) and an Upper GI
fluoroscopic swallow study (UGI) were performed on all patients prior to conversional surgery. The RDQ
and the GERD-HRQL questionnaires were obtained before conversion and at follow up. Pre-operative
blood work analysis included an anemia panel, lipid profile, vitamin D, B12 and folic acid levels, bone
densitometry, thyroid and parathyroid hormone and HbA1c. Correction of abnormal values was ensued
prior to conversion.Surgical Technique Page 3/13 Page 3/13 All operations were performed laparoscopically with the patient positioned in a standard supine position
and standard 5-port trocar placement. A 10mm 30o scope optic device was used. Following port
placement, a liver retractor was placed and lysis of adhesions using a harmonic scalpel was performed to
ensure visualization of the entire sleeve. Sleeve size assessment was made in concordance with the pre-
operative UGI. In case of sleeve dilatation, a linear stapled partial-gastrectomy was ensued to resize the
sleeve over a 36F-40F bougie tube. Next, the stomach was stapled proximal to the pylorus at the level of
the gastric incisura, to form a long (12-18 cm) and narrow tubular pouch and a separated antral remnant. We then performed a side-to-side stapled gastro-jejunostomy anastomosis between the gastric pouch
and a loop of bowel (afferent limb) measuring 200-350cm from the ligament of Treitz. Common
enterotomy was closed with 2 layers of continuous 3/0 Prolene sutures. Longer afferent limbs (≥250cm)
were tailored individually, following a measurement of a common channel of more than 300cm and
performed in patients with weight recidivism who desired and comprehended enhanced long-term weight-
loss with its following consequences. A leak test of the anastomosis was performed via a naso-gastric
tube using methylene blue dye in water. A Jackson-Prat drain was left along the anastomosis and staple
line of stomach. Statistical Analysis Group comparison was performed using non-parametric, Wilcoxon signed rank test for two dependent
groups, and Friedman test for non-parametric comparison of more than two dependent groups. Significant levels were considered at p value <0.05. %TWL was calculated from initial weight (prior to
LSG) and current weight (post-OAGB). Results During the study period, 37 patients underwent conversion from LSG to OAGB, with 5 patients (13%) lost
to follow up. Of the remaining 32 patients undergoing conversion from LSG to OAGB, 26 were female
(70%), mean age at LSG and at conversion was 38.8 ± 11.75 years (range 14–59) and 46 ± 12.75 years
(range 20–66 years), respectively (Table 1). Median time interval between LSG and conversion to OAGB
was 7 years (range 1–14) and median follow-up time was 21.5 months (range 3–65). Mean BMI pre-LSG,
pre-OAGB and post-OAGB nadir were 44.2 (range 35-61.7) kg/m2, 38.9 (23.2–48.3) kg/m2and 29.7 (18.4–
39.5) kg/m2, respectively (p < 0.0001, Table 1). Partial gastrectomy of enlarged sleeves was performed in Page 4/13 Page 4/13 all patients and the median afferent loop length was 230cm (range 200–360) from the ligament of Treitz
to the gastro-jejunostomy. Three patients (10%) had a previous laparoscopic adjustable gastric band prior
to their LSG. %TWL at post-LSG nadir was 33.9% (range 10–55%) and the %TWL at nadir weight
following conversion was 33.3% (range 7%-56%). all patients and the median afferent loop length was 230cm (range 200–360) from the ligament of Treitz
to the gastro-jejunostomy. Three patients (10%) had a previous laparoscopic adjustable gastric band prior
to their LSG. %TWL at post-LSG nadir was 33.9% (range 10–55%) and the %TWL at nadir weight
following conversion was 33.3% (range 7%-56%). following conversion was 33.3% (range 7%-56%). Results Table 1
Patients demographics, anthropometrics and co-morbidities
Variable
Pre-LSG
Pre-OAGB
Post-OAGB
p value
Age in years, mean
(range)
39.7 (14–62)
47.81 (22–67)
/
/
Gender
/
/
/
Male, n (%)
11 (34.4%)
Female, n (%)
21 (65.6%)
BMI mean (range)
44.21 (34.06–
61.71)
38.89 (23.2–
48.3)
29.66 (18.4–
39.5)
<
0.0001
TWL at nadir, % (range)
33.9% (10–55%)
33.3% (7%-56%)
NS
Excess weight in Kg
54.47 (25.28–99.9)
39.47 (-5.2-64.4)
12.71 (-20.4-
44.4)
<
0.0001
Nadir weight in Kg
/
82.28 (56–120)
83.73 (57–121)
0.78
Indication
Weight, n (%)
32 (100%)
28 (87.5%)
/
/
Reflux, n (%)
9 (28.1%)
Comorbidity, n (%)
DM
7 (21.8%)
2 (6.2%)
4 (12.5%)
HTN
6 (18.8%)
6 (18.8%)
8 (25%)
Hyper-cholesterolemia
6 (18.8%)
8 (25%)
8(25%)
NS
Hyper TG
2 (6.3%)
4 (12.5%)
4 (12.5%)
Proteinuria
1 (3.1%)
1 (3.1%)
0
OSA
3 (9.4%)
1 (3.1%)
2 (6.3%)
Fatty liver
12 (37.5%)
11 (34.4%)
11 (34.4%)
LSG – Laparoscopic sleeve gastrectomy, OAGB – One-anastomosis gastric bypass, BMI – body mass
index, DM – diabetes mellitus, HTN – hypertension, %TWL – percent total weight loss Table 1 LSG – Laparoscopic sleeve gastrectomy, OAGB – One-anastomosis gastric bypass, BMI – body mass
index, DM – diabetes mellitus, HTN – hypertension, %TWL – percent total weight loss LSG – Laparoscopic sleeve gastrectomy, OAGB – One-anastomosis gastric bypass, BMI – body mass
ndex, DM – diabetes mellitus, HTN – hypertension, %TWL – percent total weight loss Page 5/13 Pre-conversion EGD showed narrowing of the sleeve in 2 patients (6%), LA grade A esophagitis in 9
patients (28%), HH in 8 patients (25%) and 13 patients (40%) had an unremarkable exam. Pre-conversion
UGI showed reflux of contrast in 9 patients (28%), a widened esophagus in 3 patients (9%), a HH in 10
patients (31%) and 18 patients (56%) had an unremarkable exam. There were no findings of Barrette’s
dysplasia or malignancy in any of the patients. Table 2 represents the outcomes of the DRQ and GERD-HRQL scores at a median interval of 14 months
(range 3–51) between pre- and post-OAGB. Median RDQ score pre-OAGB vs post-OAGB was significantly
reduced [30 (range 12–72) vs 14 (range 12–60), p = 0.007]. Results All 3 parts of the GERD-HRQL questionnaires
were significantly reduced between pre-OAGB and post-OAGB: Symptoms (20; 62.5% vs 10; 31.3%, p =
0.012), overall score [15(0–39) vs 7(0–28), p = 0.04] and subjective improvement [10; 31% vs 20; 62.5%, p
= 0.025). Table 2
Gastro-esophageal reflux disease questionnaires
Variable
Pre-OAGB
Post-OAGB
p value
RDQ score (median)
30 (12–72)
14 (12–60)
0.007
GERD-HRQL score
Symptoms
20 (62.5%)
10 (31.3%)
0.012
Score
15 (0–39)
7 (0–28)
0.04
subjective
10 (31.3%)
20 (62.5%)
0.025
RDQ- reflux disease questionnaire, GERD-HRQL- gastro-esophageal reflux disease quality of life scale Table 2 Major perioperative complications (CD ≥ 3) occurred in 8 (25%) patients (Table 3). Complications
requiring re-operation included 2 proximal staple line leaks from the partial gastrectomy which required
laparoscopic lavage with drainage with one patient undergoing endoluminal stent placement. Further
fluoroscopic studies confirmed leak resolution 4 weeks post-op for both patients with subsequent
removal of drains and endoluminal stent. Dysphagia with reflux requiring conversion to RYGB occurred in
3 patients, 2 in the immediate post-operative course (POD 2 & 14), both for technical problems, one pouch
stenosis and one anastomotic stenosis, and 1 within one year of conversion to OAGB. Complications
beyond the 30-days post-op period included loose stools (n = 6, 19%) and marginal ulcers (n = 2, 6%)
which were managed with oral PPI continuation. There were no conversions to “open” operations and no
conversion related deaths. Page 6/13 Table 3
Post-operative complications
n = 32
CD ≥ 3
Total
16 (50%)
8 (25%)
Diarrhea/loose stools
6 (19%)
0
Leakage
2 (6%)
2 (6%)
Dysphagia
4 (12.5%)
2 (6%)
Anastomosis ulcer
2 (6%)
2 (6%)
CD- Clavien-Dindo classification score Table 3 Discussion LSG is the most popular bariatric operation in the world[1]. Although the majority of patients undergoing
LSG achieve adequate weight loss without concomitant complications, a substantial amount of patients
undergo secondary operations [8, 22]. As LSG is extensively utilized, bariatric surgeons worldwide are
frequently encountered with patients requiring revision of their LSG, with several options for conversions
available. Nonetheless, specific guidelines for conversion of LSG for any indication are lacking. OAGB is a
prominent primary and revisional bariatric operation that is under scrutiny for inducing GERD and bile
reflux [17, 18]. Our study examines whether revising LSG to OAGB induces or worsens GERD by assessing
patients’ subjective GERD complaints by 2 validated clinical questionnaires. Population of our study was
composed of predominantly morbidly obese, adult women with a median time interval between LSG and
conversion of 7 years and a short to medium median follow up time of 21 months. Our results show a
significant improvement of reflux symptoms in both the RDQ (p = 0.007) and GERD-HRQL (p = 0.012, p =
0.04 and p = 0.025; Table 2) while adding and maintaining adequate weight-loss (mean %TWL 33%). As
expected for revisional bariatric operations, the peri-operative major complications (CD ≥ 3) rate was high
(n = 8, 25%) with 2 (6%) patients undergoing early reoperations for conversion to RYGB. We believe that
happened due to overly tight trimming of the enlarged sleeve which may have been avoided by
abstaining from resizing. The link between morbid obesity, LSG and GERD has multiple proposed mechanisms that include a
hypotensive lower esophageal sphincter, decreased gastric emptying, increase in intraluminal gastric
pressure, hiatal hernia (HH) presence and angle of His anatomy disruption [9, 23–27]. Several long term
(> 5 years) post-LSG studies weigh on the impact of de-novo GERD following LSG. Kowalewski et al. have
reported that 93% of post-LSG patients develop de-novo GERD in over 8 years of follow-up, without any
correlation between weight loss and reflux development [10]. Himpens et al. have documented that post-
LSG GERD is evident in 20% of patients and have postulated that post-LSG GERD occurs in the setting of
a neo-fundus formation, secondary to mid-stomach stenosis, which in turn causes stasis of food and Page 7/13 increased acid production. The authors showed increased GERD frequency at 6 years vs. 3 years post-
LSG, which suggests a delayed development of post-LSG GERD [28]. Discussion For decades, RYGB was considered the optimal operative management for GERD [29]. A recent large (n =
2454) Swedish nationwide cohort study by Holmberg et al. assessed the long-term impact of GERD by
chronic use of PPI and showed a 48% recurrence of GERD symptoms in 10 years following RYGB [30]. Nevertheless, the optimal operation for GERD resolution has yet to be determined and many patients rely
on life-long PPI use. Landreneau et al., Yorke et al. and Parmar et al. have all reported on conversions of
LSG to RYGB for the surgical treatment of post-LSG GERD for patients refractory to medical therapy, with
effective treatment and resolution of GERD in over 70% in all series [31–33]. Weight-regain and de-novo GERD following LSG are closely linked. As conversion to RYGB may resolve
GERD symptoms, its effectiveness as a revisional bariatric operation for weight-regain following LSG is
limited. On the other hand, revision to OAGB following a failed LSG induces a more efficient weight-loss
compared to RYGB [8]. If OAGB resolves or improves GERD symptoms, it may turn out to be the optimal
conversion option for post-LSG patients suffering from both weight regain and GERD. Though OAGB is
increasingly utilized worldwide as a primary bariatric operation with respectable outcomes, its safety for
both primary and as a revisional procedure is still debated. Several publications postulate that OAGB by
itself can induce GERD and unsurprisingly, OAGB has been under scrutiny for inducing GERD, bile reflux
and their sequelae. Furthermore, there is a concern that patients undergoing OAGB are at an increased
risk of developing erosive esophagitis, esophageal carcinoma and gastric stump cancer [34]. As the
potential biliary reflux induced by OAGB may stimulate esophageal metaplasia, converting LSG with de-
novo GERD may further contribute to increased risk of carcinogenesis. In a systemic review of the
literature, Georgiadou et al. have found that bile reflux and esophagitis are rare events following OAGB
that occur at rates of 0–2% [35]. Similarly, in a comparison between RYGB and OAGB, Lee WJ et al. reported no significant difference in clinical symptoms of bile reflux following either procedure [14]. Kassir et al. reported on 2780 OAGB patients with a 1.2% (n = 32) rate of biliary reflux occurrence requiring
revision to RYGB at 30 months follow up with 75% of them having a previous LSG prior to OAGB. Discussion Conversely, other publications document higher rates of bile reflux following OAGB. A randomized control
trial of 40 patients by Saarinen et al., utilizing EGD and bile reflux scintigraphy at 6 months following
primary OAGB showed 2.6% (1 patient) with esophageal bile reflux and 31.6% (12 patients) had bile reflux
in their gastric pouch. Keleidari et al., reviewed 5 cohort studies with a wide range of biliary reflux
incidence of 7.8–55%. As for factors increasing the frequency of GERD following OAGB, a multi-institutional survey of 2678
patients with 5 Years of follow-up by Musella et al. showed that GERD following primary OAGB is
significantly higher in patients with gastric pouch length of less than 9cm [36]. Additionally, in a long-term
follow-up of more than 6 years of 1200 primary OAGB procedures, Carbajo et al. have shown that 53% (n
= 636) of their cohort had pre-operative GERD which resolved in 92% and improved in 8% following OAGB
[37]. Conversely, in a long-term follow up of over 10 years of 385 patients undergoing a OAGB by Page 8/13 Caradina et al., biliary reflux was reported in 9.8% with the majority of them having a previous banding
operation and 5.7% suffered from intractable reflux which required further conversion to RYGB[38]. Though the majority of our cohort benefited from conversion of LSG to OAGB with significant
improvement of subjective symptoms, 3 patients (9%) suffered from intractable reflux symptoms and
required further revision to RYGB, 2 in the immediate post-op period and 1 in the year following
conversion to OAGB. Chevallier et al.[39] and Musela et al.[36] showed an OAGB to RYGB conversion rate
of 0.9% (9 of 1000 cases) and 2.5% (28 of 1091 cases), respectively, both at 5 years of follow up. Conversely, Winstanely et al.[40] reported a 14% conversion rate(n = 5/34) in patients suffering from
preoperative GERD at a median interval of 16 months. Whereas our results fall somewhat in the range of
these conversion rates, future reflux recurrence may be inevitable and longer follow up is needed to
estimate the true rate of further conversion to RYGB. It is still unclear and thus challenging to predict which patients will suffer exacerbation of reflux
symptoms following conversion to OAGB. Our study shows that OAGB can be safely performed for failed
LSG, with an acceptable subjective post-conversion GERD rate along with improvement of subjective
GERD symptoms in a short-term follow up. Author Contribution: DA- Statistical and data analysis AK- Study conception and design, interpretation of data and critical revision of manuscript. Discussion However, a careful review of the pre-operative EGD and UGI is
necessary, in order to tailor patient-directed treatment and decrease the chances of post-conversion GERD
and thus decrease the need for further revision to RYGB. Furthermore, we advocate the formation of a
long and narrow gastric pouch to prevent GERD symptoms following conversion to OAGB. The benefits and shortcomings of sleeve re-sizing in revisional bariatric surgery are uncertain. The desire
to reinstate further weight loss led us to resize the sleeve, and in two patients it caused complication of
immediate postoperative dysphagia, which required an anastomosis resection with subsequent
conversion to RYGB. Although we believe that a smaller and narrower pouch in OAGB has reflux-
protective properties and promotes further weight loss, this purported benefit must be balanced with
constructing a too narrow pouch and stricture. As malabsorption has a substantial contribution to weight-
loss in OAGB, trimming of the gastric sleeve may be unnecessary in any circumstances. Furthermore, as
the malabsorptive properties of OAGB may potentially lead to severe malnutrition, determining the
afferent limb length for individual patients is essential, as well as careful post-operative nutritional
assessment. Our study has several limitations, as the majority of subjects underwent their primary LSG at outside
hospitals with various pre-operative evaluation, surgical technique and post-operative care. Furthermore,
the diagnosis and improvement of GERD was made by clinical symptoms, pre-conversion EGD findings,
PPI use and the aforementioned questionnaires, without pH studies or post-conversion EGD. Findings of
biliary reflux were absent which may reflect our small population size and short-term follow up. There are
also multiple patients which had a previous bariatric operation (banding) prior to their LSG and patients
who underwent conversion due to different indications, which may confound our findings. Despite these
limitations, our study deals with daily situations of patients resorting to a secondary operation following Page 9/13 LSG. It is also a viable addition to the literature regarding GERD following OAGB and following conversion
of LSG to OAGB. Conclusion OAGB does not induce or worsens subjective GERD in patients with a previous LSG on a short term. OAGB does not induce or worsens subjective GERD in patients with a previous LSG on a short term. Author disclosure: All authors have no conflict of interest or financial ties to disclose, relevant for this paper. References 1. Welbourn R, Hollyman M, Kinsman R, et al (2019) Bariatric Surgery Worldwide: Baseline
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Follow-up. Obes Surg 27:2956–2967. https://doi.org/10.1007/s11695-017-2726-2 36. Musella M, Susa A, Manno E, et al (2017) Complications Following the Mini/One Anastomosis
Gastric Bypass (MGB/OAGB): a Multi-institutional Survey on 2678 Patients with a Mid-term (5 Years)
Follow-up. Obes Surg 27:2956–2967. https://doi.org/10.1007/s11695-017-2726-2 37. Carbajo MA, Luque-de-León E, Jiménez JM, et al (2017) Laparoscopic One-Anastomosis Gastric
Bypass: Technique, Results, and Long-Term Follow-Up in 1200 Patients. Obes Surg 27:1153–1167. https://doi.org/10.1007/s11695-016-2428-1 37. Carbajo MA, Luque-de-León E, Jiménez JM, et al (2017) Laparoscopic One-Anastomosis Gastric
Bypass: Technique, Results, and Long-Term Follow-Up in 1200 Patients. Obes Surg 27:1153–1167. https://doi.org/10.1007/s11695-016-2428-1 38. Carandina S (2021) Long-Term Results of One Anastomosis Gastric Bypass: a Single Center
Experience with a Minimum Follow-Up of 10 Years. 3468–3475 38. Carandina S (2021) Long-Term Results of One Anastomosis Gastric Bypass: a Single Center
Experience with a Minimum Follow-Up of 10 Years. 3468–3475 39. References Chevallier JM, Arman GA, Guenzi M, et al (2015) One Thousand Single Anastomosis (Omega Loop)
Gastric Bypasses to Treat Morbid Obesity in a 7-Year Period: Outcomes Show Few Complications
and Good Efficacy. Obes Surg 25:951–958. https://doi.org/10.1007/s11695-014-1552-z 39. Chevallier JM, Arman GA, Guenzi M, et al (2015) One Thousand Single Anastomosis (Omega Loop)
Gastric Bypasses to Treat Morbid Obesity in a 7-Year Period: Outcomes Show Few Complications
and Good Efficacy. Obes Surg 25:951–958. https://doi.org/10.1007/s11695-014-1552-z 40. Winstanley J, Ahmed S, Courtney M, et al (2021) One Anastomosis Gastric Bypass in Patients with
Gastrooesophageal Reflux Disease and/or Hiatus Hernia. Obes Surg 31:1449–1454. https://doi.org/10.1007/s11695-020-05149-0 40. Winstanley J, Ahmed S, Courtney M, et al (2021) One Anastomosis Gastric Bypass in Patients with
Gastrooesophageal Reflux Disease and/or Hiatus Hernia. Obes Surg 31:1449–1454. https://doi.org/10.1007/s11695-020-05149-0 Page 13/13
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Conjugation of the 9-kDa Isoform of Granulysin with Liposomes Potentiates Its Cytotoxicity
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Citation: Soler-Agesta, R.;
Guerrero-Ochoa, P.; Marco-Brualla, J.;
Ibáñez-Pérez, R.; Marzo, I.;
Martínez-Lostao, L.; Anel, A. Conjugation of the 9-kDa Isoform of
Granulysin with Liposomes
Potentiates Its Cytotoxicity. Int. J. Mol. Sci. 2022, 23, 8705. https://
doi.org/10.3390/ijms23158705
Academic Editor: Christian Celia
Received: 13 July 2022
Accepted: 3 August 2022
Published: 5 August 2022 Citation: Soler-Agesta, R.;
Guerrero-Ochoa, P.; Marco-Brualla, J.;
Ibáñez-Pérez, R.; Marzo, I.;
Martínez-Lostao, L.; Anel, A. Conjugation of the 9-kDa Isoform of
Granulysin with Liposomes
Potentiates Its Cytotoxicity. Int. J. Mol. Sci. 2022, 23, 8705. https://
doi.org/10.3390/ijms23158705 Keywords: granulysin; lipid nanoparticles; acute lymphoid leukemia; apoptosis; immunotherapy Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations. International Journal of
Molecular Sciences International Journal of
Molecular Sciences International Journal of
Molecular Sciences International Journal of
Molecular Sciences Article Ruth Soler-Agesta 1, Patricia Guerrero-Ochoa 1
, Joaquín Marco-Brualla 1
, Raquel Ibáñez-Pérez 1,
Isabel Marzo 1
, Luis Martínez-Lostao 2,3 and Alberto Anel 1,* Ruth Soler-Agesta 1, Patricia Guerrero-Ochoa 1
, Joaquín Marco-Brualla 1
, Raquel Ibáñez-Pérez 1
Isabel Marzo 1
, Luis Martínez-Lostao 2,3 and Alberto Anel 1,* 1
Apoptosis, Immunity & Cancer Group, Department of Biochemistry and Molecular and Cell Biology,
Faculty of Sciences, Aragón Health Research Institute (IIS Aragón), University of Zaragoza,
50009 Zaragoza, Spain Nanoscience Institute of Aragon (INA), 50018 Zaragoza, Spain
3
Immunology Department, Clinical University Hospital “Lozano Blesa”, 50009 Zaragoza, Spain
*
C
d
l@
i *
Correspondence: anel@unizar.es Abstract: Nine kDa granulysin (GRNLY) is a human cytolytic protein secreted by cytotoxic T lym-
phocytes (CTL) and NK cells of the immune system whose demonstrated physiological function is
the elimination of bacteria and parasites. In previous studies by our group, the anti-tumor capacity
of recombinant granulysin was demonstrated, both in vitro and in vivo. In the present work, we
developed lipid nanoparticles whose surfaces can bind recombinant granulysin through the forma-
tion of a complex of coordination between the histidine tail of the protein and Ni2+ provided by
a chelating lipid in the liposome composition and termed them LUV-GRNLY, for granulysin-bound
large unilamellar vesicles. The objective of this formulation is to increase the granulysin concen-
tration at the site of contact with the target cell and to increase the cytotoxicity of the administered
dose. The results obtained in this work indicate that recombinant granulysin binds to the surface
of the liposome with high efficiency and that its cytotoxicity is significantly increased when it is
in association with liposomes. In addition, it has been demonstrated that the main mechanism of
death induced by both granulysin and LUV-GRNLY is apoptosis. Jurkat-shBak cells are resistant
to GRNLY and also to LUV-GRNLY, showing that LUV-GRNLY uses the mitochondrial apoptotic
pathway to induce cell death. On the other hand, we show that LUV-GRNLY induces the expression
of the pro-apoptotic members of the Bcl-2 family Bim and especially PUMA, although it also induced
the expression of anti-apoptotic Bcl-xL. In conclusion, we demonstrate that binding of GRNLY to the
surfaces of liposomes clearly augments its cytotoxic potential, with cell death executed mainly by the
mitochondrial apoptotic pathway. 1. Introduction Granulysin (GRNLY) is a protein with two isoforms of 9 and 15 kDa molecular weight,
respectively. The 9 kDa isoform is a cytolytic protein present in the granules of activated
human cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, while the 15 kDa
isoform is rather an immune alarmin [1–3]. The antibacterial and antiparasitic functions
of 9 kDa GRNLY have long been known, and they have been confirmed and expanded in
recent studies [4–6]. We have shown previously that recombinant GRNLY is able to kill
tumor cells in vitro using the mitochondrial apoptotic pathway [7–9]. On the other hand,
there are abundant data that relate granulysin expression to an active antitumor immune
response and to patient good prognosis [10–13]. Although mice do not express a granulysin
homologue, transgenic mice that expressed human granulysin were generated, showing
increased resistance to tumor development [14]. Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article
distributed
under
the
terms
and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/). https://www.mdpi.com/journal/ijms Int. J. Mol. Sci. 2022, 23, 8705. https://doi.org/10.3390/ijms23158705 2 of 13 Int. J. Mol. Sci. 2022, 23, 8705 More recently, we demonstrated the efficacy of recombinant GRNLY in three xeno-
transplantation models of human tumors in athymic mice, the mammary adenocarcinoma
MDA-MB-231, the multiple myeloma NCI-H929 and the melanoma UACC62 [15,16]. The
intra-tumor administration of GRNLY in these models correlated with apoptosis induction
in the tumor tissue and with prominent NK cell infiltration into the tumor mass, indicat-
ing that granulysin-induced tumor cell death in vivo could be immunogenic [15,16]. In
an effort to target recombinant GRNLY specifically to tumors, we developed an immuno-
toxin by GRNLY gene fusion to the anti- carcinoembryonic antigen (CEA/CEACAM5)
single chain Fv antibody fragment MFE23. Systemic administration of the immunotoxin
demonstrated a decrease in tumor growth in a CEA+ tumor-bearing mouse model, whereas
GRNLY did not exhibit a therapeutic effect [17]. Other GRNLY-based immunotoxins di-
rected against the MUC1-Tn tumor antigen have been applied, demonstrating in vitro and
in vivo efficacy in pre-clinical models [18,19]. These immunotoxins could have a broader
application to different solid tumors and leukemia than the anti-CEA immunotoxin [20]. Considering the perspective of the therapeutic use of GRNLY in a broader spectrum
of cancers, it is important to develop strategies that allow its systemic administration. 1. Introduction This
will require vehicles that increase GRNLY ability to access the tumor while preserving or
increasing its bioactivity. In previous experiences using large unilamellar vesicles (LUVs),
a drug delivery vehicle that consists of a phospholipid bilayer containing an inner, aque-
ous pocket [21], our group demonstrated greater cytotoxicity against tumors using LUV
conjugated with TNF-related apoptosis-inducing ligand (TRAIL) compared with TRAIL in
soluble phase [22–24]. We also demonstrated both in vitro and in vivo that this anti-tumor
effect was increased if doxorubicin was encapsulated in the TRAIL-decorated LUVs [25]. In the present study, we generated LUV conjugated with GRNLY (LUV-GRNLY)
and tested its antitumor efficacy and mechanism of tumor cell death induction. Results
demonstrate that our hypothesis of a possible increase in GRNLY cytotoxicity by binding
to liposomes was correct, and offer new perspectives for this novel cytotoxic formulation
based on a human protein. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid
. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid In order to optimize the binding of GRNLY-His6 to DOGS-NTA-Ni in the liposom
everal concentrations of granulysin, between 4 and 30 μM, were incubated with lipo
omes, ultracentrifugated, and pellet and supernatant collected separately. The presenc
of the recombinant protein in each fraction was assessed by Western blot using an ant
body against the histidine-tag motif. As shown in Figure 1B, from 4 to 10 μM, all of th
ecombinant protein was found only in the pellet fraction, indicating that all of the protei
was bound to the liposome surfaces. Nevertheless, at 15 μM, a small portion of the protei
emained free in the supernatant, indicating that the surfaces of the liposomes began t
be saturated. Finally, at 30 μM, a significant protein band appeared in the supernatan
raction, showing the full saturation of the liposome surface. In the following experiment
he stock of LUV GRNLY was prepared with a 15 μM concentration of recombinan
In order to optimize the binding of GRNLY-His6 to DOGS-NTA-Ni in the liposome,
several concentrations of granulysin, between 4 and 30 µM, were incubated with liposomes,
ultracentrifugated, and pellet and supernatant collected separately. The presence of the
recombinant protein in each fraction was assessed by Western blot using an antibody against
the histidine-tag motif. As shown in Figure 1B, from 4 to 10 µM, all of the recombinant
protein was found only in the pellet fraction, indicating that all of the protein was bound
to the liposome surfaces. Nevertheless, at 15 µM, a small portion of the protein remained
free in the supernatant, indicating that the surfaces of the liposomes began to be saturated. Finally, at 30 µM, a significant protein band appeared in the supernatant fraction, showing
the full saturation of the liposome surface. In the following experiments, the stock of
LUV-GRNLY was prepared with a 15 µM concentration of recombinant GRNLY. he stock of LUV-GRNLY was prepared with a 15 μM concentration of recombinan
GRNLY. To confirm that the recombinant protein binds to the liposome surface through th
ipid DOGS-NTA-Ni, increasing granulysin concentrations were incubated with LUV.0,
variant liposome formulation without DOGS-NTA-Ni. As shown in Figure 1C, recomb
nant granulysin was found mainly in the supernatant fractions for all tested concentra
ions. 2. Results 2.1. Production and Purification of the Recombinant 9 kDa GRNLY in Pichia Pastoris As described in Materials and Methods, granulysin was subcloned into the pPICZαA
vector for its production in Pichia pastoris. The recombinant protein was secreted in
yeast culture supernatant and purified using a gravity-flow column containing an Ni+2-
NTA resin. During the purification process, the presence of granulysin was controlled
by recollecting samples in each step (concentrated, dialysis, resin washes, post-resin and
post-amicon fractions) and resolved in an SDS-PAGE 15% polyacrylamide gel stained with
Coomassie blue. The migration pattern of the dialysate fraction, as shown in Figure 1A,
revealed several bands that correspond to a mixture of proteins produced by Pichia pastoris. Discarded fractions such as the permeate, the dialysis buffer and the resin washes showed
that there was no loss of protein at the granulysin molecular weight. Finally, the migration
pattern of post-resin and post-amicon fractions showed a single concentrated band that was
consistent with the molecular weight of glycosylated recombinant granulysin produced in
Pichia pastoris [17,26]. 3 of 13
3 of 1 Int. J. Mol. Sci. 2022, 23, 8705
. J. Mol. Sci. 2022, 23, x FOR P Figure 1. (A) Analysis of the purification process using SDS-PAGE polyacrylamide 15% gel staine
with Coomassie blue. (B) Western-blot analysis of ultracentrifugated pellets (P) and supernatant (S
fractions from LUV-GRNLY using an anti-His antibody. (C) Western blot of ultracentrifugated pe
lets and supernatant fractions from LUV.0-GRNLY using an anti-His antibody. (D) Schematic rep
resentation of the interaction between GRNLY-His6 and liposome surface through DOGS-NTA-N
Figure 1. (A) Analysis of the purification process using SDS-PAGE polyacrylamide 15% gel stained
with Coomassie blue. (B) Western-blot analysis of ultracentrifugated pellets (P) and supernatant
(S) fractions from LUV-GRNLY using an anti-His antibody. (C) Western blot of ultracentrifugated
pellets and supernatant fractions from LUV.0-GRNLY using an anti-His antibody. (D) Schematic
representation of the interaction between GRNLY-His6 and liposome surface through DOGS-NTA-Ni. Figure 1. (A) Analysis of the purification process using SDS-PAGE polyacrylamide 15% gel staine
with Coomassie blue. (B) Western-blot analysis of ultracentrifugated pellets (P) and supernatant (
ractions from LUV-GRNLY using an anti-His antibody. (C) Western blot of ultracentrifugated pe
ets and supernatant fractions from LUV.0-GRNLY using an anti-His antibody. (D) Schematic rep
esentation of the interaction between GRNLY-His6 and liposome surface through DOGS-NTA-N
Figure 1. (A) Analysis of the purification process using SDS-PAGE polyacrylamide 15% gel stained
with Coomassie blue. 2. Results (B) Western-blot analysis of ultracentrifugated pellets (P) and supernatant
(S) fractions from LUV-GRNLY using an anti-His antibody. (C) Western blot of ultracentrifugated
pellets and supernatant fractions from LUV.0-GRNLY using an anti-His antibody. (D) Schematic
representation of the interaction between GRNLY-His6 and liposome surface through DOGS-NTA-Ni. .2. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid
2.2. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid
. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid A small portion of the protein was also found in the pellet, showing that granulysi
To confirm that the recombinant protein binds to the liposome surface through the lipid
DOGS-NTA-Ni, increasing granulysin concentrations were incubated with LUV.0, a variant
liposome formulation without DOGS-NTA-Ni. As shown in Figure 1C, recombinant
granulysin was found mainly in the supernatant fractions for all tested concentrations. A small portion of the protein was also found in the pellet, showing that granulysin
binds partially to the lipid membrane. A schematic representation of LUV-GRNLY once
synthesized is shown in Figure 1D. Int. J. Mol. Sci. 2022, 23, 8705
Int. J. Mol. Sci. 2022, 23, x FOR 4 of 13
4 of 13 2.3. In Vitro Cytotoxic Effect of LUV-GRNLY on the Jurkat Cell Line
We then determined the in vitro cytotoxicity of LUV-GRNLY
lymphocytic leukemia cell line and compared it with soluble GRN We then determined the in vitro cytotoxicity of LUV-GRNLY against the Jurkat acute
lymphocytic leukemia cell line and compared it with soluble GRNLY using flow cytometry. It has been described previously that soluble GRNLY is cytotoxic against Jurkat cells and
that it is cytotoxic against a large panel of cancer cells [7,8]. We confirmed this observation
in the dose–response assays shown in Figure 2A, showing an LC50 of around 10 µM,
compatible with previous data using GRNLY produced in Pichia pastoris [17]. Besides that,
as shown in Figure 2B, we demonstrated that LUV-GRNLY exhibited a higher cytotoxicity
than GRNLY in soluble phase, reducing the LC50 by at least two-fold. In addition, the
mortality rate of cells that were treated with liposomes alone was not significant compared
to the control. Therefore, we concluded that the cytotoxicity of LUV-GRNLY is attributed to
the formula by itself, discarding the possibility that liposomes could be toxic at this dose. lymphocytic leukemia cell line and compared it with soluble GRNLY using flow cytome
try. It has been described previously that soluble GRNLY is cytotoxic against Jurkat cells
and that it is cytotoxic against a large panel of cancer cells [7,8]. We confirmed this obser-
vation in the dose–response assays shown in Figure 2A, showing an LC50 of around 10
μM, compatible with previous data using GRNLY produced in Pichia pastoris [17]. Be-
sides that, as shown in Figure 2B, we demonstrated that LUV-GRNLY exhibited a higher
cytotoxicity than GRNLY in soluble phase, reducing the LC50 by at least two-fold. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid
. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid In ad-
dition, the mortality rate of cells that were treated with liposomes alone was not signifi-
cant compared to the control. Therefore, we concluded that the cytotoxicity of LUV-
GRNLY is attributed to the formula by itself, discarding the possibility that liposomes
could be toxic at this dose. Figure 2. In vitro cytotoxicity of GRNLY and LUV-GRNLY against Jurkat cell line. (A) Jurkat cells
were incubated with increasing concentrations of GRNLY for 24 h. Cell death was determined by
detection on phosphatidylserine exposure (PS) by staining with annexin-V-FITC using flow cytom-
etry. (B) Jurkat cells were incubated with increasing concentrations of GRNLY and LUV-GRNLY
(2.5, 5 and 7.5 μM) for 24 h, and cell death was determined by flow cytometry as previously de-
scribed. The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. (C)
Representative flow cytometry histograms corresponding to one of the experiments performed,
showing the Annexin-V-FITC staining data (FL1-H channel) on Jurkat cells treated with control
LUVs, with 7.5 μM GRNLY, or with 7.5 μM LUV-GRNLY, as indicated. 2 4 A
l
i
f h M h
i
f C ll D
h I d
d b GRNLY
d LUV GRNLY i
J
k
Figure 2. In vitro cytotoxicity of GRNLY and LUV-GRNLY against Jurkat cell line. (A) Jurkat cells
were incubated with increasing concentrations of GRNLY for 24 h. Cell death was determined by
detection on phosphatidylserine exposure (PS) by staining with annexin-V-FITC using flow cytometry. (B) Jurkat cells were incubated with increasing concentrations of GRNLY and LUV-GRNLY (2.5, 5
and 7.5 µM) for 24 h, and cell death was determined by flow cytometry as previously described. The
results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. (C) Representative
flow cytometry histograms corresponding to one of the experiments performed, showing the Annexin-
V-FITC staining data (FL1-H channel) on Jurkat cells treated with control LUVs, with 7.5 µM GRNLY,
or with 7.5 µM LUV-GRNLY, as indicated. Figure 2. In vitro cytotoxicity of GRNLY and LUV-GRNLY against Jurkat cell line. (A) Jurkat cells
were incubated with increasing concentrations of GRNLY for 24 h. Cell death was determined by
detection on phosphatidylserine exposure (PS) by staining with annexin-V-FITC using flow cytom-
etry. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid
. GRNLY Binds Efficiently to LUV Surface through the DOGS-NTA-Ni Lipid (B) Jurkat cells were incubated with increasing concentrations of GRNLY and LUV-GRNLY
(2.5, 5 and 7.5 μM) for 24 h, and cell death was determined by flow cytometry as previously de-
scribed. The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. (C)
Representative flow cytometry histograms corresponding to one of the experiments performed,
showing the Annexin-V-FITC staining data (FL1-H channel) on Jurkat cells treated with control
LUVs, with 7.5 μM GRNLY, or with 7.5 μM LUV-GRNLY, as indicated. Figure 2. In vitro cytotoxicity of GRNLY and LUV-GRNLY against Jurkat cell line. (A) Jurkat cells
were incubated with increasing concentrations of GRNLY for 24 h. Cell death was determined by
detection on phosphatidylserine exposure (PS) by staining with annexin-V-FITC using flow cytometry. (B) Jurkat cells were incubated with increasing concentrations of GRNLY and LUV-GRNLY (2.5, 5
and 7.5 µM) for 24 h, and cell death was determined by flow cytometry as previously described. The
results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. (C) Representative
flow cytometry histograms corresponding to one of the experiments performed, showing the Annexin-
V-FITC staining data (FL1-H channel) on Jurkat cells treated with control LUVs, with 7.5 µM GRNLY,
or with 7.5 µM LUV-GRNLY, as indicated. 2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat
Cells
2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat Cells However, over-expression o
he anti-apoptotic protein Bcl-xL in mutant cells provides protection against granulysin
ut not against LUV-GRNLY (Figure 3C), suggesting that the LUV-GRNLY-induced cel
eath signal is more powerful than that of GRNLY alone. Figure 3. Analysis of the mechanism of cell death induced by GRNLY and LUV-GRNLY. (A) Jurkat
cells were treated with 7.5 μM of GRNLY or LUV-GRNLY for 24 h, respectively. Then, cells were
simultaneously stained with annexin-V-FITC and 7-AAD and were analyzed using flow cytometry
The dot-plots (upper, left panel) represent the evolution of treated cell population compared to the
Figure 3. Analysis of the mechanism of cell death induced by GRNLY and LUV-GRNLY. (A) Jurkat
cells were treated with 7.5 µM of GRNLY or LUV-GRNLY for 24 h, respectively. Then, cells were
simultaneously stained with annexin-V-FITC and 7-AAD and were analyzed using flow cytometry. The dot-plots (upper, left panel) represent the evolution of treated cell population compared to the
control. The values shown correspond to a percentage of cells in each quadrant. The upper right
figure corresponds to a graphical representation of obtained data. Data shown are representative
of four different experiments. (B,C) Jurkat and mutant cells (Jurkat-Bcl-xL, Jurkat-plvTHM and
Jurkat-shBak) were treated with 7.5 µM of GRNLY or LUV-GRNLY, respectively, for 24 h. Cell death
was determined by exposure of PS by staining with annexin-V-APC and analyzing by flow cytometry. The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. igure 3. Analysis of the mechanism of cell death induced by GRNLY and LUV-GRNLY. (A) Jurka
ells were treated with 7.5 μM of GRNLY or LUV-GRNLY for 24 h, respectively. Then, cells wer
imultaneously stained with annexin-V-FITC and 7-AAD and were analyzed using flow cytometry
he dot-plots (upper, left panel) represent the evolution of treated cell population compared to th
Figure 3. Analysis of the mechanism of cell death induced by GRNLY and LUV-GRNLY. (A) Jurkat
cells were treated with 7.5 µM of GRNLY or LUV-GRNLY for 24 h, respectively. Then, cells were
simultaneously stained with annexin-V-FITC and 7-AAD and were analyzed using flow cytometry. The dot-plots (upper, left panel) represent the evolution of treated cell population compared to the
control. The values shown correspond to a percentage of cells in each quadrant. The upper right
figure corresponds to a graphical representation of obtained data. Data shown are representative
of four different experiments. 2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat
Cells
2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat Cells Cells
To further investigate the mechanism of cell death induced by GRNLY and LUV-
GRNLY, we carried out flow cytometry experiments in which cells were stained at the
same time with annexin-V and 7-AAD. The presence of a population of cells that were
positive for annexin-V staining and still negative for 7-AAD staining was indicative of an
apoptotic type of cell death, although at long times of in vitro exposure to toxic agents,
To further investigate the mechanism of cell death induced by GRNLY and LUV-
GRNLY, we carried out flow cytometry experiments in which cells were stained at the same
time with annexin-V and 7-AAD. The presence of a population of cells that were positive
for annexin-V staining and still negative for 7-AAD staining was indicative of an apoptotic
type of cell death, although at long times of in vitro exposure to toxic agents, cells were
found to be positive for both markers in a secondary necrosis process. The single positive
population could be detected after treatment with 7.5 µM GRNLY for 24 h, constituting Int. J. Mol. Sci. 2022, 23, 8705 5 of 13
nd thus
o the in 5 of 13
nd thus
o the in 7% of the total population; at this time, the double positive population represented 15%
(Figure 3A). This observation indicated the presence of an apoptotic type of cell death, in
agreement with previous observations made with this cell line [7]. Cells treated with 7.5 µM
LUV-GRNLY for 24 h showed the same staining characteristics: we observed again the
single positive population (16% of the total population) and the double positive population
(45%). Confirming data shown in Figure 2, the total percentage of cell death induced
by LUV-GRNLY was higher (61.4% vs. 22.3%). Thus, we showed that both GRNLY and
LUV-GRNLY induce a rather apoptotic type of cell death, although LUV-GRNLY was more
cytotoxic than GRNLY alone. Indeed, the silencing of the pro-apoptotic protein Bak in the mutant Jurkat-shBak cel
ne was able to fully inhibit cell death induced by both treatments compared with it
ositive control (Jurkat plvTHM), indicating that GRNLY and LUV-GRNLY-induced cel
eath depends on the presence of the pro-apoptotic proteins Bak and Bax and proceed
hrough the mitochondrial apoptosis pathway (Figure 3B). 2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat
Cells
2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat Cells (B,C) Jurkat and mutant cells (Jurkat-Bcl-xL, Jurkat-plvTHM and
Jurkat-shBak) were treated with 7.5 µM of GRNLY or LUV-GRNLY, respectively, for 24 h. Cell death
was determined by exposure of PS by staining with annexin-V-APC and analyzing by flow cytometry. The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. he dot-plots (upper, left panel) represent the evolution of treated cell population compared to th
The dot-plots (upper, left panel) represent the evolution of treated cell population compared to the
control. The values shown correspond to a percentage of cells in each quadrant. The upper right
figure corresponds to a graphical representation of obtained data. Data shown are representative
of four different experiments. (B,C) Jurkat and mutant cells (Jurkat-Bcl-xL, Jurkat-plvTHM and
Jurkat-shBak) were treated with 7.5 µM of GRNLY or LUV-GRNLY, respectively, for 24 h. Cell death
was determined by exposure of PS by staining with annexin-V-APC and analyzing by flow cytometry. The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. Previous work has shown that recombinant 9 kDa GRNLY was able to induce apoptosis
mainly through the mitochondrial apoptotic pathway [7]. In order to assess if LUV-GRNLY
followed the same type of mechanism, we carried-out cytotoxicity experiments with modi-
fied Jurkat cell lines: Jurkat-Bcl-xL, which over-expressed the anti-apoptotic protein Bcl-xL,
and Jurkat-shBak, which did not express the pro-apoptotic protein Bak. Jurkat cells are
naturally deficient in the expression of the pro-apoptotic protein Bax and thus, Jurkat-
shBak is a double Bax and Bak mutant and, in consequence, is resistant to the intrinsic
apoptosis pathway [22]. Indeed, the silencing of the pro-apoptotic protein Bak in the mutant Jurkat-shBak
cell line was able to fully inhibit cell death induced by both treatments compared with its
positive control (Jurkat plvTHM), indicating that GRNLY and LUV-GRNLY-induced cell Int. J. Mol. Sci. 2022, 23, 8705 6 of 13
per righ
ntative o death depends on the presence of the pro-apoptotic proteins Bak and Bax and proceeds
through the mitochondrial apoptosis pathway (Figure 3B). However, over-expression of
the anti-apoptotic protein Bcl-xL in mutant cells provides protection against granulysin,
but not against LUV-GRNLY (Figure 3C), suggesting that the LUV-GRNLY-induced cell
death signal is more powerful than that of GRNLY alone. 2.5. GRNLY and LUV-GRNLY Treatments Increase PUMA, Bim and Bcl-xL Expression
the induction of expression of BH3-only pro-apoptotic proteins of the Bcl-2 supe
such as Bim and PUMA [27] Since the mitochondrial apoptotic pathway is impl 2.5. GRNLY and LUV-GRNLY Treatments Increase PUMA, Bim and Bcl-xL Expression
the induction of expression of BH3-only pro-apoptotic proteins of the Bcl-2 supe
such as Bim and PUMA [27] Since the mitochondrial apoptotic pathway is impli The mitochondrial apoptotic pathway or intrinsic cell death pathway is initiated by
the induction of expression of BH3-only pro-apoptotic proteins of the Bcl-2 superfamily,
such as Bim and PUMA [27]. Since the mitochondrial apoptotic pathway is implicated in
GRNLY- or LUV-GRNLY-induced cell death, we next studied if GRNLY or LUV-GRNLY
was able to induce Bim or PUMA expression in Jurkat cells. such as Bim and PUMA [27]. Since the mitochondrial apoptotic pathway is implicated in
GRNLY- or LUV-GRNLY-induced cell death, we next studied if GRNLY or LUV-GRNLY
was able to induce Bim or PUMA expression in Jurkat cells. As shown in Figure 4, we observed that GRNLY clearly induced PUMA expression,
while the induction of Bim was rather limited. However, LUV-GRNLY clearly induced
the expression of both Bim and PUMA further demonstrating that it is a more potent p
As shown in Figure 4, we observed that GRNLY clearly induced PUMA expression,
while the induction of Bim was rather limited. However, LUV-GRNLY clearly induced the
expression of both Bim and PUMA, further demonstrating that it is a more potent cellular
stressor and cell death inductor than GRNLY alone. We also confirmed the absence of
expression of Bax in these cells, which is not induced by either GRNLY or LUV-GRNLY. Re-
markably, both GRNLY and LUV-GRNLY also induced the expression of the anti-apoptotic
member of the Bcl-2 family Bcl-xL, probably as a mechanism of cell defense. Finally, the
low levels of Bcl-2 were not affected by the treatments. the expression of both Bim and PUMA, further demonstrating that it is a more potent
cellular stressor and cell death inductor than GRNLY alone. We also confirmed the ab-
sence of expression of Bax in these cells, which is not induced by either GRNLY or LUV-
GRNLY. Remarkably, both GRNLY and LUV-GRNLY also induced the expression of the
anti-apoptotic member of the Bcl-2 family Bcl-xL, probably as a mechanism of cell defense. Finally, the low levels of Bcl-2 were not affected by the treatments. Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. 2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat
Cells
2.4. Analysis of the Mechanism of Cell Death Induced by GRNLY and LUV-GRNLY in Jurkat Cells s
a )
e e
ea e
i
5 μ
o G N Y o
U
G N Y, espe i e y, o
Ce
ea
as
determined by exposure of PS by staining with annexin-V-APC and analyzing by flow cytometry
The results are expressed as the mean ± SD of 3 independent experiments. *** p < 0.001. 2.5. GRNLY and LUV-GRNLY Treatments Increase PUMA, Bim and Bcl-xL Expression
The mitochondrial apoptotic pathway or intrinsic cell death pathway is initiated by 2.5. GRNLY and LUV-GRNLY Treatments Increase PUMA, Bim and Bcl-xL Expression
the induction of expression of BH3-only pro-apoptotic proteins of the Bcl-2 supe
such as Bim and PUMA [27] Since the mitochondrial apoptotic pathway is impl The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 μM of
GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell ly-
sates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. 2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors
Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 µM
of GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell
lysates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. 2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 μM of
GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell ly-
sates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 µM
of GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell
lysates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. Figure 4 Expression levels of proteins from the Bcl 2 family upon treatment with GRNLY or LUV
Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. 2.5. GRNLY and LUV-GRNLY Treatments Increase PUMA, Bim and Bcl-xL Expression
the induction of expression of BH3-only pro-apoptotic proteins of the Bcl-2 supe
such as Bim and PUMA [27] Since the mitochondrial apoptotic pathway is impl The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 μM of
GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell ly-
sates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. Figure 4. Expression levels of proteins from the Bcl-2 family upon treatment with GRNLY or LUV-
GRNLY. The expression of Bim, PUMA, Bax, Bcl-xL or Bcl-2 in Jurkat cells treated with 7.5 µM
of GRNLY or LUV-GRNLY for 24 h was analyzed by Western blot using specific antibodies. Cell
lysates (5 × 106 cells) were separated by SDS-PAGE 12% polyacrylamide gel, transferred to PVDF
membranes and analyzed by Western blot using specific antibodies. Levels of β-actin were used as
a control of protein loading. 3. Discussion
3. Discussion Our previous studies using recombinant TRAIL anchored to the surface of liposomes
(LUV-TRAIL) demonstrated that this new formulation was much more potent than solu-
ble TRAIL both in different tumor types both in vitro and in vivo [22–24]. Although the
liposomes for disease treatment have been extensively used in different diseases, lipo-
somes have also been used as a vehicle to encapsulate drugs [28–30], or more recently,
mRNA in vaccine development [31]. However, attachment of bioactive compounds on the
liposome surface has been a less explored therapeutic strategy. In this line, the attachment
of TRAIL to the surface of liposomes, an improvement proposed by our group, resulted
in increased anti-tumor bioactivity, and in fact tried to mimic the natural way of secretion
of TRAIL and FasL bound to exosomes, described initially in human T cell blasts [32–34]. Liposome-based treatments show several advantages: biocompatibility, increased efficacy
and stability of encapsulated agents as well as reduction of their toxicity, and provide
selective passive targeting to tumor tissues. In fact, liposome-based formulations would
take advantage of the well-known enhancing permeability and retention (EPR) effect. Ac-
cording to the EPR effect, nanoparticles in the 100 nm diameter range spontaneously lo-
calize in tumor sites by extravasation in the leaky blood capillary system irrigating the
Our previous studies using recombinant TRAIL anchored to the surface of liposomes
(LUV-TRAIL) demonstrated that this new formulation was much more potent than soluble
TRAIL both in different tumor types both in vitro and in vivo [22–24]. Although the lipo-
somes for disease treatment have been extensively used in different diseases, liposomes
have also been used as a vehicle to encapsulate drugs [28–30], or more recently, mRNA in
vaccine development [31]. However, attachment of bioactive compounds on the liposome
surface has been a less explored therapeutic strategy. In this line, the attachment of TRAIL
to the surface of liposomes, an improvement proposed by our group, resulted in increased
anti-tumor bioactivity, and in fact tried to mimic the natural way of secretion of TRAIL and
FasL bound to exosomes, described initially in human T cell blasts [32–34]. Liposome-based
treatments show several advantages: biocompatibility, increased efficacy and stability of
encapsulated agents as well as reduction of their toxicity, and provide selective passive
targeting to tumor tissues. In fact, liposome-based formulations would take advantage of
the well-known enhancing permeability and retention (EPR) effect. 2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors
2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors * p <
0.5; ** p < 0.01; *** p < 0.001. Figure 5. Toxicity of GRNLY or LUV-GRNLY towards fresh PBMC or 7-day T cell blasts obtained
from healthy donors. (A) Freshly isolated PBMCs from healthy donors were treated for 24 h with
increasing concentrations of LUV-GRNLY, as indicated. (B) Seven-day T cell blasts from the same
healthy donors were treated for 24 h with increasing concentrations of GRNLY or LUV-GRNLY, as
indicated. Then, cells were stained with annexin-V-FITC and analyzed using flow cytometry. * p < 0.5;
** p < 0.01; *** p < 0.001. 2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors
2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors 2.6. Toxicity against PBMC and T Cell Blasts from Healthy Donors
We have previously shown that recombinant GRNLY, while being toxic against tu-
mor cells, was not active against fresh PBMC obtained from healthy donors [7]. We per-
formed a similar experiment using LUV-GRNLY and found that it was toxic against
freshly isolated PBMC (Figure 5A). In addition, we also demonstrated that, while GRNLY
We have previously shown that recombinant GRNLY, while being toxic against tumor
cells, was not active against fresh PBMC obtained from healthy donors [7]. We performed
a similar experiment using LUV-GRNLY and found that it was toxic against freshly isolated
PBMC (Figure 5A). In addition, we also demonstrated that, while GRNLY was not toxic
against day-7 T cell blasts, at least until a concentration of 7.5 µM, LUV-GRNLY proved to
be highly toxic (Figure 5B). 7 of 13
LUV- Int. J. Mol. Sci. 2022, 23, 8705 Figure 5. Toxicity of GRNLY or LUV-GRNLY towards fresh PBMC or 7-day T cell blasts obtained
from healthy donors. (A) Freshly isolated PBMCs from healthy donors were treated for 24 h with
increasing concentrations of LUV-GRNLY, as indicated. (B) Seven-day T cell blasts from the same
healthy donors were treated for 24 h with increasing concentrations of GRNLY or LUV-GRNLY, as
indicated. Then, cells were stained with annexin-V-FITC and analyzed using flow cytometry. * p <
0.5; ** p < 0.01; *** p < 0.001. Figure 5. Toxicity of GRNLY or LUV-GRNLY towards fresh PBMC or 7-day T cell blasts obtained
from healthy donors. (A) Freshly isolated PBMCs from healthy donors were treated for 24 h with
increasing concentrations of LUV-GRNLY, as indicated. (B) Seven-day T cell blasts from the same
healthy donors were treated for 24 h with increasing concentrations of GRNLY or LUV-GRNLY, as
indicated. Then, cells were stained with annexin-V-FITC and analyzed using flow cytometry. * p < 0.5;
** p < 0.01; *** p < 0.001. Figure 5. Toxicity of GRNLY or LUV-GRNLY towards fresh PBMC or 7-day T cell blasts obtained
from healthy donors. (A) Freshly isolated PBMCs from healthy donors were treated for 24 h with
increasing concentrations of LUV-GRNLY, as indicated. (B) Seven-day T cell blasts from the same
healthy donors were treated for 24 h with increasing concentrations of GRNLY or LUV-GRNLY, as
indicated. Then, cells were stained with annexin-V-FITC and analyzed using flow cytometry. 3. Discussion
3. Discussion A possible explanation for the increased cyto-
toxicity of LUV-GRNLY, as mentioned above, is that association of GRNLY to liposome
surface increases the local concentration of recombinant protein that can interact with cell
membrane surface, in turn increasing its bioactivity. We have also investigated the cell death mechanisms induced by LUV-GRNLY, finding
that it was similar to that previously described for recombinant GRNLY, mainly depending
on the mitochondrial apoptotic pathway. Remarkably, we found that although LUV-
GRNLY-induced cell death was abrogated in the absence of Bax and Bak expression in
Jurkat-shBak cells, LUV-GRNLY was still effective against Jurkat cells over-expressing
Bcl-xL, while GRNLY was not. This is an interesting observation regarding the possible
clinical application of our formulation, since in many instances, tumor cells resistant to
conventional chemotherapy over-express anti-apoptotic members of the Bcl-2 family [37]. This, in fact, has led to the recent introduction, into the antitumor arsenal, of BH3 mimetics
that counteract these types of resistance, such as venetoclax, which has been approved for
the treatment of a variety of hematological malignancies [38,39]. In a previous study, we showed that although recombinant GRNLY was toxic against
hematological tumor cells, it was not active against fresh PBMCs obtained from healthy
donors [7]. This indicated that GRNLY had some tumor selectivity, probably dependent on
the different membrane lipid compositions of normal and tumor cells [20,40], something
that has been confirmed by its absence of in vivo toxicity [15]. However, LUV-GRNLY
proved to be toxic against freshly isolated PBMCs and also against T cell blasts, indicating
that increases in its bioactivity could also lead to undesired secondary effects. Although
one of the advantages of liposomal formulations is the reduction in toxic effects of the
bioactive molecules, mainly for encapsulated drugs, a crucial step in the generation of
functionalized liposomes is the final concentration of the bioactive compounds either
encapsulated or attached to their surface, to avoid their adverse effects. One possibility
that could explain the toxicity of LUV-GRNLY against healthy cells would be that the
liposome surface is saturated with GRNLY molecules. In this line, previous studies by
our group have demonstrated that reducing the concentration of bioactive compounds in
liposomal formulations reduced their toxic adverse effects while retaining their cytotoxic
effects against tumor cells [25]. 3. Discussion
3. Discussion According to the EPR
effect, nanoparticles in the 100 nm diameter range spontaneously localize in tumor sites by
extravasation in the leaky blood capillary system irrigating the tumor [35,36]. calize in tumor sites by extravasation in the leaky blood capillary system irrigating the
tumor [35,36]. Based on our previous work, our working hypothesis was that the association of
GRNLY with liposomes could increase protein concentration at the site of contact with the
ta get cell a d the efo e it could pote tiate the cytoto icity of the ad
i iste ed dose
Based on our previous work, our working hypothesis was that the association of
GRNLY with liposomes could increase protein concentration at the site of contact with the
target cell, and, therefore, it could potentiate the cytotoxicity of the administered dose. This
approach could lead to a reduction in the dose needed to attain anti-tumor effects. target cell, and, therefore, it could potentiate the cytotoxicity of the administered dose. This approach could lead to a reduction in the dose needed to attain anti-tumor effects. Analysis of interaction of recombinant GRNLY containing a histidine tag with LUV
demonstrated that the attachment of GRNLY using a novel Ni2+-NTA–containing lipid in
Analysis of interaction of recombinant GRNLY containing a histidine tag with LUV
demonstrated that the attachment of GRNLY using a novel Ni2+-NTA–containing lipid
in the liposome composition was extremely efficient, with recoveries close to 100% at
10–15 µM GRNLY concentrations. The chemical basis for conjugation of GRNLY to lipo-
some surface is the formation of a stable coordination complex between the histidine tag of
the recombinant GRNLY and the Ni2+ cation of DOG-NTA-Ni. When higher concentrations Int. J. Mol. Sci. 2022, 23, 8705 8 of 13 8 of 13 of recombinant GRNLY (more than 15 µM) were used, the liposome surface was saturated,
not admitting higher loading of more GRNLY molecules. In any case, assuming that the
binding efficiency of GRNLY to liposomes surface is 100%, we estimated that each liposome
should harbor around 1438 GRNLY molecules on its surface when using 15 µM GRNLY. We have shown that our hypothesis was correct, since the cytotoxicity of LUV-GRNLY
is higher than that of the same dose of GRNLY in the soluble phase, reducing the LC50
against Jurkat cells between 2- and 3-fold. 3. Discussion
3. Discussion Therefore, further studies generating LUV-GRNLY with
lower amounts of GRNLY on their surface could show that this non-saturated LUV-GRNLY
is able to retain its anti-tumoral effects while reducing its toxic effects against healthy cells. 4.2. Expression and Purification of 9 kDa Granulysin Synthetic genes encoding 6× His-tagged 9 kDa granulysin, kindly provided by
Dr. Alan M. Krensky, were synthesized by Geneart GmbH (Thermo Fisher Scientific Re-
gensburg, Regensburg, Germany) and subcloned between Cla I and XbaI sites into pCR3.1,
resulting in pCR3.1-GRNLY, as indicated in [17]. Then, 293 T cells were transiently trans-
fected with the vector using calcium phosphate, and supernatants were analyzed for protein
expression. The Cla I/XbaI -digested fragments of pCR3.1-GRNLY were then ligated into
the Cla I/XbaI digested backbone of plasmid pPICZα A to obtain pPICZα A-GRNLY. The plasmid was then amplified in E.coli and isolated by NucleoSpin® Plasmid EasyPure
(Macherey-Nagel, Düren, Germany). Plasmids were linearized with SacI (Takara) and
purified by Ilustra™GFX™PCR DNA and Gel Band Purification kit (GE Healthcare). p
y
(
)
Competent cultures of Pichia pastoris were then transfected with the pPICZαA vector
containing recombinant 9 kDa granulysin and expanded in aseptic YPD agar (Formedium,
Hunstanton, UK) plate supplemented with zeocin (100 µg/mL) (Invitrogen, Carlsbad, CA,
USA) for 3 days, as indicated in [17]. One of the colonies was transferred in a BMGY
medium (10 g/L yeast extract; 20 g/L de peptone; 100 mM potassium phosphate pH = 6.0;
13.4 g/L yeast base; 1 ml/L glycerol and 0.4 mg/L biotin, all purchased from Formedium,
Hunstanton, UK) and was incubated at 30 ◦C and 250 rpm for 24 h. Next, culture medium
was exchanged with BMMY medium (10 g/L yeast extract; 20 g/L peptone; 100 mM
phosphate buffer pH = 6.0; 13.4 g/L yeast base; 0.5 mL/L methanol y 0.4 mg/L de biotin,
all purchased from Formedium, Hunstanton, UK) by centrifugation at 4400 rpm for 25 min. Then, yeast culture was incubated at 18 ◦C with agitation for 48 h. Every 24 h, methanol
was added in a weight ratio of 1:100 in order to induce granulysin expression. For protein
purification, the supernatant was filtered through 0.45 and 0.22 µm filters (Merck Milli-
pore, Tullagreen, Ireland) and concentrated with a Pellicon XL Ultracel 50 cm2 cassette
(Merck Millipore, Jaffrey, NH, USA) connected to a vacuum pump. The concentrated
supernatant was dialyzed overnight in a dialysis buffer (300 mM NaCl; 50 mM Tris-HCl
y 20 mM imidazole, pH = 7.8) at 4 ◦C. Next, the dialyzed fraction was incubated with
Ni-NTA resin (Qiagen, Redwood City, CA, USA) at 4 ◦C for 2 h, gently shaking. 4. Materials and Methods
4.1. Cell Culture The acute T cell leukemia Jurkat cell line was purchased from ATCC. Cells over-
expressing the anti-apoptotic protein Bcl-xL (Jurkat-Bcl-xL) and cells lacking the expression
of the pro-apoptotic protein Bak (Jurkat-shBak) were generated in our laboratory using
a lentiviral system, as previously described [22]. These cell lines are completely resistant to
doxorubicin, a drug that kills cells through the mitochondrial apoptotic pathway [22]. Cell
lines were routinely cultured in RPMI 1640 medium with GlutaMAX (Life Technologies,
Paisley, UK) supplemented with 10% fetal calf serum (FCS), penicillin (1000 U/mL) and
streptomycin (10 mg/mL) (PanBiotech, Aidenbach, Germany) at 37 ◦C and 5% CO2 using
standard procedures. Human PBMCs from healthy donors were obtained by Ficoll density
centrifugation from Leukopacks provided by the “Banco de Sangre y Tejidos de Aragón”. T-cell blasts were generated from PBMCs from the same donors by stimulation with PHA
at 10 µg/mL overnight, with posterior washing and culture for at least 7 days in the Int. J. Mol. Sci. 2022, 23, 8705 9 of 13 9 of 13 presence of 30 IU/mL of IL-2, with medium changes each 48 h, as described in [41]. The
use of human samples was approved by the “Comité Etico de la Investigación de Aragón”
(CEICA) and written informed consent was obtained from each donor. 4.4. Optimization Procedure for LUV-GRNLY Synthesis; Binding and Affinity Assays In order to examine the affinity of the histidine-tagged granulysin to DOGS-NTA-Ni
and the protein load that each liposome can harbor on its surface, different concentrations
of granulysin (4, 6, 8, 10, 15 y 30 µM) were incubated with liposomes in KHE buffer for
30 min at 37 ◦C and 800 rpm. Every mixture was ultracentrifugated for 5 h at 14,000 rpm
in an L8-60M Ultracentrifuge (Beckman and Coulter). The supernatant was separated
from the pellet and dissolved in the same volume of KHE buffer. Finally, the presence
of protein in both fractions was analyzed by Western-blot technique using an anti-His
antibody (GenScript, Piscataway, NJ, USA) and Coomassie blue staining in 15% SDS-PAGE
gel electrophoresis. Equally, in order to demonstrate that granulysin binds to liposome
through DOGS-NTA-NI, liposomes without DOGS-NTA-Ni (LUV.0) were synthetized and
incubated with increased concentrations of granulysin. The protein union to the surface
was assessed by reproducing the same procedure. 4.2. Expression and Purification of 9 kDa Granulysin The resin
was washed 3 times and then transferred in a gravity-flow column in which the protein was
eluted with an elution buffer composed of 400 mM imidazole, 300 mM NaCl and 50 mM
de Tris- HCl, pH 7.4. The imidazole was exchanged with KHE buffer using Amicon® filters
(Merck Millipore, Tullagreen, Ireland). Protein concentration was measured using a BCA
assay (Thermo Fisher, Rockford, IL, USA), and its purity was checked by SDS-PAGE in
15% polyacrylamide gel, Coomassie blue staining and immunoblot incubated with specific
anti-His antibody (Genescript, Piscataway, NJ, USA). Finally, the protein was sterilized
through a 0.22 µm filter and was stored at 4 ◦C. The stability of the protein was maintained
at 4 ◦C for at least 1 month. 4.3. Large Unilamellar Vesicle (LUV) Synthesis and Preparation of Lipid Nanoparticles Coated
with 9 kDa Recombinant Granulysin (LUV-GRNLY) The generation of large unilamellar vesicles (LUVs) was achieved by preparing a mix-
ture of phosphatidylcholine, sphingomyelin, cholesterol, 1,2-dioleoyl-sn-glycero-3[N-(5-
amino-1-carboxypentyl)-iminodiacetic acid]succinyl (DOGS-NTA-Ni) and polyethylene
glycol (PEG) in a weight ratio of 55:30:10:5:5, previously dissolved in chloroform/methanol
(2:1), as originally described in [42]. All lipids were purchased from Avanti Polar Lipids,
Alabama, AL, USA. The chloroform and methanol were removed under nitrogen gas for
10 min and then under vacuum conditions at 45 ◦C for 6 h. After that, lipids were dissolved
in a KHE buffer, and the aliquots were frozen overnight (−20 ◦C). The next day, aliquots
were thawed and extruded at least 10 times through a polycarbonate filter with 200 nm Int. J. Mol. Sci. 2022, 23, 8705 10 of 13 pore diameter (Whatman, Maidstone, UK) using an extruder (Northern Lipids, Burnaby,
BC, Canada), to generate classical large unilamellar vesicles (LUVs), which mimic the com-
position of natural exosomes. Finally, LUVs were incubated with 9 KDa granulysin in KHE
buffer for 30 min at 37 ◦C with gentle shaking (800 rpm). During this step, the polyhistidine
tail of granulysin established a complex of coordination with Ni2+ provided by a chelating
lipid (DOGS-NTA-Ni) in the liposome composition that remained attached permanently. LUV-GRNLY could be stored at 4 ◦C for 1 month without losing its bioactivity. 4.5. Estimation of the Number of GRNLY Molecules per Liposome Assuming that 100% of the generated liposomes are unilamellar and that their di-
ameters are approximately 150 nm, the lipid number that composes one liposome can be
calculated with the following equation: N◦lipo TOT =
4π
d
2
2
+ 4π
h
d
2 −h
i2
a a where: d is the diameter of the liposome (150 nm) d is the diameter of the liposome (150 nm) h is the thickness of the liposome (5 nm) a is the area of the hydrophilic heads of phospholipids (0.55 nm2) From the equation, we calculated that one liposome is composed of approximately
240,000 lipid molecules, of which 5% correspond to DOGS-NTA-Ni. Therefore, the number
of DOGS-NTA-Ni molecules that would be theoretically available for binding to the protein
was 12,000. For a final concentration of lipids/mL of 2.5 mM, we calculated that the total number
of liposomes/mL would be 6.26 × 1012. Finally, if we prepared an aliquot of 15 µM of
LUV-GRNLY, the number of GRNLY molecules in 1 mL would be 9 × 1015. Assuming that
the bonding efficiency of GRNLY to liposome surfaces is 100%, we estimated that each
liposome should harbor around 1438 GRNLY molecules on its surface. 4.7. Western-Blot Analysis 4.7. Western-Blot Analysis A total of 5 × 106 cells were lysed with 100 µL of a lysis buffer 1× (1% Triton-X-100;
150 mM NaCl; 50 mM Tris/HCl pH 7.6; 10% v/v glycerol; 1mM EDTA; 1mM sodium
orthovanadate; 10 mM sodium pyrophosphate; 10 µg/mL leupeptin; 10 mM sodium
fluoride; 1 mM methyl phenyl sulfide, Sigma, St. Louis, MO, USA) for 30 min in ice. The
mixture was centrifuged at 12,000 rpm for 20 min at 4 ◦C. The protein concentration in
supernatant was analyzed using a BCA assay (Thermo Fisher, Rockford, IL, USA) and was
mixed with lysis buffer 3× (SDS; 150 mM Tris/HCl; 0.3 mM sodium molybdate; 30% v/v
glycerol; 30 mM sodium pyrophosphate; 30 mM sodium fluoride; 0.006% w/v bromophenol
blue; 30% v/v 2-mercaptoethanol, all purchased from Sigma, St. Louis, MO, USA). Protein
separation was performed using SDS-PAGE 12% polyacrylamide gel, and then proteins
were transferred to nitrocellulose membranes using a semi dry electro transfer (Biorad,
Alcobendas, Spain). Membranes were blocked with TBS-T buffer (Tris/HCl 10 mM, pH 8;
NaCl 0.12 M; Tween-20 0.1%, thimerosal 0.1 g/L, Sigma, St. Louis, MO, USA) containing
5% skimmed milk. Protein detection was performed by the Western-blot technique, using
specific antibodies against PUMA (Novus International, St. Louis, MO, USA), Bax, Bim, Bcl-
xL (Cell Signaling, Danvers, MA, USA), Bcl-2 (Santa Cruz, Dallas, USA) and β-actin (Cell
Signaling, Danvers, MA, USA) that were incubated overnight at 4 ◦C with agitation. Anti-
rabbit and anti-mouse secondary antibodies labeled with peroxidase (Sigma, St. Louis, MO,
USA) were incubated for 1 h at room temperature, gently shaking. Proteins were revealed
with the reagent Pierce ELC Western Blotting Substrate (Thermo Scientific, Rockford, IL,
USA) using Amersham Imager 680 (GE Healthcare Life Sciences). 4.6. In Vitro Cytotoxicity Assays—Apoptosis Quantification by Flow Cytometry Cytotoxicity assays were carried-out as follows: 50 µL aliquots of 3 × 104 cells were
seeded per well in 96-well plates and 50 µL aliquots of increasing concentrations of GRNLY
or LUV-GRNLY were added and incubated for 24 h at 37 ◦C. For controls wells the same
volume of KHE buffer was added. Cell death was analyzed using a FACScalibur flow
cytometer (BD, Biosciences, Franklin Lakes, NJ, USA) after incubation with annexin-V-
FITC or APC (BD Biosciences) in annexin binding buffer (140 mM NaCl, 2.5 mM CaCl2,
10 mM HEPES/NaOH, pH 7.4) for 20 min. The 7-AAD staining (BD Biosciences) was also
performed in some experiments. The data obtained was analyzed using FlowJo 0.7 (Tree
star Inc., San Francisco, CA, USA). Int. J. Mol. Sci. 2022, 23, 8705 11 of 13 11 of 13 1.
Clayberger, C.; Finn, M.W.; Wang, T.; Saini, R.; Wilson, C.; Barr, V.A.; Sabatino, M.; Castiello, L.; Stroncek, D.; Krensky, A.M.
15 kDa Granulysin Causes Differentiation of Monocytes to Dendritic Cells but Lacks Cytotoxic Activity. J. Immunol. 2012, 188,
6119–6126. [CrossRef] [PubMed] 4.8. Statistical Analysis Computer-based statistical analysis was performed using the GraphPad Prism pro-
gram (GraphPad Software Inc., San Diego, CA, USA). For quantitative variables, results are
shown as median ± standard deviation (SD). Statistical significance was evaluated using
Student t test, and differences were considered significant when p < 0.05. Author Contributions: Conceptualization, A.A. and L.M.-L.; methodology, J.M.-B. and I.M.; investi-
gation, R.S.-A., P.G.-O., J.M.-B. and R.I.-P.; resources, J.M.-B. and I.M.; data curation, R.S.-A. and A.A.;
writing—original draft preparation, R.S.-A. and A.A.; writing—review and editing, L.M.-L., J.M.-B. and IM; visualization, R.S.-A.; supervision, A.A. and L.M.-L.; project administration, A.A.; funding
acquisition, A.A. All authors have read and agreed to the published version of the manuscript. Funding: This research was financed in part by the project PID2019-105128RB-I00 financed by
MCIN/AEI/10.13039/501100011033/ and “FEDER Una manera de hacer Europa” to AA and IM
and was also supported by Government of Aragon grant B31_20R to AA. PGO was supported by
a Senescyt fellowship (Ecuador). Funding: This research was financed in part by the project PID2019-105128RB-I00 financed by
MCIN/AEI/10.13039/501100011033/ and “FEDER Una manera de hacer Europa” to AA and IM
and was also supported by Government of Aragon grant B31_20R to AA. PGO was supported by
a Senescyt fellowship (Ecuador). Institutional Review Board Statement: The study was conducted in accordance with the Declaration
of Helsinki, and approved by the Ethics Committee for Research of the Government of Aragón,
“Comité Etico de la Investigación de Aragón” (CEICA; protocol code PI19/452, date of approval
12 April 2019). Informed Consent Statement: Informed consent was obtained from all donors. Data Availability Statement: The data presented in this study are available on request from the
corresponding author. Data Availability Statement: The data presented in this study are available on request from the
corresponding author. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest. Conflicts of Interest: The authors declare no conflict of interest. [
] [
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Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available
under the terms and conditions applicable to Other Posted Material, as set forth at http://
nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Permanent link http://nrs.harvard.edu/urn-3:HUL.InstRepos:5332929 Citation Fritsch, Christine, Johan Hoebeke, Hayet Dali, Vincent Ricchiuti, David A Isenberg, Olivier Meyer,
and Sylviane Muller. 2006. 52-kDa Ro/SSA epitopes preferentially recognized by antibodies
from mothers of children with neonatal lupus and congenital heart block. Arthritis Research &
Therapy 8(1): R4. Share Your Story The Harvard community has made this article openly available. Please share how this access benefits you. Submit a story . Accessibility Available online http://arthritis-research.com/content/8/1/R4 Abstract Antibodies to Ro52 peptide 365–382
have been shown previously to cross-react with residues 165–
185 of the heart 5-HT4 serotoninergic receptor, and might be
pathologically important. The level of these Ro52 antibody
subsets decreased at the end of pregnancy and after delivery. IgG antibodies to Ro52 peptides 1–13, 107–122, 277–292
and 365–382 may therefore represent important biomarkers to
predict a complication in pregnant lupus women with Ro52
antibodies. Christine Fritsch1, Johan Hoebeke1, Hayet Dali1, Vincent Ricchiuti1,2, David A Olivier Meyer4 and Sylviane Muller1 1UPR 9021 Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
2Division of Endocrinology, Diabetes & Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
3Centre for Rheumatology, The Middlesex Hospital, University College London, UK
4G
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F Corresponding author: Sylviane Muller, S.Muller@ibmc.u-strasbg.fr Received: 24 Aug 2005 Revisions requested: 22 Sep 2005 Revisions received: 30 Sep 2005 Accepted: 6 Oct 2005 Published: 4 Nov 2005 Received: 24 Aug 2005 Revisions requested: 22 Sep 2005 Revisions received: 30 Sep 2005 Accepted: 6 Oct 2005 Published: 4 Nov 2005
A th iti R
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2006 8 R4 (d i 10 1186/
1848) Received: 24 Aug 2005 Revisions requested: 22 Sep 2005 Revisions received: 30 Sep 2005 Accepted: 6 O Arthritis Research & Therapy 2006, 8:R4 (doi:10.1186/ar1848)
This article is online at: http://arthritis-research.com/content/8/1/R4 p
© 2005 Fritsch et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract differences were found between Sjögren's syndrome and
asymptomatic mothers of group I, who had at least one infant
with neonatal lupus, and of group II, who had healthy babies
only, significant differences were observed between lupus
mothers from both groups. In the former group of lupus mothers,
a significantly higher frequency of antibodies to Ro52 peptides
107–122 and 277–292 was observed. Between 18 and 30
weeks of gestation, the period of risk, there was clearly an
elevated level of antibodies reacting with Ro52 peptides 1–13,
277–292 and 365–382. Antibodies to Ro52 peptide 365–382
have been shown previously to cross-react with residues 165–
185 of the heart 5-HT4 serotoninergic receptor, and might be
pathologically important. The level of these Ro52 antibody
subsets decreased at the end of pregnancy and after delivery. IgG antibodies to Ro52 peptides 1–13, 107–122, 277–292
and 365–382 may therefore represent important biomarkers to
predict a complication in pregnant lupus women with Ro52
antibodies. Neonatal lupus erythematosus is a rare disorder caused by the
transplacental passage of maternal autoantibodies. The 52-kDa
Ro/SSA antigen (Ro52) ribonucleoprotein represents an
antigenic target strongly associated with the autoimmune
response in mothers whose children have neonatal lupus and
cardiac conduction disturbances, mainly congenital heart block. The objective of this study was to identify putative Ro52/60-kDa
Ro/SSA antigen (Ro60) epitopes associated with neonatal
lupus and congenital heart block. The reactivity of IgG
antibodies present in the sera from mothers with systemic lupus
erythematosus and Sjögren's syndrome and in the sera from
asymptomatic mothers (a longitudinal study of 192 samples
from 66 subjects) was investigated by ELISA using Ro52, Ro60
and 48-kDa La/SSB antigen proteins, as well as 45 synthetic
peptides, 13–24 residues long, of Ro52/Ro60 proteins. One to
19 samples collected before, during and after pregnancy were
available for each mother. Forty-three disease controls selected
randomly and normal sera were tested in parallel. Although no differences were found between Sjögren's syndrome and
asymptomatic mothers of group I, who had at least one infant
with neonatal lupus, and of group II, who had healthy babies
only, significant differences were observed between lupus
mothers from both groups. In the former group of lupus mothers,
a significantly higher frequency of antibodies to Ro52 peptides
107–122 and 277–292 was observed. Between 18 and 30
weeks of gestation, the period of risk, there was clearly an
elevated level of antibodies reacting with Ro52 peptides 1–13,
277–292 and 365–382. CHB = congenital heart block; ELISA = enzyme-linked immunosorbent assay; 5-HT4-R, 5-HT4 receptor; La, 48-kDa La/SSB antigen; NLE, neonatal
lupus erythematosus; OD, optical density; Ro52, 52-kDa Ro/SSA antigen; Ro60, 60-kDa Ro/SSA antigen; SLE, systemic lupus erythematosus; SS,
Sjögren's syndrome. Patients and methods
Patients Two groups of mothers were defined in this study (Table 1). Group I was composed of 41 consecutive mothers who gave
birth to 58 children, of whom at least one infant per mother
was affected with NLE. In this group, 10 mothers had a lupus,
15 mothers had SS and 16 mothers were asymptomatic. Among the 58 children of these 41 mothers, 45 children had
a CHB (14 males, 18 females, 13 unknowns), five children had
a cutaneous NLE (one male, four females), and eight children
were healthy (three males, four females, one unknown). The
diagnosis of complete CHB was based on fetal echocardiog-
raphy when the diagnosis of CHB was obtained during fetal
life, and was based on postnatal electrocardiogram when
bradycardia was detected. Among the 41 mothers who gave
birth to a child with NLE, four had a pregnancy that resulted in
at least one abortion after an in utero fetal demise or early
death of a baby younger than 6 months. These 41 mothers
were aged 19–56 years (average 32.9 years) when their blood
was collected, for some of them a long period of time after
pregnancy (maximum 12 years). Group II corresponded to 25
mothers with 30 healthy children. In this group, 18 mothers
had a lupus and seven mothers had an SS, the mothers were
aged 23–42 years (average 33.6 years) and three abortions
occurred. Patients selected in our study mainly presented
rheumatological and dermatological manifestations. The association of CHB with maternal autoantibodies to Ro
and La antigens might be due to cross-reactions between
maternal anti-Ro/La antibodies and fetal cardiac-specific anti-
gens. A possible antigen targeted by La antibodies might be
laminin, a major component of the sarcolemmal membrane of
cardiomyocytes, which undergoes conformational changes
during development (residues EAKLRA are common to La and
B1 laminin) [10,11]. Molecular mimicry between these two
self-antigens could thus contribute to the pathogenesis of
CHB at an early stage during fetal cardiac development. We
have more recently identified a cross-reactive B-cell epitope
between the Ro52 protein (in residues 365–382) and the
heart 5-HT4 serotoninergic receptor (residues 165–185), and
have demonstrated that these cross-reactive antibodies
antagonized the serotonin-induced L-type Ca2+ channel acti-
vation on human atrial cells [12]. Introduction ble. In contrast, noncardiac manifestations are transient,
resolving by 1 year of age without specific treatment [1]. The
mothers of these children often have an autoimmune disorder
(i.e. systemic lupus erythematosus [SLE] and/or Sjögren's
syndrome [SS]), with antibodies against SSA/Ro and/or SSB/
La antigens. However, entirely asymptomatic mothers with
these antibodies (generally diagnosed after delivery) can also Neonatal lupus erythematosus (NLE) is a rare, but severe, pas-
sively acquired autoimmune syndrome of neonates character-
ized by cardiac, dermatological, hepatic and hematological
manifestations. Autoimmune-associated congenital heart
block (CHB) is often detected between 18 and 24 weeks of
gestation and, to date, in its complete form, remains irreversi- CHB = congenital heart block; ELISA = enzyme-linked immunosorbent assay; 5-HT4-R, 5-HT4 receptor; La, 48-kDa La/SSB antigen; NLE, neonatal
lupus erythematosus; OD, optical density; Ro52, 52-kDa Ro/SSA antigen; Ro60, 60-kDa Ro/SSA antigen; SLE, systemic lupus erythematosus; SS,
Sjögren's syndrome. Page 1 of 11
(page number not for citation purposes) Page 1 of 11
(page number not for citation purposes) Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. heart [14]. The expression of 5-HT4-R in the human fetal heart
has also been confirmed [15]. give birth to infants with CHB. Maternal antibodies to the 52-
kDa Ro/SSA (Ro52) and 48-kDa La/SSB (La) antigens have
been reported to be more strongly associated with CHB than
antibodies to the 60-kDa (Ro60) alone [2,3]. The prevalence
of CHB in newborns of prospectively followed women with
anti-SSA antibodies and known autoimmune rheumatic dis-
ease is 2% [4]. give birth to infants with CHB. Maternal antibodies to the 52-
kDa Ro/SSA (Ro52) and 48-kDa La/SSB (La) antigens have
been reported to be more strongly associated with CHB than
antibodies to the 60-kDa (Ro60) alone [2,3]. The prevalence
of CHB in newborns of prospectively followed women with
anti-SSA antibodies and known autoimmune rheumatic dis-
ease is 2% [4]. Although many questions remain to be solved to understand
the involvement of 5-HT4-R in the pathogenicity of CHB, the
quest for biomarkers that predict mothers at risk remains an
important challenge. Introduction In this study, we have tested the sera
from 66 mothers (a longitudinal study of 192 samples) in dif-
ferent clinical subgroups for the presence in their serum of IgG
antibodies reacting with Ro52, Ro60 and La proteins, as well
as with 39 synthetic peptides covering the whole sequence of
the Ro52 protein and with six peptides of the Ro60 protein. The appearance of protein and peptide-reactive antibodies
was examined regularly in mothers before, during and after
delivery. The aim of this study was twofold; first, to determine
whether antibodies to the Ro52 peptide 365–382 are impor-
tant in predicting a complication in pregnant women with Ro
antibodies; and, second, to identify other putative Ro52
epitopes associated with neonatal lupus and CHB. Several lines of evidence support the pathogenic role of Ro
and La antibodies, which presumably cross the placenta and
damage the conduction system of the developing fetus. It is
notable, however, that abnormalities are not detectable in
maternal cardiac functions despite exposure to the identical
antibodies. The pathogenic role of maternal antibodies is
poorly understood. Direct implication of Ro/La antibodies has
been described in two studies of fatal CHB. Maternal IgG
bearing anti-La idiotypes were identified on the surface of fetal
cardiac myocytes [5] and Ro antibodies were found in an
affected fetal heart [6]. In addition, complete atrioventricular
block could be induced in the rabbit and human fetal heart
after perfusion of the aorta with anti-Ro52 antibodies [7,8]. These same antibodies inhibited the whole-cell and single-
channel L-type Ca2+ channels. The pathogenic role of Ro52
antibodies in the development of CHB was also supported by
an experiment using BALB/c mice as a murine model [9]. Page 2 of 11
(page number not for citation purposes) ELISA, immunodiffusion and Western blotting From each mother of groups I and II, 1–19 serum samples
were available to study. A total of 192 sera from mothers were
tested all together. All of the women gave informed consent to
participate, and the study was approved by the Ethics Com-
mittee at the Paris Bichat-Claude Bernard Hospital. Disease
controls were studied in addition, including the serum from
patients with SLE (n = 14), with SS (n = 15) and with rheuma-
toid arthritis (RA; n = 14) selected randomly (women without
indication of pregnancy), and the sera from 24 healthy blood
donors were also tested. Lupus patients' sera were randomly
taken from the serum collection from one of the authors (DAI)
and no pre-selection according to disease manifestation or
severity was made. The global score (British Isles Lupus
Assessment Group system) used to measure the lupus dis-
ease severity of 14 female patients (aged 17–58 years; aver-
age 28.4 years) was between 1 and 22 (inactive/mildly active
disease, score 1–5, n = 6; moderately to severely active dis-
ease, score 6 or greater, n = 8). Eight of these patients were
Caucasian, four patients were Afro-Caucasian and two
patients were Chinese. Informed consent was obtained from
all participants in accordance with the medical ethical regula-
tions of the local committee. Sera were stored at -70°C until
use. The methods used for testing antibodies reacting with rRo52,
Ro60 and La proteins in the three types of assay and Ro52/
Ro60 peptides in ELISA have been previously described
[16,17]. Only the IgG response was tested in the ELISA and
Western blotting assay. Peptides were found to be satisfacto-
rily attached to the plastic surface of ELISA plates using anti-
bodies induced in rabbits against these peptides [18]. For
calculations, all optical density (OD) values >3 measured in
the ELISA were considered as 3.0. The cutoff points of each
assay were determined from a series of sera collected from 24
normal donors using the mean OD values of these normal sera
tested in parallel + 2 standard deviations. For convenience,
the 192 sera screened with the 48 antigens (proteins and
peptides) were considered positive when OD ≥0.3. When this
threshold value was used, none of the normal sera was found
positive. Mean OD values correspond to the arithmetic mean
of all OD values, including values under the cutoff line for pos-
itivity. Patients and methods
Patients Further studies showed that
antibodies against the human 5-HT4 receptor (5-HT4-R) have
no intrinsic activity on the receptor itself but block receptor
activation on human atrial cells by the cognate hormone sero-
tonin [13]. Most importantly, it was also demonstrated that
pups from normal female mice immunized with the 5-HT4-R
peptide 165–185 showed bradycardia, atrioventricular blocks
of type I and type II, longer QT intervals, skin rash and neuro-
motoric problems [14]. We have thus clearly demonstrated
that anti-5-HT4-R antibodies are associated with neonatal
lupus, that they are pathogenic and that they cross-react with
the Ro52 antigen [12-14]. It is notable that while the 5-HT4-R
is not functional in adult rodents, it is expressed in mouse fetal For patients with SLE, the symptoms were usually mild to mod-
erately severe, and generally no treatment was necessary by
the time surrounding pregnancy. Those who needed to be
treated were well controlled by either corticosteroids (about
5–20 mg/day Cortancyl®) or hydroxychloroquine (Plaquenil®). The latter was in most cases interrupted during pregnancy. Only a few mothers (3/22 documented lupus mothers)
required
a
more
aggressive
treatment
such
as Page 2 of 11
(page number not for citation purposes) Available online http://arthritis-research.com/content/8/1/R4 Table 1 Table 1 Table 1
Description of the study groups
Symptom
Group I
Group II
Total
Mothers
Children
Mothers
Children
Mothers
Children
Systemic lupus erythematosus
10 (24)
13
18 (91)
21
28 (115)
34
Sjögren's syndrome
15 (17)
26
7 (40)
9
22 (57)
35
Asymptomatic
16 (20)
19
0
0
16 (20)
19
Total
41 (61)
58
25 (131)
30
66 (192)
88
Numbers in parentheses indicate the number of serum samples tested in each group. Description of the study groups Numbers in parentheses indicate the number of serum samples tested in each jugated to ovalbumin through the -SH group of cysteine 38
using m-maleimido benzoyl-N-hydroxy succinimide ester as a
coupling agent [17]. cyclophosphamide (Endoxan®), which was replaced by corti-
costeroids during pregnancy. Plasmapheresis was realized to
prevent CHB when the risk was high. Aspirin was introduced
during pregnancy to prevent the risk of thrombosis. ELISA, immunodiffusion and Western blotting Statistically significant frequency differences between
groups were determined by Student's t test. Mean OD values
differences between groups were analyzed using the Mann-
Whitney U test. P < 0.05 was considered significant. Page 3 of 11
(page number not for citation purposes) Table 2 Thus, for each
mother, the frequency of positivity (%) to each peptide was determined as the number of positive sera reported to the total number of samples. quently detected in the serum from patients with SLE and SS
than in the serum from asymptomatic mothers (Table 2). Inter-
estingly most of the sera from SLE, SS and asymptomatic
mothers contained antibodies reacting with both Ro52 and
Ro60. Very few sera contained antibodies reacting with only
one Ro protein (or with La only; data not shown), and this reac-
tivity profile was consistently observed in mothers of both
groups I and II. No statistically significant difference was
observed between the sera of groups I and II when the reac-
tivity of sera with the Ro52 and Ro60 proteins was examined. peptide 277–292 (83% versus 49%; P = 0.049) and to Ro60
peptide 21–41 (64% versus 27%, P = 0.044) was more fre-
quently elevated in the serum from mothers of group I. These
differences were statistically significant with P ≤ 0.050. Some
peptides were recognized much more frequently by the anti-
bodies from mothers of group I, although in a non-statistically
significant manner; for example, with the Ro52 peptide 107–
126 (37% versus 7%; P = 0.062) and the Ro52 peptide 365–
382 (77% versus 47%; P = 0.054). quently detected in the serum from patients with SLE and SS
than in the serum from asymptomatic mothers (Table 2). Inter-
estingly most of the sera from SLE, SS and asymptomatic
mothers contained antibodies reacting with both Ro52 and
Ro60. Very few sera contained antibodies reacting with only
one Ro protein (or with La only; data not shown), and this reac-
tivity profile was consistently observed in mothers of both
groups I and II. No statistically significant difference was
observed between the sera of groups I and II when the reac-
tivity of sera with the Ro52 and Ro60 proteins was examined. It is noticeable that in contrast to what was observed with the
sera from lupus mothers, the sera from mothers with SS
reacted with fewer Ro peptides; namely, four Ro52 peptides
(sequences 1–13, 107–122, 277–292 and 365–382) and
two Ro60 peptides (sequences 21–41 and 304–324), which
were recognized by at least 25% of sera. The percentage of
sera positive with these peptides in groups I and II was not sta-
tistically significantly different (Table 3). Ro proteins and Ro synthetic peptides Affinity-purified Ro60 and La proteins were obtained from
Immunovision (ref. SSA-300; Springdale, AR, USA). The pro-
duction and purification of human recombinant Ro52 (rRo52),
a kind gift from G Pruijn and W van Venrooij (Nijmegen, The
Netherlands), has been described previously [16]. Synthesis
and purification of 39 overlapping peptides of Ro52 and of six
peptides of Ro60 have been described previously [16,17]. Ro52 peptides encompassed 13–24 amino acid residues
and, in general, overlapped each other by 1–10 residues. Selection of peptides that have been synthesized have also
been made according to difficulties of synthesis and/or solu-
bility in aqueous solvents. The Ro60 peptide 21–41 was con- The sera from mothers with SLE and SS as well as sera from
asymptomatic mothers were tested with Ro proteins by immu-
nodiffusion, Western blotting and ELISA. Previous studies
have shown that distinct antibody subsets are identified using
these different immunoassays [16]. This observation was con-
firmed in the present study (Table 2). In general, the ELISA
detected Ro52 and Ro60 antibodies in a higher number of
sera than Western blotting. A number of sera were positive in
immunodiffusion tests but negative in ELISA and/or Western
blotting tests. Conversely, some immunodiffusion-negative
sera were positive in the ELISA and/or Western blotting tests. It is noticeable, however, that Ro antibodies were more fre- Page 3 of 11
(page number not for citation purposes) Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. Page 4 of 11
(page number not for citation purposes) Table 2 Table 2
Reactivity in different tests of sera from mothers of groups I and II
Mothers
Immunodiffusion
Western blotting
ELISA
Ro (%)
Ro52 (%)
Ro60 (%)
Ro52 (%)
Ro60 (%)
Systemic lupus erythematosus
Group I (n = 9 mothers; 12 samples)
25
67
25
92
67
Group II (n = 14 mothers; 26 samples)
69
12
23
62
69
Total (n = 23 mothers; 38 samples)
47
39
24
77
68
Sjögren's syndrome
Group I (n = 14 mothers; 14 samples)
71
57
29
64
64
Group II (n = 6 mothers; 12 samples)
100
50
25
100
100
Total (n = 20 mothers; 26 samples)
86
54
27
82
82
Asymptomatic
Group I (n = 13 mothers; 13 samples)
38
23
8
31
38
The results are shown for mothers, the serum of whom has been systematically tested in the three assays. Only the IgG antibody response was
tested in Western blotting and ELISA. The first figure in parentheses represents the number of mothers and the second represents the total
number of samples tested. The data take into account the number of samples collected from each mother, which differs from 1 to 5. Thus, for each
mother, the frequency of positivity (%) to each peptide was determined as the number of positive sera reported to the total number of samples. Reactivity in different tests of sera from mothers of groups I and II The results are shown for mothers, the serum of whom has been systematically tested in the three assays. Only the IgG antibody response was
tested in Western blotting and ELISA. The first figure in parentheses represents the number of mothers and the second represents the total
number of samples tested. The data take into account the number of samples collected from each mother, which differs from 1 to 5. Thus, for each
mother, the frequency of positivity (%) to each peptide was determined as the number of positive sera reported to the total number of samples. The results are shown for mothers, the serum of whom has been systematically tested in the three assays. Only the IgG antibody response was
tested in Western blotting and ELISA. The first figure in parentheses represents the number of mothers and the second represents the total
number of samples tested. The data take into account the number of samples collected from each mother, which differs from 1 to 5. Table 2 The 192 sera from 41 mothers of group I and from 25 mothers
of group II were then tested for their ability to react in the
ELISA with 39 overlapping peptides covering the whole Ro52
sequence and with six Ro60 peptides. The reactivity of autoim-
mune sera with these 45 peptides has been described previ-
ously [16,17,19]. The data (frequency and P values)
presented in Table 3 take into account the number of samples
collected from each mother that differs from 1 to 19. The anal-
ysis of data showed that, among the 45 peptides tested in
ELISA, only three (sequences 191–208, 262–279 and 326–
340 of Ro52) were never recognized by IgG antibodies con-
tained in the sera of groups I and II. Thirty-one other peptides
were recognized by less than 25% of sera, and 11 peptides
were recognized by at least 25% of sera (Table 3). The sera from asymptomatic mothers with affected children
collected 3 months-10 years after delivery (mean 4.8 years)
reacted weakly and infrequently with Ro52 and Ro60 peptides
(Table 3). The reactivity of sera with La protein follows the
same pattern of reactivity; namely, a highly significant elevation
of positive sera from lupus mothers of group I as compared
with lupus mothers of group II, positivity of sera from mothers
with SS that was not statistically different in groups I and II,
and a low frequency of positive sera in the group of asympto-
matic mothers of group I (Table 3). When the reactivity of SLE sera was analyzed and compared
in both groups I and II, we observed first that the spectrum of
reactivity of antibodies from mothers of group I was larger (11
peptides versus 5 peptides recognized by at least 25% of
sera). Table 2 Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. 436–451 CAFTGPLRPFFSPGFN
13
7
13
10
0
447–463 SPGFNDGGKNTAPLTLC
8
9
0
6
0
463–475 CPLNIGSQGSTDY
0
7
7
1
0
Ro60 PROTEIN
80
67
67
99
0.022*
31
1–23 MEESVNQMQPLNEKQIANSQDGY
15
6
17
1
6
18–38 NSQDGYVWQVTDMNRLHRFLC
32
11
20
1
0.097
0
21–41 DGYVWQVTDMNRLHRFLCFGS
64
27
0.044*
23
38
0
304–324 VCEKLCNEKLLKKARIHPFHI
50
18
27
4
13
495–518 KLIVCGMTSNGFTIADPDDRGMLD
10
24
0.058
7
11
0.079
13
524–538 TGALDVIRNFTLDMI
10
17
3
9
0
La PROTEIN
93
30
<0.00
01*
40
68
13
The 192 samples described in Table 1 were systematically tested in at least two independent tests. Only the IgG response was tested. Patients'
sera were diluted 1:1,000. To be tested in the ELISA, peptide 21–41 of Ro60 protein was conjugated to ovalbumin. The sera were considered
positive when optical density ≥0.3. Statistically significant differences between groups were determined by Student's t test. *P < 0.05 considered
significant. Table 3 (Continued)
Reactivity in ELISA of sera from mothers of groups I and II The 192 samples described in Table 1 were systematically tested in at least two independent tests. Only the IgG response was tested. Patients'
sera were diluted 1:1,000. To be tested in the ELISA, peptide 21–41 of Ro60 protein was conjugated to ovalbumin. The sera were considered
positive when optical density ≥0.3. Statistically significant differences between groups were determined by Student's t test. *P < 0.05 considered
significant. antigens (Ro52, Ro60, La proteins and the 45 peptides of
Ro52 and Ro60) was then examined in serial samples from
lupus mothers of groups I and II in order to establish, in a more
individual manner, whether correlations exist between the
presence of these antibody subsets and different parameters
related to the disease, the treatment and the course of preg-
nancy. Figure 1 shows longitudinal testing of sera from four
representative mothers. Table 2 In summary, the most significant differences observed
between mothers of groups I and II were in lupus mothers of
group I, who possessed a significantly higher frequency of IgG
antibodies to Ro52 peptides 107–122 and 277–292 and to
Ro60 peptide 21–41. In a series of disease control sera col-
lected from randomly selected patients with SLE, SS and RA,
the data showed that, in good agreement with our previous
results, the two Ro52 peptides were not recognized or were
recognized infrequently [16,19] by the sera from these
patients. In summary, the most significant differences observed
between mothers of groups I and II were in lupus mothers of
group I, who possessed a significantly higher frequency of IgG
antibodies to Ro52 peptides 107–122 and 277–292 and to
Ro60 peptide 21–41. In a series of disease control sera col-
lected from randomly selected patients with SLE, SS and RA,
the data showed that, in good agreement with our previous
results, the two Ro52 peptides were not recognized or were
recognized infrequently [16,19] by the sera from these
patients. Table 2 The cumulative data are reported in
Figure 2, in which we have subdivided the analysis into three
periods: before pregnancy (in a range of 18 months with a
mean at 11 weeks for group I, and in a range of 21 months with
a mean at 48 weeks for group II; Figure 2a,d), during preg-
nancy (Figure 2b,e) and after pregnancy (in a range of 26
months with a mean at 21 weeks for the group I, and in a range
of 12 months with a mean at 17 weeks for the group II; Figure
2c,f). In a general manner, whichever period is examined and
for most of the antibody specificities, the level of IgG antibod-
ies (expressed as mean OD values) and their frequency (%)
were clearly higher in the mothers of group I as compared with
mothers of group II. This observation is true for antibodies
reacting with several Ro peptides and for the antibodies to
whole Ro proteins (most particularly for La and Ro52 antibod-
ies). Before pregnancy, the levels of antibodies to Ro52 pep-
tides 277–292 and 365–382 (in terms of mean OD values) as
well as Ro52 peptides 1–13, 107–122 and 107–126 (in
terms of frequency) were particularly elevated in group I. Dur-
ing pregnancy the same antibodies except the antibodies to
Ro52 peptide 107–126 were also elevated, and after preg-
nancy antibodies to Ro52 peptides 277–292 and 365–382
were elevated. account the number of serum samples available for each
mother, very similar results were obtained. Between group I (n
= 10) and group II (n = 18) of mothers with lupus, statistically
different reactivities were found with Ro52 peptide 107–122
(88% versus 33%, P = 0.011), peptide 277–292 (100% ver-
sus 44%, P = 0.007) and peptide 365–382 (100% versus
61%, P = 0.039), and with Ro60 peptide 21–41 (75% versus
33%, P = 0.049) and peptide 304–324 (75% versus 33%, P
= 0.049). Reactivities with recombinant Ro52 protein (100%
versus 78%), Ro52 peptide 1–13 (88% versus 56%) and La
protein (100% versus 50%) were no longer statistically differ-
ent between groups I and II of lupus patients. No difference
was observed between groups I and II of mothers with SS. Table 2 Second, we found that the level of IgG antibodies to
Ro52 peptide 107–122 (69% versus 28%; P = 0.023) and If we considered a mother positive when at least one of sam-
ples was positive with a given peptide, instead of taking into Page 4 of 11
(page number not for citation purposes) Available online http://arthritis-research.com/content/8/1/R4 Available online http://arthritis-research.com/content/8/1/R4 Table 3 Table 3
Reactivity in ELISA of sera from mothers of groups I and II
Antigen
Systemic lupus erythematosus
Sjögren's syndrome
Asymptoma
Group I (%)
Group II (%)
P
Group I (%)
Group II (%)
P
Group I (%)
Recombinant Ro52 protein
97
66
0.009*
67
98
0.027*
31
1–13 MASAARLTMMWEE
77
46
0.084
47
58
31
10–25 MWEEVTPICLDPFVE
0
14
0
0
0
12–35 EEVTCPICLDPFVEPVSIECGHSF
10
16
20
8
13
25–40 EPVSIECGHSFCQECI
0
13
10
0
6
34–56 SFCQECISQVGKGGGSVCAVCRQ
0
1
7
0
13
38–53 ECISQVGKGGGSVCAV
3
4
7
0
0
50–64 VCAVCRQRFLLKNLR
25
3
13
5
6
63–79 LRPNRQLANMVNNLKEI
0
6
0
3
0
77–94 KEISQEAREGTQGERCAV
18
1
3
0
0
93–116 AVHGERLHLFCEKDGKALCWVCAQ
40
12
10
9
0
94–109 VHGERLHLFCEKDGKA
3
13
0
0
0
107–122 GKALCWVCAQSRKHRD
69
28
0.023*
47
33
13
107–126 GKALCWVCAQSRKHRDHAMV
37
7
0.062
13
8
13
121–137 RDHAMVPLEEAAQEYQE
0
4
0
0
0
135–151 YQEKLQVALGELRRKQE
3
14
0
0
0
149–166 KQELAEKLEVEIAIKRAD
0
12
0
1
0
164–180 RADWKKTVETQKSRIHA
0
9
0
0
6
178–193 IHAEFVQQKNFLVEEE
3
14
0
0
0
191–208 EEEQRQLQELEKDEREQL
0
0
0
0
0
206–224 EQLRILGEKEAKLAQQSQA
0
1
7
0
9
222–235 SQALQELISELDRRCHS
17
3
23
1
6
236–250 CHSSALELLQEVIIV
27
6
10
7
0
249–264 IVLERSESWNLKDLDI
0
5
7
0
0
262–279 LDITSPELRSVCHVPGLK
0
0
0
0
0
277–292 GLKKMLRTCAVHITLD
83
49
0.049*
40
24
6
290–304 TLDPDTANPWLILSE
0
7
7
0
0
302–317 LSEDRRQVRLGDTQQS
10
2
7
0
0
314–328 TQQSIPGNEERFDSY
0
9
0
9
0
326–340 DSYPMVLGAQHFHSG
0
0
0
0
0
337–352 FHSGKHYWEVDVTGKE
23
11
3
12
6
350–367 GKEAWDLGVCRDSVRRKG
0
1
0
0
9
365–382 RKGHFLLSSKSGFWTIWL
77
47
0.054
50
33
25
380–396 IWLWNKQKYEAGTYPQT
0
5
0
2
0
394–412 PQTPLHLQVPPCQVGIFLD
18
1
3
10
0
411–423 LDYEAGMVSFYNI
0
2
0
0
0
422–438 NITDHGSLIYSFSECAF
16
2
0
0
0 Reactivity in ELISA of sera from mothers of groups I and II g
(page number not for citation purposes) Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. Page 6 of 11
(page number not for citation purposes) I and II All samples were systematically tested in at least two independent tests – the results shown in the figure
correspond to one complete representative experiment. The sera were considered positive when the optical density (OD) values were ≥0.3 (horizon-
tal lane). All sera were tested with the 48 antigens. Only the Ro antigens showing the highest reactivity are depicted in the figures; ◆, recombinant
Ro52; ■, Ro52 peptide 1–13; •, Ro52 peptide 107–122; , Ro52 peptide 277–292; ❍, Ro52 peptide 365–382; ▲, La. Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens
Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens. The sera from lupus mothers of (a) group I and (b)–(d) group II
were tested by ELISA before (b), during (g, for gestation) and after (p, for post) pregnancy. The number of weeks is indicated. Mother D had two
consecutive pregnancies (D1 and D2). The rectangles represent the period known to be at risk (approximately weeks 16–26 of gestation), knowing
that autoimmune-associated congenital heart block most often occurs between 18 and 24 weeks of gestation. Sera were tested at a 1:1,000 dilu-
tion. Only the IgG response was evaluated. All samples were systematically tested in at least two independent tests – the results shown in the figure
correspond to one complete representative experiment. The sera were considered positive when the optical density (OD) values were ≥0.3 (horizon-
tal lane). All sera were tested with the 48 antigens. Only the Ro antigens showing the highest reactivity are depicted in the figures; ◆, recombinant
Ro52; ■, Ro52 peptide 1–13; •, Ro52 peptide 107–122; , Ro52 peptide 277–292; ❍, Ro52 peptide 365–382; ▲, La. sequentially during her pregnancy. The mother gave birth to a
healthy child. In Figure 3, the analysis was further focused on the pregnancy
period and the data were examined by defining four testing
periods: weeks 1–8, weeks 16–20, weeks 26–30 and weeks
31–35 of pregnancy. Seven samples from five mothers and 24
samples from 17 mothers were examined for group I and
group II, respectively. I and II The major features of this study were
that the overall level of antibodies was higher in the mothers of
group I as compared with group II, and that between 16 and
30 weeks of gestation, the period of risk, there was clearly an
elevated level of antibodies reacting with Ro52 peptides 1–
13, 277–292 and 365–382. I and II The data already described indicate that certain antibody sub-
types occur more frequently in the serum of lupus mothers of
children with NLE than in the samples from lupus mothers with
healthy children. The appearance of IgG antibodies to Ro Page 6 of 11
(page number not for citation purposes) Available online http://arthritis-research.com/content/8/1/R4 Figure 1 Figure 1
Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens
Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens. The sera from lupus mothers of (a) group I and (b)–(d) group II
were tested by ELISA before (b), during (g, for gestation) and after (p, for post) pregnancy. The number of weeks is indicated. Mother D had two
consecutive pregnancies (D1 and D2). The rectangles represent the period known to be at risk (approximately weeks 16–26 of gestation), knowing
that autoimmune-associated congenital heart block most often occurs between 18 and 24 weeks of gestation. Sera were tested at a 1:1,000 dilu-
tion. Only the IgG response was evaluated. All samples were systematically tested in at least two independent tests – the results shown in the figure
correspond to one complete representative experiment. The sera were considered positive when the optical density (OD) values were ≥0.3 (horizon-
tal lane). All sera were tested with the 48 antigens. Only the Ro antigens showing the highest reactivity are depicted in the figures; ◆, recombinant
Ro52; ■, Ro52 peptide 1–13; •, Ro52 peptide 107–122; , Ro52 peptide 277–292; ❍, Ro52 peptide 365–382; ▲, La. Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens
Longitudinal study of sera from lupus mothers of groups I and II with Ro antigens. The sera from lupus mothers of (a) group I and (b)–(d) group II
were tested by ELISA before (b), during (g, for gestation) and after (p, for post) pregnancy. The number of weeks is indicated. Mother D had two
consecutive pregnancies (D1 and D2). The rectangles represent the period known to be at risk (approximately weeks 16–26 of gestation), knowing
that autoimmune-associated congenital heart block most often occurs between 18 and 24 weeks of gestation. Sera were tested at a 1:1,000 dilu-
tion. Only the IgG response was evaluated. Discussion The antigenic structure of Ro52, Ro60 and La has been exten-
sively studied by several independent groups, and a number of
dominant epitopes have been identified in these proteins [20-
22]. However, probably because the number of available sera
is relatively low, there are very few systematic mapping studies
aimed at the characterization of particular regions of Ro and La
antigens recognized by CHB-associated antibodies from
mothers of affected infants or, in this context, from children suf-
fering from NLE [11,23]. Studies with Ro antigens reported
the reactivity of selected sera with recombinant fragments
tested by ELISA and Western blotting assay, and it was found
that anti-Ro reactivity in mothers of infants with CHB reacted
mainly against the Ro52 sequence 200–239, whereas the
predominant activity in control mothers was against the
sequence 176–196 [23]. This result was confirmed with syn-
thetic peptides, and the most recent study demonstrated that
pups born from rats immunized with the Ro52 peptide 200–
239 developed atrioventricular block [24]. In the present One of our patients with high levels of IgG antibodies reacting
with Ro60, rRo52, Ro52 peptides 1–13, 107–122, 277–292
and 365–382, and Ro60 peptide 21–41 was treated by plas-
mapheresis. This lupus mother had a first baby with CHB. Plasmapheresis was used for her second pregnancy as a
method of treatment aimed at removing antibodies from her
plasma to decrease potential autoimmune activity after placen-
tal passage. IgG antibodies were efficiently removed from the
bloodstream as measured in serum samples collected Page 7 of 11
(page number not for citation purposes) Page 7 of 11
(page number not for citation purposes) Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. Figure 2
Reactivity in ELISA of sera from lupus mothers of groups I and II with Ro antigens
Reactivity in ELISA of sera from lupus mothers of groups I and II with Ro antigens. Sera were classified into three subgroups: (a), (d) before, (b), (e)
during, and (c), (f) after pregnancy. The results are expressed in terms of frequency (%) of positive reaction ((a)–(c)) and antibody level (mean optical
density [OD] values + standard deviation) ((d)–(f)). Mothers' sera were tested at a 1:1,000 dilution and the IgG response only was evaluated. Discussion The
number of samples (number of mothers) was as follows; group I (black bars): (a)–(d), 5 (3); (b)–(e), 8 (5); (c)–(f), 6 (5); group II (white bars): (a)–(d),
18 (4); (b)–(e), 44 (16); (c)–(f), 12 (7). All samples were systematically tested in at least two independent tests. The results shown in the figure cor-
respond to one complete representative experiment. The sera were considered positive when OD ≥0.3 (visualized by a longitudinal lane in panels
(d)–(f)). All sera were tested with the 48 antigens. Only the Ro antigens showing reactivity are depicted. For clarity, the first residue of each peptide
sequence is indicated in the figures (107-1 for 107–122; 107-2 for 107–126). (a)–(c) Student's t test, *0.05 > P > 0.01, **P ≤ 0.01; (d) and (e)
Mann-Whitney U test, *0.05 > P > 0.005, **P ≤ 0.005. Reactivity in ELISA of sera from lupus mothers of groups I and II with Ro antigens
Reactivity in ELISA of sera from lupus mothers of groups I and II with Ro antigens. Sera were classified into three subgroups: (a), (d) before, (b), (e)
during, and (c), (f) after pregnancy. The results are expressed in terms of frequency (%) of positive reaction ((a)–(c)) and antibody level (mean optical
density [OD] values + standard deviation) ((d)–(f)). Mothers' sera were tested at a 1:1,000 dilution and the IgG response only was evaluated. The
number of samples (number of mothers) was as follows; group I (black bars): (a)–(d), 5 (3); (b)–(e), 8 (5); (c)–(f), 6 (5); group II (white bars): (a)–(d),
18 (4); (b)–(e), 44 (16); (c)–(f), 12 (7). All samples were systematically tested in at least two independent tests. The results shown in the figure cor-
respond to one complete representative experiment. The sera were considered positive when OD ≥0.3 (visualized by a longitudinal lane in panels
(d)–(f)). All sera were tested with the 48 antigens. Only the Ro antigens showing reactivity are depicted. For clarity, the first residue of each peptide
sequence is indicated in the figures (107-1 for 107–122; 107-2 for 107–126). (a)–(c) Student's t test, *0.05 > P > 0.01, **P ≤ 0.01; (d) and (e)
Mann-Whitney U test, *0.05 > P > 0.005, **P ≤ 0.005. Page 8 of 11
(page number not for citation purposes) Discussion The IgG response only was evaluated. The sera were considered positive when OD ≥0.3 (horizontal lane). All sera were tested with the 48 antigens. Only the Ro antigens showing reactivity are depicted in the figures. Antigens tested: columns 1, 6 and 9 (black bars), recombinant Ro52, Ro60 and
La proteins, respectively; columns 2–5 (grey bars), Ro52 peptides 1–13, 107–122, 277–292 and 365–382; columns 7 and 8, Ro60 peptides 21–
41 and 304–324. Reactivity in ELISA of sera collected from lupus mothers of groups I and II during pregnancy
Reactivity in ELISA of sera collected from lupus mothers of groups I and II during pregnancy. Sera were classified in four subgroups, corresponding
to weeks 1–8, 16–20, 26–30 and 31–35 of gestation. The number of sera in each subgroup is indicated (n). Sera were tested at a 1:1,000 dilution. The IgG response only was evaluated. The sera were considered positive when OD ≥0.3 (horizontal lane). All sera were tested with the 48 antigens. Only the Ro antigens showing reactivity are depicted in the figures. Antigens tested: columns 1, 6 and 9 (black bars), recombinant Ro52, Ro60 and
La proteins, respectively; columns 2–5 (grey bars), Ro52 peptides 1–13, 107–122, 277–292 and 365–382; columns 7 and 8, Ro60 peptides 21–
41 and 304–324. envisaged study will be to evaluate the reactivity of mother's
sera with overlapping La peptides. ity of sera with the whole proteins Ro52, Ro60 and La was
high in subgroups of SLE and SS mothers and did not help to
distinguish the group of mothers at risk, the overall level of IgG
antibodies reacting with several Ro peptides, however, was
significantly higher in lupus mothers of group I as compared
with group II. These peptides encompass residues 107–122
and 277–292 of Ro52 and residues 21–41 of Ro60. Antibod-
ies reacting with Ro52 peptides 1–13 and 365–382 were
also particularly elevated in lupus mothers of group I. In con-
trast, no statistically significant difference was observed
between groups I and II of mothers with SS, and low levels of
Ro peptide reactive antibodies were measured in asympto-
matic mothers who gave birth to babies with NLE. An important feature demonstrated in this study was that, dur-
ing the critical window of pregnancy between 18 and 30
weeks of gestation, there was a high level of IgG antibodies
reacting with Ro52 peptides 1–13, 277–292 and 365–382 in
lupus mothers of group I. Discussion total test antigen used in immunodiffusion or to the fact that
the Ro antigen used was extracted from bovine spleen, which
is known to be less effectively recognized by patients' autoan-
tibodies than human Ro [25,26]. study, synthetic peptides 13–24 residues long were used in
an ELISA to analyze the Ro52 and Ro60 antibody response in
mothers whose children have NLE. The whole proteins Ro52,
Ro60 and La were also included in this study. The 192 sera
from a total of 66 mothers in the two different clinical groups I
and II (with or without infants with NLE) as well as the 43 dis-
ease controls were studied. The appearance of protein and
peptide-reactive antibodies was examined before and during
the time of pregnancy, as well as after delivery. A second set of data was obtained by examining the reactivity
of sera with 45 peptides of Ro52 and Ro60 proteins. Eleven
Ro peptides were recognized by IgG antibodies from at least
25% of mothers included in this study. These peptides encom-
pass residues 1–13, 50–64, 93–116, 107–122, 107–126,
236–250, 277–292, 365–382 of Ro52 and residues 18–38,
21–41 and 304–324 of Ro60. Although the actual fragments
176–196 and 200–239 of Ro52 described by Wahren-Herle-
nius and colleagues [23,24] were not tested in this study, thus
precluding any direct conclusion, we noted infrequent reactiv-
ity in the four peptides covering these regions (Ro52 peptides
178–193, 191–208, 206–224, 222–235). While the reactiv- A thorough mapping of autoantibody specificities was under-
taken. The high frequency of IgG antibodies to the whole pro-
teins Ro52, Ro60 and La in all selected sera was notable, but
a large number of discrepancies between the results obtained
via immunodiffusion, Western blotting and ELISA was
observed. This lack of correlation has been described previ-
ously and may be due, for example, to the absence of Ro52 in Page 8 of 11
(page number not for citation purposes) Page 8 of 11
(page number not for citation purposes) Available online http://arthritis-research.com/content/8/1/R4 Figure 3 Figure 3
Reactivity in ELISA of sera collected from lupus mothers of groups I and II during pregnancy
Reactivity in ELISA of sera collected from lupus mothers of groups I and II during pregnancy. Sera were classified in four subgroups, corresponding
to weeks 1–8, 16–20, 26–30 and 31–35 of gestation. The number of sera in each subgroup is indicated (n). Sera were tested at a 1:1,000 dilution. Authors' contributions 13. Sallé L, Eftekhari P, Aupart M, Cosnay P, Hoebeke J, Argibay JA:
Inhibitory activity of antibodies against the human atrial 5-HT4
receptor. J Mol Cell Cardiol 2001, 33:405-417. CF performed and analyzed the immunoassays. JH was
involved in the analysis of the immunoassay results. HD per-
formed and analyzed the immunoassays. VR performed and
analyzed the immunoassays. DAI collected the patient sera
and provided patient data. OM conceived of the study,
participated in its design, collected the patient sera and pro-
vided patient data. SM conceived of the study and was
involved in its design and coordination. All authors read and
approved the final manuscript. 14. Eftekhari P, Roegel JC, Lezoualc'h F, Fischmeister R, Imbs JL, Hoe-
beke J: Induction of neonatal lupus in pups of mice immunized
with synthetic peptides derived from amino acid sequences of
the serotoninergic 5-HT4 receptor. Eur J Immunol 2001,
31:573-579. 15. Buyon JP, Clancy R, Di Donato F, Miranda-Carus ME, Askanase
AD, Garcia J, Qu Y, Hu K, Yue Y, Chan EK, Boutjdir M: Cardiac 5-
HT4 serotoninergic receptors, 52 kD SSA/Ro and autoim-
mune-associated congenital heart block. J Autoimmun 2002,
19:79-86. 16. Ricchiuti V, Briand JP, Meyer O, Isenberg DA, Pruijn G, Muller S:
Epitope mapping with synthetic peptides of 52-kD SSA/Ro
protein reveals heterogeneous antibody profiles in human
autoimmune sera. Clin Exp Immunol 1994, 95:397-407. Conclusion Longitudinal analysis of mothers with SLE and SS showed that
in the group of lupus mothers whose at least one child had
NLE, a significantly higher frequency of IgG antibodies to
Ro52 peptides 107–122 and 277–292 was observed. Between 18 and 30 weeks of gestation, the period of risk,
there was clearly an elevated level of circulating antibodies
reacting with Ro52 peptides 1–13, 277–292 and 365–382. This result is particularly important since antibodies to Ro52
peptide 365–382 have been shown previously to cross-react
with residues 165–185 of the heart 5-HT4 serotoninergic
receptor and might be pathologically important. The level of
these Ro52 antibody subsets decreased at the end of preg-
nancy and after delivery. IgG antibodies to Ro52 peptides 1–
13, 107–122, 277–292 and 365–382 could therefore be
important to predict a complication in pregnant lupus women
with Ro52 antibodies. 7. Garcia S, Nascimiento JH, Bonfa E, Levy R, Oliveira SF, Tavares
AV, de Carvalho AC: Cellular mechanisms of the conduction
abnormalities induced by serum from anti-Ro/SSA-positive
patients in rabbit hearts. J Clin Invest 1994, 93:718-724. 8. 8. Boutjdir M, Chen L, Zhang ZH, Tseng CE, Di Donato F, Rashbaum
W, Morris A, el-Sherif N, Buyon JP: Arrhythmogenicity of IgG and
anti-52 kD SSA/Ro affinity purified antibodies from mothers of
children with congenital heart block. Circ Res 1997,
80:354-362. 9. Miranda-Carus ME, Boutjdir M, Tseng CE, DiDonato F, Chan EK,
Buyon JP: Induction of antibodies reactive with SSA/Ro-SSB/
La and development of congenital heart block in a murine
model. J Immunol 1998, 161:5886-5892. 10. Li JM, Horsfall AC, Maini RN: Anti-La (SS-B) but not anti-Ro52
(SS-A) antibodies cross-react with laminin – a role in the
pathogenesis of congenital heart block? Clin Exp Immunol
1995, 99:316-324. ,
11. Chang SH, Huh MS, Kim HR, Kim IS, Lee JS, Semsei I, Grölz D,
Bachmann M: Cross reactivity of antibodies immunoadsorbed
to laminin with recombinant human La (SS-B) protein. J
Autoimmun 1998, 11:163-167. Acknowledgements The authors thank G Pruijn and W van Venrooij (Nijmegen) for a gift of
recombinant Ro52, and thank J-P Briand for the synthesis of peptides. This work was supported by CNRS. p
17. Barakat S, Meyer O, Torterotot F, Youinou P, Briand JP, Kahn MF,
Muller S: IgG antibodies from patients with primary Sjögren's
syndrome and systemic lupus erythematosus recognize dif-
ferent epitope in 60-kD SSA/Ro protein. Clin Exp Immunol
1992, 89:38-45. Competing interests ,
12. Eftekhari P, Sallé L, Lezoualc'h F, Mialet J, Gastineau M, Briand JP,
Isenberg DA, Fournié GJ, Argibay J, Fischmeister R, et al.: Anti-
SSA/Ro52 autoantibodies blocking the cardiac 5-HT4 serot-
oninergic receptor could explain neonatal lupus congenital
heart block. Eur J Immunol 2000, 30:2782-2790. p
g
The authors declare that they have no competing interests. Arthritis Research & Therapy Vol 8 No 1 Fritsch et al. 3. Dörner T, Feist E, Pruss A, Chaoui R, Göldner B, Hiepe F: Signif-
icance of antibodies in neonatal lupus erythematosus. Int Arch
Allergy Immunol 2000, 123:58-66. Our previous studies have provided some important features
concerning the pathological consequences for the fetal heart
of antibodies to 5-HT4-R [12-14]. It would be of interest to
prolong this study by demonstrating the possible physiopatho-
logical role of Ro antibodies reacting with Ro52 peptide 365–
382, and to determine whether the other antibody subsets of
Ro52 antibodies (antibodies reacting with Ro52 peptides 1–
13, 107–122 and 277–292, for example) also generate elec-
trophysiological disturbances compatible with CHB. 4. Brucato A, Frassi M, Franceschini F, Cimaz R, Faden D, Pisoni MP,
Muscara M, Vignati G, Stramba-Badiale M, Catelli L, et al.: Risk of
congenital complete heart block in newborns of mothers with
anti-Ro/SSA antibodies detected by counterimmunoelectro-
phoresis: a prospective study of 100 women. Arthritis Rheum
2001, 44:1832-1835. 5. ,
5. Horsfall AC, Venables PJ, Taylor PV, Maini RN: Ro and La anti-
gens and maternal anti-La idiotype on the surface of myocar-
dial fibres in congenital heart block. J Autoimmun 1991,
4:165-176. 6. Reichlin M, Brucato A, Frank MB, Maddison PJ, McCubbin VR,
Wolfson-Reichlin M, Lee LA: Concentration of autoantibodies to
native 60-kd Ro/SS-A and denatured 52-kd Ro/SS-A in elu-
ates from the heart of a child who died with congenital com-
plete heart block. Arthritis Rheum 1994, 37:1698-1703. Discussion This result is particularly important to
highlight because these antibodies might play an important
role in the pathogenesis of CHB at an early stage during fetal
cardiac development, and also because the Ro52 sequence
365–382 does correspond to the site of homology with the
serotoninergic 5-HT4-R [12-14]. It has been confirmed
recently that IgG antibodies reacting with peptide 165–185 of
5-HT4-R effectively occurred in a higher proportion of mothers
whose children had CHB [27]. Although a meta-analysis
should be performed to confirm the data, this study raises the
point that tracing IgG antibodies reacting with peptide 365–
382 of Ro52 might be important in patients with lupus to fol-
low at-risk pregnancies. The lack of significant association of any antibody subset in
groups I and II of patients with SS is intriguing. It is not known
whether this result suggests that there are different physio-
pathological mechanisms involved in SLE and SS. This
important question will be examined further in a larger group of
mothers. On the other hand, since La reactivity within the
group of mothers with SLE seems to be significantly more
prevalent in group I compared with group II (Table 3), another Page 9 of 11
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heart block: dissecting the cascade from immunologic insult
to relentless fibrosis. Anat Rec A Discov Mol Cell Evol Biol
2004, 280:1027-1035. 1. Clancy RM, Buyon JP: Autoimmune-associated congenital
heart block: dissecting the cascade from immunologic insult
to relentless fibrosis. Anat Rec A Discov Mol Cell Evol Biol
2004, 280:1027-1035. 18. Ricchiuti V, Pruijn GJM, Thijssen JP, van Venrooij WJ, Muller S:
Accessibility of epitopes on the 52-kD Ro/SSA protein (Ro52)
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anti-peptide antibodies. J Autoimmun 1997, 10:181-191. 2. Buyon JP, Winchester RJ, Slade SG, Arnett F, Copel J, Friedman
D, Lockshin MD: Identification of mothers at risk for congenital
heart block and other neonatal lupus syndromes in their chil-
dren. Comparison of enzyme-linked immunosorbent assay
and immunoblot for measurement of anti-SS-A/Ro and anti-
SS-B/La antibodies. Arthritis Rheum 1993, 36:1263-1273. 2. Buyon JP, Winchester RJ, Slade SG, Arnett F, Copel J, Friedman
D, Lockshin MD: Identification of mothers at risk for congenital
heart block and other neonatal lupus syndromes in their chil-
dren. Comparison of enzyme-linked immunosorbent assay
and immunoblot for measurement of anti-SS-A/Ro and anti-
SS-B/La antibodies. Arthritis Rheum 1993, 36:1263-1273. anti peptide antibodies. J Autoimmun 1997, 10:181 191. 19. Ricchiuti V, Isenberg D, Muller S: HLA association of anti-Ro60
and anti-Ro52 antibodies in Sjögren's syndrome. J Autoimmun
1994, 7:611-621. ,
20. Scofield RH, Farris AD, Horsfall AC, Harley JB: Fine specificity of
the autoimmune response to the Ro/SSA and La/SSB
ribonucleoproteins. Arthritis Rheum 1999, 42:199-209. Page 10 of 11
(page number not for citation purposes) Available online http://arthritis-research.com/content/8/1/R4 21. Wahren-Herlenius M, Muller S, Isenberg D: Analysis of B-cell
epitopes of the Ro/SSA autoantigens. Immunol Today 1999,
20:234-240. 22. Moutsopoulos NM, Routsias JG, Vlachoyiannopoulos PG, Tzioufas
AG, Moutsopoulos HM: B-cell epitopes of intracellular autoan-
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S D
T Th
d
E B
K L
P ,
p
p
p
tigens: myth and reality. Mol Med 2000, 6:141-151. 23. Salomonsson S, Dörner T, Theander E, Bremme K, Larsson P,
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genital heart block. Arthritis Rheum 2002, 46:1233
S
S S
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(page number not for citation purposes) References Salomonsson S, Sonesson SE, Ottosson L, Muhallab S, Olsson T,
Sunnerhagen M, Kuchroo VK, Thorén P, Herlenius E, Wahren-Her-
lenius M: Ro/SSA autoantibodies directly bind cardiomyocytes,
disturb calcium homeostasis, and mediate congenital heart
block. J Exp Med 2005, 201:11-17. p
25. Reichlin M, Wolfson Reichlin M: Autoantibodies to the Ro/SS-A
particle react preferentially with the human antigen. J Immunol
1989, 2:359-365. 26. Slobbe RL, Pruijn GJ, Damen WG, Van der Kemp JW, Van Venrooij
WJ: Detection and occurence of the 60- and 52-kD Ro (SS-A)
antigens and of autoantibodies against these proteins. Clin
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27. Kamel R, Eftekhari P, Clancy R, Buyon JP, Hoebeke J: Autoanti-
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Meningitis caused by Salmonella enterica serotype Panama in Brazil: first case reported
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Revista da Sociedade Brasileira de Medicina Tropical
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Abstract Salmonella infections usually occur as gastroenteritis that is generally self-limited. However, some serotypes of Salmonella can
cause severe extra-intestinal infections, such as bacteremia and meningitis. Here, we report the first Salmonella Panama case of
meningitis in 4-month-old male newborn in Brazil. The invasive strain isolated was susceptible to all antimicrobial agents tested. The genes agfA, fimA, invA, sfbA, phoP, and slyA were detected using polymerase chain reactions. These findings are relevant
and physicians should be alert to the possibility of meningitis in newborns due to S. Panama, which can present a high rate of
mortality or recurrence of infection. Keywords: S. Panama. Meningitis. Newborn. Keywords: S. Panama. Meningitis. Newborn. Keywords: S. Panama. Meningitis. Newborn. INTRODUCTION and the concentration of glucose was 134mg/dL. Gram staining
of the CSF was positive for gram-negative bacilli. The patient
showed drowsiness with a fixed upward stare, irritation, a lack
of appetite to the extent of rejecting food, and uncontrolled
movements in the right arm resembling convulsions or shock. The patient was then moved to a larger medical center in the
City of Fortaleza, where he was diagnosed with neck rigidity
and fontanel protuberant. Salmonella Panama belongs to the D1 serogroup and is
frequently found in cases of nontyphoid salmonellosis in patients
from different countries1,2. This serotype generally causes
gastroenteritis, but it is one of the many serotypes that tends to
cause invasive illnesses and may be associated with bacteremia
and meningitis in children1-4. We describe here the first case of
meningitis in humans caused by S. Panama in Brazil. The CSF sample was subjected to bacteriological analysis
and standard biochemical reactions yielded the presence
of Salmonella spp., which was subsequently typed as
S. enterica serotype Panama. Blood culture testing was
not carried out. The isolate was sensitive to ampicillin,
ceftazidime, ceftriaxone, ciprofloxacin, chloramphenicol, and
sulfamethoxazole-trimethoprim. The patient was initiated on
intravenous ceftriaxone for 21 days (80mg/kg of body weight/
day). CSF analysis carried out before his discharge from the
hospital revealed a cell count of 40/mm3, of which 89% were
lymphocytes and 7% were neutrophils. The protein and glucose
concentrations were 132mg/dL and 12mg/dL, respectively. Blood analysis revealed a leucocyte concentration of 8.6×103
cells/mm3, with a neutrophilic versus mononuclear cell ratio of
64% versus 34%. The platelet count was 393,000 cells/mm3. The CSF bacterioscopy and culture, and the urine cultures were
negative for S. Panama. Stool culture was not carried out on
admission or on discharge. The patient lived with his parents and
his 5-year-old brother, who were all healthy, in a good-standard
residence in terms of plumbing and sanitary conditions, and the
family had a pet dog. Maria Regina Pires Carneiro[1], Maria Iracema de Aguiar Patrício[2], Sona Jain[1],
Dalia dos Prazeres Rodrigues[3] and Sergio Eduardo Longo Fracalanzza[4] [1]. Departamento de Morfologia, Universidade Federal de Sergipe, São Cristóvão, SE, Brasil. [2]. Laboratório Central de Saúde Pública, Secretaria de Saúde do Estado do Ceará, Fortaleza, CE, Brasil. [3]. Laboratório de Referência Nacional de Enteroinfecções Bacterianas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil. [4]. Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil. Rev Soc Bras Med Trop 51(2):244-246, March-April, 2018
doi: 10.1590/0037-8682-0367-2017 Case Report Corresponding author: Drª Maria Regina Pires Carneiro.
e-mail: profregina@hotmail.com
Received 23 September 2017
Accepted 25 January 2018 DISCUSSION incriminated as the source of S. Panama in a case of meningitis
in a newborn. On the other hand, rehydration of powdered milk
with contaminated water could also carry infection. However,
we did not find any reference of the type of food consumed in
the patient’s records. The fecal-oral transmission from an adult
living in the same house is a possibility1, but this hypothesis was
not investigated in cultures of fecal material from the parents
or the brother, even if they did not exhibit symptoms, which
does not exclude the possibility of an asymptomatic infection
or carrier condition. S. Panama has been found to colonize or
cause infection in dogs12 and the family of the patient studied
considered the presence of a pet dog, but this hypothesis was
not analyzed either. An interesting point in our study was the susceptibility of
the S. Panama isolate to all the antimicrobials tested. Similar
results were obtained in a wider study carried out with 43
S. Panama isolates obtained from the same geographical region
(NE Brazil), from different sources such as human, animal, and
food (unpublished data). In contrast with our findings, studies
carried out in other countries including Brazil have suggested
that invasive strains of S. Panama generally present a very high
resistance rate to antimicrobial agents3,5-7. Our results suggest
that the acquisition of antimicrobial resistance may not be
the main factor of virulence that favors the colonization and
posterior invasion of S. Panama in humans in Brazil. Thus, we report in this paper the first case of meningitis
caused by S. Panama in a 4-month-old baby in Brazil. This
finding is relevant and Brazilian physicians should be alert to
the possibility of the occurrence of meningitis in newborns
under 12 months of age that have Salmonella detected in feces,
urine, and blood, especially S. Panama, which can be invasive
and present a high rate of mortality or recurrence of infection. Virulence markers produced by the invasive strain were
analyzed using polymerase chain reaction (PCR) assays, which
revealed the presence agfA and fimA (related to adherence to
host cell receptors), invA (invasion), sfbA (component of the
iron transport system), phoP (survival in macrophages), and
slyA (resistance to oxidative stress) genes. Acknowledgements The authors thank Central Laboratory of Public Health [Laboratório Central
de Saúde Pública (LACEN)] of the Ceará, Pernambuco, Bahia, Sergipe and
Rio Grande do Norte States for providing Salmonella strains. DISCUSSION The presence and
expression of these virulence genes could play an important
role and contribute to the capacity of this serotype to cause
illnesses, including invasive illnesses such as meningitis, as
has already been shown with other serotypes of Salmonella
species8. Experiments carried out using the murine infection
model showed that some serotypes of Salmonella could have
invasive characteristics, but S. Panama did not show this
ability9. However, another study suggested that S. Panama is
more invasive than S. Typhimurium when tested in Hep-2 cells2. CASE REPORT A 4-month-old male newborn weighing 5,500g with a body
temperature of 39ºC, diarrhea, and cough was taken to a small
hospital in the town of Russas, 150km from Fortaleza, the capital
of Ceará State, Northeast (NE) Brazil, where he was admitted
and remained for two days with suspected virosis. Without
showing any improvement, the patient underwent lumbar
puncture and the cerebrospinal fluid (CSF) presented intense
pleocytosis with a leucocytic count of 11.9×103 cells/mm3
(neutrophilic versus mononuclear cells, 93% versus 7%). The
erythrocyte count in the CSF was 320 cells/mm3, concentration
of proteins was 440mg/dL, and glucose level was 1 mg/dL. The
blood analysis revealed a leucocytic count of 11.1 x 103 cells/
mm3 (neutrophilic versus mononuclear cells, 86% versus 14%) Corresponding author: Drª Maria Regina Pires Carneiro. e-mail: profregina@hotmail.com
Received 23 September 2017
Accepted 25 January 2018 244 Carneiro MRP et al. - Meningitis caused by S. panama Conflict of interest The authors declare that there is no conflict of interest. The authors declare that there is no conflict of interest. Few articles in the international scientific literature show the
presence of virulence-related genes in S. Panama isolates8-11. In
strains of animals originating from Spain, it was demonstrated
that S. Panama harbored all the virulence genes tested, such as
invE/A, phoP/Q, stn, iroB, slyA, hin/H2, and agfA10. Another
study also carried out in Spain in the Principality of Asturias with
isolates from different sources showed that all the strains of S. Panama were negative for spvC, which is a virulence plasmidial
gene, but were positive for invA, phoP, stn, and slyA8. More
studies are necessary to clarify the role of virulence-related
genes in the invasiveness of the S. Panama serotype. 12. Tsai HJ, Huang HC, Lin CM, Lien YY, Chou CH. Salmonellae and
campylobacters in household and stray dogs in northern Taiwan.
Vet Res Commun. 2007;31(8):931-9. 8. Soto SM, Guerra B, del Cerro A, González-Hevia MA, Mendoz
MC. Outbreaks and sporadic cases of Salmonella serovar panama
studied by DNA fingerprinting and antimicrobial resistance. Int J
Food Microbiol. 2001;71(1):35-43. REFERENCES 1. Choudhury SA, Berthaud V, Weitkamp JH. Meningitis caused by
Salmonella Panama in infants. J Natl Med Assoc. 2006;98(2):219-22. 2. Yang YJ, Huang MC, Wang SM, Wu JJ, Cheng CP, Liu CC. Analysis
of risk factors for bacteremia in children with nontyphoidal
Salmonella gastroenteritis. Eur J Clin Microbiol Infect Dis. 2002;21(4):290-3. 3. Tsai KS, Yang YJ, Wang SM, Chiou CS, Liu CC. Change of
serotype pattern of Group D non-typhoidal Salmonella isolated
from pediatric patients in southern Taiwan. J Microbiol Immunol
Infect. 2007;40(3):234-9. Unfortunately, we were not able to determine the source
and the route of transmission of the invasive S. Panama strain
in the patient. In children with gastroenteritis from nontyphoid
Salmonella, prolonged fever over five or more days and infection
by a specific serotype of Salmonella, such as S. Panama, are
strong factors associated with the development of bacteremia2,
and consequently, meningitis. The newborn studied in this
work presented a fever of 39ºC for more than five days and had
diarrhea, which suggested gastroenteritis, but a stool culture was
not requested by the physician that was taking care of the patient. 4. Chen TL, Thien PF, Liaw SC, Fung CP, Siu LK. First report of
Salmonella enterica serotype Panama meningitis associated with
consumption of contaminated breast milk by a neonate. J Clin
Microbiol. 2005;43(10):5400-2. 5. Carvalho FCT, Sousa OV, Carvalho EMR, Hofer E, Vieira RHSF. Antibiotic resistance of Salmonella spp. isolated from shrimp
farming freshwater environment in Northeast region of Brazil. J Pathog. 2013;2013, ID 685193:5p. doi:10.1155/2013/685193. 6. Palmeira ALB, Santos LR, Borsoi A, Rodrigues LB, Calasans M,
Nascimento VP. Serovars and antimicrobial resistance of Salmonella
spp. isolated from turkey and broiler carcasses in southern Brazil
between 2004 and 2006. Rev Inst Med Trop São Paulo. 2016;58:19. It is widely known that salmonellosis in humans occurs
mainly due to the consumption of contaminated water and food. Due to the age of the patient (4 months), it is probable that he
only fed on maternal milk or another type of milk, whether it
was natural, pasteurized, or even reconstituted powdered milk. In this situation, contamination could have originated from
different sources. In this study, contaminated maternal milk was 7. Huang SC, Chiu CH, Chiou CS, Yang YJ. Multidrug-resistant
Salmonella enterica serovar Panama carrying class 1 integrons
is invasive in Taiwanese children. J Formos Med Assoc. 2013;112(5):269-75. Salmonella isolated from samples of animal origin. Food Microbiol.
2003;20(4):431-8. Salmonella isolated from samples of animal origin. Food Microbiol.
2003;20(4):431-8. REFERENCES 245 Rev Soc Bras Med Trop 51(2):244-246, March-April, 2018 Salmonella isolated from samples of animal origin. Food Microbiol. 2003;20(4):431-8. 8. Soto SM, Guerra B, del Cerro A, González-Hevia MA, Mendoz
MC. Outbreaks and sporadic cases of Salmonella serovar panama
studied by DNA fingerprinting and antimicrobial resistance. Int J
Food Microbiol. 2001;71(1):35-43. 11. Rowlands REG, Ristori CA, Ikuno AA, Barbosa ML, Jakabi M,
Franco BDGM. Prevalence of drug resistance and virulence
features in Salmonella spp. isolated from foods associated or
not with salmonellosis in Brazil. Rev Inst Med Trop Sao Paulo. 2014;56(6):461-7. 11. 9. Helmuth R, Stephan R, Bunge C, Hoog B, Steinbeck A, Bulling E. Epidemiology of virulence-associated plasmids and outer membrane
protein patterns within seven common Salmonella serotypes. Infect
Immun. 1985;48(1):175-82. 12. Tsai HJ, Huang HC, Lin CM, Lien YY, Chou CH. Salmonellae and
campylobacters in household and stray dogs in northern Taiwan. Vet Res Commun. 2007;31(8):931-9. 10. Del Cerro A, Soto SM, Mendoza MC. Virulence and antimicrobial-
resistance gene profiles determined by PCR-based procedures for 246
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74-week follow-up of safety of infliximab in patients with refractory rheumatoid arthritis
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RESEARCH ARTICLE Open Access © 2010 Delabaye and De Keyser; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and repro-
duction in any medium, provided the original work is properly cited. Abstract Introduction: The objective was to describe the prevalence, types, and predictors of adverse events (AEs) in
rheumatoid arthritis (RA) patients treated with infliximab and methotrexate in a daily clinical setting. Methods: This was a prospective, multi-center, open-label, 74-week observational study in patients with active RA
despite treatment with methotrexate and at least one other disease-modifying anti-rheumatic drug. Patients were
treated with 3 mg/kg infliximab at weeks 0, 2, and 6 and then every 8 weeks. At weeks 0, 6, 26, 50, and 74, patients
answered a health assessment questionnaire, a swollen joint count was made, and adverse events (AEs) occurring
during the previous period were registered. Results: Five hundred and seventy-five patients were treated with infliximab, of which 346 were still on infliximab at
the study end, 158 discontinued treatment, and 71 were lost to follow-up. Reasons for discontinuation included safety
(n = 74), elective reasons (n = 43), and inefficacy (n = 41). Infusion reactions (n = 33) and infections (n = 20) were the
most common AEs causing discontinuation and the most common AEs overall. There were four cases of tuberculosis,
all of which occurred in patients negative at screening. Total AEs, serious AEs, and infusion reactions as well as
discontinuations for AEs were most frequent during the first 26 weeks. Higher age was a predictor of serious adverse
events (SAEs), infection, and discontinuation due to an SAE, but odds ratios were close to one. Conclusions: AEs and discontinuations due to AEs occur most frequently during the first half year of infliximab
treatment in refractory RA patients. The main reasons for discontinuing treatment are infections and infusion reactions. Tuberculosis and other infections remain an important concern in these patients. advance in the treatment of RA [1]. Many of these biolog-
ical agents act by neutralizing TNF-α, which plays a cen-
tral role in the chronic inflammation and tissue damage
of RA [6]. Infliximab is a monoclonal antibody that binds
with high affinity and specificity to human TNF and neu-
tralizes its biologic activity [7]. To date, four double-
blind, placebo-controlled, randomized studies have been
completed in patients with active RA despite DMARD
therapy [8-11]. These studies have shown clinical
response rates of 40% to 60% in patients treated with a
combination of MTX and infliximab. * Correspondence: filip.dekeyser@ugent.be
2 Ghent University, Department of Rheumatology, Ghent University Hospital,
De Pintelaan 185, Ghent, B-9000, Belgium
Full list of author information is available at the end of the article Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Research article
74-week follow-up of safety of infliximab in
patients with refractory rheumatoid arthritis Isabelle Delabaye1,3, Filip De Keyser*2 for the REMITRACT study group Isabelle Delabaye1,3, Filip De Keyser*2 for the REMITRACT study group Introduction Rheumatoid arthritis (RA) is a chronic inflammatory
autoimmune disorder of unknown etiology that occurs in
approximately 0.8% of the population [1]. Initial therapy
for RA has included non-steroidal anti-inflammatory
drugs (NSAIDs), ultimately giving way to oral steroids
and disease-modifying antirheumatic drugs (DMARDs). More recent practice is to initiate DMARDs early [2-4]. Methotrexate (MTX) has become the DMARD of choice
because of its relatively rapid mode of action and good
control during prolonged use; however, for many
patients, MTX provides only partial relief of signs and
symptoms [5]. The most common adverse events (AEs) found in clini-
cal trials of infliximab include upper respiratory tract
infection, headache, nausea, sinusitis, rash, pharyngitis,
and cough, with infusion reactions (IRs) reported in 5%
to 20% of patients [9,12]. Although the clinical trials did
not show a significant increase in the risk of infections
with the use of infliximab, a meta-analysis of randomized
clinical studies found a significantly higher rate of serious The development of biological agents targeting the
interaction between effector cells has been a major Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 2 of 12 infections [13]. Also, some reports have suggested an
increased risk of malignancies, especially lymphoma, in
RA patients treated with anti-TNF-α therapies [13-15],
but this has been refuted by several recent studies [16-
18]. Several observational and retrospective studies have
shown that, in daily practice, up to one-fourth or one-
third of patients discontinue infliximab within one year
and that roughly one-third of discontinuations are due to
AEs, with IRs the most common type causing discontinu-
ation [19-21]. teins; serious infections, such as hepatitis, pneumonia,
and pyelonephritis in the previous three months; history
of opportunistic infections such as herpes zoster within
two months of screening; evidence of active cytomegalo-
virus, active Pneumocystis carinii, drug-resistant atypical
mycobacterium, or other opportunistic infections; docu-
mented infection with HIV; current signs or symptoms of
severe, progressive, or uncontrolled renal, hepatic, hema-
tologic, endocrine, pulmonary, cardiac, neurologic, or
cerebral disease; previous or concurrent malignancies,
with the exception of surgically cured carcinoma in situ
of the cervix and surgically cured basal or squamous cell
carcinoma of the skin; alcoholism, alcoholic liver disease,
or other chronic liver disease; and congestive heart failure
grade III and IV. Here, we performed a multi-center, prospective, obser-
vational study on the safety of infliximab in combination
with MTX. Treatments Treatment was initiated in eligible patients within four
weeks of the screening visit. Patients received an infusion
of 3 mg/kg infliximab (Remicade®; Centocor, Leiden, The
Netherlands) at weeks 0, 2, and 6 and then every 8 weeks. Dose escalations or shortening of treatment intervals
were not permitted. Introduction The aims of this study were to describe the
prevalence and types of AEs and identify predictors of
AEs and treatment discontinuation. This information
should provide expanded data to health care workers and
authorities to help estimate and support the appropriate
use of infliximab. Study design and patient selection This was a prospective, multi-center, open-label, observa-
tional study of infliximab in the treatment of patients
with active RA despite treatment with MTX and at least
one other DMARD. The study was carried out at 77 cen-
ters in Belgium between July 2002 and June 2006. The
protocol was approved by the ethics committees of the
participating study centers, and the study was conducted
in accordance with the Declaration of Helsinki. Prior to
initiating treatment, written informed consent was
obtained from all patients by the treating physician using
a form approved by the ethics committees. The study was
not registered because it was purely observational and
was started in 2002. Clinical evaluations At screening, demographic data and medical history were
obtained, and the patient underwent a physical examina-
tion, had routine baseline (hematology and chemistry)
exams, a chest X-ray, and a Mantoux test. At screening
and at weeks 6, 26, 50, and 74 after the start of treatment,
patients completed a HAQ [22]. In addition, a swollen
joint count (SJC) based on 66 joints was determined [23]. Concurrent medications were recorded at weeks 6, 26,
50, and 74. Patients eligible for this study had to be diagnosed with
erosive RA and have evidence of active disease despite
treatment with MTX and at least one other DMARD. Eli-
gible patients also had to be on a stable dose of 15 mg/wk
or more of MTX given orally or parenterally for at least
three months. Patients with intolerance to MTX despite
the association with folic acid could also be included. Additional inclusion criteria were as follows: men or
women 17 years or older; 8 or more swollen joints; Health
Assessment Questionnaire (HAQ) index of 25 or more
(HAQ score × 10 ÷ 6); and absence of tuberculosis dem-
onstrated by simultaneous negative Mantoux test and
negative chest X-ray. In the case of a positive Mantoux
test or X-ray, the patient had to have had adequate treat-
ment of the tuberculosis for six months before treatment
with infliximab. Women of childbearing potential had to
be using adequate birth control measures. Statistical analysis 77). Other common (>5%) AEs included dermatological
reactions (n = 40), cardiovascular disorders (n = 22), RA-
related disease manifestations (n = 17), and gastrointesti-
nal disorders (n = 17). The most common SAE was infec-
tion (n = 47), followed by IRs (n = 15), cardiovascular
events (n = 15), and RA-related disease manifestations (n
= 11). 77). Other common (>5%) AEs included dermatological
reactions (n = 40), cardiovascular disorders (n = 22), RA-
related disease manifestations (n = 17), and gastrointesti-
nal disorders (n = 17). The most common SAE was infec-
tion (n = 47), followed by IRs (n = 15), cardiovascular
events (n = 15), and RA-related disease manifestations (n
= 11). Descriptive statistics were used for groups with and with-
out AEs, SAEs, and IRs. T-tests were used to examine dif-
ferences in the age, age at diagnosis, severity (HAQ index
and SJC), the dose of MTX, and the duration of disease
between the patients with AEs or SAEs and the patients
who had no AEs or SAEs. Fisher's Exact Tests (or chi
square tests) were used to look for association between
the presence of an AE/SAE and the use of corticosteroids,
the use of MTX, and sex. Logistic (stepwise) regression
analysis was used to assess the ability of baseline charac-
teristics to predict the manifestation of AEs, SAEs, or
infections. Fisher's exact test was used to examine the
association between the use of corticosteroids and the
manifestation of an infection. Means are presented ±
standard deviations, and odds ratios are given with 95%
confidence intervals (CI). There were 93 reported infections in 81 patients. Infec-
tions were most common during the first 26 weeks of the
study (Figure 2b). Approximately half (n = 47) of the
infections were reported as SAEs (Table 2). For cases
where the infectious agent was known, the most common
type was non-tuberculosis-type bacteria (n = 38). Tuber-
culosis accounted for four of the infections (three con-
firmed, one suspected), all of which were considered
SAEs. One was a confirmed case of unspecified tubercu-
losis in a 28-year-old woman who had been exposed to a
family member with an overt tuberculosis infection. The
remaining two confirmed cases were pulmonary tubercu-
losis in a 38-year-old woman and a 43-year-old man who
did not have known exposure to overt tuberculosis. Baseline demographics and patient disposition A total of 596 patients were screened for this study. Of
the 596 screened patients, 575 started infliximab. There
were 71 losses to follow-up, so that 504 patients were
evaluable (Figure 1a). Of these, 158 discontinued inflix-
imab before week 74, and the remaining 346 patients
were still on infliximab according to protocol at week 74. The baseline demographics of the patients receiving at
least one dose of infliximab are shown in Table 1. Nearly
three-quarters of the patients (n = 419; 72.9%) were
female. The mean age of patients was 57 ± 13 years, and
the mean duration of disease was 10.3 ± 9.4 years. The
mean HAQ index at screening was 56.1 ± 15.4, and the
mean SJC at screening was 16.3 ± 7.5. Almost all patients
(n = 537; 93.4%) were taking MTX, and the mean MTX
dose was 14.5 mg/week. A total of 596 patients were screened for this study. Of
the 596 screened patients, 575 started infliximab. There
were 71 losses to follow-up, so that 504 patients were
evaluable (Figure 1a). Of these, 158 discontinued inflix-
imab before week 74, and the remaining 346 patients
were still on infliximab according to protocol at week 74. The baseline demographics of the patients receiving at
least one dose of infliximab are shown in Table 1. Nearly
three-quarters of the patients (n = 419; 72.9%) were
female. The mean age of patients was 57 ± 13 years, and
the mean duration of disease was 10.3 ± 9.4 years. The
mean HAQ index at screening was 56.1 ± 15.4, and the
mean SJC at screening was 16.3 ± 7.5. Almost all patients
(n = 537; 93.4%) were taking MTX, and the mean MTX
dose was 14.5 mg/week. The 77 reported IRs occurred in 64 patients. Fifteen of
these IRs were recorded as SAEs, and 33 led to treatment
discontinuation. Overall, the highest incidence of IRs and
the highest incidence of IRs leading to discontinuation
occurred during the first 26 weeks (Figure 2c). The most
common specific symptoms associated with IRs were
allergic skin reactions (n = 24) and hemodynamic events
(n = 16; Table 3). Both allergic skin reactions and hemo-
dynamic events were most frequent during the first 26
weeks (i.e., following infusion at weeks 6, 14, and 22). Safety evaluations Safety data were collected at weeks 6, 26, 50, and 74 for
events occurring during weeks 0 to 6, 7 to 26, 27 to 50,
and 51 to 74, respectively. A serious adverse event (SAE)
was defined as any AE that resulted in death, was life-
threatening, resulted in a persistent or significant disabil-
ity or incapacity, required hospitalization or prolonged a
hospitalization, or resulted in a congenital anomaly or
birth defect. Also, important medical events that may not
have resulted in death, were not life-threatening, or did
not require hospitalization may have been considered a
SAE when, according to the investigator, they jeopardized
the subject or required medical or surgical intervention
to prevent one of the outcomes defining a SAE. An IR was
defined as any AE that occurred during an infusion,
within one hour after an infusion, or was considered by
the investigator to be infusion-related. For each time
period, the presence or absence of IRs was recorded only
once. Exclusion criteria were as follows: women pregnant,
nursing, or planning a pregnancy within two years of
enrollment; a history of known allergies to murine pro- Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 3 of 12 Efficacy of therapy Efficacy of the treatment was assessed using the HAQ
and by counting the number of swollen joints. The mean
HAQ index decreased from 56.0 ± 15.4 at baseline to 29.0
± 21.4 at week 74 (P < 0.0001), and the SJC decreased
from 16.3 ± 7.5 at baseline to 3.2 ± 4.0 at week 74 (P <
0.0001). During the study, seven tumors were reported in seven
patients (Table 2). Four of the tumors were malignant
(one epidermoid epithelioma of the right lung, one lung
cancer, one carcinoma in situ of the cervix, and one case
of chronic myelomonocytic leukemia). Tumors led to dis-
continuation of treatment in five cases. Further details
about these cases are presented in the Supporting infor-
mation in Additional file 1. Baseline demographics and patient disposition Other common IRs (>5%) included hyperventilation/dys-
pnea (n = 13), flushing (n = 7), hypertension (n = 6),
tachycardia/palpitation (n = 5), and headache (n = 4), all
of which were most frequent during the first 26 weeks of
treatment. Statistical analysis The
fourth case was suspected tuberculosis meningitis in a
69-year-old man that was not confirmed by laboratory
tests and later had a differential diagnosis of viral menin-
gitis. All four reported cases of tuberculosis were in
patients taking corticosteroids at baseline. Further details
about the cases of tuberculosis are presented in the Sup-
porting information in Additional file 1. Adverse events Patients screened
(n=596)
Did not start infliximab (n=21)
Patients started on infliximab
(n=575)
Treatment discontinuations (n=158)
Safety (n=74)
Non-serious AE (n=27)
SAE (n=47)
Inefficacy (n=41)
Elective (n=43)
Noncompliance with protocol (n=22)
Patient withdrew consent (n=17)
Other (n=4)
Patients still on infliximab at study
end (week 74)
(n=346)
Lost to follow-up (n=71)
(a)
(b)
Evaluable patients
(n=504)
Discontinuation-
safety (n=74)
14.7%
Discontinuation-
inefficacy (n=41)
8.1%
Discontinuation-
elective (n=43)
8.5%
Completed to
w eek 74 (n=346)
68.7%
(c)
575
524
444
369
346
0
100
200
300
400
500
600
700
Week 0
Week 6
Week 26
Week 50
Week 74
Patients on infliximab Patients screened
(n=596)
Did not start infliximab (n=21)
Patients started on infliximab
(n=575)
Treatment discontinuations (n=158)
Safety (n=74)
Non-serious AE (n=27)
SAE (n=47)
Inefficacy (n=41)
Elective (n=43)
Noncompliance with protocol (n=22)
Patient withdrew consent (n=17)
Other (n=4)
Patients still on infliximab at study
end (week 74)
(n=346)
Lost to follow-up (n=71)
(a)
Evaluable patients
(n=504) Patients screened
(n=596)
Did not start infliximab (n=21)
Patients started on infliximab
(n=575)
Treatment discontinuations (n=158)
Safety (n=74)
Non-serious AE (n=27)
SAE (n=47)
Inefficacy (n=41)
Elective (n=43)
Noncompliance with protocol (n=22)
Patient withdrew consent (n=17)
Other (n=4)
Patients still on infliximab at study
end (week 74)
(n=346)
Lost to follow-up (n=71)
(a)
Evaluable patients
(n=504) (a) Patients screened
(n=596) Did not start infliximab (n=21) Lost to follow-up (n=71) Evaluable patients
(n=504) Treatment discontinuations (n=158)
Safety (n=74)
Non-serious AE (n=27)
SAE (n=47)
Inefficacy (n=41)
Elective (n=43)
Noncompliance with protocol (n=22)
Patient withdrew consent (n=17)
Other (n=4) (b)
Discontinuation-
safety (n=74)
14.7%
Discontinuation-
inefficacy (n=41)
8.1%
Discontinuation-
elective (n=43)
8.5%
Completed to
w eek 74 (n=346)
68.7%
(c)
575
524
444
369
346
0
100
200
300
400
500
600
700
Week 0
Week 6
Week 26
Week 50
Week 74
Patients on infliximab (c) (b) Discontinuation-
safety (n=74)
14.7% Figure 1 Patient disposition. (a) Flow chart of patient disposition. A total of 596 patients were screened for this study, of which 575 started infliximab. Of these, 71 were lost to follow-up, so that 504 were evaluated. There were 158 patients that discontinued treatment before week 74, and the remain-
ing 346 completed the study according to protocol and were still on infliximab at study end. 'Other' under treatment discontinuations included three
patients that wished to become pregnant and one that withdrew prior to an elective surgery. (b) Patients remaining on infliximab at each visit. Adverse events A total of 338 AEs were registered during the study. Of
these, 121 (35.8%) were considered SAEs (Table 2). The
highest number of AEs occurred during the first 26 weeks
of treatment with infliximab (Figure 2a). Thereafter, the
incidence of AEs decreased gradually over time. Similarly,
AEs considered serious (SAEs) were most common dur-
ing the first 26 weeks. There were 22 cardiovascular disorders reported dur-
ing the study, 15 of which (68.2%) were considered SAEs. Four of these events led to discontinuation, including one As detailed in Table 2, infection was the most com-
monly reported type of AE (n = 93), followed by IRs (n = Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 4 of 12 Figure 1 Patient disposition. (a) Flow chart of patient disposition. A total of 596 patients were screened for this study, of which 575 started infliximab. Of these, 71 were lost to follow-up, so that 504 were evaluated. There were 158 patients that discontinued treatment before week 74, and the remain-
ing 346 completed the study according to protocol and were still on infliximab at study end. 'Other' under treatment discontinuations included three
patients that wished to become pregnant and one that withdrew prior to an elective surgery. (b) Patients remaining on infliximab at each visit. (c)
Fraction of evaluable patients completing the study or discontinuing for safety reasons, inefficacy, or elective reasons. Treatment discontinuations The number of patients remaining in the study at each
visit is shown in Figure 1b. Of the 504 evaluable patients,
a total of 158 (31.3%) discontinued treatment before week
74, so that the continuation rate at the end of the study
was 68.7% (Figure 1c). The leading reason for discontinu-
ation was safety (n = 74; 14.7% of evaluable patients). Dis-
continuation due to inefficacy occurred in 41 cases (8.1%;
Figure 1c). The remaining discontinuations (n = 43; 8.5%)
were due to elective reasons, including withdrawal of
consent (n = 17), noncompliance with the study protocol
(n = 22), wish for pregnancy (n = 3), and wish to stop
prior to an elective surgery (n = 1). Of the 74 discontinua-
tions for safety, the majority (n = 47) were for SAEs,
although many (n = 27) were for AEs that were not seri-
ous (Figure 1a). Treatment discontinuations overall and
for safety or inefficacy were most common during the
first 26 weeks (Figure 3). The AEs most commonly leading to discontinuation
were IRs (n = 33), infections (n = 20), tumors (n = 5 (2
benign and 3 malignant)), cardiovascular events (n = 4),
and dermatological disorders (n = 4; Table 2). There was a
significant association between the occurrence of an AE
and discontinuation due to the AE for IRs (P < 0.0001),
tuberculosis (P = 0.034), tumors (P = 0.0065), and malig-
nant tumors (P = 0.034). Non-serious AEs leading to dis-
continuation included IRs (n = 21), dermatological
disorders (n = 3), neurological (optical neuritis) disorders
(n = 1), psychiatric disorders (n = 1), and RA-related
symptoms (n = 1). Adverse events (c)
Fraction of evaluable patients completing the study or discontinuing for safety reasons, inefficacy, or elective reasons. Page 5 of 12 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Table 1: Baseline demographics of patients receiving at
least one dose of infliximab
Characteristic
Value
Age (years) (n = 575)
Mean ± SD
57 ± 13
Median
58
Range
19 -99
Sex
Female, N (%)
419 (72.9%)
Male, N (%)
156 (27.1%)
Age at diagnosis (years) (n = 564)
Mean ± SD
46.2 ± 13.6
Median
47
Range
5-81
Duration of disease (years) (n = 564)
Mean ± SD
10.3 ± 9.4
Median
8
Range
0-53
HAQ index at screening (n = 573)
Mean ± SD
56.1 ± 15.4
Median
55
Range
2-98
Swollen joint count at screening (n = 568)
Mean ± SD
16.3 ± 7.5
Median
14
Range
0-49
MTX doses in mg/week (n = 425)
Mean ± SD
14.5 ± 3.0
Median
15
Range
5-25
MTX use
Yes, N (%)
537 (93.4%)
No, N (%)
14 (2.4%)
Unknown, N (%)
24 (4.2%)
NSAID use
Yes, N (%)
414 (72%)
No, N (%)
46 (8%)
Unknown, N (%)
115 (20%)
Corticosteroid use
Yes, N (%)
341 (59.3%)
No, N (%)
84 (14.6%)
Unknown, N (%)
150 (26.1%)
HAQ, health assessment questionnaire; MTX, methotrexate;
NSAIDs, nonsteroidal anti-inflammatory drugs; SD, standard Table 1: Baseline demographics of patients receiving at
least one dose of infliximab pulmonary thromboembolism, one case of cardiac isch-
emia, and two fatal events (one myocardial infarct and
one cardiac arrest). Of the dermatological and gastroin-
testinal disorders reported, most (38/40 (95%) and 16/17
(94.1%), respectively) were not considered SAEs. There were a total of nine deaths during the study,
including five for which the main cause of death was
infection (three bacterial, one other opportunistic infec-
tion, and one unknown type), two due to cardiovascular
events (one cardiac arrest and one myocardial infarct),
one due to a traumatic event (traffic accident), and one
due to a psychiatric disorder (suicide). All patients that
died for health reasons were at least 69 years old at the
time of death. Details about the deaths occurring during
this study are provided in the Supporting information in
Additional file 1. Predictors of adverse events, infusion reactions, and
treatment discontinuation Statistical tests were used to determine whether baseline
demographics (age at screening, age at diagnosis, dura-
tion of disease, HAQ index, SJC, sex, use of corticoster-
oids, and dose of MTX) were associated with or could Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 6 of 12 Table 2: Types and severity of adverse events
All AEs
SAEs
AEs Leading to discontinuation
Any
338 (168)
121 (89)
74
Infection
93 (81)
47 (42)
20
Tuberculosisa
4 (4)
4 (4)
3
Other bacterial Infection
38 (33)
29 (24)
10
Viral Infection
8 (8)
5 (5)
1
Opportunistic infectiona
8 (8)
3 (3)
2
Other
35 (32)
6 (6)
4
Infusion reactionb
77 (64)
15 (15)
33
Dermatological disorders
40 (33)
2 (2)
4
Cardiovascular disorders
22 (20)
15 (13)
4
RA-related disease manifestations
17 (16)
11 (11)
2
Gastrointestinal disorders
17 (16)
1 (1)
-
Respiratory disorders
11 (10)
4 (4)
-
Neurologic disorder
11 (10)
1 (1)
1
Non-RA joint manifestations
8 (8)
4 (4)
-
Tumora
7 (7)
6 (6)
5
Benign
3 (3)
2 (2)
2
Malignant
4 (4)
4 (4)
3
Traumatic event
7 (7)
4 (4)
1
Hematologic disorders
4 (4)
4 (4)
1
Psychiatric disorders
3 (3)
1 (1)
2
Liver toxicities
2 (2)
1 (1)
-
Other
19 (16)
5 (5)
1
Values are numbers of AEs, with the number of patients affected shown in parentheses. a See Supporting information in Additional file 1 for further details. b Individual infusion reactions are described in Table 3. AE, adverse event; RA, rheumatoid arthritis; SAE, serious adverse event. Table 2: Types and severity of adverse events was longer than most randomized clinical trials that have
examined the safety of infliximab (mean 0.8 years) [16]. In this study, the most common reason for discontinuing
treatment was an AE, of which infections and IRs were
the most frequent causes. We also found that AEs as well
as discontinuations for AEs most often occurred during
the first 26 weeks of treatment. predict the manifestation of AEs overall, infections, or
IRs or the discontinuation of treatment. Higher age at
screening was significantly associated with (P = 0.043)
AEs. Predictors of adverse events, infusion reactions, and
treatment discontinuation In addition, higher age was a predictor of the mani-
festation of AEs (P = 0.0016), infection (P = 0.018), and
discontinuation due to an SAE (P = 0.0017), but the odds
ratios were all close to 1.0 (1.047 (95% CI, 1.018 to
1.077)), 1.047 (95% CI, 1.008 to 1.087), and 1.076 (95% CI,
1.028 to 1.127), respectively). Neither corticosteroid use
nor any of the other baseline variables besides age was
associated with or was predictive (P > 0.05) of the occur-
rence of AEs overall, SAEs, infections, IRs, or discontinu-
ation for AEs, SAEs, IRs, or inefficacy. Our study confirmed that infections are the most com-
mon type of AE in RA patients receiving the combination
of infliximab and MTX [20,24,25]. Approximately half of
all infections were considered SAEs, and infections were
also the most common type of SAE. The rate of infections
considered SAEs in this study (7.4%; (42 of 575 patients))
was similar to that reported using the same dose of inflix-
imab in ATTEST (Abatacept or infliximab vs placebo, a
Trial for Tolerability, Efficacy and Safety in Treating rheu-
matoid arthritis) (8.5%) [26]. In addition, after IRs, infec-
tions were the second leading cause of discontinuation. Discussion This was a 74-week prospective study on the safety of inf-
liximab in patients that had active RA despite treatment
with MTX and at least one other DMARD. This study Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 7 of 12 (a)
124
49
36
71
33
15
0
50
100
150
200
250
Week 0-26
Week 27-50
Week 51-74
Number of AEs
SAE
Non-serious AE (a) Figure 2 Incidence of (a) AEs, (b) infections, and (c) IRs during the study. The incidence of (a) all adverse events (AEs), (b) infections, and (c) in-
fusion reactions (IRs) are shown for weeks 0 to 26, 27 to 50, and 51 to 74. The week 0 to 26 values were calculated by summing the number events for
weeks 0 to 6 and weeks 7 to 26. For each time period, the presence or absence of IRs was recorded only a single time. However, this did not affect the
calculation of the week 0 to 26 value from the week 0 to 6 and week 7 to 26 values. (a)
(b)
39
12
11
12
3
0
10
20
30
40
50
60
Week 0-26
Week 27-50
Week 51-74
Number of IRs
SAE
Non-serious AE
124
49
36
71
33
15
0
50
100
150
200
250
Week 0-26
Week 27-50
Week 51-74
Number of AEs
SAE
Non-serious AE
(c)
23
12
11
28
13
6
0
10
20
30
40
50
60
Week 0-26
Week 27-50
Week 51-74
Number of Infections
SAEs
Non-serious AEs (b)
23
12
11
28
13
6
0
10
20
30
40
50
60
Week 0-26
Week 27-50
Week 51-74
Number of Infections
SAEs
Non-serious AEs (b) 39
12
11
12
3
0
10
20
30
40
50
60
Week 0-26
Week 27-50
Week 51-74
Number of IRs
SAE
Non-serious AE
(c) (c) Figure 2 Incidence of (a) AEs, (b) infections, and (c) IRs during the study. The incidence of (a) all adverse events (AEs), (b) infections, and (c) in-
fusion reactions (IRs) are shown for weeks 0 to 26, 27 to 50, and 51 to 74. The week 0 to 26 values were calculated by summing the number events for
weeks 0 to 6 and weeks 7 to 26. For each time period, the presence or absence of IRs was recorded only a single time. Discussion However, this did not affect the
calculation of the week 0 to 26 value from the week 0 to 6 and week 7 to 26 values. Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 8 of 12 Table 3: Infusion-related events and symptoms Table 3: Infusion-related events and symptoms
Week 0 to 6
Week 7 to 26
Week 27 to 50
Week 51 to 74
Total
Infusion-related eventsa
23
28
15
11
77
Symptom
Allergic skin reaction
2
13
6
3
24
Hemodynamic events (hypotension,
syncope, bradycardia, cyanosis)
4
8
2
2
16
Hyperventilation/dyspnea
1
5
5
2
13
Flushing
0
4
2
1
7
Hypertension
2
3
0
1
6
Tachycardia/palpitation
2
2
1
0
5
Headache
1
1
1
1
4
Throat, Quincke's, or mouth edema
0
2
1
0
3
Polyathralgia
2
0
0
1
3
Limb edema
1
1
0
0
2
Flu-like symptom
2
0
0
0
2
Allergic reaction, unspecified
1
0
0
0
1
Other
9
8
5
4
26
a Each infusion reactions could result in multiple symptoms so that the total number of symptoms (n = 112) exceeded the number of infusion-
related events (n = 77). Also, infections led to five of the nine deaths. The most
common type of infection was non-tuberculosis bacteria,
although viral infections were also common. This agrees
with data from the Swedish practice-based registry
ARTIS (AntiRheumatic Therapies In Sweden), which
indicate that there is a slight increase in the risk of infec-
tion in RA patients treated with anti-TNF-α agents but
that it is not driven by any particular type of infection
[27]. A recent meta-analysis of randomized clinical trials
by Leombruno and colleagues, however, did not find an
increased risk of serious infections in RA patients treated with recommended doses of anti-TNF-α therapies [16]. Similar to Takeuchi and colleagues [28], we found that
older patients were more likely to have infections,
although the odds ratio was close to 1.0. It is also note-
worthy that all patients that died from infections were at
least 69 years old. Finally, although our study confirms
that infections are a reason for concern in refractory RA
patients, we cannot determine whether the risk for infec-
tion or death due to an infection was increased by treat-
ment with infliximab. Discussion There were four cases of malignant tumors, three of
which led to treatment discontinuation. However, there
were no cases of lymphoma, all four were different tumor
types, and there were no obvious relations between the
incidence of tumors and any of the patient characteris-
tics. Infections were also most common during the first 26
weeks of the study. This agrees with the findings of the
ARTIS study, where the risk of infection was highest in
the first year [27]. We suspect that this was due to the dis-
continuation of susceptible patients rather than an adap-
tation to the treatment. This is supported by the fact that
discontinuation for any AE was most common during the
first 26 weeks. Moreover, using data from a registry of
British patients, Dixon and colleagues showed that the
risk of serious infection is highest in the first six months
after the initiation of anti-TNF-α therapies and that the
reduction in risk thereafter is associated with physicians
excluding patients considered at high risk [41]. Regard-
less of the reason for the lower risk for infection with
time, some risk is always present, so physicians should
remain vigilant during the course of treatment with inf-
liximab or any other anti-TNF-α therapy. We also paid close attention to the incidence of cardio-
vascular AEs because RA patients are at increased risk
[33]. Cardiovascular events accounted for 4 of 74 treat-
ment discontinuations, and they were the fourth most
common AE overall. They also accounted for two of the
nine deaths. Despite the importance of cardiovascular
events, there is good evidence that anti-TNF-α therapies
reduce the risk in patients with RA to the level in the non-
RA population [33-35]. AEs overall, SAEs, and IRs were most common during
the first 26 weeks of treatment. We found an association
with higher age and the appearance of AEs overall. Also,
higher age was a predictor of SAEs, infections, and dis-
continuation due to a SAE, but the odds ratios were all
close to 1.0. Otherwise, we did not identify significant
risk factors for AEs overall, SAEs, infections, or IRs in this
study. Prior to beginning the study, we speculated that the use
of corticosteroids would reduce the frequency of IRs and
increase the frequency of infections. Discussion With regard to infections, of particular concern is the
increased risk for tuberculosis in patients treated with
infliximab, which is generally thought to be due to a lack
of compliance with recommendations to prevent reacti-
vation of latent tuberculosis infections [29,30]. In the cur-
rent study, there were four cases of tuberculosis (three
confirmed, one suspected). All four were in patients with
negative Mantoux tests and chest X-rays at screening. One of the confirmed cases of tuberculosis appeared to
be a new case caused by exposure to a family member
with overt tuberculosis. The remaining could have been
new cases of tuberculosis, but they may have also been
due to latent infections that went undetected by the
screening tests [30]. Interestingly, all four cases of tuber-
culosis were in patients taking corticosteroids at baseline,
which could have masked the Mantoux test or caused
further suppression of the patient's immune system. Regardless of the reasons for these infections, we concur Figure 3 Treatment discontinuations over time. 43
25
6
14
5
21
18
4
22
0
10
20
30
40
50
60
70
80
90
100
Week 0-26
Week 27-50
Week 51-74
Patients discontinuing
Elective
Inefficacy
Safety Figure 3 Treatment discontinuations over time. Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Page 9 of 12 with the conclusion of Theis and Rhodes [30] that,
despite screening and efforts to treat latent infections, cli-
nicians need to carefully monitor for the emergence of
tuberculosis infections in patients receiving anti-TNF-α
therapies. respectively) in a previous multicenter study carried out
in Belgium [39]. This difference was partly due to the fact
that dose increases were possible in the previous study
but not here. In addition, the current study took place
after etanercept and adalimumab became available, so
that patients had the option of switching to alternative
anti-TNF-α therapies. Thus, patients would have been
more likely in the current study to discontinue treatment
if they or the investigator were uncomfortable with the
AEs or the level of efficacy. In addition to infection, IRs are common in patients
treated with anti-TNF-α therapies and are a frequent rea-
son for discontinuation [31]. In this study, IRs were the
second-most common type of AE. Discussion In nearly half of these
cases (42.8%), the IRs caused treatment discontinuation,
although, in many cases, the IR causing discontinuation
was not considered an SAE. In agreement with
Kapetanovic and colleagues [32], age, sex, and HAQ
results were not risk factors for IRs. In contrast to their
report, however, we did not find an association between
IRs and age at diagnosis/onset or longer disease duration. In addition to infection, IRs are common in patients
treated with anti-TNF-α therapies and are a frequent rea-
son for discontinuation [31]. In this study, IRs were the
second-most common type of AE. In nearly half of these
cases (42.8%), the IRs caused treatment discontinuation,
although, in many cases, the IR causing discontinuation
was not considered an SAE. In agreement with
Kapetanovic and colleagues [32], age, sex, and HAQ
results were not risk factors for IRs. In contrast to their
report, however, we did not find an association between
IRs and age at diagnosis/onset or longer disease duration. Some early studies suggest that anti-TNF-α agents may
increase the risk of malignancies, especially lymphoma
[13-15]. However, this is not supported by a more recent
meta-analysis of clinical trial data or more recent data
from clinical registries [16-18]. Nevertheless, we paid
close attention to the appearance of malignant tumors. There were four cases of malignant tumors, three of
which led to treatment discontinuation. However, there
were no cases of lymphoma, all four were different tumor
types, and there were no obvious relations between the
incidence of tumors and any of the patient characteris-
tics. Treatment discontinuations were most frequent during
the first 26 weeks. The AEs most frequently leading to
discontinuation were IRs, followed by infections. Baseline
characteristics, including age, did not appear to predis-
pose patients to discontinuation due to an AE. Higher age
was a significant predictor of discontinuation due to an
SAE, but the odds ratio was close to 1.0. Similarly, Chevil-
lotte-Maillard et al. reported no difference in discontinu-
ation rates (median one-year follow-up) or drug survival
curves between older and younger patients treated with
infliximab [40]. Some early studies suggest that anti-TNF-α agents may
increase the risk of malignancies, especially lymphoma
[13-15]. However, this is not supported by a more recent
meta-analysis of clinical trial data or more recent data
from clinical registries [16-18]. Nevertheless, we paid
close attention to the appearance of malignant tumors. Discussion Poriau S., Elisa-
bethziekenhuis - Sijsele; Dr. Praet J., Aalst; Dr. Raeman F.,
Jan Palfijnziekenhuis - Merksem; Dr. Ravelingien I., Onze
Lieve Vrouwziekenhuis - Aalst; Dr. Ribbens C., CHU Sart
Tilman - Liège; Dr. Ronsmans I., Clinique Sainte-Elisa-
beth - Namur; Dr. Schatteman L., AZ Sint-Augustinus -
Wilrijk; Dr. Schreiber S., CHU Tivoli - La Louvière; Dr. Stappaerts G., AZ Maria Middelares St.Jozef - Gent; Dr. Stasse P., Clinique St-Joseph - Mons; Dr. Stuer A., Heilig
Hart Ziekenhuis - Roeselare; Dr. Van Bruwaene F., Heilig
Hart Ziekenhuis - Roeselare; Dr. Van Den Berghe M., AZ
Zusters van Barmhartigheid - Ronse; Dr. Van Den Bosch
F., Elisabethziekenhuis - Sijsele; Dr. Van den Bossche N.,
Stadskliniek - St.Niklaas; Dr. Van Essche E., Onze Lieve
Vrouwziekenhuis - Mechelen; Dr. Van Wanghe P., Virga
Jesse Ziekenhuis - Hasselt; Dr. Vanden Berghe M., Hôpit-
al St- Thérèse - Montignies-Sur-Sambre; Dr. Vanhoof J.,
ZOL - Genk; Dr. Vanneuville B., Stedelijk Ziekenhuis -
Roeselare; Dr. Villers C., CH Grand Hornu; Dr. Volders P.,
Reuma Centrum - Genk; Dr. Vroninks P., Salvatorzieken-
huis -Hasselt;Dr. Walravens M., Mol; Dr. Williame L., AZ
Middelheim - Antwerp; Dr. Wouters M., Parc Leopold -
Brussels; Dr. Zmierczak HG., Kliniek St-Elisabeth - Zotte-
gem; Prof. Appelboom T., ULB - Hôpital Erasme - Brus-
sels; Prof. Boutsen Y., UCL Mont-Godinne; Prof. De
Clerck L., UZ Antwerp; Prof. Devogelaer JP., UCL Saint-
Luc - Brussels; Prof. E.M. Veys, UZ Gent; Prof. Houssiau
F., UCL Saint-Luc - Brussels; Prof. Mielants H., AZ Sint-
Augustinus - Wilrijk; Prof. Peretz A., CHU Brugmann -
Brussels; Prof. Steinfeld S., ULB - Hôpital Erasme - Brus-
sels; Prof. Verbruggen G., Prive Praktijk - Izegem; Prof. Verbruggen L., AZ VUB - Brussels; Prof. Westhovens R.,
UZ Gasthuisberg - Leuven. oids masked the Mantoux results or increased the risk for
tuberculosis infections in these patients by suppressing
their immune systems. Acknowledgements The authors would like to thank Dr. Phillip Leventhal
(4Clincs, Paris) for assistance in writing this manuscript,
and Mrs. Annelies Vanneuville (Denys Research Consul-
tants bvba, Gent) for assistance in data management, and
Mrs. Hermine Leroi for assistance in data analysis. The members of the REMITRACT study group are Dr. Ackerman C., AZ St-Lucas Gent; Dr. André B., CHU Sart
Tilman - Liège; Dr. Badot V., CHU Brugmann - Brussels;
Dr. Bailleul Y., CH Institut Bracops site Anderlecht; Dr. Bentin J., RHMS Louis Caty - Baudour; Dr. Berghs H.,
ZOL - Genk; Dr. Brasseur J.P., Clinique St-Pierre - Ottig-
nies; Dr. Castro S., AZ Maria Middelares St.Jozef - Gent;
Dr. Cheroutre G., Polikliniek Bond Moyson - Wetteren;
Dr. Coigné E., Jan Yperman Ziekenhuis - Ieper; Dr. Cop-
pens M., ZOL - Genk; Dr. Corluy L., Virga Jesse Zieken-
huis - Hasselt; Dr. Cornet Fr., CHR La Tourelle - Verviers;
Dr. Courtois C., Clinique Notre Dame - Tournai; Dr. Cou-
tellier P., Clinique Saint Luc - Bouge; Dr. Dall Armellina
S., Clinique Notre Dame De Grace - Gosselies; Dr. Daumerie F., Hôpital de Jolimont - Haine-Saint-Paul; Dr. De Brabanter G., AZ Sint Lucas/Sint Jozef - Assebroek;
Dr. De Clercq L., AZ Sint-Augustinus - Wilrijk; Dr. De
Decker V., CHU André Vésale - Montigny-le-tilleul; Dr. De Graeve B., Maria Middelares - St.Niklaas; Dr. De Vlam
K., Sint Andries Ziekenhuis - Tielt; Dr. Declerck K.,
Imeldaziekenhuis - Mechelen; Dr. Dhondt E., AZ St-Jan -
Brugge; Dr. Di Romana S., CHU St-Pierre - Brussels; Dr. Docquier C., Hôpital de Jolimont - Haine-Saint-Paul; Dr. Dufour JP., UCL Saint-Luc - Brussels; Dr. Dumont M.,
CH Bois Abbaye et Hesbaye - Waremme; Dr. Durez P.,
UCL Saint-Luc - Brussels; Dr. Engelbeen J.P., Clinique
Ste-Anne/St-Rémi - Brussels; Dr. Fernandez Lopez MJ.,
CHU Brugmann - Brussels; Dr. Francois D., Clinique
Europe St-Michel - Brussels; Dr. Geusens P., ZOL - Genk;
Dr. Ghyselen G., OCMW Stadskliniek - Lokeren; Dr. Goemaere S., UZ Gent; Dr. Goethals L., AZ Stuyvenberg
- Antwerp; Dr. Golstein M., Hôpital César de Paepe -
Brussels; Dr. Gyselbrecht L., Aalsters Stedelijk Zieken-
huis; Dr. Halleux R., Clinique Sainte-Elisabeth - Heusy;
Dr. Herman H., AZ Sint Blasius - Dendermonde; Dr. Her-
manns P., AZ Maria Middelares - Gent; Dr. Heuse E., Conclusions In conclusion, we found that, in RA patients treated with
infliximab and MTX, discontinuations and AEs occur
most frequently during the first 26 weeks of treatment. The study also emphasizes that physicians should care-
fully monitor patients for the appearance of infections,
including but not limited to tuberculosis and other bacte-
rial infections. Discussion Ronsmans I., Clinique Sainte-Elisa-
beth - Namur; Dr. Schatteman L., AZ Sint-Augustinus -
Wilrijk; Dr. Schreiber S., CHU Tivoli - La Louvière; Dr. Stappaerts G., AZ Maria Middelares St.Jozef - Gent; Dr. Stasse P., Clinique St-Joseph - Mons; Dr. Stuer A., Heilig
Hart Ziekenhuis - Roeselare; Dr. Van Bruwaene F., Heilig
Hart Ziekenhuis - Roeselare; Dr. Van Den Berghe M., AZ
Zusters van Barmhartigheid - Ronse; Dr. Van Den Bosch
F., Elisabethziekenhuis - Sijsele; Dr. Van den Bossche N.,
Stadskliniek - St.Niklaas; Dr. Van Essche E., Onze Lieve
Vrouwziekenhuis - Mechelen; Dr. Van Wanghe P., Virga
Jesse Ziekenhuis - Hasselt; Dr. Vanden Berghe M., Hôpit-
al St- Thérèse - Montignies-Sur-Sambre; Dr. Vanhoof J.,
ZOL - Genk; Dr. Vanneuville B., Stedelijk Ziekenhuis -
Roeselare; Dr. Villers C., CH Grand Hornu; Dr. Volders P.,
Reuma Centrum - Genk; Dr. Vroninks P., Salvatorzieken-
huis -Hasselt;Dr. Walravens M., Mol; Dr. Williame L., AZ
Middelheim - Antwerp; Dr. Wouters M., Parc Leopold -
Brussels; Dr. Zmierczak HG., Kliniek St-Elisabeth - Zotte-
gem; Prof. Appelboom T., ULB - Hôpital Erasme - Brus-
sels; Prof. Boutsen Y., UCL Mont-Godinne; Prof. De
Clerck L., UZ Antwerp; Prof. Devogelaer JP., UCL Saint-
Luc - Brussels; Prof. E.M. Veys, UZ Gent; Prof. Houssiau
F., UCL Saint-Luc - Brussels; Prof. Mielants H., AZ Sint-
Augustinus - Wilrijk; Prof. Peretz A., CHU Brugmann -
Brussels; Prof. Steinfeld S., ULB - Hôpital Erasme - Brus-
sels; Prof. Verbruggen G., Prive Praktijk - Izegem; Prof. Verbruggen L., AZ VUB - Brussels; Prof. Westhovens R.,
UZ Gasthuisberg - Leuven. Additional material Hôpital de la Citadelle - Liège; Dr. Heylen A., Clinique
Sainte-Elisabeth - Namur; Dr. Immesoete C., Aalsters
Stedelijk Ziekenhuis; Dr. Itzkowitch D., CH Tubize-Niv-
elle; Dr. Janssens X., AZ St-Lucas Gent; Dr. Jeukens T.,
CH Bois Abbaye et Hesbaye - Waremme; Dr. Joos R., Jan
Palfijnziekenhuis - Merksem; Dr. Kaiser M-J., CHU Sart
Tilman - Liège; Dr. Langenaken C., Virga Jesse Ziekenhuis
- Hasselt; Dr. Lefebvre S., CH Mouscron Site Refuge; Dr. Lenaerts J., Virga Jesse Ziekenhuis - Hasselt; Dr. Léon M.,
CHU Ambroise Pare - Mons; Dr. Luyten H., Volkskliniek
E.Moyson - Gent; Dr. Maenaut K., Sint Jozefziekenhuis -
Malle; Dr. Maertens M., AZ Damiaan - Oostende; Dr. Maeyaert B., AZ Sint Lucas/Sint Jozef - Assebroek; Dr. Martin F., Hôpital de Warquignies - Boussu; Dr. Moens
Ph., Cliniques de l'Europe/Ste Elisabeth - Brussels; Dr. Pater C., Clinique St.Joseph - Arlon; Dr. Discussion However, our analy-
sis showed that the use of corticosteroids was not associ-
ated with a difference in the likelihood of AEs overall,
SAEs, IRs, allergic skin reactions, or infections, nor did it
appear to influence the likelihood of discontinuation due
to AEs or IRs. These results suggest that patients can con-
tinue corticosteroid use during treatment with inflix-
imab, if indicated, without increasing the chance for
discontinuation or occurrence of an AE, including infec-
tions. The results also suggest that corticosteroids do not
prevent infliximab-induced IRs. Notably, all four
reported cases of tuberculosis were in patients taking
corticosteroids at baseline, and all had negative Mantoux
tests at screening. Thus, it is possible that the corticoster- One of the key aims of this study was to identify rea-
sons for discontinuation in RA patients treated with inf-
liximab. In the evaluable population, the continuation
rate at 74 weeks was 68.7%. This is comparable with most
other studies of daily clinical practice, which have shown
one-year continuation rates between 65% and 73% and
two-year continuation rates between 67% and 75%
[21,36-38]. The continuation rate in the current study
was lower than the one-and two-year rates (91% and 81%, Page 10 of 12 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Hôpital de la Citadelle - Liège; Dr. Heylen A., Clinique
Sainte-Elisabeth - Namur; Dr. Immesoete C., Aalsters
Stedelijk Ziekenhuis; Dr. Itzkowitch D., CH Tubize-Niv-
elle; Dr. Janssens X., AZ St-Lucas Gent; Dr. Jeukens T.,
CH Bois Abbaye et Hesbaye - Waremme; Dr. Joos R., Jan
Palfijnziekenhuis - Merksem; Dr. Kaiser M-J., CHU Sart
Tilman - Liège; Dr. Langenaken C., Virga Jesse Ziekenhuis
- Hasselt; Dr. Lefebvre S., CH Mouscron Site Refuge; Dr. Lenaerts J., Virga Jesse Ziekenhuis - Hasselt; Dr. Léon M.,
CHU Ambroise Pare - Mons; Dr. Luyten H., Volkskliniek
E.Moyson - Gent; Dr. Maenaut K., Sint Jozefziekenhuis -
Malle; Dr. Maertens M., AZ Damiaan - Oostende; Dr. Maeyaert B., AZ Sint Lucas/Sint Jozef - Assebroek; Dr. Martin F., Hôpital de Warquignies - Boussu; Dr. Moens
Ph., Cliniques de l'Europe/Ste Elisabeth - Brussels; Dr. Pater C., Clinique St.Joseph - Arlon; Dr. Poriau S., Elisa-
bethziekenhuis - Sijsele; Dr. Praet J., Aalst; Dr. Raeman F.,
Jan Palfijnziekenhuis - Merksem; Dr. Ravelingien I., Onze
Lieve Vrouwziekenhuis - Aalst; Dr. Ribbens C., CHU Sart
Tilman - Liège; Dr. References 1. Venkateshan SP, Sidhu S, Malhotra S, Pandhi P: Efficacy of biologicals in
the treatment of rheumatoid arthritis. a meta-analysis. Pharmacology
2009, 83:1-9. 19. Bertoli AM, Strusberg I, Baravalle M, Betelu Z, Calas D, Morales L, Strusberg
AM: Rate and causes of infliximab discontinuation in patients with
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arthritis. Med J Aust 2006, 184:122-125. Roberts LJ, Cleland LG, Thomas R, Proudman SM: Early combina 3. Rubbert-Roth A, Finckh A: Treatment options in patients with
rheumatoid arthritis failing initial TNF inhibitor therapy: a critical
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66:173-178. 21. Wendling D, Materne GE, Michel F, Lohse A, Lehuede G, Toussirot E,
Massol J, Woronoff-Lemsi MC: Infliximab continuation rates in patients
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72:309-312. 5. Swierkot J, Szechinski J: Methotrexate in rheumatoid arthritis. Pharmacol Rep 2006, 58:473-492. 5. Swierkot J, Szechinski J: Methotrexate in rheumatoid arthritis. Pharmacol Rep 2006, 58:473-492. 22. Fries JF, Spitz P, Kraines RG, Holman HR: Measurement of patient
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Immunol 1993, 30:1443-1453. 24. Schaible TF: Long term safety of infliximab. Can J Gastroenterol 2000,
14(Suppl C):29C-32C. 25. References Flendrie M, Creemers MC, Welsing PM, van Riel PL: The influence of
previous and concomitant leflunomide on the efficacy and safety of
infliximab therapy in patients with rheumatoid arthritis; a longitudinal
observational study. Rheumatology (Oxford) 2005, 44:472-478. 8. Lipsky PE, van der Heijde DM, St Clair EW, Furst DE, Breedveld FC, Kalden
JR, Smolen JS, Weisman M, Emery P, Feldmann M, Harriman GR, Maini RN:
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Concomitant Therapy Study Group. N Engl J Med 2000, 343:1594-1602. 26. Schiff M, Keiserman M, Codding C, Songcharoen S, Berman A, Nayiager S,
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and safety of abatacept or infliximab vs placebo in ATTEST: a phase III,
multi-centre, randomised, double-blind, placebo-controlled study in
patients with rheumatoid arthritis and an inadequate response to
methotrexate. Ann Rheum Dis 2008, 67:1096-1103. Concomitant Therapy Study Group. N Engl J Med 2000, 343:1594-1602. 9. Maini R, St Clair EW, Breedveld F, Furst D, Kalden J, Weisman M, Smolen J,
Emery P, Harriman G, Feldmann M, Lipsky P: Infliximab (chimeric anti-
tumour necrosis factor alpha monoclonal antibody) versus placebo in
rheumatoid arthritis patients receiving concomitant methotrexate: a
randomised phase III trial. ATTRACT Study Group. Lancet 1999,
354:1932-1939. 27. Askling J, Fored CM, Brandt L, Baecklund E, Bertilsson L, Feltelius N, Coster
L, Geborek P, Jacobsson LT, Lindblad S, Lysholm J, Rantapaa-Dahlqvist S,
Saxne T, van Vollenhoven RF, Klareskog L: Time-dependent increase in
risk of hospitalisation with infection among Swedish RA patients
treated with TNF antagonists. Ann Rheum Dis 2007, 66:1339-1344. 10. Quinn MA, Conaghan PG, O'Connor PJ, Karim Z, Greenstein A, Brown A,
Brown C, Fraser A, Jarret S, Emery P: Very early treatment with infliximab
in addition to methotrexate in early, poor-prognosis rheumatoid
arthritis reduces magnetic resonance imaging evidence of synovitis
and damage, with sustained benefit after infliximab withdrawal:
results from a twelve-month randomized, double-blind, placebo-
controlled trial. Arthritis Rheum 2005, 52:27-35. 28. Takeuchi T, Tatsuki Y, Nogami Y, Ishiguro N, Tanaka Y, Yamanaka H,
Kamatani N, Harigai M, Ryu J, Inoue K, Kondo H, Inokuma S, Ochi T, Koike
T: Postmarketing surveillance of the safety profile of infliximab in 5000
Japanese patients with rheumatoid arthritis. Ann Rheum Dis 2008,
67:189-194. 11. Competing interests ID was an employee of Schering-Plough at the time the study was performed
and the article was written. FDK received financial support from Schering-
Plough and has received research grants from (in alphabetic order): Abbott,
Centocor, Roche, Schering-Plough, and UCB. 14. Brown SL, Greene MH, Gershon SK, Edwards ET, Braun MM: Tumor
necrosis factor antagonist therapy and lymphoma development:
twenty-six cases reported to the Food and Drug Administration. Arthritis Rheum 2002, 46:3151-3158. Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 12. Augustsson J, Eksborg S, Ernestam S, Gullstrom E, van Vollenhoven R:
Low-dose glucocorticoid therapy decreases risk for treatment-limiting
infusion reaction to infliximab in patients with rheumatoid arthritis. Ann Rheum Dis 2007, 66:1462-1466. Author Details 1Department of Immunology, Schering-Plough nv, 73 Rue de Stalle, Brussels
1180, Belgium, 2Ghent University, Department of Rheumatology, Ghent
University Hospital, De Pintelaan 185, Ghent, B-9000, Belgium and 319 Avenue
des Vieux Amis, Waterloo 1410, Belgium 1Department of Immunology, Schering-Plough nv, 73 Rue de Stalle, Brussels
1180, Belgium, 2Ghent University, Department of Rheumatology, Ghent
University Hospital, De Pintelaan 185, Ghent, B-9000, Belgium and 319 Avenue 1Department of Immunology, Schering-Plough nv, 73 Rue de Stalle, Brussels
1180, Belgium, 2Ghent University, Department of Rheumatology, Ghent 1Department of Immunology, Schering-Plough nv, 73 Rue de Stalle, Brussels
1180, Belgium, 2Ghent University, Department of Rheumatology, Ghent
University Hospital, De Pintelaan 185, Ghent, B-9000, Belgium and 319 Avenue
des Vieux Amis, Waterloo 1410, Belgium 17. Wolfe F, Michaud K: The effect of methotrexate and anti-tumor necrosis
factor therapy on the risk of lymphoma in rheumatoid arthritis in
19,562 patients during 89,710 person-years of observation. Arthritis
Rheum 2007, 56:1433-1439. University Hospital, De Pintelaan 185, Ghent, B-9000, Belgium and 319 Avenue
des Vieux Amis, Waterloo 1410, Belgium Received: 29 October 2009 Revised: 17 March 2010
Accepted: 22 June 2010 Published: 22 June 2010
This article is available from http //arthritis research com/content/12/3/R121
© 2010 Delabaye and De Keyser licensee BioMed Central Ltd
This is an open access article distributed under the terms of the Creative Commons Attribution License (http //creativecommons org/licenses/by/2 0) which permits unrestricted use distribution an
Arthritis Research & Therapy 2010 12 R121 Received: 29 October 2009 Revised: 17 March 2010
Accepted: 22 June 2010 Published: 22 June 2010
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2010 12 R121 18. Askling J, Baecklund E, Granath F, Geborek P, Fored M, Backlin C, Bertilsson
L, Coster L, Jacobsson LT, Lindblad S, Lysholm J, Rantapaa-Dahlqvist S,
Saxne T, van Vollenhoven R, Klareskog L, Feltelius N: Anti-tumour necrosis
factor therapy in rheumatoid arthritis and risk of malignant
lymphomas: relative risks and time trends in the Swedish Biologics
Register. Ann Rheum Dis 2009, 68:648-653. Abbreviations
d AE: adverse event; CI: confidence interval; DMARD: disease-modifying anti-
rheumatic drug; HAQ: health assessment questionnaire; IR: infusion reaction;
MTX: methotrexate; NSAIDs: nonsteroidal anti-inflammatory drugs; RA: rheu-
matoid arthritis; SAE: serious adverse event; SJC: swollen joint count; TNF:
tumor necrosis factor. 13. Bongartz T, Sutton AJ, Sweeting MJ, Buchan I, Matteson EL, Montori V:
Anti-TNF antibody therapy in rheumatoid arthritis and the risk of
serious infections and malignancies: systematic review and meta-
analysis of rare harmful effects in randomized controlled trials. JAMA
2006, 295:2275-2285. Authors' contributions
d
d 15. Wolfe F, Michaud K: Lymphoma in rheumatoid arthritis: the effect of
methotrexate and anti-tumor necrosis factor therapy in 18,572
patients. Arthritis Rheum 2004, 50:1740-1751. ID and FDK interpreted and analyzed the data and participated in the writing
of the manuscript. 16. Leombruno JP, Einarson TR, Keystone EC: The safety of anti-tumour
necrosis factor treatments in rheumatoid arthritis: meta and exposure-
adjusted pooled analyses of serious adverse events. Ann Rheum Dis
2009, 68:1136-1145. Additional material Additional file 1 Supporting information. This file contains the three
supplemental tables. Supplemental table 1 gives details on opportunistic
infections during the study, Supplemental table 2 on tuberculosis cases
during the study, Supplemental table 3 on tumor cases during the study,
and supplemental table 4 on deaths during the study. Page 11 of 12 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
http://arthritis-research.com/content/12/3/R121 Delabaye et al. Arthritis Research & Therapy 2010, 12:R121
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Treatment of rheumatoid arthritis with tumor necrosis factor inhibitors
may predispose to significant increase in tuberculosis risk: a Page 12 of 12 multicenter active-surveillance report. Arthritis Rheum 2003,
48:2122-2127. multicenter active-surveillance report. Arthritis Rheum 2003,
48:2122-2127. 30. Theis VS, Rhodes JM: Review article: minimizing tuberculosis during
anti-tumour necrosis factor-alpha treatment of inflammatory bowel
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Comparison of drug retention rates and causes of drug
discontinuation between anti-tumor necrosis factor agents in
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Predictors of infusion reactions during infliximab treatment in patients
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predictors, and the effect of anti-tumor necrosis factor therapy. Am J
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Geborek P: Treatment with tumor necrosis factor blockers is associated
with a lower incidence of first cardiovascular events in patients with
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Schneider M, Rau R: Treatment continuation in patients receiving
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Survival during treatment with tumour necrosis factor blocking agents
in rheumatoid arthritis. Ann Rheum Dis 2003, 62(Suppl 2):ii30-33. 38. Geborek P, Crnkic M, Petersson IF, Saxne T: Etanercept, infliximab, and
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Rheum Dis 2002, 61:793-798. 39. Vander Cruyssen B, Van Looy S, Wyns B, Westhovens R, Durez P, Van den
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Vastesaeger N, Geldhof A, Boullart L, De Keyser F: Four-year follow-up of
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40. Chevillotte-Maillard H, Ornetti P, Mistrih R, Sidot C, Dupuis J, Dellas JA,
Tavernier C, Maillefert JF: Survival and safety of treatment with
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44:695-696. doi: 10.1186/ar3058
Cite this article as: Delabaye et al., 74-week follow-up of safety of infliximab
in patients with refractory rheumatoid arthritis Arthritis Research & Therapy
2010, 12:R121 multicenter active-surveillance report. Arthritis Rheum 2003,
48:2122-2127. 40. Chevillotte-Maillard H, Ornetti P, Mistrih R, Sidot C, Dupuis J, Dellas JA,
Tavernier C, Maillefert JF: Survival and safety of treatment with
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Serious infection following anti-tumor necrosis factor alpha therapy in
patients with rheumatoid arthritis: lessons from interpreting data from
observational studies. Arthritis Rheum 2007, 56:2896-2904. doi: 10.1186/ar3058
Cite this article as: Delabaye et al., 74-week follow-up of safety of infliximab
in patients with refractory rheumatoid arthritis Arthritis Research & Therapy
2010, 12:R121 doi: 10.1186/ar3058
Cite this article as: Delabaye et al., 74-week follow-up of safety of infliximab
in patients with refractory rheumatoid arthritis Arthritis Research & Therapy
2010, 12:R121
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English
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A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-Dependent Ecosystem Health
|
Frontiers in environmental science
| 2,019
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Lawrence Berkeley National Laboratory
LBL Publications
Title
A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-
Dependent Ecosystem Health
Permalink
https://escholarship.org/uc/item/6bc6791n
Authors
Rohde, Melissa M
Sweet, Sara B
Ulrich, Craig
et al.
Publication Date
2019
DOI
10.3389/fenvs.2019.00175
Copyright Information
This work is made available under the terms of a Creative Commons Attribution License
available at https://creativecommons.org/licenses/by/4.0/
Peer reviewed Lawrence Berkeley National Laboratory
LBL Publications
Title
A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-
Dependent Ecosystem Health
Permalink
https://escholarship.org/uc/item/6bc6791n
Authors
Rohde, Melissa M
Sweet, Sara B
Ulrich, Craig
et al. Publication Date
2019
DOI
10.3389/fenvs.2019.00175
Copyright Information
This work is made available under the terms of a Creative Commons Attribution License
available at https://creativecommons.org/licenses/by/4.0/
Peer reviewed Lawrence Berkeley National Laboratory
LBL Publications
Title
A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-
Dependent Ecosystem Health
Permalink
https://escholarship.org/uc/item/6bc6791n
Authors
Rohde, Melissa M
Sweet, Sara B
Ulrich, Craig
et al. Publication Date
2019
DOI
10.3389/fenvs.2019.00175
Copyright Information
This work is made available under the terms of a Creative Commons Attribution License
available at https://creativecommons.org/licenses/by/4.0/
Peer reviewed Lawrence Berkeley National Laboratory A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-
Dependent Ecosystem Health 10.3389/fenvs.2019.00175 Copyright Information Copyright Information
This work is made available under the terms of a Creative Commons Attribution License,
available at https://creativecommons.org/licenses/by/4.0/ This work is made available under the terms of a Creative Commons Attribution License,
available at https://creativecommons.org/licenses/by/4.0/ Peer reviewed Peer reviewed eScholarship.org
Powered by the California Digital Library
University of California Powered by the California Digital Library
University of California A Transdisciplinary Approach to
Characterize Hydrological Controls
on Groundwater-Dependent
Ecosystem Health Sustainable groundwater management provides an opportunity for environmental
water needs to be considered and secured by establishing appropriate groundwater
thresholds. Ecosystems that require access to groundwater for some or all their
water requirements are referred to as groundwater dependent ecosystems (GDEs). However, large data gaps often exist around the cause-and-effect relationships between
groundwater conditions and the impacts they have on GDEs. These data gaps are
largely attributed to a lack of shallow monitoring wells near GDEs, and a lack of practical
biological metrics to characterize ecosystem health. This transdisciplinary study explores
the use of geophysics (electrical resistivity tomography) to fill in our understanding of
shallow subsurface soil-hydrological conditions within GDEs. In addition, we develop an
approach to characterize ecosystem health within GDEs, using groundwater-dependent
vegetation (phreatophytes) as indicators. Ten vegetation variables were used to
characterize six biological indicators—growth, diversity, recruitment, structure, native
plant dominance, and survivorship—which were used to infer ecosystem health
conditions. Health indicators for groundwater-dependent vegetation were found to
directly correlate with subsurface conditions, where greater groundwater availability
(higher soil moisture content and shallower groundwater levels) was associated with
“healthier” vegetation. This study provides a new approach to integrate hydrological,
geophysical, and biological data to strengthen monitoring programs and inform water
resource management decisions. Reviewed by: Reviewed by:
Nitin Kaushal,
World Wide Fund for Nature, India
Josep Mas-Pla,
Catalan Institute for Water
Research, Spain *Correspondence:
Melissa M. Rohde
melissa.rohde@tnc.org Specialty section:
This article was submitted to
Freshwater Science,
a section of the journal
Frontiers in Environmental Science Keywords: groundwater dependent ecosystem, electrical resistivity tomography, groundwater, riparian forest,
ecosystem health, sustainable groundwater management, biological response functions, vegetation surveys Received: 29 January 2019
Accepted: 16 October 2019
Published: 06 November 2019 INTRODUCTION Sustainable groundwater management policies worldwide are increasingly incorporating
environmental considerations (Rohde et al., 2017), creating new opportunities to maintain
and preserve ecosystems. Groundwater-dependent ecosystems (GDEs), which are species and
ecosystems maintained by direct or indirect access to groundwater, offer a wide range of ecosystem
services that benefit our economy and society such as soil preservation, water purification, carbon
sequestration, flood control, pollination of crops, and recreational opportunities [Schuyt and
Brander, 2004; Blevins and Aldous, 2011; Water Land Ecosystems (WLE) and CRPO, 2015]. Sustainable groundwater management policies worldwide are increasingly incorporating
environmental considerations (Rohde et al., 2017), creating new opportunities to maintain
and preserve ecosystems. Groundwater-dependent ecosystems (GDEs), which are species and
ecosystems maintained by direct or indirect access to groundwater, offer a wide range of ecosystem
services that benefit our economy and society such as soil preservation, water purification, carbon
sequestration, flood control, pollination of crops, and recreational opportunities [Schuyt and
Brander, 2004; Blevins and Aldous, 2011; Water Land Ecosystems (WLE) and CRPO, 2015]. Powered by the California Digital Library
University of California eScholarship.org eScholarship.org ORIGINAL RESEARCH
published: 06 November 2019
doi: 10.3389/fenvs.2019.00175 Edited by:
Sergi Sabater,
University of Girona, Spain Citation: Rohde MM, Sweet SB, Ulrich C and
Howard J (2019) A Transdisciplinary
Approach to Characterize
Hydrological Controls on
Groundwater-Dependent Ecosystem
Health. Front. Environ. Sci. 7:175. doi: 10.3389/fenvs.2019.00175 November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. would otherwise be isolated from deeper aquifers by attenuating
recharge rates and flow pathways within unconfined aquifers
and thereby supporting gaining conditions in streams (Palkovics
et al., 1975; Fleckenstein et al., 2006; Rassam et al., 2006;
Niswonger and Fogg, 2008). This is the particular case for GDEs
in regions where large seasonal or interannual fluctuations occur
in the water table of unconfined regional aquifers. Figure 1
provides a conceptual model of how large seasonal fluctuations
in the position of the water table within an aquifer can support
perched groundwater near a seasonally intermittent river. While
perched groundwater itself cannot directly be managed due to its
position in the vadose zone, the water table position within the
aquifer, and its interactions with surface water can be managed
(via pumping rate restrictions, restricted pumping at certain
depths, restricted pumping around GDEs, well density rules,
managed aquifer recharge projects) to prevent adverse impacts to
ecosystems due to changes in groundwater quality and quantity. The presence of groundwater and its interconnections with
surface water provide critical habitat conditions for a wide
range of species, including rare and endangered species, by
sustaining instream flows and providing access to groundwater
through the rooting network. However, as humans increasingly
depend upon groundwater for irrigation and drinking water
supplies (Wada et al., 2012), this reliable water source for
GDEs is threatened (Gleeson et al., 2015), especially during dry
summer months of Mediterranean climates and drought years. As water managers work toward bringing groundwater basins
into balance under sustainable groundwater policies, there is a
need for practical approaches to monitor how ecosystems are
responding to changing groundwater conditions and determine
what groundwater thresholds protect GDEs. GDEs can rely on groundwater occurring near, on, or within
the ground surface. Riparian vegetation within GDEs can access
groundwater by either: (1) hydraulically lifting groundwater from
the water table via capillary action to fill pore spaces in the
vadose zone; or (2) accessing soil water in the unsaturated zone
residual from seasonal water table fluctuations. 1ftp://ftp.consrv.ca.gov/pub/dmg/rgmp/Prelim_geo_pdf/Lodi_100K_prelim.pdf
2https://casoilresource.lawr.ucdavis.edu/soilweb-apps/ Citation: Only more recently has geophysics been used to
characterize and monitor the interaction between subsurface soil
moisture and plant roots (Binley and Kemna, 2005; Robinson
et al., 2008, 2012; Schwartz et al., 2008; Nijland et al., 2010;
Ma et al., 2014; Hübner et al., 2015; Cassiani et al., 2016). ERT
was more specifically used in this study to develop a subsurface
conceptual model beneath each GDE. FIGURE 2 | Study Site Map: Cosumnes River Preserve, Sacramento
County, California. p
To sustainably manage groundwater for GDEs, baselines
and thresholds need to be established to prevent groundwater
conditions from having impacts on ecosystem conditions. While numerous field-based studies have investigated the
short- and long-term impacts of groundwater pumping on
individual biological responses (i.e., growth, reproduction,
recruitment, ecosystem structure, ecosystem function, and
survivorship) for individual groundwater-dependent species,
there are fewer studies that examine multiple biological responses
across multiple groundwater-dependent species (Costanza and
Mageau, 1999; Eamus et al., 2015). Integrating ecosystem-
scale biological indicators into water management monitoring
programs can provide water managers the ability to integrate
biological concerns into basin-wide hydrological monitoring
efforts. In combination with hydrological data, biological
data provides an opportunity for water managers to assess
the cause-and-effect relationships between the groundwater
conditions and ecosystem-scale biological responses. Since
it can be onerous to examine the biological response of
all organisms within an ecosystem, groundwater-dependent
vegetation is investigated in this study as a practical proxy
for monitoring ecosystem-scale changes in GDE health. This
is because changes in groundwater conditions impact not only
the health of plants themselves, but also subsequently impact
the food supply and habitat conditions for animals within
the ecosystem. However, if a GDE is a seep or spring with
little vegetation associated with it or there are particular focal
groundwater-dependent species, then other proxies may be
more appropriate. FIGURE 2 | Study Site Map: Cosumnes River Preserve, Sacramento
County, California. hydrology, geophysics, and ecology to better understand how
subsurface conditions can influence GDE health. Citation: Characterizing
groundwater reliance in GDEs can be challenging, especially
in river environments where groundwater and surface water
interactions occur around heterogeneous sedimentary units
that support perched groundwater, such as clay-rich aquitards
formed by fluvial deposits. Clay lenses in the subsurface that
support perched groundwater can contribute an important
groundwater supply for riparian ecosystems and wetlands that Near-surface aquifer environments, especially at the interface
of groundwater and surface water are difficult to capture in
regional-scale groundwater numerical models typically used
by water managers for water balancing and management. Alternatively,
geophysics—specifically
electrical
resistivity
tomography (ERT)—provides the opportunity to investigate
subsurface conditions over small and large spatial scales that are
applicable to understanding subsurface conditions in shallow
portions of the aquifer. ERT is a well-established geophysical
technique and has been used to investigate subsurface lithology FIGURE 1 | Conceptual model of how seasonal fluctuations in the water table and its interactions with surface water can support perched groundwater availability
near intermittent rivers for GDEs in (A) Wet season and (B) Dry season. FIGURE 1 | Conceptual model of how seasonal fluctuations in the water table and its interactions with surface water can support perched groundwater availability
near intermittent rivers for GDEs in (A) Wet season and (B) Dry season. FIGURE 1 | Conceptual model of how seasonal fluctuations in the water table and its interactions with surface water can support perched groundwater availability
near intermittent rivers for GDEs in (A) Wet season and (B) Dry season. Frontiers in Environmental Science | www.frontiersin.org Frontiers in Environmental Science | www.frontiersin.org Frontiers in Environmental Science | www.frontiersin.org November 2019 | Volume 7 | Article 175 2 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. (Tabbagh et al., 2000; Samouëlian et al., 2005; Sudha et al., 2009)
and moisture state (Rhoades et al., 1976; Kean et al., 1987; Daily
et al., 2010). Only more recently has geophysics been used to
characterize and monitor the interaction between subsurface soil
moisture and plant roots (Binley and Kemna, 2005; Robinson
et al., 2008, 2012; Schwartz et al., 2008; Nijland et al., 2010;
Ma et al., 2014; Hübner et al., 2015; Cassiani et al., 2016). ERT
was more specifically used in this study to develop a subsurface
conceptual model beneath each GDE. (Tabbagh et al., 2000; Samouëlian et al., 2005; Sudha et al., 2009)
and moisture state (Rhoades et al., 1976; Kean et al., 1987; Daily
et al., 2010). Frontiers in Environmental Science | www.frontiersin.org Study Site Qhb is a basin deposit consisting of fine-grained sediments from
the late Holocene that were generally deposited with horizontal
stratification in topographic lows. The study sites are underlain
by the Columbia, Cosumnes, and San Joaquin soil units. Both
the Cosumnes and San Joaquin typical pedons are silty loams
and loams, compared to a typical Columbia pedon that is a fine
sandy loam. All of these soil types are typical of 0–2% slopes,
moderately to poorly drained, and occur along the Cosumnes
River floodplain. current from the instrument into the ground through electrodes
(metal stakes inserted into the ground) along a profile. The
change in the potential voltage as the current travels through
the ground is measured at other adjacent electrode pairs along
the profile (for more detail see Reynolds, 2011). Alternating
combinations of the electrodes results in large resistivity datasets
(thousands of measurements) that are collected in a relatively
short time period. The resulting resistivity distributions are
inverted to get the true spatial distribution of resistivity within
the subsurface that describes the actual soil and moisture
distributions. This results in ERT images that map how resistive
the subsurface based on how quickly the electrical pulses return
to the sensors at the land surface. The flow of current through the
ground is controlled by the water content and soil type, and can
be influenced by rapid temperature change or salinity, if present. Seven ERT profiles were collected in total: one in Tall Forest,
two in Shaw Forest, two in Castello Forest, and two at the
Oneto-Denier site (Figure 3). Four ERT profiles (one in Tall,
one in Shaw, and two at Castello) were collected in September
2016; and, two in Oneto-Denier and one in Shaw Forest in
October 2016. ERT data was collected at the end of the summer
dry season, in September 2016 and October 2016, to capture
subsurface conditions when the riparian forests are most reliant
on groundwater. This timing also circumvents any subsurface
moisture irregularities due to rewetting fronts, because (1) no
rain fell for the previous ∼5 months due to the strongly seasonal
Mediterranean climate, and (2) the relatively low elevation of
the headwaters precluded substantial snowmelt effects on river
flow. ERT data collected in September used a Multi-Phase
Technologies (MPT) eight-channel resistivity system with 128
electrodes and 1-m electrode spacing. Study Site The Cosumnes River drains ∼3,400 km2 and flows 129 km
westward from its headwaters at ∼2,200 m in California’s Sierra
Nevada Mountains toward its outlet in the Sacramento-San
Joaquin Delta. Within the study reach (Figure 2), the river
follows the boundary between two administratively defined
groundwater basins: South American Basin (Sacramento River
Hydrologic Region) and Cosumnes Basin (San Joaquin River
Hydrologic Region). Human reliance on groundwater for
agricultural and domestic use in both basins has substantially
lowered regional groundwater levels, creating two cones of
depression in the groundwater basins adjacent to the Cosumnes
River. Both basins are subject to California’s Sustainable
Groundwater Management Act of 2014 (SGMA). This study explores the health of three groundwater-
dependent riparian forests along an interconnected surface
water body within groundwater basins with an unconfined
aquifer, which is not bounded on top by an aquitard and
the upper surface of the saturated zone is the water table. By monitoring vegetative growth, species diversity, regenerative
capacity (sapling recruitment), native plant density, vegetative
structure (strata), and survivorship (canopy cover remaining
over time), we explore whether hydrological conditions in
the subsurface are correlated with the health of GDEs. The
objectives of this paper are to: (1) characterize shallow subsurface
hydrological conditions in each forest using ERT, (2) identify
practical biological indicators to assess the health of GDEs, and
(3) evaluate how differences in hydrological conditions correlate
to health indicators for groundwater-dependent riparian forests. These objectives are intended to illustrate how discipline-specific
tools can be combined to solve a common problem in sustainable
groundwater management. The research presented in this paper
adopts this transdisciplinary approach to bridge the fields of A soil and geological evaluation of the study sites along the
Cosumnes River was completed using USGS and CA Geological
Survey maps1 and the SoilWeb interactive soil maps2 The local November 2019 | Volume 7 | Article 175 3 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. geology is dominated by Quaternary Period unconsolidated
clays, silts, and sands deposited during the Holocene Epoch. The
CA Geological Survey map shows that two deposits dominate
the study area, Qha and Qhb; both are alluvial. Qha is an
undivided deposit on fans, terraces, or in basins, and consists
of sand, gravel, and silts that are poorly to moderately sorted. Electrical Resistivity Tomography Electrical resistivity tomography is a geophysical technique
for imaging subsurface environments by transmitting electrical Study Site ERT data collected in
October again used an MPT resistivity system, but with 112
electrodes and 1.5-m electrode spacing. The average time to
collect a full dataset was ∼2 h or less. A maximum current
of 2,000 milliamps (mA) and 400 volts (V) was set during
data acquisition, but the system automatically optimizes the
injected current if less is needed; on average 42 mA and 140 V
were injected during each measurement using a dipole-dipole
configuration with 100% reciprocals. The ERT data were inverted
using the BERT inversion code (Gunther and Rucker, 2006),
which is based on a finite-element model that discretizes the
subsurface as a tetrahedral mesh with a grid cell spacing equal
to ½ the electrode spacing. All ERT profiles were inverted using
a flat surface, since topographic changes along each profile were
<30 cm and the dense tree canopy prevented the use of a high-
accuracy Global Positioning System (GPS). ERT data of low
quality, defined as a measured potential <2 mV, were removed
from each data set along with reciprocal errors >5%, which
resulted in <10% of data removal from each data set. Model
convergence resulted in a mean absolute difference (MAD)
error of <6% for all ERT profiles between the measured and
modeled data. The Cosumnes River Preserve (Preserve) consists of over
20,000 ha of wildlife habitat that includes riparian forests,
seasonal wetlands, grasslands, and habitat for birds migrating
along the Pacific Flyway (Kleinschmidt Group, Inc., 2008). Three riparian stands were included in this study: Castello
Forest (40 ha), Shaw Forest (60 ha), and Tall Forest (52 ha). Each of these riparian forest stands have been identified in the
Natural Communities Commonly Associated with Groundwater
Dataset3 (NC Dataset), which is hosted by the California
Department of Water Resources (DWR). The NC dataset is a
compilation of 48 publicly available State and Federal agency
datasets that maps vegetation, wetlands, springs, and seeps
that are commonly associated with groundwater in California
(Klausmeyer et al., 2018). The overstory is dominated by valley
oak (Quercus lobata) in all three forest stands, but the understory
differs. The understory in Castello Forest is heavily dominated
by non-native winter annual grasses, with very few shrubs or
young trees. In contrast, the understory at Shaw and Tall Forests
is multi-layered, containing young trees, shrubs, vines, and
herbaceous plants. Hydrologic Data Six groundwater monitoring wells (Figure 2) were selected for
this study to corroborate groundwater levels and lithological data
with the ERT results. One well (MW2) is within Shaw Forest
and two wells (MW5 and MW9) are within the Oneto-Denier
site (open land within the Preserve). The remaining three wells
are historic groundwater monitoring wells from DWR’s Water
Data Library4 two near Castello Forest (06N06E28C002M and
06N06E29K001M) and one near Tall Forest (05N05E28L003M). Precipitation data were accessed using the PRISM (Parameter-
elevation Regressions on Independent Slopes Model) Monthly
Spatial Climate Dataset5, produced by the PRISM Climate Group
at Oregon State University. Electrical Resistivity Tomography 3https://gis.water.ca.gov/app/NCDatasetViewer/
4http://wdl.water.ca.gov/waterdatalibrary/
5https://developers.google.com/earth-engine/datasets/catalog/
OREGONSTATE_PRISM_AN81m Vegetation Monitoring 3https://gis.water.ca.gov/app/NCDatasetViewer/
4http://wdl.water.ca.gov/waterdatalibrary/
5https://developers.google.com/earth-engine/datasets/catalog/
OREGONSTATE_PRISM_AN81m Vegetation data were collected during the summer of 2016 as part
of a multi-year vegetation monitoring program. Crown dieback
calculations also relied on canopy cover data collected during November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 4 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. FIGURE 3 | Location of ERT profiles, monitoring wells, and vegetation macroplots at the four study sites: (A) Shaw Forest and Oneto-Denier, (B) Castello Forest, (C)
Tall Forest. GURE 3 | Location of ERT profiles, monitoring wells, and vegetation macroplots at the four study sites: (A) Shaw Forest and Oneto-Denier, (B) Castello Forest, (C)
all Forest. monitoring wells, and vegetation macroplots at the four study sites: (A) Shaw Forest and Oneto-Denier, (B) Castello Forest, (C) FIGURE 3 | Location of ERT profiles, monitoring wells, and vegetation macroplots at the four study sites: (A) Shaw Forest and Oneto-Denier, (B) Castello Forest, (C)
Tall Forest. FIGURE 3 | Location of ERT profiles, monitoring wells, and vegetation macroplots at the four study sites: (A) Shaw Forest and O
Tall Forest Model C, Robert E. Lemmon, Forest Densiometers). Diameter at
breast height (DBH) was recorded for all mature tree individuals
≥135 cm tall (Bernhardt and Swiecki, 1991). The number of trees
that were saplings (defined arbitrarily as those between 50 and
135 cm tall) and young trees (DBH of 0.1 to 10 cm) were also
recorded by species. the summer of 2013. Each forest stand was sampled with evenly
spaced, permanent 20 × 20 m macroplots. We visually estimated
absolute vascular plant cover by species within seven strata that
were based on a simplified version of the California Wildlife
Habitat Relationships protocol (CDFW, 1988) and categorized as:
(1) herb, (2) small shrub (0–2 m tall), (3) tall shrub (>2 m tall), (4)
tree seedling (<0.5 m tall), (5) understory tree (0.5–<10 m tall),
(6) overstory tree (≥10 m tall), and (7) woody vine. For percent
cover calculations, the cover class values were first converted
to their midpoints (Table 1). Total canopy cover per macroplot
was the mean of four spherical densiometer measurements taken
at the center of the macroplot, one facing in each of the four
cardinal directions (according to the manufacturer protocol; Frontiers in Environmental Science | www.frontiersin.org Growth The amount of vegetative canopy cover in the overstory was
used to characterize growth. Growth was quantified using a
spherical densiometer, which is a handheld instrument with a
spherical-shaped mirror on which small squares are engraved to
assist in determining the amount of tree canopy in the mirror’s
reflection (Strickler, 1959). Canopy cover represents the amount
of overstory tree biomass that exists at a given point in time. It
is a relative value and can range from 0 to 100%, where higher
percentages denote denser growth. ecosystem can be characterized as one that is sustainable—
having the ability to “maintain its structure (organization) and
function (vigor) over time in face of external stress (resilience)”
(Costanza and Mageau, 1999). In general, stress to ecosystems
caused by changes in groundwater availability can influence
six key ecological processes: growth, reproduction, recruitment,
mortality, ecosystem structure, and ecosystem function (Eamus
et al., 2006b). In response to stress, the response functions
of native plants and aquatic ecosystems follow a reasonably
predictable and progressive series of events that cascade across
molecular, individual, landscape, and ecosystem scales (Davies
and Jackson, 2006; Eamus et al., 2006a; USEPA, 2016). For
vegetation, a natural progression in response to insufficient water
availability would begin with stomatal closure, resulting in a
reduction in transpiration and photosynthesis. If water stress
persists, xylem embolism can result in reductions in growth
rates and contribute to die-back. Reduced growth would then
subsequently result in a reduction in reproduction (seed set)
and recruitment (sapling growth) processes that are necessary
for forest succession to occur. In extreme cases of water stress,
the absence of growth and recruitment of younger plants may
reduce the biomass physically present in various elevations above
the ground surface. The absence may also create the opportunity
for new species with different growth forms (e.g., grasses instead
of shrubs) to populate the area, thus changing the ecosystem
structure (Eamus et al., 2006a). This could then result in the
alteration of ecosystem function, since changes in ecosystem
structure (the species composition and diversity) could change
the functional traits expressed by individual species where the
absence of key species could alter ecosystem processes, such as
nutrient cycling, predator-prey relationships, and competition
for resources (Chapin, 1997). Health Indicators Ecosystems are complex systems composed of living organisms
interacting with each other and their environment (e.g., soil,
water, and air). The health of an ecosystem is a measure of its
overall performance resulting from the biological responses of
individual species and their interaction with each other. A healthy November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. TABLE 1 | Classes used to record the visual estimation of percent cover for each
plant species as well as each stratum as a whole. TABLE 1 | Classes used to record the visual estimation of percent cover for each
plant species as well as each stratum as a whole. Percent cover (%)
Midpoint (%)
<1
0.5
1 to <5
3
5 to <25
15
25 to <50
37.5
50 to <75
62.5
75 to <95
85
>95
97.5
The midpoint value was used to represent each cover class during quantitative analyses. TABLE 1 | Classes used to record the visual estimation of percent cover for each
plant species as well as each stratum as a whole. Percent cover (%)
Midpoint (%)
<1
0.5
1 to <5
3
5 to <25
15
25 to <50
37.5
50 to <75
62.5
75 to <95
85
>95
97.5
The midpoint value was used to represent each cover class during quantitative analyses. the open-source software R (R Development Core Team, 2008). Mean values for each vegetation health indicator were compared
between forests using a one-way ANOVA followed by the Tukey
HSD statistical test. This post-hoc test was performed using the
glht() function in the multcomp package (Hothorn et al., 2017). This parametric statistical test was applied using the argument
vcov=vcocHC for its robustness and ability to work with
unbalanced group sizes, non-normality, and heteroscedasticity
(Herberich et al., 2010). Diversity
Th Sh The Shannon-Wiener Evenness Index, which incorporates both
species richness and the abundance of each species, was used
to characterize diversity. The index represents the relative
abundance of different species comprising the richness of an area. The index for each forest stand was calculated using the following
Shannon-Wiener Evenness Index equation: Hj = −
s
X
i=1
piln
pi
where for each macroplot (j), H is the Shannon-Wiener Evenness
Index value, S is the total number of species (richness), and pi
is the proportional cover of each species (i) to the total cover
of all species in the macroplot. Each index value, which varies
between 0 and 1, was converted into a percentile value that ranges
between 0 and 100%, where higher percentages denote greater
species richness and abundance. Frontiers in Environmental Science | www.frontiersin.org November 2019 | Volume 7 | Article 175 Hydrologic Conditions Figure 4 shows precipitation by month and groundwater levels
for three wells from the mid-1960s through August 2019. Historical depth to groundwater (defined as the position of
the water table relative to the ground surface) near Castello
Forest has ranged between 9.0 and 25.2 m at 06N06E28C002M
(Figure 4B) and 5.1 and 23.7 m at 06N06E29K001M (Figure 4C),
and near Tall forest has ranged between 0.5 and 3.7 m at
05N05E28L003M (Figure 4D). Depth to groundwater in the
unconfined aquifer at four of the ERT sites (ERT-P1, ERT-P2,
ERT-P5, and ERT-P6) fluctuated between 6.2 and 14.0 m at
MW5, 1.5 and 12.0 m at MW9, and 4.2 and 13.1 m at MW2
(Figure 5), since groundwater data collection began in December
2012. At all three monitoring wells within the study area, depth
to groundwater was deepest after the dry summer season and
before the rainy winter season. Depth to groundwater gradually
increased between 2012 and 2016, which corresponds to the
historic drought conditions California experienced during this
period. At the time of ERT data collection, depth to groundwater
was 11.6 m at ERT-P1, 10.0 m at ERT-P2, and 12.5 m at ERT-P6. Structure Ecosystem structure is generally defined as the community
of living organisms coexisting in conjunction with abiotic
components (e.g., soil, air, and water). In most habitats,
vegetation provides the main structure of the environment
(Rutten et al., 2015). More vertical structure (or vertical
layering) creates habitat complexity that can support a greater
vertical distribution of birds (Pearson, 1971), mammals (Grelle,
2003), and insects (Schulze et al., 2001). Vertical stratification,
or the number of layers (strata) present, was used to
characterize ecosystem structure and was calculated using the
following equation: Regeneration The number of saplings (defined in this study as tree individuals
either 50–135 cm tall or with DBH <10 cm) present was used
to characterize regeneration. The height and DBH of plants
were used to reflect age, where smaller trees are younger
than larger ones. At a given time, the presence of trees at
different sizes, particularly smaller ones (saplings), indicates that
recruitment is occurring. Regeneration was calculated using the
following equation: To characterize, infer, and spatially compare health conditions
between forest stands in this study, six indicators were
derived from the vegetation survey data: growth (species)
diversity, regeneration, structure, native plant dominance,
and survivorship. A brief description of the rationale and
assumptions used to define each health indicator, as well as how
vegetation survey data were used to quantify each indicator for
this study, is provided in the subsections below. Rj =
Sapj
Sapj + YTj + MTj where for each macroplot (j), R is Regeneration, Sap is the
number of saplings, YT is the number of young trees (DBH
10–25 cm), and MT is the number of mature trees (DBH
>25 cm). Regeneration was converted into a percentile value that The health indicators determined for each forest were
statistically compared to the other forests in the study using November 2019 | Volume 7 | Article 175 6 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. ranges between 0 and 100%, where higher percentages denote
greater recruitment. introduced (non-native) plant species. Ecosystem function was
converted into a percentile value that ranges between 0 and 100%,
where higher values denote greater function. Survivorship The percentage of overstory vegetation cover remaining from
2013 to 2016 was used to characterize survivorship and was
quantified using spherical densiometer data. Survivorship was
calculated using the following equation: Sj =
SDj (t)
SDj (t−1) where for macroplot (j), S is survivorship, SD is the spherical
densiometer value, (t) represents data from 2016, and (t-1)
represents data from 2013. Survivorship was converted into a
percentile value, where higher percentages denote less crown
dieback. Percentages over 100% were possible if cover increased
during this time period. ESj =
Strataj
Stratamax ESj =
Strataj
Stratamax where for each macroplot (j), ES is the ecosystem structure,
Strata is the number of strata, and Stratamax is the maximum
number of strata. In this case, Stratamax was seven based on the
chosen protocol to characterize vegetation. Ecosystem structure
was converted into a percentile value that ranges between 0 and
100%, where higher percentages denote greater vertical structure
in the forest. Native Plant Dominance Native plant dominance was used as a health indicator
because it can provide insight on whether the ecosystem’s
function is intact. Ecosystem function is generally defined as
an ecosystem’s ability to maintain multiple functions, such as
carbon storage, nutrient cycling, and the transfer of energy
via growth and decomposition. Functional responses to stress
induced by changes in groundwater have been reported to cause
changes in community composition such that native species
are outcompeted by non-native species (Keddy and Reznicek,
1986; Moore and Keddy, 1988; Sommer and Froend, 2014). Numerous studies have also shown the ability of non-native
invasive species to alter the flow of energy and cycling of materials
within an ecosystem, and thus its functioning (Vitousek et al.,
1987; D’Antonio, 1992; Vitousek, 1997; Gordon, 1998; Mack and
D’Antonio, 1998; Cicchetti and Diaz, 2002; Meyerson et al., 2002;
Ehrenfeld, 2003; Kourtev et al., 2003; Levine et al., 2003; Dukes
and Mooney, 2004; USEPA, 2016). Although the presence of non-
native invasive species may not necessarily alter the functioning
of an ecosystem (Barney et al., 2013), the presence of native
species can at a minimum be indicative that ecosystem function
is more likely to be intact. In this study, we use native plant
dominance as a rough proxy for ecosystem function, which was
calculated by comparing the percent of native plant cover to total
plant cover: Frontiers in Environmental Science | www.frontiersin.org Electrical Resistivity Tomography ect ca
es st
ty o
og ap y
The following subsections outline the ERT results from the
Oneto-Denier area and each forest block (Castello, Shaw, and
Tall). At the time of the survey no rainfall had been recorded in
the area for 5+ months, leaving the water table at the bottom
extents of the ERT images. Data acquisition was completed in
<2 h per profile and temperatures remained constant throughout
the survey. The study area is known to have low salinity. Therefore, ERT responses are interpreted as a function of soil
texture and water content. Well logs indicate the lower resistivity
values (20 m or less) to be associated with clay-dominated
sediments, and higher resistivity values (40 m and greater) with
sand-dominated sediments. Fj =
NPj
NPj + IPj where for macroplot (j), F is the ecosystem function, NP is the
total cover of native plant species, and IP is the total cover of November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 7 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. Rohde et al. Hydrological Controls on Groundwater-Dependent Ecosystem Health
FIGURE 4 | Long-term hydrologic time series. (A) Monthly precipitation (mm), and depth to groundwater in the unconfined aquifer (meters below ground surface) near
(B) Castello forest, (C) Castello forest, and (D) Tall forest. The vertical red line denotes when ERT data collection occurred nearby. FIGURE 4 | Long-term hydrologic time series. (A) Monthly precipitation (mm), and depth to groundwater in the unconfined aquifer (meters below ground surface) near
(B) Castello forest, (C) Castello forest, and (D) Tall forest. The vertical red line denotes when ERT data collection occurred nearby. Frontiers in Environmental Science | www.frontiersin.org Oneto-Denier sediments is expected to be the cause of this shallow high-
resistive zone. The ERT results correlated well with local
geologic maps1 and lithologic data from the MW5 well log
(Figure 6B). At the time of ERT-P1 data acquisition, the
groundwater table (pink triangle, Figure 6B) at MW5 was 11.6 m
below ground and was obscured by the clay content of the
local soil. ERT-P1 results (Figure 6) show some lateral and vertical soil
heterogeneity. The MW5 lithologic log (Figure 6B) is dominated
by silts and clays with some sand that result in low (cool colors)
resistivity values throughout the profile, with the exception
of a slightly more resistive zone at 6–12 m depth from 60
to 120 m along the profile, which we interpret is associated
with sandier material below the more laterally extensive silt
and clay observed in the lithologic log. Near the river bank
at the beginning of ERT-P1 (0–50 m along the profile) we
observed a shallow highresistivity zone that corresponds to
coarser alluvial substrate that has been deposited in an eroded
elevated part of the channel (like an over-flow channel) when
stream flows exceed capacity. The deposition of these coarse The results for ERT-P2 (Figure 6C) show strong heterogeneity
both laterally and vertically, where more resistive soils at 40–
60 m (depth of 6–10 m) and 100–130 m (depth of 6–12 m)
indicate sandy soil zones that are consistent with the MW9
lithological log data. At the time of ERT-P2 data acquisition,
the groundwater table at MW9 was 10.0 m below ground (pink
triangle, Figure 6C) and again was obscured by the soil texture. November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 8 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. FIGURE 5 | Recent hydrologic time series. (A) Monthly precipitation (mm), and depth to groundwater in the unconfined aquifer (meters below ground surface) at (B)
MW5 in Oneto-Denier, (C) MW9 in Oneto-Denier, and (D) MW2 in Shaw forest. The vertical red line denotes when ERT data collection occurred at each site. FIGURE 5 | Recent hydrologic time series. (A) Monthly precipitation (mm), and depth to groundwater in the unconfined aquifer (meters below ground surface) at (B)
MW5 in Oneto-Denier, (C) MW9 in Oneto-Denier, and (D) MW2 in Shaw forest. The vertical red line denotes when ERT data collection occurred at each site. Oneto-Denier Both ERT-P1 and ERT-P2 exhibit a more resistive layer near
the ground surface (<2 m depth), which likely corresponds to
and is affected by the vegetative root zone. Differences in the
duration of plant water uptake between ERT-P1 (dead winter
annual grass) and ERT-P2 (live perennial grass) likely contributed
to the more resistive topsoil in ERT-P2. documents indicates that in the mid-1800s, the Cosumnes River
ran west of its current course, breaking into distributaries just
south of present-day Shaw Forest and creating a mosaic of
seasonal and perennial wetlands (Whipple et al., 2012). Frontiers in Environmental Science | www.frontiersin.org Castello Forest Overall, results from ERT-P2 and lithologic logs indicate the
west side of the river at Oneto-Denier has slightly more sandy
soils than ERT-P1 on the east side of the river. The observed
differences in soil type at depth between ERT-P1 and ERT-P2 are
supported by the geologic and land history record. The geologic
map (how to cite?) shows the very clay-dominated Riverbank
Formation underlying soils on the east side of the river at
this latitude. Recent compilation and interpretation of historical Profiles ERT-P3 and ERT-P4 were collected at Castello Forest
(Figure 7A) adjacent to macroplots (MP) MP-6 and MP-13,
respectively. ERT-P3 was enclosed within the canopy of mature
trees except for a gap at ∼70 m, and ERT-P4 was positioned
across a boundary between mature canopy and a more open
area dominated by annual grasses with few scattered shrubs. Both ERT-P3 and ERT-P4 (Figures 7B,C) show a more resistive
subsurface with greater vertical heterogeneity than any of the November 2019 | Volume 7 | Article 175 9 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. Oneto-Denier (A) ERT study site, (B) ERT-P1 inversion results, and (C) ERT-P2 inversion results. ERT data were collected in October 2016 after significant
cm). The water table at the time of data collection is denoted by the pink inverted triangle. FIGURE 6 | Oneto-Denier (A) ERT study site, (B) ERT-P1 inversion results, and (C) ERT-P2 inversion results. ERT data were collected in October 2016 after significant
rainfall (∼5 cm). The water table at the time of data collection is denoted by the pink inverted triangle. FIGURE 6 | Oneto-Denier (A) ERT study site, (B) ERT-P1 inversion results, and (C) ERT-P2 inversion results. ERT data were collected in October 2016 after significant
rainfall (∼5 cm). The water table at the time of data collection is denoted by the pink inverted triangle. other ERT profiles (see Figures 6B,C, 8B,C, 9B,C). In ERT-P3,
a zone of higher resistivity in the near surface (∼2 m depth)
extends along the entire profile except where it thins to ∼1 m
depth around 70 m (red box, Figure 7B). This variation in
the near-surface resistive zone is consistent with the greater
water demands and water lifting capabilities of mature trees
as compared to shallowly rooted grasses. Frontiers in Environmental Science | www.frontiersin.org Castello Forest Likewise, from 0
to 40 m in ERT-P4, the near-surface resistive zone is thinner
than after the transition from the grass to the tree coverage (red box, Figure 7C), again showing a potential influence of
plant life form (grass vs. tree) on soil moisture. Beyond 40 m
in ERT-P4 within the tree coverage, the near-surface resistive
zone extends even slightly deeper than observed in ERT-
P3. Given the overall higher subsurface resistivity values at
Castello Forest, along with the observed sandier surface soils
and their similarity to the higher resistivity values in the
sandy soil zones in ERT-P2 (MW9), these soils are interpreted
as sandy. November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 10 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. FIGURE 7 | Castello Forest (A) ERT study site, (B) ERT inversion results for ERT-P3, and (C) ERT inversion results for ERT-P4. Red boxes denote sections along the
ERT transect with less woody vegetation and resulting wetter soils (low resistivity) compared to remainder of the vegetated transect line. FIGURE 7 | Castello Forest (A) ERT study site, (B) ERT inversion results for ERT-P3, and (C) ERT inversion results for ERT-P4. Red boxes denote sections along the
ERT transect with less woody vegetation and resulting wetter soils (low resistivity) compared to remainder of the vegetated transect line. FIGURE 7 | Castello Forest (A) ERT study site, (B) ERT inversion results for ERT-P3, and (C) ERT inversion results for ERT-P4. Red boxes denote sections along the
ERT transect with less woody vegetation and resulting wetter soils (low resistivity) compared to remainder of the vegetated transect line. Shaw Forest resistivity that is interpreted as sandier soils (based on interpreted
resistivity values at ERT-P2, ERT-P3, and ERT-P4). The near-
surface soils (<2 m depth) are more resistive from 60 to 128 m
along ERT-P5, which correlates to denser understory vegetation
(red box, Figure 8B). A lower density of understory vegetation
along the first half of ERT-P5 correlates with less resistive
near-surface soils. The ERT-P6 profile correlates well with
MW2 (Figure 8C) and the low-density understory vegetation
matches with less resistive near-surface soils (<2 m depth). The Perpendicular profiles ERT-P5 and ERT-P6 were collected
at Shaw Forest (Figure 8A) adjacent to MP-18 and MW-2,
respectively. ERT-P5 results (Figure 8B) indicate silt/clay soils,
much like those at ERT-P1 (Oneto-Denier), with both vertical
and lateral soil heterogeneity. Nearby lithologic data from the
MW-2 well log indicate pervasive silts and clays from 0 to 12 m
depth. Resistivity values along ERT-P5 show agreement with this
well log, except at 80 m where there is an isolated zone of low November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 11 Rohde et al. Hydrological Controls on Groundwater-Dependent Ecosystem Health aw forest (A) ERT study site, (B) ERT inversion results for ERT-P5, and (C) ERT inversion results for ERT-P6. Dashed yellow lines in (B,C) denote the
nt between these two ERT profiles. The red box in (B) denotes the section of the ERT profile that is more vegetated by thick blackberry bushes,
er resistivity. FIGURE 8 | Shaw forest (A) ERT study site, (B) ERT inversion results for ERT-P5, and (C) ERT inversion results for ERT-P6. Dashed yellow lines in (B,C) denote the
intersection point between these two ERT profiles. The red box in (B) denotes the section of the ERT profile that is more vegetated by thick blackberry bushes,
resulting in higher resistivity. FIGURE 8 | Shaw forest (A) ERT study site, (B) ERT inversion results for ERT-P5, and (C) ERT inversion results for ERT-P6. Dashed yellow lines in (B,C) denote the
intersection point between these two ERT profiles. The red box in (B) denotes the section of the ERT profile that is more vegetated by thick blackberry bushes,
resulting in higher resistivity vegetation along ERT-P6 and the beginning (0–60 m) of ERT-P5
comprised the same dominant plant species compared to the end
of ERT-P5. with mild lateral and vertical heterogeneity. Shaw Forest Although there are
no monitoring wells nor lithological logs in Tall Forest, ERT-
P7 resistivity values were compared to the range of values in
Shaw Forest and Oneto-Denier, where monitoring wells exist. The subsurface soils at ERT-P7 are interpreted as silt and
clay deposits from 0 to 60 m along the profile. Conversely,
beyond 60 m the soils show slightly higher resistivity, which
based on results observed at ERT-P2 were interpreted as
slightly sandier. Tall Forest One ERT profile (ERT-P7) was collected at Tall Forest (Figure 9)
adjacent to a dirt access road just inside the edge of the
forest due to the density of the forest undergrowth. ERT-P7
resistivity results (Figure 9B) show low resistivity conditions November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 12 Rohde et al. Hydrological Controls on Groundwater-Dependent Ecosystem Health FIGURE 9 | Tall Forest (A) ERT study site and (B) ERT inversion results for ERT-P7. Forest (A) ERT study site and (B) ERT inversion results for ERT-P7. FIGURE 9 | Tall Forest (A) ERT study site and (B) ERT inversion results for ERT-P7. FIGURE 9 | Tall Forest (A) ERT study site and (B) ERT inversion results for ERT-P7. DISCUSSION Vegetation Health Indicators November 2019 | Volume 7 | Article 175 Vegetation Health Indicators For each forest stand, summary statistics were calculated for:
(1) the 2013 and 2016 vegetation survey data (Table 2) used to
calculate each health indicator, and (2) the six health indicators
for each forest (Table 3; Figure 10). Castello Forest was found to
be statistically different (p < 0.05) from both Shaw Forest and Tall
Forest for all six health indicators. Shaw Forest and Tall Forest
were statistically similar (Table 3) for four of the health indicators
(growth, diversity, structure, and survivorship), and statistically
different (p < 0.05) for two of the health indicators (regeneration
and native plant dominance). Castello Forest scored lower than
both Shaw Forest and Tall Forest on every health indicator, and
Tall Forest scored higher than Shaw Forest for the regeneration
and native plant dominance indicators. Relative differences in
health indicators between forests resulted in Castello Forest
having the least healthy conditions due to lower growth, species
diversity, regeneration, vertical structure, and survivorship of
canopy from between 2013 and 2016. Health conditions of Tall
and Shaw Forests were more similar to each other in comparison
to Castello Forest, but slightly higher scores for regeneration
and native plant dominance resulted in Tall Forest having the
healthiest conditions. Lithological and Hydrological Conditions
Subsurface
lithological
conditions
in
each
forest
were
characterized using ERT and lithological logs from available
monitoring wells. These independent data sources corroborated
each other and indicated broad qualitative differences across the
forest stands studied. Castello Forest showed sandier soils than
Shaw and Tall Forests, which both showed high clay/silt content. Strong precedence exists to link soil texture as imaged by
ERT with the hydrological factor of soil moisture. It is broadly
accepted that clays and silts have much greater water retention
capacity than sands. Development of the ERT method identified
soil moisture as a separate factor influencing resistivity, and when
present with clay, the two are highly correlated. These principles
developed from empirical testing were applied in a similar study
by Robinson et al. (2008), where soil electrical conductivity
(inverse of resistivity) was used to map soil spatial distributions
across a large landscape with diverse plant communities. After
testing soil samples for clay content and volumetric water
content, they found soil resistivity to be controlled by both
factors, which were also positively correlated with each other and
soil water retention. These results are very similar to findings Frontiers in Environmental Science | www.frontiersin.org Lithological and Hydrological Conditions n
Mean
SD
Min
Max
Castello forest
Total species count
19
14.1
2.5
11
18
Total # of native species
19
6.7
1.3
5
9
Total # of invasive species
19
7.3
1.9
4
11
Spherical Densiometer (2013)
19
66.1
25.9
18.2
98.7
Spherical Densiometer (2016)
19
35.0
14.7
12.2
59.1
Total cover of native plants
19
30.5
17.7
6.0
80.5
Total cover of introduced plants
19
95.0
19.8
17.0
114.5
Shannon-Wiener Evenness index
19
0.4
0.1
0.2
0.6
Total # of saplings
19
0.8
1.2
0
4
Total # of young trees
19
2.1
1.3
0
4
Total # of mature trees
19
1.7
1.1
0
4
Number of strata
19
3.6
1.4
2
6
Shaw forest
Total species count
20
16.1
5.5
10
32
Total # of native species
20
9.8
3.0
5
18
Total # of invasive species
20
6.2
2.8
3
13
Spherical Densiometer (2013)
19
90.9
8.7
61.7
98.4
Spherical Densiometer (2016)
20
69.1
13.8
27.6
92.4
Total cover of native plants
20
90.5
39.2
32.0
182.0
Total cover of introduced plants
20
34.0
31.0
2.0
124.0
Shannon-Wiener Evenness index
20
0.6
0.1
0.3
0.7
Total # of saplings
20
12.1
10.7
0
43
Total # of young trees
20
5.8
3.2
0
15
Total # of mature trees
20
3.3
2.1
0
9
Number of strata
20
6.4
0.7
5
7
Tall forest
Total species count
17
14.0
8.4
5
37
Total # of native species
17
10.8
5.3
5
24
Total # of invasive species
17
2.9
3.2
0
13
Spherical Densiometer (2013)
17
88.1
14.6
46.1
99.2
Spherical Densiometer (2016)
14
71.1
18.7
22.9
93.2
Total cover of native plants
17
117.6
35.7
64.5
170.5
Total cover of introduced plants
17
4.8
8.8
0.0
35.5
Shannon-Wiener Evenness index
17
0.6
0.1
0.5
0.8
Total # of saplings
17
35.5
22.6
2
78
Total # of young trees
17
9.2
4.9
1
20
Total # of mature trees
17
3.6
2.8
0
10
Number of strata
17
5.9
0.9
4
7
All forests
Total species count
56
14.8
5.8
5
37
Total # of native species
56
9.1
3.8
5
24
Total # of invasive species
56
5.6
3.2
0
13
Spherical Densiometer (2013)
55
81.4
21.0
18.2
99.2
Spherical Densiometer (2016)
53
57.4
22.8
12.2
93.2
Total cover of native plants
56
78.4
48.2
6.0
182.0
Total cover of introduced plants
56
45.8
43.5
0.0
124.0
Shannon-Wiener Evenness index
56
0.5
0.1
0.2
0.8
Total # of saplings
56
15.4
19.8
0
78
Total # of young trees
56
5.6
4.4
0
20
Total # of mature trees
56
2.9
2.2
0
10
Number of strata
56
5 3
1 6
2
7 TABLE 2 | Summary statistics for vegetation data included in analyses. Lithological and Hydrological Conditions g
y
g
Subsurface
lithological
conditions
in
each
forest
were
characterized using ERT and lithological logs from available
monitoring wells. These independent data sources corroborated
each other and indicated broad qualitative differences across the
forest stands studied. Castello Forest showed sandier soils than
Shaw and Tall Forests, which both showed high clay/silt content. Strong precedence exists to link soil texture as imaged by
ERT with the hydrological factor of soil moisture. It is broadly
accepted that clays and silts have much greater water retention
capacity than sands. Development of the ERT method identified
soil moisture as a separate factor influencing resistivity, and when
present with clay, the two are highly correlated. These principles
developed from empirical testing were applied in a similar study
by Robinson et al. (2008), where soil electrical conductivity
(inverse of resistivity) was used to map soil spatial distributions
across a large landscape with diverse plant communities. After
testing soil samples for clay content and volumetric water
content, they found soil resistivity to be controlled by both
factors, which were also positively correlated with each other and
soil water retention. These results are very similar to findings November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 13 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. TABLE 2 | Summary statistics for vegetation data included in analyses. Lithological and Hydrological Conditions from this study, where low resistivity values were associated with
soils of high clay content as observed in well logs. We therefore
adopt the fundamental concept that water retention was higher
in our clay-rich soils compared to the sandier soils. Hydrologic evidence from the lower Cosumnes study
system also strongly supports the connection between ERT
measurements and soil moisture. Figures 4, 5 show that the
predominance of silt and clay that was observed in Tall Forest was
also coincident with the shallowest groundwater levels observed
through the historical record over nearly 50 years (Figure 4C),
with groundwater levels ranging between 0.5 and 3.7 m. In
contrast, Castello forest had predominantly sandy soils and the
deepest groundwater levels observed (5.1–25.2 m; Figures 4A,B). Four years of data over a prolonged drought show that Shaw
Forest had groundwater levels intermediate between these two
(4.2–13.5 m; Figure 5C). Therefore, groundwater availability
(higher soil moisture content and shallower groundwater levels)
increased progressively downstream from Castello Forest to
Shaw Forest to Tall Forest. Increasing groundwater availability
along the Cosumnes River is likely a combination of groundwater
flow gradients and soil type differences between forests. The
spatial distribution of riparian forests along this groundwater
gradient provides an opportunity to observe which groundwater
levels are supportive of healthy conditions within a GDE. GDE Health In this study, we developed an approach to quantify ecosystem
health within GDEs, using metrics of groundwater-dependent
vegetation as indicators, so that health conditions could be
statistically compared across the landscape. Vegetation indicators
used to infer GDE health conditions demonstrated that Shaw
and Tall Forests have statistically similar and greater health
conditions than Castello Forest. One of the major biological
differences between the forests was that Shaw and Tall Forests
both had a lush understory, whereas Castello Forest did
not. This difference was captured in the vegetative growth,
regeneration, and structure indicators, such that both Shaw and
Tall Forests exhibited higher vegetative growth (canopy cover),
regeneration (sapling recruitment), and structure (number of
strata present, including young trees) than Castello Forest. A lack
of regeneration at Castello Forest indicates that health conditions
may be in an unsustainable state in comparison to Shaw and
Tall Forests. Greater vertical structure at Tall and Shaw Forests compared
to Castello Forest was also correlated to the diversity and native
plant dominance indicators. Greater species diversity in Tall
and Shaw Forests in comparison to Castello Forest was also
accompanied by a greater proportion of native plant cover. These
observations are consistent with previous research studies, which
found changes in groundwater availability to cause a functional
shift in the ecosystem away from native habitat toward more
favorable conditions for invasive species (Keddy and Reznicek,
1986; Moore and Keddy, 1988; Sommer and Froend, 2014). Frontiers in Environmental Science | www.frontiersin.org Hydrological Controls on GDE Health y
g
On the larger scale of the river reach studied, comparisons among
ERT profiles and groundwater monitoring well data showed November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 14 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. TABLE 3 | Statistical results for each ecological health indicator. Growth
Diversity
Regeneration
Ecosystem structure
Native plant dominance
Survivorship
Castello
n
19
19
18
19
19
19
Mean
35.0
0.4
20.2
51.9
24.4
56.8
SD
14.7
0.1
32.5
19.8
15.2
19.3
Min
12.2
0.2
0
28.6
6.4
14.1
Max
59.1
0.6
100
85.7
74.4
86.9
Shaw
n
20
20
20
20
20
19
Mean
69.1
0.6
50.5
91.4
73.1
77.4
SD
13.8
0.1
24.2
9.7
20.5
14
Min
27.6
0.3
0
71.4
32.8
32.5
Max
92.4
0.7
100
100
98.4
101.7
Tall
n
17
17
17
17
17
15
Mean
73.8
0.6
68.6
84.9
96.7
80.5
SD
18.0
0.1
16.9
12.8
5.3
18.6
Min
22.9
0.5
18.2
57.1
79.2
30.4
Max
93.2
0.8
95.8
100
100
113.4
ANOVA (Herberich et al., 2010)
Castello: shaw
p < 0.05
p < 0.05
p < 0.05
p < 0.05
p < 0.05
p < 0.05
Castello: tall
p < 0.05
p < 0.05
p < 0.05
p < 0.05
p < 0.05
p < 0.05
Shaw: tall
p = 0.68
p = 0.26
p < 0.05
p = 0.22
p < 0.05
p = 0.87 TABLE 3 | Statistical results for each ecological health indicator. that clay-dominated sites (Shaw and Tall Forests) had shallower
depth to groundwater, retained more soil moisture, and sustained
healthier vegetation than the sandier site (Castello Forest),
with its greater depth to groundwater, reduced soil moisture,
and less healthy vegetation. This shows the strong influence
of groundwater availability and soil type on groundwater-
dependent riparian vegetation. Further studies may elucidate
more detailed mechanisms shaping groundwater availability,
such as hydraulic effects of root networks and surface flood
regimes. Further work may also refine the spatial scale at
which within-forest differences could be affected by small-scale
variations in underlying sediments. Our study, however, operated
at the scale of entire forest stands underlain by a sequence
of substantially different groundwater and soil conditions that
together influenced subsurface water retention and availability of
that water to a broad suite of plant species. Hydrological Controls on GDE Health can range in severity from declines in productivity to increased
mortality (Scott et al., 1999; Shafroth et al., 2000; Canham et al.,
2012, 2015). Even in cases where some individual groundwater-
dependent plants have the capacity to adapt to gradual increases
in water stress due to groundwater decline, changes in the
ecosystem structure and community composition can still result
(Froend and Sommer, 2010). This phenomenon is consistent
with the decrease in number of strata and greater presence of
non-native species in Castello Forest in contrast to Shaw and Tall
Forests, thereby suggesting that long-term trends in groundwater
conditions may be contributing to the poorer health conditions
observed in Castello Forest. The absence of understory trees at Castello Forest sends a
strong biological signal that regeneration is lacking and that the
current groundwater regime may not be accessible to younger
plants with shallower root systems. This is problematic because
if the groundwater regime is not restored to conditions where
sapling recruitment can occur, there will be no younger trees
present to replace mature trees once they inevitably reach
mortality. Groundwater depths near Castello Forest were also
deeper than the water depth value of ∼10 m that is often
used to indicate the likelihood that plant rooting depths are
capable of accessing groundwater (Canadell et al., 1996; Eamus
et al., 2015; Rohde et al., 2018). Routine monitoring of health
indicators within each of the forest blocks, in conjunction with
groundwater level data from monitoring wells over time, would
help identify the groundwater level thresholds necessary to enable
regeneration and support GDE health in this area. However,
healthy conditions in Shaw Forest provide a preliminary insight
into what groundwater levels (observed at MW2) may be
necessary to support nearby riparian forests. With only 5
years of groundwater level data available at MW2, continuous
monitoring of groundwater levels and biological responses over Therefore, differences in groundwater availability are most
likely the cause for the observed differences in ecosystem health
at our study sites, due to the spatial differences in groundwater
availability influenced by soil type and the groundwater level
gradient along the Cosumnes River. Our results support our
hypothesis that differences in ecosystem health correlate to
hydrological conditions, such that access to greater subsurface
moisture from shallower groundwater levels results in the
healthier conditions that were observed in Shaw and Tall Forests
in comparison to Castello Forest. Frontiers in Environmental Science | www.frontiersin.org Hydrological Controls on GDE Health Some groundwater-dependent plants may have the adaptive
capacity to cope with absolute and relative changes to
groundwater availability depending on the rate, magnitude, and
duration of groundwater changes. However, previous research
demonstrates that if absolute and relative groundwater changes
are too drastic for rooting networks to adapt, groundwater
changes can result in a spectrum of biological responses, which November 2019 | Volume 7 | Article 175 15 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. FIGURE 10 | Box plots for each vegetation health indicator by forest stand. Dots represent data points outside the 25th and 75th percentiles (represented as the
vertical, thin black line). FIGURE 10 | Box plots for each vegetation health indicator by forest stand. Dots represent data points outside the 25th and 75th percentiles (represented as the
vertical, thin black line). vegetation health indicator by forest stand. Dots represent data points outside the 25th and 75th percentiles (represented as the FIGURE 10 | Box plots for each vegetation health indicator by forest stand. Dots represent data points outside the 25th and 75th
vertical, thin black line). time would help elucidate cause-and-effect relationships between
groundwater and the riparian forest, so adaptive management
can occur as more information becomes available. approach for deducing the subsurface structure and soil
moisture distribution within ecosystems. Transdisciplinary
approaches such as these can elucidate insights on how these
systems functionally respond to changes or spatial differences in
groundwater availability. Frontiers in Environmental Science | www.frontiersin.org November 2019 | Volume 7 | Article 175 CONCLUSION This study also demonstrated the value of using vegetation
survey data to deduce GDE health. Vegetation survey data
offers the ability to determine a wide variety of biological
responses in an ecosystem ranging from growth to survivorship,
which can be used to investigate groundwater impacts to
ecosystems. It is highly advised that groundwater sustainability
managers interpret biological information in conjunction with
hydrologic data so that only those changes to ecosystem health
due to groundwater are addressed (Rohde et al., 2018). It is
important to note that although using vegetation data to deduce
ecosystem health is best used as a surveillance indicator in
routine monitoring, that it may overlook some critical biological
responses of rare, threatened, and endangered species. In these
circumstances, it is highly advised that water managers consider This transdisciplinary study exemplifies the utility of combining
geophysical,
geological,
hydrological,
and
biological
data
to
explore
potential
groundwater
impacts
on
GDEs
in
an
unconfined
aquifer
system. Hydrologic
data
gaps
in
interconnected surface water systems are common due to
heterogeneous subsurface conditions, but are important to
understand since the interconnections between surface water
and groundwater can support perched groundwater, which can
offer an accessible source of groundwater to riparian vegetation
when unconfined aquifers are too deep. While it may be difficult
to accurately represent subsurface conditions in these aquifer
settings using sparse monitoring well networks and numerical
groundwater
models,
geophysics
offers
a
complementary November 2019 | Volume 7 | Article 175 Frontiers in Environmental Science | www.frontiersin.org 16 Hydrological Controls on Groundwater-Dependent Ecosystem Health Rohde et al. additional biological investigations that can better characterize
the condition of these valuable environmental assets. led collection and management of the vegetation survey data,
assisted with the ERT data collection, helped in all aspects
of the research especially those pertaining to the vegetation
data, and assisted with the writing of the manuscript. CU
collected and analyzed all of the ERT data, and assisted
in writing of the manuscript. JH assisted in the analysis
and writing. Successful
implementation
of
sustainable
groundwater
legislation relies on practical biological and hydrologic metrics
that can be incorporated into monitoring regimes. For practical
reasons, monitoring regimes should at a minimum provide some
basic surveillance of the hydrologic conditions supporting GDEs
and the biological conditions within the GDE, so that cause-
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2.0.CO;2 Canham, C. A., Froend, R. H., Stock, W. D., and Davies, M. (2012). ACKNOWLEDGMENTS The authors would like to thank The Nature Conservancy’s
seasonal staff(Audrey Kelly, Victor Oelschlaegel, Troy Shea,
and Jane Thompson) for their help in the field with vegetation
monitoring and geophysical data collection. We also would like
to thank Jesse Roseman for inspiring this research work in the
Cosumnes River Preserve. We also thank Dr. Graham Fogg,
Stephen Maples, and Alysa (Amy) Yoder at the University of
California, Davis for providing monitoring well data within
the Cosumnes River Preserve. We also thank Dr. Baptiste
Dafflon and Dr. Emmanuel Leger for their help interpreting
ERT data by integrating the BERT inversion code using
Matlab routines. AUTHOR CONTRIBUTIONS MR was the lead researcher, developed the ecosystem health
indicators, analyzed the results, and drafted the manuscript. SS CONCLUSION Practical biological
indicators that can integrate ecosystem-scale biological data
into water management monitoring programs and be used to
assess the health of GDEs in relation to hydrological conditions
are necessary but often missing in groundwater management
and monitoring programs. This study provides an approach for
water managers to integrate practical biological indicators that
can characterize GDE health into monitoring programs, so that
groundwater thresholds can be locally determined and adverse
impacts to ecosystems can be avoided. By monitoring GDE health
over time, water practitioners can determine if a correlation
exists between GDE health metrics and hydrologic datasets that
signal that potential groundwater impacts to the ecosystem are
occurring. This would help water managers identify groundwater
thresholds that can sustain GDEs and prioritize limited funds
and management efforts so that adaptive management of GDEs
under sustainable groundwater management can ensue. FUNDING We would like to thank the S. D. Bechtel, Jr. Foundation
for their philanthropic financial support to The Nature
Conservancy’s ongoing groundwater research on GDEs in
sustainable groundwater management. We would like to thank the S. D. Bechtel, Jr. Foundation
for their philanthropic financial support to The Nature
Conservancy’s ongoing groundwater research on GDEs in
sustainable groundwater management. We would like to thank the S. D. Bechtel, Jr. Foundation
for their philanthropic financial support to The Nature
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Association between executive function and excess weight in pre-school children
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PLOS ONE RESEARCH ARTICLE Narueporn LikhitweerawongID1, Jiraporn Khorana2,3,4, Nonglak Boonchooduang1,
Phichayut Phinyo3,5, Jayanton Patumanond3, Orawan Louthrenoo1* 1 Department of Pediatrics, Division of Growth and Development, Faculty of Medicine, Chiang Mai
University, Chiang Mai, Thailand, 2 Department of Surgery, Division of Pediatric Surgery, Faculty of
Medicine, Chiang Mai University, Chiang Mai, Thailand, 3 Center of Clinical Epidemiology and Clinical
Statistic, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, 4 Department of Surgery, Clinical
Surgical Research Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, 5 Department
of Family Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 * orawan.l@cmu.ac.th * orawan.l@cmu.ac.th Editor: Hae Sang Lee, Ajou University School of
Medicine, REPUBLIC OF KOREA Copyright: © 2022 Likhitweerawong et al. This is
an open access article distributed under the terms
of the Creative Commons Attribution License,
which permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. Data Availability Statement: The data and code
used to generate plots and perform statistical
analyses have been uploaded to the Open Science
Framework archive: https://osf.io/jdq6z/?view_
only=b2081b6607804ab8b95ada2ae27ba6d4. Association between executive function and
excess weight in pre-school children Narueporn LikhitweerawongID1, Jiraporn Khorana2,3,4, Nonglak Boonchooduang1,
Phichayut Phinyo3,5, Jayanton Patumanond3, Orawan Louthrenoo1* OPEN ACCESS Citation: Likhitweerawong N, Khorana J,
Boonchooduang N, Phinyo P, Patumanond J,
Louthrenoo O (2022) Association between
executive function and excess weight in pre-school
children. PLoS ONE 17(10): e0275711. https://doi. org/10.1371/journal.pone.0275711 Editor: Hae Sang Lee, Ajou University School of
Medicine, REPUBLIC OF KOREA
Received: May 10, 2022
Accepted: September 20, 2022
Published: October 10, 2022
Copyright: © 2022 Likhitweerawong et al. This is
an open access article distributed under the terms
of the Creative Commons Attribution License,
which permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited. Editor: Hae Sang Lee, Ajou University School of
Medicine, REPUBLIC OF KOREA
Received: May 10, 2022
Accepted: September 20, 2022
Published: October 10, 2022 Editor: Hae Sang Lee, Ajou University School of
Medicine, REPUBLIC OF KOREA PLOS ONE PLOS ONE Abstract The association between executive function and excess weight is becoming increasingly
evident. However, the results of previous studies are still inconclusive, and there is a lack of
evidence in early childhood. This study aims to examine the association between executive
function, in terms of overall and subscales of executive function (e.g., inhibition, working
memory, and shifting), and weight excess in preschoolers. A population-based cross-sec-
tional study was conducted on children aged 2–5 years of age from public and private
schools in Chiang Mai, Thailand. Participants’ weights and heights were measured and clas-
sified into three weight status groups (i.e., children with normal weight, overweight, and obe-
sity groups). Executive function was assessed using the parent-report Behavior Rating
Inventory of Executive Function-Preschool (BRIEF-P). Multivariable polynomial regression
was performed to analyze the association between executive function and weight status. A
total of 1,181 children were included in the study. After adjusting for confounders, impaired
overall executive function significantly increased the probability of being overweight (odds
ratio [OR] = 2.47; 95% confidence interval [CI] 1.33 to 4.56). A similar trend of association
was also found between impaired inhibition and overweight status (OR = 2.33; 95%CI 1.11
to 4.90). Furthermore, poor working memory was associated with both overweight and obe-
sity (OR = 1.87; 95%CI 1.09 to 3.20 and OR = 1.74; 95%CI 1.09 to 2.78, respectively). Our
data suggest that deficits in executive function, particularly inhibition and working memory,
are associated with weight excess in preschoolers. Early promotion of executive function
may be needed at this developmental age to prevent unhealthy weight status. Competing interests: The authors have declared
that no competing interests exist. EF involves the high-level mental processes required to control thoughts, emotions, and
behaviors. Three fundamental EFs are inhibitory control/inhibition, working memory, and
cognitive flexibility/shifting [10]. These three core EFs contribute to higher-order EF, such as
problem-solving, reasoning, and planning [10]. EF develops dramatically in the preschool
period [11], corresponding to the time of decline in body fat mass, before reaching the inflec-
tion point of adiposity rebound (adiposity rebound usually occurs about 6 years of age) [12]. The energy expenditure to develop the brain, especially the area of the brain related to EF, dur-
ing this early childhood might influence the composition of body fat and the changes in body
mass index (BMI) later [13, 14]. Several studies investigating the correlation between lower EF and higher BMI have focused
mainly on school-age children, adolescents, and adults [15–18]. Most of the key results from
these studies are found to be a small to medium effect size of the association. A paucity of stud-
ies regarding EF and weight excess has been conducted on preschool children due to the rela-
tively low prevalence of overweight and obesity in preschoolers (whose body fat typically
declines during this period) and the scarcity of valid instruments to measure EF in this age
group [19]. Furthermore, the results of some studies conducted on young children are incon-
sistent. For example, Pieper and Laugero reported that BMI percentile was not correlated with
most measures of EF in children 3–6 years old [20]. Tandon and colleagues showed that effort-
ful control and delay ability were not associated with BMI changes [21]. Similarly, a recent
study by Gross and colleagues reported that the EF score was not a predictor of weight status
in preschoolers [22]. On the other hand, Hughes and colleagues indicated that eating self-regu-
lation was related to the child’s BMI-for-age z-scores [23]. Schmitt and colleagues also sug-
gested a negative correlation between the composite EF score and BMI percentile in
preschoolers [24]. Due to a few studies focusing on young children and the inconsistent results mentioned
above, this study aims to investigate the association between EF and weight excess in pre-
school-aged children by controlling for potential confounders reviewed from previous litera-
ture. The findings of this study may contribute to an understanding of the relationship
between these variables in early childhood and obesity intervention by promoting EF. Introduction Funding: This work was supported by the Faculty
of Medicine, Chiang Mai University (Grant number
087/2564 to Narueporn Likhitweerawong) (https://
www.med.cmu.ac.th/web/research/). The funders
had no role in study design, data collection and Children and adolescents are increasingly facing the health problems of weight excess. The
worldwide prevalence of overweight and obesity in young children has continuously increased
over the past few decades, regardless of geography and culture [1]. In the conceptual 1 / 13 PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE Association between executive function and excess weight in preschoolers understanding of obesity, it is a chronic metabolic disease that primarily involves increased
calorie intake and decreased physical exercise. To date, the evidence is apparent that obesity is
a multifactorial disease, originating not only from obesity-related behaviors but also influenced
by genetics, environments, and gene-environment interactions [2]. Robust evidence has dem-
onstrated several risk factors associated with weight excess in childhood, such as preterm, low
birth weight, lack of breastfeeding, excessive screen time, and deficient amount of sleep [3–7]. Neurocognition, particularly executive function (EF), has been assumed to contribute to excess
weight through the theoretical hypothesis of lacking control related to eating behaviors [8, 9]. understanding of obesity, it is a chronic metabolic disease that primarily involves increased
calorie intake and decreased physical exercise. To date, the evidence is apparent that obesity is
a multifactorial disease, originating not only from obesity-related behaviors but also influenced
by genetics, environments, and gene-environment interactions [2]. Robust evidence has dem-
onstrated several risk factors associated with weight excess in childhood, such as preterm, low
birth weight, lack of breastfeeding, excessive screen time, and deficient amount of sleep [3–7]. Neurocognition, particularly executive function (EF), has been assumed to contribute to excess
weight through the theoretical hypothesis of lacking control related to eating behaviors [8, 9]. analysis, decision to publish, or preparation of the
manuscript. Competing interests: The authors have declared
that no competing interests exist. Competing interests: The authors have declared
that no competing interests exist. Measures Study determinants–executive function. The parent-report version of the Behavior Rat-
ing Inventory of Executive Function–Preschool version (BRIEF-P) in Thai was used to mea-
sure EF of the child [25]. There were 63 items with a three-point Likert scale asking whether
each behavior issue is problematic relative to other children of the same age, as never, some-
times, or often in the preceding six months. BRIEF-P measured overall EF (global executive
composite) and EF subscales (i.e., inhibit, shift, emotional control, working memory, and
plan/organize). The T-score for each scale was calculated based on standardized age and sex. Participants were categorized into impaired or normal EF groups, according to the cut-off
point (T-score at or above 65), which was considered clinically significant regarding the diffi-
culty of executive functioning [25]. This tool demonstrated good reliability with a Cronbach’s
alpha of 0.80–0.95 for the EF subscales and global executive composite scale [25]. Study endpoints–weight status. The weight status was divided into three groups: 1) nor-
mal weight group was defined as preschoolers with BMI equal to or greater than the 5th per-
centile but not reaching the 85th percentile for children of the same age and sex; 2) overweight
group was defined as preschoolers with BMI equal to or greater than the 85th percentile but
not reaching the 95th percentile; 3) obesity group was defined as preschoolers with BMI equal
to or greater than the 95th percentile [26]. The body weight and height of the participants were
measured at school using a digital weighing scale and stadiometer by teachers or school nurses. Then, the outcome assessors computed the percentile of BMI. Pre-specified confounders. Potential confounders of overweight/obesity, including
child’s age, sex, birth weight, gestational age, breastfeeding, maternal age, maternal BMI,
maternal education, socioeconomic status, screen time, physical activity, sleep, and parenting
styles, were reviewed from previous literature [3–7, 27–30]. Due to this substantial number of
variables contributing to obesity and their potential complex interactions, we created a
directed acyclic graph (DAG) using DAGitty [31] to determine confounding factors that
require conditioning and to evaluate minimally sufficient adjustment sets of confounders
when handling causal assumptions [32], as summarized in S1 Fig. A consensus was reached
with all authors (i.e., developmental-behavioral pediatricians and clinical epidemiologists) to
determine the conditioning and adjustments of confounders in DAG. Study design and participants This cross-sectional study was conducted on preschoolers from seven public and private
schools in Chiang Mai, Thailand, between June to December 2021. Seven participating schools
in Chiang Mai represented middle-class socioeconomic status (SES) based on the characteris-
tics and facilities of the individual schools, such as the size of the school, number of students,
teaching facilities, and school fees. The inclusion criteria were children aged 2–5 years and
studying at the pre-kindergarten or kindergarten level. The exclusion criteria were 1) under-
weight children (BMI less than the 5th percentile); 2) children diagnosed with neurodevelop-
mental disorders or genetic diseases reported by parents (e.g., autism spectrum disorder, PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 2 / 13 PLOS ONE Association between executive function and excess weight in preschoolers attention-deficit/hyperactivity disorder, intellectual disability, and Down syndrome); 3) not
being ethnically Thai; and 4) parents refusing to participate in the study. This study was
approved by the Research Ethics Committee of the Faculty of Medicine, Chiang Mai Univer-
sity (051/2564). Before participating in the research, all parents/guardians of the child were
informed of the relevant study detail. Their written informed consent was obtained. PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 Measures Age, sex, birth weight, gestational age, breastfeeding, maternal age, maternal BMI, maternal
education, and screen time were evaluated using a general questionnaire. SES was assessed
using the parent-report family income and classified into low (a monthly family income of not
more than 18,000 Thai baht aTHB), and high SES (a monthly family income of over 85,000
THB) based on the Thai SES classification [33]. Physical activity and sleep questions were
developed to assess the child’s duration of moderate to vigorous physical activity and sleep. These questions were validated and found to be acceptable in reliability and validity, as pre-
sented in S1 Table. Parenting styles were evaluated and classified into authoritative, authoritar-
ian, and permissive styles based on Baumrind [34] using the Short Form of Parenting Styles
and Dimensions Questionnaires (PSDQ)–Thai version [35]. PSDQ demonstrated good reli-
ability and validity [35]. 3 / 13 PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE Association between executive function and excess weight in preschoolers Sample size The sample size was calculated using the combination of ‘comparing two independent means’
and ‘rule of thumb of logistic regression’ methods, and then the largest sample size would be
selected. Using the comparing two independent means method with alpha 0.05 (two-sided
test), power 0.80, and effect size (mean and SD) from the previous study [24] required at least
500 samples, while using the rule of thumb of logistic regression needed at least 600 samples
(overweight 60/obesity 60/normal weight 480) to evaluate six factors (5 EF subscales and 1
global executive composite scale), considering the prevalence of overweight and obesity
approximately 10–20% [1, 36–38]. Finally, the total sample sizes of the overweight, obesity,
and normal weight groups were at least 72, 72, and 576 individuals, respectively, considering
an expected incomplete data/no response rate of 20%. Baseline characteristics and comparing variables among individuals with
overweight, obesity, and normal weight A total of 1,181 healthy children were included in this study, as presented in the study flow dia-
gram (Fig 1). The baseline characteristics are shown in Table 1. The potential variables contrib-
uting to weight excess categorized by weight status are presented in Table 2. The results show
that there are significant differences in the variables of birth weight (p = 0.002), breastfeeding
(p = 0.042), and maternal weight status (p < 0.001) across the three groups. Statistical analysis Statistical analyses in this study were performed using Stata version 16 (StataCorp, College Sta-
tion, Texas, USA) [39]. We used frequency (%), mean (SD), and median (IQR) to report
descriptive statistics. To evaluate statistically significant differences between groups, the exact
probability test and the one-way ANOVA test were performed for categorical data and nor-
mally distributed continuous data, respectively. The study endpoint “weight status” were con-
sidered as three discrete categories: overweight, obesity, and normal weight (a reference
category) in the polynomial logistic regression model, rather than a range in the ordinal one. Although it was likely to have severity grading of weight excess (i.e., overweight and obesity), it
could not be guaranteed that there is an association between the levels of the variables in this
context of EF impacting weight excess. However, the goodness of fit of the two models was
compared using the log-likelihood ratio test with no significant differences between the two
models. Therefore, we selected the polynomial logistic regression as our representative model
to assess the association between executive functioning and overweight/obesity in preschool-
ers. We also performed a multivariable polynomial logistic regression analysis separately for
each EF subscale/global executive composite scale on weight status and reported the odds ratio
estimates with 95% CI. We used a pairwise deletion technique to handle missing data. Statisti-
cal significance was defined as a p-value of less than 0.05. Comparing executive function among individuals with overweight, obesity,
and normal weight For EF T-scores, overweight and obesity groups have higher T-scores on all EF subscales and
global executive composite scale compared to the normal weight group, as presented in Fig
2A. The result also shows that the working memory subscale has the highest T-score compared
to the other EF subscales. No significant differences are found in T-scores between the three
groups in most of the EF subscales and global executive composite scale, except for the 4 / 13 PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE Association between executive function and excess weight in preschoolers Fig 1. Study flow diagram. https://doi.org/10.1371/journal.pone.0275711.g001 Fig 1. Study flow diagram. https://doi.org/10.1371/journal.pone.0275711.g001 https://doi.org/10.1371/journal.pone.0275711.g001 marginally significant contribution of the working memory subscale (p = 0.045). After using a
Bonferroni method for the multiple pairwise comparisons of the working memory subscale
among the three groups, there are no significant differences in the T-scores between groups. When categorizing EF T-scores into EF status based on the cut-off point (impaired EF and
normal EF), overweight and obesity groups show a higher percentage of participants with
impaired EF than normal weight group on the global executive composite scale and most EF
subscales, except for emotional control and plan/organize, as shown in Fig 2B. There is a sig-
nificant difference only in the global executive composite scale (p = 0.005) between the three
groups. After using the exact probability test for pairwise comparison for the global executive
composite scale, the significant difference in the percentage of participants is found only in the
normal weight and overweight groups (p = 0.001), while the other two comparisons (normal
weight vs. obesity groups and overweight vs. obesity groups) do not show significant
differences. PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 Association between executive function and excess weight The association between EF and excess weight using multivariable polynomial logistic regres-
sion (overweight vs. normal weight groups and obesity vs. normal weight groups) is presented
in Table 3. After adjusting for confounders, the significant odds ratio observed in the polyno-
mial logistic regression model (overweight vs. normal weight groups) indicates that individuals
with impaired inhibition, working memory, and global EF are more likely to be overweight
compared to those with normal EFs. The polynomial logistic regression model (obesity vs. normal weight groups) suggests that participants with impaired working memory are signifi-
cantly associated with higher odds of being obese compared to those with normal working
memory. The increased probability of being both overweight and obese is associated with
impaired working memory. However, the effect of impaired working memory on overweight PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 5 / 13 PLOS ONE Association between executive function and excess weight in preschoolers Table 1. General characteristics of the study participants. Characteristic
No. of participants (Total N = 1,181)
Value
Male, n (%)
1,181
546 (46.23)
Age (years), mean (SD)
1,181
4.68 (0.85)
Grade, n (%)
1,181
Pre-kindergarten
93 (7.87)
Kindergarten-1
260 (22.02)
Kindergarten-2
477 (40.39)
Kindergarten-3
351 (29.72)
BMI, mean (SD)
1,181
16.38 (2.48)
BMI percentile, median (IQR)
1,181
58.20 (29.80, 88.40)
Weight status, n (%)
1,181
Normal weight
860 (72.82)
Overweight
126 (10.67)
Obesity
195 (16.51)
Maternal age (years), mean (SD)
1,157
35.53 (5.02)
Maternal weight status, n (%)
1,081
Normal weight
816 (75.49)
Overweight
193 (17.85)
Obesity
72 (6.66)
Maternal educational level, n (%)
1,134
Lower than bachelor’s degree
250 (22.05)
Bachelor’s degree or higher
884 (77.95)
Socioeconomic status, n (%)
1,125
Low
174 (15.47)
Middle
831 (73.87)
High
120 (10.67)
Abbreviations: BMI: body mass index; SD: standard deviation; IQR: interquartile range. https://doi org/10 1371/journal pone 0275711 t001 Table 1. General characteristics of the study participants. vs. normal weight does not significantly differ from the effect of impaired working memory on
obesity vs. normal weight (X2 = 0.05, p = 0.832). vs. normal weight does not significantly differ from the effect of impaired working memory on
obesity vs. normal weight (X2 = 0.05, p = 0.832). vs. normal weight does not significantly differ from the effect of impaired working memory on
obesity vs. normal weight (X2 = 0.05, p = 0.832). PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 Discussion After adjusting for confounders using multivariable polynomial regression analysis, we found
the associations between overall EF/EF subscales and excess weight. These associations were: i)
overall EF was significantly related to the overweight status, but not obesity; ii) EF subscale–
inhibition was significantly associated with overweight, but not obesity; and iii) EF subscale–
working memory was significantly related to both overweight and obesity. For the overall EF, this study was in line with previous studies that showed lower EF was
significantly associated with weight excess [24, 40, 41]. Evidence shows that executive dysfunc-
tion can cause excess weight through unhealthy lifestyle behaviors such as increased high-calo-
rie intake, decreased fruit/vegetable consumption, less physical activity, and more sedentary
behaviors [17]. However, when we categorized excess weight into overweight and obesity sepa-
rately, a significant association remained only in overweight. In our opinion, deficits in overall
executive functioning in young children may not be a strong factor contributing to obesity, as
seen in the previous study [41]. As we all know, additional factors contribute to obesity, such
as genetics, eating behaviors, physical activity, and parenting and feeding styles. Most of the PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 6 / 13 Association between executive function and excess weight in preschoolers PLOS ONE Table 2. Possible variables contributing to weight excess categorized by weight status. Variables
No. of participants (Total
N = 1,181)
Obesity group
(n = 195)
Overweight group
(n = 126)
Normal weight group
(n = 860)
p-value
Male, n (%)
1,181
99 (50.77)
61 (48.41)
386 (44.88)
0.289
Age (years), mean (SD)
1,181
4.78 (0.82)
4.77 (0.82)
4.64 (0.85)
0.052
Gestational age, n (%)
999
Preterm
41 (23.98)
20 (17.70)
115 (16.08)
0.058
Term
130 (76.02)
93 (82.30)
600 (83.92)
Birth weight, n (%)
1,043
Low birth weight
20 (11.05)
7 (6.19)
54 (7.21)
0.002
Normal birth weight
145 (80.11)
97 (85.84)
671 (89.59)
High birth weight
16 (8.84)
9 (7.96)
24 (3.20)
Breastfeeding, n (%)
1,041
Never
13 (7.47)
9 (8.11)
37 (4.89)
0.042
No more than 6 months
33 (18.97)
20 (18.02)
98 (12.96)
At least 6 months
128 (73.56)
82 (73.87)
621 (82.14)
Moderate to vigorous physical activity,
n (%)
1,179
Less than 1 hour per day
163 (83.59)
106 (84.13)
711 (82.87)
0.951
At least 1 hour per day
32 (16.41)
20 (15.87)
147 (17.13)
Screen use, n (%)
1,171
More than 1 hour per day
140 (72.92)
87 (70.73)
601 (70.21)
0.774
Not more than 1 hour per day
52 (27.08)
36 (29.27)
255 (39.79)
Sleep, n (%)
1,176
Adequate amount for age
151 (77.84)
98 (78.40)
715 (83.43)
0.097
Inadequate amount for age
43 (22.16)
27 (21.60)
142 (16.57)
Maternal age (years), mean (SD)
1,157
35.82 (5.28)
35.89 (4.78)
35.41 (5.00)
0.419
Maternal weight status, n (%)
1,081
Normal weight
103 (55.98)
88 (76.52)
625 (79.92)
<0.001
Overweight
59 (32.07)
20 (17.39)
114 (14.58)
Obesity
22 (11.96)
7 (6.09)
43 (5.50)
Maternal education level, n (%)
1,134
Lower than bachelor’s degree
52 (27.96)
22 (18.49)
176 (21.23)
0.092
Bachelor’s degree or higher
134 (72.04)
97 (81.51)
653 (78.77)
Socioeconomic status, n (%)
1,125
Low
25 (13.23)
16 (13.11)
133 (16.34)
0.314
Middle
150 (79.37)
91 (74.59)
590 (72.48)
High
14 (7.41)
15 (12.30)
91 (11.18)
Parenting styles, n (%)
1,168
Authoritative
187 (97.91)
123 (98.40)
826 (96.95)
0.973
Authoritarian
0 (0)
0 (0)
4 (0.47)
Permissive
4 (2.09)
2 (1.60)
22 (2.58)
Abbreviations: SD: standard deviation. h
//d i
/10 1371/j
l
0275711 002 Table 2. Possible variables contributing to weight excess categorized by weight status. contributing to weight excess categorized by weight status. PLOS ONE time, access to food and eating behaviors in young children depends on parental management
of the food environment. Therefore, the EF of children may not have a direct and robust
impact on their weight [22]. time, access to food and eating behaviors in young children depends on parental management
of the food environment. Therefore, the EF of children may not have a direct and robust
impact on their weight [22]. p
g
When considering the aspect of EF subscales, we found only inhibition and working mem-
ory related to excess weight. This finding was consistent with the previous study that showed a PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 7 / 13 PLOS ONE Association between executive function and excess weight in preschoolers Fig 2. Boxplot and bar chart. The boxplot depicting T-scores of executive function subscales/global executive composite scale (a) and bar chart
depicting the percentage of the number of children with impaired executive function among three weight status groups (b). https://doi.org/10.1371/journal.pone.0275711.g002 Fig 2. Boxplot and bar chart. The boxplot depicting T-scores of executive function subscales/global executive composite scale (a) and bar chart
depicting the percentage of the number of children with impaired executive function among three weight status groups (b). https://doi.org/10.1371/journal.pone.0275711.g002 https://doi.org/10.1371/journal.pone.0275711.g002 significant association between these EF subscales and weight excess [42, 43]. For EF subscale–
inhibition, the possible link between inhibition and the risk of having excess weight is
unhealthy eating behaviors. For example, children with lower inhibition usually have larger
self-served portions and more food servings, display more compulsive overeating due to diffi-
culties inhibiting response to food stimuli, and have less control to eat despite the absence of
hunger [9, 23]. Subsequently, all these obesity-related eating behaviors lead to excess weight in
later life. For EF subscale–working memory, working memory is the fundamental EF support-
ing self-regulation and inhibitory control by holding mental representation, cutting off distrac-
tions, and maintaining behaviors to achieve long-term goals [44, 45]. The explanation of the
association between working memory and weight excess is that, in terms of maintaining a
healthy weight, working memory helps engage with healthy habits and consequently leads to
favorable physical health outcomes [46]. Unlike working memory, inhibition was significantly associated with overweight but not
obesity. The undetectable association between inhibition and obesity in this study may reflect,
to some extent, the clues to the direction of the association. PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE Impaired inhibitory control could
precede weight excess through overeating and obesity-related behavior mechanisms. Nonethe-
less, inhibition is not a sufficiently potent factor by itself to affect obesity, and hence it merely
produces overweight. Conversely, working memory deficit could be a result from excessive
weight via inflammation activity. Inflammatory responses from adipose tissue chronically
induce brain alterations via neurohormonal transport perturbation, endothelial-neurovascular
disruption, and ultimately changes in cortical gray matter and microstructure of white matter, 8 / 13 PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE Association between executive function and excess weight in preschoolers Table 3. Multivariable polynomial logistic regression analysis of weight status outcome and executive function
subscales/global executive function scalea (N = 799). Executive Function
Obesity groupb
Overweight groupb
mORc (95% CI)
p-value
mORc
(95% CI)
p-value
Impaired inhibit
1.84 (0.94–3.61)
0.077
2.33
(1.11–
4.90)
0.026
Impaired shift
1.71 (0.66–4.45)
0.268
2.32
(0.86–
6.22)
0.095
Impaired emotional control
0.60 (0.15–2.31)
0.457
0.80
(0.17–
3.81)
0.777
Impaired working memory
1.74 (1.09–2.78)
0.019
1.87
(1.09–
3.20)
0.023
Impaired plan/organize
0.66 (0.31–1.41)
0.280
1.07
(0.47–
2.42)
0.866
Impaired overall executive function (GEC)
1.30 (0.73–2.34)
0.374
2.47
(1.33–
4.56)
0.004
Abbreviations: mOR: multivariable polynomial logistic regression odds ratio; 95% CI: 95% confidence interval; GEC:
global executive composite. a note that the multivariable polynomial logistic regression models were separately executed for each executive
function subscales/global executive composite scale. b the reference group was the normal weight group. c adjusted for age, gender, gestational age, birth weight, breastfeeding, maternal age, maternal weight status, maternal
education, socioeconomic status, parenting styles, screen use, moderate to vigorous intensity of physical activity, and
sleep variables. https://doi.org/10.1371/journal.pone.0275711.t003 Table 3. Multivariable polynomial logistic regression analysis of weight status outcome and executive function
subscales/global executive function scalea (N = 799). c adjusted for age, gender, gestational age, birth weight, breastfeeding, maternal age, maternal weight status, maternal
education, socioeconomic status, parenting styles, screen use, moderate to vigorous intensity of physical activity, and
sleep variables. https://doi.org/10.1371/journal.pone.0275711.t003 which connect areas of the brain that facilitate working memory [47–49]. Therefore, once obe-
sity presents, both overweight and obesity can impair working memory. However, there may
be a bidirectional effect between these EFs and weight excess [15, 50]. Executive dysfunction
may lead to a cycle of obesogenic behaviors and excess weight, which in turn induces inflam-
matory activity in the EF-related brain areas, resulting in impaired executive control over time
[46]. PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 PLOS ONE We did not find a significant association between the other EF subscales (e.g., shifting and
planning) and excess weight. Our finding contrasts with a previous study that reported shifting
was significantly negatively correlated with the BMI percentile in preschool children [24]. This
could be from the prior study that used performance tasks to assess EF, while our study used
the parent-report BRIEF-P questionnaire. Another explanation is that a relatively low number
of participants identified impaired shifting, which decreased the power to detect the significant
association. The possible reason for the absence of significant relationships between planning
and weight status is that planning is a higher-level EF that needs time to develop; thus, this
ability at the younger age of our study is comparable among the normal weight and over-
weight/obesity groups. The strength of our study is that we conducted a large sample size of typically developing
preschool-aged children. We used DAG to manage the potential source of confounding for
causal assumptions, which is an efficient and systematic method [51]. The findings found in PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 9 / 13 PLOS ONE Association between executive function and excess weight in preschoolers this study support the body of knowledge in the prevention and early intervention of child-
hood obesity by promoting EF since early childhood. Emerging EF-targeted interventions
such as computerized EF training and episodic future thinking, adjunct to the mainstay treat-
ment of obesity, are mostly in preliminary studies but promising therapeutic paradigms to
help promote EF and weight loss-related behaviors in children [52]. There are some limitations to this study. Firstly, we were unable to conclude the association
as a causal relationship due to the cross-sectional nature of the design. Secondly, an indirect
measure, such as BMI, may not be the best representative measure of obesity as body fat. How-
ever, BMI could be a good substitute for measuring obesity, as it is closely related to body fat,
particularly in prepubescent children [53]. Thirdly, we were unable to examine all potential
associated factors of weight excess, including unmeasured genetic effects that might confound
the weight excess outcomes. Nonetheless, we collected maternal BMI and weight status as sur-
rogate variables of genetic influence. Fourthly, there were a large number of sample exclusions;
however, this study yielded sufficient power to detect the differences in executive functioning
between weight status groups. PLOS ONE Lastly, there could be benefits and weaknesses due to the homo-
geneity of the middle-class SES samples included in this study. This sample homogeneity
could facilitate controlling covariates between individuals as they shared common ethnic and
cultural behaviors, but it might limit the generalizability of the study to the low-/high-class
SES populations. In conclusion, this study found an association between deficits in EF and weight excess in
preschoolers. The result suggests that inhibition and working memory might be key compo-
nents of such a relationship. Strategies directly targeting the promotion of EF, specifically inhi-
bition and working memory, in early childhood might help young children maintain a healthy
weight throughout their developmental period. However, longitudinal studies are needed to
investigate further the causal effect between EF and weight excess, and the treatment effect of
EF intervention on weight outcomes. Acknowledgments The authors thank these people comprising: Prof. Weerasak Chonchaiya for translating the
PSDQ and BRIEF-P into the Thai version; Mahippathorn Chinnapha, Eric B Tedstrom, and
the Language Learning Center team for editing and proofreading the manuscript; and all chil-
dren and their parents for participating in this study. Supporting information S1 Fig. Directed acyclic graph (DAG). DAG presents the causal model of the association
between executive function and overweight/obesity. Thirteen confounders (ancestor of expo-
sure and outcome) were determined as the minimal sufficient adjustment sets for estimating
the effect of executive function on overweight/obesity. (TIF) Author Contributions Conceptualization: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak Boonchoo-
duang, Phichayut Phinyo, Jayanton Patumanond, Orawan Louthrenoo. PLOS ONE | https://doi.org/10.1371/journal.pone.0275711
October 10, 2022 10 / 13 PLOS ONE Association between executive function and excess weight in preschoolers Data curation: Narueporn Likhitweerawong. Formal analysis: Narueporn Likhitweerawong, Jiraporn Khorana. Investigation: Narueporn Likhitweerawong, Orawan Louthrenoo. Methodology: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak Boonchooduang,
Phichayut Phinyo, Jayanton Patumanond, Orawan Louthrenoo. Supervision: Jiraporn Khorana, Nonglak Boonchooduang, Phichayut Phinyo, Jayanton Patu-
manond, Orawan Louthrenoo. Validation: Narueporn Likhitweerawong. Writing – original draft: Narueporn Likhitweerawong. Writing – review & editing: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak
Boonchooduang, Phichayut Phinyo, Jayanton Patumanond, Orawan Louthrenoo. Data curation: Narueporn Likhitweerawong. Formal analysis: Narueporn Likhitweerawong, Jiraporn Khorana. Formal analysis: Narueporn Likhitweerawong, Jiraporn Khorana. Investigation: Narueporn Likhitweerawong, Orawan Louthrenoo. nvestigation: Narueporn Likhitweerawong, Orawan Louthrenoo. Methodology: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak Boonchooduang,
Phichayut Phinyo, Jayanton Patumanond, Orawan Louthrenoo. Methodology: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak Boonchooduang,
Phichayut Phinyo, Jayanton Patumanond, Orawan Louthrenoo. Supervision: Jiraporn Khorana, Nonglak Boonchooduang, Phichayut Phinyo, Jayanton Patu-
manond, Orawan Louthrenoo. Validation: Narueporn Likhitweerawong. Validation: Narueporn Likhitweerawong. Writing – original draft: Narueporn Likhitweerawong. Writing – original draft: Narueporn Likhitweerawong. Writing – review & editing: Narueporn Likhitweerawong, Jiraporn Khorana, Nonglak
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Pharmacological effects and target analysis of Guipi wan in the treatment of cerebral ischemia-reperfusion injury
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Frontiers in pharmacology
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OPEN ACCESS KEYWORDS
guipi wan, ischemia-reperfusion injury, network analysis, GABBR1, PI3K/AKT KEYWORDS
guipi wan, ischemia-reperfusion injury, network analysis, GABBR1, PI3K/AKT frontiersin.org TYPE Original Research
PUBLISHED 07 March 2024
DOI 10.3389/fphar.2024.1346226 TYPE Original Research
PUBLISHED 07 March 2024
DOI 10.3389/fphar.2024.1346226 TYPE Original Research
PUBLISHED 07 March 2024
DOI 10.3389/fphar.2024.1346226 guipi wan, ischemia-reperfusion injury, network analysis, GABBR1, PI3K/AKT OPEN ACCESS Jianfeng Zhang1†, Li Luo 2†, Yanyan Guo2, An Liu2, Mengjia Zhang3,
Wei Jiang2, Xi Li2, Qingqing Liu2 and Jiaoyan Yu2* 1Department of Pharmacy, Eighth Hospital of Xi’an City, Xi’an, China, 2Department of Pharmacy, The
Second Affiliated Hospital of Air Force Medical University, Xi’an, China, 3Air Force Medical University,
Xi’an, China Guipi wan (GPW) is a traditional Chinese medicine commonly used in clinical
practice, typically to treat neurological diseases such as neurasthenia and
traumatic brain injury. It may have positive effects on cerebral ischemia‒
reperfusion injury (cI/R). This study aimed to assess the effects of GPW in a
mouse model of cI/R and find its possible targets. C57BL/6J mice were used to
establish the cI/R model, and the laser speckle doppler was used to determine the
success of the model. GPW was administered intragastrically for 7 days, brain
tissue sections were stained with TTC, HE, and TUNEL, Western blot assay was
performed to detect the effect of apoptosis-related proteins. Furthermore, we
screened active ingredients from the TCM Database and constructed a
compound‒target network using the Cytoscape 3.8.0 software. Moreover, we
employed protein‒protein interaction and component‒target‒pathway network
analyses to determine the potential components of GPW and its target genes, the
key target was verified through molecular docking. Finally, we detected the
influence of the downstream signaling pathway of the target through Western
blot. The results showed that GPW decreased the cerebral infarction area,
neurological function scores, and neuronal apoptosis in mice by regulating
PI3K/AKT
signaling
pathway. Network
analysis
indicated
that
gamma-
aminobutyric acid B receptor 1 (GABBR1) might be a potential target for the
treatment of cI/R. Molecular docking indicated that 9 active components in GPW
could bind to GABBR1 with desirable binding energy. This study represented the
demonstratable effect of GPW in the treatment of cI/R injury and suggested
GABBR1 as a potential target using network analysis. Front. Pharmacol. 15:1346226. doi: 10.3389/fphar.2024.1346226 COPYRIGHT
© 2024 Zhang, Luo, Guo, Liu, Zhang, Jiang, Li,
Liu and Yu. This is an open-access article
distributed under the terms of the Creative
Commons Attribution License (CC BY). The use,
distribution or reproduction in other forums is
permitted, provided the original author(s) and
the copyright owner(s) are credited and that the
original publication in this journal is cited, in
accordance with accepted academic practice. No use, distribution or reproduction is
permitted which does not comply with these
terms. Pharmacological effects and
target analysis of Guipi wan in the
treatment of cerebral
ischemia-reperfusion injury OPEN ACCESS
EDITED BY
Junfeng Wang,
Massachusetts General Hospital and Harvard
Medical School, United States
REVIEWED BY
Shuang Pan,
Tufts University, United States
Weirong Wang,
Xi’an Jiaotong University, China
*CORRESPONDENCE
Jiaoyan Yu,
969027046@qq.com
†These authors have contributed equally to
this work
RECEIVED 29 November 2023
ACCEPTED 19 February 2024
PUBLISHED 07 March 2024
CITATION
Zhang J, Luo L, Guo Y, Liu A, Zhang M, Jiang W,
Li X, Liu Q and Yu J (2024), Pharmacological
effects and target analysis of Guipi wan in the
treatment of cerebral ischemia-
reperfusion injury. Front. Pharmacol. 15:1346226. doi: 10.3389/fphar.2024.1346226 OPEN ACCESS
EDITED BY
Junfeng Wang,
Massachusetts General Hospital and Harvard
Medical School, United States
REVIEWED BY
Shuang Pan,
Tufts University, United States
Weirong Wang,
Xi’an Jiaotong University, China
*CORRESPONDENCE
Jiaoyan Yu,
969027046@qq.com
†These authors have contributed equally to
this work
RECEIVED 29 November 2023
ACCEPTED 19 February 2024
PUBLISHED 07 March 2024
CITATION
Zhang J, Luo L, Guo Y, Liu A, Zhang M, Jiang W,
Li X, Liu Q and Yu J (2024), Pharmacological
effects and target analysis of Guipi wan in the
treatment of cerebral ischemia-
reperfusion injury. Front. Pharmacol. 15:1346226. doi: 10.3389/fphar.2024.1346226 1 Introduction Ischemic stroke (IS) is the second leading cause of death worldwide and shows a high
disability rate (Walter., 2022). It accounts for 70% of all strokes and carries a high risk of
long-term recurrence. In 2019, the total number of IS-related deaths reached 3.29 million,
accounting for 50.3% of stroke deaths and 17.7% of all cardiovascular disease-related deaths. And research predictive analysis suggested that this number could increase to 4.9 million by
2030 (Fan et al., 2023). Ischemic stroke occurs when blood flow to the brain is blocked due 01 Frontiers in Pharmacology frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 1
GPW reduces the brain damage caused by cerebral ischemia/reperfusion injury (cI/R). (A) Laser speckle Doppler shows the success of cI/R induction. (B) Neurological function score. N = 8 (C) Representative images of TTC staining in brain sections from different experimental groups. (D) Quantitative
assessments of the infarct area from TTC staining. N = 6; #p < 0.01 versus the sham group; *p < 0.05, **p < 0.01 compared with the Model group. FIGURE 1
GPW reduces the brain damage caused by cerebral ischemia/reperfusion injury (cI/R). (A) Laser speckle Doppler shows the success of cI/R induction. (B) Neurological function score. N = 8 (C) Representative images of TTC staining in brain sections from different experimental groups. (D) Quantitative
assessments of the infarct area from TTC staining. N = 6; #p < 0.01 versus the sham group; *p < 0.05, **p < 0.01 compared with the Model group. Codonopsis radix, Atractylodes macrocephala rhizoma, Astragali
radix, Glycyrrhizae radix et rhizoma, Poria, Polygalae radix, The
seed of Ziziphus jujuba var. Spinos, Longan arillus, Angelicae
sinensis radix, Aucklandiae radix and Jujubae fructus. Clinical
experimental studies have confirmed that Astragali radix can
significantly recover the clinical symptoms of cerebral ischemia,
and play anti-atherosclerosis and neuroprotective roles. (Li et al.,
2023a). Atractylenolide III in Atractylodes macrocephala Koidz
ameliorates
cerebral
ischemic injury and neuroinflammation
associated
with
inhibiting
JAK2/STAT3/Drp1-dependent
mitochondrial fission in microglia (Zhou et al., 2019). Several
medicinal materials and components of GPW have been reported
to improve cerebral ischemia reperfusion injury (Hao et al., 2023). These results suggest that GPW, as a clinical prescription of
traditional Chinese medicine, may be effective in treating cerebral
ischemia-reperfusion injury, but the underlying pharmacological
mechanism remains unclear. to a blocked or ruptured artery, disrupting the brain’s energy supply,
causing tissue damage, and leading to widespread neuronal death
(Tuo et al., 2022). Frontiers in Pharmacology frontiersin.org 1 Introduction The current treatment for this condition is the use
of a recombinant tissue plasminogen activator, which triggers
intravenous
thrombolysis. However,
the
window
for
this
treatment
is
narrow,
and
patients
often
face
the
risk
of
permanent disability after a stroke (Lin and Lang, 2022). In
addition, blood flow restoration can cause more serious cerebral
ischemia‒reperfusion injury (cI/R) (Campbell and Khatri, 2019). Therefore, a reliable treatment plan is urgently needed to improve
the disability and nerve damage caused by reperfusion injury after
a stroke. To date, many drugs have been experimentally shown to have
neuroprotective effects, but their clinical application has not yet
been confirmed (Tsivgoulis et al., 2023). Specifically, traditional
Chinese medicine (TCM) has been used to treat patients during the
recovery period after a stroke, and many compound prescriptions
have been demonstrated to be effective (Tao et al., 2020). Guipi wan
(GPW) is often used to treat neurasthenia and traumatic brain
injury,
and
also
to
improve
the
emotional
and
cognitive
dysfunctions that arise after stroke (Li et al., 2020). It mainly
comprises 11 traditional Chinese active ingredients, including The systemic nature of TCM, which comprises multiple
components with numerous downstream targets and complex
mechanisms of action, cannot be accurately captured by the
principles
of
Western
medical
research,
which
focuses
on
individual targets and components. Consequently, the Western 02 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 2
GPW alleviates the pathological damage of model mice. (A) Hematoxylin and eosin staining results of infarct area (20×). (B) Nissl staining results of
infarct area (20×), The black arrow shows the Nissl corpuscles. (C) Numerical analysis of Nissl staining with ImageJ program. (D) TUNEL staining results of
brain tissue sections in different experimental groups. (E) Statistical analysis of the percentage of intact neurons in the infarct area of mice by TUNEL
staining. Scale bar = 75 μm; N = 6 mice per group; #p < 0.01 versus the sham group; *p < 0.05, **p < 0.01 compared with the Model group. FIGURE 2
GPW alleviates the pathological damage of model mice. (A) Hematoxylin and eosin staining results of infarct area (20×). (B) Nissl staining results of
infarct area (20×), The black arrow shows the Nissl corpuscles. (C) Numerical analysis of Nissl staining with ImageJ program. (D) TUNEL staining results of
brain tissue sections in different experimental groups. (E) Statistical analysis of the percentage of intact neurons in the infarct area of mice by TUNEL
staining. 1 Introduction Scale bar = 75 μm; N = 6 mice per group; #p < 0.01 versus the sham group; *p < 0.05, **p < 0.01 compared with the Model group. FIGURE 2
GPW alleviates the pathological damage of model mice. (A) Hematoxylin and eosin staining results of infarct area (20×). (B) Nissl staining results of
infarct area (20×), The black arrow shows the Nissl corpuscles. (C) Numerical analysis of Nissl staining with ImageJ program. (D) TUNEL staining results of
brain tissue sections in different experimental groups. (E) Statistical analysis of the percentage of intact neurons in the infarct area of mice by TUNEL
staining. Scale bar = 75 μm; N = 6 mice per group; #p < 0.01 versus the sham group; *p < 0.05, **p < 0.01 compared with the Model group. signaling pathway was verified, with the intent to elucidate
elucidate the therapeutic effect and molecular mechanism of
GPW on cI/R injury. approach
has
not
been
satisfactory
in
elucidating
the
pharmacodynamics of TCM compound prescriptions (Li et al.,
2023b). However, with the advancement of network analysis
techniques, more and more studies have begun to use this
method to conduct holistic and systematic exploration to explain
the mechanism of action of Chinese herbal medicine (Wang et al.,
2021a), thus broadening their range of clinical applications. Many
studies have successfully used network analysis to explain how
effectively these drugs treat various diseases. Therefore, this study
intends to combine pharmacological experiments and network
analysis techniques to clarify the efficacy and possible targets of
GPW in the treatment of cI/R. Frontiers in Pharmacology frontiersin.org 2.2 MCAO model underwent middle cerebral artery occlusion (MCAO) under
anesthesia and then were administered a gastric injection with
0.9% saline or GPW extract (Lanzhou Foci Pharmaceutical,
Lanzhou, 200,934, China). The MCAO model was established with a modified suture
method (Barthels and Das, 2020) After intraperitoneal injection
of sodium pentobarbital anesthetized, the mouse was fixed in the
supine position. Following alcohol disinfection of the neck skin, we
incised the midline of the neck, bluntly separating the right common
carotid artery (CCA), external carotid artery (ECA), and internal
carotid artery (ICA). We threaded the CCA, ICA, and ECA
separately. Next, we clamped the proximal end of the CCA and
the ICA, and tied the two cords at the proximal end of the ECA to a
dead knot, while we tied the cords at the proximal end of the ECA to
a slipknot. We cut a small “V" between the two cords at the proximal
end of the ECA, inserted the thread plug, and insert the thread. We
tightened the proximal end of the ECA line, fixed the line tether,
lifted the ECA, and untied the ICA arterial clamp. We then slowly
pushed the line tether toward the ICA. When the thread end entered
about 1.2 cm, we stopped when we felt some resistance. We then
untied the CCA artery clip, at this time. The end of the thread plug
was just at the beginning of the middle cerebral artery (MCA),
causing an occlusion. After 2 h of ischemia, the thread plug was
pulled out to generate the ischemia‒reperfusion model. GPW extraction process: Codonopsis radix (80 g), Atractylodes
macrocephala rhizoma (60 g), Astragali radix (80 g), Glycyrrhizae
radix et rhizoma (40 g), Poria (160 g), Polygalae radix (160 g). The
seed of Ziziphus jujuba var. Spinosa (80 g), Longan arillus (160 g),
Angelicae sinensis radix (160 g), Aucklandiae radix (40 g), Jujubae
fructus (40 g), total 1,000 g. 2.1 Animals and drug administration Adult male C57BL/6J mice aged 6–8 weeks, weighing 20–25 g,
were provided by the Experimental Animal Center of the Fourth
Military Medical University. The mice were housed at a constant
temperature of 25°C ± 2°C and humidity of 50% ± 10%, with an
alternating 12 h light/dark cycle and free access to food and water,
they were randomly divided into five groups. Four groups This study confirmed that GPW has a significant therapeutic
effect on cI/R model mice, in addition, predicted that GABBR1 is an
important target for its therapeutic effect, and the downstream 03 frontiersin.org frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 3
Effect of GPW on apoptosis-related proteins. (A) Western blot detection of caspase 3, cleaved-caspase 3, Bax, and Bcl-2 bands in the brain tissue of
each group of mice. (B–E) Statistical analysis of protein expression. N = 6 mice per group; #p < 0.01 versus the sham group; *p < 0.05, **p <
0.01 compared with the Model group. FIGURE 3
Effect of GPW on apoptosis-related proteins. (A) Western blot detection of caspase 3, cleaved-caspase 3, Bax, and Bcl-2 bands in the brain tissue of
each group of mice. (B–E) Statistical analysis of protein expression. N = 6 mice per group; #p < 0.01 versus the sham group; *p < 0.05, **p <
0.01 compared with the Model group. 2.2 MCAO model Codonopsis radix, Angelicae sinensis
radix, Glycyrrhizae radix et rhizoma and Aucklandiae radix were
crushed into fine powder, and the other medicinal materials 10 times
the volume of water boiled 2 times, for 2 h each time, combined and
concentrated into extract, and mixed with fine powder to make pill,
weighing about 167 g, that is, 1,000 g of crude drug is equivalent to
167 g of extract, The quality of the extract was identified and the
content of astragaloside in the extract detected by HPLC was
0.33 mg/g, which met the extraction requirement of ≥0.1 mg/g in
Chinese Pharmacopoeia, as shown in Supplementary Figure S1. During gastric administration, 1 g extract was dissolved in 10 mL
normal saline to obtain 6 g crude drug/1g extract/10 mL GPW
administration solution. The clinical dose of drug 15 g crude drug/60 kg used in humans
was converted to approximately 3 g crude drug/kg in mouse, with a
proportion of 12.3 times based on body surface areas (Reagan-Shaw
et al., 2008), this dose was selected as the medium dose group. The
low, medium and high doses calculated by the equal ratio of 2 times
were 1.5, 3 and 6 crude drugs/kg. These values corresponded to the
extract dosage of 0.25, 0.5, 1 g/kg, thereby obtaining the intragastric
volume of 2.5 mL/kg, 5 mL/kg, and 10 mL/kg, respectively. The
remaining group underwent a sham operation and then received
intragastric administration of 0.9% normal saline. Frontiers in Pharmacology 2.3 Laser speckle Doppler Mice were anesthetized by intraperitoneal injection of 1%
sodium pentobarbital solution at 50 μg/kg of body weight. Once
anesthetized, the head was fixed on the operating table, the skin was
cut along the midline, connective tissue was removed, and brain
blood flow images were collected by laser speckle doppler flow
imager (RFLSI 111). Frontiers in Pharmacology 04 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 4
GPW component selection and target prediction. (A) The active ingredients of GPW and their targets are represented by nodes. The circles represent
the plant components of GPW, the number of the corresponding compound is found in Supplementary Table S1, the polygons of different colors
represent the main components of each plant, and the purple square represents the relevant target of the component. Edges represent the interaction
between the biologically active ingredient and the target. (B) The Venn diagram of GPW and cI/R targets. Purple represents component targets,
yellow represents disease targets, and the intersection represents common targets. (C) Protein‒protein interaction network diagram. Nodes represent
different proteins, and lines represent interactions. FIGURE 4
GPW component selection and target prediction. (A) The active ingredients of GPW and their targets are represented by nodes. The circles represent
the plant components of GPW, the number of the corresponding compound is found in Supplementary Table S1, the polygons of different colors
represent the main components of each plant, and the purple square represents the relevant target of the component. Edges represent the interaction
between the biologically active ingredient and the target. (B) The Venn diagram of GPW and cI/R targets. Purple represents component targets,
yellow represents disease targets, and the intersection represents common targets. (C) Protein‒protein interaction network diagram. Nodes represent
different proteins, and lines represent interactions. Frontiers in Pharmacology 2.8 TUNEL staining Sections were washed twice for 5 min with xylene. After gradient
ethanol immersion, sections were infused with proteinase K to
increase cell permeability and incubated at 37°C for 20 min. Next, sections were first incubated with 100 μL of TUNEL (6-
Diamidino-2-phenylindole) reaction mixture (ab66110, Abcam)
at 37°C for 1 h under dark conditions, and then with 100 μL
DAB solution at room temperature for 10 min. Counterstaining
with hematoxylin was performed for 3 min and, after rinsing,
sections were dehydrated in a graded series of ethanol, made
transparent in xylene, and mounted on neutral gum. The
number
of
TUNEL-positive
cells
was
counted
under
a
fluorescence microscope (Ts2-FL, Nikon), and the percentage of
TUNEL-positive
cells
was
calculated
to
calculate
the
rate
of apoptosis. 2.4 Neurological scores 2021). According to this method, a score of 0–4 corresponds
to no neurological dysfunction, inability to fully extend the
left
front
paw,
hovering
left,
falling
left,
low
level
of
consciousness and inability to walk autonomously. A score of
5 represents death. After
model
establishment
and
drug
or
saline
administration, neurological deficits were assessed with a
5 point scoring system, as previously described (Kuai et al., 05 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 TABLE 1 Compounds screened according to degree value and druggability. Molecule name
Degree
Molecule name
Degree
Nuciferine
31
Selina-4(14),7(11)-dien-8-one
11
Atractylone
19
(−)-Caryophyllene oxide
11
Beta-carotene
19
5,6,7,8-Tetrahydro-2,4-dimethylquinoline
11
3β-Acetoxyatractylone
17
Benzo [a]carbazole
16
Juniper camphor
10
Coumarin
14
Harman
10
Harmine
13
Ermanthin
9
(+/−)-Isoborneol
13
2-[(2R,5S,6S)-6,10-dimethylspiro [4.5]dec-9-en-2-yl]propan-2-ol
9
α-Cubebol
13
(5E,9Z)-3,6,10-trimethyl-4,7,8,11-tetrahydrocyclodeca [b]furan
11 (5E,9Z)-3,6,10-trimethyl-4,7,8,11-tetrahydrocyclodeca [b]furan TABLE 2 The top 20 targets out of 213 possible GPW targets. Target name
Degree
Target name
Degree
GABBR1
38
SLC6A2
15
PTGS2
30
ADRB2
13
CHRM1
29
ADRA1A
13
CHRM2
29
GABRA3
13
CHRM3
28
BCHE
12
NCOA2
21
GABRA6
12
GABRA2
20
ADRA1B
13
PTGS1
18
SCN5A
10
PRSS3
16
SLC6A3
10
CHRNA7
16
RXRA
10 brain tissue structure was observed under an optical microscope
(Ts2-FL, Nikon, Tokyo, Japan). TABLE 2 The top 20 targets out of 213 possible GPW targets. 2.7 Nissl staining Paraffin sections were sequentially dehydrated with xylene, and
absolute, 95%, 80%, and 70% ethanol. Sections were then washed
with distilled water, soaked in 1% tar violet dye for 10 min, washed
with distilled water again, and decolorized with gradient ethanol
immersion. After becoming transparent, sections were mounted on
clear slides with neutral gum, and tissue was observed under an
optical microscope. 2.5 2,3,5-Triphenyltetrazolium
chloride staining After 24 h, the mice in each group were deeply anesthetized,
their brain tissue was removed, and residual blood was washed out
with normal saline. Brains were then quickly frozen at −20°C for
20 min and cut into 2 mm slices with a brain slice mold (68,714,
RWD Life Science). Sections were stained with 1% 2,3,5-
triphenyltetrazolium
chloride
(TTC,
purity
>98.0%;
Sigma-
Aldrich, St Louis, MO, United States) for 30 min at 37°C. ImageJ
software (NIH) was used to measure the percentage of tissue affected
by cerebral infarction. Frontiers in Pharmacology frontiersin.org 2.9 Western blotting For Western blotting, 20 mg of brain tissue from the infarct
area was lysed in 100 μL RIPA buffer, and homogenized by
ultrasonication. Samples were centrifuged at 12,000 rpm for
10 min at 4 °C. The supernatant was removed, and the total Brain tissue was immersed in 4% paraformaldehyde for 24 h and
then embedded in paraffin. Thereafter, 4-μm-thick sections were
prepared
for
hematoxylin
and
eosin
(HE)
staining. After
dehydration with a gradient series of ethanol and xylene, the 06 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 5
Enrichment analysis of core targets. (A) The top 10 results for the biological process (BP), cell component (CC), and molecular function (MF)
categories in Gene Ontology (GO) annotation analysis. The y-axis represents the target-enriched GO, and the x-axis represents the gene number in the
GO annotation results. (B) Top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment bubble chart (p < 0.05). The y-axis represents
the name of the enriched pathway, and the x-axis represents the enrichment value. FIGURE 5
Enrichment analysis of core targets. (A) The top 10 results for the biological process (BP), cell component (CC), and molecular function (MF)
categories in Gene Ontology (GO) annotation analysis. The y-axis represents the target-enriched GO, and the x-axis represents the gene number in the
GO annotation results. (B) Top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment bubble chart (p < 0.05). The y-axis represents
the name of the enriched pathway, and the x-axis represents the enrichment value. protein
concentration
in
each
sample
was
quantified
by
bicinchoninic acid assay (Pierce BCA Protein Assay Kit;
Thermo Fisher Scientific, Waltham, MA, United States). After
heating the samples in the presence of a loading buffer, SDS-
PAGE
(sodium
dodecyl
sulphate-polyacrylamide
gel
electrophoresis) was performed on 8–10% gels. Proteins were
later transferred to PVDF membranes, which were blocked in 5%
skim milk for 1 h and incubated at 4°C overnight with primary
antibodies (1:1,000 dilution) for PI3K (13666S; Cell Signaling
Technology, Danvers, MA, United States), AKT (2920ST, Cell
Signaling
Technology),
P-AKT
(13038S,
Cell
Signaling
Technology), caspase-3 (9664T, Cell Signaling Technology),
cleaved caspase-3 (9664s, Cell Signaling Technology), Bcl-2
(3498s,
Cell
Signaling
Technology),
Bax
(14796s,
Cell
Signaling
Technology),
and
β-actin
(059M4770v,
Sigma-
Aldrich). After repeated washing, membranes were incubated
with secondary antibodies (1:5,000 dilution) at room temperature
for 1 h and subsequently washed. 2.9 Western blotting Membranes were then observed
and photographed through a gel imager (Bio-Rad, United States). ImageJ was utilized to analyze the relative expression levels of the
proteins, with β-actin as a reference. (DL) ≥0.1, and blood‒brain barrier (BBB) ≥1 (Liu et al., 2020). The
information concerning the main active compounds of GPW and
their corresponding targets was collected and standardized through
the Uniport database (https://www.uniprot.org/), and the gene
names of each target were obtained. 2.11 Compound-target network
construction Cytoscape 3.8.0 (National Institute of General Medical Sciences,
Bethesda, MD, United States) was used to construct a compound-
target network for GPW. We also used the GeneCards (https://www. genecards.org/), OMIM (https://omim.org) and DisGeNET (https://
www.disgenet.org/) databases with cI/R as the keyword to acquire
the key therapeutic targets for cI/R. The downstream targets of GPW
and cI/R were imported into the online platform of Venny 2.1.0 for
analysis, and Venn diagrams were used to visualize the common
targets of GPW and cI/R injury. Frontiers in Pharmacology 2.10 Target prediction of GPW components The common targets were imported into the STRING database
(https://string-db.org/),
and
“multiple
proteins”
and
“Homo
sapiens” were selected to obtain protein-protein interaction (PPI)
data. This information was imported into Cytoscape 3.8.0 to
perform a visual analysis by drawing PPI network diagrams. The
CytoHubba plug-in was employed for network topology analysis
(Athanasios et al., 2017). We selected targets with a degree higher
than the average as the key targets in the PPI network. We
used
the
Traditional
Chinese
Medicine
System
Pharmacological Analysis Platform (TCMSP, http://tcmspw.com/
tcmsp.php) and the Bioinformatics Analysis Tool for Molecular
mechanism of Traditional Chinese Medicine (BATMAN-TCM)
database
(http://bionet.ncpsb.org/batman-tcm)
to
identify
the
main active compounds of GPW. The screening conditions were
the following: oral bioavailability (OB) ≥30%, drug-like activity 07 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 FIGURE 6
Representative results of molecular docking analyses. (A) Binding of the positive control baclofen to GABBR1. (B) Representative docking results of
3 GPW components. b1: (−)-Caryophylleneoxide; b2: 3β-acetoxyatractylone; b3: Ermanthin. FIGURE 6
Representative results of molecular docking analyses. (A) Binding of the positive control baclofen to GABBR1. (B) Representative docking results of
3 GPW components. b1: (−)-Caryophylleneoxide; b2: 3β-acetoxyatractylone; b3: Ermanthin. Frontiers in Pharmacology 2.14 Molecular docking studies concerning the lowest binding energy resulting from molecular
docking was obtained. The lower the binding energy, the
stronger the binding force between the active ingredient and
the target protein: a drug molecule with binding energy ≤−5. 0 kJ/mol is considered to have a good binding activity to the
target (Li et al., 2021). The main chemical components and the core targets obtained
from database screening were verified by molecular docking analyses
(Taha et al., 2020). The structures of the key components were
searched on the PubChem database (http://zinc. docking. org/),
optimized, and saved in. mol format (Xia et al., 2020). The Cryo-EM
structure of GABBR1 was downloaded from the Protein Data Bank
(PDB) and saved in. pdb format. Water molecules and the docking
ligand were removed with the PyMOL software (Schrödinger, New
York, NY, United States). The obtained protein structures were then
imported into AutoDock (Center for Computation Structural
Biology,
The
Scripps
Research
Institute,
La
Jolla,
CA,
United States) to apply pre treatments such as hydrogenation. The active ingredients of GPW and the target proteins were
saved as. pdbqt files, and AutoDock was utilized to simulate the
docking of each active ingredient and target protein. The data 2.13 Gene function annotation and pathway
enrichment analysis Finally,
Cytoscape
3.8.0
was
employed
to
construct
a
component‒target‒path (CTP) network to study the reciprocity
of components, targets, and paths (Cui et al., 2020). In such a
network, the degree value of a node was defined as the number of
edges connected to the rest of the network, where each edge
corresponds to the interaction between a biologically active
ingredient and its target, thus representing the physiological
relevance of the node in the network. To study the potential molecular mechanism through which
GPW exerts positive effects on cI/R, the key targets were analyzed by
gene function annotation (Gene Ontology, GO), and pathway
enrichment
analysis
(Kyoto
Encyclopedia
of
Genes
and
Genomes, KEGG). Statistical significance was set at p < 0.05. 08 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 TABLE 3 Molecular docking results between ligands and core target receptors. Molecule name
Binding energy (kcal/mol)
Baclofen (GABBR1 agonist)PTGS2
−7.0
3β-acetoxyatractylone
−5.3
(+/−)-Isoborneol
−4.2
α-Cubebol
−5.1
Selina-4(14),7(11)-dien-8-one
−3.4
(−)-Caryophyllene oxide
−6.3
Juniper camphor
−4.8
2-[(2R,5S,6S)-6,10-dimethylspiro [4.5]dec-9-en-2-yl]propan-2-ol
−5.7
Ermanthin
−5.8
FIGURE 7
Effect of GPW on PI3K/AKT signaling pathways in the infarct area. (A) WB representative result chart. (B) Statistical analysis results of PI3K expression. (C) Quantitative statistical results of AKT expression. (D) Quantitative statistical results of the p-AKT expression. N = 6 mice per group; #p < 0.01 versus the
sham group; *p < 0.05, **p < 0.01 compared with the Model group. TABLE 3 Molecular docking results between ligands and core target receptors. Molecule name
Binding energy (kcal/mol)
Baclofen (GABBR1 agonist)PTGS2
−7.0
3β-acetoxyatractylone
−5.3
(+/−)-Isoborneol
−4.2
α-Cubebol
−5.1
Selina-4(14),7(11)-dien-8-one
−3.4
(−)-Caryophyllene oxide
−6.3
Juniper camphor
−4.8
2-[(2R,5S,6S)-6,10-dimethylspiro [4.5]dec-9-en-2-yl]propan-2-ol
−5.7
Ermanthin
−5.8 FIGURE 7
Effect of GPW on PI3K/AKT signaling pathways in the infarct area. (A) WB representative result chart. (B) Statistical analysis results of PI3K expression. (C) Quantitative statistical results of AKT expression. (D) Quantitative statistical results of the p-AKT expression. N = 6 mice per group; #p < 0.01 versus the
sham group; *p < 0.05, **p < 0.01 compared with the Model group. Frontiers in Pharmacology 3.2 GPW reduced neuronal damage in
MCAO mice To predict the target receptor of GPW for the treatment of cI/R,
we performed the analysis from three aspects. First, we list the top
20 targets among the 213 possible action targets selected based on
the degree values (Table 2) and found theγ-aminobutyric acid
receptor (GABBR1) with the degree value of 38. Second, we
selected 130 target receptors that are relevant to the treatment of
cI/R with GPW from 5,992 (Figure 4B). After drawing the PPI
network structure with the STRING database website, 36 targets
with degree values greater than the average were obtained for
visualization
(Figure
4C). The
results
showed
GABBR1
is
included in the main genes that can be exploited for treatment of
cI/R. Finally, we employed the GO and KEGG pathway enrichment
combined with CTP network analysis. As illustrated in Figure 5A,
the top 10 biological process (BP), molecular function (MF), and
cellular composition (CC) were represented from 130 potential
targets. Furthermore, KEGG analysis revealed that 112 signal
pathways are involved in GPW-mediated effects on cI/R injury,
among which the top 20 were selected to make a bubble map
(Figure 5B). According to the results, GPW mainly acts on cI/R
injury through neuroactive ligand‒receptor interaction, fluid shear
stress, atherosclerosis, calcium signaling pathway, and the cAMP
and PI3K/AKT signaling pathways. Interestingly, GABBR1 is a key
target in the neuroactive ligand-receptor interaction signaling
pathway. Thus, these results, taking three aspects of drug
intervention,
disease
correlation,
and
pathway
enrichment,
demonstrated GABBR1 may be an important target for GPW
treatment of cI/R. HE staining showed that, in the sham group, hippocampal
neuronal cell bodies were large and round with obvious nucleoli,
and the cells were arranged in multiple well-organized layers. In the
model group, the number of cells on the affected side was reduced,
the arrangement was sparse, the cell bodies were shrunken, the
nuclei were constricted in triangles, and some cell nuclei had
disappeared. On the contrary, the proportion of atrophied
neurons in the GPW-treated groups was significantly reduced
(Figure 2A). Nissl staining showed the same trend. Compared
with the sham group, the number of Nissl bodies in the model
group was significantly reduced, while that in GPW-treated model
groups was significantly increased (Figures 2B, C). Furthermore, almost no TUNEL-positive cells were observed in
the sham group, but their number was significantly increased in the
model group. 3.3 GPW decreased the expression of
apoptosis-related proteins in MCAO mice The expression of the pro-apoptotic proteins caspase-3, cleaved
caspase-3, and Bax was significantly increased in the model group
but significantly decreased after GPW administration (Figure 3A‒
D). Accordingly, the expression of the anti-apoptotic protein Bcl-2
was
significantly
reduced
in
the
model
group,
while
the
administration of GPW was able to counteract this decrease
(Figure 3E). These results indicated that GPW had the potential
to inhibit neuronal apoptosis at the molecular level. 3 Results from 11 herbs (Supplementary Table S1). Using the uniprot
databases to normalize cI/R targets and delete duplicates, a total
of 213 targets were obtained. Then we used cystoscope software to
construct the “component-target network” diagram of GPW
(Figure 4A). In this diagram, the “degree” is defined as the
number of connected edges in the network, representing the
importance of the network. We found a total of 29 compounds
with a degree value greater than the average value of 8.76. Among
these, we further excluded 12 compounds due to a lack of
compatibility with Lipinski’s rules (Chen et al., 2020); 2) the
structure
conforming
to
the
characteristics
of
Pan-Assay
Interference Compounds (PAINS), which could indicate positive
readouts
in
biochemical
assays
via
different
mechanisms
(Grigalunas et al., 2020). Thus, only 17 compounds were selected
for the prediction of subsequent targets (Table 1). The total blood flow on the ischemic side after reperfusion was
measured by laser speckle Doppler, and blood flow recovery was
greater
than
70%,
indicating
successful
induction
of
cI/R
(Figure 1A). Different doses of GPW significantly improved the
neurological score of the model mice (Figure 1B). TTC staining
showed that GPW significantly reduced the size and volume of the
infarct in the model mice compared with that in the sham operation
group (Figures 1C, D). 3.2 GPW reduced neuronal damage in
MCAO mice After GPW administration, the number of TUNEL-
positive cells in the model mice was reduced in a dose-dependent
manner (Figures 2D, E). This further revealed that GPW could
reduce neuronal apoptosis of cI/R injury. 3.5 Molecular docking further confirmed
that GABBR1 might be a reliable target for
GPW therapy cI/R To further explore the binding mechanism of GPW on cI/R, we
obtained
8
compounds
including
3β-acetoxyatractylone,
(+/−)-isoborneol,
α-cubebol,
selina-4(14),7(11)-dien-8-one,
(−)-caryophyllene oxide, juniper camphor, 2-[(2R,5S, 6S)-6,10-
dimethylspiro
[4.5]dec-9-en-2-yl]propan-2-ol,
and
ermanthin
after intersecting the 17 main components of the preliminary
screening with 38 components that interact with GABBR1
(Supplementary Figure S2A). Here, we intend to explore the
binding
mechanism
between
these
active
compounds
and
GABBR1. As illustrated in Figure 6A, taking baclofen as a probe, 2.15 Statistical analysis All data are expressed as mean ± standard deviation (Mean ±
SD). SPSS19.0 (IBM, Armonk, NY, United States) and GraphPad 9.0
(GraphPad, La Jolla, CA, United States) were used for statistical
analysis and graph plotting. t-test was used to compare the means of
two samples. A one-way analysis of variance and Tukey’s test were
employed for comparisons of three or more group means. Statistical
significance was set at p < 0.05. 09 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 Frontiers in Pharmacology 3 Results
3.1 GPW reduced the cerebral infarction area
in MCAO mice 3 Results 3.4 Network analysis predicted the main
related targets of GPW The role of GPW in the treatment of cI/R has been determined;
further, it is intended to predict its possible targets through network
analysis. Through TCMSP, according to the conditions of OB ≥
30%, DL ≥0.1, and BBB ≥1, 95 active components were selected Frontiers in Pharmacology 10 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 prescription in TCM, which has been reported to be effective
against many neurological diseases. However, its effect and
mechanism of action on cI/R injury have not been reported. This
study is of great significance for the development of therapeutic
drugs for ischemic stroke based on TCM. prescription in TCM, which has been reported to be effective
against many neurological diseases. However, its effect and
mechanism of action on cI/R injury have not been reported. This
study is of great significance for the development of therapeutic
drugs for ischemic stroke based on TCM. we observed baclofen formed one hydrogen bond with Glu251, the
alkyl conjugation interactions with Tyr279, and Ile276, and π-π
interactions with Tyr250 and Trp278. In addition, the formation of
the ligand-receptor complex was also dependent on van der Waals
forces with Ser153, Ser131, Trp65, Tyr279, and Phe202. The binding
energy of baclofen was −7.0 kcal/mol, indicating the strong binding
ability between baclofen and GABBR1. Firstly, we used the classical mouse MCAO model to further
evaluate the therapeutic effect of GPW (Walter, 2022). The success
of the model was verified by laser speckle Doppler, and GPW was
found to reduce cerebral infarction size and neural function score
and reduce neuronal apoptosis in model mice. Apoptosis is an
important pathway leading to neuronal death after stroke, and
caspase-3, bax, and blc-2 are apoptosis-related proteins. We
further used WB to find that GPW can counteract these changes
in stroke levels. The effect of GPW on cI/R was confirmed by
experimental pharmacological methods. Next, we performed the molecular docking between these
8
compounds
and
GABBR1. As
illustrated
in
Figure
6B;
Supplementary Figure S2B, we obtained the binding energies
ranked −6.3 to −3.4 kcal/mol (Table 3), whereby suggested that
these 8 compounds had good binding ability with GABBR1. Similarly, the formation of these 8 ligand-receptor complexes was
also based on the hydrogen bond, conjugation interactions, and van
der Waals forces formed by 8 compounds with the above-mentioned
key amino acid residues in GABBR1. 3.4 Network analysis predicted the main
related targets of GPW In parallel, these results
indicated
that
the
mechanism
of
the
interaction
between
bioactive compound and GABBR1 was similar to that of clinical
drugs, thus proving the promising potential of GPW for cI/
R treatment. Next, the main components and targets of cI/R treatment with
GPW were screened and predicted by network analysis. Using the
TCMSP database and according to OB, DL, and BBB standards,
96 components of 11 kinds of Chinese herbs in GPW were screened
out. Further, the degree values were ranked according to the number
of corresponding targets, those less than the average are excluded,
and those greater than the average are 29 in total. The druggability of
the compound requires compliance with Lipinski’s Rule of Five and
the PAIN rule, which further excludes some compounds, S-(2-
Carboxyethyl)-L-Cysteine and Stigmasterol meet the druggability
rules, but there are many targets and poor specificity. Therefore,
17 compounds such as nuciferine, atractylone, β-carotene, and
coumarin were obtained. Among these, previous studies have
shown
that
nuciferine
was
found
to
significantly
improve
neurological deficit scores, cerebral edema, and infarction by
regulating fat metabolism and inflammatory response (Wu et al.,
2020). Similarly, patients with higher serum β-carotene were found
to have a significantly lower risk of stroke and death (Huang et al.,
2018). Additionally, coumarin is a common oral anticoagulant used
for the prevention and treatment of stroke (Cordonnier, 2018). These findings, together with our results, confirm that the core
components of GPW can effectively reduce cI/R injury. However,
although atractylone, 3β-acetoxyatractylone, and harmine have not
been reported to have a therapeutic effect on ischemic stroke, they
may play a synergistic role in the treatment of GPW, which needs to
be verified by subsequent experiments. 3.6 GPW affected the expression of PI3K/
AKT signaling pathway-related proteins It has been shown that modulating GABBR1 can inhibit
apoptosis of rat hippocampal neurons through the PI3K/Akt
pathway in the treatment of refractory epilepsy. We speculate
that GPW may affect the PI3K/AKT signaling pathway by
activating GABBR1, Therefore, We used Western blotting to
evaluate changes in the expression of the related proteins
(Figure 7A). Compared with the sham group, the model group
had significantly reduced levels of PI3K, whose expression increased
after GPW administration (Figure 7B). Also, while the total
expression
of
AKT
did
not
change
(Figure
7C),
that
of
phosphorylated AKT (p-AKT) was significantly reduced in the
model group; this reduction was restored in GPW-treated mice
(Figure 7D). In summary, the results show that GPW can activate
the PI3K/AKT signaling pathway. frontiersin.org Frontiers in Pharmacology 4 Discussion Furthermore, in the results of network analysis, GABBR1 was
found to have the highest degree in the target of GPW components. Additionally, combined with the analysis results of PPI, GO, and
KEEG analysis found that GABBR1 was closely related to the effect
of GPW on cI/R. Combined with the above results, we analyzed and
speculated that GABBR1 may be a key target for the treatment of cI/
R by GPW. Molecular docking provides further validation and
suggests that multiple components in GPW may synergistically
act on GABBR1 to produce neuroprotective effects. GABBR1 is
the metabolic receptor 1 subtype of the inhibitory neurotransmitter
gamma-aminobutyric acid (GABA), It is a G protein-coupled
receptor expressed in neurons and glial cells throughout the brain
(Cediel et al., 2022). GABBR1 exerts presynaptic and postsynaptic
effects to inhibit the release of neurotransmitters and produce a later
inhibitory postsynaptic potential, respectively (Gassmann and
Bettler, 2012). It has been shown that GABBR1 controls neuronal
activity to prevent overexcitation, thereby preventing excitotoxicity In this study, we validated the pharmacological effect of GPW in
the treatment of cI/R injury. The prevention and treatment of
ischemic stroke remain a worldwide challenge. A central issue is
the risk of bleeding associated with anticoagulants and antiplatelet
drugs (Sandercock et al., 2015). Due to its low side effects, TCM is
often sought as an alternative drug therapy for ischemic stroke
prevention and rehabilitation intervention in China. Natural
medicines in TCM are the origin of many new medicines, such
as Salvia miltiorrhiza, which has been used to treat cerebrovascular
diseases in China for thousands of years. TCM has been used in
humans for more than 2,000 years. The valuable experience
provided by this practice can provide powerful guidance for drug
discovery (Sun et al., 2015). However, there are still some limitations
of TCM, such as the low quality of TCM tests and unclear
ingredients and mechanisms. GPW in this study is a classic 11 frontiersin.org Zhang et al. 10.3389/fphar.2024.1346226 study was conducted in accordance with the local legislation and
institutional requirements. study was conducted in accordance with the local legislation and
institutional requirements. and cell death. Selective continuous activation of GABBR1 can
provide neuroprotection in vitro and in vivo models of cerebral
ischemia (Kim et al., 2014). Moreover, studies have shown that the
GABBR-mediated
PI3K/AKT
signaling
pathway
can
reduce
oxidative stress and neuronal cell damage in rat models of
Alzheimer’s disease (Sun et al., 2020). 4 Discussion After a stroke, activation of
the PI3K/AKT signaling pathway can counteract neuronal apoptosis
(Lv et al., 2019). Further, we found that GPW reduced the amount
of PI3K protein in cI/R mice and inhibited the phosphorylation
of AKT. Our analysis showed that GPW may be mediated by
GABBR1 to produce neuroprotective effects in cI/R injury by
activating PI3K/AKT signaling. Publisher’s note All claims expressed in this article are solely those of the authors
and
do
not
necessarily
represent
those
of
their
affiliated
organizations, or those of the publisher, the editors and the
reviewers. Any product that may be evaluated in this article, or
claim that may be made by its manufacturer, is not guaranteed or
endorsed by the publisher. Funding The author(s) declare financial support was received for the
research, authorship, and/or publication of this article. This work
was supported by the project of Shaanxi Provincial Administration
of Traditional Chinese Medicine (grant number 2021-ZZ-JC030),
Tangdu Hospital National Natural Science Foundation Support
Program (grant number 2021ZTXM-025). Data availability statement The original contributions presented in the study are included in
the article/Supplementary Material, further inquiries can be directed
to the corresponding author. 5 Conclusion The authors declare that the research was conducted in the
absence of any commercial or financial relationships that could be
construed as a potential conflict of interest. In conclusion, this study confirmed the neuroprotective effect of
GPW by regulating the PI3K/AKT signaling pathway. In addition,
the combination of network analysis and molecular docking
predicted that GPW might target GABBR1 for the treatment of
cI/R, preliminarily indicating that GPW may be a candidate herb for
further research. This work provided a theoretical basis for the
clinical application of GPW. Author contributions JZ: Writing–original draft. LL: Writing–original draft. YG:
Writing–original draft. AL: Writing–review and editing. MZ:
Writing–review and editing. WJ: Writing–review and editing. XL:
Writing–review and editing. QL: Writing–review and editing. JY:
Writing–original draft, Writing–review and editing. It is necessary to acknowledge the limitations of this work. First,
the composition and target of GPW are statistically obtained from the
database, which cannot contain all the compounds and target genes. Second, the effect of GPW on cerebral ischemia-reperfusion injury
needs more clinical verification. Finally, in addition to GABBR1,
PTGS2, CHRM1, CHRM3, and other targets are also highly
correlated. Whether other components of GPW interact with them
and participate in the treatment of cerebral ischemia-reperfusion
injury is still unclear, and more experiments are needed to verify it. Ethics statement The Supplementary Material for this article can be found online
at: https://www.frontiersin.org/articles/10.3389/fphar.2024.1346226/
full#supplementary-material The animal study was approved by the Animal Experiment
Ethics Committee of Air Force Military Medical University. The Fan, J., Li, X., Yu, X., Liu, Z., Jiang, Y., Fang, Y., et al. (2023). Global burden, risk factor
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Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study
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PloS one
| 2,020
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cc-by
| 3,538
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Results Of these 46 cases, 16 cases with confirmed COVID-19 were tested for HFABP> 7 ng / mL
upon admission; among them, 14 cases were diagnosed with severe COVID-19 within the
hospitalization. The Odds ratio of the measured HFABP elevation was 6.81(95% confidence
interval [CI] 5.23–8.40), and 3 patients with severe COVID-19 progressed in 5 patients with
mild HFABP> 7 ng/mL. Copyright: © 2020 Yin et al. This is an open access
article distributed under the terms of the Creative
Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in
any medium, provided the original author and
source are credited. Background Heart-fatty acid binding protein (HFABP) has been recognized as a highly heart-specific
marker. However, it is currently unknown that its HFABP is also closely related to the sever-
ity of COVID-19. Citation: Yin L, Mou H, Shao J, Zhu Y, Pang X,
Yang J, et al. (2020) Correlation between Heart
fatty acid binding protein and severe COVID-19: A
case-control study. PLoS ONE 15(4): e0231687. https://doi.org/10.1371/journal.pone.0231687 RESEARCH ARTICLE
Correlation between Heart fatty acid binding
protein and severe COVID-19: A case-control
study RESEARCH ARTICLE Li Yin1☯, Huaming Mou1☯, Jiang Shao1☯, Ye Zhu2☯, Xiaohua Pang1☯, Jianjun Yang1☯,
Jianming Zhang1☯, Wei Shi1☯, Shimei Yu3☯, Hailong WangID1☯* 1 Department of Cardiology, Heart Center, Chongqing Three Gorges Central Hospital, Affiliated Three
Gorges Hospital of Chongqing University, Chongqing, China, 2 Department of Cardiology, West China
Hospital of Sichuan University, Chengdu, China, 3 Department of Otorhinolaryngology, Wanzhou First
People Hospital, Chongqing, China a1111111111
a1111111111
a1111111111
a1111111111
a1111111111 ☯These authors contributed equally to this work. * wangjinlong2007666@163.com * wangjinlong2007666@163.com Methods Editor: Xia Jin, Institut Pasteur of Shanghai
Chinese Academy of Sciences, CHINA Editor: Xia Jin, Institut Pasteur of Shanghai
Chinese Academy of Sciences, CHINA Editor: Xia Jin, Institut Pasteur of Shanghai
Chinese Academy of Sciences, CHINA
Received: February 26, 2020
Accepted: March 26, 2020
Published: April 29, 2020 We retrospectively screened 46 patients who met our inclusion criteria within 4 weeks. They
were tested for HFABP after the diagnosis of COVID-19, and monitored for HFABP during
their hospital stay. We tracked the patients during their hospital stay to determine if they had
severe COVID-19 or mild-to-severe transition features. We calculated the chi-square test
values found for HFABP to predict the correlation between HFABP levels and the severity of
the COVID-19. Peer Review History: PLOS recognizes the
benefits of transparency in the peer review
process; therefore, we enable the publication of
all of the content of peer review and author
responses alongside final, published articles. The
editorial history of this article is available here:
https://doi.org/10.1371/journal.pone.0231687 PLOS ONE PLOS ONE Trial registration Competing interests: No authors have competing
interests. Competing interests: No authors have competing
interests. Our study has been registered with the Chinese Clinical Trial Registry, the registration num-
ber: ChiCTR2000029829. Conclusion These data indicate that the elevation of HFABP is closely related to the severity of COVID-
19 in the patients, and the elevated HFABP may cause rapid development of patients with
mild COVID-19 into severe COVID-19. But serum HFABP negative maybe make patients
with mild COVID-19 safer, the current data show no effect on the all-cause mortality. Data Availability Statement: All relevant data are
within the manuscript and its Supporting
Information files. Funding: Unfunded studies. 1 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study Introduction Coronaviruses belong to the Coronaviridae family of non-segmented positive-sense RNA
viruses and are widely parasitic in humans and other mammals [1]. Although most infections
with human coronavirus are mild, two coronaviruses, including severe acute respiratory syn-
drome coronavirus (SARS-CoV) [2–4] and Middle East respiratory syndrome coronavirus
(MERS-CoV) [5,6], cause severe infection. They can cause fulminant disease and severe illness. In December 2019, a new coronavirus named 2019 New Coronavirus (2019-nCoV) was found
in Wuhan, Hubei, China. The disease caused by this coronavirus is COVID-19 [7–11]. At pres-
ent, many cases have been confirmed in all provinces of China and in other countries. For
making the diagnosis of patients with COVID-19, it is a great challenge for doctors to deter-
mine the condition of patients with severe illness as early as possible. Heart fatty acid-binding protein, a serum biomarker for myocardial injury, is highly cardiac
specific [12–14]. Recently, we have found that elevated HFABP levels are associated with
severe COVID-19 or mild-to-severe transition features. Our study sought to determine
whether the measurement of the HFABP can predict short-term turnover and prognosis in
patients with COVID-19. Our study retrospectively analyzed the epidemiological, clinical, and laboratory characteris-
tics of patients with COVID-19 and compared HFABP levels with severe COVID-19 and
mild-to-severe transition features. We hope that our findings will provide information to the
global community about predicting the condition and outcomes of patients with COVID-19. Measurement All blood samples were collected and sent to the laboratory immediately. All selected patients
were measured for HFABP. The results were provided to the clinical medical staff. HFABP lev-
els were measured by the Roche Modular Analyzer (Roche Diagnostics, Laval, Quebec). These
tests were performed with reagents provided by the manufacturer and in strict accordance
with the procedures. The cut-off value is defined as the internationally agreed value of 7 ng /
mL. Patients and trial designs During January 2020, we retrospectively screened all patients with COVID-19 admitted to
Chongqing Three Gorges Central Hospital, and we obtained approval from the Ethics Com-
mittee of the Chongqing Three Gorges Central Hospital. Eligible patients included patients
older than 14 years of age, patients who were diagnosed with COVID-19, and patients who
had been assessed for HFABP serum concentrations at any time during the hospital stay. We
excluded patients who were younger than 14 years of age, patients who had not received the
measurement of HFABP serum concentrations at any time during the hospital stay. We per-
formed follow-up (during the hospital stay, 9–21 days) of the patients in the study and
recorded their status (mild, severe, or death) and whether they changed from mild to severe,
defined as any of the following conditions: Mild COVID-19: The patient presents with only fever, respiratory tract infection, and other
symptoms, and imaging shows pneumonia. Those who have one of the following pathogenic
evidences: 1. Real-time fluorescent RT-PCR of respiratory specimens or blood specimens for
detection of novel coronavirus nucleic acid; 2. Sequencing of viral genes of respiratory speci-
mens or blood specimens, highly homologous to known novel coronavirus. 2 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study Severe COVID-19: confirmed as COVID-19 and meets any of the following criteria: 1. Respi-
ratory distress, RR 30 times / min; 2. Means oxygen saturation 93%; Arterial blood oxygen
partial pressure (PaO2) / oxygen concentration (FiO2) 300 mmHg (1 mmHg = 0.133 kPa). Death: Total deaths from all causes during the hospital stay. Patients During the research period, 245 patients arrived at our hospital and were diagnosed with
COVID-19. Of these patients, 199 patients were excluded from our research because they did
not undergo testing for serum HFABP within a week of admission, and 46patients (25 patients
with severe disease and 21 patients with mild disease) were finally included. In our study, 45
patients were tested for serum HFABP from the day of admission to the 5th day of admission,
and one patient was tested for serum HFABP on the 6th day of admission. In addition, 2 criti-
cally severe COVID-19 patients died during hospitalization. Three COVID-19 patients with
serum HFABP-positive result changed from mild to severe state during hospitalization. Demo-
graphic and disease characteristics of 15 patients with serum HFABP-positive COVID-19 and
30 patients with serum HFABP- negative COVID-19 are presented in Table 1. The results of
HFABP analysis showed a normal distribution, with values decreasing from 1.76 ng/mL to
24.68 ng/mL (mean 6.81, 95% CI 5.23–8.40, SD 5.33). Statistical analyses Categorical data were expressed as counts and percentages. Continuous data for normal and
skew distribution are expressed as mean standard deviation and median, respectively. The Kol-
mogorov Smirnov test was used to test the normality of the data distribution. Categorical vari-
ables are expressed as numbers (%) and compared between the HFABP-raised group and the
normal group by the Chi2 test or the Fisher’s exact test, and classification clinical, characteris-
tics, and outcome rates were tested using the Chi2 test. A P value of less than 0.05 was considered statistically significant. Statistical analysis was
performed using SPSS software(version 23, IBM Inc., Armonk, NY, USA). Outcomes Table 2 summarizes the relationship between positive HFABP and severe COVID-19. In the
HFABP positive group, a significant increase in the prevalence of severe illness was observed
during hospitalization of patients with COVID-19 (87.5% vs 40%, P = 0.002). Among them, in
the HFABP positive group, 3 of 5 patients with mild COVID-19 worsened to severe COVID-
19 during hospitalization, and the incidence was 60%. One patient died in each of the two
groups (P > 0.05), which was not statistically significant (Table 2). 3 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study Table 1. Demographic and disease characteristics of enrolled patients. Characteristic
Group; no. (%) of patients
All n = 45
HFABP Positive n = 15
HFABP negative n = 30
Male
25
5
22
Age, mean (SD), yr
52.4
65.3(17.9)
45.6(12.5)
Tobacco smoking
3
0(0)
3(9.6)
Car T
39
3(7.6)
2(5.1)
Any comorbidity
Diabetes
7
2(14.2)
5(16.1)
Hypertension
4
1(7.1)
3(9.6)
Cardiovascular disease
2
1(7.1)
1(3.2)
Malignancy
3
1(7.1)
2(6.4)
COPD
2
0(0)
2(6.4)
CLD
0
0(0)
0(0)
CKD
0
0(0)
0(0)
Chronic obstructive pulmonary disease = COPD, Chronic liver disease = CLD, Chronic kidney disease = CKD,
Cardiac troponin T = Ca T. Note: All differences were statistically nonsignificant. SD = standard deviation. Except as indicated for Age. https://doi.org/10.1371/journal.pone.0231687.t001 Table 1. Demographic and disease characteristics of enrolled patients. PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 hronic obstructive pulmonary disease = COPD, Chronic liver disease = CLD, Chronic kidney disease = CKD, Discussion Both SARS-CoV and MERS-CoV are thought to originate in bats, and many studies have
found coronaviruses with many other genomic sequences in bats. In 2013, Ge and colleagues
reported the genome-wide sequence of a new coronavirus similar to SARS in bats. This virus
can utilize human receptors and has the potential to replicate in human cells. 2019-nCoV has
the potential to cause a pandemic, and it is still being studied in depth to prevent it from
becoming a global health threat. Reliable and rapid differential diagnosis and reasonable treat-
ment of diagnosed patients with COVID-19 are still essential to control the epidemic [15,16]. Our study screened 46 laboratory-confirmed patients with COVID-19. The patient was severe
viral pneumonia and was fatal. All patients were sent to Chongqing Three Gorges Central Hos-
pital before February 22, 2020, and their clinical symptoms were very similar to SARS. Acute
respiratory distress syndrome (ARDS) can occur in severe patients, and they will require
admission to the Intensive Care Unit and assistant treatment with mechanical ventilation. During the retrospective study, 2 of 46 patients included in this research died (4.3%); thus, the
mortality of COVID-19 was very high. At present, the determination of severe COVID-19 is mainly based on the comprehensive
analysis of clinical symptoms, signs, and blood gas analysis results. The global judgment of the
severity of COVID-19 is based on the Chinese guidelines, and there is no clinical serum
marker for comprehensive judgment. This study shows that in patients with COVID-19, Table 2. Clinical outcomes of the matched study population of COVID-19 with HFABP levels. Clinical outcomes
HFABP Positive group N = 15
HFABP Negative group N = 30
P value
Severe COVID-19
13
12
0.002
Mild-to-severe COVID-19
0
3
/
Death
1
1
>0.05
Heart fatty acid-binding protein = HFABP. https://doi.org/10.1371/journal.pone.0231687.t002 Table 2. Clinical outcomes of the matched study population of COVID-19 with HFABP levels. 4 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study elevated serum HFABP is closely related to the severity of disease in the patients, and there is a
significant statistical difference from patients with normal serum HFABP. Therefore, elevated
serum HFABP can be used as an indicator of severe COVID-19 and an independent risk factor
for patient prognosis. Discussion Among the patients in this study, 40 patients were monitored for tropo-
nin T, and only 6 patients were positive for troponin T; however, there was no statistical differ-
ence between the serum HFABP-negative and HFABP-positive groups. The hypothesis that
HFABP is affected by troponin T does not hold, and the serum HFABP levels show an inde-
pendent stable performance. This can happen because, like SARS-CoV and MERS-CoV, novel
coronavirus infections also induce the secretion of a large number of cytokines [17–21], lead-
ing to inflammatory lung injury, which reduces blood oxygen concentration and puts myocar-
dial cells in a hypoxic state, thereby increasing the release of HFABP into the blood. We noted
that 86.7% of patients with elevated serum HFABP are patients with severe COVID-19; there-
fore, it is of great significance to judge and predict the outcome of patients with severe
COVID-19. At present, there is no objective laboratory index for assessing the outcome of
patients with COVID-19. Serum HFABP can be used as an effective index; thus, it can guide
the clinicians to judge patients with severe COVID-19 in the short term, and elevated HFABP
can also severely affect the outcome of patients with COVID-19. We also observed a phenomenon in which five patients with mild COVID-19 were positive
for serum HFABP upon admission. Three patients deteriorated to severe neo-coronavirus
pneumonia very quickly after admission, and the incidence of this event was 60%. However,
30 patients with mild COVID-19 were negative for serum HFABP, and none of these patients
developed severe disease. Therefore, we speculate that if patients with mild COVID-19 are pos-
itive for serum HFABP, they can easily deteriorate to severe COVID-19. Based on the small
sample size of our screened cases, we did not perform a statistically significant difference
analysis. In addition, two deaths were reported in our study, and they were severe COVID-19
patients. There was one case in the HFABP positive group, and the other case was in the
HFABP negative group. We performed a statistical analysis for these groups, and there was no
statistical difference in mortality between the two groups. However, we avoided sensitivity and
specificity analysis because the sample size was small and we could not draw convincing con-
clusions. A larger sample size is needed for further confirmation. Conclusion Our conclusion is that the elevation of HFABP is closely related to the severity of COVID-19
in the patients, and the elevated HFABP may cause rapid development of patients with mild
COVID-19 into severe COVID-19. But serum HFABP negative maybe make patients with
mild COVID-19 safer, the current data show no effect on the all-cause mortality. New corona-
viruses have acquired effective human transmission capabilities [17,22]. We are deeply aware
of the challenges and concerns that our global medical care encounters with COVID-19. Every
effort should be made to study and control this disease. Therefore, we recommend worldwide
promotion of HFABP application, which will help to judge and predict severe COVID-19. Supporting information S1 Data. (XLSX)
S2 Data. (XLSX) 5 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study Author Contributions Conceptualization: Li Yin, Jiang Shao, Ye Zhu, Hailong Wang. Conceptualization: Li Yin, Jiang Shao, Ye Zhu, Hailong Wang. Data curation: Li Yin, Jiang Shao, Hailong Wang. Formal analysis: Li Yin, Huaming Mou, Ye Zhu, Jianming Zhang, Wei Shi, Shimei Yu, Hai-
long Wang. Formal analysis: Li Yin, Huaming Mou, Ye Zhu, Jianming Zhang, Wei Shi, Shimei Yu, Hai-
long Wang. Funding acquisition: Li Yin, Hailong Wang. Funding acquisition: Li Yin, Hailong Wang. Investigation: Xiaohua Pang, Jianjun Yang, Jianming Zhang. Methodology: Li Yin, Huaming Mou, Jiang Shao, Ye Zhu, Hailong Wang. Project administration: Li Yin, Hailong Wang. Resources: Huaming Mou. Software: Jianming Zhang. Supervision: Jiang Shao. Supervision: Jiang Shao. Validation: Huaming Mou. Visualization: Jianming Zhang, Wei Shi, Shimei Yu. Visualization: Jianming Zhang, Wei Shi, Shimei Yu. Writing – original draft: Li Yin, Huaming Mou, Jiang Shao, Hailong Wang. Writing – review & editing: Li Yin, Huaming Mou, Jiang Shao, Ye Zhu, Xiaohua Pang, Jian-
jun Yang, Jianming Zhang, Wei Shi, Shimei Yu, Hailong Wang. Acknowledgments We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this
manuscript. References 1. Richman DD, Whitley RJ, Hayden FG, eds. Clinical virology, 4th edn. Washington: ASM Press, 2016. 2. Ksiazek TG, Erdman D, Goldsmith CS, Zaki SR, Peret T, Emery S, et al. A novel coronavirus associ-
ated with severe acute respiratory syndrome. N Engl J Med 2003; 348: 1953–66. https://doi.org/10. 1056/NEJMoa030781 PMID: 12690092 3. Kuiken T, Fouchier RAM, Schutten M, Rimmelzwaan GF, Amerongen G, Riel D, et al. Newly discovered
coronavirus as the primary cause of severe acute respiratory syndrome. Lancet 2003; 362: 263–70. https://doi.org/10.1016/S0140-6736(03)13967-0 PMID: 12892955 4. Drosten C, Gu¨nther S, Preiser W, Werf S, Brodt BR, Becker S, et al. Identification of a novel coronavirus
in patients with severe acute respiratory syndrome. N Engl J Med 2003; 348: 1967–76. https://doi.org/
10.1056/NEJMoa030747 PMID: 12690091 5. de Groot RJ, Baker SC, Baric RS, Brown CS, Drosten C, Enjuanes L, et al. Middle East respiratory syn-
drome coronavirus (MERS-CoV): announcement of the Coronavirus Study Group. J Virol 2013; 87:
7790–92. https://doi.org/10.1128/JVI.01244-13 PMID: 23678167 6. Zaki AM, van Boheemen S, Bestebroer TM, Osterhaus ADME, Fouchierr RAM. Isolation of a novel
coronavirus from a man with pneumonia in Saudi Arabia. N Engl J Med 2012; 367: 1814–20. https://
doi.org/10.1056/NEJMoa1211721 PMID: 23075143 7. WHO. Novel coronavirus Thailand (ex-China). Geneva: World Health Organization, Jan 14, 2020. https://www.who.int/csr/don/14-january-2020-novel-coronavirus-thailand/en/ (accessed Jan 23, 2020). 8. WHO. Novel Coronavirus Japan (ex-China). Geneva: World Health Organization, Jan 16, 2020. https://www.who.int/csr/don/16-january-2020-novel-coronavirus-japan-ex-china/en/ (accessed Jan 23,
2020). 6 / 7 PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 PLOS ONE Correlation between Heart fatty acid binding protein and severe COVID-19: A case-control study 9. China National Health Commission. Update on the novel coronavirus pneumonia outbreak (Jan 24,
2020). Beijing: China National Health Commission, 2020. http://www.nhc.gov.cn/xcs/yqfkdt/202001/
c5da49c4c5bf4bcfb320ec2036480627.shtml (accessed Jan 24, 2020). 10. WHO. Novel coronavirus Republic of Korea (ex-China). Geneva: World Health Organization, 2020. https://www.who.int/csr/don/21-january-2020-novel-coronavirus-republic-of-korea-ex-china/en/
(accessed Jan 24, 2020). 11. US Centers for Disease Control and Prevention. First travel-related case of 2019 novel coronavirus
detected in United States. Atlanta, GA: US Centers for Disease Control and Prevention, 2020. https://
www.cdc.gov/media/ releases/2020/p0121-novel-coronavirus-travel-case.html (accessed Jan 24,
2020). 12. Glatz JF, Kleine AH, van Nieuwenhoven FA, Hermens WT, van Dieijen-Visser MP, van der Vusse GJ. Fatty-acid-binding protein as a plasma marker for the estimation of myocardial infarct size in humans. British Heart Journal 1994; 71 (2): 135–40. https://doi.org/10.1136/hrt.71.2.135 PMID: 8130020 13. Kleine AH, Glatz JF, Van Nieuwenhoven FA, Van der Vusse GJ. PLOS ONE | https://doi.org/10.1371/journal.pone.0231687
April 29, 2020 References Release of heart fatty acid-binding pro-
tein into plasma after acute myocardial infarction in man. Molecular and Cellular Biochemistry 1992;
116 (1–2): 155–62. https://doi.org/10.1007/bf01270583 PMID: 1480144 14. Hai-Long W, Xiao-Hua P, Jian-Jun Y. The Prognostic Value of Heart-Type Fatty Acid Binding Protein in
Patients with Acute Coronary Syndrome. J Coll Physicians Surg Pak. 2018 Jan; 28(1):56–60. https://
doi.org/10.29271/jcpsp.2018.01.56 PMID: 29290194 15. Ge X-Y, Li J-L, Yang X-L, Chmura AA, Zhu G-J, Epstein JH, et al. Isolation and characterization of a bat
SARS-like coronavirus that uses the ACE2 receptor. Nature 2013; 503: 535–38. https://doi.org/10. 1038/nature12711 PMID: 24172901 16. Wang M, Hu Z. Bats as animal reservoirs for the SARS coronavirus: hypothesis proved after 10 years of
virus hunting. Virol Sin 2013; 28: 315–17. https://doi.org/10.1007/s12250-013-3402-x PMID: 24174406 17. Wong CK, Lam CWK, Wu AKL, Lp W K, Lee NLS, Chan IHS, et al. Plasma inflammatory cytokines and
chemokines in severe acute respiratory syndrome. Clin Exp Immunol 2004; 136: 95–103. https://doi. org/10.1111/j.1365-2249.2004.02415.x PMID: 15030519 18. Mahallawi WH, Khabour OF, Zhang Q, Makhdoum HM, Suliman BA. MERS-CoV infection in humans is
associated with a pro-inflammatory Th1 and Th17 cytokine profile. Cytokine 2018; 104: 8–13. https://
doi.org/10.1016/j.cyto.2018.01.025 PMID: 29414327 19. He L, Ding Y, Zhang Q, Che X, He Y, Shen H, et al. Expression of elevated levels of pro-inflammatory
cytokines in SARS-CoV-infected ACE2+ cells in SARS patients: relation to the acute lung injury and
pathogenesis of SARS. J Pathol 2006; 210: 288–97. https://doi.org/10.1002/path.2067 PMID:
17031779 20. Faure E, Poissy J, Goffard A, Fournier C, Kipnis E, Titecat M, et al. Distinct immune response in two
MERS-CoV-infected patients: can we go from bench to bedside? PLoS One 2014; 9: e88716. https://
doi.org/10.1371/journal.pone.0088716 PMID: 24551142 21. Falzarano D, de Wit E, Rasmussen AL, Feldmann F, Feldmann H. Treatment with interferon-α2b and
ribavirin improves outcome in MERS-CoVinfected rhesus macaques. Nat Med 2013; 19: 1313–17. https://doi.org/10.1038/nm.3362 PMID: 24013700 22. Assiri A, Al-Tawfiq JA, Al-Rabeeah AA, Al-Rabiah FA, Al-Hajjar S, Al-Barrak A, et al. Epidemiological,
demographic, and clinical characteristics of 47 cases of Middle East respiratory syndrome coronavirus
disease from Saudi Arabia: a descriptive study. Lancet Infect Dis 2013; 13: 752–61. https://doi.org/10. 1016/S1473-3099(13)70204-4 PMID: 23891402 7 / 7
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Моделювання аеродинаміки турбулізаторів теплообмінних елементів
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ENERGETICS ENERGETICS DOI 10.51582/interconf.19-20.06.2023.028 Моделювання аеродинаміки
турбулізаторів теплообмінних елементів Денисенко Олександр Іванович1,
Савранська Алла Володимирівна2 1 кандидат технічних наук, доцент, доцент кафедри
системного аналізу та обчислювальної математики;
Національний університет «Запорізька політехніка»; Украї 2 кандидат фізико-математичних наук, доцент, доцент кафедри
системного аналізу та обчислювальної математики;
Національний університет «Запорізька політехніка»; Україна 2 кандидат фізико-математичних наук, доцент, доцент кафедри
системного аналізу та обчислювальної математики;
Національний університет «Запорізька політехніка»; Україна 2 кандидат фізико-математичних наук, доцент, доцент кафедри
системного аналізу та обчислювальної математики; Національний університет «Запорізька політехніка»; Україна ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023).
Prague, Czech Republic
No
159 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic Анотація. Анотація. За допомогою програмного комплексу COMSOL Multiphisics, використовуючи метод скінчених
елементів
проведено
3-D
моделювання
аеродинаміки
турбулізаторів
циліндричних
теплообмінників різної геометрії. Отримана візуалізація структури потоків газоповітряної
суміші. Проведено серію чисельних експериментів для різних геометричних параметрів та
фізичних умов. Ключові слова:
тубулізатори
3-D моделювання
теплообмінники This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). 286 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» (June 19-20, 2023). Prague, Czech Republic 287
This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License (https://creativecommons.org/licenses/by-sa/4.0/). This work is distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International License ENERGETICS Проблема ефективного використання енергоресурсів останнім
часом набула особливої актуальності. Коефіцієнт корисної дії
опалювального
обладнання
в
значній
мірі
залежить
від
конструктивних
особливостей
опалювальних
котлів
та
теплообмінних елементів. З метою інтенсифікації теплообміну
в опалювальних пристроях використовують турбулізатори різної
геометрії [1-2]. Зазвичай, теплообмінні елементи у таких
пристроях
мають
призматичну
або
циліндричну
форму
з
вбудованими турбулізаторами у вигляді скрученої стрічки, або
зигзагоподібного каналу, або іншої, більш складної геометрії. В
роботі
досліджуються
аеродинамічні
характеристики
конструкцій теплообмінників у вигляді циліндричних патрубків
з вбудованими турбулізаторами різної геометрії (рис.1). а)
б)
в)
г)
д)
Рисунок
1. Турбулізатори з різною геометрією: а) скручена стрічка; б) подвійна
скручена стрічка; в) потрійна скручена стрічка; г) стрічка зі змінним
кроком закрутки; д) фрагментована стрічка з різноспрямованою закруткою д) г) б) а) в)
Рисунок в)
Рисунок д) г) б) а) Рисунок у
1. Турбулізатори з різною геометрією: а) скручена стрічка; б) подвійна
скручена стрічка; в) потрійна скручена стрічка; г) стрічка зі змінним
кроком закрутки; д) фрагментована стрічка з різноспрямованою закруткою у
1. Турбулізатори з різною геометрією: а) скручена стрічка; б) подвійна
скручена стрічка; в) потрійна скручена стрічка; г) стрічка зі змінним
кроком закрутки; д) фрагментована стрічка з різноспрямованою закруткою у
1. Турбулізатори з різною геометрією: а) скручена стрічка; б) подвійна
скручена стрічка; в) потрійна скручена стрічка; г) стрічка зі змінним
кроком закрутки; д) фрагментована стрічка з різноспрямованою закруткою Процес теплообміну відбувається в результаті проходження
гарячої газоповітряної суміші через теплообмінник, який
омивається зовні рідинним теплоносієм. Проведення натурних експериментів для дослідження таких 287
This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). 287 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» ENERGETICS пристроїв вимагає великих витрат, а використання спрощених
балансових моделей дає досить наближені результати без
можливості візуалізації складних аеродинамічних ефектів. Враховуючи
складну
геометрію
розрахункової
області,
аналітичний розв’язок задачі неможливий. Тому, використання
сучасних чисельних методів і алгоритмів є оптимальним шляхом
для аналізу складних тривимірних моделей. пристроїв вимагає великих витрат, а використання спрощених
балансових моделей дає досить наближені результати без
можливості візуалізації складних аеродинамічних ефектів. Враховуючи
складну
геометрію
розрахункової
області,
аналітичний розв’язок задачі неможливий. Тому, використання
сучасних чисельних методів і алгоритмів є оптимальним шляхом
для аналізу складних тривимірних моделей. В роботі досліджувались окремо тільки аеродинамічні
характеристики турбулізаторів, тобто температурний фактор не
враховувався. В якості математичної моделі використовувалась
тривимірна
система
диференційних
рівнянь
Нав’є-Стокса. Розрахунки здійснювалися методом скінчених елементів за
допомогою програмного комплексу COMSOL Multiphisics [3]. Геометрія розрахункової області та форми турбулізаторів
будувались за допомогою внутрішніх інструментів COMSOL
Multiphisics. COMSOL має змогу імпортувати геометричні
об’єкти з інших програмних продуктів, а саме з AutoCAD, але
в даному випадку достатньо вбудованих можливостей COMSOL. Всі
фізичні характеристики обирались із вбудованої в COMSOL
бібліотеки матеріалів. Розбивка розрахункової області на
скінчені елементи також виконувалась вбудованими засобами. Поверхня
турбулізатора
визначалась
параметричними
рівняннями 𝑥= 𝑠1 cos 𝑠2 , 𝑦= 𝑠1 sin 𝑠2, 𝑧= ℎ(
𝑠2
𝜋𝑘𝑣)
𝑛
,
(1)
𝑠1 ∈[−𝑟, 𝑟], 𝑠2 ∈[0, 𝜋𝑘𝑣], (1) де r - внутрішній радіус патрубка, h – висота патрубка,
kv – кількість витків стрічки, n – параметр, який визначає
щільність витків стрічки. де r - внутрішній радіус патрубка, h – висота патрубка,
kv – кількість витків стрічки, n – параметр, який визначає
щільність витків стрічки. Для n=1 будемо мати стрічку з рівномірним кроком закрутки,
інші значення n створюють змінний рівень щільності закрутки
по степеневому закону. Така параметризація дозволяє досить
гнучко змінювати геометрію стрічки для нових чисельних
експериментів. Проведено серію чисельних експериментів для різних
геометричних
параметрів
турбулізаторів
та
властивостей
газоповітряної суміші. Розглядались випадки граничних умов, This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). 288 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» (June 19-20, 2023). Prague, Czech Republic This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). ENERGETICS коли на границях патрубка задавався перепад тиску, а також
випадки, коли на вході в патрубок задавалась швидкість
газового потоку. На внутрішніх поверхнях патрубків та на
стрічках задавались умови прилипання. коли на границях патрубка задавався перепад тиску, а також
випадки, коли на вході в патрубок задавалась швидкість
газового потоку. На внутрішніх поверхнях патрубків та на
стрічках задавались умови прилипання. р
д
у
р
В
наведених
прикладах
розрахунків
для
порівняння
характеристик турбулізаторів з різною геометрією розглядались
циліндричні теплообмінники однакової висоти h=0.3 м та
однакових радіусів r=0.028м, перепад тиску на границях
патрубків теж був фіксований ∆𝑃= 5Па. Кількість витків стрічок
у всіх наведених прикладах теж однакова і дорівнює 5. На Рис
2
7 наведені деякі результати розрахунків В
наведених
прикладах
розрахунків
для
порівняння
характеристик турбулізаторів з різною геометрією розглядались
циліндричні теплообмінники однакової висоти h=0.3 м та
однакових радіусів r=0.028м, перепад тиску на границях
патрубків теж був фіксований ∆𝑃= 5Па. Кількість витків стрічок
у всіх наведених прикладах теж однакова і дорівнює 5. На Рис. 2 – 7 наведені деякі результати розрахунків. Рисунок 3
Ізобари в структурі потоку
повітряної суміші Рисунок 2
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з однією стрічкою
Рисунок 3
Ізобари в структурі потоку
повітряної суміші Рисунок 2
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з однією стрічкою Рисунок 3
Ізобари в структурі потоку
повітряної суміші Рисунок 3
Ізобари в структурі потоку
повітряної суміші Рисунок 2
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з однією стрічкою This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). 289 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» (June 19-20, 2023). Prague, Czech Republic (June 19-20, 2023). Prague, Czech Republic This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). ENERGETICS Турбулізатори зі скручених стрічок з постійним кроком
закрутки формують структуру потоку, де лінії току мають
гвинтоподібну форму адаптовану до геометрії турбулізатора
(Рис. 2-5). Як
показали
розрахунки,
аеродинамічні
характеристики пристроїв з подвійною і потрійною стрічкою
мало чим відрізняться, тому немає потреби ускладнювати
технологію виготовлення та використання багатострічкових
турбулізаторів. Рисунок 4
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з подвійною стрічкою
Рисунок 5
Розподіл швидкостей в
поперечних перерізах
теплообмінника з потрійною
стрічкою
Турбулізатори зі змінним кроком закрутки (Рис. 6)
дозволяють перерозподіляти теплове навантаження по довжині
теплообмінника, збільшуючи турбулізацію потоку за рахунок Рисунок 4
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з подвійною стрічкою Рисунок 5
Розподіл швидкостей в
поперечних перерізах
теплообмінника з потрійною
стрічкою Рисунок 4
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
з подвійною стрічкою Турбулізатори зі змінним кроком закрутки (Рис. 6)
дозволяють перерозподіляти теплове навантаження по довжині
теплообмінника, збільшуючи турбулізацію потоку за рахунок 290 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential» 291
This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). ENERGETICS Таблиця 1
Витратні характеристики турбулізаторів
Тип конструкції
турбулізатора
а
б
в
г
д
Витрати повітря
(м3/с)
0,0019
0,00127
0,0011
0,00872
0,00154 Таблиця 1 Проведення чисельних експериментів дозволяє дослідити
складну структуру та визначити витратні характеристики
газових потоків. Відомо, що використання турбулізаторів
підвищує
ефективність
теплообміу. З
іншого
боку,
турбулізатори суттєво збільшують аеродинамічний опір газовому
потоку. Оскільки в побутових системах опалення зазвичай
використовують теплообмінники з вільною конвекцією, при
проектуванні необхідно обирати такі геометричні параметри
турбулізаторів,
які
б
дозволяли
в
критичних
умовах
забезпечити
повну
евакуацію
продуктів
горіння. Для
остаточного висновку щодо обрання оптимальної геометрії
турбулізаторів
необхідно
вирішення
спряженої
задачі
тепломасообміну, що також можливо за допомогою програмного
комплексу COMSOL Multiphisics. Використання чисельного моделювання дозволяє на стадії
проектування прогнозувати поведінку теплообмінників в різних
фізичних умовах та для різних геометричних параметрів, що
надає можливість заощадити на проведенні коштовних натурних
експериментів. This work is distributed under the terms of the Creative
Commons Attribution-ShareAlike 4.0 International License
(https://creativecommons.org/licenses/by-sa/4.0/). ENERGETICS підвищення
щільності
закрутки
в
зонах
з
невеликими
температурними градієнтами і зменшуючи щільність закрутки в
зонах з великими температурними градієнтами. Як показали
розрахунки, в порівнянні з іншими конструкціями такий тип
турбулізатора має найбільший аеродинамічний опір Турбулізатори з різноспрямованою закруткою (Рис. 7) в
порівняні з попередніми більш інтенсивно перемішують газовий
потік, що має позитивний вплив на інтенсифікацію теплообміну. Технологія
виготовлення
таких
турбулізаторів
також
ускладнена. Рисунок 6
Розподіл швидкостей в поперечних
перерізах теплообмінника зі
стрічкою з нерівномірним кроком
закрутки
Рисунок 7
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
зі стрічкою з різноспрямованою
закруткою
В Таблиці 1 наведені витратні характеристики розглянутих
конструкцій. Рисунок 7
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
зі стрічкою з різноспрямованою
закруткою Рисунок 6
Розподіл швидкостей в поперечних
перерізах теплообмінника зі
стрічкою з нерівномірним кроком
закрутки Рисунок 7
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
зі стрічкою з різноспрямованою
закруткою
і Рисунок 6
Розподіл швидкостей в поперечних
перерізах теплообмінника зі
стрічкою з нерівномірним кроком
закрутки Рисунок 7
Лінії току та розподіл швидкостей в
поперечних перерізах теплообмінника
зі стрічкою з різноспрямованою
закруткою В Таблиці 1 наведені витратні характеристики розглянутих
конструкцій. В Таблиці 1 наведені витратні характеристики розглянутих
конструкцій. 291 ENERGETICS
Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic
No
159 Proceedings of the 4th International
Scientific and Practical Conference
«Concepts for the Development of
Society’s Scientific Potential»
(June 19-20, 2023). Prague, Czech Republic References: [1] Денисенко А.И., Пархоменко Л.А. 3D-моделирование закрученных потоков
в трубах с ленточными винтообразными вставками/ А.И Денисенко.,
Л.А. Пархоменко
//
TENDENZE
ATTUALI
DELLA
MODERNA
RICERCA
SCIENTIFICA: der Sammlung wissenschaftlicher Arbeiten «ΛΌГOΣ» zu den
Materialien
der
internationalen
wissenschaftlich-praktischen
Konferenz (B. 3), 5. Juni, 2020. Stuttgart, Deutschland: Europäische
Wissenschaftsplattform. – р.63-65. [2] Goodarzi, K., Goudarzi, S.Y., Zendehbudi G. (2015). Investigation of
the effect of using tube inserts for the intensification of heat
transfer. Thermal Engineering, 62(1), 68–75. [3] Математическое моделирование физико-химических процессов в среде
COMSOL Multiphysics 5.2 [Текст]: учебное пособие /Коваленко А.В.,
Узденова А.М., Уртенов М.X. и др. – С-Петербург. : Лань, Планета
музыки, 2017– 238 с. 292
|
https://openalex.org/W2613956224
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https://iris.uniroma1.it/bitstream/11573/961904/1/Casciaro_Promising_2017.pdf
|
English
| null |
Promising Approaches to Optimize the Biological Properties of the Antimicrobial Peptide Esculentin-1a(1–21)NH2: Amino Acids Substitution and Conjugation to Nanoparticles
|
Frontiers in chemistry
| 2,017
|
cc-by
| 6,280
|
Citation: Casciaro B, Cappiello F,
Cacciafesta M and Mangoni ML
(2017) Promising Approaches to
Optimize the Biological Properties of
the Antimicrobial Peptide
Esculentin-1a(1–21)NH2: Amino Acids
Substitution and Conjugation to
Nanoparticles. Front. Chem. 5:26. doi: 10.3389/fchem.2017.00026 Promising Approaches to Optimize
the Biological Properties of the
Antimicrobial Peptide
Esculentin-1a(1–21)NH2: Amino Acids
Substitution and Conjugation to
Nanoparticles Bruno Casciaro 1, Floriana Cappiello 1, Mauro Cacciafesta 2 and Maria Luisa Mangoni 1* 1 Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza
University of Rome, Rome, Italy, 2 Department of Cardiovascular, Respiratory, Nephrological, Anesthesiological and Geriatric
Sciences, Sapienza University of Rome, Rome, Italy Antimicrobial peptides (AMPs) represent an interesting class of molecules with expanding
biological properties which make them a viable alternative for the development of future
antibiotic drugs. However, for this purpose, some limitations must be overcome: (i) the
poor biostability due to enzymatic degradation; (ii) the cytotoxicity at concentrations
slightly higher than the therapeutic dosages; and (iii) the inefficient delivery to the target
site at effective concentrations. Recently, a derivative of the frog skin AMP esculentin-1a,
named esculentin-1a(1–21)NH2, [Esc(1–21): GIFSKLAGKKIKNLLISGLKG-NH2] has
been found to have a potent activity against the Gram-negative bacterium Pseudomonas
aeruginosa; a slightly weaker activity against Gram-positive bacteria and interesting
immunomodulatory properties. With the aim to optimize the antimicrobial features of
Esc(1–21) and to circumvent the limitations described above, two different approaches
were followed: (i) substitutions by non-coded amino acids, i.e., α-aminoisobutyric acid or
D-amino acids; and (ii) peptide conjugation to gold nanoparticles. In this mini-review, we
summarized the structural and functional properties of the resulting Esc(1–21)-derived
compounds. Overall, our data may assist researchers in the rational design and
optimization of AMPs for the development of future drugs to fight the worldwide problem
of antibiotic resistance. MINI REVIEW MINI REVIEW
published: 25 April 2017
doi: 10.3389/fchem.2017.00026 Edited by:
John D. Wade,
Florey Institute of Neuroscience and
Mental Health, Australia Reviewed by:
Predrag Cudic,
Florida Atlantic University, USA
Daniel Knappe,
Leipzig University, Germany *Correspondence:
Maria Luisa Mangoni
marialuisa.mangoni@uniroma1.it Specialty section:
This article was submitted to
Chemical Biology,
a section of the journal
Frontiers in Chemistry Received: 30 January 2017
Accepted: 05 April 2017
Published: 25 April 2017 Keywords:
antimicrobial
peptide,
frog-skin,
antibiotic-resistance,
D-amino
acids,
gold
nanoparticles,
Pseudomonas aeruginosa Esculentin-1a(1–21)NH2: Synthesis and
Characterization All members of the esculentin-1 family have a primary structure
composed of 46 amino acids and contain a C-terminal hepta-
membered ring stabilized by a disulfide bridge (Mangoni
et al., 2015). They adopt an amphipathic α-helix structure in
membrane mimicking environments and have a net charge of
+5 at neutral pH (Wang et al., 2016). AMPs belonging to the
esculentin-1 family were initially isolated and purified by reverse-
phase high performance liquid chromatography (RP-HPLC)
from the cutaneous secretions of Pelophylax lessonae/ridibundus
(previously classified as Rana esculenta) specimen (Simmaco
et al., 1993). They have a highly conserved C-terminal half and
differ by only one or two residues in the N-terminal region
(Simmaco et al., 1994). Interestingly, a fragment corresponding
to the 19–46 portion of esculentin-1 peptides was isolated from
one of the HPLC fractions but it was devoid of antimicrobial
activity, probably due to its low net positive charge (+1 vs. +5 of the full-length AMP, Simmaco et al., 1994). It was then
investigated whether the antimicrobial activity was retained
in the N-terminal half of the molecule. For this reason, a
peptide corresponding to the 1–18 fragment of esculentin-1b was
chemically synthesized and amidated at its C-terminus (Mangoni
et al., 2003). Note that the C-terminal amidation is a common
post-translational modification in linear AMPs from frog skin
(Nicolas and El Amri, 2009). This peptide, named Esc(1–18),
had a comparable antimicrobial activity to that of the full-length
parent esculentin-1, but a lower hemolytic capacity (Mangoni
et al., 2003). Structurally, Esc(1–18) was found to adopt an α-helix
structure in lipid vesicles mimicking the anionic character
of microbial membranes (Mangoni et al., 2003). It rapidly
killed bacteria (e.g., Escherichia coli) within 15–20 min with
concomitant leakage of cytosolic material, presumably due to the
formation of transient membrane-breakages (Marcellini et al.,
2009). Since the minimum length for a peptide in α-helix
conformation to span a phospholipid bilayer (∼30 Å thick) is
about 20 amino acids, a longer analog named esculentin-1a(1–
21)NH2, Esc(1–21), was further synthesized and characterized
for its biological properties. Esc(1–21) shares the first 20
residues with esculentin-1a (Figure 1) followed by an amidated ANTIMICROBIAL PEPTIDES: GENERAL FEATURES Peptide-membrane interaction is the most important step
controlling the selectivity of AMPs toward microbial membranes,
which are much richer in anionic phospholipids compared to
those of mammalian cells mainly made of electrically-neutral
(zwitterionic) lipids (Oren et al., 1999). However, peptide-
membrane interaction is dictated not only by the peptide’s
cationicity, but also by other physiochemical parameters of AMPs
encompassing their length, hydrophobicity, amphipathicity,
and helicity (Marín-Medina et al., 2016). Remarkably, unlike
conventional antibiotics, this non-specific mechanism of action
of AMPs very rarely induces resistance (Bechinger and Gorr,
2017) and makes them an interesting class of molecules for
the development of new antimicrobial compounds (Mazer-
Amirshahi et al., 2016). To date, thousands of AMPs have
been characterized from a variety of natural sources as well
as their synthetic derivatives (Liu et al., 2016). Noteworthy, an
increasing number of AMPs has already entered into advanced
stages of clinical trials for topical treatment of different types
of infections. Nevertheless, several limitations can hinder their
development as new therapeutics (da Cunha et al., 2017). Among
them: (i) the cytotoxicity at concentrations slightly higher than
antimicrobial dosing; (ii) the low peptide biostability due to
fast proteolytic degradation; and (iii) the inefficient delivery to
the target site at effective concentrations (Fjell et al., 2012). Nowadays, thanks to the progress in computational studies and
nanotechnologies, it is possible to circumvent these issues. In
this mini-review article, after a brief overview on amphibian
AMPs and the structural/functional relationships of the frog
skin-derived AMP esculentin-1a(1–21)NH2, Esc(1–21), we will
mainly focus on the principal approaches that have been used to
optimize the biological properties of Esc(1–21): (i) substitution
by non-coded amino acids and (ii) conjugation to inorganic
nanoparticles. ANTIMICROBIAL PEPTIDES: GENERAL FEATURES Gene-encoded antimicrobial peptides (AMPs) are evolutionally conserved molecules produced by
almost all living organisms (e.g., bacteria, fungi, higher eukaryotes including humans, Ageitos et al.,
2016). As part of key effectors of the innate immunity, they act as a sudden response against a
multitude of microorganisms before the adaptive immune system comes into action (Boman, 1995;
Hemshekhar et al., 2016). Despite their different length and secondary structure ranging from an April 2017 | Volume 5 | Article 26 Frontiers in Chemistry | www.frontiersin.org Amino Acids Substitution and Gold-Nanoparticles Casciaro et al. α-helix, a β-strand, a loop, or an extended conformation in
hydrophobic environments, most of them share an amphipathic
and cationic character at neutral pH (Powers and Hancock,
2003). These two properties are crucial factors, especially for
the mechanism of action of α-helical AMPs, which is generally
based on the perturbation of the target microbial membrane
(Bechinger and Gorr, 2017). More specifically, it consists
in an initial electrostatic interaction between the positively-
charged AMP and the negatively-charged components of the
microbial cell surface, such as lipoteichoic acids in Gram-positive
bacteria, or lipopolysaccharides (LPS) in Gram-negatives, to
finally reach the plasma-membrane. This is then destabilized by
pores formation/local cracks or disintegration in a detergent-
like manner, with consequent cell death (Hall and Aguilar,
2010). Peptide-membrane interaction is the most important step
controlling the selectivity of AMPs toward microbial membranes,
which are much richer in anionic phospholipids compared to
those of mammalian cells mainly made of electrically-neutral
(zwitterionic) lipids (Oren et al., 1999). However, peptide-
membrane interaction is dictated not only by the peptide’s
cationicity, but also by other physiochemical parameters of AMPs
encompassing their length, hydrophobicity, amphipathicity,
and helicity (Marín-Medina et al., 2016). Remarkably, unlike
conventional antibiotics, this non-specific mechanism of action
of AMPs very rarely induces resistance (Bechinger and Gorr,
2017) and makes them an interesting class of molecules for
the development of new antimicrobial compounds (Mazer-
Amirshahi et al., 2016). To date, thousands of AMPs have
been characterized from a variety of natural sources as well
as their synthetic derivatives (Liu et al., 2016). Noteworthy, an
increasing number of AMPs has already entered into advanced
stages of clinical trials for topical treatment of different types
of infections. Nevertheless, several limitations can hinder their
development as new therapeutics (da Cunha et al., 2017). ANTIMICROBIAL PEPTIDES: GENERAL FEATURES Among
them: (i) the cytotoxicity at concentrations slightly higher than
antimicrobial dosing; (ii) the low peptide biostability due to
fast proteolytic degradation; and (iii) the inefficient delivery to
the target site at effective concentrations (Fjell et al., 2012). Nowadays, thanks to the progress in computational studies and
nanotechnologies, it is possible to circumvent these issues. In
this mini-review article, after a brief overview on amphibian
AMPs and the structural/functional relationships of the frog
skin-derived AMP esculentin-1a(1–21)NH2, Esc(1–21), we will
mainly focus on the principal approaches that have been used to
optimize the biological properties of Esc(1–21): (i) substitution
by non-coded amino acids and (ii) conjugation to inorganic
nanoparticles. surface in a holocrine mechanism after stress or tissue injury
(König et al., 2015). It was first discovered that amphibian AMPs
do not only protect the host from invading microbial pathogens,
but also regulate the animal’s natural flora (Simmaco et al., 1998);
a trait which has then been confirmed also for human AMPs
(Mangoni et al., 2016). Over the years, since the discovery of
magainins from the skin of Xenopus laevis (Zasloff, 1987), an
increasing number of AMPs has been identified from different
Anuran species (Coccia et al., 2011; Conlon, 2011a). In particular,
from various Rana genera, a large number of AMPs has been
isolated and characterized. On the basis of their common
structural features, they have been classified into several families
encompassing brevinins-1, brevinins-2, nigrocins, temporins,
esculentins-1, and esculentins-2 (Conlon et al., 2004). α helix, a β strand, a loop, or an extended conformation in
hydrophobic environments, most of them share an amphipathic
and cationic character at neutral pH (Powers and Hancock,
2003). These two properties are crucial factors, especially for
the mechanism of action of α-helical AMPs, which is generally
based on the perturbation of the target microbial membrane
(Bechinger and Gorr, 2017). More specifically, it consists
in an initial electrostatic interaction between the positively-
charged AMP and the negatively-charged components of the
microbial cell surface, such as lipoteichoic acids in Gram-positive
bacteria, or lipopolysaccharides (LPS) in Gram-negatives, to
finally reach the plasma-membrane. This is then destabilized by
pores formation/local cracks or disintegration in a detergent-
like manner, with consequent cell death (Hall and Aguilar,
2010). Frontiers in Chemistry | www.frontiersin.org AMPHIBIAN SKIN ANTIMICROBIAL
PEPTIDES Among natural storehouses of AMPs, frog skin is one of the
richest (Conlon, 2011b). The expression of genes encoding for
these peptides in dermal serous glands is induced upon contact
with microorganisms (Mangoni et al., 2001); and the produced
AMPs are stored within granules that are released onto the skin Frontiers in Chemistry | www.frontiersin.org April 2017 | Volume 5 | Article 26 2 Casciaro et al. Amino Acids Substitution and Gold-Nanoparticles FIGURE 1 | Schematic representation of the amino acids substitutions used to design the Esc(1–21)-analogs and a representative image of the
peptide-conjugated AuNPs. FIGURE 1 | Schematic representation of the amino acids substitutions used to design the Esc(1–21)-analogs and a representative image of the
peptide-conjugated AuNPs. glycine (Islas-Rodrìguez et al., 2009). It differs from Esc(1–
18) for having (i) an Ile residue at position 11 instead of a
Leu and (ii) three additional C-terminal residues (Leu-Lys-Gly)
which confer it a higher net positive charge at neutral pH
(+6). This should strengthen the electrostatic interaction of
the peptide with the negatively-charged membrane of microbial
cells. Indeed, Esc(1–21) exhibited a higher antimicrobial potency
than Esc(1–18) (Mangoni et al., 2015), especially against Gram-
negative bacteria, e.g., the opportunistic pathogen Pseudomonas
aeruginosa (Gellatly and Hancock, 2013). Esc(1–21) displayed a
quick bactericidal activity within 15 min against both reference
and clinical isolates of P. aeruginosa with concentrations causing
99.9% killing between 0.5 and 1 µM in physiological solution
(Luca et al., 2013). Differently, a weaker activity was detected
against Gram-positive bacteria, as pointed out by the higher
values of minimum inhibitory concentration (MIC) compared to
those recorded toward Gram-negatives (Kolar et al., 2015). to increase the biostability of this peptide and to decrease its
cytotoxicity without compromising its antimicrobial efficacy:
modification of Esc(1–21) by non-coded amino acids i.e.,
α-aminoisobutyric acid (Aib) or
D-amino acids, and (ii)
its conjugation to gold nanoparticles (AuNPs). All these
modifications are represented in Figure 1. The Analog [Aib1,10,18]-Esc(1–21) Aib-rich peptides, such as peptaibiotics, Aib residues are located
either within the hydrophobic face or at its boundary with the
hydrophilic one (Toniolo et al., 1994; De Zotti et al., 2012b). Aib-rich peptides, such as peptaibiotics, Aib residues are located
either within the hydrophobic face or at its boundary with the
hydrophilic one (Toniolo et al., 1994; De Zotti et al., 2012b). replacement of two L-amino acids with the corresponding D-
enantiomers was carried out at position 14 and 17. Note that it
was improbable that the C-terminal tail Gly18-Gly21 of Esc(1–
21) folded in a stable helical conformation. y
p
The secondary structure of both Esc(1–21) and its [Aib1,10,18]-
Esc(1–21) was initially investigated by circular dichroism
(CD) (Biondi et al., 2016) in water and two different
membrane-mimicking environments e.g., sodium dodecyl sulfate
(SDS)
aqueous
solution
and
trifluoroethanol
(TFE). The
results confirmed that both peptides adopted an unordered
conformation in water and an α-helix structure in both SDS
and TFE. However, at increasing concentration of TFE (from
20 to 50%) the helical content in [Aib1,10,18]-Esc(1–21) sharply
increased with respect to the parent peptide. The helical and less
flexible structure of [Aib1,10,18]-Esc(1–21) compared to Esc(1–
21) was also confirmed by 2D-NMR analysis in TFE solution
(Biondi et al., 2016). The stability of both isomers was initially examined in the
presence of 10 and 30% fresh human serum after 24 h incubation
at 37◦C. The data revealed that in comparison with Esc(1–21)
<50% of the diastereomer was degraded (Di Grazia et al., 2015a). Besides, the presence of these two D-amino acids made the
peptide significantly more resistant to the proteolytic cleavage
caused by both human and bacterial elastases (Cappiello et al.,
2016). When the structure of the two peptides was analyzed by CD in
lysophosphatidylcholine (LPC), which simulates the zwitterionic
nature of mammalian cell membranes, a loss of α-helix structure
was clearly detected for Esc(1–21)-1c (Di Grazia et al., 2015a). In
contrast with data obtained for the Aib-analog, this diastereomer
was significantly less toxic than Esc(1–21) against mammalian
cells, either circulating cells (e.g., erythrocytes, macrophages) or
epithelial cells. More precisely, its LD50 was higher than 256 µM
in comparison with a LD50 ranging from 64 to 150 µM for the all-
L peptide toward macrophages and epithelial cells, respectively
(Di Grazia et al., 2015a; Cappiello et al., 2016). The Analog [Aib1,10,18]-Esc(1–21) Interestingly,
the introduction of these two residues in the D-configuration
also conferred the peptide: (i) a higher tendency than the all-L
counterpart to kill P. aeruginosa biofilms at concentrations lower
than 25 µM (despite the diastereomer had a slightly reduced
bactericidal activity against the free-living form of this pathogen);
and (ii) a higher “wound” healing activity in vitro (Di Grazia et al.,
2015a). Overall, the greater stability and content of α-helix in the
Aib-analog were found to influence the biological properties of
the peptide. More precisely, the Aib-analog gained an overall
higher activity against Gram-positive bacteria, especially those
belonging to Staphylococcus genus [MIC of 2–4 vs. 16–64 µM
of Esc(1–21)] without losing its efficacy against Gram-negative
bacteria and Candida species (Biondi et al., 2016). It is possible
that differences in the composition of the membrane or cell wall
among these microorganisms account for the different activity of
the two esc-peptides against them. However, a higher α-helicity in [Aib1,10,18]-Esc(1–21) resulted
in increased cytotoxicity against mammalian cell lines (e.g.,
alveolar epithelial cells and keratinocytes). The experimental
data showed that, at the antimicrobial concentrations, Esc(1–21)
and [Aib1,10,18]-Esc(1–21) were harmless to human cells, while
at higher concentrations the cytotoxic effect of the Aib-analog
became clearly evident in comparison with the parent Esc(1–
21) (Biondi et al., 2016). This is consistent with the notion that
both α-helix conformation and its stability are crucial parameters
for mammalian membrane perturbation and cell lysis, likely
assisting the peptide’s penetration into the hydrophobic core of
phospholipids bilayers (Shai and Oren, 1996). AuNPs@Esc(1–21) Amino acids replacement is not the only strategy to increase the
stability of a peptide to proteolytic degradation. Moreover, this
approach does not allow a peptide to overcome biological barriers
(e.g., mucus, skin layers) before reaching the site of infection at
high active concentrations (d’Angelo et al., 2015). A different
biochemical approach to also assist drug delivery at effective
concentrations is given by its conjugation to nanoparticles (NPs). This would enable not only to protect the drug from the external
environment but also to increase its local concentration. The Analog [Aib1,10,18]-Esc(1–21) The Analog [Aib1,10,18]-Esc(1–21)
The Aib residue is a non-natural amino acid mainly used to
increase the stability of α-helix conformation (Bellanda et al.,
2001). Due to their strong helicogenicity (De Zotti et al., 2012a),
when Aib residues are inserted into the primary structure of
peptides, they are expected to increase their helical content and
to protect them from proteolytic attack (Rink et al., 2010). The
usage of Aib residues is also expected to enlarge the spectrum
of activity of Esc(1–21). This is because a stabilized α-helix
structure is reported to be correlated to the AMPs’ activity
against Gram-positive bacteria (Giangaspero et al., 2001) toward
which Esc(1–21) is not particularly active. The Aib-analog was
synthesized by replacing three amino acids in positions 1, 10, and
18 with Aib residues (Figure 1). This replacement was rationally
designed on the basis of the following considerations: (i) an Aib
residue in position 1 should prevent enzymatic degradation by
aminopeptidases, while the protection of the C-terminus from
carboxypeptidases would not be necessary, due to the presence
of an amidated glycine in Esc(1–21) (Rink et al., 2010); (ii) Aib
residues in positions 10 and 18 should contribute to stabilize
the α-helix structure, due to their stronger α-helix-promoting
activity when placed internally to the primary structure of a
peptide; (iii) according to an ideal α-helix folding of Esc(1–21), it
was possible to identify an hydrophobic face and an hydrophilic
one (Biondi et al., 2016). It is known that in naturally-occurring Among other interesting biological features, Esc(1–21) was
found to have the ability (i) to hinder the secretion of the
pro-inflammatory cytokine TNF-α from P. aeruginosa LPS-
stimulated immune cells and (ii) to induce re-epithelialization
of a pseudo-“wound” area generated in a monolayer of
keratinocytes, the most abundant cells in epidermis (Haslam
et al., 2014), at a faster rate than the mammalian AMP LL-37 (Di
Grazia et al., 2015b). This is a relevant matter, which is not shown
by any traditional antibiotic. Note that the healing of an injured
infected tissue does not only require elimination of microbial
pathogens but also the recovery of the tissue integrity along with
its barrier function to prevent pathogens penetration. Nevertheless, Esc(1–21) is not free from the restrictions
mentioned above. In the following sections, we summarize
the outcome of two different rational approaches employed April 2017 | Volume 5 | Article 26 3 Amino Acids Substitution and Gold-Nanoparticles Casciaro et al. Frontiers in Chemistry | www.frontiersin.org FUNDING The work was supported by grants from Sapienza University
of Rome (Ricerca Università 2016). Part of the work was also
supported by FILAS Grant Prot. FILAS RU-2014-1020. CONCLUSIONS • Greater efficacy in promoting
migration of human lung
epithelial cells Antibiotic-resistant microbial infections cause thousands of
deaths per year worldwide and this necessitates the discovery
of new compounds to counter them. In this scenario, AMPs
represent promising anti-infective molecules with expanding
properties. However, their low biostability, cytotoxic effect
at concentrations higher than therapeutic dosages and the
difficulty in reaching target sites at active concentration, remain
disadvantages that must be overcome. In this mini-review, by
using Esc(1–21) as a reference, we have summarized how (i)
substitution of natural amino acids by non-coded residues as
well as (ii) peptide conjugation to AuNPs represent encouraging
methodologies to optimize the biological properties of an AMP. Each synthetized analog/compound showed its own peculiarities
according to its structural features (Table 1). Overall, the two
different approaches should serve as an example to assist and to
ameliorate the development of new peptide-based formulation
for an efficient treatment of different types of infectious diseases. AuNPs@Esc(1–21)
• Conjugation to
AuNPs via PEG linker
(∼16 peptide
molecules per
AuNP@PEG)
• Higher activity against both
planktonic and sessile forms
of P. aeruginosa
• Higher resistance to trypsin
degradation
• Invariant
membrane-
perturbing activity
• Negligible
cytotoxicity
on
human keratinocytes
• Similar ≪wound≫healing
effect
*with respect to Esc(1–21). • Higher resistance to trypsin
degradation • Invariant
membrane-
perturbing activity • Negligible
cytotoxicity
on
human keratinocytes • Similar ≪wound≫healing
effect *with respect to Esc(1–21). attached to the AuNPs via a gold-thiol bond (AuNPs@PEG),
while the carboxylic group was used for further derivatization
with the peptide via carbodiimide-mediated coupling (Casciaro
et al., 2017). The Analog Esc(1–21)-1c Compound
Structural
Properties*
Biological Features*
[Aib1,10,18]-
Esc(1–21)
• Higher α-helical
content in the
secondary structure
• Same activity against Gram-
negative bacteria and yeasts
• Higher activity against Gram-
positive bacteria
• Higher cytotoxicity against
mammalian cells
Esc(1–21)-1c
• Lower α-helical
content in the
secondary structure
• Higher
resistance
to
proteolytic degradation
• Slightly lower activity against
the
planktonic
form
of
P. aeruginosa
• Higher activity against the
sessile form of P. aeruginosa
• Lower
cytotoxicity
against
mammalian cells
• Greater efficacy in promoting
migration of human lung
epithelial cells
AuNPs@Esc(1–21)
• Conjugation to
AuNPs via PEG linker
(∼16 peptide
molecules per
AuNP@PEG)
• Higher activity against both
planktonic and sessile forms
of P. aeruginosa
• Higher resistance to trypsin
degradation
• Invariant
membrane-
perturbing activity
• Negligible
cytotoxicity
on
human keratinocytes
• Similar ≪wound≫healing
effect
*with respect to Esc(1–21). TABLE 1 | Structural properties and biological features of the designed
Esc(1–21)-derived compounds. disruption of the membrane and leakage of cytosolic material. Otherwise, our unconjugated bare-AuNPs did not show any anti-
pseudomonal activity and were not detected around bacterial
cells (Casciaro et al., 2017). This is in line with the findings that
non-functionalized AuNPs are harmless also to other bacterial
pathogens (Williams et al., 2006) and suggests that the cationic
AMP represents the driving force allowing AuNPs@Esc(1–21)
to reach the target site at high concentration. In addition,
AuNPs@Esc(1–21) were resistant to proteolytic degradation
preserving their antibacterial activity 2 h after treatment with
trypsin (Casciaro et al., 2017). Finally, AuNPs@Esc(1–21) were
harmless to keratinocytes and retained the peptide’s capability
to stimulate migration of keratinocytes in a pseudo-“wound”
healing assay. Altogether these findings make AuNPs@Esc(1–
21) an attractive nano-formulation for topical treatment of skin
infections (Casciaro et al., 2017). • Slightly lower activity against
the
planktonic
form
of
P. aeruginosa • Higher activity against the
sessile form of P. aeruginosa • Lower
cytotoxicity
against
mammalian cells The Analog Esc(1–21)-1c The Analog Esc(1 21) 1c
With the aim to reduce the cytotoxicity and to protect Esc(1–
21) from proteolytic degradation, another analog carrying two
D-amino acids was synthesized: Esc(1–21)-1c. It was obtained
by replacing two L-amino acids i.e., Leu14 and Ser17 with
the corresponding D-amino acid enantiomers (Figure 1). This
diastereomer was rationally designed on the basis of the following
considerations: (i) D-amino acids are known to be “α-helix
breakers” (Grieco et al., 2013) and a reduction in the α-helix
content of the peptide should reduce its propensity to perturb
mammalian membranes leading to cell death (Strahilevitz et al.,
1994); (ii) previous studies on the shorter analog Esc(1–18)
pointed out that in electrically-neutral lipid vesicles the peptide
adopted an α-helix conformation at its C-terminal half. With the
purpose to disrupt at least the first turn of the α-helix expected
to be present in the C-terminal half of Esc(1–21) in mammalian
cell membranes, analogously to what found for Esc(1–18), Among the various NPs produced in recent years, AuNPs have
attracted most attention due to their small size, high solubility,
stability, biocompatibility, and chemical inertness (Connor et al.,
2005). They can diffuse through all layers of human skin
(Williams et al., 2006) and because of their large surface area,
they can be functionalized with a high number of molecules
(Yih and Al-Fandi, 2006; Pietro et al., 2016; Soica et al., 2016). Nevertheless, only a limited number of studies has been reported
to date on the effects of conjugation of AMPs to AuNPs (Rai
et al., 2016). By using Esc(1–21) as a model peptide, it was
demonstrated for the first time how a chemical conjugation of an
AMP via polyethylene glycol (PEG) linker to AuNPs increases its
antimicrobial activity while retaining its mode of action without
becoming toxic to human keratinocytes. AuNPs were synthetized
by the citrate reduction of gold and stabilized with a bifunctional
PEG bearing a thiol and a carboxylic group. The PEG was April 2017 | Volume 5 | Article 26 4 Amino Acids Substitution and Gold-Nanoparticles Casciaro et al. TABLE 1 | Structural properties and biological features of the designed
Esc(1–21)-derived compounds. AUTHOR CONTRIBUTIONS Remarkably, the obtained AuNPs@Esc(1–21) resulted to be
more active than the free peptide against both planktonic
and sessile forms of P. aeruginosa. This was indicated by the
corresponding minimal concentrations causing 50% killing of
both bacterial phenotypes which were found to be ∼15-fold
lower than those of the free Esc(1–21). This is presumably
due to the higher concentration of peptide molecules at
the site of bacterium-NP contact, as visualized by electron
microscopy images which evidenced how these AuNPs@Esc(1–
21) form clusters at various points on the bacterial surface with BC wrote the review article; FC prepared and assembled the
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selective activity. Biochem. J. 341(Pt 3), 501–513. Gellatly, S. L., and Hancock, R. E. (2013). Pseudomonas aeruginosa: new
insights into pathogenesis and host defenses. Pathog. Dis. 67, 159–173. doi: 10.1111/2049-632X.12033 Giangaspero, A., Sandri, L., and Tossi, A. (2001). Amphipathic alpha helical
antimicrobial peptides. Eur. J. Biochem. 268, 5589–5600. doi: 10.1002/1097-
0282(2000)55:1<4::AID-BIP30>3.0.CO;2-M Pietro, P. D., Strano, G., Zuccarello, L., and Satriano, C. (2016). Gold and silver
nanoparticles for applications in theranostics. Curr. Top. Med. Chem. 16,
3069–3102. April 2017 | Volume 5 | Article 26 Frontiers in Chemistry | www.frontiersin.org 6 Amino Acids Substitution and Gold-Nanoparticles Casciaro et al. Powers,
J. P.,
and
Hancock,
R. E. (2003). The
relationship
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structure
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activity and assembly of dermaseptin-b and its precursor form in phospholipid
membranes. Biochemistry 33, 10951–10960. j
Rai, A., Pinto, S., Velho, T. R., Ferreira, A. F., Moita, C., Trivedi, U.,
et
al. (2016). One-step
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gold nanoparticles with antimicrobial efficacy in a systemic infection
model. Biomaterials
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D. S. (1994). Structure determination of racemic trichogin A IV using
centrosymmetric crystals. Nat. Struct. Biol. 1, 908–914. Wang, Y., Zhang, Y., Lee, W. H., and Yang, X. (2016). Novel peptides from skins of
amphibians showed broad-spectrum antimicrobial activities. Chem. Biol. Drug
Des. 87, 419–424. doi: 10.1111/cbdd.12672 Rink, R., Arkema-Meter, A., Baudoin, I., Post, E., Kuipers, A., Nelemans, S. A., et al. (2010). To protect peptide pharmaceuticals against peptidases. J. Pharmacol. Toxicol. Methods 61, 210–218. doi: 10.1016/j.vascn.2010. 02.010. Williams, D. N., Ehrman, S. H., and Pulliam Holoman, T. R. (2006). Evaluation of
the microbial growth response to inorganic nanoparticles. J. Nanobiotechnology
4:3. doi: 10.1186/1477-3155-4-3 Shai, Y., and Oren, Z. (1996). Diastereoisomers of cytolysins, a novel class of potent
antibacterial peptides. J. Biol. Chem. 271, 7305–7308. Yih, T. C., and Al-Fandi, M. (2006). Frontiers in Chemistry | www.frontiersin.org REFERENCES Engineered nanoparticles as precise drug
delivery systems. J. Cell. Biochem. 97, 1184–1190. doi: 10.1002/jcb.20796. Zasloff, M. (1987). Magainins, a class of antimicrobial peptides from Xenopus skin:
isolation, characterization of two active forms, and partial cDNA sequence of a
precursor. Proc. Natl. Acad. Sci. U.S.A. 84, 5449–5453. Simmaco, M., Mangoni, M. L., Boman, A., Barra, D., and Boman, H. G. (1998). Experimental infections of Rana esculenta with Aeromonas hydrophila: a
molecular mechanism for the control of the normal flora. Scand. J. Immunol. 48, 357–363. Simmaco, M., Mignogna, G., Barra, D., and Bossa, F. (1993). Novel antimicrobial
peptides from skin secretion of the European frog Rana esculenta. FEBS Lett. 324, 159–161. Conflict of Interest Statement: The authors declare that the research was
conducted in the absence of any commercial or financial relationships that could
be construed as a potential conflict of interest. Simmaco, M., Mignogna, G., Barra, D., and Bossa, F. (1994). Antimicrobial
peptides from skin secretions of Rana esculenta. Molecular cloning of cDNAs
encoding esculentin and brevinins and isolation of new active peptides. J. Biol. Chem. 269, 11956–11961. Copyright © 2017 Casciaro, Cappiello, Cacciafesta and Mangoni. This is an open-
access article distributed under the terms of the Creative Commons Attribution
License (CC BY). The use, distribution or reproduction in other forums is permitted,
provided the original author(s) or licensor are credited and that the original
publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these
terms. Copyright © 2017 Casciaro, Cappiello, Cacciafesta and Mangoni. This is an open-
access article distributed under the terms of the Creative Commons Attribution
License (CC BY). The use, distribution or reproduction in other forums is permitted,
provided the original author(s) or licensor are credited and that the original
publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these
terms. Soica, C., Coricovac, D., Dehelean, C., Pinzaru, I., Mioc, M., Danciu,
C., et al. (2016). Nanocarriers as tools in delivering active compounds
for immune system related pathologies. Recent Pat. Nanotechnol. 10,
128–145. April 2017 | Volume 5 | Article 26 Frontiers in Chemistry | www.frontiersin.org 7
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Dynamics control in four-wave mixing processes in optical fiber
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Dynamics control in four-wave mixing processes in optical fiber
Anastasiia Sheveleva1,*, Pierre Colman1, John M. Dudley2, Christophe Finot1
1Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, Dijon, France
2Université de Franche-Comté, Institut FEMTO-ST, CNRS UMR 6174, Besançon, France Anastasiia Sheveleva1,*, Pierre Colman1, John M. Dudley2, Christophe Finot1 Abstract. A nonlinear interaction of waves in a dispersive medium manifests itself in a four-wave mixing
process that can be described as an evolution of waves’ parameters on a phase plane in a form of closed orbits. Here we propose a method to control these trajectories and to switch from one state to another in an optimal
manner by implementing an abrupt change of the average power. The method is confirmed experimentally by
the reconstruction of a fundamental four-wave mixing dynamics in an idealized model using iterative
propagation in a short segment of fiber. 1.2 Experimental setup In order to remain in the framework of the ideal FWM
without any new cascaded spectral component, we
developed a devoted experimental setup presented in
Fig. 1 which relies on standard components of the
telecommunication industry [3]. We generate a comb at
40 GHz from a continuous wave (CW) laser modulated
by a phase modulator, which is then shaped in the
frequency domain to reach the desired ,. The signal is
amplified by an erbium-doped fiber amplifier (EDFA) to
reach P0 and then propagates in a single-mode fiber (2 =
-8 ps2 km-1 ; = 1.7 W-1 km-1). By using a limited length
of optical fiber (500 m), we avoid cascaded interactions
as well as spurious additional nonlinear effects. The level
of dissipation is negligeable. The output relative
amplitude is measured with an optical spectrum analyser
(OSA), and the phase is obtained from relative sinusoidal
beating of two filtered signals measured on a high-speed
sampling oscilloscope. After the output , are measured,
the input is updated, and the process is repeated * Corresponding author: anastasiia.sheveleva@u-bourgogne.fr , 06020 (2023)
EPJ Web of Conferences
EOSAM 2023
287 , 06020 (2023)
EPJ Web of Conferences
EOSAM 2023
287 https://doi.org/10.1051/epjconf/202328706020 1 Introduction (
)
(
)
2
2
3
2
1
cos
1
2
H
=
−
+ +
−
, (1)
and
H
H
=
= −
. (2) The nonlinear Schrodinger equation is a basis of nonlinear
fiber optics. In the focusing regime of propagation, the
four-wave mixing (FWM) process can explain a broad
range of observations such as modulation instability,
generation of ultrashort high-repetition pulse trains,
parametric amplification… In its simplest configuration,
FWM involves the interaction of three waves (a strong
continuous wave pump and two other components located
symmetrically on both sides of this pump) with exchange
of energy and phase variation. The dynamics of this
system is of recurrent nature and can be depicted as closed
orbits in reduced coordinates on a phase plane. The
trajectories follow unique paths depending on the initial
energy distribution and dephasing between the three
waves as well as the average power [1]. Hence, it is
impossible to link two states unless they belong to the
same orbit. Here we seek to remove this fundamental
limitation by introducing an approach based on an abrupt
change of the average power. If it is done at a relevant
point on the phase plane the switching allows an efficient
transition between the two desired states. Here the 2 = sign(2)(2πfm )2/(|2|/P0) is a nonlinear
mismatch parameter with P0 being the average power, 2
and - the second-order dispersion and the nonlinear
coefficient of a fiber, respectively. = z/(P0) is the
normalized distance. To characterize the dynamics, the evolution of and
can be put on a phase plane: ( cos , sin). There
exist two families of solutions following the recurrent
orbits, that are divided by a separatrix [1, 2]. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
(http ://creativecommons.org/licenses/by/4.0/).
s DP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0
nses/by/4.0/). References 1. S. Trillo and S. Wabnitz, Opt. Lett. 16, 986-988 (1991). 2. C. Naveau et al., Front. Phys. 9 :637812 (2021)
3. Sheveleva, U. Andral, B. Kibler, P. Colman, J.M. Dudley, C. Finot, Optica 9, 656-662 (2022)
4. A. Sheveleva, P. Colman, J. M. Dudley, and C. Finot,
Opt. Lett. 47, 6317-6320 (2022). 5. A. Bendahmane et al, Opt. Lett. 39, 4490-4493 (2014). 6. A. Gomel et al, Phys. Rev. Lett. 126, 174501 (2021). 7. Z. Deng, J. Zhang, D. Fan, and L. Zhang, New J. Phys. 24, 063018 (2022). 8. A. Sheveleva, P. Colman, J.M. Dudley, C. Finot, Opt. Comm. 129472 (2023). arXiv:2303.08469 1. S. Trillo and S. Wabnitz, Opt. Lett. 16, 986-988 (1991). 1. S. Trillo and S. Wabnitz, Opt. Lett. 16, 986-988 (1991). 3. Sheveleva, U. Andral, B. Kibler, P. Colman, J.M. Dudley, C. Finot, Optica 9, 656-662 (2022) 4. A. Sheveleva, P. Colman, J. M. Dudley, and C. Finot,
Opt. Lett. 47, 6317-6320 (2022). 5. A. Bendahmane et al, Opt. Lett. 39, 4490-4493 (2014). 6. A. Gomel et al, Phys. Rev. Lett. 126, 174501 (2021). 3.1 Principle Early experiments in fiber optics or hydrodynamics have
already explored the idea of an abrupt change of the
medium properties to freeze the longitudinal evolution of
a breathing wave [5,6]. Indeed, depending on the fiber
characteristics the orbits would have different shapes and
the normalized mismatch parameter in Eq. (1) will
change. Therefore, represents a key control parameter
[7] which change will enable a control of dynamics and
states transitions. In our approach, instead of varying the
fiber properties, we choose the average power as a the
degree of freedom and we do not restrict ourself to
targeting a stationary state. Fig. 2 Experimental trajectories that connect (a) IN = 0.90, IN
= and OUT = 0.90, OUT = 0, (b) IN = 0.90, IN = 0 and
OUT = 0.80, OUT = 0, by an abrupt power change. The colour
depicts value of input average power that is used for each part
of the trajectory. Conclusion We have conceptually and experimentally demonstrated
that an abrupt change of the average power allows tailored
manipulation of the ideal FWM dynamics and can help to
connect two states that are not part of the same orbit [8]. We have conceptually and experimentally demonstrated
that an abrupt change of the average power allows tailored
manipulation of the ideal FWM dynamics and can help to
connect two states that are not part of the same orbit [8]. This switching technique is robust to small deviations
from the ideal simulations. The results follow well the
numerical predictions, and the theoretical estimation of
the switching point is accurate. If there are no limitations in reachable values of ,
any two points on the phase plane can be connected by a
single abrupt change of this parameter. In practice,
however, experimental conditions limit the control: we
consider fixed fiber characteristics, and the input power is
restricted in order not to damage the equipment. In our
case, only values 2 [-2.51 : -0.95] can be reached. This switching technique is robust to small deviations
from the ideal simulations. The results follow well the
numerical predictions, and the theoretical estimation of
the switching point is accurate. To make a state transition, first, we select the input
IN, IN and the output OUT, OUT points we want to
connect. Then, using a Hamiltonian conservation, we find
all reachable states for both points within the given limits
of . Out of this range of reachable states we find an
optimum, i.e. an intersection point that allows to connect
input and output on the shortest propagation length. To
change the we adjust the input power accordingly in the
intersection point. 1.1 Theoretical background An ideal FWM assumes that nonlinear interaction occurs
solely between the pump 0 and the two spectral lines ±1
at ±m (with m = 2πfm being the modulation frequency). To describe the dynamics, one may use reduced
parameters: the relative spectral amplitude = |0|2/
|i|2 and the relative phase = -1 + 1 - 20 with i
being the phase of each spectral line. In this case the
evolution of spectral lines with propagation distance can
be described by the one-dimensional conservative
Hamiltonian [1]: , 06020 (2023)
EPJ Web of Conferences
EOSAM 2023
287 https://doi.org/10.1051/epjconf/202328706020 continuously, so that a complete trajectory can be
reconstructed. Note that an alternative design of this setup
has been developed to benefit to machine-learning
approaches [4]. the trajectory can cross the separatrix and switch to
another type of dynamics (panel (a)). The transition takes
11 km with a switching taking place after 6.5 km. It is also possible to control the orbits within the same
family of solutions (panel (b)). Here a trajectory starting
on the right side makes a transition to the inner orbit after
power increase by 1 dB. Fig. 1 Experimental setup. PC – polarization controller, Att. –
attenuator, OBPF – optical band pass filter, PD – photodiode,
RF amp. – radiofrequency amplifier. Fig. 2 Experimental trajectories that connect (a) IN = 0.90, IN
= and OUT = 0.90, OUT = 0, (b) IN = 0.90, IN = 0 and
OUT = 0.80, OUT = 0, by an abrupt power change. The colour
depicts value of input average power that is used for each part
of the trajectory. Fig. 1 Experimental setup. PC – polarization controller, Att. –
attenuator, OBPF – optical band pass filter, PD – photodiode,
RF amp. – radiofrequency amplifier. 8.
A. Sheveleva, P. Colman, J.M. Dudley, C. Finot, Opt.
Comm. 129472 (2023). arXiv:2303.08469 3.1 Experimental demonstration 7. Z. Deng, J. Zhang, D. Fan, and L. Zhang, New J. Phys. 24, 063018 (2022). Two examples of experimental demonstrations are
presented in Fig. 2 (solid lines ; dashed lines represent
ideal close orbits for the input and output powers). We
confirm that with a single change in the average power, 8. A. Sheveleva, P. Colman, J.M. Dudley, C. Finot, Opt. Comm. 129472 (2023). arXiv:2303.08469 2
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cc-by
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Novel Deep Learning Approaches for Mapping Variation of Ground Level from Spirit Level
Measurements Abstract: This study investigates the use of new machine learning techniques in mapping variation in
15
ground levels based on ordinary spirit levelling (SL) measurements. Convolution Neural Network (CNN),
16
Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), and bi-directional LSTM (BI-
17
LSTM) were developed and compared in the current study to estimate the leveling through SL
18
measurements. SL measurements of the Manzalla region, Egypt, were used in the current study. 3253
19
datasets of SL observation points, including 229 benchmarks of precise levelling (PL), were used to design
20
and verify the proposed model’s results. The results show the developed LSTM model outperforms CNN,
21
RNN, and BI-LSTM in modeling ground leveling in the training and testing stages. The root mean square
22
error and correlation determination of the LSTM model are 7.4 cm and 0.99, respectively, in the testing
23
stage. The accuracy of mapping ground levelling through the developed LSTM model is close to 99% in
24
terms of model error. 25 https://doi.org/10.5194/gmd-2023-62
Preprint. Discussion started: 12 April 2023
c⃝Author(s) 2023. CC BY 4.0 License. Novel Deep Learning Approaches for Mapping Variation of Ground Level from Spirit Level
1
Measurements
2
Fawzi Zarzoura 1, Mosbeh R. Kaloop1,2,3,4, Pijush Samui5, Jong Wan Hu2,3*, Md Shayan Sabri5, Tamer
3
ElGharbawi6
4
1Public Works Engineering Department, Mansoura University, Mansoura, Egypt
5
2Department of Civil and Environmental Engineering, Incheon National University, Incheon, Korea
6
3Incheon Disaster Prevention Research Center, Incheon National University, Incheon, Korea
7
4 DigInnoCent s.r.o., Liberec, Czech Republic
8
5Department of Civil Engineering, National Institute of Technology Patna, Patna, India
9
6Civil Engineering Department, Suez Canal University, Ismailia, Egypt
10
*Correspondence to: Jong Wan Hu (jongp24@inu.ac.kr)
11
(F.Zarzoura: fawzihamed@mans.edu.eg ; M.Kaloop:mosbeh@mans.edu.eg, P.Samui: pijush@nitp.ac.in ;
12
M.Sabri: mds.pg21.ce@nitp.ac.in; T.ElGharabawi: tgh@eng.suez.edu.eg)
13
14
Abstract: This study investigates the use of new machine learning techniques in mapping variation in
15
ground levels based on ordinary spirit levelling (SL) measurements. Convolution Neural Network (CNN),
16
Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), and bi-directional LSTM (BI-
17
LSTM) were developed and compared in the current study to estimate the leveling through SL
18
measurements. SL measurements of the Manzalla region, Egypt, were used in the current study. 3253
19
datasets of SL observation points, including 229 benchmarks of precise levelling (PL), were used to design
20
and verify the proposed model’s results. The results show the developed LSTM model outperforms CNN,
21
RNN, and BI-LSTM in modeling ground leveling in the training and testing stages. The root mean square
22
error and correlation determination of the LSTM model are 7.4 cm and 0.99, respectively, in the testing
23
stage. The accuracy of mapping ground levelling through the developed LSTM model is close to 99% in
24
terms of model error. 25 Novel Deep Learning Approaches for Mapping Variation of Ground Level from Spirit Level
1
Measurements
2
Fawzi Zarzoura 1, Mosbeh R. Kaloop1,2,3,4, Pijush Samui5, Jong Wan Hu2,3*, Md Shayan Sabri5, Tamer
3
ElGharbawi6
4
1Public Works Engineering Department, Mansoura University, Mansoura, Egypt
5
2Department of Civil and Environmental Engineering, Incheon National University, Incheon, Korea
6
3Incheon Disaster Prevention Research Center, Incheon National University, Incheon, Korea
7
4 DigInnoCent s.r.o., Liberec, Czech Republic
8
5Department of Civil Engineering, National Institute of Technology Patna, Patna, India
9
6Civil Engineering Department, Suez Canal University, Ismailia, Egypt
10
*Correspondence to: Jong Wan Hu (jongp24@inu.ac.kr)
11
(F.Zarzoura: fawzihamed@mans.edu.eg ; M.Kaloop:mosbeh@mans.edu.eg, P.Samui: pijush@nitp.ac.in ;
12
M.Sabri: mds.pg21.ce@nitp.ac.in; T.ElGharabawi: tgh@eng.suez.edu.eg)
13
14
Abstract: This study investigates the use of new machine learning techniques in mapping variation in
15
ground levels based on ordinary spirit levelling (SL) measurements. Convolution Neural Network (CNN),
16
Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), and bi-directional LSTM (BI-
17
LSTM) were developed and compared in the current study to estimate the leveling through SL
18
measurements. SL measurements of the Manzalla region, Egypt, were used in the current study. 3253
19
datasets of SL observation points, including 229 benchmarks of precise levelling (PL), were used to design
20
and verify the proposed model’s results. The results show the developed LSTM model outperforms CNN,
21
RNN, and BI-LSTM in modeling ground leveling in the training and testing stages. The root mean square
22
error and correlation determination of the LSTM model are 7.4 cm and 0.99, respectively, in the testing
23
stage. The accuracy of mapping ground levelling through the developed LSTM model is close to 99% in
24
terms of model error. 25 1. Introduction
27 54
However, due to the limitations of the data used in modeling the geoid, the use of deep learning in geoid
55
modeling is still limited. 56 Nowadays, Deep learning techniques, such as convolutional neural networks (CNN), recurrent neural
57
networks (RNN), long short-term memory (LSTM), have been used in modeling and classifying land
58
use/land cover (LULC) based on satellite images. Rußwurm and Korner (Rußwurm and Körner 2017) found
59
LSTM to be more efficient in LULC classification. Sun et al. (Sun et al. 2019) evaluated LSTM-RNN,
60
RCNN, and CNN in mapping and classification LULC; their results found the LSTM-RNN model can be
61
precisely used in LULC. Modeling of Land-use and land-cover change (LULCC) through machine learning
62
techniques was collected and discussed in Wang et al. (Wang et al. 2022); the review summarized that
63
machine and deep learning may be limited in “(i) describing occurrence, transition, and spatial patterns of
64
changes ; (ii) unavailability of training data for all the change drivers, particularly sequence data, and (iii)
65
lack of inclusion of local ecological, hydrological, and social-economic drivers when addressing the
66
spectral feature change”. Bi-directional long short-term memory (Bi-LSTM) was integrated with the
67
optimal guidance-whale optimization algorithm (OG-WOA) technique to classify and map the LULC
68
(Vinaykumar et al. 2023). The accuracy of Bi-LSTM was found to be better than that of CNN and RNN in
69
LULC classification. Furthermore, CNN, Deep Boltzmann Machines (DBM), Deep Belief Net (DBN), and
70
RNN are used to estimate and evaluate the geodetic velocity, and the results showed that the CNN was
71
better than other deep learning models (Sorkhabi et al. 2022). Other applications of soft computing
72
techniques in water leveling and wave height modeling can be found in (Kaloop et al. 2016, 2020a; Miky et
73
al. 2021; Sinha and Abernathey 2021; Minuzzi and Farina 2023). 74 Therefore, this study aims to use deep learning techniques, such as CNN, RNN, LSTM, and BI-LSTM, in
75
the elevation interpolation of grid points. With modeling the ground leveling, even in the relative
76
measurements, the time and cost of traditional leveling fieldworks should be decreased. To train the
77
proposed models, 3253 datasets leveling points of SL, including 229 benchmarks of precise levelling (PL),
78
were used. These measurements were collected from a project in the Manzalla region, Egypt. 1. Introduction
27 2021; Sinha and Abernathey 2021; Minuzzi and Farina 2023). 74
Therefore, this study aims to use deep learning techniques, such as CNN, RNN, LSTM, and BI-LSTM, in
75
the elevation interpolation of grid points. With modeling the ground leveling, even in the relative
76
measurements, the time and cost of traditional leveling fieldworks should be decreased. To train the
77
proposed models, 3253 datasets leveling points of SL, including 229 benchmarks of precise levelling (PL),
78
were used. These measurements were collected from a project in the Manzalla region, Egypt. The accuracy
79
of the proposed models was evaluated based on the collected datasets; this means the accuracy should be
80
changed based on the volume of data used and the topography of the study regions. However, the concept
81
of the proposed models can be used in a similar area. 82 found in (Kemboi 2016; LSC 2018). Machine learning was applied for modeling the geoid undulation
41
(Yιlmaz et al. 2006; Kaloop et al. 2020b; Tütüncü et al. 2021; Asenso-Gyambibi et al. 2022). However,
42
mapping variation in earth surface or surface elevation through SP is still limited based on our literature. 43
Latitude and longitude are commonly used in leveling modeling (Veronez et al. 2011; Erol and Erol 2013). 44
Erol and Erol (Erol and Erol 2013) applied multivariable polynomial regression equations (MPRE), artificial
45
neural networks (ANNs), adaptive network-based fuzzy inference system (ANFIS) and especially wavelet
46
neural networks (WNNs) to interpolate the geoid surface; ANFIS and WNN outperformed other models. 47
In addition, the ANN model was tested to estimate the geoid height in Brazil, and the results found it was
48
efficient compared to the Brazilian geoid model (MAPGEO2004) (Veronez et al. 2011). Kernel Ridge
49
Regression (KRR) was applied to estimate the Kuwait geoid model based on GPS/Levelling measurements,
50
with the results that its performance is better than that of least squares support vector regression (LSSVR),
51
gaussian process regression (GPR), and multivariate adaptive regression splines (MARS) in modeling the
52
geoid (Kaloop et al. 2019). More studies can be found in (Zhong 1997; Veronez et al. 2011; Rabah and
53
Kaloop 2013; Sorkhabi et al. 2015; Kaloop et al. 2018; Tütüncü et al. 2021) for modeling the geoid. 1. Introduction
27 Modeling the variation of the earth's surface is one of the essential requirements in engineering applications. 28
Traditional leveling methods are commonly used in small scale engineering projects; however, satellite
29
systems, e.g., satellite images and coordinate systems such as global positioning systems (GPS), are
30
commonly used in large-scale projects (Ahmed EL-Mowafy 2004; IHO 2011; CDT 2012; Shanker and
31
Acharya 2022). Ordinary spirit levelling (SP) is a lower-cost method compared to other surveying methods,
32
and it is almost always used to cover a wide area of construction projects. However, satellite systems and
33
precise leveling (PL) are almost as costly and used in special survey engineering networks (Karila et al. 34
2013; Kemboi 2016; Janos et al. 2022). In order to decrease the cost and time of survey engineering works,
35
this study aims to develop a soft computing technique that can be used to map variations of the earth's
36
surface through SP measurements in construction and infrastructure projects. 37 SP, or levelling, is a process to estimate the land elevation of a measured point based on the known elevation
38
of another point with a level instrument and an ordinary vertical staff. It is known as a relative measurement
39
of leveling with low accuracy. However, it is widely used in construction projects. The details of SP can be
40 1 https://doi.org/10.5194/gmd-2023-62
Preprint. Discussion started: 12 April 2023
c⃝Author(s) 2023. CC BY 4.0 License. https://doi.org/10.5194/gmd-2023-62
Preprint. Discussion started: 12 April 2023
c⃝Author(s) 2023. CC BY 4.0 License. found in (Kemboi 2016; LSC 2018). Machine learning was applied for modeling the geoid undulation
41
(Yιlmaz et al. 2006; Kaloop et al. 2020b; Tütüncü et al. 2021; Asenso-Gyambibi et al. 2022). However,
42
mapping variation in earth surface or surface elevation through SP is still limited based on our literature. 43
Latitude and longitude are commonly used in leveling modeling (Veronez et al. 2011; Erol and Erol 2013). 44
Erol and Erol (Erol and Erol 2013) applied multivariable polynomial regression equations (MPRE), artificial
45
neural networks (ANNs), adaptive network-based fuzzy inference system (ANFIS) and especially wavelet
46
neural networks (WNNs) to interpolate the geoid surface; ANFIS and WNN outperformed other models. 47
In addition, the ANN model was tested to estimate the geoid height in Brazil, and the results found it was
48
efficient compared to the Brazilian geoid model (MAPGEO2004) (Veronez et al. 2011). 1. Introduction
27 Kernel Ridge
49
Regression (KRR) was applied to estimate the Kuwait geoid model based on GPS/Levelling measurements,
50
with the results that its performance is better than that of least squares support vector regression (LSSVR),
51
gaussian process regression (GPR), and multivariate adaptive regression splines (MARS) in modeling the
52
geoid (Kaloop et al. 2019). More studies can be found in (Zhong 1997; Veronez et al. 2011; Rabah and
53
Kaloop 2013; Sorkhabi et al. 2015; Kaloop et al. 2018; Tütüncü et al. 2021) for modeling the geoid. 54
However, due to the limitations of the data used in modeling the geoid, the use of deep learning in geoid
55
modeling is still limited. 56
Nowadays, Deep learning techniques, such as convolutional neural networks (CNN), recurrent neural
57
networks (RNN), long short-term memory (LSTM), have been used in modeling and classifying land
58
use/land cover (LULC) based on satellite images. Rußwurm and Korner (Rußwurm and Körner 2017) found
59
LSTM to be more efficient in LULC classification. Sun et al. (Sun et al. 2019) evaluated LSTM-RNN,
60
RCNN, and CNN in mapping and classification LULC; their results found the LSTM-RNN model can be
61
precisely used in LULC. Modeling of Land-use and land-cover change (LULCC) through machine learning
62
techniques was collected and discussed in Wang et al. (Wang et al. 2022); the review summarized that
63
machine and deep learning may be limited in “(i) describing occurrence, transition, and spatial patterns of
64
changes ; (ii) unavailability of training data for all the change drivers, particularly sequence data, and (iii)
65
lack of inclusion of local ecological, hydrological, and social-economic drivers when addressing the
66
spectral feature change”. Bi-directional long short-term memory (Bi-LSTM) was integrated with the
67
optimal guidance-whale optimization algorithm (OG-WOA) technique to classify and map the LULC
68
(Vinaykumar et al. 2023). The accuracy of Bi-LSTM was found to be better than that of CNN and RNN in
69
LULC classification. Furthermore, CNN, Deep Boltzmann Machines (DBM), Deep Belief Net (DBN), and
70
RNN are used to estimate and evaluate the geodetic velocity, and the results showed that the CNN was
71
better than other deep learning models (Sorkhabi et al. 2022). Other applications of soft computing
72
techniques in water leveling and wave height modeling can be found in (Kaloop et al. 2016, 2020a; Miky et
73
al. 1. Introduction
27 The accuracy
79
of the proposed models was evaluated based on the collected datasets; this means the accuracy should be
80
changed based on the volume of data used and the topography of the study regions. However, the concept
81
of the proposed models can be used in a similar area. 82 83 2 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. 2. Methods
84
In this study, four input-output deep learning techniques, CNN, RNN, LSTM, and BI-LSTM, are applied
85
and compared to map the leveling based on Latitude and longitude measurements. The following is a theory
86
summary of the proposed models. 87
2.1. Convolution neural network (CNN)
88
CNN is one of the most essential deep learning methods, in which multiple layers are powerfully trained. 89
The convolutional layer is the center of the CNN and is the cause of its name. This layer receives and
90
processes data by performing a convolution function. The CNN is made up of multiple convolutional layers
91
that can be integrated or completely connected, as well as multilayer perceptron’s (Oh et al. 2019; Wang et
92
al. 2020; Zhang et al. 2022; Sorkhabi et al. 2022). This approach is very effective and one of the most
93
popular approaches in a variety of computer vision applications. The convolution layer, the pooling layer,
94
and the fully connected layer are the three major layers that make up a CNN network. 95
Different layers carry out different tasks (Jang et al. 2019). The architecture of 1D conventional Neural
96
Network (1D-CNN) for layer-by-layer leveling is shown in Figure 1.a. In general, there are two training
97
phases in each CNN: the feedforward phase and the backpropagation phase. The input signal is fed into the
98
network in the first stage, which consists of multiplying the input by the parameters of each neuron and
99
then performing convolution in each layer to produce the network output (Sorkhabi et al. 2022). In this
100
case, the network parameters are modified, or to put it another way, the network is trained, and the output
101
product is used to figure out how much network error there is. To do this, compute the error rate by
102
comparing the network output with an accurate response using an error function (loss function). 1. Introduction
27 Based on
103
the calculated error rate, the backpropagation process starts in the following step. The gradient of each
104
parameter is determined in this phase using the chain rule, and all parameters are changed based on their
105
impact on the error introduced into the network (Sorkhabi et al. 2022). Following the updating of the
106
parameters, the following feed-forward process starts. The network training comes to a conclusion after
107
repeating a significant number of these steps (Sorkhabi et al. 2022). In general, a convolutional neural
108
network is a hierarchical neural network that has a number of completely connected layers after the pooling
109
and convolutional layers. 110 Different layers carry out different tasks (Jang et al. 2019). The architecture of 1D conventional Neural
96
Network (1D-CNN) for layer-by-layer leveling is shown in Figure 1.a. In general, there are two training
97
phases in each CNN: the feedforward phase and the backpropagation phase. The input signal is fed into the
98
network in the first stage, which consists of multiplying the input by the parameters of each neuron and
99
then performing convolution in each layer to produce the network output (Sorkhabi et al. 2022). In this
100
case, the network parameters are modified, or to put it another way, the network is trained, and the output
101
product is used to figure out how much network error there is. To do this, compute the error rate by
102
comparing the network output with an accurate response using an error function (loss function). Based on
103
the calculated error rate, the backpropagation process starts in the following step. The gradient of each
104
parameter is determined in this phase using the chain rule, and all parameters are changed based on their
105
impact on the error introduced into the network (Sorkhabi et al. 2022). Following the updating of the
106
parameters, the following feed-forward process starts. The network training comes to a conclusion after
107
repeating a significant number of these steps (Sorkhabi et al. 2022). In general, a convolutional neural
108
network is a hierarchical neural network that has a number of completely connected layers after the pooling
109
and convolutional layers. 110 2.2. Recurrent neural networks (RNN) The convolutional model works with a fixed number of inputs and produces a fixed vector as an output
113
with a predefined number of steps. We can manipulate vector sequences at both the input and the output
114
thanks to return grids (Hang et al. 2019; Sorkhabi et al. 2022; Amalou et al. 2022). In the case of the RNN,
115
the link between the units forms a direct cycle. The inputs and outputs of a recursive neural network are
116
connected rather than independent, in contrast to conventional neural networks. Additionally, each layer of
117
the RNN uses the same standard settings. RNN design is shown in Figure 1.b. The backpropagation method
118
can be used to train the return network to mimic a conventional neural network (Hang et al. 2019). Here,
119
the flow step is only one factor that is considered in the computation of the gradient. The two-way neural
120
network takes into account both the expected future output and the prior output. Deep learning can be
121
achieved in two-way and direct RNN by adding numerous hidden levels. With a lot of learning data, these
122
deep networks have a greater learning capacity (Sorkhabi et al. 2022). 123 3 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. (a)
(b)
Figure 1. Diagram of Leveling estimation using (a) 1D convolution CNN and (b) Simple RNN (b)
D
l i
CNN
d (b) Si
l RNN Figure 1. Diagram of Leveling estimation using (a) 1D convolution CNN and (b) Simple RNN 2.3. Long short-term memory (LSTM) LSTM is a model or structure for sequential data created by (Hochreiter and Schmidhuber 1997) for the
126
advancement of RNN. It employs a unique combination of hidden units, elementwise products, and sums
127
between units to create gates that control "memory cells." These cells are intended to store information
128
without modification for extended periods of time (Apaydin et al. 2020). The most important feature of
129
LSTM is its capacity to learn long-term dependency, which RNNs cannot do. To anticipate the next step,
130
the weight values on the network must be updated, which necessitates the preservation of information from
131
the previous steps. RNN can only learn a finite number of short-term relationships and cannot learn long-
132
term series. 2.2. Recurrent neural networks (RNN) However, because LSTM has three gates—input, forget, and output—it can effectively learn
133
these long-term relationships. (Figure 2a). To show how much of the prior memory is remembered and how
134
much of it has been lost, the forget gate is embedded. The concealed state ℎ𝑡 for LSTM is calculated as
135
follows:
136 𝑖𝑡= 𝜎(𝑤𝑖𝑋𝑡+ 𝑢𝑖ℎ𝑡−1 + 𝑏𝑖) (1)
137
𝑓𝑡= 𝜎(𝑤𝑓𝑋𝑡+ 𝑢𝑓ℎ𝑡−1 + 𝑏𝑓) (2)
138
𝑂𝑡= 𝜎(𝑤𝑂𝑋𝑡+ 𝑢𝑂ℎ𝑡−1 + 𝑏𝑂) (3)
139
𝐶̃𝑡= 𝑡𝑎𝑛ℎ(𝑤𝐶𝑋𝑡+ 𝑢𝐶ℎ𝑡−1 + 𝑏𝐶) (4)
140
𝐶𝑡= 𝑓𝑡× 𝐶𝑡−1 + 𝑖𝑡× 𝐶̃𝑡 (5)
141
ℎ𝑡= tanh(𝐶𝑡) × 𝑂𝑡 (6)
142 Where, 𝑖𝑡, 𝑓𝑡, 𝑎𝑛𝑑𝑂𝑡 are the input, forget, and output gates at time t, respectively; 𝑤𝑖, 𝑤𝑓, 𝑤𝑂, 𝑎𝑛𝑑𝑤𝐶 are
143
weights that map the hidden layer input to the three gates of input, forget, and output while
144
𝑢𝑖, 𝑢𝑓, 𝑢𝑂, 𝑎𝑛𝑑𝑢𝐶 weights matrices map the hidden layer output to gates; 𝑏𝑖, 𝑏𝑓, 𝑏𝑂, 𝑎𝑛𝑑𝑏𝐶are vectors. 145
Additionally, 𝐶𝑡𝑎𝑛𝑑ℎ𝑡 represent the results of the cell and stratum, respectively (Apaydin et al. 2020). 146
147 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 Similarly, the optimal BI-LSTM network
172
consist of a two-input layer, one hidden BI-LSTM layer with 64 neurons, and one output layer. Notably,
173
the 'sigmoid' function was utilized in each hidden layer, while the Adam and mean squared errors were used
174
for model fitness and optimization, respectively, in both of the models. It is also noted that, different epoch
175
numbers of 100, 300, and 500 were tested in each run of the LSTM and BI-LSTM models, with the optimum
176
epoch found to be 500. 177
Table 1. Parametric configuration of the developed models
178
Model
Optimum model configuration
CNN
1D convolutional layer, flatten layer, dense layer, learning rate = 0.0001 batch size =
10, epoch = 500
RNN
20 hidden neurons in simple RNN layer, 8 hidden neurons in dense layer, input shape
= (2,1), learning rate = 0.0001, batch size = 16, epoch = 500
LSTM
100 hidden neurons, input shape = (2,1), learning rate = 0.01, batch size = 15, epoch =
500
BI-LSTM
64 hidden neurons, input shape = (2,1), learning rate = 0.01, batch size = 15, epoch =
500 repeatedly using inverted inputs [36]. Both the forward and backward layers outputs are calculated similarly
155
to the unidirectional LSTM. In the Bi-LSTM layer, Yt is computed from Equation (7):
156
𝑌= 𝜎(ℎ⃗ ℎ⃖⃗)
(7)
157 repeatedly using inverted inputs [36]. Both the forward and backward layers outputs are calculated similarly
155
to the unidirectional LSTM. In the Bi-LSTM layer, Yt is computed from Equation (7):
156
⃗
⃖⃗ repeatedly using inverted inputs [36]. Both the forward and backward layers outputs are calculated similarly
155
to the unidirectional LSTM. In the Bi-LSTM layer, Yt is computed from Equation (7):
156
𝑌𝑡= 𝜎(ℎ⃗ 𝑡, ℎ⃖⃗𝑡) (7)
157
where 𝜎 function is used to combine the two output sequences. 158
Figure 2. LSTM (a) and BI-LSTM (b) diagrams for levelling prediction (Apaydin et al. 2020)
159 (7) ( )
sequences. where 𝜎 function is used to combine the two output sequences. where 𝜎 function is used to combine the two output sequences. Figure 2. LSTM (a) and BI-LSTM (b) diagrams for levelling prediction (Apaydin et al. 2020) 2.5. Design models and evaluation
160 g
To design the proposed models, CNN, RNN, LSTM, and BI-LSTM, trial-and-error runs were performed. 161
Table 1 proposes the details of the model`s configuration. 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 In fact, the network is processed in two directions rather than just one: backward and forward, with two
149
distinct hidden levels. Bidirectional networks performed better than unidirectional networks in situations
150
like phonemic grouping, as shown by Graves and Schmidhuber (Graves and Schmidhuber 2005). Figure
151
2b shows the bidirectional network's layout. These networks have a structure with a forward and backward
152
LSTM layer based on this image. The forward layer output order, ℎ⃗ 𝑡, is computed repeatedly from time𝑡−
153
𝑛 to time𝑡−1 using positive order inputs, whereas the backward layer outcome order, ℎ⃖⃗𝑡, is computed
154 4 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. repeatedly using inverted inputs [36]. Both the forward and backward layers outputs are calculated similarly
155
to the unidirectional LSTM. In the Bi-LSTM layer, Yt is computed from Equation (7):
156
𝑌𝑡= 𝜎(ℎ⃗ 𝑡, ℎ⃖⃗𝑡) (7)
157
where 𝜎 function is used to combine the two output sequences. 158
Figure 2. LSTM (a) and BI-LSTM (b) diagrams for levelling prediction (Apaydin et al. 2020)
159
2.5. Design models and evaluation
160
To design the proposed models, CNN, RNN, LSTM, and BI-LSTM, trial-and-error runs were performed. 161
Table 1 proposes the details of the model`s configuration. The optimum CNN consists of two input layers,
162
one convolutional layer with 32 neurons followed by a flat layer, a dense layer with 64 neurons, and an
163
output layer. For the best model fit and optimization, mean square error and Adam were used. For a simple
164
RNN, the number of hidden neurons in the hidden layers was investigated in the range of 2 to 40 using trial
165
and error approach, the appropriate value of hidden neuron was determined to be 20 and 8 for the two
166
hidden layers, respectively. The optimum RNN model consists of two input layers, a simple RNN hidden
167
layer with 20 neurons followed by a dense layer with 8 neurons, and an output layer. In each hidden layer,
168
ReLU (rectified linear unit) was used as the activation function. In particular, "mean square error" and
169
"rmsprop" were utilized in the processes of model fitness and optimization, respectively. To achieve optimal
170
performance, LSTM neural networks are structured into the following layers: two input layers, one LSTM
171
hidden layers consisting of 50 neurons each, and an output layer. 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 The optimum CNN consists of two input layers,
162
one convolutional layer with 32 neurons followed by a flat layer, a dense layer with 64 neurons, and an
163
output layer. For the best model fit and optimization, mean square error and Adam were used. For a simple
164
RNN, the number of hidden neurons in the hidden layers was investigated in the range of 2 to 40 using trial
165
and error approach, the appropriate value of hidden neuron was determined to be 20 and 8 for the two
166
hidden layers, respectively. The optimum RNN model consists of two input layers, a simple RNN hidden
167
layer with 20 neurons followed by a dense layer with 8 neurons, and an output layer. In each hidden layer,
168
ReLU (rectified linear unit) was used as the activation function. In particular, "mean square error" and
169
"rmsprop" were utilized in the processes of model fitness and optimization, respectively. To achieve optimal
170
performance, LSTM neural networks are structured into the following layers: two input layers, one LSTM
171
hidden layers consisting of 50 neurons each, and an output layer. Similarly, the optimal BI-LSTM network
172
consist of a two-input layer, one hidden BI-LSTM layer with 64 neurons, and one output layer. Notably,
173
the 'sigmoid' function was utilized in each hidden layer, while the Adam and mean squared errors were used
174
for model fitness and optimization, respectively, in both of the models. It is also noted that, different epoch
175
numbers of 100, 300, and 500 were tested in each run of the LSTM and BI-LSTM models, with the optimum
176
epoch found to be 500. 177 Table 1. Parametric configuration of the developed models
178
Model
Optimum model configuration
CNN
1D convolutional layer, flatten layer, dense layer, learning rate = 0.0001 batch size =
10, epoch = 500
RNN
20 hidden neurons in simple RNN layer, 8 hidden neurons in dense layer, input shape
= (2,1), learning rate = 0.0001, batch size = 16, epoch = 500
LSTM
100 hidden neurons, input shape = (2,1), learning rate = 0.01, batch size = 15, epoch =
500
BI-LSTM
64 hidden neurons, input shape = (2,1), learning rate = 0.01, batch size = 15, epoch =
500 5 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 179
To assess the accuracy of the proposed models, different statistical indices were used. The accuracy of the
180
proposed models in term of the correlation between measured and estimated values was evaluated using
181
the coefficient of determination (R2), where 1 is the best, and Nash-Sutcliffe efficiency (NAF), where 100
182
is the best. In addition, the model errors were evaluated using root mean square error (RMSE); where 0 is
183
the best, mean absolute error (MAE), where 0 is the best, and mean bias error (MBE), where 0 is the best. 184
Furthermore, percentage error (PE) is applied to measure the accuracy of the proposed models in error
185
terms, 0 is the best, and the overall performance of models is tested using the performance index (PI), where
186
2 is the best. These indices are presented as follows:
187 𝑅2 =
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
−∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
(8)
188
𝑉𝐴𝐹= 100 × (1 −
𝑣𝑎𝑟(𝑍𝑖−𝑍𝑝𝑖)
𝑣𝑎𝑟(𝑍𝑖)
) (9)
189
𝑅𝑀𝑆𝐸= √∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
𝑁
(10)
190
𝑀𝐴𝐸=
∑
|(𝑍𝑖−𝑍𝑝𝑖)|
𝑁
𝑖=1
𝑁
(11)
191
𝑀𝐵𝐸=
1
𝑁∑
(𝑍𝑖−𝑍𝑝𝑖)
𝑁
𝑖=1
(12)
192
𝑃𝐼= 𝑎𝑑𝑗. 𝑅2 + (0.01 × 𝑉𝐴𝐹) −𝑅𝑀𝑆𝐸 (13)
193
𝑃𝐸= 100 ×
𝑅𝑀𝑆𝐸
𝑍𝑚𝑎𝑥−𝑍𝑚𝑖𝑛 (14)
194 𝑅2 =
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
−∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
(8)
188
𝑉𝐴𝐹= 100 × (1 −
𝑣𝑎𝑟(𝑍𝑖−𝑍𝑝𝑖)
𝑣𝑎𝑟(𝑍𝑖)
) (9)
189
𝑅𝑀𝑆𝐸= √∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
𝑁
(10)
190
𝑀𝐴𝐸=
∑
|(𝑍𝑖−𝑍𝑝𝑖)|
𝑁
𝑖=1
𝑁
(11)
191
𝑀𝐵𝐸=
1
𝑁∑
(𝑍𝑖−𝑍𝑝𝑖)
𝑁
𝑖=1
(12)
192
𝑃𝐼= 𝑎𝑑𝑗. 𝑅2 + (0.01 × 𝑉𝐴𝐹) −𝑅𝑀𝑆𝐸 (13)
193
𝑃𝐸= 100 ×
𝑅𝑀𝑆𝐸
𝑍𝑚𝑎𝑥−𝑍𝑚𝑖𝑛 (14)
194 𝑅2 =
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
−∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
∑
(𝑍𝑖−𝑍𝑚𝑒𝑎𝑛)2
𝑁
𝑖=1
(8)
188
𝑉𝐴𝐹= 100 × (1 −
𝑣𝑎𝑟(𝑍𝑖−𝑍𝑝𝑖)
𝑣𝑎𝑟(𝑍𝑖)
) (9)
189
𝑅𝑀𝑆𝐸= √∑
(𝑍𝑖−𝑍𝑝𝑖)2
𝑁
𝑖=1
𝑁
(10)
190
𝑀𝐴𝐸=
∑
|(𝑍𝑖−𝑍𝑝𝑖)|
𝑁
𝑖=1
𝑁
(11)
191
𝑀𝐵𝐸=
1
𝑁∑
(𝑍𝑖−𝑍𝑝𝑖)
𝑁
𝑖=1
(12)
192
𝑃𝐼= 𝑎𝑑𝑗. 𝑅2 + (0.01 × 𝑉𝐴𝐹) −𝑅𝑀𝑆𝐸 (13)
193
𝑃𝐸= 100 ×
𝑅𝑀𝑆𝐸
𝑍𝑚𝑎𝑥−𝑍𝑚𝑖𝑛 (14)
194 = 𝑎𝑑𝑗. 𝑅2 + (0.01 × 𝑉𝐴𝐹) −𝑅𝑀𝑆𝐸 (13)
= 100 ×
𝑅𝑀𝑆𝐸
𝑍𝑚𝑎𝑥−𝑍𝑚𝑖𝑛 (14) (14) Where, 𝑍𝑖𝑎𝑛𝑑𝑍𝑝𝑖 represent the measured and predicted levelling, 𝑧𝑚𝑒𝑎𝑛, 𝑧𝑚𝑎𝑥, 𝑎𝑛𝑑𝑧𝑚𝑖𝑛 are the average,
195
maximum and minimum, respectively, of measured values, 𝑎𝑑𝑗. 𝑅2 is the adjustment R2, and N is the
196
number of the data sample. 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 All the
219
benchmarks that presented a standard deviation of more than 1 cm were removed from the network, leaving
220
229 benchmarks used in the ground level observations. 221
After estimating the corrected reduced levels of the selected benchmarks, they were used as a reference for
222 Figure 3. Data processing and modeling flowchart Figure 3. Data processing and modeling flowchart 2.4. Bi-directional long short-term memory (Bi-LSTM)
148 197 Where, 𝑍𝑖𝑎𝑛𝑑𝑍𝑝𝑖 represent the measured and predicted levelling, 𝑧𝑚𝑒𝑎𝑛, 𝑧𝑚𝑎𝑥, 𝑎𝑛𝑑𝑧𝑚𝑖𝑛 are the average,
195
maximum and minimum, respectively, of measured values, 𝑎𝑑𝑗. 𝑅2 is the adjustment R2, and N is the
196
number of the data sample. 197 Figure 3 proposes the data processing and mapping in three stages. Data collection, adjustment, and
198
improvement are implemented in the first stage using the least squares method and PL benchmarks. E and
199
N are collected using GPS observation networks. Z was calculated at observed points using SL equipment. 200
The data were divided into training and testing stages. The training datasets were used to design the
201
proposed models in the second stage. In the last stage, training and testing datasets were used to assess the
202
performance of the proposed models. In addition, the whole datasets were used to validate the best-fit
203
model. Also, grids of 500 m were generated to map the ground level of the study area. 204
205 6 6 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. Figure 3. Data processing and modeling flowchart
206
3. Data collection
207
The ground level observations were collected in 2019 for a national Egyptian project that aims at the full
208
rehabilitation of the sanitary networks of the Egyptian small cities. The Sokkia B40 automatic level device
209
was utilized to measure elevations, and the benchmarks were connected by paths to form a closed network. 210
The corrections for the measurements were estimated using the Least Squares method. The observations
211
were carried out by a professional team of surveyors under the management of a consulting engineering
212
team. Figure 4 shows the study area, Manzalla region, and distribution of levelling points. The project
213
started by fixing more than 250 benchmarks covering the whole study region. Then these benchmarks were
214
connected using a full, precise leveling network, which was observed with great care by professional
215
surveyors and calibrated spirit level instruments. The network leveling observations were analyzed, filtered,
216
and corrected using the main principles of random error theory and rejection of outlier observations. Then,
217
the precise leveling network was corrected using the least squares method, which presented an estimated
218
standard deviation of nearly 6 millimeters for the estimated observations of the benchmarks. 3. Data collection The ground level observations were collected in 2019 for a national Egyptian project that aims at the full
208
rehabilitation of the sanitary networks of the Egyptian small cities. The Sokkia B40 automatic level device
209
was utilized to measure elevations, and the benchmarks were connected by paths to form a closed network. 210
The corrections for the measurements were estimated using the Least Squares method. The observations
211
were carried out by a professional team of surveyors under the management of a consulting engineering
212
team. Figure 4 shows the study area, Manzalla region, and distribution of levelling points. The project
213
started by fixing more than 250 benchmarks covering the whole study region. Then these benchmarks were
214
connected using a full, precise leveling network, which was observed with great care by professional
215
surveyors and calibrated spirit level instruments. The network leveling observations were analyzed, filtered,
216
and corrected using the main principles of random error theory and rejection of outlier observations. Then,
217
the precise leveling network was corrected using the least squares method, which presented an estimated
218
standard deviation of nearly 6 millimeters for the estimated observations of the benchmarks. All the
219
benchmarks that presented a standard deviation of more than 1 cm were removed from the network, leaving
220
229 benchmarks used in the ground level observations. 221
After estimating the corrected reduced levels of the selected benchmarks, they were used as a reference for
222
ground leveling observations which were conducted along the longitudinal center of every street in the
223 After estimating the corrected reduced levels of the selected benchmarks, they were used as a reference for
222
ground leveling observations, which were conducted along the longitudinal center of every street in the
223
study region with spacing ranging between 10 and 20 meters. The ground level observations were collected,
224
analyzed, and filtered to remove any blunder observations. 225 7 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. https://doi.org/10.5194/gmd-2023-62
Preprint. Discussion started: 12 April 2023
c⃝Author(s) 2023. CC BY 4.0 License. Figure 4. Study area and levelling points (a) study location, (b) leveling points and routes (Images
resources from Esri) Figure 4. Study area and levelling points (a) study location, (b) leveling points and routes (Images
resources from Esri)
6 226
Figure 5 and Table 1 present the data collection evaluation. 3. Data collection histogram of trend data used, and the normal
227
distribution of data used. The mean (M), maximum (MX), minimum (MN), standard deviation (STDEV),
228
and correlation (Corr) between input variables (E and N) and output variables (Z) are presented in Table 1. 229
The data distribution is shown to be non- normal. Negative and positive correlations between E and N and
230
Z, respectively, are observed. The statistical evaluation and data distribution show there is a nonlinear
231
correlation between Z and E,N. This indicates that a non-linear relationship between the input and output
232 8 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. variables can be detected, which is advantageous for using deep learning approaches in modeling the ground
233
levels. 234
235
Figure 5. Histogram and normal distribution of data used
Table 1. Statistical evaluation of measured datasets
236
Variables
E
N
Z
M
399952.067
3447484.489
2.023
MX
403979.133
3451633.725
6.640
MN
393723.542
3444154.308
-2.939
STDEV
3089.666
1558.468
0.876
Corr
-0.394
0.218
1.000
237
4. Results and Discussion
238
Figure 6 and Table 2 present the performance evaluations of the proposed models. The rank of the proposed
239
models is presented in Table 2. A high score value indicates the best performance. In the training stage,
240
LSTM outperformed other deep learning techniques. The correlation between measured and predicted
241
levels for LSTM is shown to be high, R2 and VAF are 0.99 and 99%, respectively. The estimation error of
242
the LSTM model is shown to be low: RMSE = 8.0 cm, MAE = 7.2 cm, and MBE = -2 cm. The overall
243
performance of LSTM is the best compared to other models PI = 1.9, and the percentage of the model error
244
is 0.84%. The rank of LSTM is 26, followed by BI-LSTM, rank = 22. The model followed in modeling the
245
leveling is BI-LSMT with PI=1.67 and PE = 2.18%; while the worst model is shown to be the CNN model. 246
From Figure 6, it can be seen that the scatter plot of LSTM is very close to the best fitting line (dashed line),
247
while the variation around the best fitting line is high for CNN and RNN. 248
As a result, in the testing stage, the LSTM model outperformed other models in all statistical indices. 3. Data collection The
249
rank evaluation of the proposed models showed that LSTM has a high rank compared to other models. 250
CNN was shown to be better than RNN at this stage. BI-LSTM still followed LSTM in the testing stage to
251
model the ground levels. From Figure 6, it can be seen that the scatter plot of LSTM is very close to the
252
best fitting line, while the variation around the best fitting line is high for CNN and RNN. The performance
253
of BI-LSTM is shown to be acceptable in the testing stage, rank = 21; however, LSTM performance
254
achieved a high rank (28) in estimating ground levels. 255 variables can be detected, which is advantageous for using deep learning approaches in modeling the ground
233
levels. 234
235 Figure 5. Histogram and normal distribution of data used
Table 1. Statistical evaluation of measured datasets
236
Variables
E
N
Z
M
399952.067
3447484.489
2.023
MX
403979.133
3451633.725
6.640
MN
393723.542
3444154.308
-2.939
STDEV
3089.666
1558.468
0.876
Corr
-0.394
0.218
1.000
237 Figure 5. Histogram and normal distribution of data used 9 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. Figure 6. Training and testing scatter plot of predicted and measured leveling 10
Figure 6. Training and testing scatter plot of predicted and measured leveling
Table 2. Models’ performance assessments in the training and testing stages
256
Training
R2
VAF
PI
RMSE
MAE
MBE
PE
Total score
CNN
Value
0.614
60.807
0.840
0.382
0.426
-0.189
3.986
7
Ranke
1
1
1
1
1
1
1
RNN
Value
0.890
89.003
1.510
0.270
0.239
-0.015
2.819
15
Ranke
2
2
2
2
2
3
2
LSTM
Value
0.991
99.145
1.903
0.080
0.072
-0.020
0.839
26
Ranke
4
4
4
4
4
2
4
BI-LSTM
Value
0.940
93.961
1.670
0.209
0.126
-0.001
2.180
22
Ranke
3
3
3
3
3
4
3
Testing
CNN
Value
0.645
63.232
0.905
0.372
0.429
-0.186
4.685
13
Ranke
2
2
2
2
2
1
2
RNN
Value
0.516
48.580
0.439
0.562
0.557
0.053
7.082
8
Ranke
1
1
1
1
1
2
1
LSTM
Value
0.993
99.326
1.912
0.074
0.062
-0.012
0.936
28
Ranke
4
4
4
4
4
4
4
BI-LSTM
Value
0.978
97.840
1.825
0.132
0.100
-0.014
1.663
21
Ranke
3
3
3
3
3
3
3 Figure 6. 3. Data collection Training and testing scatter plot of predicted and measured leveling
Table 2. Models’ performance assessments in the training and testing stages Figure 6. Training and testing scatter plot of predicted and measured leveling
Table 2. Models’ performance assessments in the training and testing stages Figure 6. Training and testing scatter plot of predicted and measured leveling 10 10 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. 257
In addition, the performances, of LSTM and BI-LSTM models in modeling ground variation levels are
258
presented in Figure 7 in the testing phase. From the figure, it can be seen that the variation of errors for both
259
models are small. The error ranges of LSTM and BI-LSTM are (-0.13 to 0.07) and (-1.09 to 0.26) m,
260
respectively. Thus, both models can be used to estimate levelling. 261
Figure 7. Modeling performance of LSTM and BI-LSTM models in the testing stage In addition, the performances, of LSTM and BI-LSTM models in modeling ground variation levels are
258
presented in Figure 7 in the testing phase. From the figure, it can be seen that the variation of errors for both
259
models are small. The error ranges of LSTM and BI-LSTM are (-0.13 to 0.07) and (-1.09 to 0.26) m,
260
respectively. Thus, both models can be used to estimate levelling. 261 respectively. Thus, both models can be used to estimate levelling. 261
Figure 7. Modeling performance of LSTM and BI-LSTM models in the testing stage
262
For more investigation, a visualization plot is used to assess the performance of the proposed models. The
263
Taylor diagram (Figure 8.a) and boxplot (Figure 8.b) are presented to evaluate overall performance and
264
model errors, respectively. Taylor's diagram is a two-dimensional diagram that provides a comparative
265
review of models in terms of R-value, root mean square deviation (RMSD), and ratio of standard deviation
266
between measured and predicted values. The best model is the one closest to the reference point. The details
267
of the Taylor diagram can be found in (Taylor 2005). Here, test datasets are used to assess the proposed
268
models based on untuned datasets of models. Taylor's diagram shows the overall performance of LSTM in
269
modeling ground level is better than that of BI-LSTM, CNN, and RNN, respectively. 3. Data collection The accuracy of BI-
270
LSTM is close to that of LSTM, and it can be used for ground level estimation. However, boxplots show
271
there are outliers that can be observed with BI-LSTM. In addition, the model error range of LSTM is very
272 Figure 7. Modeling performance of LSTM and BI-LSTM models in the testing stage 262
For more investigation, a visualization plot is used to assess the performance of the proposed models. The
263
Taylor diagram (Figure 8.a) and boxplot (Figure 8.b) are presented to evaluate overall performance and
264
model errors, respectively. Taylor's diagram is a two-dimensional diagram that provides a comparative
265
review of models in terms of R-value, root mean square deviation (RMSD), and ratio of standard deviation
266
between measured and predicted values. The best model is the one closest to the reference point. The details
267
of the Taylor diagram can be found in (Taylor 2005). Here, test datasets are used to assess the proposed
268
models based on untuned datasets of models. Taylor's diagram shows the overall performance of LSTM in
269
modeling ground level is better than that of BI-LSTM, CNN, and RNN, respectively. The accuracy of BI-
270
LSTM is close to that of LSTM, and it can be used for ground level estimation. However, boxplots show
271
there are outliers that can be observed with BI-LSTM. In addition, the model error range of LSTM is very
272 11 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. small, and the interquartile range of LSTM is very small compared to other models. Although the CNN
273
model outperforms the RNN model in terms of overall performance, it has a high number of outliers. 274
Boxplot obviously shows the LSTM model can be accurately used in ground level estimation. 275 small, and the interquartile range of LSTM is very small compared to other models. Although the CNN
273
model outperforms the RNN model in terms of overall performance, it has a high number of outliers. 274
Boxplot obviously shows the LSTM model can be accurately used in ground level estimation. 275 76
(a)
(b)
Figure 8. Visualization analysis of the proposed models (a) Taylor diagram (b) boxplot
77
Figure 9 shows the map estimation of the study area for ground levels and the error of the estimation levels. 3. Data collection 78
The error is the difference between levels of mapping and measurements. From the map, it can be seen that
79
the ground level is smooth and slopes from 0 to 6 m in one direction. From the measured errors, it can be
80
seen that the absolute mean error of the estimated ground levels is 0.187 cm, and the standard deviation of
81
error is 0.666 m. The error distribution is roughly normal, and the majority of the confidence in the model
82
error falls within the 95% confidence interval. This indicates that the estimated levels are acceptable, and
83
that LSTM can be accurately applied to estimate the ground level of the study area. These results reveal the
84 (a) (a) (b)
Fi
8 Vi
li
ti
l
i
f th
d
d l ( ) T
l
di
(b) b
l t (b) Figure 8. Visualization analysis of the proposed models (a) Taylor diagram (b) boxplot gure 9 shows the map estimation of the study area for ground levels and the error of the estimation levels. Figure 9 shows the map estimation of the study area for ground levels and the error of the estimation levels. 278
The error is the difference between levels of mapping and measurements. From the map, it can be seen that
279
the ground level is smooth and slopes from 0 to 6 m in one direction. From the measured errors, it can be
280
seen that the absolute mean error of the estimated ground levels is 0.187 cm, and the standard deviation of
281
error is 0.666 m. The error distribution is roughly normal, and the majority of the confidence in the model
282
error falls within the 95% confidence interval. This indicates that the estimated levels are acceptable, and
283
that LSTM can be accurately applied to estimate the ground level of the study area. These results reveal the
284 12 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. proposed model is accurate in estimating ground level, and LSTM can be applied in similar areas to decrease
285
the cost and time of SL field works. 286
287
(a)
(b)
Figure 9. Mapping of the ground level, (a) contour map and (b) model error
288
5. 3. Data collection Conclusions
289
In the current study, the applicability of using deep learning techniques for mapping ground relative
290
levelling from spirit leveling (SL) measurements was investigated. Convolution Neural Network (CNN),
291
Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), and bi-directional LSTM (BI-
292
LSTM) were developed and compared to estimate the leveling through SL measurements of Manzalla
293
region, Egypt. 3253 datasets leveling points of SL including 229 benchmark points of precise levelling (PL)
294
were used to map an area of about 77 Km2 and to verify the proposed models. 295
In a comparative study, the proposed models showed overall performances of RNN, BI-LSTM, and LSTM
296
models of 1.51, 1.67, and 1.90, respectively, in the training stage. The overall performance of CNN is 0.91,
297
while the overall performance (PI) of the BI-LSTM and LSTM models is 1.82 and 1.91, respectively, in
298
the testing stage. The accuracy of BI-LSTM and LSTM models in estimating ground level reaches up to
299
98.5% and 99% in terms of model error (PE). The visualization evaluation of the proposed models showed
300
LSTM outperformed other models in terms of the Taylor diagram and box plot. Thus, the LSTM model can
301
be considered an accurate soft computing model that can be used to estimate the ground level of the study
302
area. With the same concepts, it can be applied in the same regions. LSTM is applied to map the ground
303
level of the study area, and the results show that the estimated accuracy of the ground level of the study
304
area is 0.187 cm + 0.666 m. The error distribution of the model error is significantly within the 95% interval. 305
These results reveal the proposed model is accurate in estimating ground level, and LSTM can be applied
306
in similar areas to decrease the cost and time of SL field works. 307
308 proposed model is accurate in estimating ground level, and LSTM can be applied in similar areas to decrease
285
the cost and time of SL field works. 286 proposed model is accurate in estimating ground level, and LSTM can be applied in similar areas to decrease
285
the cost and time of SL field works. 286 proposed model is accurate in estimating ground level, and LSTM can be applied in similar areas to decrease
285
the cost and time of SL field works. 3. Data collection 286
287 287
(a)
(b)
Figure 9. Mapping of the ground level, (a) contour map and (b) model error
288 (b) (a) Figure 9. Mapping of the ground level, (a) contour map and (b) model error In a comparative study, the proposed models showed overall performances of RNN, BI-LSTM, and LSTM
296
models of 1.51, 1.67, and 1.90, respectively, in the training stage. The overall performance of CNN is 0.91,
297
while the overall performance (PI) of the BI-LSTM and LSTM models is 1.82 and 1.91, respectively, in
298
the testing stage. The accuracy of BI-LSTM and LSTM models in estimating ground level reaches up to
299
98.5% and 99% in terms of model error (PE). The visualization evaluation of the proposed models showed
300
LSTM outperformed other models in terms of the Taylor diagram and box plot. Thus, the LSTM model can
301
be considered an accurate soft computing model that can be used to estimate the ground level of the study
302
area. With the same concepts, it can be applied in the same regions. LSTM is applied to map the ground
303
level of the study area, and the results show that the estimated accuracy of the ground level of the study
304
area is 0.187 cm + 0.666 m. The error distribution of the model error is significantly within the 95% interval. 305
These results reveal the proposed model is accurate in estimating ground level, and LSTM can be applied
306
in similar areas to decrease the cost and time of SL field works. 307 13 13 https://doi.org/10.5194/gmd-2023-62
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c⃝Author(s) 2023. CC BY 4.0 License. Author contributions: FZ, MRK, and TE conceptualized the study, collected, and analyze the data,
312
evaluated the results, and wrote the manuscript. MRK, PS, and MSS visualize the data, modeling designed
313
and evaluated, and revised the manuscript. MRK and JWH revised the final form. 314
315
Competing interests: The contact author has declared that none of the authors has any competing interests. 316
317
Acknowledgements: Authors are grateful for the Sustainable Rural Sanitation Services Program (SRSSP)
318
in Dakahlia Governorate for providing ground level observations. 319
320
Financial support: This work is supported by the Korea Agency for Infrastructure Technology
321
Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant RS-2022-
322
00143541). 3. Data collection 323
324
Data availability: The used data in this study can be found in the supplementary materials. 325
326
327
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English
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Loss to follow-up in a randomized controlled trial study for pediatric weight management (EPOC)
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BMC pediatrics
| 2,016
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cc-by
| 6,788
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© The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. * Correspondence: warschb@uni-potsdam.de
1Department of Psychology, University of Potsdam, Counseling Psychology,
Potsdam University, Karl- Liebknecht- Str. 24/25, 14476 Potsdam, Germany
Full list of author information is available at the end of the article Loss to follow-up in a randomized
controlled trial study for pediatric weight
management (EPOC) Petra Warschburger1*
and Katja Kröller1,2 Warschburger and Kröller BMC Pediatrics (2016) 16:184
DOI 10.1186/s12887-016-0727-2 Warschburger and Kröller BMC Pediatrics (2016) 16:184
DOI 10.1186/s12887-016-0727-2 Abstract Background: Attrition is a serious problem in intervention studies. The current study analyzed the attrition rate
during follow-up in a randomized controlled pediatric weight management program (EPOC study) within a tertiary
care setting. Methods: Five hundred twenty-three parents and their 7–13-year-old children with obesity participated in the
randomized controlled intervention trial. Follow-up data were assessed 6 and 12 months after the end of treatment. Attrition was defined as providing no objective weight data. Demographic and psychological baseline
characteristics were used to predict attrition at 6- and 12-month follow-up using multivariate logistic regression
analyses. Results: Objective weight data were available for 49.6 (67.0) % of the children 6 (12) months after the end of
treatment. Completers and non-completers at the 6- and 12-month follow-up differed in the amount of weight loss
during their inpatient stay, their initial BMI-SDS, educational level of the parents, and child’s quality of life and well-
being. Additionally, completers supported their child more than non-completers, and at the 12-month follow-up,
families with a more structured eating environment were less likely to drop out. On a multivariate level, only
educational background and structure of the eating environment remained significant. Conclusions: The minor differences between the completers and the non-completers suggest that our retention
strategies were successful. Further research should focus on prevention of attrition in families with a lower
educational background. Trial registration: Current Controlled Trials ISRCTN24655766. Registered 06 September 2008, updated 16 May 2012. Trial registration: Current Controlled Trials ISRCTN24655766. Registered 06 September 2008, updated 16 May 2012. Keywords: Attrition Obesity Child Predictors Weight management trial Trial registration: Current Controlled Trials ISRCTN24655766. Registered Keywords: Attrition, Obesity, Child, Predictors, Weight management trial Demographic and weight data Parents were asked to provide demographic information
such as age, family status and educational level (number
of years spent in school) at the beginning of their child’s
inpatient stay. In addition, all parents reported their own
height and weight, as well as the respective data of their
partners. Children were weighed in light underwear by a
physician on a standard beam scale (accurate to 100 g)
and measured using a calibrated stadiometer (accurate
to 1 cm). Thereafter, a standardized BMI (BMI-SDS) for
age and sex was calculated [19]. Several steps were taken
to minimize loss to follow-up. To obtain objective
weight data, we conducted a 6- and 12-month follow-up
by contacting families and physicians by post. If families
did not provide the weight data within 3 weeks, a re-
minder was sent by post. For the 12-month follow-up,
we also telephoned the families that had still not replied
and encouraged them to visit their physician or a phar-
macy in order to provide the data. As a final option, we
offered them a home visit. Both families and physicians
were reimbursed for returning the respective question-
naire (50 and 25€, respectively). Other studies examined the determining factors for
drop-out during treatment [9], with fairly inconclusive
results, as almost no overlap was found between the in-
dicators analyzed. Although some studies reported a
higher attrition rate for those with a higher BMI z-score
[10–13], others did not find a significant effect (n.s. [14,
15]), older age [10, 11, 13] (n.s. [14–16]), ethnic minority
status [10, 14, 15] (n.s. [11, 16]), lower socioeconomic
status (SES)/education (trend [17]; n.s. [12, 16]) or psy-
chological problems [10, 13, 17] (n.s. [11, 12]). Consist-
ently, no study reported gender effects [11–13, 15–17]. To be able to adequately interpret study results, it is
crucial to achieve high retention rates in intervention re-
search. Participants’ motivation to devote time and effort
to filling in questionnaires or attending medical check-
ups will decrease over time, and this may be particularly
true when treatment takes place in inpatient facilities
that are far from patients’ homes. Hence, knowledge re-
garding predictors of attrition during follow-up in clin-
ical trials is limited. Therefore, we analyzed the data of a
large randomized controlled study (Empowering Parents
of Obese Children – EPOC study) in order to examine
which factors predicted failure to provide objective
weight-related measurements. Demographic and weight data We hypothesized that
parents
with
a
lower
educational
background
and Background confounding influences. Therefore, high attrition rates
can cause a significant bias in the study. Such a bias
might alter the characteristics of a sample and impede
the comparability to the original sample. Moreover, the
bias might alter the covariance of the variables included,
possibly affecting outcomes or other correlated variables
(as reviewed by Ahern [1]). Attrition is a serious problem in intervention studies,
which can threaten reliability and validity for several rea-
sons: First, when participants drop out of a study, ana-
lyses are limited to a smaller sample, which can lead to
insufficient statistical power. Second, although partici-
pants may drop out for various reasons, some of these
can be related to the outcome. Third, the drop-out pat-
tern may differ between treatment groups, altering the
random composition of the groups and leading to Reviewing the attrition rates in randomized controlled
studies of chronic illness in childhood, Karlson and Rap-
off [2] reported that on average, 37 % (range 0–75 %) re-
fused to take part in the study at the beginning, 4 %
(range 0–35 %) provided no baseline data, 20 % (range
0–54 %) no initial follow-up data, and 32 % (range 0–
59 %) no long-term follow-up data. The majority of the * Correspondence: warschb@uni-potsdam.de
1Department of Psychology, University of Potsdam, Counseling Psychology,
Potsdam University, Karl- Liebknecht- Str. 24/25, 14476 Potsdam, Germany
Full list of author information is available at the end of the article Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 2 of 9 children experiencing less success during treatment and
higher
psycho-social
strain
would
return
objective
weight data less frequently. studies did not analyze differences between completers
and non-completers. Collins et al. [3] assessed the effi-
cacy of dietetic interventions for children with obesity. From the 37 randomized controlled trials (RCT) they ex-
tracted,
26
included
follow-up
data
(1
month
to
10 years). Attrition rates during follow-up varied from 5
to 37 %. Only 9 studies reported efficacy data on the
basis of an intention-to-treat analysis. Sample and procedure Written consent was obtained from parents of 7–13-
year-old children with obesity to take part in the EPOC
study examining the effects of supplementary parent
training as part of the child’s inpatient obesity interven-
tion. Inclusion and exclusion criteria are described in de-
tail elsewhere [18]. The study was approved by the
Ethics Committee of the University of Potsdam on 19
May 2006. In general, only a small number of studies have re-
ported explicit loss at follow-up. In a recent family-
focused intervention study [4], approximately 20 % of
participants dropped out at the follow-up assessments. These children were significantly older and had a higher
body mass index (BMI) z-score at baseline. This is in
line with the findings of van den Aker et al. [5], who re-
ported an attrition rate of 33 % at the 1-year follow-up,
with drop-outs being older and less successful during
treatment. McCallum et al. [6] stated that the children
lost in follow-up were slightly heavier, and that their par-
ents reported a lower quality of life for their children. Unfortunately, it was not reported whether these differ-
ences were statistically significant. Hughes et al. [7] ob-
served a 34.9–36.9 % loss during follow-up 12 months
after the start of treatment, and did not report any
demographic differences between completers and non-
completers. This is in line with the data of Savoye et al. [8], who found no differences between completers and
non-completers with respect to baseline characteristics
(BMI, age, gender). y
Children’s weight and height were measured by a
physician, who was blind to the treatment group to
which they were assigned, at different time periods: at
baseline
(beginning
of
the
intervention),
post-
intervention and six and twelve months thereafter. In
addition, parents and their children filled in a set of
questionnaires. Table 1 provides a sample description of
the study’s 523 children (274, 52.4 % girls) and their par-
ents at baseline. Parental aspects p
Parental quality of life was measured by the well-
established SF12 [27], including physical and mental
well-being. The parents’ perception of their support of
their child was measured with a self-constructed instru-
ment including aspects such as being a role model, and
emotional and instrumental support. The postulated fac-
tor structure was confirmed [24], showing acceptable re-
liability values for the summarized scale (α = .80). The
parental self-efficacy in changing family eating and activ-
ity habits even in the face of problems or challenges was
measured by a further self-constructed scale that in-
cludes aspects of care-taking, personal changes made
and social demands. The Cronbach’s α indicated a high
reliability of the scale (α = .95). (HRQoL) was measured with the KID-KINDL-R [20]. The total score (including the 4 subscales ‘psychological
well-being’, ‘self-esteem’, ‘family’ and ‘peers’) revealed an
acceptable reliability value (α = .85) comparable with the
original form (α = .70 [21]). The child’s weight-related
quality of life (WRQoL) was measured with an estab-
lished German instrument [22]. In line with previous
validation values (α = .87 [23]), the reliability was good
(α = .85). In addition, parents reported on the child’s
food intake pertaining to ‘problematic’ (e.g., sweets, salty
snacks, fast food and soft drinks) and ‘healthy’ (fruits,
vegetables) food items on a 5-point scale (“never” – “sev-
eral times a day”). Latent structure models confirmed
the postulated factor structure [24]. The child’s eating
behavior was measured with the FKE-KJ [22], which
combines the 2 subscales ‘speed of eating’ (4 items) and
‘family eating environment’ (4 items). In accordance with
previous evaluations, both scales showed an acceptable
reliability within the current sample (α = .77 and .70, re-
spectively). Furthermore, the child’s activity level, includ-
ing media consumption and physical exercise, was
assessed with an instrument from the KIGGS-study [25]. The instrument includes the mean duration (in hours) Child factors Since the results regarding the factors that influence the
attrition rate in clinical trials are inconsistent, we ana-
lyzed a wide range of child and parental factors. All data
with the exception of the child’s self-efficacy are based
on parent reports. The health-related quality of life Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 3 of 9 Page 3 of 9 Page 3 of 9 Table 1 Sample description of the total sample at baseline
Children (n = 523)
Sex
female
52.4 %
male
47.6 %
Age (in years of age)
11.3 ± 1.29 (7–13)
BMI- SDS (measured)
2.56 ± 0.39 (1.89–4.57)
Weight classification
obesea
57.2 %
extremely obeseb
42.8 %
Parents (n = 523)
Age (in years of age)
40.56 ± 5.77 (25.94–58.78)
Educational level
(in years of school completed)
10.3 ± 1.40 (6–13)
Family status
relationship
68.8 %
single
31.2 %
BMI (self-reported in kg/m2)
29.19 ± 6.89 (14.10–59.06)
Weight classification
normal- or under-weightc
32.2 %
overweightd
28.7 %
obesee
39.1 %
Note: BMI-SDS body mass index - standard deviation score
a 97th percentile < BMI-SDS ≤99.5th percentile based on the classification by
Kromeyer-Hauschild et al. [19]
b BMI-SDS > 99th percentile
c BMI ≤25
d 25 < BMI ≤30
e BMI > 30 Table 1 Sample description of the total sample at baseline
Children (n = 523) of the child’s use of television, video or computers as
well as physical activity assessed by a 5-point Likert-
scale. We formed a summarized score indicating the
overall media consumption and activity level during an
entire week. The child’s psychosocial strain was mea-
sured with the Strengths and Difficulties Questionnaire
SDQ [26]. The sum score is made up of four subscales:
‘emotional problems’, ‘behavioral problems’, ‘peer prob-
lems’ and ‘hyperactivity’. The scale showed good reliabil-
ity (α = .84). Children assessed their own weight-related
self-efficacy, answering the GW-SW-KJ [22], which in-
cludes 24 items rated on a 5-point Likert scale. Previous
reliability values (α = .89) were replicated in the current
study (α = .89). All scales were transformed to a 0–100
scale. Statistical analyses y
All statistical analyses were performed using SPSS 21.0. Attrition was defined as missing objective weight data at
the 6- or 12-month follow-up. In the first step, we ana-
lyzed univariate differences between completers and
non-completers (Chi-square, (M)ANOVA) and in the
second step, we used logistic regression analysis to ex-
plore the variables that were associated with a higher
risk of quitting the study on a multivariate level. For the
logistic regression, variables were included stepwise: (1)
demographic and inpatient stay-related aspects, (2) par-
ental aspects, (3) the child’s psychosocial strain, and (4)
secondary treatment outcomes, such as the child’s qual-
ity of life and self-efficacy, as well as activity level, food
intake and eating behavior. Differences between completers and non-completers Univariate differences between completers and non-
completers at the 6-month follow-up are presented in
Table 2. The children’s initial weight status and weight
change during the inpatient stay differed significantly be-
tween completers and non-completers, indicating a
higher initial weight status and a lower weight loss in
non-completers. These
differences
between
completers
and
non-
completers at the 6-month follow-up were also observed
in the one-year follow-up (see Table 3). In addition,
there were significant differences regarding the parents’
educational level (completers had a higher level of edu-
cation than non-completers) and parental support (com-
pleters reported more support for their child than non-
completers), as well as the child’s psychosocial strain
(completers reported less psychosocial strain than non-
completers), the child’s WRQoL (completers reported
higher scores than non-completers), and family eating
environment (completers reported higher scores than
non-completers). p y
g
q
BMI at baseline and weight loss during intervention
are often reported to influence the drop-out in obesity
interventions. With respect to the baseline BMI, we ob-
served a higher drop-out rate in families whose children
were heavier at baseline [4, 6]. In line with other reports
[4, 5, 10], a lower initial weight loss increased the risk of
not returning the follow-up assessments in our study. However, analyzing the variables in a multivariate model,
only weight loss during intervention remained significant
in terms of predicting drop-out at the 6-month follow-
up, whereas at the 12-month follow-up, neither the
baseline weight status nor the initial weight loss was
relevant for individual attrition. Moreover, only at the
short-term follow-up did drop-out rates differ between
treatment groups, with parents in the intervention group
seemingly more willing to return the follow-up data. This group took part in a weekend seminar, which
stressed the important role of the parents in supporting
their child. Since the two treatment groups did not differ
in terms of BMI-SDS, this observation is not merely an
effect of treatment effectiveness. Drop-out rates 6 and 12 months after the intervention
The logistic regression to predict those families that
missed the weight and height measurement explained
16 % of the variance after 6 months and 14 % after
12 months. It was also able to predict 60 % of the sam-
ple correctly after 6 months and 67 % after 12 months. Results At the end of the intervention, the data of one child
could not be obtained. Therefore, only the data from
522 children were available. Complete weight and height
data were available for 259 (49.6 %) children at the 6- Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 4 of 9 Page 4 of 9 month follow-up and for 350 (67.0 %) at the 12-month
follow-up. an expensive and time-consuming method (re-sending
questionnaires and reminder postcards, repeated tele-
phone calls, offering home visits and financial incen-
tives). These strategies were considered as successful
retention strategies to facilitate parents’ participation
and receive the long-term data [30]. We assume that this
strategy did at least pay off a little, since we invested the
greatest efforts before the second follow-up and the at-
trition rate at 12 months was slightly lower than that at
the 6-month follow-up. Nevertheless, the attrition rate
was high, and retention rates fell below our expectations. Further studies are needed to indicate empirically vali-
dated retention strategies. In order to enhance study
commitment and decrease attrition, the study by Ger-
mann et al. [31] used an orientation session to give in-
formation about achievable and healthy weight loss. We
agree that this might be helpful in decreasing the num-
ber of unsuccessful weight loss attempts, but it also ex-
cludes many individuals with weight problems and
focuses only on highly motivated patients. Further re-
search is needed on how to increase the retention rate in
clinical trials, especially when not only self-reports but
also physiological measurements are required [28]. Differences between completers and non-completers At the 6-month follow-up, participation in the interven-
tion group (odds ratio (OR)) = 0.60) and having older
parents (OR = 0.95) was associated with a lower risk of
dropping out, whereas a lower weight loss during the in-
patient stay was associated with a higher risk (OR =
24.05). After 12 months, higher parental educational
level (OR = 0.81) and a more structured family eating en-
vironment (OR = 0.97) were associated with a lower risk
of dropping out. Table 4 shows the results for the 12-
month follow-up. Discussion Attrition is a highly relevant and prevalent problem in
pediatric weight management trials. In the current study,
we observed an attrition rate of 33.0 % at the 12-month
follow-up. Our results are in line with those reported in
the literature [3, 5, 7]. A recent review reported higher
attrition rates in studies that focused on children with
overweight or obesity (79.6 %) as well in long-term stud-
ies (74 %) [28]. Based on the results of a previous study
assessing parental factors which might impede or facili-
tate their participation [29],8 we assumed time and fi-
nancial constraints to be important. Therefore, we used Previous
research
results
concerning
the
socio-
demographic data were controversial. We observed no
influence from the child’s age, which contradicts the re-
sults of two other studies [4, 5]. Consistent with the lit-
erature, no effects of gender were observed [4, 5, 7, 8]. In our study, parents’ age influenced the retention rate
for the short-term follow-up, an effect that was no lon-
ger visible 6 months later. Only at the 12-month follow-
up was a higher level of parents’ education associated
with a higher retention rate. Discussion We are aware of only one Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 5 of 9 Table 2 Comparison of completers and non-completers at 6-month follow-up
Completers (n = 259)
Non-Completers (n = 264)
F (X2)
p
η2 Table 2 Comparison of completers and non-completers at 6-month follow-up
Completers (n = 259)
Non-Completers (n = 264)
F (X2)
p
η2
Children
Sex
female
135
139
.02
.90
male
124
125
Age (years)
11.24
11.34
.85
.36
<.001
Initial BMI-SDS
2.52
2.60
5.63
.02
.01
Duration of inpatient stay (days)
39.67
39.69
<0.001
.98
<.001
Study arm
IG
130
119
1.37
.24
CG
129
145
Weight change during stay (BMI-SDS)
−0.35
−0.32
6.77
.01
.01
Health-related QoLa
67.94
66.28
2.48
.12
.01
Weight-related QoLa
46.40
44.08
2.24
.14
<.001
Self-efficacya
55.91
57.97
2.26
.13
.01
Psychosocial strain
6,41
6,35
<.001
.96
<.001
Food intake
healthya
69.46
65.00
3.06
.08
.01
Problematica
48.69
47.28
.87
.35
<.001
Eating
speeda
35.67
34.68
.29
.59
<.001
Structurea
72.46
69.66
4.19
.04
.01
Media consumptiona
12.06
11.74
.08
.78
<.001
Activity levela
1.06
1.05
.02
.90
<.001
Parents
Age (years)
41.05
40.06
3.15
.08
.01
Educational level (years of school)
10.37
10.24
.95
.33
<.001
Family status
in relationship
149
142
.14
.71
single
65
67
BMI (kg/m2; self-reported)
28.91
29.46
.68
.41
<.001
LQ
mentala
48.71
47.71
1.18
.28
<.001
Physicala
50.05
49.65
.29
.59
<.001
Self-efficacya
64.99
63.77
.85
.36
<.001
Child’s supporta
73.07
71.66
2.28
.13
<.001
Note: F statistical test value, p significance value, η2 explained variance
a mean scores on a scale ranging from 0 to 100 Note: F statistical test value, p significance value, η2 explained variance
a mean scores on a scale ranging from 0 to 100 problems reported by the parents in the drop-out group. This concurs with the findings, with respect to prema-
turely stopping the intervention [10, 13, 17]. However,
the reported differences in psychological characteristics
in this study were not independent predictors in the
multivariate logistic regression. study in the field of pediatric weight management that
reported similar results, even if only as tendencies [17]. With regard to psychological characteristics, the avail-
able evidence is sparse. In line with our observation re-
garding the differences between completers and non-
completers, McCallum et al. [6] indicated that those
who dropped out reported a lower quality of life for chil-
dren. Discussion In
addition,
we
found
more
psychological Further aspects that differ between the groups were
the eating environment, in which a low degree of family Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 6 of 9 meal structure remained a significant predictor for attri-
ti
t 12
th
ft
i t
ti
Th
i fl
f
35]. Our results are further supported by the data of
th
t th t t
t l i fl
i
t
t
t
Table 3 Comparison of completers and non-completers at 12-month follow-up
Completers (n = 350)
Non-Completers (n = 173)
F (X2)
p
η2
Children
Sex
female
177
97
1.40
.24
male
173
76
Age (years)
11.28
11.34
0.28
.60
<.001
BMI-SDS (measured)
2.52
2.63
8.53
<.001
.02
Duration of inpatient stay (days)
39.95
39.14
0.76
.39
<.001
Study arm
IG
169
80
0.19
.66
CG
181
93
Weight change during stay (BMI-SDS units)
−0.35
−0.32
5.04
.03
.01
Health-related QoLa
67.81
65.65
3.66
.06
.01
Weight-related QoLa
46.79
41.97
8.51
<.001
.02
Self-efficacya
57.01
56.79
0.02
.88
<.001
Psychosocial straina
12.89
14.42
5.85
.02
.01
Food intake
healthya
68.23
65.16
1.25
.26
<.001
Problematica
47.76
48.52
0.22
.64
<.001
Eating
speeda
35.52
34.45
0.29
.59
<.001
Structurea
72.42
68.18
8.34
<.001
.02
Media consumptiona
23.83
24.34
0.19
.66
<.001
Activity levela
1.12
0.93
3.38
.07
.01
Parents
Age
40.62
40.42
0.11
.74
<.001
Educational level (years of school)
10.41
10.08
4.77
.03
.01
Family status
relationship
206
85
2.63
.11
single
83
49
BMI (kg/m2; self-reported)
29.21
29.15
0.01
.94
<.001
QoL
mentala
48.45
47.72
0.55
.46
<.001
Physicala
49.83
49.89
0.01
.95
<.001
Self-efficacya
64.32
64.54
0.02
.88
<.001
Child’s supporta
73.09
70.83
5.12
.02
.01
Note: F statistical test value, p significance value, η2 explained variance, QoL quality of life, IG intervention group, CG control group, BMI-SDS body mass index -
standard deviation score
a mean scores on a scale ranging from 0 to 100 Table 3 Comparison of completers and non-completers at 12-month follow-up
Completers (n = 350)
Non-Completers (n = 173)
F (X2)
p
η2 35]. Our results are further supported by the data of
other reports that stress parental influence in treatment
adherence [10, 17]. meal structure remained a significant predictor for attri-
tion at 12 months after intervention. Discussion The influence of
the family eating environment may be interpreted as
sign of a successful change in family habits – a major
goal in pediatric weight loss interventions [32, 33]. In
addition, studies from family-oriented intervention ap-
proaches suggest that parents play a key role in sustain-
ing the treatment effect at the long-term follow-up [34, Our study is limited in several ways. First, we could
not assess any data at the follow-up measurements con-
cerning the reasons for discontinuing the study. Some
participants reported that when called by phone, they
lost interest and that completing the questionnaires was Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 7 of 9 Table 4 Logistic regression to predict drop-out at 12-month follow-up
Wald
df
p
Exp(B)
95 % CI
Children
Sex
1.715
1
.190
1.386
.850–2.260
Age (years)
0.070
1
.791
1.025
.856–1.227
BMI-SDS (measured)
3.278
1
.070
1.870
.950–3.682
Study arm
1.038
1
.308
.785
.492–1.251
Weight change during stay
0.396
1
.529
1.886
.261–13.621
Weight-related QoL
0.260
1
.610
0.996
.982–1.011
Psychosocial strain
1.216
1
.270
1.023
.983–1.064
Eating
structure
8.429
1
.004
.977
.962–0.992
Parents
Educational level (years of school)
4.038
1
.044
.839
.707–0.996
Child’s support
0.117
1
.733
.996
.974–1.019
Note: Wald statistical test, df degrees of freedom, p significance level, Exp(B) odds ratio, 95 % CI confidence interval, QoL quality of life, BMI-SDS body mass index -
standard deviation score Table 4 Logistic regression to predict drop-out at 12-month follow-up term (12 months after intervention) follow-ups. De
Niet et al. [10] also found different predictors for at-
trition at different stages of treatment. Whereas at
the 6-month follow-up, mainly aspects associated with
the intervention (randomization in the intervention group
and initial weight loss) predicted the retention, at the 12-
month follow-up, only family aspects such as educational
level and family eating environment remained predictive. These differences indicate the risks inherent in only in-
cluding a short-term follow-up, which might be biased in
terms of success rates – especially when drop-out rates
are high. Taking into account that in particular, short-
term success in weight management does not necessarily
imply positive long-term results, intervention studies
should include longer follow-up periods and report their
results on the basis of intention-to-treat analyses. too time-consuming. This is in line with the data reported
by Savoye et al. [8]. and with our previous study [29]. Abbreviations
95 % CI C
fid An important strength of our study is that we col-
lected data from a highly diverse and representative
sample of participants, rather than only including those
families with a higher level of education or income. Moreover, the weight data were based on blind assess-
ment, thus decreasing the risk of underreporting weight
status (see self-reported measurements) [36]. 95 % CI: Confidence interval; BMI: Body mass index; BMI-SDS: Body mass
index - standard deviation score; CG: Control group; df: Degrees of freedom;
EPOC: Empowering parents of obese children; Exp(B): Odds ratio; F: Statistical
test value; HRQoL: Health-related quality of life; IG: Intervention group;
OR: Odds ratio; p: Significance value; QoL: Quality of life; RCT: Randomized
controlled trial; SES: Socioeconomic status; Wald: Statistical test;
WRQoL: Weight-related quality of life; η2: Explained variance Discussion In
addition, our analyses were exploratory and we included
many variables. We decided to take that path in order to
not miss relevant features, and were willing to accept the
increased risk of overestimating the clinical significance of
the results. Furthermore, we also ran multivariate analyses
in order to combat alpha error inflation. When interpret-
ing our results in terms of comparing the pattern of short-
and long-term follow-up data, it should be noted that we
invested much more effort in gathering long-term data. Especially at the 12-month follow-up, we successfully con-
tacted those parents who had simply forgotten to fill in
the questionnaires due to time constraints or other prior-
ities. Thus, we were able to observe differences otherwise
obscured by organizational problems reported by the ma-
jority of parents [8]. g
We greatly appreciate the support of our cooperating clinics:
• Kinder-Reha-Klinik “Am Nicolausholz” Bad Kösen
• Charlottenhall Vorsorge und Rehabilitationsklinik für Kinder und
Jugendliche Bad Salzungen
• Fachklinik Prinzregent Luitpold Scheidegg
• Edelsteinklinik Bruchweiler
• Spessart-Klinik Bad Orb
• Viktoriastift Bad Kreuznach
• Kinder- und Jugendklinik Gesundheitspark Bad Gottleuba
• Auguste-Viktoria-Klinik Bad Lippspringe
• AHG Klinik für Kinder und Jugendliche Beelitz-Heilstätten
Special thanks to Nadine Häusler for critical proofreading. Funding
h
d 12. Jelalian E, Hart CN, Mehlenbeck RS, Lloyd-Richardson EE, Kaplan JD, Flynn-
O'Brien KT, Wing RR. Predictors of attrition and weight loss in an adolescent
weight control program. Obesity. 2008;16:1318–23. g
This study was funded by a DFG (German Research Foundation) grant (WA
1143/4-1; 4–2). The funding organization played no role in the design of the
study and collection of the data, their analysis and interpretation and in
writing the manuscript. 13. Zeller MH, Saelens BE, Roehrig H, Kirk S, Daniels SR. Psychological
adjustment of obese youth presenting for weight management treatment. Obes Res. 2004;12:1576–86. 14. Dolinsky DH, Armstrong SC, Ostbye T. Predictors of attrition from a clinical
pediatric obesity treatment program. Clin Pediatr. 2012;51:1168–74. 14. Dolinsky DH, Armstrong SC, Ostbye T. Predictors of attrition from a clinical
pediatric obesity treatment program. Clin Pediatr. 2012;51:1168–74. Ethics approval and consent to participate pp
p
p
Written informed consent to participate was obtained. The study approved by the Ethics Committee of the University of Potsdam on 19 May
2006. (no reference number) approved by the Ethics Committee of the University of Potsdam on 19 May
2006. (no reference number) 20. Ravens-Sieberer U, Bullinger M. KINDL-R. Fragebogen zur Erfassung der
gesundheitsbezogenen Lebensqualität bei Kindern und Jugendlichen. Revidierte Form. Manual. 2000. Availability of data and materials Data will be deposited in a repository (doi: 10.5281/zenodo.164417 ). 15. Tershakovec AM, Kuppler K. Ethnicity, insurance type, and follow-up in a
pediatric weight management program. Obesity. 2003;11:17–20. Consent to publish Consent to publish
Consent to publish is part of the ethics approval. Consent to publish
Consent to publish is part of the ethics approval. 19. Kromeyer-Hauschild K, Wabitsch M, Kunze K, Geller F, Hesse V, von
Hippel A, Jaeger U, Johnsen D, Korte W, Müller G, Müller JM,
Niemann-Pilatus A, Remer T, Wittchen H, Zabransky S, Zellner K,
Ziegler A, Hebebrand J. Perzentile für den Body-mass-Index für das
Kindes- und Jugendalter unter Heranziehung verschiedener deutscher
Stichproben. Monatsschr Kinderheilkd. 2001;149:807–18. Consent to publish is part of the ethics approval. Conclusions We greatly appreciate the support of our cooperating clinics:
• Kinder-Reha-Klinik “Am Nicolausholz” Bad Kösen
• Charlottenhall Vorsorge und Rehabilitationsklinik für Kinder und
Jugendliche Bad Salzungen
• Fachklinik Prinzregent Luitpold Scheidegg
• Edelsteinklinik Bruchweiler
• Spessart-Klinik Bad Orb
• Viktoriastift Bad Kreuznach
• Kinder- und Jugendklinik Gesundheitspark Bad Gottleuba
• Auguste-Viktoria-Klinik Bad Lippspringe
• AHG Klinik für Kinder und Jugendliche Beelitz-Heilstätten
Special thanks to Nadine Häusler for critical proofreading. Our study results suggest that the strategies to reduce
the attrition rate, which we employed after the first
follow-up, were successful, but still could not prevent a
final attrition rate of over 33 % for the second follow-up. We were able to replicate differences between com-
pleters and non-completers found in previous studies. However, we observed a different pattern of predic-
tors between the short-term (6 months) and long- Our study results suggest that the strategies to reduce
the attrition rate, which we employed after the first
follow-up, were successful, but still could not prevent a
final attrition rate of over 33 % for the second follow-up. • Fachklinik Prinzregent Luitpold Scheidegg Page 8 of 9 Page 8 of 9 Page 8 of 9 Warschburger and Kröller BMC Pediatrics (2016) 16:184 Page 8 of 9 Warschburger and Kröller BMC Pediatrics (2016) 16:184 Author details
1
f 21. Ravens-Sieberer U, Redegeld M, Bauer CP, Mayer H, Stachow R, Kiosz D, van
Egmond-Fröhlich B, Rempis R, Kraft D, Bullinger M. Lebensqualität chronisch kranker
Kinder und Jugendlicher in der Rehabilitation. Z Med Psychol. 2005;14:5–12. 1Department of Psychology, University of Potsdam, Counseling Psychology,
Potsdam University, Karl- Liebknecht- Str. 24/25, 14476 Potsdam, Germany. 1Department of Psychology, University of Potsdam, Counseling Psychology,
Potsdam University, Karl- Liebknecht- Str. 24/25, 14476 Potsdam, Germany. 1Department of Psychology, University of Potsdam, Counseling Psychology,
Potsdam University, Karl- Liebknecht- Str. 24/25, 14476 Potsdam, Germany. 2Department of Health Psychology, H:G Hochschule für Gesundheit & Sport,
Technik & Kunst, Vulkanstraße 1, 10367 Berlin, Germany. Department of Health Psychology, H:G Hochschule für Gesundheit & Sport,
Technik & Kunst, Vulkanstraße 1, 10367 Berlin, Germany. 22. Warschburger P, Fromme C, Petermann F. Konzeption und Analyse
eines gewichtsspezifischen Lebensqualitätsfragebogens für
übergewichtige und adipöse Kinder und Jugendliche (GW-LQ-KJ). Z Klin
Psychol Psychiatr Psychother. 2005;4:356–69. Technik & Kunst, Vulkanstraße 1, 10367 Berlin, Germany. Received: 2 April 2016 Accepted: 8 November 2016 p
p 23. Warschburger P, Fromme C, Petermann F. Gewichtsbezogene
Lebensqualität bei Schulkindern: Validität des GW-LQ-KJ. Z
Gesundheitspsychol. 2004;12:159–66. Competing interests Competing interests
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Empowering parents of obese children (EPOC): A randomized-controlled trial on
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weight management clinic. Child Obes. 2011;7:185–93. Page 9 of 9 Warschburger and Kröller BMC Pediatrics (2016) 16:184 • We accept pre-submission inquiries
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172 Ausgaben mit 18.427 Seiten. Die Redaktion von Communicatio Socialis verabschiedet die dienstältesten Mitarbeiter
|
Communicatio socialis
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In eigener Sache In eigener Sache Communicatio Socialis 45 (2012), Nr. 4: 335–340
Quelle: www.communicatio-socialis.de Communicatio Socialis 45 (2012), Nr. 4: 335–340
Quelle: www.communicatio-socialis.de 1 1988 erschien Communicatio Socialis nicht (nur ein Register), 1989 nur ein Heft;
auch kamen einzelne Ausgaben als Doppelnummern heraus. Nicht bei dieser Sta-
tistik eingerechnet sind die zwölf Beihefte, die zwischen 1972 und 2010 zumeist
in Buchform erschienen. Bei fünf dieser Sonderausgaben wirkte Schmolke als
alleiniger Herausgeber oder Mitherausgeber (1972 zu „Communio et Progressio“,
1974 zu „Publik“, 1977 zur katholischen Publizistik in den Niederlanden, 1992
zur Situation der Kirchenpresse in Europa und den USA sowie 2010 als Fest-
schrift für Walter Hömberg). 172 Ausgaben mit 18 427 Seiten
Die Redaktion von Communicatio Socialis
verabschiedet die dienstältesten Mitarbeiter Diese Ausgabe bildet eine Zäsur in der 45-jährigen Geschichte von Com-
municatio Socialis. Die Redaktion hat bei ihrer letzten Zusammenkunft
mit großer Wehmut ihre drei dienstältesten Mitarbeiter verabschiedet. Nicht ohne Grund fand dieses Treffen, bei dem wie immer die jüngsten
Hefte lobend und kritisierend besprochen und die nächsten Ausgaben
geplant wurden, in Salzburg statt. Seit dem 6. Jahrgang, Heft 4, fin-
det sich eine Salzburger Anschrift im Impressum von Communicatio
Socialis. Der Name, der bei dieser Adresse steht, lautet Michael
Schmolke. Er war jugendliche 33 Jahre alt, frisch promoviert mit
einer Arbeit über „Kolping als Publizist“ und Assistent am Institut
für Publizistik in Münster, als ihn Franz-Josef Eilers von den Steyler
Missionaren dafür gewinnen konnte, mit ihm gemeinsam diese „Zeit-
schrift für Publizistik in Kirche und Welt“ (so lautete der Untertitel
bis 1992) zu gründen. Nach Vorarbeiten im Jahr 1967 erschien die
erste Ausgabe Anfang 1968. Unter der Überschrift „Publizistik als
Aufgabe“ hieß es in der programmatischen Einleitung: „Die neue Zeitschrift soll solchen Erkenntnissen und Erfahrungen aus dem Ge-
samtbereich der Publizistik ihre Seiten öffnen, die mittelbar oder unmittelbar für
kirchliche publizistische Arbeit bedeutsam sein können. Sie soll durch Beiträge
von Fachleuten auf Probleme und Aufgaben hinweisen und zu ihrer Lösung bei-
tragen – durch Information, Anregung und Kritik. […] Diese Zeitschrift, die der
Bereitschaft verschiedener privater Stellen und dem Mut des Verlages ihr Ent-
stehen verdankt, möchte ihren Teil zu der Erfüllung der publizistischen Aufgabe
der Kirche beitragen. Sie ist nach dem zweiten Weltkrieg die erste katholische
Fachzeitschrift dieser Art – nichtsdestoweniger ist sie auf das Wohlwollen und
die Mitarbeit aller angewiesen, die sich ihren Zielen verpflichtet fühlen.“ Wohl niemand fühlte sich dem publizistischen Projekt mehr verpflich-
tet als Michael Schmolke. Das Amt des Herausgebers war für ihn zwar
auch ein Ehrenamt, aber nicht bloß schmückender Ehrentitel. Er ver-
stand darunter wahrhaftig „Publizistik als Aufgabe“, verbunden mit
manchen Mühen. Das Amt des Herausgebers nahm Michael Schmolke
mit, als er 1973 Ordinarius für Publizistik und Kommunikationswis-
senschaft an der Universität Salzburg wurde, und er füllte es mit glei-
chem Herzblut aus, nachdem er 2002 emeritiert wurde. Nun, mit fast
79 Jahren, verabschiedet sich der Gründer aus dem aktiven Dienst. 335
https://doi.org/10.5771/0010-3497-2012-4-335, am 24.10.2024, 06:46:36
Open Access –
- https://www.nomos-elibrary.de/agb In eigener Sache In eigener Sache Vor kurzem hat Michael Schmolke dem Verfasser dieser Zeilen ei-
nen Satz aller jemals erschienen Communicatio-Hefte zur Archivierung
übergeben, den er doppelt besaß. In Ermangelung eines passenden
Regalfaches mussten die Zeitschriften auf dem Klavier zwischenge-
lagert werden. Sie reichen, nebeneinander aufgestellt, vom tiefsten A
bis zum höchsten C, einmal entlang der kompletten Klaviatur und so-
gar noch etwas darüber hinaus – insgesamt 132 Zentimeter. Mit dieser
Ausgabe sind es 172 Hefte mit 18 427 Seiten1, an deren Konzeption
Michael Schmolke beteiligt war und die er – wie wir aus der Zusam-
menarbeit der vergangenen Jahre wissen – vor der Drucklegung stets
akribisch auf inhaltliche und satztechnische Fehler gelesen hat. Vor allem aber war Michael Schmolke selbst der fleißigste Autor. Seit der ersten Ausgabe trugen 194 Beiträge in dieser Zeitschrift
seinen Namen oder das Kürzel „M.S.“. Damit füllte er zusammenge-
rechnet 481 Seiten – also gut und gerne noch einmal so viel Stoff
wie seine 1971 als Buch erschienene Habilitation über „Die schlech-
te Presse – das Verhältnis der deutschen Katholiken zur Publizistik
zwischen ‚Katholik‘ (1821) und ‚Publik‘ (1968)“, die der Rezensent
Konrad Simons in dieser Zeitschrift eine „verdienstvolle und ins Mark
kirchlicher Publikationsscheu vorstoßende Darstellung“ nannte (Heft
4/1972). Die Besprechung endet mit dem Satz: „Die Fortsetzung zu
Michael Schmolkes Untersuchung […] könnte ein neuer Schmolke
werden etwa mit dem Arbeitstitel: der unbegrenzte Spielraum ka-
tholischer Publizistik an der Schwelle des Jahres 2000.“ Dass dieser
Band nie erschienen ist, lag wohl weniger am Autor. g
g
Die Geschichte und aktuelle medienpolitische Fragestellungen der
katholischen Publizistik sowie die immer wieder untersuchte Lage
der Kirchenzeitungen (so z. B. „Die Bistumspresse von Analyse zu
Analyse“; Heft 3/1996) bilden den Schwerpunkt von Michael Schmol-
kes Veröffentlichungen in Communicatio Socialis. Daneben findet sich
Grundsätzliches zu seinem Lehrgebiet, etwa schon im ersten Jahrgang
ein Essay über die neue Ausrichtung der Publizistikwissenschaft und
ihre Bezüge zur alten, normativen Zeitungswissenschaft („Fragen
zum Ort von Gesinnungskräften im publizistischen Funktionieren“, 336
https://doi.org/10.5771/0010-3497-2012-4-335, am 24.10.2024, 06:46:36
Open Access –
- https://www.nomos-elibrary.de/agb 336
p 172 Ausgaben mit 18 427 Seiten Mitherausgeber von Communicatio Socialis seit der ersten Ausgabe 1968:
Michael Schmolke
(Foto: Christian Klenk) Mitherausgeber von Communicatio Socialis seit der ersten Ausgabe 1968:
Michael Schmolke
(Foto: Christian Klenk) Heft 2/1968). Außerdem war Michael Schmolke von Beginn an eifri-
ger Rezensent. Für die Vorstellung von Neuerscheinungen in „seiner“
Zeitschrift las er ein ganzes Bücherregal. In eigener Sache 129 Buchbesprechungen
sind mit seinem Namen gekennzeichnet (teilweise sind es Sammelre-
zensionen mehrerer Bände). Schließlich belieferte er die Redaktion
regelmäßig mit Beiträgen für die Rubrik „Zur Person“. Viele Freunde
und Kollegen hat Michael Schmolke damit auf dem Weg in den Ruhe-
stand und auch in letztem ehrenden Andenken gewürdigt. Heft 2/1968). Außerdem war Michael Schmolke von Beginn an eifri-
ger Rezensent. Für die Vorstellung von Neuerscheinungen in „seiner“
Zeitschrift las er ein ganzes Bücherregal. 129 Buchbesprechungen
sind mit seinem Namen gekennzeichnet (teilweise sind es Sammelre-
zensionen mehrerer Bände). Schließlich belieferte er die Redaktion
regelmäßig mit Beiträgen für die Rubrik „Zur Person“. Viele Freunde
und Kollegen hat Michael Schmolke damit auf dem Weg in den Ruhe-
stand und auch in letztem ehrenden Andenken gewürdigt. In seinem letzten Beitrag als Herausgeber (hoffentlich nicht der
letzte überhaupt!) erinnert Michael Schmolke in diesem Heft noch ein-
mal an all jene Menschen, die in den vergangenen Jahrzehnten mit ihm
an dieser Zeitschrift gearbeitet haben. Zwei von ihnen verabschieden
sich zusammen mit dem Gründungsherausgeber aus der aktiven Re-
daktionsarbeit. Ute Stenert engagierte sich für diese Zeitschrift als
Mitherausgeberin neben ihrer zeitintensiven Tätigkeit als Referats-
leiterin Presse und Verlagswesen im Sekretariat der Deutschen Bi-
schofskonferenz in Bonn. Seit rund einem Jahr ist sie für das Referat
Rundfunk und Medienethik verantwortlich. Ute Stenert studierte Pub-
lizistik, Politikwissenschaft und Soziologie in Mainz und Münster, war 337 In eigener Sache Ferdinand Oertel (Autor seit 1969, Redakteur seit 2003) und Ute Stenert
(Mitherausgeberin seit 2005)
(Fotos: Christian Klenk) Ferdinand Oertel (Autor seit 1969, Redakteur seit 2003) und Ute Stenert
(Mitherausgeberin seit 2005)
(Fotos: Christian Klenk) nach ihrem Examen PR-Redakteurin und anschließend wissenschaft-
liche Mitarbeiterin am Mainzer Institut für Publizistik. Eine Kurzfas-
sung ihrer Dissertation über die Entstehung des Südwestrundfunks
erschien in Communicatio Socialis (Heft 3/2004) – und nur zwei Aus-
gaben später war sie Mitherausgeberin. Dank ihrer guten Kontakte im
Bereich der katholischen Publizistik konnte sie der Redaktion in den
vergangenen acht Jahren häufig neue Themen und Autoren vermitteln,
regelmäßig hat sie selbst geschrieben und Interviews geführt. g
g
g
g
Der Name Ferdinand Oertel taucht in dieser Zeitschrift das ers-
te Mal 1969 auf. In Heft 4 schrieb der damalige Chefredakteur der
katholischen Wochenzeitung „Die christliche Familie“ über „Die Zu-
kunft der katholischen Sonntagspresse im Licht einer Leser-Umfrage“. Die kirchliche Presse war und ist bis heute das Lebensthema von Ferdi
Oertel, wie er seine Mails und Briefe unterzeichnet. In eigener Sache Folgerichtig trägt
seine 2009 erschienene Biografie den Titel „Der Kirchenzeitungsmann“
(die zweite Auflage erschien 2012). Oertels Lebensstationen färbten
allesamt auf sein publizistisches Wirken ab. Neben dem Anglistik-,
Germanistik- und Kunstgeschichte-Studium im heimatlichen Köln war
er für zwei Semester als Austauschstudent in St. Louis in den USA,
wo er auch Journalistik studierte. Bis heute beobachtet er wie kein
anderer in Deutschland die Entwicklung der katholischen Publizistik
in den Vereinigten Staaten und verfasst dazu regelmäßig Lageberichte
in Communicatio Socialis und in der „Herder Korrespondenz“. 338
https://doi.org/10.5771/0010-3497-2012-4-335, am 24.10.2024, 06:46:36
Open Access –
- https://www.nomos-elibrary.de/agb 338 172 Ausgaben mit 18 427 Seiten 172 Ausgaben mit 18 427 Seiten 172 Ausgaben mit 18 427 Seiten Nach der Promotion und einem Volontariat bei der Kölner Kirchen
zeitung begann seine berufliche Karriere: 1956 Leiter der Pressestelle
des Kölner Katholikentages, 1957 bis 1960 Kulturredakteur und Chef
vom Dienst bei der Katholischen Nachrichtenagentur, 1961 bis 1973
Chefredakteur der Wochenzeitung „Die christliche Familie“, 1973
bis 1980 Chefredakteur der „Aachener Kirchenzeitung“, von 1980
an schließlich Chefredakteur der Zeitschrift „Leben & Erziehen“. Daneben engagierte er sich in verschiedenen Gremien: als Vorsitzen-
der der Arbeitsgemeinschaft Katholische Presse, als Berater publi-
zistischer Kommissionen der Deutschen Bischofskonferenz und beim
Zentralkommitee der deutschen Katholiken, als Mitbegründer und
Präsident der Internationalen Föderation der katholischen Presse im
Dachverband Katholische Weltunion der Presse. Als Ferdinand Oertel
1992 in den Unruhestand eintrat, würdigte Michael Schmolke seine
Lebensleistungen auch in Communicatio Socialis (Heft 1/1993): „Wer die Stationen seines Lebenslaufes bedenkt, sieht, daß er immer Täter
war, aber für viele Jahre zugleich Beobachter. Beobachter, Kritiker und Ana-
lysator […]. Ein Berater, der auf der Grundlage des Nachdenkens über den
eigenen Beruf Rat gegeben hat, der aber reflektierend in der Lage war, sein
Metier und seine Branche in Frage zu stellen. Unter den Redakteuren der Kir-
chenpresse war er kein Enfant terrible, gehörte wohl gerade noch zum Main-
stream, machte aber gelegentlich Vorschläge, die von der Mehrheit nicht als
verwirklichenswert eingestuft wurden.“ Ferdinand Oertel hat in allen Positionen und Ämtern eine Öffnung
der Kirchenpresse zur Welt und zu einem professionellen Journalis-
mus propagiert. Seine Beobachtungen und Kommentierungen setzte
er auch nach der Pensionierung fort – als „Redakteur i. N. (im Ne-
benberuf)“ (Oertel über Oertel). Mit 75 Jahren war er wieder Chefre-
dakteur. Von Heft 1/2003 an stand sein Name zusammen mit dieser
Funktionsbezeichnung im Impressum von Communicatio Socialis. In eigener Sache Fünf
Jahrgänge der Zeitschrift redigierte er alleine, danach konzentrierte
er sich vor allem auf die Rubrik „Notabene“, schrieb aber weiterhin
auch noch Berichte, Kommentare und Rezensionen. Insgesamt 51
Beiträge hat Ferdinand Oertel für diese Zeitschrift verfasst (die Ru-
brik „Notabene“ nicht eingerechnet). Am 24. Oktober 2012 hat Fer-
dinand Oertel gemeinsam mit seiner Frau während einer Italienreise
seinen 85. Geburtstag gefeiert. Den Generationenwechsel bei Com-
municatio Socialis nimmt er nun zum Anlass, sich ganz jener Tätig-
keit zuzuwenden, die am Anfang seines Werdegangs stand: als „freier
Schriftsteller“ literarische Prosa zu scheiben, „denn im Innern fühlte
ich mich zum Dichten berufen“, schreibt er in seiner Biografie. 339 In eigener Sache Den allerersten Aufsatz in dieser Zeitschrift verfasste der Wiener
Kardinal Franz König. Sein Beitrag mit dem Titel „Kirche und Kom-
munikation“ (Heft 1/1968) endet so: Den allerersten Aufsatz in dieser Zeitschrift verfasste der Wiener
Kardinal Franz König. Sein Beitrag mit dem Titel „Kirche und Kom-
munikation“ (Heft 1/1968) endet so: „Die moderne Gesellschaft befindet sich in einem raschen Wandel; die Ver-
lautbarung religiöser Inhalte muß also mit einer Umgebung rechnen, die sich
in unausgesetzter Veränderung befindet. Religiöse Inhalte in der Massenkom-
munikation werden immer schärfer von Inhalten konkurrenziert, die sehr ein-
fachen menschlichen Bedürfnissen – z. B. der Schaulust – entgegenkommen
und erstaunlicherweise nicht selten archaisch-mythische Inhalte in moderner
Verpackung anbieten; man hat in diesem Zusammenhang von der modernen
Massenkultur gesprochen. Ein sehr entscheidender Faktor dürfte auch die
weitverbreitete Verbraucher- oder Konsumentenmentalität sein, die einer mehr
kontemplativen Lebensweise direkt entgegengesetzt ist. Schließlich darf auch
noch auf jenes Phänomen hingewiesen werden, das heute unter dem Namen
der „Säkularisation“ immer mehr Beachtung findet und für zukünftige Strate-
gien religiöser Kommunikation in Rechnung gestellt werden muß.“ Königs Ausführungen sind auch 45 Jahre nach ihrer Formulierung
als Aufgabenstellung für diese Zeitschrift zu verstehen – mit dem Un-
terschied, dass die beschriebenen Herausforderungen seither um ein
Vielfaches mächtiger geworden sind. Die Strategien religiöser Kom-
munikation wird Communicatio Socialis weiterhin analysieren und
kommentieren. Medienethische Fragestellungen, denen sich auch die
katholischen Bischöfe in letzter Zeit unter anderem mit einem Impuls
papier zu „Virtualität und Inszenierung“ in der digitalen Welt gewid-
met haben (vgl. Heft 4/2011), werden darüber hinaus künftig in dieser
Zeitschrift einen größeren Raum einnehmen. Das neue Heftkonzept
haben die scheidenden Herausgeber und die neue Generation in den
vergangenen Monaten gemeinsam entwickelt – es soll im Laufe des
Jahres 2013 umgesetzt und dann auch näher erläutert werden. In eigener Sache Für die neue Blattlinie stehen künftig diese drei Herausgeber:
Klaus-Dieter Altmeppen (Inhaber des Lehrstuhls für Journalistik II
an der Katholischen Universität Eichstätt-Ingolstadt), Andreas
Büsch (Professor für Medienpädagogik und Kommunikationswissen-
schaft an der Katholischen Hochschule Mainz und Leiter der von der
Bischofskonferenz eingerichteten Clearingstelle Medienkompetenz)
sowie Alexander Filipovic´ (Akademischer Rat am Institut für Christ-
liche Sozialwissenschaften an der Westfälischen Wilhelms-Universi-
tät Münster). Die Eichstätter Redaktion von Communicatio Socialis,
Annika Franzetti, Renate Hackel-de Latour und Christian Klenk,
freut sich auf die Zusammenarbeit. Im Namen der Redaktion
Ch i ti
Kl
k 340
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Energy and economic analysis of environmental upgrading of existing office buildings
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Citation: Ding, G., Nguyen,
D. M., and Runeson, G. 2020.
Energy and economic analysis
of environmental upgrading
of existing office buildings.
Construction Economics and
Building, 20:4, 82-102. http://
dx.doi.org/10.5130/AJCEB.
v20i4.7239 ISSN 2204-9029 | Published by
UTS ePRESS | https://epress.
lib.uts.edu.au/journals/index.
php/AJCEB Construction
Economics and
Building
Vol. 20, No. 4
December 2020 RESEARCH ARTICLE DECLARATION OF CONFLICTING INTEREST The author(s) declared no potential conflicts of interest with
respect to the research, authorship, and/or publication of this article. FUNDING The author(s) received no
financial support for the research, authorship, and/or publication of this article. DOI: 10.5130/AJCEB.v20i4.7239
Article history: Received 01/06/2020; Revised 15/09/2020; Accepted 02/10/2020;
Published 07/12/2020 DOI: 10.5130/AJCEB.v20i4.7239
Article history: Received 01/06/2020; Revised 15/09/2020; Accepted 02/10/2020;
Published 07/12/2020 DOI: 10.5130/AJCEB.v20i4.7239 © 2020 by the author(s). This
is an Open Access article
distributed under the terms
of the Creative Commons
Attribution 4.0 International
(CC BY 4.0) License (https://
creativecommons.org/licenses/
by/4.0/), allowing third parties
to copy and redistribute the
material in any medium
or format and to remix,
transform, and build upon the
material for any purpose, even
commercially, provided the
original work is properly cited
and states its license. Energy and economic analysis of
environmental upgrading of existing office
buildings Vol. 20, No. 4
December 2020 Vol. 20, No. 4
December 2020 Dinh Manh Nguyen, Grace Ding* and Göran Runeson Dinh Manh Nguyen, Grace Ding* and Göran Runeson
School of Built Environment, Faculty of Design, Architecture and Building, University of
Technology Sydney Dinh Manh Nguyen, Grace Ding* and Göran Runeson
School of Built Environment, Faculty of Design, Architecture and Building, University of
Technology Sydney School of Built Environment, Faculty of Design, Architecture and Building, University of
Technology Sydney *Corresponding author: Grace Ding, School of Built Environment, Faculty of Design,
Architecture and Building, University of Technology Sydney. Email - grace.ding@uts.edu.au Introduction Over the years, the building sector has been recognised as one of the main sectors to
negatively impact on the environment, creating shortages of natural resources, ozone
depletion, emissions of carbon dioxide (CO2), climate changes, and the deterioration of
living and working environments. This means that the building sector must improve to meet
sustainability requirements. The major challenge in the building sector today, therefore, is to
construct and maintain buildings in a more sustainable manner (Chan, Wang and Raffoni,
2014). Climate change, as debated for several decades, has captured people’s attention because of
the increase in the earth’s average temperature (IPCC, 2014). The building sector is one of the
sectors contributing to accelerated climate change. However, in return, climate change also
impacts on buildings with extreme weather conditions occurring more frequently, hampering
indoor comfort, and impacting productivity (Clarke, 2009; Cleugh et al., 2011). Increased
temperatures make many advanced technologies applied in buildings ineffective, which then
require more energy to maintain indoor comfort (Ürge-Vorsatz et al., 2007; Hinnells et al.,
2008). The situation is particularly severe in office buildings as people spend most of the time
indoor during working hours. The operating phase is the most extended period over a building’s lifecycle. In this
period, buildings consume most of the energy and consequently emit the highest amount of
greenhouse gases (GHG) into the environment (Huovila et al., 2009; Ibn-Mohammed et al.,
2013). The primary substance that contributes to climate change is CO2 (Lynas, 2007; Li and
Yao, 2009). Existing buildings are one of the major sources responsible for emitting high levels
of CO2 into the environment in the process of material manufacture and consumption for
maintenance in addition to the operating phase of a building (Wilson and Tagaza, 2006; Ürge-
Vorsatz, Koeppel and Mirasgedis, 2007; Ürge-Vorsatz et al., 2007; Kohler and Yang, 2007;
Wright, 2009; Zhou et al., 2016). Even though new buildings are increasingly constructed more sustainably, the number
of new buildings added each year is small compared to the many largely old and outdated
buildings in the stock (Wilkinson and Reed, 2006; Zhou et al., 2016). Since the general
conditions of the existing building stock is deteriorating, the adverse impacts on the
environment will continue unless the buildings’ performance is improved (Wilkinson and
Reed, 2006). Keywords: Energy upgrading, existing office buildings, energy efficiency, upgrading activities, economic
analysis. Abstract Over many decades, buildings have been recognised as a significant area contributing to the
negative impacts on the environment over their lifecycle, accelerating climate change. In
return, climate change also impacts on buildings with extreme heatwaves occurring more
frequently and raising the earth’s temperature. The operation phase is the most extended
period over a building’s lifespan. In this period, office buildings consume most energy and emit
the highest amount of greenhouse gas pollution into the environment. Building upgrading to
improve energy efficiency seems to be the best way to cut pollution as the existing building
stock is massive. The paper presents an economic analysis of energy efficiency upgrade of
buildings with a focus of office buildings. The paper identifies upgrading activities that are
commonly undertaken to upgrade energy efficiency of office buildings and a case study of
three office buildings in Sydney, Australia has been used to analyse the results. The upgrading
activities can improve the energy performance of the case study buildings from 3 stars to 5
stars NABERS energy rating in compliance with the mandatory requirement in the Australian
government’s energy policy. With the potential increase in energy price, energy efficiency
upgrading will become more affordable, but currently, most of them, except solar panels and
motion sensors show a negative return and would not be undertaken if they did not also
contribute to higher rental income and an increased life span of the building. The upgrading 82 Energy and economic analysis of environmental upgrading of existing office buildings discussed in the paper represent a potentially attractive alternative to demolition and building
anew. discussed in the paper represent a potentially attractive alternative to demolition and building
anew. Introduction Hence, the approach to alleviating the environmental impact of existing
buildings is to either demolish and rebuild or retain and upgrade the existing building
stock. The primary target in reducing the impact of buildings in the environment is to reduce
CO2 emissions (Lynas, 2007; Li and Yao, 2009; Burroughs, 2018). Research has shown that
sustainable upgrading of the existing building stock can achieve this and so improve the
value of buildings (Newell, MacFarlane and Walker, 2014; Wilkinson, 2014). However, 83 Construction Economics and Building, Vol. 20, No. 4, December 2020 Ding, Nguyen and Runeson many barriers limit stakeholders’ willingness to make their buildings more environmentally
friendly. The main obstacles include budgetary constraint, insufficient information, various
uncertainties as well as the lack of knowledge of and confidence in new technologies for
upgrading (Wilson and Tagaza, 2006; Elmualim et al., 2010; Bruce et al., 2015; Regnier et al.,
2018). The research aims at identifying upgrading activities commonly undertaken to improve
energy efficiency to the base building of existing office buildings. The research design includes
a comprehensive literature review to characterise upgrading activities and the associated
potential savings on energy consumption. There are several research objectives, including
identifying activities and technologies that cause minimal disturbance to the existing operation
of buildings. Therefore, activities that require major renovation, such as building envelope,
are excluded from the study. Secondly, analyse potential saving in energy consumption, CO2
emissions and the associated upgrading costs and saving of these activities and technologies. The final objective is to validate the analysis of these upgrading activities through a case study
of three buildings. The paper began with a discussion of the impact of existing office buildings on the
environment, followed by a discussion of upgrading activities that are commonly conducted
to improve energy efficiency of existing office buildings. The discussion focuses on analysing
upgrading cost and the potential savings in energy cost, energy consumption and CO2
emissions after upgrading. Finally, the paper presents a case study of three office buildings in
Sydney, Australia to analyse the upgrading improvement, potential savings and compliance
with the energy requirements for buildings in Australia. Environmental impact of existing office buildings and the
role of energy upgrading Recently, the rapidly increasing average temperature on earth has influenced the living
environment significantly. As a direct result of climate change, and in particular, the continual
and extreme heatwaves, people are responding by increasing the use of indoor climate
modifiers such as Heating, Ventilation and Air Conditioning (HVAC) systems to maintain
indoor comfort, which has escalated the demand for energy and hence CO2 emissions
(Kentwell, 2007; Anderson, Hawkins and Jones, 2016). The operating phase is the most extended and complicated period in a building’s lifecycle. The most significant emissions happen in the operating phase, approximately 80-90% of CO2
emissions, which is typically about 20-60 years, compared to the construction phase of usually
2-3 years (Huovila et al., 2009). The cost of operation and maintenance of office buildings can be as high as two times
more than the cost of the initial construction for a period of 30 years and it can increase up
to five times more for a longer lifespan (Ive, 2006; Snodgrass, 2008). The most significant
expenses are for indoor comfort, lighting, and the operation of equipment. Office buildings
are among the highest consumers of energy, and consequently, contribute high levels of GHG
emissions (Ibn-Mohammed et al., 2013). The annual energy consumption of office buildings
varies between 100 and 1,000 kWh per square metre depending on many variables, such as
geographic location, type and use of office equipment, operational schedules, type of envelope,
use of HVAC and lighting systems (Juan, Gao and Wang, 2010). In order to keep an office building functioning, it generally requires a major refurbishment
every 20–25 years (Wilkinson and Reed, 2006; Bruce et al., 2015). Furthermore, most of the Construction Economics and Building, Vol. 20, No. 4, December 2020 84 Energy and economic analysis of environmental upgrading of existing office buildings existing office buildings are several decades old and therefore are becoming energy inefficient
and may require upgrading to alleviate their impact in the environment (Wilkinson and
Reed, 2006; Taylor, 2009). A deteriorating building decreases in value and the quality of
the indoor environment will also deteriorate to the extent that it may harm the occupants,
threaten production and cost more to operate (Pitt, Goyal and Sapri, 2006; Huovila et al.,
2009). Therefore, old buildings need refurbishment to meet green standards and regulations
and improve energy performance (Bullen, 2007; Connelly and Adam, 2009). Environmental impact of existing office buildings and the
role of energy upgrading Improving the
energy efficiency of existing buildings attracts much attention as an important strategy to
reduce energy consumption and CO2 emissions (Huovila et al., 2009; Ibn-Mohammed et al.,
2013). Energy efficiency upgrading of existing office buildings is a key target for public policy
addressing climate change (Kentwell, 2007; Wild, 2008; Burroughs, 2018; Regnier et al.,
2018). However, budget constraint is a major barrier to restrict building upgrading activities. Additional costs, increased risks, and unknown performance of technologies to meet green
building standards may lead stakeholders to become reluctant to considering upgrading their
buildings (Regnier et al., 2018). However, even though there are barriers that may prevent owners from upgrading an
existing building, there are many drivers that may lead stakeholders to consider upgrading
their buildings. The financial return is one of the major drivers as sustainable upgrading has
the potential to improve an existing building to satisfy the economic needs of long-term
wealth and the requirements of environmental protection (Pitt et al., 2009; Häkkinen and
Belloni, 2011). Tenant demand is another significant driver for energy efficiency upgrading as
these buildings will benefit from the green branding, meet standards for the building leases
and occupations, and provide an indoor environment quality that improves user’s health
and productivity (Henderson, 2006; Wilson and Tagaza, 2006; Clarke, 2009; Cleugh et al.,
2011; Burroughs, 2018). The building sector is moving towards becoming greener with more
injections of green buildings, and when a building is deemed outdated, building owners could
consider upgrading the building, so that it can re-entering the building market (Chan, Qian
and Lam, 2009). IMPROVING ENERGY EFFICIENCY IN EXISTING OFFICE BUILDINGS The rapid growth of the property industry has accelerated change in the environment,
including technologies, standards, policies, and regulations. Existing office buildings,
particularly older ones, may not have kept up with the changes. However, under the current
environmental protection policies and regulations, older buildings are required to satisfy
environmental protection standards. For the existing building stock, the target is to improve buildings to be more
environmentally friendly (Abdallah and El-Rayes, 2015). The primary demand for improving
buildings for sustainability is to ensure energy consumption and CO2 emissions reductions in
buildings (Henderson, 2006; Wright, 2009). This can be achieved by upgrading buildings to
improve their energy efficiency, indoor comfort for occupants, lighting and air conditioning 85 Construction Economics and Building, Vol. 20, No. 4, December 2020 85 Ding, Nguyen and Runeson systems, and waste reusing and recycling (Jentsch, James and Bahaj, 2010; Abdallah and El-
Rayes, 2015). While almost every new office building is now constructed encompassing green
technologies and innovative design, existing office buildings can also be improved or
upgraded to meet sustainability standards (Abdallah and El-Rayes, 2015). The most
significant advantage that existing office buildings gain by being sustainable is that they
will stay competitive, increase energy efficiency, reduce vacancy rates, increase rental levels,
improve assets and counteract obsolescence (Wilkinson and Reed, 2006; Chan, Qian and
Lam, 2009). Sustainable buildings increase in value, gain positive influence in keeping
tenants, who will be provided with considerable savings on energy and water in running their
businesses. The challenge is improving the performance of existing buildings to lessen their negative
environmental impact. The challenge is not only to limit CO2 emissions but to reduce CO2
emissions with a target level that is high but achievable. Reducing energy consumption will
result in reduced CO2 emissions. As reported by the Fourth Assessment Report of the IPCC
(2007), the commercial sectors can save approximately 1.4 billion tonnes (approximately 29%)
of CO2 by 2020 when buildings are improved for energy efficiency. These GHG emissions
can be reduced by approximately 29% or even to zero-net with a further commitment (Ürge-
Vorsatz, Koeppel and Mirasgedis, 2007). During the operating stage of a building, energy consumption to provide heating, cooling,
lighting and to operate equipment and appliances is recognised as the most important (Juan,
Gao and Wang, 2010; Lecamwasam, Wilson and Chokolich, 2012; Abdallah and El-Rayes,
2015; Regnier et al., 2018). IMPROVING ENERGY EFFICIENCY IN EXISTING OFFICE BUILDINGS In the US, the building sector is responsible for approximately 39%
of the total primary energy requirements, of which 35% was used for HVAC as about 80%
of buildings in the US are equipped with air-conditioning systems (Nicol, 2009; Wan et al.,
2012). In Canada, building space heating and cooling account for 54% and 6% of energy use
respectively; while equipment, lighting, and hot water systems account for 20%, 13% and 7%
respectively (Ürge-Vorsatz et al., 2007). In China, energy use in the building stock has been steadily increased since the 1980s. Buildings consumed around 24% of the total national energy use in 1996, rose to around 28%
in 2001 and the growth was projected to rise to about 35% in 2020 (Wan et al., 2012). In
Australia, office buildings account for 25% of the total energy which is projected to increase
to 29% in 2020 (Department of Climate Change and Energy Efficiency, 2012; Higgins et al.,
2014). The CO2 emissions will increase from 23% in 2005 to 110% by 2050 if no action is
taken (CIE 2008; Höhne et al., 2017). Therefore, energy efficiency upgrading of the existing
building stock plays a crucial role in reducing energy demand and the associated CO2
emissions. Energy and economic analysis of environmental upgrading of existing office buildings due to climate change on working days. Consequently, CO2 emissions and pollution will also
increase. Lecamwasam (2014) also suggests that HVAC systems in older buildings can waste
approximately 20 to 40% of total energy consumption. Therefore, in achieving the efficient use
of energy and reducing CO2 emissions relating to indoor thermal comfort, conventional air-
conditioned offices have to be upgraded to improve productivity and maintain a comfortable
work environment (Barlow and Fiala, 2007; Kwon, Chun and Kwak, 2011; Au-Yong, Ali and
Ahmad, 2014). Artificial lighting is another important area to improve energy efficiency in buildings. In the life of a building, the combined HVAC and lighting accounts for about 80% of total
energy use during the operating stage (Juan, Gao and Wang, 2010; Abdallah and El-Rayes,
2015; DIS, 2015). In existing office buildings, the lighting systems that include inefficient
lamps and fixtures can be upgraded with more energy effective ones or by eliminating the
use of unnecessary lamps. Daylighting in office buildings is broadly considered an important
design strategy of energy preservation that demanded cautious architectural design to satisfy
that optimum benefits are achieved (Ko, Elnimeiri and Clarke, 2008; Raimondia et al.,
2016). Improving the lighting load will not only reduce annual energy consumption but also
reduce heat gains in buildings. The reduction of electricity consumption in office buildings
can be achieved with proper design, which integrates daylight and artificial lighting systems. Thus, building energy expenses can be affected by two key climatic factors, solar radiation and
outdoor illuminance, which can cool the buildings without the use of electricity where there is
a proper strategic plan (Li, Lam and Wong, 2006; Li et al., 2009). Another factor affecting the effectiveness of the lighting system in office buildings is
that the lighting system continuously interacts with the HVAC system. To improve energy
efficiency for heating in the winter and reducing energy use for cooling in summer, the
upgrading of the lighting systems must be coordinated with HVAC systems (Juan, Gao and
Wang, 2010; Abdallah and El-Rayes, 2015; Regnier et al., 2018). Due to daylight constantly
being associated with solar heat gain, when design levels exceed the space luminance required,
solar heat gains will increase, and consequently, the electrical cooling load will also increase
(Li, Lam and Wong, 2006; Li et al., 2009). Energy efficiency upgrading activities A way to minimise adverse environmental impacts is the upgrading of building systems or
components (Abdallah and El-Rayes, 2015). As stated previously, the HVAC system consumes
a significant amount of energy and it is a crucial element that provides the required indoor
comfort (Lecamwasam, Wilson and Chokolich, 2012). The quality of indoor air has negative
and positive effects on the productivity of users, in particular occupant health and safety. According to Barlow and Fiala (2007), by 2050, buildings which installed conventional HVAC
systems will increase energy use by more than 20% to provide the required indoor comfort Construction Economics and Building, Vol. 20, No. 4, December 2020 86 Energy and economic analysis of environmental upgrading of existing office buildings Research method The research aims at undertaking an economic analysis of energy efficiency upgrade of existing
office buildings. The literature review identified ten activities that are commonly upgraded, and
details are summarised in Table 1. Economic analysis of energy efficiency upgrade is important
as a budgetary constraint is one of the major barriers to the upgrading of existing office
buildings. Three case studies are used to analyse the economic impact of different upgrading
activities. The case studies involve three existing office buildings in Sydney, Australia, selected
to illustrate the potential economic impact of energy efficiency upgrades. Energy and economic analysis of environmental upgrading of existing office buildings When a large office building is upgraded with an
automation system, such as building management and control systems (BMCS), a savings
of 30% can be achieved from energy consumption (Colmenar-Santos et al., 2013). It can be
expected that the initial capital outlay for becoming green can be recovered by decreasing
long-term energy costs. The literature review has identified areas that are commonly upgraded to improve energy
efficiency of existing office buildings and are summarised in Table 1. The table presents
the upgrading activities that have contributed to reducing energy consumption and CO2
emissions. The potential savings in the table may vary according to various variables such
as climatic situation, geographical location of buildings, size, shape, operating and physical
conditions of individual buildings, and should be considered as a guide only. From the table
installing dimming control to the lighting system is found to have the most potential savings,
followed by upgrading to the HVAC, BMCS, lifts and escalators, and replacing conventional
hot water supply with a solar-boosted hot water system. 87 Construction Economics and Building, Vol. 20, No. 4, December 2020 Ding, Nguyen and Runeson Table 1
Summary of energy efficiency of common upgrading activities in office
buildings Energy and economic analysis of environmental upgrading of existing office buildings Australia commercial building grading that represent high quality office buildings in the CBD
(PCA, 2019). These three buildings were considered the best suited for the study due to the following
reasons: • These buildings range from 24 to 33 years old represents a suitable range of ages for
the investigation as literature review reveals that buildings within this range are due for
refurbishment or upgrade (Burroughs, 2018). • They are medium and high-rise office buildings having gross floor area (GFA) from
17,000m2 to 45,000m2. • The three case study buildings have annual energy consumption per GFA of 128,
103 and 135 kWh/m2/annum which is considered high (Hestnes and Kofoed, 2002;
Steinfeld, Bruce and Watt, 2011). Therefore, these buildings have opportunities for
improvement in the annual usage and savings on energy and CO2 emissions The maintenance and upgrade records and three years of utility bills (2015-2018) from the
facility management department were collected from each building. Additional data were also
collected from meetings with facility managers and site visits to each building to examine
building conditions and investigation into the maintenance and renovation records. Table 2
Characteristics of the three case study buildings Table 2
Characteristics of the three case study buildings Table 2
Characteristics of the three case study buildings The GFA of Building 2 is about 127% more than that of Building 1 but about 13% smaller
than Building 3. Even though Building 3 has the biggest GFA its average annual energy
consumption and CO2 emissions are not much higher than Building 1 per m2. Building 2
has the best performance of 103 kWh/m2/year and 112 kg CO2/m2/year respectively for the
average annual energy consumption and CO2 emissions. The GFA of Building 2 is about 127% more than that of Building 1 but about 13% smaller
than Building 3. Even though Building 3 has the biggest GFA its average annual energy
consumption and CO2 emissions are not much higher than Building 1 per m2. Building 2
has the best performance of 103 kWh/m2/year and 112 kg CO2/m2/year respectively for the
average annual energy consumption and CO2 emissions. Case study buildings The case study buildings, located in the Sydney Central Business District (CBD), are referred
to as Building 1, 2 and 3. The characteristics of the three buildings are summarised in Table
2. The three case study buildings are A-Grade buildings according to the Property Council of 88 Construction Economics and Building, Vol. 20, No. 4, December 2020 Energy and economic analysis of environmental upgrading of existing office buildings Potential energy savings and economic analysis of
upgrading activities The principal concern in upgrading an office building is financial; however, the other factor
that should be considered in decision-making is the environmental impacts. Key stakeholders
may be reluctant to invest money to improve their existing buildings. They face uncertainty
about the long-term benefits of their investment. Financial concerns can prevent or delay Construction Economics and Building, Vol. 20, No. 4, December 2020 89 Ding, Nguyen and Runeson stakeholders in improving buildings due to the required capital outlays (Ellison and Sayce,
2007; Sev, 2009). Therefore, for energy efficiency upgrade to be implemented in an existing
office building, affordability and long-term financial return must be included in the decision
making In the assessment of economic impact and potential energy savings in the case study, the
analysis concentrates on estimating the costs and savings of upgrading in the areas identified
from the literature review to improve energy efficiency of buildings. The estimated costs and
savings of upgrading are based on the data from research studies and published data. The
annual costs of upgrading are calculated in cost per square metre ($/m2), and savings are by
percentage (%) on energy consumption and CO2 emissions. The end-use shares of energy
consumed in office buildings are computed for electricity use only as gas consumption is very
little in this type of building (DIS, 2015). Construction Economics and Building, Vol. 20, No. 4, December 2020 1 Tenancy space is defined as an office space occupied by individual tenants for their intended business Estimating potential energy savings of upgrading activities The energy savings are based on savings on building services running on normal and peak
loads. The energy savings calculated are the end-use of energy consumption per annum. The
upgrading activities for energy efficiency and potential savings in the table were derived from
the literature review and published data on a typical office building in Australia for the base
building load only. Tenancy spaces1 were excluded from the study. Table 3 is developed based on the information in Table 1. Table 3 presents the calculation
of the percentage savings on various upgrading activities. According to the Department
of Industry and Science (DIS, 2015), the peak electricity demand in office buildings (base
building load) is HVAC accounting for 67%, lighting for 16%, equipment for 11%, domestic
hot water for 2% and others for 4%. Table 3
Summary of energy efficiency upgrading in office buildings (Base building
load) Table 3
Summary of energy efficiency upgrading in office buildings (Base building
load) Table 3
Summary of energy efficiency upgrading in office buildings (Base building
load) In the table, Column 3 represents the energy consumption distribution of a typical office
building and it indicates that HVAC consumes the most electricity, followed by lighting. The
fourth column shows the estimated savings in percentage should the systems be upgraded. 1 Tenancy space is defined as an office space occupied by individual tenants for their intended business. Construction Economics and Building, Vol. 20, No. 4, December 2020 90 Energy and economic analysis of environmental upgrading of existing office buildings Therefore, in considering the various energy demand per upgrade activity, the estimated annual
savings (Column 4) is calculated by multiplying the potential savings (Column 2) with the
energy consumption distribution (Column 3) in Table 3. From the table, a major upgrade
of the HVAC generates the highest potential saving of 20%, followed by lighting dimming
control of 7% in energy consumption. 2 GST is Goods and Services Tax in Australia levied on market transaction of goods and services, similar
to VAT in UK. Analysing potential energy savings and upgrading costs for
the case study buildings The maintenance and renovation records for the three buildings were collected and analysed. The analysis found that the following upgrading activities have been undertaken in the past
three years: • Both Building 1 and 2 have upgraded BMCS • Building 2 and 3 have upgraded electrical/power switchgear • All three buildings have replaced all lightings to T5 Therefore, the analysis has focused on the rest of the upgrading activities as included in Tables
3 and 4. Table 5 summarises the estimated potential savings in energy consumption (kWh/
m2), CO2 emissions (kg CO2/m2) and energy cost ($/m2) for the three buildings. The potential
annual savings on energy cost is calculated from the energy price of approximately $0.35/kWh
adapted from WePowr (2019) and Synergy (2019) and multiplied with annual savings on
energy consumption for each building. The annualised upgrading cost in the table includes both the capital and maintenance
costs. The three case studies, with current ages from 24 to 33 years old, are all due for a major
refurbishment within the next few years. This means that all items with lifespans of 15 and 30
years will have to be replaced in this process. Therefore, it provides a significant opportunity
to improve the energy performance of these buildings. In the table, the highest savings on
annual energy cost is the HVAC with a saving in the range of $7.2–$9.5/m2, followed by an
automatic dimming of lighting ($2.7–$3.5/m2) and double glazing to windows ($2.2–$2.8/
m2). Similar outcomes can be found for the potential savings of energy consumption and CO2
emissions. When comparing annualised upgrading cost and the potential savings of energy
cost after upgrading, only for BMCS, solar panels and motion sensors do savings outweigh the
upgrading cost. All other activities have higher annualised upgrading cost than the potential
saving in energy cost which may have tendered the upgrading unprofitable. However, the gap
between upgrading cost and energy cost saving can be narrowed or reversed with the likely
increases in the price of energy. The annualised upgrading cost and potential savings are also presented graphically in
Figure 1. The annualised upgrading cost is presented from the lowest to highest ($/m2). The
horizontal axis represents upgrading activities. The vertical axis on the left is the annualised
upgrading cost ($/m2), ranging approximately from $0.1–39/m2. Estimating annualised upgrading costs The estimation of upgrading costs that include both capital and maintenance during the
lifecycle of the building has been summarised and presented in Table 4. The capital costs in
upgrading are priced as at 2019 in terms of $/m2 of GFA (excluding GST2 or VAT). The
maintenance costs were developed from journal articles and building maintenance websites
(Menzies and Wherrett, 2005; Kubba, 2010; Steinfeld, Bruce and Watt, 2011; CostWeb,
2019; Rawlinsons, 2019; WePowr, 2019; Synergy, 2019). However, according to Nalewaik
and Venters (2009) and Wu (2010), there are no fixed costs in the maintenance of building
service system. Annual maintenance costs may vary depending on the frequency in schedules,
the size and operation of systems. Therefore, the maintenance cost for each upgrade activity
is estimated from information from facility managers of each case study buildings with
appropriate adjustment to suit. The lifespan of each system or equipment is also included in Table 4. It is expected that
each system or equipment may need to be upgraded one or more times over the building’s
lifecycle. To simplify the calculation, the upgrading cost is annualised on a 30-year study
period at a discount rate of 5%. Table 4
Economic analysis of energy efficiency upgrading in office buildings (base
building load) Table 4
Economic analysis of energy efficiency upgrading in office buildings (base
building load) 2 GST is Goods and Services Tax in Australia levied on market transaction of goods and services, similar
to VAT in UK. 91 Construction Economics and Building, Vol. 20, No. 4, December 2020 91 Construction Economics and Building, Vol. 20, No. 4, December 2020 Ding, Nguyen and Runeson In the table, the minor upgrade to HVAC and lighting have been left open due to significant
variations in the type and size of upgrading activities. From the table, the highest annualised
upgrading cost is the installation of double glazing to windows to reduce heat gain and loss in
the building of approximately $39/m2 with an approximate potential saving of 6% on annual
energy consumption and CO2 emission. While upgrading the entire HVAC system has an
annualised cost of approximately $22/m2 but will give a saving on annual energy consumption
and CO2 emissions of 20%. The lowest upgrading cost is the installation of BMCS with an
annualised cost of $0.1/m2 for a potential savings of 3%. Analysing potential energy savings and upgrading costs for
the case study buildings The vertical axis on the right
shows the percentage of potential savings on energy consumption and CO2 emissions, which
range from approximately 0.6–20%. 92 Construction Economics and Building, Vol. 20, No. 4, December 2020 Energy and economic analysis of environmental upgrading of existing office buildings Energy and economic analysis of environmental upgrading of existing office buildings Table 5
Summary of potential savings for the three buildings 93 Construction Economics and Building, Vol. 20, No. 4, December 2020 Ding, Nguyen and Runeson The budgetary constraint may dictate the upgrading activities to be undertaken or may even
have forbidden energy efficiency upgrade of existing office buildings to take place. The figure
presents the annualised upgrading costs from the least to the most expensive activities to suit
the appropriate work for the budget allowed in improving a building. Each building can be independently assessed and upgrading criteria selected depending
on its geographic location, type, use of equipment, operational and maintenance schedules. Improvements can start from basic and consider activities with lesser intervention through to Each building can be independently assessed and upgrading criteria selected depending
on its geographic location, type, use of equipment, operational and maintenance schedules. Each building can be independently assessed and upgrading criteria selected depending
on its geographic location, type, use of equipment, operational and maintenance schedules. Improvements can start from basic and consider activities with lesser intervention through to
more major upgrading to one or more parts of a system rather than upgrading or replacing the
entire system unless it is necessary. Improvements can start from basic and consider activities with lesser intervention through to
more major upgrading to one or more parts of a system rather than upgrading or replacing the
entire system unless it is necessary. Figure 1
Compare upgrading activities between annualised upgrading costs and
potential energy savings over a 30-year period Figure 1
Compare upgrading activities between annualised upgrading costs and
potential energy savings over a 30-year period The upgrading can start with basic activities such as upgrading BMCS to monitor building
services, install solar panels to offset energy demand from the main grid, motion sensors to
turn off lightings of unoccupied space and replace hot water supply with solar-boosted hot
water systems. Upgrading these basic activities can contribute approximately 10% reduction of
energy consumption and the associated CO2 emission with an annualised upgrading cost of
$1.8/m2. Analysing potential energy savings and upgrading costs for
the case study buildings With a more generous budget, more expensive upgrading activities can take place to
achieve more reduction. A major upgrade to the HVAC system and installation of automatic
dimming control can lead to a potential reduction of energy consumption and CO2 emissions
by approximately 28% with an annualised upgrading cost of $31.4/m2. However, for
more expensive upgrading activities such as double glazing to windows, upgrading can be
undertaken to part of the system only. In most cases, HVAC systems can be upgraded partially
by replacing components such as cooling towers, chillers, or air handling units with more
efficient alternatives. fi
The results of the analysis are also presented in Table 6 to compare the outcomes of
the three buildings. Building 1 has the highest annualised upgrading costs of $95/m2 with
potential annual savings on the energy cost of $19/m2. Buildings 2 and 3 have similar
annualised upgrading costs of approximately $76/m2. However, Building 3 generates more
potential annual energy cost savings of $21/m2, approximately 29% more than Building 2 with
the same amount of investment. Construction Economics and Building, Vol. 20, No. 4, December 2020 94 Energy and economic analysis of environmental upgrading of existing office buildings Energy and economic analysis of environmental upgrading of existing office buildings Table 6
Comparing annual potential savings of energy cost, energy consumption and
CO2 emissions for the three buildings
Case study
building
Annualised
upgrading cost
($/m2)
Potential savings after upgrading
Energy cost*
($/m2)
Energy
consumption
(kWh/m2)
CO2
emissions
(kg CO2/m2)
1
94.8
19.1
54.5
61.1
2
76.1
15
42.8
46.7
3
76.2
21
60.1
65.1
Note:
* Energy cost refers to the savings on the cost of electricity consumption per
annum on undertaking the upgrading activities as detailed in Table 2
Energy and economic analysis of environmental upgrading of existing office buildings Table 6
Comparing annual potential savings of energy cost, energy consumption and
CO2 emissions for the three buildings Note:
* Energy cost refers to the savings on the cost of electricity consumption per
annum on undertaking the upgrading activities as detailed in Table 2 With regards to energy consumption and CO2 emissions, Building 2 outperforms the other
two buildings. Building 2 is lower in energy consumption by approximately 22% and 29%,
CO2 emission by approximately 24% and 28% respectively for Buildings 1 and 3. Analysing potential energy savings and upgrading costs for
the case study buildings With the
upgrading activities in the table, Building 1 can be improved to achieve total potential annual
savings of approximately 55 kWh/m2 of energy consumption and 61 kg CO2/m2 of CO2
emissions, which results in an annual saving of approximately $19/m2 of operating energy
costs. The calculation can reduce the energy consumption of Building 1 from the annual
average of 128 to approximately 73 kWh/m2 and CO2 emissions from 143 to approximately
82 kg CO2/m2 annually. In a similar context, Building 2 can be improved to achieve total potential annual savings
of approximately 43 kWh/m2 of energy consumption and 47 kg CO2/m2 of CO2 emissions. The upgrading may result in an annual savings of approximately $15/m2 on energy costs. The upgrading activities can reduce the energy consumption of Building 2 from the original
annual consumption of 103 to approximately 60 kWh/m2 and CO2 emissions from 112 to
approximately 65 kg CO2/m2 per annum. Building 3 can also be improved to achieve total
potential annual savings of approximately 60 kWh/m2 of energy consumption and 65 kg CO2/
m2 CO2 emissions which results in an annual savings of approximately $21/m2 on energy costs. The upgrading activities can reduce the energy consumption of Building 3 from the average
annual consumption of 135 to approximately 75 kWh/m2 and CO2 emissions from 147 to
approximately 82 kg CO2/m2 per year. Compliance with the Australian government energy
efficiency policy The sustainability agenda in green office buildings in Australia have significant developments
in recent years. This has been driven at all levels. Nationally, the government has implemented
an energy efficiency policy and has introduced the Green Lease policy which requires tenant
occupied buildings to have a low impact on the environment, such as a 4.5 star or higher
in the National Australian Built Environment Rating Scheme (NABERS) energy rating
(Bannister, 2012; Burroughs, 2018). Under the national energy program for Commercial
Building Disclosure, from 1 November 2010, when selling or leasing an office space greater
than 2,000 m2 sellers or lessors are required to obtain or disclose up-to-date NABERS energy 95 Construction Economics and Building, Vol. 20, No. 4, December 2020 95 Ding, Nguyen and Runeson ratings with the Building Energy Efficiency Certificates for all existing buildings (Newell,
MacFarlane and Walker, 2014; DIS, 2015). According to the guidelines from the NABERS rating, a 2 stars NABERS is equivalent
to the energy consumption of 150-190 kWh/m2/year whilst 5 stars rating accounts for 40-
80 kWh/m2/year (Steinfeld, Bruce and Watt, 2011; Bannister, 2012; DIS, 2015). The three
case study buildings undertaking the upgrading activities in Table 6 can improve the energy
performance from 3 stars to a 5 stars NABERS energy rating which could make a significant
impact to improve performance of the existing building stock. The increased star rating of
these buildings is likely to have better tenant retention with higher rents as potential tenants
of office buildings would recognise the energy efficiency of NABERS rating which would help
to pay for the costs of upgrading. The Australian building stock comprises many older buildings which consume great
quantities of energy and produce a high rate of CO2 emission (Burroughs, 2018). Traditionally,
to maintain its intended function a building must be well maintained and, particularly, have a
major refurbishment every 20–25 years (Wilkinson and Reed, 2006). However, according to
Wilkinson and Reed (2006), and Mulholland, Hartman and Plumb (2005), the average age of
the office building stock in major CBDs throughout Australia varies from 25 to 31 years since
construction or from 13 to 19 years since the last refurbishment; and the average age of office
buildings in Sydney is 28 years and 19 years respectively. Existing building stock continues to
contribute negatively to the environment and the well-being of users. Compliance with the Australian government energy
efficiency policy Therefore, the current
existing office buildings in Australia must be improved to meet environmental standards
(Remøy and Wilkinson, 2012; Strachan and Banfill, 2012; Xu, Chan and Qian, 2012). With
CBD office buildings being the primary focus for economic and financial activity in Australia,
the existing office space accounts for approximately 25 million square metres (Newell,
MacFarlane and Walker, 2014). For undertaking the upgrading activities as identified in the
study, a potential saving of 4,7222,300 GJ and 1,440,750 t CO2 of energy consumption and
CO2 emissions could be achieved each year. Construction Economics and Building, Vol. 20, No. 4, December 2020 Energy and economic analysis of environmental upgrading of existing office buildings m2/year respectively for Building 1, 2 and 3. The energy efficiency of the three buildings could
be improved from 3 stars to 5 stars NABERS Energy rating. The improved 5 stars NABERS
Energy rating of the three case study buildings can achieve the requirement set by the
Commercial Building Disclosure stipulated by the government in 2011. From the study, the
annualised upgrading costs still outweighed annual saving in energy cost in most activities. The
likely increase in future energy prices is likely to improve the attractiveness of energy efficiency
upgrade. In the long-term, the improvement in the energy efficiency of the existing building
stock will no doubt benefit both the natural and man-made environment. i
Creating sustainable buildings from existing office buildings is an attractive and important
alternative to demolition and rebuilding as a means to entice tenants. It is argued that
sustainability is the expected way forward where retrofitting or upgrading of mature buildings
is seen as necessary to meet the environmental protection requirements. The sustainable
improvement of existing office buildings would help in harmonising the growth of the economy
and environmental protection. A balance must be achieved between protecting and improving
the natural environment and contributing positively to the economy over the building’s lifecycle. Buildings which offer multiple uses that meet market demands will reduce vacancy rates and
thus survive longer and stay competitive, yet, improving the sustainable performance of existing
office buildings in a long-tern approach has been largely untapped. However, the paper has
limitations similar to other case studies in the literature. The generalisation of research result is
often difficult with case studies that are subjected to variances such as geographical location and
climate conditions. The research focuses on economic and environmental aspects only while the
social aspect is an equally important consideration for future research. Conclusion The paper examined and analysed the cost implication of energy efficiency upgrading of
existing office buildings and a case study of three Sydney office buildings has been conducted
to present research results. The objectives set for the study have been researched and addressed
in the paper. Firstly, the paper identified and discussed ten upgrading activities that are
commonly undertaken to improve energy efficiency of existing office buildings. These include
upgrades to HVAC, BMCS, hot water systems, lightning, lifts, and escalators Secondly. The upgradings were applied to a case study of three buildings located in the Sydney CBD
and varying in age from 24 to 33 years old. to demonstrate the potentials for significant
improvement in reducing energy consumption and the associated CO2 emissions. As discussed in the paper, existing office building stock is largely dated and energy
inefficient. The literature review indicates that an existing office building can be improved
to meet environmental protection standards by upgrading that may be a better alternative
than knocking down and rebuilding. When undertaking energy efficiency upgradings, the
annual energy consumption (kWh/m2) and emissions (kg CO2/m2) can be significantly
decreased. Most existing office buildings in Australia, especially in Sydney, are outdated. It was
demonstrated in the case studies that by undertaking upgrading activities, energy consumption
could be reduced by 55, 42 and 60 kWh/m2/year and CO2 emissions by 61, 47 and 65 kg CO2/ Construction Economics and Building, Vol. 20, No. 4, December 2020 96 References Abdallah, M. and El-Rayes, K., 2015. Optimizing the selection of building upgrade measures
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Data-Driven Interpolation of Sea Level Anomalies Using Analog Data Assimilation
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Remote sensing
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Received: 21 January 2019; Accepted: 4 April 2019; Published: 9 April 2019 Abstract: From the recent developments of data-driven methods as a means to better exploit
large-scale observation, simulation and reanalysis datasets for solving inverse problems, this study
addresses the improvement of the reconstruction of higher-resolution Sea Level Anomaly (SLA)
fields using analog strategies. This reconstruction is stated as an analog data assimilation issue,
where the analog models rely on patch-based and Empirical Orthogonal Functions (EOF)-based
representations to circumvent the curse of dimensionality. We implement an Observation System
Simulation Experiment (OSSE) in the South China Sea. The reported results show the relevance
of the proposed framework with a significant gain in terms of Root Mean Square Error (RMSE)
for scales below 100 km. We further discuss the usefulness of the proposed analog model as a
means to exploit high-resolution model simulations for the processing and analysis of current and
future satellite-derived altimetric data with regard to conventional interpolation schemes, especially
optimal interpolation. Keywords: analog data assimilation; sea level anomaly; sea surface height; interpolation;
data-driven methods Redouane Lguensat 1,*
, Phi Huynh Viet 2, Miao Sun 3, Ge Chen 4, Tian Fenglin 4
,
Bertrand Chapron 5 and Ronan Fablet 2 Redouane Lguensat 1,*
, Phi Huynh Viet 2, Miao Sun 3, Ge Chen 4, Tian Fenglin 4
,
Bertrand Chapron 5 and Ronan Fablet 2 1
IGE, Université Grenoble Alpes, CNRS, IRD, Grenoble INP, 38000 Grenoble, France 2
IMT Atlantique, Lab-STICC UMR CNRS 6285, UBL, 29200 Brest, France; Vietphi3892@gmail.com (P.H. ronan.fablet@imt-atlantique.fr (R.F.) q
(
)
3
Key Laboratory of Digital Ocean, National Marine Data and Information Service, Tianjin 300171, China;
miaomiao_1987qq@126.com 3
Key Laboratory of Digital Ocean, National Marine Data and Information Service, Tianjin 300171, China;
miaomiao_1987qq@126.com qq
4
Department of Marine Information Technology, Ocean University of China, Qingdao 266100, China;
gechen@ouc.edu.cn (G.C.); tianfenglin@ouc.edu.cn (T.F.) 4
Department of Marine Information Technology, Ocean University of China, Qingdao 266100, China;
gechen@ouc.edu.cn (G.C.); tianfenglin@ouc.edu.cn (T.F.) 5
Laboratoire d’Océanographie Physique et Spatiale, IFREMER, 29200 Brest, France;
bertrand.chapron@ifremer.fr *
Correspondence: redouane.lguensat@univ-grenoble-alpes.fr remote sensing remote sensing remote sensing www.mdpi.com/journal/remotesensing 1. Introduction Typically, horizontal scales from
a few tens of kilometers to ≈100 km may be poorly resolved by OI-derived SSH fields, while they
may be partially revealed by along-track altimetric data. This has led to a variety of research studies
to improve the reconstruction of the altimetric fields. One may cite both methodological alternatives
to OI, for instance locally-adapted convolutional models [17] and variational assimilation schemes
using model-driven dynamical priors [18], as well as studies exploring the synergy between different
sea surface tracers, especially the synergy between SSH and SST (Sea Surface Temperature) fields and
Surface Quasi-Geostrophic dynamics [17,19–23]. Q
p
y
[
,
]
In this work, we build upon our recent advances in analog data assimilation and its application to
high-dimensional fields. While the works in [12,13] presented the AnDA framework by combining
the analog forecasting method and stochastic filtering, these works have only shown applications to
geophysical toy models. It was not until the work in [24] that the AnDA methodology was applied to
realistic high dimensional fields, namely, Sea Surface Temperature (SST). Dealing with the curse of
dimensionality is a critical challenge, in [24] we have shown that the use of patch-based representations
(a patch is a term used by the image processing community to refer to smaller image parts of a given
global image [25]) combined with EOF-based representations (EOF stands for Empirical Orthogonal
Function, a classic dimensionality reduction technique also known as Principal Component Analysis
(PCA)) leads to a computationally-efficient interpolation of missing data in SST maps outperforming
classical OI-based interpolation schemes. Another development in AnDA applied to high dimensional
fields was the introduction of conditional and physically-derived operators [26], where the analog
forecasting operators account for the theoretical studies relating to synergies between ocean variables
(e.g., SSH and SST) and those highlighting the importance of inter-scale dependencies. In this paper,
we make use of these previously developed methodologies and tools and apply the AnDA to Sea Level
Anomaly fields. 1. Introduction Over the last two decades, ocean remote sensing data has benefited from numerous remote earth
observation missions. These satellites measured and transmitted data about several ocean properties,
such as sea surface height, sea surface temperature, ocean color, ocean current, sea ice, etc. This has
helped building big databases of valuable information and represents a major opportunity for the
interplay of ideas between the ocean remote sensing community and the data science community. Exploring machine learning methods in general and non-parametric methods in particular is now
feasible and is increasingly drawing the attention of many researchers [1,2]. More specifically, analog forecasting [3] which is among the earliest statistical methods explored
in geoscience benefits from recent advances in data science. In short, analog forecasting is based on
the assumption that the future state of a system can be predicted throughout the successors of past
(or simulated) similar situations (called analogs). The amount of currently available remote sensing
and simulation data offers analog methods a great opportunity to catch up their early promises. Several Remote Sens. 2019, 11, 858; doi:10.3390/rs11070858 www.mdpi.com/journal/remotesensing 2 of 22 Remote Sens. 2019, 11, 858 recent works involving applications of analog forecasting methods in geoscience fields contribute in
the revival of these methods, recent applications comprise the prediction of soil moisture anomalies [4],
the prediction of sea-ice anomalies [5], rainfall nowcasting [6], numerical weather prediction [7–9],
etc. One may also cite methodological developments such as dynamically-adapted kernels [10] and
novel parameter estimation schemes [11]. Importantly, analog strategies have recently been extended
to address data assimilation issues within the so-called analog data assimilation (AnDA) [12,13],
where the dynamical model is stated as an analog forecasting model and combined to state-of-the-art
stochastic assimilation procedures such as Ensemble Kalman filters. Producing time-continuous and gridded maps of Sea Surface Height (SSH) is a major challenge
in ocean remote sensing with important consequences on several scientific fields from weather and
climate forecasting to operational needs for fisheries management and marine operations (e.g., [14]). The reference gridded SSH product commonly used in the literature is distributed by Copernicus
Marine Environment Monitoring Service (CMEMS) (formerly distributed by AVISO+). This product
relies on the interpolation of irregularly-spaced along-track data using an Optimal Interpolation (OI)
method [15,16]. While OI is relevant for the retrieval of horizontal scales of SSH fields up to ≈100 km,
the prescribed covariance priors lead to smoothing out finer-scales. 2.1. Model Simulation Data The Ocean General Circulation Model (OGCM) for the Earth Simulator (OFES) is considered in
this study as the true state of the ocean. The simulation data is described in [27,28]. The coverage of the
model is 75◦S–75◦N with a horizontal resolution of 1/10◦. 34 years (1979–2012) of 3-daily simulation
of SSH maps are considered, we proceed to a subtraction of a temporal mean to obtain SLA fields. In this study, our region of interest is located in the South China Sea (105◦E to 117◦E, 5◦N to 25◦N). This dataset is split into a training dataset corresponding to the first 33 years (4017 SLA maps) and a
test dataset corresponding to the last year of the time series (122 SLA maps). 1. Introduction The contribution of this work is two-fold: (i) Confronting AnDA to the reconstruction
of an ocean tracer with scarce observations compared to SST (due to the nature of the available
altimeters); (ii) designing an Observation System Simulation Experiment (OSSE) based on numerical
simulation data to build the archived datasets used for the analog search; (iii) Reconstructing Sea
Level Anomaly (SLA) by using SST or large scale SLA as auxiliary variables embedded in the analog
regression techniques as shown in Section 4. Using OFES (Ocean General Circulation Model (OGCM) for the Earth Simulation) numerical
simulations [27,28], we design an Observation System Simulation Experiment (OSSE) for a case-study
in the South China Sea using real along-track sampling patterns of spaceborne altimeters. Several
particular mesoscale variation patterns characterizing this region were studied in the literature, we refer
the reader to [29] and references therein. We also note that our method is not region specific and can be 3 of 22 Remote Sens. 2019, 11, 858 applied to any region of interest. Using the resulting groundtruthed dataset, we perform a qualitative
and quantitative evaluation of the proposed scheme, including comparisons to state-of-the-art schemes. The remainder of the paper is organized as follows: Section 2 presents the different datasets used
in this paper to design an OSSE, Section 3 gives insights on the classical methods used for mapping SLA
from along track data, Section 4 introduces the proposed analog data assimilation model. Experimental
settings are detailed in section 5 and results for the considered OSSE are shown in Section 6. Section 7
further discusses the key aspects of this work. 2. Data: OFES (OGCM for the Earth Simulator) An Observation System Simulation Experiment (OSSE) based on numerical simulations is
considered to assess the relevance of the proposed analog assimilation framework. Our OSSE uses
these numerical simulations as a groundtruthed dataset from which simulated along-track data are
produced. We describe further the data preparation setup in the following sections. 3.1. Data Assimilation and Optimal Interpolation 3.1. Data Assimilation and Optimal Interpolation Data assimilation consists in estimating the true state of a physical variable x(t) at a specific time t,
by combining (i) equations governing the dynamics of the variable, (ii) available observations y(1, ..., T)
measuring the variable and (iii) a background or first guess on its initial state xb. The estimated state is
generally called the analyzed state and noted by xa. Data assimilation is a typical example of inverse
problems, and similar formulations are known to the statistical signal processing community through
optimal control and estimation theory [30]. We adopt here the unified notation of [31] and formulate
the problem as a stochastic system in the following: (
x(t) = M(x(t −1)) + η(t),
(1)
y(t) = H(x(t)) + ϵ(t). (2) (1)
(2) (1)
(2) (2) Equation (1) represents the dynamical model governing the evolution of state x through time,
while η is a Gaussian centered noise of covariance Q that models the process error. Equation (2)
explains the relationship between the observation y(t) and the state to be estimated x(t) through the
operator H. The uncertainty of the observation model is represented by the ϵ error, considered here
to be Gaussian centered and of covariance R. We assume that ϵ and η are independent and that Q
and R are known. Two main approaches are generally considered for the mathematical resolution of
the system (1) and (2), namely, variational data assimilation and stochastic data assimilation. They
differ in the way they infer the analyzed state xa, the first is based on the minimization of a certain cost
function while the latter aims to obtain an optimal a posteriori estimate. We encourage the reader to
consider the book of [32] for detailed insights on the various aspects and methods of data assimilation. A popular data assimilation algorithm that is largely used in the literature to grid sea level
anomalies from along-track data is called Optimal Interpolation (OI) (e.g., [15,33]), this algorithm is
also the method adopted in CMEMS altimetry product. Optimal Interpolation (OI) aims at finding
the Best Linear Unbiased Estimator (BLUE) of a field x given irregularly sampled observations y in
space and time and a background prior xb. The multivariate OI equations were derived in [34] for
meteorology and numerous applications in oceanography have been reported since the early work
of [16]. 2.2. Along Track Data We consider a realistic situation with a high rate of along track data. More precisely we use
along-track data positions registered in 2014 where four satellites (Jason2, Cryosat2, Saral/AltiKa,
HY-2A) were operating. Data is distributed by Copernicus Marine and Environment Monitoring
Service (CMEMS). From the reference 3-daily SLA dataset and real along-track data positions, we generate simulated
along-track data from the sampling of a reference SLA field: More precisely, for a given along-track
point, we sample the closest position of the 1/10◦regular model grid at the closest time step of
the 3-daily model time series. As we consider a 3-daily assimilation time step (see Section 2.1 for
details), we create a 3-daily pseudo-observation field, to be fed directly to the assimilation model. For a
given time t, we combine all along-track positions for times t −1, t and t + 1 to create an along-track
pseudo-observation field at time t. We denote by s3dAT the simulated 3-daily time series of along-track
pseudo-observation fields. An example of these fields is given in Figure 1. 4 of 22 Remote Sens. 2019, 11, 858 Ground Truth
114 oE
106 oE
108 oE
110 oE
112 oE
116 oE
8 oN
12 oN
16 oN
20 oN
24 oN
-0.3
-0.2
-0.1
0
0.1
0.2
Simulated Along track
24 oN
20 oN
16 oN
12 oN
8 oN
116 oE
114 oE
112 oE
110 oE
108 oE
106 oE
-0.3
-0.2
-0.1
0
0.1
0.2
Figure 1. An example of a ground-truth Sea Level Anomaly (SLA) field (meters) in the considered
region and its associated simulated pseudo-along track. Ground Truth
114 oE
E
108 oE
110 oE
112 oE
116 oE Figure 1. An example of a ground-truth Sea Level Anomaly (SLA) field (meters) in the considered
region and its associated simulated pseudo-along track. 3.1. Data Assimilation and Optimal Interpolation Supposing that the background state xb has covariance B, and the observation operator is Remote Sens. 2019, 11, 858 5 of 22 linear H = H, the analyzed state xa and the analyzed error covariance Pa can be calculated using the
following OI set of equations: K = BH(R + HBHT)−1
called the Kalman gain,
(3)
xa = xb + K(y −Hxb),
(4)
Pa = (I −KH)B. (5) (3) (3)
(4)
(5) (5) It is worth mentioning that [35] showed that OI is closely related to the 3D-Var variational data
assimilation algorithm which obtains xa by minimizing the following cost function: J(x) = (x −xb)TB−1(x −xb) + (y −Hx)TR−1(y −Hx). (6) (6) An important limitation of OI is that the Gaussian-like covariance priors lead to smoothing out
the small-scale information (e.g., mesoscale eddies), more specifically, this is a limitation due to the
use of a static climatological B matrix. For satellite-derived altimetry fields, this usually results in
over-smoothing altimetry fields for structures below ≈100 km [18]. This limitation may be even more
critical in the context of future high-resolution altimetry missions, which supports the development of
new OI-based methods (e.g., multi-scale OI schemes as in [36]) or alternatives as addressed by our
work. 3.2. Analog Data Assimilation Endorsed by the recent development in data-driven methods and data storage capacities,
the Analog Data Assimilation (AnDA) was introduced as an alternative to classical model-driven data
assimilation under one or more of the following situations [13]: •
The model is inconsistent with observations. •
The model is inconsistent with observations. •
The cost of the model integration is high computationally. The cost of the model integration is high computationally. •
The cost of the model integration is high computationally. •
(mandatory) The availability of a represenative (large) dataset of the dynamics of the state
variables to be estimated. These datasets are hereinafter called catalogs and denoted by C. The catalog is organized in a two-column dictionary where each state of the system is associated
with its successor in time, forming a set of couples (Ai, Si) where Ai is called the analog and Si
its successor. Given the considerations above, AnDA resorts to evaluating filtering, respectively smoothing,
posterior likelihood, i.e., the distribution of the state to be estimated x(t) at time t, given past
and current observations y(1, ..., t), respectively given all the available observation y(1, ..., T). This evaluation relies on the following state-space model: (
x(t) = F(x(t −1)) + η(t),
(7)
y(t) = H(x(t)) + ϵ(t). (8) (7) (7)
(8) (8) The difference between AnDA and classical data assimilation resides in the transition model
Equation (7). The counterpart of a model-driven operator M of Equation (1) is here the operator
F which refers to the considered data-driven operator, so called, the analog forecasting operator. This operator makes use of the available catalog C and assumes that the state forecast can be inferred
from similar situations in the past. Provided the definitions of the analogs and successors given above, the derivation of this operator
resorts to characterizing the transition distribution i.e., p(x(t)|x(t −1)). Following [13], a Gaussian
conditional distribution is adopted: p(x(t)|x(t −1)) = N (µ(x(t −1)), Σ(x(t −1))),
(9) (9) 6 of 22 Remote Sens. 2019, 11, 858 where N is a Gaussian distribution of mean µ(x(t −1)) and covariance Σ(x(t −1)). These parameters
of the Gaussian distribution are calculated using the result of a K nearest neighbors search. 3.2. Analog Data Assimilation The K
nearest neighbors (analogs) Ak∈(1,...,K) of state x(t −1) and their successors Sk∈(1,...,K), along with a
weight associated to each pair (Ak, Sk) are used to calculate µ(x(t −1)) and Σ(x(t −1)) as we will
show in the next paragraph, the forecast state x(t) is then sampled from N (µ(x(t −1)), Σ(x(t −1))). The weights are defined using a Gaussian kernel KG. KG (u, v) = exp
−∥u −v∥2
σ
. (10) (10) Scale parameter σ is locally-adapted to the median value of the K distances ∥x(t −1) −Ak∥2 to
the K analogs. Other types of kernels might be considered (e.g., [4,10]), investigating kernel choice is
out of the scope of this paper. The mean and the covariance of the transition distribution might be calculated following several
strategies. We consider in this work the three analog forecasting operators introduced in AnDA [13],
more details can be found in Appendix A: •
Locally-constant operator: Mean µ(x(t −1)) and covariance Σ(x(t −1))) are given by the
weighted mean and covariance of the K successors Sk∈(1,...,K). y
p
µ( (
))
( (
)))
g
weighted mean and covariance of the K successors Sk∈(1,...,K). •
Locally-incremental operator:
Here, the increments between the K analogs and their
corresponding successors are calculated Sk∈(1,...,K) −Ak∈(1,...,K). The weighted mean of the K
increments is then added to the x(t −1) to obtain µ(x(t −1)). While Σ(x(t −1))) results in the
weighted covariance of these differences. •
Locally-linear operator: A weighted least-square estimation of the linear regression of the state at
time t given the state at time t −1 is performed based on the K pairs (Ak, Sk). The parameters of the
linear regression are then applied to state x(t −1) to obtain µ(x(t −1)). Covariance Σ(x(t −1)))
is represented by the covariance of the residuals of the fitted weighted linear regression. We may state clearly the key difference between the AnDA and reduced-rank Kalman filters
and the OI method. It lies in the fact that the AnDA introduces a dynamical operator and not a
prescribed space-time covariance model, and this dynamical operator is state-dependent and globally
non-linear. The proposed analog forecasting operator can be seen as a state-dependent linear Gaussian
operator, meaning that it is locally Gaussian and linear at each time step with a parameterization that
depends on the current state, such that globally the dynamical operator is non-linear and non-Gaussian. 3.2. Analog Data Assimilation We may state clearly the key difference between the AnDA and reduced-rank Kalman filters
and the OI method. It lies in the fact that the AnDA introduces a dynamical operator and not a
prescribed space-time covariance model, and this dynamical operator is state-dependent and globally
non-linear. The proposed analog forecasting operator can be seen as a state-dependent linear Gaussian
operator, meaning that it is locally Gaussian and linear at each time step with a parameterization that
depends on the current state, such that globally the dynamical operator is non-linear and non-Gaussian. A special case where AnDA is equivalent to OI is when all the elements of the catalog are considered
as neighbors of any state vector. This case comes to assume that the dynamical operator is linear and
state-independent. It is obviously of low interest due to the computational burden resulting from
using all the catalog. A special case where AnDA is equivalent to OI is when all the elements of the catalog are considered
as neighbors of any state vector. This case comes to assume that the dynamical operator is linear and
state-independent. It is obviously of low interest due to the computational burden resulting from
using all the catalog. The application of the AnDA framework faces the curse of dimensionality i.e., the search of
analogs is highly affected by the dimensionality of the problem and can fail at finding good analogs
for state vector dimensions above 20 [13]. As proposed in [24], the extension of AnDA models
to high-dimensional fields may then rely on turning the global assimilation issue into a series of
lower-dimensional ones. We consider here an approach similar to [24] using a patch-based and
EOF-based representation of the two-dimensional (2D) fields, i.e., the 2D fields are decomposed into
a set of overlapping patches, each patch being projected onto an EOF space. Analog strategies then
apply to patch-level time series in the EOF space. Overall, as detailed in the following section, the proposed analog data assimilation model for SLA
fields relies on three key components: A patch-based representation of the SLA fields, the selection of
a kernel to retrieve analogs and the specification of a patch-level analog forecasting operator. 7 of 22 Remote Sens. 2019, 11, 858 4. Analog Reconstruction for Altimeter-Derived SLA 4.1. Patch-Based State-Space Formulation 4.2. Patch-Based Analog Dynamical Models Given the considered patch-based representation of field dX, the proposed patch-based analog
assimilation scheme involves a dynamical model stated in the EOF space. Formally, Equation (9) leads
to the following Gaussian conditional distribution in the EOF space: (13) p(Φ(Ps, t)|Φ(Ps, t −1)) = N (µ(Φ(Ps, t −1)), Σ(Φ(Ps, t −1))),
(13) We consider the three analog forecasting operators presented in Section 3.2, namely, the locally-constant,
the locally-incremental and the locally-linear. The calculation of the weights associated to each
analog-successor pair relies on a Gaussian kernel KG (Equation (10)). The search for analogs in the
NE-dimensional patch space (in practice, NE ranges from 5 to 20) ensures a better accuracy in the
retrieval of relevant analogs compared to a direct search in the high-dimensional space of state dX. It also reduces the computational complexity of the proposed scheme. Another important extension of the current study is the possibility of exploiting auxiliary variables
with the state vector Φ in the analog forecasting models. Such variables may be considered in the
search for analogs as well as regression variables in a locally-linear analog setting. Regarding the
targeted application to the reconstruction of SSH fields and the proposed two-scale decomposition
(Equation (11)), two types of auxiliary variables seem to be of interest: The low-resolution component
¯X to take into account inter-scale relationship [17], and Sea Surface Temperature (SST) with respect
to the widely acknowledged SST-SSH synergies [17,19,21]. We also apply patch-level EOF-based
decompositions to include both types of variables in the considered analog forecasting models
(Equation (13)). 4.1. Patch-Based State-Space Formulation As stated above, OI may be considered as an efficient model-based method to recover
large-scale structures of SLA fields. Following [24], this suggests considering the following two-scale
additive decomposition: X = ¯X + dX + ξ,
(11) (11) where ¯X is the large-scale component of the SLA field, typically issued from an optimal interpolation,
dX the fine-scale component of the SLA field we aim to reconstruct and ξ is the remaining
unresolved scales. The reconstruction of field dX involves a patch-based and EOF-based representation. It consists in
regarding field dX as a set of P × P overlapping patches (e.g., 2◦× 2◦), an example of patch locations
is shown in Figure 2. This set of patches is referred to as P, and we denote by Ps the patch centered on
position s. After building a catalog CP of patches from the available dataset of residual fields X −¯X
(see Section 3.2), we proceed to an EOF decomposition of each patch in the catalog. The reconstruction
of field dX(Ps, t) at time t is then stated as the analog assimilation of the coefficients of the EOF
decomposition in the EOF space given an observation series in the patch space. Formally, dX(Ps, t)
decomposes as a linear combination of a number NE of EOF basis functions: dX(Ps, t) =
NE
∑
k=1
αk(s, t)EOFk,
(12) (12) with EOFk the kth EOF basis and αk(s, t) the corresponding coefficient for patch Ps at time t. Let
us denote by Φ(Ps, t) the vector of the NE coefficients αk(s, t): Φ(Ps, t) = {α1(s, t), ..., αNE(s, t)}. This vector represents the projection of dX(Ps, t) in the lower-dimensional EOF space. Figure 2. Two examples of patch locations and their overlapping patch neighbours. Figure 2. Two examples of patch locations and their overlapping patch neighbours. Remote Sens. 2019, 11, 858 8 of 22 4.3. Numerical Resolution Given the proposed analog assimilation model, the proposed scheme first relies on the creation
of patch-level catalogs from the training dataset. This step requires the computation of a training
dataset of fine scale data dXtraining, this is done by subtracting a large-scale component ¯Xtraining from
the original training dataset. Here, we consider the large-scale component of training data to be the
result of a global (By global, we mean here an EOF decomposition over the entire case study region, by
contrast to the patch-level decomposition considered in the analog assimilation setting.) EOF-based
reconstruction using a number of EOF components that retains 95% of the dataset variance, which
accounts for horizontal scales up to ≈100 km. This global EOF-based decomposition provides a
computationally-efficient means for defining large-scale component ¯X. This EOF-based decomposition
step is followed by the extraction of overlapping patches for all variables of interest, namely ¯Xtraining,
dXtraining and potential auxiliary variables, and the identification of the EOF basis functions from the
resulting raw patch datasets. This leads to the creation of a patch-level catalog CP from the EOF-based
representations of each patch. p
p
Given the patch-level catalog, the algorithm applied for the mapping SLA fields from along-track
data, referred to PB-AnDA (for Patch-Based AnDA), is stated in Algorithm 1 and a sketch of the
method is shown in Figure 3. 9 of 22 Remote Sens. 2019, 11, 858 Algorithm 1 Patch-Based AnDA 5: the reconstruction of fields X as ¯X + dX. 5: the reconstruction of fields X as ¯X + dX. We may point out two important aspects in the implementation of the proposed patch-level
AnDA setting: •
(step 3) In the analog forecasting setting, the search for analogs is restricted to patch exemplars in
the catalog within a local spatial neighborhood (typically a patch-level 8-neighborhood), except
for patches along the seashore for which the search for analogs is restricted to patch exemplars at
the same location. •
(step 3) In the analog forecasting setting, the search for analogs is restricted to patch exemplars in
the catalog within a local spatial neighborhood (typically a patch-level 8-neighborhood), except
for patches along the seashore for which the search for analogs is restricted to patch exemplars at
the same location. •
(step 4) In practice, we do not apply the patch-level assimilation to all grid positions. Consequently,
the spatial averaging may result in blocky artifacts. We then apply a patchwise EOF-based
decomposition-reconstruction with a smaller patch-size (here, 17 × 17 patches) to remove these
blocky artifacts. •
(step 4) In practice, we do not apply the patch-level assimilation to all grid positions. Consequently,
the spatial averaging may result in blocky artifacts. We then apply a patchwise EOF-based
decomposition-reconstruction with a smaller patch-size (here, 17 × 17 patches) to remove these
blocky artifacts. 𝑋𝑡𝑟𝑎𝑖𝑛𝑖𝑛𝑔
Creation of patch-based catalogs from training datasets
X𝑡𝑟𝑎𝑖𝑛𝑖𝑛𝑔
𝑑𝑋𝑡𝑟𝑎𝑖𝑛𝑖𝑛𝑔
substraction
Global EOF
reconstruction (95%
variance retained)
Extracted dataset for
each patch position
EOF
X𝑂𝐼
Simulated
along-track
data
𝑓𝑖𝑛𝑒𝑠𝑐𝑎𝑙𝑒
𝑜𝑏𝑠𝑒𝑟𝑣𝑎𝑡𝑖𝑜𝑛𝑠
substraction
Optimal
Interpolation
Extracted observations
for each patch position
Catalog of EOF
coefficients
𝑑𝑋
AnDA for each patch +
spatial averaging over
overlapping patches +
postprocessing
X
𝑋𝑟𝑒𝑐𝑜𝑛𝑠𝑡
Global EOF
projection on
the training
dataset
Figure 3. Sketch of the proposed patch-based Analog Data Assimilation (PB-AnDA). The left block
details the construction of the patch-based catalogs from the training dataset. The right block illustrates
the process of obtaining the large-scale component of the SLA reconstructed field. The orange dashed
rectangle represents the application of the AnDA using the catalog and the fine-scale observations. Finally, the green dashed rectangle shows the final addition operation that yields the reconstructed
SLA field. Figure 3. Sketch of the proposed patch-based Analog Data Assimilation (PB-AnDA). The left block
details the construction of the patch-based catalogs from the training dataset. The right block illustrates
the process of obtaining the large-scale component of the SLA reconstructed field. Algorithm 1 Patch-Based AnDA 1: Compute the large-scale component ¯X, here, we consider the result of optimal interpolation (OI)
projected onto the global EOF basis functions. 1: Compute the large-scale component ¯X, here, we consider the result of optimal interpolation (OI)
projected onto the global EOF basis functions. 2: Split the case study region into overlapping P × P patches, here, 20 × 20 patches 3: For each patch position s, use the Analog Ensemble Kalman Smoother (AnEnKS) [13], for patch
Ps of field dX. As stated in (13), the assimilation is performed in the EOF space, i.e., for EOF
decomposition Φ(Ps, t), using the operator derived from EOF-based reconstruction (12) and
decomposition (11) as observation model H in (8) and the patch-level training catalog described in
the previous section. The assimilation is sequential and is performed each 3-days. 4: Reconstruct fields dX from the set of assimilated patches {dX(Ps, ·)}s. This relies on a spatial
averaging over overlapping patches (here, a 5-pixel overlapping in both directions). 4: Reconstruct fields dX from the set of assimilated patches {dX(Ps, ·)}s. This relies on a spatial
averaging over overlapping patches (here, a 5-pixel overlapping in both directions). 5. Experimental Setting We detail below the parameter setting of the models evaluated in the reported experiments,
including the proposed PB-AnDA scheme: We detail below the parameter setting of the models evaluated in the reported experiments,
including the proposed PB-AnDA scheme: •
PB-AnDA: We consider 20 × 20 patches with 15-dimensional EOF decompositions (NE = 15),
which typically accounts for 99% of the data variance for the considered dataset. The
postprocessing step exploits 17 × 17 patches and a 15-dimensional EOF decomposition. Regarding
the parametrization of the AnEnKS procedure, we experimentally cross-validated the number of
nearest neighbors K to 50, the number of ensemble members nensemble to 100 and the observation
covariance error in Equation (8) is considered to be diagonal R = κ2I and κ = 0.001m. •
Optimal Interpolation: We apply an Optimal Interpolation to the processed along-track data. It provides the low-resolution component for the proposed PB-AnDA model and a model-driven
reference for evaluation purposes. The background field is a null field. We use a Gaussian
covariance model with a spatial correlation length of 100 km and a temporal correlation
length of 15 days (±5 timesteps since our data is 3-daily). These choices result from a
cross-validation experiment. •
VE-DINEOF: We apply a second state-of-the-art interpolation scheme using a data-driven strategy
solely based on EOF decompositions, namely VE-DINEOF [37]. Using an iterative reconstruction
scheme, VE-DINEOF starts by filling the missing data with a first guess, here along-track
pseudo-observation field for along-track data positions and ¯X for missing data positions. For each
iteration, the resulting field is projected on the most significant EOF components calculated from
the clean catalog data, then missing data positions are updated using pixels from the reconstructed
new field. We run this iterative process until convergence. To make this algorithm comparable
to the proposed PB-AnDA setting, we perform the reconstruction for each patch position then
regroup the results as in PB-AnDA. G-AnDA: With a view to evaluating the relevance of the patch-based decomposition, we also
apply AnDA at the region scale, referred to as G-AnDA. It relies on an EOF-based decomposition
of the detail field dX. We use 150 EOF components, which accounts for more than 99% of the total
variance of the SSH dataset. 5: the reconstruction of fields X as ¯X + dX. The orange dashed
rectangle represents the application of the AnDA using the catalog and the fine-scale observations. Finally, the green dashed rectangle shows the final addition operation that yields the reconstructed
SLA field. 10 of 22 10 of 22 Remote Sens. 2019, 11, 858 5. Experimental Setting From cross-validation experiments, the associated AnEnKS procedure
relies on a locally-linear analog forecasting model with K = 500 analogs, nensemble = 100 ensemble
members and a diagonal observation covariance similar to as in PB-AnDA. The patch-based experiments were run on Teralab infrastructure using a multi-core virtual
machine (30 CPUs, 64G of RAM). We used the Python toolbox for patch-based analog data
assimilation [24] (available at github.com/rfablet/PB_ANDA). Optimal Interpolation was
implemented on Matlab using [36]. Throughout the experiments, two metrics are used to assess
the performance of the considered interpolation methods: (i) Daily and mean Root Mean Square Error
(RMSE) series between the reconstructed SLA fields X and the groundtruthed ones; (ii) daily and mean
correlation coefficient between the fine-scale component dX of the reconstructed SLA fields and of the
groundtruthed ones. These two metrics allow a good evaluation on image reconstruction capabilities
and are widely used in missing data interpolation literature [38,39]. 6. Results We evaluate the proposed PB-AnDA approach using the OSSE presented in Section 2. We perform
a qualitative and quantitative comparison to state-of-the-art approaches. We first describe the
parameter setting used for the PB-AnDA as well as benchmarked models, namely OI, an EOF-based
approach [37] and a direct application of AnDA at the region level. We then report numerical
experiments for noise-free and noisy observation data as well the relevance of auxiliary variables in
the proposed PB-AnDA scheme. Remote Sens. 2019, 11, 858 11 of 22 11 of 22 6.1. SLA Reconstruction from Noise-Free Along-Track Data 6.1. SLA Reconstruction from Noise-Free Along-Track Data We first performed an idealized noise-free experiment, where the along-track observations were
not contaminated with noise. The interpolation performances for this experiment are illustrated in
Table 1. Our PB-AnDA algorithm significantly outperforms OI. More specifically, the locally-linear
PB-AnDA results in the best reconstruction among the competing methods. We suggest that this
improvement comes from the reconstruction of fine-scale features learned from the archived model
simulation data. Figure 4a reports interpolated SSH fields and their gradient fields which further
confirm our intuition. PB-AnDA interpolation shows an enhancement of the gradients and comes out
with some fine-scale eddies that were smoothed out in OI and VE-DINEOF. This is also confirmed by
the Fourier power spectrum of the interpolated SLA fields in Figure 4b. Table 1. SLA Interpolation performance for a noise-free experiment: Root Mean Square Error (RMSE)
(meters), correlation statistics for Optimal Interpolation (OI), VE-DINEOF, G-AnDA and PB-AnDA
with regard to the groundtruthed SLA fields. The relative gain with regard to OI is also shown in
percentage. See Section 5 for the corresponding parameter settings. Criterion
RMSE
Correlation
RMSEOI−RMSE
RMSEOI
OI
0.026 ± 0.007
0.81 ± 0.08
-
VE-DINEOF
0.023 ± 0.007
0.85 ± 0.07
11.53%
G-AnDA
0.020 ± 0.006
0.89 ± 0.04
23.07%
PB-AnDA
Locally-constant
0.014 ± 0.005
0.95 ± 0.03
46.15%
Locally-Increment
0.014 ± 0.005
0.95 ± 0.03
46.15%
Locally-Linear
0.013 ± 0.005
0.96 ± 0.02
50.00%
(a)
Figure 4. Cont. Table 1. SLA Interpolation performance for a noise-free experiment: Root Mean Square Error (RMSE)
(meters), correlation statistics for Optimal Interpolation (OI), VE-DINEOF, G-AnDA and PB-AnDA
with regard to the groundtruthed SLA fields. The relative gain with regard to OI is also shown in
percentage. See Section 5 for the corresponding parameter settings. Table 1. SLA Interpolation performance for a noise-free experiment: Root Mean Square Error (RMSE)
(meters), correlation statistics for Optimal Interpolation (OI), VE-DINEOF, G-AnDA and PB-AnDA
with regard to the groundtruthed SLA fields. The relative gain with regard to OI is also shown in
percentage. See Section 5 for the corresponding parameter settings. Criterion
RMSE
Correlation
RMSEOI−RMSE
RMSEOI
OI
0.026 ± 0.007
0.81 ± 0.08
-
VE-DINEOF
0.023 ± 0.007
0.85 ± 0.07
11.53%
G-AnDA
0.020 ± 0.006
0.89 ± 0.04
23.07%
PB-AnDA
Locally-constant
0.014 ± 0.005
0.95 ± 0.03
46.15%
Locally-Increment
0.014 ± 0.005
0.95 ± 0.03
46.15%
Locally-Linear
0.013 ± 0.005
0.96 ± 0.02
50.00% (a)
Figure 4. Cont. 6.2. SLA Reconstruction from Noisy Along-Track Data We also evaluated the proposed approach for noisy along-track data. Here, we ran two
experiments with an additive zero-mean Gaussian noise applied to the simulated along-track data. We considered a diagonal noise covariance of γ2I where γ = 0.01 m (Experiment A) and γ = 0.03 m
(Experiment B) which was more close to the instrumental error of conventional altimeters. Given the
resulting noisy along-track dataset, we applied the same methods as for the noise-free case study. We ran PB-AnDA using different values for κ. For Experiment A, Table 2 shows that the minimum
is reached using the true value of the error κ = 0.01 m. While for Experiment B, Table 3 shows that the
minimum is counter-intuitively reached again using value of the error κ = 0.01 m with a negligible
margin compared to the true value. Table 2. Impact of standard variation of observation error κ in AnDA interpolation performance using
noisy along-track data (γ = 0.01 m): RMSE (meters) of AnDA interpolation for different values of
parameter κ. For the same dataset, OI RMSE is 0.039. Table 2. Impact of standard variation of observation error κ in AnDA interpolation performance using
noisy along-track data (γ = 0.01 m): RMSE (meters) of AnDA interpolation for different values of
parameter κ. For the same dataset, OI RMSE is 0.039. κ
0.1
0.05
0.03
0.01
0.005
0.001
0.0001
rmsePB−AnDA
0.035
0.030
0.028
0.025
0.025
0.029
0.044 Table 3. Impact of standard variation of observation error κ in AnDA interpolation performance using
noisy along-track data (γ = 0.03 m): RMSE (meters) of AnDA interpolation for different values of
parameter κ. For the same dataset, OI RMSE is 0.066. Table 3. Impact of standard variation of observation error κ in AnDA interpolation performance using
noisy along-track data (γ = 0.03 m): RMSE (meters) of AnDA interpolation for different values of
parameter κ. For the same dataset, OI RMSE is 0.066. Table 3. Impact of standard variation of observation error κ in AnDA interpolation performance using
noisy along-track data (γ = 0.03 m): RMSE (meters) of AnDA interpolation for different values of
parameter κ. For the same dataset, OI RMSE is 0.066. κ
0.1
0.05
0.03
0.01
0.005
0.001
0.0001
rmsePB−AnDA
0.038
0.036
0.035
0.0349
0.037
0.046
0.076 Our algorithm is then compared with the results of the application of the competing algorithms
considered in this work. 6.1. SLA Reconstruction from Noise-Free Along-Track Data (a)
Figure 4. Cont. (a) Figure 4. Cont. 12 of 22 Remote Sens. 2019, 11, 858 (b)
Figure 4. Reconstructed SLA fields (meters) using noise-free along-track observation using OI,
VE-DINEOF, G-AnDA, PB-AnDA on the 54th day (24 February 2012): From left to right, the first
row shows the ground truth field, the simulated available along-tracks for that day, the ground truth
gradient field. The second and third rows show each of the reconstruction and their corresponding
gradient fields, from left to right, OI, VE-DINEOF, G-ANDA and PB-AnDA. The Fourier power
spectrum of the competing methods is also included. (b) (b) Figure 4. Reconstructed SLA fields (meters) using noise-free along-track observation using OI,
VE-DINEOF, G-AnDA, PB-AnDA on the 54th day (24 February 2012): From left to right, the first
row shows the ground truth field, the simulated available along-tracks for that day, the ground truth
gradient field. The second and third rows show each of the reconstruction and their corresponding
gradient fields, from left to right, OI, VE-DINEOF, G-ANDA and PB-AnDA. The Fourier power
spectrum of the competing methods is also included. 6.2. SLA Reconstruction from Noisy Along-Track Data Results are shown in Table 4. PB-AnDA still outperforms OI in terms of RMSE
and correlation statistics in both experiments. The locally-linear version of PB-AnDA depicts the best
reconstruction performance. We report an example of the reconstruction in Figure 5. Similarly to the
noise-free case study, PB-AnDA better recovers finer-scale structures in Figure 5a compared with OI, emote Sens. 2019, 11, 858
13
E-DINEOF and G-AnDA. In Figure 5b, PB-AnDA also better reconstructs a larger-scale North-E
tructure, poorly sampled by along-track data and hence poorly interpolated by OI. Table 4. SLA Interpolation performance for noisy along-track data: RMSE (meters) and correlation
statistics for OI, VE-DINEOF, G-AnDA and PB-AnDA w.r.t. the groundtruthed SLA fields. The relative gain with regard to OI is also shown in percentage. See Section 5 for the corresponding
parameter settings. Criterion
RMSE
Correlation
RMSEOI−RMSE
RMSEOI
γ = 0.01 m
OI
0.039 ± 0.005
0.64 ± 0.09
-
VE-DINEOF
0.035 ± 0.005
0.68 ± 0.09
10.25%
G-AnDA
0.030 ± 0.005
0.78 ± 0.06
23.07%
PB-AnDA
Locally constant
0.026 ± 0.005
0.82 ± 0.05
33.33%
Increment
0.028 ± 0.005
0.81 ± 0.05
28.20%
Local Linear
0.0245 ± 0.005
0.83 ± 0.05
37.17%
γ = 0.03 m
OI
0.066 ± 0.006
0.41 ± 0.09
-
VE-DINEOF
0.060 ± 0.006
0.45 ± 0.09
9.09%
G-AnDA
0.039 ± 0.006
0.67 ± 0.09
40.90%
PB-AnDA
Locally constant
0.035 ± 0.006
0.688 ± 0.064
46.96%
Increment
0.036 ± 0.006
0.656 ± 0.07
45.45%
Local Linear
0.032 ± 0.006
0.708 ± 0.063
51.51%
(a)
Figure 5. Cont. 13 of 22 Remote Sens. 2019, 11, 858 VE-DINEOF and G-AnDA. In Figure 5b, PB-AnDA also better reconstructs a larger-scale North-East
structure, poorly sampled by along-track data and hence poorly interpolated by OI. Table 4. SLA Interpolation performance for noisy along-track data: RMSE (meters) and correlation
statistics for OI, VE-DINEOF, G-AnDA and PB-AnDA w.r.t. the groundtruthed SLA fields. The relative gain with regard to OI is also shown in percentage. See Section 5 for the corresponding
parameter settings. Table 4. SLA Interpolation performance for noisy along-track data: RMSE (meters) and correlation
statistics for OI, VE-DINEOF, G-AnDA and PB-AnDA w.r.t. the groundtruthed SLA fields. The relative gain with regard to OI is also shown in percentage. See Section 5 for the corresponding
parameter settings. Table 4. SLA Interpolation performance for noisy along-track data: RMSE (meters) and correlation
statistics for OI, VE-DINEOF, G-AnDA and PB-AnDA w.r.t. the groundtruthed SLA fields. 6.2. SLA Reconstruction from Noisy Along-Track Data The relative gain with regard to OI is also shown in percentage. See Section 5 for the corresponding
parameter settings. ,
,
g
The relative gain with regard to OI is also shown in percentage. See Section 5 for the corresponding
parameter settings. Criterion
RMSE
Correlation
RMSEOI−RMSE
RMSEOI
γ = 0.01 m
OI
0.039 ± 0.005
0.64 ± 0.09
-
VE-DINEOF
0.035 ± 0.005
0.68 ± 0.09
10.25%
G-AnDA
0.030 ± 0.005
0.78 ± 0.06
23.07%
PB-AnDA
Locally constant
0.026 ± 0.005
0.82 ± 0.05
33.33%
Increment
0.028 ± 0.005
0.81 ± 0.05
28.20%
Local Linear
0.0245 ± 0.005
0.83 ± 0.05
37.17%
γ = 0.03 m
OI
0.066 ± 0.006
0.41 ± 0.09
-
VE-DINEOF
0.060 ± 0.006
0.45 ± 0.09
9.09%
G-AnDA
0.039 ± 0.006
0.67 ± 0.09
40.90%
PB-AnDA
Locally constant
0.035 ± 0.006
0.688 ± 0.064
46.96%
Increment
0.036 ± 0.006
0.656 ± 0.07
45.45%
Local Linear
0.032 ± 0.006
0.708 ± 0.063
51.51%
(a)
Figure 5. Cont. Criterion
RMSE
Correlation
RMSEOI−RMSE
RMSEOI
γ = 0.01 m
OI
0.039 ± 0.005
0.64 ± 0.09
-
VE-DINEOF
0.035 ± 0.005
0.68 ± 0.09
10.25%
G-AnDA
0.030 ± 0.005
0.78 ± 0.06
23.07%
PB-AnDA
Locally constant
0.026 ± 0.005
0.82 ± 0.05
33.33%
Increment
0.028 ± 0.005
0.81 ± 0.05
28.20%
Local Linear
0.0245 ± 0.005
0.83 ± 0.05
37.17%
γ = 0.03 m
OI
0.066 ± 0.006
0.41 ± 0.09
-
VE-DINEOF
0.060 ± 0.006
0.45 ± 0.09
9.09%
G-AnDA
0.039 ± 0.006
0.67 ± 0.09
40.90%
PB-AnDA
Locally constant
0.035 ± 0.006
0.688 ± 0.064
46.96%
Increment
0.036 ± 0.006
0.656 ± 0.07
45.45%
Local Linear
0.032 ± 0.006
0.708 ± 0.063
51.51% (a)
Figure 5. Cont. (a)
Figure 5. Cont. Figure 5. Cont. 14 of 22 Remote Sens. 2019, 11, 858 (b)
Figure 5. Reconstruction of SLA fields (meters) from noisy along-track data using OI, VE-DINEOF,
G-AnDA & PB-AnDA on day 225th (a) & 228th (b). b) ( (b) Figure 5. Reconstruction of SLA fields (meters) from noisy along-track data using OI, VE-DINEOF,
G-AnDA & PB-AnDA on day 225th (a) & 228th (b). 6.3. PB-AnDA Models with Auxiliary Variables 6.3. PB-AnDA Models with Auxiliary Variables We further explore the flexibility of the analog setting to the use of additional geophysical
variable information as explained in Section 4.2. Intuitively, we expect SLA fields to involve inter-scale
dependencies as well as synergies with other tracers [19,40]. The use of auxiliary variables provide the
means for evaluating such dependencies and their potential impact on reconstruction performance. We consider two auxiliary variables that are used in the locally-linear analog forecasting model (7):
(i) To account for the relationship between the large-scale and fine-scale component, we may consider
variable ¯X; (ii) considering potential SST-SSH synergies, we consider SST fields. Overall, we consider
four parameterization of the regression variables used in PB-AnDA: The sole use of dX (PB-AnDA-dX),
the joint use of dX and SST fields (PB-AnDA-dX+SST), the joint use of dX and ¯X (PB-AnDA-dX+ ¯X), the
joint use of dX and the groudntruthed version of ¯X denoted by ¯XGT, (PB-AnDA-dX+ ¯XGT). The later
provides a lower-bound for the reconstruction performance, assuming the low-resolution component
is perfectly estimated. We report mean RMSE (meters) and correlation statistics for these four PB-AnDA parameterizations
in Table 5 for the noisy case-study. Considering PB-AnDA-dX as reference, these results show a very
slight improvement when complementing dX with SST information. Though limited, we report a
greater improvement when adding the low-resolution component ¯X. Interestingly, a significantly
greater improvement is obtained when adding the true low-resolution information. The mean results
are in accordance with [17], which reported that large-scale SLA information was more informative
than SST to improve the reconstruction of the SLA at finer scales. Though mean statistics over one
year leads to rather limited improvement, daily RMSE time series (Figure 6) reveal that for some
periods, for instance between day 130 and 150, relative improvements in terms of RMSE may reach 10%
with the additional information brought by the large-scale component. In this respect, it may noted 15 of 22 Remote Sens. 2019, 11, 858 that PB-AnDA-dX+ ¯X always perform better than PB-AnDA-dX. An example of the reconstruction in
reported in Figure 7. Table 5. PB-AnDA reconstruction performance using noisy along-track data for different choices of
the regression variables in the locally-linear analog forecasting model: PB-AnDA-dX using solely dX,
PB-AnDA-dX+ SST (Sea Surface Temperature) using both dX and SST, PB-AnDA-dX + ¯X using both
dX and ¯X, and PB-AnDA-dX + ¯XGT using dX and the true large-scale component ¯XGT. 6.3. PB-AnDA Models with Auxiliary Variables The table
shows the RMSE (meters) and correlation statistics. PB-AnDA Model
RMSE
Correlation
γ = 0.01 m
PB-AnDA-dX
0.025 ± 0.005
0.83 ± 0.05
PB-AnDA-dX + SST
0.024 ± 0.005
0.83 ± 0.05
PB-AnDA-dX + ¯X
0.023 ± 0.005
0.84 ± 0.05
PB-AnDA-dX + ¯XGT
0.021 ± 0.004
0.87 ± 0.04
γ = 0.03 m
PB-AnDA-dX
0.032 ± 0.006
0.708 ± 0.06
PB-AnDA-dX + SST
0.031 ± 0.006
0.710 ± 0.06
PB-AnDA-dX + ¯X
0.029 ± 0.006
0.717 ± 0.06
PB-AnDA-dX + ¯XGT
0.026 ± 0.005
0.730 ± 0.05
Figure 6. Daily RMSE (meters) time series of PB-AnDA SLA reconstructions using noisy along-track
data for different choices of the regression variables in the locally-linear analog forecasting model:
PB-AnDA-dX (light blue), PB-AnDA-dX+ SST (orange) and PB-AnDA-dX + ¯X (green). PB-AnDA Model
RMSE
Correlation
γ = 0.01 m
PB-AnDA-dX
0.025 ± 0.005
0.83 ± 0.05
PB-AnDA-dX + SST
0.024 ± 0.005
0.83 ± 0.05
PB-AnDA-dX + ¯X
0.023 ± 0.005
0.84 ± 0.05
PB-AnDA-dX + ¯XGT
0.021 ± 0.004
0.87 ± 0.04
γ = 0.03 m
PB-AnDA-dX
0.032 ± 0.006
0.708 ± 0.06
PB-AnDA-dX + SST
0.031 ± 0.006
0.710 ± 0.06
PB-AnDA-dX + ¯X
0.029 ± 0.006
0.717 ± 0.06
PB-AnDA-dX + ¯XGT
0.026 ± 0.005
0.730 ± 0.05 Figure 6. Daily RMSE (meters) time series of PB-AnDA SLA reconstructions using noisy along-track
data for different choices of the regression variables in the locally-linear analog forecasting model:
PB-AnDA-dX (light blue), PB-AnDA-dX+ SST (orange) and PB-AnDA-dX + ¯X (green). Figure 6. Daily RMSE (meters) time series of PB-AnDA SLA reconstructions using noisy along-tra
data for different choices of the regression variables in the locally-linear analog forecasting mod Figure 6. Daily RMSE (meters) time series of PB-AnDA SLA reconstructions using noisy along-track
data for different choices of the regression variables in the locally-linear analog forecasting model:
PB-AnDA-dX (light blue), PB-AnDA-dX+ SST (orange) and PB-AnDA-dX + ¯X (green). 16 of 22 Remote Sens. 2019, 11, 858 (a)
(b)
Figure 7. (Noisy observation) Reconstruction of SLA fields (meters) using PB-AnDA with different
multivariate regression models on day 57th (a) & 237th (b). ( ) (a) (a) (a)
(b)
Figure 7. (Noisy observation) Reconstruction of SLA fields (meters) using PB-AnDA with different
multivariate regression models on day 57th (a) & 237th (b). (a (b) (b) Figure 7. 7. Discussion Analog data assimilation can be regarded as a means to fuse ocean models and satellite-derived
data. We regard this study as a proof-of-concept, which opens research avenues as well as new
directions for operational oceanography. Our results advocate for complementary experiments at the
global scale or in different ocean regions for a variety of dynamical situations with a view to further
evaluating the relevance of the proposed analog assimilation framework. Such experiments should
evaluate the sensitivity of the assimilation with respect to the size of the catalog. The scaling up to
the global ocean also suggests investigating computationally-efficient implementation of the analog
data assimilation. In this respect, the proposed patch-based framework intrinsically ensures high
parallelization performance. From a methodological point of view, a relative weakness of the analog
forecasting models (9) may be their low physical interpretation compared with physically-derived
priors [18]. The combination of such physically-derived parameterizations to data-driven strategies
appear to be a promising research direction. While we considered an OSSE to evaluate the proposed
scheme, future work will investigate applications to real satellite-derived datasets, including the use of
independent observation data such as surface drifters’ track data to further assess the performance of
the proposed algorithm. The analog method is at the heart of this work as it is appealing by its implementation ease and its
intuitive strategy, but it must not be seen as the only data-driven method adapted to the framework we
presented. As long as a data-driven forecasting operator can be derived, other data-driven methods can
be investigated [41,42]. One promising path is the use of neural networks, as they sparked off a series
of breakthroughs in other fields [42–46]. While neural network based approaches can lead to better
performances due to their superior regressing capabilities, two clear advantages of adopting analog
methods are the fact that they do not need a time consuming training phase and that analog methods
are easy to understand and interpret compared to black-box approaches such as neural networks. The Analog Data Assimilation method as used in this work relies on several hyperparameters,
assumptions and design choices. These considerations are discussed in the following: The Analog Data Assimilation method as used in this work relies on several hyperparameters,
assumptions and design choices. 6.3. PB-AnDA Models with Auxiliary Variables (Noisy observation) Reconstruction of SLA fields (meters) using PB-AnDA with different
multivariate regression models on day 57th (a) & 237th (b). Remote Sens. 2019, 11, 858 17 of 22 17 of 22 8. Materials and Methods The experimental results presented in this work were obtained using the Python PB-AnDA
toolbox made available by the authors at https://github.com/rfablet/PB_ANDA. 7. Discussion •
We encourage the reader to refer to the discussion section in [24] for more insights about the
rationale behind the use of patch-based representations and EOF-based dimensionality reduction. Through the experiments conducted in this work, it was shown that the best performance
was always reached using the locally-linear analog operator, which is in line with our previous
findings [13,24]. An explanation for the superiority of this approach is that it better approximates
locally the true dynamical model [48]. Beyond along-track altimeter data as considered in this study, future missions such as SWOT
(NASA/CNES) promise an unprecedented coverage around the globe. More specifically, the large
swath is expected to provide a large number of data, urging for the inspection of the potential
improvements that this new mission will bring compared to classical along-track data. In the context
of analog data assimilation, the interest of SWOT data may be two-fold. First, regarding observation
model (8), SWOT mission will both significantly increase the number of available observation data
and enable the definition of more complex observation models exploiting for instance velocity-based
or vorticity-based criterion. Second, SWOT data might also be used to build representative patch-level
catalogs of exemplars. Future work should investigate these two directions using simulated SWOT
test-beds [49]. 7. Discussion These considerations are discussed in the following: •
In this work, we used all the available data for the creation of the catalog, we expect that a rich
dataset is important in increasing the likelihood of finding good analogs, yet a more thorough
study is needed to assess the impact of reducing the temporal resolution of the dataset versus
reducing the amount of the total available data. To compensate the computational impact of using
a large dataset for the search for analogs, we used the FLANN (Fast Library for Approximate
Nearest Neighbors) library as in [26]. This method makes use of tree-indexing techniques and is
suitable for this kind of high dimensional applications [47]. •
While we used a conditional Gaussian distribution in Equation (9), another alternative is the use of
a conditional multinomial distribution. This resorts to sampling one of the analogs’ successors as
the forecast. Adopting this alternative would mean that we rely strongly on the archived catalog,
so that forecasts of each ensemble member are actual elements of the catalog. This reduces the
ability of the model to generate a rich variability of forecast scenes as done by the conditional
Gaussian distribution. •
While we used a Gaussian kernel in Equation (10), other alternatives include cone kernels [10]
which are more adapted to finding analogs in time series. The performance of our algorithm was
slightly improved at the expense of more time execution and an additional hyperparameter to
tune empirically, and we decided to prioritize simpler and efficient kernels. Regarding the scale
parameter, the median was chosen due to its robustness to outliers. •
Although the AnEnKS was used in this work, a possible alternative is the use of an analog based
Particle Smoother which drops Gaussian assumptions, however techniques based on particle
filters need more ensemble members than their Ensemble Kalman Filter counterparts, thus causing
a considerable increase in computational demands which was impractical for our application. Remote Sens. 2019, 11, 858 18 of 22 •
We encourage the reader to refer to the discussion section in [24] for more insights about the
rationale behind the use of patch-based representations and EOF-based dimensionality reduction. •
We encourage the reader to refer to the discussion section in [24] for more insights about the
rationale behind the use of patch-based representations and EOF-based dimensionality reduction. 9. Conclusions This work sheds light on the opportunities that data science methods are offering to improve
altimetry in the era of big data. Assuming the availability of high-resolution numerical simulations, we
show that Analog Data Assimilation (AnDA) can outperform the Optimal Interpolation method and
retrieve smoothed out structures resulting from the sole use of OI both with idealized noise-free
and more realistic noisy observations for the considered case study. Importantly, the reported
experiments point out the relevance for combining OI for larger scales (above 100 km) whereas
the proposed patch-based analog setting successfully applies to the finer-scale range below 100 km. This is in agreement with the recent application of the analog data assimilation to the reconstruction of
cloud-free SST fields [24]. We also demonstrate that AnDA can embed complementary variables in a
simple manner through the regression variables used in the locally-linear analog forecasting operator. In agreement with our recent analysis [17], we demonstrate that the additional use of large-scale SLA
information may further improve the reconstruction performance for fine-scale structures. We may state here the limitations of the present work and possible research avenues for the future. The experiments presented in this work were conducted on a numerical simulation derived dataset. A major future work direction would be then to apply the same procedure on real satellite-derived
SLA contaminated with more complex noise models, then investigate the contribution of the use of
numerical simulation datasets as catalogs. As combining multi-source datsets can also be challenging
when using auxiliary variables relationships with SLA, an interesting experiment for example would be
constructing a catalog with real SST observations combined with numerical simulation SLA datasets. More efforts should be directed to assess the quality of the catalogs (spatio-temporal resolution,
total years of measurements to consider, occurence of rare events, etc.). Besides, building a good
catalog can represent an opportunity for the use of neural networks based methods, and confronting
these powerful regressors to our method is a promising future step. We also note that PB-AnDA can
be a relevant candidate for the interpolation of other geophysical variables (e.g., Sea Surface Salinity,
Chlorophyll concentrations, etc.) under the condition that they verify the set of assumptions made in
this work. 19 of 22 19 of 22 Remote Sens. 2019, 11, 858 Author Contributions: R.L., R.F. and G.C. conceived and designed the experiments; R.L. and M.S. created the
datasets; R.L. and P.H.V. 9. Conclusions performed the experiments; R.L. and M.S. analyzed the data; T.F., B.C. contributed
materials/analysis tools; R.L. and R.F. wrote the paper. Funding: Redouane Lguensat is funded through a CNES (French Space Agency) postdoctoral grant. This work is
also supported by ANR (Agence Nationale de la Recherche, grant ANR-13-MONU-0014), Labex Cominlabs (grant
SEACS) and TeraLab (grant TIAMSEA). Conflicts of Interest: The authors declare no conflict of interest. The funders had no role in the design of the
study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to
publish the results. References 1. Zhang, L.; Zhang, L.; Du, B. Deep learning for remote sensing data: A technical tutorial on the state of the
art. IEEE Geosci. Remote Sens. Mag. 2016, 4, 22–40. [CrossRef] 1. Zhang, L.; Zhang, L.; Du, B. Deep learning for remote sensing data: A technical tutorial on the state of the
art. IEEE Geosci. Remote Sens. Mag. 2016, 4, 22–40. [CrossRef] 2. Lary, D.J.; Alavi, A.H.; Gandomi, A.H.; Walker, A.L. Machine learning in geosciences and remote sensing. Geosci. Front. 2016, 7, 3–10. [CrossRef] 3. Lorenz, E.N. Atmospheric predictability as revealed by naturally occurring analogues. J. Atmos. Sci. 1969,
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26, 636–646. [CrossRef] 4. McDermott, P.L.; Wikle, C.K. A model-based approach for analog spatio-temporal dynamic forecasting. Environmetrics 2015. [CrossRef] 4. McDermott, P.L.; Wikle, C.K. A model-based approach for analog spatio-temporal dynamic forecasting. Environmetrics 2015. [CrossRef] 5. Comeau, D.; Giannakis, D.; Zhao, Z.; Majda, A.J. Predicting regional and pan-Arctic sea ice anomalies with
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kernel analog forecasting. arXiv 2017, arXiv:1705.05228. 6. Atencia, A.; Zawadzki, I. A Comparison of Two Techniques for Generating Nowcasting Ensembles
Analogs Selection and Comparison of Techniques. Mon. Weather Rev. 2015, 143, 2890–2908. [CrossR 7. Delle Monache, L.; Eckel, F.A.; Rife, D.L.; Nagarajan, B.; Searight, K. Probabilistic weather prediction w
an analog ensemble. Mon. Weather Rev. 2013, 141, 3498–3516. [CrossRef] 8. Yiou, P. AnaWEGE: A weather generator based on analogues of atmospheric circulation. Geosci. Model Dev. 2014, 7, 531–543. [CrossRef] 8. Yiou, P. AnaWEGE: A weather generator based on analogues of atmospheric circulation. Geosci. Model Dev. 2014, 7, 531–543. [CrossRef] 9. Hamill, T.M.; Whitaker, J.S. Probabilistic quantitative precipitation forecasts based on reforecast analogs:
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years of altimetric data. In Proceedings of the CI 2015: 5th International Workshop on Climate Informatics,
Boulder, CO, USA, 24–25 September 2015; pp. 1–2. 13. Locally-Linear Operator Fitting a weighted least square between the K analogs and their successors we obtain slope
α(x(t −1)) and intercept β(x(t −1)) parameters, and residuals ξk(x(t −1)) that lead us to µ and Σ: ξk(x(t −1)) = Sk(x(t −1)) −(α(x(t −1))Ak(x(t −1) + β(x(t −1)))
µ = α(x(t −1)).x(t −1) + β(x(t −1)) ξk(x(t −1)) = Sk(x(t −1)) −(α(x(t −1))Ak(x(t −1) + β(x(t −1)))
µ = α(x(t −1)).x(t −1) + β(x(t −1)) µ
( (
)) (
)
β(
Σ = cov((ξk(x(t −1)))k∈1,K) Σ = cov((ξk(x(t −1)))k∈1,K) Locally-Incremental Operator Locally-Incremental Operator τk(x(t −1)) = Sk(x(t −1)) −Ak(x(t −1))
µ = x(t −1) + ∑K
k=1 KG(x(t −1), Ak)τk(x(t −1))
Σ = covKG(x(t −1) + τk(x(t −1))k∈1,K) k(x(t −1)) = Sk(x(t −1)) −Ak(x(t −1)) Locally-Linear Operator Abbreviations The following abbreviations are used in this manuscript: AVISO+
Archivage, Validation et Interprétation des données des Satellites Océanographiques
CMEMS
Copernicus Marine Environment Monitoring Service
OSSE
Observation System Simulation Experiment
OGCM
Ocean General Circulation Model
OFES
OGCM for the Earth Simulation Appendix A. Analog Forecasting Operators In this appendix, we present the calculations needed for the three analog forecasting operators
used in this work. An illustration is also given in Figure A1. Following [13], we give for each operator,
the equations for µ and Σ given A the analogs of x(t −1), their successors S and the corresponding
weights KG: Figure A1. Illustration of the three analog forecasting operator. Figure A1. Illustration of the three analog forecasting operator. ocally-Constant Operator
µ = ∑K
k=1 KG(x(t −1), Ak)Sk(x(t −1))
Σ = covKG(Sk(x(t −1)))k∈1,K) where covKG is a weighted covariance. Locally-Constant Operator
µ = ∑K
k=1 KG(x(t −1), Ak)Sk(x(t −1))
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article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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Report from the 18th International Symposium on Advances in Extraction Technologies (ExTech’2016) and the 22nd International Symposium on Separation Science (ISSS’2016), Toruń, 3–6 July 2016
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Chromatographia
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Report from the 18th International Symposium on Advances
in Extraction Technologies (ExTech’2016) and the 22nd
International Symposium on Separation Science (ISSS’2016),
Torun´, 3–6 July 2016 Bogusław Buszewski1 Published online: 22 October 2016
© The Author(s) 2016. This article is published with open access at Springerlink.com Province, Mayor of Torun´, and His Magnificence Rector of
Nicolaus Copernicus University in Torun´. One might say that history repeats itself. The best confir-
mation of that fact is the 18th International Symposium
on Advances in Extraction Technologies—ExTech’2016
and the 22nd International Symposium on Separation Sci-
ence—ISSS’2016 which took place at the Culture and Con-
gress Center in Torun´, 3–6 July 2016. One more time, over
350 specialists from 41 countries specialising in analytical
chemistry, particularly the physicochemical methods of
separation, met in the Gothic city of Torun´ to summarise
their achievements and to present new concepts both in the
theory and practice of separation, enrichment, isolation and
determination of the entire range of chemical substances. For the first time in history, the two great symposia ExTech
and ISSS have been combined as one event. The former
pertains to the methods of sample preparation based mainly
on the extraction techniques. The latter deals with the phys-
icochemical methods of separation and determination of
organic and inorganic substances of different molecular
mass and structure, both individual substances and their
derivatives occurring in different matrices. The symposia
were organised by the Committee of Analytical Chemis-
try of the Polish Academy of Sciences, Chair of Analytical
Chemistry, Faculty of Chemistry of the Nicolaus Coperni-
cus University and the Central European Group for Sepa-
ration Science (CEGSS). The honorary patronage of this
scientific event was assumed by the Minister of Science
and Higher Education, Marshal of Kuyavian-Pomeranian Province, Mayor of Torun´, and His Magnificence Rector of
Nicolaus Copernicus University in Torun´. p
y
The program of the symposium was exceptionally rich. It included 49 plenary and panel lectures as well as 22
oral announcements mostly presented by young scientists. Moreover, during the four subject sessions, there were 258
poster presentations. An integral part of the conference
were workshops and the exhibition of 17 manufacturers
and distributors of equipment, reagents and accessories. During the symposium, particular attention was drawn to
the accomplishments of the founders and pioneers of both
extraction science (Prof. Walter Ernst) and chromatography
(Prof. Mikhail Tswett). The first session was devoted to the
theoretical achievements and fundamental aspects in the
field of separation methods. It began with an insightful lec-
ture by Prof. J. DOI 10.1007/s10337-016-3182-1
Chromatographia (2016) 79:1679–1681 DOI 10.1007/s10337-016-3182-1
Chromatographia (2016) 79:1679–1681 FEATURE ARTICLE 1
Chair of Environmental Chemistry and Bioanalytics, Faculty
of Chemistry, Nicolaus Copernicus University, 7 Gagarin St.,
87‑100 Torun´, Poland * Bogusław Buszewski
bbusz@chem.umk.pl Report from the 18th International Symposium on Advances
in Extraction Technologies (ExTech’2016) and the 22nd
International Symposium on Separation Science (ISSS’2016),
Torun´, 3–6 July 2016 Pichon and Dr. D. Thiebaut from
France, Prof. L. Chimuka from RSA, Prof. J. Nogueira
from Portugal and Prof. G. Ouyang from China). These
subjects well correspond with the issues connected with
developing new generation of materials such as packings,
analytical columns and columns used in micro- or nano-
scale (Prof. Z. Jang from China, Prof. E. Psillakis from
Greece, Dr. L. Pelit from Turkey, Dr. M. Szumski from
Poland and Prof. A. Malik and J. Anderson from the USA). The so-called chip laboratory (pill-lab) is a challenge not
only for researchers studying miniaturisation and roboti-
sation of the combined process of sample preparation and
final determination (Prof. M. Kaljurand from Estonia or Dr. Vaitz from Germany). This issue was superbly presented in
the research paper presented by Prof. Z. Brzóska (Poland),
who pointed out the possibilities of using these solutions in
modern analytics. • C. Molins-Legua, P. Camping-Falco, Y. Moliner-Mar-
tinez, J. Vordu-Andres, J. Pla-Tolos & M. Munnos-
Ortuno, University of Valencia (Spain), poster S3-P19, • C. Molins-Legua, P. Camping-Falco, Y. Moliner-Mar-
tinez, J. Vordu-Andres, J. Pla-Tolos & M. Munnos-
Ortuno, University of Valencia (Spain), poster S3-P19, • E. Gijonfriddo, E.A. Souza-Silva, S. De Grazia, X. Li & J. Pawliszyn, University of Waterloo, (Canada),
poster S4-P17, • L. Rivoira, S. Studzin´ska, M. Szultka-Młyn´ska, M. C. Bruzzonitti, M. Ligor & B. Buszewski, University
of Torino (Italy)/UMK(NCU) Torun´ (Poland), poster
S4-P33. • L. Rivoira, S. Studzin´ska, M. Szultka-Młyn´ska, M. C. Bruzzonitti, M. Ligor & B. Buszewski, University
of Torino (Italy)/UMK(NCU) Torun´ (Poland), poster
S4-P33. The material and book prizes were funded by: Springer,
Wiley–VCH, Polygen company, Polish Chemical Society
and the Committee of Chemical Analytics of the Polish
Academy of Sciences. The jury also awarded two prizes for the oral presenta-
tions of young researchers: • M. Buszewska-Forajta & R. Kaliszan, Gdan´ski Medi-
cal University (Poland), OP-7, The solutions aimed at the application of these achieve-
ments for the determination of toxic substances of endo-
and exogenic origin or xenobiotics in different matri-
ces, particularly in water, were presented by Prof. H. Lee
(Singapore), Prof. M. Bruzzonitti (Italy), Prof. D. Knapp
(Germany), Dr. V. Comann (Romania) or Dr. M. Gerstiuk
(Ukraine), in cosmetics (Prof. M. Llompart from Spain)
or monitoring of technological processes (Prof. E. Rosen-
berg from Austria). All this was perfectly complemented by
works devoted to the theoretical considerations containing
description of separation mechanisms presented by: Prof. S. Report from the 18th International Symposium on Advances
in Extraction Technologies (ExTech’2016) and the 22nd
International Symposium on Separation Science (ISSS’2016),
Torun´, 3–6 July 2016 Pawliszyn (Canada) concerning the accom-
plishments and the future of sample preparation technol-
ogy. Professor P. Jandera (Czech Republic), laureate of
the European Tswett-Nerst award, presented the advances
which have been made in multi-dimensional separation
techniques. A new concept in characterising stationary
phases and columns used in the so-called fast chromatogra-
phy was presented by Prof. A. Felinger (Hungary). Profes-
sor O. J. Schmitz (Germany) presented new methodological
solutions in the use of coupled separation techniques (LC–
MS) for determination of biologically active substances. Similarly, the other sessions brought numerous inno-
vative and interesting solutions and proposals. They con-
cerned such issues as new advances in sample preparation
for the needs of biological and environmental analysis
including analytics of food and natural products (Prof. E. Stashenko from Columbia, Prof. G. Mills from the UK,
Prof. I. Vovk from Slovenia, Prof. D. Corradini from Italy
or Prof. H. Jelen´ from Poland). A particular emphasis was
placed on the application of multi-dimensional systems * Bogusław Buszewski
bbusz@chem.umk.pl 1 3 1 1680 B. Buszewski and coupled and combined systems in the determina-
tion of biologically active substances on the cellular level
(metabolism and omics) (Prof. H. Górecki from Canada,
Prof. L. Mondello from Italy, Dr. J. Trafkowski from Ger-
many, Prof. B. Bojko from Poland and Dr. P. Zuvela from
South Korea) and monitoring changes which take place in
the metabolic pathways and biogenic changes (Prof. M. Markuszewski and Dr. S. Studzin´ska and Dr. K. Skalicka
Woz´niak from Poland, Prof. A. Marus´ka from Lithuania,
Dr. W. Filipiak and Prof. P. Mochalski from Austria). • J. Mazina, A. Tretjakova, P. Saar-Reismaa, J. Gorbats-
ova, M. Kulp, M. Vaher, E. Erme & M. Kaljurand, Tech-
nical University, Tallin (Estonia), poster S1-P71, • M. Gładysz, M. Woz´niakiewicz, P.M. Nowak & P. Kos´cielniak, UJ Kraków (Poland), poster S1-P34, • T. Hajek, P. Jandera & M. Stankova, University of Par-
dubice (Czech Rep.), poster S2-P17, • M. Skoczylas, Sz. Bocian & B. Buszewski, UMK Torun´
(Poland), poster S2-P35, • M. Skoczylas, Sz. Bocian & B. Buszewski, UMK Torun´
(Poland), poster S2-P35, • M. Matczuk, J. Legat & M. Jarosz, Politechnika War-
szawska (Poland), poster S3-P17, • M. Matczuk, J. Legat & M. Jarosz, Politechnika War-
szawska (Poland), poster S3-P17, The research paper speeches concerned miniaturisa-
tion and robotisation both in the sample preparation and
determination of analytes on the sub-ultra traces (Prof. S. Fanali from Italy, Prof. V. 1 3 Report from the 18th International Symposium on Advances
in Extraction Technologies (ExTech’2016) and the 22nd
International Symposium on Separation Science (ISSS’2016),
Torun´, 3–6 July 2016 Pedersen-Bjergaard from Norway, Prof. I. Malinowska
(Poland), Dr. T. Edge (UK), Prof. H. Bagheri (Iran), Dr. J. Weiss from Germany, Dr. D. Berek from Slovakia and Prof. J. Koziel (USA). • G. A. Gomez-Rios, N. Reyes-Garces, E. Boyaci & J. Pawliszyn, Waterloo University (Canada), OP-12. • G. A. Gomez-Rios, N. Reyes-Garces, E. Boyaci & J. Pawliszyn, Waterloo University (Canada), OP-12. The prizes in the form of the covered registration fee at
the next conferences of ExTech 2017 (Santiago di Compos-
tella, Spain) and ISSS 2017 (Vienna, Austria) were spon-
sored by the organising committees of these symposia. Moreover, the organising committee of ITP 2017 in Gdan´sk
awarded a prize to L. Rivoira (Turin, Italy) by financing the
participation in this conference. During ExTech 2016 & ISSS 2016, apart from the up-
to-date and abundant scientific program, the organisers
provided the participants with an extensive and attractive
cultural offer and the presentation of the traditions of the
Kuyavian-Pomeranian region and the city of Torun´. The
opening concert by Sławek Wiercholski and Nocna Zmi-
ana Bluesa band at the Jordanki Congress and Culture
Center does not require any comment. It was an excel-
lent prelude to the working sessions of the symposium. Similarly, the performance given by the Culture Center
from S´wiecie presenting the folk dance, songs and cus-
toms of Poland and the region in the setting of the open-air The presented subject matter was also well suited by
short oral announcements made by young researchers (20
papers) and research news presented in the form of post-
ers (258). The latter were also accompanied by short oral
presentation in front of a panel of judges headed by Prof. T. Górecki. The jury evaluated the scientific innovation, the
form and manner of the presentation. The winners/laureates
of the contest were: 1 3 1 3 1681 Report from the 18th International Symposium on Advances in Extraction Technologies… Ethnographic Museum showed the richness and diversity
of Polish culture. All this would not have been possible without the inval-
uable financial support of the government institutions, local
and regional authorities and commercial companies (Minis-
try of Science and Higher Education, Marshal of Kuyavian-
Pomeranian region, Mayor of Torun´, Polish Academy of
Sciences, companies such as: LECO-Polska, Perlan Tech-
nologies, Shim-Pol, AlChem, VWR, TZMO, La Rive and
many others. The organisers and the participants express
their gratitude for this support on numerous occasions. Report from the 18th International Symposium on Advances
in Extraction Technologies (ExTech’2016) and the 22nd
International Symposium on Separation Science (ISSS’2016),
Torun´, 3–6 July 2016 The show also included a performance by a traditional
gypsy band as well as young musical and vocal talents dur-
ing a common feast, which warmed up the atmosphere of
the meeting. Similarly, the participants enthusiastically
received the performance of the Torun´ singer M. Lubomski
and his band given after the official gala dinner at Jordanki
Congress and Culture Center. The participants thoroughly
enjoyed the delicious dishes served by Gołe˛biewscy cater-
ing company and the excellent music by Rumin´scy band. An
important element of the program was the post-conference
sightseeing tour of Torun´ Along the Gothic Trail including a
visit to the Live Museum of Gingerbreads. Despite the rainy
weather, the participants enjoyed the tour which was con-
firmed by numerous letters and expressions of thanks for the
organisation and the warm familiar atmosphere. This gives
us enormous satisfaction of the well-done important tasks
that we were entrusted with and makes us committed to live
up to the expectations of the future. Open Access This article is distributed under the terms of the Creative
Commons Attribution 4.0 International License (http://creativecom-
mons.org/licenses/by/4.0/), which permits unrestricted use, distribu-
tion, and reproduction in any medium, provided you give appropriate
credit to the original author(s) and the source, provide a link to the
Creative Commons license, and indicate if changes were made. Prof. Dr. Bogusław Buszewski, DSc. Chairman of the Scientific and Organising Committee
Torun´, 15 July 2016
ExTech’2016 & ISSS’2016 1 3
|
https://openalex.org/W2971710701
|
https://authors.library.caltech.edu/101948/1/Sirunyan2019_Article_SearchForSupersymmetryUsingHig.pdf
|
English
| null |
Search for supersymmetry using Higgs boson to diphoton decays at $$ \sqrt{s} $$ = 13 TeV
|
The Journal of high energy physics/The journal of high energy physics
| 2,019
|
cc-by
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JHEP11(201
Published for SISSA by
Springer
Received: August 22, 2019
Accepted: November 4, 2019
Published: November 20, 2019
Search for supersymmetry using Higgs boson to
diphoton decays at √s = 13 TeV
The CMS collaboration
E-mail: cms-publication-committee-chair@cern.ch JHEP11(201
Published for SISSA by
Springer
Received: August 22, 2019
Accepted: November 4, 2019
Published: November 20, 2019
Search for supersymmetry using Higgs boson to
diphoton decays at √s = 13 TeV
The CMS collaboration
E-mail: cms-publication-committee-chair@cern.ch Published for SISSA by
Springer Received: August 22, 2019
Accepted: November 4, 2019
Published: November 20, 2019 Received: August 22, 2019
Accepted: November 4, 2019
Published: November 20, 2019 Received: August 22, 2019
Accepted: November 4, 2019
Published: November 20, 2019 JHEP11(2019)109 The CMS collaboration Open Access, Copyright CERN, for the benefit of the CMS Collaboration. The CMS collaboration E-mail: cms-publication-committee-chair@cern.ch E-mail: cms-publication-committee-chair@cern.ch Abstract: A search for supersymmetry (SUSY) is presented where at least one Higgs
boson is produced and decays to two photons in the decay chains of pair-produced SUSY
particles. Two analysis strategies are pursued: one focused on strong SUSY production and
the other focused on electroweak SUSY production. The presence of charged leptons, addi-
tional Higgs boson candidates, and various kinematic variables are used to categorize events
into search regions that are sensitive to different SUSY scenarios. The results are based on
data from proton-proton collisions at the Large Hadron Collider at a center-of-mass energy
of 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of
77.5 fb−1. No statistically significant excess of events is observed relative to the standard
model expectations. We exclude bottom squark pair production for bottom squark masses
below 530 GeV and a lightest neutralino mass of 1 GeV; wino-like chargino-neutralino pro-
duction in gauge-mediated SUSY breaking (GMSB) for chargino and neutralino masses
below 235 GeV with a gravitino mass of 1 GeV; and higgsino-like chargino-neutralino pro-
duction in GMSB, where the neutralino decays exclusively to a Higgs boson and a gravitino
for neutralino masses below 290 GeV. Keywords: Hadron-Hadron scattering (experiments), Supersymmetry, Higgs physics ArXiv ePrint: 1908.08500 https://doi.org/10.1007/JHEP11(2019)109 Contents
1
Introduction
1
2
The CMS detector
3
3
Event simulation
3
4
Event reconstruction and selection
4
5
Analysis strategy
5
6
Backgrounds
8
7
Systematic uncertainties
12
8
Results and interpretation
12
9
Summary
16
A Additional simplified model interpretations
24
The CMS collaboration
30 Contents
1
Introduction
1
2
The CMS detector
3
3
Event simulation
3
4
Event reconstruction and selection
4
5
Analysis strategy
5
6
Backgrounds
8
7
Systematic uncertainties
12
8
Results and interpretation
12
9
Summary
16
A Additional simplified model interpretations
24
The CMS collaboration
30 JHEP11(2019)109 1
Introduction The Higgs boson (H) provides an intriguing opportunity to explore physics beyond the
standard model (SM) of particle physics. Many scenarios of physics beyond the SM pos-
tulate the existence of cascade decays of heavy states involving Higgs bosons [1, 2]. In
minimal supersymmetry (SUSY) [3], a Higgs boson may appear in processes involving the
bottom squark (eb), the SUSY partner of the bottom quark. Bottom squarks are produced
via strong interactions and then may decay to a Higgs boson, quarks, and the lightest
SUSY particle (LSP). Similarly charginos or neutralinos produced through the electroweak
interaction may decay to a Higgs boson and the LSP. Of particular interest are gauge-
mediated SUSY breaking (GMSB) scenarios, where the lightest neutralino may decay to a
Higgs boson and the gravitino LSP (eG) [4, 5]. Similar searches have been performed by the
ATLAS and CMS Collaborations using proton-proton (pp) collisions at the CERN LHC
at center-of-mass energies of 8 [6, 7] and 13 TeV [8–11]. We search for evidence of SUSY that produces an excess of events with one or more
Higgs bosons decaying to two photons and large missing transverse momentum using pp
collision data collected by the CMS experiment at the LHC at a center-of-mass energy of
13 TeV in 2016 and 2017, corresponding to an integrated luminosity of 77.5 fb−1. Kinematic – 1 – p
p
eb1
eb1
eχ0
2
eχ0
2
b
H
eχ0
1
eχ0
1
H
b
p
p
eχ0
2
eχ±
1
W±
eχ0
1
eχ0
1
H
p
p
eχ0
1
eχ0
1
H
eG
eG
H
p
p
eχ0
1
eχ0
1
Z
eG
eG
H
Figure 1. Diagrams displaying the simplified models that are being considered. Upper left: bottom
squark pair production; upper right: wino-like chargino-neutralino production; lower: the two
relevant decay modes for higgsino-like neutralino pair production in the GMSB scenario. p
p
eχ0
2
eχ±
1
W±
eχ0
1
eχ0
1
H
p
p
eχ0
1
eχ0
1
Z
eG
eG
H p
p
eb1
eb1
eχ0
2
eχ0
2
b
H
eχ0
1
eχ0
1
H
b
p
p
eχ0
1
eχ0
1
H
eG
eG
H H b H H JHEP11(2019)109 H Z Figure 1. Diagrams displaying the simplified models that are being considered. 2
The CMS detector The central feature of the CMS detector is a superconducting solenoid of 6 m internal di-
ameter, providing a magnetic field of 3.8 T. Within the solenoid volume are a silicon pixel
and strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass
and scintillator hadron calorimeter, each composed of a barrel and two endcap sections. Forward calorimeters extend the pseudorapidity (η) coverage provided by the barrel and
endcap detectors. Muons are measured in gas-ionization detectors embedded in the steel
flux-return yoke outside the solenoid. The first level of the CMS trigger system [12], com-
posed of custom hardware processors, uses information from the calorimeters and muon
detectors to select the most interesting events in a fixed time interval of less than 4 µs. The
high-level trigger processor farm further decreases the event rate from around 100 kHz to
less than 1 kHz before data storage. A more detailed description of the CMS detector, to-
gether with a definition of the coordinate system used and the relevant kinematic variables,
can be found in ref. [13]. JHEP11(2019)109 1
Introduction Upper left: bottom
squark pair production; upper right: wino-like chargino-neutralino production; lower: the two
relevant decay modes for higgsino-like neutralino pair production in the GMSB scenario. variables that discriminate the SUSY signal from SM backgrounds are used to separate
events into several mutually exclusive categories, and the diphoton mass from the H →γγ
decay is used to extract the signal from the background. The branching ratio for H →γγ of
0.227% from the SM is assumed. The dominant backgrounds are SM production of diphoton
and photon+jets, which are modeled by functional fits to the diphoton mass distribution. The SM Higgs boson background constitutes a small fraction of the background for most
of the phase space used in the search and is estimated from simulation samples. We have designed a new analysis to extend our sensitivity to both strong and elec-
troweak SUSY production over the previously published result [8]. Two analysis strategies
are pursued: one focuses on the electroweak production of charginos and neutralinos by
introducing additional event categories containing one or two charged-lepton candidates,
thereby enhancing the sensitivity to SUSY signatures involving W and Z bosons, and
the other is optimized for strong production by categorizing events in the number of jets
and the number of jets identified as originating from the fragmentation of b quarks (“b-
tagged”). The use of the two strategies enhances the overall sensitivity of the search, and
increases the robustness of the result by exploring alternative phase space regions. Finally,
we interpret the results in various simplified model scenarios of SUSY as summarized in
figure 1, including bottom squark pair production, chargino-neutralino, and neutralino-pair
production. In this paper, we discuss the CMS detector in section 2, the event simulation in sec-
tion 3, the event reconstruction and selection in section 4, the analysis strategy in section 5,
the background estimation in section 6, the systematic uncertainties in section 7, and the
results and interpretations in section 8. A summary is given in section 9. – 2 – 3
Event simulation Simulated Monte Carlo (MC) event samples are used to model the SM Higgs boson
backgrounds and the SUSY signal models. Simulated samples of SM Higgs boson pro-
duction through gluon fusion, vector boson fusion, associated production with a W or
a Z boson, b¯bH, and t¯tH are generated using the next-to-leading order (NLO) Mad-
Graph5 amc@nlo v2.2.2 [14] event generator. The Higgs boson mass is assumed to be
125 GeV for the simulated event samples and is within the uncertainty of the currently
best measured value [15, 16]. The Higgs boson production cross sections are taken from
ref. [17] and are computed to next-to-next-to-leading order plus next-to-next-to-leading
logarithm in the quantum chromodynamics (QCD) coupling constant and to NLO in the
electroweak coupling constant. For the gluon fusion production mode, the sample is gen-
erated with up to two extra partons from initial-state radiation (ISR) at NLO accuracy
and uses the FxFx matching scheme described in ref. [18]. The SUSY signal MC sam-
ples are generated using MadGraph5 amc@nlo at leading order accuracy with up to
two extra partons in the matrix element calculations, with the MLM matching scheme
described in ref. [19]. For samples simulating the 2016 data set, pythia v8.212 [20] is
used to model the fragmentation and parton showering with the CUETP8M1 tune [21],
while for samples simulating the 2017 data set, pythia v8.226 is used with the CP5 [22]
tune. The NNPDF3.0 [23] and NNPDF3.1 [24] parton distribution function (PDF) sets
are used for the 2016 and 2017 simulation samples, respectively. The production cross
section for squark pair production is computed at NLO plus next-to-leading logarithmic
(NLL) accuracy in QCD [25–30] under the assumption that all SUSY particles other than
those in the relevant diagram are too heavy to participate in the interaction. The cross
sections for higgsino pair production are computed at NLO+NLL precision in the limit
of mass-degenerate higgsinos eχ0
2, eχ±
1 , and eχ0
1, with all the other sparticles assumed to be
heavy and decoupled [31–33]. Following the convention of real mixing matrices and signed – 3 – neutralino or chargino masses [34], we set the mass of eχ0
1 (eχ0
2) to positive (negative) values. The product of the third and fourth elements of the corresponding rows of the neutralino
mixing matrix N is +0.5 (−0.5). The elements U12 and V12 of the chargino mixing matrices
are set to 1. 3
Event simulation The SM Higgs boson background samples are simulated using a Geant4-based
model [35] of the CMS detector. To cover the large SUSY signal parameter space in
reasonable computation time, the signal model samples are simulated with the CMS fast
simulation package [36, 37], which has been validated to produce accurate predictions of ob-
ject identification efficiencies and momentum resolution. All simulated events include the
effects of additional pp interactions in the same or adjacent beam bunch crossings (pileup),
and are processed with the same chain of reconstruction programs used for collision data. JHEP11(2019)109 To improve the MadGraph modeling of ISR in the SUSY signal MC samples, we
apply a shape correction as a function of the multiplicity of ISR jets for bottom squark
pair production and as a function of the transverse momentum (pISR
T ) of the chargino-
neutralino system for chargino-neutralino production, derived from studies of t¯t and Z
+jets events, respectively [38]. The correction factors vary between 0.92 and 0.51 for the
ISR jet multiplicity between one and six, and between 1.18 and 0.78 for pISR
T
between 125
and 600 GeV. The corrections have a small effect on the signal yields for all the simplified
models considered at the level of about 1%. For the bottom squark pair production signal
model, the full effect of the correction is propagated as a systematic uncertainty. For
the chargino-neutralino production one half of effect of the correction is propagated as a
systematic uncertainty. 4
Event reconstruction and selection The search with the 2016 data set uses events selected by the diphoton high-level trigger,
which requires two photons with pT above 30 and 18 GeV for the leading and subleading
photons, respectively. For the 2017 data set, to cope with the increased instantaneous
luminosity, the pT requirement on the subleading photon was increased to 22 GeV in order
to reduce the trigger rate. The efficiency of the trigger for events with two identified
photons is above 98%. Events are reconstructed using the CMS particle flow (PF) algorithm [39], which uses
the information from the tracker, calorimeter, and muon systems to construct an optimized
global description of the event. The reconstructed vertex with the largest value of summed
physics-object p2
T is taken to be the primary interaction vertex. The physics objects used
in this context are the objects returned by a jet finding algorithm [40, 41] applied to
all charged tracks associated with the vertex under consideration, plus the corresponding
associated missing transverse momentum. As the signal is predominantly produced in the central region of the detector, we
select events with at least two photons reconstructed in the barrel region (|η| < 1.44). The measured energy of photons is corrected for clustering and local geometric effects
using an energy regression trained on Monte Carlo (MC) simulation, and calibrated using
a combination of π0 →γγ, η →γγ, and Z →ee candidates [42]. The regression also – 4 – provides an estimate of the uncertainty of the energy measurement that is used to separate
events into high- and low-resolution categories. The photons are required to satisfy the
photon identification requirements based on electromagnetic shower shape, hadronic to
electromagnetic energy ratio, and isolation around the photon candidate. A photon is
considered isolated if the pT sum of the PF candidates from charged and neutral hadrons
and photons within a cone of 0.3 in ∆R =
√
(∆η)2 + (∆φ)2, where φ is the azimuthal angle
in radians, are each below a set threshold. The isolation sums are corrected for the effect
of pileup by subtracting the average energy deposited as estimated by the pileup energy
density ρ [43]. If the photon is matched to a reconstructed electron that is inconsistent
with a conversion candidate, it is discarded. A loose working point is used for the photon
identification, which has an efficiency of approximately 90%, uniform in pT and η. 4
Event reconstruction and selection The
leading (subleading) photon is required to have pT/mγγ > 0.33 (0.25), where mγγ is the
reconstructed diphoton mass. The diphoton mass is required to be larger than 100 GeV. The two photons with the largest pT, selected according to the identification criteria above,
are considered to be the decay products of the Higgs boson candidate. JHEP11(2019)109 The PF candidates are clustered into jets using the anti-kT algorithm [40, 41] with
a distance parameter of 0.4. Jet energy corrections are applied and derived based on a
combination of simulation studies, accounting for the nonlinear detector response and the
presence of pileup, together with in-situ measurements of the energy balance in dijet and
γ+jet events using the methods described in ref. [44]. Jets originating from a heavy-flavor
parton are identified by the combined secondary vertex (CSVv2) tagger algorithm [45]
using a loose working point. The resulting efficiency is about 80%, while the mistag rate
for light-quark and gluon jets is approximately 10%. We identify each jet with pT > 20 GeV
that satisfies the loose working point as a b-tagged jet. Other jets with pT > 30 GeV and
|η| < 2.4 are considered in this analysis for the purpose of jet counting. Electrons and muons
in the region |η| < 2.4 and with pT > 20 GeV are selected from the PF candidates, and
a loose identification working point is used. Jets that overlap with the selected electrons,
muons, and photons in a cone of size ∆R = 0.4 are discarded. Electrons in a cone of size
∆R = 1.0 and muons in a cone of size ∆R = 0.5 around the selected photons are discarded. A larger veto cone is used for electrons to suppress photon conversions. The transverse component of the negative vectorial sum of the momenta of all PF
candidates is the missing transverse momentum ⃗pmiss
T
, and its magnitude is defined as pmiss
T
. Dedicated filters [46] reject events with possible beam halo contamination or anomalous
noise in the calorimeter systems that can give rise to a large pmiss
T
. 5
Analysis strategy Two analysis strategies are pursued that employ two alternative event categorization
schemes: one focused on electroweak production (EWP analysis) of charginos and neu-
tralinos; and another focused on strong production (SP analysis) of bottom squarks. For
both strategies, we define event categories based on the pT of the diphoton Higgs boson
candidate, and the presence of additional Z, W, or H →b¯b candidates. Within each event
category, we define search region bins based on the number of jets and b-tagged jets, and the – 5 – values of kinematic variables that discriminate between SUSY signal and SM backgrounds
events. Finally, to test specific SUSY simplified model hypotheses, we perform an unbinned
extended maximum likelihood fit to the diphoton mass distribution, simultaneously in all
of the search bins defined for each analysis. The dominant background results from SM production of diphoton or photon+jets,
and is collectively referred to as the nonresonant background. This background exhibits
a regular falling shape as validated in the MC simulation samples, and is modeled with a
fit to a family of falling functions independently in each search region bin as described in
the next section. The SM Higgs boson background and the SUSY signal model under test
exhibit a resonant shape in the diphoton mass and are constrained to the MC simulation
predictions within uncertainties. A more detailed discussion of the background fit model
and the systematic uncertainties can be found in sections 6 and 7, respectively. JHEP11(2019)109 In the EWP approach, we build upon the strategy employed in a previous publica-
tion [8], which categorized events according to the pT of the diphoton Higgs boson candi-
date, the presence of an additional Higgs boson candidate, the estimated diphoton mass
resolution, and the values of the “razor” kinematic variables [47, 48]. In addition, we add
event categories with one or two identified leptons, and further optimize the binning in
the kinematic variables for the enlarged data set. The bin boundaries have been chosen
to yield the best expected signal significance as estimated using simulation predictions of
the signal and background yields. These enhancements improve the signal sensitivity to
electroweak production of charginos and neutralinos. By isolating events with a Z, W, or
H →b¯b candidate in addition to the H →γγ candidate, we improve the sensitivity to the
simplified signal models shown in figure 1. 5
Analysis strategy The Higgs boson candidate and any additional identified leptons or jets are clustered
into two hemispheres (megajets) according to the razor megajet algorithm [48], which
minimizes the sum of the squared-invariant-mass values of the two megajets. In order to
form two hemispheres, we require that events have at least one identified lepton or jet in
addition to the Higgs boson candidate. The razor variables [47, 48] MR and R2 are then
computed as follows: MR ≡
q
(|⃗p j1| + |⃗p j2|)2 −(pzj1 + pzj2)2,
(5.1)
R2 ≡
MR
T
MR
2
,
(5.2) (5.1) (5.2) where ⃗p is the momentum of a megajet, pz is its longitudinal component, and j1 and j2 are
used to label the two megajets. In the definition of R2, the variable MR
T is defined as: MR
T ≡
s
pmiss
T
(pTj1 + pTj2) −⃗pmiss
T
· (⃗pT j1 + ⃗pT j2)
2
. (5.3) (5.3) 2 The razor variables MR and R2 provide discrimination between SUSY signal models and
SM background processes, with SUSY signals typically having large values of MR and R2,
while the SM diphoton and photon+jets backgrounds exhibit a falling spectrum in each
variable. – 6 – – 6 – The selected events are first categorized according to the number of electrons or muons. Events with two same-flavor opposite-sign leptons are placed in the “Two-Lepton” category
if the dilepton mass satisfies the constraint |mZ −mℓℓ| ≤20 GeV. Among the remaining
events, those with at least one muon (electron) are placed in the “Muon” (“Electron”)
category, with the Muon category taking precedence. Events in the Electron and Muon
categories are further subdivided into the “High-pT” and “Low-pT” subcategories depend-
ing on whether the pT of the Higgs boson candidate is larger or smaller than 110 GeV. For
events which do not have any leptons, we search for pairs of b-tagged jets, whose mass is
between 95 and 140 GeV, and place them into the “Hb¯b” category. If no such jet-pairs are
found, then we search for pairs of b-tagged jets whose mass is between 60 and 95 GeV, and
place them into the “Zb¯b” category. Events in the Hb¯b and Zb¯b categories are also further
subdivided into the High-pT and Low-pT subcategories using the same criteria stated above. 5
Analysis strategy Among the remaining events, those with the pT of the Higgs boson candidate larger than
110 GeV are placed in the High-pT category. Finally, the remaining events are categorized
as “High-Res” or “Low-Res” if the diphoton mass resolution estimate σm/m is smaller or
larger than 0.85%, respectively, with σm defined as: JHEP11(2019)109 JHEP11(2019)109 σm = 1
2
q
(σEγ1/Eγ1)2 + (σEγ2/Eγ2)2,
(5.4) (5.4) where Eγ1,2 is the energy of each photon and σEγ1,2 is the estimated energy resolution for
each photon. The choice of the 0.85% threshold was made to be identical to past results [8],
which was previously optimized for signal to background discrimination. The leptonic categories select SUSY events containing decays to W or Z bosons; the
Hb¯b (Zb¯b) categories select events that contain an additional Higgs (Z) boson, which decays
to a pair of b jets; the High-pT category selects SUSY events producing high-pT Higgs
bosons; and the separation into the High-Res and Low-Res categories further improves
the discrimination between any signal containing an H →γγ candidate and non-resonant
background in the remaining event sample. Finally, to distinguish SUSY signal events
from the SM background, each event category is further divided into bins in the MR and
R2 variables, provided there are a sufficient number of data events in the diphoton mass
sideband to be able to estimate the background. These bins define the exclusive search
regions. For all categories except the Two-Lepton category, we impose the requirement
MR > 150 GeV to suppress the SM backgrounds. In the SP approach, we optimize the event categorization for strong production of
bottom squark pairs, which typically produce a larger number of jets and b-tagged jets. An
alternative clustering algorithm is employed, following ref. [49], to produce two hemispheres
referred to as pseudojets, and the kinematic variable mT2 [50] is calculated as mT2 =
min
⃗p missX(1)
T
+⃗p missX(2)
T
=⃗p miss
T
h
max
m(1)
T , m(2)
T
i
,
(5.5) (5.5) where ⃗p missX(i)
T
(with i=1,2) are trial vectors obtained by decomposing ⃗pmiss
T
and m(i)
T ,
the transverse masses obtained by pairing any of these trial vectors with one of the two
pseudojets. The minimization is performed over all trial momenta satisfying the ⃗pmiss
T
con-
straint. 5
Analysis strategy The pγγ
T /mγγ and mT2 kinematic variables are used to enhance the discrimination – 7 – between the SUSY signal and the SM background. Two bins in the mT2 variable are used:
mT2 < 30 and mT2 ≥30 GeV; and three bins in pγγ
T /mγγ: 0–0.6, 0.6–1.0 and ≥1.0. Events are also separated into the Two-Lepton, Muon, Electron, Hb¯b, and Zb¯b cat-
egories following the same procedure as described above for the EWP approach. The
remaining events are separated into the hadronic categories depending on the number of
jets and b-tagged jets. Within each of the event categories, the exclusive search region bins
are then defined based on the values of the pγγ
T /mγγ and mT2 observables. A summary of the 35 search region bins is shown in table 1 for the EWP analysis and
of the 64 search region bins in tables 2 and 3 for the SP analysis. Finally, to test specific SUSY simplified model hypotheses, we perform a combined
simultaneous fit using all the search regions defined for each analysis. The final result for
each signal model is obtained from the analysis with the best expected sensitivity. The
diphoton mass distribution is fit independently in each search region, while the expected
yields for the SM Higgs background and SUSY signal model among the different search
regions are constrained to the predicted values. JHEP11(2019)109 Search region bins with large values of pγγ
T and large values of the kinematic variables
MR and mT2 yield the best sensitivity for SUSY signals with larger squark or neutralino
masses, as backgrounds are heavily suppressed. The event categories with one lepton, two
leptons, a Z →b¯b candidate, or a H →b¯b candidate yield increasingly better sensitivity
for more compressed regions as the neutralino mass approaches the Higgs boson mass. 6
Backgrounds Two types of backgrounds can be identified for this search: a nonresonant one stemming
from the SM production of diphotons or a photon and a jet, and a resonant background
from SM Higgs boson production. To model the nonresonant background, a set of possible
functions is chosen from sums of exponential functions, sums of Bernstein polynomials,
Laurent series, and sums of power-law functions. To determine the best functional form,
two alternative strategies are followed for the EWP and SP analyses. As we do not know
a priori the exact shape of the background, it is important that the functional form used
is capable of adequately describing a sufficiently large range of background shapes to cover
potential systematic effects that affect the shapes. At the same time we do not want to
arbitrarily increase the number of fit parameters without yielding additional robustness
against systematic uncertainties. The EWP analysis uses the Akaike information criterion (AIC) [51] to determine which
functional forms are most appropriate to describe the background spectrum. The same
procedure was employed in the previous version of this search [8]. Bias tests are performed
by drawing random events using one functional form and fitting the resulting pseudo-data
set to another functional form. The functional form with the best AIC measure passing
the bias test is chosen to describe the nonresonant background. For the SP analysis, the background fit is performed by discrete profiling using the
“envelope” method [52]. The background functional form is treated as a discrete nuisance
parameter in the likelihood fit. A penalty is assigned to the likelihood for each parameter in – 8 – Bin number
Category
pγγ
T (GeV)
MR (GeV)
R2
EWP 0
Two-Lepton
No req. No req. No req. 6
Backgrounds EWP 1
Muon High-pT
≥110
≥150
≥0.0
EWP 2
Muon Low-pT
0–110
≥150
≥0.0
EWP 3
Electron High-pT
≥110
≥150
≥0.0
EWP 4
Electron Low-pT
0–110
≥150
0.000–0.055
EWP 5
Electron Low-pT
0–110
≥150
0.055–0.125
EWP 6
Electron Low-pT
0–110
≥150
≥0.125
EWP 7
Hb¯b High-pT
≥110
≥150
0.000–0.080
EWP 8
Hb¯b High-pT
≥110
≥150
≥0.080
EWP 9
Hb¯b Low-pT
0–110
≥150
0.000–0.080
EWP 10
Hb¯b Low-pT
0–110
≥150
≥0.080
EWP 11
Zb¯b High-pT
≥110
≥150
0.000–0.035
EWP 12
Zb¯b High-pT
≥110
≥150
0.035–0.090
EWP 13
Zb¯b High-pT
≥110
≥150
≥0.090
EWP 14
Zb¯b Low-pT
0–110
≥150
0.000–0.035
EWP 15
Zb¯b Low-pT
0–110
≥150
0.035–0.090
EWP 16
Zb¯b Low-pT
0–110
≥150
≥0.090
EWP 17
High-pT
≥110
≥150
≥0.260
EWP 18
High-pT
≥110
150–250
0.170–0.260
EWP 19
High-pT
≥110
≥250
0.170–0.260
EWP 20
High-pT
≥110
≥150
0.000–0.110
EWP 21
High-pT
≥110
150–350
0.110–0.170
EWP 22
High-pT
≥110
≥350
0.110–0.170
EWP 23
High-Res
0–110
≥150
≥0.325
EWP 24
High-Res
0–110
≥150
0.285–0.325
EWP 25
High-Res
0–110
≥150
0.225–0.285
EWP 26
High-Res
0–110
≥150
0.000–0.185
EWP 27
High-Res
0–110
150–200
0.185–0.225
EWP 28
High-Res
0–110
≥200
0.185–0.225
EWP 29
Low-Res
0–110
≥150
≥0.325
EWP 30
Low-Res
0–110
≥150
0.285–0.325
EWP 31
Low-Res
0–110
≥150
0.225–0.285
EWP 32
Low-Res
0–110
≥150
0.000–0.185
EWP 33
Low-Res
0–110
150–200
0.185–0.225
EWP 34
Low-Res
0–110
≥200
0.185–0.225
A summary of the search region bins used in the EWP analysis. Events are
ories based on the number of leptons, the presence of H →b¯b candidates,
γγ candidate, and the estimated diphoton mass resolution. The High-Res and
are defined by the estimated diphoton resolution mass σm/m being smaller
%, respectively. For the Two-Lepton category, “No req.” means that no require
the given observables. JHEP11(2019)109 Table 1. A summary of the search region bins used in the EWP analysis. Events are separated
into categories based on the number of leptons, the presence of H →b¯b candidates, the pT of
the H →γγ candidate, and the estimated diphoton mass resolution. The High-Res and Low-Res
categories are defined by the estimated diphoton resolution mass σm/m being smaller or larger
than 0.85%, respectively. For the Two-Lepton category, “No req.” means that no requirements are
placed on the given observables. Table 1. A summary of the search region bins used in the EWP analysis. 6
Backgrounds Events are separated
into categories based on the number of leptons, the presence of H →b¯b candidates, the pT of
the H →γγ candidate, and the estimated diphoton mass resolution. The High-Res and Low-Res
categories are defined by the estimated diphoton resolution mass σm/m being smaller or larger
than 0.85%, respectively. For the Two-Lepton category, “No req.” means that no requirements are
placed on the given observables. – 9 – Bin number
Bin name
Category
pγγ
T /mγγ
mT2 (GeV)
SP 0
Zℓℓ
Two-Lepton
No req. No req. SP 1
1µ p0
T, m0
T2
Muon
0.0–0.6
0–30
SP 2
1µ p0
T, m30
T2
Muon
0.0–0.6
≥30
SP 3
1µ p75
T , m0
T2
Muon
0.6–1.0
0–30
SP 4
1µ p75
T , m30
T2
Muon
0.6–1.0
≥30
SP 5
1µ p125
T , m0
T2
Muon
≥1.0
0–30
SP 6
1µ p125
T , m30
T2
Muon
≥1.0
≥30
SP 7
1e p0
T, m0
T2
Electron
0.0–0.6
0–30
SP 8
1e p0
T, m30
T2
Electron
0.0–0.6
≥30
SP 9
1e p75
T , m0
T2
Electron
0.6–1.0
0–30
SP 10
1e p75
T , m30
T2
Electron
0.6–1.0
≥30
SP 11
1e p125
T , m0
T2
Electron
≥1.0
0–30
SP 12
1e p125
T , m30
T2
Electron
≥1.0
≥30
SP 13
Zb¯b p0
T, m0
T2
Zb¯b
0.0–0.6
0–30
SP 14
Zb¯b p75
T , m0
T2
Zb¯b
0.6–1.0
0–30
SP 15
Zb¯b p125
T , m0
T2
Zb¯b
≥1.0
0–30
SP 16
Zb¯b p0
T, m30
T2
Zb¯b
0.0–0.6
≥30
SP 17
Zb¯b p75
T , m30
T2
Zb¯b
0.6–1.0
≥30
SP 18
Zb¯b p125
T , m30
T2
Zb¯b
≥1.0
≥30
SP 19
Hb¯b p0
T, m0
T2
Hb¯b
0.0–0.6
0–30
SP 20
Hb¯b p75
T , m0
T2
Hb¯b
0.6–1.0
0–30
SP 21
Hb¯b p125
T , m0
T2
Hb¯b
≥1.0
0–30
SP 22
Hb¯b p0
T, m30
T2
Hb¯b
0.0–0.6
≥30
SP 23
Hb¯b p75
T , m30
T2
Hb¯b
0.6–1.0
≥30
SP 24
Hb¯b p125
T , m30
T2
Hb¯b
≥1.0
≥30
Table 2. A summary of the search region bins in the leptonic and Higgs boson categories used in the
SP analysis, along with the requirements on pγγ
T /mγγ and mT2. There are no explicit requirements
on the number of jets or b-tagged jets for these categories. 6
Backgrounds For the Two-Lepton category, “No req.”
means that no requirements are placed on the given observables. JHEP11(2019)109 Table 2. A summary of the search region bins in the leptonic and Higgs boson categories used in the
SP analysis, along with the requirements on pγγ
T /mγγ and mT2. There are no explicit requirements
on the number of jets or b-tagged jets for these categories. For the Two-Lepton category, “No req.”
means that no requirements are placed on the given observables. the function. The envelope with the best likelihood is determined by the discrete profiling
method taking penalties into account. These two alternative background modeling methods
were studied in a past CMS measurement of the SM Higgs process in the diphoton decay
channel and similar accuracy is expected [53]. the function. The envelope with the best likelihood is determined by the discrete profiling
method taking penalties into account. These two alternative background modeling methods
were studied in a past CMS measurement of the SM Higgs process in the diphoton decay
channel and similar accuracy is expected [53]. The shape of the SM Higgs boson background and the SUSY signals is modeled by a
double Crystal Ball function [54, 55], fitted to the diphoton mass distribution from the MC
simulation separately in each search region bin. The parameters of each double Crystal
Ball function are held constant in the signal extraction fit procedure. The normalization of
the SM Higgs boson background in each bin is constrained to the MC simulation prediction
to within systematic uncertainties. – 10 – Bin number
Bin name
Jets
b-tagged jets
pγγ
T /mγγ
mT2 (GeV)
SP 25
0j, ≥0b, p0
T
0
No req. 0.0–0.6
No req. SP 26
0j, ≥0b, p75
T
0
No req. 0.6–1.0
No req. SP 27
0j, ≥0b, p125
T
0
No req. ≥1.0
No req. 6
Backgrounds SP 28
1–3j, 0b, p0
T, m0
T2
1–3
0
0.0–0.6
0–30
SP 29
1–3j, 0b, p0
T, m30
T2
1–3
0
0.0–0.6
≥30
SP 30
1–3j, 0b, p75
T , m0
T2
1–3
0
0.6–1.0
0–30
SP 31
1–3j, 0b, p75
T , m30
T2
1–3
0
0.6–1.0
≥30
SP 32
1–3j, 0b, p125
T , m0
T2
1–3
0
≥1.0
0–30
SP 33
1–3j, 0b, p125
T , m30
T2
1–3
0
≥1.0
≥30
SP 34
1–3j, 1b, p0
T, m0
T2
1–3
1
0.0–0.6
0–30
SP 35
1–3j, 1b, p0
T, m30
T2
1–3
1
0.0–0.6
≥30
SP 36
1–3j, 1b, p75
T , m0
T2
1–3
1
0.6–1.0
0–30
SP 37
1–3j, 1b, p75
T , m30
T2
1–3
1
0.6–1.0
≥30
SP 38
1–3j, 1b, p125
T , m0
T2
1–3
1
≥1.0
0–30
SP 39
1–3j, 1b, p125
T , m30
T2
1–3
1
≥1.0
≥30
SP 40
1–3j, ≥2b, p0
T, m0
T2
1–3
≥2
0.0–0.6
0–30
SP 41
1–3j, ≥2b, p0
T, m30
T2
1–3
≥2
0.0–0.6
≥30
SP 42
1–3j, ≥2b, p75
T , m0
T2
1–3
≥2
0.6–1.0
0–30
SP 43
1–3j, ≥2b, p75
T , m30
T2
1–3
≥2
0.6–1.0
≥30
SP 44
1–3j, ≥2b, p125
T , m0
T2
1–3
≥2
≥1.0
0–30
SP 45
1–3j, ≥2b, p125
T , m30
T2
1–3
≥2
≥1.0
≥30
SP 46
≥4j, 0b, p0
T, m0
T2
≥4
0
0.0–0.6
0–30
SP 47
≥4j, 0b, p0
T, m30
T2
≥4
0
0.0–0.6
≥30
SP 48
≥4j, 0b, p75
T , m0
T2
≥4
0
0.6–1.0
0–30
SP 49
≥4j, 0b, p75
T , m30
T2
≥4
0
0.6–1.0
≥30
SP 50
≥4j, 0b, p125
T , m0
T2
≥4
0
≥1.0
0–30
SP 51
≥4j, 0b, p125
T , m30
T2
≥4
0
≥1.0
≥30
SP 52
≥4j, 1b, p0
T, m0
T2
≥4
1
0.0–0.6
0–30
SP 53
≥4j, 1b, p0
T, m30
T2
≥4
1
0.0–0.6
≥30
SP 54
≥4j, 1b, p75
T , m0
T2
≥4
1
0.6–1.0
0–30
SP 55
≥4j, 1b, p75
T , m30
T2
≥4
1
0.6–1.0
≥30
SP 56
≥4j, 1b, p125
T , m0
T2
≥4
1
≥1.0
0–30
SP 57
≥4j, 1b, p125
T , m30
T2
≥4
1
≥1.0
≥30
SP 58
≥4j, ≥2b, p0
T, m0
T2
≥4
≥2
0.0–0.6
0–30
SP 59
≥4j, ≥2b, p0
T, m30
T2
≥4
≥2
0.0–0.6
≥30
SP 60
≥4j, ≥2b, p75
T , m0
T2
≥4
≥2
0.6–1.0
0–30
SP 61
≥4j, ≥2b, p75
T , m30
T2
≥4
≥2
0.6–1.0
≥30
SP 62
≥4j, ≥2b, p125
T , m0
T2
≥4
≥2
≥1.0
0–30
SP 63
≥4j, ≥2b, p125
T , m30
T2
≥4
≥2
≥1.0
≥30
le 3. Table 3. A summary of the search region bins in the leptonic and Higgs boson categories used
in the SP analysis, along with the requirements on pγγ
T /mγγ and mT2. “No req.” means that no
requirements are placed on the given observables. 7
Systematic uncertainties The dominant systematic uncertainties in this search are the normalization and shape of
the nonresonant background associated with the fitted functional form. They are propa-
gated by profiling the associated unconstrained functional form parameters. The fraction
of the total uncertainty due to the nonresonant background fit ranges from 75% to 99%,
and is above 90% for most search region bins. The subdominant systematic uncertainties
in the SM Higgs boson background and SUSY signal are propagated through independent
log-normal nuisance parameters that take both theoretical and instrumental effects into
account. These systematic uncertainties affect the event yield predictions of the SM Higgs
boson background and SUSY signal in the different search region bins, and are propagated
as shape uncertainties. The independent systematic effects considered include missing
higher-order QCD corrections, PDFs, trigger and object selection efficiencies, jet energy
scale uncertainties, b-tagging efficiency, lepton identification efficiencies, fast simulation
pmiss
T
modeling, and the uncertainty in the integrated luminosity. The typical size of these
effects on the signal and background yields are summarized in table 4, and are approxi-
mately the same for the SP and EWP analyses. Systematic uncertainties due to missing
higher-order corrections are estimated by the use of the procedure outlined in ref. [56],
where the factorization (µF) and renormalization (µR) scales are varied independently by
factors of 0.5 and 2.0. The PDF systematic uncertainties are propagated for the SM Higgs
background as a shape uncertainty using the LHC4PDF procedure [57]. JHEP11(2019)109 Because of the imperfect simulation of the effects of pileup and transparency loss
from radiation damage in the ECAL crystals, we observe some simulation mismodeling
of the estimated mass resolution, which can migrate events between the High-Res and
Low-Res event categories of the EWP analysis. As a result, a systematic uncertainty of
10–24%, measured using a Z →e+e−control sample, is propagated to the prediction of
the SM Higgs boson background and SUSY signal yields in the High-Res and Low-Res
event categories. The systematic uncertainty in the photon energy scale is implemented as
a Gaussian-distributed nuisance parameter that shifts the Higgs boson mass peak position,
constrained in the fit to lie within approximately 1% of the nominal Higgs boson mass
observed in simulation. The systematic uncertainty for the modeling of the ISR for the
signal process is also propagated. 6
Backgrounds A summary of the search region bins in the leptonic and Higgs boson categories u
he SP analysis, along with the requirements on pγγ
T /mγγ and mT2. “No req.” means tha
irements are placed on the given observables JHEP11(2019)109 Table 3. A summary of the search region bins in the leptonic and Higgs boson categories used
in the SP analysis, along with the requirements on pγγ
T /mγγ and mT2. “No req.” means that no
requirements are placed on the given observables. Table 3. A summary of the search region bins in the leptonic and Higgs boson categories used
in the SP analysis, along with the requirements on pγγ
T /mγγ and mT2. “No req.” means that no
requirements are placed on the given observables. – 11 – 8
Results and interpretation The fit results for the search region bins including the data yields, fitted background, and
signal yields are summarized in tables 5 and 6 for the SP analysis and in table 7 for the
EWP analysis. Example fit results are shown in figure 2 to illustrate the background-only
and signal plus background fits. We observe no statistically significant deviation from the
SM background expectation. The search results are interpreted in terms of limits on the product of the production
cross section and branching fraction for simplified models of bottom squark pair production
and chargino-neutralino production indicated in figure 1. In the case of bottom squark pair – 12 – Uncertainty source
Uncertainty size (%)
PDFs and QCD scale variations
10–30 (SM Higgs boson)
5–10 (EWK SUSY signal)
15–30 (Strong SUSY signal)
Signal ISR modeling
5–25
σm/m categorization
10–24
Fast simulation pmiss
T
modeling
3–16
Luminosity
2.3–2.5
Trigger and selection efficiency
3
Lepton efficiency
4
Jet energy scale
1–5
Photon energy scale
1
b-tagging efficiency
4
H →γγ branching fraction
2
Table 4. Summary of systematic uncertainties on the SM Higgs boson background and signal yield
predictions, and the size of their effect on the signal yield. JHEP11(2019)109 Table 4. Summary of systematic uncertainties on the SM Higgs boson background and signal yie
predictions, and the size of their effect on the signal yield. Table 4. Summary of systematic uncertainties on the SM Higgs boson background and signal yield
predictions, and the size of their effect on the signal yield. production, we consider the scenario where the bottom squark subsequently decays to a
bottom quark and the next-to-lightest neutralino (eχ0
2), where the eχ0
2 decays to a Higgs
boson and the LSP (eχ0
1). The mass splitting between the eχ0
2 and eχ0
1 is assumed to be
130 GeV, slightly above threshold to produce an on-shell Higgs boson. production, we consider the scenario where the bottom squark subsequently decays to a
bottom quark and the next-to-lightest neutralino (eχ0
2), where the eχ0
2 decays to a Higgs
boson and the LSP (eχ0
1). The mass splitting between the eχ0
2 and eχ0
1 is assumed to be
130 GeV, slightly above threshold to produce an on-shell Higgs boson. In the case of chargino-neutralino production, we consider two different scenarios. 8
Results and interpretation In
the first scenario, the pure wino-like charginos (eχ±
1 ) and the eχ0
2 are mass-degenerate and
are produced together, with the chargino decaying to a W boson and the eχ0
1 LSP, and the
eχ0
2 decaying to a Higgs boson and the LSP. The production cross sections are computed at
NLO+NLL accuracy in QCD in the limit of mass-degenerate wino eχ0
2 and eχ±
1 , light bino
eχ0
1, and with all the other sparticles assumed to be heavy and decoupled [31–33]. In the second scenario, we consider a GMSB [4, 5] simplified model where higgsino-like
charginos and neutralinos are nearly mass-degenerate and are produced in pairs through
the following combinations: eχ0
1eχ0
2, eχ0
1eχ±
1 , eχ0
2eχ±
1 , and eχ±
1 eχ∓
1 . Because of the mass degeneracy,
both the eχ0
2 and eχ±
1 will decay to eχ0
1 and other low-pT (soft) particles, leading to a signature
with a eχ0
1 pair. Each eχ0
1 will subsequently decay to a Higgs boson and the eG LSP, or to a
Z boson and the LSP. We consider the case where the branching fraction of the eχ0
1 →HeG
decay is 100%, and the case where the branching fraction of the eχ0
1 →HeG and eχ0
1 →ZeG
decays are each 50%. This scenario is represented by the eχ0
1-pair production simplified
model shown on figure 1. We show the expected event yields from a representative selection of the different
simplified SUSY models considered in the different search region bins of the SP analysis
in tables 8 and 9, and in the different search region bins of the EWP analysis in table 10. The details of the particular signal model are described in the caption of table 8. 8
Results and interpretation Following the CLs criterion [58–60], we use the profile likelihood ratio test statistic and
the asymptotic formula [61] to evaluate the 95% confidence level (CL) observed and ex- – 13 – Search
Bin name
Observed
Fitted
SM Higgs boson
region bin
data
nonresonant bkg
bkg
SP 0
Zℓℓ
2
1.7 ± 0.2
0.84 ± 0.09
SP 1
1µ p0
T, m0
T2
24
20.0 ± 0.9
1.6 ± 0.1
SP 2
1µ p0
T, m30
T2
10
8.9 ± 1.4
1.1 ± 0.1
SP 3
1µ p75
T , m0
T2
3
2.6 ± 0.5
0.89 ± 0.07
SP 4
1µ p75
T , m30
T2
7
2.4 ± 0.4
0.79 ± 0.07
SP 5
1µ p125
T , m0
T2
4
3.1 ± 0.4
1.0 ± 0.1
SP 6
1µ p125
T , m30
T2
3
2.2 ± 0.4
1.1 ± 0.1
SP 7
1e p0
T, m0
T2
93
87.2 ± 10.6
1.1 ± 0.1
SP 8
1e p0
T, m30
T2
15
13.8 ± 0.9
0.59 ± 0.05
SP 9
1e p75
T , m0
T2
10
18.6 ± 3.0
0.74 ± 0.06
SP 10
1e p75
T , m30
T2
3
4.3 ± 0.3
0.48 ± 0.04
SP 11
1e p125
T , m0
T2
7
6.2 ± 0.4
1.1 ± 0.1
SP 12
1e p125
T , m30
T2
1
1.4 ± 0.2
0.89 ± 0.08
SP 13
Zb¯b p0
T, m0
T2
227
224 ± 17
4.4 ± 0.6
SP 14
Zb¯b p75
T , m0
T2
33
42.2 ± 7.4
1.7 ± 0.2
SP 15
Zb¯b p125
T , m0
T2
15
15.7 ± 3.6
2.9 ± 0.3
SP 16
Zb¯b p0
T, m30
T2
44
43.4 ± 7.5
0.83 ± 0.40
SP 17
Zb¯b p75
T , m30
T2
13
10.8 ± 2.3
0.48 ± 0.13
SP 18
Zb¯b p125
T , m30
T2
5
4.5 ± 0.4
0.82 ± 0.11
SP 19
Hb¯b p0
T, m0
T2
179
179 ± 15
3.4 ± 0.3
SP 20
Hb¯b p75
T , m0
T2
45
41.2 ± 1.9
1.9 ± 0.2
SP 21
Hb¯b p125
T , m0
T2
22
18.4 ± 1.8
3.0 ± 0.9
SP 22
Hb¯b p0
T, m30
T2
47
42.5 ± 7.4
0.93 ± 0.32
SP 23
Hb¯b p75
T , m30
T2
13
12.1 ± 0.8
0.62 ± 0.06
SP 24
Hb¯b p125
T , m30
T2
6
4.4 ± 0.7
1.3 ± 0.2
Table 5. 8
Results and interpretation The observed data, fitted nonresonant background yields, and SM Higgs boson ba
ground yields within the mass window between 122 and 129 GeV are shown for each search reg
bin in the Hb¯b, Zb¯b, and leptonic categories of the SP analysis. The uncertainties quoted are t
fit uncertainties, which include the impact of all systematic uncertainties. The bin names giv
short-form description of the search region bin definition which are given in full in table 2. T
labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0
between 0.6 and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to b
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. JHEP11(2019)109 Table 5. The observed data, fitted nonresonant background yields, and SM Higgs boson back-
ground yields within the mass window between 122 and 129 GeV are shown for each search region
bin in the Hb¯b, Zb¯b, and leptonic categories of the SP analysis. The uncertainties quoted are the
fit uncertainties, which include the impact of all systematic uncertainties. The bin names give a
short-form description of the search region bin definition which are given in full in table 2. The
labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6,
between 0.6 and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. Table 5. The observed data, fitted nonresonant background yields, and SM Higgs boson back-
ground yields within the mass window between 122 and 129 GeV are shown for each search region
bin in the Hb¯b, Zb¯b, and leptonic categories of the SP analysis. The uncertainties quoted are the
fit uncertainties, which include the impact of all systematic uncertainties. The bin names give a
short-form description of the search region bin definition which are given in full in table 2. The
labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6,
between 0.6 and 1.0, and greater than 1.0, respectively. 8
Results and interpretation [GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
16
18
20
Data
Signal plus background
Total background
Signal
SP analysis bin 21
0
T2
m
125
T
p
bb
H
CMS
(13 TeV)
-1
77.5 fb [GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
16
18
20
Data
Full background model
Nonresonant background
SP analysis bin 21
0
T2
m
125
T
p
bb
H
CMS
(13 TeV)
-1
77.5 fb JHEP11(2019)109 [GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
Data
Full background model
Nonresonant background
EWP analysis bin 2
category
T
Muon Low-p
110 GeV
≤
γ
γ
T
p
CMS
(13 TeV)
-1
77.5 fb [GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
Data
Signal plus background
Total background
Signal
EWP analysis bin 2
category
T
Muon Low-p
110 GeV
≤
γ
γ
T
p
CMS
(13 TeV)
-1
77.5 fb Figure 2. The diphoton mass distribution for two example search bin is shown with the
background-only fit (left) and the signal-plus-background fit (right) to illustrate the signal ex-
traction procedure. The search region bins shown corresponds to the Hb¯b p125
T , m0
T2 category, bin
21, of the SP analysis (upper) and the Muon Low-pT category, bin 2, of the EWP analysis (lower). of the bottom squark mass and the LSP mass. We exclude bottom squarks with masses
below about 530 GeV for an LSP mass of 1 GeV. For the simplified models of chargino-neutralino production, the EWP analysis has
slightly better expected sensitivity because of the inclusion of bins with smaller MR and
larger R2. Events in such bins typically have lower values of pmiss
T
and are not in the
regions of high signal sensitivity for the SP analysis, while the R2 variable is able to
suppress backgrounds more effectively in these regions of phase space. For the wino-like
chargino-neutralino production, the limits obtained using the EWP analysis are shown in
figure 4 as a function of the chargino mass and the LSP mass. 8
Results and interpretation The labels m0
T2 and m30
T2 refer to bins
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. pected limits on the signal production cross sections. For the simplified models of bottom
squark pair production where the bottom squark undergoes a cascade decay to a Higgs
boson and the LSP, the SP analysis yields better expected sensitivity because of the bin-
ning in the number of jets and b-tagged jets, as more jets and more heavy-flavor jets are
produced. The limits obtained using the SP analysis are shown in figure 3, as a function – 14 – [GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
16
18
20
Data
Full background model
Nonresonant background
SP analysis bin 21
0
T2
m
125
T
p
bb
H
CMS
(13 TeV)
-1
77.5 fb
[GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
16
18
20
Data
Signal plus background
Total background
Signal
SP analysis bin 21
0
T2
m
125
T
p
bb
H
CMS
(13 TeV)
-1
77.5 fb
[GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
Data
Full background model
Nonresonant background
EWP analysis bin 2
category
T
Muon Low-p
110 GeV
≤
γ
γ
T
p
CMS
(13 TeV)
-1
77.5 fb
[GeV]
γ
γ
m
100
110
120
130
140
150
160
170
180
Events / GeV
0
2
4
6
8
10
12
14
Data
Signal plus background
Total background
Signal
EWP analysis bin 2
category
T
Muon Low-p
110 GeV
≤
γ
γ
T
p
CMS
(13 TeV)
-1
77.5 fb
Figure 2. The diphoton mass distribution for two example search bin is shown with the
background-only fit (left) and the signal-plus-background fit (right) to illustrate the signal ex-
traction procedure. The search region bins shown corresponds to the Hb¯b p125
T , m0
T2 category, bin
21, of the SP analysis (upper) and the Muon Low-pT category, bin 2, of the EWP analysis (lower). 8
Results and interpretation We exclude chargino masses
below about 235 GeV for an LSP mass of 1 GeV. For the higgsino-like chargino-neutralino
production simplified models, the limits obtained using the EWP analysis are shown in
figure 5 as a function of the chargino mass for the case where the branching fraction of the
eχ0
1 →HeG decay is 100%, and for the case where the branching fraction of the eχ0
1 →HeG
and eχ0
1 →ZeG decays are both 50%. We exclude charginos below 290 and 230 GeV in
the former and latter cases, respectively. The corresponding limits from the EWP analysis
as applied to bottom squark production and limits from the SP analysis as applied to
chargino-neutralino production are included in the appendix for completeness. – 15 – [GeV]
b~
m
250 300 350 400 450 500 550 600 650 700
[GeV]
0
1
χ∼
m
0
50
100
150
200
250
300
350
400
450
500
1
−
10
1
(13 TeV)
-1
77.5 fb
CMS
1
0
χ∼
bH
→
2
0
χ∼
b
→
b~
,
b~
b~
→
pp
theory
1 s.d. ±
Observed
experiment
1, 2 s.d. ±
Expected
95% CL upper limit on cross section [pb]
SP analysis
Figure 3. The observed 95% CL upper limits on the bottom squark pair production cross section
are shown for the SP analysis. The bold and light solid black contours represent the observed
exclusion region and the ±1 standard deviation (s.d.)
band, including both experimental and
theoretical uncertainties. The analogous red dotted contours represent the expected exclusion
region and its ±1 and ±2 s.d. bands. [GeV]
b~
m
250 300 350 400 450 500 550 600 650 700
[GeV]
0
1
χ∼
m
0
50
100
150
200
250
300
350
400
450
500
1
−
10
1
(13 TeV)
-1
77.5 fb
CMS
1
0
χ∼
bH
→
2
0
χ∼
b
→
b~
,
b~
b~
→
pp
theory
1 s.d. ±
Observed
experiment
1, 2 s.d. ±
Expected
95% CL upper limit on cross section [pb]
SP analysis JHEP11(2019)109 Figure 3. The observed 95% CL upper limits on the bottom squark pair production cross section
are shown for the SP analysis. The bold and light solid black contours represent the observed
exclusion region and the ±1 standard deviation (s.d.)
band, including both experimental and
theoretical uncertainties. 8
Results and interpretation The analogous red dotted contours represent the expected exclusion
region and its ±1 and ±2 s.d. bands. The search region bins with large pγγ
T in the H →b¯b category yield the best overall
sensitivity. For signal models with squark or neutralino masses exceeding the Higgs boson
mass by 100 GeV or more, the search region bins with large values of pγγ
T and large values
of the kinematic variables MR and mT2 in the untagged jet categories of the SP analysis
or the High-pT category for the EWP analysis also contribute significantly to the search
sensitivity. For more compressed regions of the signal model parameter space, where the
neutralino mass approaches the Higgs boson mass, the search region bins with large pγγ
T in
the leptonic categories contribute significantly to the search sensitivity. The search region
bins with small values of pγγ
T and small values of the kinematic variables MR, R2, and mT2
typically have low sensitivity to the simplified models considered due to higher levels of
background, but are included to maintain inclusivity for this search. 9
Summary band. Figure 4. The observed 95% CL upper limits on the wino-like chargino-neutralino production
cross section are shown for the EWP analysis. The bold and light black contours represent the
observed exclusion region and the ±1 standard deviation (s.d.) band, including both experimental
and theoretical uncertainties. The analogous red dotted contours represent the expected exclusion
region and its ±1 s.d. band. [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
(100%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
[GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
(50%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
(50%)
G~
Z
→
1
0
χ∼
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
Figure 5. The observed 95% CL upper limits on the production cross section for higgsino-like
chargino-neutralino production are shown for the EWP analysis. We present limits in the scenario
where the branching fraction of eχ0
1 →HeG decay is 100% (left plot), and where the eχ0
1 →HeG
and eχ0
1 →ZeG decays are each 50% (right plot). The dotted and solid black curves represent the
expected and observed exclusion region, and the green dark and yellow light bands represent the ±1
and ±2 standard deviation regions, respectively. The red solid and dotted lines show the theoretical
production cross section and its uncertainty band. 9
Summary We have presented a search for supersymmetry (SUSY) in the final state with a Higgs
boson (H) decaying to a photon pair, using data collected with the CMS detector at the
LHC in 2016 and 2017, corresponding to 77.5 fb−1 of integrated luminosity. To improve the
sensitivity over previously published results, we pursue two strategies that are optimized for
strong and electroweak SUSY production, respectively. Photon pairs in the central region of
the detector are used to reconstruct Higgs boson candidates. Charged leptons and b jets are – 16 – [GeV]
0
2
χ∼
= m
±
1
χ∼
m
140 160 180 200 220 240 260 280 300
[GeV]
0
1
χ∼
m
0
20
40
60
80
100
120
140
160
180
200
1
−
10
1
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
0
1
χ∼
H
→
0
2
χ∼
,
0
1
χ∼
±
W
→
±
1
χ∼
,
0
2
χ∼
±
1
χ∼
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
Figure 4. The observed 95% CL upper limits on the wino-like chargino-neutralino production
cross section are shown for the EWP analysis. The bold and light black contours represent the
observed exclusion region and the ±1 standard deviation (s.d.) band, including both experimental
and theoretical uncertainties. The analogous red dotted contours represent the expected exclusion
region and its ±1 s d band [GeV]
0
2
χ∼
= m
±
1
χ∼
m
140 160 180 200 220 240 260 280 300
[GeV]
0
1
χ∼
m
0
20
40
60
80
100
120
140
160
180
200
1
−
10
1
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
0
1
χ∼
H
→
0
2
χ∼
,
0
1
χ∼
±
W
→
±
1
χ∼
,
0
2
χ∼
±
1
χ∼
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb] (13 TeV)
-1
77.5 fb JHEP11(2019)109 Figure 4. The observed 95% CL upper limits on the wino-like chargino-neutralino production
cross section are shown for the EWP analysis. The bold and light black contours represent the
observed exclusion region and the ±1 standard deviation (s.d.) band, including both experimental
and theoretical uncertainties. The analogous red dotted contours represent the expected exclusion
region and its ±1 s.d. 9
Summary [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
(50%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
(50%)
G~
Z
→
1
0
χ∼
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
EWP analysis
(13 TeV)
-1
77.5 fb
CMS [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
(100%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
EWP analysis
(13 TeV)
-1
77.5 fb
CMS Figure 5. The observed 95% CL upper limits on the production cross section for higgsino-like
chargino-neutralino production are shown for the EWP analysis. We present limits in the scenario
where the branching fraction of eχ0
1 →HeG decay is 100% (left plot), and where the eχ0
1 →HeG
and eχ0
1 →ZeG decays are each 50% (right plot). The dotted and solid black curves represent the
expected and observed exclusion region, and the green dark and yellow light bands represent the ±1
and ±2 standard deviation regions, respectively. The red solid and dotted lines show the theoretical
production cross section and its uncertainty band. 9
Summary – 17 – Search
Bin name
Observed
Fitted
SM Higgs boson
region bin
data
nonresonant bkg
bkg
SP 25
0j, ≥0b, p0
T
53 252
53 662 ± 104
973 ± 68
SP 26
0j, ≥0b, p75
T
586
574 ± 27
33.3 ± 4.1
SP 27
0j, ≥0b, p125
T
51
49.5 ± 8.0
7.4 ± 0.8
SP 28
1–3j, 0b, p0
T, m0
T2
14 648
14 753 ± 138
308 ± 33
SP 29
1–3j, 0b, p0
T, m30
T2
2732
2725 ± 10
125 ± 10
SP 30
1–3j, 0b, p75
T , m0
T2
781
708 ± 30
101 ± 9
SP 31
1–3j, 0b, p75
T , m30
T2
103
101 ± 11
0.90 ± 0.38
SP 32
1–3j, 0b, p125
T , m0
T2
47
46.6 ± 7.7
0.95 ± 0.28
SP 33
1–3j, 0b, p125
T , m30
T2
52
37.2 ± 6.9
3.9 ± 0.6
SP 34
1–3j, 1b, p0
T, m0
T2
4184
4149 ± 7
78.4 ± 7.7
SP 35
1–3j, 1b, p0
T, m30
T2
928
902 ± 34
35.3 ± 3.1
SP 36
1–3j, 1b, p75
T , m0
T2
273
270 ± 19
36.4 ± 3.1
SP 37
1–3j, 1b, p75
T , m30
T2
75
78.0 ± 10.0
1.3 ± 0.1
SP 38
1–3j, 1b, p125
T , m0
T2
52
43.7 ± 7.5
0.97 ± 0.26
SP 39
1–3j, 1b, p125
T , m30
T2
38
30.8 ± 6.3
3.7 ± 0.8
SP 40
1–3j, ≥2b, p0
T, m0
T2
312
292 ± 19
5.6 ± 0.8
SP 41
1–3j, ≥2b, p0
T, m30
T2
79
79.6 ± 10.1
3.0 ± 0.3
SP 42
1–3j, ≥2b, p75
T , m0
T2
37
34.3 ± 6.6
4.5 ± 0.6
SP 43
1–3j, ≥2b, p75
T , m30
T2
26
24.0 ± 5.6
0.57 ± 0.06
SP 44
1–3j, ≥2b, p125
T , m0
T2
16
12.3 ± 0.8
0.54 ± 0.10
SP 45
1–3j, ≥2b, p125
T , m30
T2
15
10.0 ± 0.8
1.7 ± 0.2
SP 46
≥4j, 0b, p0
T, m0
T2
2429
2426 ± 7
35.3 ± 2.6
SP 47
≥4j, 0b, p0
T, m30
T2
339
339 ± 21
12.9 ± 1.2
SP 48
≥4j, 0b, p75
T , m0
T2
118
97.8 ± 11.2
11.1 ± 2.2
SP 49
≥4j, 0b, p75
T , m30
T2
15
19.5 ± 3.1
0.16 ± 0.05
SP 50
≥4j, 0b, p125
T , m0
T2
13
10.0 ± 1.7
0.08 ± 1.76
SP 51
≥4j, 0b, p125
T , m30
T2
7
6.5 ± 0.6
0.73 ± 0.18
SP 52
≥4j, 1b, p0
T, m0
T2
833
800 ± 32
12.3 ± 2.5
SP 53
≥4j, 1b, p0
T, m30
T2
132
135 ± 13
4.6 ± 0.3
SP 54
≥4j, 1b, p75
T , m0
T2
33
42.5 ± 7.4
4.8 ± 0.7
SP 55
≥4j, 1b, p75
T , m30
T2
13
20.2 ± 5.1
0.35 ± 0.04
SP 56
≥4j, 1b, p125
T , m0
T2
10
11.4 ± 1.5
0.34 ± 0.04
SP 57
≥4j, 1b, p125
T , m30
T2
9
8.4 ± 0.6
0.97 ± 0.11
SP 58
≥4j, ≥2b, p0
T, m0
T2
90
88.4 ± 10.7
1.1 ± 0.3
SP 59
≥4j, ≥2b, p0
T, m30
T2
25
20.9 ± 4.6
0.52 ± 0.06
SP 60
≥4j, ≥2b, p75
T , m0
T2
11
8.7 ± 0.6
0.84 ± 0.17
SP 61
≥4j, ≥2b, p75
T , m30
T2
12
11.5 ± 3.7
0.26 ± 0.09
SP 62
≥4j, ≥2b, p125
T , m0
T2
6
3.7 ± 0.4
0.24 ± 0.08
SP 63
≥4j, ≥2b, p125
T , m30
T2
4
5.2 ± 1.1
0.69 ± 0.09 JHEP11(2019)109 Table 6. 9
Summary The observed data, fitted nonresonant background yields, and SM Higgs boson back-
ground yields within the mass window between 122 and 129 GeV are shown for each search region
bin in the all-hadronic categories of the SP analysis. The uncertainties quoted are the fit uncer-
tainties, which include the impact of all systematic uncertainties. The bin names give a short-form
description of the search region bin definition which are given in full in table 3. The labels p0
T,
p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6, between 0.6
and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins defined by the
requirement that mT2 is less than and greater than 30 GeV, respectively. Table 6. The observed data, fitted nonresonant background yields, and SM Higgs boson back-
ground yields within the mass window between 122 and 129 GeV are shown for each search region
bin in the all-hadronic categories of the SP analysis. The uncertainties quoted are the fit uncer-
tainties, which include the impact of all systematic uncertainties. The bin names give a short-form
description of the search region bin definition which are given in full in table 3. The labels p0
T,
p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6, between 0.6
and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins defined by the
requirement that mT2 is less than and greater than 30 GeV, respectively. 9
Summary – 18 – Search
Category
Observed
Fitted
SM Higgs boson
region bin
data
nonresonant bkg
bkg
EWP 0
Two-Lepton
2
1.5 ± 0.4
1.1 ± 0.6
EWP 1
Muon High-pT
11
6.2 ± 0.9
3.7 ± 0.8
EWP 2
Muon Low-pT
28
15.8 ± 1.4
3.0 ± 0.8
EWP 3
Electron High-pT
17
11.9 ± 1.3
3.4 ± 1.1
EWP 4
Electron Low-pT
8
5.2 ± 0.8
0.6 ± 0.2
EWP 5
Electron Low-pT
18
31.5 ± 1.9
0.9 ± 0.4
EWP 6
Electron Low-pT
9
13.7 ± 1.3
0.7 ± 0.3
EWP 7
Hb¯b High-pT
9
7.0 ± 0.9
1.2 ± 0.4
EWP 8
Hb¯b High-pT
19
17.8 ± 1.5
3.8 ± 0.7
EWP 9
Hb¯b Low-pT
34
25.8 ± 1.8
0.8 ± 0.1
EWP 10
Hb¯b Low-pT
60
51.0 ± 2.4
1.9 ± 0.3
EWP 11
Zb¯b High-pT
3
7.2 ± 1.1
0.5 ± 0.1
EWP 12
Zb¯b High-pT
17
14.0 ± 1.3
2.8 ± 1.1
EWP 13
Zb¯b High-pT
10
9.4 ± 1.1
1.3 ± 0.3
EWP 14
Zb¯b Low-pT
27
35.2 ± 2.0
0.8 ± 0.2
EWP 15
Zb¯b Low-pT
84
75.1 ± 2.9
2.5 ± 1.3
EWP 16
Zb¯b Low-pT
45
46.3 ± 2.3
1.2 ± 0.4
EWP 17
High-pT
11
14.4 ± 1.3
1.8 ± 0.2
EWP 18
High-pT
31
21.8 ± 1.6
2.1 ± 0.4
EWP 19
High-pT
11
13.5 ± 1.3
1.2 ± 0.3
EWP 20
High-pT
1834
1648 ± 14
248 ± 38
EWP 21
High-pT
91
100.2 ± 3.7
8.9 ± 1.5
EWP 22
High-pT
12
14.4 ± 1.4
1.2 ± 0.2
EWP 23
High-Res
30
20.6 ± 1.6
0.6 ± 0.2
EWP 24
High-Res
46
49.1 ± 4.0
1.5 ± 0.5
EWP 25
High-Res
9
17.0 ± 1.4
0.4 ± 0.1
EWP 26
High-Res
5186
5057 ± 25
219 ± 42
EWP 27
High-Res
53
63.0 ± 2.6
2.4 ± 1.0
EWP 28
High-Res
19
17.7 ± 1.5
0.5 ± 0.1
EWP 29
Low-Res
26
33.8 ± 2.1
0.3 ± 0.1
EWP 30
Low-Res
61
65.8 ± 3.0
0.9 ± 0.2
EWP 31
Low-Res
24
18.3 ± 1.5
0.2 ± 0.1
EWP 32
Low-Res
5548
5328 ± 22
141 ± 27
EWP 33
Low-Res
78
79.1 ± 2.9
1.4 ± 0.4
EWP 34
Low-Res
25
23.7 ± 1.8
0.4 ± 0.1
ble 7. Table 7. The observed data, fitted nonresonant background yields, and SM Higgs boson back-
ground yields within the mass window between 122 and 129 GeV are shown for each search region
bin of the EWP analysis. The uncertainties quoted are the fit uncertainties, which include the
impact of all systematic uncertainties. 9
Summary The observed data, fitted nonresonant background yields, and SM Higgs boson ba
und yields within the mass window between 122 and 129 GeV are shown for each search reg JHEP11(2019)109 – 19 – Search
Bin name
HH
ZH
WH (200,1)
eb (450,1)
eb (450,300)
region bin
SP 0
Zℓℓ
0.15 ± 0.02
1.2 ± 0.2
0.0 ± 0.0
0.07 ± 0.01
0.10 ± 0.01
SP 1
1µ p0
T, m0
T2
0.67 ± 0.11
0.22 ± 0.04
0.63 ± 0.07
0.69 ± 0.06
0.10 ± 0.01
SP 2
1µ p0
T, m30
T2
0.59 ± 0.10
0.23 ± 0.04
1.1 ± 0.1
0.88 ± 0.07
0.09 ± 0.01
SP 3
1µ p75
T , m0
T2
0.68 ± 0.09
0.22 ± 0.03
0.44 ± 0.04
0.40 ± 0.03
0.17 ± 0.01
SP 4
1µ p75
T , m30
T2
0.74 ± 0.09
0.27 ± 0.03
1.0 ± 0.1
0.45 ± 0.04
0.18 ± 0.01
SP 5
1µ p125
T , m0
T2
1.6 ± 0.3
0.51 ± 0.08
0.72 ± 0.14
0.24 ± 0.02
1.2 ± 0.1
SP 6
1µ p125
T , m30
T2
1.7 ± 0.3
0.58 ± 0.10
1.7 ± 0.3
0.32 ± 0.03
1.6 ± 0.1
SP 7
1e p0
T, m0
T2
0.43 ± 0.12
0.18 ± 0.03
0.41 ± 0.05
0.52 ± 0.04
0.06 ± 0.00
SP 8
1e p0
T, m30
T2
0.43 ± 0.11
0.19 ± 0.04
0.78 ± 0.12
0.52 ± 0.03
0.05 ± 0.00
SP 9
1e p75
T , m0
T2
0.45 ± 0.11
0.19 ± 0.02
0.30 ± 0.03
0.27 ± 0.02
0.12 ± 0.01
SP 10
1e p75
T , m30
T2
0.48 ± 0.09
0.22 ± 0.02
0.66 ± 0.07
0.29 ± 0.02
0.12 ± 0.01
SP 11
1e p125
T , m0
T2
1.3 ± 0.3
0.46 ± 0.09
0.60 ± 0.11
0.24 ± 0.02
0.87 ± 0.07
SP 12
1e p125
T , m30
T2
1.5 ± 0.3
0.57 ± 0.09
1.4 ± 0.3
0.28 ± 0.02
1.1 ± 0.1
SP 13
Zb¯b p0
T, m0
T2
1.3 ± 0.2
0.50 ± 0.08
0.09 ± 0.02
3.0 ± 0.2
0.29 ± 0.02
SP 14
Zb¯b p75
T , m0
T2
1.3 ± 0.1
0.52 ± 0.06
0.05 ± 0.01
1.7 ± 0.1
0.63 ± 0.04
SP 15
Zb¯b p125
T , m0
T2
2.9 ± 0.5
1.2 ± 0.2
0.11 ± 0.02
1.3 ± 0.1
5.1 ± 0.3
SP 16
Zb¯b p0
T, m30
T2
1.1 ± 0.2
0.49 ± 0.08
0.12 ± 0.02
2.5 ± 0.3
0.13 ± 0.01
SP 17
Zb¯b p75
T , m30
T2
1.1 ± 0.1
0.52 ± 0.07
0.13 ± 0.02
1.5 ± 0.1
0.31 ± 0.03
SP 18
Zb¯b p125
T , m30
T2
2.3 ± 0.4
1.3 ± 0.2
0.25 ± 0.05
1.1 ± 0.1
2.2 ± 0.2
SP 19
Hb¯b p0
T, m0
T2
2.9 ± 0.5
0.81 ± 0.14
0.03 ± 0.01
5.9 ± 0.4
1.4 ± 0.1
SP 20
Hb¯b p75
T , m0
T2
3.3 ± 0.3
0.91 ± 0.13
0.04 ± 0.01
3.4 ± 0.3
2.6 ± 0.2
SP 21
Hb¯b p125
T , m0
T2
9.6 ± 1.8
2.6 ± 0.5
0.06 ± 0.01
3.0 ± 0.2
22.7 ± 1.7
SP 22
Hb¯b p0
T, m30
T2
2.5 ± 0.4
0.71 ± 0.10
0.10 ± 0.01
4.7 ± 0.5
0.49 ± 0.05
SP 23
Hb¯b p75
T , m30
T2
2.9 ± 0.3
0.82 ± 0.10
0.11 ± 0.02
3.0 ± 0.3
0.86 ± 0.08
SP 24
Hb¯b p125
T , m30
T2
8.2 ± 1.6
2.4 ± 0.4
0.15 ± 0.04
2.8 ± 0.2
8.7 ± 0.7
Table 8. 9
Summary The expected signal yields for the SUSY simplified model signals considered are shown for
each search region bin in the Hb¯b, Zb¯b, and leptonic categories of the SP analysis. The bin names
give a short-form description of the search region bin definition which are given in full in table 2. The labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than
0.6, between 0.6 and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. The labels
HH and ZH refer to the signal models for higgsino-like chargino and neutralino production where
the branching fractions of the decays eχ0
1 →HeG and eχ0
1 →ZeG are 100% and 0% , and 50% and 50%,
respectively. For the above two scenarios, the mass of the chargino and next-to-lightest neutralino
is 175 GeV, while the LSP mass is 45 GeV. The label WH (200,1) refers to the signal model for
wino-like chargino and neutralino production, where the mass of the chargino and next-to-lightest
neutralino is 200 GeV and the LSP mass is 1 GeV. The labels eb (450,1) and eb (450,300) refer to the
signal models for bottom squark pair production where the bottom squark mass is 450 GeV and the
LSP mass is 1 and 300 GeV, respectively. JHEP11(2019)109 used to tag the decay products of an additional boson, while kinematic quantities such as
mT2 and the razor variables MR and R2 are used to suppress standard model backgrounds. Data driven fits determine the shape and normalization of the nonresonant background. 9
Summary – 20 – Search
Bin name
HH
ZH
WH (200,1)
eb (450,1)
eb (450,300)
region bin
SP 25
0j, ≥0b, p0
T
3.9 ± 0.6
2.9 ± 0.5
2.6 ± 0.3
2.7 ± 0.1
0.0 ± 0.0
SP 26
0j, ≥0b, p75
T
2.4 ± 0.3
2.1 ± 0.2
1.8 ± 0.2
0.54 ± 0.02
0.0 ± 0.0
SP 27
0j, ≥0b, p125
T
1.7 ± 0.2
2.7 ± 0.4
1.7 ± 0.2
0.15 ± 0.01
0.01 ± 0.00
SP 28
1–3j, 0b, p0
T, m0
T2
4.7 ± 0.8
2.7 ± 0.4
2.9 ± 0.3
4.2 ± 0.5
0.03 ± 0.00
SP 29
1–3j, 0b, p0
T, m30
T2
4.7 ± 0.5
2.6 ± 0.3
2.1 ± 0.2
1.6 ± 0.3
0.03 ± 0.01
SP 30
1–3j, 0b, p75
T , m0
T2
9.0 ± 1.5
5.1 ± 0.9
3.1 ± 0.6
0.73 ± 0.15
0.27 ± 0.05
SP 31
1–3j, 0b, p75
T , m30
T2
0.21 ± 0.04
0.10 ± 0.02
0.10 ± 0.01
0.34 ± 0.09
0.04 ± 0.01
SP 32
1–3j, 0b, p125
T , m0
T2
0.18 ± 0.02
0.10 ± 0.01
0.07 ± 0.01
0.15 ± 0.04
0.05 ± 0.01
SP 33
1–3j, 0b, p125
T , m30
T2
0.66 ± 0.14
0.35 ± 0.07
0.19 ± 0.04
0.14 ± 0.03
0.35 ± 0.07
SP 34
1–3j, 1b, p0
T, m0
T2
6.1 ± 0.9
2.2 ± 0.3
1.1 ± 0.1
7.1 ± 1.0
0.12 ± 0.02
SP 35
1–3j, 1b, p0
T, m30
T2
6.6 ± 0.6
2.4 ± 0.2
0.81 ± 0.06
3.4 ± 0.3
0.20 ± 0.02
SP 36
1–3j, 1b, p75
T , m0
T2
13.7 ± 2.1
5.1 ± 0.9
1.4 ± 0.2
2.2 ± 0.3
1.7 ± 0.2
SP 37
1–3j, 1b, p75
T , m30
T2
0.23 ± 0.03
0.09 ± 0.01
0.08 ± 0.01
0.82 ± 0.13
0.27 ± 0.04
SP 38
1–3j, 1b, p125
T , m0
T2
0.36 ± 0.04
0.13 ± 0.01
0.07 ± 0.00
0.39 ± 0.06
0.59 ± 0.08
SP 39
1–3j, 1b, p125
T , m30
T2
1.2 ± 0.2
0.47 ± 0.09
0.18 ± 0.03
0.37 ± 0.05
3.5 ± 0.5
SP 40
1–3j, ≥2b, p0
T, m0
T2
0.60 ± 0.09
0.21 ± 0.04
0.08 ± 0.01
1.9 ± 0.2
0.43 ± 0.05
SP 41
1–3j, ≥2b, p0
T, m30
T2
0.81 ± 0.07
0.27 ± 0.02
0.07 ± 0.01
1.2 ± 0.1
0.69 ± 0.07
SP 42
1–3j, ≥2b, p75
T , m0
T2
2.0 ± 0.4
0.67 ± 0.11
0.09 ± 0.03
0.98 ± 0.12
5.0 ± 0.6
SP 43
1–3j, ≥2b, p75
T , m30
T2
0.08 ± 0.01
0.03 ± 0.01
0.02 ± 0.01
0.38 ± 0.04
1.3 ± 0.1
SP 44
1–3j, ≥2b, p125
T , m0
T2
0.11 ± 0.03
0.04 ± 0.00
0.03 ± 0.00
0.28 ± 0.03
2.2 ± 0.2
SP 45
1–3j, ≥2b, p125
T , m30
T2
0.44 ± 0.10
0.16 ± 0.03
0.05 ± 0.03
0.37 ± 0.03
15.5 ± 1.3
SP 46
≥4j, 0b, p0
T, m0
T2
3.9 ± 0.6
3.1 ± 0.5
6.6 ± 0.7
3.3 ± 0.8
0.01 ± 0.00
SP 47
≥4j, 0b, p0
T, m30
T2
4.2 ± 0.5
3.4 ± 0.4
5.6 ± 0.5
1.2 ± 0.2
0.03 ± 0.01
SP 48
≥4j, 0b, p75
T , m0
T2
7.5 ± 1.2
6.9 ± 1.2
8.0 ± 1.4
0.56 ± 0.11
0.13 ± 0.03
SP 49
≥4j, 0b, p75
T , m30
T2
0.14 ± 0.02
0.10 ± 0.01
0.19 ± 0.02
0.52 ± 0.11
0.02 ± 0.00
SP 50
≥4j, 0b, p125
T , m0
T2
0.16 ± 0.02
0.13 ± 0.02
0.19 ± 0.02
0.25 ± 0.05
0.02 ± 0.00
SP 51
≥4j, 0b, p125
T , m30
T2
0.81 ± 0.18
0.50 ± 0.11
0.51 ± 0.11
0.27 ± 0.05
0.16 ± 0.03
SP 52
≥4j, 1b, p0
T, m0
T2
5.0 ± 0.8
2.3 ± 0.3
2.5 ± 0.3
5.1 ± 0.9
0.08 ± 0.01
SP 53
≥4j, 1b, p0
T, m30
T2
5.4 ± 0.6
2.5 ± 0.2
2.1 ± 0.2
2.3 ± 0.2
0.15 ± 0.02
SP 54
≥4j, 1b, p75
T , m0
T2
11.4 ± 1.8
5.5 ± 0.9
3.5 ± 0.6
1.4 ± 0.2
1.1 ± 0.1
SP 55
≥4j, 1b, p75
T , m30
T2
0.27 ± 0.03
0.14 ± 0.02
0.18 ± 0.02
1.2 ± 0.2
0.11 ± 0.01
SP 56
≥4j, 1b, p125
T , m0
T2
0.33 ± 0.03
0.14 ± 0.01
0.17 ± 0.01
0.81 ± 0.13
0.15 ± 0.03
SP 57
≥4j, 1b, p125
T , m30
T2
1.4 ± 0.3
0.65 ± 0.12
0.42 ± 0.09
0.76 ± 0.12
1.5 ± 0.2
SP 58
≥4j, ≥2b, p0
T, m0
T2
0.42 ± 0.06
0.18 ± 0.03
0.16 ± 0.03
1.4 ± 0.1
0.18 ± 0.02
SP 59
≥4j, ≥2b, p0
T, m30
T2
0.65 ± 0.07
0.26 ± 0.03
0.13 ± 0.02
0.86 ± 0.08
0.35 ± 0.03
SP 60
≥4j, ≥2b, p75
T , m0
T2
1.6 ± 0.3
0.67 ± 0.11
0.24 ± 0.07
0.71 ± 0.08
2.4 ± 0.3
SP 61
≥4j, ≥2b, p75
T , m30
T2
0.08 ± 0.02
0.03 ± 0.00
0.03 ± 0.01
0.73 ± 0.07
0.44 ± 0.04
SP 62
≥4j, ≥2b, p125
T , m0
T2
0.14 ± 0.03
0.05 ± 0.02
0.03 ± 0.00
0.53 ± 0.06
0.82 ± 0.09
SP 63
≥4j, ≥2b, p125
T , m30
T2
0.51 ± 0.11
0.20 ± 0.06
0.11 ± 0.03
0.57 ± 0.05
6.4 ± 0.6
Table 9. 9
Summary The expected signal yields for the SUSY simplified model signals considered are shown
for each search region bin in the all-hadronic categories of the SP analysis. The bin names give a
short-form description of the search region bin definition which are given in full in table 3. The
labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6,
between 0.6 and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. The labels
for the different signal models are explained in detail in the caption of table 8. JHEP11(2019)109 Table 9. The expected signal yields for the SUSY simplified model signals considered are shown
for each search region bin in the all-hadronic categories of the SP analysis. The bin names give a
short-form description of the search region bin definition which are given in full in table 3. The
labels p0
T, p75
T , and p125
T
refer to bins defined by the requirement that pγγ
T /mγγ is less than 0.6,
between 0.6 and 1.0, and greater than 1.0, respectively. The labels m0
T2 and m30
T2 refer to bins
defined by the requirement that mT2 is less than and greater than 30 GeV, respectively. The labels
for the different signal models are explained in detail in the caption of table 8. 9
Summary – 21 – Search
Category
HH
ZH
WH (200,1)
eb (450,1)
eb (450,300)
region bin
EWP 0
Two-Lepton
0.2 ± 0.01
1.6 ± 0.1
0.0 ± 0.000
0.2 ± 0.1
0.1 ± 0.03
EWP 1
Muon High-pT
4.5 ± 0.2
1.5 ± 0.1
3.3 ± 0.2
4.4 ± 1.8
0.9 ± 0.4
EWP 2
Muon Low-pT
1.6 ± 0.04
0.6 ± 0.02
1.7 ± 0.05
0.6 ± 0.2
1.8 ± 0.7
EWP 3
Electron High-pT
4.0 ± 0.2
1.5 ± 0.1
2.7 ± 0.1
3.2 ± 1.3
0.8 ± 0.3
EWP 4
Electron Low-pT
0.5 ± 0.01
0.2 ± 0.01
0.9 ± 0.04
0.1 ± 0.03
0.7 ± 0.3
EWP 5
Electron Low-pT
0.3 ± 0.01
0.1 ± 0.01
0.2 ± 0.02
0.2 ± 0.1
0.2 ± 0.1
EWP 6
Electron Low-pT
0.3 ± 0.01
0.2 ± 0.004
0.3 ± 0.02
0.1 ± 0.04
0.4 ± 0.2
EWP 7
Hb¯b High-pT
11.9 ± 0.5
3.4 ± 0.2
0.2 ± 0.01
4.3 ± 4.3
4.7 ± 1.9
EWP 8
Hb¯b High-pT
9.1 ± 0.6
2.5 ± 0.2
0.1 ± 0.005
30.1 ± 12.1
2.2 ± 0.8
EWP 9
Hb¯b Low-pT
1.9 ± 0.2
0.6 ± 0.05
0.1 ± 0.003
0.8 ± 1.0
6.5 ± 2.8
EWP 10
Hb¯b Low-pT
1.2 ± 0.1
0.4 ± 0.04
0.03 ± 0.002
3.7 ± 1.5
2.4 ± 1.0
EWP 11
Zb¯b High-pT
3.2 ± 0.3
1.7 ± 0.2
0.3 ± 0.02
0.6 ± 0.6
1.9 ± 0.8
EWP 12
Zb¯b High-pT
1.3 ± 0.2
0.6 ± 0.1
0.1 ± 0.01
4.8 ± 2.2
0.4 ± 0.2
EWP 13
Zb¯b High-pT
2.5 ± 0.1
1.1 ± 0.1
0.1 ± 0.02
2.3 ± 2.2
1.0 ± 0.4
EWP 14
Zb¯b Low-pT
1.7 ± 0.2
0.8 ± 0.1
0.2 ± 0.01
0.1 ± 0.1
3.7 ± 1.5
EWP 15
Zb¯b Low-pT
0.6 ± 0.2
0.2 ± 0.04
0.02 ± 0.002
0.6 ± 0.3
0.8 ± 0.4
EWP 16
Zb¯b Low-pT
1.0 ± 0.05
0.4 ± 0.02
0.04 ± 0.01
0.3 ± 0.3
1.5 ± 0.6
EWP 17
High-pT
5.3 ± 1.6
5.5 ± 0.6
7.2 ± 0.5
0.3 ± 0.2
1.4 ± 0.7
EWP 18
High-pT
1.8 ± 0.1
0.8 ± 0.05
0.5 ± 0.03
0.01 ± 0.1
0.3 ± 0.1
EWP 19
High-pT
6.0 ± 1.4
4.0 ± 0.7
3.6 ± 0.2
0.6 ± 0.4
1.4 ± 0.6
EWP 20
High-pT
42.1 ± 3.9
19.6 ± 1.8
9.1 ± 0.8
40.1 ± 15.8
6.1 ± 2.4
EWP 21
High-pT
4.9 ± 0.2
2.3 ± 0.1
1.4 ± 0.1
0.03 ± 0.04
0.9 ± 0.4
EWP 22
High-pT
7.3 ± 1.2
4.2 ± 0.6
3.0 ± 0.2
1.5 ± 1.4
1.3 ± 0.5
EWP 23
High-Res
1.1 ± 1.2
1.0 ± 0.4
3.0 ± 0.6
0.03 ± 0.02
2.2 ± 1.2
EWP 24
High-Res
1.5 ± 0.5
0.9 ± 0.2
1.1 ± 0.1
0.03 ± 0.01
1.4 ± 0.6
EWP 25
High-Res
0.6 ± 0.3
0.4 ± 0.1
0.6 ± 0.1
0.01 ± 0.2
0.6 ± 0.3
EWP 26
High-Res
13.7 ± 2.1
6.5 ± 1.0
4.4 ± 0.7
4.1 ± 1.7
10.4 ± 4.4
EWP 27
High-Res
0.5 ± 0.1
0.3 ± 0.04
0.2 ± 0.03
0.0 ± 0.000
0.4 ± 0.2
EWP 28
High-Res
0.8 ± 0.2
0.5 ± 0.1
0.6 ± 0.1
0.1 ± 0.2
0.9 ± 0.4
EWP 29
Low-Res
0.7 ± 0.7
0.7 ± 0.3
1.9 ± 0.5
0.02 ± 0.01
1.5 ± 0.8
EWP 30
Low-Res
1.0 ± 0.3
0.5 ± 0.1
0.7 ± 0.2
0.02 ± 0.01
1.0 ± 0.5
EWP 31
Low-Res
0.5 ± 0.4
0.3 ± 0.2
0.4 ± 0.1
0.01 ± 0.003
0.5 ± 0.3
EWP 32
Low-Res
8.4 ± 2.2
4.1 ± 1.0
3.0 ± 0.8
2.7 ± 1.3
7.1 ± 3.6
EWP 33
Low-Res
0.4 ± 0.1
0.2 ± 0.05
0.2 ± 0.04
0.002 ± 0.001
0.2 ± 0.1
EWP 34
Low-Res
0.6 ± 0.2
0.3 ± 0.1
0.4 ± 0.1
0.01 ± 0.01
0.6 ± 0.3
Table 10. 9
Summary The expected signal yields for the SUSY simplified model signals considered are shown
for each search region bin of the EWP analysis. The category that each search region bin belongs
to is also indicated in the table. The search region bins definitions are summarized in table 1. The
labels for the different signal models are explained in detail in the caption of table 8. JHEP11(2019)109 The resonant background from standard model Higgs boson production is estimated from
simulation. The results are interpreted in terms of exclusion limits on the production cross
section of simplified models of bottom squark pair production and chargino-neutralino
production. As a result of the improvements in the event categorization and the larger
data set, we extend the mass limits over the previous best results [8] by about 100 GeV
for bottom squark pair production and about 50 GeV for chargino-neutralino production. The resonant background from standard model Higgs boson production is estimated from
simulation. The results are interpreted in terms of exclusion limits on the production cross
section of simplified models of bottom squark pair production and chargino-neutralino
production. As a result of the improvements in the event categorization and the larger
data set, we extend the mass limits over the previous best results [8] by about 100 GeV
for bottom squark pair production and about 50 GeV for chargino-neutralino production. – 22 – We exclude bottom squark pair production for bottom squark masses below 530 GeV for
a lightest neutralino mass of 1 GeV; wino-like chargino-neutralino production, for chargino
and neutralino (eχ0
1) masses of up to 235 GeV and a gravitino (eG) mass of 1 GeV; and
higgsino-like chargino-neutralino production, for chargino and neutralino (eχ0
1) masses of
up to 290 and 230 GeV for the cases where the branching fraction of the lightest neutralino
eχ0
1 →HeG decay is 100%, and where the branching fractions of the eχ0
1 →HeG and eχ0
1 →ZeG
decays are both 50%, respectively. Acknowledgments JHEP11(2019)109 We congratulate our colleagues in the CERN accelerator departments for the excellent per-
formance of the LHC and thank the technical and administrative staffs at CERN and at
other CMS institutes for their contributions to the success of the CMS effort. In addition,
we gratefully acknowledge the computing centers and personnel of the Worldwide LHC
Computing Grid for delivering so effectively the computing infrastructure essential to our
analyses. Finally, we acknowledge the enduring support for the construction and operation
of the LHC and the CMS detector provided by the following funding agencies: BMBWF
and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COL-
CIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador);
MoER, ERC IUT, PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Fin-
land); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT
(Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN
(Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and
UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico);
MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland);
FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR, and NRC KI (Russia);
MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER (Spain); MOSTR (Sri Lanka); Swiss
Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA
(Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United
Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European
Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (Eu-
ropean Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von
Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Forma-
tion `a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap
voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and
FWO (Belgium) under the “Excellence of Science – EOS” – be.h project n. 30820817;
the Beijing Municipal Science & Technology Commission, No. Acknowledgments Z181100004218003; the
Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lend¨ulet
(“Momentum”) Program and the J´anos Bolyai Research Scholarship of the Hungarian
Academy of Sciences, the New National Excellence Program ´UNKP, the NKFIA research – 23 – grants 123842, 123959, 124845, 124850, 125105, 128713, 128786, and 129058 (Hungary);
the Council of Science and Industrial Research, India; the HOMING PLUS program of
the Foundation for Polish Science, cofinanced from European Union, Regional Develop-
ment Fund, the Mobility Plus program of the Ministry of Science and Higher Educa-
tion, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428,
Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-
bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National
Research Fund; the Ministry of Science and Education, grant no. 3.2989.2017 (Russia); the
Programa Estatal de Fomento de la Investigaci´on Cient´ıfica y T´ecnica de Excelencia Mar´ıa
de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de As-
turias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the
Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the
Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand);
the Welch Foundation, contract C-1845; and the Weston Havens Foundation (USA). JHEP11(2019)109 A
Additional simplified model interpretations The bold and light solid black contours represent the
ved exclusion region and the ±1 standard deviation (s.d.) band, including both experimental
heoretical uncertainties. The analogous red dotted contours represent the expected exclusion
n and its ±1 s.d. band. [GeV]
b~
m
250 300 350 400 450 500 550 600 650 700
[GeV]
0
1
χ∼
m
0
50
100
150
200
250
300
350
400
450
500
1
−
10
1
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
1
0
χ∼
bH
→
2
0
χ∼
b
→
b~
,
b~
b~
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
[GeV]
0
2
χ∼
= m
±
1
χ∼
m
140 160 180 200 220 240 260 280 300
[GeV]
0
1
χ∼
m
0
20
40
60
80
100
120
140
160
180
200
1
−
10
1
(13 TeV)
-1
77.5 fb
CMS
0
1
χ∼
H
→
0
2
χ∼
,
0
1
χ∼
±
W
→
±
1
χ∼
,
0
2
χ∼
±
1
χ∼
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
SP Analysis
e observed 95% CL upper limits on the bottom squark pair production
lysis (upper plot), and on the wino-like chargino-neutralino product
alysis (lower plot), are shown. The bold and light solid black contou
usion region and the ±1 standard deviation (s.d.) band, including bo
al uncertainties. The analogous red dotted contours represent the ex
±1 s.d. band. 250 300 350 400 450 500 550 600 650 700
[GeV]
0
1
χ∼
m
0
50
100
150
200
250
300
350
400
450
500
1
−
10
1
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
1
0
χ∼
bH
→
2
0
χ∼
b
→
b~
,
b~
b~
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. A
Additional simplified model interpretations While the EWP and SP analyses have greater expected sensitivity to electroweak and
strong SUSY production, respectively, both analyses do have sensitivity to both production
modes. In this appendix, we present limits obtained from the EWP and SP analyses for
the simplified models that were not shown in section 8. The upper plot of figure 6 shows the limits for sbottom pair production obtained using
the EWP analysis, as a function of the bottom squark mass and the LSP mass. For the wino-like chargino-neutralino production, the limits obtained using the SP
analysis are shown in the lower plot of figure 6 as a function of the chargino mass and the
LSP mass. Figure 7 shows the limits for the higgsino-like chargino-neutralino production
simplified models obtained using the SP analysis as a function of the chargino mass for the
case where the branching fraction of the eχ0
1 →HeG decay is 100% on the left, and for the
case where the branching fraction of the eχ0
1 →HeG and eχ0
1 →ZeG decays are both 50% on
the right. – 24 – [GeV]
b~
m
250 300 350 400 450 500 550 600 650 700
[GeV]
0
1
χ∼
m
0
50
100
150
200
250
300
350
400
450
500
1
−
10
1
EWP analysis
(13 TeV)
-1
77.5 fb
CMS
1
0
χ∼
bH
→
2
0
χ∼
b
→
b~
,
b~
b~
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
[GeV]
0
2
χ∼
= m
±
1
χ∼
m
140 160 180 200 220 240 260 280 300
[GeV]
0
1
χ∼
m
0
20
40
60
80
100
120
140
160
180
200
1
−
10
1
(13 TeV)
-1
77.5 fb
CMS
0
1
χ∼
H
→
0
2
χ∼
,
0
1
χ∼
±
W
→
±
1
χ∼
,
0
2
χ∼
±
1
χ∼
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
SP Analysis
re 6. The observed 95% CL upper limits on the bottom squark pair production cross section for
WP analysis (upper plot), and on the wino-like chargino-neutralino production cross section
e SP analysis (lower plot), are shown. A
Additional simplified model interpretations ±
Expected
95% CL upper limit on cross section [pb] JHEP11(2019)109 [GeV]
0
2
χ∼
= m
±
1
χ∼
m
140 160 180 200 220 240 260 280 300
[GeV]
0
1
χ∼
m
0
20
40
60
80
100
120
140
160
180
200
1
−
10
1
(13 TeV)
-1
77.5 fb
CMS
0
1
χ∼
H
→
0
2
χ∼
,
0
1
χ∼
±
W
→
±
1
χ∼
,
0
2
χ∼
±
1
χ∼
→
pp
theory
1 s.d. ±
Observed
experiment
1 s.d. ±
Expected
95% CL upper limit on cross section [pb]
SP Analysis Figure 6. The observed 95% CL upper limits on the bottom squark pair production cross section for
the EWP analysis (upper plot), and on the wino-like chargino-neutralino production cross section
for the SP analysis (lower plot), are shown. The bold and light solid black contours represent the
observed exclusion region and the ±1 standard deviation (s.d.) band, including both experimental
and theoretical uncertainties. The analogous red dotted contours represent the expected exclusion
region and its ±1 s.d. band. – 25 – [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
(100%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
(13 TeV)
-1
77.5 fb
CMS
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
SP analysis
[GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
(50%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
(50%)
G~
Z
→
1
0
χ∼
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
(13 TeV)
-1
77.5 fb
CMS
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
SP analysis
Figure 7. A
Additional simplified model interpretations The observed 95% CL upper limits on the production cross section for higgsino-like
chargino-neutralino production are shown for the SP analysis. The charginos and neutralinos un-
dergo several cascade decays producing either Higgs bosons (left plot), or a Higgs boson and a Z
boson (right plot). We present limits in the scenario where the branching fraction of eχ0
1 →HeG decay
is 100% (left plot), and where the eχ0
1 →HeG and eχ0
1 →ZeG decays are each 50% (right plot). The
dotted and solid black curves represent the expected and observed exclusion region, and the green
dark and yellow light bands represent the ±1 and ±2 standard deviation regions, respectively. The
red solid and dotted lines show the theoretical production cross section and its uncertainty band. [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
(50%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
(50%)
G~
Z
→
1
0
χ∼
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
(13 TeV)
-1
77.5 fb
CMS
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
SP analysis [GeV]
1
0
χ∼
Higgsino mass m
150
200
250
300
350
400
450
[pb]
excl
95%
σ
1
−
10
1
10
2
10
3
10
(100%)
G~
H
→
1
0
χ∼
;
soft
+ X
1
0
χ∼
1
0
χ∼
→
j
±
0,
χ∼
i
±
0,
χ∼
→
pp
1
0
χ∼
m
≈
1
±
χ∼
m
≈
2
0
χ∼
= 1 GeV; m
G~
m
(13 TeV)
-1
77.5 fb
CMS
NLO+NLL theory
Observed limit (95% CL)
Median expected limit
68% expected
95% expected
SP analysis JHEP11(2019)109 Figure 7. The observed 95% CL upper limits on the production cross section for higgsino-like
chargino-neutralino production are shown for the SP analysis. The charginos and neutralinos un-
dergo several cascade decays producing either Higgs bosons (left plot), or a Higgs boson and a Z
boson (right plot). A
Additional simplified model interpretations We present limits in the scenario where the branching fraction of eχ0
1 →HeG decay
is 100% (left plot), and where the eχ0
1 →HeG and eχ0
1 →ZeG decays are each 50% (right plot). The
dotted and solid black curves represent the expected and observed exclusion region, and the green
dark and yellow light bands represent the ±1 and ±2 standard deviation regions, respectively. The
red solid and dotted lines show the theoretical production cross section and its uncertainty band. Open Access. This article is distributed under the terms of the Creative Commons
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A.M. Sirunyan†, A. Tumasyan Institut f¨ur Hochenergiephysik, Wien, Austria
W. Adam, F. Ambrogi, T. Bergauer, J. Brandstetter, M. Dragicevic, J. Er¨o, A. Es-
calante Del Valle, M. Flechl, R. Fr¨uhwirth1, M. Jeitler1, N. Krammer, I. Kr¨atschmer,
D. Liko, T. Madlener, I. Mikulec, N. Rad, J. Schieck1, R. Sch¨ofbeck, M. Spanring,
D. Spitzbart, W. Waltenberger, C.-E. Wulz1, M. Zarucki JHEP11(2019)109 Institute for Nuclear Problems, Minsk, Belarus
V. Drugakov, V. Mossolov, J. Suarez Gonzalez Institute for Nuclear Problems, Minsk, Belarus
V. Drugakov, V. Mossolov, J. Suarez Gonzalez Universiteit Antwerpen, Antwerpen, Belgium M.R. Darwish, E.A. De Wolf, D. Di Croce, X. Janssen, A. Lelek, M. Pieters, H. Rejeb Sfar,
H. Van Haevermaet, P. Van Mechelen, S. Van Putte, N. Van Remortel Vrije Universiteit Brussel, Brussel, Belgium Vrije Universiteit Brussel, Brussel, Belgium F. Blekman, E.S. Bols, S.S. Chhibra, J. D’Hondt, J. De Clercq, D. Lontkovskyi, S. Lowett F. Blekman, E.S. Bols, S.S. Chhibra, J. D’Hondt, J. De Clercq, D. Lontkovskyi, S. Lowette,
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P. Van Mulders P. Van Mulders Universit´e Libre de Bruxelles, Bruxelles, Belgium The CMS collaboration The CMS collaboration Yerevan Physics Institute, Yerevan, Armenia
A.M. Sirunyan†, A. Tumasyan Universit´e Libre de Bruxelles, Bruxelles, Belgium D. Beghin, B. Bilin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B. Dorne D. Beghin, B. Bilin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B. Dorney,
L. Favart, A. Grebenyuk, A.K. Kalsi, A. Popov, N. Postiau, E. Starling, L. Thomas,
C. Vander Velde, P. Vanlaer, D. Vannerom Ghent University, Ghent, Belgium Ghent University, Ghent, Belgium
T. Cornelis, D. Dobur, I. Khvastunov2, M. Niedziela, C. Roskas, D. Trocino, M. Tytgat,
W. Verbeke, B. Vermassen, M. Vit, N. Zaganidis Universit´e Catholique de Louvain, Louvain-la-Neuve, Belgium q
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V. Lemaitre, A. Magitteri, J. Prisciandaro, A. Saggio, M. Vidal Marono, P. Vischia,
J. Zobec Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
F.L. Alves, G.A. Alves, G. Correia Silva, C. Hensel, A. Moraes, P. Rebello Teles Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato3, E. Coelho, E.M. Da Costa,
G.G. Da Silveira4, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza,
L.M. Huertas Guativa, H. Malbouisson, J. Martins5, D. Matos Figueiredo, M. Med-
ina Jaime6,
M. Melo De Almeida,
C. Mora Herrera,
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A. Santoro,
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E.J. Tonelli Manganote3, F. Torres Da Silva De Araujo, A. Vilela Pereira – 30 – Universidade Estadual Paulista a, Universidade Federal do ABC b, S˜ao Paulo,
Brazil C.A. Bernardesa,
L. Calligarisa,
T.R. Fernandez Perez Tomeia,
E.M. Gregoresb,
D.S. Lemos, P.G. Mercadanteb, S.F. Novaesa, SandraS. Padulaa Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of
Sciences, Sofia, Bulgaria A. Aleksandrov, G. Antchev, R. Hadjiiska, P. Iaydjiev, M. Misheva, M. Rodozov,
M. Shopova, G. Sultanov University of Sofia, Sofia, Bulgaria
M. Bonchev, A. Dimitrov, T. Ivanov, L. Litov, B. Pavlov, P. Petkov JHEP11(2019)109 University of Sofia, Sofia, Bulgaria University of Sofia, Sofia, Bulgaria M. Bonchev, A. Dimitrov, T. Ivanov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China
W. Fang7, X. Gao7, L. Yuan Beihang University, Beijing, China
W. Fang7, X. Gao7, L. Yuan Beihang University, Beijing, China Institute of High Energy Physics, Beijing, China M. Ahmad, G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Li . Ahmad, G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Liu,
M Shaheen8 A Spiezia J Tao E Yazgan H Zhang S Zhang8 J Zhao M. Ahmad, G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Liu,
S.M. Shaheen8, A. Spiezia, J. Tao, E. Yazgan, H. Zhang, S. Zhang8, J. Zhao State Key Laboratory of Nuclear Physics and Technology, Peking University,
Beijing, China A. Agapitos, Y. Ban, G. Chen, A. Levin, J. Li, L. Li, Q. Li, Y. Mao, S.J. Qian, D. Wang,
Q. Wang Tsinghua University, Beijing, China
Z. Hu, Y. Wang Tsinghua University, Beijing, China
Z. Hu, Y. Wang Zhejiang University - Department of Physics
M. Xiao Universidad de Los Andes, Bogota, Colombia
C. Avila, A. Cabrera, C. Florez, C.F. Gonz´alez Hern´andez, M.A. Segura Delgado ,
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C. Avila, A. Cabrera, C. Florez, C.F. Gonz´alez Hern´andez, M.A. Segura Delgado
Universidad de Antioquia, Medellin, Colombia
J. Mejia Guisao, J.D. Ruiz Alvarez, C.A. Salazar Gonz´alez, N. Vanegas Arbelaez Universidad de Antioquia, Medellin, Colombia
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J. Mejia Guisao, J.D. Ruiz Alvarez, C.A. Salazar Gonz´alez, N. Vanegas Arbelaez University of Split, Faculty of Electrical Engineering, Mechanical Engineering
and Naval Architecture, Split, Croatia
D. Giljanovi´c, N. Godinovic, D. Lelas, I. Puljak, T. Sculac University of Split, Faculty of Science, Split, Croatia
Z. Antunovic, M. Kovac Institute Rudjer Boskovic, Zagreb, Croatia
V Brigljevic S Ceci D Ferencek K Kadija B Mesic M Roguljic A Starodumov9 Institute Rudjer Boskovic, Zagreb, Croatia Universidad San Francisco de Quito, Quito, Ecuador
E. Carrera Jarrin Universidad San Francisco de Quito, Quito, Ecuador
E. Carrera Jarrin Academy of Scientific Research and Technology of the Arab Republic of Egypt,
Egyptian Network of High Energy Physics, Cairo, Egypt
S. Abu Zeid11, S. Khalil12 National Institute of Chemical Physics and Biophysics, Tallinn, Estonia National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
S. Bhowmik, A. Carvalho Antunes De Oliveira, R.K. Dewanjee, K. Ehataht, M. Kadastik,
M. Raidal, C. Veelken S. Bhowmik, A. Carvalho Antunes De Oliveira, R.K. Dewanjee, K. Ehataht, M. Kadasti
M. Raidal, C. Veelken Department of Physics, University of Helsinki, Helsinki, Finland
P. Eerola, L. Forthomme, H. Kirschenmann, K. Osterberg, M. Voutilainen Helsinki Institute of Physics, Helsinki, Finland Helsinki Institute of Physics, Helsinki, Finland F. Garcia, J. Havukainen, J.K. Heikkil¨a, T. J¨arvinen, V. Karim¨aki, M.S. Kim, R. Kinnunen,
T Lamp´en K Lassila-Perini S Laurila S Lehti T Lind´en P Luukka T M¨aenp¨a¨a F. Garcia, J. Havukainen, J.K. Heikkil¨a, T. J¨arvinen, V. Karim¨aki, M.S. Kim, R. Kinnunen,
T. Lamp´en, K. Lassila-Perini, S. Laurila, S. Lehti, T. Lind´en, P. Luukka, T. M¨aenp¨a¨a,
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T. Lamp´en, K. Lassila-Perini, S. Laurila, S. Lehti, T. Lind´en, P. Luukka, T. M¨aenp¨a¨a,
H. Siikonen, E. Tuominen, J. Tuominiemi Lappeenranta University of Technology, Lappeenranta, Finland
T. Tuuva IRFU, CEA, Universit´e Paris-Saclay, Gif-sur-Yvette, France
M. Besancon, F. Couderc, M. Dejardin, D. Denegri, B. Fabbro, J.L. Faure, F. Ferri,
S. Ganjour, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, C. Leloup, E. Locci,
J. Malcles, J. Rander, A. Rosowsky, M. ¨O. Sahin, A. Savoy-Navarro13, M. Titov Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Universit´e
Paris-Saclay, Palaiseau, France S. Ahuja, C. Amendola, F. Beaudette, P. Busson, C. Charlot, B. Diab, G. Falmagn S. Ahuja, C. Amendola, F. Beaudette, P. Busson, C. Charlot, B. Diab, G. Falmagne,
R. Granier de Cassagnac, I. Kucher, A. Lobanov, C. Martin Perez, M. Nguyen, C. Ochando,
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R. Granier de Cassagnac, I. Kucher, A. Lobanov, C. Martin Perez, M. Nguyen, C. Ochando, R. Granier de Cassagnac, I. Kucher, A. Lobanov, C. Martin Perez, M. Nguyen, C. Ochando,
P. Paganini, J. Rembser, R. Salerno, J.B. Sauvan, Y. Sirois, A. Zabi, A. Zghiche P. Paganini, J. Rembser, R. Salerno, J.B. Sauvan, Y. Sirois, A. Zabi, A. Zghiche Universit´e de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
J.-L. Agram14, J. Andrea, D. Bloch, G. Bourgatte, J.-M. Brom, E.C. Chabert, C. Collard,
E. Conte14, J.-C. Fontaine14, D. Gel´e, U. Goerlach, M. Jansov´a, A.-C. Le Bihan, N. Tonon,
P. Van Hove Universit´e de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
J.-L. Agram14, J. Andrea, D. Bloch, G. Bourgatte, J.-M. Brom, E.C. Chabert, C. Collard,
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T. Susa – 31 – University of Cyprus, Nicosia, Cyprus
M.W. Ather, A. Attikis, E. Erodotou, A. Ioannou, M. Kolosova, S. Konstantinou,
G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H. Rykaczewski,
D. Tsiakkouri Charles University, Prague, Czech Republic
M. Finger10, M. Finger Jr.10, A. Kveton, J. Tomsa Escuela Politecnica Nacional, Quito, Ecuador
E. Ayala JHEP11(2019)109 Helsinki Institute of Physics, Helsinki, Finland Collard,
E. Conte14, J.-C. Fontaine14, D. Gel´e, U. Goerlach, M. Jansov´a, A.-C. Le Bihan, N. Tonon,
P. Van Hove P. Van Hove P. Van Hove – 32 – Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique
des Particules, CNRS/IN2P3, Villeurbanne, France
S. Gadrat Universit´e de Lyon, Universit´e Claude Bernard Lyon 1, CNRS-IN2P3, Institut
de Physique Nucl´eaire de Lyon, Villeurbanne, France Universit´e de Lyon, Universit´e Claude Bernard Lyon 1, CNRS-IN2P3, Institut
de Physique Nucl´eaire de Lyon, Villeurbanne, France
S. Beauceron, C. Bernet, G. Boudoul, C. Camen, A. Carle, N. Chanon, R. Chierici,
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S. Perries, V. Sordini, L. Torterotot, G. Touquet, M. Vander Donckt, S. Viret JHEP11(2019)109 Georgian Technical University, Tbilisi, Georgia
A. Khvedelidze10 Tbilisi State University, Tbilisi, Georgia
Z. Tsamalaidze10 RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
C. Autermann, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, D. Meuser, A. Pauls,
M. Preuten, M.P. Rauch, C. Schomakers, J. Schulz, M. Teroerde, B. Wittmer RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
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trolorenzo, M. Merschmeyer, A. Meyer, P. Millet, G. Mocellin, S. Mondal, S. Mukherjee,
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J. Roemer, A. Schmidt, S.C. Schuler, A. Sharma, S. Wiedenbeck, S. Zaleski RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
A. Albert, M. Erdmann, B. Fischer, S. Ghosh, T. Hebbeker, K. Hoepfner, H. Keller, L. Mas-
trolorenzo, M. Merschmeyer, A. Meyer, P. Millet, G. Mocellin, S. Mondal, S. Mukherjee,
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J. Roemer, A. Schmidt, S.C. Schuler, A. Sharma, S. Wiedenbeck, S. Zaleski RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany
G. Helsinki Institute of Physics, Helsinki, Finland Fl¨ugge, W. Haj Ahmad15, O. Hlushchenko, T. Kress, T. M¨uller, A. Nehrkorn,
A. Nowack, C. Pistone, O. Pooth, D. Roy, H. Sert, A. Stahl16 Deutsches Elektronen-Synchrotron, Hamburg, Germany Deutsches Elektronen-Synchrotron, Hamburg, Germany Deutsches Elektronen Synchrotron, Hamburg, Germany
M. Aldaya Martin, P. Asmuss, I. Babounikau, H. Bakhshiansohi, K. Beernaert, O. Behnke,
A. Berm´udez Mart´ınez, D. Bertsche, A.A. Bin Anuar, K. Borras17, V. Botta, A. Campbell,
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M. Van De Klundert, R. Walsh, Y. Wen, K. Wichmann, C. Wissing, O. Zenaiev, R. Zlebcik
University of Hamburg, Hamburg, Germany
R. Aggleton, S. Bein, L. Benato, A. Benecke, V. Blobel, T. Dreyer, A. Ebrahimi, F. Feindt, University of Hamburg, Hamburg, Germany University of Hamburg, Hamburg, Germany R. Aggleton, S. Bein, L. Benato, A. Benecke, V. Blobel, T. Dreyer, A. Ebrahimi, F. Feindt,
A. Fr¨ohlich, C. Garbers, E. Garutti, D. Gonzalez, P. Gunnellini, J. Haller, A. Hinzmann, – 33 – A. Karavdina, G. Kasieczka, R. Klanner, R. Kogler, N. Kovalchuk, S. Kurz, V. Kutzner,
J. Lange, T. Lange, A. Malara, J. Multhaup, C.E.N. Niemeyer, A. Perieanu, A. Reimers,
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G. Steinbr¨uck, F.M. Stober, M. St¨over, B. Vormwald, I. Zoi Karlsruher Institut fuer Technologie, Karlsruhe, Germany Karlsruher Institut fuer Technologie, Karlsruhe, Germany M. Akbiyik, C. Barth, M. Baselga, S. Baur, T. Berger, E. Butz, R. Caspart, T. Chwalek,
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M. Schr¨oder, I. Shvetsov, H.J. Simonis, R. Ulrich, M. Wassmer, M. Weber, C. W¨ohrmann,
R. Wolf JHEP11(2019)109 Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia
Paraskevi, Greece Anagnostou, P. Asenov, G. Daskalakis, T. Geralis, A. Kyriakis, D. Loukas, G. Paspalaki National and Kapodistrian University of Athens, Athens, Greece
M. Diamantopoulou, G. Karathanasis, P. Kontaxakis, A. Manousakis-katsikakis, A. Pana-
giotou, I. Papavergou, N. Saoulidou, A. Stakia, K. Theofilatos, K. Vellidis, E. Vourliotis National Technical University of Athens, Athens, Greece
G. Bakas, K. Kousouris, I. Papakrivopoulos, G. Tsipolitis University of Io´annina, Io´annina, Greece I. Evangelou, C. Foudas, P. Gianneios, P. Katsoulis, P. Kokkas, S. Mallios, K. Manitara,
N. Manthos, I. Papadopoulos, J. Strologas, F.A. Triantis, D. Tsitsonis MTA-ELTE Lend¨ulet CMS Particle and Nuclear Physics Group, E¨otv¨os Lor´and
University, Budapest, Hungary M. Bart´ok20, R. Chudasama, M. Csanad, P. Major, K. Mandal, A. Mehta, M.I. Nagy,
G. Pasztor, O. Sur´anyi, G.I. Veres Wigner Research Centre for Physics, Budapest, Hungary
G. Bencze, C. Hajdu, D. Horvath21, F. Sikler, T.´A. V´ami, V. Veszpremi, G. Vesztergombi† Institute of Nuclear Research ATOMKI, Debrecen, Hungary
N. Beni, S. Czellar, J. Karancsi20, A. Makovec, J. Molnar, Z. Szillasi Institute of Nuclear Research ATOMKI, Debrecen, Hungary
N. Beni, S. Czellar, J. Karancsi20, A. Makovec, J. Molnar, Z. Szillasi Institute of Physics, University of Debrecen, Debrecen, Hungary
P. Raics, D. Teyssier, Z.L. Trocsanyi, B. Ujvari Eszterhazy Karoly University, Karoly Robert Campus, Gyongyos, Hungary
T. Csorgo, W.J. Metzger, F. Nemes, T. Novak Indian Institute of Science (IISc), Bangalore, India
S. Choudhury, J.R. Komaragiri, P.C. Tiwari Indian Institute of Science (IISc), Bangalore, India
S. Choudhury, J.R. Komaragiri, P.C. Tiwari – 34 – National Institute of Science Education and Research, HBNI, Bhubaneswar,
India National Institute of Science Education and Research, HBNI, Bhubaneswar,
India S. Bahinipati23, C. Kar, G. Kole, P. Mal, V.K. Muraleedharan Nair Bindhu, A. Nayak24,
D.K. Sahoo23, S.K. Swain Panjab University, Chandigarh, India Panjab University, Chandigarh, India S. Bansal, S.B. Beri, V. Bhatnagar, S. Chauhan, R. Chawla, N. Dhingra, R. Gupta,
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. Naimuddin, P. Priyanka, K. Ranjan, Aashaq Shah, R. Sharma M. Naimuddin, P. Priyanka, K. Ranjan, Aashaq Shah, R. Sharma Saha Institute of Nuclear Physics, HBNI, Kolkata, India Saha Institute of Nuclear Physics, HBNI, Kolkata, India
R. Bhardwaj25, M. Bharti25, R. Bhattacharya, S. Bhattacharya, U. Bhawandeep25,
D. Bhowmik, S. Dutta, S. Ghosh, M. Maity26, K. Mondal, S. Nandan, A. Purohit,
P.K. Rout, G. Saha, S. Sarkar, T. Sarkar26, M. Sharan, B. Singh25, S. Thakur25 Indian Institute of Technology Madras, Madras, India
P.K. Behera, P. Kalbhor, A. Muhammad, P.R. Pujahari, A. Sharma, A.K. Sikdar Indian Institute of Technology Madras, Madras, India
P.K. Behera, P. Kalbhor, A. Muhammad, P.R. Pujahari, A. Sharm Bhabha Atomic Research Centre, Mumbai, India
D. Dutta, V. Jha, V. Kumar, D.K. Mishra, P.K. Netrakanti, L.M. Pant, P. Shukla Tata Institute of Fundamental Research-A, Mumbai, India
T. Aziz, M.A. Bhat, S. Dugad, G.B. Mohanty, N. Sur, RavindraKumar Verma Tata Institute of Fundamental Research-B, Mumbai, India ata Institute of Fundamental Research-B, Mumbai, India S. Banerjee, S. Bhattacharya, S. Chatterjee, P. Das, M. Guchait, S. Karmakar, S. Kumar,
G. Majumder, K. Mazumdar, N. Sahoo, S. Sawant Indian Institute of Science Education and Research (IISER), Pune, India Indian Institute of Science Education and Research (IISER), Pune, India
S. Chauhan, S. Dube, V. Hegde, B. Kansal, A. Kapoor, K. Kothekar, S. Pandey, A. Rane,
A. Rastogi, S. Sharma Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
S. Chenarani27, E. Eskandari Tadavani, S.M. Etesami27, M. Khakzad, M. Mohammadi Na-
jafabadi, M. Naseri, F. Rezaei Hosseinabadi University College Dublin, Dublin, Ireland
M. Felcini, M. Grunewald INFN Sezione di Bari a, Universit`a di Bari b, Politecnico di Bari c, Bari, Italy
M. Abbresciaa,b, R. Alya,b,28, C. Calabriaa,b, A. Colaleoa, D. Creanzaa,c, L. Cristellaa,b,
N. De Filippisa,c, M. De Palmaa,b, A. Di Florioa,b, L. Fiorea, A. Gelmia,b, G. Iasellia,c,
M. Incea,b, S. Lezkia,b, G. Maggia,c, M. Maggia, G. Minielloa,b, S. Mya,b, S. Nuzzoa,b,
A. Pompilia,b, G. Pugliesea,c, R. Radognaa, A. Ranieria, G. Selvaggia,b, L. Silvestrisa,
R. Vendittia, P. Verwilligena R. Vendittia, P. Verwilligena – 35 – INFN Sezione di Bologna a, Universit`a di Bologna b, Bologna, Italy
G. Abbiendia, C. Battilanaa,b, D. Bonacorsia,b, L. Borgonovia,b, S. Braibant-Giacomellia,b,
R. Campaninia,b, P. Capiluppia,b, A. Castroa,b, F.R. Cavalloa, C. Cioccaa, G. Codispotia,b,
M. Cuffiania,b, G.M. Dallavallea, F. Fabbria, A. Fanfania,b, E. Fontanesia,b, P. Giacomellia,
C. Grandia, L. Guiduccia,b, F. Iemmia,b, S. Lo Meoa,29, S. Marcellinia, G. Masettia,
F.L. Navarriaa,b, A. Perrottaa, F. Primaveraa,b, A.M. Rossia,b, T. Rovellia,b, G.P. Sirolia,b,
N. Tosia INFN Sezione di Bologna a, Universit`a di Bologna b, Bologna, Italy G. Abbiendia, C. Battilanaa,b, D. Bonacorsia,b, L. Borgonovia,b, S. Braibant-Giacomellia R. Campaninia,b, P. Capiluppia,b, A. Castroa,b, F.R. Cavalloa, C. Cioccaa, G. Codispotia R. Campanini
, P. Capiluppi
, A. Castro
, F.R. Cavallo , C. Ciocca , G. Codispoti
,
M. Cuffiania,b, G.M. Dallavallea, F. Fabbria, A. Fanfania,b, E. Fontanesia,b, P. Giacomellia,
C. Grandia, L. Guiduccia,b, F. Iemmia,b, S. Lo Meoa,29, S. Marcellinia, G. Masettia,
F.L. Navarriaa,b, A. Perrottaa, F. Primaveraa,b, A.M. Rossia,b, T. Rovellia,b, G.P. Sirolia,b,
N. Tosia F.L. Navarriaa,b, A. Perrottaa, F. Primaveraa,b, A.M. Rossia,b, T. Rovellia,b, G.P. Sirolia,b,
N. Tosia INFN Sezione di Catania a, Universit`a di Catania b, Catania, Italy
S. Albergoa,b,30, S. Costaa,b, A. Di Mattiaa, R. Potenzaa,b, A. Tricomia,b,30, C. Tuvea,b JHEP11(2019)109 INFN Sezione di Firenze a, Universit`a di Firenze b, Firenze, Italy
G. Barbaglia, A. Cassese, R. Ceccarelli, K. Chatterjeea,b, V. Ciullia,b, C. ata Institute of Fundamental Research-B, Mumbai, India Civininia,
R. D’Alessandroa,b, E. Focardia,b, G. Latinoa,b, P. Lenzia,b, M. Meschinia, S. Paolettia,
G. Sguazzonia, L. Viliania INFN Laboratori Nazionali di Frascati, Frascati, Italy
L. Benussi, S. Bianco, D. Piccolo INFN Sezione di Genova a, Universit`a di Genova b, Genova, Italy
M. Bozzoa,b, F. Ferroa, R. Mulargiaa,b, E. Robuttia, S. Tosia,b INFN Sezione di Milano-Bicocca a, Universit`a di Milano-Bicocca b, Milano,
Italy A. Benagliaa, A. Beschia,b, F. Brivioa,b, V. Cirioloa,b,16, S. Di Guidaa,b,16, M.E. Dinardoa,b,
P. Dinia, S. Gennaia, A. Ghezzia,b, P. Govonia,b, L. Guzzia,b, M. Malbertia, S. Malvezzia,
D. Menascea, F. Montia,b, L. Moronia, M. Paganonia,b, D. Pedrinia, S. Ragazzia,b, A. Benagliaa, A. Beschia,b, F. Brivioa,b, V. Cirioloa,b,16, S. Di Guidaa,b,16, M.E. Dinardoa
P. Dinia, S. Gennaia, A. Ghezzia,b, P. Govonia,b, L. Guzzia,b, M. Malbertia, S. Malvezzi A. Benagliaa, A. Beschia,b, F. Brivioa,b, V. Cirioloa,b, 6, S. Di Guidaa,b, 6, M.E. Dinardoa,b,
P. Dinia, S. Gennaia, A. Ghezzia,b, P. Govonia,b, L. Guzzia,b, M. Malbertia, S. Malvezzia,
D. Menascea, F. Montia,b, L. Moronia, M. Paganonia,b, D. Pedrinia, S. Ragazzia,b,
T. Tabarelli de Fatisa,b, D. Zuoloa,b D. Menascea, F. Montia,b, L. Moronia, M. Paganonia,b, D. Pedrinia, S. Ragazzia,b,
T. Tabarelli de Fatisa,b, D. Zuoloa,b INFN Sezione di Napoli a, Universit`a di Napoli ’Federico II’ b, Napoli, Italy,
Universit`a della Basilicata c, Potenza, Italy, Universit`a G. Marconi d, Roma,
Italy S. Buontempoa, N. Cavalloa,c, A. De Iorioa,b, A. Di Crescenzoa,b, F. Fabozzia,c, F. Fiengaa, G. Galatia, A.O.M. Iorioa,b, L. Listaa,b, S. Meolaa,d,16, P. Paoluccia,16, B. Rossia,
C. Sciaccaa,b, E. Voevodinaa,b INFN Sezione di Padova a, Universit`a di Padova b, Padova, Italy, Universit`a di
Trento c, Trento, Italy P. Azzia, N. Bacchettaa, D. Biselloa,b, A. Bolettia,b, A. Bragagnoloa,b, R. Carlina P. Azzia, N. Bacchettaa, D. Biselloa,b, A. Bolettia,b, A. Bragagnoloa,b, R. Carlina,b,
P. Checchiaa, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, F. Gasparinia,b,
U. Gasparinia,b, A. Gozzelinoa, S.Y. Hoha,b, P. Lujana, M. Margonia,b, A.T. Meneguzzoa,b,
J. Pazzinia,b, M. Presillab, P. Ronchesea,b, R. Rossina,b, F. Simonettoa,b, A. Tikoa,
M. Tosia,b, M. Zanettia,b, P. Zottoa,b, G. Zumerlea,b P. Checchia , P. De Castro Manzano , T. Dorigo , U. Dosselli , F. Gasparini
,
U. Gasparinia,b, A. Gozzelinoa, S.Y. Hoha,b, P. Lujana, M. Margonia,b, A.T. Meneguzzoa,b,
J. Pazzinia,b, M. Presillab, P. Ronchesea,b, R. Rossina,b, F. Simonettoa,b, A. Tikoa,
M. Tosia,b, M. Zanettia,b, P. Zottoa,b, G. Zumerlea,b INFN Sezione di Pavia a, Universit`a di Pavia b, Pavia, Italy
A. Braghieria, D. Fiorinaa,b, P. Montagnaa,b, S.P. ata Institute of Fundamental Research-B, Mumbai, India Rattia,b, V. Rea, M. Ressegottia,b, INFN Sezione di Pavia a, Universit`a di Pavia b, Pavia, Italy
A. Braghieria, D. Fiorinaa,b, P. Montagnaa,b, S.P. Rattia,b, V. Rea, M. Ressegottia,b,
C. Riccardia,b, P. Salvinia, I. Vaia, P. Vituloa,b A. Braghieria, D. Fiorinaa,b, P. Montagnaa,b, S.P. Rattia,b, V. Rea, M. Ressegottia,b,
C. Riccardia,b, P. Salvinia, I. Vaia, P. Vituloa,b – 36 – INFN Sezione di Perugia a, Universit`a di Perugia b, Perugia, Italy
M. Biasinia,b, G.M. Bileia, D. Ciangottinia,b, L. Fan`oa,b, P. Laricciaa,b, R. Leonardia,b,
G. Mantovania,b, V. Mariania,b, M. Menichellia, A. Rossia,b, A. Santocchiaa,b, D. Spigaa INFN Sezione di Perugia a, Universit`a di Perugia b, Perugia, Italy
M. Biasinia,b, G.M. Bileia, D. Ciangottinia,b, L. Fan`oa,b, P. Laricciaa,b, R. Leonardia,b,
G. Mantovania,b, V. Mariania,b, M. Menichellia, A. Rossia,b, A. Santocchiaa,b, D. Spigaa INFN Sezione di Perugia a, Universit`a di Perugia b, Perugia, Italy M. Biasinia,b, G.M. Bileia, D. Ciangottinia,b, L. Fan`oa,b, P. Laricciaa,b, R. Leonardia G. Mantovania,b, V. Mariania,b, M. Menichellia, A. Rossia,b, A. Santocchiaa,b, D. Spigaa INFN Sezione di Pisa a, Universit`a di Pisa b, Scuola Normale Superiore di Pisa
c, Pisa, Italy K. Androsova, P. Azzurria, G. Bagliesia, V. Bertacchia,c, L. Bianchinia, T. Boccalia,
b K. Androsova, P. Azzurria, G. Bagliesia, V. Bertacchia,c, L. Bianchinia, T. Boccalia,
R. Castaldia, M.A. Cioccia,b, R. Dell’Orsoa, G. Fedia, L. Gianninia,c, A. Giassia,
b K. Androsova, P. Azzurria, G. Bagliesia, V. Bertacchia,c, L. Bianchinia, T. Boccalia,
R. Castaldia, M.A. Cioccia,b, R. Dell’Orsoa, G. Fedia, L. Gianninia,c, A. Giassia,
M.T. Grippoa, F. Ligabuea,c, E. Mancaa,c, G. Mandorlia,c, A. Messineoa,b, F. Pallaa,
A. Rizzia,b, G. Rolandi31, S. Roy Chowdhury, A. Scribanoa, P. Spagnoloa, R. Tenchinia,
G. Tonellia,b, N. Turini, A. Venturia, P.G. Verdinia JHEP11(2019)109 INFN Sezione di Roma a, Sapienza Universit`a di Roma b, Rome, Italy
F. Cavallaria, M. Cipriania,b, D. Del Rea,b, E. Di Marcoa,b, M. Diemoza, E. Longoa,b,
B. Marzocchia,b,
P. Meridiania,
G. Organtinia,b,
F. Pandolfia,
R. Paramattia,b,
C. Quarantaa,b, S. Rahatloua,b, C. Rovellia, F. Santanastasioa,b, L. Soffia,b INFN Sezione di Torino a, Universit`a di Torino b, Torino, Italy, Universit`a del
Piemonte Orientale c, Novara, Italy N. Amapanea,b, R. Arcidiaconoa,c, S. Argiroa,b, M. Arneodoa,c, N. Bartosika, R. Bellana,b,
A
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t a b Bellora,
C. Biinoa,
A. Cappatia,b,
N. Cartigliaa,
S. Comettia,
M. Costaa,b, R. Covarellia,b, N. Demariaa, B. Kiania,b, C. Mariottia, S. Masellia, E. Migliorea V. Sejong University, Seoul, Korea Seoul National University, Seoul, Korea
J. Almond, J.H. Bhyun, J. Choi, S. Jeon, J. Kim, J.S. Kim, H. Lee, K. Lee, S. Lee, K. Nam,
M. Oh, S.B. Oh, B.C. Radburn-Smith, U.K. Yang, H.D. Yoo, I. Yoon, G.B. Yu University of Seoul, Seoul, Korea
D. Jeon, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, I.J Watson University of Seoul, Seoul, Korea
D. Jeon, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, I.J Watson D. Jeon, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, I.J Watson Sungkyunkwan University, Suwon, Korea
Y. Choi, C. Hwang, Y. Jeong, J. Lee, Y. Lee, I. Yu Sungkyunkwan University, Suwon, Korea
Y. Choi, C. Hwang, Y. Jeong, J. Lee, Y. Lee, I. Yu JHEP11(2019)109 Y. Choi, C. Hwang, Y. Jeong, J. Lee, Y. Lee, I. Yu
Riga Technical University, Riga, Latvia
V. Veckalns32
Vilnius University, Vilnius, Lithuania
V. Dudenas, A. Juodagalvis, G. Tamulaitis, J. Vaitkus
National Centre for Particle Physics,
Universiti Malaya,
Kuala Lumpur,
Malaysia
Z.A. Ibrahim, F. Mohamad Idris33, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli
Universidad de Sonora (UNISON), Hermosillo, Mexico
J.F. Benitez, A. Castaneda Hernandez, J.A. Murillo Quijada, L. Valencia Palomo
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz34, R. Lopez-Fernandez,
A. Sanchez-Hernandez
Universidad Iberoamericana, Mexico City, Mexico
S. Carrillo Moreno, C. Oropeza Barrera, M. Ramirez-Garcia, F. Vazquez Valencia
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
J. Eysermans, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada
Universidad Aut´onoma de San Luis Potos´ı, San Luis Potos´ı, Mexico
A. Morelos Pineda
University of Montenegro, Podgorica, Montenegro
J. Mijuskovic, N. Raicevic
University of Auckland, Auckland, New Zealand
D. Krofcheck
University of Canterbury, Christchurch, New Zealand
S. Bheesette, P.H. Butler
National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, M.A. Shah, M. Shoaib,
M. Waqas Riga Technical University, Riga, Latvia
V. Veckalns32 Riga Technical University, Riga, Latvia
V. Veckalns32 Vilnius University, Vilnius, Lithuania
V. Dudenas, A. Juodagalvis, G. Tamulaitis, J. Vaitkus Vilnius University, Vilnius, Lithuania
V. Dudenas, A. Juodagalvis, G. Tamulaitis, J. Vaitkus National Centre for Particle Physics,
Universiti Malaya,
Kuala Lumpur,
Malaysia Z.A. Ibrahim, F. Mohamad Idris33, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli Universidad de Sonora (UNISON), Hermosillo, Mexico
J.F. Benitez, A. Castaneda Hernandez, J.A. Murillo Quijada, L. ata Institute of Fundamental Research-B, Mumbai, India Monacoa,b, E. Monteila,b, M. Montenoa, M.M. Obertinoa,b, G. Ortonaa,b, L. Pachera N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia,b, A. Romeroa,b, M. Ruspaa,c,
R. Salvaticoa,b, V. Solaa, A. Solanoa,b, D. Soldia,b, A. Staianoa N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia,b, A. Romeroa,b, M. Ruspaa N. Pastrone , M. Pelliccioni , G.L. Pinna Angioni
, A. Romero
, M. Ruspa
,
R. Salvaticoa,b, V. Solaa, A. Solanoa,b, D. Soldia,b, A. Staianoa INFN Sezione di Trieste a, Universit`a di Trieste b, Trieste, Italy S. Belfortea, V. Candelisea,b, M. Casarsaa, F. Cossuttia, A. Da Rolda,b, G. Della Riccaa,b,
F. Vazzolera,b, A. Zanettia Kyungpook National University, Daegu, Korea B. Kim, D.H. Kim, G.N. Kim, J. Lee, S.W. Lee, C.S. Moon, Y.D. Oh, S.I. Pak, S. Sekmen,
D.C. Son, Y.C. Yang Chonnam National University, Institute for Universe and Elementary Particles,
Kwangju, Korea
H. Kim, D.H. Moon, G. Oh H. Kim, D.H. Moon, G. Oh Hanyang University, Seoul, Korea
B. Francois, T.J. Kim, J. Park Hanyang University, Seoul, Korea
B. Francois, T.J. Kim, J. Park Hanyang University, Seoul, Korea B. Francois, T.J. Kim, J. Park Korea University, Seoul, Korea
S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, K. Lee, K.S. Lee, J. Lim, J. Park,
S.K. Park, Y. Roh, J. Yoo Kyung Hee University, Department of Physics
J. Goh Kyung Hee University, Department of Physics
J. Goh – 37 – Sejong University, Seoul, Korea Valencia Palomo Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz34, R. Lopez-Fernandez,
A. Sanchez-Hernandez Universidad Iberoamericana, Mexico City, Mexico
S. Carrillo Moreno, C. Oropeza Barrera, M. Ramirez-Garcia, F. Vazquez Valen Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
J. Eysermans, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada Universidad Aut´onoma de San Luis Potos´ı, San Luis Potos´ı, Mexico
A. Morelos Pineda University of Montenegro, Podgorica, Montenegro
J. Mijuskovic, N. Raicevic University of Auckland, Auckland, New Zealand
D. Krofcheck University of Canterbury, Christchurch, New Zealand
S. Bheesette, P.H. Butler National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, M.A. Shah, M. Shoaib,
M. Waqas National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, M.A. Shah, M. Shoaib,
M. Waqas – 38 – AGH University of Science and Technology Faculty of Computer Science,
Electronics and Telecommunications, Krakow, Poland
V. Avati, L. Grzanka, M. Malawski National Centre for Nuclear Research, Swierk, Poland
H. Bialkowska, M. Bluj, B. Boimska, M. G´orski, M. Kazana, M. Szleper, P. Zalewski Institute of Experimental Physics, Faculty of Physics, University of Warsaw,
Warsaw, Poland K. Bunkowski, A. Byszuk35, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski,
M. Misiura, M. Olszewski, M. Walczak JHEP11(2019)109 Laborat´orio de Instrumenta¸c˜ao e F´ısica Experimental de Part´ıculas, Lisboa,
Portugal Portugal M. Araujo, P. Bargassa, D. Bastos, A. Di Francesco, P. Faccioli, B. Galinhas, M. Gallinaro,
J. Hollar, N. Leonardo, J. Seixas, K. Shchelina, G. Strong, O. Toldaiev, J. Varela Joint Institute for Nuclear Research, Dubna, Russia Joint Institute for Nuclear Research, Dubna, Russia
V. Alexakhin, P. Bunin, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavine, V. Korenkov,
A. Lanev, A. Malakhov, V. Matveev36,37, P. Moisenz, V. Palichik, V. Perelygin, M. Savina,
S. Shmatov, S. Shulha, V. Trofimov, N. Voytishin, A. Zarubin, V. Zhiltsov Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia
L. Chtchipounov, V. Golovtcov, Y. Ivanov, V. Kim38, E. Kuznetsova39, P. Levchenko,
V. Murzin, V. Oreshkin, I. Smirnov, D. Sosnov, V. Sulimov, L. Uvarov, A. Vorobyev Institute for Nuclear Research, Moscow, Russia Institute for Nuclear Research, Moscow, Russia
Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov,
N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin Institute for Theoretical and Experimental Physics named by A.I. Alikhanov
of NRC ‘Kurchatov Institute’, Moscow, Russia
V. Epshteyn, V. Gavrilov, N. Lychkovskaya, A. Nikitenko40, V. Popov, I. Pozdnyakov,
G. Safronov, A. Spiridonov, A. Stepennov, M. Toms, E. Vlasov, A. Zhokin Epshteyn, V. Gavrilov, N. Lychkovskaya, A. Nikitenko40, V. Popov, I. Pozdnyakov,
Safronov, A. Spiridonov, A. Stepennov, M. Toms, E. Vlasov, A. Zhokin Moscow Institute of Physics and Technology, Moscow, Russia
T. Aushev National Research Nuclear University ’Moscow Engineering Physics Institute’
(MEPhI), Moscow, Russia
M. Chadeeva41, P. Parygin, D. Philippov, E. Popova, V. Rusinov P.N. Lebedev Physical Institute, Moscow, Russia P.N. Lebedev Physical Institute, Moscow, Russia
V. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Terkulov y
,
,
V. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Terkulov V. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Terkulov Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University,
Moscow, Russia A. Belyaev, E. Boos, V. Bunichev, M. Dubinin42, L. Dudko, A. Ershov, A. Gribushin,
V. Klyukhin, O. Kodolova, I. Lokhtin, S. Obraztsov, V. Savrin, A. Snigirev V. Klyukhin, O. Kodolova, I. Lokhtin, S. Obraztsov, V. Savrin, A. Snigirev – 39 – Novosibirsk State University (NSU), Novosibirsk, Russia
A. Barnyakov43, V. Blinov43, T. Dimova43, L. Kardapoltsev43, Y. Skovpen43 Novosibirsk State University (NSU), Novosibirsk, Russia A. Barnyakov43, V. Blinov43, T. Dimova43, L. Kardapoltsev43, Y. Skovpen43 Institute for High Energy Physics of National Research Centre ‘Kurchatov
Institute’, Protvino, Russia I. Azhgirey, I. Bayshev, S. Bitioukov, V. Kachanov, D. Konstantinov, P. Mandrik,
V. Petrov, R. Portugal Ryutin, S. Slabospitskii, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian,
A. Volkov Centro
de
Investigaciones
Energ´eticas
Medioambientales
y
Tecnol´ogica
(CIEMAT), Madrid, Spain M. Aguilar-Benitez, J. Alcaraz Maestre, A. ´Alvarez Fern´andez, I. Bachiller, M. Barrio Lun M. Aguilar-Benitez, J. Alcaraz Maestre, A. Alvarez Fernandez, I. Bachiller, M. Barrio Luna,
J.A. Brochero Cifuentes, C.A. Carrillo Montoya, M. Cepeda, M. Cerrada, N. Colino,
B. De La Cruz, A. Delgado Peris, C. Fernandez Bedoya, J.P. Fern´andez Ramos, J. Flix,
M.C. Fouz, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, D. Moran,
´A. Navarro Tobar, A. P´erez-Calero Yzquierdo, J. Puerta Pelayo, I. Redondo, L. Romero,
S. S´anchez Navas, M.S. Soares, A. Triossi, C. Willmott Universidad Aut´onoma de Madrid, Madrid, Spain
C. Albajar, J.F. de Troc´oniz, R. Reyes-Almanza Universidad de Oviedo, Instituto Universitario de Ciencias y Tecnolog´ıas
Espaciales de Asturias (ICTEA), Oviedo, Spain B. Alvarez Gonzalez, J. Cuevas, C. Erice, J. Fernandez Menendez, S. Folgueras, I. Gon-
zalez Caballero, J.R. Gonz´alez Fern´andez, E. Palencia Cortezon, V. Rodr´ıguez Bouza,
S. Sanchez Cruz National Research Tomsk Polytechnic University, Tomsk, Russia
A. Babaev, A. Iuzhakov, V. Okhotnikov National Research Tomsk Polytechnic University, Tomsk, Russia
A. Babaev, A. Iuzhakov, V. Okhotnikov JHEP11(2019)109 Tomsk State University, Tomsk, Russia
V. Borchsh, V. Ivanchenko, E. Tcherniaev University of Belgrade: Faculty of Physics and VINCA Institute of Nuclear
Sciences P. Adzic44, P. Cirkovic, D. Devetak, M. Dordevic, P. Milenovic, J. Milosevic, M. Stojanov Centro
de
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(CIEMAT), Madrid, Spain Instituto de F´ısica de Cantabria (IFCA), CSIC-Universidad de Cantabria,
Santander, Spain Instituto de F´ısica de Cantabria (IFCA), CSIC-Universidad de Cantabria,
Santander, Spain I.J. Cabrillo, A. Calderon, B. Chazin Quero, J. Duarte Campderros, M. Fernandez,
P.J. Fern´andez Manteca, A. Garc´ıa Alonso, G. Gomez, C. Martinez Rivero, P. Mar-
tinez Ruiz del Arbol, F. Matorras, J. Piedra Gomez, C. Prieels, T. Rodrigo, A. Ruiz-Jimeno,
L. Russo45, L. Scodellaro, N. Trevisani, I. Vila, J.M. Vizan Garcia University of Colombo, Colombo, Sri Lanka
K. Malagalage University of Colombo, Colombo, Sri Lanka
K. Malagalage University of Ruhuna, Department of Physics, Matara, Sri Lanka
W.G.D. Dharmaratna, N. Wickramage – 40 – CERN, European Organization for Nuclear Research, Geneva, Switzerland
D. Abbaneo, B. Akgun, E. Auffray, G. Auzinger, J. Baechler, P. Baillon, A.H. Ball,
D. Barney, J. Bendavid, M. Bianco, A. Bocci, P. Bortignon, E. Bossini, C. Botta,
E. Brondolin, T. Camporesi, A. Caratelli, G. Cerminara, E. Chapon, G. Cucciati,
D. d’Enterria, A. Dabrowski, N. Daci, V. Daponte, A. David, O. Davignon, A. De Roeck,
N. Deelen, M. Deile, M. Dobson, M. D¨unser, N. Dupont, A. Elliott-Peisert, N. Emriskova,
F. Fallavollita46, D. Fasanella, S. Fiorendi, G. Franzoni, J. Fulcher, W. Funk, S. Giani,
D. Gigi, A. Gilbert, K. Gill, F. Glege, M. Gruchala, M. Guilbaud, D. Gulhan, J. Hegeman,
C. Heidegger, Y. Iiyama, V. Innocente, P. Janot, O. Karacheban19, J. Kaspar, J. Kieseler,
M. Krammer1, N. Kratochwil, C. Lange, P. Lecoq, C. Louren¸co, L. Malgeri, M. Mannelli,
A. Massironi, F. Meijers, J.A. Merlin, S. Mersi, E. Meschi, F. Moortgat, M. Mulders,
J. Ngadiuba, J. Niedziela, S. Nourbakhsh, S. Orfanelli, L. Orsini, F. Pantaleo16, L. Pape,
E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, F.M. Pitters,
D. Rabady, A. Racz, M. Rieger, M. Rovere, H. Sakulin, C. Sch¨afer, C. Schwick, M. Selvaggi,
A. Sharma, P. Silva, W. Snoeys, P. Sphicas47, J. Steggemann, S. Summers, V.R. Tavolaro,
D. Treille, A. Tsirou, G.P. Van Onsem, A. Vartak, M. Verzetti, W.D. Zeuner CERN, European Organization for Nuclear Research, Geneva, Switzerland
D. Abbaneo, B. Akgun, E. Auffray, G. Auzinger, J. Baechler, P. Baillon, A.H. Ball,
D. Barney, J. Bendavid, M. Bianco, A. Bocci, P. Bortignon, E. Bossini, C. Botta,
E. Brondolin, T. Camporesi, A. Caratelli, G. Cerminara, E. Chapon, G. Cucciati,
D. d’Enterria, A. Dabrowski, N. Daci, V. Daponte, A. David, O. Davignon, A. De Roeck,
N. Deelen, M. Deile, M. Dobson, M. D¨unser, N. Dupont, A. Elliott-Peisert, N. Emriskova,
F. Fallavollita46, D. Fasanella, S. Fiorendi, G. Franzoni, J. Instituto de F´ısica de Cantabria (IFCA), CSIC-Universidad de Cantabria,
Santander, Spain Fulcher, W. Funk, S. Giani,
D. Gigi, A. Gilbert, K. Gill, F. Glege, M. Gruchala, M. Guilbaud, D. Gulhan, J. Hegeman,
C. Heidegger, Y. Iiyama, V. Innocente, P. Janot, O. Karacheban19, J. Kaspar, J. Kieseler,
M. Krammer1, N. Kratochwil, C. Lange, P. Lecoq, C. Louren¸co, L. Malgeri, M. Mannelli,
A. Massironi, F. Meijers, J.A. Merlin, S. Mersi, E. Meschi, F. Moortgat, M. Mulders,
J. Ngadiuba, J. Niedziela, S. Nourbakhsh, S. Orfanelli, L. Orsini, F. Pantaleo16, L. Pape,
E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, F.M. Pitters,
D. Rabady, A. Racz, M. Rieger, M. Rovere, H. Sakulin, C. Sch¨afer, C. Schwick, M. Selvaggi,
A. Sharma, P. Silva, W. Snoeys, P. Sphicas47, J. Steggemann, S. Summers, V.R. Tavolaro,
D. Treille, A. Tsirou, G.P. Van Onsem, A. Vartak, M. Verzetti, W.D. Zeuner JHEP11(2019)109 Universit¨at Z¨urich, Zurich, Switzerland ,
,
T.K. Aarrestad, C. Amsler49, D. Brzhechko, M.F. Canelli, A. De Cosa, R. Del Burgo, S. Do-
nato, B. Kilminster, S. Leontsinis, V.M. Mikuni, I. Neutelings, G. Rauco, P. Robmann,
D. Salerno, K. Schweiger, C. Seitz, Y. Takahashi, S. Wertz, A. Zucchetta National Central University, Chung-Li, Taiwan National Central University, Chung-Li, Taiwan
T.H. Doan, C.M. Kuo, W. Lin, A. Roy, S.S. Yu T.H. Doan, C.M. Kuo, W. Lin, A. Roy, S.S. Yu National Taiwan University (NTU), Taipei, Taiwan
P. Chang, Y. Chao, K.F. Chen, P.H. Chen, W.-S. Hou, Y.y. Li, R.-S. Lu, E. Paganis, National Taiwan University (NTU), Taipei, Taiwan National Taiwan University (NTU), Taipei, Taiwan P. Chang, Y. Chao, K.F. Chen, P.H. Chen, W.-S. Hou, Y.y. Li, R.-S. Lu, E. Paganis,
A. Psallidas, A. Steen Paul Scherrer Institut, Villigen, Switzerland Paul Scherrer Institut, Villigen, Switzerland Paul Scherrer Institut, Villigen, Switzerland
L. Caminada48, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli,
D. Kotlinski, U. Langenegger, T. Rohe, S.A. Wiederkehr ETH Zurich - Institute for Particle Physics and Astrophysics (IPA), Zurich,
Switzerland M. Backhaus, P. Berger, N. Chernyavskaya, G. Dissertori, M. Dittmar, M. Doneg`a, C. Dor-
fer, T.A. G´omez Espinosa, C. Grab, D. Hits, T. Klijnsma, W. Lustermann, R.A. Manzoni,
M. Marionneau, M.T. Meinhard, F. Micheli, P. Musella, F. Nessi-Tedaldi, F. Pauss,
G. Perrin, L. Perrozzi, S. Pigazzini, M.G. Ratti, M. Reichmann, C. Reissel, T. Reitenspiess,
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Ol D. Ruini, D.A. Sanz Becerra, M. Sch¨onenberger, L. Shchutska, M.L. Vesterbacka Olsson,
R. Wallny, D.H. Zhu R. Wallny, D.H. Zhu University of Bristol, Bristol, U.K. University of Bristol, Bristol, U.K. F. Ball, E. Bhal, S. Bologna, J.J. Brooke, D. Burns64, E. Clement, D. Cussans, H. Flacher,
J. Goldstein, G.P. Heath, H.F. Heath, L. Kreczko, S. Paramesvaran, B. Penning,
T. Sakuma, S. Seif El Nasr-Storey, V.J. Smith, J. Taylor, A. Titterton Rutherford Appleton Laboratory, Didcot, U.K. K.W. Bell, A. Belyaev65, C. Brew, R.M. Brown, D. Cieri, D.J.A. Cockerill, J.A. Coughlan,
K. Harder, S. Harper, J. Linacre, K. Manolopoulos, D.M. Newbold, E. Olaiya, D. Petyt,
T. Reis, T. Schuh, C.H. Shepherd-Themistocleous, A. Thea, I.R. Tomalin, T. Williams,
W.J. Womersley Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok,
Thailand Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok,
Thailand Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok,
Thailand B. Asavapibhop, C. Asawatangtrakuldee, N. Srimanobhas, N. Suwonjandee B. Asavapibhop, C. Asawatangtrakuldee, N. Srimanobhas, N. Suwonjandee B. Asavapibhop, C. Asawatangtrakuldee, N. Srimanobhas, N. Suwonjandee – 41 – C¸ ukurova University, Physics Department, Science and Art Faculty, Adana,
Turkey A. Bat, F. Boran, A. Celik50, S. Cerci51, S. Damarseckin52, Z.S. Demiroglu, F. Dole A. Bat, F. Boran, A. Celik
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C. Dozen, I. Dumanoglu, G. Gokbulut, EmineGurpinar Guler53, Y. Guler, I. Hos54,
C. Isik, E.E. Kangal55, O. Kara, A. Kayis Topaksu, U. Kiminsu, M. Oglakci, G. Onengut,
K. Ozdemir56, S. Ozturk57, A.E. Simsek, D. Sunar Cerci51, U.G. Tok, S. Turkcapar,
I.S. Zorbakir, C. Zorbilmez Middle East Technical University, Physics Department, Ankara, Turkey
B. Isildak58, G. Karapinar59, M. Yalvac JHEP11(2019)109 Bogazici University, Istanbul, Turkey
I.O. Atakisi, E. G¨ulmez, M. Kaya60, O. Kaya61, ¨O. ¨Oz¸celik, S. Tekten, E.A. Yetkin62 Istanbul Technical University, Istanbul, Turkey
A. Cakir, K. Cankocak, Y. Komurcu, S. Sen63 Istanbul Technical University, Istanbul, Turkey
A. Cakir, K. Cankocak, Y. Komurcu, S. Sen63 Istanbul University, Istanbul, Turkey
B. Kaynak, S. Ozkorucuklu Istanbul University, Istanbul, Turkey
B. Kaynak, S. Ozkorucuklu Institute for Scintillation Materials of National Academy of Science of Ukraine,
Kharkov, Ukraine
B. Grynyov National Scientific Center, Kharkov Institute of Physics and Technology,
Kharkov, Ukraine L. Levchuk L. Levchuk L. Levchuk University of Bristol, Bristol, U.K. Baylor University, Waco, U.S.A. Baylor University, Waco, U.S.A. K. Call, B. Caraway, J. Dittmann, K. Hatakeyama, C. Madrid, B. McMaster, N. Pastika,
C. Smith Catholic University of America, Washington, DC, U.S.A. Catholic University of America, Washington, DC, U.S.A. R. Bartek, A. Dominguez, R. Uniyal, A.M. Vargas Hernandez JHEP11(2019)109 The University of Alabama, Tuscaloosa, U.S.A. A B
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C W t The University of Alabama, Tuscaloosa, U.S.A. A. Buccilli, S.I. Cooper, C. Henderson, P. Rumerio, C. West Boston University, Boston, U.S.A. D. Arcaro, Z. Demiragli, D. Gastler, D. Pinna, C. Richardson, J. Rohlf, D. Sperka,
I. Suarez, L. Sulak, D. Zou Brown University, Providence, U.S.A. G. Benelli, B. Burkle, X. Coubez17, D. Cutts, Y.t. Duh, M. Hadley, J. Hakala, U. Heint J.M. Hogan68, K.H.M. Kwok, E. Laird, G. Landsberg, J. Lee, Z. Mao, M. Narain, S. Sagir69,
R. Syarif, E. Usai, D. Yu, W. Zhang University of California, Davis, Davis, U.S.A. R. Band, C. Brainerd, R. Breedon, M. Calderon De La Barca Sanchez, M. Chertok, R. Band, C. Brainerd, R. Breedon, M. Calderon De La Barca Sanchez, M. Chertok,
J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk, F. Jensen, W. Ko, J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk, F. Jensen, W. Ko,
O. Kukral, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, M. Shi, D. Taylor, K. Tos,
M. Tripathi, Z. Wang, F. Zhang O. Kukral, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, M. Shi, D. Taylor, K. Tos, O. Kukral, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, M. Shi, D. Taylor, K. Tos,
M Tripathi Z Wang F Zhang M. Tripathi, Z. Wang, F. Zhang Imperial College, London, U.K. Imperial College, London, U.K. R. Bainbridge, P. Bloch, J. Borg, S. Breeze, O. Buchmuller, A. Bundock, GurpreetS-
ingh CHAHAL66, D. Colling, P. Dauncey, G. Davies, M. Della Negra, R. Di Maria,
P. Everaerts, G. Hall, G. Iles, T. James, M. Komm, C. Laner, L. Lyons, A.-M. Magnan,
S. Malik, A. Martelli, V. Milosevic, J. Nash67, V. Palladino, M. Pesaresi, D.M. Raymond,
A. Richards, A. Rose, E. Scott, C. Seez, A. Shtipliyski, M. Stoye, T. Strebler, A. Tapper,
K. Uchida, T. Virdee16, N. Wardle, D. Winterbottom, J. Wright, A.G. Zecchinelli,
S.C. Zenz K. Uchida, T. Virdee16, N. Wardle, D. Winterbottom, J. Wright, A.G. Zecchinelli,
S.C. Zenz – 42 – Brunel University, Uxbridge, U.K. Brunel University, Uxbridge, U.K. J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, C.K. Mackay, A. Morton, I.D. Reid,
L. Teodorescu, S. Zahid University of Colorado Boulder, Boulder, U.S.A. J.P. Cumalat, W.T. Ford, A. Johnson, E. MacDonald, T. Mulholland, R. Patel, A. Perloff,
K. Stenson, K.A. Ulmer, S.R. Wagner JHEP11(2019)109 Fermi National Accelerator Laboratory, Batavia, U.S.A. S. Abdullin, M. Albrow, M. Alyari, G. Apollinari, A. Apresyan, A. Apyan, S. Banerjee,
L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, K. Burkett, J.N. Butler, A. Canepa,
G.B. Cerati, H.W.K. Cheung, F. Chlebana, M. Cremonesi, J. Duarte, V.D. Elvira,
J. Freeman, Z. Gecse, E. Gottschalk, L. Gray, D. Green, S. Gr¨unendahl, O. Gutsche,
AllisonReinsvold Hall, J. Hanlon, R.M. Harris, S. Hasegawa, R. Heller, J. Hirschauer,
B. Jayatilaka, S. Jindariani, M. Johnson, U. Joshi, B. Klima, M.J. Kortelainen, B. Kreis,
S. Lammel, J. Lewis, D. Lincoln, R. Lipton, M. Liu, T. Liu, J. Lykken, K. Maeshima,
J.M. Marraffino, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, V. O’Dell,
V. Papadimitriou, K. Pedro, C. Pena, G. Rakness, F. Ravera, L. Ristori, B. Schneider,
E. Sexton-Kennedy, N. Smith, A. Soha, W.J. Spalding, L. Spiegel, S. Stoynev, J. Strait,
N. Strobbe, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernieri,
R. Vidal, M. Wang, H.A. Weber J.M. Marraffino, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, V. O’Dell, E. Sexton-Kennedy, N. Smith, A. Soha, W.J. Spalding, L. Spiegel, S. Stoynev, J. Strait,
N. Strobbe, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernieri,
R Vidal M Wang H A Weber E. Sexton-Kennedy, N. Smith, A. Soha, W.J. Spalding, L. Spiegel, S. Stoynev, J. Strait,
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i N. Strobbe, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernie R. Vidal, M. Wang, H.A. Weber University of California, Los Angeles, U.S.A. University of California, Los Angeles, U.S.A. . Bachtis, C. Bravo, R. Cousins, A. Dasgupta, A. Florent, J. Hauser, M. Ignatenko, M. Bachtis, C. Bravo, R. Cousins, A. Dasgupta, A. Florent, J. Hauser, M. Ignatenko,
N. Mccoll, W.A. Nash, S. Regnard, D. Saltzberg, C. Schnaible, B. Stone, V. Valuev N. Mccoll, W.A. Nash, S. Regnard, D. Saltzberg, C. Schnaible, B. Stone, V. Valuev University of California, Riverside, Riverside, U.S.A. K. Burt, Y. Chen, R. Clare, J.W. Gary, S.M.A. Ghiasi Shirazi, G. Hanson, G. Karapostoli,
E. Kennedy, O.R. Long, M. Olmedo Negrete, M.I. Paneva, W. Si, L. Wang, S. Wimpenny,
B.R. Yates, Y. Zhang B.R. Yates, Y. Zhang University of California, San Diego, La Jolla, U.S.A. J.G. Branson, P. Chang, S. Cittolin, M. Derdzinski, R. Gerosa, D. Gilbert, B. Hashemi,
D. Klein, V. Krutelyov, J. Letts, M. Masciovecchio, S. May, S. Padhi, M. Pieri, V. Sharma,
M. Tadel, F. W¨urthwein, A. Yagil, G. Zevi Della Porta University of California, Santa Barbara - Department of Physics, Santa Bar-
bara, U.S.A. N. Amin, R. Bhandari, C. Campagnari, M. Citron, V. Dutta, M. Franco Sevilla, L. Gouskos, N. Amin, R. Bhandari, C. Campagnari, M. Citron, V. Dutta, M. Franco Sevilla, L. Gouskos,
J Incandela B Marsh H Mei A Ovcharova H Qu J Richman U Sarica D Stuart J. Incandela, B. Marsh, H. Mei, A. Ovcharova, H. Qu, J. Richman, U. Sarica, D. Stuart,
S. Wang – 43 – University of Florida, Gainesville, U.S.A. D. Acosta, P. Avery, D. Bourilkov, A. Brinkerhoff, L. Cadamuro, A. Carnes, V. Cherepanov,
D. Curry, F. Errico, R.D. Field, S.V. Gleyzer, B.M. Joshi, M. Kim, J. Konigsberg,
A. Korytov, K.H. Lo, P. Ma, K. Matchev, N. Menendez, G. Mitselmakher, D. Rosenzweig,
K. Shi, J. Wang, S. Wang, X. Zuo Florida International University, Miami, U.S.A. Florida International University, Miami, U.S.A. Y.R. Joshi Y.R. Joshi Florida State University, Tallahassee, U.S.A. T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, R. Khurana, T. Kolber T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, R. Khurana, T. Kolberg,
G. Martinez, T. Perry, H. Prosper, C. Schiber, R. Yohay, J. Zhang Martinez, T. Perry, H. Prosper, C. Schiber, R. Yohay, J. Zhang G. Martinez, T. Perry, H. Prosper, C. Schiber, R. Yohay, J. Zhan Florida Institute of Technology, Melbourne, U.S.A. Cornell University, Ithaca, U.S.A. J. Alexander, J. Chaves, Y. Cheng, J. Chu, A. Datta, A. Frankenthal, K. Mcdermott,
J.R. Patterson, D. Quach, A. Rinkevicius70, A. Ryd, S.M. Tan, Z. Tao, J. Thom, P. Wittich,
M. Zientek Fermi National Accelerator Laboratory, Batavia, U.S.A. California Institute of Technology, Pasadena, U.S.A. California Institute of Technology, Pasadena, U.S.A. D. Anderson, A. Bornheim, O. Cerri, I. Dutta, J.M. Lawhorn, N. Lu, J. Mao, H.B. Newman,
T.Q. Nguyen, J. Pata, M. Spiropulu, J.R. Vlimant, S. Xie, Z. Zhang, R.Y. Zhu Carnegie Mellon University, Pittsburgh, U.S.A. M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, M. Sun, I. Vorobiev, M. Weinberg M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, M. Sun, I. Vorobiev, M. Weinbe University of Colorado Boulder, Boulder, U.S.A. Florida Institute of Technology, Melbourne, U.S.A. Acosta, S. Oliveros Florida Institute of Technology, Melbourne, U.S.A. M.M. Baarmand, M. Hohlmann, D. Noonan, M. Rahmani, M. Saunders, F. Yumiceva – 44 – University of Illinois at Chicago (UIC), Chicago, U.S.A. M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, R. Cavanaugh, X. Chen, S. Dittmer,
O. Evdokimov, C.E. Gerber, D.A. Hangal, D.J. Hofman, K. Jung, C. Mills, T. Roy,
M.B. Tonjes, N. Varelas, J. Viinikainen, H. Wang, X. Wang, Z. Wu The University of Iowa, Iowa City, U.S.A. M. Alhusseini, B. Bilki53, W. Clarida, K. Dilsiz71, S. Durgut, R.P. Gandrajula, M. Hayt-
myradov, V. Khristenko, O.K. K¨oseyan, J.-P. Merlo, A. Mestvirishvili72, A. Moeller,
J. Nachtman, H. Ogul73, Y. Onel, F. Ozok74, A. Penzo, C. Snyder, E. Tiras, J. Wetzel Johns Hopkins University, Baltimore, U.S.A. JHEP11(2019)109 B. Blumenfeld, A. Cocoros, N. Eminizer, D. Fehling, L. Feng, A.V. Gritsan, W.T. Hung,
P. Maksimovic, J. Roskes, M. Swartz P. Maksimovic, J. Roskes, M. Swartz The University of Kansas, Lawrence, U.S.A. The University of Kansas, Lawrence, U.S.A. C. Baldenegro Barrera, P. Baringer, A. Bean, S. Boren, J. Bowen, A. Bylinkin,
T. Isidori, S. Khalil, J. King, G. Krintiras, A. Kropivnitskaya, C. Lindsey, D. Majumder,
W. Mcbrayer, N. Minafra, M. Murray, C. Rogan, C. Royon, S. Sanders, E. Schmitz,
J.D. Tapia Takaki, Q. Wang, J. Williams, G. Wilson Kansas State University, Manhattan, U.S.A. S. Duric, A. Ivanov, K. Kaadze, D. Kim, Y. Maravin, D.R. Mendis, T. Mitchell, A. Modak,
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1: Also at Vienna University of Technology, Vienna, Austria 1: Also at Vienna University of Technology, Vienna, Austria 2: Also at IRFU, CEA, Universit´e Paris-Saclay, Gif-sur-Yvette, France 2: Also at IRFU, CEA, Universit´e Paris-Saclay, Gif-sur-Yvette, France 3: Also at Universidade Estadual de Campinas, Campinas, Brazil 3: Also at Universidade Estadual de Campinas, Campinas, Brazil 4: Also at Federal University of Rio Grande do Sul, Porto Alegre, Brazil 4: Also at Federal University of Rio Grande do Sul, Porto Alegre, 4: Also at Federal University of Rio Grande 5: Also at UFMS, Nova Andradina, Brazil 6: Also at Universidade Federal de Pelotas, Pelotas, Brazil 6: Also at Universidade Federal de Pelotas, Pelotas, Brazil 7: Also at Universit´e Libre de Bruxelles, Bruxelles, Belgium 7: Also at Universit´e Libre de Bruxelles, Bruxelles, Belgium 8: Also at University of Chinese Academy of Sciences, Beijing, China 8: Also at University of Chinese Academy of Sciences, Beijing, China 9: Also at Institute for Theoretical and Experimental Physics named by A.I. Alikhanov of NRC
‘Kurchatov Institute’, Moscow, Russia 10: Also at Joint Institute for Nuclear Research, Dubna, Russia 10: Also at Joint Institute for Nuclear Research, Dubna, Russia 11: Also at Ain Shams University, Cairo, Egypt 11: Also at Ain Shams University, Cairo, Egypt 12: Also at Zewail City of Science and Technology, Zewail, Egypt 12: Also at Zewail City of Science and Technology, Zewail, Egypt – 47 – 13: Also at Purdue University, West Lafayette, U.S.A. 14: Also at Universit´e de Haute Alsace, Mulhouse, France 15: Also at Erzincan Binali Yildirim University, Erzincan, Turkey 16: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland 17: Also at RWTH Aachen University, III. Texas Tech University, Lubbock, U.S.A. Physikalisches Institut A, Aachen, Germany 18: Also at University of Hamburg, Hamburg, Germany 19: Also at Brandenburg University of Technology, Cottbus, Germany 20: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary, Debrecen, Hungary 21: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary 1: Also at Institute of Nuclear Research ATOMK 22: Also at MTA-ELTE Lend¨ulet CMS Particle and Nuclear Physics Group, E¨otv¨os Lor´and
University, Budapest, Hungary, Budapest, Hungary 22: Also at MTA-ELTE Lend¨ulet CMS Particle and Nuclear Physics Group, E¨otv¨os Lor´and
U i
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t H 22: Also at MTA-ELTE Lend¨ulet CMS Particle and Nuclear Physics Group, E¨otv¨os Lor´and
University, Budapest, Hungary, Budapest, Hungary JHEP11(2019)109 23: Also at IIT Bhubaneswar, Bhubaneswar, India, Bhubaneswar, India 23: Also at IIT Bhubaneswar, Bhubaneswar, India, Bhubaneswar, India 24: Also at Institute of Physics, Bhubaneswar, India 25: Also at Shoolini University, Solan, India 26: Also at University of Visva-Bharati, Santiniketan, India 26: Also at University of Visva-Bharati, Santiniketan, India 27: Also at Isfahan University of Technology, Isfahan, Iran 27: Also at Isfahan University of Technology, Isfahan, Iran 28: Now at INFN Sezione di Bari a, Universit`a di Bari b, Politecnico di Bari c, Bari, Ita 28: Now at INFN Sezione di Bari a, Universit`a di Bari b, Politecnico di Bari c, Bari, Italy 29: Also at Italian National Agency for New Technologies, Energy and Sustainable Economic
Development, Bologna, Italy 29: Also at Italian National Agency for New Technologies, Energy and Sustainable Economic
Development, Bologna, Italy 30: Also at Centro Siciliano di Fisica Nucleare e di Struttura Della Materia, Catania, Italy 30: Also at Centro Siciliano di Fisica Nucleare e di Struttura Della Materia, Catania, I 31: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy 31: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy 32: Also at Riga Technical University, Riga, Latvia, Riga, Latvia 32: Also at Riga Technical University, Riga, Latvia, Riga, Latvia 33: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia 34: Also at Consejo Nacional de Ciencia y Tecnolog´ıa, Mexico City, Mexico 34: Also at Consejo Nacional de Ciencia y Tecnolog´ıa, Mexico City, Mexico 35: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland 35: Also at Warsaw University of Technology, Institute of Ele 35: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland at Institute for Nuclear Research, Moscow, Russ 37: Now at National Research Nuclear University ’Moscow Engineering Physics Institute’
(MEPhI), Moscow, Russia 37: Now at National Research Nuclear University ’Moscow Engineering Physics Institute’
(MEPhI), Moscow, Russia 38: Also at St. Texas Tech University, Lubbock, U.S.A. Petersburg State Polytechnical University, St. Petersburg, Russia 38: Also at St. Petersburg State Polytechnical University, St. Petersburg, Russia 39: Also at University of Florida, Gainesville, U.S.A. 40: Also at Imperial College, London, U.K. 41: Also at P.N. Lebedev Physical Institute, Moscow, Russia 41: Also at P.N. Lebedev Physical Institute, Moscow, Russia 42: Also at California Institute of Technology, Pasadena, U.S.A. 42: Also at California Institute of Technology, Pasadena, U.S.A. 43: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia 43: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia Also at Budker Institute of Nuclear Physics, Nov 44: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia 44: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia 45: Also at Universit`a degli Studi di Siena, Siena, Italy 46: Also at INFN Sezione di Pavia a, Universit`a di Pavia b, Pavia, Italy, Pavia, Italy 46: Also at INFN Sezione di Pavia a, Universit`a di Pavia b, Pavia, Italy, Pavia, Italy 47: Also at National and Kapodistrian University of Athens, Athens, Greece 48: Also at Universit¨at Z¨urich, Zurich, Switzerland 49: Also at Stefan Meyer Institute for Subatomic Physics, Vienna, Austria, Vienna, Austria 50: Also at Burdur Mehmet Akif Ersoy University, BURDUR, Turkey 51: Also at Adiyaman University, Adiyaman, Turkey 52: Also at S¸ırnak University, Sirnak, Turkey 53: Also at Beykent University, Istanbul, Turkey, Istanbul, Turkey 53: Also at Beykent University, Istanbul, Turkey, Istanbul, Turkey 54: Also at Istanbul Aydin University, Istanbul, Turkey 54: Also at Istanbul Aydin University, Istanbul, Turkey 55: Also at Mersin University, Mersin, Turkey 56: Also at Piri Reis University, Istanbul, Turkey 57: Also at Gaziosmanpasa University, Tokat, Turkey – 48 – 58: Also at Ozyegin University, Istanbul, Turkey 58: Also at Ozyegin University, Istanbul, Turkey 59: Also at Izmir Institute of Technology, Izmir, Turkey 59: Also at Izmir Institute of Technology, Izmir, Turkey 60: Also at Marmara University, Istanbul, Turkey 60: Also at Marmara University, Istanbul, Turkey 61: Also at Kafkas University, Kars, Turkey 62: Also at Istanbul Bilgi University, Istanbul, Turkey 62: Also at Istanbul Bilgi University, Istanbul, Turkey 63: Also at Hacettepe University, Ankara, Turkey 63: Also at Hacettepe University, Ankara, Turkey 64: Also at Vrije Universiteit Brussel, Brussel, Belgium 64: Also at Vrije Universiteit Brussel, Brussel, Belgium 65: Also at School of Physics and Astronomy, University of Southampton, Southampton, U.K. 65: Also at School of Physics and Astronomy, University of Southampton, Southampton, U.K. Texas Tech University, Lubbock, U.S.A. 65: Also at School of Physics and Astronomy, University of Southamp Also at IPPP Durham University, Durham, U.K 67: Also at Monash University, Faculty of Science, Clayton, Australi 67: Also at Monash University, Faculty of Science, Clayton, Australia JHEP11(2019)109 69: Also at Karamano˘glu Mehmetbey University, Karaman, Turkey 69: Also at Karamano˘glu Mehmetbey University, Karaman, Turkey 70: Also at Vilnius University, Vilnius, Lithuania 70: Also at Vilnius University, Vilnius, Lithuania 71: Also at Bingol University, Bingol, Turkey 71: Also at Bingol University, Bingol, Turkey 72: Also at Georgian Technical University, Tbilisi, Georgia 72: Also at Georgian Technical University, Tbilisi, Georgia 72: Also at Georgian Technical University, T 73: Also at Sinop University, Sinop, Turkey 73: Also at Sinop University, Sinop, Turkey 74: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey 74: Also at Mimar Sinan University, Istanbu 74: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey 75: Also at Texas A&M University at Qatar, Doha, Qatar 75: Also at Texas A&M University at Qatar, Doha, Qatar 76: Also at Kyungpook National University, Daegu, Korea, Daegu, Korea 76: Also at Kyungpook National University, Daegu, Korea, Daegu, Korea 77: Also at University of Hyderabad, Hyderabad, India 77: Also at University of Hyderabad, Hyderabad, India – 49 –
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Oxytocin Shapes Spontaneous Activity Patterns in the Developing Visual Cortex by Activating Somatostatin Interneurons
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In Brief Maldonado etal. uncover oxytocin’s rolein
developing sensory cortices. In vivo, they
show that oxytocin decreases the
frequency and correlations of
spontaneous activity patterns in V1 by
specifically activating somatostatin+
interneurons. In S1, oxytocin increases
both excitation and inhibition and does not
affect spontaneous activity frequency. Article Article Paloma P. Maldonado,
Alvaro Nuno-Perez, Jan H. Kirchner,
Elizabeth Hammock,
Julijana Gjorgjieva, Christian Lohmann Correspondence
c.lohmann@nin.knaw.nl (C.L.) Correspondence
c.lohmann@nin.knaw.nl (C.L.) Oxytocin Shapes Spontaneous Activity Patterns in
the Developing Visual Cortex by Activating
Somatostatin Interneurons Maldonado et al., 2021, Current Biology 31, 322–333
January 25, 2021 ª 2020 The Author(s). Published by Elsevier Inc.
https://doi.org/10.1016/j.cub.2020.10.028 Authors Graphical Abstract Paloma P. Maldonado,
Alvaro Nuno-Perez, Jan H. Kirchner,
Elizabeth Hammock,
Julijana Gjorgjieva, Christian Lohmann SUMMARY Spontaneous network activity shapes emerging neuronal circuits during early brain development prior to
sensory perception. However, how neuromodulation influences this activity is not fully understood. Here,
we report that the neuromodulator oxytocin differentially shapes spontaneous activity patterns across sen-
sory cortices. In vivo, oxytocin strongly decreased the frequency and pairwise correlations of spontaneous
activity events in the primary visual cortex (V1), but it did not affect the frequency of spontaneous network
events in the somatosensory cortex (S1). Patch-clamp recordings in slices and RNAscope showed that
oxytocin affects S1 excitatory and inhibitory neurons similarly, whereas in V1, oxytocin targets only inhibitory
neurons. Somatostatin-positive (SST+) interneurons expressed the oxytocin receptor and were activated by
oxytocin in V1. Accordingly, pharmacogenetic silencing of V1 SST+ interneurons fully blocked oxytocin’s ef-
fect on inhibition in vitro as well its effect on spontaneous activity patterns in vivo. Thus, oxytocin decreases
the excitatory/inhibitory (E/I) ratio by recruiting SST+ interneurons and modulates specific features of V1
spontaneous activity patterns that are crucial for the wiring and refining of developing sensory circuits. 8Lead Contact 8Lead Contact *Correspondence: p.maldonado@nin.knaw.nl (P.P.M.), alvaro.nunoperez@unil.ch (A.N.-P.), jan.kirchner@brain.mpg.de (J.H.K.), hammock@
psy.fsu.edu (E.H.), gjorgjieva@brain.mpg.de (J.G.), c.lohmann@nin.knaw.nl (C.L.)
https://doi.org/10.1016/j.cub.2020.10.028 Article
Oxytocin Shapes Spontaneous Activity
Patterns in the Developing Visual Cortex
by Activating Somatostatin Interneurons
Paloma P. Maldonado,1 Alvaro Nuno-Perez,1,7 Jan H. Kirchner,3,4 Elizabeth Hammock,5,6 Julijana Gjorgjieva,3,4
and Christian Lohmann1,2,8,*
1Department of Synapse and Network Development, Netherlands Institute for Neuroscience, 1105 BA Amsterdam, the Netherlands
2Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, 1081 HV Amsterdam,
the Netherlands
3Max Planck Institute for Brain Research, Computation in Neural Circuits, 60438 Frankfurt am Main, Germany
4TUM School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
5Program in Neuroscience, The Florida State University, Tallahassee, FL 32306, USA
6Department of Psychology, The Florida State University, Tallahassee, FL 32306, USA
7Present address: The Department of Fundamental Neuroscience, The University of Lausanne, Rue du Bugnon 9, Lausanne 1005,
Switzerland
8Lead Contact
ll
OPEN ACCESS ll
OPEN ACCESS 322
Current Biology 31, 322–333, January 25, 2021 ª 2020 The Author(s). Published by Elsevier Inc.
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Paloma P. Maldonado,1 Alvaro Nuno-Perez,1,7 Jan H. Kirchner,3,4 Elizabeth Hammock,5,6 Julijana Gjorgjieva,3,4
and Christian Lohmann1 2 8 * Paloma P. Maldonado,1 Alvaro Nuno-Perez,1,7 Jan H. Kirchner,3,4 Elizabeth Hammock,5,6 Julijana Gjorgjieva,3,4
and Christian Lohmann1,2,8,* 1Department of Synapse and Network Development, Netherlands Institute for Neuroscience, 1105 BA Amsterdam, the Netherlands
2Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, 1081 HV Amsterdam, 1Department of Synapse and Network Development, Netherlands Institute for Neuroscience, 1105 BA Amsterdam, the Netherlands
2Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam, 1081 HV Amsterdam
the Netherlands 5Program in Neuroscience, The Florida State University, Tallahassee, FL 32306, USA
6D
t
t
f P
h l
Th
Fl
id
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U i
it
T ll h
FL 32306 USA *Correspondence: p.maldonado@nin.knaw.nl (P.P.M.), alvaro.nunoperez@unil.ch (A.N.-P.), jan.kirchner@brain.mpg.de (J.H.K.), hammock@
psy.fsu.edu (E.H.), gjorgjieva@brain.mpg.de (J.G.), c.lohmann@nin.knaw.nl (C.L.)
https://doi.org/10.1016/j.cub.2020.10.028 Highlights d Oxytocin modulates spontaneous activity event patterns in
the developing V1 d Oxytocin increases inhibition by activating somatostatin+
interneurons d SST+ neuron activity reduces event frequency and
correlations, but not amplitude d In S1, oxytocin increases excitation and inhibition and does
not modulate frequency ll ll Figure 1. Oxytocin Affects Spontaneous Network
Events Differentially across Sensory Cortices 0
2
4
1
3
5
6
V1
S1
in vivo calcium imaging in lightly anesthetized
pups between postnatal days (P) 9 and 13. We
observed spontaneous network activity in V1,
S1, and higher visual areas (Figures 1A and 1B). Frequently, network events were confined to in-
dividual sensory regions but sometimes occurred
across the entire field of view. After topical appli-
cation of oxytocin (1 mM) onto the cortical surface
(for details, see STAR Methods), the occurrence
of network events was strongly decreased in V1
but only modestly changed in S1 (Figures 1A–1D). Control appli-
cation of cortex buffer without oxytocin did not change the fre-
quency of calcium events (V1 mean frequency before cortex
buffer 0.042 ± 0.002 Hz; after 0.044 ± 0.004 Hz; p > 0.05; n =
4; Wilcoxon test. S1 mean frequency before cortex buffer
0.042 ± 0.003 Hz; after 0.044 ± 0.004 Hz; p > 0.05; n = 4; Wil-
coxon test). Surprisingly, the response of V1 and S1 differed
significantly (percentage of change V1: 43.5% ± 7.9%; S1:
7.9% ± 5.2%; p = 0.0026; n = 7; unpaired two-tailed t test). Network event area, amplitude, or duration was not affected
(Figures 1E–1G). 0
2
4
3
5
6
V1
S1
in vivo calcium imaging in lightly anesthetized
pups between postnatal days (P) 9 and 13. We
observed spontaneous network activity in V1,
S1, and higher visual areas (Figures 1A and 1B). Frequently, network events were confined to in-
dividual sensory regions but sometimes occurred
across the entire field of view. After topical appli-
cation of oxytocin (1 mM) onto the cortical surface
(for details, see STAR Methods), the occurrence
of network events was strongly decreased in V1
but only modestly changed in S1 (Figures 1A–1D). Control appli-
cation of cortex buffer without oxytocin did not change the fre-
quency of calcium events (V1 mean frequency before cortex
buffer 0.042 ± 0.002 Hz; after 0.044 ± 0.004 Hz; p > 0.05; n =
4; Wilcoxon test. S1 mean frequency before cortex buffer
0.042 ± 0.003 Hz; after 0.044 ± 0.004 Hz; p > 0.05; n = 4; Wil-
coxon test). Surprisingly, the response of V1 and S1 differed
significantly (percentage of change V1: 43.5% ± 7.9%; S1:
7.9% ± 5.2%; p = 0.0026; n = 7; unpaired two-tailed t test). Network event area, amplitude, or duration was not affected
(Figures 1E–1G). INTRODUCTION During the period when synaptic connections are shaped by
spontaneous activity, neuromodulators play an important role
in the development of cortical circuits.12–14 One of them,
oxytocin, is particularly prominently expressed in sensory
cortices during the first 2 postnatal weeks and decreases there-
after until the end of the 3rd postnatal week, when it reaches adult
levels.15 Similarly, oxytocin receptor ligand binding, immunolab-
eling, and mRNA expression in sensory cortices peak during the
2nd postnatal week and decrease thereafter.15–17 Thus, oxytocin
is most likely required for the development of sensory circuits
during the 1st postnatal weeks in addition to its roles in social
sensory processing in adults, where oxytocin increases the
sensitivity of auditory cortex neurons to pup calls,18 modulates
odor processing in the olfactory and accessory systems,19 and
shapes social sensory perception.20,21 Oxytocin modulates syn-
aptic transmission in the developing forebrain. For example,
oxytocin is required for cross-modal, experience-driven synaptic
plasticity in the somatosensory cortex during the first 2 weeks of
life.15 Moreover, oxytocin triggers a temporary switch of In the developing brain, neuronal connections form with remark-
able precision. First, axons grow to predetermined target areas
guided by molecular cues. Subsequently, activity-dependent
processes refine synaptic connections:1–3 already before the
senses become active, spontaneous activity drives synaptic
refinement to prepare the brain for interacting with the
outside world. Finally, circuits adapt to the prevalent environ-
mental conditions through sensory-experience-driven plasticity
mechanisms. Spontaneous activity is expressed in specific patterns, and
these patterns are crucial for the appropriate wiring of neurons. For example, in the developing retina, waves of spontaneous ac-
tivity travel at specific speeds, in various directions, and with
different wave front shapes.4,5 Retinal waves drive highly struc-
tured activity patterns in the central visual system, including
the primary visual cortex.6–8 Perturbing these activity patterns
leads to miswiring of the central visual system.9–11 ll
OPEN ACCESS hippocampal GABA receptor action from excitatory to inhibi-
tory.12,22 However, it has been unclear whether spontaneous
activity patterns, which drive synaptic plasticity before experi-
ence-driven refinement occurs,23 are regulated by oxytocin as
well. Oxytocin Desynchronizes Spontaneous V1 Network
Activity To evaluate how oxytocin modulates the activity of individual
neurons in the developing cortical network, we performed
in vivo two-photon calcium imaging in V1 of lightly anesthetized
neonatal mice. Layer 2/3 cells were labeled with the calcium in-
dicator Oregon Green BAPTA-1 (OGB-1) by bolus loading.24
Oxytocin application decreased the frequency of calcium
events transiently (Figures 2A–2C) without affecting their ampli-
tude (Figure 2D), in line with our wide-field experiments. In con-
trol experiments, where we applied cortex buffer without
oxytocin, frequency and amplitude were unaffected (Figures
S1A and S1B). Figure 1. Oxytocin Affects Spontaneous Network
Events Differentially across Sensory Cortices 0
20
40
60
80
V1
S1
Amplitude (%∆F/F0) 0
20
40
60
80
V1
S1
(
)
Oxt
20
40
60
0
50 75 100
0
Time (min)
25
F
Amplitude (%∆F/F0)
Amplitude (%∆F/F0) 0
Duration (s)
2
4
1
3
5
6
V1
S1
Oxt
Duration (s)
2
4
1
3
5
0
6
50 75 100
0
Time (min)
25
G Oxt
20
40
60
0
50 75 100
0
Time (min)
25
F
Amplitude (%∆F/F0) G F Duration (s) hippocampal GABA receptor action from excitatory to inhibi-
tory.12,22 However, it has been unclear whether spontaneous
activity patterns, which drive synaptic plasticity before experi-
ence-driven refinement occurs,23 are regulated by oxytocin as
well. Here, we asked whether oxytocin signaling shapes neuronal
activity patterns in the primary visual (V1) and somatosensory
cortices (S1) during the 2nd postnatal week. We found that, while
in S1, oxytocin activates inhibitory and excitatory neurons simi-
larly and does not affect the frequency of network activity, in
V1,
oxytocin
recruits
specifically
somatostatin-expressing
(SST+) interneurons to control network activity frequency and
correlation, properties known to determine the refinement of
synaptic connections in V1 prior to eye opening. Figure 1. Oxytocin Affects Spontaneous Network
Events Differentially across Sensory Cortices A A (A) Wide-field calcium imaging of spontaneous activity in V1
and S1 before eye opening. (Left) Single-frame images
depict network events activating V1 and/or S1 during
baseline recordings before oxytocin application. (Right)
Network events after oxytocin (Oxt) application are shown. (B) Traces show fluorescent changes in V1 and S1 before
and after oxytocin application. (C) Superimposition of all network events detected during a
5-min baseline recording (left) and after oxytocin application
(right). Color code indicates the frequency of the detected
events. V1 activity is strongly reduced. C (D) Network event frequency in V1 and S1 during baseline
and after oxytocin application. Time courses represent 5-
min averages. The horizontal bars above the line plots
indicate the time points when the values for each time bin
differed significantly from baseline (dark shades; paired
two-tailed t test; p < 0.05; without multi-measurement
correction). *p = 0.016 (n = 7 animals; Wilcoxon test). hippocampal GABA receptor action from excitatory to inhibi-
V1
S1
0
20
40
60
80
Frequency (Hz)
6
2
4
8
0
*
V1
S1
Baseline
Oxt
Oxt
6
2
4
Frequency (Hz)
0
75
50
100
0
S1
V1
Time (min)
25
Oxt
20
40
60
0
50 75 100
0
Time (min)
25
0
0
0.8
0.4
2
1.2
1.6
Duration (s)
2
4
1
3
5
6
V1
S1
V1
S1
2
Area (mm )
Oxt
0.8
0.4
0
2
2
Area (mm )
1.2
1.6
50
100
0
Time (min)
25
75
Oxt
Duration (s)
2
4
1
3
5
0
6
50 75 100
0
Time (min)
25
D
E
F
G
Amplitude (%∆F/F0)
Amplitude (%∆F/F0)
-2
x10
-2
x10
but only mod V1
S1
Frequency (Hz)
6
2
4
8
0
*
Baseline
Oxt
0
0.8
0.4
2
1.2
1.6
V1
S1
2
Area (mm )
Oxt
0.8
0.4
0
2
2
Area (mm )
1.2
1.6
50
100
0
Time (min)
25
75
E
-2
x10 Oxt
6
2
4
Frequency (Hz)
0
75
50
100
0
S1
V1
Time (min)
25
D
-2
x10 D (E) Network event area. Frequency (Hz) (F) Network event amplitude. (F) Network event amplitude. (G) Network event duration. (G) Network event duration. Data are represented as mean ± SEM. See also Figure S6. Data are represented as mean ± SEM. See also Figure S6. INTRODUCTION Here, we asked whether oxytocin signaling shapes neuronal
Baseline
Oxt
0
0.03
Hz
Baseline
Oxt
V1
S1
20
280
0
180
-10
270
50 s
50% ΔF/F0
Visual cortex
Somatosensory cortex
Baseline
Oxt
V1
S1
0
20
40
60
80
Frequency (Hz)
6
2
4
8
0
*
V1
S1
Baseline
Oxt
Oxt
6
2
4
Frequency (Hz)
0
75
50
100
0
S1
V1
Time (min)
25
Oxt
20
40
60
0
50 75 100
0
Time (min)
25
0
0
0.8
0.4
2
1.2
1.6
Duration (s)
2
4
1
3
5
6
V1
S1
V1
S1
2
Area (mm )
Oxt
0.8
0.4
0
2
2
Area (mm )
1.2
1.6
50
100
0
Time (min)
25
75
Oxt
Duration (s)
2
4
1
3
5
0
6
50 75 100
0
Time (min)
25
A
B
C
D
E
F
G
Amplitude (%∆F/F0)
Amplitude (%∆F/F0)
%∆F/F0
%∆F/F0
%∆F/F0
0.5 mm
-2
x10
-2
x10
but only mod
cation of cort
quency of ca
buffer 0.042
4; Wilcoxon
0.042 ± 0.003
Article Baseline
Oxt
0
0.03
Hz
50 s
50% ΔF/F0
Visual cortex
Somatosensory cortex
Baseline
Oxt
B
C Baseline
Oxt
V1
S1
20
280
0
180
-10
270
A
%∆F/F0
%∆F/F0
%∆F/F0
0.5 mm B Figure 1. Oxytocin Affects Spontaneous Network
Events Differentially across Sensory Cortices Oxytocin Modulates Spontaneous Cortical Activity
Differentially across Sensory Areas Again, we
observed that oxytocin, but not cortex buffer application,
strongly decreased correlations across the entire population. There were essentially no neuronal pairs that showed increased
correlations (Figure S1C). We further found that oxytocin had a
subtractive effect on neuronal correlations (Figures 2G and
2H), such that more distal pairs of neurons were proportionally
decorrelated more strongly by oxytocin than nearby neuronal
pairs (Figures 2I and 2J). Finally, we investigated whether the
changes in correlations between all neurons occurred uniformly
or whether specific pairs of neurons underwent changes in their
correlations. To address this question, we first computed the
correlation matrices at different time points (Figure 2K). Interest-
ingly, we saw that, during late oxytocin, when the frequency of
calcium events had returned to baseline (mean baseline:
0.032 ± 0.004 Hz; mean 125–135 min: 0.027 ± 0.003 Hz; p =
0.14; paired two-tailed t test), the correlation matrices exhibited
sustained structural differences in the correlational structure of
subsets of cells (Figure 2K, inset). To quantify these differences,
we computed the mean squared distance (MSD) between the
baseline matrix and the matrices computed at varying time
points and found that networks treated with oxytocin exhibited
a sustained higher distance compared to baseline (p = 0.038,
repeated-measures one-way ANOVA; mean baseline: 0.1 ±
0.04; mean 60–70 min: 6.36 ± 1.56, p = 0.007; mean 90–
100 min: 4.52 ± 1.12, p = 0.008; mean 125–135 min: 2.94 ±
0.6, p = 0.009; post hoc paired two-tailed t test). Conversely,
the MSD was unchanged with cortex buffer application (p =
0.19; repeated-measures one-way ANOVA; Figure 2L). These
oxytocin-induced changes in network activity patterns may
reflect differences in functional connectivity between the imaged
neurons or their shared inputs, because response correlations
are indicative of strong synaptic connections in the adult and
probably common feedforward inputs in the developing visual
cortex.26,27 In contrast to V1, in S1, oxytocin bath application increased
sEPSC frequency in layer 2/3 pyramidal cells (Figures 4H and
4I). Again, sEPSC amplitude was unaffected (Figure 4J). The fre-
quency of sIPSCs was increased but less pronounced than in V1
(Figures 4K and 4L); amplitudes were unaffected (Figure 4M). Thus, oxytocin shifted the E/I ratio in V1 toward inhibition (Fig-
ure 4G; p < 0.001; repeated-measurement two-way ANOVA)
but did not affect E/I significantly in S1 (Figure 4N). Oxytocin Modulates Spontaneous Cortical Activity
Differentially across Sensory Areas To study the role of the neuromodulator oxytocin in developing
sensory cortices, we first asked whether oxytocin receptor acti-
vation modulates large-scale spontaneous activity patterns. We
used in utero electroporation to express the calcium sensor
GCaMP6s in layer 2/3 pyramidal cells across V1, higher visual
areas, and the barrel cortex. Then, we performed wide-field Current Biology 31, 322–333, January 25, 2021
323 A
i l Article ll
OPEN ACCESS oxytocin receptor expression on the cellular level could explain
oxytocin’s differential effect in these areas. To test this idea func-
tionally, we examined how oxytocin regulated excitatory and
inhibitory synaptic transmission in V1 and S1. Whole-cell
patch-clamp recordings of layer 2/3 pyramidal neurons in slices
from V1 showed that oxytocin affected neither the frequency nor
the amplitude of spontaneous excitatory postsynaptic currents
(sEPSCs) (Figures 4A–4C). Next, we measured spontaneous
inhibitory postsynaptic currents (sIPSCs) at the reversal potential
of glutamate-receptor-mediated currents. We found that the fre-
quency of sIPSCs, in contrast to that of sEPSCs, was strongly
increased after oxytocin bath application (Figures 4D and 4E). The amplitude of sIPSCs was unaffected (Figure 4F). To test
whether this increase in frequency was mediated by the specific
activation of the oxytocin and not the vasopressin 1A receptor,28
which can be activated by oxytocin as well,29 we blocked the
oxytocin receptor using its specific antagonist OTA.30 OTA pre-
vented the oxytocin-mediated increase in sIPSC frequency
entirely (fold-change oxytocin only, Figure 4E: 4.95 ± 1.53;
oxytocin + OTA, Figure S2: 0.98 ± 0.32; p = 0.012; unpaired
two-tailed Mann-Whitney test), demonstrating that this effect
was mediated by the oxytocin receptor. Thus, activation of the
oxytocin receptor increased the inhibitory tone in V1 dramatically
but did not affect excitatory synaptic transmission. Because the correlational structure of spontaneous network
activity determines its role in network refinement,25 we also
investigated whether oxytocin affected the pairwise correlations
between spontaneously active neurons. We observed that
oxytocin application decreased the mean Pearson correlation
coefficients across pairs of neurons (Figures 2E and 2F),
whereas cortex buffer applications did not affect such correla-
tions (Figures 2E and 2F). Next, we explored changes in correla-
tions at the level of individual neurons after oxytocin application
in more detail. We plotted pairwise correlations for all experi-
ments during baseline against the correlations after oxytocin or
cortex buffer application (Figures S1C and S1D). Oxytocin Targets SST+ Interneurons in the Developing
V1 Because we observed that oxytocin shaped spontaneous activ-
ity patterns effectively in V1, but not in S1, we focused next on
the cellular mechanism of oxytocin-mediated facilitation of inhi-
bition in V1. First, we measured miniature IPSCs (mIPSCs) before
and after oxytocin bath application and found that mIPSC fre-
quency and amplitude were unaffected by oxytocin (Figures
5A–5C). This indicated that the number of inhibitory synapses,
the density of postsynaptic receptors, or changes in the presyn-
aptic release machinery could not explain the increase in sIPSC
frequency described above. Oxytocin Modulates Spontaneous Cortical Activity
Differentially across Sensory Areas These exper-
iments suggested that differences in the magnitude of inhibitory
versus excitatory synaptic activity modulation accounted for the
differences in the effect of oxytocin on spontaneous network ac-
tivity in V1 versus S1. Oxytocin Targets SST+ Interneurons in the Developing
V1 Sensory Areas To search for alternative causes of the increased inhibitory ac-
tivity, we performed voltage-clamp recordings in inhibitory inter-
neurons. We used two mouse lines expressing TdTomato to
target inhibitory neurons in general (GAD2-Cre;Rosa26-TdTo-
mato)
or
somatostatin-expressing
interneurons
specifically
(SST-Cre;Rosa26-TdTomato). We focused on SST+ interneu-
rons for four reasons: (1) RNA sequencing (RNA-seq) data in
adulthood showed that V1 oxytocin receptors are expressed pri-
marily in SST+ interneurons (Figure S3A; Allen Brain Atlas data
portal: http://casestudies.brain-map.org/celltax).31 (2) We found To investigate whether the differential modulation of V1 and S1
by oxytocin as described above (Figure 1) can be explained by
differences in the distribution of the oxytocin receptor in these
areas, we used RNAscope to detect Oxtr, Scl17a7 (coding for
VGLUT1), and Gad1 mRNA in the cortex at P10. We found that
Oxtr was expressed in V1 as well as in S1 (Figure 3). However,
in V1, Oxtr co-localized almost exclusively with the Gad1 signal
(Figures 3B–3D), whereas in S1, the Oxtr signal co-localized
with both the VGLUT1 and Gad1 signal (Figures 3F–3H). These
observations suggested that differences between V1 and S1 in 324
Current Biology 31, 322–333, January 25, 2021 ll
OPEN ACCESS Pairwise correlation
**
0
0.2
0.4
0.6
0.8
0
0.2
0.4
0.6
0.8
Pairwise correlation
F
Baseline
Oxt
Oxt
-2
x10
A
B
20 s
10% ΔF/F0
0
5
10
15
20
25
Baseline
Oxt
Amplitude (%∆F/F0)
1'
2'
3' 40 μm
1
2
3
whole field
1
2
3
0
25 50 75 100
1
2
3
4
Frequency (Hz)
Oxt
C
0
2
4
6
-2
x10*
Frequency (Hz)
125
0
Time (min)
Time (min)
whole field
1
2
3
K
0
0
25 50 75 100
12
16
20
4
8
D
Amplitude (%∆F/F0)
0
125
300
200
100
150
50
% change in
correlation
Distance (μm)
0
200
100
Corr 0.01
I
300
200
100
150
50
% change in
correlation
Distance (μm)
0
200
100
Corr -0.32
J
Distance vs. Figure 2. Oxytocin Desynchronizes Network
Activity in V1 B A (A and B) V1 network activity before and after
oxytocin
application. (Left)
Layer
2/3
neurons
labeled with the calcium indicator Oregon Green-
BAPTA 1 are shown. Traces show fluorescent
changes of three example neurons and the average
activity across all cells. (C) Network event frequency during baseline and
after
oxytocin
application. Imaging
resumed
approximately 10 min after oxytocin application. The
frequency of network events was reduced after
oxytocin application. The horizontal bar indicates
significant deviations from baseline as in Figure 1
(dark shades; paired two-tailed t test; p < 0.05;
without multi-measurement correction). *p = 0.015
(n = 8 animals; paired two-tailed t test). (D) Network event amplitude during baseline and
after oxytocin application. Oxt
20 s
0
5
10
15
20
25
Baseline
Oxt
Amplitude (%∆F/F0)
Time (min)
0
25 50 75 100
12
16
20
4
8
D
Amplitude (%∆F/F0)
0
125 -2
x10
0
25 50 75 100
1
2
3
4
Frequency (Hz)
Oxt
C
0
2
4
6
-2
x10*
Frequency (Hz)
125
0
Time (min) D C (E) Time course of pairwise Pearson correlation co-
efficients before and after oxytocin and cortex buffer
application. Dashed vertical line indicates the time
point of oxytocin or cortex buffer application. Time
course represents averages of sliding 7-min window
(for details see STAR Methods). The horizontal bar
indicates significant deviations from baseline as in
Figure 1 (dark shades; paired two-tailed t test; p <
0.05; without multi-measurement correction). Time (min)
25 50 75 50 75 100
Time (min) 25
50
75 100 125
0
Time (min)
0
0.2
0.4
0.6
Pairwise correlation
E
Cortex buffer
Oxt Pairwise correlation
**
0
0.2
0.4
0.6
0.8
0
0.2
0.4
0.6
0.8
Pairwise correlation
F
Baseline/Cortex buffer
Baseline/Oxt E (F) Mean correlations after oxytocin or cortex buffer
control applications. **p = 0.003 (n = 7 for oxytocin;
n = 6 for cortex buffer; paired two-tailed t test). (G) Pairwise correlations plotted against interneu-
ronal distance for an example of oxytocin (left) and
cortex buffer (right) conditions. Sensory Areas correlation change
Oxt
-0.2
0
0.2
0.4
*
-0.4
0
100
200
-3
0
3
Normalized correlation
Distance (μm)
25
50
75 100 125
0
Time (min)
0
0.2
0.4
0.6
Pairwise correlation
E
300
Distance (μm)
0
200
100
1
0.5
0
-0.5
Pairwise correlation
H
25
50
75 100 125
0
Time (min)
0
-5
5
10
15
20
Normalized MSD
L
Cortex buffer
Oxt
Baseline
Oxt
Cortex buffer
0.7
Pairwise
correlation
Baseline
Early oxt (60 min)
CB
1
0.5
0
-0.5
300
Distance (μm)
0
200
100
Pairwise correlation
G
Cortex buffer
Oxt
Cortex buffer
Oxt
Late oxt (125 min)
Baseline
Oxt
Baseline
Cortex buffer
Baseline/Cortex buffer
Baseline/Oxt Baseline
A
B
1
2
3
whole field
1
2
3 Oxt
B
20 s
10% ΔF/F0
1'
2'
3' 40 μm
whole field
1
2
3 Figure 2. Oxytocin Desynchronizes Network
Activity in V1 Figure 2. Oxytocin Desynchronizes Network
Activity in V1 Left: low magnification is shown. Right: high magnification is shown; note that
the Oxtr signal co-localized with both Gad1+ and Gad1 signal (double arrowheads indicate Gad1+/Oxtr+; arrowhead indicates Gad1/Oxtr+ neuron). (H) Q
tifi
ti proportion of SST+ neurons within the entire population of V1 in-
terneurons (23%).35 here that, already at P10, oxytocin receptor mRNA is expressed
almost exclusively in SST+ interneurons in layer 2/3 of V1 (Fig-
ure 5D). (3) Decreases in network correlations similar to those
described above can be induced by SST+ interneuron-mediated
lateral inhibition.32,33 (4) We observed here that the rise rate of V1
and S1 sIPSCs increased in response to oxytocin application
(Figure S3B). Because the sIPSC rise rate is larger for synapses
that are located distally in the dendritic tree, this result indicated
that oxytocin preferentially increased the frequency of inhibitory
inputs at distal dendrites, which receive the majority of SST+
interneuron inputs.34 here that, already at P10, oxytocin receptor mRNA is expressed
almost exclusively in SST+ interneurons in layer 2/3 of V1 (Fig-
ure 5D). (3) Decreases in network correlations similar to those
described above can be induced by SST+ interneuron-mediated
lateral inhibition.32,33 (4) We observed here that the rise rate of V1
and S1 sIPSCs increased in response to oxytocin application
(Figure S3B). Because the sIPSC rise rate is larger for synapses
that are located distally in the dendritic tree, this result indicated
that oxytocin preferentially increased the frequency of inhibitory
inputs at distal dendrites, which receive the majority of SST+
interneuron inputs.34 Together, these results indicated that oxytocin mediated the
increase in inhibitory synaptic activity in V1 through activation
of SST+ interneurons. To test this idea directly, we asked
whether specifically downregulating SST+ interneurons might
prevent the oxytocin-induced increase in overall inhibition (Fig-
ure 5H). We performed voltage-clamp recordings of layer 2/3
neurons in acute slices from V1 of transgenic neonatal mice
where SST+ interneurons expressed inhibitory designer recep-
tors activated by designer drugs (iDREADDs) (SSTCre;Gi-
Dreadd). Bath application of CNO, the activator of iDREADDs,
did not affect the baseline frequency of sIPSCs (Figures 5I and
5J), suggesting that SST+ interneurons were only sparsely active
in our slice preparation. Figure 2. Oxytocin Desynchronizes Network
Activity in V1 0
100
200
-3
0
3
Normalized correlation
Distance (μm)
H
Cortex buffer
Oxt
Baseline 300
Distance (μm)
0
200
100
1
0.5
0
-0.5
Pairwise correlation
Baseline
Cortex buffer Time (min)
1
0.5
0
-0.5
300
Distance (μm)
0
200
100
Pairwise correlation
G
Baseline
Oxt Time (min)
300
Distance (μm)
0
200
100
1
0.5
0
-0.5
Pairwise correlation
1
0.5
0
-0.5
300
Distance (μm)
0
200
100
Pairwise correlation
G
Baseline
Oxt
Baseline
Cortex buffer G H (H) Mean pairwise correlations in oxytocin and cor-
tex buffer condition. Note that baseline condition
and cortex buffer display the same profile. (I) Change in pairwise correlations plotted against
interneuronal distance for an example of oxytocin
(left) and cortex buffer (right) conditions. Dashed
lines indicate zero change in correlations. Colored
lines indicate linear fits (left, p < 1010; right, p = 0.47;
paired two-tailed t test). (J) Pearson correlation coefficients between pair-
wise distances and percentages of change in cor-
relations for all animals in oxytocin and cortex buffer
condition. Arrowheads indicate the examples shown
in (I). *p = 0.037 (n = 7 for oxytocin; n = 6 for cortex
buffer; unpaired two-tailed t test). J
Distance vs. correlation change
Oxt
-0.2
0
0.2
0.4
*
-0.4
CB 300
200
100
150
50
% change in
correlation
Distance (μm)
0
200
100
Corr 0.01
I
300
200
100
150
50
% change in
correlation
Distance (μm)
0
200
100
Corr -0.32
Oxt
Cortex buffer J
Distance vs. I J (K) Correlation matrices computed baseline, early
oxytocin (60 min), and late oxytocin (125 min). Red
dotted square indicates an example of a subgroup of
neurons that undergo structural changes. 25
50
75 100 125
0
Time (min)
0
-5
5
10
15
20
Normalized MSD
L
Cortex buffer
Oxt (L) Normalized mean squared distances (MSDs)
between the baseline matrix and the correlation
matrices computed from a sliding 7-min window (see
STAR Methods for details) as function of time for
oxytocin and cortex buffer conditions. K
0
0.7
Pairwise
correlation
Baseline
Early oxt (60 min) Late oxt (125 min) L K 1
2
Normalized MSD
L Pairwise
l ti Data are represented as mean ± SEM. See also
Figure S1. Current Biology 31, 322–333, January 25, 2021
325 A
B
C
D
E
F
G
H
gure 3. Figure 2. Oxytocin Desynchronizes Network
Activity in V1 Oxytocin Receptor mRNA Is Differentially Expressed across Sensory Cortices
A) Cresyl violet Nissl staining of a sagittal section from V1 at low magnification. Numbers indicate cortical layers. B) Dual-color RNAscope staining of VGLUT1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown. Note
at the Oxtr signal was largely non-overlapping with the VGLUT1 signal (arrowheads indicate VGLUT1/Oxtr+ neurons). C) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note that
e Oxtr signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. D) Quantification
ll
OPEN ACCESS
Article Article ll
OPEN ACCESS C B D A C D A B E F G E F H H G Figure 3. Oxytocin Receptor mRNA Is Differentially Expressed across Sensory Cortices Figure 3. Oxytocin Receptor mRNA Is Differentially Expressed across Sensory Cortices g
y
p
y
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(A) Cresyl violet Nissl staining of a sagittal section from V1 at low magnification. Numbers indicate cortical layers. (A) Cresyl violet Nissl staining of a sagittal section from V1 at low magnification. Numbers indicate cortical layers. (B) Dual-color RNAscope staining of VGLUT1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown. Note
that the Oxtr signal was largely non-overlapping with the VGLUT1 signal (arrowheads indicate VGLUT1/Oxtr+ neurons). (C) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note that
the Oxtr signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. (D) Quantification. (A) Cresyl violet Nissl staining of a sagittal section from V1 at low magnification. Numbers indicate cortical layers. (B) Dual-color RNAscope staining of VGLUT1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown. Note
that the Oxtr signal was largely non-overlapping with the VGLUT1 signal (arrowheads indicate VGLUT1/Oxtr+ neurons). (C) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Figure 2. Oxytocin Desynchronizes Network
Activity in V1 Right: high magnification is shown; note that
the Oxtr signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons ( )
y
g
g
g
y
(B) Dual-color RNAscope staining of VGLUT1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Righ
that the Oxtr signal was largely non-overlapping with the VGLUT1 signal (arrowheads indicate VGLUT1/Oxtr+ neurons). (C) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: hi
the Oxtr signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. (D) Quantification. that the Oxtr signal was largely non-overlapping with the VGLUT1 signal (arrowheads indicate VGLUT1 /Oxtr neurons). (C) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high m
the Oxtr signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. (D) Quantification. color RNAscope staining of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnifica
signal co-localized with the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. tification ning of Gad1 and Oxtr mRNA in a V1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note th
ith the Gad1 signal (double arrowhead Gad1+/Oxtr+) and not with Gad1 neurons. (E) Cresyl violet Nissl staining of a sagittal section from S1 (same section as in A) at low magnification. Numbers indicate cortical layers. (F) Dual-color RNAscope staining of VGLUT1 and Oxtr mRNA in an S1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note
the superposition of the two signals (double arrowheads, VGLUT1+/Oxtr+). (G) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in an S1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note that
the Oxtr signal co-localized with both Gad1+ and Gad1 signal (double arrowheads indicate Gad1+/Oxtr+; arrowhead indicates Gad1/Oxtr+ neuron). (H) Q
tifi
ti (G) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in an S1 sagittal section. Left: low magnification is shown. Right: high magnification is shown; note that
the Oxtr signal co-localized with both Gad1+ and Gad1 signal (double arrowheads indicate Gad1+/Oxtr+; arrowhead indicates Gad1/Oxtr+ neuron). (H) Quantification. (G) Dual-color RNAscope staining of Gad1 and Oxtr mRNA in an S1 sagittal section. Figure 2. Oxytocin Desynchronizes Network
Activity in V1 Then, we applied oxytocin and found
that it did not increase sIPSC frequency in the presence of
CNO (Figures 5I and 5J), in contrast to our previous results in sli-
ces from wild-type (WT) mice (Figure 4E; fold-change WT: 4.95 ±
1.53; iDREADD: 0.95 ± 0.07; p < 0.0001; Mann-Whitney test). Additional control experiments showed that oxytocin did in-
crease the frequency of sIPSCs in neurons from iDREADD-ex-
pressing animals in the absence of CNO, but not their amplitude
(Figures 5J, inset; S4A; and S4B), and that CNO by itself did not
change the sIPSC frequency (Figures S4C and S4D). These Therefore, we investigated the effect of oxytocin on SST+ in-
terneurons. We recorded from SST+ neurons in voltage-clamp
mode at 60 mV and blocked NMDA, AMPA, and GABAA recep-
tor-mediated currents using D-AP5, NBQX, and SR95531,
respectively, to prevent oxytocin-mediated network effects. In
this configuration, we recorded oxytocin-mediated inward cur-
rents in almost all SST+ neurons (83%; amplitude: 27 ±
16 pA; Figures 5E–5G). Oxytocin did not trigger inward currents
in any of the SST neurons in slices from the same SST-Cre;R-
osa26-TdTomato mice. We concluded that oxytocin triggered
depolarizing inward currents specifically in SST+ interneurons. Accordingly, we observed oxytocin induced inward currents in
29% of GAD2+ interneurons (Figure 5G), which is similar to the 326
Current Biology 31, 322–333, January 25, 2021 ll
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for the oxytocin-induced increase in inhibition. Figure 4. Oxytocin Affects Synaptic Activity Differentially
across Sensory Cortices C Figure 4. Oxytocin Affects Synaptic Activity Differentially
across Sensory Cortices B (A) Voltage-clamp recordings of spontaneous excitatory post-
synaptic currents (sEPSCs) during baseline (Bl) and after oxytocin
bath application in acute visual cortex slices. (B) Frequency of sEPSCs before, during, and after oxytocin
application. In the visual cortex, oxytocin did not affect EPSC
frequency. p > 0.05 (n = 7 cells; paired two-tailed t test). (C) Oxytocin did not affect sEPSC amplitude. p > 0.05 (n = 7 cells;
paired two-tailed t test). ****
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and after oxytocin application. (E) Oxytocin led to a strong increase in sIPSCs. ****p = 8.2 3 105
(n = 8 cells; paired two-tailed t test). (F) Oxytocin did not affect the amplitude of sIPSCs. p > 0.05 (n = 8
cells; paired two-tailed t test). (G) In the visual cortex, oxytocin led to a 5 times increase of
sIPSCs, but sEPSCs were unaffected. ***p = 0.0003 (n = 7 and n =
8 cells for V1 sEPSCs and sIPSCs, respectively; Mann-Whitney
test). EPSC
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oxytocin bath application in somatosensory cortex slices. (I) Application of oxytocin increased the frequency of sEPSCs in
the somatosensory cortex slightly. **p = 0.0014 (n = 7; paired two-
tailed t test). (J) Oxytocin did not affect the amplitude of sEPSCs. p > 0.05 (n = 7
cells; paired two-tailed t test). (J) Oxytocin did not affect the amplitude of sEPSCs. p > 0.05 (n = 7
cells; paired two-tailed t test). Figure 4. Oxytocin Affects Synaptic Activity Differentially
across Sensory Cortices 20
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0 L M N (K) sIPSCs before and after oxytocin application. (L) Oxytocin led to a transient increase in sIPSCs. **p = 0.002 (n = 8
cells; paired two-tailed t test). (L) Oxytocin led to a transient increase in sIPSCs. **p = 0.002 (n = 8
cells; paired two-tailed t test). (M) Oxytocin did not affect the amplitude of sIPSCs. p > 0.05 (n = 8
cells; paired two-tailed t test). (M) Oxytocin did not affect the amplitude of sIPSCs. p > 0.05 (n = 8
cells; paired two-tailed t test). (N) In the somatosensory cortex, oxytocin led to similar increases
in sIPSC and sEPSC frequency. p = 0.11 (n = 7 and n = 8 cells for
S1 sEPSCs and sIPSCs, respectively; unpaired two-tailed t test). Data are represented as mean ± SEM. See also Figure S2. results showed that activation of SST+ interneurons is required
for the oxytocin-induced increase in inhibition. an AP from the onset of current injection (1.97 ± 0.32 ms; Fig-
ure 6F). In addition, oxytocin modulated AP kinetics as it
decreased the maximal speed of voltage change (dV/dt; Figures
S5B and S5C). Thus, oxytocin increased the firing capacity and
AP properties of V1 layer 2/3 SST+ neurons, most likely by depo-
larizing their resting membrane potential, as described for PV+ in-
terneurons in the hippocampus.36 Knowing how oxytocin affects
SST+ interneuron activity, we used this information to better un-
derstand how oxytocin generated the observed distance-depen-
dent change in correlations. We implemented a recurrent spiking
neural network based on a multi-layer model of the thalamocort-
ical system (Figure 6G).37 To mimic the effect of oxytocin, we
increased the resting membrane potential of 25% of the inhibi-
tory neurons, corresponding to the population of SST+ interneu-
rons (Figure 6H). This elevation in membrane potential increased
the firing rate of SST+ interneurons for identical current injections
(Figure 6I) similarly as observed in our data (Figure 6C). Conse-
quently, in the simulated network, firing of excitatory neurons
was strongly suppressed. Inhibitory neurons fired slightly less
as well, because their excitatory inputs were largely diminished
(Figure 6J). Figure 4. Oxytocin Affects Synaptic Activity Differentially
across Sensory Cortices In addition, oxytocin strongly decreased the temporal
synchronization of excitatory neurons (Figures 6K and 6L),
generating a comparable decrease of correlations over distance
as in our experimental data (Figures 2G–2J). This result sup-
ported the idea that the increased inhibitory drive produced by an AP from the onset of current injection (1.97 ± 0.32 ms; Fig-
ure 6F). In addition, oxytocin modulated AP kinetics as it
decreased the maximal speed of voltage change (dV/dt; Figures
S5B and S5C). Thus, oxytocin increased the firing capacity and
AP properties of V1 layer 2/3 SST+ neurons, most likely by depo-
larizing their resting membrane potential, as described for PV+ in-
terneurons in the hippocampus.36 Knowing how oxytocin affects
SST+ interneuron activity, we used this information to better un-
derstand how oxytocin generated the observed distance-depen-
dent change in correlations. We implemented a recurrent spiking
neural network based on a multi-layer model of the thalamocort-
ical system (Figure 6G).37 To mimic the effect of oxytocin, we
increased the resting membrane potential of 25% of the inhibi-
tory neurons, corresponding to the population of SST+ interneu-
rons (Figure 6H). This elevation in membrane potential increased
the firing rate of SST+ interneurons for identical current injections
(Figure 6I) similarly as observed in our data (Figure 6C). Conse-
quently, in the simulated network, firing of excitatory neurons
was strongly suppressed. Inhibitory neurons fired slightly less
as well, because their excitatory inputs were largely diminished
(Figure 6J). In addition, oxytocin strongly decreased the temporal
synchronization of excitatory neurons (Figures 6K and 6L),
generating a comparable decrease of correlations over distance
as in our experimental data (Figures 2G–2J). This result sup-
ported the idea that the increased inhibitory drive produced by Figure 2. Oxytocin Desynchronizes Network
Activity in V1 an AP f
ure 6F)
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C Figure 4. Oxytocin Affects Synaptic Activity Differentially
across Sensory Cortices Activation of SST+ Interneurons Is Required for
Oxytocin-Mediated Modulation of Spontaneous Activity
Patterns B A A Finally, we asked whether the oxytocin-mediated decrease in
the frequency of spontaneous network activity was the result
of the activation of oxytocin receptors expressed in SST+ inter-
neurons in vivo. We specifically inactivated SST+ interneurons
by using a Cre-dependent inhibitory DREADD delivered by virus
injection, which results in 80% of the SST+ interneurons express-
ing the hM4Di-DREADD construct.33 We showed previously that
bath application of clozapine in vitro reduced the excitability of
SST+ interneurons,33 replicating previous findings that hM4Di-
DREADD activation reduces the excitability of developing layer
2/3 neurons.38 We performed in vivo wide-field calcium imaging
to monitor spontaneous network activity in V1 and then activated
the iDREADD receptor by injecting clozapine subcutaneously
(Figure 7A). 5 min after clozapine injection, oxytocin was applied
topically (Figures 7A and 7B). In this condition, oxytocin failed to
decrease
the
frequency
of
spontaneous
network
events
compared with oxytocin application alone (Figure 7C, % of
change clozapine + oxytocin: 18.1% ± 10.5%; Figure 1D, %
of change oxytocin: 49.2% ± 6.2%; p = 0.023; unpaired two-
tailed t test). Area, amplitude, and duration were not affected
either (Figures 7D–7F). Therefore, SST+ neurons are required
for the inhibitory effect of exogenous oxytocin on the frequency
of spontaneous activity in the developing visual cortex. E
F
G F
G E F E G E J I I
J H J H H Figure 5. SST+ Interneurons Mediate the Oxytocin-Induced Increase
in Inhibitory Synaptic Activity in V1 (A) Voltage-clamp recordings of spontaneous miniature synaptic excitatory
postsynaptic currents (mIPSCs) in the presence of tetrodotoxin (TTX) (0.5 mM)
before and after oxytocin bath application in V1 slices. We demonstrated here that oxytocin receptor activation can
modulate spontaneous activity patterns by specifically acti-
vating SST+ interneurons; however, the source of oxytocin was
exogenous. To evaluate whether endogenous oxytocin indeed
modulates spontaneous activity patterns under physiological
conditions, we performed wide-field in vivo calcium imaging re-
cordings in awake animals, when SST+ interneurons are intrinsi-
cally active (SST+ interneurons are largely silent under anes-
thesia).32 When we blocked oxytocin receptors, we observed a
small but significant increase in the frequency of calcium events
(Figure 7G), whereas the amplitude remained unchanged (Fig-
ure 7H), as predicted based on our results after topical applica-
tion of exogenous oxytocin. This result suggested that the
oxytocin receptor is activated by its endogenous ligand and
modulates spontaneous activity patterns. Activation of SST+ Interneurons Is Required for
Oxytocin-Mediated Modulation of Spontaneous Activity
Patterns Finally, we verified
that focal oxytocin application modulates spontaneous activity
in the awake condition as well. As in anesthetized animals, we
found that the frequency of network events was decreased
although their amplitude remained unaffected (mean baseline
frequency: 0.047 ± 0.007; mean oxytocin frequency: 0.036 ±
0.005; p = 0.043; paired two-tailed t test; n = 6 animals). (B) The frequency of mIPSCs was not affected by oxytocin. p > 0.05 (n = 7 cells;
paired two-tailed t test). (C) The amplitude of mIPSCs was not affected by oxytocin. p > 0.05 (n = 7 cells;
paired two-tailed t test). (D) V1 Oxtr and Sst mRNA transcripts. Note the superposition of the two sig-
nals (arrowhead: Sst+/Oxtr+ neurons: 93%; Sst/Oxtr+ neurons: 2%). (E) Examples of voltage-clamp recordings at holding potential of 60 mV from
a somatostatin-expressing neuron (SST+) (SST-Cre;Rosa26-TdTomato), an
unlabeled neuron (SST), and a GAD2+ neuron (GAD2+) (GAD2-Cre;Rosa26-
TdTomato) before and after oxytocin application. Oxytocin induced an inward
current in the SST+ neuron, but not in the unlabeled (most likely excitatory)
neuron or in the GAD2+ neuron. (F) Group data of oxytocin-induced inward currents: SST+ n = 17 cells; SST
n = 7 cells; and GAD2+ n = 7 cells. *p = 0.021; **p = 0.0044. Kruskal-Wallis test,
followed by a Dunn test. (F) Group data of oxytocin-induced inward currents: SST+ n = 17 cells; SST
n = 7 cells; and GAD2+ n = 7 cells. *p = 0.021; **p = 0.0044. Kruskal-Wallis test,
followed by a Dunn test. (G) Percentage of cells with oxytocin-induced inward currents. Almost all SST+
neurons show oxytocin-mediated currents (14/17 cells) but none of the SST
neurons (0/7 cells) and a fraction of GAD2+ cells (2/7 cells). (G) Percentage of cells with oxytocin-induced inward currents. Almost all SST+
neurons show oxytocin-mediated currents (14/17 cells) but none of the SST
neurons (0/7 cells) and a fraction of GAD2+ cells (2/7 cells). (H) Schematic representation of the experimental paradigm: pyramidal neu-
rons in slices from a transgenic mouse expressing inhibitory DREADDs spe-
cifically in SST+ interneurons (SST-Cre;Rosa26-Gi-hMD4i) were recorded in
voltage-clamp mode. Oxytocin was applied while SST+ neuron activity was
suppressed by CNO to test whether SST+ activation is required for the
oxytocin-induced increase in inhibitory synaptic activity. Oxytocin Enhances SST+ Neuron Excitability Our results suggested that oxytocin triggered inward currents in
SST+ interneurons (Figures 5E–5G) and that oxytocin-dependent
enhancement of SST+ interneuron firing mediated its effect on
network activity (Figures 5H–5J). Therefore, we investigated
next whether and how oxytocin-induced inward currents
enhanced SST+ neuron firing. In current-clamp mode, we in-
jected a constant current to set the membrane potential of V1
layer 2/3 SST+ interneurons to 60 mV in the presence of the
transmitter receptor blockers D-AP5, NBQX, and SR95531. Then, we applied oxytocin while keeping the holding current con-
stant. We observed that oxytocin induced a depolarization of
4.5 ± 0.4 mV (Figure 6A), which exhibited the same transient tem-
poral profile as the sIPSC frequency increase shown in Figure 4E. Current-clamp recordings (Figure 6B) revealed an increase in the
firing rate of SST+ interneurons after oxytocin application (Fig-
ure 6C). We further studied how oxytocin affected the action po-
tential (AP) properties of SST+ interneurons. Oxytocin (1)
increased the AP amplitude and overshoot (Figures 6D and
S5A; +2.63 ± 0.78 mV and +2.01 ± 0.93 mV, respectively), (2)
broadened the AP width (+0.18 ± 0.03 ms at half-maximum; Fig-
ures 6D and 6E), and (3) decreased the time required to generate Current Biology 31, 322–333, January 25, 2021
327 Article E
F
G
H
C
B
A
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Figure 5. SST+ Interneurons Mediate the Oxytocin-Induced Increase
in Inhibitory Synaptic Activity in V1 C
B
A
D Activation of SST+ Interneurons Is Required for
Oxytocin-Mediated Modulation of Spontaneous Activity
Patterns DISCUSSION Right: group data of SST+ interneuron membrane
potential in baseline and oxytocin conditions are
shown. ****p = 4.7 3 1010 (n = 34 cells; paired two-
tailed t test). D E F E F D (B) Train of APs generated with a ramp protocol in
current-clamp mode in baseline and oxytocin condi-
tions. (C) Instantaneous frequency versus current plot. ***p <
0.0001 (n = 34 cells; repeated-measurements two-
way ANOVA). (D) Left: single APs aligned to the peak in baseline
and oxytocin conditions. Right: group data of AP
amplitude in baseline and oxytocin conditions are
shown. *p = 0.038 (n = 34 cells; paired two-tailed t
test). I H G
H
I H G (E) AP width. ****p = 1.8 3 106 (paired two-tailed t
test). (F) AP. Left: single APs in response to a square current
step in baseline and oxytocin conditions. The time
required to elicit an action potential was strongly
reduced in the presence of oxytocin. ****p = 8.9 3
107 (paired two-tailed t test). Data are represented as
mean ± SEM. K L L J K
J J K (G) Left: schematic of the model with excitatory
background input and recurrently connected excit-
atory (red) and inhibitory populations (blue). We,
excitatory
weight;
Wi,
inhibitory
weight. Right:
connection probability as a function of distance be-
tween cells is shown. (H) Resting membrane potential of SST+ interneurons
during baseline and oxytocin. (I) Firing rate of inhibitory cells as a function of the input current in baseline and oxytocin. (I) Firing rate of inhibitory cells as a function of the input current in baseline and oxytocin. (J) Spike raster plot of excitatory (red) and SST+ interneurons (blue) neuron populations before and after application of oxytocin (see STAR Methods). (K) Correlation as a function of distance for baseline and oxytocin conditions. See STAR Methods for calculation details. (L) Change in correlation as a function of distance. See also Figure S5 and Table S1. (I) Firing rate of inhibitory cells as a function of the input current in baseline and oxytocin. (J) Spike raster plot of excitatory (red) and SST+ interneurons (blue) neuron populations before and after application of oxytocin (see STAR Methods)
(K) Correlation as a function of distance for baseline and oxytocin conditions. See STAR Methods for calculation details. (L) Change in correlation as a function of distance. See also Figure S5 and Table S1. The Effect of Oxytocin Receptor Activation Differs
between V1 and S1 endogenous ligand and modulates spontaneous activity pat-
terns during development. DISCUSSION (I) Example recordings of sIPSCs in baseline condition, in the presence of CNO
alone, and after bath application of oxytocin in the presence of CNO. (I) Example recordings of sIPSCs in baseline condition, in the presence of CNO
alone, and after bath application of oxytocin in the presence of CNO. (J) Oxytocin did not increase sIPSC frequency in the presence of CNO. p > 0.05
(n = 12 cells; repeated-measurements one-way ANOVA). Inset: sIPSC fre-
quency is shown. Oxytocin led to an increase in the frequency in the absence
of CNO. *p = 0.032 (n = 3 cells; paired two-tailed t test). In adults, oxytocin is a potent modulator of brain activity and
behavior, and it is important for brain development. Here, we
demonstrate that, before eye opening, during the 2nd postnatal
week, oxytocin modulates specific characteristics of sponta-
neous activity patterns in the visual cortex: it selectively in-
creases SST+ interneuron excitability through oxytocin receptor
activation and sparsifies and decorrelates neuronal activity in
layer 2/3 of V1 without affecting event area, amplitude, or
duration. In adults, oxytocin is a potent modulator of brain activity and
behavior, and it is important for brain development. Here, we
demonstrate that, before eye opening, during the 2nd postnatal
week, oxytocin modulates specific characteristics of sponta-
neous activity patterns in the visual cortex: it selectively in-
creases SST+ interneuron excitability through oxytocin receptor
activation and sparsifies and decorrelates neuronal activity in
layer 2/3 of V1 without affecting event area, amplitude, or
duration. ta are represented as mean ± SEM. See also Figures S3 and S4 Data are represented as mean ± SEM. See also Figures S3 and S4. oxytocin is sufficient to generate the here-observed effects of
oxytocin
applications
on
spontaneous
activity
patterns,
including the distance-dependent changes in interneuronal
correlations. 328
Current Biology 31, 322–333, January 25, 2021 Article ll
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B
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Figure 6. Oxytocin-Induced Increase o
Excitability of SST+ Interneurons Is Suffi
to Explain Distance-Dependent Chang
Correlation
(A) Average of current-clamp recordings of
neurons before and after oxytocin bath appli
Right: group data of SST+ interneuron mem
potential in baseline and oxytocin conditio
shown. ****p = 4.7 3 1010 (n = 34 cells; paire
tailed t test). (B) Train of APs generated with a ramp prot
current-clamp mode in baseline and oxytocin
tions. between V1 and S1 Independently of the source of oxytocin, we find here that this
neuropeptide strongly decreases spontaneous network activity
in V1, although its effect on spontaneous network activity in S1
is comparably mild. The differences between oxytocin’s effect
on V1 and S1 network activity are consistent with differences
in the expression of its receptor across cell types and their spe-
cific responses to oxytocin. Oxytocin receptor mRNA expression
co-localizes with the interneuron marker GAD1 in both V1 and
S1; however, its expression in excitatory neurons is higher in
S1 than V1. Furthermore, oxytocin increases specifically inhibi-
tory synaptic transmission in V1, but in S1, it results in a smaller
and more-balanced activation of both spontaneous inhibitory
and excitatory currents. Thus, the specific effect of oxytocin on
inhibitory signaling is most likely responsible for its effect on
network activity patterns in V1. In the adult, various brain regions
differ in their responses to oxytocin due to differences in the dis-
tribution of the oxytocin receptor in inhibitory neurons as
well;17,18,36,44–47 however, whether oxytocin signaling differs be-
tween V1 and S1 in adulthood too is currently unknown. A large body of evidence suggests that maternal care behaviors
induce activation of hypothalamic neurons and release of
oxytocin in the pup’s brain (e.g., during mother-pup skin-to-
skin contact,39 anogenital stimulation,40 or stroking stimuli,41
and most likely after milk suckling activity42). Accordingly, so-
matosensory stimuli specifically activate parvocellular oxytocin
neurons in the paraventricular nucleus (PVN).43 How oxytocin
reaches the developing cortex is not entirely clear. It might be
released within V1, because hypothalamic oxytocin neurons
project to the cortex, including V1, at least in adult mice.17,44
Alternatively, oxytocin may diffuse into the developing cortex af-
ter somatodendritic release from the hypothalamus into the third
ventricle.15,28,42 To fully disentangle how oxytocin reaches the
developing cortex and to induce endogenous release, it will be
required to adapt technical approaches currently available in
adults18,36,44 to neonatal animals. Nevertheless, our observation
that blocking cortical oxytocin receptors increases the fre-
quency of spontaneous network activity in V1 of awake animals
indicates
that
the
oxytocin
receptor
is
activated
by
its A large body of evidence suggests that maternal care behaviors
induce activation of hypothalamic neurons and release of
oxytocin in the pup’s brain (e.g., during mother-pup skin-to-
skin contact,39 anogenital stimulation,40 or stroking stimuli,41
and most likely after milk suckling activity42). DISCUSSION (C) Instantaneous frequency versus current plot
0.0001 (n = 34 cells; repeated-measurement
way ANOVA). (D) Left: single APs aligned to the peak in ba
and oxytocin conditions. Right: group data
amplitude in baseline and oxytocin conditio
shown. *p = 0.038 (n = 34 cells; paired two-t
test). (E) AP width. ****p = 1.8 3 106 (paired two-
test). (F) AP. Left: single APs in response to a square
step in baseline and oxytocin conditions. Th
required to elicit an action potential was s
reduced in the presence of oxytocin. ****p =
107 (paired two-tailed t test). Data are represen
mean ± SEM. (G) Left: schematic of the model with exc
background input and recurrently connected
atory (red) and inhibitory populations (blue
excitatory
weight;
Wi,
inhibitory
weight. connection probability as a function of distan
tween cells is shown. (H) Resting membrane potential of SST+ intern
during baseline and oxytocin. (I) Firing rate of inhibitory cells as a function of the input current in baseline and oxytocin. (J) Spike raster plot of excitatory (red) and SST+ interneurons (blue) neuron populations before and after application of oxytocin (see STAR Methods). (K) Correlation as a function of distance for baseline and oxytocin conditions. See STAR Methods for calculation details. (L) Change in correlation as a function of distance. See also Figure S5 and Table S1. A
B
C
D
E
F
G
H
I
L
K
J
(I) Firing rate of inhibitory cells as a function of the input current in baseline and oxytocin. (J) Spike raster plot of excitatory (red) and SST+ interneurons (blue) neuron populations before and after ap
(K) Correlation as a function of distance for baseline and oxytocin conditions. See STAR Methods for calcu
(L) Change in correlation as a function of distance. See also Figure S5 and Table S1. B A C Figure 6. Oxytocin-Induced Increase of the
Excitability of SST+ Interneurons Is Sufficient
to Explain Distance-Dependent Changes in
Correlation Figure 6. Oxytocin-Induced Increase of the
Excitability of SST+ Interneurons Is Sufficient
to Explain Distance-Dependent Changes in
Correlation C B A (A) Average of current-clamp recordings of SST+
neurons before and after oxytocin bath application. (A) Average of current-clamp recordings of SST+
neurons before and after oxytocin bath application. Right: group data of SST+ interneuron membrane
potential in baseline and oxytocin conditions are
shown. ****p = 4.7 3 1010 (n = 34 cells; paired two-
tailed t test). Oxytocin Desynchronizes the Network in a
Structured Manner 0
We observed that oxytocin decreases pairwise cor-
relations between neurons. This decorrelation is
mediated most likely by oxytocin-induced activation
of SST+ interneurons, in agreement with previously published
findings: activation of interneurons decreases neuronal corre-
lations in general.53,54 More specifically, lateral inhibition, a
role attributed to SST+ interneurons, decorrelates spike
trains55 or stimulus-evoked patterns,56 and pharmacogenetic
inactivation of SST+ interneurons increases pairwise correla-
tions during spontaneous network activity in the developing vi-
sual cortex.33 Our analyses and simulations suggest that cor-
relations are downregulated in a spatially specific manner:
correlation decreases are more pronounced between pairs
of neurons that are farther apart. Neuronal correlations and
the spatial extent of spontaneous network activity patterns
determine their effectiveness in refining synaptic connections
in the visual system.11,25,57,58 Therefore, the regulation of
spatial correlations through oxytocin may be necessary to
shape spontaneous activity patterns to drive the refinement
of synaptic connections and to prepare the emerging network
optimally for computing visual inputs after eye opening. It
might be tempting to speculate that oxytocin contributes to
improved
visual
acuity
after
tactile
stimulation
during
development.59 SST+ Interneuron Activation Accounts for the Oxytocin-
Mediated Increase in V1 Inhibitory Transmission We propose here that the specific activation of SST+ interneu-
rons through oxytocin modulates spontaneous activity patterns
in the developing V1 based on five observations: (1) the oxytocin
receptor is transcribed in V1 SST+ interneurons but barely de-
tected in other interneuron types, excitatory neurons, or glia
cells.31 (2) Pharmacogenetic suppression of SST+ neurons pre-
vents the oxytocin-mediated decrease in network event fre-
quency in vivo. (3) Oxytocin induces an inward current in almost
all SST+ interneurons and in a fraction of GAD2+ interneurons. (4)
Oxytocin-mediated depolarization of SST+ interneurons in-
creases the frequency of inhibitory synaptic inputs in pyramidal
cells 5-fold, and (5) this increase is abolished entirely by SST+
interneuron inactivation. Our finding that oxytocin increases inhibitory function through
SST+ interneuron activation and decreases spontaneous activity
during an important step in visual cortex development supports
the idea that oxytocin modulation of inhibition facilitates the
developmental progression across critical periods.19,48 During
development, changes in the E/I balance are important, because
they determine the opening or closure of critical periods, during
which sensory pathways become sensitive to experience.49
Furthermore, the maturation of inhibition may be required for
decreasing spontaneous activity,50 thereby increasing the rela-
tive importance of visually evoked activity. Figure 7. Role for SST+ Interneurons and Endogenous
Oxytocin Receptor Activation in Modulating Network Ac-
tivity In Vivo B A (A) Schematic representation of the experimental design: wide-
field calcium imaging of spontaneous network activity in SST-Cre
mice where V1 neurons express GCaMP6s and GiDreadd after
viral transduction. Baseline
Cloz + Oxt
0
1
2
3
Time (min)
20
40
60
80
ClozapineOxt
2
Area (mm )
D
0
1
2
3
2
Area (mm )
50 s
0 2
0
2
6
4
8
Frequency (Hz)
Frequency (Hz)
ClozapineOxt
-2
x10
-2
x10
C
Time (min)
6
0
20
40
60
80
4
0 D C (B) Fluorescent changes before and after clozapine + oxytocin
application. (C) Network event frequency during baseline and after oxytocin
application. Time courses represent 5-min averages. Dashed
light blue curve represents data shown in Figure 1D, V1, for
comparison. (D) Network event area. (D) Network event area. (E) Network event amplitude. (F) Network event duration. Data are represented as mean ± SEM. (G) Network event frequency during baseline and after oxytocin
receptor antagonist application, in awake animals. *p = 0.037 (n =
7 animals; paired two-tailed t test). Data are represented as
mean ± SEM. (
)
ClozapineOxt
Time (min)
20
40
60
80
0
1
2
3
4
5
Duration (s)
0
1
2
3
4
Duration (s)
F
0 0
40
80
120
Amplitude (ΔF/F )
0
ClozapineOxt
Time (min)
20
40
60
80
0
40
80
120
Amplitude (ΔF/F )
0
E
(
)
0 F 5
F E (H) Network event amplitude during baseline and after oxytocin
receptor antagonist application, in awake animals. 2
0
4
6
8
Frequency (Hz)
*
OxtR ant
Normalized
frequency
0
1
1.1
1.2
0
20 40 60 80
Time (min)
0.9
G
x10-2 Baseline
OxtR antagonist
0
50
100
Amplitude (%ΔF/F )
0
75
25
OxtR ant
0
20 40 60 80
Time (min)
Normalized
amplitude
0
1
1.2
0.8
H G H Baseline
OxtR antagonist 2 weeks after eye opening.51 Thus, oxytocin may be
an important regulator of ‘‘phenotypic checkpoints’’
important for sensitive periods during postnatal
development.52 between V1 and S1 Our finding that oxytocin increases inhibitory function through
SST+ interneuron activation and decreases spontaneous activity
during an important step in visual cortex development supports
the idea that oxytocin modulation of inhibition facilitates the
developmental progression across critical periods.19,48 During
development, changes in the E/I balance are important, because
they determine the opening or closure of critical periods, during
which sensory pathways become sensitive to experience.49
Furthermore, the maturation of inhibition may be required for
decreasing spontaneous activity,50 thereby increasing the rela-
tive importance of visually evoked activity. This relative increase
in experience-driven activity could initiate the critical period
2
0
2
6
4
8
Frequency (Hz)
Frequency (Hz)
ClozapineOxt
-2
x10
-2
x10
0
40
80
120
Amplitude (ΔF/F )
0
ClozapineOxt
Time (min)
20
40
60
80
0
40
80
120
Amplitude (ΔF/F )
0
C
E
Time (min)
6
0
20
40
60
80
4
Baseline
Cloz + Oxt
0
1
2
3
Time (min)
20
40
60
80
ClozapineOxt
2
Area (mm )
ClozapineOxt
Time (min)
20
40
60
80
0
1
2
3
4
5
Duration (s)
0
1
2
3
4
Duration (s)
D
F
0
1
2
3
2
Area (mm )
A
B
50 s
Baseline
Clozapine + Oxt
50% ΔF/F0
SSTCre mice
GiDreadd virus
Oxt
Clozapine
0
0
0
0
2
0
4
6
8
Frequency (Hz)
Baseline
OxtR antagonist
0
50
100
Amplitude (%ΔF/F )
0
75
25
*
OxtR ant
OxtR ant
0
20 40 60 80
Time (min)
Normalized
amplitude
0
1
1.2
0.8
Normalized
frequency
0
1
1.1
1.2
0
20 40 60 80
Time (min)
0.9
G
H
x10-2
F
O
t
(A
fi
m
v
(B
a
(C
a
li
c
(D
(E
(F
(G
r
7
m
(H
r
2
a
im
d
O
S
W
r
m
of SST+ int
findings: ac
lations in g
role attrib
trains55 or
inactivation
tions during
sual cortex
relations a
correlation
of neurons
the spatial
determine
in the visu
spatial cor
shape spo
of synaptic
optimally f
might be t
improved
developme
During th
from high-c
sparser an
patterns ha
Because ox
week and A
SSTCre mice
GiDreadd virus
Oxt
Clozapine B
50 s
Baseline
Clozapine + Oxt
50% ΔF/F0 330
Current Biology 31, 322–333, January 25, 2021 between V1 and S1 Accordingly, so-
matosensory stimuli specifically activate parvocellular oxytocin
neurons in the paraventricular nucleus (PVN).43 How oxytocin
reaches the developing cortex is not entirely clear. It might be
released within V1, because hypothalamic oxytocin neurons
project to the cortex, including V1, at least in adult mice.17,44 Current Biology 31, 322–333, January 25, 2021
329 Article ll
OPEN ACCESS SST+ Interneuron Activation Accounts for the Oxytocin-
Mediated Increase in V1 Inhibitory Transmission
2
0
2
6
4
8
Frequency (Hz)
Frequency (Hz)
ClozapineOxt
-2
x10
-2
x10
0
40
80
120
Amplitude (ΔF/F )
0
ClozapineOxt
Time (min)
20
40
60
80
0
40
80
120
Amplitude (ΔF/F )
0
C
E
Time (min)
6
0
20
40
60
80
4
Baseline
Cloz + Oxt
0
1
2
3
Time (min)
20
40
60
80
ClozapineOxt
2
Area (mm )
ClozapineOxt
Time (min)
20
40
60
80
0
1
2
3
4
5
Duration (s)
0
1
2
3
4
Duration (s)
D
F
0
1
2
3
2
Area (mm )
A
B
50 s
Baseline
Clozapine + Oxt
50% ΔF/F0
SSTCre mice
GiDreadd virus
Oxt
Clozapine
0
0
0
0
2
0
4
6
8
Frequency (Hz)
Baseline
OxtR antagonist
0
50
100
Amplitude (%ΔF/F )
0
75
25
*
OxtR ant
OxtR ant
0
20 40 60 80
Time (min)
Normalized
amplitude
0
1
1.2
0.8
Normalized
frequency
0
1
1.1
1.2
0
20 40 60 80
Time (min)
0.9
G
H
x10-2
of SST+
findings: SST+ Interneuron Activation Accounts for the Oxytocin-
Mediated Increase in V1 Inhibitory Transmission
We propose here that the specific activation of SST+ interneu-
rons through oxytocin modulates spontaneous activity patterns
in the developing V1 based on five observations: (1) the oxytocin
receptor is transcribed in V1 SST+ interneurons but barely de-
tected in other interneuron types, excitatory neurons, or glia
cells.31 (2) Pharmacogenetic suppression of SST+ neurons pre-
vents the oxytocin-mediated decrease in network event fre-
quency in vivo. (3) Oxytocin induces an inward current in almost
all SST+ interneurons and in a fraction of GAD2+ interneurons. (4)
Oxytocin-mediated depolarization of SST+ interneurons in-
creases the frequency of inhibitory synaptic inputs in pyramidal
cells 5-fold, and (5) this increase is abolished entirely by SST+
interneuron inactivation. Oxytocin Desynchronizes the Network in a
Structured Manner This relative increase
in experience-driven activity could initiate the critical period During the 2nd postnatal week, V1 activity patterns change
from high-correlation, high-cell-participation patterns toward
sparser and less-correlated activity. Sparsification of activity
patterns has been shown to be largely pre-programmed.60–62
Because oxytocin signaling ramps up during the 2nd postnatal
week and sparsifies activity patterns as discussed above, During the 2nd postnatal week, V1 activity patterns change
from high-correlation, high-cell-participation patterns toward
sparser and less-correlated activity. Sparsification of activity
patterns has been shown to be largely pre-programmed.60–62
d Because oxytocin signaling ramps up during the 2nd postnatal
week and sparsifies activity patterns as discussed above, 330
Current Biology 31, 322–333, January 25, 2021 Article ll
OPEN ACCESS ll
OPEN ACCESS AUTHOR CONTRIBUTIONS oxytocin and potentially other neuromodulators may drive the
sparsification and decorrelation seen in spontaneous activity
patterns toward the onset of sensation. In this regard, it is
interesting to note that activity patterns in the Fmr1 knockout
(KO) mouse, a model for the neurodevelopmental disorder
fragile X syndrome, show increased correlations in the devel-
oping somatosensory and visual cortices compared to WT lit-
termates.63,64 In addition, atypical oxytocin signaling has been
implicated as a risk factor for neurodevelopmental disor-
ders.65–67 Thus, oxytocin may be important for healthy brain
development to specifically shape activity patterns for synap-
tic refinement by regulating SST+ interneuron function. Conceptualization, P.P.M. and C.L.; Experiments, P.P.M., A.N.-P., and E.H.;
Analysis, P.P.M., A.N.-P., J.K., and J.G.; Writing, P.P.M. and C.L. d KEY RESOURCES TABLE 3. Kirkby, L.A., Sack, G.S., Firl, A., and Feller, M.B. (2013). A role for corre-
lated spontaneous activity in the assembly of neural circuits. Neuron 80,
1129–1144. d KEY RESOURCES TABLE
d RESOURCE AVAILABILITY
B Lead Contact
B Materials Availability
B Data and Code Availability
d EXPERIMENTAL MODEL AND SUBJECT DETAILS
B Animal
d METHOD DETAILS
B In utero electroporation and surgery
B Virus injection
B Wide-field imaging
B 2-photon imaging
B Patch-clamp experiments
B RNAscope
B Model
d QUANTIFICATION AND STATISTICAL ANALYSIS
B 2-photon imaging analysis
B Wide-field imaging analysis
B Electrophysiological analysis
B RNAscope analysis
B Statistics d RESOURCE AVAILABILITY
B Lead Contact
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mammalian retina. Science 252, 939–943. B Data and Code Availability d EXPERIMENTAL MODEL AND SUBJECT DETAILS
B Animal 5. Feller, M.B., Wellis, D.P., Stellwagen, D., Werblin, F.S., and Shatz, C.J. (1996). Requirement for cholinergic synaptic transmission in the propaga-
tion of spontaneous retinal waves. Science 272, 1182–1187. 6. Ackman, J.B., Burbridge, T.J., and Crair, M.C. (2012). Retinal waves coor-
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Stryker, M.P. (2005). Development of precise maps in visual cortex re-
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Revised: August 28, 2020
Accepted: October 9, 2020
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reading the manuscript; Gertjan Houwen for his help with MATLAB coding;
Maurice Manning for the donation of the oxytocin receptor antagonist; Moni-
que van Mourik for performing the in utero electroporations and virus injection;
Fred de Winter for the production of AAV-hSyn-DIO-hM4D(Gi)-mCherry virus;
and Marko Popovic for sharing with us the Rapid LED Switching System for
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supported by grants of the Netherlands Organization for Scientific Research
(NWO, ALW Open Program grants nos. 819.02.017, 822.02.006, and AL-
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OPEN ACCESS ll
OPEN ACCESS STAR+METHODS
KEY RESOURCES TABLE STAR+METHODS
KEY RESOURCES TABLE REAGENT or RESOURCE
SOURCE
IDENTIFIER
0Bacterial and Virus Strains
pAAV1-hSyn-DIO-hM4D(Gi)-
mCherry
33
N/A
pAAV1.Syn.GCaMP6s. WPRE.SV40
UPenn viral core
AV-1-PV2824
Chemicals, Peptides, and Recombinant Proteins
Oregon Green 488 BAPTA-1
AM
Invitrogen
Thermo Fisher Scientific
#O6807
Oxytocin
Sigma
O6379
desGly-NH2,d(CH2)5[D-
Tyr2,Thr4]OVT
Synthesized and given by Dr. Maurice Manning, University
of Toledo30
N/A
Clozapine N-oxide
Tocris
#0444
Clozapine
Tocris
#4936
SR95531
Tocris
#1262
NBQX
Tocris
#1044
D-AP5
Tocris
#0103
TTX
Tocris
#1078
Critical Commercial Assays
RNAscope 2.5HD Duplex
Assay
Advanced Cell Diagnostics
#322430
Experimental Models: Organisms/Strains
Mouse: C57B/6J
Janvier
N/A
SstCre
The Jackson Laboratory
013044
Gad2Cre
The Jackson Laboratory
010802
Gt(ROSA)26SorCAG-tdTomato
The Jackson Laboratory
007908
Oligonucleotides
Oxtr
Advanced Cell Diagnostics
#411101-C2
Slc17a7, VGLUT1
Advanced Cell Diagnostics
#416631
Gad1
Advanced Cell Diagnostics
#400951
Sst
Advanced Cell Diagnostics
#404631
Recombinant DNA
pCAGGS-DsRed
Gift from Dr. Christiaan
Levelt
N/A
pCAGGS-GCaMP6s
Gift from Dr. Christiaan
Levelt
N/A
Software and Algorithms
Enhanced correlation
coefficient algorithm
68
N/A
NEST
69
RRID:SCR_002963
Model simulations
This paper
https://github.com/
comp-neural-circuits/
OTmodel
LabView
National Instruments
LabView, RRID:SCR_014325
(Continued on next page) (Continued on next page) e1
Current Biology 31, 322–333.e1–e5, January 25, 2021 Article ll
OPEN ACCESS Continued
REAGENT or RESOURCE
SOURCE
IDENTIFIER
ScanImage
http://scanimage. vidriotechnologies.com/
display/SIH;jsessionid=
06CBF1F1626C33338
4D74630886127FF70
ScanImage,
RRID:SCR_014307
NIS-Elements
Nikon
(NIS-Elements,
RRID:SCR_014329
ImageJ
https://imagej.net/
ImageJ, RRID:SCR_003070
MATLAB
MathWorks
MATLAB,
RRID:SCR_001622
Clampfit
Molecular Devices
pClamp, RRID:SCR_011323
AxoGraph
Axograph Scientific
Axograph,
RRID:SCR_014284
IGOR Pro
Wave Metrics
IGOR Pro,
RRID:SCR_000325
Prism 7
GraphPad
GraphPad Prism,
RRID:SCR_002798
Other
TEAMSTER (Open-source
rapid LED switching system
for one-photon imaging and
photo-activation)
71
https://github.com/Kolelab/
Image-analysis
OPEN ACCESS
Article Data and Code Availability The datasets generated during this study have not been deposited in a public repository but are available from the Lead Contact on
request. This study used standard, custom-built MATLAB programmed scripts that are available from the Lead Contact upon
request. The code used for the simulations is available at https://github.com/comp-neural-circuits/OTmodel. Materials Availability This study did not generate new unique reagents. Lead Contact Further information and requests for resources and reagents may be directed to and will be fulfilled by the Lead Contact, Christian
Lohmann, c.lohmann@nin.knaw.nl. Animal All experimental procedures were approved by the institutional animal care and use committee of the Royal Netherlands Academy of
Arts and Sciences and in agreement with the European Community Directive 2010/63/EU and with the Institutional Animal Care and
Use Committee at Florida State University in accordance with state and federal guidelines (Guide for the Care and Use of Laboratory
Animals of the National Institutes of Health). We used neonatal C57BL/6J, SST-Cre, SST-Cre;Rosa26-TdTomato and GAD2-Cre;R-
osa26-TdTomato males and females mice from postnatal day 9 to 14 (P9-14). The SST-Cre;Rosa26-TdTomato and GAD2-Cre;R-
osa26-TdTomato lines were generated by crossing the reporter Rosa26-TdTomato line (The Jackson Laboratory, 007908) with either
the SST-Cre (The Jackson Laboratory, 013044) or the GAD2-Cre (The Jackson Laboratory, 010802) lines. Neonatal pups were
housed with one mother, with exception of pups coming from in utero electroporation. They were housed with two mothers and
the nest trimmed to 6 pups to facilitate the caring behavior of the mothers. Animals were kept in a 12h-12h light/dark cycle with
food and water ad libitum. All the experiments were performed during the light cycle. No effects related to sex were observed. No
animal was excluded from the analysis. Current Biology 31, 322–333.e1–e5, January 25, 2021
e2 Article ll
OPEN ACCESS 2-photon imaging Bolus load of the calcium indicator Oregon Green 488 BAPTA-1 AM (OGB-1, Invitrogen) was performed as described7. Imaging was
performed by using a two-photon microscope (MOM, Sutter, or A1RMP, Nikon) and a mode-locked Ti:Sapphire laser (MaiTai,
Spectra Physics or Chamaleon, Coherent, l = 810 nm). Consecutive xyt-stacks were acquired at a frame rate of 4-7 Hz (pixel
size 0.3 - 0.6 mm) through a 40x (0.8 NA, Olympus) or a 16x (0.8 NA, Nikon) water-immersion objective, controlled by ScanImage70
or NIS-Elements AR4.51.00 software (Nikon). For in vivo experiments, oxytocin (1 mM, Sigma) and the oxytocin receptor antagonist (desGly-NH2,d(CH2)5[D-Tyr2,Thr4]OVT,
250 mM, synthesized and kindly donated by Dr. Maurice Manning, University of Toledo) was diluted in cortex buffer solution7 and
applied topically at the craniotomy. The craniotomy was filled with approximately 300 ml of solution and that volume was kept con-
stant until the end of the experiment. In utero electroporation and surgery In utero electroporation was performed as described previously23. To perform calcium imaging of layer 2/3 pyramidal cells,
GCaMP6s was cloned into pCAGGS (Addgene plasmid 4075372) and used in combination with DsRed in pCAGGS for visualization
(gift from Christiaan Levelt). Pups were in utero electroporated at embryonic day (E) 16.5 after injection of the GCaMP6s (2 mg/ml) and
DsRed (1 mg/ml) vectors into the ventricles. Electrode paddles were positioned to target the subventricular zone and 50 V pulses of
50 ms duration were applied. For in vivo experiments, surgery for craniotomy was performed as described previously7,33. Pups were kept at 36-37C and anes-
thetized with 2% isoflurane and lidocaine was applied into the skin before neck muscle removal. A head bar was fixed above the V1/
S1 region. Isoflurane was dropped to 0.7% before the imaging session. This lightly anesthetized state, which is characterized by rapid
and shallow breathing and a relatively high heart rate, was maintained throughout the imaging session. During experiments in the
absence of anesthesia, pups were kept undisturbed in the dark and covered by a custom-made holder that prevents heat loss
and mimic the conditions in the nest, for one hour before the imaging session started. The welfare of the pup was monitored to mini-
mize distress during the whole imaging session. Virus injection Virus injections were performed at P0-1. Virus injected were pAAV1-Syn-GCaMP6s (AV-1-PV2824, UPenn viral core) and pAAV1-
hSyn-DIO-hM4D(Gi)-mCherry (produced by Fred Winter33). SST-Cre neonatal mice were anesthetized by cold-induced hypothermia
and kept cold in a stereotactic frame for pups (RWD Life Science). Stereotactic injections targeting V1 were performed with a micro-
injection pipet (Nanoject II, Drummond; volume 27 nl; mix of 1:1 AAV1-hSyn-DIO-hM4D(Gi)-mCherry and AAV1-Syn-GCaMP6; from
Bregma in mm: 0.3 posterior, 1.4 lateral). Immediately after injection, pups were kept warm on a heating pad and placed back to their
mother after they awoke from anesthesia. Wide-field imaging In utero electroporated or virus injected pups were used for calcium imaging of visual and somatosensory cortex. Calcium events
were recorded with a Movable Objective Microscope (MOM, Sutter Instrument). Time-lapse recordings were acquired with a 4x
objective (0.8 NA, Olympus) and blue light excitation from a Xenon Arc lamp (Lambda LS, Sutter Instrument Company). A CCD cam-
era (Evolution QEi, QImaging) was controlled by custom-made LabVIEW (National Instruments) based software and images were ac-
quired at a frame rate of 20 Hz. s injected subcutaneously (0.5 mg/kg) and oxytocin was applied five minutes after clozapine injection. Clozapine (Tocris) was injected subcutaneously (0.5 mg/kg) and oxytocin was applied five m Clozapine (Tocris) was injected subcutaneously (0.5 mg/kg) and oxytocin was applied five minutes after clozapine injection. METHOD DETAILS In utero electroporation and surgery Patch-clamp experiments Acute 300 mm coronal slices of the visual or somatosensory cortex were dissected between P9-P14. Pups were sacrificed by decap-
itation and their brains were immersed in ice-cold cutting solution (in mM): 2.5 KCl, 1.25 NaH2PO4, 26 NaHCO3, 20 Glucose, 215 Su-
crose, 1 CaCl2, 7 MgCl2 (Sigma), pH 7.3-7.4, bubbled with 95%/5% O2/CO2. Slices were obtained with a vibratome (Microm HM
650V, Thermo Scientific) and subsequently incubated at 34C in artificial cerebrospinal fluid (ACSF, in mM): 125 NaCl, 3.5 KCl,
1.25 NaH2PO4, 26 NaHCO3, 20 Glucose, 2 CaCl2, 1 MgCl2 (Sigma), pH 7.3-7.4. After 45 minutes, slices were transferred to the elec-
trophysiology setup, kept at room temperature and bubbled with 95%/5% O2/CO2. For patch-clamp recordings, slices were trans-
ferred to a recording chamber and perfused (3 ml/min) with ACSF solution bubbled with 95%/5% O2/CO2 at 34C. Layer 2/3 pyramidal cells and interneurons were identified using an IR-DIC video microscope (Olympus BX51WI). GAD2+ and SST+
interneurons were identified by the TdTomato protein fluorescence from the transgenic mice GAD2-Cre;Rosa26-TdTomato and SST-
Cre;Rosa26-TdTomato, respectively. Quick change between bright-field imaging and epifluorescence was achieved using a foot-
switch device TEAMSTER71. Whole-cell voltage or current-clamp recordings were made with a MultiClamp 700B amplifier (Molecular
Devices), filtered with a low pass Bessel filter at 10 kHz and digitized at 20-50 kHz (Digidata 1440A, Molecular Devices). Series resis-
tance was assessed during recordings and neurons showing a series resistance > 30 MU or a change > 30% were discarded. Digi-
tized data were analyzed offline using Clampfit 10 (Molecular Devices), Igor (WaveMetrics) and AxoGraph (Axograph Scientific). e3
Current Biology 31, 322–333.e1–e5, January 25, 2021 Article ll
OPEN ACCESS Spontaneous and miniature IPSCs were recorded at a holding potential of 10 mV with glass pipettes (3-6 MU) containing (in mM):
115 CsCH3SO3, 10 HEPES, 20 CsCl, 2.5 MgCl2, 4 ATP disodium hydrate, 0.4 GTP sodium hydrate, 10 phosphocreatine disodium
hydrate, 0.6 EGTA (Sigma), pH 7.3. For sIPSC recordings during selective silencing of SST+ interneurons, clozapine N-oxide
(CNO) (10 mM, Tocris) was administered 1 minute prior to oxytocin (1 mM, Sigma). mIPSCs were recorded in the presence of tetro-
dotoxin (0.5 mM, Tocris). The oxytocin receptor antagonist desGly-NH2,d(CH2)5[D-Tyr2,Thr4]OVT (50 mM, synthesized and kindly
donated by Dr. Maurice Manning, University of Toledo) was applied for 5-10 minutes before oxytocin wash-in. Patch-clamp experiments sEPSCs were re-
corded at a holding potential of 60 mV (with junction potential correction) with an intracellular solution containing (in mM): 122 po-
tassium gluconate, 10 HEPES, 13 KCl, 10 phosphocreatine disodium hydrate, 4 ATP magnesium salt, 0.3 GTP sodium hydrate
(Sigma), pH 7.3. Oxytocin-induced currents in GAD2+ and SST+ interneurons were recorded at a holding potential of 60 mV
(with junction potential correction) in the presence of 10 mM SR95531, 10 mM NBQX, 50 mM D-AP5 (Tocris). Current-clamp recordings
of SST+ interneurons were performed using the same KGluconate-based intracellular solution and in the presence of the synaptic
blockers mentioned above. After breaking the seal, variable current injection was applied to keep the cells at 60 mV. The injected
current was kept constant from the time of oxytocin wash-in. Model We simulated a large-scale computational model of the visual cortex37 in the NEST framework69. We focused only on modeling the
cortical network of excitatory and inhibitory neurons with 25% of the inhibitory population corresponding to SST+ neurons in L2/3,
receiving excitatory input from the thalamus. To achieve network activity similar to that described for the developing cortex7,62, we
adjusted the intrinsic membrane properties and synaptic weights in the model based on measurements from the present study (Table
S1) and applied an external current of 50 pA (to excitatory neurons) or 40 pA (to SST+ interneurons) and a sinusoidal background input
to the excitatory population to generate spontaneous activity. The oxytocin effect was modeled by increasing the resting membrane
potential of SST+ interneurons from 60.8 mV to 56.3 mV as the change observed in our experiments (Figure 6A). After simulating
the system for 60 s in baseline condition, we modeled application of oxytocin and simulated again for 60 s. Correlations are computed
between the voltage traces of excitatory units. RNAscope Fresh frozen brain tissue from C57BL/6J mice was sectioned in the sagittal plane at 20 mm in 6 series on SuperFrost Plus microscope
slides and stored at 80C until further processing. RNA transcripts were detected with RNAscope 2.5HD Duplex Assay (Cat. No. 322430, Advanced Cell Diagnostics (ACD), Hayward, CA). Synthetic oligonucleotide probes complementary to the nucleotide
sequence 1198 – 2221 of Oxtr (NM_001081147.1; ACD Cat. No. 411101-C2), 464 - 1415 of Slc17a7 (VGLUT1; NM_182993.2;
ACD Cat. No. 416631), 62 – 3113 of Gad1 (NM_008077.4; ACD Cat. No. 400951) and 18 – 407 of Sst (NM_009215.1; ACD Cat. No. 404631) were used. Slides were fixed for 2 hours in ice cold 4% paraformaldehyde (pH 9.5) followed by increasing concentrations
of ethanol and dehydration in 100% ethanol overnight at 20C. Slides were air-dried for 10 minutes and boiled for 5 minutes in a
target retrieval solution (ref. 322001, ACD), followed by 2 room temperature water rinses and a rinse in 100% ethanol. Slides were
air-dried, after which targeted sections were incubated with Protease Plus solution (ref. 322331, ACD) for 15 minutes at 40C, fol-
lowed by room temperature water rinses. These prepared slides were then probed for 2 hours with individual probe mixtures
(Oxtr in the red channel 2 and the other probes in the blue-green channel 1) at 40C. Unbound probes were rinsed off in wash buffer
and slides were stored overnight in 5X SSC at room temperature. Signal amplification and detection were performed using the
detailed instructions provided in the RNAscope 2.5HD Duplex Assay. Sections were counterstained with Gill’s hematoxylin (Amer-
ican Mastertech Scientific, Inc. Lodi, CA) and coverslipped with Vectamount (Vector Laboratories, Inc. Burlingame, CA). Images were
captured with brightfield microscopy (Keyence BZ-X710, Keyence Corp., Osaka, Japan). Wide-field imaging analysis Network events were detected automatically. First, DF/F0 stacks were generated using a moving average across 500 frames as F0. The detection threshold was 12% DF/F0, which was at least 3x larger than the standard deviation of the noise during inactivity for all
recordings. Pixels below threshold were reduced to zero. Network events were defined as groups of at least 300 non-zero pixels that
were connected in time and/or space. Since the frame rate was 20 Hz and the pixel size 7.68 mm (area covered by 1 pixel: 59 mm2), this
criterion included events of e.g., > 1 s duration that covered on average > 885 mm2 of cortical surface. Since this criterion was chosen
empirically, we investigated how robust our findings were with respect to this criterion. We performed analyses where we varied the
total number of connected pixels that defined a network event on a subset of the data. We found that the number of detected events
and the changes observed in frequency after oxytocin application were very robust across different pixel numbers between 200 and
800 pixels (not shown). Since wide-field microscopy is inherently prone to scattered light, we found that the area that network events
covered across the cortex was overestimated when we used the 12% cutoff. Therefore, we restricted the area to those pixels that
reached 67% of the maximal DF/F0 value for each event (Figure S6). Recordings from un-anaesthetized animals showed increased movement artifacts. Therefore, we restricted our analysis to fre-
quency and amplitude of network events in traces generated from the entire area of V1. Traces were long-pass filtered to remove
high-frequency movement artifacts. Network events were automatically detected using MATLAB’s ‘‘Find peaks’’ function where
the parameters prominence and peak were optimized for detecting events during the baseline period and kept constant throughout
the experiment. Electrophysiological analysis p y
g
y
m/sIPSCs and sEPSCs were detected using an Igor-based tool SpAcAn (Igor Pro 7, WaveMetrics). Frequency timelines of postsyn-
aptic currents were built by calculating the frequency of 50-or 90 s bins. The 20%–80% rise time was calculated for each IPSC event
and the rise rate was determined as amplitude/rise time (pA/ms). Excitability of SST+ interneurons was assessed with a one-step
ramp protocol, from 100 pA to 140 pA at a rate of 96 pA/second. Single action potentials (APs) were elicited by injecting moderate
pulses of current (< 1 nA, < 15 ms). Changes in membrane potential upon oxytocin treatment were calculated as the voltage differ-
ence between the trace exhibiting the peak effect and the last trace of baseline condition. A minority of cells that did not exhibit a
depolarization (6%) were discarded for subsequent analyses. A voltage timeline was built by calculating the baseline membrane po-
tential of 45 s bins. For analysis of SST+ interneuron excitability, the duration of the ramp was divided into 175-milisecond bins and the
mean inter-spike interval (ISI) was calculated for each period bin. Then, the instantaneous frequency (ISI-1) was plotted against the
mean current injected within the same bin. AP features were determined as follows: (1) overshoot was quantified as the amplitude of
the AP above 0 mV. (2) Amplitude was calculated as the voltage difference between the peak of the AP and its threshold. (3) Width
was determined at half the amplitude of the AP. (4) DTime was described as the time difference between the onset of pulse injection
and the time point when the membrane potential reached the action potential threshold. (5) dVdt-1 was defined as the first derivative
of the voltage trace with respect to time. 2-photon imaging analysis For the matrix correlation analysis, we computed the squared distance between the baseline matrix, cBL
ij , computed for the entire
baseline period of 45 minutes, and the correlation matrix computed from a shifting 7-minute slice centered at time point t, ct
ij, and then
summing over all the element-wise differences of all matrix entries, MSD = P
ij
ðct
ij cBL
ij Þ
2 . To remove any potential drift that occurs
already during the baseline and that might distort the MSD analysis, we performed a linear regression on the baseline MSD and sub-
tracted the linear contributions from all time points. To further pool across multiple animals, we normalized the squared distances by
the mean and standard deviation of the baseline period. j
already during the baseline and that might distort the MSD analysis, we performed a linear regression on the baseline MSD and sub-
tracted the linear contributions from all time points. To further pool across multiple animals, we normalized the squared distances by
the mean and standard deviation of the baseline period. 2-photon imaging analysis Images were analyzed with ImageJ (NIH) and custom-written MATLAB scripts (MathWorks) as described previously63. First, to re-
move movement artifacts and align all recordings we performed an image alignment step based on the enhanced correlation coef-
ficient algorithm68. DF/F0 stacks were generated by subtracting and dividing each frame by the mean fluorescence (F0). Regions of
interest (ROIs) were placed on cells that showed clear activity and were visible in all recordings. Glial cells in the field of view showed
elevated basal intensity and were not active. All included ROIs were neuronal. DF/F0 traces were obtained by calculating the mean
intensity within the ROI for each frame. Increases in fluorescence intensity, which reflect increases in the intracellular calcium con-
centration due to action potential firing, were then detected automatically for all ROIs and subsequently verified manually. The detec-
tion threshold was adjusted for each experiment (at least 2x the standard deviation of the signal in the absence of events) but re-
mained the same within an experiment. Pearson correlation coefficients were computed from the DF/F0 stacks. The total number of pairs of cells (computed as N(N – 1) /2)
was balanced across conditions (oxytocin – 8806 pairs; cortex buffer – 8023 pairs). In Figure 2E each x-coordinate corresponds to a
window of length 7 minutes around the time point. The y-coordinate of the line is computed as the average across all animals of the
condition over the correlation coefficients computed from the window. The shaded area is the standard error of the mean (computed
as bs=
ffiffiffiffi
N
p
, where bs is the estimated standard deviation over animals and N is the number of animals). In Figure 2F, we averaged the Current Biology 31, 322–333.e1–e5, January 25, 2021
e4 Current Biology 31, 322–333.e1–e5, January 25, 2021
e4 ll
OPEN ACCESS Article A
i l correlation coefficients computed from the windows over all animals and time points before or after oxytocin application. The filled
contour plot was made by plotting pairwise correlations after oxytocin (average of 40 minutes period after oxytocin) against baseline
correlations (average of 40 minutes period before oxytocin). correlation coefficients computed from the windows over all animals and time points before or after oxytocin application. The filled
contour plot was made by plotting pairwise correlations after oxytocin (average of 40 minutes period after oxytocin) against baseline
correlations (average of 40 minutes period before oxytocin). RNAscope analysis p
y
Quantification was done on the 40x images. The total number of cells was determined by the nucleus visualization given by Gill’s
hematoxalin staining. Oxtr+/VGLUT1+/Gad1+ neurons were manually identified and counted with ImageJ. Statistics All data are shown as mean ± SEM. The number of animals and the test used for each analysis is specified in the Results section. To
determine statistical differences we used Prism 7 (GraphPad). Sets of data R 6 were tested for normality with a Shapiro-Wilk test,
then a paired or unpaired t test was applied for two-group comparisons. Comparisons between more than two groups were per-
formed with one or two-way ANOVAs. For not normally distributed data or data < 6, the non-parametric Wilcoxon and Mann-Whitney
tests were applied for paired or unpaired experiments, respectively, for two-group comparisons. Datasets with more than two groups
were analyzed using the Kruskal-Wallis and Friedman test. e5
Current Biology 31, 322–333.e1–e5, January 25, 2021
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The Impact of Green Technology Innovation on Capital Cost of Heavy Polluting Enterprises: The Mediating Effect of Carbon Performance
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∗e-mail: trieumyan@gmail.com © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons
Attribution License 4.0 (https://creativecommons.org/licenses/by/4.0/). The Impact of Green Technology Innovation on Capital
Cost of Heavy Polluting Enterprises: The Mediating Effect
of Carbon Performance Liming Zhang1, Jingyi Li1, Kuankuan Luo1, and Thi My An Trieu2,∗ Liming Zhang1, Jingyi Li1, Kuankuan Luo1, and Thi My An Trieu2,∗
1Business School, Sichuan University, Chengdu 610065, People’s Republic of China
2Department of Chinese Language, Thanh Dong University, Hai Duong Province 34000, Socialist Re-
public of Vietnam Liming Zhang1, Jingyi Li1, Kuankuan Luo1, and Thi My An Trieu2,∗
1Business School, Sichuan University, Chengdu 610065, People’s Republic of China
2Department of Chinese Language, Thanh Dong University, Hai Duong Province 34000, Socialist Re-
public of Vietnam 1Business School, Sichuan University, Chengdu 610065, People’s Republic of China usiness School, Sichuan University, Chengdu 610065, People’s Republic of China 2Department of Chinese Language, Thanh Dong University, Hai Duong Province 34000, Socialist
public of Vietnam Abstract. Under the background of the carbon peaking and carbon neutrality
goals proposed in 2020, making heavy polluting enterprises realize that low-
carbon measures can bring enough economic benefits is conducive to enhancing
their enthusiasm to adopt green behaviors. Using data from 320 listed compa-
nies in heavily polluting industries from 2006 to 2019 as samples, our study
used multiple linear regression to explore the relationship between green tech-
nology innovation, carbon performance, board characteristics and cost of capi-
tal. Based on these data, we draw the following conclusions: green technology
innovation and carbon performance are significantly negatively correlated with
capital cost, carbon performance plays a mediating role in the relationship be-
tween green technology innovation and capital cost, and board characteristics
play a moderating role in the relationship between green technology innova-
tion and carbon performance. These conclusions bring some implications for
enterprises to develop and implement low-carbon measures and reduce capital
cost. Keywords: Green manufacturing, Technology and innovation, Carbon
performance, Capital cost, Characteristics of board of directors. E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 https://doi.org/10.1051/e3sconf/202340901016 1 Introduction According to the Vision 2035, we will continue to innovate in technology, and promote the
interaction between technology, finance and industry. The 19th National Congress stressed
that to make ecological progress, we need to establish the economic system with green, low-
carbon and circular development, and comprehensively promote sustainable technological
innovation. Green technology innovation can effectively help enterprises break through diffi-
culties and achieve long-term development. Heavy polluting enterprises face greater pressure
of legitimacy. The active practice of green innovation concepts by enterprises is conducive to
the coordinated development of economy and ecology. In the past, many heavy polluters ignored the environmental costs and made super-high
profits. However, faced with the increasingly serious environmental problems, the impact of
government environmental policies has become an unavoidable topic in the decision-making
of enterprises and investors. The investment and production activities of enterprises will
be directly constrained by environmental policies. Investors tend to take green innovation E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 https://doi.org/10.1051/e3sconf/202340901016 and carbon performance into account when investing in heavily polluting industries. Under
environmental pressure, heavy polluting enterprises which are no matter forced to survive
passively or adapt to policy changes actively, need to make changes such as updating outdated
equipment or adjusting development strategies. Such changes in investment direction will
affect the cost of capital of enterprises to a large extent. and carbon performance into account when investing in heavily polluting industries. Under
environmental pressure, heavy polluting enterprises which are no matter forced to survive
passively or adapt to policy changes actively, need to make changes such as updating outdated
equipment or adjusting development strategies. Such changes in investment direction will
affect the cost of capital of enterprises to a large extent. Under the background of carbon peaking and carbon neutrality goals and national eco-
nomic transformation, how does the green technology innovation of heavy polluting enter-
prises affect the capital cost? What role does carbon performance play? What effect does
the characteristics of the board of directors play in the process of carrying out environmental
responsibilities of heavy polluting enterprises? These problems are the core issues of great
concern in this study. We constructed panel data of heavy polluting enterprises from 2006 to
2019 to explore the relationship between green technology innovation, carbon performance
and capital cost of heavy polluting enterprises. 1 Introduction The main contributions of this work are: (1) In this study, carbon performance is in-
troduced as the mediating variable between green technology innovation and capital cost,
which increases the degree of information transparency and exposes the "black box" between
green technology innovation and capital cost of heavily polluting enterprises. (2) We explore
how two types of green technology innovation affect the decisions of two different types of
investors which broadens the research perspective on the relationship between green technol-
ogy innovation and capital cost. (3) From the three dimensions of board characteristics, we
explore the influence of internal governance on low-carbon strategy and behavior of heavy
polluting enterprises, which is of enlightening significance for enterprise management prac-
tice. The rest of this paper is organized as follows. Section 2 discusses relevant literature
and develops our hypotheses. Section 3 describes the data, measure and models. Section
4 presents the results from our analysis. Section 4.5 summarizes the main conclusions and
makes corresponding suggestions for governments and enterprises. 2.2 Green Technology Innovation and Carbon Performance Enterprises actively carry out carbon emission reduction activities in response to the na-
tional call, which puts forward higher requirements for technological innovation. Meanwhile,
through green technological innovation, carbon emissions can be effectively reduced and car-
bon performance can be promoted. Dong et al. (2022) found that green technology inno-
vation can promote economic development and urbanization process, thus improving carbon
emission efficiency [5]. Green technology innovation affects carbon performance from three
aspects: green process innovation, green product innovation and end-treatment technology
innovation [1]. First of all, through green process innovation, enterprises optimize produc-
tion process, improve energy efficiency, use clean energy, optimize energy structure, reduce
carbon emissions from the source, and improve environmental performance. Secondly, the
use of advanced technology to develop and produce green products, improve product design,
product quality and packaging design, so that the product can be recycled and recover the
residual value of it, and then form a green circular economy, relieve the legal pressure of
enterprises. Finally, innovate end treatment technology, update pollution control equipment
or change the way of pollutant treatment to realize harmless emissions or reducing emissions
of pollutants and then promoting sustainable development. Therefore, we predict the following: Hypothesis 2. Green technology innovation will be positively to carbon performance. Therefore, we predict the following: p
g
Hypothesis 1. Green technology innovation will be negative to enterprise capital cost. 2.1 Green Technology Innovation and Capital Cost Green product innovation labels products as “green”, which satisfies consumers’ require-
ments for corporate environmental responsibility, increases product premium, enhances cus-
tomer loyalty, and accumulates social capital for enterprises [1]. The product sales situation
is reflected in the financial statements, which conveys to creditors that the enterprise has
good profitability, which can effectively reduce creditors’ borrowing risks and enhance their
borrowing willingness. Companies are more willing to provide private information to banks
than other investors. Therefore, creditors can obtain more information, reduce the degree of
information asymmetry, and reduce the financing cost of borrowers [2]. The capital demand of technological innovation is great, the cycle is long and the un-
certainty is high, which leads to the increase of enterprise risk and makes investors ask for
higher financing costs [3]. Green technology innovation has problems of information asym-
metry and moral hazard, which will lead to the increase of financing costs [4]. Enterprises
improve production process, increase productivity and reduce cost through green process in-
novation and also, they achieve differentiated development and expand market share through
green product innovation. These ways of green technology innovation are all conducive to
establishing a good reputation for the enterprise, enhancing its competitiveness, highlighting
the enterprise’s good development prospects and strong ability to create value. At this time,
equity investors have a strong investment intention for the enterprises. 2 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 2.3 Carbon Performance and Capital Cost Environmental performance is an important basis for creditors to evaluate enterprise risk and
financial cash flow [6]. Carbon performance reflects the performance of enterprises’ environ-
mental responsibility and the moral level of enterprises. Creditors usually take the moral level
into consideration when evaluating enterprise credit risk [7]. Enterprises with good environ-
mental performance can establish long-term relationships with stakeholders [8], gain their
trust and support, and reduce litigation costs. The reduction of carbon emissions is conducive
to establishing a good image for enterprises, reducing carbon risks and pollution control costs
[9], thus reducing credit risks and gaining the trust of creditors, which is conducive to the
signing of a loan agreement between both parties. National financial institutions strictly ex-
amine the loan qualification of enterprises in heavily polluting industries, which puts forward
further requirements on the carbon performance of enterprises [10]. Enterprises with good environmental performance are considered to have less investment
risk, more trust from investors [2], and more hope to increase stock price and reduce capital
cost. The signal transmission theory points out that information disclosure can convey the
signal that enterprises actively fulfill their social responsibilities to the outside world, which
is conducive to reducing the information asymmetry between enterprises and stakeholders,
so that external stakeholders can grasp the operation and financial condition of enterprises. A
good carbon performance level can set up a good image for enterprises, enable enterprises to
form unique competitive advantages in the market, obtain more resources from the outside,
improve corporate financial performance, increase corporate valuation and improve investor
confidence. Therefore, we predict the following: Hypothesis 3. Carbon performance will be negative to capital cost. Hypothesis 3. Carbon performance will be negative to capital cost. 3 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 2.5 The Moderating Effect of Board Characteristics One of the purposes of the establishment of the board of directors is to alleviate agency
conflicts and reduce agency costs. Independent directors are usually industry experts or suc-
cessful people with strong professional ability, social responsibility and legal consciousness,
so they can better exercise supervision and management functions. Because independent
directors do not hold positions in the enterprise, their decisions are more independent and
objective, and they are more able to make scientific decisions compared with internal direc-
tors [11]. The higher the proportion of independent directors is, the more conducive it is to
make decisions to achieve a win-win situation between the enterprise and the environment
from the overall perspective of the enterprise, so as to actively support the enterprise’s green
technology innovation, avoid the short-sighted behavior of the management to the maximum
extent, and ensure the improvement of carbon performance. According to the high-level echelon theory, the cognitive ability, perception ability and
value of management affect the strategic decision and organizational performance of an en-
terprise. Female directors pay more attention to environmental pollution than male direc-
tors. They are willing to participate in environmental protection activities, assume social
responsibilities, solve environmental problems from the perspective of stakeholders, improve
environmental performance, meet stakeholders’ expectations of corporate environmental re-
sponsibility, and strengthen the relationship with stakeholders. The role of directors is to supervise the decisions and actions of management so as not
to harm the long-term interests of company. Board interlocking occurs when board members
hold board positions in different enterprises. However, each person’s time and energy are
limited. Serving as a director of several enterprises will cause members to be unable to take
care of these enterprises at the same time, and may be absent from the board of directors,
weakening the supervision of the board of directors, and easily leading to the management
violating shareholders’ rights and interests for their own interests, thus aggravating agency
conflicts and increasing the principal-agent costs. The strategy of enterprises to improve
carbon performance through green technology innovation requires a lot of time and energy
to be deployed, and faces uncertain investment risks. Board interlocking will weaken the
supervision effectiveness and investment prudence, and reduce the governance role of the
board of directors. Therefore, we predict the following: Hypothesis 5. Board independence and board gender diversity will positively moderate
the relationship between green technology innovation and carbon performance. 2.4 Mediating Effects of Carbon Performance Enterprises invest more in green technology innovation, which leads to greater risks, stronger
uncontrollability and information asymmetry. Without disclosure of patent output or inno-
vation performance, investors cannot know the situation of innovation investment, which is
likely to lead to adverse selection and moral hazard and increase the uncertainty of invest-
ment. Carbon performance can reliably reflect an enterprise’s innovation ability and social
responsibility performance. The higher the level of green technology innovation is, the higher
the enterprise’s carbon performance is. Creating a good social image can attract the atten-
tion of investors and government policy support, so as to effectively integrate resources and
reduce the cost of capital. Therefore, we predict the following: Hypothesis 4. Carbon performance plays an intermediary role in the relationship between
green technology innovation and capital cost. 2.5 The Moderating Effect of Board Characteristics Board link-
age will negatively moderate the relationship. 4 4 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 3.1 Data Source The A-share listed companies in the heavily polluting industries in China from 2006 to 2019
were selected as the research object, and the industry codes of the heavily polluting enter-
prises were determined according to the Guidelines published by the MEP in 2010 and the
industry codes from the National Bureau of Statistics. In order to ensure the quality of data,
the following processing was carried out in this study: companies with ST and ST* were ex-
cluded, companies without fourteen years of continuous data were excluded, and companies
with serious data missing were excluded. After summarizing and collating the data, 4480
observed values of 320 heavy polluting enterprises were obtained. Data sources for our study
include the CSMAR database, the official website of the People’s Bank of China, the State
Intellectual Property Office of the People’s Republic of China (SIPO), the Carbon Emissions
Trading Network and the China Statistical Yearbook. Winsorize each continuous variable by
up or down 1% to reduce the impact of outliers. (1) Explained variables (1) Explained variables Cost of debt capital (Kd): Refer to Gong et al. (2021) and Bacha (2021) to express the
cost of debt capital (Kd) in terms of the ratio of interest expense to total liabilities. Cost of Equity Capital (Ke): Currently commonly used methods to measure the cost
of equity capital include capital asset pricing method (CAPM), multi-factor model method,
historical average earnings method, dividend discount method and dividend growth model
method, among which CAPM method and multi-factor model method are the most widely
used and CAPM method is the most classic. CAPM method was applied to the research of
Faysal et al. (2021) and Abu et al. (2022). We use CAPM method to calculate the cost of
equity capital of listed companies in heavy pollution industries. Ke = Rf + β ∗(Rm −Rf). (1) (1) Total cost of capital (K): Using Kling et al. (2021) and Khanchel (2022) as reference, the
simplified formula of weighted average cost of capital is adopted to calculate capital. Total cost of capital (K): Using Kling et al. (2021) and Khanchel (2022) as reference, the
simplified formula of weighted average cost of capital is adopted to calculate capital. K = Kd ∗(1 −T) ∗D
A + Ke ∗E
A. (2) (2) Where, T is the corporate income tax rate, D is total liabilities, E is ownership equity, and
A is total assets. (2) Explanatory variables Green technology innovation (GTI): Feng et al. (2022) measured corporate green in-
novation by the number of green patent applications. In order to eliminate the right-biased
distribution of green patent application data, this study added 1 to the number of green patent
applications and took the natural logarithm. According to Ma et al. (2021), green invention
patents are identified as disruptive green technology innovation and green utility patents as
progressive green technology innovation. (3) Mediating variable Carbon performance (CP): Referring to Aslam (2021) and Peng (2021), the operating
revenue of an enterprise’s unit carbon emissions is used to measure carbon performance. The 5 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 Table 1. Variable definition. (1) Explained variables Variable Type
Variable Name
Symbol
Definition
Explained Variable
Total Cost of Capital
K
The cost of raising and using funds
Cost of Debt Capital
Kd
The cost of bearing liabilities
Cost of Equity Capital
Ke
The price of issuing common stock
Explanatory Variable
Green Technology Innovation
GTI
It is aimed at reducing environmental
pollution and realizing sustainable
development of ecological environment
and social economy
Disruptive Green Technology Innovation
Inb
The number of green invention patents
Progressive Green Technology Innovation
Inr
The number of green utility patents
Mediating Variable
Carbon Performance
CP
The operating revenue of an enterprise’s
unit carbon emissions
Regulating Variable
Independence of the Board of Directors
BI
Proportion of the number of independent
directors in the scale of the board of
directors
Board Gender Diversity
BGD
The number of female directors as a
percentage of board size
Board Interlocking
IB
The logarithm of the number of listed
companies in which the average
interlocking board member concurrently
serves
Control Variable
Enterprise Size
Size
The logarithm of the total assets of the
business
Growth
Grow
Current main business revenue growth
rate
Asset-liability Ratio
Lev
Ratio of total liabilities to total
assets
Return on Total Assets
ROA
Ratio of net profit to average annual
total assets
Profitability
Profit
The company’s gross profit margin on
sales for the year
Book Ratio
B/M
The ratio of book value of owners’
equity to market value
Listing Years
Age
The logarithm of the distance between
the reporting year and the listing year higher the value is, the better the carbon performance will be. Enterprise carbon emissions
cannot be obtained directly, so we use operating costs and industrial carbon emissions to
obtain. The formula for calculating carbon performance is shown below. higher the value is, the better the carbon performance will be. Enterprise carbon emissions
cannot be obtained directly, so we use operating costs and industrial carbon emissions to
obtain. The formula for calculating carbon performance is shown below. Carbon performance (CP) = enterprise revenue/(Enterprise operating cost * Industry car-
bon emission/industry operating cost) (4) Regulating variables This study selects board independence, board gender diversity and board interlocking as
three dimensions of board characteristics. The independence of the board of directors (BI) is
expressed by the proportion of the number of independent directors in the scale of the board
of directors. Board gender diversity (BGD) is expressed as the number of female directors
as a percentage of board size; Board interlocking (IB) is expressed as the logarithm of the
number of listed companies in which the average interlocking board member concurrently
serves. 4.1 Descriptive Statistics The minimum value of capital cost (K) is 0.0101, the maximum value is 0.132, and the
average value is 0.0598, indicating that the financing cost of some companies is high. The
mean value of green technology innovation (GTI) is 0.485, the minimum value is 0, and
the maximum value is 7.810. It can be seen that the green technology innovation level of
listed companies with heavy pollution varies greatly, and some enterprises do not pay enough
attention to green technology innovation, and their green technology innovation efforts need
to be improved. The mean value of carbon performance (CP) is 6.016, the minimum value is
0.00652, the maximum value is 187.4, and the standard deviation is 12.00, indicating that the
gap between the carbon performance of different enterprises is increasing. Many enterprises
did not actively carry out carbon emission reduction management from 2006 to 2019, and
there is still a large room for improvement of their carbon performance. 3.3 Model Setup Model Setup
order to test our hypotheses, we employ the following econometric models:
Kit = α0 + β1GTIit + β2S izeit + β3Growit + β4Levit + β5ROAit + β6Profitit+
+β7 B
M it + β8Ageit + εit. (3)
CPit = α0 + β1GTIit + β2S izeit + β3Growit + β4Levit + β5ROAit + β6Profitit+
β7 B
Mit + β8Ageit + εit. (4)
Kit = α0 + β1CPit + β2S izeit + β3Growit + β4Levit + β5ROAit + β6Profitit+
β7 B
Mit + β8Ageit + εit. (5)
Kit = α0 + β1CPit + β2GTIit + β3S izeit + β4Growit + β5Levit + β6ROAit + β7Profitit+
β7Pro fitit + β8
B
Mit+β9Ageit+εit . (6)
CPit = α0 + β1GTIit + β2BIit + β3BGDit + β4IBit + β5GTIit ∗BIit + β6GTIit ∗BGDit+
β7GTIit ∗IBit + β8S izeit + β9Growit + β10Levit + β11ROAit + β12Profitit+
β13 B
Mit + β14Ageit + εit. (7) 3.3 Model Setup In order to test our hypotheses, we employ the following econometric models: Kit = α0 + β1GTIit + β2S izeit + β3Growit + β4Levit + β5ROAit + β6Profitit+
+β7 B
M it + β8Ageit + εit. (3) Kit = α0 + β1GTIit + β2S izeit + β3Growit + β4Levit + β5ROAit + β6Profitit+
+β7 B
M it + β8Ageit + εit. (3) (3) (6) CPit = α0 + β1GTIit + β2BIit + β3BGDit + β4IBit + β5GTIit ∗BIit + β6GTIit ∗BGDit+
β7GTIit ∗IBit + β8S izeit + β9Growit + β10Levit + β11ROAit + β12Profitit+
β13 B
Mit + β14Ageit + εit. (7) (7) (5) Control variables The control variables selected in this study include enterprise size (S ize ), growth (Grow),
asset-liability ratio (Lev), return on total assets (ROA), profitability (Profit), book ratio ( B
M)
and listing years (Age). The definition of all the above variables are shown in table 1. 6 6 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023) 4.2 Correlation Analysis In this study, Stata16.0 was used to test the correlation of sample data. The correlation coef-
ficient between enterprise capital cost and green technology innovation is negative and sig-
nificant at the level of 1%, which is consistent with hypothesis 1. The correlation coefficient
between carbon performance and green technology innovation is significantly positive at the
level of 10%, which is consistent with hypothesis 2. The correlation coefficient between car-
bon performance and cost of equity capital and cost of debt capital is significantly negative
at the level of 1%, which is consistent with hypothesis 3. The correlation coefficients of the
main variables are all significantly correlated at 1% or 5% level, and the correlation coeffi-
cients among all variables are less than 0.5, indicating that there is no serious multicollinearity
problem in the model. 7 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 Table 2. Regression Analysis for Hypothesis 1
Model1
Model2
Model3
Modle4
Model5
Model6
Model7
Variable
K
Kd
Kd
Kd
Ke
Ke
Ke
GTI
-0.031***
-0.063***
-0.036**
(-2.64)
(-4.58)
(-2.08)
Size
-0.144***
-0.080***
-0.079***
-0.090***
-0.214***
-0.207***
-0.220***
(-8.34)
(-3.93)
(-3.87)
(-4.40)
(-8.95)
(-8.61)
(-9.33)
Grow
0.041***
-0.006
-0.006
-0.005
0.007
0.007
0.007
-3.66
(-0.44)
(-0.44)
(-0.36)
-0.46
-0.42
-0.48
Lev
-0.719***
0.298***
0.297***
0.301***
0.088***
0.086***
0.090***
(-47.08)
-14.89
-14.79
-15.04
-4.98
-4.82
-5.09
ROA
-0.100***
-0.119***
-0.120***
-0.120***
-0.016
-0.017
-0.016
(-5.70)
(-5.35)
(-5.36)
(-5.37)
(-0.78)
(-0.82)
(-0.77)
Profit
-0.112***
-0.040**
-0.039**
-0.040**
-0.169***
-0.170***
-0.169***
(-7.39)
(-2.05)
(-2.01)
(-2.07)
(-9.54)
(-9.57)
(-9.47)
B/M
0.067***
0.141***
0.138***
0.143***
0.077***
0.075***
0.078***
-4.14
-7.18
-7.05
-7.28
-3.81
-3.68
-3.89
Age
-0.055***
-0.081***
-0.080***
-0.083***
-0.016
-0.016
-0.016
(-4.19)
(-4.72)
(-4.69)
(-4.83)
(-0.97)
(-1.01)
(-1.01)
Inb
-0.067***
-0.049***
(-5.14)
(-2.90)
Inr
-0.045***
-0.026
(-3.26)
(-1.43)
Constant
0.039***
-0.01
-0.01
-0.011
0.001
0.001
0.001
-3.35
(-0.72)
(-0.71)
(-0.73)
-0.1
-0.1
-0.1
Observations
4,014
4,054
4,054
4,054
4,439
4,439
4,439
R-squared
0.483
0.203
0.204
0.202
0.092
0.093
0.091
F test
0
0
0
0
0
0
0
r2_a
0.482
0.202
0.202
0.2
0.0903
0.0913
0.0898
F
459.6
114.5
115.6
113.4
53.28
54.31
52.77
Note: *, ** and *** are significant at the level of 10%, 5% and 1% respectively Table 2. Regression Analysis for Hypothesis 1 4.3 Hypotheses Testing (1) Green Technology Innovation and Capital Cost To verify hypothesis 1, multiple linear regression analysis was carried out on models (1)
- (7), and the results were shown in table 2. Green technology innovation has a negative
impact on both the cost of capital and the cost of debt capital, and the result is significant at
the 1% level, and the negative impact of green technology innovation on the cost of equity
capital is significant at the 5% level, indicating that improving the level of green technology
innovation can significantly reduce the cost of debt and equity capital and the total cost of
capital. Hypothesis 1 is verified. (2) Green Technology Innovation and Carbon Performance (2) Green Technology Innovation and Carbon Performance To verify hypothesis 2, multiple linear regression analysis was carried out on models (8)
- (10), and the results were shown in table 3. The total value of green technology innova-
tion and disruptive green technology innovation have a significant positive impact on carbon
performance at the level of 1%, and the progressive green technology innovation has a sig-
nificant positive impact on carbon performance at the level of 10%, indicating that improving
the level of green technology innovation can significantly improve the carbon performance
of enterprises. Hypothesis 2 is verified. (3) Carbon Performance and Capital Cost 8 https://doi.org/10.1051/e3sconf/202340901016 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 Table 3. Regression Analysis for Study
Model8
Model9
Model10
Model11
Model12
Model13
Model14
Variable
CP
CP
CP
K
Kd
Ke
K
CP
-0.119***
-0.122***
-0.072***
-0.117***
(-8.07)
(-6.82)
(-3.92)
(-7.95)
GTI
0.056***
-0.024**
-2.85
(-2.10)
Size
0.081***
0.073***
0.090***
-0.147***
-0.098***
-0.216***
-0.135***
-3.8
-3.47
-4.29
(-9.20)
(-5.08)
(-9.86)
(-7.84)
Grow
0.037**
0.037**
0.035**
0.047***
0.001
0.092***
0.045***
-2.13
-2.17
-2.07
-4.3
-0.06
-6.45
-4.17
Lev
-0.106***
-0.103***
-0.108***
-0.729***
0.291***
0.071***
-0.731***
(-7.34)
(-7.19)
(-7.48)
(-48.03)
-14.52
-3.92
(-47.98)
ROA
-0.121***
-0.120***
-0.120***
-0.114***
-0.132***
-0.056***
-0.114***
(-6.70)
(-6.67)
(-6.71)
(-6.49)
(-5.90)
(-2.73)
(-6.51)
Profit
0.599***
0.600***
0.600***
-0.039**
0.036
-0.121***
-0.042**
-30.12
-30.16
-30.11
(-2.24)
-1.61
(-5.56)
(-2.41)
B/M
-0.108***
-0.105***
-0.110***
0.055***
0.129***
0.063***
0.053***
(-6.53)
(-6.37)
(-6.63)
-3.37
-6.54
-3.12
-3.3
Age
0.078***
0.078***
0.080***
-0.045***
-0.071***
-0.01
-0.045***
-6.56
-6.53
-6.81
(-3.44)
(-4.19)
(-0.64)
(-3.46)
Inb
0.077***
-3.8
Inr
0.037*
-1.74
Constant
0
0
0
0.039***
-0.01
0.001
0.039***
(-0.00)
(-0.00)
(-0.00)
-3.37
(-0.71)
-0.09
-3.38
Observations
4,480
4,480
4,480
4,014
4,054
4,439
4,014
R-squared
0.405
0.407
0.403
0.491
0.209
0.103
0.491
F test
0
0
0
0
0
0
0
r2_a
0.404
0.406
0.402
0.49
0.207
0.101
0.49
F
169
174
167.9
474.2
120.7
65.64
423.8
Note: *, ** and *** are significant at the level of 10%, 5% and 1% respectively Table 3. Regression Analysis for Study In order to verify hypothesis 2, multiple linear regression analysis was carried out on
models (11) - (13), and the results were shown in table 3. (2) Green Technology Innovation and Carbon Performance The negative effects of carbon
performance on total cost of capital, cost of debt capital and cost of equity capital are all
significant at the level of 1%, indicating that enterprises’ active carbon emission reduction
measures and improvement of carbon performance can significantly improve their carbon
performance. Hypothesis 3 is verified. (4) Mediating Effect of Carbon Performance (4) Mediating Effect of Carbon Performance According to the first column of 2, the regression coefficient of capital cost to green
technology innovation is 0.031, and it is significant at the level of 1%, indicating that the
influence of green technology innovation on capital cost has an intermediary effect. It can be
seen from the first and seventh columns of table 3 that the regression coefficient of carbon
performance on green technology innovation is 0.031, the coefficient of capital cost on carbon
performance is -0.117, and the coefficient of green technology innovation is -0.024, both of
which are significant. Therefore, carbon performance plays a partial mediating effect. (5) Moderating Effect of Board Characteristics According to the regression result, the interaction term between green technology in-
novation and board independence and the regression coefficient between green technology
innovation and board gender diversity are both negative and significant. Therefore, board 9 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 https://doi.org/10.1051/e3sconf/202340901016 independence and board gender diversity play a moderating role in the influence of green
technology innovation on carbon performance. The regulating effect of board linkage is not
significant. independence and board gender diversity play a moderating role in the influence of green
technology innovation on carbon performance. The regulating effect of board linkage is not
significant. 4.4 Robustness Test Some studies have pointed out that the influence of green patents on enterprises has a hys-
teresis effect. Therefore, in the robustness test, the regression test is carried out on the green
technology innovation variables with a lag of one stage, and the results have not changed
substantially from the results above, which indicates that the conclusions of this study have
certain robustness and reliability to a certain extent. 4.5 Discussion and Conclusion We integrate the latest research and theory on green innovation and cost of capital. The direct
effect, mediating effect and the moderating effect of the hypothesis in our study are sup-
ported. Green technology innovation influences the cost of debt capital and the cost of equity
capital through the mediating role of carbon performance. Meanwhile, the characteristics of
the board of directors play a moderating role in the relationship between green technology
innovation and carbon performance. The researchers found that green technology innovation can reduce carbon emissions
through product innovation, process innovation and end-treatment technology innovation. As a manifestation of corporate responsibility and moral level, carbon performance is widely
concerned by investors. Companies with good carbon performance can gain the trust of
investors and thus reduce the cost of capital. Consistent with the above views, our results
also support the hypothesis that green technology innovation and carbon performance are
negatively correlated with firms’ cost of capital. The results of our study are of practical significance to the development of green econ-
omy. Firstly, the government should strengthen the incentives and penalties for carbon emis-
sion reduction, link the effect of emission reduction to the economic costs of enterprises, and
encourage heavy polluting enterprises to actively carry out green production. Secondly, en-
terprises should actively respond to national policies, fulfill the social responsibility of carbon
emission reduction, and enhance the level of green technology innovation. Finally, compa-
nies should adjust the structure of the board of directors according to the actual situation and
improve the effectiveness of the supervisory function of the board of directors. In the com-
plex and changeable environment, companies should constantly improve their adaptability
and strive to achieve coordinated development of environmental and economic benefits. This research was supported by Sichuan University Innovation Spark Project, grant number 2019hhs-17
and the Fundamental Research Funds for the Central Universities, grant number skbsh2020-23. This research was supported by Sichuan University Innovation Spark Project, grant number 2019hhs-17
and the Fundamental Research Funds for the Central Universities, grant number skbsh2020-23. ] F. Dong, J. Zhu, et al, Environmental Science and Pollution Research 29, 35780 (2022) [6] G. Zhou, L. Liu, S. Luo, Business Strategy and the Environment 31, 3371 (2022) g
g
9] S. Khan, D.I. Godil, et al, Sustainable Development 30, 275 (2022) [10] S. Yao, Y. Pan, et al, Energy Economics 101, 105415 (2021) [7] R. Garzón-Jiménez, A. Zorio-Grima, Sustainability 13, 696 (2021) y
(
)
] C. Jiang, F.A. Zhang, C.A. Wu, Science of The Total Environment 764, 144248 (2021) [11] B.K. Agyei-Mensah, Corporate Governance International Journal of Business in Soci-
ety 21, 569 (2021) [6] G. Zhou, L. Liu, S. Luo, Business Strategy and the Environment 31, 3371 (2022)
[7] R. Garzón-Jiménez, A. Zorio-Grima, Sustainability 13, 696 (2021)
[8] C. Jiang, F.A. Zhang, C.A. Wu, Science of The Total Environment 764, 144248 (2021)
[9] S. Khan, D.I. Godil, et al, Sustainable Development 30, 275 (2022)
[10] S. Yao, Y. Pan, et al, Energy Economics 101, 105415 (2021)
[11] B.K. Agyei-Mensah, Corporate Governance International Journal of Business in Soci-
ety 21, 569 (2021) References [1] M. Wang, L. Y, et al, Journal of Environmental Management 297, 113282 (2021)
[2] M. Du, S. Chai, et al, Environmental Science and Pollution Research 29, 47661 (2022)
[3] H. Beladi, J. Deng, M. Hu, International Review of Financial Analysis 76, 101785
(2021)
[4] X. Xiang, C. Liu, M. Yang, International Review of Economics & Finance 78, 321
(2022)
[5] F. Dong, J. Zhu, et al, Environmental Science and Pollution Research 29, 35780 (2022) 10 E3S Web of Conferences 409, 01016 (2023)
ICMSEM 2023 https://doi.org/10.1051/e3sconf/202340901016 11 11
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English
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Can Simulator Sickness Be Avoided? A Review on Temporal Aspects of Simulator Sickness
|
Frontiers in psychology
| 2,018
|
cc-by
| 14,840
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Can Simulator Sickness Be Avoided?
A Review on Temporal Aspects of
Simulator Sickness Natalia Du˙zma ´nska1*, Paweł Strojny1,2 and Agnieszka Strojny1,2 1 R&D Unit, Nano Games sp. z o.o., Kraków, Poland, 2 Institute of Applied Psychology, Faculty of Management and Social
Communication, Jagiellonian University, Kraków, Poland Simulator sickness is a syndrome similar to motion sickness, often experienced during
simulator or another virtual reality (VR) exposure. Many theories have been developed
or adapted from the motion sickness studies, in order to explain the existence of the
syndrome. The simulator sickness can be measured using both subjective and objective
methods. The most popular self-report method is the Simulator Sickness Questionnaire. Attempts have also been made to discover a physiological indicator of the described
syndrome, but no definite conclusion has been reached on this issue. In the present
paper, three temporal aspects of the simulator sickness are discussed: the temporal
trajectory of the progression of simulator sickness, possibility of adapting VR users in
advance and persistence of the symptoms after VR exposure. Evidence found in 39
articles is widely described. As for the first aspect, it is clear that in most cases severity
of the simulator sickness symptoms increases with time of exposure, although it is
impossible to develop a single, universal pattern for this effect. It has also been proved,
that in some cases a threshold level or time point exists, after which the symptoms
stop increasing or begin to decrease. The adaptation effect was proved in most of the
reviewed studies and observed in different study designs – e.g., with a couple of VR
exposures on separate days or on 1 day and with a single, prolonged VR exposure. As for the persistence of the simulator sickness symptoms after leaving the VR, on the
whole the study results suggest that such an effect exists, but it varies strongly between
individual studies – the symptoms may persist for a short period of time (10 min) or
a relatively long one (even 4 h). Considering the conclusions reached in the paper, it
is important to bear in mind that the virtual reality technology still evokes unpleasant
sensations in its users and that these sensations should be cautiously controlled while
developing new VR tools. Certainly, more research on this topic is necessary. Edited by:
Alb
Ri Edited by:
Albert Rizzo,
University of Southern California,
United States Reviewed by:
Eugene Nalivaiko,
University of Newcastle, Australia
Inmaculada Remolar Remolar,
Universitat Jaume I, Spain Reviewed by:
Eugene Nalivaiko,
University of Newcastle, Australia
Inmaculada Remolar Remolar,
Universitat Jaume I, Spain *Correspondence:
Natalia Du˙zma ´nska
nduzmanska@nano-games.com Specialty section:
This article was submitted to
Human-Media Interaction,
a section of the journal
Frontiers in Psychology Received: 28 June 2018
Accepted: 16 October 2018
Published: 06 November 2018 Keywords: simulator sickness, temporal aspects, time, virtual reality, VR REVIEW published: 06 November 2018
doi: 10.3389/fpsyg.2018.02132 November 2018 | Volume 9 | Article 2132 Citation: Du˙zma ´nska N, Strojny P and
Strojny A (2018) Can Simulator
Sickness Be Avoided? A Review on
Temporal Aspects of Simulator
Sickness. Front. Psychol. 9:2132. doi: 10.3389/fpsyg.2018.02132 The simplest definition of virtual reality states that is “the use of computer-generated virtual
environments and the associated hardware to provide the user with the illusion of physical presence
within that environment” (Jayaram et al., 1997, p. 576). Virtual reality systems are widely used
in the fields of scientific research (e.g., Anderson-Hanley et al., 2011), anxiety disorders therapy November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 1 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. (e.g., Gerardi et al., 2010; Łukowska, 2011) or for professional
training [e.g., in the army – (Braithwaite and Braithwaite, 1990);
fire department – (Bliss et al., 1997); aviation – (Kennedy et al.,
2000); medicine – (Bric et al., 2016)]. simulator training may lead to alleviation of the simulator
sickness symptoms. A very detailed list of variables, which may
have influence on simulator sickness occurrence and severity,
may be found in the report by Kolasinski (1995). Many different virtual reality hardware systems and devices
have been developed over the years and will be briefly described
herein. Nowadays, the most popular are the head-mounted
devices (HMDs), such as HTC Vive or Oculus Rift. The VR
user wears a headset and holds two controllers which enable
them to move and interact in a three-dimensional environment. Such devices are now being sold commercially. According to
a recent Business Insider report (Hollander, 2018), there are
four main VR headset types: stand-alone (which do not need
any additional hardware to function), smartphone-powered, PC-
powered and game console-powered. The report predicts that
the stand-alone headsets will grow in popularity in the coming
years. This could be of advantage for research employing the VR
technology, as eliminating the wire which connects the headset
to a PC or a console will make conducting experiments with
multiple participants at the same time much easier. The main aims of this paper are to summarize the existing
knowledge on simulator sickness with emphasis on its temporal
aspects, to provide an overview of research on this topic and to
propose further research directions and practical implications for
virtual reality developers. Firstly, the most common theories which could serve as
an explanation of the simulator sickness phenomenon will
be discussed. Citation: Secondly, the methods of simulator sickness
measurement, both subjective and objective, will be described in
detail. Thirdly, three temporal aspects of simulator sickness will
be discussed based on evidence found in empirical studies. And
lastly, general conclusions drawn from the reviewed studies and
practical implications for further research will be provided. Theories Potentially Explaining Simulator
Sickness Another example of a VR system is a CAVE (cave automatic
virtual environment). In such system, the environment is
displayed and generated on several projectors, directed to the
walls of the room and the user wears 3D glasses. Several theories have been developed to explain why individuals
suffer from motion sickness. According to authors focused on
virtual simulators, they may be also applicable in the field of
simulator sickness during exposure to virtual reality (Brooks
et al., 2010). The Sensory Conflict Theory, proposed by Reason
and Brand (1975), explains motion and simulator sickness
through a conflict that arises between different sensory systems;
namely the signals from visual, vestibular and non-vestibular
proprioceptors differ from one another and inevitably differ with
expectations based on previous experience. According to the
theory, only the conflict between present sensory information
and that retained from immediate past elicits sickness. That is
claimed on the basis of observation that continuous exposition
to a stimulus results in eventual disappearance of symptoms
(adaptation) even if the present conflict still exists (Reason, 1978). The vestibular system, which is responsible for perception and
detection of direction, is crucial for occurrence of simulator and
motion sickness symptoms (Reason and Brand, 1975). Different additional devices are used in order to provide the
VR user with a realistic, multisensory experience. For example,
treadmills are often used to simulate movement in the virtual
environment (e.g., Jaeger and Mourant, 2001; Sinitski et al.,
2018). For driving and flight simulators, a part of a plane cockpit
or a body of a car may be used (e.g., Feenstra et al., 2011; Domeyer
et al., 2013; Reinhard et al., 2017). Definition of Simulator Sickness Simulator sickness is a syndrome similar to motion sickness and
can be experienced as a side effect during and after exposure
to different virtual reality environments. Originally, the term
“simulator sickness” was linked to effects induced by simulators
consisting of a platform, often mobile, and with the visual stimuli
generated by a computer, without head-tracking. The invention
of HMDs led to developing another term, “cybersickness,” as
such devices generate another issues, which may also lead to
the unpleasant symptoms, such as the delay between actual head
movements and the generated image. However, nowadays both of
the terms are being used by researchers to describe the unpleasant
symptoms evoked by the virtual reality technology (e.g., Sharples
et al., 2008; Bruck and Watters, 2011; Serge and Moss, 2015; Lee
et al., 2017). Reason (1978) proposed the Neural Mismatch Model which
identifies the source of simulator sickness in discrepancies
between expectations derived on a basis of present moves and
contents kept in the neural store which, according to Reason
(1978), contains information about typical combination of
command signals (efference) and the integrated patterns of inputs
from the orientation senses generated by them (reafference). That
is the theoretical mechanism of adaptation to motion sickness
observed for example by Reason and Brand (1975). To conclude,
according to this model, sickness occurs when the received
sensory information does not match one’s experiences based on
past situations. The symptomatology and severity of the malaise depend
on many variables – e.g., age, gender, stress, anxiety, one’s
individual proneness to such ailment or the characteristics of the
simulator itself (Kolasinski, 1995; Cobb et al., 1999; Mourant and
Thattacherry, 2000; Jaeger and Mourant, 2001; Lin et al., 2002;
Sharples et al., 2008; Brooks et al., 2010; Bruck and Watters,
2011; Classen et al., 2011; Moss and Muth, 2011; Zu˙zewicz et al.,
2011; Biernacki and Dziuda, 2012; Dziuda et al., 2014; Helland
et al., 2016; Lee et al., 2017). Lin et al. (2002) have also suggested
that a relationship between one’s enjoyment experienced during Another theory, widely used to explain simulator and motion
sickness, is the Postural Instability Theory. Riccio and Stoffregen
(1991) have criticized the Sensory Conflict Theory – they state
that sensory conflicts such as those described by Reason and
Brand (1975) happen very often and are nothing unusual. Frontiers in Psychology | www.frontiersin.org Measurements of Simulator Sickness
Self-Report Measures Simulator Sickness Questionnaire (SSQ) Originally published by Kennedy et al. (1993), the Simulator
Sickness Questionnaire (SSQ) is a tool widely used for assessing
the subjective severity of simulator sickness symptoms. In the
pre-experiment part of the questionnaire, information about
the current physical condition and participant’s experience with
simulators is collected. The questionnaire consists of 16 items,
derived from the Pensacola Motion Sickness Questionnaire
(MSQ). Data collected during previous simulator studies using
the MSQ was gathered and the items describing symptoms with
less than 1% frequency of appearance or with no change in
frequency between pre- and post-exposure were excluded from
further analyses (12 of 28 items of MSQ). The severity of each
symptom in the SSQ is measured on a four-point scale (0-3). The two aforementioned theories are most prevalent in
the literature concerning simulator sickness. Other theoretical
approaches to this phenomenon have been developed as well. The Eye Movement Theory developed by Ebenholtz (1992,
2001), uses the vagus nerve stimulation as an explanation for
motion and simulator sickness. The mechanism is initiated by
two specific eye movements (namely the optokinetic nystagmus
and vestibular ocular response1) creating tension in the muscles
of the eye, which stimulates the vagus nerve and leads to
unpleasant symptoms such as difficulty concentrating, eye strain
and headaches. According to the results of a factor analysis, the items
of the SSQ can be grouped into three factors: nausea
(e.g., sweating, difficulty concentrating, stomach awareness),
oculomotor disturbance (e.g., headache, eyestrain, blurred
vision) and disorientation (e.g., fullness head, dizziness with
open and closed eyes, vertigo). The factors are not entirely
independent – some of the items were included in more than one
factor, e.g., the score on difficulty focusing is used to assess the
severity of oculomotor disturbance and disorientation. In total,
there are five such items. To calculate scores on each factor, all
relevant items’ scores should be added (each factor consists of
7 items) and multiplying the obtained sum by a specific weight:
for nausea by 9.54 (therefore the scores on this scale range from
0 to 200.34), for disorientation by 13.92 (scores ranging from 0
to 292.32) and for oculomotor disturbance by 7.58 (with scores
ranging from 0 to 159.18). Bruck and Watters (2011) have also attempted to develop a
comprehensive theory of cybersickness. Measurements of Simulator Sickness
Self-Report Measures They suggest a following
chain of causality: an increase in arousal leads to changes in
respiration rate, which causes carbon dioxide levels in cerebral
blood flow to decrease. These changes lead to the symptoms
of simulator sickness: dizziness, fatigue, difficulty concentrating,
fullness of head and anxiety. The authors propose dividing the
simulator sickness symptoms into four factors: (1) general
cybersickness
factor,
including
most
of
the
simulator sickness symptoms and indicated by feeling sick
(generally) and nausea, (2) vision factor, including respiration, eyestrain and headache, (3) arousal
factor,
including
respiration,
blurred
vision,
vertigo, difficulty focusing and concentrating and stomach
awareness, (4) fatigue factor, including the following symptoms: eyestrain,
fullness of head, self-reported fatigue, dizziness and blurred
vision. The overall score can be measured as well and it can serve
as an indicator of total severity of the simulator sickness. It is
calculated by adding scores on the 16 items and multiplying
the achieved sum by 3.74, therefore the total score can range
from 0 to 179.52. In addition to the quantitative data, qualitative
information about peculiar sensations during the simulator
experience and symptoms other that those listed in the main
part of the questionnaire can be gathered (Kennedy et al., 1993;
Biernacki et al., 2016). The Evolutionary Theory, proposed by Treisman (1977),
originally explains the motion sickness, but its assumptions can
be adapted to simulator conditions as well. Treisman (1977)
suggests that people experience motion sickness, because –
evolutionally – our species has not managed to adapt to new
transportation modes yet. Therefore, the human body reacts to
sensory conflicts with nausea – it acts as if poison had been
ingested (Brooks et al., 2010). It can be assumed that similar
reasons may stand behind the simulator sickness symptoms,
as the human species had even less time to adapt to the
virtual reality conditions. Although this theory does not propose
any physiological mechanisms that may be responsible for Simulator Sickness Questionnaire has been used in numerous
studies (e.g., Lampton et al., 1994; Mourant and Thattacherry,
2000; Jaeger and Mourant, 2001; Lin et al., 2002; Min et al., 2004;
Sharples et al., 2008; Bruck and Watters, 2009a,b, 2011; Moss
and Muth, 2011; Biernacki and Dziuda, 2014; Brunnström et al.,
2017). 1Optokinetic nystagmus – an eye pursues a target object from one end of a visual
field to the other. When the eye can pursue the object no further, it snaps back to
the far side of the visual field where it begins to pursue again. Vestibular ocular
response – responsible for keeping a target object on the fovea, the center of the
retina where one’s vision is sharpest, when the head is turning. Definition of Simulator Sickness Furthermore, the difference (or lack of it) between what one’s November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 2 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. experiencing simulator sickness, it can give a valuable insight on
reasons why such ailment exists. senses experience and what an individual expects to feel is
immeasurable. They have proposed that the symptoms of motion
or simulator sickness may be experienced when one has been
exposed to long-lasting postural instability and has not yet
learned how to adjust to this situation and maintain proper
balance. The most vivid example of such phenomenon is the
feeling of instability one experiences when traveling by ship. A similar situation occurs during rollercoaster rides as well
(Riccio and Stoffregen, 1991). Physiological Measures Although a conclusion has not yet been reached on which
specific physiological parameters are the best indicators of
simulator sickness, some researchers (e.g., Min et al., 2004; Bruck
and Watters, 2011; Zu˙zewicz et al., 2011) have tested various
physiological variables and some of them appear promising
for evaluating simulator sickness without relying on self-report
measures or as a supportive method for questionnaires such
as SSQ. It has been noted (Min et al., 2004) that during
driving (and most of the studies concerning simulator sickness
were conducted with various driving simulators) the increase
of autonomic nervous system activation may relate to tension,
which then causes the heart rate and skin conductance to
increase and skin temperature to decrease. Moreover, the
physiological measures may be useful, as it has been proved that
the subjective evaluation of simulator sickness (e.g., with the
SSQ questionnaire) is slightly delayed when compared to the
physiological indicators (Min et al., 2004). Therefore, establishing
the best physiological indicators of simulator sickness could shed
more light on the exact triggering time of the syndrome and
therefore allow a more accurate description of the temporal
characteristics of simulator sickness. Other autonomic variables. In the course of research, some other
measures of the autonomic nervous system activity have been
tested. This paragraph will provide a brief overview of them. Kim
et al. (2005) have observed an interesting pattern of the gastric
tachyarrhythmia changes – in increased significantly in the first
4 min of virtual reality exposure and then continued to increase
until the final 4 min of a 9.5 min trial. The eyeblink rate did also
change in the study by Kim et al. (2005) – it decreased in the first
minute of the exposure (when compared to the baseline rate), but
then increased and in the middle of the trial it was significantly
higher than the baseline level. Another interesting measure is
the skin temperature – as observed by Kim et al. (2005), when
measured at the fingertip, the skin temperature decreased in
the middle of the trial and remained significantly lower than
the baseline level even after leaving the VR environment. Such
decrease in skin temperature was also observed by Chung et al. (2007) and Brooks et al. (2010). Furthermore, according to
the results obtained by Kim et al. (2005), the respiratory sinus
arrhythmia (a variation in heart rate occurring during breath
cycle) increases during VR exposure. Heart rate Bruck and Watters (2011) propose that the heart rate may serve
as an indicator of simulator sickness, as it had been previously
proved that it correlates with such syndrome. In experiments
conducted by Cobb et al. (1999) heat rate tended to accelerate
during the simulator task and returned to a resting rate in
approximately 30 min after completing the task. Furthermore, the
heart rate of the participants who reported more severe simulator
sickness symptoms was also higher than the heart rate of the
individuals who did not experience such unpleasant sensations. Additionally, the heart rate of the participants who showed
symptoms of adapting to the VR (virtual reality) conditions
during several exposures decreased over the three sessions. Changes in heart rate were observed in a couple of studies. Dahlman et al. (2008, 2009) have noted an increase in heart
rate during a VR exposure. In a study by Gavgani et al. (2016)
the subjects participated in three roller coaster simulator rides,
which took place on separate days. For the first 2 days, an initial
tachycardia and tachypnoea that gradually lowered during the
ride was observed. No such patterns were discovered on the
third day. Physiological Measures As no unambiguous physiological indicators of simulator
sickness have been discovered, some examples of use of
physiological indicators for measuring this syndrome will be
described in this paragraph. Other self-report measures Other self-report measures
It should be noted that in some studies self-report methods
of
measurement
different
from
the
Simulator
Sickness
Questionnaire had been used – Brooks et al. (2010) report having
used the Motion Sickness Assessment Questionnaire, Mali´nska
et al. (2014) used a self-developed, concise questionnaire and
Helland et al. (2016) measured subjective severity of simulator
sickness symptoms simply by asking – “To what extent did
you experience simulator sickness during the driving test?”. Several other authors used other short self-report measures (e.g.,
McCauley et al., 1990; Helland et al., 2016; Reinhard et al., 2017). As these methods are either a questionnaire originally created for
measuring a different ailment or have not been psychometrically
tested, they will not be described more widely herein. Measurements of Simulator Sickness
Self-Report Measures The brevity and simplicity of the questionnaire are its
assets, as in many study designs it is being used at least twice
to assess the changes in occurrence and severity of simulator
sickness’ symptoms. In most cases SSQ is used as a paper-and-
pencil test, but it can also be conducted orally – as in Min et al. (2004) study, where the items of the questionnaire were read to
the participants by the experimenter (according to the authors of November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 3 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. the study, conducting the SSQ orally requires only circa 30–40 s)
or in the study by Moss and Muth (2011), where a cassette was
pre-recorded and then played back to the participants. Kim et al. (2005) – in their study a decrease in the respiration
rate (when compared to baseline levels) was observed. What is
more, a positive correlation was observed between respiration
rate and the Simulator Sickness Questionnaire scores (for all of
the subscales and the total score, with the r values oscillating
between 0.342 for nausea and 0.392 for the total score). Frontiers in Psychology | www.frontiersin.org Autonomic nervous system Respiration (breaths per minute). According to one of the theories
of simulator sickness (or “cybersickness,” as referred to by the
authors; Bruck and Watters, 2011), the changes in respiration
rate are crucial to evoking the unpleasant symptoms, especially
when the person subjected to a virtual reality environment
has no control. Respiration loads two factors in the theory of
cybersickness developed by Bruck and Watters (2011): Vision
and Arousal. They even propose that hyperventilation may be
the cause of arousal experienced by individuals exposed to high
levels of movement in a virtual reality. Empirical evidence of
changes in respiration rate during VR exposure were achieved by What is interesting about the above mentioned measures is
the fact that for all of them, except for skin temperature, positive
correlations with the subjective measurement of the simulator
sickness (SSQ) were observed (Kim et al., 2005), with the Pearson
r values ranging between 0.265 (eyeblink rate and oculomotor
disturbance scale) and 0.359 (gastric tachyarrhythmia and nausea
scale). Furthermore, in a study by Gavgani et al. (2016), a rapid
increase in finger skin conductance levels was observed during Frontiers in Psychology | www.frontiersin.org November 2018 | Volume 9 | Article 2132 4 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. the first minute of the VR exposure – the subjects experienced
increased sweating in the finger; this trend was present until
the end of the experimental trial. However, what is the most
interesting, in the cited study phasic SCL activity in the forehead
was observed during the experimental trial (compared to none
during baseline measurement). This activity – and only this of
all of the measured physiological responses – was proven to be
associated with the experience of nausea. Cobb et al. (1999) report using a more complex set of postural
stability tests: in their research program, the following methods of
measurement were used: measuring the extent to which a static
posture could be held, measuring the extent of hip sway over a
30 s period, walking on the floor and navigating over an uneven
path with open eyes. Additionally, the authors administered two
scales: task difficulty scale and subjective postural stability scale
(Postural Stability Questionnaire – PSQ; Hamilton et al., 1989)
after completing all the tasks. associated with the experience of nausea. Central nervous system As a measure of the central nervous system activation, EEG has
been used in some of the studies (Min et al., 2004; Chung et al.,
2007). According to the results obtained by Min et al. (2004),
there are significant differences in brainwaves patterns between
rest and driving in a driving simulator. Such results have been
obtained both for the frontal (Fz) and parietal lobe (Cz), giving
similar patterns. After 5 min of simulator exposure, the δ/total
increased and α/total, ß/total and θ/total decreased significantly
in 5–35 min of simulator exposure. Furthermore, the δ/total at
Fz correlates positively, and both θ/total and ß/total at Fz and
Cz negatively, with the total SSQ score. The correlation with the
SSQ score was the strongest for the θ/total parameter (r = −0.842
at Fz and r = −0.93 at Cz), therefore the authors of the study
(Min et al., 2004) propose that it could serve as the most effective
physiological indicator of simulator sickness occurrence. This
proposal was also supported by Chung et al. (2007). Temporal Aspects of Simulator Sickness Temporal Aspects of Simulator Sickness
Questions regarding the temporal characteristics of the virtual
reality experience which influence simulator sickness seem to
recur in many papers (e.g., Kennedy et al., 2000; Moss and Muth,
2011; Domeyer et al., 2013). Although no unambiguous answers
have yet been provided, some useful and promising leads can be
found in literature and will be discussed herein. Since the main
goal of the present work was to review research on simulator
sickness from the temporal perspective, we decided to focus on
research regarding one (or more) of the three issues described
below. As Kennedy et al. (2000) have observed, there are two main
phenomena regarding the temporal aspect of simulator sickness:
that the severity of simulator sickness increases with the increase
of exposure duration during a single session, and that subjecting
a person to several repeated simulator exposures may result in
adaptation to the simulator conditions and thus in decrease
of simulator sickness symptoms severity. The aforementioned
aspects will be discussed in the present paper, as they seem to
be crucial as far as virtual reality development is concerned. Furthermore, according to some research (e.g., Moss and Muth,
2011; Biernacki and Dziuda, 2014; Mali´nska et al., 2014), the
simulator sickness symptoms appear to persist for some time after
the simulator exposure – this aspect will be discussed below as
well. Search Strategy A search of literature was performed in three electronic databases
(Web of Science ‘all databases,’ PsychArticles, Scopus) with no
publication date restriction. Since temporal aspects of simulator
sickness rarely are the main focus of studies, we decided
to retrieve a wide range of articles using the broadest term
“simulator sickness” and assuming intensive article selection
in subsequent stages. Thousand two hundred records were
obtained. The search was conducted on 19th April 2018. Behavioral Measures – Postural Stability Tests Behavioral Measures – Postural Stability Tests
When relying on the Postural Instability Theory (Riccio and
Stoffregen, 1991), one could use a postural stability test in order
to assess the lack of postural stability as a specific manifestation
of simulator sickness. Mourant and Thattacherry (2000) report
using such test in their study. It is a simple and brief method –
the person is asked to stand on the leg of their choice for 30 s
in two separate trials. The time of standing without putting the
other leg down is recorded and can be compared to the results
of the same test after experimental manipulation or can serve as
an independent measure. Although this method does not give
a broad insight into simulator sickness symptoms, it can be
useful when assessing changes in postural stability dependent on
simulator exposure. Autonomic nervous system The authors (Gavgani et al., 2016) give an interesting
interpretation of their findings, which may shed new light on the
physiological components of the simulator sickness experience. Some of the physiological symptoms (initial tachycardia,
tachypnoea, finger sweating) were present at the initial phase
of the VR exposure, in the time during which no self-reported
nausea was present. This conclusion is supported by the fact
that the above mentioned effects (except for finger sweating)
became non-significant on the last, third exposure. The authors
conclude that these symptoms may be evoked by emotions
and arousal connected with the novelty of the VR experience. The forehead sweating, however, is related to the development
of nausea. These results correspond with Treisman’s (1977)
evolutionary theory of motion sickness – reducing the body
temperature by increasing sweating serves as a survival strategy
during intoxication. Study Selection Authors conducted a title and abstract screening, in order to
exclude obviously irrelevant articles. Following keywords were
used: time, temporal, durat∗, adapt∗, persist∗. The articles which
titles and abstracts suggested an irrelevant area of research were
excluded on this basis (1086 records). In the second stage of the
screening process, full texts were retrieved and duplicated records
removed (34 records). For 10 records full texts were unavailable November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 5 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. and thus these records were excluded from the database as well. 70 articles were retrieved and evaluated in full text using the
following criteria: statistical significance of these effects. Nevertheless, these results
are interesting and worth being taken into consideration when
planning further experiments on extended VR exposure. Kennedy et al. (2000) examined SSQ data from a military
pilots’ flight simulator training database and categorized them
by exposure duration into four categories (0–1, 1–2, 2–3 h, 3
or more hours). An analysis of variance revealed that the mean
SSQ scores increase gradually when exposure duration increases. This trend proved to be statistically significant. No information
on statistical significance of differences between each of the
categories was given and it also should be noted that the analyzed
data concerned many different simulator environments. It was
also a between-subject design, therefore no conclusions about
individual temporal patterns of simulator sickness severity can be
made. (1) published in full in English or Polish, (2) based on empirical data, (3) temporal aspects of simulator sickness are investigated, (4) at least three time points for measurement of simulator
sickness (applicable for studies regarding the temporal
trajectory of the progression of simulator sickness), (5) the study subjects were human, (6) not investigating an intervention on simulator sickness, (7) testing simulators or other forms of virtual reality (not 3D
movies or desktop applications), (8) measuring simulator sickness using psychometric methods
(questionnaires). Min et al. (2004) have tested various measures of simulator
sickness severity. In their study, both physiological and
self-report methods were used – the Simulator Sickness
Questionnaire was used for assessing the subjective severity of
the syndrome. Only the results of the psychometric measurement
will be reported herein. The Temporal Trajectory of the
Progression of Simulator Sickness Studies on simulator sickness have been conducted since 1990s,
using a wide array of virtual reality devices. Therefore, it is
important to emphasize the fact that direct comparisons between
studies using different hardware should be treated with extreme
caution. Some trends may be observed, but it should be always
borne in mind that for different devices and scenarios the
temporal patterns of simulator sickness may vary significantly. Moreover, as some of the cited studies have been conducted
almost 20 years ago, caution should be taken while making
conclusions. However, the insight provided by the researchers
appears to be valuable – while the technological development
might have solved some of the problems, the methodology and
qualitative conclusions are worth knowing. Moss and Muth (2011) tested several characteristics of HMDs
as possible factors influencing simulator sickness severity, as
well as the effect of a prolonged exposure. Only the latter
of these effects will be reported herein. The participants’ task
was to locate several objects in the virtual environment (a
virtual laboratory), according to verbally given instructions, using
only head movements. Each participant completed two practice
sessions and five 2-min trials with 1-min breaks between them. A number of Simulator Sickness Questionnaire results were
collected: before the experiment, after a practice session, after
each trial, 5 and 10 min after the experiment. It was noted that
the severity of simulator sickness symptoms increased with time –
a significant effect of duration of the VR exposure was revealed. The most severe symptoms were noted after the last trial. In one of the studies conducted by Cobb et al. (1999), four
subjects were immersed in a virtual reality environment for 1–
2 h. Simulator sickness severity was measured with the Simulator
Sickness Questionnaire. The participants were asked to remain
in the virtual reality for up to 2 h. All participants reported the
severity of symptoms increasing up to 1 h of exposure. Two
of the participants withdrew after an hour when the simulator
sickness symptoms experienced by them were too severe (mean
scores for nausea: M = 67, oculomotor disturbance: M = 57
and disorientation: M = 82). The remaining two participants
completed the 2-h immersion and reported that after 75 min
the severity of symptoms decreased greatly. Study Selection After baseline signal measurement
and pre-experiment SSQ administration, the participants of
the study drove a car simulator for 60 min, during which
physiological measurements were conducted and the SSQ was
completed orally after every 5 min of the simulator exposure,
as well as after completing the whole trial. The authors of
the study report that all of the participants showed symptoms
of nausea, disorientation (after 10 min of simulator exposure)
and oculomotor disturbance (after 25 min). The first significant
difference between the baseline SSQ score and trial score
appeared 10 min after beginning of the trial. The obtained results
confirm the hypothesis that the severity of simulator sickness
increases with time. After this process, 30 articles were retrieved. The authors
decided to add 5 articles on the basis of hand search and previous
knowledge. The final database consisted of a total of 35 articles
(41 studies). A flow chart describing the search and screening
process is presented in Supplementary Figure S1. Frontiers in Psychology | www.frontiersin.org (1) a gamepad,
( )
d The Temporal Trajectory of the
Progression of Simulator Sickness This suggests that
although the simulator sickness symptoms severity increases with
time, for some individuals it may be possible to adapt to the
VR environment during a single exposure. Unfortunately, the
sample in the study was too small to provide information on The type of walking interaction was the main topic explored
by Lee et al. (2017), but their results also provide information
about the temporal characteristics of simulator sickness. In their
experimental design three types of walking control were included: (2) sensors detecting hand movements and thus using specific
hand gestures for walking control, (3) a walk-in-place marching simulator with sensors and
portable walking simulators attached to legs. November 2018 | Volume 9 | Article 2132 6 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. thoroughly analyze the pattern of the symptoms during the whole
exposure. All of the participants of the study were exposed to three
different VR environments (a cartoon town, a realistic nature
environment and a low poly2 landscape in a three-step walking
interaction: they either experienced them in the order of:
gamepad, hand interface, walking simulator or in the reverse
order – each of the participants completed nine VR experiences in
total. The following variables were tested in the study: immersion,
presence and simulator sickness (measured with the Simulator
Sickness Questionnaire). The authors reported that the simulator
sickness symptoms became more severe with time, although on
the whole they were of moderate severity. An experiment conducted by Moss et al. (2008) consisted
of a short practice and five 2-min experimental trials. It was
confirmed that the simulator sickness (measured with the SSQ)
severity increases with time – it was more severe after the last
(5th) trial than: before the practice, after the practice, after
the 1st, 2nd, and 3rd trials. As no significant differences were
discovered between the 4th and 5th trial, it may be hypothesized
that after circa 9 min of exposure the simulator sickness has
reached its peak severity and would not become more unpleasant
if the exposure duration was even longer. In a similar study
(Moss et al., 2011), a phenomenon of the simulator sickness
severity (measured with the SSQ) increase with the increased
VR exposure duration was confirmed. The Temporal Trajectory of the
Progression of Simulator Sickness In the study by Classen and Owens
(2010), simulator sickness severity was measured at three time
points: before VR exposure, after a 5-min acclimation exposure
and after a 20-min trial. The obtained results indicated that the
simulator sickness severity increased between the baseline score
and both after-acclimation and post-exposure, but no significant
differences were discovered between the after-acclimation and
post-exposure scores. Therefore, one may presume, that the peak
simulator sickness severity in this study was reached very early. However, no data was gathered during the 20-min exposure, so
it is possible that some differences might have been discovered
if more systematic simulator sickness measurements had been
conducted. A similar procedure was conducted by Sinitski et al. (2018) – they measured the simulator sickness severity (with the
SSQ) before the exposure, after an acclimation period (which
lasted for 15 min) and after a 45-min trial. In this study, however,
only a small increase in the disorientation scale was observed after
the acclimation period and these symptoms decreased by the end
of the session. Again, the period between the second and the third
measurement was quite long, and therefore it is impossible to A systematic increase of simulator sickness severity (measured
with the SSQ) with time was confirmed by Chung et al. (2007),
Park et al. (2008), and Choi et al. (2009) during a 60-min trial and
Aldaba et al. (2017), who measured simulator sickness severity
with the SSQ, and by Reinhard et al. (2017), who used the Fast
Motion Sickness Scale (FMS – a single-item scale, the scores on
which range from 0 to 20). An increase of simulator sickness
symptoms severity was also observed by McCauley et al. (1990),
when it was rated on a 7-point scale (“normal, symptom-free” –
“severe discomfort, I am unable to continue”) – it increased
between measurement time points: before the exposure, in the
middle of the 10-min task and after the whole 10-min task. There
were 4 such trials and an increase in severity of the symptoms was
observed for all of them. A brief summary of all reviewed studies
is provided in the Supplementary Table S1. Several conclusions can be drawn from the perspective of
the temporal trajectory of the progression of simulator sickness
on the basis of the studies retrieved. The Temporal Trajectory of the
Progression of Simulator Sickness Serge and Moss (2015)
measured simulator sickness severity with the Revised Simulator
Sickness Questionnaire and proved that it does increase with time
when measured before VR exposure and after 8 and 16 min of
exposure. Singer et al. (1998) report as well that the simulator
sickness severity increases with time during a VR exposure,
although the difference between a “Mid-Experiment” and “Post-
Experiment” scores was not significant, suggesting an appearance
of a threshold simulator sickness level. The authors, however, did
not give information on how long the trials were, and therefore
any conclusions drawn from this study should be treated with
caution. Feenstra et al. (2011) have discovered a slightly different
phenomenon than the ones above described – in their study,
the differences in simulator sickness severity began to become
statistically significant after the participants spent 10 min in the
VR and then it increased until the end of the 20-min trial. The above-mentioned study results support the hypothesis,
that the severity of simulator sickness does increase with
time during a single exposure, to various extents, which
may differ depending on many variables (e.g., simulator
type and its characteristics, length of the whole exposure,
individual characteristics of the participants, etc.). Such results
are confirmed in many other studies, which will be briefly
summarized herein. Lo and So (2001) have confirmed that
the nausea severity (measured by one question with answers
ranging from 0 – “no symptom” to 6 – “moderate nausea,
want to stop”) increases linearly with time during a 20-min
exposure. Furthermore, the increase was significant in all of
the comparisons, except for the one between the 15th and
20th minute of the trial. A similar study was conducted (So
et al., 2001), and during a 30-min exposure the nausea ratings
(measured in the same way as above) increased as well, but the
differences were significant only in the 5th and 10th minute. Jarchow and Young (2007) have also measured the simulator
sickness severity by asking just a single question (with a scale
from 0 – “normal” to 20 – “about to vomit”). The subjects were
tested on two consecutive days, as the main aim of the study
was to assess the adaptation effect. It was however, discovered
as well that within a single session the severity of symptoms
increases, but this effect was observed in only one of the
experimental conditions. 2Consisting of a small number of polygons. November 2018 | Volume 9 | Article 2132 The Temporal Trajectory of the
Progression of Simulator Sickness Firstly, there is empirical
evidence to expect that severity of simulator sickness grows along
time of exposure, as several studies using various approaches
confirmed this hypothesis. In light of the reviewed research, this
trend seems to be stable regardless of the technological progress
in the field of VR presentation – the oldest studies (McCauley
et al., 1990) and the most recent one (Sinitski et al., 2018) lead
to the same conclusion. Even using between-subject comparisons
leads – in most of the cases – to the conclusion that the severity
of simulator sickness symptoms is greater when the exposure November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 7 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. duration is longer (e.g., Kennedy et al., 2000). However, it is
important to note that several moderators, which are not the
main focus of this paper, may play a role here – for example,
a simulator control method. Secondly, it is difficult to establish
a universal rule regarding the maximum time individuals can
spend in VR on the basis of the analyzed study results. On
the other hand, in most of the studies the simulator sickness
symptoms were experienced by all of the participants, not only
the ones who reported some kind of tendency to feel sick. identical virtual environment, but also by similar experiences,
such as video gaming. It has been shown that individuals with
more gaming experience and more self-reported “computer
skills” experienced less unpleasant symptoms during a VR session
(Häkkinen et al., 2006a). However, there are also studies which
do not support this claim (e.g., Häkkinen et al., 2002, 2006b),
therefore this issue needs further testing. Some adaptation effects were observed by Lampton et al. (2000). In their study, five separate VR immersions were
conducted (trainings 1 and 2 and missions 1, 2, and 3). The
SSQ was administered before and after each immersion. The
pre-post immersion score difference was significant for the first
training and the second and third mission, and not significant
for the second training and first mission. Therefore, it can be
concluded, that after the first training the participants achieved
some adaptation, but its effect wore offwith time. Similarly,
in the study by Domeyer et al. 3“In the SRS, participants were asked to raise their right hands above their heads
and grasp their right earlobe with their left hand, bend at the waist, and spin in a
clockwise direction under self-propelled condition. The participants spun 10 times
in 30 s (20 RPMs) and this constituted a trial” (Smither et al., 2008, pp. 330–331). The Temporal Trajectory of the
Progression of Simulator Sickness (2013), the adaptation effect
was obtained during a series of VR exposures conducted on
1 day, and in this study the subjects did adapt to the simulator
conditions (the effect was visible on the total Revised Simulator
Sickness Questionnaire score). Such effects may occur even
during a relatively short exposure, lasting 45 min in total (Sinitski
et al., 2018). In the quoted study the participants experienced an
increase in disorientation symptoms (measured with the SSQ) at
first, but it decreased by the end of VR exposure. However, such
effect was not confirmed for the remaining SSQ subscales and for
the total score. Additionally, it should be stressed that all of the
VR immersions of the two studies mentioned above took place
during a single day, which is quite unusual for studies exploring
adaptation effects – usually each of the immersions is conducted
on a separate day. Moreover, in some of the studies it was observed that the
simulator sickness severity increases with time, but after reaching
a certain level or after a certain amount of time it either begins
to decrease (Cobb et al., 1999; Sinitski et al., 2018) or remains
on the same level (Singer et al., 1998; Lo and So, 2001; So et al.,
2001; Moss et al., 2008; Classen and Owens, 2010). It can lead
to a conclusion, that during a single VR exposure it is possible
for some people to achieve simulator sickness adaptation (or, for
some simulator types, to evoke the adaptation effect). However,
it should be further explored whether this effect transfers to
subsequent VR sessions. On the other hand, it has also been proved that in some cases
the simulator sickness symptoms begin to show after some time
spent in VR and that this time threshold may be different for
various simulator sickness symptoms (Min et al., 2004; Feenstra
et al., 2011). Although this type of evidence is less prevalent
than the one described above, it is also worth being taken into
consideration. If the symptoms start being unpleasant after some
time, a single VR session should be short enough to prevent these
symptoms from occurring. Keeping in mind several moderators which may vary between
software (e.g., way of control, setting, graphics quality), another
strategy of testing temporal tolerance may be reasonable, viz. testing of certain VR software using precisely selected methods. The Temporal Trajectory of the
Progression of Simulator Sickness In order to make it possible, various methods need to be
integrated, and standardized methodology needs to be developed. In the study program developed by Cobb et al. (1999),
12 individuals participated in three consecutive virtual reality
sessions, each of which lasted 20 min, with a 1-week break
between the sessions. The simulator sickness symptoms severity
(measured with the Simulator Sickness Questionnaire) decreased
after each consecutive VR exposure, especially strongly for
the disorientation symptoms, which is consistent with the
results obtained by Sinitski et al. (2018). A similar effect of
adaptation was observed by Braithwaite and Braithwaite (1990)
and Bailenson and Yee (2006) – in their studies, the simulator
sickness symptoms (measured with the SSQ) decreased in
severity with time. Frontiers in Psychology | www.frontiersin.org Possibility of Adapting VR Users in
Advance (2000) analyzed data collected from 53
individuals
–
military
pilots,
who
participated
in
seven
consecutive helicopter simulator trainings. A repeated-measures
analysis of variance indicated that a monotonic decrease in
simulator sickness severity (measured with the SSQ) as a
function of flight number can be observed. Furthermore, for
some subjects a floor effect was observed – they reached a
total adaptation and the SSQ 0 score at some point, which did
not increase in further trials. This effect is responsible for the
deceleration in the decline of simulator sickness severity with
time. The authors propose that, according to their results, short,
repeated simulator exposures may be used in order to achieve
adaptation to the VR environment and to prevent simulator
sickness. Moreover, they further conclude that the decrease in
simulator sickness severity after several trials exceeds the increase
in severity with a single longer exposure duration. Helland et al. (2016) conducted an experiment on a
driving simulator, during which the effects of simulator
sickness, blood alcohol concentration and repeated simulator
exposures on driving performance were studied. Herein, only the
results concerning the relationship between repeated simulator
exposures and simulator sickness severity will be discussed. A driving simulator consisting of the body of a car and three
screens were used. The study included three 60-min long driving
tests in the simulator (with at least 2-day breaks between the
trials). After every trial each of the 20 participants assessed the
simulator sickness severity by rating it on a scale from 0 to
10 – they were asked – “To what extent did you experience
simulator sickness during the driving test?”. It is worth noting
that the mean simulator sickness score was very low in this study
(M = 2.5), which might have had an impact on the results. For the
participants, who did not interrupt any of the sessions (N = 13),
the mean simulator sickness severity score was 3.4 for the first,
1.8 for the second and 1.5 for the third session. Although the
simulator sickness severity appears to decrease with consecutive
sessions, the relationship was not statistically significant. It could
be hypothesized that had the authors used a more precise method
for assessing the simulator sickness severity, the results could
have been different. Possibility of Adapting VR Users in
Advance With the concise, one-question simulator
sickness severity measurement, the data given in the study report
do not fully support the hypothesis that simulator users adapt to
the virtual reality conditions. Brooks et al. (2010) conducted two studies – an exploratory
and a confirmatory one. In the exploratory study (a combination
of results of three independent studies), the participants were
immersed in a driving simulator. After a training session, four
5-min trials using slightly different conditions (e.g., a curvy
road instead of a straight one) were conducted. Between the
sessions, 2-min rest periods took place. Before and after each
trial, the participants completed the Motion Sickness Assessment
Questionnaire, the score of which served as an indicator of
simulator sickness severity. In the confirmatory study the main
difference was that the participants completed three 30-min
experimental trials in the same simulator. The authors report that
for some participants an adaptation effect was showed – their
symptoms’ severity increased at first, but then decreased as they
became accustomed to the simulator experience. No statistical
parameters were provided to describe this tendency, but it still
appears to be a promising information. y
Another study providing evidence supporting the hypothesis,
that simulator sickness adaptation is possible, was conducted by
Reinhard et al. (2017). Twenty eight participants took part in
the experiment, it had two parts, separated by 7–14 days of a
break. On the first day, six 20-min drives in a simulator took
place and on the second day there were four of them. To assess
the simulator sickness severity, two scales were used: the FMS
and the SSQ. The authors report an interesting pattern of results. During both sessions, the severity of symptoms did increase,
but that increase was less visible during the second session. Thus, an adaptation effect was proved, but it was not a complete
disappearance of symptoms. It was stressed in the paper, that the
first VR immersion should be treated with extreme caution – the
subjects should be monitored for unpleasant symptoms, the rests
between trials should be longer and the trials themselves shorter
than usual. For a summary of studies reviewed in this aspect, see
the Supplementary Table S2. pp
p
g
In a study by Newman et al. (2013) the subjects took part
in 6 VR immersions, five of which happened on consecutive
days and the last – 22 days after the first immersion. Possibility of Adapting VR Users in
Advance As Nader and Kruszewski (2013) suggest, simulator sickness can
be avoided when the virtual reality users are allowed a sufficient
amount of time to adapt to the simulator conditions. They
propose that such adaptation sessions may last for a number of
days and involve an increase in time spent in the simulator during
a single training, as well as an increased difficulty of the task. This
proposal appears to be congruent with the assumptions of some
of the theories. For example, according to the Neural Mismatch
Model (Reason, 1978), unpleasant symptoms occur when the
present sensory information is inconsistent with past experiences
of the individual. Gaining such experience in the specific virtual
reality environment might prevent the aforementioned conflict. Similarly, when one is allowed to immerse in virtual reality
several times, one can learn how to maintain balance in such an
environment – adaptation appears to be possible in the paradigm
of the Postural Instability Theory (Riccio and Stoffregen, 1991) as
well. It should also be emphasized that adaptation to simulator
sickness in VR may be achieved not only by exposure to an An interesting form of adaptation training was proposed by
Smither et al. (2008). They tested the ability of a self-propelled
rotation stimulation (SRS)3 to provide adaptation to simulator
sickness. Ten subjects took part in five SRS trials on separate days
and on the last day were exposed to a VR, and 10 other subjects
took part only in the latter part of the experiment, providing
a control group. The control group experienced significantly
more severe dizziness symptoms and higher total, disorientation
and oculomotor disturbance SSQ scores. These results show that
adaptation can be achieved without immersing in the virtual November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org Frontiers in Psychology | www.frontiersin.org 8 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. reality, but some form of pre-immersion training is needed to
prevent the unpleasant symptoms, as the participants from the
control group, who did not have a chance to adapt in any form,
suffered from the simulator sickness. simulator sickness severity should be chosen cautiously, as the
effects may slightly differ when using different methods. Probably
the best option would be to use at least two reliable methods of
comparison as it was done by Newman et al. (2013). Kennedy et al. Frontiers in Psychology | www.frontiersin.org Persistence of the Simulator Sickness
Symptoms After VR Exposure Tanaka and Takagi (2004) discovered, that not only the simulator
sickness symptoms persist for some time after VR exposure, but
also the length of the persistence is dependent on the initial
symptom severity. For the participants who suffered from severe
symptoms (total SSQ score of more than 60), the recovery time
was longer than 30 min. On the other hand, the subjects, who
experienced only slight symptoms (total SSQ score of 25 or less)
needed no longer that 5 min to recover from the simulator
sickness symptoms. Biernacki and Dziuda (2014) have studied simulator sickness
symptoms on a group of professional truck drivers, who
participated in three 30-min truck simulator drives – the first
one on a fixed-base platform with poor visibility (created by a
simulated fog) and twice with good visibility: on a fixed base and
on a mobile platform. The simulator consisted of a truck cabin
and a cylinder screen, on which all visual stimuli were displayed. The simulator sickness was measured with the Simulator Sickness
Questionnaire. The questionnaire was completed five times for
each exposure: before each trial, 2 and 30 min after all of the trials,
in the evening of the same day and next day, in the morning. The level of nausea, disorientation and oculomotor disturbance,
as well as the total severity of simulator sickness symptoms
proved to be dependent on the measurement time point. The
level of nausea was higher 2 min than 30 min after exposure. The
time profile for oculomotor disturbance, disorientation and the
total SSQ score turned out to be similar: the scores 2 min after
exposure were significantly higher than 30 min after exposure
and the baseline scores. The symptoms of simulator sickness
seem to retreat after leaving the virtual reality environment, but
only for the nausea factor the simulator sickness severity 30 min
post exposure did not differ significantly from the baseline score. Half an hour appears not to be sufficient time for the symptoms
to disappear completely. In another paper (Dziuda et al., 2014)
describing the results of this study, the authors state, that the
severity of nausea measured 2 and 30 min post exposure and in
the evening of the same day was significantly higher than in the
morning of the next day. In the study by Bos et al. Persistence of the Simulator Sickness
Symptoms After VR Exposure (2005) it was also confirmed that
the simulator sickness symptoms tend to persist for some time
after VR exposure, but they return to baseline [a score of 0 on
the Misery Scale (MISC); the maximum score on this scale is
10] in an hour following the end of the VR exposure for most
of the participants. Only 4 of 24 subjects did not fully recover
within 2 h post exposure, with the maximum MISC score of
3. These conclusions are supported by the results obtained by
Keshavarz et al. (2018). In their study simulator sickness was
measured using the FMS and 36 of 121 participants were forced
to drop out before the end of the experimental task. The total
time until recovery (operationalized by a FMS score of 1 or less)
between the participants who finished the task and those who
dropped out earlier varied significantly – the latter needed more
time to recover. However, only five subjects (all from the drop-out
group) did not fully recover 15 min post exposure. Furthermore,
for all of the participants there was a significant decrease of
simulator sickness symptoms severity between immediately after
exposure and 3 min later. Results achieved by Singer et al. (1998)
support the hypothesis that the simulator sickness symptoms
persist for some time after leaving the VR and then return to the
baseline levels. In their study, all of the specific symptoms except
disorientation (viz. nausea and oculomotor disturbance; the same
effect was confirmed for the total SSQ score as well) returned to
baseline levels after a 30-min rest. McCauley et al. (1990) state
that the simulator sickness symptoms severity decreases after
leaving the VR (between two measurement points: immediately
after leaving the VR and 30 min later). Mali´nska et al. (2014) tested subjective sensations (simulator
sickness and fatigue; the latter will not be discussed herein)
felt after exposure to virtual reality. In this study, individual
proneness to motion sickness was tested using the Coriolis test
before the experimental trial. Twenty men participated in the
experiment. The study was conducted in two separate phases. During the first phase, all of the participants watched a part
of the “Avatar” movie – both in 2D and 3D versions. The
results concerning only the impact of the movie will not be
discussed herein. Possibility of Adapting VR Users in
Advance It was
discovered, that the simulator sickness symptoms assessed on
a 0–10 scale decreased rapidly after the first exposure – the
comparisons were significant for Day 1 and each of the other
times and not significant for any other comparisons. It appears
that the adaptation achieved by the study subjects happened
between the two first sessions. What is more, that adaptation
effect did not wear offwith time – on Day 22 the symptoms
severity was still significantly smaller that on Day 1. The SSQ
was also administered in this study and the total score, nausea
and disorientation scores did significantly decrease in time. This
effect, however, was visible between Day 1 – Day 4 and Day
1 – Day 5 (for the total and nausea scores) and between Day
1 – Day 4 (for the disorientation score). Furthermore, for the
total and nausea scores, adaptation was retained during the last
measurement on Day 22. The results of this study prove that it
is possible to adapt people to VR conditions and that this effect
can be long-lasting. However, the method of measurement for In light of the reviewed studies, the possibility of adapting to
VR is reasonable – several authors reported results suggesting
it. However, a large number of the studies did not report
statistical tests proving this claim or reported statistical non-
significance. Various adaptation patterns have been observed –
the effect was visible when all of the VR immersions were
conducted on a single day (Lampton et al., 2000; Domeyer
et al., 2013), on separate days (e.g., Cobb et al., 1999; Brooks
et al., 2010; Reinhard et al., 2017), or even during a single VR
exposure (Sinitski et al., 2018). A floor effect of no symptoms November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 9 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. after some exposures was observed by Kennedy et al. (2000). The effect of adaptation does not wear with time, as in was
observed by Newman et al. (2013). Furthermore, virtual reality
is not necessarily essential for evoking the adaptation effect
(Smither et al., 2008). 6 participants reported experiencing other symptoms, which
cannot be classified as typical simulator sickness symptoms
(visual flashbacks, unsteadiness or symptoms different from the
ones experienced during the VR exposure). Unfortunately, no
information on the VR exposure length was given by the authors. Possibility of Adapting VR Users in
Advance The patterns and extents to which adaptation was observed
in the aforementioned studies are diversified. Certainly, further
research on this issue is necessary. It is also intriguing what is the
relationship between possible adaptation along with subsequent
VR experiences and increasing severity of simulator sickness
during one long experience. These relationships would be worth
testing in future studies. In the study by Moss and Muth (2011), more widely described
above, it was discovered that the simulator sickness symptoms
persist for some time after leaving the virtual reality environment. The total SSQ score in this study measured 10 min post exposure
was still significantly higher than the baseline score. This means,
that for the virtual reality environment tested in the study, not
only did the simulator sickness’ symptoms increase with time,
but they also persisted for at least 10 min after leaving the virtual
reality. Therefore, it cannot be confirmed when did the symptoms
subside. However, in a similar study by Moss et al. (2011), the
severity of symptoms did return to baseline level after a 10-min
rest. Frontiers in Psychology | www.frontiersin.org Persistence of the Simulator Sickness
Symptoms After VR Exposure In the second phase, the participants engaged
in a virtual reality task, which included transporting various
elements on a virtual workstation. A questionnaire created by the
authors of the study was used as a method of measurement for A more detailed, qualitative description of the simulator
sickness symptoms persistence pattern was given by Braithwaite
and Braithwaite (1990). From 14 of the participants, 6 suffered
from severe headaches, which lasted for 2-6 h, 2 suffered
from nausea (up to 2 h after leaving the simulator) and November 2018 | Volume 9 | Article 2132 10 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. the simulator sickness. It included 8 symptoms (e.g., eye pain,
headache, dizziness, nausea), which were assessed on a five-point
scale. This questionnaire was conducted thrice – straight after the
simulator exposure, 20 min and up to 24 h later (and sent by
email). 20 min post exposure, 7 of 8 simulator sickness symptoms
were reported by at least one participant. No one experienced
increased sweating and the most prevalent symptoms were: eye
pain, drowsiness, fatigue and apathy. According to the results, the
participants experienced the simulator sickness symptoms up to
4 h after completing the virtual reality task. Reported symptoms
included: headache, dizziness, disorientation and drowsiness. Unfortunately, no comparison between the different time periods
was given, and therefore any conclusions drawn from this study
regarding the temporal aspects of simulator sickness should
be treated with extreme caution. The results of the studies
concentrated on simulator sickness persistence are given in the
Supplementary Table S3. some time after exposure, although it remains unknown for how
long and it may vary depending on the initial severity of the
symptoms. Apart from the points concerning each specific temporal
aspect of simulator sickness, some general conclusions can be
drawn. The virtual reality technology and simulators still have
the tendency to evoke unpleasant symptoms among their users;
although the technology advances, this problem has not yet been
solved. It is the most vivid for the first aspect discussed herein –
the temporal trajectory of the progression of simulator sickness –
the severity of symptoms grows along exposure time both in the
studies conducted almost 20 years ago (Cobb et al., 1999) and
in the most recent ones (Lee et al., 2017). 4Steam (https://store.steampowered.com) is a digital distribution platform, on
which various types of games can be bought, played and stored in a cloud. CONCLUSION To summarize the conclusions reached about each of the
temporal aspects of simulator sickness, a sufficient amount of
evidence appears to exist in order to confirm the hypothesis
that the severity of simulator sickness symptoms increases with
increased exposure time. There appears to be no universal rule
regarding maximum exposure time until unpleasant symptoms
are evoked. A correct direction of research in this aspect would
be to test the temporal pattern of simulator sickness progression
for each VR technology separately – as it has been reported by Lee
et al. (2017), different devices used for controlling the individual’s
movement in the virtual environment tend to evoke slightly
different levels of simulator sickness. Despite the development
of technology, the issue of simulator sickness appears to still
remain unsolved. Interesting trends have been reported – in some
studies, the simulator sickness severity either begins to stabilize
(e.g., Moss et al., 2008) or decreases (e.g., Sinitski et al., 2018)
after some time and in other – the symptoms become noticeably
unpleasant after some time spent in the VR (e.g., Min et al., 2004). As it has been broadly discussed above, adaptation to the VR
environment appears to be possible, but the quoted studies do
not provide conclusive data – further inquiry regarding this topic
is necessary. Some simulator sickness symptoms may prevail for The researchers and developers employing the virtual reality
technology should always bear in mind the fact that simulator
sickness exists and can disturb the desired outcomes. Therefore,
before it becomes widely implemented, every VR technology
needs to be tested for its tendency to evoke unpleasant symptoms
in its users in the three temporal aspects discussed above. Persistence of the Simulator Sickness
Symptoms After VR Exposure Although this trend
appears to be stable regardless the technological progress, such
statements should be treated with caution, as the studies used
various types of VR technologies, which may not be comparable. Until the technology reaches the point when the simulator
sickness will be wholly preventable, some standards should
be developed when it comes to research on virtual reality
and simulators. The issue of how often the simulator sickness
symptoms should be measured (not only during the experimental
trial, but also after it), should be addressed. Regarding simulator sickness persistence, it may be assumed
that at least some of the symptoms may prevail after the exposure
(10 min, Moss et al., 2011; circa 30 min, Singer et al., 1998;
more than 30 min, Biernacki and Dziuda, 2014; Dziuda et al.,
2014), in some cases even for relatively long time (more than
4 h after approximately 2 h of exposure, Mali´nska et al., 2014;
for even 4 h after leaving the VR, Braithwaite and Braithwaite,
1990). On the other hand, the results of Biernacki and Dziuda
(2014) suggest that the severity of symptoms changes rapidly –
it is increased directly after exposure, but significantly decreased
30 min afterward. The time of the symptoms’ prevalence differs
between various VR environments. Furthermore, the length of
recovery depends on the initial symptoms’ severity – it takes
longer to fully recover, when the experienced symptoms were
more severe (Bos et al., 2005; Keshavarz et al., 2018). It would be advisable to test the tendency of a new virtual
reality tool to evoke the simulator sickness symptoms in the three
above discussed dimensions: temporal pattern of the symptoms’
progression, adaptation possibility and persistence of symptoms
after exposure. These parameters would provide vital information
on how long the training, game or any other scenarios should
be, in order to provide the user with an enjoyable experience
and to prevent unpleasant sensations. This issue appears to
be exceptionally crucial for professional training simulators,
where the quality of the experience may have an influence on
results of the training session. Furthermore, the physiological
measurement of simulator sickness should be developed and
given more focus, as it might be more precise and less biased than
a self-report. Frontiers in Psychology | www.frontiersin.org Practical Implications for Further
Research The above described research provides interesting insight into the
temporal aspects of the simulator sickness and it appears that
there are still issues which demand further inquiry. First of all,
most of the research concerns driving or flight simulators, most
often used for training professional drivers and pilots, but the
virtual reality technology is advancing rapidly and has already
been applied to the gaming industry (2.704 titles on Steam4 when
the searching parameters were restricted to “VR only” and 3.243
with the “VR supported” search restriction; data collected on June
14, 2018) – creating a brand-new field for research. It would be November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org Frontiers in Psychology | www.frontiersin.org 11 Can Simulator Sickness Be Avoided? Du˙zma ´nska et al. advisable to explore the temporal aspects of simulator sickness,
not only on professional training simulators and professional
drivers and pilots, but also on virtual reality-supported games and
everyday, non-professional VR users and gamers. A significant number of the reviewed studies turned out
to have drawbacks or did not include as thorough analysis
of the temporal aspects of simulator sickness as it may have
been expected, which can be considered a limitation of the
present review. Very often the study reports did not include
any information on statistical significance of the results, or the
sample size was extremely small, which made it impossible to
draw definite conclusions. Furthermore, as the temporal aspects
of simulator sickness is most often analyzed alongside other
study objectives, it is possible that some interesting results on
the topic have been omitted in the search process. Despite these
limitations, the present review is believed to give insight into
the temporal aspects of simulator sickness and serve as a basis
for further research focused on temporal aspects of simulator
sickness. It would also be advisable to further explore the temporal
aspects of simulator sickness and to develop a standardized
methodology which would allow a comparison between studies
focusing on different virtual reality environments. Researchers
should bear in mind the need to compare the SSQ scores between
time periods [a good example of such methodology is the Moss
and Muth (2011) study, where simulator sickness severity was
assessed each 5 min] and to control the severity of symptoms for
several hours after virtual reality exposure, in order to be able to
determine the moment when the symptoms subside. Practical Implications for Further
Research Moreover, it would be intriguing to compare the effect of
one prolonged VR exposure to a number of shorter exposures,
summing up to the same total time. According to the evidence
found in past studies, it could be expected that the severity of
symptoms after one long exposure should be greater than after
a series of short ones. A pattern of symptoms’ persistence after
such two types of exposures could also be explored. FUNDING This
work
was
co-financed
by
the
Polish
National
Centre
for
Research
and
Development
under
the
grant
“Widespread Disaster Simulator – research and preparation for
implementation” (project number POIR.01.01.01-00.0042/16;
the Smart Growth Operational Programme, sub-measure 1.1.1. Industrial research and development work implemented by
enterprises) received by Nano Games sp. z o.o. Strengths and Limitations The main strength of the present paper is that it covers a very wide
array of study reports – not only from the most recent times, but
also the older ones, from the 1990s. Consideration has been taken
to analyze all the results thoroughly. Caution has been exercised
to allow for any possible bias and limitations of every single study. Moreover, efforts have been taken to shed more light on the
subject which, despite being an important factor of simulator and
VR experience, has not been given much attention in research. FIGURE S1 | Flow chart of the search and screening process for the relevant
literature. FIGURE S1 | Flow chart of the search and screening process for the relevant
literature. TABLE S1 | Studies focusing on the temporal trajectory of the progression of
simulator sickness. TABLE S1 | Studies focusing on the temporal trajectory of the progression of
simulator sickness. TABLE S2 | Studies focusing on the possibility of adapting VR users in advance. TABLE S2 | Studies focusing on the possibility of adapting VR users in advance. TABLE S2 | Studies focusing on the possibility of adapting VR users in advance. TABLE S3 | Studies focusing on how long the simulator sickness persists after VR
exposure. AUTHOR CONTRIBUTIONS ND wrote major part of the paper, contributed to the conception
and design of the review. PS designed the review and wrote
minor part of the paper. AS contributed to the conception and
design of the review. All authors listed have made substantial
intellectual contribution to the work, revised the manuscript,
read and approved the submitted version. It is also worth suggesting that the simulator sickness severity
should be assessed not only before the experimental procedure,
but also after the initial training phase, in order to establish if the
training could serve as the adaptation period. In light of the past research which suggest that most of
the people suffer from simulator sickness to some extent, the
researchers should care for the study participants, who report
strong and unpleasant symptoms not only straight after the
experimental procedure, but also as long as the symptoms
persist. Brooks et al. (2010) propose a number of means that
can be taken in order to provide the participants with proper
care. Supplies such as sick bags, plastic gloves, mouthwash and
cleaning products should be kept in the lab. The participants
should be provided with light snacks and water. They should
also be advised not to drive a car until they feel that all the
symptoms have subsided. Brooks et al. (2010) suggest as well that
the participants should stay in the lab for at least an hour after the
experiment. It would also be advisable to contact the participants
after the study and ask them if they experienced any unpleasant
side-effects of VR exposure. SUPPLEMENTARY MATERIAL The Supplementary Material for this article can be found
online
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conducted in the absence of any commercial or financial relationships that could
be construed as a potential conflict of interest. Nader,
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and
Kruszewski,
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zaawansowanych
symulatorów jazdy w badaniach zachowania i umiej˛etno´sci kierowców. Prace
naukowe Politechniki Warszawskiej 96, 321–331. Copyright © 2018 Du˙zma´nska, Strojny and Strojny. This is an open-access article
distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the
original author(s) and the copyright owner(s) are credited and that the original
publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these
terms. Newman, M. C., McCarthy, G. W., Glaser, S. T., Bonato, F., and Bubka, A. (2013). Motion sickness adaptation to Coriolis-inducing head movements in
a sustained G flight simulator. Aviat. Space Environ. Med. 84, 104–109. doi: 10.3357/ASEM.3170.2013 Park, J. November 2018 | Volume 9 | Article 2132 REFERENCES R., Lim, D. W., Lee, S. Y., Lee, H. W., Choi, M. H., and Chung, S. C. (2008). Long-term study of simulator sickness: differences in EEG response November 2018 | Volume 9 | Article 2132 Frontiers in Psychology | www.frontiersin.org 14
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Inhibition of Aurora B by CCT137690 sensitizes colorectal cells to radiotherapy
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RESEARCH Open Access Abstract Colorectal cancer is the third most commonly diagnosed cancer worldwide. Although surgery remains the best
treatment for this disease, adjuvant chemotherapy and radiotherapy are also very important in clinical practice. However, the notorious refractory lack of responses to radiochemotherapy greatly limits the application of
radiochemotherapy in the context of colorectal cancer. y
There is a growing interest in the role that Aurora B may play in colorectal cancer cell survival as well as other
cancer subtypes. In the current study, we sought to ascertain whether blocking of Aurora B signaling machinery by
a small molecule inhibitor, CCT137690, could synergize radiation-induced colorectal cancer cell death. Results
showed that CCT137690 increases the sensitivity of SW620 cells to radiation. Mechanistic studies revealed that
Aurora B-Survivin pathway may be involved in this synergistic effect. Taken together, our results for the first time show that Aurora B inhibition and radiation exert a synergistic effect,
resulting in enhanced colorectal cancer cell death. This synergistic effect is clinically relevant as lower doses of
radiation could be used for cancer treatment, and could provide significant clinical benefits in terms of colorectal
cancer management, while reducing unwanted side-effects. Keywords: CCT137690, Aurora B, Radiotherapy, Colorectal cancer Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 * Correspondence: dryxq186@163.com
†Equal contributors
1Department of Surgical Oncology, Affiliated Hospital of Nanjing University
of Traditional Chinese Medicine, 155 Guangzhou Road, Nanjing 210029,
China
Full list of author information is available at the end of the article Inhibition of Aurora B by CCT137690 sensitizes
colorectal cells to radiotherapy Xiaoyu Wu1†, Wentao Liu2†, Qinhong Cao1, Che Chen1, Zhiwei Chen1, Zhe Xu1, Weisu Li1, Fukun Liu1
and Xuequan Yao1* © 2014 Wu et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated. Introduction kinases which regulate the function of centrosomes, spin-
dles, and kinetochores for proper mitotic progression
[9,11]. Aurora A overexpression has been observed in vari-
ous cancers including colorectal cancers. Baba et. al. re-
ported overexpression of Aurora A protein in 19% of CRC
by immunohistochemistry [12]. High copy amplification of
the Aurora A gene was found in colorectal tumors [13]
and associated with chromosomal instability phenotypes
[14]. In another report, up-regulation of Aurora kinases
were detected in 48.5% (97/200) of patients with colorectal
carcinoma [15]. Similarly, a previous study reported that
the presence of nuclear Aurora B was strongly associated
with lymph node metastasis in colorectal cancer [16]. In
metastatic colorectal cancer, patients with a high expres-
sion level of Aurora B lived significantly shorter compared
with patients with a low expression level [17]. Taken to-
gether, these studies highlight the association of altered
aurora kinases and CRC. Colorectal cancer (CRC) is the third most commonly di-
agnosed cancer worldwide with over 1.4 million new
cancer cases and 0.6 million estimated deaths every year
[1-3]. The incidence of CRC has rapidly increased in
China and other Asian countries over the last few de-
cades [4-8], and identifying better ways of treating this
cancer is paramount. Although surgery of CRC remains
the best treatment, adjuvant chemotherapy and radio-
therapy are also very important and beneficial treat-
ments for patients [9,10]. After surgery, chemotherapy
and radiotherapy is used to target small cancerous tis-
sues that may be missed during surgery and help to
prevent cancer recurrence. Aurora kinases (of which there are 3 isoforms: Aurora A,
B and C) are the most important serine/threonine-protein As far as therapeutic options, 5-Fluorouracil (5-FU) re-
mains the most commonly used chemotherapeutic agent
for CRC. However, CRC tumors are highly refractory to ll list of author information is available at the end of the article Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Page 2 of 9 Page 2 of 9 Anti-Histone H3 and GAPDH antibody were obtained
from Santa Cruz Biotechnology. Anti-Histone H3 and GAPDH antibody were obtained
from Santa Cruz Biotechnology. chemotherapy and many patients eventually relapse. Determination of surviving fraction
5 2 × 105 cells were plated in a 60-mm dish. 24 hours later,
the cells were exposed to different dosages of ionization
radiation. After a 6-hour recovery, one percent of the cells
were re-plated in a new dish. After 10 days the number of
colonies formed were counted. Introduction Be-
cause of the established roles of Aurora kinases in tumor
initiation and progression, many inhibitors of Aurora ki-
nases have been specifically tested for the treatment of
colorectal cancers in combination with 5-FU, with some
currently in clinical trials [18-22]. Combination effect of radiation and CCT137690 Cells were first treated with CCT137690 at different con-
centrations for 48 hours before they were exposed to dif-
ferent dosages of ionization radiation. Cell culture The human colorectal adenocarcinoma cell lines, SW48
and SW620, were obtained from the American Type
Culture Collection. The cells were maintained in DMEM
supplemented with 10% heat inactivated FBS at 37°C, 5%
CO2, and 95% humidity. Recent studies showed that overexpression of Aurora
kinases might have a role in chemo- and radiotherapy
resistance of cancers [23,24]. Consistent with this notion,
inhibition of Aurora kinases can enhance radiation sen-
sitivity of cancer cells [25,26]. For example, inhibition of
Aurora B sensitizes mesothelioma cells by enhancing
mitotic arrests [27] and also potently suppresses repopu-
lation during fractionated irradiation of human lung
cancer cell lines [28]. Reagents DMEM and fetal bovine serum (FBS) were purchased from
Thermo Fisher Scientific at CHINA (Shanghai, China). 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazoliumbro-
mide (MTT) was obtained from Sigma-Aldrich (Shanghai,
China). Anti-Aurora B antibody and anti-Histone H3
(phospho S10) antibody were obtained from Abcam. Anti-
Survivin antibody was purchased from Cell Signaling. Silencing of Aurora A and B in cells
5 1.5 × 105 cells were seeded in 60-mm plates and incu-
bated for 24 h before transfection. The negative control
siRNA or Aurora A or B siRNA was diluted in Opti-MEM
I Reduced Serum Medium and mixed with Lipofectamine
2000 according to the manufacturer’s instructions. The
mix of DNA and Lipofectamine was added to cells. After
72 hours post-transfection, expression levels of Aurora
genes were determined by Real-time PCR and cells were
used for different assays. The main cause of treatment failure and recurrence is
resistance of cancer cells to radiation and drugs [32,33]. Since inhibition of Aurora kinases can sensitize cancer
cells to radiotherapy, it is expected that combining radio-
therapy and Aurora inhibition for colorectal cancers may
achieve a synergistic therapeutic effects. Concomitant in-
hibition of Aurora kinases and radiotherapy can also
potentially decrease the dosages of either medicine or
radiation, which in turns can reduce the side effects of
the treatments. Therefore, in our current study we
sought to explore whether the combination of radio-
therapy with CCT137690 may prove efficacious in the
treatment of colorectal cancer cell lines. In this way,
optimized combinatorial treatment may lead to a de-
crease in the requirement of CCT137690 for thera-
peutic benefit. Ionization radiation
ll
l
d Cells were plated in dishes, and then irradiated with
X-ray (104.93 cGy/min at 210 kV and 12 mA) by using an
X-ray irradiator (MBR-1505R2; Hitachi Medico, Tokyo,
Japan) for indicated dosages. Materials and methods The authors declared that the current research has been
approved by The Ethics Committee of Nanjing University
of Traditional Chinese Medicine. Plasmids and transfection The full-length cDNA sequence of survivin was amp-
lified from total RNA of SW620 cells by using Reverse
Transcription PCR. The fragment was inserted into
pBABE-Puro vector. The control vector plasmid or the
plasmid encoding survivin was transfected into Phoenix
Retroviral Expression System. Virus was produced and ap-
plied onto target cells according to the standard protocol. The cells were subjected to drug-selection for 3 days
(0.5 μg/ml of puromycin) to enrich for the desired cells. CCT137690 is a newly synthesized compound which
has been shown to inhibit the activities of Aurora ki-
nases. IC50 values of CCT137690 are 15 and 25 nM for
Aurora A and B, respectively. Although CCT137690 has
shown promising therapeutic effects on different cancer
cells (especially for colorectal cancer) [29-31], a narrow
safety margin (due to its activity against hERG ion-channel)
may limit its preclinical development [28]. Cell cycle assay Cells were collected by trypsinization and washed with
PBS, centifuged and then resuspended in 0.4 ml of PBS
and fixed by adding 1ml cold ethanol slowly. Cells were Page 3 of 9 Page 3 of 9 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 in the dark. Samples then were measured on a Guava
System (Millipore). The data were analyzed by using the
software provided by the company. kept at 4°C overnight. For analysis, cell suspensions were
centrifuged at 1500 rpm for 5 mins, washed with PBS and
re-suspended in 500 μl staining solution (PBS with 50 μg/
ml PI together with 50 μg/ml RNase A) at 37°C for 30
mins in the dark. Cells were analyzed by flow cytometry. MTT assay for cell viability
4 104 cells were seeded into 96-well plates and were treated
to either vehicle (DMSO) or different concentrations of
CCT137690 for 48 hours. Cell viability was determined
and quantified by using MTT assay. Results In the current study, we sought to identify whether the
combination of radiotherapy and inhibition of Aurora ki-
nases could exert a synergistic inhibitory effect on colo-
rectal cancer cell growth. To test this hypothesis, we
first characterized the sensitivity of two different colo-
rectal cancer cell lines SW-48 and SW-620 to an Aurora
kinase inhibitor, CCT137690. We show that both SW-
48 and SW-620 exhibit dose-dependent responses to
CCT137690 treatment. Moreover, we found that SW-
620 is relatively more resistant to CCT137690 treatment
as compared to SW-48 cells as manifested by a higher
IC50 (430 nM vs 157 nM) (Figure 1A). In addition, when
cells were treated with CCT137690 at their respective Guava Nexin assay To determine sensitivity of the cell lines to radiother-
apy, GUAVA assay was employed and revealed that radi-
ation was able to induce significant apoptosis in both
SW-48 and SW-620 cell lines (Figure 2B-G). However,
the cell lines displayed different sensitivities to IR: SW-
620 cells exhibits a higher resistance to radiation compared
to SW-48 cells (Figure 2A). Indeed, higher amounts of ra-
diation (3 Gy vs 1 Gy) were required for a similar apoptosis
response in SW-620 cell vs SW-48 cell (Figure 2F and G). To test whether there is any synergistic effects of radio-
therapy and Aurora kinase inhibition, SW620 cells were
treated with different concentrations of CCT137690 be-
fore they were treated with a low-dose radiation (1 Gy) or
without IR (Figure 3A). Our data suggested that a low-
dose radiation dramatically enhances the inhibitory effect
of CCT137690 on cell growth. 100 nM of CCT137690
has very limited effects on SW620. But surprisingly, To determine sensitivity of the cell lines to radiother-
apy, GUAVA assay was employed and revealed that radi-
ation was able to induce significant apoptosis in both
SW-48 and SW-620 cell lines (Figure 2B-G). However,
the cell lines displayed different sensitivities to IR: SW-
620 cells exhibits a higher resistance to radiation compared
to SW-48 cells (Figure 2A). Indeed, higher amounts of ra-
diation (3 Gy vs 1 Gy) were required for a similar apoptosis
response in SW-620 cell vs SW-48 cell (Figure 2F and G). Since CCT137690 inhibits the activities of both Aurora
A and Aurora B, we wished to clarify whether the syner-
gistic effects of CCT137690 to radiation were due to in-
hibition of Aurora A or Aurora B. We therefore used
siRNA to deplete either Aurora A or Aurora B in SW620
cells (Figure 5A and B). As shown in Figure 5C, only
knockdown of Aurora B dramatically decreases cell sur-
vival following radiation (p < 0.001) while knockdown of
Aurora A does not exert a similar effect (Figure 5C). We
found that radiation induced Aurora B protein expression
and correspondingly higher Aurora B activity, as manifested To test whether there is any synergistic effects of radio-
therapy and Aurora kinase inhibition, SW620 cells were
treated with different concentrations of CCT137690 be-
fore they were treated with a low-dose radiation (1 Gy) or
without IR (Figure 3A). Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Guava Nexin assay The Guava Nexin assay was performed following manu-
factory protocol (Millipore). Briefly, attached and sus-
pended cells were all collected. Cells were resuspended in
100 μL of medium and incubated together with 100 μL of
Guava Nexin Reagent for 20 minutes at room temperature Figure 1 The effects of CCT37690 on proliferation of SW48 and SW620 cells. A, relative cell viabilities of SW48 and SW620 cells treated by
different concentrations of CCT137690 were measured by using MTT assay. B, representative figures of cell cycle assays; SW48 with (157 nM) or
without drug-treatment, SW620 with (430 nM) or without drug-treatment. C and D, quantification of cell cycle assays; C for SW48, D for SW620,
mean ± SD, (n = 3). Figure 1 The effects of CCT37690 on proliferation of SW48 and SW620 cells. A, relative cell viabilities of SW48 and SW620 cells treated by
different concentrations of CCT137690 were measured by using MTT assay. B, representative figures of cell cycle assays; SW48 with (157 nM) or
without drug-treatment, SW620 with (430 nM) or without drug-treatment. C and D, quantification of cell cycle assays; C for SW48, D for SW620,
mean ± SD, (n = 3). Figure 1 The effects of CCT37690 on proliferation of SW48 and SW620 cells. A, relative cell viabilities of SW48 and SW620 cells treated by
different concentrations of CCT137690 were measured by using MTT assay. B, representative figures of cell cycle assays; SW48 with (157 nM) or
without drug-treatment, SW620 with (430 nM) or without drug-treatment. C and D, quantification of cell cycle assays; C for SW48, D for SW620,
mean ± SD, (n = 3). Page 4 of 9 Page 4 of 9 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 IC50, we observed cell cycle perturbations in both cell
lines. There was a lower proportion of cells in G1/G0
and S phase, and a higher proportion of cells in G2/M
and > G2 (Figure 1B-D). when combined with radiation, a big proportion of the
cells treated with CCT137690 died through apoptosis
(Figure 3D). In light of these observations, we ascertained whether
low-dose CCT137690 pretreatment could exert a similar
effect to radiation. As shown in Figure 4A, 100 nM of
CCT137690 pre-treatment dramatically decreases survival
of SW620 cells exposed to radiation. In line with this no-
tion, we also found that CCT137690 pre-treatment dramat-
ically enhances radiation-induced apoptosis (Figure 4B-D). Guava Nexin assay Our data suggested that a low-
dose radiation dramatically enhances the inhibitory effect
of CCT137690 on cell growth. 100 nM of CCT137690
has very limited effects on SW620. But surprisingly, Figure 2 The effects of radiation on SW48 and SW620 cells. A, surviving curves of cells after ionization-radiation. B and C, representative
figures of Guava Nexin assay of SW48 cells, B is for cells without radiation while C is for cells with 1 Gy of radiation. D and E, representative figures
of Guava Nexin assay of SW620 cells, D is for cells without radiation while E is for cells with 3 Gy of radiation. F and G, quantification of Guava
Nexin assays, F for SW48, G for SW620, mean ± SD, (n = 3). Figure 2 The effects of radiation on SW48 and SW620 cells. A, surviving curves of cells after ionization-radiation. B and C, representative
figures of Guava Nexin assay of SW48 cells, B is for cells without radiation while C is for cells with 1 Gy of radiation. D and E, representative figures
of Guava Nexin assay of SW620 cells, D is for cells without radiation while E is for cells with 3 Gy of radiation. F and G, quantification of Guava Figure 2 The effects of radiation on SW48 and SW620 cells. A, surviving curves of cells after ionization-radiation. B and C, representative
figures of Guava Nexin assay of SW48 cells, B is for cells without radiation while C is for cells with 1 Gy of radiation. D and E, representative figures
of Guava Nexin assay of SW620 cells, D is for cells without radiation while E is for cells with 3 Gy of radiation. F and G, quantification of Guava
Nexin assays, F for SW48, G for SW620, mean ± SD, (n = 3). Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Page 5 of 9 Figure 3 Low-dose radiation can increase the sensitivity of SW620 to CCT137690. A, SW620 cells were treated with different concentrations
of CCT137690 for 48 hours before they were treated with (1 Gy) or without radiation. B and C, representative figures of Guava Nexin assays of
cells pre-treated with 100 nM of CCT137690 and then treated with (C) or without (B) radiation. D, quantification of Guava Nexin assays on above
cells, mean ± SD, (n = 3). Guava Nexin assay Figure 3 Low-dose radiation can increase the sensitivity of SW620 to CCT137690. A, SW620 cells were treated with different concentrations
of CCT137690 for 48 hours before they were treated with (1 Gy) or without radiation. B and C, representative figures of Guava Nexin assays of
cells pre-treated with 100 nM of CCT137690 and then treated with (C) or without (B) radiation. D, quantification of Guava Nexin assays on above
cells, mean ± SD, (n = 3). by increased phosphorylation of histone H3 (at serine 10)
(Figure 5D). In addition, survivin is a reported target of
Aurora B-mediated phosphorylation, and it inhibits cas-
pase activation thereby mediating cell survival through
inhibiting apoptosis [34]. We corroborated these results
by showing that radiation induced higher Aurora B activ-
ity and correspondingly increased survivin protein expres-
sion. However, when cells were additionally treated with
CCT137690 to inhibit activity of Aurora B, the protein
levels of survivin decreased (Figure 5D). Since survivin
is a very important anti-apoptotic protein, the decrease
of survivin may explain the synergistic effects between ra-
diation and CCT137690. Consistent with this notion, sur-
vivin protein expression in SW-48 cells was much lower
than that in SW-620 cells (Figure 5E), which may explain
the different sensitivities of these cells to radiation. To
confirm this point, we managed to over-express survivin
in SW48 cells (Figure 5F). As expected, survivin over-
expression significantly increases the surviving rates of the cells after radiation (Figure 5G). To further con-
firm the central role of Aurora B-survivn signaling path-
way in regulating survival upon radiation, we treated
SW620 cells with CCT137690 before radiation, lower sur-
vivin protein level correlates with lower surviving rate
after radiation (Figure 5H and I). In addition, survivin
over-expression in drug-treated cells greatly ameliorates
radiation induced cell death (Figure 5H and I) further
confirmed our hypothesis. by increased phosphorylation of histone H3 (at serine 10)
(Figure 5D). In addition, survivin is a reported target of
Aurora B-mediated phosphorylation, and it inhibits cas-
pase activation thereby mediating cell survival through
inhibiting apoptosis [34]. We corroborated these results
by showing that radiation induced higher Aurora B activ-
ity and correspondingly increased survivin protein expres-
sion. However, when cells were additionally treated with
CCT137690 to inhibit activity of Aurora B, the protein
levels of survivin decreased (Figure 5D). Guava Nexin assay Since survivin
is a very important anti-apoptotic protein, the decrease
of survivin may explain the synergistic effects between ra-
diation and CCT137690. Consistent with this notion, sur-
vivin protein expression in SW-48 cells was much lower
than that in SW-620 cells (Figure 5E), which may explain
the different sensitivities of these cells to radiation. To
confirm this point, we managed to over-express survivin
in SW48 cells (Figure 5F). As expected, survivin over-
expression significantly increases the surviving rates of Discussion Radiotherapy stands a major adjunctive therapeutic op-
tion for colorectal cancer management. Although there
have been intensive investigations on the optimal regi-
men of radiotherapy for this lethal disease, very limited
success have been made during the past several decades. CRC is notorious for being refractory to both chemo-
therapy and radiotherapy. Thus investigators are particu-
larly interested in characterizing novel molecule targets Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
Page 6 of 9
http://www.jeccr.com/content/33/1/13 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Page 6 of 9 Figure 4 Low dosage of CCT137690 sensitizes SW620 cells to radiation. A, SW620 cells (with or without drug treatment (100 nM)) were
exposed to different dosages of radiation. B and C, representative figures of Guava Nexin assays of cells (with (C) or without (B) drug treatment)
exposed to 1 Gy of radiation. D, quantification of Guava Nexin assays on above cells, mean ± SD, (n = 3). Figure 4 Low dosage of CCT137690 sensitizes SW620 cells to radiation. A, SW620 cells (with or without drug treatment (100 nM)) were
exposed to different dosages of radiation. B and C, representative figures of Guava Nexin assays of cells (with (C) or without (B) drug treatment)
exposed to 1 Gy of radiation. D, quantification of Guava Nexin assays on above cells, mean ± SD, (n = 3). by CCT137690 and to radiation (Figures 1 and 2). How-
ever, we found that the combination of Aurora B inhib-
ition and radiation exerts synergistic effects on cancer cell
growth inhibition. Our results showed that low-dose radi-
ation (1 Gy) greatly exaggerates the growth inhibitory ef-
fect of CCT137690 on SW-620 cells (Figure 3A), as well
as a low-dose of CCT137690 dramatically increases the
sensitivity of cells to radiation (Figure 4A). which exert regulatory effects on sensitivity to radioche-
motherapy in CRC patients. Positive results from these
studies might be clinically important since untoward side
effects from radiotherapy or chemotherapy stands as
major concerns for clinicians in tumor management and
sensitizers of radiochemotherapy may help to reduce dos-
age load and associated toxic side effects. In light of this notion, we started to search for poten-
tial sensitization targets for radiotherapy of CRC subjects
and we found that there is a recent growing interest in
the role of Aurora B and cancer biology. Discussion Our observations provide a good proof of concept that
both chemotherapy and radiotherapy doses could be
greatly lowered by taking the advantages of synergistic
effects of those two interventions. This could be trans-
lated into the clinic where the expectation is that there
would be less adverse side-effects and better patient
tolerance at lower doses. These findings are especially
important given that CT137690 has a narrow safety
margin. In terms of synergistic effect of Aurora B inhibition
and radiotherapy sensitivity, a previous study has shown
that Aurora B inactivation sensitizes mesothelioma cells
[27]. In addition, Aurora B inhibition also potently sup-
presses repopulation during fractionated irradiation of
human lung cancer cells [28]. In terms of understanding of the mechanism by which
inhibiting Aurora B increases radiosensitivity of CRC In the current study, we first show that SW-620 colorec-
tal cancer cells are relatively resistant to Aurora B inhibition Page 7 of 9 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
http://www.jeccr.com/content/33/1/13 Page 7 of 9 Figure 5 The mechanism underlying the synergic action between CCT137690 and radiation. A and B, relative expression of the indicated
genes in SW620 cells treated by control or siRNA of the indicated target, mean ± SD, (n = 3). C, surviving fractions of siRNA transfected cells
(from A, B) with or without radiation. D, Western blot analysis of Aurora B, Ser10-phosphorated Histone H3, Histone H3, survivin and GAPDH in
cells with indicated treatments (IR means 1 Gy, drug = 100 nM). E, the protein levels of survivin and GAPDH in SW48 and SW620 cells. F, protein
levels of survivin and GAPDH in SW48 cells with or without survivin over-expression. G, the surviving fractions of SW48 cells with or without
survivin over-expression upon radiation. H, the protein levels of survivin and GAPDH in cells with or without survivin over-expression under Figure 5 The mechanism underlying the synergic action between CCT137690 and radiation. A and B, relative expression of the indicated
genes in SW620 cells treated by control or siRNA of the indicated target, mean ± SD, (n = 3). C, surviving fractions of siRNA transfected cells
(from A, B) with or without radiation. D, Western blot analysis of Aurora B, Ser10-phosphorated Histone H3, Histone H3, survivin and GAPDH in
cells with indicated treatments (IR means 1 Gy, drug = 100 nM). Discussion E, the protein levels of survivin and GAPDH in SW48 and SW620 cells. F, protein
levels of survivin and GAPDH in SW48 cells with or without survivin over-expression. G, the surviving fractions of SW48 cells with or without
survivin over-expression upon radiation. H, the protein levels of survivin and GAPDH in cells with or without survivin over-expression under
indicated treatments (IR =1 Gy, drug = 100 nM). I, the surviving fractions of cells described in H, mean ± SD, (n = 3). Page 8 of 9 Page 8 of 9 cells, we found that Aurora B-survivin pathway may be
involved (Figure 5). These findings are consistent with
several reports showing the association of Aurora B and
survivin in context of CRC. For example, Tuncel et al. reported that nuclear Aurora B and cytoplasmic survivin
expression is involved in lymph node metastasis of colo-
rectal cancer [16]. Moreover, Aurora-survivin signaling
machinery has been implicated in other cancers such as
myelodysplasia [35], chronic lymphocytic leukemia [36],
head and neck squamous cell cancer [37]. In this regard,
we observed that forced-expression of survivin dramatic-
ally ameliorates Aurora B-inhibition induced CRC cell
death in the context of radiation (Figure 5I). 8. Zhang C, Fang Z, Xiong Y, Li J, Liu L, Li M, Zhang W, Wan J: Copy number
increase of aurora kinase A in colorectal cancers: a correlation with
tumor progression. Acta Biochim Biophys Sin 2010, 42:834–838. 9. Berdnik D, Knoblich JA: Drosophila Aurora-A is required for centrosome
maturation and actin-dependent asymmetric protein localization during
mitosis. Curr Biol 2002, 12:640–647. 10. Esposito A, Mancini R, Ettorre G, Garufi C, Saracca E, Arcieri S, Cosimelli M:
A combined approach of neoadjuvant chemotherapy and surgery for
colorectal liver metastases. J Exp Clin Can Res: CR 2003, 22:197–202. 11. Marumoto T, Honda S, Hara T, Nitta M, Hirota T, Kohmura E, Saya H:
Aurora-A kinase maintains the fidelity of early and late mitotic
events in HeLa cells. J Biol Chem 2003, 278:51786–51795. 12. Baba Y, Nosho K, Shima K, Irahara N, Kure S, Toyoda S, Kirkner GJ, Goel A,
Fuchs CS, Ogino S: Aurora-A expression is independently associated with
chromosomal instability in colorectal cancer. Neoplasia 2009, 11:418–425. 13. Authors’ contributions 17. Pohl A, El-Khoueiry A, Yang D, Zhang W, Lurje G, Ning Y, Winder T,
Hu-Lieskoven S, Iqbal S, Danenberg KD, et al: Pharmacogenetic
profiling of CD133 is associated with response rate (RR) and
progression-free survival (PFS) in patients with metastatic colorectal
cancer (mCRC), treated with bevacizumab-based chemotherapy. Pharmacogenomics J 2013, 13:173–180. XYW and WTL designed the current study, performed the experiments,
collected the data and drafted the manuscript. QHC, CC, ZWC, ZX, WSL
provided scientific inputs for study design and technical support for GUAVA
assay, construct cloning and radiation treatment. FKL and XQY mentored the
whole project, drafted and revised the manuscript. All authors read and
approved the final manuscript. 18. Manfredi MG, Ecsedy JA, Chakravarty A, Silverman L, Zhang M, Hoar KM,
Stroud SG, Chen W, Shinde V, Huck JJ, et al: Characterization of Alisertib
(MLN8237), an investigational small-molecule inhibitor of aurora A
kinase using novel in vivo pharmacodynamic assays. Clin Can Res: an
Official Journal of the American Association for Cancer Research 2011,
17:7614–7624. Competing interests 16. Tuncel H, Shimamoto F, Kaneko Guangying Qi H, Aoki E, Jikihara H, Nakai S,
Takata T, Tatsuka M: Nuclear Aurora B and cytoplasmic Survivin
expression is involved in lymph node metastasis of colorectal cancer. Oncol Lett 2012, 3:1109–1114. All authors agreed that there is nothing to disclose for the current study. Funding disclosure statement No current external funding sources for this study, all fundings for the
current study are from intramural funding program to Liu FK and Yao XQ. Received: 16 October 2013 Accepted: 20 January 2014
Published: 29 January 2014 21. Carpinelli P, Ceruti R, Giorgini ML, Cappella P, Gianellini L, Croci V, Degrassi A,
Texido G, Rocchetti M, Vianello P, et al: PHA-739358, a potent inhibitor of
Aurora kinases with a selective target inhibition profile relevant to cancer. Mol Cancer Ther 2007, 6:3158–3168. Discussion Dotan E, Meropol NJ, Zhu F, Zambito F, Bove B, Cai KQ, Godwin AK,
Golemis EA, Astsaturov I, Cohen SJ: Relationship of increased aurora
kinase A gene copy number, prognosis and response to chemotherapy
in patients with metastatic colorectal cancer. Br J Cancer 2012,
106:748–755. Taken together, our results for the first time showed
that Aurora B inhibition, via CCT137690, and radiation
exposure may play synergistic effects in colorectal cancer
death. Taking advantage of this synergistic effect, a lower
dose of radiation exposure and/or chemical exposure is
required for cancer cell death induction, which may have
significant clinical implications for CRC management. 14. Nishida N, Nagasaka T, Kashiwagi K, Boland CR, Goel A: High copy
amplification of the Aurora-A gene is associated with chromosomal
instability phenotype in human colorectal cancers. Cancer Biol Ther 2007,
6:525–533. 15. Lam AK, Ong K, Ho YH: Aurora kinase expression in colorectal
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http://www.jeccr.com/content/33/1/13 Author details
1 19. Shimomura T, Hasako S, Nakatsuru Y, Mita T, Ichikawa K, Kodera T, Sakai T,
Nambu T, Miyamoto M, Takahashi I, et al: MK-5108, a highly selective
Aurora-A kinase inhibitor, shows antitumor activity alone and in
combination with docetaxel. Mol Cancer Ther 2010, 9:157–166. 1Department of Surgical Oncology, Affiliated Hospital of Nanjing University
of Traditional Chinese Medicine, 155 Guangzhou Road, Nanjing 210029,
China. 2Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University,
Shanghai Institute of Digestive Surgery, Shanghai 200025, China. 1Department of Surgical Oncology, Affiliated Hospital of Nanjing University
of Traditional Chinese Medicine, 155 Guangzhou Road, Nanjing 210029, China. 2Department of Surgery, Ruijin Hospital, Shanghai Jiaotong University,
Shanghai Institute of Digestive Surgery, Shanghai 200025, China. 20. Harrington EA, Bebbington D, Moore J, Rasmussen RK, Ajose-Adeogun AO,
Nakayama T, Graham JA, Demur C, Hercend T, Diu-Hercend A, et al: VX-680,
a potent and selective small-molecule inhibitor of the Aurora kinases,
suppresses tumor growth in vivo. Nat Med 2004, 10:262–267. Received: 16 October 2013 Accepted: 20 January 2014
Published: 29 January 2014 References Page 9 of 9 Page 9 of 9 Wu et al. Journal of Experimental & Clinical Cancer Research 2014, 33:13
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Cite this article as: Wu et al.: Inhibition of Aurora B by CCT137690
sensitizes colorectal cells to radiotherapy. Journal of Experimental &
Clinical Cancer Research 2014 33:13. Submit your next manuscript to BioMed Central
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and take full advantage of:
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at
www.biomedcentral.com/submit Submit your next manuscript to BioMed Central
and take full advantage of:
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at
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and take full advantage of: Submit your next manuscript to BioMed Central
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https://openalex.org/W3003241334
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http://publikationen.ub.uni-frankfurt.de/files/54536/Hoehl2020_Article_ThirtyYearsOfCMVSeroprevalence.pdf
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English
| null |
Thirty years of CMV seroprevalence—a longitudinal analysis in a German university hospital
|
European journal of clinical microbiology & infectious diseases
| 2,020
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cc-by
| 5,163
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Abstract Human cytomegalovirus (CMV) is a significant cause of morbidity and mortality in patient groups at risk. We have previously
shown that the anti-CMV IgG seroprevalence in an urban region of Germany has changed over the last decades. Overall, a
decline from 63.7 to 57.25% had been observed between 1988–1997 and 1998–2008 (p < 0,001). Here, we continuously follow
the trends to the most recent decade 2009 to 2018. In a retrospective analysis, we determined the seroprevalence of CMV IgG
antibodies in our patient cohort, stratified by gender and selected groups at risk (e.g., patients with HIV infection; women of
childbearing age). The overall prevalence of anti-CMV IgG non-significantly declined further from 57.25% in 1998–2008 to
56.48% in 2009–2018 (p = 0.881). Looking at gender differences, overall CMV seroprevalence in males declined to 52.82%
(from 55.54% in 1998–2008; p = 0.0254), while it non-significantly increased in females to 59.80%. The high seroprevalence in
patients with a known HIV infection further increased from 87.46% in 1998–2008 to 92.93% in the current period (p = 0.9999). In women of childbearing age, no significant changes over the last three decades could be observed. The CMV seroprevalence in
oncological patients was determined to be 60.64%. Overall, the former significant decline of CMV seroprevalence between the
decades 1988–1997 and 1998–2008 in this urban region of Germany slowed down to a non-significant decrease of 0.77% (1998–
2008 vs. 2009–2018). This might be an indicator that CMV seroprevalence has reached a plateau. Keywords Cytomegalovirus (CMV) . Seroprevalence . Anti-CMV IgG . Human immunodeficiency virus (HIV) . Congenital
CMVinfection . CMVepidemiology Keywords Cytomegalovirus (CMV) . Seroprevalence . Anti-CMV IgG . Human immunodeficiency virus (HIV) . Congenital
CMVinfection . CMVepidemiology Thirty years of CMV seroprevalence—a longitudinal analysis
in a German university hospital Received: 8 November 2019 /Accepted: 12 January 2020
# The Author(s) 2020 1
Institute for Medical Virology, University Hospital, Goethe
University Frankfurt am Main, Paul-Ehrlich-Straße 40,
60496 Frankfurt am Main, Germany European Journal of Clinical Microbiology & Infectious Diseases
https://doi.org/10.1007/s10096-020-03814-x European Journal of Clinical Microbiology & Infectious Diseases
https://doi.org/10.1007/s10096-020-03814-x ORIGINAL ARTICLE * Holger F. Rabenau
rabenau@em.uni-frankfurt.de * Sebastian Hoehl
sebastian.hoehl@kgu.de Patient collective Due to the possibility of maternal antibody detection, infants
below the age of 1 year were excluded. Of each patient, only
the first CMV IgG test in the time period was considered, and
seropositivity defined as a positive result in the anti-CMV
antibody IgG assay. Patients with an unspecific or borderline
reactivity on the CMV IgG test were excluded. Group, age-
and gender-dependent analysis was performed. The mathe-
matical median of the positive test results was calculated. The comparative changes of CMV seroprevalence
among the patients of the urban University Hospital of
Frankfurt, Germany, over the period of 1988 to 1997
and 1998 to 2008 have previously been assessed. An
overall decline in CMV seroprevalence among its pa-
tients without a known HIV infection from the first to
the second decade, decreasing from 63.70% to 57.25%,
was observed. This decrease in CMV seroprevalence
has also been observed in other studies in Germany
[13, 16] and, in some groups, in Spain [14], but not
in the USA [12]. The decrease has also been observed
in bone marrow donors in Germany [16]. In the former
study conducted in Frankfurt, females had a slightly
higher CMV seroprevalence than men (63.83% com-
pared with 65.54% in 1988–1997 and 58.73% compared
with 55.54% in 1998–2008). Patients with a known
HIV infection had a significantly higher CMV seroprev-
alence (in females, 83.17% in 1988–1997 and 87.80%
in 1998–2008, in males, 88.76% in 1988–1997 and
87.32% in 1998–2008) [13]. Patients with a confirmed HIV infection were analyzed
separately to avoid bias by a higher-than-average CMV sero-
prevalence within this group and overrepresentation in our
patient cohort. Positive HIV status was defined as a positive
result in a 4th generation antibody/antigen-HIV screening test
followed by a positive confirmation test by HIV immunoblot
and/or HIV-PCR in the studied time period. The data of all three decades was revisited to determine the
CMV IgG seroprevalence of women of childbearing age. We
chose samples of women of childbearing age sent in by our
Department of Obstetrics and Gynecology, as testing of those
samples was presumed to be indicated by pregnancy or birth. We compared the CMV seroprevalence in this group between
the three decades, and formed four age groups for comparative
analysis. Material and methods Insight into the dynamics of CMV epidemiology is there-
fore highly relevant for diverse, vulnerable groups of patients. We conducted a retrospective analysis of the data routinely
acquired during patient care at the University Hospital of
Frankfurt. All results of anti-CMV IgG antibody tests from
our Institute of Medical Virology in the time frame January 1,
2009, and December 31, 2018, were analyzed. The University
Hospital of Frankfurt is the largest hospital and a maximum
care provider in Germany’s fifth largest city. It treats about
49,000 in-patients and 229,000 out-patients a year. Different areas of the world can be divided in low (50 to
70%) and high seroprevalence settings (> 70%) [8]. It is usu-
ally higher in low income countries [9–14]. A limited number
of studies have focused on the CMV seroprevalence in
Germany. In children and adolescents in Germany, a study
of the CMV IgG seroprevalence (KiGGS study, 2003–2006)
found a range between 21.4% in boys at 1–2 years of age and
33.5% in girls at 14–17 years of age. CMV seroprevalence
increased with age in both genders. Risk factors for higher
seroprevalence included migration background, place of birth
other than Germany, having attended daycare, and having
younger siblings [15]. In a study in the adult population of
Germany, sera collected throughout Germany in 1998, pub-
lished 2018, the overall CMV seroprevalence was 56.7% and
also increased with age. It was higher in females (62.3%) than
in males (51.0%). Total seroprevalence in women of child-
bearing age (18 to 45 years of age) was 51.7%. The study also
identified risk factors associated with seropositivity, with
country of birth and age being the strongest independent fac-
tors [11]. All anti-CMV IgG tests (Enzygnost anti-CMV IgG, Dade
Behring, Marburg, Germany) were performed on the Behring
ELISA Processor BEP 2000, the results were recorded semi-
quantitatively as arbitrary units per milliliter (AU/mL). The
test results of the decade 2009–2018 were compared with
the two decades of the former study (1988–1997; 1998–
2008) [13] in which the same diagnostic test had been used. Introduction 2 cases per 1000 pregnant women in Germany [5], making it
the most common infectious cause of birth defects. Permanent
sequelae include sensorineural hearing loss (SNHL), micro-
cephaly, seizures, neurologic deficits, and retinitis. Counseling about hygiene can lower the risk of anti-CMV
IgG negative women to get infected during pregnancy [5, 6]. The rate of SNHL appears to be similar for children born after
primary and non-primary maternal CMV infection, but seems
to be more severe in the primary maternal infection group [7]. Primary CMV infection in immunocompetent hosts may be
asymptomatic, or may cause mostly mild, self-limiting disease
with fever, fatigue, headaches, and myalgia [1, 2]. After pri-
mary infection, the virus remains latent. Infants and toddlers
are an import source of infection, as they can shed the virus by
urine or saliva for months or even years after infection [3, 4]. Primary infection, reactivation, or reinfection shortly be-
fore or during pregnancy can result in congenital CMV infec-
tion, which is estimated to lead to permanent disability in 1 to In immunocompromised hosts, CMV poses a major burden
of disease. People living with HIV/AIDS usually have a high
rate of CMV seropositivity. Therefore, the risk of primary
CMV infection is low, but reactivation or reinfection as an
opportunistic infection most commonly manifests as retinitis,
colitis or esophagitis, hepatitis, encephalitis,
myeloradiculopathy, or pneumonia. Otherwise immunocom-
promised hosts, such as oncological patients and solid organ
or stem cell transplant recipients, are additional groups affect-
ed by increased risk of morbidity and mortality associated
with CMV. Eur J Clin Microbiol Infect Dis CMV seroprevalence by gender Samples of a total of 31,401 patients above the age of 1 year
had been tested for anti-CMV IgG antibodies in the years
between 2009 and 2018. A total of 258 patients who had
borderline or unspecific test results were excluded, leaving
31,143 patients with an unambiguous result. The overall CMV seroprevalence in the most recent decade
2009–2018 was significantly higher in females (59.80%, n =
15,420) than in males (50.82%, n = 13,983, p < 0.0001). During the studied period of 30 years, CMV seroprevalence
decreased in both sexes. However, from the time period of
1998–2008 to 2009–2018, there was a non-significant in-
crease in females (p = 0.0811) (Fig. 2), and a significant de-
crease of 2.72% in males (p = 0.0254). Patient collective Patients younger than 16 or older than 45 years of
age were excluded from age-dependent analysis, since there
were a relatively low number of those samples, and therefore,
CMV seroprevalence could not be determined with confi-
dence. In addition, we determined the accumulated CMV se-
roprevalence of patients whose samples were sent in from an
oncological department or ward. We stratified by pediatric and
adult patients, defined by patient age. All patients younger
than 18 years of age were considered to be pediatric. In the current study, we set out to determine whether the
decline continued to the most recent decade, and especially
observed the changes over in time in two selected groups of
vulnerable patients, the developing fetus, examined in proxy
by the status of their pregnant mothers, as well as people living
with HIV/AIDS. As another important group affected by CMV disease, we
also looked at oncological patients. We determined the accu-
mulated CMV seroprevalence of those patients whose sam-
ples were sent in from oncology wards, stratified by pediatric
and adult patients. Statistical testing was performed using BiAS® for
Windows (version 11.10, epsilon-Verlag, Hochheim, Eur J Clin Microbiol Infect Dis older,” respectively (p values < 0.0001) (Fig. 1). CMV sero-
prevalence throughout all age groups declined significantly
when compared with the decade 1988–1997. A sustained de-
crease spanning all three decades can be observed in the group
of 1 to 9 year olds, and in all age groups 40 years and older
(Fig. 1). Germany, 2019), including the calculation of the 95% confi-
dence intervals. P values were calculated using the two-tailed,
not Yates rectified chi-squared test. A p value of ≤0.05 was
defined as statistically significant. Germany, 2019), including the calculation of the 95% confi-
dence intervals. P values were calculated using the two-tailed,
not Yates rectified chi-squared test. A p value of ≤0.05 was
defined as statistically significant. Figures were created using GraphPad Prism 6. Women of childbearing age declining up to the age group 31 to 35 years of age, followed
by a continuous increase with progressing age (Fig. 5). The
decrease from 16 to 20 years of age (76.22%) to 31 to 35 years
of age (60.13%) is statistically highly significant (p < 0.0001). There was no major change in the overall CMV seropreva-
lence of women of childbearing age presenting to the
Department of Gynecology and Obstetrics during the last
three decades. A slight increase from 64.18% (n = 3395) in
the decade 1988–1997 to 65.95% (n = 2429) in 2009–2018
cannot be asserted with confidence (p = 0.1627) (Fig. 4). All patients after exclusion of those known to be HIV
positive (p
)
Looking at the most recent decade only, CMV seropreva-
lence is higher in females in all age groups, however, not
statistically significant in the age groups 1 to 9 and 10 to
19 years of age (p = 0.1046 and p = 0.2503, respectively),
while significant in all other age groups. In the group 20 to
29 years of age, there is a sharp increase in females of 10.69%
and a decline in males, resulting in a large gap between the
genders of 17.09% (39.75% in males, 56.84% in females). In
males, CMV seroprevalence increases sharply between the
age groups 20 to 29 and 30 to 39 years of age, by 10.58%. Finally, CMV seroprevalence in both sexes merge toward a
linear increase, with seroprevalence in females about 7.5%
higher than in men (Fig. 3). The overall CMV IgG seroprevalence in the cohort in the
decade 2009–2018, after exclusion of 1740 patients with
known HIV infection, was 56.48% (n = 29,403). The median
value in the HIV-negative population was 1400 AU/mL. When comparing anti-CMV IgG seropositivity to the data
of the former decades, a continuous decline is visible: from
63.70% (n = 29,374) in the decade 1988–1997 and 57.27%
(n = 20,397) in the decade 1998–2008. While the slight overall decrease from the previous to the
most recent decade (1998–2008 to 2009–2018) of 0.77% was
not statistically significant (p = 0.0881), a significant decrease
can confidently be assessed when looking at the age groups
“20 to 29,” “40 to 49,” “50 to 59,” and “60 years of age and Fig. 1 CMV IgG seroprevalence
by age group and decade. Patients
with a known HIV infection were
excluded in all decades. *Data
previously published by our
group (Lübeck et al.) [13]; y/o,
years old Fig. 1 CMV IgG seroprevalence
by age group and decade. Patients
with a known HIV infection were
excluded in all decades. *Data
previously published by our
group (Lübeck et al.) [13]; y/o,
years old Eur J Clin Microbiol Infect Dis Women of childbearing age
declining up to the age group 31 to 35 years of age followed
Fig. 2 CMV IgG seroprevalence
by gender and decade. *Data
previously published by our
group (Lübeck et al.) [13] Fig. 2 CMV IgG seroprevalence
by gender and decade. *Data
previously published by our
group (Lübeck et al.) [13] CMV seroprevalence in HIV-positive patients In our cohort, 1740 patients had a known HIV infection. Of
those, 1617 had a positive anti-CMV IgG test result; the sero-
prevalence was 92.93%. The median of all positive samples
was 2409 AU/mL. Compared with the data of the two previous A look at the distribution between different age groups
spanning all three decades reveals the highest seroprevalence
rate in the youngest age group (16 to 20 years of age), that is Fig. 3 CMV IgG seroprevalence 2009–2018 by age group [13] Fig. 3 CMV IgG seroprevalence 2009–2018 by age group [13] Eur J Clin Microbiol Infect Dis Fig. 4 CMV IgG seroprevalence
of women of childbearing age, by
decade
Eur J Clin Microbiol Infect Dis Fig. 4 CMV IgG seroprevalence
of women of childbearing age, by
decade intervals overlapped. When compared with 1988–1997, how-
ever, the increase is highly significant (p < 0.0001) (Fig. 6). decades, we could observe an increase in seropositivity of
5.47%, which is not statistically significant (p = 0.9999). A significant difference in CMV seroprevalence between
males and females with a known HIV infection had not been
observed in the decades of 1988–1997 and 1998–2008. In the
most recent decade, however, the CMV seroprevalence of
females with a known HIV infection was higher than in males When looking at the genders separately, the largest increase
was in females with a known HIV infection, with an increase
of 6.81% when compared with 1998–2008, and 11.44% when
compared with 1988–1997. Between the former two decades,
the increase had little confidence, since the 95% confidence Fig. 5 CMV IgG seroprevalence
1988–2019 by age group from
women of childbearing age Eur J Clin Microbiol Infect Dis Fig. 6 CMV IgG seroprevalence
by gender and decade of patients
with known HIV infection. *Data
previously published by our
group (Lübeck et al) [13] 29 years of age and all groups above the age of 40 years. In our
youngest patients, below the age of 20 years, and in the age
group 30–39 years, however, the trend halted or even re-
versed. In the youngest patients, this might be associated with
more children below the age of 3 years attending daycare,
where the exposure to potentially infectious toddlers as a
source of infection is increased, a known factor associated
with CMV seropositivity in Germany [15]. Fig. 6 CMV IgG seroprevalence
by gender and decade of patients
with known HIV infection. *Data
previously published by our
group (Lübeck et al) [13] CMV seroprevalence in oncological patients In patients whose samples were sent in from oncological de-
partments, we determined a combined CMV seroprevalence
of 60.64% (n = 2091). It was lower in the pediatric population,
where it was 51.60% (n = 219), and higher in the adult popu-
lation (61.70%, n = 1872). CMV seroprevalence in HIV-positive patients Notably, from
2006 to 2017, the percentage of children below the age of
3 years attending day care in Germany increased from 13.6
to 33.1% [22]. Another factor offsetting the decreasing trend
in CMV prevalence might be associated with increased mi-
gration from non-EU countries, especially to the urban centers
of Germany. This could most markedly affect the age group
with the largest number of patients: 30 to 39 year olds saw an
increase of 1.28% in CMV seroprevalence (Fig. 3). Non-EU
nationals currently make up 22.08% of all 25- to 44-year olds
living in Frankfurt. Non-EU nationals living in Frankfurt
largely stem from regions with high CMV seroprevalence,
most markedly Turkey [23], where CMV seroprevalence is
reported to be between 94.9% and 96.4% in pregnant women
[19, 24]. Especially in children, migration background is well
characterized as a factor associated with a higher CMV sero-
prevalence [15]. It remains unclear if the overall declining
trend in CMV seroprevalence possibly continued in the sub-
population of patients without a migration background, as we
did not have information on the ethnicity of our patients. (94.61% and 92.36%, respectively), but with little confidence
(p = 0.1099). High CMV seroprevalence in patients with a known HIV
infection could be observed in all age groups with little vari-
ation. In the analysis by sex and age in the group of patients
with a known HIV infection, the sample size was too small to
confidently identify differences. Discussion In this study, we present an overview of the changes in CMV
IgG seroprevalence of the patients of the urban University
Hospital of Frankfurt over a time period of 30 years. In the most recent decade (2009 to 2018), the overall CMV
seroprevalence in patients without a known HIVinfection was
56.48%. This number is within the wide range of the previ-
ously published data for population groups in Europe of 30.4
to 89.7%. [9, 11, 13–19]. The slight decrease of 0.77% from
the previous decade (1998 to 2008) was not statistically sig-
nificant (p = 0.0881). Therefore, the decline in overall CMV
seroprevalence in Germany, that has also been observed in
other studies [16], appears to be slowing down or even halting. Changes in lifestyle, such as well-documented tendency to-
ward smaller households [20] in Germany, with fewer young
children as possible sources of infection [21] during the last
decades, may have been a driver behind the decreasing trend,
which was continuously observed in the age group of 20 to In the most recent decade (2009–2018), women had a sig-
nificantly higher CMV seroprevalence than men (59.80 versus
50.82%), a surplus of 8.98%. Other studies also observed a
higher seroprevalence in females [11, 13, 16]. Even though
this phenomenon has been observed before, it is not entirely
understood why women have a higher CMV seroprevalence. While social factors like earlier and more extensive involve-
ment in the care of potentially infectious toddlers and infant
might be contributing, this would not explain the higher CMV Eur J Clin Microbiol Infect Dis seroprevalence in females of all age groups. A sharp increase
in CMV seroprevalence occurs in females between the age
groups 10 to 19 and 20 to 29 years of age, and in males
between the age groups 20 to 29 and 30 to 39 years of age
(Fig. 4). The delayed increase in men, as well as the higher
overall prevalence in women after puberty, might be attributed
to CMV, like other sexually transmitted infections, being sex-
ually transmitted at a higher rate from infectious men to sus-
ceptible women than from infectious women to susceptible
men [25]. all combined oncological patients. The main goal of this study
was the description of changes in CMV seroprevalence over
time. Discussion In the case of oncological patients, however, we cannot
compare this number to the previous decades, as the structures
of our University Hospital as well as the data accompanying
the samples has changed in the last 30 years, and no congruent
groups could be defined. Patients could also not be divided
into further subgroups of interest, such as solid organ or stem
cell recipients, since such data was not easily attained. This is
an area that should be further examined in future studies. Other limitations of our study include our hospital cohort
setting in an urban region of Germany, which is not represen-
tative of the general population. We also cannot be sure that
the sent-in practices for CMVassays in our university hospital
did not change during the examined period of 30 years, and
influenced the comparability of the studies. During the last
three decades, there was an increased awareness of the dan-
gers of primary CMV infection during pregnancy, and there-
fore, more testing occurred in pregnant women, distorting the
overall numbers by over-representing this group. In women of childbearing age presenting to the Department of
Obstetrics and Gynecology, we observed a CMV seroprevalence
of 65.95%, which is significantly higher than the overall rate of
59.80%. There was no significant change during the last 30 years
(Fig. 4). Other studies in women of childbearing age in Germany
reported lower rates in pregnant women, ranging from 34% in a
small group of 34 pregnant women from all over Germany [11]
to 46–52%, with data from a central German University Hospital
[11, 18]. Stratified by age group and spanning over three decades,
we could see the highest CMV seroprevalence in young women
(76.22% in the age group 16 to 20 years of age) that was declin-
ing up to the group 31 to 35 years of age. This phenomenon has
previously been observed in studies from 1991 (Friese et al.) and
2011 (Enders et al.) [16, 17], and might be due to women with
lower socioeconomic status [26] as well as women with migra-
tion background from non-EU countries [27] tending to give
birth to their first child earlier in life, both factors associated with
higher CMV prevalence [16, 18, 28]. In the following age
groups, CMV seroprevalence rises continuously (Fig. 4). Funding Information Open Access funding provided by Projekt DEAL. Funding Information Open Access funding provided by Projekt DEAL. Discussion The strength of this study lies in the large number of pa-
tients (31,401 in the decade 2009–2018), and the good com-
parability of the test results, as the same diagnostic test had
been applied over the last three decades. Overall, the former significant decline of CMV seropreva-
lence between the decades 1988–1997 and 1998–2008 in this
urban region of Germany slowed down to a non-significant
decrease of 0.77% (1998–2008 vs. 2009–2018). This might
be an indicator that the dynamic of the CMV seroprevalence
has reached a plateau. It remains unclear whether the herein
described changes in CMV immunity over time have a tangi-
ble impact on the incidence of CMV disease in groups at risk. In women of childbearing age, there was no significant change
in CMV seropositivity in the last three decades, and therefore,
no change in the proportion of women who are at risk of
primary CMV infection during pregnancy. In patients with a known HIV infection, a further increase
in the already high CMV seroprevalence could be observed,
most strikingly in women, who had a CMV seroprevalence of
94.61%, an increase of 6.81% when compared with the former
decade. In males, CMV seroprevalence also increased, but not
quite as much, and was 92.36%. Especially in women with a
known HIV infection, this trend might be associated with
migration from Sub-Saharan Africa after 2013 [29], where
CMV seropositivity in asymptomatic, HIV-positive patients
approaches 100% [10]. It is noteworthy that the median value
of all positive samples was higher in the group of patients that
are known to be HIV positive, with a value of 2409 AU/mL,
as compared with 1400 AU/mL in the HIV-negative group. It
needs to be taken into account that this does not represent the
mathematical mean, which could not be calculated due to a
recorded upper limit in the AU/mL value, and it is unclear if
this less than twofold difference represents a clinically rele-
vant gap. In patients that could be identified as oncological, a
CMV seroprevalence of 60.64% (n = 2091) was determined in
the current decade. In pediatric patients, it was 51.60%, and
61.70% in adult patients. The excess from the overall sero-
prevalence of 56.48% in the HIV-negative cohort is statisti-
cally significant (p = 0.0002), but there are no numbers avail-
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interest. Ethical approval
This study was permitted by a vote of our University
Hospital’s ethics board. Informed consent
Our study was based on the retrospective analysis of
anonymous patient data only. Informed consent was not obtainable, and
not required by vote of our University Hospital’s ethics board. Open Access This article is licensed under a Creative Commons
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in cytomegalovirus seroepidemiology in Spain? Eur J Epidemiol
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article's Creative Commons licence and your intended use is not permitted
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what has changed? Med Microbiol Immunol 199(1):53–60. https://doi.org/10.1007/s00430-009-0136-3 Publisher’s note Springer Nature remains neutral with regard to jurisdic-
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wileyonlinelibrary.com/journal/hpm 1
wileyonlinelibrary.com/journal/hpm DOI: 10.1002/hpm.3574
Received: 3 May 2020 Revised: 16 May 2022 Accepted: 31 August 2022 DOI: 10.1002/hpm.3574
Received: 3 May 2020 Revised: 16 May 2022 Accepted: 31 August 2022 Received: 3 May 2020 Revised: 16 May 2022 Accepted: 31 August 2022 DOI: 10.1002/hpm.3574 Thérèse Eriksson | Lars-Åke Levin | Ann-Charlotte Nedlund Division of Society and Health (SH),
Department of Health, Medicine and Caring
Sciences (HMV), Linköping University,
Linkoping, Sweden Abstract Abstract
Reimbursement programmes are used to manage care
through financial incentives. However, their effects are
mixed and the programmes can motivate behaviour that
goes against professional values. Value-based reimburse-
ment programmes may better align professional values
with financial incentives. The aim of this study is to analyse
if and how healthcare providers adapt their practices to a
value-based reimbursement programme that combines
bundled payment with performance-based payment. Forty-one semi-structured interviews were conducted with
representatives from healthcare providers within spine
surgery in Sweden. Data were analysed using thematic
analysis with an abductive approach and a conceptual
framework based on neo-institutional theory. Healthcare
providers were positive to the idea of a value-based reim-
bursement programme. However, during its introduction it
became evident that some aspects were easier to adapt to
than others. The bundled payment provided a more compre-
hensive picture of the patients' needs but to an increased
administrative burden. Due to the financial impact of the
bundled payment, healthcare providers tried to decrease
the amount of post-discharge care. The performance-based
payment was appreciated. However, the lack of finan-
cial impact and transparency in how the payment was Correspondence
Thérèse Eriksson, Division of Society and
Health (SH), Department of Health, Medicine
and Caring Sciences (HMV), Linköping
University, SE-581 83, Linköping, Sweden. Email: therese.eriksson@liu.se Int J Health Plann Mgmt. 2022;1–20. 2022 The Authors. The International Journal of Health Planning and Management published by John Wiley & Sons L Highlights • The idea of value-based reimbursement was in line with
professional values. • The bundled payment increased the willingness to collaborate. • The performance-based payment based on Patient reported
outcome measures was too complex to understand. • Lack of support from purchaser and insufficient IT-systems
caused resistance. K E Y W O R D S bundled payment, institutional change, neo-institutional theory,
pay-for-performance, reimbursement, value-based reimbursement Correspondence Funding information
Region Stockholm ERIKSSON et al. 2 calculated caused providers to neglect it. Healthcare provid-
ers adapted their practices to, but also resisted aspects of
the value-based reimbursement programme. Resistance was
mainly caused by lack of understanding of how to interpret
and act on new information. Providers had to face unfamiliar
situations, which they did not know how to handle. Better
IT-facilitation and clearer definition of related care is needed
to strengthen the value-based reimbursement programme
among healthcare providers. A value-based reimbursement
programme seems to better align professional values with
financial incentives. Value-based reimbursement programmes (VBRP) focus on activities that generate value through quality enhanc-
ing, but also cost constraining, incentives. 17 Surgical procedures have been considered suitable for value-based reim-
bursement because of the discrete beginning and end of a care episode. Further, the variation in recommendations
in clinical guidelines 18 of spine surgery makes it suitable for a value-based reimbursement since the reimbursement
level is conditioned on the outcome of the surgery. Hence, the provider must assess whether the patient will improve
enough to outweigh the cost of performing the surgery. The purchaser put the financial responsibility on the provider
instead of paying for the service no matter the quality. The regional public health authority, Region Stockholm, is responsible of providing healthcare to 2.4 million
people. 19 Region Stockholm introduced a value-based reimbursement programme (STHLM-VBRP) within elective
spine surgery in 2013. The design of the programme is based upon the thoughts of value-based healthcare (VBHC),
first outlined by Porter and Teisberg in 2006, 20 and combines bundled payment with performance-based payment (also
known as pay-for-performance, P4P) in a unique design. The bundled payment extends the clinical episode to 1 year
after surgery, a longer period compared to other programmes 21,22; and the measure used for the performance-based
payment is how much pain the patient experiences 1 year after surgery. The bundled payment extends providers'
financial responsibility to incentivise coordination of care and to avoid overuse. The performance-based payment
conditions the reimbursement to the outcome of the surgery and aims to enhance and sustain quality by rewarding
high-performing providers. In this paper, we sought to contribute to the empirical value of neo-institutional theory,
by interviewing representatives from healthcare providers on how regulative changes affect daily operations within
elective spine surgery in Stockholm, Sweden. The aim of this study is to analyse if and how healthcare providers adapt their practices to a value-based reim-
bursement programme that combines bundled payment with performance-based payment. In particular, we investi-
gate the following research questions: How do healthcare staff experience and respond to the financial incentives the
STHLM-VBRP entail? How can these experiences be understood from the perspective of neo-institutional theory in
terms of alignment and resistance to the contractual changes the STHLM-VBRP imposed? 10991751, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Term ERIKSSON et al. 3 1 | INTRODUCTION According to economic theory, financial incentives are powerful means to shape the behaviour of actors in any
market, including the health care market. The reach and limits of financial incentives in health care has been widely
debated for decades. Some argue that it increases efficient use of scarce resources, 1 while others voice that it leads
to unintended and unethical outcomes. 2 Studies have shown that financial incentives can be an effective way to
affect physician behaviour. 3–5 However, the incentives do not always have the intended effects. 6–9 The use of finan-
cial incentives has for example, been criticised for increasing production disregarding the quality of care 10 and may
dampen the autonomy among physicians 11,12 who feel obliged to perform certain activities in order to get reimbursed. A study investigating physicians' perceptions of financial aspects shows that physicians commonly view financial
accountability as something that comes at the expense of autonomy, and that high levels of autonomy among physi-
cians is a pre-requisite for achieving high quality of care. 11 On the other hand, decreased professional autonomy may
increase the control of the purchaser and therefore something positive for them. Reimbursement programmes are commonly used to generate financial incentives with the ambition of aligning
the objectives of healthcare providers and the purchaser. 13,14 Thus, the incentive design in the programme must take
into account the multiple agency connections (e.g., the provider as agent to both patient and purchaser) inherent in
the reimbursement for health services. 15 Poorly designed reimbursement programmes may lead to undesired behav-
iour and inefficient activities that decrease the legitimacy of financial incentives as an instrument to manage care. Therefore, it is also important to take the context into account, in which the reimbursement programme is introduced
since the reimbursement programme alone may not be enough to affect daily operations. 16 frameworks of the shared perception, which enable sense making when meeting the ‘external world of stimuli’. 28 The
cultural-cognitive pillar emphasises features of shared understanding, professional ideologies, cognitive frames or
sets of collective meanings. These aspects condition how actors interpret and respond to the world around them. A
focus on the cultural-cognitive pillar sheds light on how knowledge is constructed and codified in models, assump-
tions and schemas, to what extent it informs and constrain behaviour. Confusion among actors usually indicates lack
of support from the cultural-cognitive pillar because they do not know how to process or interpret information. Institutions are more robust when the regulative, normative and cultural-cognitive pillars are aligned and rein-
force each other. Changes in one of the pillars may cause misalignment and resistance, thus weakening the institution
if the pillars motivate different behaviours. However, institutions tend to converge over time and institutional theory
considers misalignment of pillars as a catalyst for change. 28 The framework by Scott provides a structure to our analysis by focussing on the respective pillar, but also their
interrelationship. The introduction of the STHLM-VBRP imposed contractual changes regarding the provision of elec-
tive spine surgery in Region Stockholm and can thus be regarded as regulative. This change may work as a catalyst
for institutional change if the introduction causes a misalignment between the pillars. If healthcare providers resist to
institutional elements imposed by the VBRP, these elements will not be institutionalised. If healthcare providers align
to the institutional elements imposed by the VBRP, the elements will be institutionalised. By analysing all three pillars,
we intend to provide a deeper understanding on how and why certain aspects of the new reimbursement programme
are institutionalised or not. 2 | UNDERSTANDING REGULATIVE CHANGES FROM THE PERSPECTIVE OF
INSTITUTIONAL THEORY The implementation of VBRP varies between, but also within, different healthcare systems. 23 In the US, focus
has been on moving away from fee-for-service, 24 whereas publicly financed healthcare systems in Europe mostly
have focused on coordinating care among providers. 25 Thus, the introduction of the value-based reimbursement
programme (VBRP) does not happen in a vacuum. This may seem obvious, but many evaluations overlook contextual
factors when assessing an intervention. 5,26,27 Organisations cannot be fully understood in isolation from the exter-
nal influences that arise from a wider contextual perspective. 28 Consequently, institutional theory provides suitable
frameworks for examining the nature of external demands and the behaviour of organisations. We use an approach
to new-institutional theory based on Scott's conceptual framework. 28 According to Scott, institutions consist of
regulative, normative and cultural-cognitive pillars that in relation to each other has stabilising and meaning-making
properties. The regulative pillar refers to the practice of rule-setting, monitoring, sanctioning and incentivising. It comprises
formal legislation but also less formal rule making. Instrumentalism is very central within the regulative pillar, that
is, individuals conform to laws and rules because they seek rewards or wish to avoid sanctions. Hence, focus on
the regulative pillar sheds light on the more formalised control systems. The normative pillar encompasses values
and norms. Values refer to conceptions of the preferred or the desirable, whereas norms refer to the scripts for
how to reach the desirable goals and what means are legitimate in attaining them. 28 A focus on the normative
pillar emphasises the stabilising influence of social beliefs and norms, both internalised and imposed by others and
highlights the ‘moral roots’ of behaviour and institutions. The cultural-cognitive pillar refers to the processes and ERIKSSON et al. designing a reimbursement programme leads to an increased risk of ‘cherry picking’, that is, providers avoid clinically
complicated patients to the benefit of healthier patients. However, patients with a high potential risk of needing
intensive care are not covered by the commissioning contract and must be surgically treated at a hospital with access
to an intensive care unit. The bundled payment should cover the individual patient's healthcare utilisation related to the spine surgery
(e.g., potential complications, reoperation, rehabilitation), for the full care episode of 1 year. That means that the
bundled payment includes the patient's rehabilitation, primary care, speciality care and hospital care provided by
external healthcare providers (i.e., not the provider that performed the surgery). The provider that performs the
surgery receives an invoice from the purchaser if an external healthcare provider treats their patient after the surgery. Hence, the bundled payment is a multi-organisational bundle of service. The bundled payment should stimulate an
effective and integrated care chain by using a fixed payment to the provider for all services provided during the entire
care episode. The performance-based payment is based on the outcome measure Global Assessment (GA). The measure is a
retrospective transition question asked 1 year after surgery (‘How is your back/leg pain today compared to before
the surgery?’). 31 The patient can choose between six response options (pain free, much better, somewhat better,
unchanged, worse, did not have pain before the surgery). The registration of GA is administered and managed by the
national quality registry for spine surgery in Sweden, Swespine. 32,33 The expected performance-based payment that The performance-based payment is based on the outcome measure Global Assessment (GA). The measure is a
retrospective transition question asked 1 year after surgery (‘How is your back/leg pain today compared to before
the surgery?’). 31 The patient can choose between six response options (pain free, much better, somewhat better,
unchanged, worse, did not have pain before the surgery). The registration of GA is administered and managed by the
national quality registry for spine surgery in Sweden, Swespine. 32,33 The expected performance-based payment that
is included in the prospective payment is based on historical outcomes of GA, adjusted for patient characteristics. If
the level of pain of the patient turns out better than expected 1 year after surgery, the healthcare provider receives
an additional payment. If the level of pain turns out worse than expected the healthcare provider has to repay money
to Region Stockholm. Hence, the size of the adjustment depends on the discrepancy between the actual and the
expected outcome. A provider cannot receive a positive performance adjustment by performing surgery on a patient
that is expected to be pain free 1 year after surgery, simply because that patient cannot get any better. On the
other hand, a patient that according to historical outcomes is expected to experience a somewhat better pain will
generate a positive adjustment if the actual outcome is pain free. The idea is that the performance-based payment
should give financial incentives to investigate further, what can be done to improve the pain 1 year after surgery. Thus, performance-based payment is a complement to the bundle payment, to avoid healthcare providers stinting
on necessary care since it may negatively affect the pain patients experience. However, healthcare providers cannot
perceive the full size of the performance-based payment since it is included in the prospective payment; they only
perceive the adjustment if the actual outcome deviates from the expected. 3 | THE CASE OF THE VALUE-BASED REIMBURSEMENT PROGRAMME The Swedish healthcare system is publicly financed with universal coverage. In Sweden there are 21 regions that
are responsible for the provision and financing of healthcare, mainly through tax revenues. Since the regions are
responsible for both provision and financing, they can be considered as both commissioning and purchasing organ-
isations. As a commissioner, the region decides under what conditions healthcare organisations may provide care in
the region. As a purchaser, the region pays for the healthcare consumed by the inhabitants within the region. In our
article, Region Stockholm will synonymously be referred to as the purchaser. To receive public funding, private healthcare providers need accreditation by establishing a commissioning
contract with the region in which they wish to deliver care. This is done either through the Public Procurement Act 29
or through the Freedom of Choice Act 30 (known as Patient Choice within healthcare), two different market-oriented
solutions. Under the Public Procurement Act, healthcare providers are permitted a certain volume each year to a nego-
tiated price, specific to each healthcare provider. Whereas Patient Choice is a contract that usually have no restriction
on volume but with a set price, making providers compete based on quality and ultimately the patients' choice, a
requirement for VBHC. 17 Patient Choice entails a continuous commissioning contract between the purchaser and
healthcare providers, instead of a recurring procurement process. In 2013, Region Stockholm transitioned to accredit healthcare providers through Patient Choice instead of the
Public Procurement within elective spine surgery. An elective surgery is scheduled in advance and does not involve
an emergency. It was also decided that Patient Choice for elective spine surgery should entail a value-based reim-
bursement programme. This reimbursement programme will be referred to as the Stockholm value-based reimburse-
ment programme (STHLM-VBRP). Private healthcare providers in Region Stockholm performed most of the elective
surgeries, both before and after the introduction of Patient Choice with the STHLM-VBRP. The STHLM-VBRP combines bundled payment with performance-based payment, adjusted for patient charac-
teristics. When the surgical procedure is registered, the healthcare provider receives a prospective payment, which
includes the bundled payment and the expected performance-based payment. The prospective payment is adjusted
for age, gender, comorbidity level and surgery that covers more than two levels of the spine. The idea is to limit
differences in financial risk between patients to promote need-based healthcare. Failing to adjust for case-mix when ERIKSSON et al. 5 to talk freely about the topics. To recruit respondents for interviews, we used a purposive sampling approach 35 in
dialogue with the respective managers at the four clinics. We wanted the respondents to reflect the heterogeneity
among staff, thus both clinically active and administrative staff were included from different professions, to attain a
more comprehensive perspective. By interviewing both staff and clinicians we could reflect the potential different
contextual factors and consequences of the reimbursement programme. All staff were employed by the healthcare
provider and their salary was not affected by the new reimbursement programme. Before commencing the fieldwork,
we obtained ethical approval (2015/94-31) from the regional board of ethics in Linköping, as well as a signed consent
to participate from each respondent. The respondents were also informed that each interview was estimated to last
between 30 and 60 min. We conducted semi-structured face-to-face interviews with representatives from all four accredited healthcare
providers at respective spine surgery clinics. The interviews were carried out in two waves, May 2015–May 2016
and June–September 2017. The interviews were carried out in two waves to cover any potential time factor affecting
how respondents experienced the reimbursement programme. For the second wave, our first option was to interview
the same respondents, but because of misaligned schedules and certain staff turnover this was not always possible. In total, 41 respondents were interviewed, see Table 1. Seven respondents were interviewed in both the first and the
second wave, thus 34 unique respondents were interviewed. Three interviews were conducted with two respondents
at the same time after a query from the respondents. Two interviews were conducted over the telephone, both in the
second wave, with respondents who had already been interviewed face-to-face during the first wave. To make the
respondent feel comfortable in the situation, each interview started with more general questions about the respond-
ent's profession and responsibilities. 35 Each interview lasted between 20 and 60 min. There was some variation in
length of the interviews because respondents had been involved and affected by the reimbursement programme to
a varying degree. However, each interview started by checking available time in order to adjust the disposition to
the topic. The interviews were carried out in Swedish. All but one interview were audio recorded and transcribed
verbatim in Swedish. The interviews were analysed using a thematic analysis. 4 | STUDY DESIGN AND METHODS We conducted a systematic comparison of case studies, using respondents' own reports since neo-institutional anal-
ysis assumes that institutions are, in effect, manifested through individuals' attitudes, beliefs and motivation. The
case studies of interest were healthcare providers accredited within elective spine surgery and reimbursed based on
the STHLM-VBRP. At the time of the introduction of the STHLM-VBRP, there were three accredited healthcare providers in Region
Stockholm. A fourth provider was accredited in 2017. All of the providers were private and for-profit, one clinic was a
professional partnership whereas the other three clinics were part of a larger healthcare organisation (however, some
had a history of being a cooperative/professional partnership). Two providers were located in Stockholm city, one in
a Stockholm suburb and the fourth in a neighbouring region (Region Sörmland). Despite being located in different
regions, all healthcare providers were providing care under the same contractual conditions after the introduction of
the STHLM-VBRP. An interview guide was designed based on the structure of the reimbursement programme. The interview guide
was designed as an aide-memoire, 34 to ensure that all aspects were covered but still allowing for the respondent ERIKSSON et al. by Scott, 28 to connect the empirical findings to the conceptual framework based on institutional pillars. An iterative
process followed, where identified themes were classified, grouped and regrouped. Only the quotes used in the arti-
cle was translated from Swedish to English. The originators of the quotes used in ‘Findings’ have been encrypted to ensure that individual respondents
cannot be identified. The healthcare providers will be denoted A–D followed by a number indicating the respondent. Further, in the following text, post-discharge care will be denoted as external care when provided by a provider other
than the initial spine surgery clinic. 5 | FINDINGS The main themes correspond to the aspects of the STHLM-VBRP that the healthcare providers experienced as
most important: the bundled payment, the performance-based payment, and the continuous contract. Each theme is
followed by subthemes that were generated with the inductive approach. 36 We adopted an abductive approach that allows for
interaction with previous and newly discovered knowledge, thus allows for a combination of an inductive and deduc-
tive approach. 37 Accordingly, the interview guide provided a helpful structure for beginning the analysis, but the
themes were adapted when new aspects were discovered. The first step in the analysis was to identify what aspects
of the new regulative framework healthcare providers experienced, how these aspects were perceived and whether
they had any effect on their daily operations. Emerging themes were later sorted into the neo-institutional framework TA B L E 1 Represented professions and functions among the respondents First wave
Second wave
Total
Profession
Spine surgeon
4
6
10
Registered nurse
7
9
16
Physiotherapist
1
4
5
Accountant/controller
3
5
8
Other professions
2
0
2
Total
17
24
41
Function
Head of clinic, CEO
2
4
6
Administrative staff
9
7
16
Working in different health professions
6
13
19
Total
17
24
41
TA B L E 1 Represented professions and functions among the respondents TA B L E 1 Represented professions and functions among the respondents Represented professions and functions among the respondents ERIKSSON et al. 7 7 5.1.2 | Post-discharge care—An administrative nightmare Another aspect of the increased financial responsibility was that invoices often seemed to include care that was not
related to the spine surgery. This resulted in additional administrative work for administrators at healthcare providers,
but also for physicians since it required medical knowledge to audit the health records of the patients. Respondents
said that it would be impossible to keep auditing health records manually in the long term and emphasised the need
of better IT-facilitation for a sustainable system. And should something happen after surgery that is related to the surgery – then of course, you have
to take responsibility. The only thing that I find tiresome… is that they shift a lot of costs onto the
healthcare provider that aren't related to the surgery. It's just that parenthesis, otherwise I definitely
think you should be responsible for what you do, absolutely. D6 The unrelated care was experienced as an ‘unfair part of the contract’ (B7), a way for the purchaser to pass on
costs to the provider. Another problem with unrelated care was that they had to spend time and resources on writing
an appeal to argue as to why they should not pay the bill, thus increasing the administration even further. C1 The financial responsibility for post-discharge care affected healthcare providers. In particular, the cost of treat-
ing infections was extremely high and affected them greatly. Some respondents also said that the clinics in Stockholm
all had very low infection rates. Thus, it was rather a matter of bad luck than something that was preventable and
hence impossible to reduce further. Therefore, it seemed unfair to have them pay for necessary care for patients. It is more that it feels unfair, when it comes down to a complication that you reasonably couldn't have
avoided in any way, that you later receive a bill of half a million, it doesn't feel fair. It is more this sense
of justice, you have done your absolute best and sometimes you get hit, this penalty approach is not
good. D3 Thus, respondents expressed a level of discontent with the inclusion of infections in the responsibility of
post-discharge care. Infections requires intensive care, something the private spine surgery clinics cannot provide
themselves. 5.1.1 | A more holistic perspective All healthcare providers were strongly affected financially by the increased cost responsibility. Hence, all healthcare
providers experienced a strong incentive to take care of complications related to the surgery to avoid paying other
healthcare providers. It further stimulated the providers to discuss how to decrease the amount of external care at
other hospitals/providers. What I think is the difference, when I look at other areas of patient choice, we have a more complete
picture of the patient. Otherwise you only see the surgical procedure. So I think that is the major differ-
ence, that you have a lot more patient responsibility for much longer. It also creates other routines; it
creates another way of working. C2 Yes, it actually drives private healthcare providers to take responsibility. Not just under the knife, but
that you actually own the process for a while longer. B8 The invoices for external care created a new flow of information to the providers when their patients were treated
elsewhere. Healthcare providers expressed that this procedure gave them a more comprehensive perspective of the
care chain. They realised that not all patients contacted them if they experienced complications after the surgery. That there is a slightly clearer follow-up on how the patients turned out in the end. Because clearly
patients may be a bit different, some may not always call you if they don't feel well. They think like ‘nah
but I guess this is normal’, now we can see it in a different way – more clearly. That there is a slightly clearer follow-up on how the patients turned out in the end. Because clearly
patients may be a bit different, some may not always call you if they don't feel well. They think like ‘nah
but I guess this is normal’, now we can see it in a different way – more clearly. D4 D4 I think it's good that you have to take that responsibility because it also means that you are more
active in taking care of your own complications. You have to because of financial reasons. If one of our
patients ends up at a university hospital or something like that, then we get a huge invoice and its's not – it has happened – it's not funny. Like you see half a week's production just disappears. Yes, it's
pretty tough but I still think it's good. 5.1.1 | A more holistic perspective ERIKSSON et
8 8 ERIKSSON et al. Two of the healthcare providers perceived the more prominent role of physiotherapy as a natural step in improv-
ing spine surgery care. Healthcare professionals argued that it was good to assess patients from different perspec-
tives, that physiotherapists can better assess the physiotherapy the patient has had previously. We have a holistic perspective all the time because we have the reception, we have the surgery, we
have the physiotherapists and in the city we provide – we are accredited within Patient Choice reha-
bilitation. So I think we have a holistic approach regarding the spine. A3 At the other two clinics it was experienced as a big transition from being a spine surgery clinic responsible for
the patient from the surgery until discharge, to suddenly being responsible for post-discharge care and rehabilitation. From 1 day to the next, physiotherapists suddenly had a great responsibility. One of the providers began to drastically
change their patient flow by involving physiotherapists in the assessment but also by opening a centrally located
outpatient clinic. Another provider had a more reserved attitude to the new responsibility making no major changes. We have started up a completely new flow prior to surgery that we are implementing at the moment
and slowly getting used to. B5 Yes, a little understanding would feel good because, as I said, referring patients to avoid things they
actually need. […] I feel really sad about it and I think it's pretty difficult to work that way. It would be
nice to have an understanding of why I say it … I do as I'm told but that doesn't feel that good all times. D8 D8 Another problem was that it was not possible to assess what patients had been treated for by external physiother-
apists after surgery. This caused frustration and the spine surgery clinics felt a lack of control. Respondents expressed
the need for better registration of what kind of treatment patients received when consulting a physiotherapist. We've experienced that patients who have had minor surgery, that may not really be in need of much
physiotherapy, go to a physiotherapist in town and then loads of invoices drop into our mailbox and
we can't figure out how that happened. We don't really have any control of the situation. But the
patients do have the right to consult a physiotherapist, and then the physiotherapist can bill us. 5.1.3 | A more prominent role for physiotherapy Due to the bundled payment the cost of physiotherapy became salient to the spine surgery clinics and acquired a far
more central position as compared to before the introduction of the VBRP model. The close relationship between
spine surgery and physiotherapy became more evident and it was discussed at a management level. Now management can try to concentrate on how… before we've ignored physiotherapy. Now, we
must include physiotherapy – what physiotherapy do we really need? And how should we work with
it and to put those thoughts into practice. A1 9 C1 C1 The spine surgery clinic wants to be able to assess whether the treatment is related to the spine surgery or not, and
the necessity of the treatment. Three out of the four clinics, offered the patients regular return visits to the clinic for
physiotherapy, in an attempt to avoid being billed by external physiotherapists. This was also logistically problematic
when patients lived far from the clinic and/or already had an established relationship with another physiotherapist. To
increase the likelihood of the patient returning to the clinic for physiotherapy after surgery, one healthcare provider
started with physiotherapy before the surgery to establish a relationship with an internal physiotherapist. The damned patients who don't come here. The damned patients who don't come here. D7 As an effect, physiotherapy could be perceived as something that should not be recommended by healthcare
professionals. They could not send patients in need of physiotherapy to other physiotherapists because of the finan-
cial responsibility. But what we see is that the costs for physiotherapy are quite high because the patient still has a
choice. We have no choice; we have signed this contract. The patient has a choice not to come here,
where we already have the staff for that kind of activity. B8 But … we can't control patients, we can only ask them not to go, and if they should go, we want them
to go to this physiotherapist with whom we have an agreement. But if they don't go there, we can't
force them either. Because they have a free choice. D2 Many experienced it as frustrating not having any tools to handle the free will of the patient and wished for better
support from Region Stockholm. Because of Patient Choice they could not limit the care the patient sought elsewhere. Some respondents suggested the possibility of a patient contract as a solution. A contract that guaranteed the patient
a certain amount of physiotherapy related to the surgery, but the patient would be charged for any additional care that
exceeds the agreed amount. However, that kind of action needs regulative support from Region Stockholm. Does increased accessibility and freedom of choice require a patient contract? With an increased cost-responsibility for post-discharge care, respondents recognised that it was more important
now to establish a good relationship with the patient. If the patient wanted to return to their practice, they would
not have to pay other healthcare providers. To increase the chance of the patient returning for post-surgery care, all 10 ERIKSSON et al. healthcare providers had increased their accessibility by extending opening hours, two providers also opened up a
more centrally located outpatient clinic. We have better control and the patient has better access to us I think. So for the patient I think it's an
advantage actually. And the most positive effect is probably that we feel that we must hold on to our
patients, we lose out by not caring about them, I must say. A6 It was however logistically problematic for the providers to make patients come back in the case of complica-
tions, or to do physiotherapy when the easiest option for the patient was to turn to their primary care centre, emer-
gency department or a physiotherapist with whom they already had an established relationship. This was described
as unfair, to place this coordinating and integrating responsibility on them alone. They further expressed difficulties
in scheduling staff; there is no point of having a physiotherapist at the clinic if the patients never use it. In a way I think it's good. On the other hand, I think it's bad because you can't control if a patient
chooses a provider other than yourself. Which makes it important to speak the same language with
the external providers. You cannot force people to come back after discharge, they may think it's
better to go to their own physiotherapist. And we can sometimes differ in the way we see things, how
much care the patient needs. C3 The bundled payment made it important to build a network of external physiotherapists (and other healthcare
providers), with whom the spine surgery clinics could cooperate and agree upon an adequate level of care. Another problem respondents described was how to obtain information on whether their patient sought care
elsewhere, and how to offer them the possibility to come back. Once they receive the invoice, it is too late to react,
thus not giving them the chance to affect the healthcare provided. Respondents said that it felt like a punch in the
stomach to receive an invoice from another hospital that had treated, a patient they could have treated themselves
had they been offered the opportunity. And it can be frustrating if it is abused out there, that someone gets loads of mediocre unnecessary
care, I don't think that's okay. So we can try to have a good dialogue with them, to write referrals and
write some guidelines and such. C3 Patients usually seek care at an emergency department and are hospitalised. And then all possible
things can be done without anyone contacting us. They can perform surgery and they can do – we
don't even know that the patient is there. And then the patient is hospitalised for two weeks or some-
thing, being treated, and different things are done, and then suddenly out of no-where we receive a
bill … it can cost a month's budget, for care we don't have any opportunity to influence. D1 Respondents said that some kind of automatic notification when their patient was registered elsewhere would
be helpful, to give them a fair chance to offer their services. However, they also acknowledged the importance of
respecting the choice of the patient and their option to say no and stay with the external healthcare provider. 5.1.5 | Communication with external healthcare providers became important, but it was difficult to make them cooperate. Providers within STHLM-VBRP acknowledged that there was no direct incentive for external healthcare providers to
put time and resources into contacting them. However, from a wider perspective it would be more efficient since the
spine surgery clinic has the clinical history of the patient. They meant it would be more efficient if they got the chance
to take care of their own patients instead of using the resources of hospitals or other facilities dedicated to more seri-
ous or complex conditions. Respondents said that they had realised that they must work actively for more integrated
care, to contact external healthcare providers to set up a dialogue, and together design optimal post-surgery care. ERIKSSON et al. 11 5.2.1 | The lack of financial impact Healthcare providers experienced the performance-based payment as something positive. The idea of being reim-
bursed based on results instead of activity, was encouraging. It was aligned with the professional values of ensuring
the patient is free from pain 1 year after surgery. Respondents also expressed that they did not feel constrained by
the reimbursement model or the performance measure used. We have our own goals, but they coincide with the goal that we want to maximise for the patient –
that they should be as well as possible. So I don't think we have different goals, rather that the finan-
cial goals are in line with the goal you have with the patient, so to speak. C2 C2 Quality improvement was considered important and something they continuously worked with before the
introduction of STHLM-VBRP. All providers appreciated the idea of a performance-based payment being used as a ERIKSSON et al. 12 complement to the bundled payment. But it had no financial impact. The share of the performance-based adjustment
was too small in comparison to the prospective payment and the invoices for external care. Respondents meant that
a larger proportion of the payment had to be tied to performance to generate an effect. The performance-based payment isn't anything we look at every month, in that way, unless it diverges
a lot. It goes alright, and as long as our patients feel good we don't really follow-up on it that intensely. D4 D4 There is a certain idea behind it, so you have to make sure that the bonus, that the quality bonus
works. Because otherwise, if you only take a part of it and don't care about the other part – then some
can make as much money as they want while others can't. It's completely wrong! Why then would you
do all this, without doing this part right? There must be an incentive there. A10 Some meant that the level or structure of the performance-based payment had to be adjusted, otherwise the
whole model would lose its purpose and might have negative effects on quality. Furthermore, the healthcare provid-
ers were not able to control the performance-based payment they received from Region Stockholm. 5.2.2 | The lack of transparency in how the payment was calculated Respondents were positive to the idea of the performance-based payment but did not understand how they could
make use of it. The lack of transparency for how the performance-based payment was calculated made the model
more difficult to understand. Respondents said that they had been promised a demo that showed how different
variables affected the performance-based payment. They had not yet received any demo but said that it would most
probably be helpful to understand what aspects that affect the reimbursement level. I agree with the idea – yes. But, then there's a lot that we don't really know so much about when it
comes down to what matters when this performance-based payment is calculated. A2 Because we want to understand, why did we get minus 15,000 and why did we get 10 for that? But
then, it's so big that you cannot handle it. So you would want something just like this [snaps fingers],
some kind of search engine. D2 The complication responsibility of post-discharge care feels much more concrete, that there we can do
something and we know what we're doing. Whereas this performance-based payment, there we feel
like we're just groping in the dark. A6 Compared to the bundled payment, respondents experienced the performance-based payment as vaguer and
more complex. Respondents said that the performance-based payment was so low that it had no financial impact, it
was not worth to monitor and assess outcomes measured with GA as a part of their daily operations. surgery, some respondents expressed a concern regarding potential shifts in case-mix. The lack of effect of the
performance-based payment raised concerns regarding cherry picking. In the worst-case scenario surgeons would
only perform surgery on patients they knew for sure would benefit from it, thus not ‘taking a chance’ with patients
suffering from comorbidities. At the same time, they argued that they should not perform surgery on patients who
would not benefit from it, thus recognising the complexity of the problem. Obviously, when you do more risky things, you know that you take a greater medical and financial risk. Because if the surgery fails we must face the consequences. And of course, in the worst case scenario
Patient Choice could lead to some patients being excluded. Then personally, I don't think I actually
do that, but theoretically it could absolutely be possible. Especially if you have a lot of patients, but if
you only have a few patients obviously you can't turn them away. If you have a lot of patients, then
cherry-picking may be a problem. C1 However, when the fourth provider entered the market the competition increased, and no provider could afford
to say no to patients. Providers focused on how to build processes that decreased the need of post-discharge care
and physiotherapy. Respondents said that due to the extended cost-responsibility, the reimbursement level was rela-
tively lower compared to before and this gave incentive to increase production. Thus, the decreased reimbursement
level in combination with an increased competition, prevented cherry picking according to respondents. | Concerns regarding potential shifts in case-mix cerns regarding potential shifts in case-mix Within elective spine surgery, it was experienced by the respondents that it can be difficult to tell if a patient will
benefit from surgery or not. When relating the reimbursement to how much pain the patient experiences after a ERIKSSON et al. 13 A1 Even though all healthcare providers agreed that the reimbursement level was at reasonable level for spine
surgery procedures, it was relatively low in relation to the cost for post-discharge care. We might be more effective because we have had to make some cuts. We have had to assess our
working routines, and that's not only negative. The coin always has two sides, so it can actually be
positive as well. But it has been difficult. B9 One healthcare provider expressed concern regarding the new level, fearing that it would eventually affect
patients negatively. Although they admitted that this new level had forced them to make changes that were for the
better, but they feared that it would not be enough. Especially without future adjustment of the reimbursement to
inflation. 5.3 | The continuous contract 5.3.1 | A decreased level of uncertainty allows for long-term planning but with a diminishing
reimbursement level The continuous commissioning contract allowed accredited healthcare providers to make long-term plans because
they did not have to fear losing the contract during a competitive procurement process. Because of Patient Choice, we got more freedom to be able to decide ourselves what we think will be
the best for the patient. That made us realise immediately that we must do something preoperatively
and postoperatively. A7 Providers expressed frustration with the inability of the purchaser to monitor and assess the quality of the
healthcare provided. Respondents meant that this inability caused a competition based on price, regardless of quality
under procurement. I've been involved in quite a few procurements and in the end it's only the price that matters. And
there are many actors who are not serious, who don't take on the most difficult or weighty procedures,
more difficult patients and put in really low bids during the procurement process. A serious clinic can't
practice under those circumstances. A1 All providers had a positive attitude to competition based on quality instead of price. However, they raised
concerns regarding the lack of adjustment to the price level in line with inflation. Region Stockholm did not adjust
the reimbursement level during the first 4 years and respondents doubted that this was going to happen at any time
in the near future. It's the price erosion that I'm worried about. When there is no adjustment to inflation, and the margins
get to the level that we must begin to reduce the quality. So that is the most important question right
now. ERIKSSON
14 14 ERIKSSON et al. (−) Confusion caused by the lack of
transparency in how the payment
was calculated. The continuous contract
A continuous contract between
provider and purchaser. (+) The decreased uncertainty allows
healthcare providers to make plans
for the long term. (+) Increased autonomy. Providers can
design their own processes. A set price without adjusting the
price level in line with inflation. (+ −) Quality enhancing but the lack
of adjustment makes providers
uncertain about the purchaser's
intentions. (−) Healthcare providers still perceive
Region Stockholm to put price
before quality. No restrictions on volume. (+) The providers can assess patients
without any restrictions, everyone
in need should be treated. (+) More information on which
patients benefit from surgery is
needed. The importance of support
and communication with the
purchaser. (+) More information, give control to
providers to be able to follow-up
on care. (−) No constitutive schema to handle
information. TA B L E 2 The findings in relation to the neo-institutional pillars, (+) indicates that the aspect aligns with the
STHM-VBRP, whereas (−) indicates resistance to the STHLM-VBRP TA B L E 2 The findings in relation to the neo-institutional pillars, (+) indicates that the aspect aligns with the
STHM-VBRP, whereas (−) indicates resistance to the STHLM-VBRP 6 | THE ALIGNMENT AND MISALIGNMENT BETWEEN REGULATIVE, NORMATIVE,
AND CULTURAL-COGNITIVE ELEMENTS In Table 2, we summarise the alignment and misalignment between the regulative, normative, and cultural-cognitive
elements among healthcare providers. The bundled payment implied a new way of thinking about elective spine surgery. The idea of taking a greater
responsibility for the care chain and increase cooperation among providers was supported by all three pillars. However, how to act on these ideas was not obvious to healthcare providers. As mentioned in section two, confusion
usually indicates a lack of support from the cultural-cognitive pillar. Especially how to better integrate physiotherapy
and increase cooperation with external healthcare providers. To know how to act they ‘must learn about the new
contract and gain an understanding of it’ (B7). Without a shared understanding they cannot find appropriate means
of how to adapt their practice. Despite efforts to cooperate with external healthcare providers, it was impossible to
reach all of them and establish consent regarding optimal medical practice. Respondents experienced the situation
as rather hopeless without any authority to impose sanctions if care, in their opinion, deviated from optimal medical
practice. Since respondents experienced cooperation with other healthcare providers as difficult, they discussed
a patient contract as a potential solution by holding patients accountable for excessive rehabilitation. Hence, this
hopelessness resulted in new normative and cultural-cognitive values that lacked regulative support. New normative
and cultural-cognitive values should be taken into consideration by the purchaser when updating the reimbursement
programme. The definition of related care is important since it affects the range of healthcare providers' responsibility. Because of the vague definition, the responsibility could be perceived as both narrow and wide. Healthcare providers
that adopted a narrower definition, experienced invoices pertaining to unrelated care as something unfair. It affected
their relations with the purchaser because they felt used and experienced it as an unfair strategy. On the other hand,
healthcare providers that adopted the wider definition of related care had a more neutral perspective on the invoices
from Region Stockholm. However, the experienced ambiguity resulted in healthcare providers not knowing how to
design their processes, since they did not know to what extent they were responsible. The vague definition in the
contract weakened the regulative pillar. Due to the fact that providers did not know how to assess related care nor 15 ERIKSSON et al. (−) The logic ‘the customer is always
right’ is not aligned with the
professional logic and agency.
(−) No constitutive schema. Regulative
Normative
Cultura
The bundled payment
Increased financial responsibility for
post discharge care. (+) New identity, not only a spine
surgery clinic. Must handle care-
flows outside their clinic. (+) A ne
cre
of a
Invoices for external care. (+) High financial impact, incentive to
coordinate post-discharge care
and discuss physiotherapy at a
managerial level. (−) D
oth
con
righ
(−) Reviewing and disputing invoices
is time consuming for both
administrative and clinical staff. Information about post-discharge
care. (+) Increased focus on the relation
between provider and patient
resulted in better accessibility. (−) The
righ
pro
No authority to impose sanctions on
other healthcare providers. (−) Spine surgery clinics have no
authority to sanction undesired
behaviour. (−) No
Vague definition of related care
in the responsibility for post-
discharge care. (−) Allows for different interpretation
of related care. Unfair strategy by
Region Stockholm, decreases trust
between provider and purchaser. (−) Con
on
unc
wh
to h
(+) Something Region Stockholm
cannot sort out. As a provider
of care, they are one of the best
suited to solve the problem. (−) Con
def
(−) No
scr
The performance-based payment
Reimbursement based on patient
reported outcome measure 1 year
after surgery. (+) Aligned with professional values, no
constraining effect on perceived
autonomy. (+) Perc
the
ma
Healthcare providers only
perceived the performance-based
adjustment, not the full payment. (−) The adjustment had no financial
impact. Instead, providers focussed
on how to decrease post-discharge
care that had a more direct impact. (−) No
per
we
goo
Healthcare providers did not receive
information of how the payment
was calculated for each patient. (−) The performance-based payment
was perceived as too complex. It was not worth the effort to
understand it better. (−) Con
tran
wa
The continuous contract
A continuous contract between
provider and purchaser. (+) The decreased uncertainty allows
healthcare providers to make plans
for the long term. (+) Incr
des
A set price without adjusting the
price level in line with inflation. (+ −) Quality enhancing but the lack
of adjustment makes providers
uncertain about the purchaser's
intentions. (−) Hea
Reg
bef
No restrictions on volume. (+) The providers can assess patients
without any restrictions, everyone
in need should be treated. (+) Mo
pat
nee
The importance of support
and communication with the
purchaser. (+) More information, give control to
providers to be able to follow-up
on care. (−) No
info
TA B L E 2 The findings in relation to the neo-institutional pillars, (+) indicates that
STHM-VBRP, whereas (−) indicates resistance to the STHLM-VBRP Regulative
Normative
Cultural-cognitive
The bundled payment
Increased financial responsibility for
post discharge care. (+) New identity, not only a spine
surgery clinic. Must handle care-
flows outside their clinic. (+) A new way of thinking, requires
creative solutions. No shared logic
of action. Invoices for external care. (+) High financial impact, incentive to
coordinate post-discharge care
and discuss physiotherapy at a
managerial level. (−) Difficulties cooperating with
other providers. It is beyond their
conceptual world; do not have the
right tools. (−) Reviewing and disputing invoices
is time consuming for both
administrative and clinical staff. Information about post-discharge
care. (+) Increased focus on the relation
between provider and patient
resulted in better accessibility. (−) The logic ‘the customer is always
right’ is not aligned with the
professional logic and agency. No authority to impose sanctions on
other healthcare providers. (−) Spine surgery clinics have no
authority to sanction undesired
behaviour. (−) No constitutive schema. Vague definition of related care
in the responsibility for post-
discharge care. (−) Allows for different interpretation
of related care. Unfair strategy by
Region Stockholm, decreases trust
between provider and purchaser. (−) Confusion. Long lead times
on disputed invoices increase
uncertainty and obstruct providers
when developing new processes
to handle post-surgery care. (+) Something Region Stockholm
cannot sort out. As a provider
of care, they are one of the best
suited to solve the problem. (−) Confusion because of vague
definition of responsibility. (−) No constitutive schema or mental
scripts. The performance-based payment
Reimbursement based on patient
reported outcome measure 1 year
after surgery. (+) Aligned with professional values, no
constraining effect on perceived
autonomy. (+) Perceived as an innovative step by
the purchaser, proof that quality
matters. Healthcare providers only
perceived the performance-based
adjustment, not the full payment. (−) The adjustment had no financial
impact. Instead, providers focussed
on how to decrease post-discharge
care that had a more direct impact. (−) No difference with or without the
performance-based payment, they
were already working towards
good outcomes. Healthcare providers did not receive
information of how the payment
was calculated for each patient. (−) The performance-based payment
was perceived as too complex. It was not worth the effort to
understand it better. Cultural-cognitive (+) A new way of thinking, requires
creative solutions. No shared logic
of action. (−) Difficulties cooperating with
other providers. It is beyond their
conceptual world; do not have the
right tools. (−) Difficulties cooperating with
other providers. It is beyond their
conceptual world; do not have the
right tools. (−) Confusion. Long lead times
on disputed invoices increase
uncertainty and obstruct providers
when developing new processes
to handle post-surgery care. (+) Something Region Stockholm
cannot sort out. As a provider
of care, they are one of the best
suited to solve the problem. (−) Confusion because of vague
definition of responsibility. (−) No constitutive schema or mental
scripts. (−) No constitutive schema or mental
scripts. (+) Aligned with professional values, no
constraining effect on perceived
autonomy. (+) Perceived as an innovative step by
the purchaser, proof that quality
matters. (+) Perceived as an innovative step by
the purchaser, proof that quality
matters. Reimbursement based on patient
reported outcome measure 1 year
after surgery. (+) Aligned with professional values, no
constraining effect on perceived
autonomy. (+) Perceived as an innovative step by
the purchaser, proof that quality
matters. Healthcare providers only
perceived the performance-based
adjustment, not the full payment. (−) The adjustment had no financial
impact. Instead, providers focussed
on how to decrease post-discharge
care that had a more direct impact. (−) No difference with or without the
performance-based payment, they
were already working towards
good outcomes. Healthcare providers did not receive
information of how the payment
was calculated for each patient. (−) The performance-based payment
was perceived as too complex. It was not worth the effort to
understand it better. (−) Confusion caused by the lack of
transparency in how the payment
was calculated. The continuous contract
A continuous contract between
provider and purchaser. (+) The decreased uncertainty allows
healthcare providers to make plans
for the long term. (+) Increased autonomy. Providers can
design their own processes. A set price without adjusting the
price level in line with inflation. (+ −) Quality enhancing but the lack
of adjustment makes providers
uncertain about the purchaser's
intentions. (−) Healthcare providers still perceive
Region Stockholm to put price
before quality. No restrictions on volume. (+) The providers can assess patients
without any restrictions, everyone
in need should be treated. (+) More information on which
patients benefit from surgery is
needed. The importance of support
and communication with the
purchaser. Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Terms and Condit how to act on it, there was no support from the cultural-cognitive nor the normative pillar to strengthen the regula-
tive pillar. Hence, the vague definition weakened the institution by motivating different behaviours. Providers appreciated the performance-based payment and perceived it as a quality statement by the purchaser. To reduce the pain further than expected, it is crucial for healthcare providers to come to an understanding of what
else that can be done in addition to surgery. For a spine surgery clinic, this can be challenging since their specialisa-
tion in fact is spine surgery. Hence, the payment incentivise interprofessional collaboration and holistic healthcare
since surgery alone may not be enough to reduce the pain any further. However, healthcare providers received no
information about the expected performance-based payment nor the patient's expected pain reduction. The lack of
transparency in how the performance-based payment was calculated made the payment too complex to understand,
and because of the lack of financial impact, it was not worth trying to understand. The intended incentives to improve
quality failed to have impact on behaviour since it lacked support from the cultural-cognitive pillar (they did not
understand it) and the normative pillar (it was not worth understanding). Because of the strong financial impact of
the bundled payment, healthcare providers focussed on how to minimise costs rather than maximising their outcome
regarding the performance measure. The continuous contract with no restriction regarding volume was supported by all three pillars; it decreased
uncertainty to healthcare providers and increased their autonomy. Respondents did however express the need of
more research to better distinguish the patients that ultimately benefit from surgery and what kind of physiotherapy
that is motivated. The idea of a set price to promote competition based on quality was aligned with the normative
and cultural-cognitive pillars of healthcare providers. However, respondents experienced that the lack of adjustment
of the price level in line with inflation was undercutting quality and the existence of their practice. As one respond-
ent (B7) put it ‘they squeeze every penny out of us making it really hard for us to survive as a business’. This caused
normative resistance because respondents experienced it as unfair, and it seemed like Region Stockholm still put
price before quality. Our analysis showed that the value-based reimbursement programme caused misalignment between the insti-
tutional pillars among healthcare providers. Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Terms and Condit Even though providers supported the general idea of the value-based
reimbursement programme, how to act on these ideas and adapt their practice to it required comprehensive under-
standing of the programme. Cultural-cognitive (+) More information, give control to
providers to be able to follow-up
on care. (−) No constitutive schema to handle
information. (−) No difference with or without the
performance-based payment, they
were already working towards
good outcomes. (−) No difference with or without the
performance-based payment, they
were already working towards
good outcomes. (−) The adjustment had no financial
impact. Instead, providers focussed
on how to decrease post-discharge
care that had a more direct impact. (−) Confusion caused by the lack of
transparency in how the payment
was calculated. (−) The performance-based payment
was perceived as too complex. It was not worth the effort to
understand it better. (−) Confusion caused by the lack of
transparency in how the payment
was calculated. A continuous contract between
provider and purchaser. (+) The decreased uncertainty allows
healthcare providers to make plans
for the long term. (+) Increased autonomy. Providers can
design their own processes. A set price without adjusting the
price level in line with inflation. (+ −) Quality enhancing but the lack
of adjustment makes providers
uncertain about the purchaser's
intentions. (−) Healthcare providers still perceive
Region Stockholm to put price
before quality. No restrictions on volume. (+) The providers can assess patients
without any restrictions, everyone
in need should be treated. (+) More information on which
patients benefit from surgery is
needed. The importance of support
and communication with the
purchaser. (+) More information, give control to
providers to be able to follow-up
on care. (−) No constitutive schema to handle
information. (+) The decreased uncertainty allows
healthcare providers to make plans
for the long term. (−) Healthcare providers still perceive
Region Stockholm to put price
before quality. (+ −) Quality enhancing but the lack
of adjustment makes providers
uncertain about the purchaser's
intentions. (+) The providers can assess patients
without any restrictions, everyone
in need should be treated. (−) No constitutive schema to handle
information. (+) More information, give control to
providers to be able to follow-up
on care. ERIKSSON et al. 16 51, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Terms and Condi purchaser bodies (governmental or private) have been identified as a barrier for institutionalisation of elements of
VBHC (such as VBRP) across different healthcare systems. 23 Thus, better dialogue between purchaser and providers
in combination with compatible and agile IT-systems may enhance cooperation. The purchaser has to facilitate coop-
eration between healthcare providers to make the cost of cooperation as low as possible. The struggle of healthcare
providers does on the other hand show that patients have a free choice to choose whomever they prefer. purchaser bodies (governmental or private) have been identified as a barrier for institutionalisation of elements of
VBHC (such as VBRP) across different healthcare systems. 23 Thus, better dialogue between purchaser and providers
in combination with compatible and agile IT-systems may enhance cooperation. The purchaser has to facilitate coop-
eration between healthcare providers to make the cost of cooperation as low as possible. The struggle of healthcare
providers does on the other hand show that patients have a free choice to choose whomever they prefer. The performance-based payment has been criticised to have a negative impact on some aspects of medical profes-
sionalism. 43 Participants were positive to the performance-based payment because it did not ‘force’ them to focus on
irrelevant outcome measures. However, the lack of transparency and financial impact made the performance-based
payment too complex to understand and follow-up. Quality improvement requires ongoing feedback at all stages,
and that everyone involved is aware of the complexity of changing the culture of the organisation. 42,44 The slow
feedback from Region Stockholm caused frustration among healthcare providers. It made it more difficult for them
to adjust to the new structure. Participants in our study found that their focus on financial aspects had increased with the STHLM-VBRP, compared
to before. A potential explanation can be the experienced unbalanced incentive structure between the bundled payment
and the performance-based payment. Thus, healthcare providers focussed on minimising post-discharge care instead
of quality improvement, contrary to other studies where VBHC decreased the focus on financial aspects. 41 It has been
argued that financial incentives are not sufficient to affect daily operations in a setting where governance and manage-
ment philosophies are firmly grounded within the New Public Management paradigm. 16 We argue that financial incen-
tives are, if introduced in the right institutional context, an effective tool to manage care. 51, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Terms and Condi This highlights the importance
of acknowledging the institutional context when designing, implementing, and evaluating reimbursement programmes. Another important aspect was the transition from periodic re-contracting to a continuous commissioning
contract, which according to respondents decreased uncertainty of the future and allowed them to make long-term
plans. However, it was also clear that a continuous contract requires relevant feedback from the purchaser at the
right time. Once again, this highlights the importance of good communication and supporting IT-systems. Especially
since the text in the commissioning contract can be interpreted in different ways (as the vague definition of related
care proofed), therefore the relation to the purchaser organisation is more than just a commissioning contract. Even though this study was performed in a context of Swedish healthcare, it investigates management prac-
tices that are globally diffused and therefore should be of relevance for other healthcare contexts as well. Despite
differences in healthcare organisation and funding between healthcare systems across the world there seem to be
universal enablers and barriers for implementation of VBRP. Based on a comparison of four different healthcare
systems, Mjåset et al. 23 found that three aspects were universal for a successful implementation: (1) strong support
from governmental/purchaser bodies, (2) IT-systems that allow seamless system integration and up-to-date outcome
measurement across the full cycle of care, and (3) involvement of the medical community to make sure that the intrin-
sic values of working in healthcare are aligned with management strategies. These aspects are further manifested by
our findings from studying the introduction of the STHLM-VBRP. Because of contextual differences between and within healthcare systems, it is important to use a theoreti-
cal framework to structure findings and enable comparison. 27 We included all four healthcare providers that were
reimbursed based on the STHLM-VBRP. Despite the limited number of providers, they performed a majority of the
elective spine surgeries in Sweden. However, by that limited number, we cannot claim to cover all experiences. To
cover other perspectives from the same reimbursement programme, future studies could focus on how the purchaser
organisation act and adapt their practice to a value-based reimbursement programme. It would also be of great inter-
est to study the reimbursement programme in a context that involves more providers. The introduction of STHLM-VBRP had three defining features: the bundled payment, the performance-based
payment and the continuous contract between provider and purchaser. 7 | DISCUSSION The bundled payment imposed strong financial incentives thus making it crucial for all healthcare providers to assess
the whole care chain of their patients. Due to the responsibility, healthcare providers became more prone to strive
for optimal healthcare consumption. Similar findings have been reported in other studies, where bundled payment
reduced healthcare use and costs. 21,38 The different perceptions, of the legitimacy of increasing healthcare providers
responsibility for post-discharge, is in line with studies showing that spine surgeons allocate major responsibility to
healthcare systems to manage the cost of healthcare. 39 With STHLM-VBRP, Region Stockholm moves towards inte-
grated care with patient-centeredness and a greater responsibility to healthcare providers, thus in line with VBHC. 40 Participants in our study experienced a need for better cooperation between healthcare providers. Similar find-
ings were reported in a study that investigated the effects of introducing VBHC in another Swedish region. 41 They
found that the introduction of VBHC raised awareness about cooperation being necessary to create value for patients. The introduction of VBHC increased cooperation within the hospital but it was difficult to establish cooperation with
external healthcare providers. 41 In the case of STHLM-VBRP, the private healthcare providers experienced difficulties
in making other providers cooperate when there was no corresponding incentive for external providers. Thus, insuf-
ficient organisational structure of healthcare hinders structural changes. 42 The difficulty in establishing cooperation
reflected that health care providers did not have cognitive schemas of how to coordinate post-discharge care nor how
to act on the information they received from the invoices of external care and rehabilitation. Insufficient support from ERIKSSON et al. 17 CONFLICT OF INTEREST The authors declare that they have no conflict of interest. 51, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1002/hpm.3574 by Linkoping Universitet, Wiley Online Library on [17/10/2022]. See the Terms and Condi The general perception among providers
about these features was positive. However, our analysis showed that the resistance to STHLM-VBRP was mainly
caused by confusion in how to interpret and act on the information they received, that is, misalignment with
cultural-cognitive pillar. The misalignment between the institutional pillars in healthcare providing organisations can ERIKSSON et al. 18 DATA AVAILABILITY STATEMENT The data generated and analysed during the current study are not publicly available due to the inclusion of potentially
sensitive individual data. The ethical approval includes a statement that the data will be kept in a private repository
but are available from the corresponding author on reasonable request. be seen as a catalyst for change because of instable institutions. Whether this change will lead to more robust insti-
tutions depends on whether healthcare providers can come to an understanding of how to coordinate post-discharge
care, have access to sufficient IT-systems, and whether the purchaser is able to support the healthcare providers
when taking these steps towards integrated healthcare. ORCID Thérèse Eriksson
https://orcid.org/0000-0001-6855-6169 ACKNOWLEDGEMENTS We would like to express our gratitude to the healthcare providing organisations and the respondents for participat-
ing. We would also like to express our gratitude to Region Stockholm for financial support. ETHICS STATEMENT Before commencing the fieldwork, the study obtained ethical approval (2015/94-31) from the regional board of
ethics in Linköping, as well as a signed consent to participate from each respondent. REFERENCES 1. Conrad DA, Perry L. Quality-based financial incentives in health care: can we improve quality by paying for it? Annu Rev
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b
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purchasing programs: findings from an environmental scan, literature review, and expert panel discussions. Rand Health
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hpm.640 12. Numerato D, Salvatore D, Fattore G. The impact of management on medical professionalism: a review. Sociol Health Illn. 2012;34(4):626-644. https://doi.org/10.1111/j.1467-9566.2011.01393.x 12. Numerato D, Salvatore D, Fattore G. The impact of management on medical professionalism: a review. Sociol Health Illn. 2012;34(4):626-644. https://doi.org/10.1111/j.1467-9566.2011.01393.x 13. Conrad DA. The theory of value-based payment incentives and their application to health care. Health Serv Res. 2015;50(suppl 2):2057-2089. https://doi.org/10.1111/1475-6773.12408 13. Conrad DA. The theory of value-based payment incentives and their application to health care. Health Serv Res. 2015;50(suppl 2):2057-2089. https://doi.org/10.1111/1475-6773.12408 The patient feedback response framework – understand-
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reimbursement programme—alignment and resistance among healthcare providers. Int J Health Plann Mgmt. 2022;1-20. https://doi.org/10.1002/hpm.3574
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Proving the Correctness of Knowledge Graph Update: A Scenario From Surveillance of Adverse Childhood Experiences
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Frontiers in big data
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Proving the Correctness of
Knowledge Graph Update: A
Scenario From Surveillance of
Adverse Childhood Experiences 1 Nuffield Department of Public Health, Big Data Institute, University of Oxford, Oxford, United Kingdom, 2 Department of
Pediatrics, The University of Tennessee Health Science Center-Oak Ridge National Laboratory, Center for Biomedical
Informatics, College of Medicine, Memphis, TN, United States Knowledge graphs are a modern way to store information. However, the knowledge
they contain is not static. Instances of various classes may be added or deleted and
the semantic relationship between elements might evolve as well. When such changes
take place, a knowledge graph might become inconsistent and the knowledge it conveys
meaningless. In order to ensure the consistency and coherency of dynamic knowledge
graphs, we propose a method to model the transformations that a knowledge graph goes
through and to prove that the new transformations do not yield inconsistencies. To do so,
we express the knowledge graphs as logically decorated graphs, then we describe the
transformations as algorithmic graph transformations and we use a Hoare-like verification
process to prove correctness. To demonstrate the proposed method in action, we use
examples from Adverse Childhood Experiences (ACEs), which is a public health crisis. Edited by:
Mayank Kejriwal,
University of Southern California,
United States United States
Reviewed by:
Yanghua Xiao,
Fudan University, China
Ivan Lee,
University of South Australia, Australia
*Correspondence:
Jon Haël Brenas
jon.brenas@bdi.ox.ac.uk
Arash Shaban-Nejad
ashabann@uthsc.edu Reviewed by:
Yanghua Xiao,
Fudan University, China
Ivan Lee,
S Reviewed by:
Yanghua Xiao,
Fudan University, China
Ivan Lee,
University of South Australia, Australia *Correspondence:
Jon Haël Brenas
jon.brenas@bdi.ox.ac.uk
Arash Shaban-Nejad
ashabann@uthsc.edu Keywords: program verification, graph transformation, cloning, merging, knowledge graph, adverse childhood
experiences Received: 28 January 2021
Accepted: 06 April 2021
Published: 03 May 2021 Received: 28 January 2021
Accepted: 06 April 2021
Published: 03 May 2021 In this paper, we propose a method to tackle this issue. The proposed method aims to identify
what are the transformations entailed by adding or removing a piece of information or an axiom to
make sure that the knowledge graph remains consistent with the ontology. In our previous works,
we used graph transformation to represent and analyze changes in knowledge-based global health
surveillance systems (Brenas et al., 2017, 2018; Al-Manir et al., 2018). We represent the ontology
in C2 (Gradel et al., 1997) for convenience. The initial modification of the knowledge graphs will
be assumed to be through a query language but we will represent the transformations as graph
transformations and use Hoare-like verification methods (Hoare, 1969) to produce the proofs. The ORIGINAL RESEARCH
published: 03 May 2021
doi: 10.3389/fdata.2021.660101 1. INTRODUCTION Knowledge graphs have become ubiquitous as a framework to represent entities and the relations
that connect them. Thanks to the layer of semantic information, it has become possible to add
meaning to the entities and relations contained in graphs and to reason about the knowledge they
contain. Because graphs contain knowledge, they are expected to change with new information
added or removed depending on outside events. In a similar way, the changes in the semantic
layers may cause the meaning associated with each entity to change. Through such modifications,
a knowledge graph can become inconsistent with the ontology that describes it (Zhang, 2002),
rendering the knowledge, and thus the graph, meaningless. Specialty section:
This article was submitted to
Data Mining and Management,
a section of the journal
Frontiers in Big Data Received: 28 January 2021
Accepted: 06 April 2021
Published: 03 May 2021 Received: 28 January 2021
Accepted: 06 April 2021
Published: 03 May 2021 Citation: Brenas JH and Shaban-Nejad A
(2021) Proving the Correctness of
Knowledge Graph Update: A Scenario
From Surveillance of Adverse
Childhood Experiences. Front. Big Data 4:660101. doi: 10.3389/fdata.2021.660101 May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org Correctness of Knowledge Graph Update Brenas and Shaban-Nejad The set C (resp. R) naturally depends on the logic. It is
constructed such that C contains all “unary” (resp. “binary”)
predicates of the logic and the closure under their constructors,
i.e., class (resp. property) assertions. modifications depend only on the structure of each axiom and
the action that is performed and not on the actual ontology or
graph. It is thus possible to prove that they behave correctly
in an abstract way that is independent of the actual knowledge
graph that is modified. In particular, this means that the
complexity of the verification task is independent of the size of
the actual knowledge graph and only depends on the size of the
specification that is proven to be correct. To make our reasoning easier to understand, we describe
axioms from the ontology both as first-order formulae and in
a notation closer to Description Logics. In this paper, we focus
on the lower spectrum of the expressivity for the axioms but the
verification framework that underpins our method works with
the full expressiveness of C2 (Gradel et al., 1997), the two-variable
fragment of first-order logic with counting, that can express most
axioms in OWL.1 Informally, C2 contains all formulas of first
order logic that can be written using only two variables, as well as
the counting quantifier ∃>n and its negation ∃≤n. As an example,
∃>2x.φ(x) can be translated in first order logic as ∃x0, x1.φ(x0) ∧
φ(x1) ∧x0 ̸= x1, i.e., there exist at least two different x such
that φ(x). To showcase how the proposed method works, we use
examples coming from Adverse Childhood Experiences (ACEs),
which is a major public health concern. ACEs are negative events,
e.g., abuse, witnessing violence, etc, that have been linked to
various negative health outcomes and risky behaviors (Felitti
et al., 1998). The ACEs Ontology and knowledge graph have been
described in Brenas et al. (2019a,c). Here, we will use a clinical example. Patients or their parents
are interviewed and screened for ACEs. Citation: If they suffer from some
ACEs, e.g., if they are homeless or live in a place with mold,
they are assigned to a social worker. If they suffered from a
different set of ACEs, e.g., emotional abuse, they are assigned
to a psychologist. Additionally, if they agree to be part of a
study, they need to have provided a phone number or an email
address and they will be paired with a caseworker. In order to
avoid overworking the staff, social workers can only be assigned
10 patients and psychologists five. If the number of patients
is higher than the available number of professionals, they are
redirected toward a different clinic and it is agreed that a new
hire is required. To explain how knowledge graphs are updated and modified,
we use graph transformations. The most usual way to deal with
graph transformations is by using an algebraic approach rooted
in category theory (Barendregt et al., 1987). In this paper, we
will use a more algorithmic approach that, we argue, is more
suited to verification. In order to build transformations, we
first define atomic actions that will be composed to form more
elaborate actions. Definition 2.2. Let C (resp. R) be a set of node (resp. edge) labels. An elementary action, say a, may be of the following forms: In Section 2, we will introduce the formal framework that
underpins our method. In Section 3, we show the applicability
of this framework through some examples. Finally, in Section 4,
we discuss the limitations of the method and further work. • a node addition addN(i) (resp. node deletion delN(i)) where i is
a new node (resp. an existing node). It creates the node i. i has no
incoming nor outgoing edge and it is not labeled (resp. it deletes
i and all its incoming or outgoing edges). • a node addition addN(i) (resp. node deletion delN(i)) where i is
a new node (resp. an existing node). It creates the node i. i has no
incoming nor outgoing edge and it is not labeled (resp. it deletes
i and all its incoming or outgoing edges). • a node label addition addC(i, c) (resp. node label deletion
delC(i, c)) where i is a node and c is a label in C. It adds the
label c to (resp. removes the label c from) the labeling of node i. 1Web Ontology Language (OWL) (accessed on January 2021). 2. LOGIC, GRAPH REWRITING, AND
VERIFICATION • an edge addition addE(e, i, j, r) (resp. edge deletion
delE(e, i, j, r)) where e is an edge, i and j are nodes and r is an
edge label in R. It adds the edge e with label r between nodes i
and j (resp. removes all edges with source i and target j with label
r), i.e., s(e) = i, t(e) = j and 8E(e) = r (resp. ∀e′ ∈E.s(e′) ̸= i
or t(e′) ̸= j or 8E(e′) ̸= r). Each knowledge graph is composed of a graph and an ontology
that assigns meaning to its nodes and edges. In the following,
we present a fairly informal and succinct introduction to our
framework. We hope to manage to give readers an idea of the
logical foundation of our method without spending too much
time and space on information that would not be relevant to
most end-users. Readers interested in a more formal and in-depth
description can find it in Brenas et al. (2016a, 2018b). An action α is a finite sequence of atomic actions. An action α is a finite sequence of atomic actions. It selects a
node, b, and creates a new node named a (addN(a)) and connects
a to b with an edge labeled with lives_with (addE(a, b, lives_with)). This process is achieved by two functions: the weakest-
precondition wp(s, Q) and the verification condition vc(s, Q) for
a strategy s and a post-condition Q. More details can be found in
Brenas et al. (2016a). The definitions of these functions are given
in Figures 2, 3, respectively. A rule is applied when a match for the left-hand side is found
in the knowledge graph that we want to modify. We also define
strategies that describe the order in which the rules of a logically
decorated graph rewriting system are to be applied. The
weakest
preconditions
and
verification
conditions
introduce new logic constructors to deal with elementary actions
called substitutions and written Q[a] where Q is a logic formula
and a is an action. Intuitively, a graph G is a model of the formula
Q[a] if and only if G[a], the graph obtained by performing action
a on G, is a model of φ. Definition 2.4. Given a logically decorated graph rewrite system
GRS, a strategy is a word of the following language defined by s,
where ρ is any rule in GRS: y
s : =
ǫ
(Empty Strategy)
ρ
(Rule)
s ⊕s
(Choice)
s; s
(Composition)
s∗
(Closure) s : =
ǫ
(Empty Strategy)
ρ
(Rule)
s ⊕s
(Choice)
s; s
(Composition)
s∗
(Closure) Definition 2.7 (Substitutions). To each elementary action a is
associated a substitution, written [a], such that for all graphs G
and formula φ, (G is a model of φ[a]) ⇔(G[a] is a model of φ). Given two logically decorated graphs G and G′ and a strategy s,
we denote by G ⇒s G′ that it is possible to obtain G′ by applying s
to G. It is worth noting that the weakest precondition of a closure,
s∗, is invs, an invariant for that closure. This invariant is not part
of the original specification but needs to be specified. We thus
modify the notion of specification. Intuitively, ǫ means “do nothing,” ρ is an application of the
rule, s ⊕s is the application of either of the two strategies (but
not both), s; s is the application composition and s∗applies the
strategy as many times as possible. Definition 2.8 (Annotated Specification). An action α is a finite sequence of atomic actions. An
annotated
specification SP is a triple {Pre}(R, s){Post} where Pre and Post
are formulas (of a given logic), R is a graph rewriting system, s is a
strategy and every closure in s is annotated with an invariant. Example 2.2. For instance, strategy ρ0; (ρ∗
0 ⊕ρ1) means “apply
ρ0 followed by either as many applications of ρ0 as possible or one
application of ρ1.” Example 2.4. As the strategy in Example 2.3 contains a
closure, we annotate it. {φ0}({ρ0}, ρ∗
0{φ0}){φ0} is a possible
annotated specification. Example 2.4. As the strategy in Example 2.3 contains a
closure, we annotate it. {φ0}({ρ0}, ρ∗
0{φ0}){φ0} is a possible
annotated specification. Previously, we have shown how to use logics to label edges
and nodes of graphs. We now go a little further and show how
we can use logics to define specifications for the transformations
we want to perform, i.e., how to define conditions that we want
to be satisfied by the graph after the transformation is performed,
given that it may have satisfied another (possibly identical) set of
conditions initially. Now that the notions of the weakest precondition and the
verification condition are defined, we can look back at the
original problem we were trying to solve. We define a formula
that represents the correctness of a specification. Definition 2.9 (Correctness formula). We
call
correctness
formula of an annotated specification SP = {Pre}(R, s){Post},
the formula: Definition 2.5 (Specification). A specification SP is a triple
{Pre}(R, s){Post} where Pre (the precondition) and Post (the post-
condition) are formulas (of a given logic), R is a graph rewriting
system and s is a strategy. correct(SP) = (Pre ⇒wp(s, Post)) ∧vc(s, Post). Example 2.3. Let us assume that we want a specification
describing part of Example . φ0
≡
∀x.Psychologist(x)
⇒
∃≤5y.(Patient(y) ∧assigned_to(y, x)) is a formula that states that
at most five patients are assigned to each psychologist. Then, SP0 ≡
{φ0}({ρ0}, ρ∗
0){φ0} states that if φ0 is true, it will still be true after
applying ρ0 as many times as possible. Example 2.3. Let us assume that we want a specification
describing part of Example . φ0
≡
∀x.Psychologist(x)
⇒
∃≤5y.(Patient(y) ∧assigned_to(y, x)) is a formula that states that
at most five patients are assigned to each psychologist. An action α is a finite sequence of atomic actions. An action α is a finite sequence of atomic actions. Actions are not enough to describe all the transformations we
want to perform, as they require the knowledge of the exact nodes
and edges that are going to be modified. In order to enable the
selection of nodes that satisfy a condition, we use rewriting rules
and logically decorated graph rewriting systems. In order to represent the knowledge graphs, we use logically
decorated graphs where both nodes and edges are labeled with
formulae that are part of the ontology language. Definition 2.1. Let C (resp. R) be a set of node labels (resp. edge
labels), a logically decorated graph is a tuple (N, E, 8N, 8E, s, t)
where N is a set of nodes, E is a set of edges, 8N : N →P(C)
is a node labeling function, 8E : E →P(R) is an edge labeling
function, s : E →N is a source function and t : E →N is a target
function. The source function s and the target function t define the
orientation of an edge. For instance, edge e connects node s(e) to
node t(e). Definition 2.3. A rule ρ is a pair (LHS,α) where LHS, called the
left-hand side, is a logically-decorated graph and α, called the right-
hand side, is an action. Rules are usually written LHS →α. A
logically decorated graph rewriting system is a set of rules. May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org 2 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad In order to prove the correctness of a specification, we use a
Hoare-like approach (Hoare, 1969). The idea is that it is possible
to split the transformation into elementary changes that impact
the graph in a known and controlled way. In such a situation,
given the post-condition that needs to be achieved, it becomes
possible to generate the weakest precondition that ensures that
the post-condition will be satisfied. This can then be iterated to
generate the weakest precondition for the whole transformation. Example 2.1. Figure 1 contains an example of rule. It selects a
node, b, and creates a new node named a (addN(a)) and connects
a to b with an edge labeled with lives_with (addE(a, b, lives_with)). Example 2.1. Figure 1 contains an example of rule. An action α is a finite sequence of atomic actions. To show some examples, we use the Adverse Childhood
Experiences Ontology (ACESO) (Brenas et al., 2019a) as the
source for the axioms. The systematic study of adverse childhood
experiences and their health outcomes is recent and new data
and knowledge are routinely added in this field. As a result, both
the knowledge graphs and the associated ontology are likely to
change frequently. Theorem 2.2. (Brenas
et
al.,
2016a)
C2
is
closed
under substitutions. Example 3.1. Let us assume that the change that we want to
perform is the addition of a new node, pa, which is labeled
with PhysicalAbuse. This modification would be equivalent to
performing the action a0 ≡addN(pa); addC(pa,
PhysicalAbuse). ACESO contains the axiom PhysicalAbuse
⊆
Abuse that can be translated in C2 as ∀x.PhysicalAbuse(x) ⇒
Abuse(x). Performing
a0
would
make
the
knowledge
graph
inconsistent
with
the
ontology
as,
if
x
=
pa,
PhysicalAbuse(x)
∧
¬Abuse(x)
is
true. Instead,
the
transformation
that
is
actually
performed
is
a1
≡
addN(pa); addC(pa, PhysicalAbuse); addC(pa, Abuse). In
that
case, the correctness formula is (∀x.PhysicalAbuse(x)
⇒
Abuse(x)) ⇒(∀x.(PhysicalAbuse(x)∨x = pa) ⇒(Abuse(x)∨x =
pa)) which is obviously valid. The knowledge graph is thus still
consistent with the ontology. For all the logics that are closed under substitution, the proof
consists in a set of rewrite rules that conserve the interpretation. For instance, given C0 an atomic concept, σ a substitution, i and
j individuals and π0 a program: • ⊤σ ; ⊤
• C0[addC(C0, i)] ; C0 ∨{i}
• (∃r0.C)[delE(i, j, r0)]
;
(¬{i} ∧∃r0.(C[delE(i, j, r0)])) ∨
(∃r0.(¬{j} ∧C[delE(i, j, r0)])) • ⊤σ ; ⊤
• C0[addC(C0, i)] ; C0 ∨{i}
• (∃r0.C)[delE(i, j, r0)]
;
(¬{i} ∧∃r0.(C[delE(i, j, r0)])) ∨
(∃r0.(¬{j} ∧C[delE(i, j, r0)])) • ⊤σ ; ⊤
• C0[addC(C0, i)] ; C0 ∨{i}
• (∃r0.C)[delE(i, j, r0)]
;
(¬{i} ∧∃r0.(C[delE(i, j, r0)])) ∨
(∃r0.(¬{j} ∧C[delE(i, j, r0)])) • C0[addC(C0, i)] ; C0 ∨{i} Another possible problem is that the logic needs to be able to
express the existence (and absence) of a match. First-order logic
can express App(ρ) by using an existential variable for every node
of the left-hand side of the rule ρ. This is not possible in the other
types of logics we considered as they do not allow to define an
unlimited number of variables. There is thus a limitation on what
can appear on the left-hand side of the rules. An action α is a finite sequence of atomic actions. Then, SP0 ≡
{φ0}({ρ0}, ρ∗
0){φ0} states that if φ0 is true, it will still be true after
applying ρ0 as many times as possible. Theorem 2.1 (Soundness). Let SP = {Pre}(R, s){Post} be an
annotated specification. If correct(SP) is valid, then for all graphs
G, G′ such that G ⇒s G′, G is a model of Pre implies G′ is a model
of Post. Deciding whether a specification is correct can be translated
into deciding the validity of a given formula. This is one of the
main reasons why we focused on decidable logics in this section. Another possible choice is to only consider tractable logic so that
verification becomes achievable in a reasonable timeframe. Definition 2.6 (Correctness). A specification SP is said to be
correct ifffor all graphs G, G′ such that G ⇒s G′ and G is a model
of Pre (i.e., Pre is a logical consequence of the labeling of G), then
G′ is a model of Post. Definition 2.6 (Correctness). A specification SP is said to be
correct ifffor all graphs G, G′ such that G ⇒s G′ and G is a model
of Pre (i.e., Pre is a logical consequence of the labeling of G), then
G′ is a model of Post. May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org 3 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad FIGURE 2 | Weakest preconditions w.r.t. actions and strategies, where a (resp. α, αρ) stands for an elementary action (resp. action, the right-hand side of a rule ρ)
and Q is a formula. FIGURE 3 | Verification conditions for strategies. FIGURE 2 | Weakest preconditions w.r.t. actions and strategies, where a (resp. α, αρ) stands for an elementary action (resp. action, the right-hand side of a rule ρ)
and Q is a formula. FIGURE 3 | Verification conditions for strategies. under consideration are correct and, thus, the update can
take place. The decidability of the validity problem for the logic used
to label the graph is not, however, the only condition for the
decidability of the correctness problem. The definitions of the
weakest preconditions introduced substitutions as a new formula
constructor. In order for the correctness problem to be decidable,
these new constructs must be expressible in the logic, i.e., the logic
must be closed under substitutions. In the following, we will be
using C2. An action α is a finite sequence of atomic actions. As it is possible to modify the knowledge graph by adding
information contained in new nodes, it is also possible to add
new edges. In the previous example, only the new node, pa, was
really affected by the modification of the knowledge graph and
thus a simple action was enough to update the knowledge graph
to preserve consistency. The next example, on the other hand,
requires a rule to be applied. Frontiers in Big Data | www.frontiersin.org 3. APPLICATION ¬lives_with(y, x) is true. Instead, the transformation that is
actually performed is the application of rule ρ1 shown in Figure 4. In that case, the correctness formula is (∀x, y.lives_with(x, y) ⇒
lives_with(y, x)) ⇒(∀x, y.(lives_with(x, y) ∨(x = a ∧y =
b) ∨(x = b ∧y = a)) ⇒(lives_with(y, x) ∨(x = b ∧y =
a) ∨(x = a ∧y = b)) which is obviously valid. From the previous two examples, one can observe how
the transformations and the axioms interact. As a result, it is
possible to define a system of transformation rewriting rules
that, given the intended action and the form of an axiom,
generates a new transformation of the knowledge graph that
can be proved correct independently of the actual knowledge
graph and ontology. For instance, the previous examples show
that when in presence of an axiom of the form C ⊆D where
C and D are unary predicates (i.e., classes in OWL Lite), an
elementary action addC(i, C) should be replaced with the action
addN(i, C); addN(i, D) while, in presence of an axiom of the form
Symmetric(R) where R is a binary predicate (i.e., a property
in OWL Lite), an elementary action addN(i) should be left
unchanged. Figure 5 shows these two rules plus additional ones. FIGURE 5 | Rules rewriting transformations depending on the form of the
axioms in the ontology. FIGURE 5 | Rules rewriting transformations depending on the form of the
axioms in the ontology. FIGURE 6 | Rules inserting the knowledge that Alice, who did not exist in the
knowledge base, is a girl who lives with Bob. Example 3.3. Let us now combine the previous two examples. We assume that we want to add a new person Alice, represented
by the new node a, to the knowledge graph. We additionally
want to insert the knowledge that Alice is a girl and that she
lives with Bob, represented by the already existing node b. The
initial rule that would be applied is rule ρ2 from Figure 6. Provided that the ontology contains the axioms Girl ⊆Child and
Symmetric(lives_with), all six rules in Figure 5 can be applied. The
order in which they are applied does not change the final result,
i.e., the rewriting system is convergent, and the final result is Rule
ρ3 in Figure 6. Frontiers in Big Data | www.frontiersin.org 3. APPLICATION When adding or removing knowledge from a knowledge graph,
there is a risk to harm its consistency with the ontology that
describes its underlying structure. As a result, additional actions
may be needed before making any change to a knowledge graph. In this section, we present some of the transformations that
can be enacted to make an update. We will then prove that the
specifications resulting from the axioms and the transformations Example 3.2. Let us assume that the change that we want to
perform is the creation of a new node, a, and a new edge, e, linking a
to the already existing node b with an edge labeled lives_with. This
modification would be equivalent to applying Rule ρ0 shown in
Figure 4. ACESO contains the axiom Symmetric(lives_with) that May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org 4 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad FIGURE 5 | Rules rewriting transformations depending on the form of the
axioms in the ontology. FIGURE 6 | Rules inserting the knowledge that Alice, who did not exist in the
knowledge base, is a girl who lives with Bob. FIGURE 5 | Rules rewriting transformations depending on the form of the
axioms in the ontology. FIGURE 4 | Rules creating a new node a and connecting it via property
lives_with to the node b. can be translated in C2 as ∀x, y.lives_with(x, y) ⇒lives_with(y, x). Applying ρ0 would make the knowledge graph inconsistent with the
ontology as, if x = a and y = b, lives_with(x, y) ∧
¬lives_with(y, x) is true. Instead, the transformation that is
actually performed is the application of rule ρ1 shown in Figure 4. In that case, the correctness formula is (∀x, y.lives_with(x, y) ⇒
lives_with(y, x)) ⇒(∀x, y.(lives_with(x, y) ∨(x = a ∧y =
b) ∨(x = b ∧y = a)) ⇒(lives_with(y, x) ∨(x = b ∧y =
a) ∨(x = a ∧y = b)) which is obviously valid. gy
f
y
y
¬lives_with(y, x) is true. Instead, the transformation that is
actually performed is the application of rule ρ1 shown in Figure 4. In that case, the correctness formula is (∀x, y.lives_with(x, y) ⇒
lives_with(y, x)) ⇒(∀x, y.(lives_with(x, y) ∨(x = a ∧y =
b) ∨(x = b ∧y = a)) ⇒(lives_with(y, x) ∨(x = b ∧y =
a) ∨(x = a ∧y = b)) which is obviously valid. 3. APPLICATION As it is possible to prove that each one of the
transformation rewrite rules is correct, their combination is correct
as well. FIGURE 6 | Rules inserting the knowledge that Alice, who did not exist in the
knowledge base, is a girl who lives with Bob. Person, the same transformation rewrite rule χ1 can be applied
several times introducing in the action not only addC(a, Child), as
shown in Figure 6, but also, addC(a, Female) and addC(a, Person)
triggered by the first application of the rule. The fact that the rules
are iteratively applied does not create a risk of infinite looping
provided we assume that there is a mechanism to check that the
rule does not already contain the added elementary actions, given
that doing the same elementary action twice yields the same result
as doing it only once. Similarly, in an actual execution, the rules
that do not modify the transformation, e.g., χ0 would not be part Person, the same transformation rewrite rule χ1 can be applied
several times introducing in the action not only addC(a, Child), as
shown in Figure 6, but also, addC(a, Female) and addC(a, Person)
triggered by the first application of the rule. The fact that the rules
are iteratively applied does not create a risk of infinite looping
provided we assume that there is a mechanism to check that the
rule does not already contain the added elementary actions, given
that doing the same elementary action twice yields the same result
as doing it only once. Similarly, in an actual execution, the rules
that do not modify the transformation, e.g., χ0 would not be part One of the key advantages of using abstract rules to represent
the modification of the transformations is that it becomes
possible to use the same rule for multiple transformations. In
actual cases, the ontology is likely to contain many more axioms
and, in particular, to contain a much more developed hierarchy
of classes and properties. However, assuming that the ontology
contains additional axioms, e.g., Girl ⊆Female and Child ⊆ May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org 5 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad PhysicalAbuse ⊆Abuse to also add the fact that pa is an Abuse. We
could also have decided to remove the axiom and the knowledge
graph would have been consistent with the modified ontology. 3. APPLICATION ρ5
looks for a patient suffering from a given type of ACEs, denoted by
ACEs0, that are not assigned to anyone and for a social worker with
nine or fewer patients assigned to them. It then assigns the patient
to the social worker. ρ6 does the same for psychologists. ρ7 and ρ8
assign the (possibly) remaining patients to the default options. ρ9
and ρ10 look for patients with a phone number or an email address,
respectively, and assign them to a case worker. ρ11 and ρ12 request
the hiring of a social worker or a psychologist, respectively, if it had
not been requested before and at least one patient is assigned to the
default option. of the system. We only show them to make our reasoning clearer
and easier to understand. Hitherto, we have only added knowledge to the graph and
not removed any. Removing knowledge is not practically much
more difficult, at least as long as we keep working with less
expressive axioms. Example 3.4. Figure 7
contains
some
transformation
rules
dealing with node label deletion. χ6 is similar to the rules in
Figure 5 and doesn’t actually modify the transformation. On the
other hand, rules χ7 and χ8 are dependent on the current content
of the knowledge graph. Indeed, if C(i) is true, the axiom C ⊆D
is no longer true after the application of delC(i, D). Hence the rule
need not only to look at the ontological part of the knowledge
graph but also at the graph itself. f
p
We chose to apply the strategy s ≡(ρ5⊕ρ6)∗; (ρ7⊕ρ8)∗; (ρ9⊕
ρ10)n; ρ∗
11; ρ∗
12. In order to be able to perform verification, all
closures need to be annotated. We annotate all of them with φ,
that is all invariants are the same as the pre- and post-conditions. (ρ9 ⊕ρ10)n denotes n-iterations of the strategy ρ9 ⊕ρ10. It is
a proper strategy for any given n and the actual choice of n has
no impact on the correctness of the specification so we use this
construct to let an unspecified number of patients register for
the study. ρ11 and ρ12 can only be applied at most once each. More elaborate strategy constructors can be defined to require
that strategies are applied at most once, for instance, but we did
not introduce them in this paper to keep things simpler. 3. APPLICATION FIGURE 7 | Examples of rules rewriting transformations when deleting the
label of node. FIGURE 8 | A rule that adds the fact that has_father ⊆has_parent. PhysicalAbuse ⊆Abuse to also add the fact that pa is an Abuse. We
could also have decided to remove the axiom and the knowledge
graph would have been consistent with the modified ontology. As the last example, we will add a new axiom to the ontology. Until now, we have only used the left-hand side of the rules to
look at specific instances, either of axioms, elementary actions or
individual nodes and we only, perhaps, added a new elementary
action to a given rule. When modifying the ontology, a new rule
is added that will modify the graph. Example 3.6. Let us assume that we want to add the axiom
has_father ⊆has_parent to the ontology. Rule ρ4 presented in
Figure 8 is applied to the graph with Strategy ρ∗
4. The correctness
formula, in that case, is, after some simplification, (∀x, y. has_father(x, y) ⇒has_parent(x, y)) ⇒(∀x, y. has_father(x, y) ⇒has_parent(x, y)), an obvious tautology. Example 3.6. Let us assume that we want to add the axiom
has_father ⊆has_parent to the ontology. Rule ρ4 presented in
Figure 8 is applied to the graph with Strategy ρ∗
4. The correctness
formula, in that case, is, after some simplification, (∀x, y. has_father(x, y) ⇒has_parent(x, y)) ⇒(∀x, y. has_father(x, y) ⇒has_parent(x, y)), an obvious tautology. Example 3.7. Let
us
now
consider
the
more
elaborate
example
of
Example
. Let
us
define
φ0
≡
∀x.Psychologist(x) ⇒∃≤5y.(Patient(y) ∧assigned_to(y, x)), φ1 ≡
∀x.SocialWorker(x)
⇒
∃≤10y.(Patient(y) ∧assigned_to(y, x))
and φ2
≡
∀x.(DefSocialWorker(x) ∨DefPsychologist(x) ∨
CaseWorker(x)) ⇒ FIGURE 7 | Examples of rules rewriting transformations when deleting the
label of node. FIGURE 7 | Examples of rules rewriting transformations when deleting the
label of node. ¬(SocialWorker(x) ∨Psychologist)). The precondition and the
post-condition will then be φ ≡φ0 ∧φ1 ∧φ2. φ0 states that
psychologists are assigned less than five patients, φ1 states that
social workers are assigned <10 patients, φ2states that default
psychologists and social workers and case workers do not count as
psychologists or social workers (otherwise, they might not satisfy
φ0 or φ1). The set of rules R contains the rules shown in Figure 9. Frontiers in Big Data | www.frontiersin.org 3. APPLICATION The
annotated specification is thus s′ ≡{φ}(R, (ρ5 ⊕ρ6)∗{φ}; (ρ7 ⊕
ρ8)∗{φ}; (ρ9 ⊕ρ10)n; ρ∗
11{φ}; ρ∗
12{φ}){φ}. Up to now, we have modified the graph by adding and
changing the labeling of the knowledge graph but we have
not modified the ontology itself. It is worth pointing that the
choices that we made when the transformation presented a risk
of inconsistency always lead us to modify the graph and not the
ontology. There is, however, no reason to think that when there
is a conflict between the ontology and the content of the graph,
the ontology is always to be considered correct. Example 3.5. In the first example we presented, we chose when
adding the fact that pa was a PhysicalAbuse knowing that Giving the full proof that the specification is correct would be
long and tedious. Instead, let us give an informal description of the May 2021 | Volume 4 | Article 660101 Frontiers in Big Data | www.frontiersin.org 6 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad URE 9 | The rules used in Example 3.7. FIGURE 9 | The rules used in Example 3.7. Frontiers in Big Data | www.frontiersin.org May 2021 | Volume 4 | Article 660101 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad FIGURE 10 | A schema of the recommender system (Brenas et al., 2019b). FIGURE 10 | A schema of the recommender system (Brenas et al., 2019b). definitions. Similarly, we have only looked at the easiest of the
interactions between transformations and axioms. proof. Neither ρ11 nor ρ12 affect any of the predicates in φ thus one
can ignore them. ρ9 and ρ10 only modify assigned_to(x, y) for y
a case worker. From φ2, one gets that being a case worker excludes
the possibility of being either a social worker or a psychologist which
means that if φ is true after (ρ5 ⊕ρ6)∗; (ρ7 ⊕ρ8)∗, it will be
true at the end of the execution. Similarly, ρ7 and ρ8 only modify
the assignment to the default social worker and psychologist that,
according to φ2, are not social workers or psychologists. Thus, one
needs to prove that {φ}(R, (ρ5 ⊕ρ6)∗{φ}){φ} is correct. ρ5 only
assigns a patient to a social worker that has nine or less and thus,
after the assignment, they will only have ten or less. The same
argument works for psychologists albeit with a different number
of edges. 4. CONCLUSION Moreover, we have only presented logics with very little
expressivity in this work to make it easier to follow and
to avoid problems that arise at higher expressivity. However,
it has been proved that the verification that underpins this
method works for the whole expressivity of C2 (Brenas et al.,
2018a). Moreover, OWL allows defining more complex axioms
on properties, e.g., transitivity, that cannot be expressed in
C2 but can be expressed in other decidable logics, such as
the Guarded Fragment of first-order logic (Andréka et al.,
1998) for which the same results apply (Brenas et al., 2018b). Extending the expressivity to full first order logic and beyond
is much more difficult as satisfiability in first-order logic is
undecidable and, as a result, so is our verification process. On
the other hand, it is possible to restrict the specifications to
less expressive logics. Finding the conditions on the logic and
the change that can be performed to reduce the complexity of
the verification process is under active study. The importance
of the complexity problem is somewhat reduced by the fact
that the complexity of the verification task is dependent on
the size of the specification and not on the size of the
data it represents. In this paper, we demonstrated the feasibility of using graph
transformations for managing changes and modifications in
knowledge graphs while maintaining their consistency. We
used logically decorated graphs to represent the knowledge
graph, graph transformations for the modifications and a
Hoare-like approach to verification to prove the correctness of
the transformations. Verification of graph transformations is an active field of
computer science. Our approach is based on the method of
Brenas et al. (2016b). Several other approaches exists including
methods akin to model checking (Rensink et al., 2004) or the
use of graph programming languages, such as GP2 (Wulandari
and Plump, 2020). These methods have not been applied to
knowledge graphs as far as we know. This is only the first step toward a comprehensive solution. An important limitation to the application of our method is the
fact that not all currently existing knowledge graphs are equipped
with ontologies. In the absence of an ontology, the whole problem
is moot as there is nothing to be consistent with. Frontiers in Big Data | www.frontiersin.org 3. APPLICATION The specification s′ is thus correct. In particular, the rules that we have presented allow
automating the process in the situation that we have presented
but it is not hard to find examples where such automation is
not feasible. When increasing the expressivity of the axioms,
there are many situations where a non-trivial choice has to
be made to decide which part of the knowledge is responsible
for the inconsistency, and thus should be removed. Algorithms
exist to do repairs (Bienvenu et al., 2016) that go much further
than we did and integrating these algorithms into our method
seems promising. That said, the verification process generates
a counter model, which is a knowledge graph that invalidates
the specification. This counter model can be used to decide the
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possible to start with an empty ontology and to use our method to
provably make sure that a knowledge graph becomes consistent
with it by defining rules that modify it. Among the possible applications of the research presented
in this paper is the conception of a recommender system
to assist in the detection, prevention and treatment of
ACEs (Brenas et al., 2019b). Figure 10 shows a schema of We have presented a few transformation rewriting rules and
we are working to formulate a formal framework for their May 2021 | Volume 4 | Article 660101 8 Correctness of Knowledge Graph Update Brenas and Shaban-Nejad AUTHOR CONTRIBUTIONS the recommender system’s components. The recommender
needs
to
be
able
to
update
its
knowledge
about
the
circumstances and the health of the patients in a verifiably
correct manner. JB and AS-N contributed equally to the research and writing of
this paper. FUNDING The funding for this study has been provided by the University of
Tennessee Health Science Center. The funding for this study has been provided by the University of
Tennessee Health Science Center. The raw data supporting the conclusions of this article will be
made available by the authors, without undue reservation. Tennessee Health Science Center. REFERENCES “Ensuring correctness of
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Construção e validação do instrumento "Inventário de problemas éticos na atenção primária em saúde"
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Revista Bioética
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1. Doutor roquejunges@hotmail.com – Unisinos, São Leopoldo/RS, Brasil 2. Livre docente elma@usp.br – Universidade de São Paulo,
São Paulo/SP, Brasil 3. Doutor mppatussi@unisinos.br – Unisinos, São Leopoldo/RS, Brasil 4. Doutoranda rafaelaschaefer@hotmail.com
– Universidade Católica Portuguesa, Porto, Portugal 5. Doutoranda carliserdn@yahoo.com.br – Universidade Católica Portuguesa, Porto,
Portugal. La construcción y validación del “Inventario de problemas éticos en la atención primaria de la salud”iili Identificar los conflictos éticos contribuye para mejorar la calidad de la atención. Este estudio tuvo como obje-
tivo evaluar la validez de constructo y la consistencia interna del Inventario de Problemas Éticos en la Atención
Primaria de la Salud. El instrumento, un cuestionario estructurado y cerrado, es resultado de una década de
investigaciones sobre bioética en la atención primaria. El artículo enfoca la última etapa de validación. En
el inicio de esta etapa, el instrumento contenía 41 elementos. Se lo ha aplicado a 237 profesionales de 12
centros de salud del Grupo Hospitalar Conceição (Porto Alegre/RS). Tras el análisis factorial exploratorio de
las puntuaciones, se encontró seis dimensiones centrales con alto grado de fiabilidad y consistencia (KMO =
0,831, Bartlett p < 0,001, alpha 0,876), explicando el 61,4 % de la varianza. La versión validada del instrumento
quedó con 6 factores y 24 ítems. El instrumento contribuirá para las investigaciones en bioética, pues posibili-
ta estudios cuantitativos en grandes muestras para llevar a reconocerse los problemas éticos más frecuentes
en atención primaria.ii Artigos de pesquisa Palabras-clave: Estudios de validación. Ética. Bioética. Atención primaria de salud. Solución de pr Resumo Identificar conflitos éticos contribui para melhorar a qualidade da assistência. O estudo objetivou verificar a
validade de construto e consistência interna do “Inventário de problemas éticos na atenção primária em saú-
de”. O instrumento, questionário estruturado e fechado, é fruto de uma década de pesquisas sobre bioética
na atenção básica. O artigo enfoca a última etapa da validação. No início dessa fase, o instrumento continha
41 itens. Foi aplicado a 237 profissionais de 12 unidades de saúde do Grupo Hospitalar Conceição (Porto
Alegre/RS). Após análise fatorial exploratória dos escores, obtiveram-se seis dimensões centrais com eleva-
do grau de confiabilidade e consistência (KMO=0,831; Bartlett p<0,001; α geral 0,876), explicando 61,4% da
variância. Ao final, o instrumento validado ficou com seis fatores e 24 itens. O instrumento poderá contribuir
para pesquisas em bioética, com estudos quantitativos em grandes amostras, bem como propiciar o reconhe-
cimento dos problemas éticos mais comuns na atenção básica. Palavras-chave: Estudos de validação. Ética. Bioética. Atenção primária à saúde. Resolução de problemas. Aprovação CEP/Grupo Hospitalar Conceição 09-156 Declaram não haver conflito de interesse. Construction and validation of the instrument “Inventory of ethical problems in primary health care” sível, bastante compreensível e de fácil aplicação. Na continuidade da validação, era preciso avaliar o
construto do instrumento. Para validar a clareza, a
facilidade de leitura e a confiabilidade do construto
desenvolveu-se, entre 2006 e 2008, um estudo me-
todológico 6. A validação da clareza e confiabilidade
deu-se por meio de um painel de especialistas em
saúde da família, com uso da técnica Delphi. Cada item do IPE-APS teve seu enunciado des-
crito segundo a situação narrada pelos entrevista-
dos do estudo, cujos resultados deram origem à lista
de problemas constantes do inventário. Para cada
item do IPE-APS solicitava-se aos especialistas do
painel que avaliassem a congruência entre o enun-
ciado do problema ético e a descrição da situação
que o gerou. Havia espaço para que os especialistas
sugerissem nova redação para o enunciado, se fosse
o caso. O ponto de corte da congruência era 80%,
sendo mantida a redação dos enunciados com valor
igual ou superior a isso 6. Nessa perspectiva, desde 2000 temos estuda-
do a temática da ética na APS. O primeiro estudo,
entre 2000 e 2003, desenvolveu uma pesquisa qua-
litativa com enfermeiros e médicos de equipes de
saúde da família do município de São Paulo, objeti-
vando reconhecer um perfil das questões éticas nes-
sa nova forma de organização da APS no SUS. Como
resultado, obteve-se uma lista de 41 problemas 1,
que originaram a primeira versão do Inventário de
problemas éticos na atenção primária (IPE-APS). Para a validação da facilidade de leitura usou-
se o Índice de Facilidade de Leitura de Flesch-Kincaid
(ILFK), disponível no Microsoft Windows Word. A
redação final dos enunciados dos problemas éticos
resultante da consulta ao painel de especialistas foi
ajustada para uma facilidade de leitura compatível
com uma escolaridade aproximada ao 7o ano (antiga
6a série) do ensino fundamental (leitura razoavel-
mente fácil). A redação ajustada para cada item foi
revista por uma professora de língua portuguesa,
para verificar a adequação e correção da escrita. Com esse estudo metodológico fechou-se, em 2008,
a 2a versão do IPE-APS 6. Entre 2004 e 2005, desenvolveu-se um segun-
do estudo para reconhecer se os problemas aponta-
dos no primeiro se repetiriam na vivência de outras
equipes de saúde da família e se ainda haveria algo
a acrescentar. Construction and validation of the instrument “Inventory of ethical problems in primary health care” Identifying ethical conflicts contributes to improve healthcare quality. This study aimed to evaluate content
validity and verify internal consistency of the Inventory of Ethical Problems in Primary Health Care. The in-
strument – a close and structured questionnaire – is a result of decades of researches on bioethics in primary
health care. The article focuses on the last stage of validation. At the beginning of this stage the instrument
had 41 items. It was applied to 237 professionals of 12 primary care centers at Grupo Hospitalar Conceição
(Porto Alegre/RS). After the exploratory factor analysis, it resulted in six dimensions with high degree of reli-
ability and consistency (KMO = 0.831, Bartlett p < 0.001; alpha 0.876), which explained 61.4 % of variance. At
the end, the validated version of the instrument had 6 factors and 24 items. The instrument may contribute to
researches in bioethics through the development of studies to recognize the most common ethical problems
in primary care and to explore the influence of different contexts on ethical problems. Key words: Validation studies Ethics Bioethics Primary health care Problem solving Artigos de pesquisa Key words: Validation studies. Ethics. Bioethics. Primary health care. Problem solving. Declaram não haver conflito de interesse. Rev. bioét. (Impr.). 2014; 22 (2): 309-17 http://dx.doi.org/10.1590/1983-80422014222012 309 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Investigações sobre os desafios éticos nos ser-
viços de atenção à saúde podem levar os profissio-
nais a refletir, deliberar e avaliar atitudes éticas nas
práticas de saúde 1. Os problemas éticos são desafios
que exigem deliberação pela melhor solução. Enten-
didos como desafios, não podem ser resolvidos por
meio de receitas prontas, mas exigem permanente
criatividade, porque requerem respostas de longo
alcance, que ultrapassem a solução de um caso parti-
cular 2. No Sistema Único de Saúde (SUS), a Estratégia
de Saúde da Família (ESF) vem reorganizando a Aten-
ção Primária à Saúde (APS) por meio da efetivação
dos princípios da longitudinalidade e da integralida-
de. Tal fato reforça a necessidade de compromissos
éticos das equipes, que têm de exercer nova prática
marcada pela humanização, cuidado e cidadania 1. Construction and validation of the instrument “Inventory of ethical problems in primary health care” O estudo mostrou que a primeira ver-
são do IPE-APS era de fácil compreensão e preen-
chimento, contendo uma lista de problemas éticos
da prática na APS suficientemente abrangente, não
sendo necessário incluir novos exemplos 3. Artigos de pesquisa Até essa segunda versão o IPE-APS vinha sen-
do validado na vertente qualitativa. Sua escala para
registro da ocorrência dos problemas éticos era no-
minal e não numérica. A partir de 2009, usando a
segunda versão do IPE-APS, iniciou-se a validação
por meio de técnicas quantitativas, para viabilizar a
incorporação de uma escala do tipo Likert no instru-
mento. Com isso, seria possível seu uso em estudos
quantitativos, com amostras maiores. As pesquisas
objetivaram verificar a validade de construto e a
consistência interna do IPE-APS. O presente artigo
descreve os resultados da última dessas pesquisas
de validação do IPE-APS. De 2005 a 2009, no município de São Paulo,
outros dois estudos qualitativos investigaram as si-
tuações eticamente significativas vividas por enfer-
meiros e médicos em serviços de APS não reorgani-
zados pela ESF. Uma dessas pesquisas investigou as
unidades básicas de saúde (UBS) tradicionais e a ou-
tra enfocou os centros de saúde escola 4. Os resulta-
dos comprovaram a abrangência da lista de proble-
mas que compunha a primeira versão do IPE-APS. Um terceiro estudo desse mesmo período validou
a sensibilidade do instrumento. Para essa etapa de
validação foi desenvolvido um estudo com expertos
da área de ética e bioética. O instrumento mostrou-
se sensível, permitindo captar a variação de visão
segundo o grupo em que era aplicado: profissionais
da APS e especialistas em ética e bioética 5. Artigos de pesquisa Artigos de pesquisa Método Estudo transversal, realizado no Rio Grande do
Sul, com profissionais de 12 unidades de saúde do
Grupo Hospitalar Conceição (GHC), instituição pú- Com esses estudos, viu-se que a primeira
versão do IPE-APS se mostrava abrangente, sen- Rev. bioét. (Impr.). 2014; 22 (2): 309-17 http://dx.doi.org/10.1590/1983-80422014222012 310 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” blica federal vinculada ao Ministério da Saúde, refe-
rência no atendimento do SUS. O Grupo conta com
uma equipe de 7.913 profissionais e abrange quatro
hospitais (Conceição, Criança Conceição, Cristo Re-
dentor e Fêmina), 12 postos de saúde do Serviço de
Saúde Comunitária, três centros de atenção psicos-
social (Caps) e o Centro de Educação Tecnológica e
Pesquisa em Saúde, a Escola GHC. É nacionalmente
reconhecido como a maior rede pública de hospitais
do Sul do Brasil, com 100% de atendimento SUS 7. tuação enunciada no item. Caso contrário, tinha que
assinalar com que frequência encontrava o proble-
ma em seu trabalho na APS: nunca (1); raramente
(2); frequentemente (3); sempre (4). Registraram-se, também, algumas caracterís-
ticas dos respondentes: socioeconômicas, especial-
mente a escolaridade; demográficas (sexo, cor ou
raça e estado civil); fatores relacionados ao processo
de trabalho (profissão, tempo de formação, tempo
de trabalho na APS e tempo de trabalho na unidade
de saúde atual). O trabalho de campo teve início em julho de
2011 com um estudo piloto, realizado na unidade
de saúde Conceição, que incluiu cerca de 60 profis-
sionais. O propósito era conhecer a realidade in loco
para organizar o trabalho de campo e, também, ob-
servar a compreensibilidade do instrumento pelos
profissionais durante o seu preenchimento, vez que
só havia sido utilizado em estudos no município de
São Paulo. O Epidata versão 3.1 foi utilizado para a di-
gitação dos dados e o software Statistical Package
for the Social Sciences (SPSS) versão 12.0, para a
análise. Com o objetivo de avaliar a adequação dos
dados à análise fatorial, usou-se o teste de Kaiser-
Meyer-Olkin (KMO). Para a validação do constructo
fez-se uso da análise de componentes principais e a
rotação varimax. Método Para tanto, foram seguidos os pas-
sos propostos por Hair JF, Anderson RE, Tatham RL e
Black WC 10: formulação do problema; construção da
matriz de correlação; determinação do método de
análise fatorial; determinação do número de fato-
res; rotação dos fatores; interpretação dos fatores;
cálculo das cargas fatoriais ou escolha de variáveis
substitutas, e determinação do ajuste do modelo. A coleta de dados ocorreu entre agosto e de-
zembro de 2011, aproveitando-se as reuniões sema-
nais das equipes. Os profissionais eram convidados
a participar de forma voluntária, formando uma
amostra por conveniência. Após os esclarecimen-
tos sobre a pesquisa e a liberdade de participação,
todos os presentes à reunião recebiam o IPE-APS,
com as instruções para seu preenchimento. Ao final,
recolhiam-se todos os instrumentos distribuídos,
estivessem ou não preenchidos. Como não havia
identificação do respondente se preservava o anoni-
mato dos incluídos no estudo e também dos que se
recusaram a participar, já que a retirada dos instru-
mentos em branco não era feita no campo. Para encontrar a melhor solução em termos de
números de fatores utilizaram-se como critérios: au-
tovalor maior ou igual a 1, mínimo de três itens por
fator, e coerência com a teoria que fundamentou a
construção do instrumento em todos os estudos: a
bioética deliberativa de Diego Gracia. Os critérios de
remoção de itens foram: aumento de alpha após a
remoção do item; item carregando vários fatores ao
mesmo tempo, e remoção do item cujo conteúdo
não fosse coerente com o construto. Para avaliar a
consistência interna da escala total e sua subescala
utilizou-se o alpha de Cronbach 11. Artigos de pesquisa Artigos de pesquisa A amostra totalizou 237 profissionais. Para o
procedimento de análise fatorial exploratória, au-
tores mais rigorosos, como Dassa 8, sustentam que
o tamanho ideal da amostra é de, no mínimo, dez
sujeitos por item do inventário ou um total de pelo
menos 250 sujeitos. Outros autores, como Pestana
e Gageiro 9, propõem, no mínimo, cinco sujeitos
por questão em inventários com mais de 15 itens,
considerando-se um mínimo de 100 sujeitos. Frente
a isso, consideramos a amostra do presente estudo
suficiente para as análises propostas. Artigos de pesquisa Artigos de pesquisa A pesquisa foi aprovada pelo Comitê de Ética
em Pesquisa do Grupo Hospitalar Conceição e todos
os participantes assinaram o termo de consenti-
mento livre e esclarecido. Resultados A versão do IPE-APS submetida à validação
quantitativa continha os 41 itens da segunda ver-
são da validação qualitativa, com problemas éticos
em três âmbitos relacionais da atenção à saúde:
usuário-profissional, equipes de saúde da família e
sistema de saúde 1. A cada item os respondentes po-
diam expressar sua visão sobre o tema numa escala
que variava de zero a quatro. O zero significava que
o respondente não considerava problema ético a si- Dentre outros profissionais de saúde das equi-
pes de saúde da família, a amostra de 237 profissionais
incluía médicos (14%), agentes comunitários de saúde
(11%), auxiliares e/ou técnicos em enfermagem (10%)
e enfermeiros (9%). Predominou o sexo feminino
(79%), 82% se consideravam brancos, 50% eram sol-
teiros e 60% apresentavam idade entre 21 e 40 anos. http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 311 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” A análise dos dados considerou as respostas
dos 237 profissionais participantes. Com o intuito
de avaliar a estrutura geral dos dados, rodou-se a
análise no SPSS de forma aberta, ou seja, sem de-
limitar previamente a quantidade de fatores, com
rotação varimax. O resultado dessa análise indicou a
existência de 10 diferentes fatores, nos quais índice
KMO=0,847 e Bartlett p<0,001. A variância explica-
da nesta solução era de 63,5% e o alpha geral 0,921. Essas medidas indicaram que os resultados eram
satisfatórios, ou seja, mostraram a adequação dos
dados para se proceder ao modelo exploratório de
análise fatorial. Agrupa problemas éticos referentes à: carência de
condições para os atendimentos; falta de condições
para a realização de visitas domiciliares; deficiên-
cias do serviço de retaguarda para a remoção de
pacientes; dificuldades no sistema de referência e
contrarreferência; retorno e confidencialidade dos
resultados de exames laboratoriais e; excesso de fa-
mílias adscritas a cada equipe na ESF. Esse domínio
do IPE-APS traz a questão dos aspectos diretamente
relacionados à organização e ao funcionamento dos
serviços como fonte de problemas éticos para os
profissionais de saúde na ESF. Resultados O fator ‘longitudinalidade’ contém quatro
itens que tratam das questões relacionadas à: con-
tinuidade de tratamento; recusa em seguir a indica-
ção médica; prescrição de medicamento que o usuá
rio não terá dinheiro para comprar e; dificuldade de
cumprir na prática as responsabilidades de cada
profissional da equipe. Esse domínio do IPE-APS en-
globa os problemas éticos decorrentes da prolonga-
da relação que se estabelece entre o profissional e
o usuário. O alpha de Cronbach desse fator foi 0,70. Após a verificação da adequação dos dados,
para a sequência da análise foram retirados os itens
que, ao mesmo tempo, apresentavam dois ou mais
fatores ainda que com baixa comunalidade. Reti-
raram-se, um a um, seis itens, o que aumentou a
variância para 64,4%. Após a retirada desses itens, a análise gerava
nove fatores. Três fatores tinham apenas dois itens,
o que não é recomendável na validação, segun-
do autores como Tabachnick e Fidell 11. Portanto,
optou-se por retirar mais seis itens. Com isso, a ex-
plicação da variância diminuiu para 59,6%. Não se
esperava esse comportamento da variância com a
remoção dos itens, mas, apesar disso, devido à ne-
cessidade de eliminar fatores que continham ape-
nas dois itens, optou-se pela retirada. No fator ‘prática das equipes’ estão quatro
itens que expressam problemas éticos decorren-
tes da fragmentação do trabalho das equipes e a
dificuldade de exercer a prática interdisciplinar. Esse
domínio trata da: falta de respeito entre os mem-
bros da equipe; falta de colaboração de uma equipe
com a outra; profissionais que não apresentam per-
fil para trabalhar na ESF e; profissionais que atuam
com falta de compromisso e envolvimento. O alpha
de Cronbach desse fator foi 0,76. Artigos de pesquisa Ao se analisar a consistência teórica, foram
encontrados três itens cujos problemas éticos enun-
ciados não faziam sentido nos fatores onde se aloca-
ram. Também se optou por sua retirada. Obteve-se,
assim, a explicação de 61,4% da variância em um
modelo com seis fatores e 24 itens. O índice KMO
ficou em 0,831, Bartlett p<0,001 e alpha geral de
0,876 (tabela 1). Esse arranjo de itens e fatores foi
considerado a melhor solução de análise, pois com-
binou importantes resultados estatísticos e agrupou
os problemas éticos de forma apropriada do ponto
de vista teórico 11. Três itens formam o fator ‘perfil profissional’,
com alpha de Cronbach de 0,72. Discussão médico generalista ou equipe de saúde, nos múlti-
plos episódios de doenças e cuidados de promoção
e reabilitação da saúde. Para essa continuidade da
atenção são imprescindíveis a existência e o reco-
nhecimento de uma fonte regular de cuidados de
atenção primária, o estabelecimento de vínculo
terapêutico duradouro entre os pacientes e os pro-
fissionais de saúde da equipe local e a continuida-
de informacional 24. Nesses pontos concentram-se,
também, os principais problemas éticos relaciona-
dos à longitudinalidade. Como resultado de mais de uma década de
pesquisas explorando a interface da bioética e aten-
ção básica, logrou-se construir e validar um instru-
mento para inventariar problemas éticos na atenção
primária à saúde. A aplicação do IPE-APS permite
fazer uma ‘epidemiologia’ 15 dos problemas éticos
na visão dos profissionais de saúde que atuam na
atenção primária. Mas, ultrapassa a contabilização
porque pode se prestar à mediação da reflexão so-
bre as questões éticas para a melhoria dos serviços
de saúde. O terceiro fator, ‘prática das equipes’, corrobora
estudos que apontaram deficiências na responsabili-
dade coletiva no trabalho de equipe na ESF, pois os
profissionais fragmentam em atuações isoladas o que
deveria ser um saber coletivamente construído 25. Para se alcançar os objetivos da ESF é necessário o efe-
tivo trabalho em equipe, com todos atuando em prol
do mesmo objetivo. Nas equipes de saúde, cada pro-
fissional exerce sua profissão no bojo de um trabalho
coletivo, cujo resultado final depende da contribuição
das diferentes áreas do saber à assistência 12. Os resultados do presente estudo validaram
o IPE-APS porque mostraram que o instrumento
apresenta homogeneidade e consistência interna,
com congruência dos itens em cada fator e com o
todo 16. A variância total explicada foi aceitável. Ape-
nas 38,6% da variância permaneceu inexplorada 11. Além das medidas estatísticas satisfatórias, houve
importante coerência teórica dos fatores resultan-
tes da análise, segundo a literatura revisada 12,17. O ‘perfil profissional’, quarto fator, vem ao
encontro das evidências de estudos com gestores e
trabalhadores do SUS, das distintas esferas de go-
verno, ao mostrarem que, da mesma forma que o
desempenho e a gestão dos recursos humanos, a
formação dos profissionais afeta, profundamente,
a qualidade dos serviços e o grau de satisfação dos
usuários 26,27. O setor público tem dificuldade para
contratar profissionais com perfil adequado ao que
se pretende e se espera para a APS. Discussão No processo de
formação dos profissionais, apesar dos recentes es-
forços de mudança, especialmente com a expansão
das horas de estágio na saúde da família, persiste o
distanciamento em relação às demandas e necessi-
dades do SUS, com dificuldades para a integração de
conhecimentos clínicos e da saúde coletiva 12. O fator com maior percentual de variância ex-
plicada foi ‘gestão da atenção primária’, pois, inde-
pendentemente do número de fatores retidos, este
sempre se agrupava como o primeiro. Isso provavel-
mente decorre da importância dessa questão para a
APS, especialmente no SUS, no qual se vem propon-
do que esse nível da atenção seja a porta de entrada
do Sistema e, ao mesmo tempo, coordenadora do
cuidado pelos diversos pontos da rede de atenção
à saúde. Os problemas éticos relacionados à dimen-
são da gestão da APS guardam relação direta com
a ética na gestão dos serviços de saúde, deixando
patente a dificuldade de separar a ética dos cuida-
dos de saúde da ética na administração em saúde 18. Artigos de pesquisa Artigos de pesquisa Artigos de pesquisa Diversos estudos têm evidenciado a existên-
cia de problemas relacionados à gestão do SUS 19-21. Cada vez mais os serviços de saúde requerem dos
municípios o bom desempenho da capacidade de
gestão, que há de se voltar para a mudança posi-
tiva nos indicadores de saúde da população. Com
isso, ganha importância a figura do gestor e de suas
decisões político-gerenciais na efetividade e eficiên-
cia do SUS. Os profissionais das equipes da ESF e os
gestores devem guiar sua prática pelo princípio da
responsabilidade ética 22. O fator ‘privacidade’ revela características pró-
prias da APS, pois a casa dos usuários torna-se exten-
são do consultório. A relação deixa de ser individual
(médico-paciente) para se tornar coletiva (equipe de
saúde-família), enriquecendo a discussão de um tó-
pico essencial à bioética, a privacidade das pessoas
autônomas, com os problemas específicos e peculia-
res deste nível da atenção. A privacidade é um prin-
cípio derivado da autonomia e engloba a intimidade,
a vida privada e a honra das pessoas. No trabalho
em equipe multiprofissional, a troca de informações
é fundamental para a boa qualidade na assistência. Porém, as informações para os membros das equipes
hão de se limitar às necessárias para cada um realizar
suas atividades em benefício do usuário 28. Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Resultados São problemas éti-
cos relativos ao perfil atitudinal do profissional na
APS, reorganizada ou não pela ESF: pré-julgamento
de usuários e familiares; falta de respeito e prescri-
ções inadequadas. Artigos de pesquisa Artigos de pesquisa O quinto fator, ‘privacidade na atenção primária
à saúde’, compreende três itens, que trazem aspectos
próprios deste tema ético no contexto da APS, onde
os domicílios e a comunidade são extensões do con-
sultório. O fator teve alpha de Cronbach igual a 0,70. Os fatores podem ser tidos como categorias de
análise ou, ainda, domínios de avaliação do IPE-APS. Eles agruparam os problemas éticos na APS por fre-
quência e por suas características, os que mais acon-
tecem e de que tipo são, com base em publicações
sobre atenção básica 12: 1) Gestão da atenção primá-
ria; 2) Longitudinalidade; 3) Prática das equipes; 4)
Perfil profissional; 5) Privacidade na atenção primá-
ria à saúde e; 6) Sigilo profissional (Tabela 1 – Anexo). O fator ‘sigilo profissional’ teve alpha de Cron-
bach igual a 0,64 e agrupou quatro itens relativos
aos problemas éticos nas informações sobre a saú-
de dos usuários e o compartilhamento destas entre
profissionais, usuários e familiares. Há consistência interna das dimensões resul-
tantes da análise dos dados, com índices alpha de
Cronbach 13,14 que variaram de desejável (α=0,85) a
aceitável (α=0,64). O domínio ‘gestão da atenção primária’ con-
tém seis itens, com alpha de Cronbach igual a 0,854. http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 312 Discussão A longitudinalidade do cuidado é o segundo
fator do IPE-APS e pode ser entendido como carac-
terística central e própria da atenção primária. Para
Starfield 23, longitudinalidade refere-se ao acom-
panhamento do paciente, ao longo do tempo, por http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 313 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” No sexto fator, ‘sigilo profissional’, levanta-se
que a questão do segredo não está necessariamen-
te vinculada ao contato direto entre informante e
ouvinte. Em função do atendimento aos usuários e
famílias, a informação pode ser obtida por uma ou
mais pessoas e a confidencialidade deveria ser pre-
servada, como respeito a um direito do usuário 29. Estudo brasileiro, realizado por Fortes e Spinetti 30,
constatou que os agentes comunitários de saúde
preocupam-se com o princípio ético da privacidade
e com a necessidade de manter o sigilo, como obri-
gação ética dos profissionais de saúde. sigilo profissional que deverão observar como mé-
dicos, mas reconhecem ter dificuldades para definir
as situações nas quais é necessário partilhar infor-
mações e quando estas devem ser mantidas em se-
gredo 33. Claro está que a troca de informações entre
usuário e profissional depende diretamente do cli-
ma de confiança que perpassa a relação clínica e o
acolhimento do usuário no serviço 34. Estudo com mulheres portadoras de HIV, em
uma região do município de São Paulo, mostrou que
elas revelam sua condição para a equipe de saúde
da família somente quando estabelecem vínculo e
confiança com os profissionais. Ao contrário, quan-
do sentem medo e insegurança devido à alguma ati-
tude dos profissionais ou não confiam que o sigilo
sobre sua condição será mantido, não revelam seu
diagnóstico à equipe da atenção primária 35. O vín-
culo, a confiança e acolhimento na relação dos ser-
viços e profissionais com os usuários e famílias são
elementos fundamentais para a reflexão e condução
das questões éticas sobre sigilo e privacidade. Discussão Ressalte-se que os últimos dois fatores guar-
dam semelhanças entre si, pois os termos ‘sigilo’ e
‘privacidade’ se confundem e os problemas éticos
descritos em ambos os domínios se entrelaçam na
assistência, podendo ser diferentemente interpre-
tados pelos profissionais – talvez por isso tenham
apresentado os menores índices de alpha de Cron-
bach (0,70 e 0,64, respectivamente). De fato, a proposta do SUS de trabalho em
equipe para a atenção primária, especialmente com
a Estratégia Saúde da Família, traz questões éticas
sobre o sigilo e a privacidade que requerem apro-
fundamento das reflexões para chegarmos a res-
postas que respeitem a dignidade e autonomia dos
usuários dos serviços. Entretanto, talvez a confusão
que se manifestou na análise desses itens no instru-
mento seja reflexo de que usuários e profissionais
ainda estão atônitos com a capilaridade propor-
cionada pela ESF, onde equipes e profissionais pe-
netram na privacidade dos lares, na intimidade da
dinâmica familiar. Referências 1. Zoboli ELCP. Bioética e atenção básica: um estudo de ética descritiva com enfermeiros e médicos
do Programa Saúde da Família. [tese]. São Paulo: USP; 2003.i 2. Gracia D. Ethical case deliberation and decision making. Med Health Care Philos. 2003;6(3):227-
33. 315
22 (2): 309-17
Artigos de pesquisa 3. Silva LT, Zoboli ELCP, Borges ALV. Bioética e atenção básica: um estudo exploratório dos problemas
éticos vividos por enfermeiros e médicos no PSF. Cogitare Enferm. 2006;11(2):133-42. i
4. Zoboli ELCP Relación clínica y problemas éticos en atención primaria, São Paulo, Brasil. Aten Prim. 2010;42(8):406-1.ii 5. Silva LT, Zoboli ELCP. Problemas éticos na atenção primária: a visão de especialistas e profissionais. Revista Brasileira de Bioética. 2007;3(1):27-39. i
6. Silva LT. Construção e validação de um instrumento para mensuração de ocorrência de problema
ético na atenção básica [dissertação] São Paulo: USP; 2008 i
6. Silva LT. Construção e validação de um instrumento para mensuração de ocorrência de problema i i
6. Silva LT. Construção e validação de um instrumento para mensuraçã
ético na atenção básica. [dissertação]. São Paulo: USP; 2008. 6. Silva LT. Construção e validação de um instrumento para mensuração de ocorrência de problema
ético na atenção básica. [dissertação]. São Paulo: USP; 2008. i
7. Grupo Hospitalar Conceição. Atenção à saúde. [Internet]. (acesso 24 jun. 2012). Disponível:
http://www.ghc.com.br/default.asp?idMenu=atencao_saudeiii 8. Dassa C. Analyse multidimensionnelle exploratoire et confirmative. Montreal: Université
Montréal; 1999. 9. Pestana MH, Gageiro JG. Análise de dados para ciências sociais: a complementaridade do SPSS. 3a
ed. Lisboa: Silabo; 2003. 10. Anderson RE, Tatham RL, Black B. Multivariate data analysis. In: Hair JF, colaborador. 5th ed. New
Jersey: Prentice Hall; 1998. i
11. Tabachinick BG, Fidell LS. Using multivariate statistics. 4th ed. San Francisco: Allyn and Bacon;
2001. 12. Brasil. Conselho Nacional de Secretários de Saúde. Atenção primária e promoção da saúde. Brasília: Conass; 2011.fi 13. Cronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika. 1951;16(3):297-
334. 14. Cronbach LJ, Meehl P. Construct validity in psychological tests. Psychological Bulletin. 1955;52(4):281-302. 15. Fetters MD, Brody H. The epidemiology of bioethics. J Clin Ethics. 1999;10(2):107-15. Psicometria: teoria dos testes na psicologia e educação. Petr 17. Brasil. Portaria no 2.488, de 21 de outubro de 2011. Aprova a política nacional de atenção básica,
estabelecendo a revisão das diretrizes e normas para organização da atenção básica, para a
estratégia de saúde da família (ESF) e o programa de agentes comunitários de saúde (PACS). Considerações finais 2014; 22 (2): 309-17 314 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” estatística. Teoricamente, ancora-se na bioética de-
liberativa de Diego Gracia. Após esta última pesqui-
sa de validação do IPE-APS, com a qual chegamos
a uma terceira versão do instrumento, concluímos
que ele possibilita: traçar perfis confiáveis das ques-
tões éticas na APS; desencadear a reflexão das equi-
pes e profissionais para a reformulação de atitudes
pessoais e processos de trabalho. tados para verificar se há influência de fatores cultu-
rais, locais, sociais, de organização dos serviços de
atenção primária nos problemas éticos vivenciados
e identificados pelas equipes, podendo se aquilatar
a interferência desses fatores, em caso positivo. Esses estudos também poderão indicar se há
diferenças locais e regionais significativas no perfil
de problemas éticos da atenção primária. Com isso,
não se defende a mera descrição dos problemas éti-
cos, mas sim sistematizar o reconhecimento da situ-
ação, com a geração de evidências, para direcionar
ações de transformação da prática da atenção pri-
mária no sentido de torná-la mais ética, humanizada
e cidadã. Localizando os pontos frágeis, no sentido
ético, da atuação das equipes de atenção primária,
poderá se dirigir a formação permanente para os tó-
picos e questões mais relevantes e frequentes em
cada realidade. Com o IPE-APS abrem-se caminhos para no-
vas pesquisas na interface da bioética com a aten-
ção primária à saúde. A relevância do instrumento
é possibilitar a realização de estudos com amostras
representativas de populações profissionais para
verificar a potencialidade de generalização dos pro-
blemas indicados no IPE-APS. Ademais, o uso de um
instrumento validado em diferentes regiões, ou seja,
sua aplicação em estudos com múltiplos sítios para
coleta de dados, permitirá a comparação dos resul- Os vários projetos desenvolvidos desde o primeiro estudo em 2000 contaram com financiamento do CNPq,
Fapesp e Capes sob a forma de auxílio à pesquisa e bolsas iniciação científica, mestrado, estágio pós-doutoral
e produtividade. Considerações finais O IPE-APS é um instrumento original e inova-
dor para a proposta de desenvolver pesquisas em
bioética com o intuito de aprofundar a reflexão acer-
ca dos desafios éticos na prática profissional cotidia-
na dos serviços de saúde. Desconhece-se, até o mo-
mento, a existência de instrumentos semelhantes,
validados para medir o mesmo construto. Por isso,
o IPE-APS é importante ferramenta na melhoria da
atenção à saúde. Ele facilitará a realização de estu-
dos extensos, com grandes amostras, o que, por sua
vez, também contribuirá para seguir na validação
do próprio instrumento. A aplicação de um mesmo
instrumento validado em diferentes locais facilita a
comparação dos achados, desde que respeitadas as
questões da adaptação cultural. Artigos de pesquisa Estudo de Seoane e Fortes 31 mostra divergên-
cias nas opiniões dos usuários quanto às informa-
ções sobre sua saúde e vida familiar que repassam
ao agente comunitário de saúde. Alguns cogitam
limitar as informações, não confiando ao agente
sequer itens referentes a sua doença. Porém, há
usuários que afirmam compartilhar tudo o que diz
respeito a sua saúde, conscientes de que as informa-
ções serão levadas à equipe. Apesar de se perpetua
rem na prática cotidiana da atenção primária situa-
ções de desrespeito à confidencialidade, as equipes
de saúde consideram que a preservação do sigilo
e privacidade dos usuários é elemento chave para
ofertar um serviço de qualidade e humanizado 32. Artigos de pesquisa Artigos de pesquisa A aplicabilidade do IPE-APS mostrou-se possí-
vel em diferentes circunstâncias e locais de trabalho
da atenção primária, sendo um bom recurso para
pesquisadores, profissionais e gestores obterem in-
formações sobre o perfil de problemas éticos na vi-
são das equipes dos serviços, orientando o trabalho
de comitês de ética, comissões de bioética e progra-
mas de educação continuada para a realidade local. A perplexidade de todos os envolvidos nessa
proposta de trabalho coletivo reflete-se na forma-
ção dos futuros profissionais. Estudantes de medici-
na reconhecem que a confidencialidade da informa-
ção na sua experiência de aprendizagem na atenção
básica é ponto essencial no desenvolvimento do O IPE-APS é um instrumento elaborado com
um construto emanado da realidade do SUS e va-
lidado por meio de pesquisas qualitativas e quanti-
tativas que lançaram mão de instrumentais da aná-
lise de discurso, análise de conteúdo, psicometria, http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). Os vários projetos desenvolvidos desde o primeiro estudo em 2000 contaram com financiamento do CNPq,
Fapesp e Capes sob a forma de auxílio à pesquisa e bolsas iniciação científica, mestrado, estágio pós-doutoral
e produtividade. Referências Brasília; 2011. http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 315 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” 18. Silva JA, Dalmaso ASW. Agente comunitário de saúde: o ser, o saber, o fazer. Rio de Janeiro:
Fiocruz; 2002. p. 240. 19. Serra CG, Rodrigues PHA. Avaliação da referência e contrarreferência no programa saúde da família
na região metropolitana do Rio de Janeiro (RJ, Brasil). Ciênc. & Saúde Col. 2010;15(3):3.579-86. 20. Mendes EV. A atenção primária à saúde no SUS. Fortaleza: Escola de Saúde Pública do Ceará;
2002.ii 21. Paim JS, Teixeira CF. Configuração institucional e gestão do Sistema Único de Saúde: problemas e
desafios. Ciênc. & Saúde Col. 2007;12(Supp):1.819-29.iii 22. Amorim AG, Souza ECF. Problemas éticos vivenciados por dentistas: dialogando com a bioética
para ampliar o olhar sobre o cotidiano da prática profissional. Ciênc. & Saúde Col. 2010;15(3):869-
78. 23. Starfield B. Atenção primária: equilíbrio entre necessidades de saúde, serviços e tecnologia. Brasília: Unesco; 2002. 24. Haggerty JL, Reid RJ, Freeman GK, Starfield BH, Adair CE, McKendry R. Continuity of care: a
multidisciplinary review. BMJ. 2003;327(7.425):1219-21. DOI: http://dx.doi.org/10.1136/
bmj.327.7425.1219 25. Pedrosa JIS, Teles JBM. Consenso e diferenças em equipes do programa de saúde da família. Rev. Saúde Pública. 2001;35(3):303-11. 26. Nogueira R. Avaliação de tendências e prioridades sobre recursos
Opas; 2002. (Rede Observatório de Recursos Humanos de Saúde).tt 26. Nogueira R. Avaliação de tendências e prioridades sobre recursos humanos de saúde. Brasília:
Opas; 2002. (Rede Observatório de Recursos Humanos de Saúde).tti 26. Nogueira R. Avaliação de tendências e prioridades sobre recursos humanos de saúde. Brasília: Opas; 2002. (Rede Observatório de Recursos Humanos de Saúde).tt 27. Cotta RMM, Morales MSV, Gonzáles AL, Ricos JAD, Cotta Filho JS. Obstáculos e desafios da saúd
pública no Brasil. Rev Hospital Clínicas de Porto Alegre. 2002;22(1):25-32.ii 28. Fortes PAC, Martins CL. A ética, a humanização e a saúde da família. Rev. Bras. Enferm. 2000;53(n. esp):31-3. 29. Francisconi CF, Goldim JR. Aspectos bioéticos da confidencialidade e privacidade. In: Costa SIF,
Oselka G, Garrafa V, coordenadores. Iniciação à bioética. Brasília: Conselho Federal de Medicina;
1998. p. 269-84. p
30. Fortes CAP, Spinetti RS. O agente comunitário de saúde e a privacidade das informações dos
usuários. Cad. Saúde Pública. 2004;20(5):1.328-33. 31. Seoane AF, Fortes PAC. A percepção do usuário do programa saúde da família sobre a privacidade
e a confidencialidade de suas informações. Saúde Soc. 2009;18(1):42-9. 32. Bellenzani R, Mendes RF. Referências Sigilo na atenção em DST/Aids: do consultório aos processos
organizacionais. Polis e Psique. 2011;1(3):140-65.i 33. Ferreira RC, Silva RF, Zanolli MB, Varga CRR. Relações éticas na atenção básica em saúde: a
vivência dos estudantes de medicina. Ciênc. Saúde Coletiva. 2009;14 (1 suppl): 1.533-40. 34. Teixeira RR. O acolhimento num serviço de saúde entendido como uma rede de conversações. In:
Pinheiro R, Mattos RA, organizadores. Construção da integralidade: cotidiano, saberes e práticas
em saúde. Rio de Janeiro: Abrasco; 2003. p. 89-111.i 35. Ferreira FC, Nichiata LYI. Mulheres vivendo com Aids e os profissionais do programa saúde da
família: revelando o diagnóstico. Rev. Esc. Enferm. USP. 2008;42(3):483-9. Participação dos autores José Roque Junges: coordenador do estudo em Porto Alegre, que constituiu a última fase de validação
do IPE-APS. Elma Lourdes Campos Pavone Zoboli: desenvolveu o estudo original que identificou
os problemas éticos que compõem o IPE-APS e orientou as pesquisas que compõem as etapas
anteriores de validação do instrumento. Marcos Paschoal Patussi: pesquisador responsável pelo braço
quantitativo do estudo de Porto Alegre, para validação final e consistência interna do instrumento. Rafaela Schaefer e Carlise Rigon Della Nora: realizaram os trabalhos de campo, estruturação dos
bancos de dados e análise dos dados. Todos os autores contribuíram igualmente para a elaboração e
revisão final do artigo. Artigos de pesquisa Artigos de pesquisa http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 316 Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Construção e validação do instrumento “Inventário de problemas éticos na atenção primária em saúde” Anexo Tabela 1. Fatores, itens, índices de confiabilidade dos fatores e cargas fatoriais dos itens
Itens
Cargas fatoriais
h2
1
2
3
4
5
6
Fator 1. Gestão da atenção primária (α=0,85)
40 A UBS não tem condições para realizar atendimentos de urgência
0,567
0,804
39 A UBS não oferece às equipes de saúde da família as condições para apoiar a realização de
visitas domiciliares
0,581
0,791
41 Não há retaguarda de serviço de remoção, na UBS
0,479
0,766
37 Há dificuldades no sistema de referência e contrarreferência para a realização de exames
complementares
0,555
0,700
38 Há dificuldades quanto ao retorno e à confiabilidade dos resultados dos exames laboratoriais
0,566
0,680
33 Há um excesso de famílias adscritas para cada equipe da ESF
0,557
0,671
Fator 2. Longitudinalidade (α=0,70)
8 Os profissionais sentem-se impotentes para convencer o usuário a dar continuidade ao
tratamento
0,454
0,755
17 Usuários se recusam a seguir indicações médicas ou a fazer exames
0,466
0,683
25 É difícil definir, na prática, o papel e as responsabilidades de cada profissional da ESF
0,538
0,626
5 Os profissionais prescrevem medicamentos que o usuário não terá dinheiro para comprar
0,468
0,563
0,382
Fator 3. Participação dos autores Prática das equipes (α=0,76)
23 Existe falta de respeito entre os membros da equipe da ESF
0,390
0,768
22 As equipes de saúde da família não colaboram umas com as outras
0,563
0,324
0,678
24 Os profissionais da equipe não apresentam perfil para trabalhar na ESF
0,632
0,349
0,626
21 Os profissionais das equipes de ESF atuam com falta de compromisso e envolvimento
0,394
0,539
Fator 4. Perfil profissional (α=0,72)
4 Os profissionais fazem prescrições inadequadas ou erradas
0,366
0,778
2 A equipe da ESF prejulga os usuários e familiares com base em preconceitos e estigmas
0,214
0,694
3 O profissional trata o usuário com falta de respeito
0,281
0,412
0,668
Fator 5. Privacidade (α=0,70)
12 O ACS conta a seus vizinhos informações obtidas no seu trabalho a respeito de usuários e
famílias
0,415
0,826
10 O ACS comenta informações sobre a intimidade da família e do casal com a equipe de saúde
0,307
0,324
0,764
13 O profissional conta informações sobre a saúde de um dos membros da família que ele atende
para os demais membros dessa família
0,370
0,593
Fator 6. Sigilo (α=0,64)
27 Usuários pedem a um dos membros da equipe de saúde da família que os outros membros
não tenham acesso a alguma informação relacionada à sua saúde
0,333
0,834
30 Usuários pedem a um dos membros da equipe de saúde da família que os outros membros
não tenham acesso a alguma informação relacionada à sua saúde, mesmo em situação em que
seja necessária a participação da família no cuidado
0,404
0,601
20 O profissional conta informações sobre a saúde de um dos membros da família que ele atende
para os demais membros dessa família, quando este não consegue gerenciar o autocuidado e
se expõe a riscos
0,434
0,322
0,581
16 Menores de idade procuram a UBS e pedem à equipe exames, medicamentos ou outros
procedimentos sem autorização e/ou conhecimento dos pais
0,374
0,354
0,319
0,528
Alpha
0,85
0,70
0,76
0,72
0,70
0,64
% variância
16,02
9,75
9,72
9,03
8,67
8,20
% cumulativa
16,02
25,77
35,50
44,54
53,21
61,42 Artigos de pesquisa Artigos de pesquisa http://dx.doi.org/10.1590/1983-80422014222012 http://dx.doi.org/10.1590/1983-80422014222012 Rev. bioét. (Impr.). 2014; 22 (2): 309-17 317
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W4361869521.txt
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https://aacr.figshare.com/ndownloader/files/39819312
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en
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Supplementary Methods and Materials, Figures 1-6 from Use of a Cryptic Splice Site for the Expression of Huntingtin Interacting Protein 1 in Select Normal and Neoplastic Tissues
| null | 2,023
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cc-by
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Supplemental Materials and Methods
Survival analysis in TRAMP mice. The Hip1null/null and Hip1Δ3-5/Δ3-5 mice were
maintained on a mixed C57BL/6;129svJ background, and the TRAMP mice were
maintained on a pure C57BL/6 background. Intercross matings of TRAMP and
Hip1null/null and Hip1Δ3-5/Δ3-5 mice were performed as previously described (1). Fourteen
TRAMP;Hip1Δ3-5/Δ3-5, 13 TRAMP;Hip1+/Δ3-5, 18 TRAMP;Hip1+/null, and 15
TRAMP/Hip1null/null littermates were analyzed for tumors at 6.5 months. Prior to these
necropsies, a group of mice from these cohorts either unexpectedly died or became
moribund and required euthanasia. This survival data for each of these observation
groups was compared.
RNA isolation and northern blot. Total RNA was isolated from cultured tumor cells,
tissues, and early passage mouse embryonic fibroblast (MEF) extracts using the TRIzol
reagent (Invitrogen). Poly (A) RNA was isolated from total RNA using the Poly(A)
Purist MAG protocol (Ambion). Then, 5ug of this poly(A) RNA was separated on a 1%
agarose gel with 6% formaldehyde, stained with ethidium bromide, transferred to Nytran
membrane (Schleicher & Schuell), and cross-linked. The membrane was prehybridized
in a buffer containing 5X SSC, 5X Denhardt solution, 1% sodium dodecyl sulfate (SDS)
(wt/vol), and 100 μg of denatured salmon sperm DNA/ml for 3 h at 65°C. For the mouse
Hip1 Northern probe, an 850-bp EcoR1 and Not1 digested fragment encoded by mHip1
exons 10-14 was used. The probe was 32P labeled using a random-primed labeling kit
according to manufacturer’s directions (Roche). The blot was hybridized overnight at
65°C, washed twice in 2X SSC for 20 min, once in 1X SSC for 10 min, and twice in 0.1X
SSC for 10 min. The blot was exposed for 4 to 5 days on Kodak Biomax film. The
mRNA abundance was normalized with the signal for glyceraldehydes-3-phosphate
dehydrogenase (GAPDH).
Tissue preparation and western blot analysis. Tissue harvesting, preparation, and
immunoblotting of tissues was performed as previously described (2). A polyclonal antiHIP1 (1:5,000, UM354) antibody was used to detect HIP1 expression in MMTV-myc,
TRAMP and Mx1-Cre mice, and polyclonal anti-actin (1:1000, Sigma) antibody was used
as a control.
Co-immunoprecipitation of HIP1 and EGFR and endocytic factors. Full-length and
mutant EGFR and HIP1 cDNA constructs in pcDNA3 have previously been described
(3). A 15-cm dish of 70% confluent 293T cells was transfected with 20 μg of HIP1
cDNA and 20 μg of EGFR cDNA using Superfect reagent (Qiagen). Twenty-four hours
post-transfection, the cells were lysed using an all-purpose lysis buffer [50 mmol/L Tris
(pH7.4), 150 mmol/L NaCl, 1% Triton X-100, 1.5 mmol/L MgCl2, 5 mmol/LEGTA,
10% glycerol, Complete EDTA-free protease inhibitor tablets (Roche), 30 mmol/L
sodium pyrophosphate, 50 mmol/L sodium fluoride, and 100μmol/L sodium
orthovanadate]. Five milligrams of protein were incubated with pre-immune serum,
polyclonal anti-HIP1 serum (UM323), or sheep polyclonal anti-EGFR (Upstate). One
hundred microliters of a 3:1 slurry of protein G-sepharose beads (GE Healthcare) in lysis
buffer were then incubated with the lysate-antibody mixture at 4ºC for 60 min with
rotation. The protein G pellets were washed four times with 1 mL of lysis buffer. The
entire pellet was dissolved in SDS sample buffer, boiled for 5 min, separated on 7% SDSPAGE, and transferred to nitrocellulose membranes. Antibodies used for western blot
analysis were the anti-HIP1/4B10 antibody (mouse monoclonal, human anti-HIP1
immunoglobulin G1, 400 ng/mL), anti-adaptin-α antibody (rabbit polyclonal, BD
Biosciences), anti-clathrin heavy chain TD-1 antibody (kind gift of Linton Traub,
University of Pittsburgh), and an anti-EGFR antibody (sheep polyclonal antibody,
Upstate Biotechnology, Charlottesville, VA).
percent tumor-free
100%
Myc+;Hip1 null/null (N=6)
Myc+;Hip1 +/null (N=16)
80%
Myc+;Hip1 Δ3-5/d3-5 (N=17)
60%
Myc+;Hip1 +/Δ3-5 (N=38)
40%
20%
0%
20
30
40
50
weeks of age
Supplemental Figure 1. Tumorigenesis in MMTV-myc mice in the absence
of HIP1. Percent tumor-free survival out to 50 weeks of age is shown for MMTVMyc+ mice on various HIP1 knockout backgrounds. Mice were sacrificed when
the tumor ulcerated or impeded movement.
TRAMP
0.80
MMTV-Myc mice
6/11
19/37
3/4
0.60
0.40
nu
ll
nu
ll /
nu
ll
H
ip
1+
/
nu
l l/
nu
ll
0.20
Supplemental Figure 2. Tumor incidence in mice with Hip1D3-5 and Hip1Null
alleles. MMTV-myc transgenic and TRAMP mice were mated with mated on to
HIP1null/null and HIP1Δ3-5/Δ3-5 backgrounds and analyzed for tumor incidence.
TRAMP mice that survived to 6 months of age were scored for gross prostate
tumors. In each case the mice with the D3-5 allele were afflicted with more
tumors.
A.
A.
Survival curve TRAMP/dKIHIP1 &
TRAMP/d3-5
Percent of Mice (%)
100
80
+ null (n=18)
60
null null (n=15)
40
+/Δ3-5 (n=13)
Δ3-5/Δ3-5 (n=14)
20
0
1
2
3
4
6
7
Months
B.
bladder
Seminal
vesicle
Supplemental Figure 3. A. Survival curve of TRAMP mice in different Hip1
mutant backgrounds. B. Example of bilateral synchronous prostate tumors.
Arrows indicate tumors arising from distinct lobes of the prostate (not visible).
Mouse Hip1 cDNA
exon2/exon3 junction
exon 2
exon 2
Hip1Δ3-5 cDNA
exon 3
···························· CGTGTATTCTGGGCACCCACCATGAGAAAGGAGCGCAGACC
exon 6
GTGGCCGTGAAAGAGAAACATGCCAGGA ag AATCCCAGGTTCCCGGGCAACCTCCAGATGAGTGACCGA
exon 5
exon 6
Mouse Hip1 cDNA
exon5/exon6 junction
CTGAGAACAAGGATGGAGTACCACACCAAA
·······································
Supplemental Figure 4. Partial Hip1Δ3-5 cDNA sequence alignment with wild
type mouse Hip1 cDNA. Shown is an alignment of cDNA sequence from the
nested PCR reaction with the exon 2/3 and exon 5/6 junctions of mouse Hip1
mRNA reference sequence (NM_146001). Dots in the moue Hip1 mRNA
reference sequence denote identity with the Hip1 D3-5 cDNA sequence. Codons
are represented by alternating bold/nonbold trinucleotide sequences. Note the
AG dinucleotide insertion between exons 2 and 6 of the Hip1D3-5 cDNA
sequence, which maintains the open reading frame of the transcript.
e17.0 MEFs
+/+
+/ Δ3-5
Δ3-5/ Δ3-5
+/+
e17.0 brain
+/ Δ3-5
Δ3-5/ Δ3-5
120kD
Lane
1
2
3
4
5
6
7
8
9
10
11
12
Supplemental Figure 5. HIP1Δ3-5/insAG 106 kDa protein is present in mouse
embryonic brain and fibroblasts. Western blot analysis for HIP1 expression in the
brains (left panel) and fibroblasts (right panel) of 17-day old mouse embryos of
different genotypes demonstrated the presence of a slightly truncated HIP1
product. MEF cells of different genotypes were cultured from eleven individual
embryos from the same mother. Only 5 samples are shown here but all
demonstrated similar banding patterns as related to the distinct genotypes.
LPA
S1P
LPC
PI(3,4)P2
PI
PI(3,5)P2
PI(3)P
PI(4,5)P2
PI(4)P
PI(3,4,5)P3
PI(5)P
PA
PE
PS
PC
Blank
GST-HIP1/WT
GST-HIP1/Δ3-5
Supplemental Figure 6. Comparison of lipid binding specificity and relative
affinity GST-5’HIP1/Δ3-5 and GST-5’HIP1 using PIP strips. Protein solutions
containing 10µg of either purified GST-5’HIP1 or GST-5’HIP1/Δ3-5 protein in
TBST with 1% milk were incubated with PIP strips (Echelon) containing 15
different lipids at 100 pmol/spot. Lipid-protein interactions were detected using a
polyclonal antibody (UM354) that recognizes both GST-5’HIP1 and GST5’HIP1/Δ3-5 proteins. Both proteins bound preferentially to PI(3)P on the PIP
strips.
Supplemental Data References
1.
Bradley SV, Oravecz-Wilson KI, Bougeard G, et al. Serum antibodies to
huntingtin interacting protein-1: a new blood test for prostate cancer. Cancer Res
2005;65(10):4126-33.
2.
Hyun TS, Li L, Oravecz-Wilson KI, et al. Hip1-related mutant mice grow and
develop normally but have accelerated spinal abnormalities and dwarfism in the absence
of HIP1. Mol Cell Biol 2004;24(10):4329-40.
3.
Bradley SV, Holland EC, Liu GY, Thomas D, Hyun TS, Ross TS. Huntingtin
interacting protein 1 is a novel brain tumor marker that associates with epidermal growth
factor receptor. Cancer Res 2007;67(8):3609-15.
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English
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A systematic digital approach to implementation and dissemination of eating disorders interventions to large populations identified through online screening: implications for post-traumatic stress
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mHealth
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public-domain
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A systematic digital approach to implementation and
A systematic digital approach to implementation and
dissemination of eating disorders interventions to large
dissemination of eating disorders interventions to large
populations identified through online screening: Implications for
populations identified through online screening: Implications for
post-traumatic stress
post-traumatic stress C. Barr Taylor
Palo Alto Univesity
Josef I. Ruzek
Stanford University
Ellen E. Fitzsimmons-Craft
Washington University School of Medicine in St. Louis
Andrea K. Graham
Northwestern University
Katherine N. Balantekin
State University of New York at Buffalo Follow this and additional works at: https://digitalcommons.wustl.edu/open_access_pubs
Please let us know how this document benefits you. A systematic digital approach to implementation and
dissemination of eating disorders interventions to large
populations identified through online screening: implications for
post-traumatic stress C. Barr Taylor
1,2, Josef I. Ruzek
1,2,3, Ellen E. Fitzsimmons-Craft
4, Andrea K. G
Balantekin
6 I. Ruzek
1,2,3, Ellen E. Fitzsimmons-Craft
4, Andrea K. Graham
5, Katherine N. C. Barr Taylor
1,2, Josef I. Ruzek
1,2,3, Ellen E. Fitzsimmons-Craft
4, Andrea K. Graham
5, Katherine N. Balantekin
6 1Center for m
2 Health, Palo Alto University, Palo Alto, CA, USA;
2Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto,
CA, USA;
3National Center for PTSD, Dissemination and Training Division, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Menlo
Park, USA;
4Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA;
5Department of Medical Social Sciences,
Northwestern University, IL, USA;
6Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
Contributions: (I) Conception and design: All authors; (II) Administrative support: None; (III) Provision of study materials or patients: EE
Fitzsimmons-Craft KN Balantekin; (IV) Collection and assembly of data: None; (V) Data analysis and interpretation: None; (VI) Manuscript 1Center for m
2 Health, Palo Alto University, Palo Alto, CA, USA;
2Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto,
CA, USA;
3National Center for PTSD, Dissemination and Training Division, Veterans Affairs Palo Alto Health Care System (VAPAHCS), Menlo
Park, USA;
4Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA;
5Department of Medical Social Sciences,
Northwestern University, IL, USA;
6Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA Contributions: (I) Conception and design: All authors; (II) Administrative support: None; (III) Provision of study materials or patients: EE
Fitzsimmons-Craft, KN Balantekin; (IV) Collection and assembly of data: None; (V) Data analysis and interpretation: None; (VI) Manuscript
writing: All Authors; (VII) Final approval of manuscript: All authors. Correspondence to: Dr. C. Barr Taylor, MD. Center for m
2 Health, Palo Alto University, 1791 Arastradero Rd, Palo Alto, CA 94304, USA. Email: btaylor@stanford.edu. Background: We describe an approach to implementation and dissemination that focuses on changing
outcomes variables within a large, defined population and attempts to provide cost-effective opportunities
and resources—which might include the provision of both digital and traditional interventions—to address
individual needs and interests. We present a case example of how aspects of this model are being applied to
increase reach, engagement and outcomes for individuals who complete a national eating disorders screen,
and are likely to have an eating disorder but who are not in treatment. Recommended Citation
Recommended Citation Taylor, C. Barr; Ruzek, Josef I.; Fitzsimmons-Craft, Ellen E.; Graham, Andrea K.; and Balantekin, Katherine
N., "A systematic digital approach to implementation and dissemination of eating disorders interventions
to large populations identified through online screening: Implications for post-traumatic stress." Mhealth. 4, 25 (2018). https://digitalcommons.wustl.edu/open_access_pubs/9907 This Open Access Publication is brought to you for free and open access by Digital Commons@Becker. It has been
accepted for inclusion in Open Access Publications by an authorized administrator of Digital Commons@Becker. For more information, please contact vanam@wustl.edu. Original Article Page 1 of 13 © mHealth. All rights reserved. Introduction As will be described in this paper, the “systematic
approach” refers to frequent review of the success of the
program in achieving the desired aims and iterating new
strategies, as needed, to improve outcomes. We assume that
population monitoring and many interventions provided
to individuals will be digital, although not exclusively so. We focus on a defined eating disorder population identified
through online screening. Many individuals with post-
traumatic stress (PTS) are likewise identified through
screening. In the following we: (I) discuss how aspects of
this model have been applied to one defined population—
individuals with eating disorders identified by a nationally
disseminated screen, (II) explain how the model could
be applied to PTS populations, and (III) conclude with a
discussion of strengths and limitations of the model. In this paper, we describe an approach to implementation
and dissemination that focuses on changing outcomes
variables within a large, defined population and attempts to
provide cost-effective opportunities and resources—which
might include the provision of both digital and traditional
interventions—to address individual needs and interests. In this model, teams within organizations invested in
improving outcomes use moderator, process, and outcome
data to improve quality of care. The model differs from
traditional implementation and dissemination models in
focusing on a range of potential options and changes for the
whole defined population, rather than ensuring that a single
effective intervention for a given subset of the population
is provided consistent with best practices, and in using
intervention outcomes and monitoring teams tasked with
helping to ensure the best outcomes for the population. Such teams are now commonplace in most commercial
enterprises to increase customer satisfaction and sales. The approach is designed to be dynamic and iterative in
the sense that the prevention and intervention system
and opportunities are continuously revised to increase
reach, engagement, effectiveness, and personalization of
interventions. Such models also lend themselves to modern
analytic and intervention design methods. We refer to this
as a systematic digital approach to defined population-based
interventions. A systematic digital approach to implementation and
dissemination of eating disorders interventions to large
populations identified through online screening: implications for
post-traumatic stress We then describe how this model can
apply to post-traumatic stress (PTS) and conclude with a discussion of limitations and issues with the model. Methods: The National Eating Disorders Association (NEDA) provides online screening for eating
disorders. Results: From February 2017 through March 2018, over 200,000 individuals completed the NEDA screen. Of these, 96% screened positive or at risk for an eating disorder, and most of those who screened positive for
a clinical/subclinical eating disorder were not currently in treatment. Less than 10% engaged in self-help or
guided self-help online digital program, or expressed interest in calling a helpline for referral to treatment. Results: From February 2017 through March 2018, over 200,000 individuals completed the NEDA screen. Of these, 96% screened positive or at risk for an eating disorder, and most of those who screened positive for
a clinical/subclinical eating disorder were not currently in treatment. Less than 10% engaged in self-help or
guided self-help online digital program, or expressed interest in calling a helpline for referral to treatment. Conclusions: A systematic digital approach to implementation and dissemination has the potential to
increase the number of individuals who benefit from interventions in defined populations. Uptake rates need Conclusions: A systematic digital approach to implementation and dissemination has the potential to
increase the number of individuals who benefit from interventions in defined populations. Uptake rates need
to be improved. Keywords: Implementation; dissemination; digital mental health; eating disorders; post-traumatic stress (PTS);
post-traumatic stress disorder (PTSD) Received: 09 March 2018; Accepted: 29 May 2018; Published: 10 July 2018. doi: 10.21037/mhealth.2018.05.06
View this article at: http://dx.doi.org/10.21037/mhealth.2018.05.06 Received: 09 March 2018; Accepted: 29 May 2018; Published: 10 July 2018. doi: 10.21037/mhealth.2018.05.06
View this article at: http://dx.doi.org/10.21037/mhealth.2018.05.06 mHealth 2018;4:25 © mHealth. All rights reserved. mhealth.amegroups.com mHealth, 2018 Page 2 of 13 enrolled groups. Case example: providing better access to effective
treatments for eating disorders identified through a
national screen Eating disorders are common and disabling problems,
negatively impacting quality of life. Eating disorders
affect an estimated 3.5–6.5% and 3–3.5% of women and
men, respectively, in the Western world (1,2). Eating
disorders are associated with high medical and psychiatric
comorbidity and increased mortality with anorexia nervosa
having the highest mortality rate of all mental disorders (3). Like post-traumatic stress disorder (PTSD), eating
disorders are comorbid with several other problems, and
follow a chronic course. Furthermore, risk factors for eating
disorders have been identified and shown to be modifiable,
with reduction in risk factors associated with reduced eating
disorder onset (4,5). Also, like PTSD, effective treatments
are available but reach only a small percentage of the
affected population. Indeed, less than 20% of individuals
with eating disorders report receiving treatment (6). As
such, systematic approaches to preventing and treating
eating disorders have relevance to those experiencing PTS
symptoms and preventing and treating PTSD. © mHealth. All rights reserved. mhealth.amegroups.com mHealth 2018;4:25 A systematic digital approach to defined population-based
interventions A ‘defined population’ refers to any population with shared
characteristics, such as gender, disease, geography, or
combinations of such factors. In public health, “defined
populations” have outcome targets, such as increasing
the number of individuals who are vaccinated, who have
reduced cardiovascular risk factors, or who no longer meet
criteria for being a “case” and/or a combination of these. A defined population model does not mean that all
individuals within the population are provided the same
intervention. In fact, it is assumed that there will be multiple
pathways for different individuals and subpopulations,
depending on their level of need and interest. ‘Defined
population’ targets are particularly useful when they map
onto organizations or systems responsible for, or invested
in, achieving the desired outcomes, such as a public health
department or programs that cover medical coverage for Over the past 10 years, we have been involved in a
number of studies to integrate preventive and treatment
approaches to populations with high rates of eating
disorders (7). The following section describes a case
example of applying a digitally-based systematic approach
to disseminating and implementing interventions for eating
disorders identified through screening. The approach is
digital in the sense that the screening and feedback are mhealth.amegroups.com mHealth 2018;4:25 mHealth, 2018 Page 3 of 13 Screen
Low risk for eating
disorders:
screen negative for eating
disorders or elevated risk
status
Offered online, universal
health education
intervention
High risk for eating
disorders:
screen negative for ED;
screen positive for elevated
risk (e.g., weight/shape
concerns)
Offered online,
targeted ED prevention
intervention
Clinical/subclinical eating
disorder other than
Anorexia Nervosa (AN):
screen negative for AN;
screen positive for any
other ED
Not in treatment but
interested in treatment*:
referral,
alerted to self-help, online
treatment options
Anorexia Nervosa:
screen positive for AN
Referral for clinical
evaluation and treatment
Figure 1 NEDA Screen algorithm and general referral issues. *, population of interest. NEDA, National Eating Disorders Association. Figure 1 NEDA Screen algorithm and general referral issues. *, population of interest. NEDA, National E hm and general referral issues. *, population of interest. NEDA, National Eating Disorders Association. individuals can click on a link without beginning it, we
define uptake as using >1 session. In this model, targets are
established for each phase of identification and screening. A systematic digital approach to defined population-based
interventions The targets are arbitrary and should change as the
population recruited changes, rates of uptake, engagement
and outcome are determined and new interventions/
opportunities added. In theory, everyone who screens
positive for an eating disorder and is interested in treatment
should begin an intervention. In reality, the available
treatment options, cost and other factors make it unlikely
that most would do so. In a recent study, about 50% of
students who screened positive for an eating disorder
clicked on an on-line program (the only option available) (9). Engagement can be defined in various ways, but the most
common one, and one we use, is the number of sessions
completed. However, as discussed below, early engagement
is probably more important than later engagement, and
our primary metric is the number of individuals who begin
a program (>1 session) and go on to complete 50% of
sessions. This is also arbitrary, but for an on-line program, it
indicates that students have at least opened the program and
moved to the second session. A UK study found that about
50% of individuals referred to face-to-face treatment never
initiate treatment (11) so that 50% reach/engaged would
seem to be a reasonable target rate for both online and
face-to-face interventions. The outcomes we focus on are
a significant reduction of symptoms (>50% reduction from
baseline) and/or no longer meet case criteria. These criteria provided in a digital format and data monitoring is digital
as are many of the interventions. This approach builds on a
program of research in which we have helped identify risk
factors for eating disorders (8), developed and examined
interventions to reduce eating disorders, and shown that
reduction in eating disorder risk reduces disease onset (4,5). We have also developed an evidence-based screen that can
sort users into categories of no risk, low risk, or high risk
for an eating disorder, or eating disorder diagnosis groups
[i.e., the Stanford-Washington University Eating Disorders
Screen (SWED)] (9). These groups can then be linked to
relevant interventions for an estimated cost-benefit analysis
of this model (10). Our general model for screening and
delivering interventions can be seen in Figure 1. One
advantage of a population-based approach is that both
populations at risk for, or with clinical symptoms, can be
identified simultaneously and prevention and intervention
programs can be provided as appropriate (7). However, in
this paper we only focused on those with clinical symptoms. © mHealth. All rights reserved. mHealth 2018;4:25 Page 4 of 13 Table 1 Potential interventions for the defined population
Intervention
Provider
Access
Effects
Cost to user
Digital component
Issues
Self-help
Commercial,
bibliotherapy, various
High
Low
Low
App
Unknown impact on
subsequent use
Guided self-help
Commercial
High
Medium
Low- moderate
App
Few individuals want to
pay for on-line programs
Teletherapy or
blended
Individuals
Low
High
Low (if insured);
high if not
Teletherapy online
program; app; text; Email
Practice issues; access;
training
Face-to-face,
including group
Individuals
Low
High
Low (if insured);
high if not
None
Access; training Table 1 Potential interventions for the defined population Table 1 lists potential interventions offered for individuals
within the defined population. As noted by Munoz (13),
interventions can be characterized as (I) self-help (digital/
bibliotherapy), (II) coached/guided, (III) teletherapy, (IV)
blended therapy (digital/text/e-mail and face-to-face) and V)
pure face-to-face (Table 1). are based, in part, of those developed for the VA training
program in evidence-based interventions for depression (12)
and the effect sizes of the online and face-to-face
interventions. Our long-term goal is a significant reduction
in the prevalence of eating disorders in this population that
would occur through a combination of prevention (not
discussed in this paper) and intervention (10). One of the
advantages of the model is that it identifies upstream issues
(non-acceptance of referrals, for instance, or not showing
up) that need to be addressed to provide a significant benefit
for the defined population of interest. Screening In this model, individuals with a potential eating disorder
are identified with an evidence-based screen, the SWED
(Stanford Washington University Eating Disorder Screen). The screen has been shown to have acceptable sensitivity
and specificity (9). Starting in 2016, our research teams
based at Stanford University, Palo Alto University, and
Washington University in St. Louis partnered with the
National Eating Disorders Association (NEDA) to make
the SWED screen freely available on their websites in
2017. Individuals are made aware of the screen via NEDA
through a variety of social media sites and activities and
a weeklong campaign (NEDA awareness week) many US
colleges and universities. The screen partitions individuals
into no or low risk, high risk of ED onset, or possible ED
as per Wilfley et al. (7). (The actual screen can be found at:
www.nationaleatingdisorders.org.) © mHealth. All rights reserved. Self-help Pure self-help programs have the advantage of being
inexpensive and readily available as books and online but
are associated with high dropout rates and low to moderate
effect sizes (14). Little is known about how one might best
benefit from a self-help program, if there are downsides, and
the possible consequences of failure to improve following
self-help and effects on subsequent uptake of more intensive
forms of assistance (face-to-face therapy). For instance,
individuals who fail to improve with self-help may be
reluctant to proceed with more intensive approaches and/or
feel like ‘treatment failures’. Likewise, little is known about
moderators and mediators that predict better outcomes. Such issues illustrate the potential benefit of a systems model
of defined population-level interventions. Moderator and
mediator analyses tied to engagement and dropout levels of
individuals choosing self-help could be used to identify those
who might most benefit from this type of intervention and
suggest subpopulations where further trialing could help
improve outcomes. The work is ongoing and we discuss how we have been
trying to address providing evidence-based treatment to the
individuals identified through a national screening effort. A systematic digital approach to defined population-based
interventions For the purposes of the following discussion, the defined
population represents all individuals who completed a
national screen who are found to screen positive for an
eating disorder but are not currently in treatment (see
asterisk for in Figure 1). Defined population reach is the
number of these individuals who complete the screen
and begin a program of their choosing (i.e., uptake into
an intervention). For purpose of clarity, we will use the
term ‘reach/uptake’ rather than merely reach and, since mhealth.amegroups.com mhealth.amegroups.com mHealth 2018;4:25 mHealth, 2018 Page 4 of 13 mHealth 2018;4:25 Teletherapy Teletherapy, as used here, is the provision of psychological
services via digital means, including the telephone, text
messaging, video or combinations therefore. To reach our
widespread population, teletherapy would seem to be a
reasonable approach. Teletherapy is often limited by practice
guidelines (e.g., therapists restricted from practicing across
state lines). In the VA, teletherapy has demonstrated initial
efficacy and feasibility (17). In theory, users interested
in teletherapy could be given names of providers vetted
through some type of quality assurance/best practice model. Teletherapy might be particularly useful when some type
of specialized intervention is necessary, such as expertise
in dealing with issues relevant to a subgroup, language,
disability or diagnosis. © mHealth. All rights reserved. Discussion The first year of our joint efforts working with NEDA
suggest that efforts to reach a large number of individuals
with eating disorders who are not currently in treatment
has been very successful. However, the preliminary data
also suggest that few individuals who might benefit from
treatment engage in even minimal interventions, such as
clicking to learn more about a self-help program [although
because of the large reach, large numbers of individuals
(i.e., over 10,000) have done so]. In the next phase of our
partnership, we are considering evaluating ways to increase
reach as seen in line two of Table 2. This is not an exhaustive
list. Other analyses will compare (e.g., using ROC analyses)
those who choose the various options based on baseline
demographics, diagnoses, geographic region, and other
variables to help us gain a better understanding of what
alterations need to be considered that might improve
engagement. Of particular importance, the program does
not provide post recommendation motivational interviewing,
program selling (e.g., testimonials, promotions), or other
interventions that might increase uptake. A broader range
of interventions also needs to be considered. If even the low
cost of the Lantern program proves to be an obstacle, would
free, semi-automated programs increase uptake? While such
programs may have smaller effect sizes than guided self-
help programs guided by a human coach, if more individuals
use them, they may have great value when considering
their effects on a population. Since thousands of screens are
completed each month, it will be possible to conduct a series
of mini-experiments to examine options that might increase
uptake such as using machine learning to determine how the
helpline can be more effective in motivating individuals to
seek online therapy who have access and resources to do so. Other options included blended therapy, face-to-face
therapy and stepped care models. Of the options, NEDA currently offers the following
for individuals who screen positive for a possible eating
disorder: (I) self-help via Recovery Record (18), (II)
commercially available guided self-help (www.golantern. com), (III) access via a helpline to a treatment provider
database to find a referral to a therapist trained in evidence
based practice, and/or (IV) access to a chatline. Respondents
are also encouraged to review the information and resources
provided on the NEDA website. Guided online interventions Guided online self-help interventions are associated with
success rates that are higher than unguided programs and
comparable to face-to-face interventions for many mental
health disorders (15) including eating disorders (16). Guided mhealth.amegroups.com mHealth 2018;4:25 Page 5 of 13 mHealth, 2018 online self-help programs for eating disorders are available
through commercial companies at a cost of about $50/month
per user. proportion of those who clicked on one of the options who
actually meaningfully engaged with the option (e.g., self-help
or guided self-help program) or who engaged in in-person
treatment as a result of accessing the helpline or chatline. From other sources we can estimate, that for all interventions
the numbers would all be below 50%. mHealth 2018;4:25 mhealth.amegroups.com Results Unfortunately, data are not yet available on the mhealth.amegroups.com mhealth.amegroups.com mHealth 2018;4:25 mHealth, 2018 Page 6 of 13 Page 6 of 13 Table 2 Key variables for a systematic approach to implementation and dissemination
Component
Example of methods
Reach (those who might have an eating
disorder)
Social media
Health care providers
Local community/site activities led by volunteers
Reach & uptake
Improve readability/language of screen and feedback to make it very user friendly
Provide motivational interviewing
Introduce testimonials
Increase access to screen, including to underrepresented groups
Expand treatment choices available to the
population
Increase self-help options
Link to practitioners of teletherapy (increase access to evidence-based practice)
Add Spanish language versions
Add male version
Add version to address overweight or obesity, for a subset for whom weight loss is
appropriate
Improve engagement (for those using
online programs)
Use A/B and other digital design methods to evaluate program feature options
Monitor user satisfaction with components
Develop programs appealing to subpopulations
Personalize
Expand training to providers
Provide training in blended therapy
Provide training in evidence-based practice
Reduce cost
Automate interventions
Provide self-help
Make interventions more effective
Make training in evidence-based practice available online
Increase efficacy
Match user to most effective program
Add programs shown to be effective to treatment options menu Table 2 Key variables for a systematic approach to implementation and dissemination Of note, the system we propose should continuously try to
improve reach/engagement and outcomes towards the targets
of the organization with cost-effectiveness. self-help programs have been found to have low to medium
effect sizes, guided self-help programs moderate to large
effect sizes. However, it is important to determine if these
effects are maintained when programs are offered to larger
populations and NEDA is now collecting program use data
from their two main digital referral resources (i.e., Recovery
Record, GoLantern). It will also be important to consider
other options, such as incorporating face-to-face groups alone
or in combination with consumer-led and/or moderated on-
line groups. On-going data monitoring should also help us
to determine the relative cost/benefit and even harm of the
different approaches and to help inform recommendations. © mHealth. All rights reserved. Results From about February 2017 to April 2018, the screen has
been completed by over 200,000 individuals. The majority
of those completing the screen were classified as being
at high risk for eating disorders (ED) onset or having a
clinical/subclinical eating disorder (96%). Further, the
majority (86%) of individuals screening positive for a
clinical/subclinical eating disorder were not currently in
treatment. Screens were completed from individuals in
most counties of the US and in many places unlikely to have
practitioners with training in eating disorder treatment. In parallel studies we have been examining ways to
improve engagement in individuals using the new online
program. Followed a series of changes based on user
feedback and analyses we increased early engagement
from 69.5% (n=105/151) to 78.7% (n=70/89). As with
engagement, outcome data can be examined in more
conventional trials. For eating disorders, as discussed above, Uptake has varied relative to the population screen and
the options available, but overall, less than 10% of individuals
clicked on one of the options. Of these about 2/3s clicked on
the self-help option and about 12% on the guided self-help
program. Support accessible database and the partners have expertise in big
data analysis and intervention design. The biggest weakness
is that the project’s success depends on the goodwill and
working relationships of the partners since it is minimally
funded. Furthermore, users need to volunteer to share their
data. The model uses baseline, process and outcome data to
improve reach, engagement and outcome. While data on
users’ intentions to act on referrals is collected, except for
the small subsample willing to provide contact information
for follow-up, we can only estimate from other programs
we provide if respondents began the program, how much of
it they used and what the outcomes were. Another option
is to partner with companies that select therapists based
on their evidence-based training and requires therapists in
the network to provide periodic progress data on clients. Another limitation of the defined population model is
having a group or organization with adequate resources
committed to achieving the population level outcomes. For lack of a better term, we call this the “Outcomes
Optimization Team”—those who manage the components
of the digital interventions to achieve better outcomes
in this population. In our case, it is comprised of the
participating teams from Washington University, Palo Alto
University, University of Buffalo and NEDA in association
with their partners who provide specific expertise. For PTS,
it could be national organizations, including health care
systems or emergency response agencies. to a broader approach that combines universal, targeted/
selected prevention and intervention, as illustrated in
Figure 1. A strategy that combines both prevention
and intervention is most likely to achieve reduction of
prevalence of a disorder in a population, which is the most
difficult, but perhaps the most important outcome for
a population (10). Social media could also be leveraged
effectively in this model for such things as increasing the
reach of the screen, providing education around relative
issues, encouraging activism around important issues, and
creating supportive networks. Application to PTS The population-based strategy described above for
treating eating disorders could be applied to assisting those
experiencing problems related to trauma exposure and PTS. An advantage of the strategy is its operational definition of
the population in terms of individuals who have completed a
screening process, and this same approach might usefully be
extended to PTS initiatives. Many existing traumatic stress
response systems invoke implicit systems models applied to
populations. The Veterans Health Administration (VHA)
focuses much of its mental health resources on Veterans
exposed to combat and other war-related stressors, and
brief screening for PTSD is a standard practice in primary
care settings and elsewhere in VA and the Department of
Defense. Disaster mental health responses typically focus on
large groups of survivors of a specific traumatic event (e.g.,
9/11 attacks, Hurricane Katrina), and screening processes
taking place online or in crisis counseling settings could be
used to identify populations of interest. Below, we discuss © mHealth. All rights reserved. Critical components to the model To the extent this systematic defined population model
proves viable, it is worth considering the components of
the delivery system that might have led to our success thus
far (Table 3). First, the partnering team is diverse and has
expertise in areas critical to the design and refinement of
interventions. Second, the model is supported by a large, mHealth 2018;4:25 mHealth 2018;4:25 mhealth.amegroups.com Page 7 of 13 mHealth, 2018 Table 3 Critical components of a systematic digital approach to implementation and dissemination
Component
Characteristics
Defined population
Individuals who share common characteristics
Outcome managers (those responsible for looking after the
defined population)
Individual, groups, institutions responsible for monitoring achievement of
outcomes
Database
Reach, engagement, outcome monitoring
Data analytic team
Members responsible for monitoring the outcome/progress
Outcomes optimization team
Individuals responsible for providing interventions relevant to the population
and to individuals within the population
Support
Financial support, administrative leadership buy-in
Checks and balances
Consumer, affected members input, privacy
Delivery systems
Software, practitioners, coaches, etc. mHealth 2018;4:25 Systematic interventions for individuals with PTS
within a health care system In this example, the focus would be on individuals with
PTS served by a health maintenance organization (HMO),
characterized as a health system with a defined network of
providers and services. The defined population would be
identified by a trauma screen, such as the PC-PTSD (19),
made available to members of a health care system through
screening at health care appointments, provider websites,
and even notifications to members. As with the eating
disorder case example, the defined population would be
those people screening positive for PTS. Reach would be
defined as the number of eligible members who engage
in the intervention, and the outcome measures related to
effectiveness would focus on reduction in PTS symptoms 6
months post screening. For an HMO population, a team would need to be
responsible for enacting and monitoring the interventions. Data analytic, intervention(s) monitoring, outcomes,
and training teams would need to be established, and
first line interventions would need to be chosen based
on evidence, institutional resources, and other factors
(e.g., patient preferences). As with eating disorders,
stages of implementation might occur sequentially. Initial
implementation might include delivery of a specific
combination of screening, unguided self-help, guided
self-help, teletherapy/blended therapy, or face-to-face
treatment. The set of interventions considered for implementation
and study would be like those for eating disorders: self-help,
guided/coached self-help, teletherapy, blended therapy,
and face-to-face. Initial intervention selections would likely
include self-help, guided self-help, teletherapy, and face-to-
face interventions. Many websites provide trauma survivors
with information and self-care recommendations, and there
are a number of self-help manuals available. Increasingly,
phone apps and internet interventions designed for self-
management are being made available. For example, the
national center for PTS within the US Department of
Veterans Affairs has developed a range of smartphone apps
(e.g., PTSD Coach, PTSD Family Coach, PE Coach)
designed to assist Veterans (and others) with PTSD. Guided, coached interventions are also available for PTS
and have been shown to be effective (20,21). Research
supports comparability of face-to-face and teletherapy-
delivered treatments provided to PTS populations (17)
and teletherapy has been widely implemented for PTSD
in VA. By contrast, blended therapies have as yet seen little
application and their widespread implementation, at least
initially, would be challenging. Page 8 of 13 based interventions have been developed and specified in
clinical practice guidelines, they are not routinely available
and most practitioners have not been trained in these
interventions. Costs may limit their accessibility for low-
income groups. The treatments themselves often require
around 12 weeks to deliver, and may be inconvenient
or unpersuasive for some users. These treatments are
typically individualized and therefore cannot be delivered
more cost-effectively to larger groups. Many of those with
problems are unwilling to seek care due to stigma and other
factors, and once initiated, dropout rates from face-to-face
treatment are high. how a screen-based defined population approach could
be directed to individuals with PTS enrolled in a health
care system. Similar methods could be used with other
traumatized populations, such as those affected by a disaster
within a defined geographic area. © mHealth. All rights reserved. Universal, targeted/selected prevention and intervention Although we have focused on the systematic digital
approach as applied to clinical cases, the model lends itself mhealth.amegroups.com mHealth 2018;4:25 mhealth.amegroups.com mHealth, 2018 Page 8 of 13 Benefits, challenges, and key questions for a systematic
digital defined population approach The systematic digital approach has the potential benefit
of increasing the provision of accessible, affordable, and
evidence-based intervention resources to populations in
need, as is evident in our work with eating disorders and
the model of how it might be applied to a PTS population. The model takes advantage of databases and other digital
resources to continuously expand and adapt approaches based
on reach, engagement, efficacy, cost and other factors. In fact,
groups working in a variety of different settings with similar
populations might be able to share resources, observations,
ideas, and approaches to improve programs and outcomes
more quickly. There also are challenges to this approach, and
we touch on some of the major ones here. We note that reach is a major issue in any consideration
of the broad effectiveness of an intervention intended to
serve a population (25). A problem of many interventions
for trauma survivors, and especially of research studies
conducted to evaluate interventions, is that only a very few
members of the population of interest can participate in the
interventions. For example, Shalev et al. (26) contacted 4,224
individuals within 3 weeks of experiencing a traumatic event. Individuals reporting distress who could attend traditional
psychotherapy and did not have conflicting medical
conditions were invited to treatment. Of those contacted,
73% were not eligible, 18% refused to participate, and 9%
were invited to treatment. Price et al. (27) pointed out that
a strength of technology-based interventions is the greater
potential reach of services and relatively small number
of exclusion criteria for participation. In their work with
survivors of Hurricane Ike (2008) in Texas, their population
was defined as those who were eligible (e.g., had an internet
connection) and consented to the intervention (reach/
inclusion). Of 5,536 individuals who were contacted, 43%
were not eligible, 4% refused to participate, and 23% of
the total number of contacted individuals were invited to
treatment. Thus, a major advantage of defined populations
interventions that incorporate digital technologies is to
increase reach and engagement. j
A top-down approach. The model assumes that some
group of individuals is managing the population toward
the stated goals, and that the group has authority to modify
various aspects of the system as a whole. Systematic interventions for individuals with PTS
within a health care system Reach/engagement and effectiveness rates would be
monitored and improved for each intervention based
on ongoing reach, engagement and outcomes data, with
interventions modified and new treatment options and
supportive activities added as appropriate (e.g., asynchronous,
synchronous on-line groups, face-to-face groups, family
psychoeducational resources). Such monitoring data are likely
to be eye opening. For instance, in an older study of 20,284
veterans newly diagnosed with PTSD, 50% (n=10,127) were
prescribed a psychotropic medication but only 39% (n=7,980)
received some counseling. Only 24% (n=1,909) of those who
received any counseling had at least eight counseling sessions. In all, 33% (n=6,616) of those who received a diagnosis of
PTSD received a minimally adequate treatment trial in
the subsequent 6 months (22). If this population had been
enrolled in a defined population model, then the focus might
be on increasing counseling, which might have necessitated
including other approaches more amenable to the population. For instance, increasing the number of individuals receiving
any counseling might be achieved by adding teletherapy
and blended programs to make access easier for enrollees. Such findings have led to attempts to increase the reach of
evidence-based treatments in the VA (23). As with eating disorders, face-to-face treatments remain
the dominant model of service delivery for PTS, and as with
eating disorders, there are a variety of limitations of this
treatment modality at present. First, although evidence- An HMO might engage in a more ambitious program of mhealth.amegroups.com mHealth 2018;4:25 mHealth, 2018 Page 9 of 13 activities that may work synergistically to enhance
outcomes. trying to reduce PTS prevalence in the population. In this
case, preventive and educational resources would be added
to screening and other activities, as in the model shown in
Figure 1. Screening itself could focus on exposure to recent
traumatic events as well as PTS reactions. For those with
no PTS symptoms, general information about how to be
supportive of family members and other services would
be provided. For those at risk for PTS (i.e., those recently
exposed to traumatic events such as life-threatening illness,
accidents, assault, or sudden death of a loved one), PTS
prevention and brief intervention programs could be offered
in emergency rooms (24) or in primary care settings. In
theory, the effects of an integrated prevention and treatment
program on the prevalence of PTS could be monitored by
routine screening provided to the population. © mHealth. All rights reserved. mhealth.amegroups.com Benefits, challenges, and key questions for a systematic
digital defined population approach This assumes an
altruism that may not be realistic in many settings where
the goal may be to reduce, rather than increase, utilization,
and it may also assume a degree of managerial power and
decision-making ability that may not be present. In the
consumer world, where these models are widely practiced,
increased sales are desired outcomes but there is often the
assumption that this occurs through satisfied customers. The model we are proposing should have consumer and
user input built into all aspects of decision-making and
program deployment. In many mental health treatment
systems, outcomes, engagement, and other key variables are
not routinely monitored so that the impact of policy changes
on effectiveness, reach, and engagement of treatment
and prevention activities may remain unclear. Until the
potential advantages of the system can be demonstrated—
better population-wide outcomes and happier consumers—
the model is unlikely to be adopted. Expense. The defined population model assumes that
consumers would be provided resources based on interest. It is possible that the more expensive options (e.g., face-
to-face therapy) would be preferred and population-wide
screening is likely to generate large numbers of individuals
who could overwhelm the system, stressing already limited
services and increasing costs. An alternative is to use a
stepped care model in which less expensive options are For PTS, within a digital strategy within a defined
population that focuses on secondary prevention (e.g.,
education, well-being) of PTS problems for those exposed
to trauma, interventions would be appropriate along
with resources and activities to provide family support
and education and other services to the population. By
viewing the entirety of the population exposed to traumas,
it becomes possible to envision a range of services and mhealth.amegroups.com mHealth 2018;4:25 Page 10 of 13 mHealth, 2018 actions among interacting teams. Data showing a range
of outcomes associated with different screening and
intervention components must be analyzed. Teams must
use those data to make changes in various aspects of
intervention delivery. Such changes may require training of
providers as well as changes to software content. The effects
of these changes on effectiveness, reach, and engagement
must then also be assessed, and additional changes made
in an iterative process. It is evident that this process is
complex, involves significant personnel resources, and
requires leadership buy-in and support. Benefits, challenges, and key questions for a systematic
digital defined population approach It will be necessary
to assemble teams with the requisite expertise, and establish
procedures by which ongoing processes of data analysis and
intervention redesign can be accomplished in the service
of treatment improvement. The conditions necessary to
assemble and operate such teams seems most likely to be
achieved in health care systems that offer a comprehensive
set of services that includes screening and multiple mental
health treatment options. provided first (7). However, we believe there is a right to
accessible, affordable, evidence-based care and that, as
providers and researchers, we need to find ways to deliver
these interventions. Privacy. The model is based on HIPAA protected
information. Protecting participant privacy is essential, and
any member of the defined population who wishes to opt
out should be able to do so easily, with his/her data removed
from the system. A number of measures would need to
be taken to ensure that privacy rules and compliance with
HIPPA are both followed. Software. Another major issue is the lack of standard
software systems that facilitate rapid authoring and revision
of interventions based on lessons learned during the
monitoring process. One approach is to work with software
developers to create management platforms that allow the
outcomes optimization team to author and upload new
content on an ongoing basis. However, this approach may
warrant greater upfront costs than can be allocated, and still
requires expenses over time to maintain and improve the
technology. In disasters, most helping efforts go into secondary
prevention, in which an attempt is made to assist an affected
population in ways that prevent development of PTSD and
other problems. In part because major disasters often affect
large populations, disaster mental health response currently
includes multiple aspects of a stepped care approach,
including broad assistance for those affected via outreach
programs and delivery of Psychological First Aid (PFA) (28),
intermediate intensity crisis counseling services for those
needing more support (29), and referrals for those requiring
mental health treatment. These outreach, PFA, crisis
counseling, and tertiary mental health treatments may
be provided by a range of agencies contracted to mount
a response in an affected area, with response capabilities
distributed across a range of helping organizations rather
than located within a single organization. Such a distribution
means that systems of multi-organization collaboration will
need to be established in order to implement systematic
digital defined population interventions. © mHealth. All rights reserved. mHealth 2018;4:25 mhealth.amegroups.com Benefits, challenges, and key questions for a systematic
digital defined population approach It will likely be
necessary to designate and structure a leadership team
charged with implementing the intervention system and
an additional challenge will be to provide a suite of digital
interventions across multiple organizational settings. Defined populations and outcomes. As specified
throughout, a key factor is defining the population and
outcomes. For example, does the group want to focus on
reducing symptoms or another potentially relevant outcome,
such as improving functioning? In the case of populations
of trauma survivors, the primary needs might include not
only symptom reduction, but also a focus on empowerment,
employment, social support, political activism, or safety. Changes to interventions and the structure of the treatment
system might differentially impact different kinds of
outcomes. Additionally, in responding to traumatized populations,
as with those affected by eating disorders, we are challenged
to think about designing a model that addresses multiple,
co-occurring problems, as is often the case for individuals
with PTS. Using a systems approach to address this
challenge means that defining the population includes: (I)
identifying which groups of users are important to target
(e.g., individuals with eating disorders, major depression,
and generalized anxiety disorder, but not alcohol use
disorder), (II) determining which interventions to offer and
whether the model needs ordering rules for the timing of
intervention delivery, and (III) agreeing on which outcomes
will define success. It is also important to note that there have been many
examples of defined population interventions for PTSD,
though none to our knowledge have applied a systematic,
outcome-oriented approach. For instance, Zatzick et al. (30)
used a medical record to identify acutely injured trauma
survivors who were then randomized to an intervention or Management of defined populations intervention
systems. The approach advocated for here requires a
centrally directed systematic approach to collaborative mhealth.amegroups.com mHealth, 2018 Page 11 of 13 Page 11 of 13 usual care and followed-for 6 months. Zatzick et al. (31) also
examined reach and effect sizes to predict population-level
benefits for two PTSD prevention approaches. Engel et al. (32)
linked screening for PTSD in primary care settings to
collaborative care facilitated by a nurse care manager. The VA
has been at the forefront of providing training to providers in
evidence-based care (33)—expanding the provider pool is a key
step in any defined population intervention. Benefits, challenges, and key questions for a systematic
digital defined population approach Other studies have
examined components of a defined intervention model such as
the effects of documenting PTSD best practices templates (34),
the effectiveness of self-help (35), and many others. However,
to our knowledge none have focused on the use of digital
technology to enhance reach, engagement, and outcome in a
dynamic way. of treatment. Overall, the approach is a way of bringing
“measurement-based care” to the larger treatment system
management enterprise—that is, to enable measurement-
based management. Such an approach also presents significant obstacles. Health care organizations must reorganize aspects of
their operations and assemble multidisciplinary teams to
accomplish the various components. Top leadership must
strongly support the system because it will be necessary to
implement a series of practice changes in multiple sections
of the organization as ongoing monitoring efforts lead to
redesign of interventions. Implementation of the approach
is likely to require significant personnel resources, as well
as access to novel software systems. To some degree, large
health care organizations may already contain many of the
personnel resources and functional capabilities required for
the defined populations methods suggested here, but they
must be identified and brought together in a coordinated
system of care. Despite these significant obstacles,
we believe that a systematic digital population-based
approach to mental health interventions holds promise for
establishing significantly more effective treatment delivery
systems, and most importantly, creating a more rapid and
effective process of treatment improvement in health care
systems and other delivery environments. y
y
Technology is important because of its capacity to increase
the scope and efficiency of population-based interventions. It can enable rapid, continuous evaluation that includes
outcomes data, but also detailed information about process
variables. For example, it will be possible to determine when
and where in technology-based interventions that dropout
occurs. It can greatly increase the reach of services by more
easily including low intensity interventions that can be
accessed by large numbers of trauma-affected individuals. It
enables cost-effective online screening of large numbers of
individuals across geographic areas (36). It makes possible
more rapid modification of interventions themselves and
speeds processes of application of modified interventions
by practitioners with less training burden. Technology also
enables inclusion of a larger set of intervention types (e.g.,
blended interventions) and by strengthening delivery of self-
help interventions, makes possible more easily delivered and
effective stepped care models. Benefits, challenges, and key questions for a systematic
digital defined population approach The model we are describing is
certainly compatible with the RE-AIM (Reach, Effectiveness,
Adoption, Implementation and Maintenance model) (37) and
other implementation models, but also should make it easier
to apply them. Footnote Conflicts of Interest: The authors have no conflicts of interest
to declare. Ethical Statement: The engagement data reported in this
paper was covered by Stanford University School of
Medicine, IRB2826. Other data was obtained from the
public domain. Conclusions Advantages of the population-based approach outlined here
include a simultaneous focus on effectiveness, engagement,
and reach; potential for identification and customization
of interventions for specific subpopulations; and improved
cost-effectiveness of services. The approach also offers
potential for more thoughtful selection and testing of
alternative treatment improvement strategies, focusing
on aspects of engagement, screening methods, alternative
interventions, and different combinations of elements Acknowledgements We want to thank Sarah E. Siegel. This work was supported
in part by: (R01 MH100455), (T32 HL007456), (T32
HL130357), and (F32 HD089586). © mHealth. All rights reserved. References 1. American Psychiatric Association. Diagnostic and
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Specification, Effect Size, and Reach to Estimate and
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health impact of health promotion interventions: the RE-
AIM framework. Am J Public Health 1999;89:1322-7. 37. Glasgow RE, Vogt TM, Boles SM. Evaluating the public
health impact of health promotion interventions: the RE-
AIM framework. Am J Public Health 1999;89:1322-7. 32. Engel CC, Oxman T, Yamamoto C, et al. RESPECT-Mil:
Feasibility of a Systems-Level Collaborative Care Approach doi: 10.21037/mhealth.2018.05.06 Cite this article as: Taylor CB, Ruzek JI, Fitzsimmons-Craft
EE, Graham AK, Balantekin KN. A systematic digital approach
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2018;4:25. mHealth 2018;4:25 mhealth.amegroups.com mhealth.amegroups.com
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Cockfighting in Javanese Muslim Society during the Nineteenth and the Early Twentieth Century
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1 Parikshit Chakraborty, ―Social Impact of Cock Fight: The Study among the
Santals,‖ Research Journal of Humanities and Social Sciences 9, 4 (2018), p. 754; Eric Cockfighting in Javanese Muslim Society
DOI: 10.15642/JIIS.2021.15.2.359-386 Cockfighting in Javanese Muslim Society
DOI: 10.15642/JIIS.2021.15.2.359-386 Cockfighting in Javanese Muslim Society
during the Nineteenth and the Early
Twentieth Century Adi Putra Surya Wardhana | ISI Surakarta, Indonesia
Dennys Pradita | Universitas Jambi, Indonesia
Fiqih Aisyatul Farokhah | IAI Tarbiyatut Tholabah Lamongan, Indonesia
Andriyanto | Universitas Veteran Bangun Nusantara, Indonesia
Corresponding author: adiputra.48697@gmail.com Adi Putra Surya Wardhana | ISI Surakarta, Indonesia
Dennys Pradita | Universitas Jambi, Indonesia
Fiqih Aisyatul Farokhah | IAI Tarbiyatut Tholabah Lamongan, Indonesia
Andriyanto | Universitas Veteran Bangun Nusantara, Indonesia
Corresponding author: adiputra.48697@gmail.com Abstract: This study aims to analyze the thoughts of
Javanese Muslims on cockfighting in the nineteenth and the
early twentieth centuries. It has been a custom and culture
since humans domesticated chickens. At first, it had a
sacred connotation. It eventually devolved into a profane
gamble. Although Islam banned animals fighting and
gambling, the tradition continued during the Islamic era. This study examines (1) the reasons why Javanese Muslim
culture enjoys cockfighting, (2) the forms of Javanese
Muslim thought about cockfighting in Javanese manuscripts
from the nineteenth and the early twentieth centuries, (3) its
influence on colonial and royal rule in Java. Research
showed that some thoughts normalized cockfighting and
cockfight gambling, but some viewed the game as an evil
deed during the nineteenth and the early twentieth centuries. Keywords: Javanese Muslim, Cockfighting, Javanese
manuscripts, Colonial Government 2 Parikshit Chakraborty, ―Historic Cock Fight among the Santals: An
Anthropological View,‖ Social Science & Humanities International 2, 1 (2018), p. 14.
3 Csapo, ―Deep Ambivalence, pp. 10-16.
4 Parikshit Chakraborty and Falguni Chakrabarty, ―Cock Fight: A Symbolic View
of Social Status,‖ International Journal of Social Science 6, 1 (2017), p. 39; Parikshit
Chakraborty, ―Cock Fight: The Flow of Blood,‖ The Asian Man, an International
Journal 13, 1 (2019), pp. 95-96; Parikshit Chakraborty and Falguni Chakrabarty,
―Social-Cultural Aspects of Cock Fight: A Study among the Santals of
Foringdanga, Paschim Medinipur, West Bengal, India,‖ Imperial Journal of
Interdisciplinary Research 2, 10 (2016), p. 2116. Csapo, ―Deep Ambivalence: Notes on a Greek Cockfight (Part I),‖ Phoenix 47, 1
(1993), p. 8. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Introduction Cockfighting is a culture found in various parts of the world. It
was popular in Europe, Asia, and America from the sixteenth
century to the twentieth century. It has been found in Greece since
Themistocles (524–460 BCE). It was related to the activities of
religious rituals and political institutions in Athens, Greece.1 During JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 359 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto the Christian era, the Christian clergy opposed this tradition was. However, it continued to spread to Italy, Germany, Spain, and their
colonies, including England, Wales, Ireland, and Scotland.2 Cock-
fighting is a symbol of the fighting spirit in Greek culture. The
chicken is interpreted as a symbol of sexuality and masculinity. Therefore, the cockfighting ritual represents both military and
sexual conquest.3 In India, Cockfighting is also practiced. The Harappa culture,
which flourished in the Indus River Valley between 2500-2100
BCE, is credited with starting this custom. Since 1000 BCE,
cockfighting has had religious significance for the people of the
Indus River Valley. It developed in the West Bengal region of India. It was also popular in China, Persia, and other Eastern countries at
the time. 4 Cockfighting became an arena to protect territory and
family pride since the rooster symbolized courage and resistance.5
Cockfighting has become universal that has spread throughout
Southeast Asia, including the Nusantara (Indonesian archipelago). g
p
g
This culture can be traced back to the Javanese domestication
of chickens in Nusantara. Evidence of the domestication of
chickens (Gallus gallus) is carved in the reliefs of Borobudur
Temple.6 Reid recorded Hindu-Buddhist inscriptions in Java that
described the religious culture of cockfighting, an essential part of
temple feasts, ordinations, and pilgrimages. The blood of a rooster 5 Chakraborty and Chakrabarty, ―Cock Fight: A Symbolic View of Social Status, p. 40. 6 Bambang Agus Suripto and Listia Pranowo, ―Relief Jenis-Jenis Fauna Dan
Setting Lingkungannya Pada Pahatan Dinding Candi Borobudur,‖ Manusia Dan
Lingkungan 8, 1 (2001), p. 41. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 360 Cockfighting in Javanese Muslim Society means a sacrifice to the gods. Cockfighting took place in certain
villages, shrines, and festivals. 8 Sophia Raffles, Memoir of the Life and Public Services of Sir Thomas Stamford Raffles
(London: William Clowes and Sons, 1835), p. 333.
9 Thomas Stamford Raffles, The History of Java (London: Black Parbury and Allen
Booksellers to the Hon, 1817), p. 249 and p. 349. In Sumatra, the culture of
cockfighting was favored by the Minangkabau people, although the Padri
(religionists) group disliked it in the 19th century. 7 Anthony Reid, Southeast Asia in the Age of Commerce, 1450-1680 (Volume One: The
Lands below the Winds) (New Haven and London: Yale University Press, 1988), p.
189. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 8 Sophia Raffles, Memoir of the Life and Public Services of Sir Thomas Stamford Raffles
(London: William Clowes and Sons, 1835), p. 333. Introduction The kingdoms in Java also held
cockfighting as a royal prerogative, either for fertility rituals or
ceremonies for success in war.7 Since the thirteenth century, Islamic political forces have grown. The Hindu-Buddhist kingdoms were in decline in the fifteenth
century. Islam spread rapidly in Java. Islamic dynasties ruled over
Java in the sixteenth century. New values and norms (Islam)
influenced the cockfighting culture. Islamic religious dogmas
prohibited cockfighting activities. In Islamic teachings, fighting
animals is a terrible deed, and cockfighting is mainly used for
gambling. The cockfighting was also detested by the British colonial
authority since it was not in keeping with the British character.8 y
p g
However, cockfighting remained a popular game in Java during
the colonial era. Thomas Stamford Raffles in The History of Java
recorded áduh jágu (cockfighting), a common game among ordinary
people. The cockfighters add the spurs to make the game
enjoyable. 9 For a hedonistic society, the function of the
cockfighting ritual has shifted to gambling. Gambling in Javanese is
called botoh, while rooster in Javanese is called sawung. In the old
Javanese language, sawung also refers to cockfighting. The Javanese
people still use this word. Both sawung and sabung mean cockfighting. Even though cockfighting does not necessarily involve gambling,
the definition of sabung ayam has been characterised as cockfighting
gambling. The social context of botoh sawung (cockfighting gambling) as a
game of pleasure and gambling influenced the writing of Javanese
manuscripts. Several manuscripts, including Serat Centhini, Pranacitra
(Rara Mendut), Serat Tatacara, and Serat Adu Jago, record the Javanese
people‘s preference for cockfighting during the Islamic period. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 361 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Meanwhile, there are also regulatory texts regarding botoh sawung
(cockfighting gambling), such as Serat Angger Pradata Awal
Kasultanan Yogyakarta and Pranatan Pulisi Tumrap Băngsa Jawi ing
Indiya Nèdêrlan, H. Buning, 1913 (Algemeene Politie Reglement voor de
Inlanders in Nederlandsch-Indie). The texts reveal that cockfighting is
popular among the Javanese, despite the fact that it is prohibited by
religion and the government. Meanwhile, there are also regulatory texts regarding botoh sawung
(cockfighting gambling), such as Serat Angger Pradata Awal
Kasultanan Yogyakarta and Pranatan Pulisi Tumrap Băngsa Jawi ing
Indiya Nèdêrlan, H. Buning, 1913 (Algemeene Politie Reglement voor de
Inlanders in Nederlandsch-Indie). 10 Chakraborty, ―Social Impact of Cock Fight: The Study among the Santals;
Chakraborty, ―Historic Cock Fight among the Santals: An Anthropological View;
Chakraborty and Chakrabarty, ―Social-Cultural Aspects of Cock Fight;
Chakraborty and Chakrabarty, ―Cock Fight: A Symbolic View of Social Status;
Chakraborty, ―Cock Fight: The Flow of Blood.‖ 11 Wanni Wibulswasdi Anderson, ―Beyond The Cockfight: Masculinity and the
Thai Dove-Cooing Contest,‖ Manusya: Journal of Humanities 8, 3 (2005), p. 86. 10 Chakraborty, ―Social Impact of Cock Fight: The Study among the Santals;
Chakraborty, ―Historic Cock Fight among the Santals: An Anthropological View;
Chakraborty and Chakrabarty, ―Social-Cultural Aspects of Cock Fight;
Chakraborty and Chakrabarty, ―Cock Fight: A Symbolic View of Social Status;
Chakraborty, ―Cock Fight: The Flow of Blood.‖
11 Wanni Wibulswasdi Anderson, ―Beyond The Cockfight: Masculinity and the
Thai Dove-Cooing Contest,‖ Manusya: Journal of Humanities 8, 3 (2005), p. 86.
12 Garry Marvin, ―The Cockfight in Andalusia, Spain: Images of the Truly Male,‖
Anthropological Quarterly 57, 2 (1984), p. 60.
13 Samuel J. Walker and Hanneke J.M. Meijer, ―More than Food; Evidence for
Different Breeds and Cockfighting in Gallus Gallus Bones from Medieval and
Post-Medieval Norway,‖ Quaternary International (2020), pp. 1-10. 13 Samuel J. Walker and Hanneke J.M. Meijer, ―More than Food; Evidence for
Different Breeds and Cockfighting in Gallus Gallus Bones from Medieval and
Post-Medieval Norway,‖ Quaternary International (2020), pp. 1-10. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021
2 12 Garry Marvin, ―The Cockfight in Andalusia, Spain: Images of the Truly Male,‖
Anthropological Quarterly 57, 2 (1984), p. 60. Introduction The texts reveal that cockfighting is
popular among the Javanese, despite the fact that it is prohibited by
religion and the government. Therefore, this study examines cockfighting in Javanese Muslim
society during the 19th and early 20th centuries C.E. Some of the
problems discussed in this study are (1) the cause of the Javanese
Muslim society enjoys cockfighting, (2) the forms of Javanese
Muslim thought on cockfighting found in Javanese manuscripts
during the 19th and early 20th centuries (3) the influence of
cockfighting on the rules of the Colonial Government and the
Kingdom of Java. g
Several studies related to cockfighting serve as a literature
review in this study. Some of Chakraborty‘s ethnographic studies
are a good example.10 He examined the culture of cockfighting in
India that emerged since humans domesticated chickens. However,
he did not examine the Muslim society‘s view on this tradition. Then, Anderson analyzed the concept of cockfighting masculinity
in Thailand. 11 Marvin analyzed cockfighting as a symbol of mascu-
linity in Spain.12 Walker and Meijer studied evidence of cockfighting
in Medieval and Post-medieval Norway. 13 Sykes examined the
specialty of roosters and the culture of cockfighting in Europe, JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 362 Cockfighting in Javanese Muslim Society especially in Roman Britain. 14 Meanwhile, O‘Donnel and Smith
criticized the research conducted by Geertz on the cockfighting
tradition in Bali.15 These studies did not examine Javanese Muslim thoughts on
cockfighting or cockfighting gambling. The number of Research
done on the thoughts of Javanese Muslims about botoh sawung is
very limited. Therefore, this research deserves to be conducted to
fill the void of intellectual historiography about Javanese Muslim
thought on cockfighting from the nineteenth century to the early
twentieth centuries. This research is arranged by collecting data sources, conducting
internal and external criticism, interpreting the data, and compiling
the interpretation results in an empirical narrative. It uses data in
the form of text in Javanese manuscripts on cockfighting and botoh
sawung. This study used a history of thought or intellectual approach
to examine the thoughts of the Javanese Muslim society about
cockfighting followed by gambling. The study of thought history is a part of an attempt to
understand the human experience. This approach is used to
examine how people in the past understand ideas, thoughts,
arguments, beliefs, assumptions, attitudes, and preoccupations that
shaped the intellectual life of society. 14 Naomi Sykes, ―A Social Perspective on the Introduction of Exotic Animals: The
Case of the Chicken,‖ World Archaeology 44, 1 (2012), p. 158.
15 Philip Smith, ―The Balinese Cockfight Decoded: Reflections on Geertz, the
Strong Program and Structuralism,‖ Cultural Sociology 2, 2 (2008), pp. 169–186;
Casey O‘Donnell, ―On Balinese Cockfights: Deeply Extending Play,‖ Games and
Culture 9, 6 (2014), pp. 406–16.
16 Stefan Collini, ―What Is Intellectual History...?,‖ Juliet Gardiner (ed.), What Is
History Today? (Hampshire and London: The Macmillan Press Ltd., 1988), p. 105. Introduction Intellectual history aims to
analyze selected texts in depth.16 In this study, intellectual history is
used to analyze texts about botoh sawung in the thought of the
Javanese Muslim society during the nineteenth century and early
twentieth century. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 17 Dennys Pradita, ―Pemikiran Konservasi Burung Di Indonesia Tahun 1894
Sampai 1970an: Dari Kesadaran Kultural Ke Kesadaran Lingkungan‖ Unpublished
Master Thesis, Universitas Gadjah Mada Yogyakarta (2020), p. 68.
18 Clifford Geertz, ―Deep Play: Notes on the Balinese Cockfight,‖ Daedalus 101, 1
(1972), pp. 1-37. 20 Suripto and Pranowo, ―Relief Jenis-jenis Fauna dan Setting Lingkungannya, p.
41. Tracing the Genealogy of Cockfighting Chicken (Gallus) are a type of bird that can be domesticated or
live in the wild. Chickens have a unique value for the people of JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 363 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Nusantara. In some rituals, chicken is used as an offering. The
people of Sumba (East Nusa Tenggara) interpret chickens as
sacrifices for rituals.17 The people of Sumbawa (West Nusa Teng-
gara) use chicken as an offering at a Megalithic site. The ritual of
slaughtering chickens is carried out before the planting season,
around November. Meanwhile, Balinese people usually sacrifice chickens in the
Shiva Tattwa Purana ritual (the ancient story of Siva‘s essence) as
birth to death rituals. The tradition of cockfighting for rituals in
Bali is called Tajen.18 Cockfighting has the meaning of death, virility,
anger, pride, loss, and virtue among the Balinese.19 The blood drops
symbolize a plea for humanity to avoid harm. The chicken is a significant animal in religious life not only for
Sumbanese, Sumbawanese, and Balinese, but also for the Javanese. The proof is the temple reliefs on Java which show the figure of a
rooster, such as the relief of a chicken at Borobudur Temple,20 the
rooster medallion relief at Panataran Temple (12nd – 15th century),21
and the rooster medallion at Kidal Temple, Malang (13th century).22
The reliefs of cockfighting in Rimbi Temple. The rooster medallion is not only a temple ornament but also a
symbol of life because the rooster always crows at sunrise and is
beneficial for human life as livestock. The medallion is a sign of
strength and courage. The chicken has a mystical connotation in
the Javanese Hindu-Buddhist culture since it is often frequently
used as a sacrificial animal in rituals. The rooster is not only 21 Ranang Agung Sugihartono and Handriyotopo, Transisi: Wayang, Relief, Dan
Animasi (Surakarta: ISI Press, 2017), p. 9. 22 Ulfatun Nafi‘ah et.al., ―Perancangan Motif Batik dengan Inspirasi Relief
Ornamentasi Candi Kidal sebagai Pengembangan Corak Batik Desa Kidal,‖ Jurnal
Praksis Dan Dedikasi Sosial 1, 2 (2018), p. 114. 22 Ulfatun Nafi‘ah et.al., ―Perancangan Motif Batik dengan Inspirasi Relief
Ornamentasi Candi Kidal sebagai Pengembangan Corak Batik Desa Kidal,‖ Jurnal
Praksis Dan Dedikasi Sosial 1, 2 (2018), p. 114. 19 Smith, ―The Balinese Cockfight Decoded, p. 174. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 17 Dennys Pradita, ―Pemikiran Konservasi Burung Di Indonesia Tahun 1894
Sampai 1970an: Dari Kesadaran Kultural Ke Kesadaran Lingkungan‖ Unpublished
Master Thesis, Universitas Gadjah Mada Yogyakarta (2020), p. 68.
18 Clifford Geertz, ―Deep Play: Notes on the Balinese Cockfight,‖ Daedalus 101, 1
(1972), pp. 1-37.
19 Smith, ―The Balinese Cockfight Decoded, p. 174.
20 Suripto and Pranowo, ―Relief Jenis-jenis Fauna dan Setting Lingkungannya, p.
41.
21 Ranang Agung Sugihartono and Handriyotopo, Transisi: Wayang, Relief, Dan
Animasi (Surakarta: ISI Press, 2017), p. 9.
22 Ulfatun Nafi‘ah et.al., ―Perancangan Motif Batik dengan Inspirasi Relief
Ornamentasi Candi Kidal sebagai Pengembangan Corak Batik Desa Kidal,‖ Jurnal
Praksis Dan Dedikasi Sosial 1, 2 (2018), p. 114. 18 Clifford Geertz, ―Deep Play: Notes on the Balinese Cockfight,‖ Daedalus 101, 1
(1972), pp. 1-37. 21 Ranang Agung Sugihartono and Handriyotopo, Transisi: Wayang, Relief, Dan
Animasi (Surakarta: ISI Press, 2017), p. 9. 17 Dennys Pradita, ―Pemikiran Konservasi Burung Di Indonesia Tahun 1894
Sampai 1970an: Dari Kesadaran Kultural Ke Kesadaran Lingkungan‖ Unpublished
Master Thesis, Universitas Gadjah Mada Yogyakarta (2020), p. 68. 23 Reid, Southeast Asia in the Age of Commerce, p. 6.
24 Ibid., p. 183. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 23 Reid, Southeast Asia in the Age of Commerce, p. 6. 25 Ibid., p. 189.
26 The original version in Javanese says: ―Sang Narendra Anusapati dhawuhnya, mring
abdi gadhuh pitik, kinèn umêndhêta, sawung adon sajuga, wus inêndhêt gya tinandhing, samya
binolang, pyambak tajine mranti. Rame tarungira sawung sakalihan, sang nata lenèng galih,
kasalamur loknya, datan mawi nglagewa, Sang Panji Tohjaya aglis, narik curiga, yasanya
Êmpu Gandring....‖ See R.M. Mangkudimedja, Serat Pararaton (Jakarta: Proyek
Penerbitan Buku Sastra Indonesia dan Daerah, 1979), pp. 69–70. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Tracing the Genealogy of Cockfighting JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 364 Cockfighting in Javanese Muslim Society worshipped or sacrificed in rituals but is also participated in
cockfighting as part of sacred ceremonies. Picture 1. Rooster Medallion at Penataran Temple
Source: https://telusuri.id/cara-candi-penataran-mengawetkan-hewan/
(accessed on 14 August 2021) Picture 1. Rooster Medallion at Penataran Temple Source: https://telusuri.id/cara-candi-penataran-mengawetkan-hewan/
(accessed on 14 August 2021) The tradition of cockfighting is known as adu jago or ngaben
sawung (sabung). According to Reid, the cockfighting ritual spread
throughout the mainland of Southeast Asia. 23 Each region has
different roots or meanings for cockfighting and it evolves over
time. Reid picks up a common thread regarding cockfighting in
Southeast Asia. Every feast day in Southeast Asia, it is frequently
held as a show and spectacle in public places such as markets or
other crowded centers.24 24 Ibid., p. 183. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 365 27 Jan Wisseman Christie, Register of the Inscriptions of Java 732-1060 A.D. (The
Inscriptions of Mataram (1999), p. 209.
28 The original version in Javanese says: ―…masiwo manigel manawun karun hayam.
kapua mahyun tanda rakryan maguyuguywan umarsukhamwak nikanan rāma i sampun tanda
rakryān masawunan manigal ikanan rama kabaih molih.‖ JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Meanwhile, in ancient Java, cockfighting was practiced in
specific communities, sacred places, and festivals. The court nobles
held cockfights exclusively for fertility rituals and ceremonies for
success in war. 25 Therefore, cockfighting had the nature of ritual
and pleasure simultaneously. Perhaps in ancient Java, the pleasure
of cockfighting was wrapped in religious discourse. The story of cockfighting in ancient Java was also found in
Serat Pararaton. The manuscript, rewritten in 1912, told the story of
King Singasari, who was killed during a cockfight. King Anusapati
was a king who liked cockfighting. The king sent an exceptional
servant to take care of the rooster and train his domestic rooster to
be outstanding fighting cocks. Because the roosters were so
enormous, the cock keeper was overwhelmed when it came to
selecting and preparing the rooster. ―King Anusapati gave orders to the caretaker of the royal
rooster. The caretaker took the rooster for a long time because
he had to choose the best fighting cock. After taking, (the
rooster) was pitted; alternately, the iron stuck in the chicken‘s
leg targeting everywhere. The cockfighting went lively. The
king enjoyed according to his heart‘s desire. The cockfighting
made him complacent. Unknowingly, Sang Panji Tohjaya
immediately pulled the weapon (keris) made by Mpu
Gandring.‖26 According to the manuscript, cockfighting was a pleasure and a
spectacle for the life journey in ancient times. The king was said to
be complacent when cockfighting. The king‘s rooster was an
attraction for the people; thus, he was careless. When all were
mesmerized by the show, a keris (traditional Javanese dagger)
pierced the king‘s skin. King Anusapati died immediately. This
story was passed down orally and in writing from generation to
generation. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 366 27 Jan Wisseman Christie, Register of the Inscriptions of Java 732-1060 A.D. (The
Inscriptions of Mataram (1999), p. 209. Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society Serat Pararaton became a royal reading in Bali after the Hindu-
Buddhist kingdoms in Java fell. The Pararaton manuscript had
undergone a process of copying and translation since it was found
by J.L.A. Brandes in the 1890s. The manuscript was also translated
into Javanese. In Javanese terms, the process of copying the
manuscript is called mutrani. According to several stories of the
Hindu-Buddhist period, there were noble groups who had a
penchant for sawung. Another inscription mentioning the existence of cockfighting in
Java is the Taji Inscription. It was discovered in Ponorogo and is
thought to have been written in 901 CE. Sawung or manawung karung
hayam held at the Sima establishment ceremony. The cockfighting
was made more exciting by the presence of dance, food, and
drinks.27 ―... Playing, dancing, competing with wild boars and roosters,
Tanda Rakryan, wanted to make jokes to make the village
officials happy after Tanda Rakryan gathered to dance for four
around. It represents a warning from the ruler to its citizens
always to be careful and alert when having fun in cockfighting
gambling.‖28 An inscription mentioning cockfighting gambling is contained
in the Leran inscription. The inscription emphasises the importance
of vigilance in cockfighting because it is prone to cheating. It
represents a warning from the kingdom to its citizens always to be
careful and alert when having fun in cockfighting gambling in the
old Javanese era. ―People struggle with all bets with big prizes in gambling
games regulated by gambling controllers must be watched
carefully. They also cheat in the cockfighting game, either
without or using spurs in a cockfighting place in case it can be
a month of misfortune. Thus, it causes a loss of honor. Step
back from the crowd, play gending (traditional percussion
music), take a breath, walk around, then row carrying a wajon, JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 367 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto and cover the poles with a covering cloth like a nagapuspa (a
kind of tree, Mesua Roxburghii).‖ 29 Therefore, cockfighting gambling needs to be regulated by the
government. Several ancient inscriptions attested to the role of
rulers in regulating gambling. According to some ancient
inscriptions, a royal official (Mangilala drwya haji) took care of
gambling. 29 The original version in Javanese says: ―…sama sanak anlanakna salwiranin. totohan.
mahadinita. judi. paparihan. gawur. sahawasanya. muwah. anadwa sawun a tajya tajyana.
satajyanya. sawulananya dainya. tlas nin puja pwa. munduraramya ramyana. agdin gendina.
awaywa waywana. mideren banjar. pamikulakna wajon. sawadahanya. anulesana pikulan
sahulesanya. makadi nagapuspa....‖
30 Shafrina Fauzia, ―Sabung Ayam di Jawa dan Bali dalam Data Prasasti,‖
Prajnaparamita Jurnal Museum Nasional (2018), p. 98 JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 31 Dennys Pradita, ―Mitologi Sampai Perdagangan: Status, Peran, dan Makna
Burung dalam Masyarakat Jawa dari Zaman Kolonial Hingga Milenial,‖ Pramana
Yuda (ed.), Konferensi Peneliti dan Pemerhati Burung (KPBBI ) IV Semarang (2018), pp.
388-402. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Cockfighting in Javanese Muslim Society Wangwang Bangen (746 Śaka), Kuti (762 Śaka), Gandakuti
(964 Śaka), Talan (1058 Śaka), and Waringin Pitu (1369 Śaka)
inscriptions mention juru judi (overseer of gambling). Juru judi acts
as leaders, heads, and overseers within the kingdom that collects
gambling taxes. The inscriptions of Biluluk IV, Pabuharan, Waharu I,
Padlegan, and Lordaru (1245 Śaka) mention the tuha judi (head of
gambling) profession. Their job is the same as that of a juru judi. The Pabuharan, Kuti, Gandakuti, Pupus (1022 Saka), Lordaru,
and Wangwang Bangen inscriptions mention the malandan profession
whose job is to oversee and arrange the gambling. Malandan took a
ten percent stake in a cockfighting or gambling. There is also a lca
profession which is an assistant gambling supervisor. Cockfighting
gambling regulators are called lĕbĕlĕb. The profession of lĕbĕlĕb was
often written with the profession of malandan and lca. The three
professions are interrelated and important in gambling. There is a
taji profession that makes and installs sharp weapons in chicken
legs for cockfighting. Taji can also collect taxes on sharp weapon
installations. 30 This reality shows that cockfighting and gambling
contain power relations. Cockfighting is more than just a form of entertainment; it is a
political discourse built by the authorities to show their strength. Therefore, the nobles always competed to have the best fighting
cock. The ownership of fighting cocks became a symbol of social
status among the nobility. Of course, the king‘s fighting cock must
be the strongest. The king‘s charisma was at stake through his JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 368 32 Merle C. Ricklefs, Mystic Synthesis in Java: A History of Islamization from the
Fourteenth to the Early Nineteenth Centuries (Norwalk: EastBridge, 2006), pp. 5, 20.
33 Ibid., p. 187.
34 Jochem van den Boogert, ―Rethinking Javanese Islam Towards New
Descriptions of Javanese Traditions,‖ Ph.D Dissertation, Universiteit Leiden
(2015), p. 353.
35 Andrea Acri and Verena Meyer, ―Indic-Islamic Encounters in Javanese and
Malay Mystical Literatures,‖ Indonesia and the Malay World 47, 139 (2019), p. 280.
36 Clifford Geertz, The Religion of Java (Chicago and London: The University of
Chicago Press, 1976), p. 5. Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society fighting cock. It caused a sentiment among the royal elite. After the
ownership of fighting cocks became a prestige, the meaning of
cockfighting changed. At first, cockfighting was used to replace war. Cockfighting has resulted in fights throughout its history. This
incident often happened after cockfighting had become gambling. Owning a fighting cock became economically valuable because it
used bets. Picture 2. Illustration of cockfighting in Java c. 1596 CE
Source: Atlas of Mutual Heritage, https://data.collectienederland.nl
(accessed on 14 August 2021). Picture 2. Illustration of cockfighting in Java c. 1596 CE Source: Atlas of Mutual Heritage, https://data.collectienederland.nl
(accessed on 14 August 2021). Cockfighting is a way for court officials or relatives to express
their masculinity and channel their hobbies. It provides an overview
or common thread regarding the concept of satisfaction or pleasure
for Javanese men. Some satisfaction or symbols of perfection in
Javanese men are wanita (woman), wisma (house), turangga (horse),
curiga (kris), and kukila (bird). Kukila or bird refers to klangenan
(pleasure) which has a deep meaning in Javanese thought. For
Javanese men, klangenan can be a chirping bird or a fighting animal. It provides satisfaction or masculinity values for the owners. 31
Cockfighting in Javanese society did not only refer to a hobby but JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 369 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto also prestige for the owners. The owner felt ―manly‖ because they
had a reliable fighting animal and pride. However, gambling is a harmful act according to the
Purwadhigama state totohan pranidan totohan tan prani. It indicates
moral teaching that humans should avoid gambling because it will
bring misery. Cockfighting gambling remained popular through the
centuries, the aspects of fun, entertainment, and politics behind it
dominated more than the teachings of wisdom. 34 Jochem van den Boogert, ―Rethinking Javanese Islam Towards New
Descriptions of Javanese Traditions,‖ Ph.D Dissertation, Universiteit Leiden
(2015), p. 353. 32 Merle C. Ricklefs, Mystic Synthesis in Java: A History of Islamization from the
Fourteenth to the Early Nineteenth Centuries (Norwalk: EastBridge, 2006), pp. 5, 20.
33 Ibid., p. 187. 35 Andrea Acri and Verena Meyer, ―Indic-Islamic Encounters in Javanese and
Malay Mystical Literatures,‖ Indonesia and the Malay World 47, 139 (2019), p. 280. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 36 Clifford Geertz, The Religion of Java (Chicago and London: The University of
Chicago Press, 1976), p. 5. 37 Robert W. Hefner, ―Where Have Athe Abangan Gone? Religionization and the
Decline of Nonstandard Islam in Contemporary Indonesia,‖ Michel Picard and
Rémy Madinier (eds), The Politics of Religion in Indonesia: Syncretism, Orthodoxy, and
Religious Contention in Java and Bali (London & New York: Routledge, 2011), p. 72. 38 Koentjaraningrat, Kebudayaan Jawa (Jakarta: Balai Pustaka, 1994), p. 312. 39 Mark Woodward, Java, Indonesia, and Islam (London & New York: Springer
Dordrecht Heidelberg, 2011), p. 115. 40 Andrew Beatty, Varieties of Javanese Religion: An Anthropological Account
(Cambridge: Cambridge University Press, 2003), p. 158. 37 Robert W. Hefner, ―Where Have Athe Abangan Gone? Religionization and the
Decline of Nonstandard Islam in Contemporary Indonesia,‖ Michel Picard and
Rémy Madinier (eds), The Politics of Religion in Indonesia: Syncretism, Orthodoxy, and
Religious Contention in Java and Bali (London & New York: Routledge, 2011), p. 72.
38 Koentjaraningrat, Kebudayaan Jawa (Jakarta: Balai Pustaka, 1994), p. 312.
39 Mark Woodward, Java, Indonesia, and Islam (London & New York: Springer
Dordrecht Heidelberg, 2011), p. 115.
40 Andrew Beatty, Varieties of Javanese Religion: An Anthropological Account
(Cambridge: Cambridge University Press, 2003), p. 158. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Cockfighting in Javanese Muslims’ Thought g
g
J
g
Islam developed rapidly during sixteenth-century in Java. The
Kingdom of Demak and Mataram (Islam) had an essential role in
the Islamization of Java. Sufism influenced both Demak and
Mataram. Islamic mysticism or Sufism became the dominant sect in
Java. This sect was quickly accepted because pre-Islamic mystics
still influenced Javanese society.32 The Javanese accepted the five pillars of Islam but still adhered
to customs and mystical traditions. Therefore, Ricklefs used the
term ‗mystic synthesis to describe this reality.33 The term Kejawen
(Javanism) and Islamic-Javanese syncretism is quite problematic. Boogert criticized this conceptualization because syncretic was a
complicated term.34 Acri and Meyer also disputed the conceptuali-
zation of Javanism as part of the influence of the Hindu-Buddhist
system.35 According to some researchers, Javanese Islam was separated
from pure Islam (kaffah). Geertz called Javanese Muslims, abangan
Islam, are different from Islam putihan (santri). 36 Hefner chose the JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 370 Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society term abanganism.37 Koentjaraningrat gave the term specifically agami
Jawi (Javanese religion).38 Woodward used the term Muslim
Kejawen.39 Beatty chose Javanism as a term to distinguish between
Javanist mysticism and the practice of Islam. 40 These researchers negate the fact that the adherents of Javanese
Islam were Islam itself. They classified the belief systems and
customs of the Javanese Muslim society through the perspective of
orientalism. There were no Muslims in Java. The Javanese people
practiced Islam which was reflected in their culture. Javanese
people professed and practiced Islamic teachings while preserving
their cultural traditions. Religion and culture were no longer divided
and contrasted in Javanese Muslim society. Cockfighting is one of the problematic Javanese traditions
when it comes to the interaction between religion and culture. Cockfighting is a popular pastime among Javanese. Islam, on the
other hand, is a religion that rejects animal fighting. During the
nineteenth to the early twentieth centuries, Javanese Muslim groups
in rural and urban regions loved cockfighting. Javanese poets
recorded their thoughts on cockfighting in texts written between
the nineteenth to the twentieth centuries. Serat Centhini is one of the manuscripts documenting
cockfighting as a favorite of the Javanese Muslim society. It was
composed
by
Kanjeng
Gusti
Pangeran
Adipati
Anom
Amangkunagara III (Sunan Paku Buwana V) in 1814 CE. In Serat
Centhini (Suluk Tambangraras), the poem of Dhandhanggula canto
618 tells of a wedding celebration. The celebration was marked by
the teaching Islamic natural studies. The event was enlivened up in 40 Andrew Beatty, Varieties of Javanese Religion: An Anthropological Account
(Cambridge: Cambridge University Press, 2003), p. 158. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 371 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto the afternoon with cock and quail fighting. The evening‘s festivities
included tayub dancers (ronggeng).41 The narration in stanzas 84 and 85 tells of a wedding party
enlivened by a lively cock and quail fighting. In the next stanza,
cock and quail fights were followed by botohan (gambling). ―Both sliced through the will, battling the cock without
disappointment. The fighting cock was skilled at gripping,
making the match fun, looking without being burdensome,
and not dull. The muscles and bones hit vital points and
airways without loosening the spirit already in your grip. Angling Derma and Ki Amat Supi pitted the rooster,
explaining its superiority and belittling the others. 41 Kangjêng Gusti Pangeran Adipati Anom Amêngkunagara III (Ingkang Sinuhun
Pakubuwana
V),
Serat Centhini
(Yogyakarta:
Yayasan
Centhini,
1992).
Dhandhanggula, canto 618, stanzas 84-85.
42 The original version in Javanese says: ―(91) Wong kalih kang liningan mangarsi,
anandhing sawung datan kuciwa, prigêl nêkêm pambobote, kinarya nandhing mathuk, liring
mathuk datan ngêboti, tan kadhih ing sausap, otot balungipun, myang gring-warase tan inang,
pangiringing napas tan iwir mèlèdi, wus anèng têkêmira; (92) Angling Dêrma lan Ki Amat
Supi, panandhingirèng sata satata, mêdharakên pigunane, panglamakira rampung, sinaoskên
mring pra priyayi, tan wus sama ababag, rinamèkkên sampun, botoh kakalih turira, kang
punika sampun (ng)gèn-kawula nandhing, sawung-dalêm pun Modang; (93) Lan sawungnya
putranta Dyan Bèi, Wiryabrata kang abrit pun Gramang, kang samya dinadosake, Ke Kidang
mèsêm muwus, si Lim Dêrma bae (m)botohi, mring jagoku si Modang, ya wus pitayèng sun,
nak Dyan Bèi Wiryabrata, kêkêdhikan kewala pangajêngnèki, sapantêsing kasukan.‖
Kangjêng Gusti Pangeran Adipati Anom Amêngkunagara III (Ingkang Sinuhun
Pakubuwana
V),
Serat Centhini
(Yogyakarta:
Yayasan
Centhini,
1992).
Dhandhanggula, canto 618, stanzas 91-93. 41 Kangjêng Gusti Pangeran Adipati Anom Amêngkunagara III (Ingkang Sinuhun
Pakubuwana
V),
Serat Centhini
(Yogyakarta:
Yayasan
Centhini,
1992).
Dhandhanggula, canto 618, stanzas 84-85. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 41 Kangjêng Gusti Pangeran Adipati Anom Amêngkunagara III (Ingkang Sinuhun
Pakubuwana
V),
Serat Centhini
(Yogyakarta:
Yayasan
Centhini,
1992).
Dhandhanggula, canto 618, stanzas 84-85. Cockfighting in Javanese Muslim Society Even with
the noble, they did not talk to each other during the match,
but they were enlivened by placing bets on the two roosters in
the arena, namely Modang and Dyan Bei Wiryabrata‘s rooster,
namely Gramang. I was just a little bit hopeful about having
fun.‖42 The enthusiasm of cockfighting is described in the above tale
by village officials and religious (Islamic) leaders. Cockfighting was
one of their favorite games. They also gambled. The story in stanza
104 illustrates the value of cockfighting gambling pleasure, which
influenced the subject‘s rationality. According to the story, both
Jayengresmi and Jayengraga were Sunan Giri‘s descendants. Cockfighting was one of their favorite pastimes. The narration JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 372 Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society discusses the thrill of betting as long as one does not have a clear
mind. It indicates that the script has discussed the harmful effects
of cockfighting gambling. Someone who could explain the nature
of Islam participated in botoh sawung because it was pleasant. They
must have been aware of Islam‘s prohibitions on animal fighting
and gambling. Despite the fact that they were aware of the law prohibiting
animal fighting and gambling, they continued to hold cockfights. This story reflects the views of the Javanese Muslim society on the
non-contradictory relationship between religion and tradition. They
continue to follow Islamic religious practices while simultaneously
engage in worldly pleasures. According to Javanese Muslims, sacred
and profane demands can be satisfied in a balanced way. p
In addition to Serat Centhini, Serat Pranacitra contains Javanese
Muslim thoughts on botoh sawung. This manuscript was composed
based on a manuscript written during Sunan Paku Buwana V in the
nineteenth century. During Sunan Pakubuwana VII, this was
disclosed.43 This manuscript is still contemporary with Serat Centhini
even though it is set in the seventeenth century Mataram era. The
original manuscript was taken from Surakarta, stored at Koninklijk
Bataviaasch Genootschap van Kunsten en Wetenschappen No. 163, and
spreaded by Bale Pustaka in the 1932. The story of the fighting is told in the poem Dhandhanggula
Canto 1, stanzas 42-43. This section discusses about Ki
Tumenggung Wiraguna, who wanted to end the fighting match
because he thought about Rara Mendut, his idol girl, even though
cockfighting was Ki Tumenggung Wiraguna‘s pleasure. 43 Balai Pustaka Serie No. 449, Pranacitra (Rara Mêndut): Babon Saking Surakarta
(Batawi Sèntrêm: Bale Pustaka, 1932), p. 169. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 44 The original version in Javanese says: ―Ingkang andhèr nèng ngayun, pra botoh samya
ambêkta sawung, myang priyayi răngga dêmang lan ngabèi, ambêkta bombonganipun, sawung
ingkang wus pitados. Sampun pêpak sadarum, angandika kiyai tumênggung, mring Mas Patih
Wirakăndha kinèn tandhing, patih sandika turipun, nulya undhang mring pra botoh. Lah
suwawi ing ngriku, sami tinandhing bombonganipun, para botoh sandika nulya anandhing,
nging dèrèng wontên kang athuk, panandhinge samya reyon. Ki tumênggung nglingnya rum,
padha kapikên anandhing sawung, singa ingkang kaot wis jamaking tandhing, payo kono
goprak-gapruk, mêngko gampang arêbut toh. Dèrèng pantara dangu, ingkang samya
têtandhingan sawung, ya ta Pranacitra ingkang lagya prapti, kagyat sadaya kang dulu, cingak
sagung para botoh.‖ Balai Pustaka Serie No. 449, Pranacitra (Rara Mêndut). JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 45 Ki Mangunprawira, Serat Adu Jago (Yogyakarta: Panti Boedaja, 1939), pp. 14-16.
46 The original version in Javanese says: ―Sawoeng ingkang dipoen gadhang badhe kaaben,
poenika oemoer 9 boelan, sampoen wiwit dipoengoelawentah, dipoen sengkeri pijambak, mboten
dipoen tunggilaken wonten ing kandhang ajam, sengkeran satoenggal sawoeng satoenggal.‖ Ibid.,
p. 24.
47 M
i
S
Ad J
26 JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 47 Mangunprawira, Serat Adu Jago, p. 26. Cockfighting in Javanese Muslim Society The
following narration proves that cockfighting was Ki Tumenggung
Tirtawiguna‘s favorite. ―Those who gathered in front of the gamblers brought the
roosters. Furthermore, the noble, rangga, demang, and ngabei
brought their best-prided roosters. Everything was complete,
Kyai Tumenggung said to Mas Patih Wirakandha to compete
immediately. Patih answered. Then, he informed the gamblers. Let us go there, together to compete with their prided cock! The gamblers said to have a match soon, but nothing matched JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 373 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto up yet. The match was smooth. Ki Tumenggung said subtly
that each cockfight is too ordinary. It is like a lion in a fight. Will they collide with each other? It is easy to win. It had not
been too long; those fighting cocks, all of whom looked
surprised, saw Pranacitra, who had just arrived. The gamblers
were all amazed.‖44 Gambuh poem, canto 6, stanzas 3 to 125, tells about the
pleasure of playing botoh sawung. The spectators placed bets on the
nobles‘ fighting cocks. The story represents botoh sawung was
commonly performed by Javanese aristocrats and was enjoyed by
the people as an exciting spectacle. As an exciting game,
cockfighting was prepared very seriously. Serat Adu Jago proves the seriousness of cockfighting. This
manuscript was written by Ki Mangunprawira (Pseudonym, Ki Ajar
Panitra) in 1939. Serat Adu Jago contains knowledge about the origin
of cockfighting, equipment for cockfighting, selection of location
for cockfighting, suitable forms of fighting cock, movements when
pitted, good fighting cocks from origin, good egg selection,
maintenance of fighting cock, and terms of rooster based on their
age. Seriousness is shown by the construction of knowledge about
the rules for producing quality fighting cocks. Owners of fighting
cocks must treat them with respect, providing the highest quality
food, choosing the best brooders, and determining superior eggs. Every morning, the owner must bathe and wipe the fighting cock. Every fighting cock‘s behavior must be observed; even the mating
process of fighting cocks is explained by the writer of Serat Adu Jago
in detail. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 374 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto According to Huizinga, playing is one of the human instincts,
as long as it is older than culture.48 The game is not only enjoyable,
but it also has a spiritual component.49 Huizinga explained some
essential factors in playing both individual and communal such as
contests, shows, exhibitions, challenges, preening, presenting
oneself, pretending, and binding rules.50 In this case, botoh sawung is
a game that allows each player to distinguish himself or their group. Every player Botoh sawung is bound by a set of rules which the
gambler must follow. These rules make the game more exciting and
even turn it into a place to celebrate the Javanese people‘s
hedonism. 49 Stef Aupers, ―Spiritual Play: Encountering the Sacred in World of Warcraft,‖
Valerie Frissen et.al (eds), Homo Ludens 2.0: Play, Media, and Identity (Amsterdam:
Amsterdam University Press, 2015), p. 75. 48 Johan Huizinga, Homo Ludens: A Study of the Play-Element in Culture (London,
Boston, & Henley: Routledge & Kegan Paul Ltd, 1949), p. 1.
49 Stef Aupers, ―Spiritual Play: Encountering the Sacred in World of Warcraft,‖
Valerie Frissen et.al (eds), Homo Ludens 2.0: Play, Media, and Identity (Amsterdam:
Amsterdam University Press, 2015), p. 75.
50 Huizinga, Homo Ludens: A Study of the Play-Element in Culture, p. 47.
51 Muhammad Khalid Masud, ―Shehu Usuman and Fodio‘s Restatement of the
Doctrine of Hijrah,‖ Islamic Studies 25, 1 (1986), pp. 65-67. 48 Johan Huizinga, Homo Ludens: A Study of the Play-Element in Culture (London,
Boston, & Henley: Routledge & Kegan Paul Ltd, 1949), p. 1. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021
6 Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society Newly hatched chicks receive particular behavior from the
caretaker or the owner. The rooster must be prayed for with the
mantra ―lincak gagak welung bingung‖ for seven times. For the cock,
the mantra recited is ―lincak gagak welung bingung‖ seven times. For
the hen, the spell recited is ―Si dhendheng, si wangkeng, keng kurungkeng,
dhek keng, urat kenceng, sira wangkeng, ati wanuh.‖45 g
g
g
g
The spells contain the hope that the chick can be a fighting
cock and the hen can produce many superior eggs. After nine
months of age, fighting cocks must be carefully cared for and
separated from other roosters: ―... The rooster that will be pitted,
from the age of nine months must begin to be cared for, caged
alone, may not be combined in a rooster cage, each rooster must be
caged individually.‖ 46 g
y
In the next section, the manuscript provides knowledge on
caring for fighting cocks. It must be removed from time to time in
order to be pleasant. If the rooster is not affected by naga kalolos
(losing power), it should not commonly mate with the hen or fight
with other roosters. The fighting cock is also kept for mating; thus,
the rooster does not get bileng disease which causes the body to
become fat and lose courage when fighting.47 Serat Adu Jago also explains the location of the cockfight, the
movements of the spectators, and the amount of gambling money
during the game. This manuscript states that cockfighting was a
popular pastime among the nobles and commoners. The nobles
constantly chewed betel during the game. The game of botoh sawung
attracted people‘s attention; therefore, the cockfighting arena was
always crowded. Some of them peeked between the chairs of the
nobles to see botoh sawung. They enjoyed botoh sawung because
humans are creatures who play games (homo ludens). JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 375 50 Huizinga, Homo Ludens: A Study of the Play-Element in Culture, p. 47. 51 Muhammad Khalid Masud, ―Shehu Usuman and Fodio‘s Restatement of the
Doctrine of Hijrah,‖ Islamic Studies 25, 1 (1986), pp. 65-67. Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government Cockfighting has been a topic of debate among scholars for a
long time. The prohibition of cockfighting is contained in the
Hadith History of Abu Dawud and At-Tarmidhi from the
companions of Ibn Abbas RA. In Islamic law, the Al-Qur‘an is the
highest hierarchy. The following hierarchy is Hadith, Ijma‘, and
Qiyas.51 The issue of fighting animals is not mentioned in the verses
of the Al-Qur‘an. The Al-Qur‘an describes several types of lawful
animals to use, consume, and ride. The Al-Qur‘an also mentions
the human obligation to love animals. The obligation is interpreted
as a prohibition on harming animals. What is prohibited by the
Qur‘an is gambling. In Al-Ma‘idah verse 91, it is explained that
gambling is an act that prevents the remembrance of Allah and
prayer. Therefore, the element of gambling in cockfighting is
prohibited by Islam. Nevertheless, cockfighting is still popular
among Javanese Muslims. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 376 Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society This reality implies that cockfighting has experienced a shift in
meaning since Islam became part of the Javanese people‘s lives. Cockfighting is not practiced as a sacrificial ritual is in Islam. The
Muslim community ―obediently‖ interpreted the cockfighting ritual
as a legacy of the local belief system that was not under Islamic
teachings during the Islamic period. Other Javanese Muslim
communities interpret cockfighting as part of a tradition—those
who preserve the tradition of cockfighting interpret cockfighting as
a symbol of solidarity. Building solidarity is still in line with Islamic
teachings. Thus, they felt they had not committed a violation. Cockfighting was also considered to have educational values by the
Javanese people who preserved the game. They assumed it was an
ancestral tradition that did not conflict with Islam. Throughout the
nineteenth to the early twentieth centuries, the Javanese Muslim
community regarded cockfighting as merely a spectacle and
entertainment. At that time, cockfighting games contained elements of
spectacle and entertainment that always attracted gamblers. The
Javanese Muslim society often participated in cockfighting, which
contained gambling, because it was more pleasant than ordinary. In
addition, cockfighting became an outlet for the severe burden of
life brought on by the colonial government‘ exploitation. For the
nobility, cockfighting gambling was a way to forget the economic
and political pressures of the colonial government. They believed
that winning cockfighting bets could solve financial issues in a short
time. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 53The original version in Javanese says: ―êndêming wong dhêmên ngabotohan, yèn kalah
rupak jagade, sirna katrêsnaning marang anak bojone, dibalèjèdi nganti balindhis, suwe-suwe
mrèmèn angapus-apusi marang sanak sadulure.‖ Ki Padmasusastra, Layang Madubasa
(Surakarta: Budi Utama, 1912), p. 4. 52 Ki Padmasusastra, Sêrat Tatacara: Ngadat Sarta Kalakuwanipun Têtiyang Jawi,
Ingkang Taksih Lumèngkèt Dhatêng Gugon-Tuhon (Semarang: H. A. Benyamin, 1893),
p. 216. Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government Gambling cockfighting could fill the spare time of the
unemployed nobles due to the intervention of colonial policies
against the indigenous government. Cockfighting always draws a large crowd to watch and place
bets, making prone to chaos. In the minds of the santri community,
Botoh sawung undermines aqidah for Javanese Muslims. In Serat
Tatacara written by Ki Padmasusastra, there is a dialogue between
nobles who discusses the pleasantness of playing cockfighting. His
interlocutor is a nobleman named Mandangjaplak. After returning from the Panaraga Islamic Boarding School,
one of the nobles reported his son had stopped playing botoh sawung. His son became a devout worship student who read the Alquran
every day and enjoyed reciting the Alquran in the langgar (prayer JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 377 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto room); he went Sastrajendra to study Javanese literature. As a santri,
the nobleman‘s son studied nature, kodrat, and the science of falaq.52
Through this conversation, Padmasusastra wanted to message that
playing botoh sawung was an evil deed. Botoh sawung was like opium,
making players want to keep betting despite losing and running out
of property. Padmasusastra‘s message about the negative impact of
ngabotohan (gambling) was also conveyed in Serat Madubasa. He
said: The drunkenness person who likes to gamble, when he has
lost of control, his world is like being destroyed. He loses his love
for his wife and children, his property runs out, and he likes lying to
his family.53 The preceding description shows two Javanese Muslims‘
thoughts against cockfighting and botoh sawung. To begin with,
cockfighting and botoh sawung are consider a tradition and a source
of joy in Javanese Muslim philosophy. Second, cockfighting and
botoh sawung are considered undesirable practices that are antithetical
to religious teachings and self-destructive in Javanese Muslim
philosophy. Cockfighting was often seen as a cause of poverty among
Javanese Muslims. Therefore, the Sultanate of Yogyakarta, one of
the kingdoms in Java, established regulations to regulate the
gambling of animal fights, including cockfighting. According to
Serat Angger Pradata Awal, Quail, and candlenut fighting were
permitted at the district level and above. However, the use of spurs
was prohibited by the Sultan of Yogyakarta. Serat Angger Pradata
Chapter 40 explains this regulation. 54 The original version in Javanese says: ―Mungguh wong bĕbotohan. Ingkang ingsun lilani,
bipati sakpandhuwur, ingkang ngadĕgake ngajago, lan angadu gĕmak. Utawa ngadu kĕmiri.
Nanging iku denrĕsaa, kang bĕcik bĕcik. Mĕnawa ana wong agawe prakara, dene yen nganti
ana prakara, wong tĕtukaran. Ana kang tatu utawa mati, kang amatrapana, marang wong
kang ngadĕgagke kĕbotohan iku mau, sira dhĕndhaa sekĕt reyal. Dene wong kang mati utawa
tatu, iku mau, yen ali warise ingkang tatu utawa mati, iku ora tarima, mulura gugate, marang
pradata... Ana dene wong ngĕbotohan. Kang ura ingsun lilaniĕ, kaya ta dhadhu kĕplek, kecek,
gimĕr, sakpĕpadhane, ngĕbotohan ngadu adu kang ura ingsun lilani, kayata ngadu jago tajen,
ngadu jangkrik. Iku si Adipati Danurĕja, ingkang anatrapna. Wong kang ngadĕgake
kĕbotohan mau, sira dhĕndhaa sĕlawe reyal. Yen nora mĕtu dhĕndhane sira gitika, kaping satus.
Dene wong kang nglurug ngĕbotohan. Sira dhĕndhaa nyĕpuluh reyal. Yen nora mĕtu dhĕndhane
sira gitika kaping sekĕt.‖ Sultan Hamengku Buwana, Serat Angger Pradata Awal (P.B.A
196) (Yogyakarta: Perpustakaan Museum Negeri Sanabudaya, 1865). JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government ―In the case of gamble people, I allow for the regent degree
and above, who hold competitions and pit quail or hazelnut. However, be careful. People fight if someone makes a case; if ―In the case of gamble people, I allow for the regent degree
and above, who hold competitions and pit quail or hazelnut. However, be careful. People fight if someone makes a case; if
someone is injured or dies, punish the person who made the JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 378 Cockfighting in Javanese Muslim Society gamble. Give a fine of fifty real. If the heirs do not accept it for
dead or injured people, proceed with the lawsuit to the civil
law... Gambling against each other, I do not allow, such as
pitting roosters with spurs, pitting crickets. It was the Duke of
Danureja who set the punishment. The person who founded
the gamble earlier, you will be fined twenty-five real. If you
don‘t get a fine, you can whip a hundred times. As for those
who come to gambling, you are fined ten real each. You can
whip it fifty times if you don‘t get a fine.‖ 54 The law guarantees the safety of the quail and candlenut
fighting games for nobles with the regent and above rank. The
consideration was that the finances of the regent and the rank of
nobility above him were more secure than those of low-ranking
nobles. Ordinary people were prohibited from participating in
gambling because it interferes with the finances of less qualified
people. Therefore, the kingdom arranged that only nobles were
allowed to gamble on certain animals. If a dispute causes the victim to be injured or die, the suspect is
subject to a fine. Those who do not pay the fine will be subjected
to corporal punishment until they are expelled to Lodaya (forest) or
Ayah (area). Gambling that was not permitted was cockfighting
with spurs and the cricket fight. Violators would be fined or caned. There were types of gambling that were allowed and prohibited by
the Sultan. Regarding cockfighting, Angger-angger Pradata Awal did not
regulate the usual cockfighting game. That is, the law allows
ordinary cockfighting and quail and candlenut fighting. 55 The original version in Javanese says: ―Bab angadêgake kalangan ngadu jago, utawa
ngadu jangkrik. Ăngka 10, manawa durung kalilan ing parentah, angadêgake kalangan jago
lan ngadu jangkrik, ana ing ratan utawa ing dalan gêdhe lan ing panggonan liyane kang
kaambah ing ngakèh. Dene jago lan jangkrik mau padha kaanggrak katur ing parentah sarta JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government The JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 379 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto prohibition only applied to cockfighting with spurs as a form of
gambling. Taji (spurs) is a weapon made of metal that is often used
in cockfighting. The use of spurs can be fatal for the rooster; it can
even injure and kill the owner. In addition, the gambling game of
cockfighting with spurs made gamblers fall into poverty because it
is more pleasant to bet when cocks kill each other than in ordinary
cockfighting. Presumably, this reality was the basis for considering
the prohibition of gambling on spurred cockfighting. If the Sultanate of Yogyakarta forbade cockfighting with spurs,
the Dutch East Indies colonial government forbade cockfighting
held in public places without permission. In Pranatan Pulisi Tumrap
Băngsa Jawi ing Indiya Nèdêrlan Chapter 2, the Dutch colonial
government imposed a fine of less than sixteen rupiahs and not
more than twenty-five rupiahs for committing the following
offenses. ―Chapter establishing an arena for cock or cricket fighting. Number 10, if the government has not permitted it to set up
cock and cricket fighting arenas on roads or major roads and
in other places, many people can access them. The
government threatened to kill all the roosters and crickets. Note Number 10: Since ancient times, the Javanese have
enjoyed cock and cricket fighting accompanied by gambling. Moreover, the government has long ordered strict regulations
to abolish gambling because it can cause poverty or misery, the
regulation is stipulated in the Staatsblad of 1817, number 8, and
until now, it applies as stated in the police regulation sheet in
Surabaya, chapter 29, and in chapter 48, in the chapter
regulation sheet for people who have regional culture located
west of the Cimanok River. In the case of government efforts,
this chapter of the case also includes advantages. Since the
prohibition of people playing bats and crickets in their fences
and houses is the same as playing cards in their homes, they
cannot be categorized as government guards. Prevent people
from gambling in the house only if gambling can cause
damage to the peace of the country.‖55 55 The original version in Javanese says: ―Bab angadêgake kalangan ngadu jago, utawa
ngadu jangkrik. banjur dipatèni kabèh. Katêrangan Ăngka 10. Wiwit ing jaman kuna băngsa Jawa iku padha
karênan angadu jago lan jangkrik kalawan totohan, apamanèh paprentahan wus lawas
andhawuhake pranatan kêncêng amurih sirnaning ngabotohan mau, awit bisa andadèkake
kamlaratan utawa sangsara liyane, mungguh pranatan iku kapacak ing layang sêtatsêblad taun
1817 ăngka 8, lan saprene tansah katindakake kaya kang kasêbut ing layang pranataning
pulisi ing Surabaya bab ping 29, lan ing bab ping 48, ing layang pranatan bab wong andarbèni
kabudayan bumi kaprênah sakulone kali Cimanok. Mungguh pangudine paprentahan bab
prakara iki saantara uga kalêbu kaduk. Awit ênggone anglarangi wong angadu jago lan
jangkrik ana sajêroning cêpuri lan omahe dhewe pêpadhane kaya wong dolanan kêrtu ana ing
sajroning omah, mula kang iku uga ora kalêbu dadi pangrêksane paprentahan. Amalangi wo
ngabotohan ana sajêroning omah, kajaba yèn ênggone ngabotohan mau bisa dadi jalaran
angrusakake tata têntrêming nagara. Pranatan Pulisi Tumrap Băngsa Jawi Ing Indiya
Nèdêrlan (Almanak 1913, H. Buning, 1913), pp. 50–51. Available online at
https://www.sastra.org/arsip-dan-sejarah/hukum-dan-pemerintahan/1736-prana-
tan-pulisi-tumrap-bangsa-jawi-ing-indiya-nederlan-h-buning-1913-1509
(accessed
on 14 August 2021).
56 Ruut Veenhoven ―Hedonism and Happiness ‖ Journal of Happiness Studies 4 56 Ruut Veenhoven, ―Hedonism and Happiness,‖ Journal of Happiness Studies 4
(2003), p. 437. Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government Ăngka 10, manawa durung kalilan ing parentah, angadêgake kalangan jago
lan ngadu jangkrik, ana ing ratan utawa ing dalan gêdhe lan ing panggonan liyane kang
kaambah ing ngakèh. Dene jago lan jangkrik mau padha kaanggrak katur ing parentah sarta JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 380 Cockfighting in Javanese Muslim Society Cockfighting in Javanese Muslim Society The regulation shows that the colonial government viewed
cockfighting gambling as a game that made people miserable and
contributed to poverty. The colonial government also banned the
game of fighting in one‘s own home. All acts of cockfighting
gambling were considered to be detrimental to the peace of the
country. The contents of the regulation can be interpreted that the
regulations regarding cockfighting gambling were made based on
experiences. The colonial government considered and assessed that
cockfighting gambling had the potential to trigger a riot. Even the
colonial government used a historical approach to look at the
preferences of the Javanese people that were detrimental to
themselves, society, and the state since ancient times. The influence of cockfighting gambling has prompted the
Javanese royal government and the colonial government to enact
legal regulations. Both the Sultanate of Yogyakarta‘s government
and the colonial government enacted legal restrictions to keep the
country at peace. However, this regulation can be interpreted as a
way to maintain the exclusivity of the cockfighting gambling game. The regulations regarding cockfighting gambling include a power
dynamic, allowing only the most powerful nobles play this game. Cockfighting had become a symbol of hedonism despite the
fact that it was regulated. It has a peculiarity, namely a pleasurable
experience. 56 It focuses on the fulfillment of pleasure and JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 381 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto satisfaction.57 It is associated with the ideology and behavior of the
Javanese elite. Therefore, the hedonism of the Javanese nobility was
always related to power. Power is the strength or authority to
influence thoughts and behavior as the wishes of the power
owner.58 Power is coercive but it is not felt. The ambition to gain prestige or authority has an impact on
power.59 Therefore, the actors and nobility exploited cockfighting
to obtain power from the crowd. The players also desired to
achieve prestige from their fellow nobles. Moreover, cockfighting
symbolized masculinity and bravery for the noble who participated. 57 Masha Ksendzova et.al., ―The Portrait of a Hedonist: The Personality and
Ethics behind the Value and Maladaptive Pursuit of Pleasure,‖ Personality and
Individual Differences 79 (2015), pp. 68–74; Chris Heathwood, ―Desire
Satisfactionism and Hedonism,‖ Philosophical Studies 128 (2006), pp. 539–63. Cockfighting: Its Influence on the Rules of the Colonial and
the Javanese Government Cockfighting was used to subjugate political competitors as a sign
of virility. 57 Masha Ksendzova et.al., ―The Portrait of a Hedonist: The Personality and
Ethics behind the Value and Maladaptive Pursuit of Pleasure,‖ Personality and
Individual Differences 79 (2015), pp. 68–74; Chris Heathwood, ―Desire
Satisfactionism and Hedonism,‖ Philosophical Studies 128 (2006), pp. 539–63.
58 S.F. Marbun, ―Pemerintah Berdasarkan Otoritas dan Kekuasaan,‖ Jurnal Hukum
(1996), pp. 30–34.
59 Robert Bierstedt, ―An Analysis of Social Power,‖ American Sociological Review, 15,
6 (1950), pp. 732–33. 59 Robert Bierstedt, ―An Analysis of Social Power,‖ American Sociological Review, 15,
6 (1950), pp. 732–33. 58 S.F. Marbun, ―Pemerintah Berdasarkan Otoritas dan Kekuasaan,‖ Jurnal Hukum
(1996), pp. 30–34. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Conclusion Cockfighting has been a Javanese custom since ancient times. Initially, it had a sacred value. In its development, secular values
dominated. Profane values strengthened because it was followed by
gambling. This change occurred in the Javanese Muslim community
when the teachings of Islam forbade botoh sawung (gambling
cockfighting). Cockfighting gambling is popular among the
Javanese Muslim community since it is a pleasurable experience,
especially when one of the roosters die. The curiosity about the
toughness of the noble‘s rooster became the next pull factor. Humans, after all, have the instinct to play (homo ludens). Therefore,
botoh sawung, which was prohibited by religion, has become a top-
rated game among Javanese Muslims. The text Serat Centhini, Serat Pranacitra, Serat Adu Jago, and Serat
Tatacara contains the views of the Javanese Muslim community on
cockfighting. These texts represent the pleasures of Javanese elite
nobles, as Islamic leaders, who play botoh sawung. Moreover, some JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 382 Cockfighting in Javanese Muslim Society religious leaders play botoh sawung in Serat Centhini. These stories
represent botoh sawung as a symbol of prestige among the aristocratic
elite. In addition, botoh sawung becomes a symbol of the owner‘s
masculinity and an arena for spreading power to subdue the
political opponents of the rooster owner. The winning rooster
could increase the authority of the owner. On the other hand, a
defeat could cause the rooster owner‘s authority to decline. However, Serat Tatacara considered that botoh sawung was a lousy
game. The pleasures of Javanese Muslims playing botoh sawung
influenced the legal policies of both the Javanese kingdom and the
colonial government. The Sultanate of Yogyakarta made the initial
angger pradata which regulates cockfighting gambling. Meanwhile,
the colonial government issued prohibitions on gambling
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Sampai 1970an: Dari Kesadaran Kultural Ke Kesadaran
Lingkungan.‖ Yogyakarta: Universitas Gadjah Mada, 2020. ----. ―Mitologi Sampai Perdagangan: Status, Peran, dan Makna
Burung dalam Masyarakat Jawa dari Zaman Kolonial hingga
Milenial.‖ Pramana Yuda (ed.). Konferensi Peneliti Dan Pemerhati
Burung (KPBBI ) IV Semarang. Semarang, 2018. Pranatan Pulisi Tumrap Băngsa Jawi Ing Indiya Nèdêrlan (Almanak 1913,
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merintahan/1736-pranatan-pulisi-tumrap-bangsa-jawi-ing-in-
diya-nederlan-h-buning-1913-1509 accessed on 14 August
2021. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 385 385 Adi Putra Surya Wardhana, Dennys Pradita, Fiqih Aisyatul Farokhah, and Andriyanto Raffles, Sophia. Memoir of the Life and Public Services of Sir Thomas
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(2012). Veenhoven, Ruut. JOURNAL OF INDONESIAN ISLAM
Volume 15, Number 02, December 2021 Ph.D Dissertation, Universiteit Leiden, 2015. ―Hedonism and Happiness.‖ Journal of Happiness
Studies 4 (2003). Walker, Samuel J. and Hanneke J.M. Meijer. ―More than Food;
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Quaternary International (2020). Woodward, Mark. Java, Indonesia, and Islam. London & New York:
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7,200 Chapter 4 Chemistry in the Operation and Maintenance of
Reverse Osmosis Systems Ph.D. Robert Y. Ning Additional information is available at the end of the chapter http://dx.doi.org/10.5772/39385 http://dx.doi.org/10.5772/39385 http://dx.doi.org/10.5772/39385 © 2012 Ning; licensee InTech. This is an open access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction Across the spectrum of industrial and municipal water utilization and treatment plants, ex‐
tensive desalination and purification of water relies on the use of reverse osmosis (RO)
membranes. Sustaining the productivity of RO plants as continuous processes for water pu‐
rification has been since the late 1970s, and still is, a significant technological challenge. The
challenge is magnified on the one hand by the increasing shortages of water thus driving
down the quality of available raw waters, and on the other hand by the demand and the
high cost of lost production that can result from insufficient productivity of RO systems. Re‐
duced productivity of RO plants exerts serious economic impact on the downstream pro‐
duction of steam, power, microelectronics, pharmaceuticals and beverages among other
products. Not only used in the front-end to provide supply of high quality process water,
the loss of RO capacity to process wastewater at the back-end to allow regulated discharges
can shut down production or operation of some industrial complexes. With all these re‐
quirements, efficient operation and maintenance (O&M) of RO plants based on an under‐
standing of chemistry is essential. The design and working of an RO system as a unit operation is widely described in articles,
books, technical literature and design software of membrane manufacturers and updated
versions of user association manuals, such as from the American Water Works Association
[1] The sensitivity of RO membranes towards fouling however has presented great challeng‐
es and crises to O&M personnel [2]. Once a plant is built, changes in source water quality,
inadequacies in pretreatment unit operations, and inappropriate O&M procedures lead to
costly repairs to the RO. Even more serious, is the stoppage of water supply to the entire
production plant of high value products. Insufficient attention to changing chemistry in raw
water, and inadequate performance of pretreatment units result in our current industry © 2012 Ning; licensee InTech. This is an open access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited. Advancing Desalination 86 practice of expecting 2 to 4 years membrane service life along with frequent stoppages for
membrane cleaning and system maintenance. When optimally controlled, RO membranes
have lasted more than 12 years. Systems exist that have operated continuously, and not have
to be cleaned for many years. 2. Membrane Fouling Mechanisms Feedwaters to RO systems typically are concentrated by a factor of 2 - 10 (50%-90% recov‐
ery) during production of permeate water. For simplicity in classification, three classes of
fouling can be said to occur [8-11]. 1. Introduction In this article, we point to aspects of process chemistry pecu‐
liar to RO plants [3-21]. 2.1. Firstly, there is scaling The solubility limits of various dissolved salts in the concentrate stream may be exceeded,
leading to deposition and growth of crystals in the flow channels and membrane surface of
the RO elements. This type of fouling is referred to as scaling. Most common examples of
scales are calcium carbonate, sulfates of calcium, strontium and barium, and calcium fluo‐
ride and calcium phosphate. In the examination of foulants by naked eye or with magnify‐
ing glass, crystals have well defined shapes. Inhibitors injected continuously into feedwaters
to suppress crystallization are called antiscalants. For scaling to occur, seed crystals from in
the super-saturated concentrate. The seed crystals may grow into discernable shapes such as
plates, flakes, prisms or needles, or remain as finely dispersed particles, visible or invisible
to the naked eyes. Antiscalants work by inhibiting the growth of such seed crystals, and
forcing the RO concentrate to remain for a time in a supersaturated state. This mechanism is
known as threshold inhibition. This task of scale growth inhibition is efficiently accomplish‐
ed by low concentrations of antiscalants maintaining high super-concentrations in the RO
concentrate. The capabilities of certain antiscalants in controlling the most common scales
are listed in Table 1. Such antiscalants can be used to effectively replace traditional pretreat‐
ment methods of removing the offending foulants from the raw water stream [4-7, 21]. 2.2. Secondly, there is colloidal fouling The foulants appear typically as colorless to yellow or brown soft amorphous layer during
autopsy when membranes are cut and unrolled for visual examination [10]. Raw waters con‐
tain heavy loads of particles ranging from the visible kind to the smallest of the invisible. Colloidal particles can be considered here as less than 1.0 micron in size. Below 1 micron,
they are invisible to the naked eye, nearly undetected by turbidity and Silt Density Index
(SDI) measurements. The 0.45 micron filters used in SDI measurement do not retain colloi‐
dal particles. In fact even microfiltration and ultrafiltration pretreatment in RO systems still
pass colloidal particles that result in severe colloidal fouling of the RO membranes
[14,18,19]. Elemental composition analyses of washed and dried colloidal foulants for ele‐
mental carbon, hydrogen and nitrogen generally show predominance of complex microbial
matter from natural sources. Inorganic components clearly discernable are clays (aluminum Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385
8 87 silicate), silt (ferric-aluminium-magnesium silicates), silica (polymer represented by compo‐
sition of SiO2), and ferric and aluminum oxyhydroxides when such are used as coagulants
for water clarification upstream [10, and unpublished data]. RO Foulant
Traditional Pretreatment
Current Capability
1. Calcium Carbonate
Acidification to lower LSI, then with
antiscalant to maximum LSI=2.5
Antiscalant alone:
LSI=3.3;S&DSI="/4.5
2. Iron, manganese
Oxidation/filtration: Greensand,
manganese dioxide, catalytic oxid’n
Antiscalant alone: Fe and Mn at "/
8ppm
3. Silica: Reactive
Lime, Ion-Exchange (OH)
Antiscalant: "/280ppm
Non-reactive
None
Antifoulant: variable
4. Calcium Sulfate
Lime, Ion-Exchange
Antiscalant: "/400x sat'n
5. Strontium Sulfate
Ion-Exch ange
Antiscalant: "/43x sat'n
6. Barium Sulfate
Ion-Exchange
Antiscalant: "/51x sat'n
7. Calcium Fluoride
Lime, Ion-Exchange
Antiscalant: "/16,000x sat'n
8. Colloidal Organic
Matter
and Sulfur
UF,
MF,
coagulation/clarification/
MMF,
slow sand and carbon filter
Antifoulant alone
Table 1. RO System Design Advances Made Possible by New Antiscalant and Antifoulant Chemicals. ble 1. RO System Design Advances Made Possible by New Antiscalant and Antifoulant Chemicals. Colloidal matter pre-existing in feedwater can aggregate and adhere to the membrane and
brine flow channels due to increased concentration, salinity, compaction, flocculation, sur‐
face interactions and other physical and chemical factors [11, 17-19]. The colloids can be‐
come organic or inorganic or composite flocs. Dissolved ionic ferric, aluminum and calcium
hydroxides and silicic acid grow to increasing particle sizes by polymerization [3,17,18]. 2.2. Secondly, there is colloidal fouling Cross-linking, and complexation of organic and inorganic polymers become gels and amor‐
phous foulants commonly seen on membranes [10,11]. Biotic debris such as polysaccharides
and dead cellular matter contribute largely to this type of foulants. Through solving numer‐
ous fouling problems in existing RO plants, it has become obvious that excessive and inap‐
propriate application of pretreatment chemicals aggravate the tendency of natural colloids
present in RO feedwaters to coagulate and become foulants. Anticoagulants and anti-depo‐
sition agents recently developed show promise in inhibiting this fouling process [14]. The
term antifoulants then can be a term applied specifically in this particulate fouling context. 2.4. An over-riding effect Involving coagulation and deposition of colloidal particles in the RO system parallels the
delta effects of large river systems. Finer and finer particles in river water that survive phys‐
ical deposition during the river’s meandering course reaches the sea. When the low salinity
(low Total Dissolved Solids-TDS) river water meets the high TDS seawater, colloidal parti‐
cles coagulate and precipitate to form the river delta. This is a model of what happens in the
last stages of the RO membrane system where concentrations of colloidal particles and TDS
rise rapidly, and colloidal fouling takes place. 3. Antifoulant Chemical Design and Application The term antifoulant used here is in its broadest meaning covering scaling, particulate foul‐
ing and microbial fouling- the three classes of fouling mechanisms discussed above. Strat‐
egies aimed at controlling each type of fouling is summarized here. 2.3. Thirdly Biofouling is a prominent source of fouling. True of all water treatment or distribution sys‐
tems, is the growth and anchoring of microorganisms. Moderate temperatures and minimal
nutrient levels in RO raw waters can support at times explosive growths of microorganisms. Bacteria capable of cell division every 20 minutes can grow from a normal count per unit vol‐ Advancing Desalination 88 ume of water to millions in the period of an 8 hours shift. Due to the tendency of bacteria to se‐
crete polymers that anchor themselves to surfaces to facilitate growth as the biofilm, this
fouling mechanism is unique and poses a serious threat to the operation of RO systems. This
threat is compounded by the great difficulty of treating and completely removing biofilm from
the membrane surface. Associated with biofouling of proliferating nature, is the large pres‐
ence of non-proliferating organic materials secreted or deposited in natural waters. Microbes
and planktons secrete into their water environment large amounts of exocellular polysacchar‐
ides in the sunlit surface waters on land and at sea, then remain in the waters as cellular de‐
bris. For RO systems maintenance, biofouling then has the two separate component of biofilm
proliferation and the colloidal organic fouling by mobile colloidal particles. 3.3. Concerning prevention and management of bio-fouling In water treatment systems, the literature is extensive. Much of the art and science found
useful, is applicable to RO systems as well. Several factors peculiar to the RO system can be
mentioned. Chemicals used to sanitize and clean the system have to be chemically compati‐
ble with the thin, salt-rejecting, polyamide or cellulose acetate barrier membrane. Of prime
concern is that accumulation and exponential growth of the microorganisms should not be
allowed to occur within the system. Pretreatment of feedwater, adequate maintenance of up‐
stream unit operations, continuous flow of water through the RO unit, good monitoring and
sanitization program, and used of preservatives during downtime [15] are important to this
end. Normalized permeate flow and differential pressure in the system [20] are sensitive in‐
dicators of bio-fouling. 3.2. For controlling colloidal fouling The task is much more challenging due to the variety of types of potential foulants and the
complexity of their interactions [3,4,8-11,13,14, 17-19], with each other in the same water,
and with the membrane. Stability and agglomeration of colloidal particles is a subject of ma‐
jor importance in natural waters as well as in the treatment of process waters [14]. Drawing
on the basic science of colloids, and testing of model foulants suggested by RO foulant anal‐
ysis data [10,14,19], progress is made steadily with the development of antifoulants. 3.1. For scale control The development and application of antiscalants is well known and reviewed in the field of
boiling water and cooling water chemistry, and applied to boilers, evaporators, cooling tow‐
ers and cooling systems. Anionic polymers, polyphosphates and organo-phosphorous com‐
pounds, sometimes referred to as threshold inhibitors and dispersants, are used in sub-
stoichiometric amounts, usually in the range of 1-5 mg/liter concentrations in RO systems. By
binding to surfaces of growing crystal nuclei, the rates of crystallization from supersaturated
solutions are retarded, and crystal-packing orders are modified. By this mechanism, crystalli‐
zation rates are so retarded that although super-saturation of solutes in the water will eventu‐
ally equilibrate through crystallization, within the residence time of the water in the system,
there is little or no scale formation. The uniqueness of RO among water conditioning systems
is that the residence time is very short (a few seconds), concentration of seed crystals is low,
and temperature is constant. For this reason, higher levels of super-saturation without crystal‐
lization are possible. On the other hand, the limits of saturation and rates of scaling are hard
to model, measure and predict. Interferences come from other solutes in the water, organic or
inorganic. Assumptions of RO fouling limits vary considerably among practitioners. Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385 89 3. Decrease of 1 to 2% in salt rejection. If a cleaning procedure fails to fully restore the system performance to the reference RO
system startup values, it is certain that continued use of the same cleaning procedure will
lead to accelerating decline in system performance and increasing cleaning frequency. For
this reason, it is important to address two issues at this point: a) find an improved clean‐
ing procedure, b) investigate possible improvement of pretreatment to avoid membrane
fouling. Continue cleaning and process improvement efforts until stability of the RO per‐
formance is attained. Even with well piloted and designed RO plants, and smooth opera‐
tions initially, source water qualities invariably change over time. Equipment and personnel
changes also impact performance, requiring constant vigil and preparedness for continu‐
ous improvement of the plant. 4.1. Choosing Cleaners Major membrane manufacturers generally define five types of foulants for which various
generic chemicals are recommended for blending at the site where cleaning solutions are
prepared. The five types of foulants are: 1) Acid-soluble Foulants, 2) Bio-film/Bacterial
Slime/Biological Matter, 3) Carbon-containing Oils/Organic Matter, 4) Dual Organic and In‐
organic Coagulated Colloids, and 5) Silica and Silicates. Proprietary booster cleaners are
commercially available to fortify the effectiveness of these generic cleaners that are formu‐
lated at the site. For convenience and technical support, a large variety of proprietary RO
membrane cleaners are available from chemical suppliers that specialize in RO opera‐
tions. Such proprietary cleaners and cleaning support are available when generic cleaners
do not perform adequately. p
q
y
4.2. Cleaning Strategies 4. Membrane Cleaning Practical procedure for maintenance cleaning is limited to the re-circulation of cleaning solu‐
tions through the membrane elements. By a patented method [16] of membrane recondition‐
ing, spiral wound elements with the hard casing removed, are routinely used in selecting
effective cleaners for cleaning by re-circulation. This allows for visual inspection of mem‐
brane surface after each cleaning test. It is apparent that except for easily soluble foulants
like calcium carbonate, calcium phosphate or ferric and aluminum hydroxide, and less easi‐
ly dissolved foulants like silica, silicates, calcium sulfate and strontium sulfate, nearly all
other RO foulants are only slightly dissolved in even the best matched cleaning solutions
with extensive soaking. Removal requires high tangential flow velocities to facilitate detach‐
ment of foulants from the surfaces of the membrane and the brine-side spacer screen. Clean‐
ing is usually partially effective, especially where flow channels are clogged, and large
patches within the elements are inaccessible to the re-circulating cleaning solution. For this
reason, the need for cleaning should be minimized or completely eliminated by the new an‐
tiscalants and antifoulants now available, and adequate pretreatment and pilot testing of
cleaning process developed during pilot testing stage. When cleaning is necessary during
operation, it should be performed at the earliest stages of fouling. It is generally agreed among membrane manufacturers and practitioners that RO systems
should be cleaned before the following performance changes are reached: Advancing Desalination 90 1. Loss of 10 to 15% in normalized permeate flowrate. 1. Loss of 10 to 15% in normalized permeate flowrate. 2. Increase of 10 to 15% in differential pressure. 4.2. Cleaning Strategies Experience has shown that within the same class of foulants, responses to the same cleaning
solution can vary considerably. Elemental analyses of foulants and cleaning studies have
shown that more than one type of foulant can be present on the membrane at the same time,
requiring sequential cleaning with different cleaners. Sometimes even the order of cleaners
used would make a significant difference. All this is to say that the choice of cleaners and
the cleaning procedure to be used is an empirical science. For a given set of conditions in a
plant, cleaning efficiencies are improved by trials over time. The progress of improvement
can be greatly accelerated by conducting off-line cleaning studies on test skids for single
fouled elements taken from the plant. Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385
9 91 When a better cleaning method is needed in the plant, the following are the alternative strat‐
egies: Strategy 1: The plant has a history of using generic cleaning chemicals, and modest improve‐
ment in effectiveness is needed, consider purchase of proprietary booster cleaners. Strategy 2: A significant cleaning improvement is needed, look for proprietary cleaner sup‐
plier with associated cleaning expertise. Option 1: With prior knowledge of the characteris‐
tics of the foulant on hand, with consultation with the supplier, select a combination of
cleaners for trial in the plant. Option 2: Send one to three fouled elements to specialist for
cleaning study, foulant analysis and review of plant performance history and pretreatment
process. Document the findings along with pilot cleaning results using a recommended im‐
proved cleaning procedure. Simultaneously address recovery of the plant and avoidance of
repeated fouling. Option 3: Send all fouled elements for off-site cleaning by specialist. Strategy 3: All cleaning efforts by re-circulation of cleaning solutions have failed, consider
non-routine methods like using proprietary membrane conditioning liquids or membrane
reconstruction process by which membrane bundle is unrolled, cleaned leaf by leaf, then re‐
stored with a new hard-casing. 4.3. On-line Cleaning Procedure Basically there are six (6) steps in the cleaning of membrane elements in place in RO sys‐
tems: 1. Mix Cleaning Solution. 2. Low Flow Pumping. Pump preheated cleaning solution to the vessels at conditions of low
flow rate (about half of that shown in Table 2) and low pressure to displace the process wa‐
ter. With the RO concentrate throttling valve completely open to minimize pressure during
cleaning, use only enough pressure to compensate for the pressure drop from feed to con‐
centrate. The pressure should be low enough that essentially no permeate is produced. A
low pressure minimizes re-deposition of dirt on the membrane. Dump the concentrate, as
necessary, to prevent the dilution of the cleaning solution. 3. Re-circulate. After the process water is displaced, cleaning solution will be present in the
concentrate stream. Re-circulate the concentrate to the cleaning solution tank and allow the
temperature to stabilize. 4. Soak. Turn the pump off and allow the elements to soak. Sometimes a soaking period of
about 1 hour is sufficient. For difficult to clean foulants, an extended overnight soaking peri‐
od of 10-15 hours is beneficial. To maintain a high temperature during an extended soaking
period, use a slow re-circulation rate (about 10% of that shown in Table 2). 5. High Flow Pumping. Feed the cleaning solution at the rates shown in Table 2 for 30-60
minutes. The high cross-flow rate flushes out the foulants removed from the membrane sur‐
face by the cleaning, with minimal or no permeation through the membrane to avoid com‐
pacting the foulant. If the elements are heavily fouled (which should not be a normal Advancing Desalination 92 occurence), a flow rate which is 50% higher than shown in Table 1 may aid cleaning. At
higher flow rates excessive pressure drop may be a problem. The maximum recommended
pressure drop is 20 psi per element or 60 psi per multi-element vessel, whichever value is
more limiting. Note: In this cleaning mode, foulants are generally partially dissolved in the cleaner and par‐
tially dislodged physically from the membrane and flow channels without dissolving. An
in-line filter removes the re-circulated particles, and should be monitored for cartridge re‐
placement. 6. Flush Out. Pre-filtered raw water can be used for flushing out the cleaning solution, un‐
less there will be corrosion problems such as with seawater corroding stainless steel piping. Multi Stage Systems For tapered multi-staged systems the flushing and soaking steps can be performed simulta‐
neously in the entire array. The high flow-rate re-circulation step however should be carried
out separately for each stage, so that the flow-rate is not too low in the first stage and too
high in the last. This can be accomplished either by using one cleaning pump and operating
one stage at a time, or using a separate cleaning pump for each stage. 4.3. On-line Cleaning Procedure To prevent precipitation, the minimum flush temperature is 20 deg. C. Additional Notes: The pH should be monitored during acid cleaning. The acid is consumed
when it dissolves alkaline scales. If the pH increases more than 0.5 pH units, add more acid. Feed Pressure*
Element Diameter
Feed Flow Rate
(psig)
(inches)
Per Vessel (GPM)
20 - 60
2.5
3 - 5
20 - 60
4
8 -10
20 - 60
6
16 -20
20 - 60
8
30 -40
* Dependent on the number of elements in the pressure vessel
Table 2. Recommended High Re-circulation Flow Rates During Cleaning. Table 2. Recommended High Re-circulation Flow Rates During Cleaning. 4.4. Control and Improvement of Cleaning Process To assure complete recovery of membrane performance by cleaning, the system perform‐
ance should be adequately controlled by trending of normalized flux, differential pres‐
sure and salt rejection [20] to 1) trigger a cleaning when any monitored parameters change
from normal baseline by 10-15%, 2) record the trended parameters before and after each
cleaning, 3) initiate improvement actions for better cleaning if membrane performance does Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385 93 not fully recover. A change in responsiveness to previously effective cleaning process sig‐
nals a change in fouling pattern that requires immediate attention. If partial cleanings are
allowed to continue, the system performance will decline at increasing rate, and will be‐
come increasingly difficult to recover. In-place cleaning processes are improved primarily by the choice of cleaning chemicals and
the order of the application sequence. Depending on the composition of the complex fou‐
lants, when two or more cleaners are found necessary, often the order in which they are
used is important. Also critical, but to lesser extents are the variables of time, tempera‐
ture, and cross-flow rate. Through thorough review of the water and pretreatment chemistry, analyses of the fou‐
lant composition and source, and customized selection of antiscalants, dispersants and high
performance cleaners, both fouling avoidance and reliable plant performance can be at‐
tained. Practical experiences show that plant performances invariably change over years of
service due to imposed changes in source water, equipment, regulatory and human fac‐
tors. Attentive operation and maintenance assures early detection of developing problem,
and timely adjustments. 5. Conclusion High rejection of dissolved salts and suspended colloidal particles in RO feedwater cause
scaling and colloidal fouling of membranes. Understanding the chemistry of membrane
fouling and methods of control, coupled with keen monitoring during O&M, are necessary
for the assurance of RO process stability. Ever increasing need for maximum water extrac‐
tion, while reducing the volume of concentrate requiring disposal pose challenges to chemi‐
cal understanding and control by O&M personnel. Information provided in this chapter
provide key words and concepts for the readers to glean from the expansive literature. For readers who assume responsibilities of existing RO plants, problems may have arisen
due to inadequate pretreatment design, or due to changed sources of raw water. A compan‐
ion chapter on pretreatment for reverse osmosis systems is available on line in an open-ac‐
cess book on Desalination [22]. Author details Ph.D. Robert Y. Ning* Address all correspondence to: Rning@kingleetech.com Address all correspondence to: Rning@kingleetech.com
King Lee Technologies, San Diego, California, United States of America King Lee Technologies, San Diego, California, United States of America Advancing Desalination 94 References [1] Bergman, R. Ed (2007). Reverse Osmosis and Nanofiltration. , Manual M46, 2nd Edn.,
American Water Works Association, Denver, CO. [2] Paul, D. H. (2003). The Four Most Common Problems in Membrane Water Treatment
Today, Analyst, Winter, 1-5; and world-wide training seminars of D.H. Paul, Inc. [3] Ning, R. Y. (2003). Discussion of Silica Speciation, Fouling, Control and Maximum
Reduction. Desalination, 151, 67-73. [4] Ning, R. Y., Troyer, T. L., & Tominello, R. S. (2009). Antiscalants for Near Complete
Recovery of Water with Tandem RO Process. Desalination and Water Treatment, 9,
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Osmosis Plants. Desalination, 143, 29-34. [6] Ning, R. Y. (2001, September). Antiscalants That Permit Operation of RO Systems at
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nologists, Phoenix, AZ, September 17-20. [14] Ning, R. Y., Troyer, T. L., & Tominello, R. S. (2003). Chemical Control of Colloidal
Fouling of Reverse Osmosis Systems. World Congress on Desalination and Water Re‐
use, Intern. Desal. Assoc., Bahamas, Sept. 28-Oct.3; Desalination, 172, 1-6 (2005). [15] Varnava, W., Silbernagel, M., Kuepper, T., & Miller, M. (1996, August). Reverse Os‐
mosis Element Preservation Study. Proceedings of Biennial Conf., Amer. Desalting As‐
soc., 308-327. Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385
9 Chemistry in the Operation and Maintenance of Reverse Osmosis Systems
http://dx.doi.org/10.5772/39385
9 95 [16] Netwig, C. L., & Kronmiller, D. L. (1993). U.S. Patent No. 5,250,118. [17] Ning, R. Y. (2010). References Reactive Silica in Natural Waters- A Review. Desalination and Wa‐
ter Treatment, 21, 79-86. [18] Ning, R. Y. (2009). Colloidal Iron and Manganese in Water Affecting RO Operation. Desalination and Water Treatment, 12, 162-168. [19] Ning, R. Y., & Troyer, T. L. (2007). Colloidal Fouling of RO Membranes following
MF/UF in the Reclamation of Municipal Wastewater. Desalination, 208, 232-237. [20] Troyer, T. L., Tominello, R. S., & Ning, R. Y. (2006, September). A Method to Auto‐
mate Normalization and Trending for RO Plant Operators. Ultrapure Water, 37-43. [21] Ning, R. Y. (2003, September). Process Simplification Through the Use of Antisca‐
lants and Antifoulants. Ultrapure Water, 17-20. [22] Ning, R. Y. (2011). Pretreatment for Reverse Osmosis Systems, in Expanding Issues in
Desalination, Ning, R.Y., Editor, InTech Open Access Book. Available: http://
www.intechopen.com/articles/show/title/pretreatment-for-reverse-osmosis-systems.
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y (
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3 Statistics New Zealand New Zealand in profile: An overview of New Zealand's people, economy and
environment (Statistics New Zealand, February 2014) at 3. y
4 Kyleisha Foote & Mike Joy "The true cost of milk: Environmental deterioration vs. profit in the New Zealand
dairy industry" (paper presented at the 2014 New Zealand Agricultural & Resource Economics Society (Inc.),
Nelson, August 2014). 1 Ministry for the Environment Valuing Our Clean Green Image (Ministry for the Environment, August 2001).
2 Tim Herzog, Jonathan Pershing, and Kevin A. Baumert Navigating the Numbers: Greenhouse Gas Data and
International Climate Policy (World Resources Institute, 2005) at 22. LOTTIE BOARDMAN Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? ,
g
)
5 Alastair Cameron "New Zealand Emissions Trading Scheme" in Alastair Cameron (ed) Climate Change Law
and Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 239 at 244 – 245. 9 Office of the Minister for Climate Change Issues "Emissions Trading Scheme Review 2012 – final dec
on amendments to the Climate Change Response Act 2002". y
g
6 Ministry for the Environment "United Nations Framework Convention on Climate Change" www.mfe
7 ONE News "John Key defends Kyoto decision" (12 November 2012 ) http://tvnz.co.nz. y
g
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y
,
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2 Tim Herzog, Jonathan Pershing, and Kevin A. Baumert Navigating the Numbers: Greenhouse Gas
International Climate Policy (World Resources Institute, 2005) at 22. 8 "The Climate Change Response (2050 Emissions Target) Notice 2011" (31 March 2011) 41 New Zealand
Gazette 987. g
p
10 Jessika Luth Richter and Lizzie Chambers "Reflections and Outlook for the New Zealand ETS: must
uncertain times mean uncertain measures?" (2014) 10 Policy Quarterly 57 at 63. y
g
g
y
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2 Tim Herzog, Jonathan Pershing, and Kevin A. Baumert Navigating the Numbers: Greenhouse Gas Data and
International Climate Policy (World Resources Institute, 2005) at 22.
3 Statistics New Zealand New Zealand in profile: An overview of New Zealand's people, economy and
environment (Statistics New Zealand, February 2014) at 3.
4 Kyleisha Foote & Mike Joy "The true cost of milk: Environmental deterioration vs. profit in the New Zealand
dairy industry" (paper presented at the 2014 New Zealand Agricultural & Resource Economics Society (Inc.),
Nelson, August 2014).
5 Alastair Cameron "New Zealand Emissions Trading Scheme" in Alastair Cameron (ed) Climate Change Law
and Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 239 at 244 – 245.
6 Ministry for the Environment "United Nations Framework Convention on Climate Change" www.mfe.govt.nz.
7 ONE News "John Key defends Kyoto decision" (12 November 2012 ) http://tvnz.co.nz.
8 "The Climate Change Response (2050 Emissions Target) Notice 2011" (31 March 2011) 41 New Zealand
Gazette 987.
9 Office of the Minister for Climate Change Issues "Emissions Trading Scheme Review 2012 – final decisions
on amendments to the Climate Change Response Act 2002".
10 Jessika Luth Richter and Lizzie Chambers "Reflections and Outlook for the New Zealand ETS: must
uncertain times mean uncertain measures?" (2014) 10 Policy Quarterly 57 at 63.
11 Jonathan Boston and Frieder Lempp "Climate change: Explaining and solving the mismatch between
scientific inertia and political inertia" (2011) 24 AAAJ 1001 at 1002.
12 (
)
y Q
y
11 Jonathan Boston and Frieder Lempp "Climate change: Explaining and solving the mismatch between
scientific inertia and political inertia" (2011) 24 AAAJ 1001 at 1002.
12 At 1006. Ministry for the Environment Valuing Our Clean Green Image (Ministry for the Environment, August 200 on amendments to the Climate Change Response Act 2002 .
10 Jessika Luth Richter and Lizzie Chambers "Reflections and Outlook for the New Zealand ETS: must
uncertain times mean uncertain measures?" (2014) 10 Policy Quarterly 57 at 63.
11 Jonathan Boston and Frieder Lempp "Climate change: Explaining and solving the mismatch between I.
Introduction New Zealand and New Zealanders have a complex and somewhat contradictory relationship
with the natural environment. While New Zealanders enjoy their country's significant natural
beauty and profit from its “clean, green” image,1 New Zealand’s per capita greenhouse gas
(“GHG”) emissions are near to twice those of the United Kingdom2 and the environmental
cost of dairying (New Zealand’s highest export earner)3 arguably exceeds the profit made
from it.4 It is in this context that New Zealand's primary action on climate change is an
emissions trading scheme ("ETS") for GHGs that does not include half of its emissions (those
that come from agriculture) and would be counted as successful if it reduced emissions only
minimally.5 New Zealand did not commit to the second commitment period under the Kyoto
Protocol6 and yet the current National government continues to maintain the stance that New
Zealand should be a “fast follower” when it comes to climate change action.7 The National
government has set the goal of reducing carbon emissions by 50% by 20508 and has said that
it seeks to encourage a smooth transition to a low-carbon economy.9 While it could be
argued that current policies are not encouraging this transition at all,10 it is an understandable
goal given the significant changes that need to take place. Short of strengthening the ETS, an
initiative that could assist in this transition would be requiring companies to take into account
their environmental impact and (at least for listed companies) to report on their
environmental impacts. Disclosure of environmental impact information by companies
would be an important step in transitioning to a low-carbon and otherwise environmentally-
sustainable economy and society. To do anything about the problems that humanity faces,
the environmental impacts of business must be understood. This accounting asymmetry is
one of four political asymmetries that Boston and Lempp identify as being influential in the
inability of democracies to take action on climate change.11 As they quote:12 1 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? What we measure affects what we do; and if our measurements are flawed, decisions may be
distorted. cl 7.4; Corporations Act 2001 (Cth), s299(1)(f).
15 Sarbanes-Oxley Act of 2002, Pub. L. No. 107-204, 116 Stat. 745. y
16 Companies listed on a relevant stock exchange. p
(
)
X Corporate Governance Council Corporate Governance Principles and Recommendations (3rd ed, 2014)
; Corporations Act 2001 (Cth), s299(1)(f). 13 Companies Act 2006 (UK), s 414C. ASX Corporate Governance Council Corpora
cl 7.4; Corporations Act 2001 (Cth), s299(1)(f). y
,
,
16 Companies listed on a relevant stock exchange. y
anies listed on a relevant stock exchange. Companies Act 2006 (UK), s 414C.
14 ASX Corporate Governance Council Corporate Governance Principles and Recommendations (3rd ed, 2014),
cl 7.4; Corporations Act 2001 (Cth), s299(1)(f).
15 Sarbanes O le Act of 2002 P b L No 107 204 116 Stat 745 mpanies Act 2006 (UK), s 414C.
X Corporate Governance Council Corporate Governance Principles and Recommendations (3rd ed, 2014) I.
Introduction Choices between promoting GDP and protecting the environment may be false
choices, once environmental degradation is appropriately included in our measurement of
economic performance One reason why climate change action is not taken is because current systems are set up to
measure financial cost, without taking into account the environmental costs of particular
courses of action. As these costs are better understood, the case for climate change (or other
environmental) action becomes much stronger. Corporate environmental disclosure and
corporate consideration of the environment when making decisions are areas where New
Zealand has not been a “fast follower”. New Zealand is not the only country which lacks
mandatory corporate environmental reporting; however, other common law countries
including the United Kingdom,13 Australia,14 and the United States of America15 all have
some form of mandatory corporate environmental reporting, at least in respect of listed
companies.16 This paper addresses whether New Zealand should introduce a requirement for company
directors to consider the environment when making decisions, and, at least for listed
companies, require companies to report on their environmental impact. The first section of
the paper (Parts II – V) will examine the current relationship between New Zealand
companies and the environment, by addressing: (a) law relating to company decision-making, reporting and disclosure, with a
particular focus on companies listed with the NZX (Part II); (b) global environmental problems arising from a “business-as-usual” approach (Part
III); (c) responses to these environmental challenges in New Zealand’s environmental law
and the opportunities for corporate discretion (Part IV); and (d) voluntary responses of New Zealand companies to these issues (Part V). The paper will then consider whether New Zealand should incorporate environmental
considerations and environmental reporting into company law. Part VI will discuss the
rationale and justification for requiring corporate consideration of the environment and for
corporate environmental reporting. Part sVII - IX will critically analyse three options for
influencing corporate decision making in relation to the environment and encouraging
corporate environmental reporting. Part VII will consider the United Nations Global
Compact ("UNGC") and compare it to existing voluntary environmental initiatives in New
Zealand. Part VII will also discuss the efficacy of mandatory environmental reporting. Part 2 2 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? VIII will analyse the "enlightened shareholder value" provisions in the UK Companies Act
2006 and associated regulation. II.
The decision-making and disclosure obligations of New Zealand
companies Not surprisingly, the most important piece of legislation relating to companies in New
Zealand is the eponymous Companies Act 1993 ("CA" or "NZ Act"). The CA is the primary
source of rules for companies from incorporation through to liquidation. The vast majority of
companies incorporated under the CA are limited liability companies; 17 "owners" of the
company own shares in it. The shareholders have no direct claim on company assets as the
assets are owned by a separate legal person, the company.18 The CA provides that the
company will be managed by or under the supervision of a board of directors19 who will be
elected or appointed by the shareholders of the company.20 The board can delegate the on-
the-ground running of the company to a chief executive officer and other employees if they
so wish.21 However the overall responsibility for the company's actions lies at the feet of the
directors.22 At s 130(2).
23 Peter Watts Directors' Powers and Duties (LexisNexis, Wellington, 2009) at 125.
24 Companies Act 1993, s 131. A. Directors' duties A. Directors' duties The CA sets out a number of duties that the directors owe, some to the company and some to
shareholders. Many of the duties owed to the company are codified derivations of common
law and equitable duties.23 17 Companies Office "Legislation" www.business.govt.nz.
18 18 Companies Act 1993, s 15.
19 I.
Introduction Part IX will assess a suggested directors’ duty requiring
companies to interact with the environment in a sustainable way. Part X will discuss all three
options and conclude the paper. II. The decision-making and disclosure obligations of New Zealand
companies II. The decision-making and disclosure obligations of New Zealand
companies 22 At s 130(2). At s 36.
21 At s 130(1).
22 At s 130(2). 20 At s 36. 21 At s 130(1). p
19 At s 128. Directors owe positive duties to the company to: Directors owe positive duties to the company to: (a) "act in good faith and in what the director believes to be the best interests of the
company";24 (a) "act in good faith and in what the director believes to be the best interests of the
company";24 (b) exercise their powers for a proper purpose;25 and (c) act with "the care, diligence, and skill that a reasonable director would in the same
circumstances".26 On the other hand, directors owe duties to the company not to: 26 At s 137. 3 3 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? a) agree to or cause or allow the business of the company to be carried on in a manne likely to create a substantial risk of serious loss to the company's creditors;27 and y
p
y
;
(b) agree to the company incurring an obligation, unless the director believes at the time
on reasonable grounds that the company will be able to perform the obligation when it
is required to do so.28 The duties are broadly drawn with case law filling in some of the picture. However, there is a
broad discretion left to directors and the courts will usually defer to the judgment of directors
where decisions are taken in good faith.29 A director's primary duty is to act in the best interests of the company.30 This is usually
interpreted to mean "in the best interests of the shareholders as a whole".31 The best interests
of the shareholders as a whole are presumed to be (unless the constitution says otherwise) to
maximise the profits of the company.32 Where the company is insolvent or close to insolvent,
the best interests of the company cease to be completely identified with the interests of the
shareholders – at that point, the interests of the creditors must be considered.33 There is debate as to whether the best interests of the shareholders as a whole should be
interpreted as the best interests of the present shareholders or the best interests of both present
and future shareholders – effectively whether the directors should take a short or long term
view as to the life of the company. As shown by investor initiatives such as the Coalition for Environmentally Responsible Economies and th
arbon Disclosure Project. 27 At s 135.
28 At s 136.
29 See for instance Nicholson v Permakraft (NZ) Ltd [1985] 1 NZLR 242 per Cooke P (CA).
30 Watts, above n 23, at 143.
31 At 129.
32 At 147.
33 At 130.
34 Jonathan Boston "The Nature of the Problem and the Implications for New Zealand" in Alastair Cameron (ed)
Climate Change Law and Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 87 at 91.
35 As shown by investor initiatives such as the Coalition for Environmentally Responsible Economies and the
Carbon Disclosure Project. At 130.
34 Jonathan Boston "The Nature of the Problem and the Implications for New Zealand" in Alastair Cameron (ed)
Climate Change Law and Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 87 at 91.
35 As shown by investor initiatives such as the Coalition for Environmentally Responsible Economies and the
Carbon Disclosure Project. At s 136.
29 See for instance Nicholson v Permakraft (NZ) Ltd [1985] 1 NZLR 242 per Cooke P (CA).
30 Watts, above n 23, at 143.
31 Directors owe positive duties to the company to: This choice leads to different profit-maximising strategies - for example maximising increases in the value of shares in the short-term or maximising the
long-term value of the company which may mean sacrifices in the short term. This has
implications for the directors’ attitudes towards the environment – it may well maximise
short term profits to damage the environment whereas it may be in the long-term interests of
the company and society to conserve the natural environment.34 The profit-maximisation
strategy is a discretionary decision by the directors and as long as they act in good faith, it is
unlikely that they would face any sanction. Of course, if the shareholders are unhappy with
the strategy the director is taking, they have the power to remove the directors and appoint
new ones in their place. However, given changing attitudes of society and institutional
investors, 35 it seems unlikely that directors would be removed for seeking to be
environmentally responsible, provided the company is making some profit. - for example maximising increases in the value of shares in the short-term or maximising the
long-term value of the company which may mean sacrifices in the short term. This has
implications for the directors’ attitudes towards the environment – it may well maximise
short term profits to damage the environment whereas it may be in the long-term interests of
the company and society to conserve the natural environment.34 The profit-maximisation
strategy is a discretionary decision by the directors and as long as they act in good faith, it is
unlikely that they would face any sanction. Of course, if the shareholders are unhappy with
the strategy the director is taking, they have the power to remove the directors and appoint
new ones in their place. However, given changing attitudes of society and institutional
investors, 35 it seems unlikely that directors would be removed for seeking to be
environmentally responsible, provided the company is making some profit. 4 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? The environment does not currently feature in the directors duties. Arguably, the directors
could take into account the interests of the environment (as they can in Canada)36 provided
they still act in the best interests of the company. B. Enforcement of directors' duties to the company 36 Peoples Department Stores Inc. (Trustee of) v Wise [2004] 3 SCR 461. 37 Companies Act 1993, s373(4). 36 Peoples Department Stores Inc. (Trustee of) v Wise [2004] 3 SCR 461.
37 Companies Act 1993, s373(4).
38 At s 138A.
39 Brookers Company Law (online looseleaf ed, Thomson Reuters) at [CA373.03].
40 Companies Act 1993, s 169.
41 At s 165.
42 At s 165(1).
43 At s 165(2).
44 At s 166.
45 See s 36(c) – shareholders have a right to shares in the distribution of the surplus assets of the company.
46 At s 164.
47 At s 260 and Schedule 6. At s 166.
45 See s 36(c) – shareholders have a right to shares in the distribution of the surplus assets of the company.
46 At s 164.
47 At s 260 and Schedule 6. 39 Brookers Company Law (online looseleaf ed, Thomson Reuters) at [CA373.03].
40 Companies Act 1993 s 169 At s 138A.
39 Brookers Company Law (online looseleaf ed, Thomson Reuters) at [CA373.03]. At s 138A.
39 Brookers Company Law (online looseleaf ed Thomson Reuters) at [CA373 03] 37 Companies Act 1993, s373(4).
38 At s 138A.
39 Brookers Company Law (online looseleaf ed Thomson Reuters) at [CA373 B. Enforcement of directors' duties to the company It is an offence punishable by up to five years’ imprisonment or a fine of up to $200,000.0037
for a director to exercise powers or perform duties as a director in bad faith, believing the
conduct not to be in the best interests of the company and knowing that the conduct will
cause serious loss to the company.38 Charges under this section would be brought by the
police.39 In terms of civil enforcement, shareholders can directly enforce duties that the
directors owe to them.40 However, as outlined above, many of the important duties are not
owed to shareholders but to the company itself. The only way that a shareholder can bring an
action on behalf of the company against a director is by way of a derivative action.41 The
shareholder requires the Court's leave to bring a derivative action. 42 When considering
whether to allow the derivative action to proceed, the Court shall have regard to the
likelihood of the claim succeeding, the cost of the proceedings in relation to the relief likely
to be obtained and the interests of the company in the proceedings being commenced.43 The
costs of the proceeding, once leave is granted, will be paid for by the company, unless it
would be unjust or inequitable for it to do so.44 However, there is little incentive for a
shareholder to bring a derivative action against a director retrospectively. Any recovery that
was made would go to the company, to pay off creditors and finally shareholders in a
liquidation situation.45 The CA also contains provisions allowing the company, a shareholder or director or an
entitled person to apply for an injunction to prevent the directors or the company from taking
an action that is contrary to the company’s constitution or is in breach of the CA.46 If a
shareholder or a director knows beforehand about a potential breach of the directors’ duties to
the company, they could apply for an interim or permanent injunction to prevent the breach
from occurring. The liquidators of a company are empowered to take an action on the company’s behalf,47
and may have more of an incentive than shareholders to take an action against directors if it 43 At s 165(2). 5 5 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? B. Enforcement of directors' duties to the company would result in a greater recovery for creditors (and for the liquidators themselves in the
payment of their fees).48 At s 197.
53 See Financial Markets Conduct Act 2013, s 451 (definition of reporting entities) and s 6 (definitions of listed
issuer).
54 Financial Markets Conduct Act 2013, s 460. p
50 See s 198, which refers to the definition in s 45 of the Financial Reporting Act 2013.
51 At s 207 48 Under cl 1 of Schedule 7 of the Companies Act, the fees and expenses of the liquidator are the highest
priority. p
y
49 Companies Act 1993, s 201. Companies Act 1993, s 201.
See s 198, which refers to the definition in s 45 of the Financial Reporting Act 2013.
At
207 49 Companies Act 1993, s 201. 48 Under cl 1 of Schedule 7 of the Companies Act, the fees and expenses of the liquidator are the highest
priority.
49 Companies Act 1993, s 201.
50 See s 198, which refers to the definition in s 45 of the Financial Reporting Act 2013.
51 At s 207.
52 At s 197.
53 See Financial Markets Conduct Act 2013, s 451 (definition of reporting entities) and s 6 (definitions of listed
issuer).
54 Financial Markets Conduct Act 2013, s 460.
55 At s 461D. 50 See s 198, which refers to the definition in s 45 of the Financial Reporting Act 2013.
51 At s 207.
52 At s 197 C. Financial reporting obligations Act 2013 (“FRA”). 56 “Financial statements” must comply with the applicable financial
reporting standards. 57 These standards are produced by the External Reporting Board
(“XRB”) set up under subpart 1 of part 2 of the FRA. Under the FRA, there are four tiers of
reporting obligations. The most stringent are Tier 1 obligations; these apply to entities that
are "socially accountable" (including listed issuers)58 and to large entities.59 Therefore the
actual standards that listed issuers (covered by the FMCA) and large companies (covered by
the CA) must meet will usually be the same. Act 2013 (“FRA”). 56 “Financial statements” must comply with the applicable financial
reporting standards. 57 These standards are produced by the External Reporting Board
(“XRB”) set up under subpart 1 of part 2 of the FRA. Under the FRA, there are four tiers of
reporting obligations. The most stringent are Tier 1 obligations; these apply to entities that
are "socially accountable" (including listed issuers)58 and to large entities.59 Therefore the
actual standards that listed issuers (covered by the FMCA) and large companies (covered by
the CA) must meet will usually be the same. Importantly, the XRB can be empowered60 to produce financial reporting standards that relate
to:61 (i)
an entity’s governance:
(ii)
an entity’s strategic direction and targets:
(iii)
the social, environmental, and economic context in which an entity operates:
(iv)
any other matter relating to an entity’s performance or position As yet, the XRB has not been empowered to do so. If such standards were produced, then
companies in the defined categories would have to apply them. As yet, the XRB has not been empowered to do so. If such standards were produced, then
companies in the defined categories would have to apply them. As yet, the XRB has not been empowered to do so. If such standards were produced, then
companies in the defined categories would have to apply them. 56 Financial Reporting Act 2013, s 2(1).
57, At s 6.
58 Standard XRB A1, at paras 12 – 13. The definition of large here is slightly different – the entity must have
expenses of over $30 million.
59 Standard XRB A1, at para 17– 18.
60 By the Governor-General by Order in Council on the recommendation of the Minister responsible for the
FRA.
61 Financial Reporting Act 2013, s 17.
62 Unless they opt out for that accounting period under s 207I.
63 At s 208.
64 At s 211.
65 At s 207K. E. Disclosure under the NZX Listing Rules 56 Financial Reporting Act 2013, s 2(1). p
g
62 Unless they opt out for that accounting period under s 207I.
63 At
208 C. Financial reporting obligations Directors have duties to disclose information about the company’s activities to allow
shareholders to assess a director's performance as their (or rather the company’s) agent. As
described above, directors have significant discretion as to the running of the company. The
primary power of shareholders in relation to directors is the power to elect and remove
directors. Alternatively, the shareholders can seek to sell their shares if they are not happy
with the company’s performance. To make those decisions, shareholders have to know what
directors are doing with shareholders’ money – directors have to be accountable. The need
for accountability underlies the legislative requirements detailed below for companies to
prepare financial statements in accordance with set standards. Having set standards with
penalties in place for breaches minimises the likelihood of or the incentive to report financial
information or results in a way favourable to the company and hence to the directors
maintaining their position. The CA requires large companies, large overseas companies, companies that are public
entities and companies with more than 10 shareholders to prepare financial statements in
accordance with generally accepted accounting practice.49 Large companies are companies
that have total assets (including the assets of subsidiaries) of more than $60 million or total
revenue (including the revenue of subsidiaries) of over $30 million. 50 The financial
statements prepared must be audited by a qualified auditor, unless an exception applies.51 Companies that are reporting entities under the Financial Markets Conduct Act 2013
("FMCA") are exempt from the CA's financial reporting regime and must instead comply
with the FMCA reporting regime.52 Companies listed on the NZX are reporting entities
under the FMCA.53 Like large companies, FMC reporting entities must prepare financial
statements in accordance with generally accepted accounting practice.54 Again, the financial
statements must be audited by a qualified auditor.55 Both the CA and the FMCA define “financial statements” and “generally accepted
accounting practice” with reference to the definitions contained in the Financial Reporting 48 Under cl 1 of Schedule 7 of the Companies Act, the fees and expenses of the liquidator are the highest
priority At s 197. 53 See Financial Markets Conduct Act 2013, s 451 (definition of reporting entities) and s 6 (definitions of listed
issuer). 54 Financial Markets Conduct Act 2013, s 460. 55 At s 461D 6 6 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? 60 By the Governor-General by Order in Council on the recommendation of the Minister responsible for
FRA.
61 Financial Reporting Act 2013 s 17 61 Financial Reporting Act 2013, s 17. p
g
0 3,
62 Unless they opt out for that accounting period under s 207I. F. Enforcement of financial reporting and disclosure obligations Under the CA, it is an offence to fail to comply with the applicable reporting standards.70 A
company can be fined up to $50,000.00 while the directors can be fined that amount or can be
imprisoned for up to two years. 71 Breaches of the financial reporting provisions of the
FMCA are more strongly sanctioned. Breaches can be the subject of civil pecuniary
penalties72 whereas knowing breaches of financial reporting standards on the part of the
companies and directors can be the subject of criminal fines of up to $500,000.00 for
directors and $2.5 million73 for companies. In addition, directors can be sentenced to up to
five years in prison. In relation to the annual report required under the CA, it is an offence to fail to prepare an
annual report;74 if convicted, a director could be fined up to $10,000.00.75 The annual report
(including the financial statements and audit report, if prepared) must be made available to
shareholders, either by sending a copy to shareholders or making it available electronically. Again, if this requirement is not met, the directors could be fined up to $10,000.00.76 66 Appendix 16 to the NZX Listing Rules. pp
g
NZX Main Board/Debt Market Listing Rules, cl 10.4 p
72 Financial Markets Conduct Act 2013, s 461M. 69 See the definition at cl 1.6.1 of the Listing Rules. 71 Companies Act, s207G and s373(3). D. Requirement to produce an annual report D. Requirement to produce an annual report Separate to the financial reporting requirements, the CA also requires large companies (as
defined above), large overseas companies, companies that are public entities and companies
with more than 10 shareholders 62 and all companies that are FMC reporting entities to
produce an annual report.63 This report must, among other things, include a description of any
change during the accounting period to the “nature of the business of the company or any of
its subsidiaries” or “the classes of business in which the company has an interest” so far as is
material to allow “the shareholders to have an appreciation of the state of the company’s
affairs” and “will not be harmful to the business of the company or of any of its
subsidiaries”.64 Companies with fewer than 10 shareholders can opt into this regime.65 E. Disclosure under the NZX Listing Rules 64 At s 211. 65 At s 207K. 7 7 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? Another potential source of corporate environmental reporting regulation would be the NZX
Listing Rules. Indeed, the ASX has introduced a recommendation in its Corporate
Governance Principles and Recommendations for a listed entity to “disclose whether it has
any material exposure to economic, environmental and social sustainability risks, and if it
does, how it manages or intends to manage those risks.” There is no such equivalent
provision in the NZX Corporate Guidance. 66 While the NZX Listing Rules repeat and
augment the CA requirements for an annual report,67 listed companies are not required to
report on environmental impact. However, some environmental information may be required
to be disclosed under the “Material information” provisions.68 The “Material information”
provisions require listed companies to disclose information that “a reasonable person would
expect, it if were generally available to the market, to have a material effect on the price of
the Quoted Securities of the Issuer”.69 F. Enforcement of financial reporting and disclosure obligations 75 At s374(2). 70 Companies Act, s207G. 66 Appendix 16 to the NZX Listing Rules.
67 NZX Main Board/Debt Market Listing Rules, cl
68 At cl 10.1.
69 See the definition at cl 1.6.1 of the Listing Rules.
70 Companies Act, s207G.
71 Companies Act, s207G and s373(3).
72 Financial Markets Conduct Act 2013, s 461M.
73 At s461I.
74 Companies Act 1993, s 208(3).
75 At s374(2).
76 At s209(7) and s374(2). 77 Robert Costanza et al "The value of the world's ecosystem services and natural capital" (1998) 25 Ecological
Economics 3.
78 Millenium Ecosystem Assessment Ecosystems and Human Well-being: Synthesis (Island Press, Washington,
2005) at 1.
79 At 4.
80 Millenium Ecosystem Assessment at 14; O. E. Sala et al. "Global biodiversity scenarios for the year 2100"
(2000) 287 Science 1770.
81 Millenium Ecosystem Assessment at 14. G. Summary In summary, directors are agents of the company and owe duties to it. They have a very wide
discretion to decide how to run the company, as long as it is done in good faith, and in the 8 8 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? best interests of the company, which usually means in the interests of the shareholders as a
whole. The environment does not feature as a mandatory consideration when directors are
making decisions nor do companies have any real obligation to report on their environmental
impact. The disclosure requirements that companies do have are primarily financial. However, it would not matter if directors do not consider the environmental impact of the
company if New Zealand’s environmental law completely protected the environment and
required the remedying of any environmental damage caused. Part III will sketch the
complex environmental issues that New Zealand and the globe faces while Part IV will
identify the sources and coverage of New Zealand’s environmental laws to elucidate the areas
where directorial discretion could have an impact. III.
Environmental problems Humans are entirely dependent on ecosystem services for their survival and well-being. Ecosystems provide the air we breathe, the food we eat, the water we drink and many of the
materials we use to construct our dwellings. Ecosystem services have been estimated to be
worth on average $33 trillion US dollars per year (at a time when global Gross National
Product was $18 trillion).77 While the last few decades of the twentieth century have seen a
large increase on the material wellbeing of many people on the planet, this increased standard
of living has come at the expense of ecosystem degradation around the globe. 78 One
indicator of this degradation is the current extinction rate that is 1,000 times the background
extinction rate.79 It is clear that many past practices in relation to the environment and the “business-as-usual”
attitudes are unsustainable. Humans are eating into the planet's natural capital by exerting
unprecedented and concerted pressure on ecosystems all around the world such that the
balance of global nutrient cycles and the climate have been affected. The burning of fossil
fuels, releasing carbon dioxide into the atmosphere which has been in storage for millions of
years has had and is having a major influence on GHG levels, and hence on the climate. Satisfying the needs and wants of the burgeoning human population is influencing five
drivers of global environmental change80 of which anthropogenic climate change is the most
well-known. The other drivers are habitat loss (through land-use change and change to
waterways), the spread of invasive species, pollution (particularly nitrogen deposition) and
over-exploitation.81 These drivers are themselves driven by the processes that people utilise
to satisfy their needs and wants. Land use change is viewed as the biggest driver of global 9 9 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? environmental change.82 As more land is taken from forest, wetland or grassland and put into
agricultural production or into urban sprawl, not only is carbon dioxide often released to the
atmosphere but native biodiversity is lost, new habitat is opened up for invasive colonisation
and changes occur in the water and nutrient cycling in the area. New Zealand, unfortunately, has examples of all the global environmental drivers. III.
Environmental problems Conversion of farm or forestry land to more intensive dairy farming, a common trend over
the past decade, exemplifies agricultural intensification causing the release of carbon and also
nitrogen pollution. While New Zealand’s average temperature rise is projected to be less
than the global average,83 New Zealand will still feel the effects of rising sea levels, changes
in rainfall patterns, an increase in flooding and drought and an increase in other extreme
weather events.84 Being an island nation which relies heavily on agriculture, the effects of
climate change on New Zealand could be considerable. The warming climate could also
result in invasive species, including pests on agricultural and horticultural crops, being able to
establish here. There are also threats to New Zealand’s native biodiversity, that in a warming
world, New Zealand’s unique biota will be less able to compete with invasive plants and
animals. As regards over-exploitation, a good example is the overfishing of orange roughy in
a number of areas, requiring those areas to be closed for fishing at least a decade.85 Stocks
have now rebounded enough to allow some fishing. 82 Sala, above n 81, at 1771.
83 B. Mullan, D. Wratt, S. Dean, M. Hollis, S. Allan, T. Williams, G. Kenny and MfE Climate Change Effects
and Impacts Assessment: A Guidance Manual for Local Government in New Zealand (2nd ed, Ministry for the
Environment, Wellington 2008) at 15.
84 At 14 At 14.
85 Ministry of Fisheries Sustainable New Zealand Seafood: Orange roughy (Ministry of Fisheries, October
2011).
86 Resource Management Act 1991, s 5(1). 87 At s 5 (2). 82 Sala, above n 81, at 1771.
83 B. Mullan, D. Wratt, S. Dean, M. Hollis, S. Allan, T. Williams, G. Kenny and MfE Climate Change Effects
and Impacts Assessment: A Guidance Manual for Local Government in New Zealand (2nd ed, Ministry for the
Environment, Wellington 2008) at 15.
84 At 14.
85 Ministry of Fisheries Sustainable New Zealand Seafood: Orange roughy (Ministry of Fisheries, October
2011).
86 Resource Management Act 1991, s 5(1).
87 At s 5 (2). 86 Resource Management Act 1991, s 5(1). 82 Sala, above n 81, at 1771. IV.
New Zealand’s environmental protection laws It would be utterly astonishing if all this was known about the environment and yet New
Zealand was doing nothing about it. New Zealand has an array of environmental laws
dealing with different aspects of the drivers of ecosystem change. A. The Resource Management Act 1991 (“RMA”) The RMA is New Zealand’s primary environmental statute. It is a holistic statute that sets
out a framework for making plans and decisions about use of the land, freshwater, air and
coastal areas. Its purpose is “to promote the sustainable management of natural and physical
resources”.86 “Sustainable management” is defined as:87 At 14. 85 Ministry of Fisheries Sustainable New Zealand Seafood: Orange roughy (Ministry of Fisheries, October
2011). 86 Resource Management Act 1991, s 5(1). 87 At s 5 (2) 10 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? managing the use, development, and protection of natural and physical resources in a
way, or at a rate, which enables people and communities to provide for their social,
economic, and cultural well-being and for their health and safety while— (a) sustaining the potential of natural and physical resources (excluding minerals) to
meet the reasonably foreseeable needs of future generations; and 93 At ss 70A, 70B and 104E. 88 See ss 63 – 77D for provisions relating to regional and district plans.
89 See Part 6.
90 At s 6.
91 At s 7.
92 At ss7(i) and (j).
93 At ss 70A, 70B and 104E.
94 At s 15.
95 At s 14. 92 At ss7(i) and (j). (c) avoiding, remedying, or mitigating any adverse effects of activities on the
environment. The RMA gives powers to layers of local government to make plans for their districts and
regions. District plans and regional plans allow some activities to occur without the need for
consent – these are “permitted activities”.88 When people want to carry out an activity that is
not one of those activities, they must apply for a resource consent from the district or city
council and potentially the regional council as well. 89 This process may involve public
consultation. When decision makers are making decisions under the RMA, they must
recognise and provide for “matters of national significance”90 – broadly the protection of the
coastal and wetland areas, nationally significant landscapes, heritage areas, areas of
indigenous diversity and areas of land and water significant to Maori. Decision makers must
have particular regard to other factors including the efficiency of the use and development of
resources, the efficiency of the end use of energy, the intrinsic value of ecosystems and
maintenance and enhancement of the quality of the environment.91 Importantly, decision
makers have to have regard to the effects of climate change and to the benefits to be derived
from the use and development of renewable energy.92 However, decision makers are not
allowed to have regard to whether a proposed activity or development will release GHGs.93
The rationale behind this is that climate change action is better left to central government
action, rather than the ad hoc decisions of different councils around the country. In terms of global environmental drivers, the RMA may ameliorate the effect of land use
changes as it prohibits emissions to air, land or water,94 unless the activities are specifically
allowed for by a national policy statement (“NPS”), rule in a plan or resource consent. It also
regulates the taking of water without consent.95 For all activities which do not meet the
permitted activity threshold, an application must be prepared which contains an 95 At s 14. 11 11 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? environmental impact assessment 96 to determine whether the negative effects on the
environment will be more than minor. Adverse effects must be avoided, remedied or as a last
resort, mitigated.97 Conditions are placed on resource consents to minimise environmental
impact. (c) avoiding, remedying, or mitigating any adverse effects of activities on the
environment. If consent holders (or people operating where a consent would be required) do not
comply with the relevant consent conditions or regulations, councils may take enforcement
action.98 For newer consents, this process should be able to manage the environmental
impacts many activities. However, there still many consents that were given in earlier time
periods when standards were not as strict, resulting in residual damage to ecosystems which
will not stop until those consents expire.99 In summary, the RMA is a comprehensive statute that facilitates the consideration of the
various (sometimes divergent) values that are placed on the natural environment. The RMA
does set out a complex framework of regulation at various levels; given the complex topic,
this may well be appropriate. However, there are different criteria for the success of the
RMA. According to the current National government and to developers, the RMA’s
processes are cumbersome and add too much to the cost of development. There are moves
towards changing the RMA which may yet eventuate.100 g
(p
y
101 Climate Change Response (Emissions Trading) Amendment Act 2008. ,
,
100 Nick Smith "RMA reform agenda outlined" (press release, 21 January 2015). 96 Resource Management Act 1991, s 88. 105 Climate Change Response Act 2002, ss 63 and 63A and Schedule 3.
106 97 At s 17. 99 See for instances ss 10, 10A, 10B and 20A. 99 See for instances ss 10, 10A, 10B and 20A. 106 At s 4(1). Part 4 and Schedule 3. g
p
102 Climate Change Response Act 2002, s 3. g
p
g
102 Climate Change Response Act 2002, s 3. 103 Cameron, above n 5, at 247. 97 At s 17. 98 See Part 12 of the Act. 97 At s 17.
98 S
P t 12 f th A t 97 At s 17.
98 S
P t 12 f th A t 97 At s 17.
98 S
P t 12 f th A t At s 17.
98 See Part 12 of the Act 103 Cameron, above n 5, at 247.
104 At 247. B. Climate Change Response Act 2002 In terms of climate change, New Zealand’s most important statute is the Climate Change
Response Act 2002. In 2008, this Act was amended to include an emissions trading
scheme.101 The New Zealand ETS (“NZETS”) is a measure contributing to New Zealand’s
actions taken under the Kyoto Protocol.102 At the time of its introduction, it was envisaged as
the first “all-sectors, all-gases”103 ETS. However, the NZETS was stripped back after the
National government came into power in November 2008. The NZETS still includes “all-
gases” meaning all six of the GHGs regulated by the Kyoto Protocol (carbon dioxide,
methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride) 104
but the scheme no longer sets out a timeframe for all-sectors to be involved in the scheme. Under the NZETS, the GHG emissions from the importation or mining of liquid fossil fuel,
natural gas and coal must be accounted for by the surrender of “units”.105 These units can be
New Zealand Units (“NZU”) or Kyoto units or an approved overseas unit.106 Each NZU 12 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? allows the emitter to emit 1 tonne of carbon dioxide equivalent into the atmosphere. 107
However, “transitional” provisions introduced by the National government in 2009 and 2012,
allow participants to surrender a unit for every two tonnes of GHG emissions. 108 These
“transitional” amendments as cap the price of a unit at $25 per tonne.109 Importers and
miners of liquid fossil fuel, natural gas and coal fuel must measure, record and disclose to the
government the amount of carbon dioxide equivalent that will be emitted from the burning of
the fossil fuel, natural gas and coal.110 At the end of the year, they must then surrender NZUs
to the government, accounting for the amount of carbon dioxide equivalent that will have
been emitted to the atmosphere that year by the burning of those energy sources.111 The
importers/miners will pass down the cost of the NZUs onto their customers.112 Further down
the chain, major industrial emitters may choose to take over the obligations for the energy
sources that they purchase from up-stream participants. They may do so to better control the
cost imposed on them by the NZETS. On the other side of the ledger, participants who carry
out “removal activities” are entitled to receive NZUs. 107 Climate Change Response Act 2002, ss 4(1) and 63.
108 At s 63A.
109 At s 178A.
110 At ss 62 and 65.
111 At s 63.
112 Cameron, above n 5, at 249.
113 Climate Change Response Act 2002, ss 64 and 64A.
114 At s 57 and Schedule 4, Part 2.
115 At s 56 and Schedule 3, Part 1.
116 Climate Change Response (Emissions Trading and Other Matters) Amendment Act 2
117 Climate Change Response Act 2002, ss62 and 65 and Schedule 3.
118 See ss 80 – 86F.
119 At s 63A. 116 Climate Change Response (Emissions Trading and Other Matters) Amendment Act 2012, s 96.
117 Climate Change Response Act 2002, ss62 and 65 and Schedule 3.
118
6 107 Climate Change Response Act 2002, ss 4(1) and 63.
108 B. Climate Change Response Act 2002 113 “Removal activities” activities are
listed in Parts 1 and 2 of Schedule 4 to the CCRA and include owning or leasing post-1989
forest land and producing goods that capture and store carbon are allocated NZUs. Post-1989
forestry owners are voluntary participants in the NZETS114 while owners of pre-1990 forests
who deforest more than two hectares over a five year period are required to be participants.115 Excluding land use and land use changes, agriculture accounts for almost 50% of New
Zealand’s carbon emissions. This is unusual for a developed country where emissions from
agriculture are usually much lower.116 The farming lobby in New Zealand has exerted a
strong influence over New Zealand’s climate policy – after the 2012 amendments, there is
now no date to include biological emissions in the scheme, though certain agricultural
participants do have to record and disclose to the government their carbon emissions.117 A number of factors have kept the price of emissions low on the NZETS which has limited its
efficacy in incentivising emitters to change behaviour. One factor is the allocation of free
NZUs to some industrial emitters. 118 Participants only have to surrender one NZU (or
equivalent Kyoto credit) for every two tonnes of carbon dioxide emitted.119 The obligations
to surrender emissions units could be met using international carbon credits from other Kyoto
schemes. The resulting oversupply of credits in the market, pushed the going price down to 13 13 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? $2 per tonne of emissions in May 2013.120 A recent survey of participants in the NZETS
indicates that the scheme is not having a positive impact on afforestation and may actually be
encouraging deforestation as foresters may harvest while the carbon price is very low.121 The
scheme is to be reviewed in 2015122 but given the National government’s previous stance on
wanting to minimise the costs of emissions for emitters and for consumers, the chances of
significant improvement seem unlikely. In relation to environmental disclosure, an important point is that the NZETS requires its
participants to keep track of the GHG emissions that they are responsible for under the
scheme.123 There are methodologies in place for the various calculations to take place. This
could provide a useful background framework for a requirement for listed companies to
disclose their emissions. 120 Richter and Chambers, above n 10, at 60.
121 Richter and Chambers, above n 10, at 63.
122 Cabinet Minute “Emissions Trading Scheme Review 2012: Final Decisions on Amendments to the Climate
Change Response Act 2002” (2 July 2012) CAB Min (12) 23/10 at [111].
123 Climate Change Response Act 2002, ss 62 and 65.
124 Alastair Cameron “Corporate and Commercial Issues” in Alastair Cameron (ed) Climate Change Law and
Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 393 at 395.
125 Ministry for the Environment, Environmental Snapshot: Legally protected conservation land in New Zealand
(Ministry for the Environment, April 2010).
126 Ibid.
127 Wildlife Act 1953, s 67A.
128 At s 67A. B. Climate Change Response Act 2002 Some listed companies will already be participants in the NZETS
which would make it easier for them to comply with a new environmental disclosure
obligation. At the moment, NZETS participants only have to disclose their emissions to the
government not to other stakeholders. Participants only have to disclose their emissions from
some activities – for instance, oil companies would not have to record or disclose the
emissions related to the running of their headquarters.124 120 Richter and Chambers, above n 10, at 60. 121 Richter and Chambers, above n 10, at 63. C. Other environmental statutes Protection of native biodiversity is also part of New Zealand’s environmental law and policy. Approximately 33% of New Zealand’s land area is set aside for conservation.125 This is a
significant amount, though it is primarily in alpine areas;126 the majority of lowland areas
have long since been converted to human use. Killing endangered fauna127 is an offence as is
trading in endangered species.128 However, New Zealand’s conservation actions are more
influenced by the amount of funding the Department of Conservation receives than by the
law itself. In New Zealand, conservation of native flora and fauna is often a matter of
protecting indigenous biodiversity from the effects of invasive species, particularly mammals. New Zealand’s fauna is vulnerable to mammalian predators as it evolved without mammals
until the arrival of humans and their associated mammals. The Biosecurity Act 1993 is also
important here as it controls what organisms are allowed to come into New Zealand. Again,
funding levels have a significant effect on the action in this area. 14 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? In terms of over-exploitation, New Zealand has a quota management system for its fisheries,
set at a “sustainable level”.129 It also has entered into international agreements to prevent
certain destructive fishing practices.130 Another statute that could be classed as being environmental law is the Waste Minimisation
Act 2008. This sets up a framework encouraging producers to consider the lifecycle of their
products and provides for voluntary schemes which producers can enter into to increase
efficiency and decrease waste.131 It also sets out the responsibilities of territorial authorities
in relation to waste management and minimisation.132 129 Fisheries Act 1996.
130 Ministry of Foreign Affairs & Trade "Treaties and International Law: International Fisheries"
http://mfat govt nz 129 Fisheries Act 1996.
130 Ministry of Foreign Affairs & Trade "Treaties and International Law: International Fisheries"
http://mfat.govt.nz .
131 Waste Minimisation Act 2008, Part 2.
132 See Part 4.
133 Smith, above n 100. 129 Fisheries Act 1996. 133 Smith, above n 100. http://mfat.govt.nz .
131 Waste Minimisation Act 2008, Part 2.
132 132 See Part 4. D. Summary Like other developed countries, New Zealand has a system of environmental law addressing
some of the drivers of ecosystem change. However, whether these laws have the capacity to
keep New Zealand’s environmental impacts to sustainable levels in the long-term is debatable
especially as the current National government has shown little appetite to strengthen
measures to combat climate change and is foreshadowing changes to the RMA to make it
friendlier for developers.133 In summary, the law provides a minimum amount of protection
for the environment. E. Scope for directors to use their power for good of the environment However there is significant scope for the exercise of company directors’ discretion to
improve environmental outcomes, by refraining from taking environmentally damaging
actions or by actively promoting environmental health. An obvious example is firms
choosing to reduce their GHG emissions as there is no requirement for companies to do so at
the moment. Exercising discretion by entering into a voluntary waste minimisation scheme
would be beneficial under the Waste Minimisation Act. Companies have choices about what
to produce – whether it is legal to carry out an environmentally damaging production process
does not mean that a company has to take that step. Companies also have choices about
where to get their supplies from and so can choose to buy from suppliers who are minimising
their environmental impact – for instance by using timber sourced from forests that have been
certified by the Forest Stewardship Council. Companies also have choices about where to
invest their profits – again they can choose to invest in less environmentally damaging
enterprises. Companies can also exert influence over consumer opinion and over government
policy. Companies could improve environmental outcomes by lobbying for regulation to
protect the environment or at least not lobby against legislation leading to more sustainable
outcomes. Companies could positively influence consumer opinion on environmental issues 15 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? – for instance by encouraging higher density housing development, thereby reducing urban
sprawl. As it stands, the framework under the RMA may allow for a sprawling subdivision
or a higher density apartment building. It is the developer’s choice as to which option to
apply for. 134 Resource Management Act 1991, s 114(3). F. Disclosure obligations in environmental law The preceding analysis of New Zealand’s company law and environmental law identifies that
companies, including listed companies, do not currently have any obligation to report to
shareholders or the public about their environmental impact. Companies applying for
resource consents must assess the environmental impact of the activity they want to
undertake, and if the consent is successfully obtained, they will likely have to monitor the
ongoing environmental impact of the consented activity. These impacts must be reported to
the relevant local authority. While resource consents are publically available on request,134
there will usually be no requirement on the company to disclose the environmental effect of
the consented activity to the public. Companies who are participants in the NZETS must
keep records of their carbon emissions or of the amount of liquid fuel, natural gas or coal that
they mine or import. This must be disclosed to the government so that the company
surrenders the correct number of emissions units. Again, there is no requirement to disclose
this information to shareholders or to the public. Shareholders and the general public
therefore are dependent on the voluntary disclosures of companies to assess their
environmental impacts. V.
Voluntary responses by New Zealand companies to environmental
problems V. Voluntary responses by New Zealand companies to environmental
problems Before a legislative requirement is put in place to require companies to consider the
environment or to disclose environmental impacts, it is sensible to assess whether voluntary
efforts by New Zealand companies are fulfilling those goals. Voluntary disclosures by New
Zealand companies (particularly listed companies) are important in the assessment of both
parts of the question; the primary way that the public or shareholders determine how directors
are exercising their discretion when it comes to the environment is by examining the
environmental information that companies voluntarily disclose. However, as it stands, with
no mandatory environmental reporting standard, it is easy for companies to just report good
news, and little if any of the bad. A number of New Zealand companies do now produce some sort of “sustainability report”. Overall, New Zealand’s level of corporate reporting on sustainability is low – 16% of New 16 16 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? Zealand companies report on sustainability issues compared to a global average of 31%.135
The reporting rate is much higher for the 100 largest companies in many countries but New
Zealand’s reporting rate is still behind the global average: of the top 100 companies in each
of 41 countries KPMG surveyed, 71% of companies reported on corporate social
responsibility (“CSR”) 136 issues, 137 compared to 47% of New Zealand’s top 100
companies.138 New Zealand companies are involved in a number of reporting networks. For instance, there
are 33 New Zealand entities with reports on the Global Reporting Initiative’s (“GRI”)
Sustainability Disclosure Database,139 including local bodies, state-owned enterprises, listed
companies and others. However, only three so far have uploaded reports for the 2014 year
and only 12 for the 2013 year.140 The GRI, as its name suggests, is a global reporting
initiative which promulgates a set of sustainability reporting guidelines. It is the most
popular reporting system with large companies globally.141 These guidelines are used by
78% of N100 companies from the 41 countries surveyed by KPMG who prepare CSR reports
refer to these guidelines.142 According to KPMG’s survey of New Zealand’s largest 100
companies, more than half of the companies who prepared reports referred to the GRI
guidelines. The GRI is a not-for-profit organisation promoting sustainability reporting. 135 Grant Thornton "Corporate social responsibility: beyond financials" <www.internationalbusinessreport.com>
at 12.
136 Corporate social responsibility more generally will be discussed in Part VI.
137 KPMG International The KPMG Survey of Corporate Responsibility Reporting 2013 (KPMG International,
2013) at 20.
138 At 25.
139 Global Reporting Initiative "Sustainability Disclosure Database" <http://database.globalreporting.org/>.
140 Global Reporting Initiative "GRI Reports List”, available from <http://database.globalreporting.org/>
accessed on 2 February 2015.
141 KPMG International, above n 137, at 30.
142 At 11.
143 Global Reporting Initiative “What is GRI?” <www.globalreporting.org>.
144 Carbon Disclosure Project “About Us” <www.cdp.net>. 9 Global Reporting Initiative "Sustainability Disclosure Database" <http://database.globalreporting.org/>.
0 Global Reporting Initiative "GRI Reports List”, available from <http://database.globalreporting.org/>
cessed on 2 February 2015. 135 Grant Thornton "Corporate social responsibility: beyond financials" <www.internationalbusinessreport.com>
at 12.
136 143 Global Reporting Initiative “What is GRI?” <www.globalreporting.org>. V.
Voluntary responses by New Zealand companies to environmental
problems It
works with business, civil society and other stakeholders to prepare the guidelines. The
guidelines require companies to report on environmental, social and human rights issues. It
also provides for companies to report on supply chain sustainability. Sustainability reports
prepared in accordance with GRI guidelines also “presents the organization’s values and
governance model, and demonstrates the link between its strategy and its commitment to a
sustainable global economy.”143 Another global reporting movement is the Carbon Disclosure Project. This is a group
representing 767 institutional investors holding US$92 trillion in assets, helping to reveal the
risk in their investment portfolios.144 Surveys about environmental impact and risk and GHG
emissions are sent to the world’s largest companies. In New Zealand, the surveys are sent to
the NZX50, while in Australia, the surveys are sent to the ASX200. The individual results
for each company are put on the CDP website unless the company indicates that the results
are only to be seen by CDP’s institutional investor members. Either way, the reporting score 135 Grant Thornton "Corporate social responsibility: beyond financials" <www.internationalbusinessreport.com>
at 12. 17 17 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? for each company will be released. In 2014, only 17 companies listed on the NZX responded
to the CDP survey, with scores ranging from 10 to 98 out of a possible 100.145 The scores
reflect the comprehensiveness of reporting rather than the amount of carbon dioxide being
released to the atmosphere. The majority of NZX50 companies did not respond to the
survey. The response rate is down from the previous year when 42% of NZX50 companies
responded to the CDP survey, representing 92% of total market capitalisation.146 Another group that supports sustainability reporting is the New Zealand Sustainable Business
Council (“SBC”). SBC members must report to the SBC their carbon footprint within one
year of becoming a member and on their plans to reduce carbon intensity within two years of
joining.147 Within three years of joining, a member must prepare a “sustainable development
report demonstrating that member’s progress on environmental, social and economic
performance”148 – often referred to as a “triple-bottom-line report”. The SBC encourages its
members to report to the GRI standards. 145 CDP Australia & NZ CDP 2014 ASX 200 Climate Leadership Awards (Carbon Disclosure Project, Australia,
2014).
146 CDP Australia and New Zealand Climate Change Report 2013 (Carbon Disclosure Project, December 2013)
at 12.
147 Sustainable Business Council “Terms of Membership” <www.sbc.org.nz> at [4(g) – (h)].
148 At [4(a)].
149 Sustainable Business Council “SBC Sustainable Development Principles” <www.sbc.org.nz>. This
definition comes from the Brundtland Report – World Commission on Environment and Development, Our
Common Future (1987).
150 Markus J Milne, Helen Tregidga and Sara Walton “Words not actions! The ideological role of sustainable
development reporting” (2009) 22 Accounting, Auditing & Accountability Journal 1211 at 1241.
151 Sustainable Business Council “Our Members” <www.sbc.org.nz>.
152 CDP Australia & NZ, above n 145. p
p
g (
)
g,
g
151 Sustainable Business Council “Our Members” <www.sbc.org.nz>. (
)
150 Markus J Milne, Helen Tregidga and Sara Walton “Words not actions! The ideological role of sustainable
development reporting” (2009) 22 Accounting, Auditing & Accountability Journal 1211 at 1241. 152 CDP Australia & NZ, above n 145. [ ( )]
149 Sustainable Business Council “SBC Sustainable Development Principles” <www.sbc.org.nz>. This
definition comes from the Brundtland Report – World Commission on Environment and Development, Our
Common Future (1987). 152 CDP Australia & NZ, above n 145. V.
Voluntary responses by New Zealand companies to environmental
problems SBC members commit to the process of
“sustainable development” namely “development that meets the needs of the present without
compromising the ability of future generations to meet their own needs.” 149 However,
analysis of the discussion of sustainable development in members’ reports and in
communications from the SBC suggests support for the perpetuation of the status quo rather
than re-examining whether current business practices can ever be sustainable in the long-
term.150 As at 3 December 2014, the SBC has 68 member businesses, including Fonterra.151
However, only nine entities in the NZX50 are members of the SBC. While a reasonable number of New Zealand’s top 50 companies have started reporting on
CSR issues (including environmental issues), more than half of those companies consistently
do not report on these issues. When it comes to smaller companies, the numbers are even
lower. The standard of reporting varies widely between companies – for instance, New
Zealand responses to the CDP 2014 ranged from 10 out of 100 (very low) to 98 out of 100
(very high).152 In summary, reporting is voluntary, ad hoc and varies widely in quality. 152 CDP Australia & NZ, above n 145. 18 18 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? VI.
Justifying legislative intervention in the relationship between companies
and the environment Having established that there are opportunities within New Zealand’s framework of
environmental law for directors of companies to use their discretion to improve
environmental outcomes, the question becomes whether directors should have to exercise
their decision-making discretion in favour of the environment. To put it another way, would
it be justified for the state to require companies to interact with the environment in a
sustainable manner? If not, should directors have to take into account the environmental
impact of the company’s actions even if they do not act in a sustainable manner? A. Purpose of companies 153 Surya Deva Regulating corporate human rights violations: humanizing business (Routledge, London & New
York, 2012) at 131; James McConvill and Martin Joy "The interaction of directors' duties and sustainable
development in Australia: setting off on the uncharted road" (2003) 27 Melb.U.L.Rev. 116 at 117.
154 Richard Holme and Phil Watts Corporate social responsibility: making good business sense (World Business
Council on Sustainable Development January 2000) at 10 153 Surya Deva Regulating corporate human rights violations: humanizing business (Routledge, London & New
York, 2012) at 131; James McConvill and Martin Joy "The interaction of directors' duties and sustainable
development in Australia: setting off on the uncharted road" (2003) 27 Melb.U.L.Rev. 116 at 117. 154 Richard Holme and Phil Watts Corporate social responsibility: making good business sense (World Business
Council on Sustainable Development, January 2000) at 10. p
y
155 Deva, above n 153, at 120; Jason C Jones “Environmental Disclosure: Toward an Investor Based Corporate
Environmentalism Norm” (2010) 20 BU Pub. Int. LJ 207 at 216. ,
,
;
Environmentalism Norm” (2010) 20 BU Pub. Int. LJ 207 at 216. p
,
y
)
155 Deva, above n 153, at 120; Jason C Jones “Environmental Disclosure: Toward an Investor Based Cor Deva, above n 153, at 120; Jason C Jones Environmental Disclosure: Toward an Investor Based Co
Environmentalism Norm” (2010) 20 BU Pub. Int. LJ 207 at 216. York, 2012) at 131; James McConvill and Martin Joy The interaction of directors duties and sustainab
development in Australia: setting off on the uncharted road" (2003) 27 Melb.U.L.Rev. 116 at 117.
154 Richard Holme and Phil Watts Corporate social responsibility: making good business sense (World
Council on Sustainable Development January 2000) at 10 ,
)
;
y
evelopment in Australia: setting off on the uncharted road" (2003) 27 Melb.U.L.Rev. 116 at 117.
4 Richard Holme and Phil Watts Corporate social responsibility: making good business sense (World Bus A. Purpose of companies Whether companies should have to interact with the environment in a sustainable way or take
into account the environmental impact of a company’s actions, brings into question the
purpose of companies. Wealth creation and profit maximisation are commonly thought to be
the reasons for the existence of companies.153 While these goals undoubtedly underlie the
existence of many companies, it is increasingly recognised that these goals cannot be pursued
at all costs. There are differing opinions however about the extent of the limitations that
should be put on a company’s actions or, to put it in a positive sense, the scope of a
company’s responsibility to society. The name given to this general concept is “corporate
social responsibility”. A well-used definition of CSR is that of the World Business Council
on Sustainable Development:154 Corporate social responsibility is the commitment of business to contribute to
sustainable economic development, working with employees, their families, the local
community and society at large to improve their quality of life. B. Milton Friedman – "The social responsibility is to increase its profits" B. Milton Friedman – "The social responsibility is to increase its profits" Whether companies should owe any duties except to shareholders has been the subject of
debate in the United States since the 1930s with Professors Berle and Dodd arguing whether
directors should only act in the interests of shareholders or whether they should also act in the
interests of other stakeholders.155 Since that time, the most famous proponent of the view
that companies must act in the interests of shareholders only is the Chicago economist Milton
Friedman. He famously wrote an article titled “The social responsibility is to increase its 19 19 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? profits”.156 He argued that maintaining that businesses had social responsibilities was akin to
socialism. As he saw it, businesses that used profits to benefit the environment or other
stakeholders were effectively taxing their customers or their shareholders and deciding how
the proceeds would be spent without any of the accountability of elected politicians. A. Purpose of companies According to Friedman, business’ responsibility is “to use its resources and engage in
activities designed to increase its profits so long as it stays within the rules of the game,
which is to say, engages in open and free competition without deception or fraud.” 157
Friedman was not opposed to spending on community initiatives or other such activities that
increased the goodwill of the community and were in the long term interest of the company –
he just disdained the label of “social responsibility” as “hypocritical window-dressing”. He
was also not opposed to pollution regulation (at least in this article) provided that companies
did not go beyond their legal requirements. He disdained activist stockholders who sought to
persuade companies to go beyond their legal obligations when the activists had been
unsuccessful in using the political process to justifiably change the rules of the game. 156 Milton Friedman “The social responsibility of business is to increase its profits” The New York Times
Magazine 13 September 1970.
157 Ibid 161 At 126 – 127 – emphasis in original. 156 Milton Friedman “The social responsibility of business is to increase its profits” The New York Times
Magazine 13 September 1970.
157 Ibid.
158 Deva, above n 153, at 122.
159
123
124 At 123 – 124.
160 At 125. 158 Deva, above n 153, at 122. 159 At 123 – 124. 159 At 123 – 124. 160 At 125. 156 Milton Friedman “The social responsibility of business is to increase its profits” The New York Times
Magazine 13 September 1970.
157 Ibid.
158 Deva, above n 153, at 122.
159 At 123 – 124.
160 At 125.
161 At 126 – 127 – emphasis in original. Magazine 13 September 1970.
157 Ibid.
158 Deva above n 153 at 122 C. Critique of Friedman Friedman’s views must be put in the context of the time – during the Cold War when, as
Deva points out, any derogation from free markets was seen as a threat to capitalism as a
whole.158 However, CSR discourse is quite far from socialism. It only arises where private
companies hold positions of power and influence within an economy, such that their effects
on society can be seen.159 Deva (among other CSR theorists) presents a convincing critique
of Friedman’s thesis. One of the underlying premises to Friedman’s argument is that
shareholders are the owners of the business and so have a right to control it.160 It is they who
are taking the risk – if the company becomes insolvent, it is their money that will be lost. This approach does not take into account the contributions made and the risks taken by other
stakeholders:161 [E]mployees contribute by putting in labour, supply chains contribute by making
available necessary materials and other inputs, consumers contribute by buying goods
or services, and governments contribute by maintaining law and order and by creating
a business-favourable regulatory environment. All these stakeholders contribute to the
working and success of corporations, and take different kinds of risks while making
their respective contributions. From an environmental standpoint, shareholders may be taking a financial risk but by
damaging the environment or depleting natural capital, companies are risking the wellbeing 161 At 126 – 127 – emphasis in original. 20 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? of the rest of society, now and in the future. Given the risks taken by other stakeholders, it is
reasonable that companies should have to balance their interests as well when making
decisions. Friedman also ignores the commonalities between shareholders and other
stakeholders – shareholders are members of society as well, and have an interest in protecting
the environment.162 These interests do not disappear as soon as they invest in a company. Deva also argues that Friedman’s “CSR spending as tax” is misconceived. Spending on
environmental or community initiatives can only be seen as taxation or theft if shareholders
have a right to certain level of profit, rather than just an expectation of some profit.163 There
are many reasons why profits would not reach a maximal level – and these factors would not
be seen as “taxation”.164 163 At 128.
164 Deva gives the example of paying adequate salaries to employees.
165 At 140
141 At 140 141.
166 Boston and Lempp, above n 11, at 1006. 162 At 127.
163 At 128.
164 Deva gives the example of paying adequate salaries to employees.
165 At 140 – 141.
166 Boston and Lempp, above n 11, at 1006. 166 Boston and Lempp, above n 11, at 1006. D. The "business case" for sustainability Friedman’s thesis also suggests that “CSR” initiatives that are profitable should be
undertaken – in effect that there should be a business case for some CSR activities. The
business case for acting in an environmentally sustainable way is based on there being a
competitive advantage to it; that by acting sustainably a business will be more profitable as
consumers will prefer their products to those of businesses who do not act sustainably. This is
now a commonly used argument to encourage companies to become more socially or
environmentally responsible. As Deva explains (in the context of human rights), these sorts
of arguments rest on a number of key assumptions; that consumers know about the
sustainability practices of various companies (and the products associated with them) and
care enough to make buying decisions on that basis. 165 It also assumes that consumer
preference will generate enough profit to make the shift worthwhile. These assumptions will
not hold true in many situations. The reality is that changing to a low-carbon and
environmentally sustainable society will be a costly process for a number of businesses. Some industries will be fundamentally altered. In fact, the cost on business is one of the
contributing factors identified by Boston and Lempp resulting in climate change inaction in
democratic countries.166 The “interest group” asymmetry arises because the costs of change
to a low-carbon society will fall on concentrated groups, particularly businesses in carbon-
intensive industries, while the benefits of the change will be more widely spread in society
and over time. The groups who will bear the cost are better organised and have an incentive
to lobby government to delay action. The danger in the focus on “business case” arguments is that companies will only take action
on sustainability when it is going to be profitable for them. In order to present a positive
impression, companies will report the profitable sustainability actions they have undertaken 21 21 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? and rather than acknowledge their continuing unsustainability, instead suggest that they are
being sustainable.167 For example, in a study looking at the sustainability reports of members
of the SBC, the authors concluded that:168 With the exception of one NZBCSD [SBC] member (Landcare Research), ecology, and a
wider systems understanding of sustainability, remains largely absent from the constructions
of sustainability we have examined. 167 Gray, Rob “Does sustainability reporting improve corporate behaviour?: Wrong question? Right time?”
(2006) 36 Accounting and Business Research 65 at 81.
168
5 D. The "business case" for sustainability Business talk of sustainability seems likely to compel us
‘to adopt a narrow economic language, standard of judgement, and world view in approaching
and utilising the Earth’ The point is that in the long run, businesses should not be allowed to be profitable if certain
environmental or human rights standards are not being met. For this to happen,
environmental costs are going to need to be taken into account. But before then, businesses
should not pretend that true sustainability is achievable by making minimal changes to
business as usual. This is not to say that such changes are not useful but it should be
acknowledged that sustainability is about more than just energy efficiency. The reason why
changes should be made is because companies have a moral responsibility to account for the
impacts of their actions, not because they are going to be profitable.169 E. The moral obligations of companies At 147.
172 James Rachels The end of life: euthanasia and morality (Oxford University Press, Oxford; New York;
London, 1986) at 180.
173 [1932] AC 562 (HL) at 580. 169 Deva, above n 153, at 141. g
168 Milne et al., above n 50, at 1241. g
168 Milne et al., above n 50, at 1241.
169 169 Deva, above n 153, at 141.
170 171 At 147. 170 At 146. At 147.
2 James Rachels The end of life: euthanasia and morality (Oxford University Press, Oxford; New York;
ondon 1986) at 180 Milne et al., above n 50, at 1241.
9 Deva, above n 153, at 141.
0 At 146 E. The moral obligations of companies So what are the moral obligations of a company? Deva argues that companies are, like natural
people, “social organs” who “ought to comply with basic moral and legal norms of society”. After all, companies “consist of the people, [are] operated by the people and exist for the
people”.170 Natural persons are social organs and “their social status should not cease to exist
merely because they decide to act collectively and in an artificial form.”171 The moral
obligations that shareholders have towards other members of society should not be shielded
by the corporate veil. To put it another way, just by empowering an agent to act for a person,
the principal cannot rid him or her or itself from moral responsibility for the actions the agent
takes under his, her or its instruction. The basic duty that moral agents have is not to cause
harm to others. People are free to act to the extent that their actions do not harm others.172 In
law, this was expressed as the “Neighbour Principle” in the famous tort case of Donoghue v
Stevenson:173 22 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? The rule that you are to love your neighbour becomes in law, you must not injure your
neighbour; … You must take reasonable care to avoid acts or omissions which you can
reasonably foresee would be likely to injure your neighbour. As set out in Part II, global environmental change is being driven by human needs and wants. Burning fossil fuel to support current lifestyles in the Western world can be reasonably be
foreseen to cause harm to future generations through further climate change. Altering
ecosystems through nutrient pollution and agricultural intensification causing degraded water
and soil quality can also be reasonably foreseen to cause harm to present and future
generations. Future generations (including young people alive today) will have to live with
the harm caused by the unsustainable practices that count as business as usual now. When
the phrase “environmental cost” is used, it can be looked at as meaning a cost that someone
else is going to have to incur if they want to have the same ecosystem services that current
generations are overexploiting for free. g
(
)
Policy in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 127 at 135 – 136.
176 At 136 Deva, above n 153, at 147 148.
5 Peter Wilson “The Economics of Emissions Trading” in Alastair Cameron (ed) Climate Change Law and 4 Deva, above n 153, at 147 – 148.
5 P t
Wil
“Th E
i
f E i i
T di
” i Al
t i C
( d) Cli
Ch
L
d E. The moral obligations of companies While a tort claim is unlikely to be useful to future
generations, the Neighbour Principle is one of the basic norms of society and companies
should abide by it to the fullest extent possible.174 F. Balancing wellbeing against environmental harm 174 Deva, above n 153, at 147 – 148. 174 Deva, above n 153, at 147 – 148. g
(
)
g
y in New Zealand (LexisNexis NZ Ltd, Wellington, 2011) 127 at 135 – 136.
136 ,
,
175 Peter Wilson “The Economics of Emissions Trading” in Alastair Cameron (ed) Clim above n 153, at 147 – 148.
Wilson “The Economics of Emissions Trading” in Alastair Cameron (ed) Climate Change Law and F. Balancing wellbeing against environmental harm Having established that companies do broadly owe a moral duty to avoid environmental
harm, should this duty be quantified legally and if so, to what extent? To have an absolute
legal duty to not emit any GHGs or to not use nitrogen fertiliser for instance would be
counter-productive, as people currently derive great benefit from those environmentally-
unsustainable activities. In economic terms, environmental damage is a negative externality–
it is a cost that is being placed on a “party external to the decision making”. 175 This means
that more environmentally damaging goods and services are being produced than is societally
optimal.176 To reduce production to more societally acceptable levels, a mechanism should
be put in place (such as a tax or trading scheme) so that producers have to take into account
the effect their activities are having on others.177 Prices on those goods or services would go
up and fewer would be consumed. However, the key point is that those goods and services
will still be produced if people will pay the higher prices. The optimal amount of emissions
is not going to be zero because people will pay higher prices for the things they really
value.178 The change to a more sustainable relationship between economy and environment cannot
happen overnight – at best it will take decades. According to current predictions from the
International Energy Agency, if states want to keep global warming to under 2°C, carbon 23 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? emissions do not have stop straight away but global emissions need to peak by 2017.179 The
ideal solution would be an international agreement to reduce GHG emissions drastically. States could then set about putting in place mechanisms to incentivise emitters to decrease
emissions to the targeted level with the reassurance that everyone else will be doing the same. However, this seems unlikely to happen given that negotiations have been going on for more
than two decades180 and still there is no agreement as to the details of emissions reductions. Strengthening the NZETS would assist in incentivising emitters to decrease emissions. The
carbon price however, would need to be much higher in order to do that and the National
government has not evinced willingness to increase the price in the New Zealand market. F. Balancing wellbeing against environmental harm In
this context, it would be detrimental to the economy of New Zealand to impose a strict
obligation on New Zealand companies to drastically cut emissions and other environmental
damage. Doing nothing to incentivise decreasing emissions and other environmental damage
would not be helpful. Companies should be encouraged to prepare for a low-carbon future so
that a “smooth transition” can occur, as mentioned in the introduction. Measurement and
disclosure of environmental impact is an important first step. Strategic decisions about
minimising environmental damage while remaining profitable can only made when
companies (and governments) have information about the emissions and other environmental
impacts of companies. 180 Vernon Rive “International Framework” in Alastair Cameron (ed) Climate Change Law and Policy in New
Zealand (LexisNexis NZ Ltd, Wellington, 2011) 49 at 53 – 54. 179 International Energy Agency World Energy Outlook 2012: Executive Summary (OECD/IEA, France, 2012)
at 3.
180 V
Ri
“I t
ti
l F
k” i Al
t i C
( d) Cli
t Ch
L
d P li
i N 179 International Energy Agency World Energy Outlook 2012: Executive Summary (OECD/IEA, France, 2012)
at 3.
180 Vernon Rive “International Framework” in Alastair Cameron (ed) Climate Change Law and Policy in New
Zealand (LexisNexis NZ Ltd, Wellington, 2011) 49 at 53 – 54. 181 David Norton and Nick Reid Nature and Farming: sustaining native biodiversity in agricultural systems
(CSIRO Publishing, Collingwood, Victoria, 2013).
182 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>. The UNGC originally
had nine principles; the tenth principle relating to anti-corruption was added in 2004.
183 United Nations Global Compact “Business Participation” <www.unglobalcompact.org>.
184 United Nations Global Compact “Overview of the UN Global Compact” <www.unglobalcompact.org>.
185 United Nations Global Compact “Participant Search” <www.unglobalcompact.org>.
186 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>.
187 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>.
188 United Nations Global Compact “What is a COP?” <www.unglobalcompact.org>.
189 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>. G. Summary As identified in Part II, New Zealand’s company law is shareholder-focussed. Directors have
to act in the best interests of the company, which are usually the interests of shareholders as a
whole. Only when a company’s solvency is threatened are the company’s best interests not
identified with shareholders, but rather with creditors. The interests of shareholders as a
whole are thought to be the maximisation of profits, unless otherwise specified. This paper
will now go on to explore three options for incorporating environmental impact
considerations into New Zealand’s corporate decision making; directors voluntarily
considering the environment, imposing a legal duty to take into account the environmental
impact of the company’s action or imposing a legal duty to interact with the environment in a
sustainable manner. Part VII will consider voluntary options, namely either joining the SBC
or joining the UNGC, which is a voluntary, collaborative initiative between the United
Nations and businesses to achieve human rights, environmental protection and anti-
corruption objectives. It is principles-based and requires disclosure of a company’s progress
towards implementing the principles. The difference between this option and the other two is
that reporting would be voluntary. Hence this section will include an analysis of the efficacy
of voluntary reporting in achieving adequate disclosure. The second option, the requirements
in the UK Companies Act 2006 requiring directors to take into account the environment in 24 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? decision making, will be examined in Part VIII. The third option, to be examined in Part IX,
is an additional directors’ duty to act in an environmentally sustainable manner, which is not
currently in place in any common law country. All three options would involve companies
measuring and disclosing their environmental impacts. However, none of the options
requires companies not to seek to make a profit; a company cannot be green if it is
continually in the red.181 Companies need to make profits to continue to exist. Investors will
not want to invest money where there is no return and people will not work for a company if
they are not paid. The point is to make a profit while taking into account environmental cost. VII. Voluntary initiatives -the UNGC, the SBC and the SBN
A. Introduction to the UNGC The UNGC is a set of ten principles182 that companies can choose to adopt. It is a “leadership
initiative, involving a commitment by a company’s Chief Executive Officer (or equivalent),
and supported by the highest-level Governance body of the organization (eg, the Board).”183
The UNGC was proposed by the then UN Secretary General Kofi Annan in January 1999 and
was officially launched in July 2000. There are now more than 12,000 participants, 184
including businesses and other organisations from 145 countries. Currently, there are four
New Zealand participants in the UNGC; three small to medium enterprises (“SMEs”) and one
foundation.185 The principles are derived from the Universal Declaration of Human Rights,
the International Labour Organization’s Declaration on Fundamental Principles and Rights at
Work, the Rio Declaration on Environment and Development and the United Nations
Convention Against Corruption. 186 As the UNGC website describes “The UN Global
Compact asks companies to embrace, support and enact, within their sphere of influence, a
set of core values in the areas of human rights, labour standards, the environment and anti-
corruption.” 187 Participation in the UNGC is voluntary and except for detriments to a
company’s reputation, there are no repercussions for breaching the principles. Participants
must report on their progress every year – if a company does not report, then it will be
removed from the register of participants.188 There are three principles in the UNGC that relate to the environment:189 There are three principles in the UNGC that relate to the environment:189 190 Rio Declaration on Environment and Development A/CONF.151/26 (1992), Principle 15.
191 United Nations Global Compact "Global Compact Principle 8" <www.unglobalcompact.org>.
192 United Nations Sustainable Development Agenda 21, at para 34.1.
193 United Nations Global Compact “Local Networks” <www.unglobalcompact.org>.
194 United Nations Global Compact Guide for responsible corporate engagement in climate policy: a caring for
climate report (UNGC, 2013)
195 Afshin Akhtarkhavari, “The Global Compact, Environmental Principles, and Change in International
Environmental Politics” (2009) 38 Denv. J. Int'l L. & Pol'y 277 at 305.
196 Deva, above n 153, at 97.
197 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>. Principle 9: encourage the development and diffusion of environmentally friendly
technologies. Principle 7 is derived from the 1992 Rio Declaration which states that “where there are
threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a
reason for postponing cost-effective measures to prevent environmental degradation”. 190
Principle 8 is essentially the idea that businesses “have the responsibility to ensure that
activities on our own yard should not cause harm to the environment of our neighbours.”191
The environmentally friendly technologies referred to in Principle 9 are defined in Agenda 21
as technologies that “protect the environment, are less polluting, use all resources in a more
sustainable manner, recycle more of their wastes and products and handle residual wastes in a
more acceptable manner than the technologies for which they were substitutes.”192 There are three principles in the UNGC that relate to the environment:18 Principle 7: Businesses should support a precautionary approach to environmental challenges 25 25 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? 197 United Nations Global Compact “The Ten Principles” <www.unglobalcompact.org>. Principle 8: undertake initiatives to promote greater environmental responsibility; and Principle 8: undertake initiatives to promote greater environmental responsibility; and
Principle 9: encourage the development and diffusion of environmentally friendly
technologies. B. How well is it working? The UNGC can be regarded as successful in some respects. It has a truly global membership
as well as having local networks of participants in more than 20 countries, encouraging
collaboration between companies about the principles.193 The Compact requires participants
to at least consider the principles once a year when the Communication on Progress is filed. It also produces resources that can be used by members. For instance, the UNGC, in
partnership with the CDP and the World Wildlife Fund, among others released guidance for
companies to positively engage with governments over climate policy. 194 The UNGC is
based on the idea of collective learning. The principles are aspirational; members are to
report on progress made rather than on standards fulfilled. It also allows businesses to
interpret the principles in their own way. This can be regarded as an advantage or
disadvantage. On the positive side, it could encourage companies to join the UNGC who
otherwise may not if they had to comply with more stringently defined principles.195 Once
in, these companies may be influenced by the interpretations of other companies and come to
view their relationship with the environment and with stakeholders in a different way. On the
other hand, companies are able to interpret the principles a way that is contrary to the plain
meaning of the words. 196 For example in relation to Principle 3 of the UNGC, that
“Businesses should uphold… the effective recognition of the right to collective
bargaining”, 197 which seems on the face of it to require businesses to “institutionalize 26 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? ‘collective bargaining’, it [BHP] continued to require its new employees to sign individual
contracts and disputed that Principle 3 directed that employment be based on collective
bargaining.”198 The Global Compact Office seemed to agree.199 The UNGC has been the subject of much academic discourse over its 15 year life, examining
the types of companies that enter it, the types of companies that delist from it and the impact
it has on the companies who join. One such study examined whether US companies entering
the UNGC were using it to “blue-wash” their public image.200 This is a concern given the
relatively low membership fee and the less than onerous obligation to produce a
Communication on Progress once a year. g
206 Sustainable Business Council “Sustainable Development Principles” <www.sbc.org.nz>. 198 Deva, above n 153, at 97. At 18.
204 United Nations Global Compact “How do I prepare a COP? Advanced” <www.unglobalcompact.org>;
Sustainable Business Council “Sustainable Development Reporting Guide” <www.sbc.org.nz>.
205 Sustainable Business Network “About the Sustainable Business Network” <sustainable.org.nz>
206 Sustainable Business Council “Sustainable Development Principles” <www.sbc.org.nz>. 200 Daniel Berliner and Aseem Prakash ““Bluewashing” the Firm? Voluntary Regulations, Program Design, and
Member Compliance with the United Nations Global Compact” (2014) Policy Studies Journal (forthcoming).
201 At 1.
202 At 18.
204 United Nations Global Compact “How do I prepare a COP? Advanced” <www.unglobalcompact.org>;
Sustainable Business Council “Sustainable Development Reporting Guide” <www.sbc.org.nz>.
205 Sustainable Business Network “About the Sustainable Business Network” <sustainable.org.nz> p
p
g
g
205 Sustainable Business Network “About the Sustainable Business Network” <sustainable.org.nz> 204 United Nations Global Compact “How do I prepare a COP? Advanced” <www.unglobalcompact.org>;
Sustainable Business Council “Sustainable Development Reporting Guide” <www.sbc.org.nz>. 198 Deva, above n 153, at 97.
199 Ibid.
200 Daniel Berliner and Aseem Prakash ““Bluewashing” the Firm? Voluntary Regulations, Program Design, and
Member Compliance with the United Nations Global Compact” (2014) Policy Studies Journal (forthcoming).
201 At 1.
202 At 17.
203 At 18.
204 United Nations Global Compact “How do I prepare a COP? Advanced” <www.unglobalcompact.org>;
Sustainable Business Council “Sustainable Development Reporting Guide” <www.sbc.org.nz>.
205 Sustainable Business Network “About the Sustainable Business Network” <sustainable.org.nz>
206 Sustainable Business Council “Sustainable Development Principles” <www.sbc.org.nz>. B. How well is it working? The study found that firms who were members of
the UNGC scored worse than non-members “on costly and fundamental performance
dimensions, while showing improvements only in more superficial dimensions” such as
having environmental policies.201 Membership of the UNGC strengthened both of those
trends – more environmental concerns were reported at the same time as more superficial
positives were added.202 This suggests that the subjects of the study (large publically-listed
companies in the US) were using the UNGC for public relations purposes.203 C. Usefulness for New Zealand in comparison to existing initiatives
There is a very low uptake of UNGC membership in New Zealand. However, this does not
indicate a lack of interest in sustainability or CSR issues. New Zealand has its own voluntary
initiatives that provide similar benefits to the UNGC. The SBC, like the UNGC, provides a
network of like-minded businesses and requires its members to report on environmental
issues (among others). Both encourage the use of the GRI’s guidelines for reporting.204 The
Sustainable Business Network (“SBN”), aimed at smaller businesses in New Zealand, also
provides networking and resources for members.205 The principal difference between the
SBC and the UNGC is in their principles. The UNGC principles are wider than just
environmental sustainability, embracing human rights and labour standards, whereas the SBC
principles are much more specific in what is required of members in terms of reporting and
activity.206 However, the UNGC environmental principles suggest a decision-making metric
for members to follow. When making decisions that affect the environment, directors should
take a precautionary approach, should take responsibility for their environmental impacts and
should be looking towards using more environmentally-friendly techniques. The SBC’s
principles, centred around the concept of sustainable development, are more prescriptive 27 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? when it comes to process (members must prepare policies, connect with stakeholders etc) but
apart from “sustainable development” do not give guidance as to the type of approach that
should be taken. In this way, the UNGC principles are more accessible. Like the SBN, the
UNGC may be more appropriate to small New Zealand companies; both are significantly less
costly to join for small to medium enterprises207 and are potentially more accessible. The
compliance burdens are likely to be lesser as well. 207 Sustainable Business Council “Membership”< www.sbc.org.nz>; Sustainable Business Network “Join the
Sustainable Business Network” <sustainable.org.nz>; United Nations Global Compact “How to participate:
Business Participation” www.unglobalcompact.org. 8 Sidelle Pinto and Charl de Villiers “Do firms reduce CSR disclosures during recession?” (paper presente
e 11th A-CSEAR Conference, Wollongong, NSW, December 2012) at 6. 0 Kathy Gibson and Gary O'Donovan “Corporate governance and environmental reporting: an Australian
udy” (2007) 15 Corporate Governance: An International Review 944 at 947. 209 Bikram Chatterjee and others “An analysis of the qualitative characteristics of management commentary
reporting by New Zealand companies” (2012) 5 Australasian Accounting, Business and Finance Journal 43 at
54. 207 Sustainable Business Council “Membership”< www.sbc.org.nz>; Sustainable Business Network “Join the
Sustainable Business Network” <sustainable.org.nz>; United Nations Global Compact “How to participate:
Business Participation” www.unglobalcompact.org.
208 Sidelle Pinto and Charl de Villiers “Do firms reduce CSR disclosures during recession?” (paper presented at
the 11th A-CSEAR Conference, Wollongong, NSW, December 2012) at 6.
209 Bikram Chatterjee and others “An analysis of the qualitative characteristics of management commentary
reporting by New Zealand companies” (2012) 5 Australasian Accounting, Business and Finance Journal 43 at
54.
210 Kathy Gibson and Gary O'Donovan “Corporate governance and environmental reporting: an Australian
study” (2007) 15 Corporate Governance: An International Review 944 at 947. D. Voluntary versus mandatory environmental reporting When it comes to environmental reporting, the UNGC and the SBC both suffer from being
voluntary initiatives. Voluntary environmental reporting does, of course, have its uses. It
suggests that those companies are at least aware of and potentially engaging with their
environmental impacts. However, in a voluntary reporting regime, companies have the
capacity to choose what environmental information to report. In contrast, financial reporting
is standardised to enhance accountability and comparability; it would be much more difficult
to “spin” financial information without breaking the rules. Voluntary environmental
disclosure would not have to be audited or assured in some way and it would not have to be
reported in the same way from year to year. Voluntary environmental reporting is also influenced by the motivation of the company in
reporting it. Legitimacy theory suggests that corporations seek to maintain their legitimacy in
the community, to prove their place in society and to maintain the support of powerful
constituencies by disclosing social and environmental information. 208 In order to retain
support, companies may be tempted to report only “good” news rather than presenting a more
balanced view of environmental impact. There is a tendency in voluntary corporate
disclosures to report more “good” news and little if any bad news.209 Bolstering legitimacy
as a motivation for voluntary environmental disclosure is supported by the tendency towards
large companies operating in high-profile industries to report on environmental issues,
particularly after well-publicised instances of corporate irresponsibility.210 Environmental
disasters threaten the legitimacy of all the companies in that industry and so all respond with
increased disclosure to regain public support. Mandatory requirements would encourage consistency of reporting, making impacts more
comparable between years and across firms. Even if the legislation does not specify a 28 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? particular reporting standard, just requiring environmental impact reporting at all encourages
companies to use standards such as GRI and to get their reports assured.211 Alternatively,
legislation could require the use of the GRI guidelines or of other international standards such
as those of the Carbon Disclosure Standards Board or of the International Standards
Organisation. An argument against compulsory environmental reporting is that it could be costly for
companies to monitor and collect environmental information.212 This is likely to be the case. 214 de Villiers and van Staden, above n 212. 211 Ioannis Ioannou, and George Serafeim “The Consequences of Mandatory Corporate Sustainability
Reporting: Evidence from Four Countries” (2014)(11-100) Harvard Business School Research Working Paper.
212 Charl de Villiers and Chris van Staden “New Zealand shareholder attitudes towards corporate environmental
disclosure” (2012) 24 Pacific Accounting Review 186 215 See for instance carboNZero Ltd which has expertise in measuring, verifying and helping to reduce G
emissions of businesses. 211 Ioannis Ioannou, and George Serafeim “The Consequences of Mandatory Corporate Sustainability
Reporting: Evidence from Four Countries” (2014)(11-100) Harvard Business School Research Working Paper.
212 Charl de Villiers and Chris van Staden “New Zealand shareholder attitudes towards corporate environmental
disclosure” (2012) 24 Pacific Accounting Review 186.
213 Rory Sullivan and Andy Gouldson “Does voluntary carbon reporting meet investors’ needs?” (2012) 36 211 Ioannis Ioannou, and George Serafeim “The Consequences of Mandatory Corporate Sustainability
Reporting: Evidence from Four Countries” (2014)(11-100) Harvard Business School Research Working Paper.
212 Charl de Villiers and Chris van Staden “New Zealand shareholder attitudes towards corporate environmental
disclosure” (2012) 24 Pacific Accounting Review 186.
213 Rory Sullivan and Andy Gouldson “Does voluntary carbon reporting meet investors’ needs?” (2012) 36
Journal of Cleaner Production 60.
214 de Villiers and van Staden, above n 212.
215 See for instance carboNZero Ltd which has expertise in measuring, verifying and helping to reduce GHG
emissions of businesses. y
y
Journal of Cleaner Production 60. Reporting: Evidence from Four Countries (2014)(11 100) Harvard Business School Research Working Paper.
212 Charl de Villiers and Chris van Staden “New Zealand shareholder attitudes towards corporate environmental
disclosure” (2012) 24 Pacific Accounting Review 186.
213 Rory Sullivan and Andy Gouldson “Does voluntary carbon reporting meet investors’ needs?” (2012) 36
Journal of Cleaner Production 60. (
)
g
213 Rory Sullivan and Andy Gouldson “Does voluntary carbon reporting meet investors’ needs?” (20
Journal of Cleaner Production 60. 211 Ioannis Ioannou, and George Serafeim “The Consequences of Mandatory Corporate Sustainability
Reporting: Evidence from Four Countries” (2014)(11-100) Harvard Business School Research Working D. Voluntary versus mandatory environmental reporting However, financial reporting is also costly but it is important in order to assess directorial
performance and plan strategy. In the same way, environmental information should become
strategically important if it is not already; even the National government has accepted that the
economy must become low-carbon at some point, and so companies should be preparing for
that eventuality. However, like financial reporting requirements, the environmental reporting
requirements should also be tailored to firm size. SMEs should be encouraged to assess and
report on environmental impact to some extent but in this paper at least, it is not argued that
SMEs should have compulsory environmental reporting requirements. Listed companies
should have a fuller range of reporting requirements, in line with their greater complexity and
(probably) greater environmental impact. They should also have to provide this information
so that investors can make investment decisions based on it if they choose. Another argument against compulsory environmental reporting is that no one would use it.213
Investors who want to know can go to the CDP to find out about the impact of some of New
Zealand’s largest companies. However, not all companies report through the CDP. In
addition, research has been carried out with active shareholders who were involved in the
New Zealand Shareholders’ Association. The majority of participants wanted listed
companies to report environmental information, even though they knew that it could be
costly.214 Fewer than half of the NZX50 or the NZX100 currently report on environmental or CSR
issues. The ones who already do would have a head start on the others. The other companies
should not have too much trouble finding expertise to assist their reporting efforts; the benefit
of New Zealand being a follower in this case is that there are a number of environmental
reporting standards already prepared, and there are businesses whose expertise is in helping
to measure and report on environmental impact.215 29 29 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? There are two main benefits of requiring all listed companies to report on environmental
impact: balanced reporting and competition. Mandatory reporting requirements should
require companies to report bad as well as good environmental news, making it more difficult
for companies to spin their environmental impacts. D. Voluntary versus mandatory environmental reporting For instance, in the 2014 Fonterra Annual
Report, the company reports that its farmers have excluded stock from 95% of defined
waterways on their farms.216 This is undoubtedly positive but what the report does not say is
how much its farmers contributed to decreased water quality in those waterways and how
much stock exclusion has helped. The other benefit is that comparisons can be drawn
between the environmental impact of various companies, or even just the quality of
environmental reporting. This is likely to spur companies on to decrease emissions,
especially as consumers and investors will be able to see the environmental reports as well. E. Summary In summary, the UNGC and SBC both include useful principles for companies to follow. The UNGC, along with the SBN may be more appropriate for SMEs than the SBC, both in
terms of membership fee and accessibility of concepts. All three initiatives are positive in
that they encourage companies to consider and report on environmental issues. However,
being voluntary measures, the reporting carried out under those initiatives may be less
balanced and less comparable than mandatory reporting. VIII. “Enlightened shareholder value” provisions in the UK Companies Act
2006 (“UK Act”) VIII. “Enlightened shareholder value” provisions in the UK Companies Act
2006 (“UK Act”) 6 Fonterra Co-Operative Group Ltd Fonterra Annual Review 2014 available at <www.fonterra.com> at 42 A. The section 172 directors' duty A. The section 172 directors' duty The UK Act augmented the existing duty of directors to promote the success of the company
to include a requirement for directors to “have regard” to certain considerations. Section 172
(1) states that: A director of a company must act in a way he considers, in good faith, would be most likely
to promote the success of the company for the benefit of its members as a whole, and in doing
so have regard (amongst other matters) to – A director of a company must act in a way he considers, in good faith, would be most likely
to promote the success of the company for the benefit of its members as a whole, and in doing
so have regard (amongst other matters) to – (a) the likely consequences of any decision in the long term, (b) the interests of the company’s employees, (b) the interests of the company’s employees, (c) the need to foster the company’s business relationships with suppliers, customers
and others, (d) the impact of the company’s operations on the community and the environment, (e) the desirability of the company maintaining a reputation for high standards of
business conduct, and (f) the need to act fairly as between members of the company. 216 Fonterra Co-Operative Group Ltd Fonterra Annual Review 2014 available at <www.fonterra.com> at 42. 30 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? This section does not require a director to minimise the company’s impact on the
environment but environmental impact must be taken into consideration. In this provision,
the UK has selected an option in between the shareholder and stakeholder approach: the
approach of enlightened shareholder value. This was a change from the previously adopted
shareholder approach, which New Zealand still retains. The rationale behind it is that
“enlightened” shareholders understand taking into account the company’s stakeholders will
maximise the long term value of the company. Critics of enlightened shareholder value point
out that the end result is the same as under the shareholder approach:217 the directors must act
in the interests of the shareholders where there is a conflict as shareholders are the only ones
with power to remove directors or enforce duties against them through derivative action. B. 217 See for instance Andrew Keay “Tackling the issue of the corporate objective: an analysis of the United
Kingdom's enlightened shareholder value approach” (2007) 29 Sydney L. Rev. 577.
218 Companies Act 2006 (UK), s385(2). p
(
),
( )
219 At s 414A(1). However, s 414A(2) exempts small companies from having to prepare a strategic repo
220 At s 414C(1) ( )
221 At s 414C(2)(a). ( )( )
222 At s 414C(2)(b). Companies Act 2006 (UK), s385(2).
219 At s 414A(1). However, s 414A(2) exempts small companies from having to prepare a strategic repo
220 A
414C(1) 220 At s 414C(1). A. The section 172 directors' duty Reporting on environmental impacts by quoted companies Given these critiques, the more important parts of the enlightened shareholder value
provisions may well be the sections requiring quoted companies to report on their
environmental impact. Quoted companies are companies whose equity share capital is listed
in accordance with Part 6 of the Financial Services and Markets Act 2000 (c.8) or are
officially listed in an European Economic Area State or are admitted to dealing on either the
New York Stock Exchange or Nasdaq.218 The requirement for quoted companies to report on environmental impact and social and
community issues has been in the UK Act since 2006. Amendments to the relevant sections
were made in the Companies Act 2006 (Strategic Report and Directors’ Report) Regulations
2013 (“2013 Regulations”), which came into force on 1 October 2013. Unless otherwise
stated, the sections mentioned include the amendments brought about by the 2013
Regulations. It is compulsory for the directors of all companies to prepare a strategic report.219 The
purpose of this report is “to inform members of the company and help them assess how the
directors have performed their duty under section 172”.220 A strategic report must contain “a
fair review of the company’s business” 221 and “a description of the principal risks and
uncertainties facing the company.”222 Section 414C of the UK Act sets out that: (3) The review required is a balanced and comprehensive analysis of – (a) the development and performance of the company’s business during the financial
year, and
(b) the position of the company’s business at the end of that year, (a) the development and performance of the company’s business during the financial
year, and (b) the position of the company’s business at the end of that year, 31 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? 223 At s 414C(8). 223 At s 414C(8). p
(
),
( )
228 At s 463. However, for the director to be liable, the director must have known the statement to be untrue or
misleading or was reckless as to whether it was untrue or misleading. Likewise, to be liable for an omission, the
director must have known that the omission was dishonest concealment of a material fact.
229 At s 430. 224 Large and Medium-sized Companies and Groups (Accounts and Reports) Regulations 2008, Schedule 7, at
para 15(2).
225 A
17 consistent with the size and complexity of the business. (4) The review must, to the extent necessary for an understanding of the developmen
performance or position of the company’s business, include – (a) analysis using financial key performance indicators, and (b) where appropriate, analysis using other key performance indicators, including
information relation to environmental matters and employee matters. (b) where appropriate, analysis using other key performance indicators, including
information relation to environmental matters and employee matters. (5) In subsection (4), “key performance indicators” means factors by reference to which the
development, performance or position of the company’s business can be measured
effectively. (6) Where a company qualifies as medium-sized in relation to the financial year…, the review
for the year need not comply with the requirements of subsection (4) so far as they relate to
non-financial information. (7) In the case of a quoted company the strategic report must, to the extent necessary for an
understanding of the development, performance or position of the company’s business,
include – (a) the main trends and factors likely to affect the future development, performance
and position of the company’s business; and (b) information about – (b) information about – (i) environmental matters (including the impact of the company’s business on
the environment), (ii) the company’s employees, and (ii) the company’s employees, and (iii) social, community and human rights issues, (iii) social, community and human rights issues, including information about any policies of the company in relation to those matters
and the effectiveness of those policies. If the review does not contain information of each kind mentioned in paragraphs
(b)(i), (ii) and (iii), it must state which of those kinds of information it does not
contain. The material changes to the reporting requirements of quoted companies brought about in the
2013 Regulations include the requirement that quoted companies report on human rights
issues, and also on the gender make-up of their boards and senior management.223 Most
importantly, the 2013 Regulations amend the Large and Medium-sized Companies and 223 At s 414C(8). 32 32 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? At para 18.
227 Companies Act 2006 (UK), s 414D(2). 225 At para 17. 226 At para 18. consistent with the size and complexity of the business. Groups (Accounts and Reports) Regulations 2008 to require quoted companies to include in
their directors’ report:224 Groups (Accounts and Reports) Regulations 2008 to require quoted companies to include in
their directors’ report:224 the annual quantity of emissions in tonnes of carbon dioxide equivalent from activities for
which that company is responsible including – (a) the combustion of fuel; and (b) the operation of any facility. (3) The report must state the annual quantity of emissions in tonnes of carbon dioxide
equivalent resulting from the purchase of electricity, heat, steam or cooling by the company
for its own use. (3) The report must state the annual quantity of emissions in tonnes of carbon dioxide
equivalent resulting from the purchase of electricity, heat, steam or cooling by the company
for its own use. The directors’ report of quoted companies must also state the methodologies used to calculate
the annual quantity of emissions and include at least one ratio comparing annual emissions to
a quantifiable factor associated with the company’s activities. 225 The report must also
disclose last year’s emissions figures, including the ratio.226 The amendments make it a fineable offence to approve a strategic report which does not
comply with the Act for:227 every director of the company who – (a) knew that it did not comply, or was reckless as to whether it complied, and (a) knew that it did not comply, or was reckless as to whether it complied, and
(b) failed to take reasonable steps to secure compliance with those requirements or, as the
case may be, to prevent the report from being approved (b) failed to take reasonable steps to secure compliance with those requirements or, as the
case may be, to prevent the report from being approved The Act already contained a provision making a director of a company liable to compensate
the company for any loss suffered by it as a result of any untrue or misleading statement in a
report or the omission from a report of anything required to be included in it, provided the
director had the requisite knowledge or recklessness.228 The reports of quoted companies are
to be made available on the website of the quoted company.229 230 UK Department for Environment, Food and Rural Affairs Environmental Reporting Guidelines: Including
mandatory greenhouse gas emissions reporting guidance (June 2013).
231 Samantha Fettiplace and Rebecca Addis Department for Business, Innovation and Skills: Evaluation of the
Companies Act 2006, Volume 1 (Infogroup/ORC International, 2 August 2010) at 77.
232 At 77.
233 At 72 232 At 77.
233 At 72. C. Efficacy of "enlightened shareholder value" C. Efficacy of "enlightened shareholder value" C. Efficacy of "enlightened shareholder value" There is no specified standard that quoted companies have to report against in relation to their
environmental impact. It is possible that the provisions could be subject to the central
problem with voluntary disclosure – that is, companies choosing what to report and only
reporting good news. However, the specific requirement to report on GHG emissions from
year to year is one that quoted companies cannot escape. The requirement to include 33 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? environmental key performance indicators where applicable increases the reliability and
usefulness of the reports. The UK Departments for Environment, Food and Rural Affairs
(“Defra”) produces guidance for companies about their environmental reporting
requirements. They suggest reporting on (where applicable) GHG emissions (compulsory for
quoted companies), water, waste, resource efficiency and materials, emissions to land, water
and air, and finally on biodiversity and ecosystem services.230 An evaluation of the UK Act was published in 2010. In it, researchers found that the
majority of quoted companies surveyed (56%) were neutral when asked whether there was an
increase or decrease in difficulty to comply with the requirements in the business review
(requirements now in the strategic report).231 Directors of quoted companies appeared to find
the reporting of environmental and social information easier than providing extra information
about essential contractual arrangements and trends affecting the future development of the
business. 232 Those surveyed felt that the s 172 duty had not affected the behaviour of
directors.233 D. Compatibility with New Zealand law D. Compatibility with New Zealand law Like the UK before the 2006 reforms, and even arguably after them, New Zealand’s company
law subscribes to the shareholder approach. The best interests of the company are usually
identified with the interests of shareholders as a whole. In this way, the factors that directors
must consider under s 172 of the UK Act, including consideration of the company’s impact
on the environment, could fit quite easily into s 131 of the NZ Act. The requirement to report
on the environmental impact and GHG emissions of listed companies could be inserted into
the annual report requirements in the NZ Act. However, it is difficult at present to assess the usefulness of the enlightened shareholder
value provisions in encouraging companies to lessen their environmental impact. Changes
may occur in the long term but the early indications seem to be that directors and companies
do not consider the changes to have had much of an impact. The critiques of the “enlightened
shareholder value” approach would also suggest that the provisions will not have a significant
impact on business-as-usual corporate decision making. The reporting provisions,
particularly in relation to GHGs might have more of an impact as records develop and
consumer pressure builds. The XRB (if empowered by the Minister) could set a standard for
environmental reporting in the annual report which could make the reporting obligation more
powerful. 34 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? 234 McConvill and Joy, above n 153, at 130 and 134.
235 235 At 132. 236 At 130. IX.
Directors’ duty to interact with the environment in a sustainable way
A. The Australian proposal McConvill and Joy also suggested that a guidance note be put in place stating that the
precautionary principle must govern this provision’s interpretation so that scientific 35 35 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? uncertainty would not used as an excuse for inaction.237 The authors then went on to consider
the interaction with the directors’ other duties, primarily the traditional rule that directors
must seek to maximise the profits of shareholders. The authors’ view was that the new
directors’ duty should take precedence over the maximisation of profit in the short-term.238
To put it another way, as long as acting in accordance with the ecological judgment rule
would maximise profit in the medium or long term, the directors should not be penalised for
not maximising profit in the short term. The ecological judgment rule in subsection 3 and 4
of the proposed duty would protect directors from liability for breaches of the duty to act with
care and diligence and to act in good faith in the best interests of the company. The business
judgment rule would also be amended to include judgments made under the new duty. The authors also recognised the possibility of environmental groups seeking injunctions
against companies in anticipation of breach of the new duty, under the enhanced standing
provisions in the Australian Act.239 As they did not want business to be unduly held up,
environmental groups would not have standing to bring injunction actions directly in relation
to this section; rather, they would have to persuade the Australian Securities and Investments
Commission or Environment Australia to apply for an injunction.240 IX.
Directors’ duty to interact with the environment in a sustainable way
A. The Australian proposal A directors’ duty requiring interaction with the environment in a sustainable way was the
suggestion of two Australian authors, McConvill and Joy. The suggested duty was this:234 (1) A director or other officer of a corporation must exercise their powers and discharge their
duties to ensure that the corporation interacts with the environment in a sustainable
manner. (2) For the purposes of subsection (1), a corporation will be taken to be interacting with the
environment in a sustainable manner if it takes all steps reasonably practicable to reduce
its ecological impact and increase its resource efficiency. (3) A director or other officer of a corporation who makes an environmental judgment is
relieved from liability under subsection (1), s 180(1) and s 181(1) and their equivalent
duties at common law and in equity. (4) In this section: environmental judgment means any decision to take or not take action in
respect of a matter relevant to the business operations of the corporation which is
rationally made to comply with subsection (1). Note: The director's or officer's judgment is a rational one unless the belief is one that no
reasonable person in their position would hold. The duty was structured similarly to s 180 of the Corporations Act 2001 (Cth) (“Australian
Act”) in that it had a primary obligation (to act with a reasonable degree of care and
diligence), and then a provision deferring to the discretion of directors provided they comply
with certain standards such as acting in good faith for a proper purpose (the business
judgment rule).235 The duty would fundamentally change the relationship between companies and the
environment. Subsection 2 would ameliorate the uncertainty of subsection 1 but would still
encourage action on sustainability issues, while subsection 3 and 4 (the ecological judgment
rule) would protect directors from prosecution for not maximising profit in the short term:236 If we keep in mind that sustainability is about balance (by maintaining production of
resources for present needs, but also setting in place systems to provide for future needs), then
so long as these companies can demonstrate that they have in place systems and procedures to
achieve this balance, they will not fall foul of the proposed new statutory duty.. B. Application to New Zealand A similar provision could be inserted into the NZ Act, perhaps as s 131A. The focus of such
a provision would, appropriately, be on encouraging sustainable development. As McConvill
& Joy state:241 sustainable development inherently accommodates companies continuing to go about
making money for their shareholders through production and development, so long as
systems and policies are implemented which provide for improvements in resource
efficiency and ecological impact over time. Our proposed statutory duty does not
interfere with this balancing of considerations in any way. …A company's production
and development activities will only amount to a contravention of the Corporations
Act when it offends the standards of environmental protection that a reasonable person
in the community (which includes the perspective of shareholders and businesspeople
as well as environmentalists) would expect a company to meet. sustainable development inherently accommodates companies continuing to go about
making money for their shareholders through production and development, so long as
systems and policies are implemented which provide for improvements in resource
efficiency and ecological impact over time. Our proposed statutory duty does not
interfere with this balancing of considerations in any way. …A company's production
and development activities will only amount to a contravention of the Corporations
Act when it offends the standards of environmental protection that a reasonable person
in the community (which includes the perspective of shareholders and businesspeople
as well as environmentalists) would expect a company to meet. The duty would become stricter as standards change within the community with regard to the
importance of sustainable development. There would not be the same concern about
injunctions under the NZ Act as standing to apply is only conferred on a restricted class of 36 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? people. However, environmental groups should be able to notify a regulator of proposed
breaches and that regulator should be able to apply for an injunction. Section 164 of the CA
does not provide for a regulator to apply for an injunction; if the new duty was put in place,
this should be amended. Environmental groups should also be able to apply to take a
derivative action after a breach has occurred. The requirement that anyone seeking to take a
derivative action must have the leave of the court would stem the floodgates potentially
opened by that change. X. This paper has examined the relationship between companies and the environment in New
Zealand with a view to suggesting amendments to assist New Zealand’s smooth transition
towards a low-carbon and environmentally sustainable economy. It has found that directors
do not have to consider the environment when taking action, nor do directors have to report
on the environmental impacts of their companies. This is a stark contrast to the prescriptive
rules (particularly for listed companies) when it comes to financial reporting. This lack of
consideration of the environment by companies has contributed to the global environmental
problems that New Zealand and the wider world face. The main drivers of global
environmental change were described along with the environmental laws that New Zealand
has put in place to control some of these drivers. Opportunities were then identified for
corporate discretion to have a positive impact on the environment. The paper then went on to
consider the voluntary environmental reporting that companies are currently carrying out. Given that less than half of listed companies report on environmental or CSR issues and for
those that do, the standard of reporting varies wildly, it seems unlikely that many companies
are exercising their discretion in a way that positively benefits the environment. Next the paper next examined whether companies should have a duty to consider the
environment or to reduce environmental impact. Milton Friedman’s argument that the only
duty of companies is to maximise profit was described and critiqued. Following Deva’s
analysis, it was argued that companies do owe the moral duties that other participants in
society (natural persons) owe – the duties to act within the moral and legal norms of the
society. The primary moral duty is to do no harm to others. Causing environmental damage,
including by emitting GHGs, causes harm to future generations, and even though it can be
difficult to quantify, companies have a moral duty to minimise that harm. A moral duty to
minimise environmental damage would seem to justify the imposition of some sort of legal
duty for companies to protect or consider the environment. The imposition of such a duty
requires trade-offs between the benefits to current generations arising from environmentally
degrading activities compared to the long-run harm that is caused to the environment and
future generations by the perpetuation of business-as-usual approaches. X. Three options were examined that combined some form of environmental consideration by
companies with disclosure of environmental impacts. The UNGC and the New Zealand SBC 37 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? and SBN, all voluntary initiatives, were examined together to determine whether voluntary
initiatives were sufficient to encourage companies to consider the environment. While it was
suggested that all three had benefits to corporate decision making and corporate disclosure,
voluntary disclosure was found to be inferior to mandatory environmental disclosure in terms
of numbers of companies reporting and the quality and balance of the reports. The enlightened shareholder value provisions in the UK Act were considered next. While
directors do have to consider the environment, and importantly, quoted companies have to
report on their environmental impacts, the provisions were found to lack teeth as they do not
move far enough away from the status quo where shareholders are paramount. The
imposition of environmental reporting may increase the efficacy of the provisions overall as
environmental issues become more important. The last option examined was the Australian proposal requiring directors to ensure that
companies interact with the environment in a sustainable way. This option has the most
promise in terms of encouraging directors and companies to take action to minimise
environmental impact and become more sustainable. Like the enlightened shareholder value
provisions, balancing of various interests would occur but with the Australian proposal,
reasonable efforts would always have to be taken to reduce environmental impact. This
would not be the case under the UK provisions. The Australian proposal did not set out
environmental reporting requirements. However, as suggested for the UK provisions,
directors of listed companies could be required to report on environmental impact in the
annual report. From the above analysis, the Australian proposal combined with an environmental reporting
requirement for listed companies would be the most effective of the options assessed in
requiring companies to take responsibility for their environmental impacts and initiate change
towards a low-carbon and environmentally sustainable economy. The safeguards put in place
around the duty, such as the ecological judgment rule, would protect from prosecution
directors who were making a genuine effort to minimise environmental impact. At the same
time, the standard of environmental impact minimisation expected would be kept at the level
of reasonableness as assessed with reference to societal expectations. Word count (excluding referencing, bibliography and title page): 14, 994. X. Amending the standing
requirements to take a derivative action to include environmental groups would also act as an
encouragement for companies to take action, while retaining the leave provision would mean
that cases were only taken where they had real merit. Allowing a regulator, such as the
Financial Markets Authority or potentially the Ministry for the Environment to apply for an
injunction would also be a positive step in making sure that the provisions were taken
seriously. However, if the government is unwilling to require directors to either take into account
environmental impacts or to act in such a way as to ensure companies interact with the
environment in a sustainable way, the government should still put in place environmental 38 38 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? reporting requirements at least for listed companies. This would mean that when society
finally demands sustainability on the part of its companies, companies actually know what
their impacts are in order to reduce them. Encouraging networks such as the SBC, SBN and
UNGC would also be beneficial, particularly for smaller companies. Word count (excluding referencing, bibliography and title page): 14, 994. 39 39 Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? Being a Tidy Kiwi Company: should New Zealand require its companies to report on their environmental impacts? XI.
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https://hal.parisnanterre.fr/hal-03148895/file/Caldanietal_Dys_VisualTraining_2020.pdf
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English
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Visual Attentional Training Improves Reading Capabilities in Children with Dyslexia: An Eye Tracker Study During a Reading Task
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Brain sciences
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To cite this version: Simona Caldani, Christophe-Loïc Gerard, Hugo Peyre, Maria Pia Bucci. Visual Attentional Training
Improves Reading Capabilities in Children with Dyslexia: An Eye Tracker Study During a Reading
Task. Brain Sciences, 2020, 10 (8), pp.558. 10.3390/brainsci10080558. hal-03148895 Visual Attentional Training Improves Reading
Capabilities in Children with Dyslexia: An Eye Tracker
Study During a Reading Task
Simona Caldani, Christophe-Loïc Gerard, Hugo Peyre, Maria Pia Bucci Visual Attentional Training Improves Reading
Capabilities in Children with Dyslexia: An Eye Tracker
Study During a Reading Task
Simona Caldani, Christophe-Loïc Gerard, Hugo Peyre, Maria Pia Bucci Received: 24 July 2020; Accepted: 12 August 2020; Published: 15 August 2020 Abstract: Dyslexia is a specific disorder in reading abilities. The aim of this study was to explore
whether a short visual attentional training could improve reading capabilities in children with reading
disorders by changing their oculomotor characteristics. Two groups (G1 and G2) of 25 children with
reading disabilities and who are matched in IQ (intelligence quotient), sex, and age participated in
the study. The allocation of a subject to a specific group (G1 = experimental group; G2 = control
group) was generated in an unpredictable random sequence. The reading task was recorded twice
for G1, i.e., before (T1) and after (T2) 10 min of visual attentional training. Training consisted of
oculomotor tasks (saccades and pursuits movements) and searching tasks (three different exercises). For G2, the two reading tasks at T1 and T2 were done at an interval of 10 min instead. We found that
at T1, oculomotor performances during reading were statistically similar for both groups of children
with reading disabilities (G1 and G2). At T2, the group G1 only improved oculomotor capabilities
significantly during reading; in particular, children read faster, and their fixation time was shortest. We conclude that short visual attentional training could improve the cortical mechanisms responsible
for attention and reading capabilities. Further studies on a larger number of dyslexic children will
be necessary in order to explore the effects of different training types on the visual attentional span
given its important role on the orienting and focusing visuospatial attention and on the oculomotor
performance in children with dyslexia. Keywords: eye movements; dyslexia; children; reading disabilities; visual attentional training Visual Attentional Training Improves Reading
Capabilities in Children with Dyslexia: An Eye
Tracker Study During a Reading Task Simona Caldani 1,2,*, Christophe-Loïc Gerard 3, Hugo Peyre 3,4 and Maria Pia Bucci 1,2
1
UMR 7114 MoDyCo, CNRS-Université Paris Nanterre, 92000 Nanterre, France; mariapia.bucci@gmail.com
2
EFEE—Centre D’Exploration Fonctionnelle de L’Équilibre Chez L’Enfant, Robert Debré Hospital,
75019 Paris, France
3
Child and Adolescent Psychiatry Department Robert Debré Hospital 75019 Paris France; Simona Caldani 1,2,*, Christophe-Loïc Gerard 3, Hugo Peyre 3,4 and Maria Pia Bucci 1,2
1
UMR 7114 MoDyCo, CNRS-Université Paris Nanterre, 92000 Nanterre, France; mariapia.bucci@gm
2
EFEE—Centre D’Exploration Fonctionnelle de L’Équilibre Chez L’Enfant, Robert Debré Hospital,
75019 Paris, France
3
Child and Adolescent Psychiatry Department, Robert Debré Hospital, 75019 Paris, France;
christophe.loic@gmail.com (C.-L.G.); peyrehugo@yahoo.fr (H.P.)
4
Université de Paris, 75000 Paris, France
*
Correspondence: simona.caldani@gmail.com Simona Caldani 1,2,*, Christophe-Loïc Gerard 3, Hugo Peyre 3,4 and Maria Pia Bucci 1,2
1
UMR 7114 MoDyCo, CNRS-Université Paris Nanterre, 92000 Nanterre, France; mariapia.bucci@gmail.com
2
EFEE—Centre D’Exploration Fonctionnelle de L’Équilibre Chez L’Enfant, Robert Debré Hospital,
75019 Paris, France
3
Child and Adolescent Psychiatry Department, Robert Debré Hospital, 75019 Paris, France;
christophe.loic@gmail.com (C.-L.G.); peyrehugo@yahoo.fr (H.P.)
4
Université de Paris, 75000 Paris, France
*
Correspondence: simona.caldani@gmail.com Simona Caldani
, ,*, Christophe-Loïc Gerard , Hugo Peyre
, and Maria Pia Bucci
,
1
UMR 7114 MoDyCo, CNRS-Université Paris Nanterre, 92000 Nanterre, France; mariapia.bucci@gmail.com
2
EFEE—Centre D’Exploration Fonctionnelle de L’Équilibre Chez L’Enfant, Robert Debré Hospital, *
Correspondence: simona.caldani@gmail.com *
Correspondence: simona.caldani@gmail.com HAL Id: hal-03148895
https://hal.parisnanterre.fr/hal-03148895v1
Submitted on 22 Feb 2021 L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
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lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers. brain
sciences brain
sciences 1. Introduction Dyslexia is a disorder reported in 5–10% of school-aged children [1]. Given the heterogeneity of
this disorder in the literature there are still different theories that have tried to explain its etiology [2]. Actually, it is known that genetical investigations indicate a family risk, and the presence of a
phonological impairment in dyslexia could be considered the most robust hypothesis suggesting that
dyslexic children showed difficulties to read because they fail to acquire the skill of separating the sounds
in a word in order to match them to their visual letter counterparts [2]. However, other hypotheses have
been put forward. For instance, several studies reported deficits in auditory capabilities [3], as well
as in visual perception and oculomotor performances [4,5]. Nicolson and Fawcett [6] advanced the
hypothesis of a cerebellar impairment that leads to poor automaticity and motor control in children with
dyslexia. Facoetti et al. [7] reported also in children with dyslexia a specific disability in orienting as well www.mdpi.com/journal/brainsci Brain Sci. 2020, 10, 558; doi:10.3390/brainsci10080558 www.mdpi.com/journal/brainsci 2 of 13 Brain Sci. 2020, 10, 558 as in sustained focusing visuospatial attention. Our group further explored oculomotor capabilities in
dyslexic children and suggested a deficit in visual attentional processing in relation to the immaturity of
cortical structures responsible for saccades triggering [8–10]. Reading, in fact, corresponds to a complex
cognitive process during which several mechanisms are involved: visual perception, eye movements
such as saccades and fixations, and semantic and linguistic abilities; consequently, a deficit in one of
these different components could cause impairment in reading acquisition. Previous studies from our
group [11] and other groups [12,13] reported a longer duration of fixation in children starting to read,
explained by the immaturity of cortical structures responsible for eye fixation [14]. During the normal
development of reading skills, children learn to read rapidly by having shorter durations of fixations,
larger prosaccades, and fewer regressions; in other words, eye movement patterns become similar to
those observed in adults. In contrast, in children with dyslexia this oculomotor pattern is not observed; indeed, it is
well documented that children with dyslexia have abnormal oculomotor patterns during reading,
e.g., a slower reading speed, longer duration of fixations, frequent and smaller prosaccades, and several
regressions [15]. Interestingly, such characteristics have been reported in children with dyslexia
of different countries speaking different languages (Greek speaking [16]; English speaking [17];
Italian speaking [18], and German speaking [19]). 1. Introduction However, the hypothesis of an abnormal oculomotor
pattern in dyslexia and related visual deficits is not shared by other researchers; for instance, the authors
in [20] showed that visual deficit impairments could be causal in dyslexia, and other researchers
advanced the hypothesis that poor oculomotor behavior is a consequence and not the cause of
dyslexia [21]. This question is still under debate. One of the most important objectives of research conducted on children with dyslexia is to develop
training types able to improve reading skills, particularly reading speed—even if it is influenced by
the type of language (more or less transparent, see previously cited studies)—as it is an important
parameter for dyslexic children during school activities, given that if children need a longer time to
read they cannot do the other school exercises as nondyslexic children do. Although linguistic training
is the most studied [22], research has also been carried out on nonlinguistic training types. Firstly, Solan et al. [23], in order to study some of the visual processes of reading disability,
compared two types of training (eye movement and comprehension training for 12 one-hour sessions)
in two groups of 15 children of 11 years old with dyslexia. For the eye movement training, the perceptual
accuracy/visual efficiency method was used, while for the comprehension training the child must correct
missing words in a sentence. They found that the number of fixations as well as the number of regressive
saccades and comprehension were both improved by eye movement training; similar results were
obtained by comprehension training, supporting the notion of a cognitive link between visual attention,
eye movement’s performance, and reading comprehension. These findings support the existence of a
cognitive relationship among visual attention, eye movements, and reading comprehension. Meng et al. [24] reported reading enhancement in Chinese-speaking children with dyslexia after
ten sessions within four weeks of visual perceptual training (texture discrimination tasks lasting about
50 min/session); interestingly, such improvement was still observed two months later. These authors
advanced the hypothesis that temporal processing and spatial attentional capabilities leading to
enlarging the visual span could be the possible cause of the training effect. This study suggested
that, at least in Chinese readers, visual perceptual processing and reading ability could share a
similar network. Several studies conducted in children with dyslexia have reported an improvement of reading
performance by decreasing the crowding phenomenon (i.e., increasing letter spacing [25–27]). 1. Introduction It should
be noted, however, that for most of these studies the number of children with dyslexia was small,
and no eye movement recording during reading was performed. Our group recorded eye movements
during reading and confirmed in French children with dyslexia the beneficial effect of large letter
spacing between words for reading [28]. Recently, we showed also that a computer-based oculomotor
training (15 min per day for five/seven days per week for 8 weeks) in a small group of 16 Italian 3 of 13 Brain Sci. 2020, 10, 558 children with dyslexia could improve reading abilities by shortening the reading time and the duration
of fixation objectively measured (by an eye tracker), perhaps via visual attentional capabilities [29]. More recently, Cancer et al. [30] compared in a small group of dyslexic children (n = 12) the effect
of rhythmic reading training (RRT) on reading speed and accuracy with respect to those of two training
types already validated (i.e., Bakker’s visual hemisphere-specific stimulation and the action video
game training). Both training types were administrated for 13 h over nine days. The authors reported
that RRT improved more significantly the pseudoword reading speed, and the other training increased
general reading accuracy. Authors suggested that these different results could be due to different
cognitive mechanisms trained; in other words, the RTT could affect phonological awareness while the
other training could have an effect on rapid automatized naming. Based on these results we could
make the hypothesis that specific training types could be developed for different types of dyslexia. This hypothesis, however, needs to be tested on a large population with dyslexia. Peters and colleagues [31] made a systematic review on the effect of visual attentional training on
reading abilities in children with dyslexia aged 5–15 years old. These authors selected eighteen studies
and analyzed three types of visual attentional interventions: action video games, reading acceleration,
and visual perceptual training. Their findings showed that action video games improved speed reading
and fluency, while reading acceleration programs increased accuracy, and speed reading and visual
perceptual training benefited reading fluency and comprehension. Interestingly, these interventions
can improve reading capabilities for at least two months after training. It should be noted, however,
that other researchers [32] did not confirm these results. 1. Introduction It is important also to point out that no study
recorded eye movement behavior to confirm or not the eventual benefit of interventions, with the
exception of one study in which a small group of children were tested (nine children only) [33]. Based on these findings, the aim of the present study is to measure by an eye tracker the effect
of a short visual attentional training on the reading skills in French children with reading disorders. Eye movement recording is an objective tool that allow us to better understand the eventual changes
in oculomotor patterns in children with dyslexia after training. Our final purpose is to develop a new
functional training program for this kind of children. 2.1. Subjects Fifty children with reading disorders (from 7.8 to 12 years old) were recruited from the Robert
Debré Pediatric Hospital. The children in the study underwent a complete evaluation (see our previous
studies [8–15]). For each child, the L2MA (Langage Oral Écrit Mémoire Attention) [34] was used to measure text
comprehension and the ability to read words and pseudowords. The child was included in the study if
(i) their L2MA score was more than two standard deviations from the mean (all children included had
dyslexia); (ii) the intelligent quotient (IQ, evaluated using the) was in normal range (between 85 and
115); (iii) they had normal visual acuity at near vision (both eyes ≥10/10); (iv) any hyperactivity deficit
was excluded, using the ADHD (Attention-deficit/hyperactivity disorder) Rating Scale (ADHD-RS)
parental report. It should be noted also that no treatment was given to the children, and all of them
were naive of therapeutic intervention. For each child we also evaluated the reading age by using the ELFE test (Évaluation de la Lecture
en FluencE) (www.cognisciences.com, Grenoble, France) and the visual attentional (VA) span test [35]. For more details, the ELFE test is used to measure the reading age of children, and it is widely used in
French laboratories/clinicians to evaluate the reading age of children. Each child was allocated to a specific group (G1 = experimental group; G2 = control group)
using an unpredictable random sequence; the group G1 has only benefited from visual attentional
rehabilitation. It should be noted that the children were unaware of the experimental manipulations,
and only parents were informed about the goal of the study. The investigation adhered to the 4 of 13 Brain Sci. 2020, 10, 558 principles of the Declaration of Helsinki and was accepted by the Institutional Human Experimentation
Committee of CPP (Comité de protection des personnes) Ile de France I (INSERM CEEI-IRB, N◦16-290,
Hotel-Dieu Hospital, Paris). p
Below are details for the ELFE test and the VA (visual attention) span test. The ELFE test consisted
of two texts, i.e., “Le Geant Egoiste” and “Monsieur Petit”. The child was invited to read aloud one text
during 1 min, and the examiner counted the number of words read. 2.1. Subjects It should be noted that the two
texts are similar and comparable for their difficulty and orthography; the number of words with high
and low frequency as well as the number of longer and shorter words were similar, and consequently
the two texts can be used for measuring reading age before and after training without any risk of
learning effect. The VA span test consisted of 20 trials, in which the child was required to orally report a string of
5 letters that was briefly presented at the center of the monitor screen. At the beginning of each trial,
a central fixation point was presented for 1000 ms followed by a blank screen for 500 ms. A letter string
was then presented at the center of the display for 200 ms. The child had to report verbally all the
letters immediately after they disappeared. After having written their response, the examiner pressed a
button to start the next trial. At the end the examiner counted the number of letters accurately reported
across the trials. Clinicians in France frequently use this test. 2.2. Reading Task The text was presented on a 22-inch LCD (liquid-crystal display) screen with “full HD
(High-Definition) resolution” (image size of 1920 × 1080 pixels). The child was asked to read
aloud a text of four lines from a children’s book (extract from Jojo Lapin Fait des Farces, Gnid Bulton,
Hachette). The paragraph contained 40 words and 174 characters. The text was 29◦wide and 6.4◦high;
mean character width was 0.5◦, and the text was written in black Courier font on a white background. This reading task is showed in Appendix A (Texts 1 and 2, see Figures A1 and A2); it should be noted
that only the length, subject, and writing style were balanced. Eye movements during the reading task
were recorded two times at T1 and T2, i.e., before and after, respectively, 10 min of visual attentional
training for the group G1 (experimental group) and also before and after 10 min for the group G2
(control group). The order of the text (Texts 1 and 2) presented in T1 and T2 was counterbalanced. It should be noted that the child was instructed to read the text without asking for comprehension. 2.2.1. Visual Attentional Training Visual attentional training consisted of both oculomotor exercises without recording eye
movements (pursuits, saccades) and three searching tasks by using Metrisquare© Lebe Business
Centers Sittard, Sittard, Nederland. It should be noted that the child received specific instructions for
each test (see below in the “Oculomotor Task” and “Searching Task” sections). 2.2.3. Searching Task
2.2.3. Searching Task
Th
diff Three different types of searching exercises were used. The child had to search for some small
objects and to remove them with a pencil following the instructions of the experimenter. The objects
were presented on a tablet that was connected to a PC (Metrisquare©), and the pencil was also
connected with this PC, allowing for an objective measurement of the time needed to execute the
exercise, the errors, and the omission of each exercise (for more details, see Chatard et al. [36]). The three
exercises are referred to as “house”, “cat”, and “space rockets”. Three different types of searching exercises were used. The child had to search for some small
objects and to remove them with a pencil following the instructions of the experimenter. The objects
were presented on a tablet that was connected to a PC (Metrisquare©), and the pencil was also
connected with this PC, allowing for an objective measurement of the time needed to execute the
exercise, the errors, and the omission of each exercise (for more details, see Chatard et al. [36]). The
three exercises are referred to as “house”, “cat”, and “space rockets”. In the house exercise 36 colored houses on a white background of (2 × 2 cm) were presented In the house exercise, 36 colored houses on a white background of (2 × 2 cm) were presented,
among which 24 houses are on fire. The child was asked to remove the houses that are not on fire
(see Figure 1A). In the cat exercise, 24 black heads of cats on a white background were presented
together with 24 black stars and 24 black trees (0.5 × 1 cm). The child was asked to remove all the
heads of the cats (see Figure 1B). In the space rockets exercise, 104 black space rockets having different
characteristics were presented on a white background (2 × 1 cm). The child was requested to remove
16 rockets that match the model (see Figure 1C). In the house exercise, 36 colored houses on a white background of (2 × 2 cm) were presented,
among which 24 houses are on fire. The child was asked to remove the houses that are not on fire
(see Figure 1A). In the cat exercise, 24 black heads of cats on a white background were presented
together with 24 black stars and 24 black trees (0.5 × 1 cm). 2.2.2. Oculomotor Task Two oculomotor tasks were used: horizontal visually-guided saccades and horizontal pursuits
presented on the PC (personal computer) that was used for the reading task. For horizontal visually-guided saccades, the stimulus (both the central and eccentric targets) was
a white filled circle subtending a visual angle of 0.5◦. After a variable fixation period ranging between
2000 and 3500 ms, the central target disappeared, and a target at the left or at the right side of the
screen simultaneously appeared for 1000 ms. The central fixation target then reappeared, signaling the
beginning of the next trial. Each child performed two blocks of 30 visually-guided saccades randomly
presented to the left and to the right side of different amplitudes (5◦, 10◦, 15◦, and 20◦). The child was
instructed to look at the target as accurately and as rapidly as possible. The pursuit task requires the child to follow a slowly moving visual target displayed on the PC. The target velocity was of 15◦/s. The target (a white circle of 0.5◦) was initially placed in the central
position (0◦) and then moved horizontally to one side until it reached a ±20◦location, where it reversed 5 of 13
5 of 14 Brain Sci. 2020, 10, 558
Brain Sci. 2020, 10, x FO abruptly and moved to the opposite side. A total of nine cycles were run. Children were instructed to
keep their eyes on the target, wherever it moved. Children had to perform the same test four times. The duration of the pursuit task was 2 min. reversed abruptly and moved to the opposite side. A total of nine cycles were run. Children were
instructed to keep their eyes on the target, wherever it moved. Children had to perform the same test
four times. The duration of the pursuit task was 2 min. 2.2.3. Searching Task
2.2.3. Searching Task
Th
diff The child was asked to remove all the
heads of the cats (see Figure 1B). In the space rockets exercise, 104 black space rockets having different
characteristics were presented on a white background (2 × 1 cm). The child was requested to remove
16 rockets that match the model (see Figure 1C). Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). h d
f h
h
bl
f
d
d
h
Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). The duration of three searching exercises was variable (from 5 to 7 min), depending on the tim Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). Figure 1. Visual attentional exercises by Metrisquare©: house (A), cats (B), and space rockets (C). The duration of three searching exercises was variable (from 5 to 7 min), depending on the time
needed for the child to perform the tasks. Any feedback on the performance was given to the child
after doing the Metrisquare task
The duration of three searching exercises was variable (from 5 to 7 min), depending on the time
needed for the child to perform the tasks. Any feedback on the performance was given to the child
after doing the Metrisquare task. Eye Movement Recording During the execution of reading task, eye movements were recorded using an Eye Brain
T2® (SuriCog, Paris, France) head-mounted eye tracker. This eye tracker is a medical EC
(European Commission) certified device. The accuracy of this system is 0.25◦, and its recording
frequency reaches 300 Hz. This device can record the position of the eyes horizontally and vertically,
independently and simultaneously for each eye. Calibration is done before eye movement recording. The calibration consists of a succession of red dots (diameter of 0.5◦), presented on a flat PC screen
of dimensions 512 × 288 mm, corresponding to the nominal diagonal size of 22 inches. During this
procedure, we asked the children to look a grid of 13 points mapping the screen at a distance of 60 cm. Calibration is calculated for a 250 ms fixation period for each point. There is no obstruction of the
visual field during registration with the recording system, and the calibrated zone covers a visual angle
of ±22◦[35]. After the calibration procedure, the reading task was explained to the child. Duration of
each task varied accordingly to the specific child’s reading speed. 2.5. Statistical Analysis Statistical analysis using the GLM (general linear models) in STATISTICA®(12.0, Palo Alto,
California, United States) was performed. Univariate one-way ANOVA was performed in order to
compare the age, the IQ, and the number of words read in 1 min in the ELFE test and the visual
attentional span test (the number of letters accurately reported across the trials) in two groups of
children (G1 and G2). Repeated measurements of ANOVA were also run between the two children
groups (G1 and G2) on the oculomotor parameters recorded at T1 and T2. An analysis of covariance
(ANCOVA) on the duration of fixation with the total reading time as a covariable was also performed,
in order to eliminate variance due to reading time differences. Post hoc comparisons were made with
the Bonferroni test. The effect of a factor was considered significant when the p-value was below 0.05. 2.4. Data Analysis We used the software MeyeAnalysis (provided with the eye tracker, SuriCog, Paris, France) in
order to calibrate and to extract saccadic eye movements from the data. The onset and the end of each
saccade was automatically determined through a built-in saccade detection algorithm [37]. The number
and the amplitude of saccades or prosaccades, the number of regressions, the duration of fixation,
and the total duration of reading were calculated in a computerized manner for each reading task. Accuracy was not measured, given that the present study focuses on eye movement pattern changes
before and after visual attentional training. 2 3 Procedure
2.3. Procedure 2.3. Procedure
After the screening for dyslexia (done by the two coauthors, Dr. C.-L.G. and H.P.), the child was
invited to participate in our experiment. Firstly, the examiners (two coauthors S.C. and M.P.B.)
After the screening for dyslexia (done by the two coauthors, Dr. C.-L.G. and H.P.), the child
was invited to participate in our experiment. Firstly, the examiners (two coauthors S.C. and M.P.B.) 6 of 13 Brain Sci. 2020, 10, 558 measured their reading age by the ELFE test; children were assigned randomly to each group (G1 or
G2) in accordance to their performances in the VA and ELFE tests. Afterwards, the child underwent
oculomotor recording (T1), and then only children of G1 (experimental group) underwent visual
attentional training (i.e., both oculomotor types—without eye movements recording—and searching
task by using the Metrisquare apparatus). In contrast, children of G2 (control group) did not perform
the training, but they spoke for about 10 min with the two examiners. Then, T2 oculomotor recording
was run for both groups of children (G1 and G2). The duration of all these tests was about 45 min
because some breaks were done to avoid fatigue. 3. Results Table 1 shows clinical characteristics of the two groups of children with reading disorders (G1 and
G2). The one-way ANOVA failed to report any statistical difference between G1 (experimental group)
and G2 (control group) (F(1,48) = 0.15, p = 0.7; F(1,48) = 0.10, p = 0.8; F(1,48) = 0.02, p = 1.0; F(1,48) = 0.01,
p = 0.9; F(1,48) = 0.03, p = 1.0; F(1,48) = 0.04, p = 0.8; and F(1,48) = 0.84, p = 0.4; respectively for the age, IQ,
L2MA (oral and written languages and memory), ELFE test, and VA span test). 7 of 13
G2
E Brain Sci. 2020, 10, 558
Table 1. Clinica
o t ol
ou ) Table 1. Clinical characteristics of the two groups of dyslexic children (G1 = experimental group;
G2 = control group) with mean and standard deviations of age (years), IQ, of words/min read in the
ELFE test and visual attentional span test (the number of letters accurately reported across the trials). test and visual attentional span test (the number of letters accurately reported across the trials). G1 (n = 25)
G2 (n = 25) G1 (n = 25)
G2 (n = 25)
Age (years)
9.56 ± 0.29
9.74 ± 0.38
IQ (WISC-IV)
100 ± 6
102 ± 5.1
ADHD-RS score
5.2 ± 1
4.9 ± 1.2
L2MA standard deviation from
the mean
Oral Language
2.8
2.9
Written Language
2.6
2.7
Memory
2.7
2.8
ELFE test
48 ± 5.3
50 ± 5.8
VA span
63 ± 3.0
60 ± 2.1
Note: For the L2MA test done in both group of children the standard deviation from normal mean is reported. Age (years)
9.56 ± 0.29
9.74 ± 0.38
IQ (WISC-IV)
100 ± 6
102 ± 5.1
ADHD-RS score
5.2 ± 1
4.9 ± 1.2
L2MA standard deviation from the mean
Oral Language
2.8
2.9
Written Language
2.6
2.7
Memory
2.7
2.8 The ANOVA reported a significant training effect for the total reading time (F(1,48) = 4.78, β = 0.09
p < 0.03) and also a significant interaction T × G effect (F(1,48) = 39.56, β = 0.45 p < 0.0001). The Bonferroni
post hoc test showed only that the time of reading for G1 (experimental group) at T2 decreased with
respect to T1 (p < 0.0001) (see Figure 2). 3. Results ELFE test
48 ± 5.3
50 ± 5.8
VA span
63 ± 3.0
60 ± 2.1
Note: For the L2MA test done in both group of children the standard deviation from normal mean is reported. Figure 2. Means and standard deviations of the total time (s) of reading the text at T1 and T2 for both
groups of children (G1 = experimental group; G2 = control group). Figure 2. Means and standard deviations of the total time (s) of reading the text at T1 and T2 for both
groups of children (G1 = experimental group; G2 = control group). Figure 2. Means and standard deviations of the total time (s) of reading the text at T1 and T2 for both
groups of children (G1 = experimental group; G2 = control group). Figure 2. Means and standard deviations of the total time (s) of reading the text at T1 and T2 for both
groups of children (G1 = experimental group; G2 = control group). The ANOVA showed a significant training effect for the duration of fixation (F(1,48) = 6.43, β =
0.11 p < 0.01) and a significant interaction T × G effect (F(1,48) = 17.82, β = 0.27 p < 0.0001). The Bonferroni
post hoc test showed that for G1 (experimental group) only, the duration of fixations at T2 was shorter
in contrast to T1 (p < 0.0001). ANCOVA showed a significant group effect in T2 (F(1,48) = 10.70 p <
0.001), suggesting that all significant findings survived the removal of variance due to reading time
differences (see Figure 3). The ANOVA showed a significant training effect for the duration of fixation (F(1,48) = 6.43, β = 0.11
p < 0.01) and a significant interaction T × G effect (F(1,48) = 17.82, β = 0.27 p < 0.0001). The Bonferroni
post hoc test showed that for G1 (experimental group) only, the duration of fixations at T2 was shorter in
contrast to T1 (p < 0.0001). ANCOVA showed a significant group effect in T2 (F(1,48) = 10.70 p < 0.001),
suggesting that all significant findings survived the removal of variance due to reading time differences
(see Figure 3). differences (see Figure 3). Table 2 shows the values of amplitude of prosaccades and regressions at T1 and T2 for both
groups of children (G1 and G2). 3. Results ANOVA failed to show any significant group or time effect for either
interaction
g
Table 2 shows the values of amplitude of prosaccades and regressions at T1 and T2 for both
groups of children (G1 and G2). ANOVA failed to show any significant group or time effect for
either interaction. interaction. Therefore, in order to explore the eventual effect of the text in Table 3, the total time of reading
and the duration of fixation are reported for children of G1 (experimental group) who read Text 1 and
Text 2 before and after training (at T1 and T2, respectively). ANOVA failed to show any significant text
effect, suggesting no effect of the type of the text on reading performance. 8 of 13 Brain Sci. 2020, 10, 558
59 ± Figure 3. Means and standard deviations of the duration of fixations (ms) at T1 and T2 for both groups
of children (G1 = experimental group; G2 = control group). Figure 3. Means and standard deviations of the duration of fixations (ms) at T1 and T2 for both groups
of children (G1 = experimental group; G2 = control group). Figure 3. Means and standard deviations of the duration of fixations (ms) at T1 and T2 for both groups
of children (G1 = experimental group; G2 = control group). Figure 3. Means and standard deviations of the duration of fixations (ms) at T1 and T2 for both groups
of children (G1 = experimental group; G2 = control group). Finally, ANOVA reported only a significant interaction T × G effect for the number of regressions
(F(1,48) = 6.02, β = 0.11 p < 0.02), as seen in Figure 4. The Bonferroni test failed to show any statistical
difference between the groups and the time of testing (T1 and T2). Finally, ANOVA reported only a significant interaction T × G effect for the number of regressions
(F(1,48) = 6.02, β = 0.11 p < 0.02), as seen in Figure 4. The Bonferroni test failed to show any statistical
difference between the groups and the time of testing (T1 and T2). Brain Sci. 2020, 10, x FOR PEER REVIEW
9 of 1 Figure 4. Means and standard deviations of the number of prosaccades (A) and number of regressions
Figure 4. 4. Discussion The aim of this study was to evaluate the effect of a short visual attentional training on the reading
performance in French children with reading disabilities. Our results indicate that these children could
benefit from a short visual attentional training for reading faster with a decrease in the duration of
fixations. It should be noted, however, that such short visual attentional training did not lead to any
change concerning the number and the amplitude of prosaccades and regressions. These findings are
discussed below. In the literature, the beneficial effects of visual perceptual training on the reading comprehension
and fluency in children with dyslexia were recently reviewed (see the review of Peters et al. [31]
described in the Introduction). However, that in this review, only one study [33], recorded eye
movements during reading of the text. In more details, Judica and collaborators evaluated reading
skills after a reading training program (1 h, two times for week for 5 months) in a small group of
nine children with dyslexia (age mean of 11 years old). Training consisted of both reading a word
aloud or silently and writing it on the keyboard. Eye movements were recorded using an infrared
pupil reflection system with recording frequency at 200 Hz, and the duration of fixation, the number,
and the amplitude of pro saccades and regressions were measured. The authors reported after
training a significant shortening of fixations, suggesting that training could facilitate the process of
extracting visual information on the words. In other terms, dyslexic children became more efficient in
extrapolating information from the unit of letters composing the word. Indeed, during the reading
task the most important eye movement parameter is the duration of fixation, given that it is during
this time that the reading process takes place. These findings suggested that visual attentional training could act on the neural network
responsible of duration of fixations during reading task. In other words, the capability of orienting and
focusing visuospatial attention could be improved by a visual attentional training type even if it is
short in time. We recall that neuroimaging studies reported that a complex neural network is activated
during reading, predominantly the left-hemisphere area of inferior frontal, temporoparietal,
and occipitotemporal cortical regions [38]. Concerning attentional system, research found that
it is associated to the cingulo-frontoparietal network, linked with frontostriatal and frontoparietal
pathways [39]. 3. Results Mean and standard deviations of the total time of reading and of duration of fixation for
children of G1 = experimental group, who read Texts 1 and 2 before and after training (in T1 and T2). Total Time of Reading (s)
Duration of Fixation (ms)
Before Training (T1)
After Training (T2)
Before Training (T1)
After Training (T2)
Text 1
Text 2
Text 1
Text 2
Text 1
Text 2
Text 1
Text 2
59 ± 5
57 ± 6
45 ± 6
47 ± 5
465 ± 25
475 ± 29
411 ± 21
415 ± 20 3. Results Means and standard deviations of the number of prosaccades (A) and number of regressions
(B) at T1 and T2 for both groups of children (G1 = experimental group; G2 = control group). Figure 4. Means and standard deviations of the number of prosaccades (A) and number of regression
Figure 4. Means and standard deviations of the number of prosaccades (A) and number of regressions
(B) at T1 and T2 for both groups of children (G1 = experimental group; G2 = control group). 9 of 13 Brain Sci. 2020, 10, 558 Table 2. Means and standard deviations of the amplitude of prosaccades and regressions at T1 and T2
for both groups of children (G1 = experimental group; G2 = control group). Table 2. Means and standard deviations of the amplitude of prosaccades and regressions at T1 and T2
for both groups of children (G1 = experimental group; G2 = control group). Amplitude of Prosaccades (◦)
Amplitude of Regressions (◦)
T1
T2
T1
T2
G1 (experimental group)
2.7 ± 1.1
2.5 ± 0.1
2.6 ± 0.1
2.6 ± 0.1
G2 (control group)
2.5 ± 0.1
2.4 ± 0.1
2.7 ± 0.1
2.6 ± 0.1
Table 3. Mean and standard deviations of the total time of reading and of duration of fixation for
children of G1 = experimental group, who read Texts 1 and 2 before and after training (in T1 and T2). Total Time of Reading (s)
Duration of Fixation (ms)
Before Training (T1)
After Training (T2)
Before Training (T1)
After Training (T2)
Text 1
Text 2
Text 1
Text 2
Text 1
Text 2
Text 1
Text 2
59 ± 5
57 ± 6
45 ± 6
47 ± 5
465 ± 25
475 ± 29
411 ± 21
415 ± 20 for both groups of children (G1 = experimental group; G2 = control group). Amplitude of Prosaccades (◦)
Amplitude of Regressions (◦)
T1
T2
T1
T2
G1 (experimental group)
2.7 ± 1.1
2.5 ± 0.1
2.6 ± 0.1
2.6 ± 0.1
G2 (control group)
2.5 ± 0.1
2.4 ± 0.1
2.7 ± 0.1
2.6 ± 0.1
Table 3. Mean and standard deviations of the total time of reading and of duration of fixation for
children of G1 = experimental group, who read Texts 1 and 2 before and after training (in T1 and T2). Amplitude of Prosaccades (◦)
Amplitude of Regressions (◦) Table 3. 4. Discussion In the literature, dyslexia has been associated to a dysfunctional connectivity of
attentional networks as well as frontal and parietal regions [40]. These authors compared the resting
state using fMRI in a group of 33 children with dyslexia (age range = 7.7–15.7 years) and in a group of
control children (n = 11), and they found in children with dyslexia a reduced activity of left intraparietal Brain Sci. 2020, 10, 558 10 of 13 sulcus and left middle frontal gyrus; interestingly, they reported that the lower activity of these circuits
was also associated with higher ratings of inattention. We could suggest that a visual attentional training could play an important role in the cerebral
networks responsible of both eye movement control and attentional mechanisms, given that attention
and eye movements are linked [41]. However, attentional tests could be introduced to further explore
the role of attention abilities in dyslexic children to improve their reading capabilities. It should be noted, however, that such short visual attentional training did not lead to any change
concerning the number and the amplitude of prosaccades and regressions. Judica et al. [33] reported
similar findings, and they suggested that the lack of change in the number and the amplitude of saccades
could be explained by the fact that the dyslexic child was not able to acquired information from the
word as a single unit, and they still need to split the words. As discussed by Reichle and Sheridan [42],
reading skills develop with age, and fixation duration is an important parameter for the reading
capabilities. Interestingly, other studies in adult nondyslexic subjects showed improvement in reading
capabilities by decreasing fixation durations and the number of saccades, in cases of a manipulation
of text difficulty or text repetition [43] or shorter fixation durations when adult nondyslexic subjects
had a text with larger spaces between the letters, but they failed to report any change in the number
of fixations, in the total reading time, and in the comprehension scores [44]. Further studies on such
issues will be necessary in order to better understand the relationship between the fixation and the
saccade systems and their role in reading skills. We suggested that such an oculomotor pattern of children with dyslexia that consists of smaller
and more frequent prosaccades and regressions could be explained by the children’s reduced visual
attentional span. 4. Discussion The visual attentional span corresponded to the number of distinct visual elements that
can be processed [35], and in the literature, it was reported that the orienting and focusing visuospatial
attention is impaired in dyslexia [45]. More recently, Chen and colleagues [46], using a pathway analysis,
studied the impact of visual attentional span in a group of 105 subjects with dyslexia (mean age 17
years old), and they observed that visual attentional span have an important impact on the reading
comprehension, underlining the pivotal role of visuospatial pathways for reading processes. A reduced
visual attentional span, in fact, did not permit the subjects to skip small words during reading as
found in expert readers; after visual attentional training, dyslexic children are still reading as inexpert
readers, and the pattern of the number and amplitude of saccades is not affected by our training type. Actually, in our coming studies we try to perform tests using visual exercises to increase the visual
attention span in dyslexic children in order to explore possible improvement also in the number and
amplitude of saccades during reading, as it has been recently showed by Zhao et al. [47]. 5. Limitations The present study has several limitations that are worth noting. First, we did not examine the
psycholinguistic effect of the texts used, and the type of font is known to be quite complex for dyslexic
children. Secondly, the paragraph that the child has to read was quite short given the technical set up of
eye movement recordings, particularly due to the calibration of the eye tracker system. Indeed, to avoid
head movements of the child during the reading task, a short paragraph was presented in the center of
the screen, and reading accuracy was not recorded. Another important factor needing to be taken in account is the motivation of children; children of
the control group may have been less motivated with respect to children of the experimental group. Further studies taking in account these arguments need to be done on a large group of dyslexic children
by using a more ecological experimental setup. 11 of 13
ren
up. Brain Sci. 2020, 10, 558
Another im
of the control gr 11 of 13
ren
up. 6. Conclusions
children by Conflicts of Interest: The authors have no financial and personal relationships with other people or Conflicts of Interest: The authors have no financial and personal relationships with other people or organizat
hat could inappropriately influence or bias their work in this study. for lending the Metrisquare© system, and Emilie Lacroix for leading the visual searching tests. Conflicts of Interest: The authors have no financial and personal relationships with other people or Availability of Supporting Data: The datasets analyzed during the current study are available from
orresponding author on reasonable request. organizations that could inappropriately influence or bias their work in this study. Availability of Supporting Data: The datasets analyzed during the current study are available from the Availability of Supporting Data: The datasets analyzed during the current study are available from the
corresponding author on reasonable request. organizations that could inappropriately influence or bias their work in this study. Availability of Supporting Data: The datasets analyzed during the current study are available from the Appendix A. Texts Used in T1 and T2 for Eye Movement Recording
corresponding author on reasonable request.
A
di A Texts Used in T1 and T2 for Eye Mo ement Re ording Brain Sci. 2020, 10, x FOR PEER REVIEW
12 of 14 1.
Peterson, R.L.; Pennington, B.F. Developmental dyslexia. Lancet 2012, 379, 1997–2007, doi:10.1016/s014
6736(12)60198-6
1.
Peterson, R.L.; Pennington, B.F. Developmental dyslexia. Lancet 2012, 379, 1997–2007. [CrossRef] 6. Conclusions
children by A short visual attentional training could improve the cortical mechanism responsible for focus
attention and reading capabilities in children with dyslexia. Further studies will be necessary in order
to test different training types for improving both visual attentional span and eye movements during
reading in a dyslexic population. 6. Conclusions
A short visual attentional training could improve the cortical mechanism responsible for focus
attention and reading capabilities in children with dyslexia. Further studies will be necessary in order
to test different training types for improving both visual attentional span and eye movements during Author Contributions: Conceptualization: M.P.B. and S.C.; selection of patients: C.-L.G. and H.P.; oculomotor
measure and data analysis: S.C. and M.P.B.; writing original draft: S.C. and M.P.B.; review and editing: S.C.,
M.P.B., H.P., and C.-L.G. All authors have read and agreed to the published version of the manuscript. Author Contributions: Conceptualization: M.P.B. and S.C.; selection of patients: C.-L.G. and H.P.; oculomotor
measure and data analysis: S.C. and M.P.B.; writing original draft: S.C. and M.P.B.; review and editing: S.C.,
M P B H P and C L G All authors have read and agreed to the published version of the manuscript Acknowledgments: The authors would like to thank the children who participated in the study, Ben Vaessen for
lending the Metrisquare© system, and Emilie Lacroix for leading the visual searching tests. Funding: This research received no external funding. Acknowledgments: The authors would like to thank the children who participated in the study, Ben Vaessen
f
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th M t i
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ili L
i f
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di
th
i
l
hi
t
t Acknowledgments: The authors would like to thank the children who participated in the study, Ben Vaessen
ending the Metrisquare© system, and Emilie Lacroix for leading the visual searching tests. Funding: This research received no external funding. Acknowledgments: The authors would like to thank the children who participated in the study, Ben Vaessen
f
l
di
h M
i
©
d E
ili L
i f
l
di
h
i
l
hi Conflicts of Interest: The authors have no financial and personal relationships with other people or organizat
hat could inappropriately influence or bias their work in this study. for lending the Metrisquare© system, and Emilie Lacroix for leading the visual searching tests. 6736(12)60198-6.
2.
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i
i
i d
l
i
hild
E id
f
di
d i
l
h
d
PL S ONE 2012
1. Peterson, R.L.; Pennington, B.F. Developmental dyslexia. Lancet 2012, 379, 1997–2007. [CrossRef]
2. Stein, J. What is Developmental Dyslexia? Brain Sci. 2018, 8, 26. [CrossRef] [PubMed]
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dyslexic and normal children. Vis. Res. 1994, 34, 1345–1358. [CrossRef]
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6736(12)60198-6
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https://openalex.org/W2882533510
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English
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Leaching and uptake of nitrogen and phosphorus from cow slurry and fox manure in a lysimeter trial
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Agricultural and food science
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cc-by
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© Agricultural Science in Finland
Manuscript received January 1995 Leaching and uptake of nitrogen and phosphorus
from cow slurry and fox manure in a lysimeter trial Erkki Kemppainen
Agricultural Research Centre ofFinland, FIN-31600 Jokioinen, Finland The effects of soil type, spreading time and use of a nitrification inhibitor (Didin) on the leaching and
uptake of nitrogen and phosphorus from cow slurry and fox manure were studied in a lysimeter trial
during 1989-1992. The runoff volume and leaching of total nitrogen in peat soil were double those in fine sand soil. There was no essential difference in the leaching of nitrate nitrogen, but the amount of ammonium
nitrogen leached from peat soil was 50-fold and that of organic nitrogen about 3-fold the amounts
leached from fine sand soil. The amount of total phosphorus leached from peat soil was 23-fold and
that of soluble phosphorus 39-fold the amounts leached from fine sand soil. There were only minor differences between cow slurry and fox manure in the leaching of nitrogen. The least nitrogen was leached after manure application in May. Didin did not have any significant
effect. In peat soil, significantly more phosphorus leached from fox manure than from cow slurry. Spreading time had no effect on phosphorus leaching. Considerably higher barley grain yields were harvested from peat soil than from fine sand soil. Fox
manure proved to be a much more effective fertilizer than cow slurry. In the first experimental year,
December spreading resulted in a lower yield than other spreading times. Of the total nitrogen ap-
plied in manure, 24-41% was recovered in barley yield (grain+straw) and 4-21% in runoff; the fig-
ures for phosphorus were 6-51% and 0-2,6%, respectively. Key words: peat soil, fine sand soil, spreading time, nitrification, nitrification inhibitor, nitrate, am-
monium, organic nitrogen, soluble phosphorus, runoff Material and methods Not only manure nitrogen but also manure
phosphorus poses a threat to the environment
when leached from fields. The phosphorus con-
tent of even a moderate dose of manure may of-
ten be too high for a crop. Moreover, manure
phosphorus is more mobile in soil and thus more
susceptible to leaching than the phosphorus in
mineral fertilizer (Vetter and Steffens 1981). A lysimeter field with 66 small lysimeters (il-
lustrated in Fig. 1)was set up at the Agricultural
Research Centre of Finland, Kainuu Research
Station, Sotkamo (64° 06’N, 28° 20’E) in sum-
mer 1989.All the lysimeters are monoliths. Half
of them were filled with cultivatedfine sand soil
and half with Carex peat soil (Table 1).The treat-
ments used in the experiment are given in
Table 2. There were three replicates. German studies show that acid peat soils are
susceptible to phosphorus leaching (Scheffer et
al. 1981, Vetter and Steffens 1981). Very high
amounts of phosphorus can leach through a peat
soil when manure is applied in large quantities
(Scheffer etal. 1981. Bartels and Scheffer 1987). The risk of phosphorus leaching from acid peat
soils appears to have been overlooked in Fin-
land even though peat fields account for over
20% of the arable area. Before the experiment was set up, the lysim-
eter soils were all turned (ploughed) to a depth
of 10 cm. Manures applied to lysimeter soils in
September were harrowed into the soil about
three hours after spreading. In December, the
manures were spread on a 3-4-cm-thick snow
cover. In May, they were first spread on lysime-
ter soils which had been harrowed to a depth of
10cm and were then harrowed into the soil three
days after application. The nutrient content of
manures and the amounts of nutrients applied to
the lysimeter soils are presented in Table 3. Ma-
nure samples were analysed according to Kemp-
painen (1989b). Fur animal manure is particularly problem-
atic for environmental protection, as manures of
mink and fox contain about 10 times more ni-
trogen and 30 times more phosphorus than cow
slurry (Kemppainen 1984). Thus fur animal ma-
nures often cause considerable environmental
problems on farms (Pedersen
1991). Owing to
the high nutrient content ofthe manures it is very
difficult to spread them at rates low enough to
avoid overfertilization. Moreover, many fur an-
imal farms have too small an arable area for
manure spreading. Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... manures: cow slurry and fox manure. Cow slur-
ry was chosen because it is an important type of
manure on Finnish farms, and fox manure be-
cause of its widespread use in eastern Finland
and Ostrobothnia. Only a few studies on the fer-
tilizer value and environmental impacts of fox
manure, a very concentrated type of manure,
have been published. Two soil types typical of
northernFinland were chosen for the experiment:
Carex peat and fine sand. The effects of spread-
ing timeand use of a nitrification inhibitorwere
also studied. manure. Owing to insufficient storage capacity,
about one-third of the manure produced in Fin-
land has to be spread in autumn and some in
winter. One way in which the hazards of nitrogen
leaching have been overcome is by preventing
the oxidation of manure ammonia with nitrifi-
cation inhibitors. The use of inhibitors in com-
bination with manure application in autumn has
given rather good results. However, the profita-
bility of inhibitor use is still unclear (Amberger
1981, Kjellerup
1986, Pain et al. 1987, Görlitz
et al. 1988, Kemppainen
1989a, Tveitnes and
Håland 1989,Görlitz 1990, Meissner et al. 1991,
Nilsson 1991). Introduction ing. The same has been suggested in many re-
ports published elsewhere (e.g. Brink et al, 1979,
Vetter and Steffens 1981,Brink and Jernlås 1982,
Herrmann et al. 1983). The leaching ofnutrients from livestock manures
has been studied rather little in Finland. Yet re-
sults published by Melanen et al. (1985) and
Niinioja (1993) indicate that the use oflivestock
manure can result in considerable nutrient leach- Many farms produce excessive amounts of
livestock manure in relation to their field area. Another reason for excessive manuring may be
that farmers do not know the fertilizer value of 363 AGRICULTURAL
SCIENCE
IN
FINLAND Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... AGRICULTURAL
SCIENCE
IN
FINLAND Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... Table 2. Treatments of various lysimeters. Soil
Manure
Manure
Spreading/
Spreading date
type
type
rate
treatment
Carex
Cow
48 t/ha
September
26,09.1989
peat
slurry
"
" + Didin (15 kg/ha)
26.09.1989
”
"
"
December
19,12.1989
"
"
"
May
11.05.1990
"
Fox
23 t/ha
September
26.09,1989
"
manure
"
" +Didin (15 kg/ha)
26.09.1989
"
"
"
December
19.12.1989
"
"
”
May
11.05.1990
Fine
Cow
48 t/ha
September
26.09.1989
sand
slurry
"
" +Didin (15 kg/ha)
26.09.1989
"
"
"
December
19.12.1989
"
"
”
May
11.05.1990
"
Fox
23 t/ha
September
26.09.1989
manure
"
" +Didin (15 kg/ha)
26.09.1989
"
”
"
December
19.12.1989
"
"
"
May
11.05.1990
Carex
Unfert. -
-
-
peat
NPK
500 kg/ha
May
14.05.1990
Fine
Unfert. -
-
sand
NPK
500 kg/ha
May
14.05.1990 Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... Table 2. Treatments of various lysimeters. pies conserved withsulphuric acid. The amount
of organic nitrogen was calculated by subtract-
ing nitrate and ammonium nitrogen from the
amount of total nitrogen. Combined results for
the whole experimental period are mostly pre-
sented. In some cases, however, results for short-
er leaching periods are given as follows: The majority of the lysimeters functioned
well; a few had to be discarded owing to excep-
tionally small runoff. The results for unfertilized
peat are based on only two replicates and those
for unfertilized fine sand on one lysimeter. pies conserved withsulphuric acid. The amount
of organic nitrogen was calculated by subtract-
ing nitrate and ammonium nitrogen from the
amount of total nitrogen. Combined results for
the whole experimental period are mostly pre-
sented. In some cases, however, results for short-
er leaching periods are given as follows: In addition to nutrient leaching, grain and
straw yields were measured and their nitrogen
and phosphorus contents analysed according to
Kähäri and Nissinen (1978). Nitrogen and phos-
phorus uptake was calculated. The proportion of
manure nitrogen and phosphorus in the yield and
runoff was calculated by first subtracting the periodi
26.09.1989-09.05.1990
period II
10.05.1990-28.05.1991
period 111 29.05.1991
- 15.05.1992
period IV 16.05.1992-05.11.1992 Table 3. Nutrient content of different manure types (g/kg, on fresh weight basis) and amounts of nutrients
applied to lysimeter soils (kg/ha). Material and methods Spring barley (Hordeutn vulgare var. Arra,
500 germinating seeds/m
2 ) was grown in lysim-
eters during 1990-1992. During 1991 and 1992,
the residual effects of different treatments were
studied and the lysimeters were fertilized equal-
ly with mineral fertilizer (N-P-K
= 85-30-
60 kg/ha). This study compares the leaching and uptake
of nitrogen and phosphorus from two different 364 AGRICULTURAL
SCIENCE
IN
FINLAND Vol. 4: 363-375. Fig. 1.Diagram of a lysimeter. Vol. 4: 363-375. Fig. 1.Diagram of a lysimeter. Water tanks were emptied and water samples
taken from the lysimeters 13 times. The amount
of water was measured by weighing. Total ni-
trogen, nitrate nitrogen, ammonium nitrogen, total phosphorus and soluble phosphorus
contents were analysed as required by Finnish
standards (SFS 3031, SFS 3030, SFS 3032 and
SFS 3026). Phosphorus was analysed on sam- Table 1. Chemical properties of experimental soils. Nutrients were determined according to Vuorinen and
Mäkitie (1955), and pH from a mixture of soil/deionized water = 1/2.5. Soil type
pH
mg/1
Ca
K
Mg
P
Fine sand soil
6.3
1170
110
79
10,4
Carex peal soil
5.0
800
43
239
3.0 ble 1. Chemical properties of experimental soils. Nutrients were determined according to Vuorinen and
äkitie (1955), and pH from a mixture of soil/deionized water = 1/2.5. 365 AGRICULTURAL
SCIENCE
IN
FINLAND Runoff 11.5kg/ha). The most striking difference was in
the leaching of ammonium N: about 50 times
more ammonium N leached from peat soil than
from fine sand soil. However, there was no sig- Throughout the experimental period significantly
more water percolated through manure-treated
peat soil than through fine sand soil (Table 4),
the percolation level corresponding to 49% and
24% of precipitation, respectively. Runoff was
exceptionally high during the third leaching pe-
riod (Fig. 2). The figure also shows that the dif-
ference between soil types increased steadily as
the experiment proceeded. Table 4. Runoff from lysimeters. Averages for soil types,
manure types and spreading times, and figures for control
treatments. Table 4. Runoff from lysimeters. Averages for soil types,
manure types and spreading times, and figures for control
treatments. Table 4. Runoff from lysimeters. Averages for soil types,
manure types and spreading times, and figures for control
treatments. Treatment
Number of
lysimeters
Runoff, mm
Peat soil
24
820
Fine sand soil
HSD (P = 0.05)
24
406
322
Cow slurry
Fox manure
24
671
24
555
HSD (P = 0.05)
97
September
September+Didin
December
May
HSD (P = 0,05)
12
678
12
667
12
618
12
490
160
No significant interactions
Peat
Unfert. 2
3
294
NPK
784
Fine
Unfert. sand
NPK
1
528
3
370 Less water percolated through lysimeter soils
fertilized with fox manure than through those
fertilized with cow slurry. There always seemed
to be less runoff water from lysimeters manured
in May than from other spreading treatments. Runoff from control treatments was of the same
order as from lysimeters fertilized withlivestock
manure. However, there was substantially less
runoff from unfertilized peat thanfrom otherpeat
soils. AGRICULTURAL
SCIENCE
IN
FINLAND Nutrient
g/kg
kg/ha
Cow
Fox
Cow
Fox
NPK
Total N
3.47
24.55
167
565
85
Soluble N
2.15
14.32
103
329
85
Total P
0.72
29.50
35
679
30
Total K
3.63
9.27
174
213
60 366 Vol. 4: 363-375. Vol. 4: 363-375. Fig. 2. Cumulative runoff from manure-treated peat and
fine sand soil lysimeters. amounts of N and P in the corresponding unfer-
tilized treatments. The experiment was set up and the results
were calculated according to the split-split-plot
design. The main plots consisted of two soil
types, subplots of two manure types, and sub-
subplots of four spreading treatments. In some
cases, one-way variance analyses were also ap-
plied. AVAX 11/780computer and SAS program
were used for the calculations (SAS Institute
1985). Results Fig. 2. Cumulative runoff from manure-treated peat and
fine sand soil lysimeters. Leaching of nitrogen More ammonium N, organic N and total N
leached from manure-treatedpeat soil thanfrom
fine sand soil (Table 5). One-way variance anal-
ysis showed that the difference in the leaching
of total N was statistically significant (HSD
= 367 AGRICULTURAL
SCIENCE
IN
FINLAND Vol. 4: 363-375. phorus
way variance analysis demon
ferences were statistically s
(HSD = 660kg/ha) and in 19
ha). Fox manure invariably
grain yields than cow slurry. mental year, the advantage
rus leached from
23 times that from
difference in the
us was 39-fold. iance analysis, the
ignificant (HSD for
P = 899 g/ha). The
total P/ha, was for
l in December. Table 6. Leaching of total and
Averages for soil types, manure type
and figures for control treatments. Treatment
Tota
g/h
rom peat soil was
e latter two leach-
rmer two (Fig. 5). he differences be-
increased towards
More phosphorus
n from cow slurry
rus, however, this
e sand soil, leach-
bout 100 g/ha) and
pe. No differences
g times. Peat soil
22
Fine sand soil
HSD (P
= 0.05)
Cow slurry
227
6
Fox manure
17
HSD (P = 0.05)
September
10
11
September+Didin
December
May
7
15
12
HSD (P
= 0.05)
18
Significant interactions:
- soil x manure
ields
Peat
Unfert. 2
NPK
7
ys harvested from
oil (Table 7). One-
Fine
Unfert. sand
NPK
1
nitrogen from unferti-
red in September and
Fig. 5. Cumulative leaching of tota
manure in peat soil, cow slurry in p
fine sand soil. LTURAL
SCIENCE
IN
FINLAND 3-375. Fig. 5. Cumulative leaching of total phosphorus from fox
manure in peat soil, cow slurry in peat soil and manures in
fine sand soil. Vol. 4: 363-375. Vol. 4:
Fig. 4. Cumulative leaching of total nitrogen from unferti-
lized lysimeters and from those manured in September and
in May. 3-375. Fig. 5. Cumulative leaching of total phosphorus from fox
manure in peat soil, cow slurry in peat soil and manures in
fine sand soil. Fig. 4. Cumulative leaching of total nitrogen from unferti-
lized lysimeters and from those manured in September and
in May. Leaching of phosphorus way variance analysis demonstratedthat the dif-
ferences were statistically significant in 1991
(HSD = 660kg/ha) and in 1992 (HSD = 410 kg/
ha). Fox manure invariably produced higher
grain yields than cow slurry. In the last experi-
mental year, the advantage gained by fox ma- The amount of total phosphorus leached from
manure-treated peat soil was 23 times that from
fine sand soil (Table 6). The difference in the
leaching of soluble phosphorus was 39-fold. According to one-way variance analysis, the
differences were statistically significant (HSD for
total P = 979 g/ha, for soluble P = 899 g/ha). The
highest single figure, 4609 g total P/ha, was for
fox manure applied to peat soil in December. Treatment
Total P
Soluble P
g/ha
g/ha
Peat soil
2264
1848
Fine sand soil
HSD (P
= 0.05)
Cow slurry
99
47
2271
2102
611
437
Fox manure
1752
1457
HSD (P = 0.05)
September
1098
1042
1142
897
September+Didin
December
May
779
570
1567
1275
1238
1048
HSD (P
= 0.05)
1818
1682
Significant interactions:
- soil x manure
*
Peat
Unfert. 239
106
NPK
709
520
Fine
Unfert. sand
NPK
62
19
124
33 Leaching of phosphorus from peat soil was
considerably higher during the latter two leach-
ing periods than during the former two (Fig. 5). The figure also shows that the differences be-
tween soil and manure types increased towards
the end of the experiment. More phosphorus
leached from fox manure than from cow slurry
(Table 6). For total phosphorus, however, this
was true only in peat soil. In fine sand soil, leach-
ing of total P was very low (about 100 g/ha) and
not connected with manure type. No differences
were found between spreading times. Kemppainen , E.: Leaching and uptake ofnitrogen andphosphorus nificant difference in the leaching of nitrate N. The proportion of total nitrogen that was nitrate
nitrogen in percolated water increased in the
course of the experiment in both soil types
(Fig. 3). In peat soil, the proportion of ammoni-
um nitrogen remained significant towards the
end of the experiment whereas in fine sand soil
it was low throughout. nificant difference in the leaching of nitrate N. The proportion of total nitrogen that was nitrate
nitrogen in percolated water increased in the
course of the experiment in both soil types
(Fig. 3). In peat soil, the proportion of ammoni-
um nitrogen remained significant towards the
end of the experiment whereas in fine sand soil
it was low throughout. As a whole, manure type had no effect on
the leaching of the various nitrogen fractions. However, in peat soil slightly more total N, ni-
trate N and ammonium N seemed to leach from
fox manure than from cow slurry but in fine sand
soil the situation was reversed. Leaching of all
nitrogen fractions was lowest in spring-applied
manure. For ammonium nitrogen, however, this
was true only in peat soil. In fine sand soil, leach-
ing of ammonium nitrogen was negligible (0.3-
0.4 kg/ha) at all spreading times. Didin did not
decrease nitrogen leaching. Manure spreading
time exerted an influence throughout the ex-
perimental period (Fig. 4). Fig. 3. Proportion of organic, ammonium and nitrate nitro-
gen relative to total nitrogen in runoff from manure-treated
lysimeters during various leaching periods. Table 5. Leaching of nitrate, ammonium, organic and total nitrogen. Averages forsoil types, manure types
and spreading times, and figures for control treatments. Treatment
NOj-N
nh4-n
Org.N
kg/ha
Tot.N
kg/ha
kg/ha
kg/ha
Peat soil
33.8
15.2
19.9
68.8
Fine sand soil
HSD (P
= 0,05)
Cow slurry
27.9
0.3
6.9
35.2
50.1
3.8
5.6
47.9
32.5
7.1
14.2
53.9
Fox manure
29.2
8.4
12.5
50.1
HSD (P
= 0.05)
September
6.7
1.4
2.9
7.0
35.4
9.1
15.0
59.6
September+Didin
December
May
33.3
9.1
15.5
57.9
33.0
8.3
13.5
54.8
21.6
4.5
9.5
35.6
HSD (P
= 0.05)
14.8
3.9
4.9
18.6
Significant interactions:
- soil x manure
*
*
- soil x spreading
Peat
L
**
Unfert. NPK
10.0
3.4
6.5
19.9
28.5
12.9
13.3
54.6
Fine
sand
Unfert. NPK
15.1
0.2
3.6
18.8
14.9
0.3
3.8
19.0 368 GRICULTURAL
SCIENCE
IN
FINLAND Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus. Fig. 6. Manure nitrogen in barley yield (grain+straw) and
in runoff during the whole experimental period. Compari-
son of soil and manure types. nure was rather small in peat soil but substan-
tially higher in fine sand soil. In the first experimental year, spreading in
December resulted in a lower yield than other
treatments. Cow slurry produced the highest
yield when spread in May and fox manure when
spread in September with Didin. In the second
year, there were no significant differences be-
tween the spreading treatments but, in the third
year, spring application proved to be better than
spreading in September with Didin. However,
whilst differences between the various treatments
with cow slurry were rather small, fox manure
clearly produced the best yield when spread in
spring. Comparison with unfertilized lysimeters in-
dicated that very high yield increases were
achieved with various fertilization treatments in
thefirst year. In the second and third experimen-
tal years, there were substantial residual effects,
especially with fox manure. Fig. 6. Manure nitrogen in barley yield (grain+straw) and
in runoff during the whole experimental period. Compari-
son of soil and manure types. Barley grain yields Higher grain yields were always harvested from
peat soil than from fine sand soil (Table 7). One- 369 AGRICULTURAL
SCIENCE
IN
FINLAND Vol. 4: 363-375. Fig, 7. Manure nitrogen in barley yield (grain+straw) and
in runoff during the whole experimental period. Compari-
son of various spreading treatments. Fig. 8. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of soil and manure types. Vol. 4: 363-375. 3-375. Fig. 8. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of soil and manure types. Fig, 7. Manure nitrogen in barley yield (grain+straw) and
in runoff during the whole experimental period. Compari-
son of various spreading treatments. Fig, 7. Manure nitrogen in barley yield (grain+straw) and
in runoff during the whole experimental period. Compari-
son of various spreading treatments. Fig. 8. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of soil and manure types. soil. Of applied total phosphorus,
11.1% was
found in barley and 0.6% in runoff from peat
soil; the figures for fine sand soil were 6.2% and
0%, respectively. were of the same order for applications in Sep-
tember, September+Didin and December, but
substantially lower after application in May. Of
applied total nitrogen, 33%, 40%, 24% and 34%
were found in barley after manure application
in September,September+Didin, December and
May, respectively; thefigures for nitrogen found
in runoff were 11%, 11%, 10% and 4%, respec-
tively. Barley fertilized with fox manure contained
much higheramounts of manure phosphorus than
that fertilized with cow slurry. In peat soil, a
corresponding difference was evident in the
leaching of manure phosphorus. Of applied to-
tal phosphorus, 50.6% was found in barley and
2.6% in runoff from cow slurry in peat soil, and
9.1% in barley and 0.5% in runoff from fox ma-
nure. In fine sand soil, recovery of manure phos-
phorus in barley was 19.1% for cow slurry and
5.5% for fox manure. In peat soil, recovery of fertilizer nitrogen
(NPK plots, 85 kg N/ha) in barley was about
150% and in runoff 41%. In fine sand soil, 46%
of nitrogen applied in mineral fertilizer was re-
covered in barley but none in runoff. Recovery of manure phosphorus in barley
was highest after application in May and lowest
after application in December (Fig. 9). The
amount ofmanure phosphorus leached was high-
est after application in December but the differ-
ences between treatments were rather small. AGRICULTURAL
SCIENCE
IN
FINLAND Of
applied total phosphorus, 8.4%, 9.4%, 7.3% and
9.6% were found in barley after manure appli-
cation in September, September+Didin, Decem-
ber and May, respectively; the figures for phos- Calculated proportion of manure nitrogen
in yield and runoff Table 7. Barley grain yields. Averages for soil types, ma-
nure types and spreading times,and figures for control treat-
ments. Table 7. Barley grain yields. Averages for soil types, ma-
nure types and spreading times,and figures for control treat-
ments. Substantially higher amounts of manure nitro-
gen were found in barley (grain+straw) from peat
soil than from fine sand soil (Fig. 6). The
amounts of manure nitrogen leached from peat
soil were higher, too. Of applied total nitrogen,
41% was found in the yield and 13% in runoff
from peat soil, and 25% in the yield and 5% in
runoff from fine sand soil. Barley grain yield, kg/ha
Treatment
1990
1991
1992
Peat soil
8000
6460
4950
Fine sand soil
5750
5020
4130
HSD (P =0.05)
1800
2350
1190
Cow slurry
4720
5230
4290
Fox manure
9030
6250
4800
HSD (P =0.05)
980
1040
90
September
6990
5740
4430
September+Didin
7770
5740
4180
December
5310
5830
4630
May
7440
5660
4930
HSD (P = 0.05)
1130
1060
600
Significant interactions
- soil x manure
***
manure x spreading
**
*
Peat
Unfert. 1830
5230
4090
NPK
6970
6010
6000
Fine
Unfert. 1280
4390
3930
sand
NPK
4680
4220
3800 Barley treated with fox manure contained
much higher amounts of manure nitrogen than
that fertilized with cow slurry. However, the
amounts of nitrogen leached from fox manure
were only similar to or lower than those leached
from cow slurry. Of applied total nitrogen, 33%
was found in barley and 5% in runoff from fox
manure, and 34% in barley and 21% in runoff
from cow slurry. Recovery of manure nitrogen in barley was
highest after application in September with Di-
din, and lowest after application in December
(Fig. 7). Amounts of manure nitrogen leached 370 GRICULTURAL
SCIENCE
IN
FINLAND Calculated proportion of manure
phosphorus in yield and runoff Substantially higher amounts of manure phos-
phorus were found in barley (grain+straw) from
peat soil than from fine sand soil (Fig. 8). Sig-
nificant amounts of manure phosphorus leached
from peat soil but practically none from fine sand 371 Kemppainen, E.; Leaching and uptake ofnitrogen andphosphorus... Fig. 9. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of various spreading treatments. Considerable leaching of ammonium nitrogen
from peat soil was found by Jaakkola and Yläran-
ta (1985). Considerable leaching of ammonium nitrogen
from peat soil was found by Jaakkola and Yläran-
ta (1985). Substantially more phosphorus leached from
peat soil than from fine sand soil, indicating the
low capacity of peat soil to bind phosphorus. Marked differences in the phosphorus binding
capacity of mineral soils and organogenic soils
were noted by Steenvoorden and Oosterom
(1981) and Uhlen and Österud (1992). Very high
phosphorus losses from manure-treatedpeat soils
were demonstrated by Scheffer et al. (1981) and
Bartels and Scheffer (1987). A conspicuous feature of this study was the
high P loss during the two latter leaching
periods, especially from fox manure in peat soil. It seems that the leaching of phosphorus began
about two years after manure application. It is
probable that significant P losses will occur af-
ter the end of the experiment and the differences
between various treatments will still increase. Fig. 9. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of various spreading treatments. Fig. 9. Manure phosphorus in barley yield (grain+straw)
and in runoff during the whole experimental period. Com-
parison of various spreading treatments. Fox manure was superior to cow slurry with
respect to barley yields and nutrient uptake. However, the leaching of total nitrogen from fox
manure was more or less the same as that from
cow slurry even though the amount of total ni-
trogen supplied in fox manure was 3.4-fold that
in cow slurry. The luxuriantvegetation produced
by fox manure used much waterand thus reduced
runoff more effectively than cow slurry. Ample
fertilization and subsequent luxuriant growth
have been shown to reduce runoff in other
studies, too (Eder 1985, Jaakkola and Yläranta
1985, Stauffer and Enggist 1990). phorus found in runoff were 0.3%, 0.2%, 0.4%
and 0.3%, respectively. Of applied fertilizer phosphorus (30 kg P/ha)
in NPK plots, 78.8% was found in barley and
1.6% in runoff from peat soil; thefigures for fine
sand soil were 26.1% and 0.2%, respectively. Discussion The phenomenon described above, that is, a
higher nutrient amount increasing yield and nu-
trient uptake but not nutrient leaching, is possi-
ble only when other growth factors do not limit
plant growth. Growing conditions seem to have
been surprisingly good in the lysimeters because
barley was able to utilize the high level of nitro-
gen supplied by fox manure. However, these re-
sults are not comparable to those at field scale,
where leaching becomes important at substan-
tially lower nitrogen levels. Peat soil was superior to fine sand soil with re-
spect to barley yields and nutrient uptake. How-
ever, nutrient leaching from peat soil was also
usually higher. As to leaching of total N and or-
ganic N, the difference is explained partly by
higher natural leaching and partly by high run-
off from peat soil. High leaching of ammonium nitrogen from
peat soil is partly due to significant mineraliza-
tion of its organic nitrogen and partly to manure
ammonia. Owing to the low pH, ammonia oxi-
dizes slowly in peat (Alexander 1991, p. 252). Nitrogen uptake by barley was highest after
treatment with manure with Didin in September, 372 Vol. 4: 363-375. Vol. 4: 363-375. effective at saving nitrogen (Amberger 1989,
Asmus
1989, Görlitz 1989). According to Am-
berger (1991) Didin may have a poor effect if
manure is spread too early. Didin then decom-
poses and loses its effect before winter. In this
study, slurry treated with Didin was spread in
late September, which, according to Kemppai-
nen (1989a), is usually a favourable time for Di-
din in Finland. However, after application, the
soil temperature fell from about 11°C to 3-4°C
in a few days and remained very low until the
soil froze at the end ofNovember. It is thus very
unlikely thatDidin lost its effect through decom-
position during the autumn. It is more likely that
the soil temperature was too low for significant
nitrification to occur and so Didin had only a
minor effect (Maidl and Fischbeck 1989). This
conclusion is supported by the fact that, during
the first leaching period, leaching of nitrate ni-
trogen from lysimeters fertilized with livestock
manure was rather small. Didin, however,
seemed to have a positive effect on the recovery
of nitrogen in barley. and lowest in treatment with manure in Decem-
ber. The differences between treatments are
mainly ascribed to differences in ammonia vol-
atilization. December was an especially poor
spreading timebecause manure could not be in-
corporated into the frozen soil. September was
better because the manure was mixed into the
soil shortly after spreading. In May, manure was
left on the soil surface for three days before it
was incorporated; the delay is reflected in the N
recovery data. The effect of spreading time on the leaching
of total nitrogen, nitrate nitrogen, ammonium
nitrogen and organic nitrogen was clearly dem-
onstrated. Nitrogen leaching was lowest from the
spring application and highest from applications
in September. These results are consistent with
those reported in the literature (Vetter and Stef-
fens
1977, 1981, Brink and Jernlås 1982, Dijk
1985, Ivarsson and Brink
1985, Brink
1987,
Görlitz 1989,Torstensson
1992). Didin did not have a significant effect on ni-
trogen leaching. This was surprising because
several studies have shown that Didin is very Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... NJF
Utredninger-Rapporter74: 97-101. Steenvoorden, J. H. A. M. & Oosterom, H. P. 1981. Natural and artificial sources of nitrogen and phosphate
pollution of surface waters in the Netherlands. Nitrogen
Losses and Surface Run-off from Landspreading of Ma-
nures. p. 307-333. The Hague. -1989a. Effect of Didin (Dicyandiamide) on the fertilizer
value of cow slurry for barley. Annales Agriculturae Fen-
niae 28: 133-150. -1989b. Nutrient content and fertilizer value of livestock
manure with special reference to cow manure. Annales
Agriculturae Fenniae 28: 163-284. Torstensson, G. 1992. Kväveutlakning i storruteförsök
med stallgödsel. Hudyrgödning, Resurse
- Miljö. NJF
Utredninger-Rapporter74: 97-101. -1989b. Nutrient content and fertilizer value of livestock
manure with special reference to cow manure. Annales
Agriculturae Fenniae 28: 163-284. Kjellerup, V. 1986. Nitrogen effect of slurry mixed with
nitrification inhibitors: field experiments. Efficient Land
Use of Sludge and Manure, p. 2-6. London. Kjellerup, V. 1986. Nitrogen effect of slurry mixed with
nitrification inhibitors: field experiments. Efficient Land
Use of Sludge and Manure, p. 2-6. London. Tveitnes, S. & Håland, Å. 1989. Influence of the nitrifi-
cation inhibitor Dicyandiamide (DCD) on the nitrogen ef-
ficiency of cattle slurry. Norwegian Journal of Agricultur-
al Sciences 3: 343-350. Maldl, F. X. & Fischbeck, G. 1989. Effects of Long-term
Applications of Slurry on Soil Nitrogen Mineralization. Journalof Agronomy and Crop Science 162: 310-319. Uhlen, G. & Österud, J. G. 1992. Nitrogen, fosfor og
kalium i gröftevannspröver fra dyrket mark. Norsk Land-
bruksforskning 6: 61-72. Meissner, R., Kramer, D., Taeger, H. & Schonert, P. 1991. Lysimeterversuchsergebnisse über die Wirkung der
Nitrifizide “Dicyandiamid” (DCD) und “1-Carbamoyl-3(5)-
methylpyrazol” (CMP), Archiv fur Acker- und Pflanzen-
bau und Bodenkunde 35: 411-423. Vetter, H. & Steffens, G. 1977. Der Einfluss gestaffelter
Gullemengenund verschiedener Dungungszeitpunkte auf
die Nährstoffverlagerung in tiefere Bodenschichten und
in das Wasser. Landwirtschafliche Forschung, Sonder-
heft 34: 238-246. Melanen, M., Jaakkola, A., Melkas, M., Ahtiainen, M. & Matinvesi, J. 1985. Leaching resulting from land ap-
plication of sewage sludge and slurry. Vesientutkimus-
laitoksen julkaisuja 61. 124 p. Niinioja, R. 1993. Lietelannan levitys ja ravinteiden huuh-
toutuminen. Summary: Leaching of nutrients from land
application of slurry. Publications of the Water and Envi-
ronment Administration. A 150: 1-87. Melanen, M., Jaakkola, A., Melkas, M., Ahtiainen, M. & Matinvesi, J. 1985. Leaching resulting from land ap-
plication of sewage sludge and slurry. Vesientutkimus-
laitoksen julkaisuja 61. 124 p. -
& Steffens, G. 1981. Nährstoffverlagerung und Nähr-
stoffeintrag in das oberflachennahe Grundwasser nach
Gulledungung. References kvåve, fosfor och kalium från åker. Ekohydrologi 4/79:
7-57. kvåve, fosfor och kalium från åker. Ekohydrologi 4/79:
7-57. Alexander, M. 1991. Introduction to Soil Microbiology. 2nd ed. Malabar, Florida. 467 p. -
& Jernlås, R. 1982. Utlakning vid spridning höst och
vår av flytgödsel. Ekohydrologi 12/82: 3-14. Amberger, A. 1981. Dicyandiamid (“Didin”) als Nitrifika-
tionshemmstoff. Bayerisches Landwirtschaftliches Jahr-
buch 7/81: 845-853. Dijk, T. A. van. 1985. De uitspoeling van mineralen op
bouwland waaraan jaarlijks drijfmest wordt toegediend. Summary: Leaching of plant nutrients from arable land
as affected by annual applications of cattle slurry. Insti-
tuut voor Bodemvruchtbaarheid. Rapport 2/85. p. 1-61. Dijk, T. A. van. 1985. De uitspoeling van mineralen op
bouwland waaraan jaarlijks drijfmest wordt toegediend. Summary: Leaching of plant nutrients from arable land
as affected by annual applications of cattle slurry. Insti-
tuut voor Bodemvruchtbaarheid. Rapport 2/85. p. 1-61. Eder, G. 1985. Der Einfluss steigender Gullegaben auf
den Boden, den Pflanzenertrag, die Futterqualität und
das Sickerwasser. Veröffentlichungen der Bundesanstalt
fur alpenländischeLandwirtschaft, Gumpenstein. Heft 3:
1-19. -
1989. Research on dicyandiamide as a nitrification in-
hibitor and future outlook. Communications in Soil Sci-
ence and Plant Analysis 20: 1933-1955. -1991. Slurry fertilization with the aim of low nitrate leach-
ing. Recent Developments in Animal Waste Utilization. FAO. REUR Technical Series 17: 223-225. Eder, G. 1985. Der Einfluss steigender Gullegaben auf
den Boden, den Pflanzenertrag, die Futterqualität und
das Sickerwasser. Veröffentlichungen der Bundesanstalt
fur alpenländischeLandwirtschaft, Gumpenstein. Heft 3:
1-19. Asmus, F. 1989. Untersuchungen zur Reduzierung der
N-Verlagerung nach Gulledungung in Sand-Rosterde. Asmus, F. 1989. Untersuchungen zur Reduzierung der
N-Verlagerung nach Gulledungung in Sand-Rosterde. Archiv fur Acker- und Pflanzenbau und Bodenkunde 33:
573-579. Archiv fur Acker- und Pflanzenbau und Bodenkunde 33:
573-579. Görlitz, H. 1989. Verringerung der N-Verlagerung im
Boden nach Gulledungung durch Einsatz von Nitrifika-
tionsinhibitoren
- Ergebnisse aus Lysimeteruntersuchun-
gen. Archivfur Acker- und Pflanzenbau und Bodenkunde
33: 567-572. Bartels, R. & Scheffer, B. 1987. Limitations for slurry
application to peat grassland. Animal Manure on Grass-
land and Fodder Crops. Fertilizer or Waste? p. 365-367. Dordrecht. Brink, N. 1987. Kväve och fosfor från stallgödslad åker. Ekohydrologi 24/87: 38-39. -1990. Gulleeinsatz mit Nitrifikationsinhibitoren im Herbst
zu Wintergetreide. Agrobiological Research 43, 3: 253-
259. -, Gustafson, A. & Persson,
G. 1979. Förluster av 373 Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... Nilsson, L. G. 1991. Nitrifikationshämmare
- flytgödsel. Sveriges Lantbruksuniversitet. Institutionen för Markve-
tenskap. Rapport 181: 1-28. Asmus, F., Völker, U., Benthin, K. & Muller, H. 1988. Verminderung der Stickstoffauswaschung nach Gulledun-
gung durch Einsatz von Nitrifikationsinhibitoren und Kom-
bination mit Strohdungung. Zentralblatt fur Mikrobiologie
143: 323-330. Pain, B. F., Thompson, R. 8., De la Lande Cremer, L. C. N. & Ten Moite, L. 1987. The use of additives in live- Pain, B. F., Thompson, R. 8., De la Lande Cremer, L. C. N. & Ten Moite, L. 1987. The use of additives in live-
stock slurries to improve their flow properties, conserve
nitrogen and reduce odours. Animal Manure on Grass-
land and Fidder Crops. Fertilizer or Waste? p. 229-246. Dordrecht. Herrmann,V., Görlltz, H. & Asmus, F. 1983. Lysimeter-
untersuchungen zur Nährstoffverlagerungnach Gulledun-
gung in einer Sand-Rosterde
-
Phosphor, Kalium und
Magnesium. Archiv fur Acker- und Pflanzenbau und Bo-
denkunde 27: 687-692. Pedersen, J. B. 1991. Forurening fra pelsdyrfarme. Miljöstyrelsen (Danmark). Miljöprojekt nr. 163: 1-96. Pedersen, J. B. 1991. Forurening fra pelsdyrfarme. Miljöstyrelsen (Danmark). Miljöprojekt nr. 163: 1-96. SAS Institute 1985. SAS User’s Guide: Statistics, Ver-
sion 5 Edition. Gary, NC. 956 p. Ivarsson, K. & Brink, N. 1985. Utlakning från en grov-
mojord i Halland. Ekohydrologi 20/85: 13-25. SAS Institute 1985. SAS User’s Guide: Statistics, Ver-
sion 5 Edition. Gary, NC. 956 p. Jaakkola, A. & Yläranta, T. 1985. Typen huuhtoutumi-
nen jahyväksikäyttö lysimetrikokeessa. Summary: Leach-
ing of nitrogen and its utilization by plants in lysimeters,
SITRA. Nitrogen project. Julkaisu 22: 1-38. Scheffer, B. von, Kuntze, H. & Bartels, R. 1981. Zum
Phosphataustrag aus mit Guile gediingtem Hochmoor-
boden. Landwirtschafliche Forschung, Sonderheft 40:
288-296. Kähäri, J. & Nissinen, H. 1978. The mineral element
contents of timothy (Phleum pratense) in Finland. I. Acta
Agriculturae Scandinavica, Supplement 20: 26-39. Stauffer, W. & Enggist, A. 1990. Einfluss von Gulleaus-
bringtermin, Kultur und Wiesenumbruch auf die Nitrat-
auswaschung in einem Lysimeterversuch. Landwirtschaft
Schweiz 3,7: 373-379. Kemppainen, E. 1984. Karjanlannan ravinnepitoisuus ja
syyt sen vaihteluun. Summary: The nutrient content of
livestock manure and the causes of its variation. SITRA. Nitrogen project. Julkaisu 11: 1-80. Steenvoorden, J. H. A. M. & Oosterom, H. P. 1981. Natural and artificial sources of nitrogen and phosphate
pollution of surface waters in the Netherlands. Nitrogen
Losses and Surface Run-off from Landspreading of Ma-
nures. p. 307-333. The Hague. Torstensson, G. 1992. Kväveutlakning i storruteförsök
med stallgödsel. Hudyrgödning, Resurse
- Miljö. Kemppainen, E.: Leaching and uptake ofnitrogen and phosphorus... Zeitschrift fur Kulturtechnik und
Flur-
bereinigung 22: 159-172, Vuorinen, J. & Mäkitie, 0.1955. The method of soil test-
ing in use in Finland. Agrogeological Publications 63: 1-
44. 374 SELOSTUS
Naudan lietelannan ja ketun lannan typen ja fosforin huuhtoutuminen
ja hyväksikäyttö lysimetrikokeessa Erkki Kemppainen
Maatalouden tutkimuskeskus Lysimetrikokeessa tutkittiin maalajin, levitysajan
sekä nitrifikaatioinhibiittorin(Didin) vaikutusta nau-
dan lietelannan ja ketun lannan typen ja fosforin
huuhtoutumiseen ja hyväksikäyttöön. tui vähiten toukokuussa levitetystä lannasta. Didin ei
vähentänyt typen huuhtoutumista merkitsevästi. Ke-
tun lannasta huuhtoutui turvemaalla selvästi enem-
män fosforia kuin naudan lietelannasta. Lannan le-
vitysaika ei vaikuttanut fosforin huuhtoutumiseen. Valunta ja kokonaistypen huuhtoutuminen turve-
maasta olivat noin kaksinkertaisia hietaan verrattu-
na. Nitraattitypen huuhtoutumisessa ei ollut merkit-
tävää eroa, mutta amraoniumtyppeä turvemaasta
huuhtoutui 50-kertainen määrä ja orgaanista typpeä
3-kertainen määrä hietaan verrattuna. Turvemaasta
huuhtoutui myös kokonaisfosforia 23-kertainen mää-
rä ja liukoista fosforia 39-kertainen määrä hietaan
verrattuna. Turvemaa tuotti huomattavasti suurempia ohrasa-
toja kuin hieta. Ketun lanta oli selvästi naudan liete-
lantaa tehokkaampaa lannoitetta. Ensimmäisenä koe-
vuonna lannan levitys joulukuussa vähensi merkitse-
västi sen lannoitusvaikutusta muihin levitysaikoihin
verrattuna. Ohran jyvä- ja olkisadon perusteella las-
kettuna lannan kokonaistypen näennäinen hyväksi-
käyttö oli 24-41
% ja lannan fosforin hyväksikäyttö
6-51
%. Lannan kokonaistypestä huuhtoutui 4-21
%
ja fosforista 0-2,6
%. Naudan lietelannasta ja ketun lannasta huuhtou-
tui suunnilleen yhtä paljon typpeä. Typpeä huuhtou- 375
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Agroecological Certification of Farm Land of Agricultural Enterprises TzOV «Zhyva Zemlia Potutory» and TOV «Krona» in Ternopil region, Berezhany District
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Pavliv, A.V., Pavliv, O.V. (2017). Agroecological Certification of Farm Land of Agricultural Enterprises TzOV «Zhyva Zemlia Potutory» and TOV
«Krona» in Ternopil region, Berezhany District. Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 19(74), 196–202. 1Национальный университет биоресурсов и природопользования Украины,
ул. Героев Обороны, 11, Киев, 03041, Украина;
2Обособленное подразделение Национального университета биоресурсов и природопользования Украины
«Бережанский агротехнический институт»,
ул. Академическая 20, г. Бережаны, 47501, Украина Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 Агроекологічна оцінка земель сільськогосподарських підприємств
Тернопільської області Бережанського району ТзОВ «Жива Земля
Потутори» та ТОВ «Крона» А.В. Павлів1, О.В. Павлів2
pavliv–1978@ukr.net 1Національний університет біоресурсів і природокористування України,
вул. Героїв Оборони, 11, м. Київ, 03041, Україна;
2Відокремлений підрозділ Національного університету біоресурсів та природокористування України
«Бережанський агротехнічний інститут»,
вул. Академічна 20, м. Бережани, 47501, Україна 1Національний університет біоресурсів і природокористування України,
вул. Героїв Оборони, 11, м. Київ, 03041, Україна;
2Відокремлений підрозділ Національного університету біоресурсів та природокористування України
«Бережанський агротехнічний інститут»,
вул. Академічна 20, м. Бережани, 47501, Україна Проведено агроекологічну оцінку земель для вирощування сільськогосподарських культур підприємств ТзОВ «Жива Земля
Потутори» с. Потутори Бережанського району Тернопільської області та ТОВ «Крона» с. Жуків Бережанського району
Тернопільської області за еколого-агрохімічними показниками. В статті охарактеризовано ґрунтовий покрив за потужністю
гумосового шару, вмістом гумусу, азоту (що легко гідролізується), рухомого фосфору, обмінного калію, за сумою активних
температур вищою 10 °С, гідротермічним коефіцієнтом, рівнем ґрунтових вод, вмістом рухомих форм важких металів:
Кадмію, Свинцю, Ртуті, а також кислотність ґрунту (обмінна, рH сольове). Досліджено динаміку показників основних еко-
лого-агрохімічних властивостей та щільність забруднення темно-сірих опідзолених ґрунтів. Проаналізувавши показники
агрохімічного стану грунту земель сільськогосподарських підприємств ТзОВ «Жива Земля Потутори» с. Потутори Бере-
жанського району Тернопільської області та ТОВ «Крона» с. Жуків Бережанського району Тернопільської області, встанов-
лено, що ґрунти мають оптимальні, допустимі (задовільні) умови для вирощування зернових, технічних, кормових культур та
отримання повноцінних врожаїв сільськогосподарських культур. Лімітуючим фактором виступає низька забезпеченість
сполуками азоту, що легко гідролізується на земельних ділянках підприємств ТзОВ «Жива Земля Потутори» с. Потутори
Бережанського району Тернопільської області та ТОВ «Крона» с. Жуків Бережанського району Тернопільської області щодо
вирощування зернових, технічних, кормових культур, тобто дані умови – недопустимі (погані). Ключові слова: агроекологічна оцінка, агрохімічні показники, ґрунт, клімат, вміст елементів живлення, вміст гумусу, Ка-
дмію, Свинцю, Ртуті, кислотність, зернові, технічні та кормові культури. Агроэкологическая оценка земель сельскохозяйственных предприятий
Тернопольской области Бережанского района ООО «Живая Земля
Потуторы» и ООО «Крона»
А.В. Павлив1, О.В. Павлив2
pavliv–1978@ukr.net Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Проведено агроэкологическую оценку земель для выращивания сельскохозяйственных культур предприятий ООО «Жи-
вая Земля Потуторы» с. Потуторы Бережанского района Тернопольской области и ООО «Крона» с. Жуков Бережанского
района Тернопольской области за эколого-агрохимическим показателям. В статье охарактеризованы почвенный покров по
мощности гумосового слоя, содержанию гумуса, азота (легко гидролизуется), подвижного фосфора, обменного калия, по
сумме активных температур выше 10 °С, гидротермическому коэффициенту, уровню грунтовых вод, содержанию подви-
жных форм тяжелых металлов: Кадмия, Свинца, Ртути, а также кислотность почвы (обменная, рН солевое). Исследова-
на динамика показателей основных эколого-агрохимических свойств и плотность загрязнения темно-серых оподзоленных
почв. Проанализировав показатели агрохимического состояния почвы земель сельскохозяйственных предприятий ООО
«Живая Земля Потуторы» с. Потуторы Бережанского района Тернопольской области и ООО «Крона» с. Жуков Бережан-
ского района Тернопольской области, установлено, что почвы имеют оптимальные, допустимые (удовлетворительные)
условия для выращивания зерновых, технических, кормовых культур и получения полноценных урожаев сельскохозяйствен-
ных культур. Лимитирующим фактором выступает низкая обеспеченность соединениями азота, легко гидролизуется на
земельных участках предприятий ООО «Живая Земля Потуторы» с. Потуторы Бережанского района Тернопольской
области и ООО «Крона» с. Жуков Бережанского района Тернопольской области по выращиванию зерновых, технических,
кормовых культур, то есть данные условия – недопустимы (плохие). Ключевые слова: агроэкологическая оценка, агрохимические показатели, почва, климат, содержание элем
я, содержание гумуса, Кадмия, Свинца, Ртути, кислотность, зерновые, технические и кормовые культуры. Agroecological Certification of Farm Land of Agricultural Enterprises TzOV
«Zhyva Zemlia Potutory» and TOV «Krona» in Ternopil region,
Berezhany District A.V. Pavliv1, O.V. Pavliv2
pavliv–1978@ukr.net 1National University of life and environmental sciences of Ukraine,
Heroyiv Oborony Str., 11, Kyiv, 03041, Ukraine
2Separated subdivision of the National University of Life and Environmental Sciences of Ukraine
«Berezhansky Agricultural Institute»
Academichna Str., 20, Berezhany, 4750 ,Ukraine 1National University of life and environmental sciences of Ukraine,
Heroyiv Oborony Str., 11, Kyiv, 03041, Ukraine
2Separated subdivision of the National University of Life and Environmental Sciences of Ukraine
«Berezhansky Agricultural Institute»
Academichna Str., 20, Berezhany, 4750 ,Ukraine The agroecological assessment of land for growing crops according to agrochemical rates has been conducted at TzOV «Zhyva
Zemlia Potutory» in Potutory village, Berezhany district, Ternopil region and TOV «Krona» in Zhukiv village , Berezhany district,
Ternopil region. The article describes the mantle of soil in thickness of humus layer, content of humus, nitrogen (which is easily
hydrolysed), labile phosphorus, exchange potassium, at the sum of active temperatures above 10 °C, hydrothermal index, groundwa-
ter level, the content of mobile forms of heavy metals: cadmium, lead, mercury and acidity of soil (metabolic, pH saline). The dy-
namics of the main indicators of ecological and agrochemical properties and density of contamination of dark gray podzolized soils. Having analysed the agroecological condition of soil at farm land of TzOV «Zhyva Zemlia Potutory» in Potutory village, Berezhany
district, Ternopil region and TOV «Krona» in Zhukiv village, Berezhany district, Ternopil region. It has been stated that the soils
have optimal, acceptable (satisfactory) conditions for growing grain, industrial, forage crops and for obtaining valuable crop yields. Limiting factors are low availability of nitrogen compounds that are easily hydrolysed and concerning grain, industrial, forage crops
these conditions are unacceptable (poor) at farmland of TzOV «Zhyva Zemlia Potutory» in Potutory village, Berezhany district,
Ternopil region and TOV «Krona» in Zhukiv village, Berezhany district, Ternopil region. Key words: ahroekolohycheskaya coments, ahrohymycheskye indicators, soils, climate, pover elements content, content humus
kadmya, lead, mercury, acidity, cereal, tehnycheskye kormovue and culture. Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 Агроэкологическая оценка земель сельскохозяйственных предприятий
Тернопольской области Бережанского района ООО «Живая Земля
Потуторы» и ООО «Крона»
А.В. Павлив1, О.В. Павлив2
pavliv–1978@ukr.net А.В. Павлив1, О.В. Павлив2
pavliv–1978@ukr.net 196 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Матеріал і методи досліджень Об’єкт досліджень – агроекологічне оцінювання
земель. Предмет – землі сільськогосподарських підп-
риємств ТзОВ «Жива Земля Потутори» с. Потутори
Бережанського району Тернопільської області та ТОВ
«Крона» с. Жуків Бережанського району Тернопіль-
ської області, які представлені темно-сірими опідзо-
леними ґрунтами. Агроекологічна оцінка земель проводилась згідно
з методикою В.В.Медведєва, розробленою в Інституті
грунтознавства та агрохімії ім. О.Н. Соколовського
УААН (Medvedeva, 1997), в основі якої лежать три
рівні опису умов: 1 – оптимальні умови; 2 – допусти-
мі (задовільні); 3 – недопустимі (погані) умови. Пер-
ший рівень відповідає таким умовам, за яких можли-
во отримати найбільші екологічно чисті врожаї, за
другим рівнем є загроза зниження врожайності на 23–
30, за третім рівнем – до 50%. В основу її покладено
принцип екологічного співвідношення параметрів
довкілля (грунт, клімат), що характеризують потреби
сільськогосподарських культур до їхнього вирощу-
вання. Оцінку земель проводили з використанням показ-
ників за чинними методиками та ДСТУ: - гумус за методом Тюріна в модифікації Симако-
вої (ДСТУ 4289:2004); - рухомий Фосфор і обміний Калій за методом Чи-
рікова (ДСТУ – 4115-2002); - вміст лужногідролізованого азоту – за методом
Корнфілда; Виходячі з таблиць 1, 2, можна сказати, що допус-
тимі умови для вирощування зернових, технічних та
кормових культур за потужністю гумосового шару
(перебувають у межах від 35–45 см) сформувалися на
всіх досліджуваних полях (табл. 3–8). - ступінь кислотності (рH) – потенціометрично за
методом ЦІНАО (ГОСТ 26483-85). - ступінь кислотності (рH) – потенціометрично за
методом ЦІНАО (ГОСТ 26483-85). - вміст рухомих форм: Кадмію, Свинцю, Ртуті –
інверсійно-хронопотенціометричний метод; Таблиця 1 Таблиця 1 Таблиця 1
Дані агроекологічної оцінки ґрунтового покриву земель
ТзОВ «Жива Земля Потутори» с. Потутори
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтово-
го розчину,
рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С. Вступ їх раціональне використання в кінцевому підсумку
визначають рівень добробуту суспільства (Broshchak,
2013). Цінність землі як основного засобу сільськогоспо-
дарського виробництва у конкретній сільськогоспо-
дарській інфраструктурі визначається родючість ґру-
нтів. Саме родючість ґрунтів зумовлює рівень проду-
ктивності земель, їхню господарську значущість і
вартість. Україна – одна з не багатьох держав світу,
котра володіє величезним резервом родючих грунтів,
тому вона має бути одним зі світових лідерів вироб-
ництва високоякісних продуктів харчування. Ґрунто-
вий покрив основне загальнонаціональне багатство
нашої країни і головний засіб виробництва в сільсь-
кому господарстві. Актуальність теми: Основна властивість грунтів
– їх родючість, яка залежить від багатьох факторів:
склад ґрунту, його фізичних, хімічних, фізико-
хімічних і біологічних властивостей. Землі сільсько-
господарського використання зазнали відчутної де-
градації, серед багатьох причин якої є надзвичайно
висока розораність, ерозія, погіршення реакції та со-
льового режиму ґрунтового середовища, забруднення
їх важкими металами, радіонуклідами, пестицидами
та іншими токсинами тощо. Тому дослідження агрое-
кологічного стану земель є на сьогодні актуальним,
щоб цілеспрямовано керувати формуванням урожаю,
ростом і розвитком рослин. Ґрунтовий покрив основне загальнонаціональне
багатство нашої країни і головний засіб виробництва
в сільському господарстві. Якість земельних ресурсів, Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
197 Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 197 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Результати та їх обговорення Мета і завдання дослідження: Територіальним
об’єктом досліджень є Бережанський район Терно-
пільської області. Мета – оцінити агроекологічний
стан земель та параметри довкілля (ґрунт, клімат), що
характеризують потреби сільськогосподарських куль-
тур до їхнього вирощування. Важливе значення в народному господарстві сьо-
годні, належить вирощуванню сільськогосподарських
культур та отриманню високоякісних врожаїв та си-
ровини. Агроекологічну оцінку грунтового покриву
проводили з метою вирощування зернових, технічних
та кормових культур. Земельні ділянки розташовані в
межах населених пунктів с. Потутори Бережанського
району Тернопільської області та ТОВ «Крона»
с. Жуків Бережанського району Тернопільської обла-
сті. У земельному фонді попередньо згаданих госпо-
дарств переважають темно-сірі опідзолені ґрунти. Обстеження ґрунтів в господарстві ТзОВ «Жива Зем-
ля Потутори» проведено на площі 309,6 гектарів, а в
господарстві ТОВ «Крона» проведено на площі 148,8
гектарів (Patyka and Tarariko, 2002). Провести агроекологічну оцінку земель сільсько-
господарських підприємств ТзОВ «Жива Земля Поту-
тори» с. Потутори Бережанського району Тернопіль-
ської області та ТОВ «Крона» с. Жуків Бережанського
району Тернопільської області для вирощування
зернових, технічних та кормових культур за еколого-
агрохімічними показниками. Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 Матеріал і методи досліджень Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких мета-
лів (мг/кг): кадмію
свинцю
ртуть
Рілля
1
25–40
6,0
2,90
114
117
106
2550
1,4
8
0,09
1,26
0
2
25–40
5,4
2,15
108
80
136
2550
1,4
8
0,08
0,69
0
3
25–40
6,1
3,04
125
144
134
2550
1,4
8
0,09
1,4
0
4
25–40
6,3
2,46
109
185
134
2550
1,4
8
0,1
1,27
0 Таб
Дані агроекологічної оцінки ґрунтового покриву земель ТОВ «Крона» с.Жуків
Показники Таблиця 3
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному шарі
гумусу, %
Вміст азоту, що легко
гідролізується, мг/кг
Вміст рухомого фосфо-
ру, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище 10 °С
Гідротермічний коефіці
єнт
Рівень ґрунтових вод
(РГВ), м
Вміст рухомих форм
важких металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 4
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТОВ «Крона»
№ поля
Показники
Потужність гумусового
шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному шарі
гумусу, %
Вміст азоту, що легко
гідролізується, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних темпера-
тур вище 10 °С. Матеріал і методи досліджень Гідротермічний
коефіцієнт
Рівень ґрунтових вод
(РГВ), м
Вміст рухомих форм
важких металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Д
Н
О
О
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 3
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному шарі
гумусу, %
Вміст азоту, що легко
гідролізується, мг/кг
Вміст рухомого фосфо-
ру, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище 10 °С
Гідротермічний коефіці
єнт
Рівень ґрунтових вод
(РГВ), м
Вміст рухомих форм
важких металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Т б
4 Табл
ані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТзОВ «Жива Земля Потутори» Таблиця 4
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТОВ «Крона»
№ поля
Показники
Потужність гумусового
шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному шарі
гумусу, %
Вміст азоту, що легко
гідролізується, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних темпера-
тур вище 10 °С. Матеріал і методи досліджень Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
25–40
6,3
2,35
133
74
123
2550
1,4
7
0,14
1,78
0
2
25–40
6,4
2,48
124
62
120
2550
1,4
7
0,12
1
0
3
25–40
6,6
2,40
138
113
131
2550
1,4
7
0,08
1,49
0
4
25–40
6,3
1,86
136
77
145
2550
1,4
7
0,1
1,53
0
5
25–40
6,4
2,24
130
80
165
2550
1,4
7
0,09
1,47
0
6
25–40
5,4
2,40
144
57
161
2550
1,4
7
0,11
1,5
0
7
25–40
5,8
2,34
125
38
158
2550
1,4
7
0,07
1,69
0
9
25–40
6,2
2,00
144
35
143
2550
1,4
7
0,09
1,86
0
16
25–40
6,0
2,35
85
40
111
2550
1,4
7
0,39
1,75
0
Культурне пасовище
12
25–40
7,0
2,85
99
74
70
2550
1,4
7
0,1
1,95
0
13
25–40
6,9
2,72
132
109
105
2550
1,4
7
0,24
1,29
0 ц
Дані агроекологічної оцінки ґрунтового покриву земель
ТзОВ «Жива Земля Потутори» с. Потутори Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 198 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Таблиця 2
Дані агроекологічної оцінки ґрунтового покриву земель ТОВ «Крона» с.Жуків
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізуєть-
ся, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С. Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких мета-
лів (мг/кг): кадмію
свинцю
ртуть
Рілля
1
25–40
6,0
2,90
114
117
106
2550
1,4
8
0,09
1,26
0
2
25–40
5,4
2,15
108
80
136
2550
1,4
8
0,08
0,69
0
3
25–40
6,1
3,04
125
144
134
2550
1,4
8
0,09
1,4
0
4
25–40
6,3
2,46
109
185
134
2550
1,4
8
0,1
1,27
0
Таблиця 3
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового шару, см
Реакція ґрунтового
розчину, рНсол. Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 Матеріал і методи досліджень Вміст в орному шарі
гумусу, %
Вміст азоту, що легко
гідролізується, мг/кг
Вміст рухомого фосфо-
ру, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище 10 °С
Гідротермічний коефіці
єнт
Рівень ґрунтових вод
(РГВ), м
Вміст рухомих форм
важких металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 4
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування зернових культур
ТОВ «Крона»
№ поля
Показники
ужність гумусового
шару, см
еакція ґрунтового
розчину, рНсол. міст в орному шарі
гумусу, %
іст азоту, що легко
дролізується, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
а активних темпера-
тур вище 10 °С. Гідротермічний
коефіцієнт
вень ґрунтових вод
(РГВ), м
міст рухомих форм
ких металів (мг/кг):
кадмію
свинцю
ртуть Таблиця 2 Таблиця 2
Дані агроекологічної оцінки ґрунтового покриву земель ТОВ «Крона» с.Жуків
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтового
розчину, рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізуєть-
ся, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С. Матеріал і методи досліджень Гідротермічний
коефіцієнт
Рівень ґрунтових вод
(РГВ), м
Вміст рухомих форм
важких металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Д
Н
О
О
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74 199 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Таблиця 5
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТзОВ
«Жива Земля Потутори»
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтово-
го розчину, рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С
Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких ме-
талів (мг/кг): кад-
мію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 6
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТОВ «Крона»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Матеріал і методи досліджень Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С
Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких ме-
талів (мг/кг): кад-
мію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Т б
6 Таблиця 5
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТзОВ
«Жива Земля Потутори» Таблиця 6 Таблиця 6
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТОВ «Крона»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ), м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
О
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
О
О
3
Д
О
О
Н
О
О
О
О
О
О
Д
О
4
Д
О
Д
Н
О
О
О
О
О
О
Д
О
* О
оптимальні умови; Д
допустимі умови; Н
недопустимі умови (згідно класифікації В В Медведєва) Д
Д
Д
льні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Матеріал і методи досліджень Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур вище
10 °С
Гідротермічний
коефіцієнт
Рівень ґрунтових
вод (РГВ), м
Вміст рухомих
форм важких ме-
талів (мг/кг): кад-
мію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
Д
Н
О
О
О
О
О
О
Д
О
4
Д
О
Н
Н
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
7
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
О
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Н
Д
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таб иця 6 Таблиця 5
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТзОВ
«Жива Земля Потутори» Таблиця 5
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТзОВ
«Жива Земля Потутори»
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтово-
го розчину, рНсол. Матеріал і методи досліджень Таб Таблиця 7
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінно-
го калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ),
м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
3
Д
О
Д
Д
О
О
О
О
О
О
Д
О
4
Д
О
Н
Д
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
Д
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Д
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 7
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Матеріал і методи досліджень Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ), м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
О
О
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
О
О
3
Д
О
О
Н
О
О
О
О
О
О
Д
О
4
Д
О
Д
Н
О
О
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 7
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінно-
го калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ),
м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О Таблиця 5 Таблиця 5
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування технічних культур ТзОВ
«Жива Земля Потутори»
№ поля
Показники
Потужність гуму-
сового шару, см
Реакція ґрунтово-
го розчину, рНсол. Матеріал і методи досліджень Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінно-
го калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ),
м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
3
Д
О
Д
Д
О
О
О
О
О
О
Д
О
4
Д
О
Н
Д
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
Д
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Д
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Таблиця 7
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур
ТзОВ «Жива Земля Потутори»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Матеріал і методи досліджень За реакцією ґрунтового середовища та за вмістом
гумусу ґрунти господарств характеризуються опти-
мальними умовами з метою вирощування як кормо-
вих і технічних культур, так і зернових. Дана ситуа-
ція обумовлена тим, що загалом ґрунти мають нейт-
ральну реакцію, а також досліджувані поля характе-
ризуються середньою забезпеченістю ґрунтів за вміс-
том гумусу (знаходиться в межах 2,0–3,5% на всіх
ділянках), за винятком (поле №4 – ТзОВ «Жива Зем-
ля Потутори», характеризується недопустимими умо-
вами), дана ситуація обумовлює задовільні умови для
формування високоякісних врожаїв сільськогоспо-
дарських культур. мі умови для вирощування кормових, технічних та
зернових культур, аналогічна ситуація і в ТзОВ «Жи-
ва Земля Потутори» – вміст обмінного калію колива-
ється від 70,0 до 165 мг/кг ґрунту. На якість ґрунтів та агроекологічні умови вирощу-
вання сільськогосподарських культур значно вплива-
ють метеорологічні умови, зокрема сума активних
температур вища за 10 °С та гідротермічний коефіці-
єнт Селянінова (ГТК) (Panas, 2008). Різні культури
для своєї життєдіяльності в період від проростання
насіння до достигання потребують неоднакової кіль-
кості тепла. За вимогливістю до тепла культури умо-
вно поділяють на холодостійкі (жито, пшениця, яч-
мінь, овес, горох та ін.), середньо холодостійкі (буря-
ки, соняшник, боби, люпин, льон, та ін.), теплолюбні
(кукурудза, просо, сорго, квасоля, рис, соя, бавовник
та ін.). Згідно із нормативами агроекологічної оцінки,
оптимальні умови за сумою активних температур
(2530 °С) спостерігаються майже на всіх дослідних
ділянках, оскільки мають сума температур становить
вище 10 °С – 2530'. Аналогічна ситуація склалася в
господарстві на всіх полях відносно до гідротерміч-
ного коефіцієнту допустимі умови (ГТК–1,4). А зага-
лом метеорологічні показники ґрунтів, відповідно до
нормативів агроекологічних умов вирощування, мо-
жуть забезпечити формування біологічно повноцінної
продукції та сировини. р
у
ур
Виходячи з таблиць 3–8 можна відмітити, що ґру-
нти на досліджуваних ділянках за вмістом азоту, що
легко гідролізується, характеризуються недопусти-
мим умовами для вирощування зернових і технічних
культур. Дана ситуація обумовлена тим, що на даних
ділянках (поля № 1–7, 9, 16, 12–13 ТзОВ «Жива Зем-
ля Потутори») вміст азоту, що легко гідролізується,
перебуває в ґрунтах від 85,0 до 144 мг/кг та (поля №
1–4 ТОВ «Крона») – від 108 до 125мг/кг ґрунтуза
Корнфілдом, а для оптимальних умов при вирощу-
ванні зернових та технічних культур необхідно, щоб
ґрунти були забезпечені вмістом азоту більше ніж
200 мг/кг ґрунту. Пороте даний вміст цього показни-
ка в ґрунтах є допустимим значенням для вирощу-
вання кормових культур на підприємстві ТзОВ «Жи-
ва Земля Потутори», як це показано в таблиці 7. Матеріал і методи досліджень Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінно-
го калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ),
м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
2
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
3
Д
О
Д
Д
О
О
О
О
О
О
Д
О
4
Д
О
Н
Д
Д
О
О
О
О
О
Д
О
5
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
6
Д
О
Д
Д
Д
О
О
О
О
О
Д
О
7
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
9
Д
О
Д
Д
Н
О
О
О
О
О
Д
О
16
Д
О
Д
Н
Н
Д
О
О
О
О
Д
О
Культурне пасовище
12
Д
О
Д
Д
Д
Д
О
О
О
О
Д
О
13
Д
О
Д
Д
О
Д
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). абл
ані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур
ТзОВ «Жива Земля Потутори» Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
200 200 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 Таблиця 8
Дані агроекологічної оцінки ґрунтового покриву земель для вирощування кормових культур ТОВ «Крона»
№ поля
Показники
Потужність
гумусового
шару, см
Реакція ґрунто-
вого розчину,
рНсол. Вміст в орному
шарі гумусу, %
Вміст азоту, що
легко гідролізу-
ється, мг/кг
Вміст рухомого
фосфору, мг/кг
Вміст обмінного
калію, мг/кг
Сума активних
температур
вище 10 °С
Гідротермічний
коефіцієнт
Рівень ґрунто-
вих вод (РГВ), м
Вміст рухомих
форм важких
металів (мг/кг):
кадмію
свинцю
ртуть
Рілля
1
Д
О
Д
Н
О
Д
О
О
О
О
Д
О
2
Д
О
Д
Н
Д
О
О
О
О
О
Д
О
3
Д
О
О
Н
О
О
О
О
О
О
Д
О
4
Д
О
Д
Н
О
О
О
О
О
О
Д
О
* О – оптимальні умови; Д – допустимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Д
тимі умови; Н – недопустимі умови (згідно класифікації В.В. Медведєва). Матеріал і методи досліджень Одним із основних факторів, які впливають на
якість продукції є вміст в грунті рухомих форм важ-
ких металів. Підвищений вміст важких металів у ґру-
нті може бути наслідком застосування в сільському
господарстві меліорантів, добрив та пестицидів, а
також використання для зрошення забруднених побу-
тових і промислових стічних вод тощо. За даними
В.І. Кисіля гранично допустима концентрація (далі
ГДК) для кадмію – 0,7 мг/кг ґрунту, для Свинцю –
2,0 мг/кг ґрунту для Ртуті – 0 мг/кг (Lisovyi, 1991). За вмістом рухомих форм фосфору ґрунти дослі-
джуваних ділянок характеризуються підвищеним та
високим забезпеченням, що обумовлює оптимальні та
допустимі умови для вирощування як зернових і тех-
нічних культур, так і для кормових. Вміст даного
показника в ґрунтах ТОВ «Крона» коливається в ме-
жах від 80,0 до 185 мг/кг ґрунту за Мачигіним, що
створює задовільні умови для формування високоякі-
сних врожаїв, а в ТзОВ «Жива Земля Потутори»вміст
даного показника в ґрунтах з оптимальними та допу-
стимими умови коливається в межах від 57,0 до
109 мг/кг ґрунту (поля № 7, 9, 16) характеризується
недопустимими умовами для вирощування сільсько-
господарських культур (Ridei et al., 2011). Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
201 Висновки Отже, результати досліджень підтверджують, що
на сільськогосподарських підприємствах Тернопіль-
ської області Бережанського району ТзОВ «Жива
Земля Потутори» та ТОВ «Крона» переважають поля
з оптимальними умовами для вирощування зернових,
технічних та кормових культур, за таких умов мож- Вміств ґрунтах ТОВ «Крона» обмінного калію ко-
ливається від 106,0 до 136 мг/кг ґрунт за Мачигіним,
що, в свою чергу, обумовлює оптимальні та допусти- Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
201 201 Науковий вісник ЛНУВМБТ імені С.З. Ґжицького, 2017, т 19, № 74 lisostepu Ukrainy. TFDU «Derzhhruntokhorona»
Ternopil (in Ukrainian). ливо отримати найбільші екологічно чисті врожаї. Щодо грунтового покриву, який характеризується
допустимими (задовільними) умовами, на вище вка-
заних господарствах є поля з загрозою зниження
врожайності на 23–30%. Лімітуючим фактором, який
може знизити формування врожайності до 50%, є
низька забезпеченість поживними речовинами, а саме
сполуками азоту, що легко гідролізується, дана ситу-
ація склалась лише на окремих ділянках. Варто вста-
новити найбільш оптимальні дози органічних та мі-
неральних добрив, вести планомірну роботу щодо
підвищення родючості грунту, адже добрива – основа
живлення – елемент побудови урожаю. Patyka, V.P., Tarariko, O.H. (2002). Ahroekolohichnyi
monitorynh ta pasportyzatsiia silskohospodarskykh
uhid. K.: Fitosotsiotsentr (in Ukrainian). Medvedeva, V.V. (1997). Agroekologicheskaja ocenka
zemel' Ukraini i razmeshheniesel'skozjajsivennih
kul'tur. K.:Agrarna nauka (in Russian). Ridei, N.M., Strokal, V.P., Rybalko, Yu.V. (2011). Ekolohichna
otsinka
ahrobiotsenoziv:
teoriia,
metodyka, praktyka. Kherson: Vydavnytstvo Oldi –
plius (in Ukrainian). Panas, R.M. (2008). Ratsionalne vykorystannia ta
okhorona zemel: navch. posibnyk. Lviv: Novyi Svit
(in Ukrainian). Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
202 Бібліографічні посилання Lisovyi, M.V. (1991). Pidvyshchennia efektyvnosti
mineralnykh dobryv. K.: Urozhai (in Ukrainian). Стаття надійшла до редакції 22.02.2017 Broshchak, I.S. (2013). Rekomendatsii po udobrenniu
silskohospodarskykh kultur v umovakh zakhidnoho Scientific Messenger LNUVMBT named after S.Z. Gzhytskyj, 2017, vol. 19, no 74
202
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https://molmed.biomedcentral.com/counter/pdf/10.2119/molmed.2009.00013
|
English
| null |
Oxygen-Conserving Implications of the Trigemino-Cardiac Reflex in the Brain: The Molecular Basis of Neuroprotection?
|
Molecular medicine
| 2,009
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cc-by
| 1,477
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© 2009 The Feinstein Institute for Medical Research, www.feinsteininstitute.org
Online address: http://www.molmed.org
doi: 10.2119/molmed.2009.00013 The trigemino-cardiac reflex (TCR) is
defined as a sudden dysrhythmia with
arterial hypotension accompanied by
apnea or gastric hypermotility after stim-
ulation of any of the sensory branches of
the trigeminal nerve (1). The sensory
nerve endings of the trigeminal nerve
transmit neuronal signals via the Gasser-
ian ganglion to the sensory nucleus of
the trigeminal nerve (2). This initiates ad-
justments in the systemic and cerebral
circulation to adjust the cerebral blood
flow in a manner that is not yet well un-
derstood (3). Extensive investigations in
animals have documented the involve-
ment of supramedullary regions of the
brain in cardiovascular regulation (4–6). It appears that the cerebrovascular re-
sponse as part of the TCR is generated
by the activation of the reticulospinal
neurons of the rostral ventrolateral
medulla (RVLM) to elevate cerebral
blood flow (CBF) reflexively and most
likely slow cerebral metabolism as part
of an oxygen-conserving reflex. The exis-
tence of such endogenous neuroprotec- cal adjustments are bradycardia and pe-
ripheral vasoconstriction, but also the
initiation of apnea. Cardiac output is re-
distributed to favor blood flow to the
heart and brain, while blood flow to
most visceral organs, inactive muscle
groups, and the skin are reduced. The
TCR therefore causes redistribution in
blood supply. Transcranial Doppler ul-
trasonography (TCD) studies give a re-
producible value of brain perfusion by
continuous non-invasive real-time sam-
pling (7). With TCD, it can be shown
that the CBF rises in the middle cere-
bral artery (MCA) in healthy subjects
during facial cooling with normal venti-
lation when resting in a supine position
without any change in the systemic
blood pressure (7). This may suggest a
neuroprotective effect of the TCR and
therefore some kind of an oxygen-
conserving effect. Despite this prelimi-
nary data it is yet unknown how ex-
actly CBF and cerebral metabolism are
affected by the TCR. tive strategies also may have an impor-
tant physiological role namely by stabi-
lizing the brain function and by the pre-
vention of permanent cerebral ischemic
damage. However, examinations of higher influences on basic cardiovascular
control mechanisms in man are still
sparse. higher influences on basic cardiovascular
control mechanisms in man are still
sparse. Diving reflex is an example of a pe-
ripheral TCR. The main stimuli eliciting
the diving reflex is the chilling of the
face. Commentary Commentary Address correspondence and reprint requests to Bernhard Schaller, Rämelstrasse 12, CH-
4106 Therwil, Switzerland. E-mail: bernhard.schaller@yahoo.de.
Submitted March 2, 2009; Accepted for publication March 3, 2009; Epub (www.molmed.
org) ahead of print March 6, 2009. Bernhard J Schaller,1 Nora Sandu,2 Jan F Cornelius,1 Andreas Filis,3 and Miguel A Perez-Pinzon,4 for the
Trigemino-Cardiac-Reflex-Examination-Group (T.C.R.E.G.) 1Department of Neurosurgery, University Hospitals of Paris, Paris, France, and 2Department of Neurosurgery, University Hospital
Lausanne, Lausanne, Switzerland; 3Case Western Reserve University, Minimally Invasive Neurosurgery Lab, University Hospital,
Cleveland, Ohio, United States of America; and 4Cerebral Vascular Disease Research Center, University of Miami Miller School of
Medicine, Miami, Florida, United States of America Oxygen-Conserving Implications of the Trigemino-Cardiac
Reflex in the Brain: The Molecular Basis of Neuroprotection?
Bernhard J Schaller,1 Nora Sandu,2 Jan F Cornelius,1 Andreas Filis,3 and Miguel A Perez-Pinzon,4 for the
Trigemino-Cardiac-Reflex-Examination-Group (T.C.R.E.G.) Bernhard J Schaller,1 Nora Sandu,2 Jan F Cornelius,1 Andreas Filis,3 and Miguel
Trigemino-Cardiac-Reflex-Examination-Group (T.C.R.E.G.) REFERENCES and mediating the vasomotor compo-
nent of cardiovascular reflexes (8). In
fact, exposure of excised slices from the
RVLM to either hypoxia or sodium
cyanide (which inhibits mitochondrial
respiration), results in neuronal excita-
tion (9). Extensive studies have been car-
ried out on the mechanisms by which
these reflexes mediate vasomotor re-
sponses in response to hypoxia. For ex-
ample, two K+
ATP channel inhibitors in-
jected into RVLM, tolbutamide and
glibenclamide, elevated arterial pressure
and rCBF, potentiating the hypoxic re-
sponses (10). Finally, the RVLM neurons
are the principal relay for the cerebro-
vascular dilation mediated by the cere-
bellar fastigial nucleus (FN) (8). In fact,
direct electrical stimulation of the cere-
bellar FN protected the CA1 region of
the hippocampus and reduced infarct
volume by 50% after global (11) and
focal (12) cerebral ischemia, respectively. 1. Schaller B, Probst R, Strebel S, Gratzl O. (1999)
Trigeminocardiac reflex during surgery in the
cerebellopontine angle. J. Neurosurg. 90:215–20. 2. Schaller B. (2004) Trigeminocardiac reflex. A clin-
ical phenomenon or a new physiological entity? J. Neurol. 251:658–65. 3. Schaller B, Cornelius JF, Sandu N, Ottaviani G,
Perez-Pinzon M. (2009) Invited manuscript:
oxygen-conserving reflexes of the brain: the cur-
rent molecular knowledge. J. Cell. Mol. Med. 2009,
Jan 16 [Epub ahead of print]. 4. Delgado JM. (1960) Circulatory effects of cortical
stimulation. Physiol. Rev. Suppl 4:146–78. 5. Hoff EC, Kell JF Jr, Carroll MN Jr. (1963) Effects
of cortical stimulation and lesions on cardiovas-
cular function. Physiol. Rev. 43:68–114. 6. Hilton SM. (1975) Ways of viewing the central
nervous control of the circulation—old and new. Brain Res. 87:213–9. 7. Lohmann H, Ringelstein EB, Knecht S. (2006)
Functional transcranial Doppler sonography. Front Neurol. Neurosci. 21:251–60. 8. Reis DJ, et al. (1997) Central neurogenic neuro-
protection: central neural systems that protect
the brain from hypoxia and ischemia. Ann. N. Y. Acad. Sci. 835:168–86. 8. Reis DJ, et al. (1997) Central neurogenic neuro-
protection: central neural systems that protect
the brain from hypoxia and ischemia. Ann. N. Y. Acad. Sci. 835:168–86. 9. Sun MK, Jeske IT, Reis DJ. (1992) Cyanide excites
medullary sympathoexcitatory neurons in rats. Am. J. Physiol. 262:R182–9. Interestingly, it seems that the same
neuronal centers, the rostral neurons in
the ventrolateral medulla, play a major
role in protecting the brain of ischemic
insult whether the underlying event is
acute, chronic, or intermittent. REFERENCES In fact, in
the case of TCR, the brain is protected
instantly by a reflex-mediated response
of the cardiovascular system. If hypox-
emia is chronic or intermittent, brain
protection results from long-term adap-
tive changes on the cellular and molecu-
lar level that occur in the same cell
groups of import in the acute changes
mediated by the TCR, suggesting an
oxygen-conserving part of the TCR. The
exact relationship between reflective,
acute changes of physiological parame-
ters and long-term changes on the mo-
lecular level are unclear; more basic re-
search has to be done to underline this
hypothesis. 10. Golanov EV, Reis DJ. (1999) A role for KATP+-
channels in mediating the elevations of cerebral
blood flow and arterial pressure by hypoxic
stimulation of oxygen-sensitive neurons of ros-
tral ventrolateral medulla. Brain Res. 827:210–4. 10. Golanov EV, Reis DJ. (1999) A role for KATP+-
channels in mediating the elevations of cerebral
blood flow and arterial pressure by hypoxic
stimulation of oxygen-sensitive neurons of ros-
tral ventrolateral medulla. Brain Res. 827:210–4. 11. Golanov EV, Liu F, Reis DJ. (1998) Stimulation of
cerebellum protects hippocampal neurons from
global ischemia. Neuroreport. 9:819–24. 12. Reis DJ, Kobylarz K, Yamamoto S, Golanov EV. (1998) Brief electrical stimulation of cerebellar
fastigial nucleus conditions long-lasting salvage
from focal cerebral ischemia: Conditioned central
neurogenic neuroprotection. Brain Res. 780:161–5. C O M M E N T A R Y C O M M E N T A R Y © 2009 The Feinstein Institute for Medical Research, www.feinsteininstitute.org
Online address: http://www.molmed.org
doi: 10.2119/molmed.2009.00013 The most pronounced physiologi- The oxygen-conserving reflexes are
sympathetically mediated vasomotor re-
sponses of a small population of neu-
rons that reside in the subnucleus of the
C1 area of the RVLM (11,12). These neu-
rons mediate sympathetic and cerebro-
vascular responses to hypoxia and play
a critical role in modulating circulatory
control, maintaining arterial pressure, Address correspondence and reprint requests to Bernhard Schaller, Rämelstrasse 12, CH-
4106 Therwil, Switzerland. E-mail: bernhard.schaller@yahoo.de. Submitted March 2, 2009; Accepted for publication March 3, 2009; Epub (www.molmed. org) ahead of print March 6, 2009. M O L M E D 1 5 ( 5 - 6 ) 1 2 5 - 1 2 6 , M A Y- J U N E 2 0 0 9 | S C H A L L E R E T A L . | 1 2 5 12. Reis DJ, Kobylarz K, Yamamoto S, Golanov EV.
(1998) Brief electrical stimulation of cerebellar
fastigial nucleus conditions long-lasting salvage
from focal cerebral ischemia: Conditioned central
neurogenic neuroprotection. Brain Res. 780:161–5. 11. Golanov EV, Liu F, Reis DJ. (1998) Stimulation of
cerebellum protects hippocampal neurons from
global ischemia. Neuroreport. 9:819–24. DISCLOSURE We declare that the authors have no
competing interests as defined by Molec-
ular Medicine, or other interests that
might be perceived to influence the re-
sults and discussion reported in this
paper. 1 2 6
| S C H A L L E R E T A L . | M O L M E D 1 5 ( 5 - 6 ) 1 2 5 - 1 2 6 , M A Y- J U N E 2 0 0 9
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https://europepmc.org/articles/pmc4741494?pdf=render
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English
| null |
Transient rRNA synthesis inhibition with CX-5461 is sufficient to elicit growth arrest and cell death in acute lymphoblastic leukemia cells
|
Oncotarget
| 2,015
|
cc-by
| 8,485
|
Sandeep S. Negi1, Patrick Brown1 Sandeep S. Negi1, Patrick Brown1
1Department of Oncology and Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
Correspondence to:
Patrick Brown, e-mail: pbrown2@jhmi.edu
Keywords: CX-5461, rRNA synthesis, UCN-01, acute lymphoblastic leukemia, MAP kinase
Received: May 31, 2015
Accepted: September 30, 2015
Published: October 12, 2015 1Department of Oncology and Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
Correspondence to:
Patrick Brown e-mail: pbrown2@jhmi edu 1Department of Oncology and Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
Correspondence to:
Patrick Brown, e-mail: pbrown2@jhmi.edu
Keywords: CX-5461, rRNA synthesis, UCN-01, acute lymphoblastic leukemia, MAP kinase Keywords: CX-5461, rRNA synthesis, UCN-01, acute lymphoblastic leukemia, MAP kinase
Received: May 31, 2015
Accepted: September 30, 2015
Published: October 12 Published: October 12, 2015 www.impactjournals.com/oncotarget/ www.impactjournals.com/oncotarget/ ABSTRACT Enhanced rRNA synthesis is a downstream effect of many of the signaling
pathways that are aberrantly activated in cancer, such as the PI3K/mTOR and MAP
kinase pathways. Recently, two new rRNA synthesis inhibitors have demonstrated
therapeutic effects on cancer cells while sparing normal cells. One of them,
CX-5461, is currently in phase 1 clinical trials for hematological malignancies. Here,
we investigate the effectiveness of transient treatment with this drug on acute
lymphoblastic leukemia cells. Our results show that short exposure to CX-5461
followed by drug washout is sufficient to induce persistent G2 cell-cycle arrest and
irreversible commitment to cell death, in spite of rRNA synthesis returning to normal
within 24 hours of drug washout. The magnitude of cell death after transient exposure
is similar to continuous exposure, but the time to cell death is relatively delayed with
transient exposure. In this report, we also investigate rational drug combinations
that can potentiate the effect of continuous CX-5461 treatment. We show that the
checkpoint abrogator UCN-01 can relieve CX-5461-induced G2 arrest and potentiate
the cytotoxic effects of CX-5461. Finally, we show that ERK1/2 is activated upon
CX-5461 treatment, and that pharmacological inhibition of MEK1/2 leads to enhanced
cell death in combination with CX-5461. In summary, our results provide evidence
for the effectiveness of CX-5461 pulse treatment, which may minimize drug related
toxicity, and evidence for enhanced effectiveness of CX-5461 in combination with
other targeted agents. Oncotarget, Vol. 6, No. 33 Oncotarget, Vol. 6, No. 33 INTRODUCTION To assess the extent to which reduced
proliferation was due to induction of cell death (as opposed
to growth arrest only), we measured cell death at day 3
after washout using FACS after staining with propidium
iodide (PI). All cell lines showed significant reduction
in proportion of live cells (i.e., PI negative) in washout
cells compared to DMSO treated controls after 3 days
(Figure 1B). To investigate if a shorter incubation with
CX-5461 would still result in cytotoxicity, we exposed the
cells to CX-5461 for 3 hours and 5 hours. We measured
cell viability using trypan blue 4 days after washout. All
cell lines showed a reduction in viability in drug washout
cells (Figure 1C). We then investigated if transient
exposure would lead to cytotoxicity in primary patient
samples. We have previously shown that normal bone
marrow cells show minimal cell death when treated with
1 μM CX-5461 for two days [19]. For transient exposure,
we treated patient samples (n = 3) for 5 hours with 1 μM
CX-5461, washed them twice and resuspended in drug free
media. Cell death was measured with PI staining. All three
samples showed reduced viability in drug washout, and to
a similar extent as with continuous treatment compared to
DMSO treated controls (Figure 1D). Taken together, these
results show that short exposure to CX-5461 is sufficient
to induce cell death in acute leukemia cells. p
CX-5461 is the first potent and selective inhibitor of
RNA pol I transcription [16]. Recently, the rRNA synthesis
inhibitors, CX-5461 and BMH-21, have shown therapeutic
potential in different cancer models [10, 13, 17]. These
drugs have distinct mechanisms of action of inhibiting
rRNA synthesis. BMH-21 was initially discovered
as an activator of p53, and was later found to induce
nucleolar stress by inhibiting RNA pol I binding to the
rDNA promoter and decreased rRNA synthesis [13, 18]. In contrast, CX-5461 inhibits the interaction between
SL1 and rDNA thereby preventing the formation of pre-
initiation complex. Bywater et al. [10] showed therapeutic
potential of CX-5461 treatment in mouse model of
melanoma and MLL-AF9 acute myeloid leukemia. Their
work showed that nucleolar stress caused by CX-5461
selectively led to p53 activation and subsequent apoptosis
in cancer cells. Recently, we have shown that CX-5461
arrests acute lymphoblastic leukemia (ALL) cells in
G2 phase and induces apoptosis in p53 independent
manner [19]. INTRODUCTION of mature ribosome from the nucleus to the cytoplasm [4]. Nucleolar stress caused by drugs or environmental factors
can lead to unraveling of the nucleolus and the release of
nucleolar proteins into the nucleoplasm. Rubbi et al. [5]
first proposed that impairment of nucleolar function in
response to cellular stress leads to p53 activation, which
in turn leads to cell-cycle arrest or apoptosis. The primary role of the nucleolus is to synthesize
ribosomes. However, identification of the nucleolar
proteome showed that a majority of nucleolar proteins
have functions unrelated to ribosome biogenesis, such
as cell-cycle regulation and stress response, [1, 2] and
subsequent studies have discovered novel functions
for the nucleolus both in normal and disease states [3]. The nucleolus is a dynamic structure which is formed
by the act of making ribosome. Nucleolar stress can be
caused by inhibition of any of the many steps involved
in ribosome biogenesis including pre-ribosomal RNA
(rRNA) synthesis, rRNA processing, and assembly of
ribosomal proteins on nascent rRNA transcripts and export Ribosome biogenesis is a highly coordinated
process that is regulated by tumor suppressor proteins and
oncogenes [6]. Morphological and structural changes in
the nucleolus were one of the earliest reported markers in
cancer. RNA polymerase I (RNA pol I) is responsible for
the synthesis of pre-rRNA. Elevated RNA pol I activity
due to increased growth and protein synthesis demand is
a hallmark of cancer [6, 7]. In fact, some of the major www.impactjournals.com/oncotarget Oncotarget 34846 signaling pathways deregulated in cancers directly
affect ribosome biogenesis. Among them, c-Myc and
PI3K-AKT-mTOR signaling directly regulate multiple
steps in ribosome biogenesis [8, 9]. As ribosome
biogenesis is an essential cellular process for normal
cells, its therapeutic targeting in cancer seems unlikely. However, recently, a class of drugs targeting rDNA
transcription has shown promise as novel cancer treatment
in pre-clinical models [10, 11, 12, 13, 14, 15]. These
studies have shown that therapeutically inhibiting rDNA
transcription with these drugs selectively kills cancer cells
and spares normal cells. irrevocably induce cell death in ALL cells. Cells were
treated with 250 nM CX-5461 or DMSO for 24 hours,
washed twice in the culture medium and suspended in drug
free medium. We measured cell proliferation using the
colorimetric MTS assay at day 1 and 3 after resuspension. All cell lines showed a time dependent reduction in cell
proliferation in washout cells relative to control treated
cells (Figure 1A). INTRODUCTION In recent years, potent but transient inhibition of
BCR-ABL kinase in CML, and PI3K in breast cancer
models has been shown to be an effective therapeutic
strategy [20, 21, 22]. Here, we investigated the cellular
response to transient inhibition of rRNA synthesis with
CX-5461 treatment. We found that short exposure to
CX-5461 produces similar effects as seen with continuous
treatment. Despite reactivation of rRNA synthesis
activity within 24 h of drug washout, transient and potent
inhibition of rRNA synthesis with CX-5461 was sufficient
to commit ALL cells to irreversible cell death. Apart from
acute treatment strategy, we also investigated rational
drug combinations that can enhance the cytotoxicity of
continuous CX-5461 treatment. In this report we analyzed
the effect of inhibiting cellular pathways activated by
CX-5461 treatment. We showed that checkpoint kinase
inhibitor UCN-01 and MAPK pathway inhibitors enhance
CX-5461 mediated cytotoxicity. rRNA synthesis recovers in drug washout cells To further investigate changes induced by transient
treatment, we treated SEM and NALM-6 cells with
CX-5461 for 3 hours, washed twice and resuspended
them in drug free media. We then investigated the
effects of drug washout on cell-cycle distribution,
rRNA synthesis and cell viability. Cell-cycle results
show that 24 hours after washout (CX w/o), cells
show an increase in the G2/M population compared
to control treated cells, although the magnitude of
the increase is less than that seen with continuously
treated cells (CX-5461) (Figure 2A and Supplementary
Figure 1A). We used 45S pre-rRNA transcript levels,
which are known to have a very short half-life (several
minutes), as a measure of the rate of rRNA synthesis. We have shown previously that 250 and 500 nM CX-
5461 reduces pre-rRNA synthesis by more than 50% by
3 hours in SEM and NALM-6 cells respectively [19]. We first measured 45S pre-rRNA levels at 3 hours after
CX-5461 treatment to confirm inhibition of RNA pol
I transcription (Supplementary Figure 1B). The cells
were then washed and suspended in drug free media
for 24 hours to check if pre-rRNA synthesis recovered www.impactjournals.com/oncotarget Transient exposure to CX-5461 is cytotoxic We first established a washout procedure to evaluate
whether transient exposure to CX-5461 is sufficient to www.impactjournals.com/oncotarget Oncotarget 34847 i
Figure 1: Transient inhibition of rRNA synthesis affects cell proliferation. A. Four ALL cell lines were treated with 250 nM
CX-5461 or DMSO for 24 h. Cells were washed and equal number of CX-5461 or DMSO treated cells were seeded in drug free medium
in 96 well plates and cell proliferation was measured at Day 1 and 3. Data is normalized to the growth in DMSO treated samples. All four
ALL cell lines show time dependent decrease in proliferation relative to their DMSO treated controls. Data represents mean +/− S.D. of
three independent experiments. B. Cells were treated as in (a) and cell death was measured three days after washout by propidium iodide
staining (PI). Data represent mean +/− S.D. of three independent experiments. C. Cells were treated for 3 hours or 5 hours with CX-5461
(500 nM for NALM-6 and 250 nM for SEM, KOPN-8 and RS4;11) or DMSO followed by washing. Cells were incubated in drug free media
and cell viability was measured using trypan blue after three days. Drug washout cells show reduced viability compared to control treated
cells. Data represent mean +/− S.D. of three independent experiments. D. Three ALL patient samples were treated with 1 μM CX-5461
or DMSO for 5 hours. After 5 hours the CX-5461 treated cells were washed, incubated with either DMSO (w/o) or 1 μM CX-5461 (CX);
the DMSO treated cells were washed and incubated in DMSO (DMSO). After 2 days, cell death was measured using PI staining. All three
patient samples, continuously or transiently treated with CX-5461, showed reduced viability compared to DMSO treated control. Viable
proportion is plotted from duplicate experiments. Figure 1: Transient inhibition of rRNA synthesis affects cell proliferation. A. Four ALL cell lines were treated with 250 nM
CX-5461 or DMSO for 24 h. Cells were washed and equal number of CX-5461 or DMSO treated cells were seeded in drug free medium
in 96 well plates and cell proliferation was measured at Day 1 and 3. Data is normalized to the growth in DMSO treated samples. All four
ALL cell lines show time dependent decrease in proliferation relative to their DMSO treated controls. Data represents mean +/− S.D. of
three independent experiments. B. Transient exposure to CX-5461 is cytotoxic Cells were treated as in (a) and cell death was measured three days after washout by propidium iodide
staining (PI). Data represent mean +/− S.D. of three independent experiments. C. Cells were treated for 3 hours or 5 hours with CX-5461
(500 nM for NALM-6 and 250 nM for SEM, KOPN-8 and RS4;11) or DMSO followed by washing. Cells were incubated in drug free media
and cell viability was measured using trypan blue after three days. Drug washout cells show reduced viability compared to control treated
cells. Data represent mean +/− S.D. of three independent experiments. D. Three ALL patient samples were treated with 1 μM CX-5461
or DMSO for 5 hours. After 5 hours the CX-5461 treated cells were washed, incubated with either DMSO (w/o) or 1 μM CX-5461 (CX);
the DMSO treated cells were washed and incubated in DMSO (DMSO). After 2 days, cell death was measured using PI staining. All three
patient samples, continuously or transiently treated with CX-5461, showed reduced viability compared to DMSO treated control. Viable
proportion is plotted from duplicate experiments. from the cells. Newly synthesized EU labeled
transcripts were isolated as described in materials and
methods. Our results show no difference in the levels
of newly transcribed 45S pre-rRNA in DMSO and
CX-5461 washout cells at 0 hour (Figure 2C). Moreover,
3 hours after chase, levels of the EU labeled 45S pre-
rRNA decreases substantially. The decrease was similar
in both DMSO and CX-5461 washout cells suggesting
efficient processing of 45S pre-rRNA transcript under
both conditions. following washout. Both cell lines showed significant
pre-rRNA synthesis inhibition at 3 hours (CX 3 h) and
almost complete recovery at 24 hours after washout
(CX w/o) (Figure 2B and Supplementary Figure 1B). Ribosome biogenesis is a highly coordinated process
and inhibition of rRNA synthesis can lead to pre-
rRNA processing defects. In order to make sure that
the increase in the levels of 45S pre-rRNA in drug
washout cells is not due to pre-rRNA processing
defects, we labeled SEM cells with ethynyl uridine
(EU) for 30 min followed by chase in EU free media. RNA was isolated at 0 and 3 hours after EU washout following washout. Both cell lines showed significant
pre-rRNA synthesis inhibition at 3 hours (CX 3 h) and
almost complete recovery at 24 hours after washout
(CX w/o) (Figure 2B and Supplementary Figure 1B). Transient exposure to CX-5461 is cytotoxic Ribosome biogenesis is a highly coordinated process
and inhibition of rRNA synthesis can lead to pre-
rRNA processing defects. In order to make sure that
the increase in the levels of 45S pre-rRNA in drug
washout cells is not due to pre-rRNA processing
defects, we labeled SEM cells with ethynyl uridine
(EU) for 30 min followed by chase in EU free media. RNA was isolated at 0 and 3 hours after EU washout Next, we measured cell viability of these cells after
washout at day 1 and 3 using trypan blue. The results show www.impactjournals.com/oncotarget Oncotarget 34848 Figure 2: Transient potent rRNA synthesis inhibition with CX-5461 is sufficient to commit ALL cells to cell death
despite reactivation of rRNA synthesis. A. SEM and NALM-6 cells were treated with 250 or 500 nM CX-5461, respectively. An
aliquot was harvested after 3 hours, washed twice and cells were suspended in drug free media. Cell-cycle distribution was analyzed after
24 hours by flow cytometry of PI stained cells. Cells show aberrant cell-cycle distribution in drug washout cells compared to DMSO
treated control cells. Representative flow cytometry data is shown from one of the three experiments. B. 45S pre-rRNA transcript levels
were measured using quantitative PCR and normalized to the expression of GAPDH and Actin. DMSO and CX-5461 washout cells (CX
w/o) show no difference in pre-rRNA synthesis at 24 hours. Experiments were repeated three times and data represents mean +/− S.D. C. Schematic of EU labeling of drug washout SEM cells. Newly synthesized EU labeled 45S pre-rRNA transcript levels were measured at
0 and 3 hours after EU removal. D. Cells were treated as in (a) and cell viability was measured using trypan blue staining. Drug washout
cells show reduced viability compared to DMSO treated cells. Experiments are repeated three times. Data represents mean +/− S.D. E. SEM and NALM-6 cells were treated as before. NALM-6 cells show an increase in p53 and phospho-p53 levels at 3 hours after CX-5461
treatment. Elevated p53 levels in NALM-6 cells were substantially reduced 24 hours after drug washout. Figure 2: Transient potent rRNA synthesis inhibition with CX-5461 is sufficient to commit ALL cells to cell death
despite reactivation of rRNA synthesis. A. SEM and NALM-6 cells were treated with 250 or 500 nM CX-5461, respectively. An
aliquot was harvested after 3 hours, washed twice and cells were suspended in drug free media. Transient exposure to CX-5461 is cytotoxic Cell-cycle distribution was analyzed after
24 hours by flow cytometry of PI stained cells. Cells show aberrant cell-cycle distribution in drug washout cells compared to DMSO
treated control cells. Representative flow cytometry data is shown from one of the three experiments. B. 45S pre-rRNA transcript levels
were measured using quantitative PCR and normalized to the expression of GAPDH and Actin. DMSO and CX-5461 washout cells (CX
w/o) show no difference in pre-rRNA synthesis at 24 hours. Experiments were repeated three times and data represents mean +/− S.D. C. Schematic of EU labeling of drug washout SEM cells. Newly synthesized EU labeled 45S pre-rRNA transcript levels were measured at
0 and 3 hours after EU removal. D. Cells were treated as in (a) and cell viability was measured using trypan blue staining. Drug washout
cells show reduced viability compared to DMSO treated cells. Experiments are repeated three times. Data represents mean +/− S.D. E. SEM and NALM-6 cells were treated as before. NALM-6 cells show an increase in p53 and phospho-p53 levels at 3 hours after CX-5461
treatment. Elevated p53 levels in NALM-6 cells were substantially reduced 24 hours after drug washout. CX-5461 activates MAPK signaling pathway As ribosome biogenesis is a highly regulated
process, we investigated other signaling pathways
activated by rRNA synthesis inhibition. We incubated a
human phospho-kinase protein array with equal amounts
of cell lysates from SEM cells treated with CX-5461 or
DMSO for one day. CX-5461 treated cells showed an
increase in pERK1/2 (Thr202/Tyr204), pCHK2 (T68)
and HSP60 levels (Figure 5A). We further confirmed the
activation of ERK1/2 with western blot from CX-5461
treated SEM, NALM-6 and KOPN-8 cells (Figure 5B). We investigated if pharmacological inhibition of the
MEK/ERK
signaling
pathway
would
abrogate
CX-5461 induced ERK1/2 activation and potentiate the
effect of rRNA synthesis inhibition. We treated SEM
cells with MEK1/2 inhibitor, U-0126, in combination
with CX-5461 for one day. Western blot results show
that U-0126 reduced the levels of pERK induced
by CX-5461 treatment (Figure 6A). More-over, cell
viability was substantially reduced in cells treated with
a combination of U-0126 and CX-5461 compared to
CX-5461 or U-0126 alone (Figure 6B). To further
confirm that treatment with MEK/ERK inhibitor can
enhance CX-5461 cytotoxic effect, we treated ALL cell
lines with another MEK1/2 inhibitor, trametinib. Cells
were treated with 150 nM trametinib in combination
with CX-5461 for 2 days and cell viability was measured
by trypan blue staining. As seen with U-0126, trametinib
treated cells show significant increase in cell death in www.impactjournals.com/oncotarget www.impactjournals.com/oncotarget Oncotarget 34849 lead to increased cell death. Checkpoint kinases 1 and
2 (CHK1/2) are downstream effectors of ATM/ATR
pathway and are activated upon CX-5461 treatment
[19]. UCN-01, a staurosporine analogue, is a potent
inhibitor of CHK1/2 and sensitizes tumor cells to
genotoxic agents by abrogating G2 arrest induced by
these drugs [23, 24]. Although UCN-01 is an inhibitor
of the protein kinase C (PKC) family of enzymes, G2
checkpoint abrogation by inhibiting checkpoint kinases
play a major role in its anticancer activity [25, 26, 27]. To determine if UCN-01 can abrogate CX-5461 induced
G2 arrest, we pre-treated cells with UCN-01 followed
by continuous CX-5461 treatment for 24 hours. Cell-
cycle analysis shows that CX-5461 treatment induced
G2 arrest in SEM, KOPN-8 and NALM-6 cells. This
arrest was completely abolished by UCN-01 pre-
treatment (Figure 4A). We then investigated if UCN-
01 treatment will enhance the cytotoxicity of CX-5461
as seen previously in combination with ATR inhibitor. We pre-treated cells with UCN-01 for 1 hour followed
by CX-5461 and measured cell viability using trypan
blue. Combination treatment with CX-5461 and UCN-
01 significantly reduced cell viability in all three cell
lines compared to CX-5461 or UCN-01 treatment alone
(Figure 4B). that transient inhibition of rRNA synthesis substantially
decreased cell viability (Figure 2D). These results confirm
that despite reactivation of rRNA synthesis activity within
24 hours of drug washout, short-term rRNA synthesis
inhibition with CX-5461 was sufficient to inhibit cell
cycling and viability. We have previously shown that p53
levels were increased upon 24 hours CX-5461 treatment
in p53 wild-type cell lines, although cell-cycle arrest
and apoptotic effects were p53-independent [19]. To
investigate if p53 levels remains elevated in CX-5461
washout cells, we measured p53 and phospho-p53 levels
in drug treated and drug washout cells (Figure 2E). As
shown previously [19], there was no increase in p53 levels
in SEM cells (p53 mutant cell line). In NALM-6 cells
(p53 wild-type cell line), there was an increase in p53 and
phospho-p53 levels initially at 3 hours after drug treatment
but drug washout resulted in a decrease in p53 levels when
measured after 24 hours. Washout effectively removes residual drug from
the culture medium We considered the possibility that the cytotoxic
effect seen after drug washout is due to incomplete
removal of the drug. To test for any residual drug, the
cell culture supernatant (S) from drug treated cells after
two washes was transferred to previously untreated
cells (naïve) (Figure 3A). These cells were allowed to
grow for three days and cell viability was measured by
trypan blue staining. Our results show no reduction in
viability of cells incubated in media from drug wash
out cells similar to untreated control cells (Figure 3B). These results show effective removal of the drug from
the culture media following two washes. We further
tested the effect of washout itself on cell viability. SEM
cells were treated with CX-5461 or DMSO for 3 hours
followed by two washes in drug free media. As shown
in Figure 3C, washout has no effect on cell viability as
DMSO washout cell show similar viability as control
unwashed cells. Also, these results suggest a lag in cell
death in drug washout cells compared to continuously
treated cells (Figure 3C). UCN-01 treatment relieves cell-cycle arrest and
shows enhanced cell killing in combination with
CX-5461 SEM cells were continuously incubated in DMSO or CX-5461 and a portion was
harvested after 3 hours followed by washing in drug free media as before. Cell viability was measured using trypan blue staining at day 0,
1, 2 and 3 after washout. Results are plotted as mean +/− S.D. Figure 3: Washout procedure completely removes drug from the media. A. Schematic of drug treatment experiment in (b). SEM and NALM-6 cells were continuously treated with DMSO or with 250 or 500 nM CX-5461 (CX) respectively. A portion of CX-5461
treated cells was harvested after 3 hours, washed twice and incubated in drug free media. After second wash, cells were suspended in drug
free medium and spun again. Resulting supernatant was collected and added to drug naïve cells (S) while the cells pellet was suspended in
fresh media (w/o). B. Cell viability was measured immediately after washout and at day 1 and 3 with trypan blue staining. Experiment was
performed three times and mean +/− S.D. is plotted. C. SEM cells were continuously incubated in DMSO or CX-5461 and a portion was
harvested after 3 hours followed by washing in drug free media as before. Cell viability was measured using trypan blue staining at day 0,
1, 2 and 3 after washout. Results are plotted as mean +/− S.D. combination with CX-5461 then cells treated with single
agent (Figure 6C). ABL inhibition [20, 21]. Dasatinib, a second-generation
BCR-ABL kinase inhibitor, with a short half-life of
approximately 3–5 hours has been shown to be clinically
effective with once-daily administration despite only
intermittent BCR-ABL inhibition [28]. More-over,
tolerability of once-daily dosing was superior to the
twice-daily schedule even with partial kinase inhibition. Recently, transient inhibition of PI3K in breast cancer cells
was shown to be an effective therapeutic strategy [22]. UCN-01 treatment relieves cell-cycle arrest and
shows enhanced cell killing in combination with
CX-5461 In addition to transient treatment with CX-5461,
we investigated other rational drug combinations
that can potentiate the effect of continuous CX-5461
treatment. We have previously shown that CX-5461
activates ATM/ATR pathway in acute leukemia,
arrests cells in G2 phase and synergizes with ATR
inhibitor in killing these cells [19]. We hypothesized
that abolishing cell-cycle arrest in the G2 phase would
result in inadequate recovery from cellular stress and www.impactjournals.com/oncotarget Oncotarget 34850 mbination with CX-5461 then cells treated with single
ent (Figure 6C). ABL inhibition [20, 21]. Dasatinib, a second-generation
BCR-ABL kinase inhibitor, with a short half-life of
gure 3: Washout procedure completely removes drug from the media. A. Schematic of drug treatment experiment in (b)
M and NALM-6 cells were continuously treated with DMSO or with 250 or 500 nM CX-5461 (CX) respectively. A portion of CX-5461
ated cells was harvested after 3 hours, washed twice and incubated in drug free media. After second wash, cells were suspended in drug
e medium and spun again. Resulting supernatant was collected and added to drug naïve cells (S) while the cells pellet was suspended in
sh media (w/o). B. Cell viability was measured immediately after washout and at day 1 and 3 with trypan blue staining. Experiment was
rformed three times and mean +/− S.D. is plotted. C. SEM cells were continuously incubated in DMSO or CX-5461 and a portion was
rvested after 3 hours followed by washing in drug free media as before. Cell viability was measured using trypan blue staining at day 0
2 and 3 after washout. Results are plotted as mean +/− S.D. Figure 3: Washout procedure completely removes drug from the media. A. Schematic of drug treatment experiment in (b). SEM and NALM-6 cells were continuously treated with DMSO or with 250 or 500 nM CX-5461 (CX) respectively. A portion of CX-5461
treated cells was harvested after 3 hours, washed twice and incubated in drug free media. After second wash, cells were suspended in drug
free medium and spun again. Resulting supernatant was collected and added to drug naïve cells (S) while the cells pellet was suspended in
fresh media (w/o). B. Cell viability was measured immediately after washout and at day 1 and 3 with trypan blue staining. Experiment was
performed three times and mean +/− S.D. is plotted. C. DISCUSSION In cancer therapy, continuous target inhibition has
been seen as a pre-requisite for maximum clinical impact. Our results show that transient treatment with CX-5461
induces cellular changes similar to continuous treatment,
albeit with a lag period. Importantly, after drug washout,
cells are irreversibly committed to cell death despite
complete recovery from rRNA synthesis inhibition. This
suggests that short term blockade of rRNA synthesis is
sufficient to irreversibly inhibit cellular proliferation. The
rationale for continuous target inhibition for maximum
efficacy has been challenged in chronic myeloid leukemia
(CML). A series of studies have shown that cytotoxicity
in CML cells can be achieved with transient potent BCR- Yung et al. [29] have reported that low dose
actinomycin D treatment for short duration followed by
washout leads to complete recovery of cell growth and
rRNA synthesis, whereas higher dose or longer duration
lead to irreversible inhibition of rRNA synthesis and
cell proliferation. Recently, Ma et al. [30] showed
similar results on cell-cycle arrest with actinomycin
D treatment as seen with CX-5461. But in contrast to our
results, they showed more than 80% inhibition of rRNA www.impactjournals.com/oncotarget Oncotarget 34851 synthesis at 20 hours post washout after a 2 and 4 hour
actinomycin D treatment. Compared to their results, we
achieved 50% inhibition in 3 hours with CX-5461. It is
which intercalates into GC rich regions of rDNA and
shows selectivity for RNA pol I at low dose. It inhibits
Pol I transcription during the elongation step whereas
Figure 4: UCN-01 relieves CX-5461 induced G2/M phase arrest. A. Cells were either treated with CX-5461 and UCN-01 alone
or pretreated with 100 nM UCN-01 for 1 hour followed by 250 nM CX-5461 for 1 day. Cell-cycle distribution was determined by flow
cytometry analysis of PI stained cells. UCN-01 completely removed G2/M block induced by CX-5461. One representative experiment out
of three is shown. B. Cells were treated as in (a) and cell viability was measured at 55 hours post drug treatment using trypan blue staining. Combination treatment shows enhanced cytotoxicity compared to treatment with single agent. Experiment was repeated three times and
mean +/− S.D. is plotted. Figure 4: UCN-01 relieves CX-5461 induced G2/M phase arrest. A. Cells were either treated with CX-5461 and UCN-01 alone
or pretreated with 100 nM UCN-01 for 1 hour followed by 250 nM CX-5461 for 1 day. Cell-cycle distribution was determined by flow
cytometry analysis of PI stained cells. DISCUSSION UCN-01 completely removed G2/M block induced by CX-5461. One representative experiment out
of three is shown. B. Cells were treated as in (a) and cell viability was measured at 55 hours post drug treatment using trypan blue staining. Combination treatment shows enhanced cytotoxicity compared to treatment with single agent. Experiment was repeated three times and
mean +/− S.D. is plotted. which intercalates into GC rich regions of rDNA and
shows selectivity for RNA pol I at low dose. It inhibits
Pol I transcription during the elongation step whereas
CX-5461 disrupts the binding of the SL1 transcription
factor to rDNA promoter, which inhibits initiation of
rRNA synthesis by the Pol I complex. Nevertheless, in our
case, recovery from rRNA synthesis after washout did not
change the eventual fate of these cells. synthesis at 20 hours post washout after a 2 and 4 hour
actinomycin D treatment. Compared to their results, we
achieved 50% inhibition in 3 hours with CX-5461. It is
possible that higher inhibition may lead to irreversible
repression of rRNA synthesis. Another explanation may
be the use of a solid cancer cell line in their study. This
difference may also be due to a different mechanism of
action. Actinomycin D is a RNA polymerase inhibitor www.impactjournals.com/oncotarget Oncotarget 34852 e 5: CX-5461 activates MAPK signaling pathway. A. SEM cells were treated with 250 nM CX-5461 or DMSO for 1 day. me profiler human phospho-kinase array was incubated with equal amount of control or drug treated sample. Results show an
e in pERK (1), pCHK2 (2) and HSP60 (3) signal in CX-5461 treated cells compared to DMSO treated control. B. Increase in pERK
was confirmed with western blot of CX-5461 treated SEM, NALM-6 and KOPN-8 cells. Adjusted relative density of pERK signal
ized to corresponding DMSO treated control is indicated. Figure 5: CX-5461 activates MAPK signaling pathway. A. SEM cells were treated with 250 nM CX-5461 or DMSO for 1 day. Proteome profiler human phospho-kinase array was incubated with equal amount of control or drug treated sample. Results show an
increase in pERK (1), pCHK2 (2) and HSP60 (3) signal in CX-5461 treated cells compared to DMSO treated control. B. Increase in pERK
signal was confirmed with western blot of CX-5461 treated SEM, NALM-6 and KOPN-8 cells. Adjusted relative density of pERK signal
normalized to corresponding DMSO treated control is indicated. Figure 5: CX-5461 activates MAPK signaling pathway. A. DISCUSSION SEM cells were treated with 250 nM CX-5461 or DMSO for 1 day. Proteome profiler human phospho-kinase array was incubated with equal amount of control or drug treated sample. Results show an
increase in pERK (1), pCHK2 (2) and HSP60 (3) signal in CX-5461 treated cells compared to DMSO treated control. B. Increase in pERK
signal was confirmed with western blot of CX-5461 treated SEM, NALM-6 and KOPN-8 cells. Adjusted relative density of pERK signal
normalized to corresponding DMSO treated control is indicated. Figure 5: CX-5461 activates MAPK signaling pathway. A. SEM cells were treated with 250 nM CX-5461 or DMSO for 1 day. Proteome profiler human phospho-kinase array was incubated with equal amount of control or drug treated sample. Results show an
increase in pERK (1), pCHK2 (2) and HSP60 (3) signal in CX-5461 treated cells compared to DMSO treated control. B. Increase in pERK
signal was confirmed with western blot of CX-5461 treated SEM, NALM-6 and KOPN-8 cells. Adjusted relative density of pERK signal
normalized to corresponding DMSO treated control is indicated. that provide evidence for a p53-independent mechanism
that links nucleolar stress to inhibition of cell proliferation. We have previously shown that rRNA synthesis inhibition
by CX-5461 activates ATM/ATR kinase pathway leading
to CDC2 phosphorylation, G2 arrest and apoptosis in
both p53 mutant and wild-type acute leukemia cells
[19]. In line with that report, here we showed that p53
is activated upon 3 hours treatment in p53 wild-type cell
line but the levels go down within 24 hours after drug
washout suggesting p53-independent downstream effects
of CX-5461. Donati et al. [33] showed that knockdown One of the most studied effects of nucleolar stress
is the stabilization of p53 resulting in cell-cycle arrest
and/or apoptosis [5]. ARF tumor suppressor has been
shown to translocate to the nucleoplasm in response
to nucleolar stress where it inhibits the binding of
E3 ubiquitin ligase, MDM2, to p53 resulting in p53
stabilization [31]. Recent reports have shown that drugs
targeting rRNA synthesis activate a p53-dependent
apoptosis pathway in cancer cells displaying high rate of
ribosome biogenesis [10, 32]. Although p53 activation
upon ribosomal stress is well established, there are reports www.impactjournals.com/oncotarget Oncotarget 34853 Figure 6: MEK1/2 inhibitors enhance cytotoxicity of CX-5461. A. SEM cells were treated with 250 nM CX-5461 alone or 10 μM
U-0126 alone or their combination. Western blot shows U-0126 reduced the levels of pERK induced by CX-5461 treatment. DISCUSSION B. SEM,
KOPN-8 and NALM-6 cells were treated as in (a) and cell viability was measured using trypan blue staining at 55 hours. C. Cell lines were
treated as in (a) but with another MEK1/2 inhibitor trametinib (150 nM Ttb). Combination treatment showed reduced viability in all three
cell lines compared to single agent treated cells. (b, c) All experiments were repeated three times. Data represents mean +/− S.D. Figure 6: MEK1/2 inhibitors enhance cytotoxicity of CX-5461. A. SEM cells were treated with 250 nM CX-5461 alone or 10 μM
U-0126 alone or their combination. Western blot shows U-0126 reduced the levels of pERK induced by CX-5461 treatment. B. SEM,
KOPN-8 and NALM-6 cells were treated as in (a) and cell viability was measured using trypan blue staining at 55 hours. C. Cell lines were
treated as in (a) but with another MEK1/2 inhibitor trametinib (150 nM Ttb). Combination treatment showed reduced viability in all three
cell lines compared to single agent treated cells. (b, c) All experiments were repeated three times. Data represents mean +/− S.D. from the nucleolus [35]. One interesting question
then is why transient inhibition of rRNA synthesis by
CX-5461 affects cellular proliferation but suppression of
rRNA synthesis during mitosis does not. We speculate
that the untimely release of proteins sequestered in the
nucleolus, upon drug treatment, results in cell-cycle
arrest and apoptosis. For example, tumor suppressor
protein ARF is sequestered in the nucleolus in
association with NPM1 [36]. On nucleolar disruption
by drug treatment or radiation, ARF translocates to
the nucleoplasm, binds to E3 ligase MDM2 thereby
preventing p53 ubiquitination. Elevated p53 levels then
lead to cell-cycle arrest or apoptosis depending on the
level of cellular insult [31]. Interestingly, ARF levels
decrease during mitosis and recover in early G1 phase
[37]. ARF has also been shown to inhibit growth in
p53-independent manner by arresting cells in G2 phase
which subsequently leads to apoptosis [38]. Also, we of POLR1A gene, which encodes the catalytic subunit of
RNA polymerase I, in p53 null cells leads to cell-cycle
arrest due to the down-regulation of transcription factor
E2F-1. Ribosomal stress can also reduce the levels of
PIM1 kinase leading to inhibition of cell proliferation in
p53 null cells by stabilizing cell-cycle inhibitor p27kip1, a
target of PIM1 kinase [34]. DISCUSSION This reduction in PIM1 levels
can be seen as early as 3 hours after rRNA synthesis
inhibition, a time frame similar to one used in this study. from the nucleolus [35]. One interesting question
then is why transient inhibition of rRNA synthesis by
CX-5461 affects cellular proliferation but suppression of
rRNA synthesis during mitosis does not. We speculate
that the untimely release of proteins sequestered in the
nucleolus, upon drug treatment, results in cell-cycle
arrest and apoptosis. For example, tumor suppressor
protein ARF is sequestered in the nucleolus in
association with NPM1 [36]. On nucleolar disruption
by drug treatment or radiation, ARF translocates to
the nucleoplasm, binds to E3 ligase MDM2 thereby
preventing p53 ubiquitination. Elevated p53 levels then
lead to cell-cycle arrest or apoptosis depending on the
level of cellular insult [31]. Interestingly, ARF levels
decrease during mitosis and recover in early G1 phase
[37]. ARF has also been shown to inhibit growth in
p53-independent manner by arresting cells in G2 phase
which subsequently leads to apoptosis [38]. Also, we Many proteins involved in stress response,
proliferation and cell-cycle progression are sequestered
in the nucleolus (away from their site of action or
interacting partners) thereby controlling their action [31]. At the onset of mitosis, rRNA synthesis is suppressed and
nucleolus is disassembled in a highly regulated fashion. Many of the nucleolar proteins are phosphorylated by
CDC2/Cyclin B complex (including members of rRNA
synthesis and processing machinery) and are dissociated www.impactjournals.com/oncotarget Oncotarget 34854 ALL was based on morphology and flow cytometry data. Cytogenetic was determined by standard procedures. Cell
lines and patient samples used in this study are cannot rule out the possibility that CX-5461 has other
targets in the cells which stay inhibited even after drug
removal. We have previously shown that caffeine and an
ATR inhibitor can relieve CX-5461 induced G2 arrest,
eventually leading to enhanced apoptosis [19]. Here,
we showed that CX-5461 induced G2 arrest can be
abolished by the checkpoint inhibitor UCN-01 [23,
26, 39] which also leads to enhanced cell death. This
suggests that relieving G2 arrest by checkpoint kinase
inhibitor UCN-01 provides no opportunity to the cells
to overcome stress induced by CX-5461 treatment. As
UCN-01 has been shown to enhance the cytotoxicity of
radiation and chemotherapy, combination treatment with
UCN-01 represents a therapeutic strategy that can
potentiate the effectiveness of CX-5461 [40, 41]. Drug treatment and washout Cells were incubated with CX-5461 for indicated
time. Cells were washed twice in culture media and
reseeded in drug free media. For experiments with
drug naïve cells, CX-5461 treated cells were washed
twice and suspended in drug free media. The cells were
centrifuged again, supernatant were collected and this
supernatant was added to drug naïve cells (denoted as
“S” in Figure 3B). Cell viability was measured using
trypan blue staining or flow cytometry of PI stained cells. CX-5461 was purchased from Xcess Biosciences; UCN-
01 and U-0126 from Sigma-Aldrich; Trametinib from LC
laboratories. Cell proliferation Cells were treated with DMSO or CX-5461
for 24 hours, washed twice and equal numbers of
cells were seeded in 96 well plates. Cell proliferation
was measured at 0 hour, 24 hours and 72 hours after
washout using CellTiter 96 AQueous One Solution
Cell Proliferation solution (MTS reagent) (Promega). MTS reagent was added to each well and incubated for
1 hour at 37oC in dark and absorbance was recorded at
490 nm using Bio-Rad microplate reader. Results were
background subtracted and normalized to DMSO treated
control. DISCUSSION More-over, CX-5461 treatment activates MAP kinase
pathway and MEK inhibitors showed increased cell
killing in combination with this rRNA synthesis inhibitor
(Supplementary Figure 1C). In summary, our data suggests
that transient inhibition of rRNA synthesis is sufficient to
activate irreversible changes in cell survival and supports
the potential for pulse treatment strategy in treating ALL
with CX-5461, which in turn may minimize drug related
toxicity. Also, we have provided in vitro evidence that
rational combinations of CX-5461 with other inhibitors
of survival pathways activated upon inhibition of rRNA
synthesis can potentiate its effectiveness and should be
further investigated in an in vivo model system. Phospho kinase proteome array and western
blotting Scholar Program (P.B.). The Giant Food Pediatric
Oncology Research Fund supported use of the
FACSCalibur. Scholar Program (P.B.). The Giant Food Pediatric
Oncology Research Fund supported use of the
FACSCalibur. Phospho kinase levels were measured using
Proteome Profiler Human Phospho-Kinase Array kit
as suggested by the manufacturer (R&D System). Briefly, cells were lysed and protein concentrations
were measured. Each phospho kinase array was
incubated with 200 μg of protein lysate from DMSO or
CX-5461 treated cells. Array was developed according to
manufacturer’s instructions. For western blots, cell lysates
were run on SDS Polyacrylamide gel and transferred to
PVDF membrane. Membrane was blocked with 5%
milk and incubated with primary antibody against ERK,
Phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204) and
β-Tubulin. Antibodies were purchased from Cell Signaling
Technology. Flow cytometry RS4;11, SEM, KOPN-8 and NALM-6 cell
lines were purchased from German Collection of
Microorganisms and Cell Cultures (DSMZ). Informed
consent was obtained from patients, in accordance with the
institutional review board guidelines, for the samples used
in this study. Blasts were isolated from patient samples
using Ficoll-Hypaque density gradient centrifugation and
stored in liquid nitrogen for future use. The diagnosis of Cells were fixed in methanol and stored at −20oC
until further processing. For cell-cycle analysis cells
were spun down, washed in PBS and incubated in RNaseA
containing propidium iodide (PI) solution at 37oC for 30
min in dark. Cells were run on BD FACScaliber (BD
Biosciences) and cell-cycle analysis was performed using
FlowJo software (Tree Star). Patient Sample
Cyto-genotypes
P1
MLL-AF4
P2
TEL-AML
P3
MLL-ENL
Cell Line
Cyto-genotypes
p53 status
RS4;11
MLL-AF4
wild-type
SEM
MLL-AF4
mutant
KOPN-8
MLL-ENL
mutant
NALM-6
t(5;12)(q33.2;p13.2)
wild-type www.impactjournals.com/oncotarget www.impactjournals.com/oncotarget Oncotarget 34855 Authors declare no conflict of interest. Authors declare no conflict of interest. REFERENCES 1. Andersen JS, Lyon CE, Fox AH, Leung AK, Lam YW,
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https://openalex.org/W4225422676
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https://nottingham-repository.worktribe.com/preview/7648182/rsif.2022.0176.pdf
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Modelling the emergence of cities and urban patterning using coupled integro-differential equations
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Journal of the Royal Society interface
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Research
Cite this article: Whiteley TD, Avitabile D,
Siebers P-O, Robinson D, Owen MR. 2022
Modelling the emergence of cities and urban
patterning using coupled integro-differential
equations. J. R. Soc. Interface 19: 20220176. https://doi.org/10.1098/rsif.2022.0176 Modelling the emergence of cities
and urban patterning using coupled
integro-differential equations royalsocietypublishing.org/journal/rsif royalsocietypublishing.org/journal/rsif Timothy D. Whiteley1, Daniele Avitabile4, Peer-Olaf Siebers2, Darren Robinson3
and Markus R. Owen1 Research 1School of Mathematical Sciences, University of Nottingham, Nottingham, UK
2School of Computer Science, University of Nottingham, Nottingham, UK
3School of Architecture, University of Sheffield, Sheffield, UK
4Department of Mathematics, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
TDW, 0000-0003-4990-4644; DA, 0000-0003-3714-7973; P-OS, 0000-0002-0603-5904;
DR, 0000-0001-7680-9795; MRO, 0000-0002-3028-9138 School of Mathematical Sciences, University of Nottingham, Nottingham, U Cite this article: Whiteley TD, Avitabile D,
Siebers P-O, Robinson D, Owen MR. 2022
Modelling the emergence of cities and urban
patterning using coupled integro-differential
equations. J. R. Soc. Interface 19: 20220176. https://doi.org/10.1098/rsif.2022.0176 2School of Computer Science, University of Nottingham, Nottingham, UK TDW, 0000-0003-4990-4644; DA, 0000-0003-3714-7973; P-OS, 0000-0002-0603-5904;
DR, 0000-0001-7680-9795; MRO, 0000-0002-3028-9138 TDW, 0000-0003-4990-4644; DA, 0000-0003-3714-7973; P-OS, 0000-0002-0603-5904;
DR, 0000-0001-7680-9795; MRO, 0000-0002-3028-9138 ownloaded from https://royalsocietypublishing.org/ on 05 May 2022 /royalsocietypublishing.org/ on 05 May 2022 Human residential population distributions show patterns of higher density
clustering around local services such as shops and places of employment, dis-
playing
characteristic
length
scales;
Fourier
transforms
and
spatial
autocorrelation show the length scale between UK cities is around 45 km. We
use integro-differential equations to model the spatio-temporal dynamics of
population and service density under the assumption that they benefit from
spatial proximity, captured via spatial weight kernels. The system tends
towards a well-mixed homogeneous state or a spatial pattern. Linear stability
analysis around the homogeneous steady state predicts a modelled length-
scale consistent with that observed in the data. Moreover, we show that spatial
instability occurs only for perturbations with a sufficiently long wavelength
and only where there is a sufficiently strong dependence of service potential
on population density. Within urban centres, competition for space may
cause services and population to be out of phase with one another, occupying
separate parcels of land. By introducing competition, along with a preference
for population to be located near, but not too near, to high service density
areas, secondary out-of-phase patterns occur within the model, at a higher den-
sity and with a shorter length scale than in phase patterning. Thus, we show
that a small set of core behavioural ingredients can generate aggregations of
populations and services, and pattern formation within cities, with length
scales consistent with real-world data. The analysis and results are valid
across a wide range of parameter values and functional forms in the model. Received: 4 March 2022
Accepted: 25 March 2022 1. Introduction The world is becoming increasingly urban. In 2007, the global urban population
overtook the rural and, by 2050, two-thirds of the world population is expected
to live in cities [1]. Cities are vitally important as hubs of business, commerce,
social interaction and all the other necessary services that help us to survive. They are highly complex, resource consuming and self-organizing systems, as
people are glued together by the services that support them but also pushed
away by the problems that densification causes. Issues of urban density will affect transport networks, vehicle kilometres
travelled [2], public transport feasibility [3] as well as social implications such
as quality of life [4]. The existence and size of cities is a phenomenon largely driven from the
bottom up, by the choices of individuals and firms. Yet mathematical patterns
persist such as Zipf’s Law [5,6] which states that within a country or region, a
city’s size is inversely proportional to its rank within that region. © 2022 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution
License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original
author and source are credited. population density
(pe km–2)
0–4000
4000–7000
7000–10 000
10 000–15 000
15 000+
0
5
10
15
20 km
Figure 1. Population density distribution in London from 2019 Population data [7], illustrating decreasing density overall with distance from the centre, with
accompanying patchiness. Central London in particular displays a ‘density crater’ with lower population density due to the competing presence of commercial
land use. Other patches are driven by commercial competition and other non-residential land use such as greenspace and parks. royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176
2 R. Soc. Interface 19: 20220176 //royalsocietypublishing.org/ on 05 May 2022 nloaded from https://royalsocietypublishing.org/ on 05 May 2022 Figure 1. Population density distribution in London from 2019 Population data [7], illustrating decreasing density overall with distance from the centre, with
accompanying patchiness. Central London in particular displays a ‘density crater’ with lower population density due to the competing presence of commercial
land use. Other patches are driven by commercial competition and other non-residential land use such as greenspace and parks. Downloaded from https://royalsocietypublishing.or As a motivating example of population density within a
UK city, we show a map of London in figure 1. This is an
old city which has grown and absorbed many smaller
towns around it over time. 2. Mathematical models for urban population
density There is a global imperative to better understand how
cities can be structured to function in more efficient and
environmentally benign ways. To this end, we consider
here the emergence of patterns of population density; the
arrangement of people into and within cities. A mathematical
model that supports emergent cities and subsequent second-
ary patterning within the city may deepen our insights into
how cities’ spatial structures emerge and, more importantly,
reveal how these processes might be influenced. In 1951, Clark [8] proposed the empirical model that, exclud-
ing the central business district (CBD), population density in
cities declines exponentially with distance from the centre. Subsequently, Newling [9] suggested a revised quadratic
exponential empirical model which captures the low central
population density that corresponds to a city’s CBD. Bertaud
[10] shows examples of nine world cities that display this
characteristic profile. Newling postulated that as the popu-
lation grows the parameters change to create and reinforce
this central dip. In this paper, we will model and analyse the emergence of
cities using an integro-differential equation approach, assum-
ing a preference for people and services to locate near to each
other, with distance dependence encapsulated in spatial
weight kernels. Firstly, in §2, we will look at precedent
models showing the value of differential equation-based
modelling of cities and highlighting the scope for further
work. In §3, we show how population density in parts of
the UK demonstrates emergent length scales of 45 50 km
between cities and, in appendix A, we show a length scale
of 200 km between cities in the USA. This analysis provides
the motivation for a new, explanatory, model developed in
§4, which explains the emergence of population patterns. Linear stability analysis around the homogeneous steady
state, a technique not yet applied in the urban modelling lit-
erature, is used to predict emergent length scales from the
model in §5. This model is developed further in §6 to show One key model of polycentric configurations and the
interaction between households and firms is due to Fujita &
Ogawa [11]. Their economic agglomeration-based model
adapts Alonso’s well-known 1960s bid rent theory [12]
where retail, manufacturing and residents compete for land;
each having maximum bids for a given distance from the
CBD. In Fujita and Ogawa’s model, land is occupied by
population and firms. 1. Introduction There is a clear increase in popu-
lation towards the city centre, and a notable population crater
in the middle where services dominate. There are further
areas of patchy residential patterning seen within the city
as land uses such as parks, retail and industry outcompete
population in certain areas. areas of within city structure, as population and services
develop out-of-phase patterns. Lastly, in §7, we add popu-
lation growth to the model to show how cities may grow
and agglomerate, developing structure as they do. We con-
clude with a discussion of our main findings and directions
for future work in §8. Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 ://royalsocietypublishing.org/ on 05 May 2022 Spatial
autocorrelation
is
computed
by
comparing
Moran’s I at a set of distances [32]. Moran’s I is a measure
from −1 to 1 of the correlation of points separated by distance
d. We group the set of pairs of LSOAs into those with cen-
troid
distance
0–1 km,
1–2 km,
etc.,
and
calculate
the
correlation of points in these groups. Alan Wilson’s entropy maximization [16] is a technique
from transport modelling that has been adapted to model
shopping power per location, considering monetary flows
to predict sites with greatest potential for service growth. The transition from small corner shop to large supermarkets
[17] is explained by modelling the advantage of larger floor
area compared to the travel costs to such sites. Fry & Smith
[18] recently extended this approach to develop a time-depen-
dent model; they use entropy to define the profit of a
configuration and hence drive growth of each retail location. Simplifications of their model allow asymptotic analysis on
customer preference towards larger floor areas, showing a
bifurcation from a homogeneous state where there are no
differences between centre sizes, to a ‘winner takes all’
dynamic, whereby the centre with the original maximum
size is the site that dominates the market. We calculate I(k) for the whole of England and Wales
(encompassing 25 053 LSOAs), as well as showing the smaller
regions of: the North West, including Manchester, Liverpool,
Leeds, Sheffield and Nottingham (6712 LSOAs); and the
region of Oxfordshire including Oxford, Swindon and
Reading (1549 LSOAs) as can be seen on the map in figure 2. Secondly, we take a Fourier transform of a transect
through the supporting regions. Taking a Fourier transform
breaks the population density into a sum of sinusoidal
waves and enables us to quantify the signal strength at
each wavelength. We do this for a 140 km line through York-
shire and the Midlands, encompassing Leeds, Sheffield,
Nottingham and Leicester. This is compared with a second
slice taken through Bristol, Swindon, Oxford and Luton. We calculate I(k) for the whole of England and Wales
(encompassing 25 053 LSOAs), as well as showing the smaller
regions of: the North West, including Manchester, Liverpool,
Leeds, Sheffield and Nottingham (6712 LSOAs); and the
region of Oxfordshire including Oxford, Swindon and
Reading (1549 LSOAs) as can be seen on the map in figure 2. Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 Secondly, we take a Fourier transform of a transect
through the supporting regions. Taking a Fourier transform
breaks the population density into a sum of sinusoidal
waves and enables us to quantify the signal strength at
each wavelength. We do this for a 140 km line through York-
shire and the Midlands, encompassing Leeds, Sheffield,
Nottingham and Leicester. This is compared with a second
slice taken through Bristol, Swindon, Oxford and Luton. The results of both approaches can be seen in figure 2. In
the North East region, we see a clear peak at a length of
around 48 km and in Oxfordshire we see peaks at 43 km
and 58 km. The Fourier transform shows similar dominant
wavelengths in both regions of around 50 km. Lastly, a number of recent papers on a model of reaction–
diffusion equations of population and wealth distribution
have been released [19–21]. In their statistical analysis of the
population landscape [19], the authors show spatial corre-
lation across Canada, Australia and Mongolia that cannot
be explained by environmental factors alone, highlighting
the need for explanatory modelling. In all three papers,
they model population wealth growth. Low and high
incomes both give rise to lower growth of population,
whereas growth in wealth increases with both increased
wealth and increased population. In the non-spatial system,
there are multiple steady states with complex bifurcations
leading to sudden boom or collapse in the economy or popu-
lation levels. In multiple dimensions, their stability analysis
shows the emergence of characteristic length scales. As a brief comparison, appendix A shows similar analysis
of length scales in the USA, which gives a longer character-
istic length of around 200 km. Although these data are not
entirely free from ambiguity, it shows that a characteristic
length scale exists of around 45 km between cities in the
UK and suggests that similar patterns but with different
length scales may be found in different contexts. 2. Mathematical models for urban population
density Households wish to maximize the
commodities that they can gain from firms by balancing
income, rent and travel costs while firms wish to maximize
their profit by balancing the value gained by locating close
to other businesses (captured by a weighted integral) against
wage and rent costs. Hypothetical city structures are set up,
and the parameters under which these are valid are analysed shape of a city may form [9,13], how multiple centres can
dynamically emerge [15] and how to identify such transitions
between equilibria [11]. In this paper, we uncover a set of
underlying principles that can drive city formation and pat-
terning,
based
on
spatial
kernels
capturing
distance
preferences. We focus on the appearance of characteristic
length scales and the emergence of complementary patterns,
which is novel in the urban literature. to explain the possible equilibrium states of the system. They
show that there may be both continuous and sudden struc-
tural changes in the city dynamic at the boundaries of
where an equilibrium is supportable. 3 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 In one of the first dynamic spatio-temporal models,
Bracken & Tuckwell [13] used an integro-differential equation
for population in one radial dimension. Their model has three
terms: diffusion of population, logistic growth and an integral
term that represents growth inhibition at distance r from the
city centre. This integral is proportional to the total popu-
lation between the city centre and r, emulating the negative
impacts of travel congestion and increased house prices. 3. Length scales between cities We consider two methods to quantify the length scales
between cities: two-dimensional spatial auto-correlation and
the Fourier transform of a one-dimensional transect. These
techniques are applied to UK Office for National Statistics
(ONS) mid-2016 population density data for lower layer
super output areas in England and Wales (LSOAs, average
1700 people) [31]. A more detailed and dynamical model of the growth of
urban centres in a larger region was developed by Allen &
Sanglier [14], building on their earlier work [15]. They pro-
pose a model with logistic growth of population density at
a set of discrete locations, with a carrying capacity at each
location which depends on jobs of different types, and with
migration from higher to lower densities (penalized by dis-
tance moved). This model shows how interacting dynamics
of population and jobs or services can produce centres of
attraction;
the
resulting
patterns
always
develop
with
population and jobs co-located in a self-reinforcing pattern. 4. Integro-differential equations for population
and service dynamics Background mapping © Open street map con-
tributors. (b) Autocorrelation for England and Wales, the North West and Oxfordshire regions showing a dominant length scale of 50 km and 43 km, respectively. (c) Fourier transform of the Yorkshire/Midlands and Oxfordshire lines both showing a characteristic length scale of 45–50 km. (b)
(c)
displacement (km)
–0.10
–0.05
0
0.05
0.10
0.15
0.20
Moran's I
autocorrelation
North West
Oxfordshire
England and Wales
0
20
40
60
80
100
wavelength (km)
0
20
40
60
80
0
0.5
1.0
1.5
2.0
×105
amplitude
Fourier transform
Yorkshire/Midlands
Oxfordshire
Figure 2. (a) A map of the population density of the UK showing the regions and lines analysed in this section. Background mapping © Open street map con-
tributors. (b) Autocorrelation for England and Wales, the North West and Oxfordshire regions showing a dominant length scale of 50 km and 43 km, respectively. (c) Fourier transform of the Yorkshire/Midlands and Oxfordshire lines both showing a characteristic length scale of 45–50 km. (b)
displacement (km)
–0.10
–0.05
0
0.05
0.10
0.15
0.20
Moran's I
autocorrelation
North West
Oxfordshire
England and Wales
0
20
40
60
80
100 (c)
wavelength (km)
0
20
40
60
80
0
0.5
1.0
1.5
2.0
×105
amplitude
Fourier transform
Yorkshire/Midlands
Oxfordshire (b) Downloaded from https://royalsocietypublish 1.5 amplitude Figure 2. (a) A map of the population density of the UK showing the regions and lines analysed in this section. Background mapping © Open street map con-
tributors. (b) Autocorrelation for England and Wales, the North West and Oxfordshire regions showing a dominant length scale of 50 km and 43 km, respectively. (c) Fourier transform of the Yorkshire/Midlands and Oxfordshire lines both showing a characteristic length scale of 45–50 km. Here, is a weight kernel, which captures the non-local contri-
bution of service density. We assume a Gaussian kernel with
length scale β1, so data (table 1) and some cellular automata type models
[22,24]. The model simulations will be in one or two spatial
dimensions and the analysis is in one dimension. The differ-
ence between one and two dimensions will be the spatial
kernels and the ease of computation. 4. Integro-differential equations for population
and service dynamics Since the 1980s, there has been a growth of bottom-up
computational approaches to urban population modelling,
without
a corresponding
development of
mathematical
theory to uncover general principles. Cellular automata [22–
24] and agent-based models [25–30] are powerful tools for
simulating urban populations and for making data-driven
predictions about the future state of a city, but they tend to
lack explanatory power. On the other hand, parsimonious
models of urban populations can show how the overall We model the spatio-temporal evolution of population den-
sity p(x,t) (number of residents per square kilometre) and
service fraction, s(x,t) (fraction of land occupied by services),
at location x and time t. Here, we assume services include
all providers of employment, leisure, retail, etc. Defining
services via land use, as opposed to an abstract term such
as utility, has the advantage of tying in both with available (b)
(a)
(c)
displacement (km)
–0.10
–0.05
0
0.05
0.10
0.15
0.20
Moran's I
autocorrelation
Yorkshire/Midlands
Oxfordshire (line)
Oxfordshire (region)
North West region
population density
(people per square km)
2–346
346–1474
1474–2806
2806–4060
4060–5393
5393–7712
7712–93 469
North West
Oxfordshire
England and Wales
0
20
40
60
80
100
wavelength (km)
0
20
40
60
80
0
0.5
1.0
1.5
2.0
×105
amplitude
Fourier transform
Yorkshire/Midlands
Oxfordshire
Figure 2. (a) A map of the population density of the UK showing the regions and lines analysed in this section. Background mapping © Open street map con-
tributors. (b) Autocorrelation for England and Wales, the North West and Oxfordshire regions showing a dominant length scale of 50 km and 43 km, respectively. (c) Fourier transform of the Yorkshire/Midlands and Oxfordshire lines both showing a characteristic length scale of 45–50 km. royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176
4 (a)
Yorkshire/Midlands
Oxfordshire (line)
Oxfordshire (region)
North West region
population density
(people per square km)
2–346
346–1474
1474–2806
2806–4060
4060–5393
5393–7712
7712–93 469 (a)
Yorkshire/Midlands
Oxfordshire (line)
Oxfordshire (region)
North West region
population density
(people per square km)
2–346
346–1474
1474–2806
2806–4060
4060–5393
5393–7712
7712–93 469 (a) (b)
(c)
displacement (km)
–0.10
–0.05
0
0.05
0.10
0.15
0.20
Moran's I
autocorrelation
North West
Oxfordshire
England and Wales
0
20
40
60
80
100
wavelength (km)
0
20
40
60
80
0
0.5
1.0
1.5
2.0
×105
amplitude
Fourier transform
Yorkshire/Midlands
Oxfordshire
Figure 2. (a) A map of the population density of the UK showing the regions and lines analysed in this section. 4. Integro-differential equations for population
and service dynamics Average walk to shops is 1:1 km [33]
b p2
length scale corresponding to how far
population is willing to move to a
more desirable location
10 km
in 2013–2014, the median household move was in the ‘5-10 miles’
group [34]
λ
population scale parameter for the
carrying capacity function,
equation (4.10)
20000 pe km2
in London wards 0 < p < 14 000 [35] and 0 < s < 0.4 (assuming s
to be non-domestic land use) [36]. If P = λ then s will be
expected to approach σ(λ) = 1 −(1/e) ≈0.63 which is
significantly higher than the value for s in London. Since σ(P)
is an increasing function, this means that λ must be larger than
the maximum population density in London. Selecting λ =
20 000 seems a reasonable estimate for this upper end of
population density and service provision
μ
steepness parameter for the carrying
capacity function
3
taking the mean of London wards gives p ¼ 8400 pe km2 [35]
and s ¼ 0:06 (assuming s to be non-domestic land use) [36]. Using these values and solving the homogeneous steady-state
equation (5.1) gives μ ≈3.2, assuming λ = 20 000
D
rate of change of population density in
an area
2 yr1
at the homogeneous state, the number of people who move in or
out of a place is given by D · p0 · A0 = D · p0 · σ(p0) · (1 −
σ(p0)). In London in 2018-19, flows in and out were
approximately 290 pe km2 yr1 [37] and population density,
p0, was approximately 5700 pe km2. This gives D ≈2.2
g
speed of service followers per year
2 yr1
ignoring f, ds/dt is at its maximum value when σ = 1 and s =
0.5, giving ds/dt = 0.25g. At this rate it will take 2/g years for s
to reach σ = 1. g = 2 (1 year) seems a sensible timescale for
this maximal rate
f
speed of service innovators per year
0:05 yr1
we assume that change is mostly driven by logistic growth and
therefore service innovation is slower than service followers. If
s = 0, ds/dt = f · σ(p). 4. Integro-differential equations for population
and service dynamics At this rate it would take 1
f ¼ 20 years
to reach the steady state
Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 parameter
definition
default value
justification
βs
length scale for the kernel ws,
characterizes how close services wish
customers to be
5 km
mean trip distance to shopping in an urban conurbation is
4:7 km [33]
b p1
length scale used in kernel w p1
corresponding to how near population
wishes to be to services
1 km
assume attraction of an area is given by local services; those within
walking distance. Average walk to shops is 1:1 km [33]
b p2
length scale corresponding to how far
population is willing to move to a
more desirable location
10 km
in 2013–2014, the median household move was in the ‘5-10 miles’
group [34]
λ
population scale parameter for the
carrying capacity function,
equation (4.10)
20000 pe km2
in London wards 0 < p < 14 000 [35] and 0 < s < 0.4 (assuming s
to be non-domestic land use) [36]. If P = λ then s will be
expected to approach σ(λ) = 1 −(1/e) ≈0.63 which is
significantly higher than the value for s in London. Since σ(P)
is an increasing function, this means that λ must be larger than
the maximum population density in London. Selecting λ =
20 000 seems a reasonable estimate for this upper end of
population density and service provision
μ
steepness parameter for the carrying
capacity function
3
taking the mean of London wards gives p ¼ 8400 pe km2 [35]
and s ¼ 0:06 (assuming s to be non-domestic land use) [36]. Using these values and solving the homogeneous steady-state
equation (5.1) gives μ ≈3.2, assuming λ = 20 000
D
rate of change of population density in
an area
2 yr1
at the homogeneous state, the number of people who move in or
out of a place is given by D · p0 · A0 = D · p0 · σ(p0) · (1 −
σ(p0)). In London in 2018-19, flows in and out were
approximately 290 pe km2 yr1 [37] and population density,
p0, was approximately 5700 pe km2. This gives D ≈2.2
g
speed of service followers per year
2 yr1
ignoring f, ds/dt is at its maximum value when σ = 1 and s =
0.5, giving ds/dt = 0.25g. 4. Integro-differential equations for population
and service dynamics w p1ðxÞ ¼ Gðx, b1Þ,
ð4:3Þ ð4:3Þ We begin by defining a notion of attractiveness to the residen-
tial population, A(x,t), which captures the assumptions that a
location is more attractive if there are services near to that
place, but less attractive if the location is itself full of services
(people may not want to reside in areas of dense service pro-
vision). A is then given as the product of a non-local average
of service fraction and the local fraction of non-service space where Gðx, bÞ ¼
1
b
ffiffiffiffiffiffi
2p
p
eðx2=2b2Þ
(In 1D)
Gðx, bÞ ¼
1
2pb2 eðjxj2=2b2Þ
(In 2D)
9
>
>
>
=
>
>
>
; and ð4:1Þ Aðx, tÞ ¼ AðSðx, tÞ, sðx, tÞÞ ¼ Sðx, tÞð1 sðx, tÞÞ,
ð4:1Þ Such a kernel means that points that are further away from x Such a kernel means that points that are further away from x
have less influence than points near x. It is used elsewhere in
the urban modelling literature [16,38]. The rate of decay is
given by β where larger β gives a more spread shape, synony-
mously with the standard deviation of a normal distribution. where where Sðx, tÞ ¼
ð
w p1ðx yÞsðy, tÞdy ¼ w p1sðx, tÞ: Sðx, tÞ ¼
ð
w p1ðx yÞsðy, tÞdy ¼ w p1sðx, tÞ:
ð4:2Þ ð4:2Þ Table 1. Table of parameters corresponding to equations (4.1) to (4.10) that define dp/dt and ds/dt. These parameters are based on UK data from publicly
available data sources. Table 1. Table of parameters corresponding to equations (4.1) to (4.10) that define dp/dt and ds/dt. These parameters are based on UK data from publicly
available data sources. 5 5 parameter
definition
default value
justification
βs
length scale for the kernel ws,
characterizes how close services wish
customers to be
5 km
mean trip distance to shopping in an urban conurbation is
4:7 km [33]
b p1
length scale used in kernel w p1
corresponding to how near population
wishes to be to services
1 km
assume attraction of an area is given by local services; those within
walking distance. 5. Spatial instability leads to patterned steady
states The sigmoidal form would model a situation in which, at
low populations, the benefits of setting up a business
barely exceed the fixed costs and service carrying capacity
increases weakly. As the population increases, there may be
a tipping point where the benefits gained increasingly out-
weigh the costs, leading to a marked steepening of the
carrying capacity function, which then levels off as the
population approaches saturation. Downloaded from https://royalsocietypubl _p
_s
¼ Jðp0, s0, kÞ
p
s
ð5:4Þ ð5:4Þ so that we can analyse the stability matrix J. Calculation of J
can be found in appendix C.1, giving Jð p0; s0; kÞ
¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^w p2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þs0ð p0Þ^wsðkÞ
ð f þ gs0Þ
2
64
3
75:
ð5:5Þ ð5:5Þ For each frequency, k, perturbations are unstable if at least
one eigenvalue of J(k) has positive real part. We plot the real
part of the leading eigenvalue against spatial frequency in
dispersion relations to see the modes with a positive
growth rate. We plot these dispersion relations as we vary
the average population in the model in figure 4a. For simplicity, we assume initially that there will be no
growth of the total population. Instead, we will analyse
how the steady states of this model depend on the total
population. This shows that for small populations, modes of lower fre-
quency grow, but higher frequency, shorter wavelength
modes dissipate. As population density increases, the fastest
growing mode moves from five peaks in the domain (40 km
wavelength) to 2–3 peaks (60–100 km). For larger population
densities, the dispersion relation predicts that all pertur-
bations will dissipate. Equations (4.4) and (4.6) give a description of the spatio-
temporal interaction between population and services. A dia-
gram explaining these interactions can be seen in figure 3a. Explanations and estimates for the default parameters corre-
sponding to UK data are given in table 1. Numerical methods
are explained in appendix B. Simulations of the model with the kernels and parameters
listed show that the system tends either to a spatially homo-
geneous state, where population and services are completely
mixed, or spatial patterns emerge. These patterns take the
form of areas of increased population and service density,
as shown in figure 3b. An initial homogeneous population
is seeded with small random perturbations. 5. Spatial instability leads to patterned steady
states We wish to understand the conditions in which a homo-
geneous steady state or a spatial pattern emerge. For any
homogeneous {p0, s0}, equation (4.4) will be zero and there-
fore the homogeneous steady state for p is p0 ¼ p, the
average population density, which is dictated by the initial
conditions. Equation (4.6) gives the homogeneous steady
state for s as Pðx, tÞ ¼ ws pðx, tÞ:
ð4:7Þ ð4:7Þ We assume the spatial weight kernel ws is Gaussian;
specifically s0 ¼ sðp0Þ:
ð5:1Þ ownloaded from https://royalsocietypublishing.org/ on 05 May 2022 ð5:1Þ Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 https://royalsocietypublishing.org/ on 05 May 2022 wsðxÞ ¼ Gðx, bsÞ:
ð4:8Þ ð4:8Þ To better understand which wavelengths we expect to
emerge from an unstable homogeneous state, we consider
the perturbation from the steady state From the definition of s(x,t) being the fraction of land
occupied by services, we require 0 ≤s ≤1 and so 0 ≤σ ≤1
also. It is natural to expect that the greater the popula-
tion near x, the more services can be supported at x by
this population, therefore σ(P) should be a non-decreasing
function. We assume that carrying capacity for services will
take the form From the definition of s(x,t) being the fraction of land
occupied by services, we require 0 ≤s ≤1 and so 0 ≤σ ≤1
also. It is natural to expect that the greater the popula-
tion near x, the more services can be supported at x by
this population, therefore σ(P) should be a non-decreasing
function. We assume that carrying capacity for services will
take the form p ¼ p0 þ ~pðx, tÞ, s ¼ s0 þ ~sðx, tÞ:
ð5:2Þ ð5:2Þ In particular, we look for Turing-like instabilities; that is by
looking at sinusoidal perturbations of frequency k, given by f~pðx, tÞ, ~sðx, tÞg ¼ fpðtÞ eikx, sðtÞ eikxg:
ð5:3Þ ð5:3Þ sðPÞ ¼ 1 e(P=l)m:
ð4:9Þ ð4:9Þ Linearizing, we obtain a problem of the form Linearizing, we obtain a problem of the form This function has the features that σ(0) = 0, lim p→∞σ( p) = 1
and dσ/dP > 0. σ can be understood as the potential for
service provision for a given population. The parameter λ
represents the population scale and μ represents the shape
of the function. If μ ≤1 this function is concave and if μ > 1
it is sigmoidal with maximum steepness increasing with μ. 4. Integro-differential equations for population
and service dynamics The length scale of the pattern is 53 km according to the
spatial autocorrelation (figure 3c). 6 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 ds
dt ðx, tÞ ¼ ðf þ gsÞ(sðPÞ s):
ð4:6Þ ð4:6Þ The rates f and g represent the speed of service innova-
tors and imitators respectively. The carrying capacity for
services for a given population density is σ(P(x,t)). P(x,t)
is a weighted integral of p(x,t), where the third and
final kernel in the model, ws, encapsulates dependence of
the carrying capacity on the population distribution. The
kernel here captures the typical distance residents travel to
places of work, retailers and other services. The equation
for P(x,t) is The rates f and g represent the speed of service innova-
tors and imitators respectively. The carrying capacity for
services for a given population density is σ(P(x,t)). P(x,t)
is a weighted integral of p(x,t), where the third and
final kernel in the model, ws, encapsulates dependence of
the carrying capacity on the population distribution. The
kernel here captures the typical distance residents travel to
places of work, retailers and other services. The equation
for P(x,t) is 4. Integro-differential equations for population
and service dynamics At this rate it will take 2/g years for s
to reach σ = 1. g = 2 (1 year) seems a sensible timescale for
this maximal rate
f
speed of service innovators per year
0:05 yr1
we assume that change is mostly driven by logistic growth and
therefore service innovation is slower than service followers. If
s = 0, ds/dt = f · σ(p). At this rate it would take 1
f ¼ 20 years
to reach the steady state
Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 ://royalsocietypublishing.org/ on 05 May 2022 p0, was approximately 5700 pe km2. This gives D ≈2.2
ignoring f, ds/dt is at its maximum value when σ = 1 and s = 0.5, giving ds/dt = 0.25g. At this rate it will take 2/g years for s
to reach σ = 1. g = 2 (1 year) seems a sensible timescale for
this maximal rate where D measures the overall rate of moving and The
parameter
β1
therefore
characterizes
how
near
the
residential population wishes to be to services. w p2ðxÞ ¼ Gðx, b2Þ,
ð4:5Þ ð4:5Þ We then assume that the rate of population movement
from location y to x is proportional to the attractiveness of
x multiplied by the density of potential movers at y and
weighted according to the distance between the locations
(short distance moves being more likely [34]). The rate of
change in population at a location x will therefore be given
by the rate of moving from all other locations y to x (moves
into x), minus the rate of moving from x to all other locations
y (moves out of x): gives a Gaussian dependence of the rate on the distance
moved. The dynamics of the service fraction, s(x,t), is assumed to
be driven by a demand that is an increasing function of the
residential population that can access services at x. Growth
in the service fraction is therefore driven by innovators that
start new businesses when demand exceeds supply, and
expansion of existing businesses, imitators. However, if
supply exceeds demand, then competition would force dp
dt ðx, tÞ ¼ D
ð
½AðxÞpðyÞ AðyÞpðxÞw p2ðx yÞ dy,
ð4:4Þ ð4:4Þ some out of business. We have Continuing the simulation to 150 years shows solidification
of the city structure occurring as people move to the city. 5. Spatial instability leads to patterned steady
states After 50 years,
we start to see some areas growing more than others and,
by 100 years, clear city structures have formed. The largest
cities
have
a slight
density crater
in the
city
centre. We can further analyse this Jacobian to calculate con-
ditions for any wavelengths to be unstable. We show in
appendix C.1.1 that there are unstable frequencies if and
only if s0ð1 s0Þ
p0s0ðp0Þ þ s0 , ð1 s0Þ,
ð5:6Þ ð5:6Þ and that, if this holds, then instability occurs in a window
(0, kc) for some critical frequency kc. (a)
(b)
(c)
(–) logistic
growth
(+) carrying capacity
(–) movement
(+) attraction
non-local interaction
local interaction
services, s
population, p
–100 –50
0
50
–100 –50
0
50
–100 –50
0
50
–100 –50
0
50
–100 –50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0.5
1.0
1.5
2.0
×104
0.1
0.2
0.3
0.4
0.5
0.6
population density, p
0
Moran’s I
50
100
distance (km)
distance (km)
time = 0 years
time = 50 years
time = 100 years
time = 150 years
distance (km)
distance (km)
–100 –50
0
50
distance (km)
service density, s
–100 –50
0
50
distance (km)
–100 –50
0
50
distance (km)
150
–0.2
0
0.2
e 3. Emergence of cities from an initial random population distribution. (a) The key interactions in the model. p and s represent population and services at a
Blue lines represent non-local dynamics, that is where a spatial convolution is used to characterize the influence of a distribution in the neighbourhood around
nt. (b) We initialize a population of p = 8000 + 1000r, where r ∼N(0, 1). After 100 years, we see the clear emergence of city structures, which are further
thened at 150 years. (c) The length scale between these cities is around 53 km as can be seen in the autocorrelation plot of the final simulation. Parameters
pond to the default parameters in table 1. (a)
(–) logistic
growth
(+) carrying capacity
(–) movement
(+) attraction
non-local interaction
local interaction
services, s
population, p
royalsocietypublishing.org/journ
7 royalsocietypublishing.org/journal/rsif
J. R. Soc. 5. Spatial instability leads to patterned steady
states Interface 19: 20220176
7 (a) (b)
(–) logistic
growth
(+) carrying capacity
(–) movement
non-local interaction
local interaction
services, s
population, p
–100 –50
0
50
–100 –50
0
50
–100 –50
0
50
–100 –50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0.5
1.0
1.5
2.0
×104
population density, p
time = 0 years
time = 50 years
time = 100 years
time = 150 years
distance (km) (–) logistic
growth population, p (b) population density, p 50
–100 –50
0
50
–100 –50
0
50
–100
–50
0
50
–100
–50
0
50
0.5
1.0
1.5
2.0
×104
pulation density, p
ars
time = 100 years
time = 150 years –100 –50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0.1
0.2
0.3
0.4
0.5
0.6
distance (km)
distance (km)
–100 –50
0
50
distance (km)
service density, s
–100 –50
0
50
distance (km)
–100 –50
0
50
distance (km) –100 –50
0
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
distance (km)
(
)
–100 –50
0
50
distance (km)
service density, s
–100 –50
0
50
distance (km) service density, s –100
–50
0
50
0.1
0.2
0.3
0.4
0.5
0.6
–100 –50
0
50
distance (km) (c)
0
Moran’s I
50
100
distance (km)
150
–0.2
0
0.2 distance (km) Figure 3. Emergence of cities from an initial random population distribution. (a) The key interactions in the model. p and s represent population and services at a
point. Blue lines represent non-local dynamics, that is where a spatial convolution is used to characterize the influence of a distribution in the neighbourhood around
a point. (b) We initialize a population of p = 8000 + 1000r, where r ∼N(0, 1). After 100 years, we see the clear emergence of city structures, which are further
strengthened at 150 years. (c) The length scale between these cities is around 53 km as can be seen in the autocorrelation plot of the final simulation. Parameters
correspond to the default parameters in table 1. For a more general σ(p), if equation (5.6) holds, we must
have p0σ0(p0) > s0 = σ(p0). 5. Spatial instability leads to patterned steady
states Although technical exceptions can
be found, this suggests that σ should be convex on (0, p0) for
instabilities to the homogeneous steady state to arise. This
model analysis predicts that when service potential is highly
reactive to a change in population (convex σ(p)) then we
expect pattern generating instabilities to arise. Conversely, if a
change in population does not drive a sufficient reaction in ser-
vice potential then we expect such a perturbation to die away. We can solve for equality in (5.6) using (5.1) to find the
bifurcation point at which spatial instability arises, {p0, s0}. For the carrying capacity function given by equation (4.9),
the bifurcation point in s occurs at the solution of s0 =
μ (2s0 −1) ln(1 −s0). The bifurcation point depends only
on μ and the equation has a solution for μ ≥1. The parameter
μ is the steepness of the change in carrying capacity for
services for a change in population. It is concave with
respect to population density if μ < 1 and sigmoidal other-
wise. Using the value of μ = 3 in figure 4, we calculate
s0 = 0.37, p0 = 15 360 for the bifurcation point. Moreover, if equation (5.6) holds and there are instabilities
of the homogeneous steady state, then . Regardless of the 0
0.1
0.2
0.3
0.4
0.5
–0.08
–0.06
–0.04
–0.02
growth rate
(real part of leading eigenvalue)
maximum service provision,
spatial frequency, k
average population density, p
0
0.02
0.04
0.06
(a)
(c)
(b)
average population density
p = 5000
s (x)
p = 13 620
p = 14 743
p = 15 360
p = 17 000
0.5
1.0
1.5
2.0
2.5
×104
3.0
homogeneous solution
1 city in domain
2 cities
3 cities
4 cities
5 cities
6 cities
7 cities
8 cities
0
0.2
0.4
0.6
0.8
1.0
population density
service density
2.0
0.6
2000
1500
1000
500
0
2000
1500
1000
500
0
–100
0
100
–100
0
distance (km)
distance (km)
100
0.5
0.4
0.3
0.2
0.1
1.5
1.0
time (years)
0.5
×104
Figure 4. (a) Dispersion relations at five different values of the average population, p. The crosses correspond to the different wavenumbers. This diagram
shows which spatial frequencies are unstable; the larger the real part of the eigenvalue, the more destabilizing that frequency. 5. Spatial instability leads to patterned steady
states Interface 19: 20220176
8 maximum service provision,
average population density, p
(b)
s (x)
0.5
1.0
1.5
2.0
2.5
×104
3.0
homogeneous solution
1 city in domain
2 cities
3 cities
4 cities
5 cities
6 cities
7 cities
8 cities
0
0.2
0.4
0.6
0.8
1.0 8 (a) maximum service provision,
s (x maximum service provis population density
2.0
2000
1500
1000
500
0
–100
0
distance (km)
100
1.5
1.0
time (years)
0.5
×104 service density
0.6
2000
1500
1000
500
0
–100
0
100
distance (km)
0.5
0.4
0.3
0.2
0.1 (c) Downloaded from https://royalsocietypublishing.org/ on 05 time (years) Downloaded from https://royalsocietypublish Figure 4. (a) Dispersion relations at five different values of the average population, p. The crosses correspond to the different wavenumbers. This diagram
shows which spatial frequencies are unstable; the larger the real part of the eigenvalue, the more destabilizing that frequency. As population density p increases,
the length scale of the dominant unstable wavelength increases from around 40 km (k ¼ 0:15) to around 60 km (k ¼ 0:1). At p ¼ 15 360, the dispersion
relation is tangential to the horizontal at k = 0. This is the bifurcation point where no modes are unstable. At p . 15 360 any perturbation decays. (b) Bifurcation
diagram showing where patterned steady states exist as average population density varies. Thick lines correspond to stable solutions and thin lines correspond to
unstable solutions. The stable branch is the single city solution, but other branches display metastability. (c) Time simulation showing how a seven bump metastable
steady state suddenly transitions into a three bump state after a very long time period. The three bump solution is itself metastable but persists for any reasonable
timescales. Initial conditions were p(x,0) = 10000 + 5000 cos (7πx/100) with s(x,0) = σ( p(x,0)). in which a patterned state can exist and to explore the bifur-
cation points. This can be seen in figure 4b. The patterned
states emerge at low average populations until a series of
bifurcation points where each becomes stable. The last bifur-
cation to the homogeneous state is at confirming what we
saw with the dispersion relation. Between p ¼ 15 360 and
p ¼ 18 000, both the homogeneous steady state and the pat-
terned
state
are
stable
and
for
p . 18 000
only
the
homogeneous state is stable. 5. Spatial instability leads to patterned steady
states As population density p increases,
the length scale of the dominant unstable wavelength increases from around 40 km (k ¼ 0:15) to around 60 km (k ¼ 0:1). At p ¼ 15 360, the dispersion
relation is tangential to the horizontal at k = 0. This is the bifurcation point where no modes are unstable. At p . 15 360 any perturbation decays. (b) Bifurcation
diagram showing where patterned steady states exist as average population density varies. Thick lines correspond to stable solutions and thin lines correspond to
unstable solutions. The stable branch is the single city solution, but other branches display metastability. (c) Time simulation showing how a seven bump metastable
steady state suddenly transitions into a three bump state after a very long time period. The three bump solution is itself metastable but persists for any reasonable
timescales Initial conditions were p(x 0) = 10000 + 5000 cos (7πx/100) with s(x 0) = σ( p(x 0)) 0
0.1
0.2
0.3
0.4
0.5
–0.08
–0.06
–0.04
–0.02
growth rate
(real part of leading eigenvalue)
maximum service provision,
spatial frequency, k
average population density, p
0
0.02
0.04
0.06
(a)
(b)
average population density
p = 5000
s (x)
p = 13 620
p = 14 743
p = 15 360
p = 17 000
0.5
1.0
1.5
2.0
2.5
×104
3.0
homogeneous solution
1 city in domain
2 cities
3 cities
4 cities
5 cities
6 cities
7 cities
8 cities
0
0.2
0.4
0.6
0.8
1.0 0
0.1
0.2
0.3
0.4
0.5
–0.08
–0.06
–0.04
–0.02
growth rate
(real part of leading eigenvalue)
spatial frequency, k
0
0.02
0.04
0.06
(a)
average population density
p = 5000
p = 13 620
p = 14 743
p = 15 360
p = 17 000 royalsocietypublishing.org/journal/rsif
J. R. Soc. 5. Spatial instability leads to patterned steady
states carrying capacity function, instability can only occur where
we
have
sufficiently
small
population
densities
and
services. If the population is too high, the model predicts
that there would be urban sprawl rather than further
agglomeration. We can also see that for a solution to be unstable to a
certain perturbation, that perturbation must have a sufficien-
tly long wavelength. In an urban context, this means that we
do not expect to see lots of very small but high-density cities
next to each other. In this case, we expect agglomeration
would occur. However, if cities are far enough apart, we
can expect them to remain distinct. Figure 4b suggests that the only stable patterned state is
the single cluster pattern. This is due to the presence of meta-
stable steady states, where the instability can only be seen by
simulating the system for an extreme length of time, as in
figure 4c. All the multi-peak branches display this metastabil-
ity. However, the timescales at which this agglomeration
occurs might be of the order of greater than a millennium
or even more and these steady states are therefore only
very weakly unstable. Having analysed the homogeneous steady state, we can
now look at the patterned steady states and determine their
stability. These can be calculated using a process of numerical
continuation [39]. Beginning with a steady state produced by
simulation, we track how this state changes as we vary the
average population size, p. This allows us to see the regions Table 2. Supplement to table 1. Additional parameters for equations (6.1) and (6.2). parameter
definition
default
value
justification
ap
secondary length scale used in kernel w p1
corresponding to the population’s
preferred distance to services
1:5 km
given b p1 ¼ 1 km, ap = 1.5 creates distinct, off centre, peaks
without separating the two Gaussians completely
α1
competition parameter. How much space
does each person take away from
services
1.5 × 10−5
km2 pe1
when population dominates, α1 p = 1. In London wards, the
maximum population density is 28 863 pe km2 which
would give a1 ¼ 3:53 105 km2 pe1. We assume less
competition than this [35] Table 2. Supplement to table 1. Additional parameters for equations (6.1) and (6.2). royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176
9 Soc. 5. Spatial instability leads to patterned steady
states Interface 19: 20220176 We have shown how distinct cities can form where the
average population density is sufficiently low and there is
sufficient reaction by services to a change in population. Unstable perturbations to the homogeneous steady state
must be of sufficiently long length scale showing how
we expect agglomeration to occur over longer rather than
shorter distances. The dominant unstable wavelength of
such perturbations can be seen in the dispersion relations
given by the linear stability analysis of the steady state. We
also saw the presence of bifurcation points and metastable
steady states in the system which shows how sudden agglom-
eration may occur, particularly as population increases. With competition now included, the space requirements of
people can overcome the potential for service growth so we
assume that if there is no potential for service growth then
there are no innovators, f. This is why we have a factor of
H(σ(P) −(s + α1p)), where H is the Heaviside step function. Importantly, this ensures that s = 0 is a lower bound for ser-
vices. The default values for the new parameters ap and α1
can now be found in table 2. Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 Including competition can give both in-phase and out-of-
phase patterning at different spatial scales (figure 5a,b). In-
phase patterns are the co-location of high-densities of
people and services, such as seen on a large scale in cities. Out-of-phase
patterns
are
where
people
and
services
occupy distinct and complementary areas; here they typically
have shorter length scales and occur as secondary structures
within cities. Downloaded from https://royalsocietypub 6. Secondary patterning when services compete
for space and residents avoid high service
d
i In this example, a three bump solution with no secondary
pattern (figure 5a) persists at the same parameter values as a
two bump solution with shorter wavelength secondary pat-
terning within each bump (figure 5b). This secondary
pattern has a wavelength of around 5 km. London in figure 1 shows an example of multiple patterning. Firstly, aggregation brings people and services together to form
thecityitselfandthereisagrowthinpopulationdensitytowards
the city centre. However, there is secondary patchy patterning
on top of this framework. This may be driven by people and ser-
vices occupying distinct areas (one is high when the other is
low)—seen in particular at the centre of the city. In order to understand the emergent length scales, we
again use linear stability analysis around the homogeneous
steady state, {p0, s0}. The steady state for p is given by
p0 ¼ p, the average population density which is dictated
by
initial
conditions. For
smaller
population
densities
(p , 11 500), we have that σ( p0) < α1p0 and so the spatially
homogeneous steady state is p0 ¼ p, s0 = 0. There will not
be sufficient demand for services to overcome the compe-
tition for space and so no services can be supported. Patterned states can exist with these average population den-
sities but they are not emergent from the homogeneous
steady state. Instead, they would have to emerge from
different initial conditions. Within our model framework, we make two further
assumptions. We assume that people’s desire is to locate
‘near but not too near’ to the services that support their
needs; and that there is competition for space between
people and services within cities. The first assumption
about people’s location choice can be built into kernel w p1
by using a Gaussian kernel that has been shifted off centre
by distance ap in each direction and then summed For p . 11 500, we have that σ( p0) > α1p0 and the steady
state is w p1ðxÞ ¼ 1
2 (Gðx þ ap, b p1Þ þ Gðx ap, b p1ÞÞ:
ð6:1Þ ð6:1Þ p0 ¼ p,
s0 ¼ sðp0Þ a1p0:
ð6:3Þ ð6:3Þ G is the Gaussian previously defined in equation (4.4). This
assumes that there is an ideal distance ap which people
wish to be from service locations. Moreover, competition is
introduced into equation (4.6) as services compete for space
with residents. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i (a,b) Example simulations showing how in-phase and out-of-phase patterning are possible. Both
have the same parameters and mean population p ¼ 16 000, with α1 = 1.3 × 10−5. Initial conditions can be seen in figure 11. (c) Dispersion relations for different
values of the average population, p. At low populations, there is not sufficient service potential to overcome competition for space so no instability can persist. At
higher populations, both long wavelength in phase patterns and short wavelength out-of-phase patterns are predicted by the analysis. Finally, at higher population
densities, only out-of-phase patterning persists. (d) Spatial instabilities, their phase and spatial frequency predicted by the linear analysis in the ap, α1 parameter-
space. We use for which the spatially homogeneous steady state is stable when ap, = 0 = α1. For weak competition (α1 > 2.5 × 10−6) an in-phase instability of
low frequency (long wavelength) occurs. For sufficiently strong competition and desire for spatial separation, out-of-phase instability with higher spatial frequency is
dominant. For α1 > 2.5 × 10−5, there is so much competition for space that services do not have the population nearby to overcome this competition and they die
out completely, leaving a stable solution again. The black ‘x’ marks the point in parameter space used for the simulations in (a,b) showing how secondary patterning
persists even into regions not predicted by the linear stability analysis. and ap > 0 (appendix C.2). These are necessary but not
sufficient conditions. The
Jacobian
not
only enables
us to
see whether
an instability emerges but we can also see the phase of this
perturbation; whether we expect p and s to grow in the
same places or to separate. We do this by looking at
the eigenvector corresponding to the unstable eigenvalue. Figure 5c shows the change in the dispersion relation as we
increase the initial population. At p ¼ 5000, the homo-
geneous state is given as s0 = 0. At p ¼ 12 000, both in- and
out-of-phase patterning are predicted. As we increase the
population density to no pattern is unstable. Lastly, as the
population density further increases, the competition forces
out of phase patterning again. Moreover, we see that in
phase patterning occurs at similar frequencies to before,
with a wavelength of around 50 km. Out-of-phase patterning
occurs at a shorter wavelength of around 5 km, which is a
frequency of 1.25. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i The Jacobian is given by The Jacobian is given by Jð p0; s0; kÞ
¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^w p2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þðs0ð p0Þ^wsðkÞ a1Þ
ð f þ gs0Þ
2
64
3
75 ds
dt ðx, tÞ ¼ ðHðsðPÞ ðs þ a1pÞÞ f þ gsÞ (sðPÞ ðs þ a1pÞ): ð6:2Þ ð6:4Þ (a)
(b)
(c)
(d)
–100
–50
0
population density
service density
distance (km)
distance (km)
service density
population density
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0
2
4
6
8
×104
×104
0
0.5
1
0
2
4
6
8
0
0.5
1
0
0.5
1.0
1.5
spatial frequency, k (km–1)
ap, length scale for popn-service separation
a1, popn competition for service space
growth rate
(real part of leading eigenvalue)
2.0
2.5
3.0
–0.5
–0.4
–0.3
–0.2
–0.1
0
0.1
0
1
2
3
4
5
6
0
0.5
1.0
1.5
2.0
2.5
×10–5
in-phase only
in-phase dominant
out-of-phase dominant
kmax (km–1)
0
1.1
average population density
p = 5000
p = 12 000
p = 25 000
p = 17 000
p = 30 000
in-phase pattern
out-of-phase pattern
–
–
–
–
–
Figure 5. Out-of-phase patterning for the model with competition. (a,b) Example simulations showing how in-phase and out-of-phase patterning are possible. Both
have the same parameters and mean population p ¼ 16 000, with α1 = 1.3 × 10−5. Initial conditions can be seen in figure 11. (c) Dispersion relations for different
values of the average population, p. At low populations, there is not sufficient service potential to overcome competition for space so no instability can persist. At
higher populations, both long wavelength in phase patterns and short wavelength out-of-phase patterns are predicted by the analysis. Finally, at higher population
densities, only out-of-phase patterning persists. (d) Spatial instabilities, their phase and spatial frequency predicted by the linear analysis in the ap, α1 parameter-
space. We use for which the spatially homogeneous steady state is stable when ap, = 0 = α1. For weak competition (α1 > 2.5 × 10−6) an in-phase instability of
low frequency (long wavelength) occurs. For sufficiently strong competition and desire for spatial separation, out-of-phase instability with higher spatial frequency is
dominant. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i (a)
–100
–50
0
population density
service density
distance (km)
50
–100
–50
0
50
0
2
4
6
8
×104
0
0.5
1 (a)
(b)
–100
–50
0
population density
service density
distance (km)
distance (km)
service density
population density
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0
2
4
6
8
×104
×104
0
0.5
1
0
2
4
6
8
0
0.5
1 (b)
distance (km)
service density
population density
–100
–50
0
50
–100
–50
0
50
×104
0
2
4
6
8
0
0.5
1 (a)
(b)
(c)
(d)
–100
–50
0
population density
service density
distance (km)
distance (km)
service density
population density
50
–100
–50
0
50
–100
–50
0
50
–100
–50
0
50
0
2
4
6
8
×104
×104
0
0.5
1
0
2
4
6
8
0
0.5
1
0
0.5
1.0
1.5
spatial frequency, k (km–1)
ap, length scale for popn-service separation
a1, popn competition for service space
growth rate
(real part of leading eigenvalue)
2.0
2.5
3.0
–0.5
–0.4
–0.3
–0.2
–0.1
0
0.1
0
1
2
3
4
5
6
0
0.5
1.0
1.5
2.0
2.5
×10–5
in-phase only
in-phase dominant
out-of-phase dominant
kmax (km–1)
0
1.1
average population density
p = 5000
p = 12 000
p = 25 000
p = 17 000
p = 30 000
in-phase pattern
out-of-phase pattern
–
–
–
–
– 10 population density (c)
(d)
0
0.5
1.0
1.5
spatial frequency, k (km–1)
ap, length scale for popn-
a1, popn competition for service space
growth rate
(real part of leading eigenvalue)
2.0
2.5
3.0
–0.5
–0.4
–0.3
–0.2
–0.1
0
0.1
0
1
2
3
0
0.5
1.0
1.5
2.0
2.5
×10–5
kmax (km–1)
0
1.1
average population density
p = 5000
p = 12 000
p = 25 000
p = 17 000
p = 30 000
in-phase pattern
out-of-phase pattern
–
–
–
–
– (c)
0
0.5
1.0
1.5
spatial frequency, k (km–1)
growth rate
(real part of leading eigenvalue)
2.0
2.5
3.0
–0.5
–0.4
–0.3
–0.2
–0.1
0
0.1
average population density
p = 5000
p = 12 000
p = 25 000
p = 17 000
p = 30 000
in-phase pattern
out-of-phase pattern
–
–
–
–
– (c) ap, length scale for popn-service separation Figure 5. Out-of-phase patterning for the model with competition. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i For α1 > 2.5 × 10−5, there is so much competition for space that services do not have the population nearby to overcome this competition and they die
out completely, leaving a stable solution again. The black ‘x’ marks the point in parameter space used for the simulations in (a,b) showing how secondary patterning
persists even into regions not predicted by the linear stability analysis. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i In order for out-of-phase patterns to
be predicted by the linear analysis, we must have α1 > 0 Figure 5d maps an example of where in the α1, ap par-
ameter regime in- and out-of-phase patterning is predicted. The homogeneous steady state is given by s0 = σ( p0) −α1p0. Therefore, as we increase α1 so the steady state for s0
will decrease. If the original homogeneous steady state is
stable, as in figure 5, introducing some competition may
induce in-phase patterning. Increasing ap, the ideal length
people wish to be from services, can induce out-of-phase
patterning, as long as there is sufficient competition to
drive it. For very large α1, competition for space means that
services do not have the population nearby to overcome
this competition and they die out completely, leaving a
stable steady state again. The out-of-phase patterning seen in figure 5b is not pre-
dicted by the linear stability analysis of the homogeneous (a)
(c)
(b)
(–) logistic
growth
(–) competition
(–) competition
(+) carrying capacity
(–) movement
(+) attraction
(–) logistic
growth
Key:
non-local interaction
local interaction
services, s
population, p
0
0.5
1.0
1.5
2.0
2.5
3.0
spatial frequency, k (km–1)
–0.06
–0.04
–0.02
0
0.02
0.04
dispersion relations for 1D and 2D cases
growth rate
(real part of leading eigenvalue)
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
–40
distance (km)
–20
0
20
40
–40
distance (km)
distance (km)
–40 –20
0
20
40
distance (km)
–40 –20
0
20
40
distance (km)
–40 –20
0
20
40
distance (km)
–20
0
20
40
–40
–20
0
20
40
–40
–20
0
20
40
–40
–20
0
20
40
time = 0 years
time = 200 years
time = 500 years
time = 1000 years
×104
–40
–20
0
20
40
–40
–20
0
20
40
–40
–20
0
20
40
0
0.5
1.0
1.5
2.0
0
0.05
0.10
0.15
service density, s
population density, p
1D
2D
out-of-phase pattern
in-phase pattern
Figure 6. (a) Schematic diagram of the full model from §7 explaining the key interactions. This encompasses equations (6.2) and (7.1). (b) Dispersion relations
corresponding to the one-dimensional and two-dimensional cases for the default parameter set (tables 1, 2 & 3), also corresponding to the simulation in (c). 6. Secondary patterning when services compete
for space and residents avoid high service
d
i (a) Schematic diagram of the full model from §7 explaining the key interactions. This encompasses equations (6.2) and (7.1). (b) Dispersion relations
corresponding to the one-dimensional and two-dimensional cases for the default parameter set (tables 1, 2 & 3), also corresponding to the simulation in (c). This
shows that both in- and out-of-phase patterning can still be predicted when both the population and services grow and compete for space. (c) Simulation of the
growth and secondary pattern formation of cities. Initial conditions are p0(x, y) = 200 on 10% of the domain. We see that, firstly, population grows everywhere and
as it does, distinct cities appear. Then secondary structure emerges within the cities as population separates from services. space from services. This changes equation (4.4) to be steady state for this average population yet it can persist
across the parameter space. In this particular case, such pat-
terning is secondary, forming after an initial city has grown
and developed. dp
dt ðx, tÞ ¼ D
ð
½AðxÞpðyÞ AðyÞpðxÞwp2ðx yÞ dy
þ rp 1 p þ a2s
c
:
ð7:1Þ ð7:1Þ In summary, this model produces both in- and out-
of-phase patterns of different spatial lengths; the new
out-of-phase patterning is of shorter wavelength. Within a
city context, the desire for co-location agglomerates people
into cities and competition for space creates divisions in
land use. A schematic of the full model can be seen in figure 6a and
the new parameter values in table 3 with explanations in
appendix E. Similarly to the previous case, in- and out-of-phase pat-
terning are possible, depending upon the value for the
carrying capacity c. This can be seen in dispersion relations
as we vary the carrying capacity in figure 10 and in the
example in figure 6. The homogeneous steady state from
dp/dt is now dependent upon the carrying capacity c. The
steady state is now given by the solution to 6. Secondary patterning when services compete
for space and residents avoid high service
d
i This
shows that both in- and out-of-phase patterning can still be predicted when both the population and services grow and compete for space. (c) Simulation of the
growth and secondary pattern formation of cities. Initial conditions are p0(x, y) = 200 on 10% of the domain. We see that, firstly, population grows everywhere and
as it does, distinct cities appear. Then secondary structure emerges within the cities as population separates from services. 6. Secondary patterning when services compete
for space and residents avoid high service
d
i (b)
0
0.5
1.0
1.5
2.0
2.5
3.0
spatial frequency, k (km–1)
–0.06
–0.04
–0.02
0
0.02
0.04
dispersion relations for 1D and 2D cases
growth rate
(real part of leading eigenvalue)
1D
2D
out-of-phase pattern
in-phase pattern (a) (a)
(b)
(–) logistic
growth
(–) competition
(–) competition
(+) carrying capacity
(–) movement
(+) attraction
(–) logistic
growth
Key:
non-local interaction
local interaction
services, s
population, p
0
0.5
1.0
1.5
2.0
2.5
3.0
spatial frequency, k (km–1)
–0.06
–0.04
–0.02
0
0.02
0.04
dispersion relations for 1D and 2D cases
growth rate
(real part of leading eigenvalue)
1D
2D
out-of-phase pattern
in-phase pattern (a) (b) dispersion relations for 1D and 2D cases (–) logistic
growth
(–) competition
(–) competition
(+) carrying capacity
(–) movement
(+) attraction
(–) logistic
growth
Key:
non-local interaction
local interaction
services, s
population, p (–) logistic
growth (c)
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
–40
distance (km)
–20
0
20
40
time = 0 years
time = 200 years
time = 500 years
time = 1000 years
×104
–40
–20
0
20
40
–40
–20
0
20
40
–40
–20
0
20
40
0
0.5
1.0
1.5
2.0
population density, p (c)
–40 –20
0
20
40
–40 –20
0
20
40
–40
distance (km)
–20
0
20
40
time = 0 years
time = 200 years
–40
–20
0
20
40
–4
–2
2
4
population d 40
–40 –20
0
20
40
–40 –20
0
20
40
–40 –20
0
20
40
s
time = 200 years
time = 500 years
time = 1000 years
–40
–20
0
20
40
–40
–20
0
20
40
–40
–20
0
20
40
population density, p population density, p (c) 0
–40 –20
0
20
40
–40 –20
0
20
40
s
time = 500 years
time = 1000 years
×104
–40
–20
0
20
40
–40
–20
0
20
40
0
0.5
1.0
1.5
2.0
ulation density, p –40 –20
0
20
40
distance (km)
–40 –20
0
20
40
distance (km)
–40
–20
0
20
40
–40
–20
0
20
40
service density, s service density, s –40 –20
0
20
40
–40
distance (km)
distance (km)
–40 –20
0
20
40
distance (km)
–20
0
20
40
–40
–20
0
20
40
service –40 –20
0
20
40
distance (km)
–40
–20
0
20
40
density, s –40 –20
0
20
40
distance (km)
–40
–20
0
20
40
0
0.05
0.10
0.15 Downloaded from https://royalsocietypublish Figure 6. 7. Including population growth and competition
shows cities emerging before secondary
patterning appears Lastly, we include population growth in the model via logis-
tic growth up to some carrying capacity with competition for ð7:2Þ p0 þ a2s0 ¼ c,
s0 ¼ sðp0Þ a1p0:
ð7:2Þ ble 3. Supplement to tables 1 and 2 showing the default values for the new parameters in equation (7.1) Table 3. Supplement to tables 1 and 2 showing the default values for the new parameters in equation (7.1) 12 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 parameter
definition
default value
justification
r
intrinsic population growth rate
0:05 yr1
see appendix E
c
carrying capacity for population
density
12 000
pe km2
c will define p, therefore we consider a similar range
α2
competition of services to
population density
100 000
pe km2
at steady state, p + α2s = c. If p ¼ 10 000 pe km2, and s = 0.05,
then a2 ¼ 100 000 pe km2 The hierarchy of integro-differential equation models
developed here focuses on spatial kernels to capture the dis-
tribution of non-local dependencies. This model shows that
the preference for population location in proximity to services
can either lead to a completely mixed homogeneous state or
drive the emergence of urban centres, seen in a spatial pat-
tern. Numerical continuation and linear stability analysis of
the steady states of this model shows how different length
scales emerge, depending upon the initial conditions and
parameters (figure 4). In phase spatial instabilities are
shown to be destabilizing only if the perturbation is of a suf-
ficiently long spatial scale and only if a change in population
density produces a sufficient change in service density. One
observation from this model is that many steady states are
metastable; over long time periods, we would see transitions
at the merging of city centres as cities agglomerate. We note that it is possible to keep the previous steady
state {p0, s0} unchanged by choosing c as f
J. R. Soc. 7. Including population growth and competition
shows cities emerging before secondary
patterning appears Interface 19: 20220176 c ¼ p0 þ a2s0:
ð7:3Þ ð7:3Þ The Jacobian used to produce these dispersion relations is
as follows: nloaded from https://royalsocietypublishing.org/ on 05 May 2022 ://royalsocietypublishing.org/ on 05 May 2022 Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 Jð p0; s0; kÞ
2 Jð p0; s0; kÞ
¼
Dp0ð1 ^wp2ðkÞÞ
Ds0ð1 s0Þð1 ^w p2ðkÞÞ rp0
c
ðð1 s0Þ^w p1ðkÞ s0Þ
ra2p0
c
ð f þ gs0Þðs0ð p0Þ^wsðkÞ a1Þ
ð f þ gs0Þ
2
6666664
3
7777775
ð7:4Þ Downloaded from https://royalsocietypublishing.or ð7:4Þ The effect of logistic growth is generally stabilizing for long
wavelength perturbations. In particular, homogeneous per-
turbations would return to the steady state. However, the
competition parameter α2 will tend to be destabilizing for
higher spatial frequencies, assuming that population and ser-
vices both compete sufficiently for space (appendix C.3). Within cities, we also see patterning emerge around local
services as long scale co-location and short scale separation of
population and service provision occurs. In the model, this is
driven by competition for space and desire by people to be
near, but not too near, to the services they need to support
them (figure 5). Figure 6c shows an example simulation of the full model
in two dimensions, demonstrating growth of cities and sec-
ondary, out-of-phase, patterning that gives separation of
population and services. Population initially grows but is
not sufficient to drive urbanization. Then, after a number of
years, cities form as there is sufficient population to drive
the demand for services and colocation. Continuing time for-
ward further shows that, within these cities there are distinct
areas of service provision, surrounded by population. This
model more realistically captures the long-term growth
dynamics of population into urban areas. Length scales within the model are typical of those seen
in the data for the UK. Differences in parameters such as
house moves and preferred travel distances may explain
different length scales between the UK and the USA. In the
USA, people might tend to move greater distances, both to
move house and to travel to their desired services, which
gives rise to sprawling metropolises. Conversely, the rapidly
urbanizing cities of China and Brazil may be driven by
people moving long distances to be as close as possible to
services, generating high-density distinct megacities. Our
modelling approach would give valuable insight into the
different city formations around the world. 8.1. Conclusion Interface 19: 20220176
13 Figure 7. Increasing typical travel distances over time leads to exaggerated agglomeration. We vary b p1, b p2 and βs as in (F1). The mean population density is
p ¼ 10 000 pe km2. Initially (t ≈30), the pattern that emerges from random perturbations to the spatially homogeneous steady state has a wavelength of
approximately 16 km. As time continues, the pattern coarsens and larger agglomerations form with a wavelength of about 100 km. Further details of the parameter
variation can be found in appendix F. from https://royalsocietypublishing.org/ on 05 May 2022 Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 one example of dynamically changing length scale par-
ameters in figure 7 to highlight the potential of our
modelling approach. supported by the Leverhulme Trust research programme ‘Sustaining
urban habitats: an interdisciplinary approach’. T.D.W. acknowledges
funding from the University of Nottingham Future Food Beacon
of Excellence. Thirdly, we have assumed that people (and services) are
motivated solely by coexistence
preferences. In
reality,
people’s desires will also be affected by multiple competing
interests such as employment opportunities, housing stock
and house prices, transport and more—all of which require
attention. This would be further confounded by the disaggre-
gation of people according to factors such as income or
ethnicity, or disaggregation of service types into retail, indus-
try, etc. It is not easy to determine the relative importance of
such influences or disentangle the effects of each. Our focus
on colocation preferences of people and services has enabled
us to elicit understanding regarding the implications of those
preferences for patterning and urban length scales. Acknowledgements. The authorsthank three anonymous reviewers for their
helpful and constructive suggestions in reviewing the manuscript. Downloaded from https://royalsocietypublishin Appendix A. Length scales in the USA Figure 8 shows the results from length scale analysis of popu-
lation density data from the north east USA, from the 2010
Census at census tract level [40] similarly to §3. Autocorrela-
tion on a region of Indiana, Ohio and Kentucky demonstrates
a spatial length scale of 200 km. We also take the Fourier
transform of a slice through key cities on the East coast:
Washington, Philadelphia, New York and Boston, which
gives a similar 200 km length scale. The USA seems to
show a longer characteristic length scale than the UK. Downloaded from https://roy Despite these limitations, our approach is intuitive and
mathematically rigorous. By developing an aggregated form
of model, we have sidestepped the myriad of uncertainties
involved in bottom-up modelling and minimized the varia-
bility. We hope that this exploration can be a springboard
for future developments to accommodate these complicating
factors which could deepen our understanding of the spatial
development of populations. Appendix B. Numerical methods For timestepping and numerical continuation, we use a code
structure from Avitabile [39]. We use a pseudospectral colloca-
tion method to compute convolutional integral operators. Hence, we expect spectral accuracy for the spatial discretization
(albeit wehavenotusedde-aliasing).This requirestheuseofper-
iodic boundary conditions; implying that the region considered
is similar to its neighbouring regions. Data accessibility. All data are from publicly available and cited sources. All code is publicly available at: https://doi.org/10.5281/zenodo. 5034211. Authors’ contributions. T.D.W.: conceptualization, data curation, formal
analysis, investigation, methodology, software, writing—original
draft, writing—review and editing; D.A.: formal analysis, method-
ology,
resources,
software,
supervision,
writing—review
and
editing; P.-O.S.: supervision, writing—review and editing; D.R.:
funding acquisition, project administration, supervision, writing—
review and editing; M.R.O.: conceptualization, formal analysis, fund-
ing acquisition, investigation, methodology, project administration,
resources, software, supervision, writing—review and editing. To converge on and continue steady-states, we perform
Newton-GMRES iterations with tolerance 0.001. For the
time-stepper, we use the same spatial grid and discretization
method as the steady-state calculations, and we employ
Matlab’s in-built ode113 routine, with default tolerances. 8.1. Conclusion The emergence of spatial structure in human populations has
received relatively little attention when compared with the
quantification of urban patterns. Much focus has been on
measuring structure rather than understanding or predicting
where those structures come from. Inspired by typical length
scales that are apparent in population density data between
cities, here we have shown that a simple set of plausible
local and spatial interactions can explain the emergence of
cities via reinforced aggregation. While conceptually simple
in comparison with computer modelling techniques such as
cellular automata and agent-based models, these models
benefit from deeper explanatory power; offering the potential
not just to describe what we currently see in cities but also to
explain how such dynamics emerge. Our parsimonious approach has several limitations. Firstly,
by using an aggregated differential equation methodology,
we have gained mathematical tractability but lost the effects
of population heterogeneity. As explained in the literature
review, we believe that this approach provides a useful coun-
terpoint to the increasingly popular bottom up agent-based
methodologies. Secondly, we have considered parameters that are static
over time. Technological advances and societal changes will
doubtless affect the functions and kernels that capture behav-
iour. This simplification enables us to provide mathematical
rigour to our conclusions that would not be possible with
further complicating assumptions. Such work is beyond the
scope of this paper, but we motivate the discussion with population density
service density
2.0
250
200
150
100
50
0
250
0.6
0.5
0.4
0.3
0.2
0.1
200
150
100
50
0
time (years)
×104
1.5
1.0
0.5
100
0
–100
distance (km)
100
0
–100
distance (km)
Figure 7. Increasing typical travel distances over time leads to exaggerated agglomeration. We vary b p1, b p2 and βs as in (F1). The mean population density is
p ¼ 10 000 pe km2. Initially (t ≈30), the pattern that emerges from random perturbations to the spatially homogeneous steady state has a wavelength of
approximately 16 km. As time continues, the pattern coarsens and larger agglomerations form with a wavelength of about 100 km. Further details of the parameter
variation can be found in appendix F. service density
250
0.6
0.5
0.4
0.3
0.2
0.1
200
150
100
50
0
100
0
–100
distance (km) population density
2.0
250
200
150
100
50
0
time (years)
×104
1.5
1.0
0.5
100
0
–100
distance (km) royalsocietypublishing.org/journal/rsif
J. R. Soc. C.1. Linearization of the model without competition or
population growth We define Fðp, sÞ ¼
_pðx, tÞ
_sðx, tÞ
:
ðC 1Þ kernel with parameter
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
b 2
p1 þ b 2
p2
q
. We have that for any kernel w, kernel with parameter
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
b 2
p1 þ b 2
p2
q
. We have that for any kernel w, kernel with parameter
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
b 2
p1 þ b 2
p2
q
. We have that for any kernel w, ðC 1Þ w ~p ¼ w pðtÞ eikx ¼ pðtÞ
ð1
1
eikðxyÞwðyÞdy
¼ pðtÞ eikx
ð1
1
eikywðyÞ dy ¼ ^wðkÞ pðtÞ eikx:
ðC 5Þ Then we calculate Fðp0 þ ~p, s0 þ ~sÞ Fðp0, s0Þ where {p0,
s0} are the current state and f~p, ~sg are the perturbations
from this state of order ϵ. Using a Taylor expansion for σ,
we get ðC 5Þ Fðp0þ~p,s0þ~sÞFðp0,s0Þ
e Similarly, we have w ~s ¼ ^wðkÞsðtÞ eikx. Using this, we will
calculate the Jacobian of the temporal change in coefficients p
and s close to the steady state by substituting ~p ¼ p eikx and
~s ¼ s eikx into (C 2). At the homogeneous steady state s0 =
σ( p0), w ∗p0 = p0 and w ∗s0 = s0. ¼
D½A0ðwp2 ~pÞþ ~Aðwp2 p0Þ~pðwp2 A0Þp0ðwp2 ~AÞÞ
ðf þgs0Þð~ps0ðp0Þ~sÞþg~sðsðp0Þs0Þ
! ,
ð
Þ Factoring out eikx and writing in matrix form, we get where where _p
_s
! _p
_s
! ¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^wp2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þs0ð p0Þ^wsðkÞ
ð f þ gs0Þ
2
664
3
775
p
s
:
ðC 6Þ A ¼ A0 þ ~A
¼ ðw p1 s0Þ ð1 s0Þ þ (ðw p1 ~sÞ ð1 s0Þ ðw p1 s0Þ ~s):
ðC 3Þ ! ¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^wp2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þs0ð p0Þ^wsðkÞ
ð f þ gs0Þ
2
664
3
775
p
s
:
ðC 6Þ ðC 3Þ In order to look at different spatial frequencies, we con-
sider perturbations that are sinusoidal by considering ðC 6Þ f~pðx, tÞ, ~sðx, tÞg ¼ fpðtÞ eikx, sðtÞ eikxg:
ðC 4Þ ðC 4Þ This Jacobian can be validated against the simulation to
show it correctly approximates the behaviour of the system
close to the steady state. C.1. Linearization of the model without competition or
population growth Conflict of interest declaration. We declare we have no competing interests. Funding. All authors were supported by funding for the PhD of T.D.W. from the Leverhulme Trust Doctoral Scholarships programme,
Modelling and Analytics for a Sustainable Society (MASS, DS-2014-
024) at the University of Nottingham. P.-O.S. and D.R. were also Here, we show the linearization of _p, _s from equations (4.4)
and (4.6) for use in the Numerical continuation algorithm population density
people per hectare
0–68
68–369
369–932
932–1713
1713–3851
3851–196 149
0
200
400
600 km
0
100
200
300
400
500
displacement (km)
–0.1
0
0.1
0.2
Moran’s I
autocorrelation: Indiana/Kentucky/Ohio
100
200
300
400
500
wavelength (km)
0
0.5
1.0
1.5
2.0
2.5
amplitude
Fourier transform: north east USA
¥105
(a)
(b)
(c)
Figure 8. (a) Map of the population density of north east USA showing the areas analysed. Background mapping © Open street map contributors. (b) Correlogram
or Indiana/Kentucky/Ohio region showing length scale peaks at 200 km and 400 km. (c) Fourier transform of the line from Washington to Boston, giving a corre-
ponding wavelength of about 200 km. population density
people per hectare
0–68
68–369
369–932
932–1713
1713–3851
3851–196 149
0
200
400
600 km
(a) 100
200
300
400
500
wavelength (km)
0
0.5
1.0
1.5
2.0
2.5
amplitude
Fourier transform: north east USA
¥105
(c) 0
100
200
300
400
500
displacement (km)
–0.1
0
0.1
0.2
Moran’s I
autocorrelation: Indiana/Kentucky/Ohio
(b) (c) autocorrelation: Indiana/Kentucky/Ohio Downloaded from https://royalsocietypublishing.org/ on 05 May 20 Figure 8. (a) Map of the population density of north east USA showing the areas analysed. Background mapping © Open street map contributors. (b) Correlogram
for Indiana/Kentucky/Ohio region showing length scale peaks at 200 km and 400 km. (c) Fourier transform of the line from Washington to Boston, giving a corre-
sponding wavelength of about 200 km. Downloaded from https://royalsocietypubli that:
Fðw p12Þ ¼ Fðw p1ÞFðw p2Þ ¼ e2ðp2b2
p1 Þk2 e2ðp2b2
p2 Þk2 ¼
e2p2ðb2
p1 þb2
p2 Þk2. Thus w p12 is also a normalized Gaussian that:
Fðw p12Þ ¼ Fðw p1ÞFðw p2Þ ¼ e2ðp2b2
p1 Þk2 e2ðp2b2
p2 Þk2 ¼
e2p2ðb2
p1 þb2
p2 Þk2. Thus w p12 is also a normalized Gaussian and then obtaining the Jacobian used in the linear stability
analysis. We define and then obtaining the Jacobian used in the linear stability
analysis. C.1. Linearization of the model without competition or
population growth We will use the fact that the Fourier transform of a
Gaussian kernel, as defined in (4.9), is ^wðkÞ ¼ e2ðp2b2Þk2. This is also Gaussian and ^wð0Þ ¼ 1 for any β. It has a
maximum at k = 0 and 8k, 0 ^wðkÞ 1. Moreover,
we
define the kernel w p12 :¼ w p1 w p2. In the case that w p1
and w p2
are Gaussian, the convolution theorem gives C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 Here, we extend the linear analysis to the model with
services competing for space with population (α1 > 0) and
show that out of phase spatial instability is predicted
only if α1 > 0 and ^w p1ðkÞ , 0. This condition on the popu-
lation
location
preference
kernel
corresponds
to
the
population preferring to move to locations near to but some
preferred distance from services (ap > 0 in equation (6.1)). Downloaded from https://royalsocietypu Now assume that s0(1 −s0)/( p0σ0( p0)) + s0 < (1 −s0). Then
F(0) < G(0). However, limk→∞F(k) = s0(1 −s0)/( p0σ0( p0)) > 0
and limk→∞G(k) = 0. Therefore, there must be at least one
crossing point and hence a solution to det(J ) = 0. Conversely, if s0(1 −s0)/( p0σ0( p0)) + s0 > 1 −s0, we must
look at two cases. Including competition, the linearized dynamics close to
the spatially homogeneous steady state is given by Case 1: s0 > (1 −s0). For all k > 0, _p
_s
! ¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^wp2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þðs0ð p0Þ^wsðkÞ a1Þ
ð f þ gs0Þ
2
664
3
775
p
s
:
ðC 8Þ FðkÞ s0 ^ws . ð1 s0Þ^ws . ð1 s0Þ^ws ^w p1 ¼ GðkÞ: _p
_s
! ¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^wp2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þðs0ð p0Þ^wsðkÞ a1Þ
ð f þ gs0Þ
2
664
3
775
p
s
:
ðC 8Þ Therefore, FðkÞ = GðkÞ 8 k . 0. Therefore, FðkÞ = GðkÞ 8 k . 0. ! ¼
Ds0ð1 s0Þð1 ^w p2ðkÞÞ
Dp0ð1 ^wp2ðkÞÞ
ðð1 s0Þ^w p1ðkÞ s0Þ
ð f þ gs0Þðs0ð p0Þ^wsðkÞ a1Þ
ð f þ gs0Þ
2
664
3
775
p
s
:
ðC 8Þ ð Þ
ð Þ
Case
2:
s0 ≤(1 −s0). We
have
that
F(0) = s0(1 −s0)/
( p0σ0( p0)) + s0 > 1 −s0 = G(0). F0ðkÞ ¼ s0
d^ws
dk ð1 s0Þ d^ws
dk ð1 s0Þ dð^ws ^w p1Þ
dk
¼ G0ðkÞ: ðC 8Þ So we have that F0(k) > G0(k) and F(0) > G(0). Therefore,
these two functions are never equal and hence there is no sol-
ution to F(k) = G(k). C.1.1. Conditions for spatial instability Using the Jacobian from equation (5.5), also shown above in
equation (C 6), we wish to prove the following: processes (reaction and diffusion). However, this result
shows that, in our model, instabilities occur only if the
reaction of services to a change in population is sufficient. It is independent of the relative rates (figure 9). This indepen-
dence is largely due to the conservation of population (in the
first two model variations) which means that there is a zero
eigenvalue at frequency k=0 and instabilities occur in a
window [0, kc] rather than [k1, k2] as in a reaction–diffusion
equation. For Gaussian kernels, there are unstable frequencies if and
only
if
s0(1 −s0)/(p0σ0(p0)) + s0 < (1 −s0). If
this
holds,
then instability occurs in a window (0, kc) for some critical
frequency kc. 15 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 If the system is stable, then both eigenvalues of J will
have negative real part which is the case when trðJÞ and
detðJÞ . 0. We have that for the Fourier transform of a
Gaussian kernel, ^w 1. Moreover, s0 ≤1 and so tr(J ) < 0 for
all frequencies k. Therefore, we only need to look at the sign of detðJÞ which
can be rearranged as C.1.2. Dispersion relations for other parameters Figure 4a shows dispersion relations for the default set of par-
ameters as the total population p varies. Here, we show
dispersion relations for the other parameters in the model
illustrating how changing them modifies the predicted emer-
gent pattern. detðJðkÞÞ ¼ Dð1 ^w p2Þðf þ gs0Þp0s0ðp0Þ
s0ð1 s0Þ
p0s0ðp0Þ þ s0 ^ws ð1 s0Þ^ws ^w p1
:
ðC 7Þ ðC 7Þ We note that det(J(0)) = 0 and limk→∞det(J(k)) = D(f + gs0)
s0(1 −s0) > 0. Therefore, we look for a second zero of det(J(k)). If
a second solution to det(J ) = 0 exists at k = kc and no third sol-
ution exists, then det(J ) < 0 for k ∈(0, kc] and det(J ) > 0 for
k ∈(kc, ∞); that is, the steady state is unstable to perturbations
with wavelengths k ∈[0, kc). This gives some idea of the impact that uncertainty
about parameter values may have on model predictions. Overall, pattern formation is robust and predicted across a
wide range of parameters. On the other hand, the specific
wavelength of predicted patterns does vary with certain
key parameters as expected; parameters controlling length
scales of movement (b p1, b p2, bs) and feedback (μ) signifi-
cantly modulate wavelengths, whereas those affecting rates
of movement (D) and service growth (f, g) have a much
weaker effect. See figure 9. Downloaded from https://royalsocietypublishing.org/ on 05 May 2022 m https://royalsocietypublishing.org/ on 05 May 2022 In
order
to
analyse
det(J ),
we
first
define
FðkÞ ¼
s0ð1 s0Þ=ð p0s0ðp0ÞÞ þ s0 ^wsðkÞ,
GðkÞ ¼ ð1 s0Þ^w
sðkÞ^wp1ðkÞ. For k > 0, det(J(k)) = 0 iff F(k) −G(k) = 0. We claim that a non-
zero solution to F(k) = G(k) exists if and only if s0(1 −s0)/(p0σ0( p0-
)) + s0 < 1 −s0 and that if it exists, this solution is unique. Downloaded from https://royalsocietypublishing.org/ on 05 We will use the fact that ^wsðkÞ^w p1ðkÞ ¼ ep2k2ð1=bsþ1=b p1 Þ. From the shape of Gaussian functions, ^ws ^w p1 , ^ws 8 k . 0. Secondly,
^ws ^w p1
is
steeper
than
^ws. That
is
that
ðd=dkÞð^ws ^w p1Þ , ðd=dkÞ^ws , 0. C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 ðs0= p0Þð1 sðp0ÞÞ We note that in a typical reaction–diffusion equation,
Turing instabilities occur due to the interplay of the two –0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.05
0.10
0.15
0.20
0.25
dispersion relation:
population’s desired proximity to services
(a)
(b)
(c)
(d)
(e)
(f)
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
service catchment length scale
–0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.05
0.10
0.15
0.20
0.25
dispersion relation:
average move distance
dispersion relation:
service reaction to population change
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
(g)
0
0.05
0.10
0.15
0.20
0.25
growth rate
al part of leading eigenvalue)
dispersion relation:
rate of services innovators
dispersion relation:
rate of people moving home
dispersion relation:
rate of service followers
bp1 = 0.5
bp2 = 2
m = 1
m = 2
m = 3
m = 4
m = 5
bp2 = 5
bp2 = 10
bp2 = 20
bp2 = 50
D = 1
D = 2
D = 10
D = 20
f = 0.005
f = 0.05
f = 0.1
f = 1
g = 0.1
g = 1
g = 2
g = 10
g = 20
bp1 = 1
bp1 = 2
bs = 2
bs = 5
bs = 10
bp1 = 5 –0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.05
0.10
0.15
0.20
0.25
dispersion relation:
population’s desired proximity to services
(a)
growth rate
(real part of leading eigenvalue)
bp1 = 0.5
bp1 = 1
bp1 = 2
bp1 = 5 0
0.2
0.4
spatial frequency, k (km–1)
0.6
(b)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
service catchment length scale
bs = 2
bs = 5
bs = 10 (b) 16 (a) –0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
(c)
(d)
(e)
(f)
(real p
–0.05
0
(real p
–0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.05
0.10
0.15
0.20
0.25
dispersion relation:
average move distance
dispersion relation:
service reaction to population change
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
(g)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
rate of services innovators
dispersion relation:
rate of people moving home
dispersion relation:
rate of service followers
bp2 = 2
m = 1
m = 2
m = 3
m = 4
m = 5
bp2 = 5
bp2 = 10
bp2 = 20
bp2 = 50
D = 1
D = 2
D = 10
D = 20
f = 0.005
f = 0.05
f = 0.1
f = 1
g = 0.1
g = 1
g = 2
g = 10
g = 20
Figure 9. C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 Thus a second solution to det(J ) = 0 exists
if and only if s0(1 −s0)/( p0σ0( p0)) + s0 < 1 – s0. As previously, linear stability occurs when trðJðkÞÞ , 0
and detðJðkÞÞ . 0. For Gaussian ^w p2, the trace is negative
for all k and therefore there are instabilities occurring for
det(J(k)) < 0. Finally, we must show the solution is unique. Assume
that there is a solution to F(k) = G(k). This implies that
s0(1 −s0)/( p0σ0( p0)) + s0 < 1 −s0 and hence s0 < 1 −s0. Using
case 2 from above, F0ðkÞ . G0ðkÞ 8 k . 0. As the derivatives
are never equal, Rolle’s theorem shows that the solution
must be unique in the range k > 0. detðJðkÞÞ ¼ Dð1 ^w p2ðkÞÞðf þ gs0Þ
(s0ð1 s0Þ p0ðs0ðp0Þ^wsðkÞ a1Þðð1 s0Þ^w p1ðkÞ s0Þ)
ðC 9Þ ðC 9Þ detðJÞ 0 , s0ð1 s0Þ
p0ðs0ðp0Þ^wsðkÞ a1Þðð1 s0Þ^w p1ðkÞ s0Þ
ðC 10Þ
, s0
p0
ð1 sðp0ÞÞ þ s0s0ðp0Þ^wsðkÞ
ð1 s0Þðs0ðp0Þ^wsðkÞ a1Þ^w p1ðkÞ:
ðC 11Þ Thus we have showed that det(J ) > 0 for sufficiently large
k. Therefore, if there are no solutions to F(k) = G(k), then
det(J ) > 0 for all k > 0. A solution can occur if and only if
s0(1 −s0)/( p0σ0( p0)) + s0 < 1 −s0 and if it exists, this solution
is unique We have 1 −σ( p0) > 0 and, for Gaussian ws, ^ws . 0. This
means that the left-hand side is positive i.e. ðs0= p0Þð1 sðp0ÞÞ We have 1 −σ( p0) > 0 and, for Gaussian ws, ^ws . 0. This
means that the left-hand side is positive i.e. C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 Dispersion relations for the growth rate of spatial perturbations to a spatially homogeneous steady state in the conservative model for population and services
dynamics given in §4, for the indicated values of the parameters b p1, bs, b p2, m, D, f and g. For all length scales β, as they increase the length of pattern increases. Increasing b p1 and βs slows the rate of patterning whereas b p2 increases the speed of patterning. As shown in §5, small values of μ show stability to all frequencies. As μ increases, the instability emerges from the origin with long wavelengths (small k) and shifts to shorter wavelengths (larger k). The rates f, D and g will, as expected,
increase the growth rate of perturbations, but do not make any noteworthy change to the wavelength of the fastest growing mode or to the window of unstable frequencies. C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 (c)
–0.05
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.05
0.10
0.15
0.20
0.25
dispersion relation:
average move distance
growth rate
(real part of leading eigenvalue)
bp2 = 2
bp2 = 5
bp2 = 10
bp2 = 20
bp2 = 50 (d)
0
0.2
0.4
spatial frequency, k (km–1)
0.6
dispersion relation:
service reaction to population change
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
m = 1
m = 2
m = 3
m = 4
m = 5 (d) (c) (e)
(f)
p
q
y
(
)
p
q
y
(
)
0
0.2
0.4
spatial frequency, k (km–1)
0.6
0
0.2
0.4
spatial frequency, k (km–1)
0.6
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
rate of services innovators
dispersion relation:
rate of people moving home
D = 1
D = 2
D = 10
D = 20
f = 0.005
f = 0.05
f = 0.1
f = 1 (e)
0
0.2
0.4
spatial frequency, k (km–1)
0.6
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
rate of people moving home
D = 1
D = 2
D = 10
D = 20 (f)
0
0.2
0.4
spatial frequency, k (km–1)
0.6
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
rate of services innovators
f = 0.005
f = 0.05
f = 0.1
f = 1 (f) 0
0.2
0.4
spatial frequency, k (km–1)
0.6
(g)
–0.05
0
0.05
0.10
0.15
0.20
0.25
growth rate
(real part of leading eigenvalue)
dispersion relation:
rate of service followers
g = 0.1
g = 1
g = 2
g = 10
g = 20 (g) Figure 9. Dispersion relations for the growth rate of spatial perturbations to a spatially homogeneous steady state in the conservative model for population and services
dynamics given in §4, for the indicated values of the parameters b p1, bs, b p2, m, D, f and g. For all length scales β, as they increase the length of pattern increases. Increasing b p1 and βs slows the rate of patterning whereas b p2 increases the speed of patterning. the stability matrix In this section, we show that logistic growth will tend to be
stabilizing for smaller frequencies (longer wavelengths) but
destabilizing for larger frequencies if there is sufficient com-
petition. The Jacobian of the full model with competition
and logistic growth from equation (7.4) is Jðp0; s0; kÞ Jðp0; s0; kÞ
¼
Ds0ð1 s0Þð1 ^wp2ðkÞÞ rp0
c
Dp0ð1 ^wp2ðkÞÞ:
ðð1 s0Þ^wp1ðkÞ s0Þ
ra2p0
c
ðf þ gs0Þðs0ðp0Þ^wsðkÞ a1Þ
ðf þ gs0Þ
2
6666664
3
7777775
ðC 13Þ C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 As shown in §5, small values of μ show stability to all frequencies. As μ increases, the instability emerges from the origin with long wavelengths (small k) and shifts to shorter wavelengths (larger k). The rates f, D and g will, as expected,
increase the growth rate of perturbations, but do not make any noteworthy change to the wavelength of the fastest growing mode or to the window of unstable frequencies. –0.5
0
0.5
1.0
1.5
spatial frequency, k (km–1)
2.0
2.5
3.0
carrying capacity and
average population density
c = 5000; p0 = 5000
c = 13 426; p0 = 12 000
c = 37 389; p0 = 17 000
c = 73 317; p0 = 25 000
c = 81 578; p0 = 30 000
in-phase pattern
out-of-phase pattern
–0.4
–0.3
–0.2
growth rate
(real part of leading eigenvalue)
–0.1
0
0.1
Figure 10. Dispersion relations for the full model including logistic growth and competition for space. This figure is very similar in its trend to figure 5c. The most
notable difference is that there is no longer a zero eigenvalue at k = 0 corresponding to conservation of mass. –0.5
0
0.5
1.0
1.5
spatial frequency, k (km–1)
2.0
2.5
3.0
carrying capacity and
average population density
c = 5000; p0 = 5000
c = 13 426; p0 = 12 000
c = 37 389; p0 = 17 000
c = 73 317; p0 = 25 000
c = 81 578; p0 = 30 000
in-phase pattern
out-of-phase pattern
–0.4
–0.3
–0.2
growth rate
(real part of leading eigenvalue)
–0.1
0
0.1
re 10. Dispersion relations for the full model including logistic growth and competition for space. This figure is very similar in its trend to figure 5c. The most –0.5
0
0.5
1.0
1.5
spatial frequency, k (km–1)
2.0
2.5
3.0
carrying capacity and
average population density
c = 5000; p0 = 5000
c = 13 426; p0 = 12 000
c = 37 389; p0 = 17 000
c = 73 317; p0 = 25 000
c = 81 578; p0 = 30 000
in-phase pattern
out-of-phase pattern
–0.4
–0.3
–0.2
growth rate
(real part of leading eigenvalue)
–0.1
0
0.1 royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176
17 typublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 spatial frequency, k (km–1) ownloaded from https://royalsocietypublishing.org/ on 05 May 2022 Figure 10. C.2. Out-of-phase patterning requires α1 > 0 and ^w p1ðkÞ , 0 Dispersion relations for the full model including logistic growth and competition for space. This figure is very similar in its trend to figure 5c. The most
notable difference is that there is no longer a zero eigenvalue at k = 0 corresponding to conservation of mass. þs0s0ðp0Þ^ws . 0. For instabilities to occur the right-hand side
must be therefore also be positive. The factors ðs0ðp0Þ^ws a1Þ
and ^w p1 must at least have the same sign or else they will be
negative and this condition will not hold. frequency will become a stable mode and vice versa; if the
determinant becomes negative for some frequency, then
that mode will become unstable. The determinant detðJÞ
will increase if 1 þ a2ðs0ðp0Þ^ws a1Þ . 0, which will occur
for larger ^wsðkÞ which occurs at smaller frequencies. Notably,
the 0 frequency homogeneous solution will no longer give a
zero eigenvalue but will be stable at the steady state (as
shown in figure 10). This will also prevent the metastability
that we saw in previous model variants. Downloaded from https://royalsocietypublishing.org/ on 05 If an unstable eigenvalue, λ, occurs, then its correspond-
ing eigenvector will be l þ ðf þ gs0Þ
ðf þ gs0Þðs0ðp0Þ^wsðkÞ a1Þ
:
ðC 12Þ ðC 12Þ Downloaded from https://royalsocietypub Conversely, the determinant will decrease for some wave-
lengths if 1 −α1α2 < 0; that is if there is sufficient competition. This will occur for smaller values of ^wsðkÞ which are shorter
wavelength, typically out of phase, perturbations. As λ > 0 and (f + gs0) > 0, this vector can only be out-of-phase
if ðs0ðp0Þ^wsðkÞ a1Þ , 0. This occurs when there is sufficient
competition (a1 . s0ðp0Þ^wsðkÞÞ. As ^w p1ðkÞ must have the same sign as ðs0ðp0Þ^wsðkÞ a1Þ
for patterning to occur at all, we must have ^w p1ðkÞ , 0 as
well for out-of-phase spatial instability. C.3. Analysis of the effect of logistic growth and competition on
the stability matrix In order to generate figure 5a,b, we initiate a two ‘bump’ and
a three ‘bump’ solution with noise as can be seen in figure 11. To initialize these simulations, we begin with rectangular
bumps of length 40 that give total average population
16 000 pe km2. The two ‘bump’ solution has a peak of
40 000 pe km2 and the three bump has 26 000 pe km2. These are seeded with 100 cosine perturbations of modes 11
to 111, each of random size up to ±2% of the peak. If
needed, the total population is adjusted to ensure the average
is still 16 000 pe km2. ðC 13Þ Interface 19: 20220176
18 0
0.2
0.4
0.6
–100
–80
–60
–40
–20
0
20
40
60
80
distance (km) 0
1
2
3
4
5
6
–100
–80
–60
–40
–20
0
20
40
60
80
–100
–80
–60
–40
–20
0
20
40
60
80
0
0.2
0.4
0.6
distance (km)
distance (km)
service density
population density
×104
(b) Downloaded from https://royalsocietypubl Figure 11. Initial conditions that generated figure 5a,b, respectively. These two initial conditions both have the same total population. However, including com-
petition in the model, one simulation gives in phase patterns only whereas the other gives secondary out-of-phase patterning. London give r ¼ 0:056, 0:051 and 0:040 respectively. There-
fore, r = 0.05 seems a reasonable estimate for the intrinsic
growth rate. The model presented here has the potential to shed
further light on this in future work. For example, we show
in figure 7 a simulation in which the β parameters vary line-
arly over time, starting below and ending above their default
values in table 1 bp1 ¼ 0:5 þ 0:006t;
bs ¼ 1 þ 0:038t
bp2 ¼ 5 þ 0:08t:
ðF 1Þ Appendix F. Varying parameters temporally ðF 1Þ ðC 13Þ ðC 13Þ In this section, we wish to estimate the intrinsic growth rate,
r, in equation (7.1). To do this, we fit a simple, one dimen-
sional,
logistic
growth
model
of
the
form
dp/dt =
rp(1 −( p/c)) and fit for r, c and the initial condition p(1801). This is done using a process of minimizing the sum
of squares between the model output and the historic
data. These data are London and London borough census
data from 1801 to 2011 [41]. The results for London can be
seen in figure 12. The values for Inner, Outer and Greater Example dispersion relations can be seen in figure 10. As
in previous cases, the trace will still be negative. Assuming p0,
s0 remains unchanged (using equation (7.3)), detðJÞ ¼ detðJÞjr¼0 þ rp0ðf þ gs0Þ
c
(1 þ a2ðs0ðp0Þ^ws a1Þ): ðC 14Þ If the determinant increases such that it becomes positive for
some frequency k (and the trace is negative), then that 0
1
2
3
4
5
6
0
0.2
0.4
0.6
–100
–80
–60
–40
–20
0
20
40
60
80
–100
–80
–60
–40
–20
0
20
40
60
80
distance (km)
service density
population density
×104
(a) 0
1
2
3
4
5
6
0
0.2
0.4
0.6
0
1
2
3
4
5
6
–100
–80
–60
–40
–20
0
20
40
60
80
–100
–80
–60
–40
–20
0
20
40
60
80
–100
–80
–60
–40
–20
0
20
40
60
80
–100
–80
–60
–40
–20
0
20
40
60
80
0
0.2
0.4
0.6
distance (km)
distance (km)
service density
service density
population density
population density
×104
×104
(b)
(a)
ditions that generated figure 5a,b, respectively. These two initial conditions both have the same total population. However, including com-
one simulation gives in phase patterns only whereas the other gives secondary out-of-phase patterning. 0
1
2
3
4
5
6
–100
–80
–60
–40
–20
0
20
40
60
80
service density
population density
×104
(a) royalsocietypublishing.org/journal/rsif
J. R. Soc. and In this paper, we have made the simplifying assumption that
the parameters used are static over time. This assumption is
necessary in order to make the mathematical analysis of the
steady states possible. However, we acknowledge that there
will have been many transitions between regimes over time,
especially with the advancement of technology. For example,
Borchert [42] identifies five epochs from sail-wagons (ca 1800)
to the modern technological epoch. For simplicity, we assume there is no competition or
growth; that is r = ap = α1 = 0. This simulation shows how
increasing typical travel distances over time leads to exagger-
ated agglomeration. Of course, growth, competition and
other factors may complicate this further but this brief
example shows something of the effect of socio-technological
developments. and 1800
1900
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2000
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1800
1900
2000
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2000
1800
1900
2000
1800
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2000
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1900
2000
1800
1900
2000
1800
1900
2000
0
1
2
0
1
2
0
2
4
0
1
2
0
1
2
3
0
1
2
3
1
2
3
4
0
2
4
0
2
4
0
1
2
3
0
1
2
3
0
2
4
0
1
2
3
0
1
2
3
0
1
2
0
1
2
3
0
1
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0
1
2
3
0
2
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0
1
2
3
0
5
10
15
0
2
4
0
2
4
0
1
2
0
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0
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3
0
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2
0
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6
0
1
2
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6
0
1
2
3
0
2
4
2
4
6
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1850
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2000
2050
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1850
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2050
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1850
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2050
0
1
2
3
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6
0
1
2
3
4
5
0
2
4
6
8
10
historical data
fitted estimate
year
year
year
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
population
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
year
×106
×106
× 106
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×105
×105
×105
×105
Inner london
Outer london
Greater london
City of london
Barking... Barnet
Baxley
Brent
Bromley
Camden
Croydon
Ealing
Enfield
Greenwich
hackney
Hounslow
Hillingdon
Havering
Harrow
Haringey
Hammersmith... Islington
Kensington... Kingstion... Lambeth
Lewisham
merton
Tower H
Sutton
Richmond... and li
i
i
i
b h
i h 1800
1900
2000
0
1
2
3
population
year
×105
Hillingdon 1800
1900
2000
0
1
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3
population
year
×105
Hounslow 1800
1900
2000
0
1
2
population
year
×105
merton 1800
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1900
2000
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15
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4
population
population
population
population
population
year
year
year
year
year
×105
×105
×105
×105
×105
Islington
Kensington... Kingstion... Lambeth
Lewisham 1800
1900
2000
1800
1900
2000
0
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4
0
1
2
population
population
year
year
×105
×105
Lewisham
merton 1800
1900
2000
0
2
4
p p
l ti
year
×105
Lewisham Downloaded from https://royalsocietypubli 1800
1900
2000
1800
1900
2000
0
1
2
2
4
6
popu at o
population
year
year
×105
×105
Tower H
Sutton 1800
1900
2000
0
2
4
6
population
year
×105
Southmark 00
1800
1900
2000
1800
1900
2000
0
1
2
3
0
1
2
population
population
year
year
×105
×105
Richmond... Redbridge 1900
2000
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2000
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1900
2000
1800
1900
0
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0
1
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0
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population
population
population
year
year
year
year
×105
×105
×105
Richmond... Southmark
Redbridge
Newham population 1800
1900
2000
0
1
2
3
population
year
×105
Waltham f 1800
1900
2000
0
2
4
population
year
×105
Andsworth 1800
1900
2000
2
4
6
population
year
×105
Westminster Figure 12. Graphs showing population data for London with the logistic growth model fitted. and Southmark
Redbridge
Newham
Waltham f
Andsworth
Westminster
gure 12. Graphs showing population data for London with the logistic growth model fitted. 1800
1850
1900
1950
2000
2050
0
1
2
3
4
5
year
population
×106
Outer london 1800
1850
1900
1950
2000
2050
0
1
2
3
4
5
6
year
population
×106
Inner london 1800
1850
1900
1950
2000
2050
0
2
4
6
8
10
historical data
fitted estimate
year
population
× 106
Greater london royalsocietypublishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176
19 19 blishing.org/journal/rsif
J. R. Soc. Interface 19: 20220176 1800
1900
2000
0
1
2
3
year
×105
Brent 1900
2000
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1900
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1900
2000
1800
1900
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population
population
population
year
year
year
year
year
5
×105
×105
×105
×105
5
5
5
5
5
City of london
Barking... Barnet
Baxley
Brent
C
d
C
d
E li
E fi ld
G
i h 1800
1900
2000
1800
1900
2000
0
1
2
0
2
4
population
population
population
year
year
×105
×105
Barking... Barnet 1800
1900
2000
0
1
2
3
population
year
×105
Bromley 1800
1900
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1800
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year
×105
×105
×105
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Camden
Croydon
Ealing
E 1800
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population
year
year
×105
Greenwich 00
1900
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population
population
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population
y
y
y
y
y
year
year
year
year
year
×105
×105
×105
×105
×105
×105
Camden
Croydon
Ealing
Enfield
Greenwich 1800
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population
y
year
×105
hackney Downloaded from https://royalsocietypublishing.org/ on 05 May 20 800
1900
2000
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1800
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population
population
population
population
population
year
year
year
year
year
×105
×105
×105
×105
×105
×105
5
5
5
5
5
5
Hillingdon
Havering
Harrow
Haringey
Hammersmith... References 1. United Nations. 2014 World urbanization
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https://openalex.org/W4390713832
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https://www.degruyter.com/document/doi/10.1515/med-2023-0865/pdf
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English
| null |
Diagnostic and prognostic value of MR-pro ADM, procalcitonin, and copeptin in sepsis
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Open Medicine
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cc-by
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Open Medicine 2023; 18: 20230865 Diagnostic and prognostic value of MR-pro ADM,
procalcitonin, and copeptin in sepsis https://doi.org/10.1515/med-2023-0865
received May 4, 2023; accepted November 5, 2023 and copeptin may be useful in the prognosis of sepsis and to
predict the length of stay in hospital and mortality. https://doi.org/10.1515/med-2023-0865
received May 4, 2023; accepted November 5, 2023 Abstract: Sepsis is defined as life-threatening organ dys-
function caused by a dysregulated host response to infec-
tion. There is a need for biomarkers that can be used for
the diagnosis of sepsis and the early identification of
patients at high risk of death. In this study, we aimed to
investigate the relationship between Mid-regional pro-
adrenomedullin (MR-proADM), procalcitonin (PCT), and
copeptin in sepsis. A total of 28 sepsis, 32 septic shock,
and 30 control patients were included in our prospective
study. Patients’ MR-proADM, PCT, and copeptin levels were
recorded. Sequential organ failure assessment scores, length
of hospital stay, and 30-day mortality were also recorded. These values were compared between the sepsis, septic
shock, and control groups. The mean age of all participants
was 64.04 ± 15.83 years. In the study, 37 (61.6%) patients were
female and 23 (39.3%) were male. There was no statistically
significant difference in gender/age between all patient
groups and the control group (for all, p > 0.05). We found
a significant difference between the survivors and nonsur-
vivors in terms of MR-proADM, PCT, and copeptin levels. There was a significant difference between the sepsis and
septic shock groups in terms of MR-proADM and PCT. A
significant correlation was found between the length of hos-
pital stay and MR-proADM and copeptin. MR-proADM, PCT, Keywords: sepsis, MR-proADM, copeptin, procalcitonin This work is licensed under the Creative Commons Attribution 4.0 International License. or(s), published by De Gruyter.
This work is licensed under the Creative Commons Attribution 4.0 International License. Basar Cander: Department of Emergency Medicine, Bezmialem Vakif
University, Istanbul, Turkey
Emin Fatih Visneci: Department of Emergency Medicine, Konya City
Hospital, Konya, Türkiye, e-mail: drfatihvisneci@hotmail.com
Osman Karaoglan: Department of Emergency Medicine, Konya Numune
Hospital, Konya, Turkey
Fatma Cakmak: Department of Emergency Medicine, Erzurum City
Hospital, Erzurum, Türkiye, e-mail: dr.fatmacak@gmail.com
Alpay Tuncar: Department of Emergency Medicine, Diskapi Yildirim
Beyazit Training and Research Hospital, Ankara, Turkey
* Corresponding author: Bahadir Taslidere, Department of
Emergency Medicine, Bezmialem Vakif University, Istanbul, Turkey,
e-mail: drbahadir@yahoo.com
ORCID: Emin Fatih Visneci 0000-0001-8050-4433; Fatma Cakmak 0000-
0002-5770-3554 Open Access. © 2023 the author(s), published by De Gruyter.
This work is lice 2.2 Biochemical analysis Blood samples were obtained from all recruited patients
within 24 h of presentation to the hospital by an indwelling
arterial or venous catheter (if available) or by venipuncture. Patients with septic shock also had blood drawn every 24 h
up to 120 h after admission. After the patients were diag-
nosed with sepsis or septic shock (a blood sample was taken
before giving antibiotics), 3 cc peripheral venous blood was
taken into tubes (with ethylenediaminetetraacetic acid
[EDTA]). Blood samples were centrifuged (3,000 rpm for
10 min) within the first hour after collection and stored at
−80°C. The same procedure was applied in the control
group. MR-proADM was measured in EDTA-K2 plasma sam-
ples using the BRAHMS Kryptor Compact Plus method
(Hennigsdorf, Germany). Copeptin was evaluated by Time-
Resolved Amplified Cryptate Emission on the ultra-sensitive
Kryptor compact Plus (Henningsdorf, Germany). PCT levels
in serum were measured using reagents from Thermo
Fisher Scientific. 2.3 Statistical analysis MR-proADM, PCT, and Copeptin values of the patient and
control groups were compared. MR-proADM, PCT, and
Copeptin values were compared in both patient groups
(p-value 1, 2, 3). Data obtained in the study were statistically
analyzed using the Statistical Package for Social Sciences
software. Data were expressed as frequency (n), percen-
tage (%), and mean ± standard deviation. The comparison
of the distribution of categorical data was carried out with
the “Chi-square (χ2) test”. The normality of the continuous
variables was evaluated using the Kolmogorov–Smirnov
test. The comparison of normally distributed parameters
between more than two groups was made using a one-way
analysis of variance. The comparison of non-normally
distributed parameters between the two groups was per-
formed with the Mann–Whitney U test, and the compar-
ison between more than two groups was performed with
the Kruskal–Wally’s test. Correlations between the para-
meters were examined using Spearman’s analysis. p <
0.05 values were considered statistically significant. A receptor
operating characteristic (ROC) curve analysis was applied for
biomarkers. Ethics committee approval was obtained. The study was
carried out in accordance with the Declaration of Helsinki. 2 and shock, and this increase shows that AVP release is
increased and has diagnostic and prognostic value [14]. There is no gold standard method as a biochemical marker
in the diagnosis and prognosis of sepsis. However, it is impor-
tant to make a rapid diagnosis and start treatment early. In
this study, we aimed to investigate the diagnostic and prog-
nostic values of MR-proADM, PCT, and copeptin in sepsis. discharged patients was learned by following the new
admissions to the hospital and by telephone on the 30th
day. Following data collection, two emergency attending
physicians independently reviewed the medical records 2 Materials and methods This is a single-center, prospective controlled study of
sepsis patients visiting the Emergency Department (a tertiary
care teaching hospital). A consecutive sampling method
was used. This research was carried out between 01/12/
2017 and 01/06/2018. Patients were selected according to
the International Sepsis Conference criteria [1]. The criteria
for inclusion were the fulfillment of two of four criteria for
the systemic inflammatory response syndrome (fever or
hypothermia, tachycardia, tachypnea, and leukocytosis or
leucopenia) and systolic blood pressure no higher than
90 mm Hg (after a crystalloid-fluid challenge). Necessary
consent was obtained from the patients and control group. Those who did not want to contribute to the conduct of the
study were excluded from the study. Exclusion criteria were
those under 18 years of age, pregnant women, stroke, myo-
cardial infarction, pulmonary edema, seizure, trauma, need
for emergency surgery, cancer, non-bacterial pneumonia,
etc. Patients who were similar in age and gender and had
no signs of infection were selected as the control group. A
total of 28 sepsis, 32 septic shock, and 30 control patients
were included in our study over a six-month period. The
control group was compared with both patient groups
(sepsis and septic shock) separately. The patient group was
identified, and cases were randomly selected according to
specific inclusion criteria. 1 Introduction Sepsis is defined as life-threatening organ dysfunction
caused by a dysregulated host response to an infection
[1–3]. Septic shock is the last and most severe stage of
sepsis. The mortality rate is about 50–60% [4,5]. None of
the clinical signs and symptoms traditionally used in the
diagnosis of sepsis and laboratory findings are unique to
sepsis. Therefore, there is a need for biomarkers that can
be used for the diagnosis of sepsis and the early identifica-
tion of patients [6,7]. Mid-regional pro-adrenomedullin (MR-proADM), the
middle part of pro-adrenomedullin, consists of 45–92
amino acids and directly reflects plasma adrenomedullin
(ADM) levels [8]. Circulating levels of bioactive adreno-
medullin (BioADM) can be measured using new tech-
nology and indicate vascular dysfunction occurring in
sepsis. In this way, physiopathological deterioration in
sepsis can be detected and progression to septic shock
can be predicted [9]. ADM levels increase in sepsis, and
MR-proADM has recently been shown to be a helpful
prognostic tool in risk stratification in sepsis [10]. Procalcitonin (PCT) may aid in the diagnosis and man-
agement of patients. PCT is a useful biomarker in severe
bacterial infection. The sensitivity of PCT in sepsis ranges
from 42 to 97%, and the specificity ranges from 48 to
100% [7]. Basar Cander: Department of Emergency Medicine, Bezmialem Vakif
University, Istanbul, Turkey
Emin Fatih Visneci: Department of Emergency Medicine, Konya City
Hospital, Konya, Türkiye, e-mail: drfatihvisneci@hotmail.com
Osman Karaoglan: Department of Emergency Medicine, Konya Numune
Hospital, Konya, Turkey
Fatma Cakmak: Department of Emergency Medicine, Erzurum City
Hospital, Erzurum, Türkiye, e-mail: dr.fatmacak@gmail.com
Alpay Tuncar: Department of Emergency Medicine, Diskapi Yildirim
Beyazit Training and Research Hospital, Ankara, Turkey
* Corresponding author: Bahadir Taslidere, Department of
Emergency Medicine, Bezmialem Vakif University, Istanbul, Turkey,
e-mail: drbahadir@yahoo.com
ORCID: Emin Fatih Visneci 0000-0001-8050-4433; Fatma Cakmak 0000-
0002-5770-3554 Arginine vasopressin (AVP) is one of the most impor-
tant hypothalamic stress hormones [11]. Copeptin is the C-terminal part of the prohormone of
AVP or antidiuretic hormone [12]. Measurement of AVP is
not commonly carried out in clinical practice. In contrast,
copeptin can be immunologically tested with ease [13]. Copeptin increases rapidly in the plasma in conditions
such as cardiovascular diseases, ischemic stroke, sepsis, Open Access. © 2023 the author(s), published by De Gruyter. This work is licensed under the Creative Co 2
Basar Cander et al. 3 Results the sepsis and septic shock groups (p = 0.02, p < 0.01, p =
0.04, respectively) (Table 2). The mean age of all participants was 64.04 ± 15.83 years. The mean age of all participants was 64.04 ± 15.83 years. The mean age of the sepsis group was 63.5 ± 16.11 years, the
septic shock group was 64.1 ± 14.3 years, and the control
group was 64 ± 15.34 years. There were 37 females (61.6%)
and 23 males (39.3%) in the patient group, and 17 females
(56.7%) and 13 males (43.3%) in the control group. There
was no statistically significant difference in gender/age
between all patient groups and the control group (for all,
p > 0.05) (Table 1). There was no significant difference between the sepsis
and septic shock groups in terms of mean PCT value (p >
0.05). However, a statistically significant difference was
found between the sepsis and control groups and between
the septic shock and control groups (p = 0.05, p < 0.01,
respectively) (Table 2). When the mean copeptin values were evaluated; there
was no significant difference between the sepsis, septic
shock, and control groups in terms of the mean copeptin
values (for all, p > 0.05) (Table 2). When the correlation between mortality and biomar-
kers was evaluated, 32 of our patients were alive and 28
died. The mean MR-proADM value of the patients who
survived was 3 nmol/L and the mean MR-proADM value
of the patients who died was 5.12 nmol/L. There was a
significant difference between the MR-proADM values of
the patients who survived and nonsurvivors (p < 0.05). The
mean PCT value of the patients who survived was 1.82 ng/mL
and the mean PCT value of the patients who died was
13.85 ng/mL. There was a significant difference between
the PCT values of the patients who survived and nonsurvi-
vors (p < 0.05). The mean copeptin value of the patients who
survived was 73 pmol/L and the mean copeptin value of the
patients who died was 142 pmol/L. There was a significant
difference between the copeptin values of the patients who
survived and nonsurvivors (p < 0.05) (Table 3). 2.1 Data collection Patients’ demographic data were recorded when they were
admitted to the emergency. Vital parameters (blood pres-
sure, fever, pulse) and laboratory results (white blood cell,
hemoglobin, hematocrit, platelet, urine output, urea, crea-
tinine, sodium, potassium, total bilirubin, blood gas) were
recorded on the forms. Sequential organ failure assessment
(SOFA) scores of the patients were calculated. Length of
hospital stay and 28-day mortality were recorded for the
sepsis and septic shock groups. The mortality status of the Biomarkers in sepsis 3 3 Results Considering
the correlation of hospital stays with biomarkers; a signifi-
cant correlation was found between the MR-proADM and When the patients with sepsis were examined in terms
of the infection focus, lung-based infection was observed,
26 (43.39%), urinary tract infection, 16 (26.6%), soft tissue
infection, 10 (16.6%), intra-abdominal infection, 4 (6.6%),
central nervous system infection, 3 (5%), and cardiac infec-
tion, 1 (1.6%). When the mean MR-proADM values were evaluated;
there were significant differences between the sepsis and
control groups, the septic shock and control groups, and Table 1: Demographic, laboratory, and comorbidity
Sepsis
(n = 28)
Septic
shock
(n = 32)
Control
(n = 30)
Age
Year
63.58
± 13.9
64.06
± 10.32
64.04
± 15.83
PCT
ng/mL
1.01 ± 4.11
15 ± 52.04
0.53 ± 3.73
MR-proADM
nmol/L
2.19 ± 2.60
3.70 ± 8.90
1.07 ± 2.50
Copeptin
pmol/L
67.5 ± 42.6
126 ± 245
51 ± 188
Gender
Female,
n (%)
37 (61.6)
17 (56.7)
Male, n (%)
23 (39.3)
13 (43.3)
DM
n (%)
15 (25)
3 (10)
HT
n (%)
12 (20)
5 (16.6)
COPD
n (%)
6 (10)
4 (13)
Malignancy
n (%)
20 (33)
7 (23)
CAD
n (%)
5 (8.3)
3 (10)
Other
n (%)
6 (10)
4 (13)
DM = diabetes mellitus, HT = hypertension, COPD = chronic obstructive
pulmonary disease, CAD = coronary artery disease. Table 1: Demographic, laboratory, and comorbidity Table 3: The relationship between mortality and biomarkers
M value
p-value
PCT
A
1.82 ± 24.21 ng/mL
<0.05
B
13.85 ± 51.43 ng/mL
MR-proADM
A
3 nmol/L
<0.05
B
5.12 nmol/L
Copeptin
A
73 pmol/L
<0.05
B
142 pmol/L
A = survivors, B = non-survivors, and M = median. Table 3: The relationship between mortality and biomarkers DM = diabetes mellitus, HT = hypertension, COPD = chronic obstructive
pulmonary disease, CAD = coronary artery disease. Table 2: Mean MR-proADM and PCT values of the groups
Sepsis (n = 28)
Septic shock (n = 32)
Control (n = 30)
p1
p2
p3
MR-proADM
4.8 ± 7.7
7.2 ± 7.1
2.1 ± 2.5
0.04
0.02
<0.01
PCT
10.6 ± 25.6
15.5 ± 34.6
1.6 ± 3.7
>0.05
0.01
<0.01
Copeptin
67.5 ± 42.6
126 ± 245
51 ± 188
>0.05
>0.05
>0.05
p1 values = between sepsis and septic shock, p2 = between sepsis and control group, and p3 = between septic shock and control group. 4
Basar Cander et al. 4
Basar Cander et al. Table 4: Correlation of biomarkers with the length of stay in hospital
Biomarker
r
p-value
MR-proADM
0.403
<0.01
PCT
0.202
>0.05
Copeptin
0.398
<0.01
r = correlation coefficient (among all patients). r = correlation coefficient (among all patients). copeptin and the length of stay in hospital (both, p < 0.05)
(Table 4). Significant correlations were found between the
mean MR-proADM, PCT, and calcitonin levels and SOFA
scores. The sensitivity, specificity, positive predictive value
(PPV), AUC, and negative predictive value (NPV) of the
biomarkers examined in this study are given in Table 5. The data obtained are described in Figure 1 with the ROC
curve. Figure 1: ROC curves. BioADM is a biomarker, which has been used for vas-
cular and endothelial function and utility in sepsis [20]. We
found that significant differences were found between the
sepsis and septic shock groups and the control group in
terms of MR-pro-ADM, and we were able to predict the
prognosis, mortality, and length of stay in hospital using
MR-pro-ADM. 4 Discussion According to the latest guidelines, treatment for sepsis
should be individualized, and biomarkers should be used
to tailor therapy to each patient’s needs [15,16]. Sepsis is a
disease with high mortality and morbidity, and treatment
should be initiated quickly. There is a need for an inexpen-
sive, easily obtainable biomarker with high sensitivity and
specificity in sepsis. Peptides are not just markers, peptides
can also serve as mediators. Therefore, usage areas may
differ [17,18]. In a study by Lai et al., the most common
bacterial infection was pneumonia (40.2%) followed by
bacteremia and urinary tract infections (23.5%), intra-
abdominal infections (16.2%), and skin and soft tissue infec-
tions (14.2%) [19]. Similarly, in our study, the most common
infection was pneumonia followed by urinary tract infec-
tion, soft tissue infection, and intra-abdominal infection. We think that this may be due to the increased incidence
of ventilator-associated pneumonia due to the more fre-
quent use of mechanical ventilators in patients followed
up in the intensive care unit in recent years. Gille et al. evaluated copeptin levels in sepsis after
burn injury and found no significant difference between
patients with and without sepsis [21]. One study reported
that Copeptin levels were higher than survivors in non-
surfing [7]. In our study, in line with the literature, no
statistically significant difference was found between the
patients with sepsis or septic shock, and the control group,
in terms of the levels of copeptin, which is released in
equal amounts with AVP and is a more stable molecule
in the blood. However, there was a significant difference
between survivors and nonsurvivors. In a recent review by Di Somma and Crisanti with 773
patients investigating biomarkers in the management of
sepsis, the median PCT value was found to be significantly
higher in patients with culture-positive sepsis than in those
with culture-negative sepsis [9]. In our study, there were Table 5: Sensitivity, specificity PPV, and NPV of biomarkers in all patients
Biomarker
Sen. (%)
Spe. (%)
PPV (%)
NPV (%)
AUC
Cut-off
MR-proADM
100
16.60
70
100
504
0.55 nmol/L
PCT
91.30
50
78.50
75
793
0.5 ng/mL
Copeptin
93
20
70
60
558
19 pmol/L
NPV = negative predictive value, PPV = positive predictive value, Sen = sensitivity, Spe = specificity. 3 Results Table 2: Mean MR-proADM and PCT values of the groups p1 values = between sepsis and septic shock, p2 = between sepsis and control group, and p3 = between septic shock and control group. Figure 1: ROC curves. 4
Basar Cander et al. 4 Discussion Table 5: Sensitivity, specificity PPV, and NPV of biomarkers in all patients NPV = negative predictive value, PPV = positive predictive value, Sen = sensitivity, Spe = specificity. Biomarkers in sepsis 5 significant differences between sepsis, septic shock, and
control groups regarding PCT values. [24]. In our study, SOFA scores were significantly correlated
with the mean MR-pro ADM, PCT, and copeptin values, con-
sistently with the literature [25,26]. In a study by Novotny et al., the sepsis-related mor-
tality rate was 36%. PCT levels of nonsurvivors were found
to be significantly higher than survivors. The authors con-
cluded that PCT levels are an independent predictor of
mortality in patients with sepsis [22]. In our study, we
found a 30-day mortality rate of 46.6%. MR-proADM, PCT,
and copeptin levels were compared between the patients
who survived and nonsurvivors. Consistently with the lit-
erature, we found a significant difference between the sur-
vivors and nonsurvivors in terms of MR-proADM values. In
addition, statistically significant differences were found
between the survivors and nonsurvivors in terms of PCT
and copeptin values. In the present study, we found a sig-
nificant difference between the sepsis and septic shock
groups in PCT. In light of these findings, we think that
critical patients with high MR-proADM, PCT, and copeptin
values have a higher mortality rate and these patients
should be followed more closely. We think that these mar-
kers can be used to determine mortality. In a study by Tsangaris et al., PCT concentration was
1.00 mg/L in sepsis patients and 0.18 mg/L in the controls. When the upper cut-offvalue for PCT was determined as
1.00 ng/mL, the sensitivity was 70%, specificity 91%, PPV
90%, and NPV 72% for patients with sepsis [27]. In our
study, when the cut-offvalue for PCT was taken as 0.5 ng/mL,
the sensitivity of PCT for the diagnosis of sepsis was 91.3%,
specificity 50%, PPV 78.5%, and NPV 75%. When the cut-off
value for copeptin was taken as 19 pmol/L, the sensitivity of
copeptin for the diagnosis of sepsis was 93%, specificity 20%,
PPV 70%, and NPV 60%. When the cut-offvalue for MR-
proADM was taken as 0.55 nmol/L, the sensitivity of MR-
proADM for the diagnosis of sepsis was 100%, specificity
16.6%, PPV 70%, and NPV 100%. In our study, although the
sensitivity of copeptin and MR-proADM was high, the speci-
ficity was low. 5 Study limitations In a study by Schneider et al. including 220 patients
with sepsis, the median length of stay in the intensive care
unit was found as 13 (4–95) days in the survivors. The
median PCT values measured on the first postoperative
day were found to be significantly higher in patients who
died than in those who survived. In the same study, it was
emphasized that there was a significant correlation
between high PCT concentrations and prolonged hos-
pital stay [23]. We think that copeptin and MR-proADM values of the
patients in the control group may have been measured to
be high since it is still not known precisely in which
comorbid diseases copeptin and MR-proADM values
increase. In our study, when the correlation between the length
of hospital stay and PCT, copeptin, and MR-proADM was
examined, no significant correlation was found between
PCT and hospitalization time, unlike the literature. A
significant correlation was found between the length
of hospital stay and MR-pro ADM and copeptin. Both
acute physiology and SOFA scores are widely used in
critically ill patients [22]. In our study, SOFA scores
were significantly correlated with the mean MR-pro
ADM, PCT, and copeptin values, consistently with the
literature [25,26]. 6 Conclusion A significant difference was found between copeptin, PCT,
and MR-proADM values in surviving and non-surviving
sepsis patients. A significant correlation was found between
MR-proADM and copeptin and length of hospital stay. We
think that MR-proADM, PCT, and copeptin may be used in
predicting the prognosis of patients with sepsis, mortality,
and length of stay in the hospital. Because of the complexity
of the sepsis response, a single biomarker is unlikely to be
sufficient. With its ability to respond quickly to clinical con-
ditions, copeptin, PCT, and MR-proADM can be used for
treatment follow-up and early diagnosis. In a study by Schneider et al., the median length of stay
in the intensive care unit was 13 (4–95) days for the survi-
vors [23]. In our study, when the correlation between the
length of hospital stays and PCT, copeptin, and MR-proADM
were examined, no significant correlation was found
between PCT and hospitalization time, unlike the literature
(p > 0.05). A significant correlation was found between the
length of hospital stay and MR-pro ADM and copeptin (p <
0.05). SOFA scores are widely used to predict the outcome
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Panteghini M. Plasma mid regional pro adrenomedullin (MR-
proADM) concentrations and their biological determinants in a
reference population. Clin Chem Lab Med. 2018;56(7):1161–8. [25] Haag E, Gregoriano C, Molitor A, Kloter M, Kutz A, Mueller B, et al. Does mid-regional pro-adrenomedullin (MR-proADM) improve the
sequential organ failure assessment-score (SOFA score) for mor-
tality-prediction in patients with acute infections? Results of a
prospective observational study. Clin Chem Lab Med. 2021;59(6):1165–76. [9]
Di Somma S, Crisanti L. Can Acute Care Biomarkers Change
Patient’s Management in Sepsis? Eurasian. J Emerg Med. 2022;21(2):79–85. [26] Jiang L, Feng B, Gao D, Zhang Y. Plasma concentrations of copeptin,
C-reactive protein and procalcitonin are positively correlated with
APACHE II scores in patients with sepsis. J Int Med Res. 2015;43(2):188–95. [10]
Önal U, Valenzuela-Sánchez F, Vandana KE, Rello J. Mid-Regional
pro-adrenomedullin (MR-proADM) as a biomarker for Sepsis and
septic shock: narrative review. Healthcare (Basel). 2018;6(3):110. [11]
Katan M, Morgenthaler N, Widmer I, Puder JJ, Konig C, Muller B,
et al. Copeptin, a stable peptide derived from the vasopressin
precursor, correlates with the individual stress level. Neuro
Endocrinol Lett. 2008;29:341–6. [27]
Tsangaris I, Plachouras D, Kavatha D, Gourgoulis GM, Tsantes A,
Kopterides P, et al. Diagnostic and prognostic value of procalci-
tonin among febrile critically ill patients with prolonged ICU stay. BMC Infect Dis. 2009;9:213. [12]
Roussel R, Fezeu L, Marre M, Velho G, Fumeron F, Jungers P, et al. Comparison between copeptin and vasopressin in a population
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“Red Tomatoes” by B. Chichibabin: the poet’s path and the possibilities of the poem
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Vìsnik Harkìvsʹkogo nacìonalʹnogo unìversitetu ìmenì V.N. Karazìna. Serìâ Fìlologìâ
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доктор филологических наук, профессор кафедры истории русской литературы,
Харьковский национальный университет имени В. Н. Каразина;
e-mail: shekhovt2@gmail.com; https://orcid.org/0000-0002-6270-6549 доктор филологических наук, профессор кафедры истории русской литературы,
Харьковский национальный университет имени В. Н. Каразина;
e-mail: shekhovt2@gmail.com; https://orcid.org/0000-0002-6270-6549 В статье проведен целостный семантический, поэтологический и контекстуальный анализ стихотворения русского поэта
Бориса Чичибабина «Кончусь, останусь жив ли…» («Красные помидоры») с учетом дискуссионных моментов
существующих интерпретаций. Уточнено значение этого произведения в личностном и творческом становлении поэта. Дополнена трактовка центрального символического образа стихотворения «красные помидоры» и предложен реальный
комментарий к нему. Охарактеризованы архетипические, фольклорные и литературные претексты стихотворения. Прокомментировано соотношение внешнего, событийно-биографического, и лирического сюжетов. Прослежена
семантическая нагрузка всех формальных компонентов стиха – композиции, строфики, фоники, метрики. Показано, что
поэтическая конструкция оказывается едва ли не единственной опорой в разорванном, враждебном мире, где оказался
узник, при этом наряду с классической строфикой поэт использует неклассическую метрику – размытый трехиктный
дольник, демонстрируя возможности «свободного» стиха. Выявлены точки соприкосновения стихотворения Чичибабина с «семантической поэтикой», созданной О. Мандельштамом
и А. Ахматовой (понимание связи истории и человека, проникновение творчества в жизнь, превращение слова в дело,
соотнесенность стихотворения с реальной ситуацией, прозаизация стиха, сочетание обобщенно-философского и
конкретно-чувственного и т. д.). Прозаизация стиха проявляется во введении сюжетных элементов, скрытой диалогизации,
использовании разговорных интонаций, игре временами, кинематографичности. р
р
ц
р
р
р ф
Автор статьи приходит к выводу, что стихотворение молодого поэта становится свидетельством не просто ранней
творческой зрелости, но и особой поэтической интуиции: обнаруживая повышенную семантизацию всех элементов стиха и
реализацию перформативных возможностей поэтического высказывания, чичибабинский текст соотносится с
перспективными художественными открытиями постсимволистской эпохи. р
уд
р
Ключевые
слова:
Чичибабин,
образ-символ,
семантика,
поэтика,
контекст,
реальный
комментарий,
«семантическая поэтика» Шеховцова Т. А. «Червоні помідори» Б. Чичибабіна: шлях поета і можливості вірша Шеховцова Т. А. «Червоні помідори» Б. Чичибабіна: шлях поета і можливості вірша
У статті проведено цілісний семантичний, поетологічний і контекстуальний аналіз вірша російського поета Бориса
Чичибабіна «Скінчуся, залишуся живим...» («Червоні помідори») з урахуванням дискусійних моментів існуючих
інтерпретацій. Уточнено значення цього твору в особистісному і творчому становленні поета. Доповнено трактовку
центрального символічного образу вірша «червоні помідори» і запропоновано реальний коментар до нього. Схарактеризовано архетипічні, фольклорні та літературні претексти вірша. Простежено семантичне навантаження всіх
формальних компонентів вірша – композиції, строфіки, фоніки, метрики. Прокоментовано співвідношення зовнішнього,
подієво-біографічного, і ліричного сюжетів вірша. Показано, що поетична конструкція залишається чи не єдиною опорою в
розірваному, ворожому світі, де опинився в'язень, при цьому поряд з класичною строфікою поет використовує некласичну
метрику – розмитий трьохіктний дольник, демонструючи можливості «вільного» вірша. Вісник Харківського національного університету імені В. Н. Каразіна
Серія «Філологія». Вип. 81 Вісник Харківського національного університету імені В. Н. Каразіна
Серія «Філологія». Вип. 81 УДК 821.161.1–1 Чичибабин.09
DOI: 10.26565/2227-1864-2019-81-10 «Красные помидоры» Б. Чичибабина: путь поэта и возможности стиха Т . А . Ш е х о в ц о в а Літературознавчі дослідження: теоретичні та прикладні аспекти The author of the article comes to the conclusion that the poem written by young poet signifies not only his young creative maturity
but also a special poetic intuition – while revealing an enhanced semantic character of all the elements of the poem and
implementing the performative possibilities of the poetic expression, Chichibabin’s text correlates with the perspective artistic
discoveries of post-Symbolistic epoch. p
y
p
Keywords: Chichibabin, symbolic image, semantics, poetics, context, real comment, “semantical poetics” Лестницы, коридоры,
хитрые письмена... Красные помидоры
кушайте без меня [18, с. 24]. Лестницы, коридоры,
хитрые письмена... Красные помидоры
кушайте без меня [18, с. 24]. Стихотворение «Кончусь, останусь жив ли…»,
больше известное как «Красные помидоры»,
принято считать визитной карточкой Бориса
Чичибабина
и
началом
его
оригинального
поэтического пути. Неудивительно, что редкий из
исследователей
чичибабинского
творчества
обошел
его
стороной. История
создания,
историко-политический фон, центральный образ-
символ,
художественные
достоинства
этой
шестнадцатистрочной
миниатюры
(лаконизм,
скупость выразительных средств, оригинальная
составная рифма, образно-смысловой сдвиг и т. п.) рассматривались неоднократно, с разной
степенью подробности [1; 3; 7; 8; 13; 17]. Однако,
как справедливо заметил Ф. Рахлин, «образный
строй
совершенного
произведения
поистине
неисчерпаем» [13] (заметим, что столь же
неисчерпаемыми оказываются его смысловая
глубина, интертекстуальные и контекстуальные
связи). Задача нашей статьи – семантический,
поэтологический
и
контекстуальный
анализ
стихотворения Чичибабина, уяснение места этого
произведения
в
личностном
и
творческом
становлении поэта. Однако лирический сюжет стихотворения
существенно расширяет смысловые горизонты. Первая строка сразу ставит самый главный для
лирического героя вопрос и задает основную
оппозицию стихотворения – «жизнь/смерть». Стих
строится
как
движение
маятника
с
максимальной амплитудой и передает ужас
неопределенности
в
положении
человека,
который не знает, что у него впереди. Герой
живет в ожидании того часа, когда маятник
судьбы
замрет
в
каком-либо
определенном
положении: жить – умереть. Причем вероятность
выбора того и другого совершенно одинакова, и
это подчеркивается фонетически: кончусь –
останусь (4 звука совпадают из шести). Однако
акцент сделан не на одной из этих возможностей,
а
на
их
последствии,
которое,
как
ни
парадоксально, объединяет противоположности. Зияющий провал, который рано или поздно
закроется, зарастет – это, прежде всего, провал в
личной судьбе (если «останусь жив»), поскольку
тюремные месяцы и годы – время, как будто
вычеркнутое из жизни. Но можно ли вычеркнуть
их из памяти узника, что залечит («зарастит»)
раны его души? С другой стороны, конец чьего-
либо личного существования, в особенности
преждевременный, – провал в жизни страны и
человечества, которая складывается из жизней
отдельных людей. Но общая жизнь продолжится,
даже если умрет поэт. доктор филологических наук, профессор кафедры истории русской литературы,
Харьковский национальный университет имени В. Н. Каразина;
e-mail: shekhovt2@gmail.com; https://orcid.org/0000-0002-6270-6549 А., 2019 64 Літературознавчі дослідження: теоретичні та прикладні аспекти доктор филологических наук, профессор кафедры истории русской литературы,
Харьковский национальный университет имени В. Н. Каразина;
e-mail: shekhovt2@gmail.com; https://orcid.org/0000-0002-6270-6549 р
у
р
р
д
, д
ру
р
Виявлено точки дотику вірша Чичибабіна з «семантичною поетикою», створеною О. Мандельштамом і А. Ахматовою
(розуміння зв'язку історії і людини, проникнення творчості в життя, перетворення слова в справу, співвіднесеність вірша з
реальною ситуацією, поєднання узагальнено-філософського і конкретно-чуттєвого і т. ін.) Прозаїзацїя вірша проявляється у
введенні сюжетних елементів, прихованій діалогізації, використанні розмовних інтонацій, грі часом, кінематографічності. Автор статті приходить до висновку, що вірш молодого поета стає свідченням не просто ранньої творчої зрілості, а й
особливої поетичної інтуїції: виявляючи підвищену семантизацію всіх елементів вірша і реалізацію перформативних
можливостей поетичного висловлювання, чичибабінській текст співвідноситься з перспективними художніми відкриттями
постсимволістської доби. Ключові слова: Чичибабін, образ-символ, семантика, поетика, контекст, реальний коментар, «семантична поетика» y
p
p
p
p
The article presents a comprehensive semantic, poetological and contextual analysis of the poem Red Tomatoes («Кончусь,
останусь жив ли…») written by the Russian poet Boris Chichibabin with consideration of debatable aspects of existing
interpretations. The significance of this creation for the poet’s personal and creative formation has been specified. The interpretation
of the poem’s key symbolic image has been amplified, and a real comment has been attached to it. Archetypical, folkloric and
literary pretexts of the poem have been characterized. The correlation between the external, biographical and lyrical plots has been
commented on. The semantic load of all formal components of the poem, such as composition, verse structure, phonics, and
metrics, has been checked up. It has been shown that the poetic construction appears to be nearly the only support in a torn,
hostile world, in which a prisoner found himself; at the same time, along with a classic verse structure, the poet uses non-classic
metrics – a fuzzy three-ictus accentual verse, thus demonstrating the possibilities of a “free” poem. The meeting points of Chichibabin’s poem and the “semantical poetics”, created by Osip Mandelstam and Anna Akhmatova, have
been detected (such as the understanding of the connection between history and a person, infusion of creation into life, turning
words to deeds, relatedness of a poem to a real-life situation, prosaic character of the poem, combination of the generalized and
philosophical notions with the specific and sensual ones, etc.) The prosaic character of the poem is reflected in the introduction of
the elements with a plot, hidden dialogue, the use of colloquial intonations, playing with tenses, as well as the cinematic hints. Шеховцова Т. Літературознавчі дослідження: теоретичні та прикладні аспекти Образ взят, вероятно, из византийской военной
техники: греки из больших труб метали огонь на
русские
корабли
и
тем
сжигали
их;
эти
огнеметные трубы, изображаемые на миниатюрах,
и являются, очевидно, прообразом “пламенного
рога”, с помощью которого богиня печали сеяла
тоску по Руси» [14]. Поэт пишет о своей личной
трагедии – о потере свободы, но эта трагедия
становится бедой всей страны, причем не только
нынешней, но и во все века истории. Тяжко
голове без плеч, телу без головы, Русской земле
без Игоря, как говорил неизвестный автор
древнерусского памятника. Необычная рифма –
начальная,
гипердактилическая
(ударение
на
четвертом слоге от конца) в Игоревом – выгорела
акцентирует внимание читателя на исторических
параллелях, выделяет важную для автора мысль. является самым главным – оторванность от жизни
во всех ее проявлениях, во всей ее сочной,
красочной,
чувственной
полноте. Эта
оторванность еще больнее, еще острее ощущается
молодым и полным сил человеком. Красный цвет
символизирует
радость,
красоту,
любовь
и
полноту жизни, но его семантика поливалентна,
он ассоциируется также с кровью, смертью,
страданием. Два
слова
красные
помидоры
фонетически объединяет только звук «р», но он
рассеян по всему стихотворению, обеспечивая
доминирование центрального образа (зарастет
провал, Игоревом – выгорела, трава, горькою,
хитрые, коридоры, прозы – допросы). Образ-
символ
становится
«центром
вербальной
звукоассоциативной сети» [4, с. 41]: зарастет –
провал – трава – коридоры – прозы – горькою –
вечером – допросы. Стихотворение насыщено аллитерациями и
ассонансами,
которые
устанавливают
фоносемантические связи между элементами
поэтического текста. В эхо-повторах (эквифонии,
по Г. Векшину [4, с. 6]) перекликаются не только
отдельные
звуки,
но
и
звуковые
группы:
Игоревом – выгорела – коридоры – помидоры –
горькою – головой (семантика горя / горечи
распространяется
на
все
фонетически
сближаемые слова). Стихотворение насыщено аллитерациями и
ассонансами,
которые
устанавливают
фоносемантические связи между элементами
поэтического текста. В эхо-повторах (эквифонии,
по Г. Векшину [4, с. 6]) перекликаются не только
отдельные
звуки,
но
и
звуковые
группы:
Игоревом – выгорела – коридоры – помидоры –
горькою – головой (семантика горя / горечи
распространяется
на
все
фонетически
сближаемые слова). Строка об Игоревом Путивле не только
обращает к истории, но рождает дополнительные
ассоциации, также сближающие прошлое и
настоящее: выгоревшая трава – это напоминание
о недавней войне и нынешнем выжженном
репрессиями времени – и о войнах Древней Руси,
о монголо-татарском нашествии, перекличка с
теми строчками «Слова», где описана трава,
поникшая от жалости после поражения Игорева
войска. )
Слово «проза» в начальной строке третьей
строфы
(«как
я
дожил
до
прозы»)
М. Літературознавчі дослідження: теоретичні та прикладні аспекти Стихотворение написано в одиночной камере
на Лубянке летом 1946 года, где Чичибабин
провел два месяца [18, с. 469]. Напомним, что в
июне этого года Чичибабина, который учился на
первом курсе филфака, арестовали и после
тюремных и судебных мытарств присудили пять
лет
лагерей
«за
антисоветскую
агитацию». Внешний,
событийно-биографический
сюжет
стихотворения
вполне
прозрачен,
и
интерпретаторы «Красных помидоров» вполне
закономерно рассматривают это произведение как
стихи
«о
горькой
участи
юного
узника,
отторгнутого жестокой машиной государства от
близких, от любимой, от молодости, счастья, книг,
науки – а, может быть, и от самой жизни» [13],
или же, более обобщенно, – о «насилии над
человеческой душой» [7]. Вторая строка перекликается с четвертой:
глагол «растет» притягивает существительное
«трава». Оказывается,
что
провал
(уже
материализованный и из временной плоскости
сместившийся
в
пространственную)
должен
зарастать травой, при этом поэт сближает эпохи и
вспоминает, как когда-то выгорела трава в
Игоревом Путивле. Обращение к «Слову о полку
Игореве» разъяснено комментаторами вполне
убедительно: стихи были написаны после второго
семестра обучения на филфаке, включающего
изучение древнерусской литературы, и несли
целый ряд ассоциаций со «Словом…»: герой
попадает в руки врагов, томится в неволе, его
возлюбленная оплакивает его и просит о помощи
и т. п. [3, с. 19]. Заметим только, что в «Слове о
полку Игореве» нет прямого упоминания о
выгоревшей траве. Однако вчерашний студент
усвоил не столько букву, сколько дух древнего
текста, сблизив в своем творческом сознании два
фрагмента: «ничить трава жалощами» (никнет
трава от жалости) и «Жля поскочи по Руской Кончусь, останусь жив ли, –
чем зарастет провал? В Игоревом Путивле
выгорела трава. Школьные коридоры –
тихие, не звенят... Красные помидоры
кушайте без меня. Как я дожил до прозы
с горькою головой? Вечером на допросы
водит меня конвой. Кончусь, останусь жив ли, –
чем зарастет провал? В Игоревом Путивле
выгорела трава. Школьные коридоры –
тихие, не звенят... Красные помидоры
кушайте без меня. Как я дожил до прозы
с горькою головой? Вечером на допросы
водит меня конвой. 65 Вісник Харківського національного університету імені В. Н. Каразіна
Серія «Філологія». Вип. 81 земли, смагу людемъ мычючи въ пламянѣ розѣ»
(Жля помчалась по Русской земле, сея горе людям
из огненного рога) [16]. Как отмечал Б. Рыбаков,
«Жля, Желя (Жьля) – олицетворение печали и
тоски. В поэме она сжигает, душит горечью жара-
смаги, который она извергает из огненного рога. Головушка горькая, головушка горькая… Ах, да пришла ночка темная. Ах, да пришла ночка темная. Не с кем ночку ночевать, осеннюю коротать…
[5, с. 149]. Не с кем ночку ночевать, осеннюю коротать…
[5, с. 149]. Літературознавчі дослідження: теоретичні та прикладні аспекти Богославский
истолковал
как
унизительную
реальность тюрьмы и допросов, увенчавшую
«юношескую революционную романтику поэта»
[3, с. 21]. На наш взгляд, упоминание о прозе
отсылает к известным пушкинским строкам «Лета
к суровой прозе клонят». Поэт с горькой иронией
подчеркивает
и
преждевременность
своего
обращения к прозе, и полную противоположность
пушкинской прозы «беллетристике» протоколов и
доносов,
где
тоже
царил
вымысел. Слова
«доносы» в стихотворении нет, но, даже если
читатель не знаком с биографией Чичибабина, но
хоть немного знает об атмосфере сталинской
эпохи, он не может не услышать эту скрытую
подтекстную рифму к «допросам». В стихотворении можно увидеть отголоски и
еще одного университетского курса – фольклора. Протяжная
лирическая
песня
о
«горькой
головушке», одиночестве и разлуке с любимой
органично
соотносится
с
третьей
строфой
стихотворения,
дополняя
смысловое
и
эмоциональное поле текста, расставляя акценты в
лирическом сюжете: Головушка горькая, головушка горькая… Літературознавчі дослідження: теоретичні та прикладні аспекти 5. —UUUU—U (3) Школьные коридоры –
6. —UUUU— (4) тихие, не звенят... 7. —UUUU—U (3) Красные помидоры
8. —UU—U— (2) кушайте без меня. 9. —UU—U—U (1) Как я дожил до прозы
10. —UUUU— (4) с горькою головой? 11. —UUUU—U (3) Вечером на допросы
12. —UU—U— (2) водит меня конвой. 13. —UUUU—U (3) Лестницы, коридоры,
14. —UUUU— (4) хитрые письмена... 15. —UUUU—U (3) Красные помидоры
16. —UU—U— (2) кушайте без меня. Существует и вполне вероятная реальная
подоплека данного образа. В романе И. Багряного
«Сад Гетсиманский» переданы впечатления героя,
находящегося в следственной тюрьме НКВД:
«Наглядач розливав якусь руду юшку, що чомусь
називалася борщем. Мабуть, тому, що була зварена
з
червоних
помідорів. Від
тих
помідорів
залишилися тонюнькі шкірочки, й крім тих
шкірочок більше в «борщі» нічого не було – ані
картоплини, ані капустини, ані тим більше чогось
м’ясного, чогось від борщу. Гола червоняста юшка
з шкірочками» [2]. После ареста в 1938 году
Багряный два года находился в Харьковском
следственном изоляторе УГБ-НКВД и в своем
романе в значительной степени опирался на
собственный тюремный опыт. Тюремное меню
вряд ли особенно изменилось за годы, разделявшие
двух заключенных, – прозаика и поэта. Общность метрического рисунка сближает
отдаленные строки, внося новые смысловые
оттенки. Так, схема (2) объединяет рефрен
«кушайте без меня» со стихами «чем зарастет
провал?» и «водит меня конвой». В таком
контексте «провал» приобретает дополнительный
смысл: это пропасть, отделяющая героя от его
мучителей. Лирический герой Чичибабина отказывается
от навязываемых ему «красных помидоров», и в
этом его сила и достоинство. Главное, что он
остается поэтом – хотя стихотворение небогато
художественными
«украшениями»,
в
нем
ощущается «поэтическая дерзость» – прежде
всего в рифмах (составная, начальная, глубокая,
гипердактилическая). Самых простых, глагольных
рифм нет вообще – это не только придает некую
изысканность простой стихотворной модели, но и
подчеркивает безвыходность положения узника,
обреченного либо на неподвижность в камере,
либо на однообразные перемещения по строго
определенному
маршруту
в
замкнутом
пространстве тюрьмы. у
Детальный анализ стихотворения позволяет
обнаружить в нем приметы так называемой
«семантической
поэтики»,
созданной
О. Мандельштамом и А. Ахматовой и впервые
описанной в знаменитой статье Ю. Левина, Д. Сегала, Р. Тименчика, В. Топорова и Т. Цивьян
[11]. Речь, конечно же, не может идти о
непосредственной причастности Чичибабина к
художественным
открытиям
акмеистов,
хотя
некоторые сближения в этом плане уже имели
место («Прихильне ставлення Б. Чичибабіна до
творчості О. Літературознавчі дослідження: теоретичні та прикладні аспекти Мандельштама сприяло захопленню
основними постулатами акмеїзму: утвердження
реальних життєвих цінностей, конкретність і
ясність земного, історичного, матеріального світу
з привабливістю його чудових подробиць у
реальному житті й просторі» [9]). Тем не менее
важнейшая
функция
русской
семантической
поэтики,
которая
«послужила
инструментом
трансплантации
культуры
в
условиях
<…>
культурного провала» [15, с. 247], чичибабинской
поэзии близка, равно как близким оказывается
восприятие творчества и истории. Детальный анализ стихотворения позволяет
обнаружить в нем приметы так называемой
«семантической
поэтики»,
созданной
О. Мандельштамом и А. Ахматовой и впервые
описанной в знаменитой статье Ю. Левина, Д. Сегала, Р. Тименчика, В. Топорова и Т. Цивьян
[11]. Речь, конечно же, не может идти о
непосредственной причастности Чичибабина к
художественным
открытиям
акмеистов,
хотя
некоторые сближения в этом плане уже имели
место («Прихильне ставлення Б. Чичибабіна до
творчості О. Мандельштама сприяло захопленню
основними постулатами акмеїзму: утвердження
реальних життєвих цінностей, конкретність і
ясність земного, історичного, матеріального світу
з привабливістю його чудових подробиць у
реальному житті й просторі» [9]). Тем не менее
важнейшая
функция
русской
семантической
поэтики,
которая
«послужила
инструментом
трансплантации
культуры
в
условиях
<…>
культурного провала» [15, с. 247], чичибабинской
поэзии близка, равно как близким оказывается
восприятие творчества и истории. Классическая простота строфики (четыре
катрена
с
перекрестной
рифмовкой
и
чередованием женских и мужских рифм) также
несет определенную смысловую нагрузку. В
русской
поэзии
форма
АbАb
в
катренах
перекрестной
рифмовки
воспринимается
как
«образцово-классическая» [10, с. 128]. Число 4, по
наблюдениям
ученых,
является
образом
статической целостности, идеально устойчивой
структуры [12, с. 630]. Поэтическая конструкция
оказывается едва ли не единственной опорой в
разорванном, расшатанном, враждебном мире, где
оказался
юный
узник. Кроме
того,
четырехчастная структура может быть соотнесена
с символикой креста (не случайно в уже
упомянутом
«Саду
Гетсиманском»
метафора
крестного пути является одной из центральных). Классическая простота строфики (четыре
катрена
с
перекрестной
рифмовкой
и
чередованием женских и мужских рифм) также
несет определенную смысловую нагрузку. В
русской
поэзии
форма
АbАb
в
катренах
перекрестной
рифмовки
воспринимается
как
«образцово-классическая» [10, с. 128]. Число 4, по
наблюдениям
ученых,
является
образом
статической целостности, идеально устойчивой
структуры [12, с. 630]. Поэтическая конструкция
оказывается едва ли не единственной опорой в
разорванном, расшатанном, враждебном мире, где
оказался
юный
узник. Кроме
того,
четырехчастная структура может быть соотнесена
с символикой креста (не случайно в уже
упомянутом
«Саду
Гетсиманском»
метафора
крестного пути является одной из центральных). Не с кем ночку ночевать, осеннюю коротать…
[5, с. 149]. Тогда «хитрые письмена» – это не только
лживые
записи
следователей,
протоколы
допросов, но и письма-доносы, которые опускали
некоторые современники Чичибабина в почтовый
ящик у ворот КГБ. В таком контексте финальный
повтор
высвечивает
в
центральном
символическом образе новое, дополнительное
содержание. «Красные помидоры» – это и сытые,
довольные лица следователей, и цвет красного
знамени (красный издавна – цвет власти), и
«кровавых костей в колесе» страшной машины
сталинского правосудия, ужас Лубянки и Гулага. Тем самым в последней строфе меняется адресат
рефрена – это уже не друзья, оставшиеся на
свободе, а бездушные и ретивые исполнители
воли «отца народов». Лейтмотивный образ «красные помидоры»,
центральный для стихотворения, возникает во
второй строфе и повторяется в финале, завершая
произведение. Образ
многозначен,
как
и
полагается
символу. Исследователи
истолковывают его в гастрономически-бытовом,
биографическом и политическом аспектах: как
намек на родной Харьков (на Украине помидоры – основной летний продукт), как указание на
спелость и первосортность продукта, «конечно же,
не достигавшего скудного стола заключенного»
[7], как олицетворение «простого праздника
жизни» и даже как символ советского строя [13]. Красные помидоры – это то, что отнято
вместе со свободой и осталось в другой,
нетюремной жизни. Повтор фиксирует внимание
читателя на том, что для автора в этот момент 66 1. —UU—U—U (1) Кончусь, останусь жив ли, –
2.—UU—U— (2) чем зарастет провал?
3. —UUUU—U (3) В Игоревом Путивле
4. —UUUU— (4) выгорела трава. Літературознавчі дослідження: теоретичні та прикладні аспекти Пугачев вкладывает в исполнение энергическую
экспрессию, бунтарство, непокорность, проклятие
мучителям, вызов судьбе; он проигрывает как
внешний, так и внутренний, лирический сюжет,
расставляя
смысловые
акценты. Однако
интонация абсолютного неприятия, убежденного
противостояния и в том, и в другом прочтении
очевидна. у
ц
ц
р
) [
]
Помимо
этих
особенностей,
присущих
стихотворению
Чичибабина,
в
«Красных
помидорах»
наблюдается
и
тенденция
к
«прозаизации»,
также
характерная
для
семантической поэтики. Об этом свидетельствуют
введение сюжетных элементов («вечером на
допросы
водит
меня
конвой»),
скрытая
диалогизация («кушайте без меня», обращенное к
предполагаемому
собеседнику),
разговорные
интонации
(кончусь»
вместо
«умру»),
игра
временами (прошлое – настоящее – будущее),
«кинематографичность»
(на
эту
особенность
обратил внимание М. Богославский: «Лестницы,
коридоры,
хитрые
письмена»
–
«три
выразительных кинокадра из фильма, который
прокручивает память» [3, с. 20]). у
ц
ц
р
) [
]
Помимо
этих
особенностей,
присущих
стихотворению
Чичибабина,
в
«Красных
помидорах»
наблюдается
и
тенденция
к
«прозаизации»,
также
характерная
для
семантической поэтики. Об этом свидетельствуют
введение сюжетных элементов («вечером на
допросы
водит
меня
конвой»),
скрытая
диалогизация («кушайте без меня», обращенное к
предполагаемому
собеседнику),
разговорные
интонации
(кончусь»
вместо
«умру»),
игра
временами (прошлое – настоящее – будущее),
«кинематографичность»
(на
эту
особенность
обратил внимание М. Богославский: «Лестницы,
коридоры,
хитрые
письмена»
–
«три
выразительных кинокадра из фильма, который
прокручивает память» [3, с. 20]). Стихотворение Чичибабина, в соответствии с
законами
семантической
поэтики,
воспринимается «как часть реальной ситуации –
как вопрос или ответ, как реплика, просьба,
молитва, заклинание, проклятие, как фрагмент,
объясняемый
именно
из
ситуации
и
синтезируемый
в
целое
только
при
учете
ситуации» [11]. Именно так «проходит путь,
крестный путь поэта уже после “конца мира”,
когда стихотворение – единственный посох, Стихотворение Чичибабина, в соответствии с
законами
семантической
поэтики,
воспринимается «как часть реальной ситуации –
как вопрос или ответ, как реплика, просьба,
молитва, заклинание, проклятие, как фрагмент,
объясняемый
именно
из
ситуации
и
синтезируемый
в
целое
только
при
учете
ситуации» [11]. Именно так «проходит путь,
крестный путь поэта уже после “конца мира”,
когда стихотворение – единственный посох, Таким
образом,
стихотворение
молодого
поэта становится свидетельством не просто
ранней творческой зрелости и личностного
«самостоянья»,
но
и
особой
поэтической
интуиции:
обнаруживая
повышенную
семантизацию всех элементов стиха и реализацию
перформативных
возможностей
поэтического
высказывания, чичибабинский текст соотносится
с перспективными художественными открытиями
постсимволистской эпохи. Литература 1. Абрамович С. Д. Риторико-патетическое начало в художественном мире Б. Чичибабина: («Красные
помидоры» как образ-литота чужого мира в стихотворении «Кончусь, останусь жив ли...») // Вестник Крымских
чтений Б. А. Чичибабина: сб. науч. тр. Вып. 4: Б. А. Чичибабин в поэтическом мире России и Украины. Симферополь: Крымский Архив, 2008. С. 3–6. 2. Багряний І. Сад гетсиманський. URL: https://www.ukrlib.com.ua/ books/printit.php?tid=29 (дата обращения:
15.03.2019) Богославский М. Самостояние стиха, или встреча двух поэтик // Материалы Чичибабинских чтений. 1995
Харьков: Фолио, 1999. С. 13–28 с. 4. Векшин Г. В. Фоностилистика текста: звуковой повтор в перспективе смыслообразования: автореф. дис. …
ок ора ф
о
а к: 10 01 02
«Р сск й з к» Моск а 2006 48 с 4. Векшин Г. В. Фоностилистика текста: звуковой повтор в перспективе смыслообразования: автореф. дис. …
доктора филол. наук: 10. 01. 02 – «Русский язык». Москва, 2006. 48 с. 5. Великорусские народные песни / Изданы проф. А. И. Соболевским. Т. 5. Санкт-Петербург: Б. и., 18 Великорусские народные песни / Изданы проф. А. И. Соболевским. Т. 5. Санкт-Петербург: Б. и., 1899. 644 с. Г
М Л Р
й
й
ХХ
// Т
/ П
В Е Х 5. Великорусские народные песни / Изданы проф. А. И. Соболевским. Т. 5. Санкт-Петербург: Б. и., 1899. 644 с. 6. Гаспаров М. Л. Русский трехударный дольник ХХ века // Теория стиха / Под ред. В. Е. Холшевникова. Ленинград: Наука, 1968. С. 59–106. у
у
6. Гаспаров М. Л. Русский трехударный дольник ХХ века // Теория стиха / Под ред. В. Е. Холшевникова. Ленинград: Наука, 1968. С. 59–106. 7. Егоров Б. Еда и питье у Бориса Чичибабина // «Пир – это лучший образ счастья» // Образы трапезы в
богословии и культуре / Под ред. Светланы Панич и Ирины Языковой. Москва: Изд-во ББИ, 2016. 264 с. URL:
http://ogrik2.ru/b/svetlana-panich/pir-eto-luchshij-obraz-schastya-obrazy-trapezy-v-bogoslovii-i-kulture/28673/boris-egorov-
eda-i-pite-u-borisa-chichibabina/18 (дата обращения: 10.03.2019). 8. Егоров Б. Ф. Творческая жизнь Бориса Чичибабина. Санкт-Петербург: Росток, 2016. 192 с. 9. Зуєнко М. О. Особливості індивідуального стилю Бориса Чичибабіна: дис. … канд. філол. наук: 10.01.02
«Російська література». Полтава, 2007. URL: https://mydisser.com/ru/catalog/view/312/780/19869.html (дата обращения:
10.03.2019). 10. Илюшин А. А. Русское стихосложение. Москва: Высш. шк., 1988. 165 с. у
11. Левин Ю. И, Сегал Д. М., Тименчик Р. Д., Топоров В. Н., Цивьян Т. В. Русская семантическая поэтика как
потенциальная культурная парадигма https://studfiles.net/preview/3349604/ (дата обращения: 10.03.2019). 11. Левин Ю. И, Сегал Д. М., Тименчик Р. Д., Топоров В. Н., Цивьян Т. В. Русская семантическая поэтика как
потенциальная культурная парадигма https://studfiles.net/preview/3349604/ (дата обращения: 10.03.2019). Літературознавчі дослідження: теоретичні та прикладні аспекти р
р
р
В
числе
основных
характеристик
семантической
поэтики
ученые
называют
необыкновенно
развитое
чувство
историзма,
соотносимость истории и человека, то есть
переживании истории в себе и себя в истории,
понимание
связи
истории
с
культурой,
соотнесенности
творчества
с
историей,
вовлечение
поэзии,
творчества
в
жизнь,
превращение слова в дело в неизмеримо больших
масштабах,
чем
это
мыслилось
раньше:
«Существенным
становится
только
то,
как
человек (поэт) и история отразились друг в друге»
[11]. История
при
этом
воспринимается
синхронично,
что
объясняет
чичибабинское
«стяжение»
времен. Сам
образ
«красных
помидоров»
демонстрирует
характерное
для
семантической поэтики, в особенности для поэзии
Мандельштама,
«тесное
слияние
смысловой Наряду с классической строфикой поэт
использует неклассическую метрику – размытый
трехиктный дольник, трех- или двухударный (в
последнем случае – с пропущенным вторым
«схемным» ударением [6]). В стихотворении
присутствуют логаэдические строки:1 и 9 (1); 2, 8,
12 и 16 (2); 3, 5, 7, 11, 13, 15 (3); 4, 6, 10, 14 (4). 1. —UU—U—U (1) Кончусь, останусь жив ли, –
2.—UU—U— (2) чем зарастет провал? 3. —UUUU—U (3) В Игоревом Путивле
4. —UUUU— (4) выгорела трава. 67 Вісник Харківського національного університету імені В. Н. Каразіна
Серія «Філологія». Вип. 81 линии, связанной с разработкой глобальных тем,
со
смысловыми
линиями,
трактующими
конкретно-чувственное состояние мира (описание
цвета, звука, осязания, вкуса, других зрительных
или слуховых ассоциаций и проч.) [11]. помогающий пройти этот путь в мире, который
“жесток и груб”» [11]. Заметим, что подобная ситуативно-актуальная
трактовка, практически отождествляющая слово с
действием, была предложена другом Чичибабина,
актером и бардом Леонидом Пугачевым в
замечательной песенной версии стихотворения. Интересно, что авторское чтение и исполнение
Пугачева, интонационно и эмоционально во
многом
отличающиеся,
не
противоречат,
а
дополняют
друг
друга. Чичибабин
читает
медленно, напевно, несколько монотонно и
отрешенно, подчеркивая мелодику стиха, его
чтение напоминает молитву или заклинание. Пугачев вкладывает в исполнение энергическую
экспрессию, бунтарство, непокорность, проклятие
мучителям, вызов судьбе; он проигрывает как
внешний, так и внутренний, лирический сюжет,
расставляя
смысловые
акценты. Однако
интонация абсолютного неприятия, убежденного
противостояния и в том, и в другом прочтении
очевидна. помогающий пройти этот путь в мире, который
“жесток и груб”» [11]. Заметим, что подобная ситуативно-актуальная
трактовка, практически отождествляющая слово с
действием, была предложена другом Чичибабина,
актером и бардом Леонидом Пугачевым в
замечательной песенной версии стихотворения. Интересно, что авторское чтение и исполнение
Пугачева, интонационно и эмоционально во
многом
отличающиеся,
не
противоречат,
а
дополняют
друг
друга. Чичибабин
читает
медленно, напевно, несколько монотонно и
отрешенно, подчеркивая мелодику стиха, его
чтение напоминает молитву или заклинание. Літературознавчі дослідження: теоретичні та прикладні аспекти Літературознавчі дослідження: теоретичні та прикладні аспекти 14. Рыбаков Б. А. Язычество Древней Руси. URL: https://www.e-reading.club/bookreader.php/86163/Rybakov_-
_Yazychestvo_Drevneii_Rusi.html (дата обращения: 10.03.2019). _
y
_
_
(
р
)
15. Сегал Д. Литература как охранная грамота. Москва: Водолей Publishers, 2006. 976 с. 16
С
И
// Б б
Д
й Р
15
/ П 16. Слово о полку Игореве // Библиотека литературы Древней Руси: в 15 т. / Под ред. Д. С. Лихачева, Л. А. Дмитриева, А. А. Алексеева, Н. В. Понырко. Санкт-Петербург: Наука, 1997. Т. 4: XII век. URL:
http://lib.pushkinskijdom.ru/Default.aspx?tabid=4941 (дата обращения: 10.03.2019). 16. Слово о полку Игореве // Библиотека литературы Древней Руси: в 15 т. / Под ред. Д. С. Лихач
Дмитриева, А. А. Алексеева, Н. В. Понырко. Санкт-Петербург: Наука, 1997. Т. 4: XII в
http://lib.pushkinskijdom.ru/Default.aspx?tabid=4941 (дата обращения: 10.03.2019). 17. Фризман Л. Г., Ходос А. Э. Борис Чичибабин. Жизнь и поэзия. Харьков: Консум, 1999. 128 с 18. Чичибабин Б. А. В стихах и прозе / Борис Чичибабин; изд. подгот. Л. С. Карась-Чичибабина, Л. Г. Фризман;
[отв. ред. Б. Ф. Егоров]. Москва: Наука, 2013. 567 с. (Литературные памятники). References 1. Abramovich S. D. Ritoriko-pateticheskoe nachalo v khudozhestvennom mire B. Chichibabina: («Krasnye
pomidory» kak obraz-litota chuzhogo mira v stikhotvorenii «Konchus, ostanus zhiv li...») // Vestnik Krymskikh chteniy B. A. Chichibabina: sb nauch tr Vyp 4: B A Chichibabin v poeticheskom mire Rossii i Ukrainy Simferopol: Krymskiy Arkhiv 1. Abramovich S. D. Ritoriko-pateticheskoe nachalo v khudozhestvennom mire B. Chichibabina: («Krasnye
pomidory» kak obraz-litota chuzhogo mira v stikhotvorenii «Konchus, ostanus zhiv li...») // Vestnik Krymskikh chteniy B. A. Chichibabina: sb. nauch. tr. Vyp. 4: B. A. Chichibabin v poeticheskom mire Rossii i Ukrainy. Simferopol: Krymskiy Arkhiv,
2008. S. 3–6. 2. Bahrianyi I. Sad hetsymanskyi. URL: https://www.ukrlib.com.ua/ books/printit.php?tid=29 (data obras
15.03.2019) 3. Bogoslavskiy M. Samostoyanie stikha, ili vstrecha dvukh poetik // Materialy Chichibabinskikh chteniy. 1995–1999. Kharkov: Folio, 1999. S. 13–28 s. 4. Vekshin G. V. Fonostilistika teksta: zvukovoy povtor v perspektive smysloobrazovaniya: avtoref. dis. … doktora
filol. nauk: 10. 01. 02 – «Russkiy yazyk». Moskva, 2006. 48 s. 5. Velikorusskie narodnye pesni / Izdany prof. A. I. Sobolevskim. T. 5. Sankt-Peterburg: B. i., 1899. 644 s. 6
G
M L R
ki
t kh d
d l ik KhKh
k
// T
i
tikh
/ P d
d V Y
Kh l h 6. Gasparov M. L. Russkiy trekhudarnyy dolnik KhKh veka // Teoriya stikha / Pod red. V. Ye. Kholshevnikova. Leningrad: Nauka, 1968. S. 59–106. 7. Yegorov B. Yeda i pite u Borisa Chichibabina // «Pir – eto luchshiy obraz schastya» // Obrazy trapezy v bogoslovii
i kulture / Pod red. Svetlany Panich i Iriny Yazykovoy. Moskva: Izd-vo BBI, 2016. 264 s. URL: http://ogrik2.ru/b/svetlana-
panich/pir-eto-luchshij-obraz-schastya-obrazy-trapezy-v-bogoslovii-i-kulture/28673/boris-egoroveda-i-pite-u-borisa-
chichibabina/18 (data obrashcheniya: 10.03.2019). (
y
)
8. Yegorov B. F. Tvorcheskaya zhizn Borisa Chichibabina. Sankt-Peterburg: Rostok, 2016. 192 s. 9. Zuienko M. O. Osoblyvosti indyvidualnoho styliu Borysa Chychybabina: dys. … kand. filol. nauk: 10.01.02
«Rosiiska literatura». Poltava, 2007. URL: https://mydisser.com/ru/catalog/view/312/780/19869.html (data obrashchenyia:
10.03.2019). )
10. Ilyushin A. A. Russkoe stikhoslozhenie. Moskva: Vyssh. shk., 1988. 165 s. Ilyushin A. A. Russkoe stikhoslozhenie. Moskva: Vyssh. s y
y
11. Levin Yu. I, Segal D. M., Timenchik R. D., Toporov V. N., Tsivyan T. V. Russkaya semanticheskaya poetika kak
potentsialnaya kulturnaya paradigma https://studfiles.net/preview/3349604/ (data obrashcheniya: 10.03.2019). 12. Mify narodov mira: entsiklopediya: v 2 t. / Gl. red. S. A. Tokarev. T. 2: K–Ya. Moskva: Sov. entsiklopediya, 1992. 719 s. Rakhlin F. Krasnye pomidory kushayte bez menya… URL: https://www.proza.ru/2011/06/25/1373 (data
niya: 10.03.2019). y
14. Rybakov B. A. Yazychestvo Drevney Rusi. Литература 12. Мифы народов мира: энциклопедия: в 2 т. / Гл. ред. С. А. Токарев. Т. 2: К–Я. Москва: Сов. энциклопедия,
1992. 719 с. у
ур
р
p
p
(
р
)
12. Мифы народов мира: энциклопедия: в 2 т. / Гл. ред. С. А. Токарев. Т. 2: К–Я. Москва: Сов. энциклопедия,
1992. 719 с. 13. Рахлин Ф. Красные помидоры кушайте без меня… URL: https://www.proza.ru/2011/06/25/1373 (дата
обращения: 10.03.2019). 68 References URL: https://www.e-reading.club/bookreader.php/86163/Rybakov_-
_Yazychestvo_Drevneii_Rusi.html (data obrashcheniya: 10.03.2019). 15. Segal D. Literatura kak okhrannaya gramota. Moskva: Vodoley Publishers, 2006. 976 s. 15. Segal D. Literatura kak okhrannaya gramota. Moskva: Vodoley Publishers, 2006. 976 s. 16
Slovo o polku Igoreve // Biblioteka literatury Drevney Rusi: v 15 t / Pod red D S Likhacheva L A Dmitriev 15. Segal D. Literatura kak okhrannaya gramota. Moskva: Vodoley Publishers, 2006. 976 s. 16. Slovo o polku Igoreve // Biblioteka literatury Drevney Rusi: v 15 t. / Pod red. D. S. Likhacheva, L. A. Dm 16. Slovo o polku Igoreve // Biblioteka literatury Drevney Rusi: v 15 t. / Pod red. D. S. Likhacheva, L. A. Dmitrieva, A. A. Alekseeva,
N. V. Ponyrko. Sankt-Peterburg:
Nauka,
1997. T. 4:
XII
vek. URL:
http://lib.pushkinskijdom.ru/Default.aspx?tabid=4941 (data obrashcheniya: 10.03.2019). 17. Frizman L. G., Khodos A. E. Boris Chichibabin. Zhizn i poeziya. Kharkov: Konsum, 1999. 128 s. p
y
18. Chichibabin B. A. V stikhakh i proze / Boris Chichibabin; izd. podgot. L. S. Karas-Chichibabina, L. G. Frizman;
[otv. red. B. F. Yegorov]. Moskva: Nauka, 2013. 567 s. (Literaturnye pamyatniki) Шеховцова Тетяна Анатоліївна, доктор філологічних наук, професор кафедри історії
російської літератури, Харківський національний університет імені В. Н. Каразіна (м. Харків, майдан Свободи, 4, 61022); e-mail: shekhovt2@gmail.com; https://orcid.org/0000-
0002-6270-6549 Шеховцова Татьяна Анатольевна, доктор филологических наук, профессор кафедры
истории русской литературы, Харьковский национальный университет имени В. Н. Каразина (г. Харьков, пл. Свободы, 4, 61022); e-mail: shekhovt2@gmail.com;
https://orcid.org/0000-0002-6270-6549 Tatiana Shekhovtsova, Doctor of Philology, Professor of the Department of Russian
Literature, V. N. Karazin Kharkiv National University (Svobody Sq., 4, Kharkiv, 61022,
Ukraine); e-mail: shekhovt2@gmail.com; https://orcid.org/0000-0002-6270-6549 69
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