title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
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Systematic review of the empirical evidence of study publication bias and outcome reporting bias. | The increased use of meta-analysis in systematic reviews of healthcare interventions has highlighted several types of bias that can arise during the completion of a randomised controlled trial. Study publication bias has been recognised as a potential threat to the validity of meta-analysis and can make the readily available evidence unreliable for decision making. Until recently, outcome reporting bias has received less attention. We review and summarise the evidence from a series of cohort studies that have assessed study publication bias and outcome reporting bias in randomised controlled trials. Sixteen studies were eligible of which only two followed the cohort all the way through from protocol approval to information regarding publication of outcomes. Eleven of the studies investigated study publication bias and five investigated outcome reporting bias. Three studies have found that statistically significant outcomes had a higher odds of being fully reported compared to non-significant outcomes (range of odds ratios: 2.2 to 4.7). In comparing trial publications to protocols, we found that 40-62% of studies had at least one primary outcome that was changed, introduced, or omitted. We decided not to undertake meta-analysis due to the differences between studies. Recent work provides direct empirical evidence for the existence of study publication bias and outcome reporting bias. There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported. Publications have been found to be inconsistent with their protocols. Researchers need to be aware of the problems of both types of bias and efforts should be concentrated on improving the reporting of trials. | 18,769,481 |
Lymphotoxin-alpha plays only a minor role in host resistance to respiratory infection with virulent type A Francisella tularensis in mice. | This study examined the role of lymphotoxin (LT)-alpha in host defense against airborne infection with Francisella tularensis, a gram-negative facultative intracellular bacterium and the causative agent of tularemia. Following a low-dose aerosol infection with the highly virulent type A strain of F. tularensis, mice deficient in LTalpha (LTalpha-/-) consistently harbored approximately 10-fold fewer bacteria in their spleens at day 2 and 10-fold more bacteria in their lungs at day 4 than LTalpha+/+ mice. However, the mortality and median time to death were indistinguishable between the two mouse strains. In addition, the inflammatory responses to the infection, as reflected by the cytokine levels and leukocyte influx in the bronchoalveolar lavage fluid and histopathological analysis, were generally similar between LTalpha-/- and LTalpha+/+ mice. These data suggest that although LTalpha does not contribute significantly to the resistance and host responses of mice to airborne type A F. tularensis infection, it does play a subtle role in the multiplication/dissemination of F. tularensis. | 18,769,490 |
Activation of Penile Proadipogenic Peroxisome Proliferator-Activated Receptor gamma with an Estrogen: Interaction with Estrogen Receptor Alpha during Postnatal Development. | Exposure to the estrogen receptor alpha (ERalpha) ligand diethylstilbesterol (DES) between neonatal days 2 to 12 induces penile adipogenesis and adult infertility in rats. The objective of this study was to investigate the in vivo interaction between DES-activated ERalpha and the proadipogenic transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma). Transcripts for PPARs alpha, beta, and gamma and gamma1a splice variant were detected in Sprague-Dawley normal rat penis with PPARgamma predominating. In addition, PPARgamma1b and PPARgamma2 were newly induced by DES. The PPARgamma transcripts were significantly upregulated with DES and reduced by antiestrogen ICI 182, 780. At the cellular level, PPARgamma protein was detected in urethral transitional epithelium and stromal, endothelial, neuronal, and smooth muscular cells. Treatment with DES activated ERalpha and induced adipocyte differentiation in corpus cavernosum penis. Those adipocytes exhibited strong nuclear PPARgamma expression. These results suggest a biological overlap between PPARgamma and ERalpha and highlight a mechanism for endocrine disruption. | 18,769,493 |
Temporal Analysis of Valence & Electrostatics in Ion-Motive Sodium Pump. | The present work establishes a unique framework for the simulation study of ion-motive pumps in general and the Na(+)/K(+)-ATPase, or sodium pump, in particular. We shall discuss the implications of electrostatic analysis, valence calculations, and protein cavity data, each carried over data extracted from molecular dynamics simulations, on the structure-function relationship of Na(+)/K(+)-ATPase. These diverse set of tools will be used to investigate atomic-level characteristics that remain undetermined such as ion binding and accessibility. | 18,769,504 |
Accounting for change in declarative memory: A cognitive neuroscience perspective. | The medial temporal lobe memory system matures relatively early and supports rudimentary declarative memory in young infants. There is considerable development, however, in the memory processes that underlie declarative memory performance during infancy. Here we consider age-related changes in encoding, retention, and retrieval in the context of current knowledge about the brain systems that may underlie these memory processes. While changes in infants' encoding may be attributed to rapid myelination during the first year of life, improvements in long-term retention and flexible retrieval are likely due to the prolonged development of the dentate gyrus. Future studies combining measures of brain and behavior are critical in improving our understanding of how brain development drives memory development during infancy and early childhood. | 18,769,510 |
Identification of a 5-protein biomarker molecular signature for predicting Alzheimer's disease. | Alzheimer's disease (AD) is a progressive brain disease with a huge cost to human lives. The impact of the disease is also a growing concern for the governments of developing countries, in particular due to the increasingly high number of elderly citizens at risk. Alzheimer's is the most common form of dementia, a common term for memory loss and other cognitive impairments. There is no current cure for AD, but there are drug and non-drug based approaches for its treatment. In general the drug-treatments are directed at slowing the progression of symptoms. They have proved to be effective in a large group of patients but success is directly correlated with identifying the disease carriers at its early stages. This justifies the need for timely and accurate forms of diagnosis via molecular means. We report here a 5-protein biomarker molecular signature that achieves, on average, a 96% total accuracy in predicting clinical AD. The signature is composed of the abundances of IL-1alpha, IL-3, EGF, TNF-alpha and G-CSF. Our results are based on a recent molecular dataset that has attracted worldwide attention. Our paper illustrates that improved results can be obtained with the abundance of only five proteins. Our methodology consisted of the application of an integrative data analysis method. This four step process included: a) abundance quantization, b) feature selection, c) literature analysis, d) selection of a classifier algorithm which is independent of the feature selection process. These steps were performed without using any sample of the test datasets. For the first two steps, we used the application of Fayyad and Irani's discretization algorithm for selection and quantization, which in turn creates an instance of the (alpha-beta)-k-Feature Set problem; a numerical solution of this problem led to the selection of only 10 proteins. the previous study has provided an extremely useful dataset for the identification of AD biomarkers. However, our subsequent analysis also revealed several important facts worth reporting: 1. A 5-protein signature (which is a subset of the 18-protein signature of Ray et al.) has the same overall performance (when using the same classifier). 2. Using more than 20 different classifiers available in the widely-used Weka software package, our 5-protein signature has, on average, a smaller prediction error indicating the independence of the classifier and the robustness of this set of biomarkers (i.e. 96% accuracy when predicting AD against non-demented control). 3. Using very simple classifiers, like Simple Logistic or Logistic Model Trees, we have achieved the following results on 92 samples: 100 percent success to predict Alzheimer's Disease and 92 percent to predict Non Demented Control on the AD dataset. | 18,769,539 |
A statistical model for estimating maternal-zygotic interactions and parent-of-origin effects of QTLs for seed development. | Proper development of a seed requires coordinated exchanges of signals among the three components that develop side by side in the seed. One of these is the maternal integument that encloses the other two zygotic components, i.e., the diploid embryo and its nurturing annex, the triploid endosperm. Although the formation of the embryo and endosperm contains the contributions of both maternal and paternal parents, maternally and paternally derived alleles may be expressed differently, leading to a so-called parent-of-origin or imprinting effect. Currently, the nature of how genes from the maternal and zygotic genomes interact to affect seed development remains largely unknown. Here, we present a novel statistical model for estimating the main and interaction effects of quantitative trait loci (QTLs) that are derived from different genomes and further testing the imprinting effects of these QTLs on seed development. The experimental design used is based on reciprocal backcrosses toward both parents, so that the inheritance of parent-specific alleles could be traced. The computing model and algorithm were implemented with the maximum likelihood approach. The new strategy presented was applied to study the mode of inheritance for QTLs that control endoreduplication traits in maize endosperm. Monte Carlo simulation studies were performed to investigate the statistical properties of the new model with the data simulated under different imprinting degrees. The false positive rate of imprinting QTL discovery by the model was examined by analyzing the simulated data that contain no imprinting QTL. The reciprocal design and a series of analytical and testing strategies proposed provide a standard procedure for genomic mapping of QTLs involved in the genetic control of complex seed development traits in flowering plants. | 18,769,549 |
PPARalpha- and DEHP-Induced Cancers. | Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer and a potentially nongenotoxic carcinogen. Its mechanism had been earlier proposed based on peroxisome proliferator-activated receptor alpha (PPARalpha) because metabolites of DEHP are agonists. However, recent evidence also suggests the involvement of non-PPARalpha multiple pathway in DEHP-induced carcinogenesis. Since there are differences in the function and constitutive expression of PPARalpha among rodents and humans, species differences are also thought to exist in the carcinogenesis. However, species differences were also seen in the lipase activity involved in the first step of the DEHP metabolism, which should be considered in DEHP-induced carcinogenesis. Taken together, it is very difficult to extrapolate the results from rodents to humans in the case of DEHP carcinogenicity. However, PPARalpha-null mice or mice with human PPARalpha gene have been developed, which may lend support to make such a difficult extrapolation. Overall, further mechanical study on DEHP-induced carcinogenicity is warranted using these mice. | 18,769,559 |
Impact and outcomes of an Iyengar yoga program in a cancer centre. | Individuals have increasingly sought complementary therapies to enhance health and well-being during cancer, although little evidence of their effect is available. We investigated how an Iyengar yoga program affects the self-identified worst symptom in a group of participants. Whether quality of life, spiritual well-being, and mood disturbance change over the Iyengar yoga program and at 6 weeks after the program. How, from a participant's perspective, the Iyengar yoga program complements conventional cancer treatment. This pre-post instrumental collective case study used a mixed methods design and was conducted at a private Iyengar yoga studio. The sample consisted of 24 volunteers (23 women, 1 man; 88% Caucasian; mean age: 49 years) who were currently on treatment or who had been treated for cancer within the previous 6 months, and who participated in ten 90-minute weekly Iyengar yoga classes. The main outcome measures were most-bothersome symptom (Measure Your Medical Outcome Profile 2 instrument), quality of life and spiritual well-being (Functional Assessment of Chronic Illness Therapy-General subscale and Spiritual subscale), and mood disturbance (Profile of Mood States-Short Form). Participant perspectives were obtained in qualitative interviews. Statistically significant improvements were reported in most-bothersome symptom (t((23)) = 5.242; p < 0.001), quality of life (F((2,46)) = 14.5; p < 0.001), spiritual well-being (F((2,46)) = 14.4; p < 0.001), and mood disturbance (F((2,46)) = 10.8; p < 0.001) during the program. At follow-up, quality of life (t((21)) = -3.7; p = 0.001) and mood disturbance (t((21)) = 2.4; p = 0.025) significantly improved over time. Categorical aggregation of the interview data showed that participants felt the program provided them with various benefits not included on the outcomes questionnaires. Over the course of the Iyengar Yoga for Cancer program, participants reported an improvement in overall well-being. The program was also found to present participants with a holistic approach to care and to provide tools to effectively manage the demands of living with cancer and its treatment. | 18,769,575 |
Neural stem cell transplantation can ameliorate the phenotype of a mouse model of spinal muscular atrophy. | Spinal muscular atrophy (SMA), a motor neuron disease (MND) and one of the most common genetic causes of infant mortality, currently has no cure. Patients with SMA exhibit muscle weakness and hypotonia. Stem cell transplantation is a potential therapeutic strategy for SMA and other MNDs. In this study, we isolated spinal cord neural stem cells (NSCs) from mice expressing green fluorescent protein only in motor neurons and assessed their therapeutic effects on the phenotype of SMA mice. Intrathecally grafted NSCs migrated into the parenchyma and generated a small proportion of motor neurons. Treated SMA mice exhibited improved neuromuscular function, increased life span, and improved motor unit pathology. Global gene expression analysis of laser-capture-microdissected motor neurons from treated mice showed that the major effect of NSC transplantation was modification of the SMA phenotype toward the wild-type pattern, including changes in RNA metabolism proteins, cell cycle proteins, and actin-binding proteins. NSC transplantation positively affected the SMA disease phenotype, indicating that transplantation of NSCs may be a possible treatment for SMA. | 18,769,634 |
Constitutive and UV-B modulated transcription of Nod-like receptors and their functional partners in human corneal epithelial cells. | To determine the transcription pattern of Nod-like receptors (NLRs) and inflammasome components (apoptosis-associated speck-like protein containing a CARD [ASC], CARD inhibitor of NFkB-activating ligands [Cardinal], and caspase-1) in human corneal epithelial cells obtained from healthy individuals undergoing photorefractive keratectomy and in immortalized human corneal epithelial cells (HCE-T). Human corneal epithelial cells were taken from the eyes of healthy individuals by epithelial ablation for photorefractive keratectomy (PRK). The SV-40 immortalized human corneal epithelial cell line (HCE-T) was cultured. mRNA obtained from the cells was reverse transcribed and subjected to quantitative real-time polymerase chain reaction (PCR) measurements. Protein obtained from HCE-T cells was studied using the western blot technique. HCE-T cells were irradiated by UV-B light or treated with ultrapure peptidoglycan, and the effects were studied at the mRNA and protein level while the supernatant of the cells was tested for the presence of various cytokines by using enzyme-linked immunosorbent assay (ELISA) methods. mRNA levels of the studied proteins in the primary cells of the donors were similar in most cases. The transcription of Nod1, Nod2, NLRX1, Nalp1, and Cardinal was similar in the two cell types. While the expression of Nalp3 and Nalp10 was higher in HCE-T cells, ASC and caspase-1 showed higher transcription levels in the primary cells. NLRC5 and Nalp7 were hardly detectable in the studied cells. Functionality of the Nod1/Nod2 system was demonstrated by increased phosphorylation of IkB upon Nod1/Nod2 agonist ultrapure peptidoglycan treatment in HCE-T cells. While UV-B irradiation exerted a downregulation of both Nalp and Nod mRNAs as well as those of inflammasome components in HCE-T cells, longer incubation of the cells after exposure resulted in recovery or upregulation only of the Nalp sensors. At the protein level, we detected a short isoform of Nalp1 and its expression changed in a similar way as its RNA expression, but we could not detect Nalp3 protein. Among the studied cytokines, only IL-6 was detected in the supernatant of HCE-T cells. Its constitutively secreted level increased by only twofold after 24 h of UV-B irradiation. Based on our experiments, UV-B irradiation appears to exert an immunosilencing effect on the HCE-T cells by downregulating most of the sensor molecules as well as the components of the inflammasomes. Expression profiling of corneal epithelial cells suggested that the HCE-T cells may not serve as a good model for Nalp3 or Nalp1 inflammasome studies but it may be better suited for studies on the Nod1/Nod2 systems. | 18,769,647 |
An introduction to maternal mortality. | Approximately 529,000 women die from pregnancy-related causes annually and almost all (99%) of these maternal deaths occur in developing nations. One of the United Nations' Millennium Development Goals is to reduce the maternal mortality rate by 75% by 2015. Causes of maternal mortality include postpartum hemorrhage, eclampsia, obstructed labor, and sepsis. Many developing nations lack adequate health care and family planning, and pregnant women have minimal access to skilled labor and emergency care. Basic emergency obstetric interventions, such as antibiotics, oxytocics, anticonvulsants, manual removal of placenta, and instrumented vaginal delivery, are vital to improve the chance of survival. | 18,769,668 |
Global self-organization of the cellular metabolic structure. | Over many years, it has been assumed that enzymes work either in an isolated way, or organized in small catalytic groups. Several studies performed using "metabolic networks models" are helping to understand the degree of functional complexity that characterizes enzymatic dynamic systems. In a previous work, we used "dissipative metabolic networks" (DMNs) to show that enzymes can present a self-organized global functional structure, in which several sets of enzymes are always in an active state, whereas the rest of molecular catalytic sets exhibit dynamics of on-off changing states. We suggested that this kind of global metabolic dynamics might be a genuine and universal functional configuration of the cellular metabolic structure, common to all living cells. Later, a different group has shown experimentally that this kind of functional structure does, indeed, exist in several microorganisms. Here we have analyzed around 2.500.000 different DMNs in order to investigate the underlying mechanism of this dynamic global configuration. The numerical analyses that we have performed show that this global configuration is an emergent property inherent to the cellular metabolic dynamics. Concretely, we have found that the existence of a high number of enzymatic subsystems belonging to the DMNs is the fundamental element for the spontaneous emergence of a functional reactive structure characterized by a metabolic core formed by several sets of enzymes always in an active state. This self-organized dynamic structure seems to be an intrinsic characteristic of metabolism, common to all living cellular organisms. To better understand cellular functionality, it will be crucial to structurally characterize these enzymatic self-organized global structures. | 18,769,681 |
WDR55 is a nucleolar modulator of ribosomal RNA synthesis, cell cycle progression, and teleost organ development. | The thymus is a vertebrate-specific organ where T lymphocytes are generated. Genetic programs that lead to thymus development are incompletely understood. We previously screened ethylnitrosourea-induced medaka mutants for recessive defects in thymus development. Here we report that one of those mutants is caused by a missense mutation in a gene encoding the previously uncharacterized protein WDR55 carrying the tryptophan-aspartate-repeat motif. We find that WDR55 is a novel nucleolar protein involved in the production of ribosomal RNA (rRNA). Defects in WDR55 cause aberrant accumulation of rRNA intermediates and cell cycle arrest. A mutation in WDR55 in zebrafish also leads to analogous defects in thymus development, whereas WDR55-null mice are lethal before implantation. These results indicate that WDR55 is a nuclear modulator of rRNA synthesis, cell cycle progression, and embryonic organogenesis including teleost thymus development. | 18,769,712 |
A C-terminal protease-resistant prion fragment distinguishes ovine "CH1641-like" scrapie from bovine classical and L-Type BSE in ovine transgenic mice. | The protease-resistant prion protein (PrP(res)) of a few natural scrapie isolates identified in sheep, reminiscent of the experimental isolate CH1641 derived from a British natural scrapie case, showed partial molecular similarities to ovine bovine spongiform encephalopathy (BSE). Recent discovery of an atypical form of BSE in cattle, L-type BSE or BASE, suggests that also this form of BSE might have been transmitted to sheep. We studied by Western blot the molecular features of PrP(res) in four "CH1641-like" natural scrapie isolates after transmission in an ovine transgenic model (TgOvPrP4), to see if "CH1641-like" isolates might be linked to L-type BSE. We found less diglycosylated PrP(res) than in classical BSE, but similar glycoform proportions and apparent molecular masses of the usual PrP(res) form (PrP(res) #1) to L-type BSE. However, the "CH1641-like" isolates differed from both L-type and classical BSE by an abundant, C-terminally cleaved PrP(res) product (PrP(res) #2) specifically recognised by a C-terminal antibody (SAF84). Differential immunoprecipitation of PrP(res) #1 and PrP(res) #2 resulted in enrichment in PrP(res) #2, and demonstrated the presence of mono- and diglycosylated PrP(res) products. PrP(res) #2 could not be obtained from several experimental scrapie sources (SSBP1, 79A, Chandler, C506M3) in TgOvPrP4 mice, but was identified in the 87V scrapie strain and, in lower and variable proportions, in 5 of 5 natural scrapie isolates with different molecular features to CH1641. PrP(res) #2 identification provides an additional method for the molecular discrimination of prion strains, and demonstrates differences between "CH1641-like" ovine scrapie and bovine L-type BSE transmitted in an ovine transgenic mouse model. | 18,769,714 |
Trogocytosis of MHC-I/peptide complexes derived from tumors and infected cells enhances dendritic cell cross-priming and promotes adaptive T cell responses. | The transporter associated with antigen processing (TAP) and the major histocompatibility complex class I (MHC-I), two important components of the MHC-I antigen presentation pathway, are often deficient in tumor cells. The restoration of their expression has been shown to restore the antigenicity and immunogenicity of tumor cells. However, it is unclear whether TAP and MHC-I expression in tumor cells can affect the induction phase of the T cell response. To address this issue, we expressed viral antigens in tumors that are either deficient or proficient in TAP and MHC-I expression. The relative efficiency of direct immunization or immunization through cross-presentation in promoting adaptive T cell responses was compared. The results demonstrated that stimulation of animals with TAP and MHC-I proficient tumor cells generated antigen specific T cells with greater killing activities than those of TAP and MHC-I deficient tumor cells. This discrepancy was traced to differences in the ability of dendritic cells (DCs) to access and sample different antigen reservoirs in TAP and MHC-I proficient versus deficient cells and thereby stimulate adaptive immune responses through the process of cross-presentation. In addition, our data suggest that the increased activity of T cells is caused by the enhanced DC uptake and utilization of MHC-I/peptide complexes from the proficient cells as an additional source of processed antigen. Furthermore, we demonstrate that immune-escape and metastasis are promoted in the absence of this DC 'arming' mechanism. Physiologically, this novel form of DC antigen sampling resembles trogocytosis, and acts to enhance T cell priming and increase the efficacy of adaptive immune responses against tumors and infectious pathogens. | 18,769,733 |
[Mycoplasma genitalium detection and correlation with clinical manifestations in population of the Zulia State, Venezuela]. | Diverse studies demonstrate an association between Mycoplasma genitalium and urogenital pathologies. The aim of this study was to investigate the prevalence of M. genitalium in patients attending gynecological evaluation in private clinics (n = 172). DNA amplification assays of the genes 16S rRNA and MgPa were utilized. The prevalence of M. genitalium in the study population was 7.5%. M. genitalium was detected in 12.1% and 4.1% of the symptomatic and asymptomatic patients, respectively (p = 0.047). The infection was diagnosed in patients with cervicitis (17.2%) and mucopurulent secretion (16.6%) and the highest prevalence of infections was registered in the 31-40 years age group. No significant association between the presence of M.genitalium and individual clinical manifestations or the patients age was showed (p > 0.05). The high prevalence of M. genitalium infections, mostly in patients with clinical manifestations showed in this study, warrants the application of diagnostic strategies in the population to investigate the clinical meaning of these microorganisms and to reevaluate therapeutic schemes against non-gonococcal and non-chlamydial infections. | 18,769,771 |
[Presence of metallo beta-lactamases in imipenem-resistant Pseudomonas aeruginosa]. | Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. To detect the presence of MBL in imipenem resistant Psae strains. Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains were studied by pulse field gel electrophoresis. The presence of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. All the strains were also multiresistant. The presence of MBL was detected in 19% of imipenem resistant Psae strains. | 18,769,784 |
[Renal function during cardiac surgery with extracorporeal circulation]. | Patients with valvular heart disease are at high risk of acute renal failure after surgery with extracorporeal circulation. To describe changes in renal function parameters during surgery with extracorporeal circulation in patients with valvular heart disease and compare them with those found in patients undergoing elective coronary surgery. Two groups of patients were studied. Group 1 was composed by twelve patients undergoing elective coronary surgery and group 2 was composed by eleven patients undergoing surgery for heart valve replacement. Glomerular filtration rate and effective renal plasma now were estimated from inulin and the 131 I-hippuran clearance respectively, at five different times, during surgery and the postoperative period. Sodium filtration fraction and fractional excretion were calculated. Alpha and pi-glutathione s-transferase in urine were measured as markers of tubular damage in the pre and postoperative periods. Effective renal plasma flow was reduced in both groups before induction of anesthesia, did not change during surgery and decreased significantly in patients with valvular disease in the postoperative period. Glomerular filtration rates were normal during all the study period. There was a non significant reduction of filtration fraction during extracorporeal circulation. Alpha and pi glutathione s-transferases were normal and did not change. Fractional excretion of sodium increased significantly postoperatively. In patients with valvular disease undergoing surgery with extracorporeal circulation, renal function does not deteriorate. No significant difference was found when compared with patients undergoing coronary surgery. No evidence of functional and cellular renal disfunction or damage was found in both study groups. | 18,769,788 |
[Vitamin D receptor gene polymorphisms and risk of hip fracture in Chilean elderly women]. | Osteoporotic hip fractures are devastating events in older women. There is a genetic modulation of bone phenotypic parameters including bone density (BMD) and bone fragility fractures. Vitamin D receptor (VDR) gene polymorphisms explain a small part of the genetic influence on BMD, whereas their effect on fractures remains uncertain. To examine the contributions of VDR genotypes to the susceptibility to hip fracture in elderly Chilean women. We recruited 126 women (67 with fractures and 59 without) from Bio-Bio Region, Chile, aged 65 to 94 years. Genotyping for Bsm-l, Apa-1, Taq-1 and Fok-1 VDR polymorphisms was performed using polymerase chain reaction methods. All hip fractures were confirmed by X-ray. The allele frequencies were 0.49 for B, 0.57 for A, 0.60 for T and 0.65 for F in the Bsm-l, Apa-1, Taq-1 and Fok-1 polymorphisms respectively. The prevalence of these VDR gene polymorphisms in women with fractures were 16% BB, 69% Bb, 15% bb for Bsm-l; 30% AA, 46% Aa, 14% aa for Apa-1; 17% TT, 34 Tt, 8% tt for Taq-1 and 43%FF, 41% Ff, 16% ff for Fok-1. All VDR genotype frequencies did not differ from Hardy-Weinberg expectations. Allele or genotype frequencies did not differ between women with or without fractures. These results did not change when analysis was adjusted by age weight, height or gynecologic history. The genotype frequencies of the VDR polymorphisms are in accordance with the frequencies of other Hispanic and Caucasian populations. Our results suggest that VDR polymorphisms are not associated with the risk of hip fracture in older women of this Region of Southern Chile. | 18,769,790 |
[Energy expenditure and body composition in severe and morbid obese women after gastric bypass]. | The effects of gastric bypass (GBP) on resting energy expenditure (REE) are not well known. To evaluate the changes in REE and its relationship with body composition in severe and morbid obese women before and six and twelve months after GBP. Twenty three women aged 37+/-10 years, with a body mass index of 44+/-4 kg/m(2), were evaluated before, six and twelve months after GBP. REE was measured in a Deltatrac indirect calorimeter and expressed as kcal/day Fat mass (EM), and fat free mass (EEM) were determined by double beam X-ray densitometry (DEXA). Body weight reduction six and twelve months after GBP was 29.0+/-4.3 and 35.8+/-6.9%, respectively. The best predictor of weight reduction was initial weight (p <0.01). At six and twelve months, REE decreased by 291.7+/-260.0 and 353.8+/-378.4 kcal/day, respectively. In the same periods REE/kg body weight increased by 3.3 and 4.8 kcal/kg respectively, compared to baseline. REE/kg EEM was unchanged. GBP was associated with significant changes in body composition after six and twelve months. However, despite weight reduction, resting energy expenditure per fat free mass unit did not change significantly. | 18,769,803 |
[Prevalence of tuberculosis and its impact on mortality among HIV infected patients in Chile]. | Tuberculosis (TB) in Chile is reaching the elimination phase; however, in HIV positive individuals the incidence of TB in still very high. To describe the association between TB and HIV in different geographical regions in Chile, and to determine the association between TB and HIV/AIDS mortality. A retrospective study that included individuals from the main HIV clinics from four regions with different TB prevalence in the general population (per 100,000): Arica (>30), Concepcion/Arauco (25-29), Valparaiso/San Antonio (20-24) and Metropolitana Sur-Oriente (SSMSO) (<20), attended between January 1998 and September 2004. Nine hundred and twelve HIV positive individuals were included. Global prevalence of TB was 6.2% [95% confidence intervals (Cl) 5.2-7.2%]. TB was more common in older subjects (p =0.039) and those with lower CD4 counts (p <0.001) and higher HIV viral load (p =0.033). In 66% of cases, the disease had a pulmonary localization. TB was the recorded cause of death in 7.4% of subjects. Only 29% of patients had a tuberculin skin test performed at the moment of HIV diagnosis. The prevalence of TB in HIV positive patients, followed the trend of TB prevalence in the general population: Concepcion/Arauco (11.9%), Valparaiso/San Antonio (7.1%) and SSMSO (3.9%). However HIV positive subjects from Arica showed an unexpectedly low TB prevalence (5.5%). TB in HIV/AIDS patients included in this study is over 300 times more prevalent than in the general population. TB prevalence in HIV positive subjects follows regional TB prevalence, excepting Arica. Effectiveness and feasibility of latent TB diagnostic strategies and treatment in HIV positive individuals should be reviewed. | 18,769,804 |
[Integration of clinical and biological data in clinical practice using bioinformatics]. | The aim of our work is to describe essential aspects of Medical Informatics, Bioinformatics and Biomedical Informatics, that are used in biomedical research and clinical practice. These disciplines have emerged from the need to find new scientific and technical approaches to manage, store, analyze and report data generated in clinical practice and molecular biology and other medical specialties. It can be also useful to integrate research information generated in different areas of health care. Moreover, these disciplines are interdisciplinary and integrative, two key features not shared by other areas of medical knowledge. Finally, when Bioinformatics and Biomedical Informatics approach to medical investigation and practice are applied, a new discipline, called Clinical Bioinformatics, emerges. The latter requires a specific training program to create a new professional profile. We have not been able to find a specific training program in Clinical Bioinformatics in Spain. | 18,769,814 |
[Protocol based sedation versus conventional treatment in critically ill patients on mechanical ventilation]. | Sedatives and analgesic drugs give comfort and allow adequate respiratory support to critically ill patients in mechanical ventilation (MV). Its improper use may increase the duration of MV. Clinical guidelines suggest implementation of protocols, however this is seldom done in clinical practice. To compare in MV patients, nurse-applied guided by protocol administration of sedatives and analgesic drugs (protocol: group P) with the habitual practice using physicians criteria (control: group C). Inclusion criteria was the need of MV more than 48 h. The exclusion criteria were acute neurological diseases, hepatic cirrhosis, chronic renal failure and limitation of therapeutic efforts. Midazolam and fentanyl were used in both groups. The level of sedation was monitored with the Sedation Agitation Scale (SAS). In the P group, trained nurses applied algorithms to adjust the sedative doses according to a predefined SAS goal. Forty patients were included, 22 aged 65+/-19 years in group P and 18 aged 54+/-21 years in group C. Apache II scores were 16+/-8 and 19+/-8 in each group. SAS score was more frequently evaluated within goal boundaries in group P than in group C (44% and 32%, respectively p =0.001). No differences in the proportion of patients with inadequate sedation were observed between treatment groups. Midazolam doses were lower in P than in C group (0.04 (0.02-0.07) and 0.06 (0.03-0.08) mg/kg/h respectively, p =0.005). The implementation of sedation protocol applied by nurses improved the quality of sedation and reduced the doses of Midazolam in mechanically ventilated patients. | 18,769,826 |
[Present situation of hepatitis B in Chile]. | Hepatitis B virus infection generates carriers and 8% will evolve to a chronic phase. To perform a compilation of studies on hepatitis B in Chile and other sources of information to estimate the impact of this disease in our country. Published and unpublished evidence about the infection, in the general population and risk groups in our country, was compiled and reviewed critically. Informal interviews with experts, revision of the mandatory notification book of the Ministry of Health and collection of data from laboratories that study hepatitis B virus, were also carried out. The seroprevalence of chronic carriers in blood donors is nearly O.3%. Among risk groups such as health care personnel, the figure is O.7%, among homosexuals 29%, among HIV positive patients 30%, among sexual workers 2% and among children with chronic hemodialysis, 9%. Prevalence rate according to notified cases in 2004 was 1.8 x 100,000 inhabitants. Detection of viral hepatitis B surface antigen in laboratories occurs in 0.2% of donors and 1.396 of non donors. The seroprevalence of hepatitis B virus, the lack of notification, and the introduction of hepatitis B vaccine to our Regular Program of Immunizations, are arguments to develop in Chile a hepatitis B and C surveillance system. | 18,769,828 |
[Association between indoor contamination and respiratory diseases in children living in Temuco and Padre Las Casas, Chile]. | Indoor air pollution, is the main cause of population exposure to polluting agents. To establish an environmental profile of indoor contamination emission sources in families of children under 5 years that assist to kindergartens in Temuco and Padre Las Casas. To associate respiratory disease episodes in children with indoor contamination. Cross sectional analysis of 355 family groups subjected to questionnaires about indoor contamination and number of respiratory disease episodes. Forty six percent of mothers or caregivers smoked, 37% smoked at home and 93% smoked one to two cigarettes per day. There was a significant association between respiratory diseases in children and drying clothes in the kitchen, using firewood for heating and the presence of humidity in the dwelling. Mothers identified as indoor contaminants the use of braziers in 76% of cases and firewood stoves in 24%. Ninety seven percent considered that these appliances were detrimental for respiratory health. The lack of awareness about indoor contamination among subjects of low socioeconomic status should prompt educational campaigns to modify behaviors in their dwellings. | 18,769,835 |
[General considerations, indications and contraindications for liver transplantation in Chile: a multicenter consensus development document]. | Liver transplantation is an excellent therapeutic option for terminal liver disease. During the last decades the results of liver transplantation have improved significantly with a patient survival rate of nearly 90% at one year and 80% at 5 years of follow-up. The main indications for liver transplantation include: end-stage liver disease associated to cirrhosis, acute liver failure, and hepatic tumors (mainly hepatocarcinoma). The absolute contraindications for a transplant are less frequent than in the past, and include: severe co-morbidity (cardiac or pulmonary), sepsis, advanced HIV disease and extra-hepatic malignancy. This document presents a Consensus of the main groups performing liver transplantation in Chile, about its indications and contraindications. It also reviews general aspects of liver transplantation, including the selection and referral of liver transplant candidates, allocation of organs and the evaluation of severity of liver disease. | 18,769,839 |
Accuracy and inter-observer variation in the classification of dysarthria from speech recordings. | Dysarthria may be classified as flaccid, spastic, ataxic, hypokinetic, choreatic, dystonic, or mixed. We hypothesized that in routine neurological practice the reliability and accuracy of perceptual analysis alone in the classification of dysarthria is low and that this classification is mainly based on the clinical context rather than on the perception of speech. We therefore studied the accuracy and the inter- observer agreement in the classification of dysarthrias on the basis of perceptual analysis alone. Seventy two neurologists and neurological trainees classified recorded speech samples of 100 patients as flaccid, spastic, ataxic, extrapyramidal, or mixed dysarthria, or as not dysarthric. All observers were blinded to the patients' final diagnosis, which was based on all clinical features and investigations. In the analysis the observers were arranged in eight groups of nine observers, or four paired groups with similar levels of clinical experience. Together, the observers in a given group rated all 100 recordings. The accuracy of the classification was poor (35 % were classified correctly) and the inter-observer agreement between paired groups low (kappa 0.16 to 0.32). The level of experience in neurology did not have a significant influence. Neurological trainees as well as experienced neurologists have great difficulty in identifying specific types of dysarthria on the basis of perceptual analysis alone. In clinical practice this probably means that most neurologists will classify dysarthria in the context of other features from neurological examination or ancillary investigations. | 18,769,860 |
The in vitro anti-pathogenic activity of immunoglobulin concentrates extracted from ovine blood. | An immunoglobulin-rich fraction has been prepared from ovine blood in our laboratory. We have investigated its antibacterial activity and binding activity to pathogenic whole cell antigens, lipopolysaccharide (LPS) and staphylococcal enterotoxin B. Ovine immunoglobulin concentrate (OIC) comprised about 73 +/- 2% of IgG and 11 +/- 1% of IgM on a protein basis. It inhibited the growth of all 13 strains of pathogens tested, but the inhibitory activity varied according to bacterial strain. The inhibitory activity of OIC was attributed to the high contents of undenatured immunoglobulin present because its inhibitory activity was destroyed by pepsin digestion and heat treatment (65 degrees C for 30 min). OIC bound to all the Gram-positive and Gram-negative pathogens, regardless of cell wall structure. The highest magnitude of crossreactivity to whole cell antigens was against Staphylococcus epidermidis and Shigella soneii strains (p < 0.001). The binding activity of OIC to LPS obtained from Escherichia coli O111:B4 and Salmonella enterica serotype typhimurium was assessed by enzyme-linked immunosorbent assay and lymphoblast K-562 proliferation assay. OIC bound to LPS with a binding activity that was dependent on OIC concentration and saturable, showing typical hyperbolic curves. For toxin-binding activity, an OIC concentration-dependent trend like that for LPS-binding activity was also observed. This preliminary evidence suggests that the OIC used in this study could be a promising supplement for protecting against pathogenic bacteria. | 18,769,875 |
Stress response kinetics of two nisin producer strains of Lactococcus lactis spp. lactis. | The purpose of this study is to determine the survival and nisin production behaviors of two strains of Lactococcus lactis under different stress conditions that represent the food ecosystem. In this respect, the survival ratios of two nisin producers were determined under different pH, temperature, NaCl, and bile salt concentrations. Then, nisin production levels of the strains were determined at each stress conditions. Both strains had similar growth or inactivation patterns under the same stress conditions. NaCl and bile salt stresses on the survival ratio of the strains could be successfully described by the exponential decay function, whereas Gaussian function produced good fits for temperature and pH stresses. The nisin activity of two nisin producers (in their mid-exponential and/or early stationary phase) decreased dramatically under all stress conditions, except osmotic (NaCl) and low temperature applications. The results of this study showed that two nisin producers had similar adaptive responses under severe stress conditions, which could be described by appropriate mathematical equations. Moreover, the effect of harsh environment on the nisin activity of L. lactis strains depends on the stress factors applied. | 18,769,876 |
Effects of soya fatty acids on cassava ethanol fermentation. | Ethanol tolerance is a key trait of microbes in bioethanol production. Previous studies have shown that soya flour contributed to the increase of ethanol tolerance of yeast cells. In this paper, the mechanism of this ethanol tolerance improvement was investigated in cassava ethanol fermentation supplemented with soya flour or defatted soya flour, respectively. Experiment results showed that ethanol tolerance of cells from soya flour supplemented medium increased by 4-6% (v/v) than the control with defatted soya flour. Microscopic observation found that soya flour can retain the cell shape while dramatic elongations of cells were observed with the defatted soya flour supplemented medium. Unsaturated fatty acids (UFAs) compositions of cell membrane were analyzed and the UFAs amounts increased significantly in all tested strains grown in soya flour supplemented medium. Growth study also showed that soya flour stimulated the cell growth rate by approximately tenfolds at 72-h fermentation. All these results suggested that soya fatty acids play an important role to protect yeast cells from ethanol stress during fermentation process. | 18,769,879 |
Rational design and study on recognition property of paracetamol-imprinted polymer. | The design and study on recognition of paracetamol-imprinted polymer for application in quantification of drugs was reported. Base on our previous work, the promising monomer, itaconic acid (IA), was computationally selected rapidly from the virtual library using the interaction energy (DeltaE) between a paracetamol (PR) molecule and four monomer molecules as a measure of their interaction. The possible conformation of PR interacting with IA displayed the nature of the interaction between PR and IA; hydrogen bonds (hbs) mainly contribute to this interaction. UV spectra analysis confirmed the occurrence of the hbs interaction between PR and IA at the polymerization stage. The optimal solvents for porogen and eluant were determined by the strength of hbs interaction between PR and the solvents, which were calculated employing density functional theory. The corresponding molecularly imprinted polymers (MIPs) and non-imprinted polymers were prepared and evaluated. The experimental results were consistent with those calculated, which confirmed the validity of the above-related calculation believed to facilitate the selection of monomers and solvents for the synthesis of MIP at molecular level. | 18,769,881 |
Isolation and characterization of low-molecular-weight chromium-binding substance (LMWCr) from chicken liver. | Chromodulin (also known as low-molecular-weight chromium-binding substance, LMWCr) is a chromium-binding oligopeptide proposed to play a role in insulin signaling and chromium transport in mammals. This laboratory has isolated and purified this material from a non-mammalian source, an avian. Spectroscopic and physical characterization of the isolated material suggests the material is an oligopeptide with a multinuclear chromium assembly bridged via asparatate and glutamate residues very similar to its mammalian counterparts. The isolated material also possesses a biological activity similar to other LMWCr isolates. | 18,769,887 |
A study of acute febrile encephalopathy with special reference to viral etiology. | To study the etiological profile of patients with acute febrile encephalopathy syndrome focusing chiefly on the viral etiology, and to correlate clinical and radiological features of patients with viral encephalitis. A prospective hospital based study conducted on the consecutive patients admitted in a pediatric unit during the period of 1(st) February 2004 to 31st January 2005 based on the following inclusion criteria: (1) Age more than 1 month and less than 18 years and (2) A diagnoses of acute febrile encephalopathy, based on the following criteria: (i) fever (ii) acute depression of consciousness or mental deterioration for more than 12 hours with or without motor or sensory deficit and (iii) Total duration of illness at the time of admission 1 week or less. The final study group comprised of 151 patients with mean age of 3.21 +/- 2.9 (range of mth-13 years) and male: female ratio of 1.71: 1. A diagnosis other than viral encephalitis was reached in 94 patients (62.3 %). Pyogenic meningitis was the most frequent diagnosis 51(33.8 %) followed by tubercular meningitis 12 (7.9 %), and cerebral malaria 8 (5.2 %) in the patient group of non-viral causes. Fifty-seven cases (37.3%) were suspected as viral encephalitis and mean age of the cases suspected as viral encephalitis was 2.8 +/- 2.9 (Range 1 mth-10 yrs) with male: female ratio of 1.28: 1. Etiological diagnosis was reached or considered probable in 41 (72%) cases out of the suspected patients. The most common etiological agent identified was enterovirus 71 in 20 patients (35.1 %). The other viruses identified were mumps in 6 (10.5%), Japanese encephalitis in 5 (8.7%), and measles in 4 (7%) cases. MRI brain was done in 39 patients and was abnormal in 14 patients. Out of 57 cases of suspected viral encephalitis 10 patients expired within 48 hours, 2 > 48 hours and 19 atients had significant neurological sequels at discharge. The etiology of acute febrile encephalopathy varies from infectious etiologies to noninfectious metabolic disorders. There are no distinguishing clinical or radiological features to differentiate the various causes of viral encephalitis. The clinical and the radiological findings in encephalitis should be interpreted in the geographical and other epidemiological background. | 18,769,890 |
Recent advances in sepsis and septic shock. | Sepsis remains a common problem in all age groups. Recently surviving sepsis campaign has taken up a worldwide initiative by publishing international guidelines 2008 with a hope to disseminate information regarding management of sepsis for all age groups. This article presents a review of recent advances as they apply to pediatric age group supported by the available evidence with reference to standard definitions of pediatric sepsis and septic shock and management in the emergency room and pediatric intensive care unit. | 18,769,894 |
Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial. | Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus. All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped alpha-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA(1c) 7.9 +/- 1%, n = 12) and healthy controls (HbA(1c) 4.6 +/- 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion. Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO.) radicals (a(nitrogen) = 1.37 mT and abeta(hydrogen) = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable. These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood. ISRCTN96164937. | 18,769,906 |
Effects of oxidation, pH and lipids on amyloidogenic peptide structure: implications for fibril formation? | We have performed experimental and computational studies to investigate the influences of phospholipids, methionine oxidation and acidic pH on amyloid fibril formation by a peptide derived from human apolipoprotein C-II (apoC-II), a known component of proteinaceous atherosclerotic plaques. Fibril growth monitored by thioflavin T fluorescence revealed inhibition under lipid-rich and oxidising conditions. We subsequently performed fully-solvated atomistic molecular dynamics (MD) simulations of the peptide monomer to study its conformations under both fibril favouring (neutral and low pH) and inhibiting (lipid-rich and oxidising) conditions. Examination of the chain topology, backbone hydrogen-bonding patterns and aromatic sidechain orientations of the peptide under different conditions reveals that, while the peptide adopts similar structures under the fibril-favouring conditions, significantly different structures are obtained under fibril-disruptive conditions. Based on our results, we advance hypotheses for the roles of peptide conformation on aggregation and fibrillisation propensities. | 18,769,912 |
Expression of hepatocyte growth factor activator inhibitor type 1 on the epithelial cell surface is regulated by hypoxic and oxidative stresses. | Hepatocyte growth factor activator inhibitor type 1 (HAI-1)/spint-1 is a membrane-bound protease inhibitor that is thought to regulate the activities of hepatocyte growth factor activator, matriptase, hepsin, and prostasin. In this study, we show that the membrane form of HAI-1 was significantly upregulated immunohistochemically in epithelial cells under adverse conditions including tissue injury, necroinflammatory reactions, and invasion of carcinomas. To analyze the mechanism underlying these in vivo observations, we examined the effects of hypoxia and oxidative stress on HAI-1 expression in vitro, using three human cell lines, HLC-1, WiDr, and HeLa. Hypoxic condition significantly enhanced the expression of HAI-1 in these cells. Oxidative stress also enhanced HAI-1 expression. Promoter analyses of the human HAI-1/spint-1 gene revealed overlapping binding site for Egr-1-3 and Sp1 near the transcription start site as the key domain for HAI-1/spint-1 transcription. This site was also critical in both hypoxic- and oxidative stress-induced HAI-1 upregulation. In fact, in vivo immunohistochemical studies indicated that areas with HAI-1 upregulation tended to express markers associated with hypoxia and oxidative stress. These observations suggest that the tissue microenvironment regulates the cell surface expression of HAI-1, and thereby may regulate proteolysis and processing of bioactive molecules on the cellular surface. | 18,769,935 |
Necrotic granulomatous pseudotumours in bilateral resurfacing hip arthoplasties: evidence for a type IV immune response. | Clinical, radiological and histological findings were analysed in four patients who developed bilateral pseudotumours following metal-on-metal (MoM) resurfacing arthroplasties of both hips. Using a panel of monoclonal antibodies directed against HLA-DR, macrophages (CD14, CD68), dendritic cells (DC-SIGN, S100, CD11c), B cells (CD20), and T cells (CD3, CD4, CD8), the nature of the heavy inflammatory response seen in these cases was examined. Bilateral masses developed in periprosthetic soft tissues following the second MoM arthroplasty; these were characterised histologically by extensive coagulative necrosis, a heavy macrophage infiltrate and the presence of granulomas containing macrophages and giant cells; there was also a diffuse lymphocyte and variable plasma cell and eosinophil polymorph infiltrate. Immunohistochemistry showed strong expression of HLA-DR, CD14 and CD68 in both granulomatous and necrotic areas; lymphocytes were predominantly CD3+/CD4+ T cells. The clinical, morphological and immunophenotypic features of these necrotic granulomatous pseudotumours, which in all cases develop following a second resurfacing hip arthroplasty, is suggestive of a type IV immune response, possibly to MoM metal alloy components. | 18,769,936 |
The pre-lymphatic pathway, the rooths of the lymphatic system in breast tissue: a 3D study. | Three-dimensional (3D) visualisation of microscopic structures provides useful information about their configuration and the spatial (hence functional) relationship between different components in tissues. This paper describes 3D dynamic reconstructions of the pre-lymphatic labyrinth in two cases of "normal" breast core biopsies and one case of pseudoangiomatous stromal hyperplasia. Direct anastomoses between pre-lymphatic channels and true lymphatics of the breast were demonstrated. It is concluded that pre-lymphatics are a way of communication between breast epithelial/stromal structures and the main lymphatic system. The present findings suggest that the existence of pre-lymphatics has to be taken in consideration in the intramammary spread of malignant tumours. | 18,769,937 |
Metabolic tumor width parameters as determined on PET/CT predict disease-free survival and treatment response in squamous cell carcinoma of the esophagus. | We investigated the utility of metabolic tumor width parameters in predicting response to chemoradiotherapy and in predicting disease-free survival in patients with esophageal cancer. Furthermore, we evaluated the possible confounding effect of therapy-induced esophagitis on the evaluation of treatment response. Forty-nine patients with squamous cell carcinoma, who had undergone positron emission tomography/computed tomography (PET/CT) exams before and after neoadjuvant chemoradiotherapy, were included in the study. In the slice with the maximum 2-deoxy-2-[F-18]fluoro-D: -glucose (FDG) uptake of the tumor, the following metabolic tumor width parameters were measured: Area of the tumor, maximum diameter of the tumor, maximum and mean standardized uptake value (SUV). Furthermore, the "diameter-SUV index" was calculated by multiplying the tumor diameter by the mean SUV. The decrease of the metabolic tumor diameter between pre- and post-treatment PET/CT scans was the single best predictor of treatment response and tumor-free survival. However, the accuracy of predicting response and survival was even higher when using the decrease of the "diameter-SUV index" as the metabolic criterion for treatment response. A decrease by more than 55% of the diameter-SUV index identified pathologic responders (n = 22) with a sensitivity of 91% and a specificity of 93%. Radiation esophagitis was found to have a significant impact on the assessment of treatment response when evaluating therapy response based on the maximum SUV, whereas no confounding effect of radiation esophagitis was seen when evaluating therapy response based on the tumor diameter or the diameter-SUV index. The present study shows that tumor width parameters, especially the tumor diameter or the combination of diameter and SUV in the "diameter-SUV index", are valuable for predicting tumor-free survival and treatment response independent from the presence of radiation esophagitis. | 18,769,974 |
Prognostication in acutely admitted older patients by nurses and physicians. | The process of prognostication has not been described for acutely hospitalized older patients. To investigate (1) which factors are associated with 90-day mortality risk in a group of acutely hospitalized older medical patients, and (2) whether adding a clinical impression score of nurses or physicians improves the discriminatory ability of mortality prediction. Prospective cohort study. Four hundred and sixty-three medical patients 65 years or older acutely admitted from November 1, 2002, through July 1, 2005, to a 1024-bed tertiary university teaching hospital. At admission, the attending nurse and physician were asked to give a clinical impression score for the illness the patient was admitted for. This score ranged from 1 (high possibility of a good outcome) until 10 (high possibility of a bad outcome, including mortality). Of all patients baseline characteristics and clinical parameters were collected. Mortality was registered up to 90 days after admission. In total, 23.8% (n = 110) of patients died within 90 days of admission. Four parameters were significantly associated with mortality risk: functional impairment, diagnosis malignancy, co-morbidities and high urea nitrogen serum levels. The AUC for the baseline model which included these risk factors (model 1) was 0.76 (95% CI 0.71 to 0.82). The AUC for the model using the risk factors and the clinical impression score of the physician (model 2) was 0.77 (0.71 to 0.82). The AUC for the model using the risk factors and the clinical impression score of the nurse (model 3) was 0.76 (0.71 to 0.82) and the AUC for the model, including the baseline covariates and the clinical impression score of both nurses and physicians was 0.77 (0.72 to 0.82). Adding clinical impression scores to model 1 did not significantly improve its accuracy. A set of four clinical variables predicted mortality risk in acutely hospitalized older patients quite well. Adding clinical impression scores of nurses, physicians or both did not improve the discriminating ability of the model. | 18,769,983 |
The spectrum of abdominal tuberculosis in a developed country: a single institution's experience over 7 years. | The incidence of human immunodeficiency virus (HIV) infection is rising, and as a result, tuberculosis (TB) has become a resurgent problem in many developed countries. The aim of this study was to review the spectrum of abdominal TB and its surgical management in our institution. A retrospective review of all abdominal TB cases notified to the health authorities by our institution from Jan 01 to Oct 07 was performed. There were 57 patients (37 men) with abdominal TB, with a median age of 47 (range 14-74) years. Active pulmonary TB was present in 27 patients (47%). Positive HIV status was present in 30% and untested in 58%. The majority of patients underwent computed tomography scans (n = 50, 88%). The main radiological findings included bowel thickening, lymphadenopathy, ascites, free gas suggestive of perforation, and abscesses. The diagnosis of TB was confirmed on microbiological and/or histological examination in 72%, while the remaining 28% were diagnosed based on the clinical presentation and radiological imaging. All patients were commenced on anti-tuberculous therapy. TB involved the small or large bowel in 33 patients, mesenteric lymphadenopathy in 24, peritoneum in 13, spleen in seven, pancreas in two, anus in two, and the liver in two. Disseminated (including pulmonary) TB occurred in 27 patients (47%), while isolated intra-abdominal TB occurred in the remaining 30 patients (53%). Twenty-five patients (44%) underwent surgery--16 laparotomies (six perforated viscus, five intestinal obstruction, three suspected malignancies, and two for suspected acute abdomen), five laparoscopic procedures (four diagnostic, one gastrojejunostomy bypass for gastric outlet obstruction), two appendectomies, one drainage of abscess, and one anal fistulotomy. Although TB is eminently treatable medically, surgery is still often required for suspected or confirmed abdominal TB presenting with acute complications or as atypical diagnostic problems. The role of laparoscopy is likely to be more significant in future in the management of abdominal TB. | 18,769,984 |
Simultaneous microwave ablation using multiple antennas in explanted bovine livers: relationship between ablative zone and antenna. | Our purpose was to determine the optimal antenna spacing to achieve large ablative zones without indentations when microwave ablation is performed with simultaneous activation of two or three antennas. Microwave ablation was performed with single-antenna activation and simultaneous activation of two or three antennas with a spacing of 1.5, 2.0, 2.5, or 3.0 cm in explanted bovine livers. Microwave energy was applied for 10 min with a power of 45 W. The shapes and sizes of the ablative zones created were recorded and compared. The shape of the ablative zone was ellipsoid in the axial plane (along the antenna axis) and spherical in the transverse plane (perpendicular to the antenna axis) in single-antenna ablation. The ablative zones were spherical or ellipsoid in both the axial and transverse planes in two-and three-antenna ablation with an antenna spacing of 2.0 cm or less. Indentations were observed between the ablative zones created by the antennas when the spacing was 2.5 cm or more, reducing the minimum transverse diameter. When two-or three-antenna ablation was performed with a spacing of 2.0 cm or less, the axial and minimum transverse diameters were significantly larger than in single-antenna ablation. The largest volume (almost two or three times the single-activation volume) was achieved in two-or three-antenna ablation with an antenna spacing of 2.0 cm. We found that simultaneous microwave ablation using multiple microwave antennas creates large ablative zones without indentations when multiple antennas are activated with an antenna spacing of 2.0 cm or less. | 18,769,998 |
"Prominent ear sign" on diffusion-weighted magnetic resonance imaging in relapsing polychondritis. | Relapsing polychondritis is a rare autoimmune disease characterized by recurrent inflammation of cartilage in multiple sites of the body, including the auricles. Central nervous system involvement appears rare. We encountered a case of relapsing polychondritis with encephalitis that could be diagnosed by the unique appearance of the auricle with signal hyperintensity on diffusion-weighted magnetic resonance imaging. | 18,770,003 |
Recollections of Thomas John Wydrzynski. | In appreciation of his contribution to the Photosystsem II research and commemoration of the book Photosystem II: The Light-Driven Water-Plastoquinone Oxido-Reductase, co-edited with Kimiyuki Satoh, I present here some of my recollections of Thomas John Wydrzynski and by several others with whom he has associated over the years at Urbana (Illinois), Berkeley (California), Standard Oil Company-Indiana (Illinois), Berlin (Germany), Gothenburg (Sweden), and Canberra (Australia). We not only recognize him for his unique career path in Photosystem II research, but also for his qualities as a collaborative scientist working on the only system on Earth that has the ability to oxidize water to molecular oxygen using the energy of sunlight. | 18,770,010 |
Genomic characterization of a novel partitivirus infecting. Aspergillus ochraceus. | Three double-stranded RNA (dsRNA) segments from Aspergillus ochraceus isolate FA 0611, designated as AoR1, AoR2, and AoR3, were cloned and sequenced. AoR1 was identical with AoV dsRNA 1 previously reported from A. ochraceus ATCC 28706, which putatively encoded an RNA-dependent RNA polymerase of an unidentified mycovirus. AoR2 was found to encode a putative viral capsid protein (CP) with 63% similarity to that of Penicillium stoloniferum virus S, which was detected from P. stoloniferum ATCC 14586. The function of AoR3 was unknown. The three segments were found to contain a conserved sequence at their 5' termini, while an identical sequence was only found at the 3' termini of AoR1 and AoR2. It is suggested that AoR1, AoR2, and AoR3 originate from an independent partitivirus infecting A. ochraceus. The novel virus is suggested to be Aspergillus ochraceus virus 1, AoV1. | 18,770,020 |
Does meeting the HEDIS substance abuse treatment engagement criterion predict patient outcomes? | This study examines the patient-level associations between the Health Plan Employer Data and Information Set (HEDIS) substance use disorder (SUD) treatment engagement quality indicator and improvements in clinical outcomes. Administrative and survey data from 2,789 US Department of Veterans Affairs SUD patients were used to estimate the effects of meeting the HEDIS engagement criterion on improvements in Addiction Severity Index Alcohol, Drug, and Legal composite scores. Patients meeting the engagement indicator improved significantly more in all domains than patients who did not engage, and the relationship was stronger for alcohol and legal outcomes for patients seen in outpatient settings. The benefit accrued by those who engaged was statistically significant but clinically modest. These results add to the literature documenting the clinical benefits of treatment entry and engagement. Although these findings only indirectly support the use of the HEDIS engagement measure for its intended purpose-discriminating quality at the facility or system level-they confirm that the processes of care captured by the measure are associated with important patient outcomes. | 18,770,044 |
Targeted transport of 125I-labeled antibody to GFAP and AMVB1 in an experimental rat model of C6 glioma. | Glioblastoma is the most common high-grade glioma characterized by strikingly poor therapeutic outcome with survival time of about a year. This makes a search for new therapeutic approaches to glioblastoma treatment an area of great clinical importance. The present study aims to explore the potential of targeted delivery of 125I-radiolabeled antibodies, specific to glial fibrillary acidic protein (GFAP) and AMVB1 (antigen of abluminal membrane of endotheliocytes predominantly expressed in glioblastoma microvessels) as a strategy for in vivo tumor targeting. Rat C6 glioma model was used to test this hypothesis. Tumor bearing animals, injected with radiolabeled monoclonal antibodies to GFAP or AMVB1, were compared to control group, which received nonspecific mouse IgG. Radioactivity of blood, brain hemispheres, and some other tissues was measured 6, 24, 48, 72, and 96 h posttreatment. Our results demonstrate accumulation of both types of antibodies in tumors. Concentrations of both antibodies were significantly increased in tumor-bearing hemisphere compared to intact hemisphere. Antibodies to GFAP specifically accumulated in brain and bound tumor tissue with the high affinity. In contrast, increased accumulation of anti-AMVB1 antibody was detected in antigen-expressing organs, such as spleen and kidney. Based on results presented, we propose that the monoclonal antibodies to GFAP can be used as vectors for the delivery of diagnostic and pharmacological agents to high-grade gliomas. Development of this strategy would open new clinical perspectives for glioblastoma diagnostics and therapy. | 18,770,045 |
Systemic treatments for mesothelioma: standard and novel. | Systemic therapy is the only treatment option for the majority of mesothelioma patients, for whom age, co-morbid medical illnesses, non-epithelial histology, and locally advanced disease often preclude surgery. For many years, chemotherapy had a minimal impact on the natural history of this cancer, engendering considerable nihilism. Countless drugs were evaluated, most of which achieved response rates below 20% and median survival of <1 year. Several factors have hampered the evaluation of systemic regimens in patients with mesothelioma. The disease is uncommon, affecting only about 2500 Americans annually. Thus, most clinical trials are small, and randomized studies are challenging to accrue. There is significant heterogeneity within the patient populations of these small trials, for several reasons. Since all of the staging systems for mesothelioma are surgically based, it is almost impossible to accurately determine the stage of a patient who has not been resected. Patients with very early stage disease may be lumped together with far more advanced patients in the same study. The disease itself is heterogenous, with many different prognostic factors, most notably three pathologic subtypes--epithelial, sarcomatoid, and biphasic--that have different natural histories, and varying responses to treatment. Finally, response assessment is problematic, since pleural-based lesions are difficult to measure accurately and reproducibly. Assessment criteria often vary between trials, making some cross-trial comparisons difficult to interpret. Despite these limitations, in recent years, there has been a surge of optimism regarding systemic treatment of this disease. Several cytotoxic agents have been shown to generate reproducible responses, improve quality of life, or prolong survival in mesothelioma. Drugs with single-agent activity include pemetrexed, raltitrexed, vinorelbine, and vinflunine. The addition of pemetrexed or raltitrexed to cisplatin prolongs survival. The addition of cisplatin to pemetrexed, raltitrexed, gemcitabine, irinotecan, or vinorelbine improves response rate. The combination of pemetrexed plus cisplatin is considered the benchmark front-line regimen for this disease, based on a phase III trial in 456 patients that yielded a response rate of 41% and a median survival of 12.1 months. Vitamin supplementation with folic acid is essential to decrease toxicity, though recent data suggests that there may be an optimum dose of folic acid that should be administered; higher doses may diminish the effectiveness of pemetrexed. There are also several unresolved questions about the duration and timing of treatment with pemetrexed that are the subject of planned clinical trials. It is essential to recognize that the improvements observed with the pemetrexed/cisplatin combination, though real, are still modest. Other active drugs or drug combinations may be more appropriate for specific individuals, and further research is still needed to improve upon these results. Since the majority of mesotheliomas in the United States occur in the elderly, non-cisplatin-containing pemetrexed combinations may be more appropriate for some patients. Now that effective agents have been developed for initial treatment, several classical cytotoxic drugs and many novel agents are being evaluated in the second-line setting. These include drugs targeted against the epidermal growth factor, platelet-derived growth factor, vascular endothelial growth factor, src kinase, histone deacetylase, the proteasome, and mesothelin. Given the progress made in recent years, there is reason to believe that more effective treatments will continue to be developed. | 18,770,046 |
Antidepressant treatment of depression in rural nursing home residents. | Under-diagnosis and under-treatment of depression are major problems in nursing home residents. The purpose of this study was to determine antidepressant use among nursing home residents who were diagnosed with depression using three different methods: (1) the Geriatric Depression Scale, (2) Minimum Data Set, and (3) primary care provider assessments. As one would expect, the odds of being treated with an antidepressant were about eight times higher for those diagnosed as depressed by the primary care provider compared to the Geriatric Depression Scale or the Minimum Data Set. Men were less likely to be diagnosed and treated with antidepressants by their primary care provider than women. Depression detected by nurses through the Minimum Data Set was treated at a lower rate with antidepressants, which generates issues related to interprofessional communication, nursing staff communication, and the need for geropsychiatric role models in nursing homes. | 18,770,101 |
Further studies on vertical transmission of reticuloendotheliosis virus in turkeys. | Turkey hens were inseminated with infected semen from REV tolerant turkey stags at weekly intervals for 6 weeks, and subsequently with semen from uninfected control stags for a further 6 weeks. Cell cultures prepared from eggs produced during the experimental period were assayed for REV by an indirect fluorescent antibody test. Poults hatched from such eggs were also assayed for REV at 1 day of age or maintained to 28 weeks of age to study lateral spread of virus to uninfected hatch mates. REV was detected in 27.5% of embryos from hens inseminated with REV infected semen and 8.7% of 1-day-old poults hatched were found to be viraemic. Following the change to insemination with uninfected semen, REV was detected in 0.7% of embryos examined. REV was isolated from the lower oviduct of two of 18 hens, 12 weeks after first insemination with infected semen. REV spread readily to uninfected poults maintained in contact with progeny of hens inseminated with REV-infected semen, in that 50% had neutralising antibody by 8 weeks of age. At 28 weeks of age the leukosis mortality in such poults was 16%. | 18,770,135 |
Renal pathology of the fowl--a review. | On the basis of published literature and some original observations a comprehensive review is presented of the current concept of renal diseases in the fowl. All aspects of this important but much neglected subject are considered including autolysis, intoxications, inflammatory and degenerative conditions, specific viral diseases, gout, congenital abnormalities and neoplasms. The aetiology and pathogenesis of some forms of avian kidney disease are well understood but there are large gaps in our knowledge on others. | 18,770,139 |
Isolation of influenza a viruses from commercial ducks on a farm in Norfolk between August 1979 and March 1980. | Investigation of respiratory disease and high mortality which occurred on a commercial duck fattening farm between August 1979 and March 1980 resulted in the isolation of 10 influenza A viruses. The viruses were characterised as Hav6 N2 (three isolates), Hav4 Navl (four isolates), Hav4 Nl (two isolates) and Hav7 Neq2 (one isolate) subtypes by haemagglutination-inhibition and neuraminidase-inhibition tests. A Newcastle disease virus isolate was also obtained from the ducks. All isolates had low intravenous pathogenicity indices in 6-week-old chickens. | 18,770,140 |
Arthritis in ducks. II. Condemnation rate, economic significance and possible preventive measures. | During the period 1959 to 1968 0.4% of ducks slaughtered in Denmark were condemned because they had arthritis. The condemnation rate due to arthritis decreased 2 years after compulsory measures to control salmonella infections were introduced and in the 10 years from 1969 to 1978 this condemnation rate was 0.12%. The condemnation rate due to arthritis was relatively high during the period 1961 to 1967. A positive correlation between the condemnation rate due to arthritis and the number of ducks slaughtered and the overall condemnation rate existed at this time. Seasonal variations in the condemnation rate due to arthritis were observed. Mallards were found to be less susceptible to arthritis than White Pekin and Muscovy ducks reared under the same conditions. The hock was most frequently affected (43%) with arthritis. In 37% of arthritic birds the knee was affected, hip and toe joints being affected in 18% and 1% of cases respectively. Wing joints were affected in less than 1% of cases. The national annual cost of arthritis from 1959-1968 was estimated at 207, 579 Danish crowns. In the subsequent 10 years the cost was only one third of this sum. | 18,770,146 |
Aerosol vaccination against Newcastle disease: factors affecting the serological response in chickens. | The effects of vaccine diluent and virus concentration on the immune response following aerosol vaccination against Newcastle Disease (ND) were studied. Four diluents (saline, tap water, distilled water and 2% casitone in distilled water) were used with various concentrations of LaSota strain virus. At low virus concentrations 2% casitone produced a higher HI antibody response than the other diluents. However, when the virus was administered in concentrations exceeding 7.4 +/- 0.4 logioEID50/m3, the recommended field dosage, virus suspensions in 2% casitone, distilled water and non-chlorinated tap water produced similar responses. The effect of virus concentration on the immune response was studied in 12- to 14-week-old chickens with or without residual immunity. Tenfold dilutions of ND virus of the LaSota strain were applied intratracheally or by aerosol and haemagglutination inhibition titres measured 2 and 4 weeks later. The dose producing an antibody response in 50% of the chickens was calculated both after intratracheal application and after aerosol vaccination. After intratracheal application doses of 0.9 log(10) EID50 and 1.8 log(10)EID50 were required to obtain a 50% response in specific pathogen free chickens and chickens with residual immunity respectively. When the virus was applied by aerosol 5.0 and 6.0 to 7.0 log(10)EID50/m3 were required to produce a 50% response in chickens without and with residual immunity, respectively. | 18,770,147 |
Longitudinal studies on the egg drop syndrome 1976 (eds-76) in the fowl following experimental infection at 1-day-old. | Following oral infection of 1-day-old chicks with egg drop syndrome - 1976 (EDS-76) virus (strain D61) lateral transmission of the virus was demonstrated throughout the rearing period. At point of lay, pullets previously infected at 1-day-old responded to EDS-76 inactivated vaccine given intramuscularly with a pronounced rise in haemagglutination inhibition antibody titre, but failed to respond to oral challenge with live virus. Egg production and shell quality were not affected following EDS-76 infection at 1-day-old, but egg weight was reduced and internal egg quality adversely affected. | 18,770,160 |
Idiopathic polyneuritis in SPF chickens. | Paralysis due to peripheral neuritis occurred sporadically in a flock of Rhode Island Red chickens over a period of 8 years and is named idiopathic neuritis (IP). The flock was housed in isolators and free from many common pathogens including all known neurotropic viruses of chickens. The pathology of the nerve lesions, including their ultrastructure, is described and comparisons made with the lesions of Marek's disease and experimental allergic neuritis in chickens. Demyelination with invasion of nerve fibres with lymphocytes and macrophages occurs in all three diseases but there are differences in lesion distribution and intensity of cellular infiltration. The closest similarity is between the lesions of IP and the B-type lesions of Marek's disease. Attempts to isolate a cytopathic virus and to transmit the disease by inoculation failed to demonstrate an infectious causal agent. An autoimmune response to normal nerve is suggested as the most likely aetiology amongst several alternatives. The heritability of IP is not established, but the disease has not been detected in a light Sussex flock maintained under similar conditions. | 18,770,181 |
Bacterial and viral agents associated with tenosynovitis in broiler breeders in Western Australia. | The pathology and infectious agents associated with several outbreaks of clinical tenosynovitis in poultry were investigated. Staphylococcus aureus were recovered from tendon tissue of from 51.9% to 97.8% of affected chickens in different outbreaks of the disease. S. aureus were also present in the liver and heart blood and were considered to contribute to the high mortality observed following occurrence of clinical tenosynovitis in individual chickens. Bacteria other than S. aureus were also recovered but in a much lower proportion of chickens than was S. aureus. Adenoviruses and reoviruses were also recovered from tendon tissue of chickens with a concurrent bacterial infection. Although the pathology observed in clinically affected chickens was suggestive of a bacterial aetiology it is hypothesised that the tenosynovitis outbreaks investigated were due to an early viral infection which normally remained subclinical and that secondary infection with bacteria, particularly S. aureus, was responsible for the development of clinical signs. | 18,770,201 |
A survey of tuberculosis in birds in the Regent's Park gardens of the Zoological Society of London. | A total of 5,177 avian post mortem examinations was carried out at the Regent's Park gardens of the Zoological Society of London between 1966 and 1978 inclusive. Avian tuberculosis was found in 13 different avian orders. A total of 112 birds (2.2%) was affected; 2.1% from Regent's Park Zoo and 2.4% from other sources. The diagnosis of tuberculosis was based on the demonstration of acid-fast bacilli in association with lesions in fresh or fixed tissues stained by Ziehl-Neelsen's procedure and by cultural methods. Mycobacterium avium (including M. intracellulare) was isolated from 12 specimens, unidentified Mycobacterium spp. from 12, and M. fortuitum from one. The overall occurrence during the 13-year period of observation did not appear to decline although seasonal and yearly fluctuations were noted. No sex predilection was found and the disease generally occurred in birds that had been in captivity for many years. Avian tuberculosis was diagnosed in three free-living wood pigeons (Columba palumbus) trapped in the Zoo grounds. These birds may contribute to the transmission of the disease to other species. A high incidence of tuberculosis was found in the Anseriformes, Gruiformes and Columbiformes, but the disease appeared to be rare in the Psittaciformes, Passeriformes, Spherdsciformes and Strigiformes. | 18,770,222 |
Infectious stunting and leg weakness in broilers. II. Studies on alkaline phosphatase isoenzymes in blood plasma. | Total alkaline phosphatase (ALP) activity in blood plasma of broilers suffering from infectious stunting after artificial infection was constantly higher than that of uninoculated control birds. While total ALP activity in blood plasma from inoculated broilers of various ages decreased after incubation at 56 degrees C, it increased in similarly treated plasma collected from broilers at 3, 21 and 28 days after inoculation. Investigations into the organ origin of the plasma ALP isoenzymes with agarose electrophoresis, column chromatography, L phenylalanine inhibition and heat treatment showed that the main part of ALP activity in blood plasma of both, inoculated and uninoculated birds was most likely of intestinal origin. In 3-day-old broilers no heat sensitive part of total ALP could be measured. | 18,770,251 |
Serological survey for the prevalence of antibodies to egg drop syndrome 1976 virus in domesticated and wild birds in Israel. | A serological survey of chicken, turkey, goose and duck flocks for the presence of antibodies to egg drop syndrome virus 1976 (EDS 76) has been carried out in Israel. In most of the chicken flocks sampled egg production was not normal, but no antibodies against this virus were detected. Likewise, turkey breeding flocks were similarly negative. All Pekin duck flocks tested showed some serological activity. Muscovy ducks that were reared in direct or indirect contact with Pekin ducks had haemagglutination-inhibition antibodies to EDS 76 virus. Seven cattle egrets trapped on a duck farm were serologically positive. No antibodies were detected in a collection of water fowl raised in a zoological garden. | 18,770,279 |
Potency of live Newcastle disease vaccines. | A comparison was made of the potency of live lentogenic Newcastle disease vaccines using a multipoint challenge assay. In general, La Sota vaccines gave better protection than B1 vaccines and both were superior to products made from the Ulster 2C strain. However, variation was found within products prepared from the same strains, depending on their source. Two novel types of vaccine derived from the conventional B1 or La Sota strains were as protective as La Sota vaccines and a third gave protection similar to that of B1 vaccines. | 18,770,283 |
Effect of the removal of the Harderian gland in 1-day-old chicks on immunity following IB vaccination. | After removal of the Harderian gland in 1-day-old chicks (Hx birds), protective immunity to infectious bronchitis virus (IBV) was decreased 3 weeks after vaccination with the H120 strain of IBV. Protective immunity was measured by challenge. The decreased protection was not reflected in the neutralisation indices of the Hx birds. In contrast, the mean neutralisation index was higher in the Hx birds than in the vaccinated controls. The role of the lachrymal gland in the development of immunity to IBV is discussed. | 18,770,290 |
Antibodies to egg-drop syndrome 76 virus in wild birds in possible conjunction with egg-shell problems. | Antibodies against egg drop syndrome 1976 (EDS 76) virus (strain 127) were detected with the aid of the haemagglutination inhibition test and virus neutralisation test in serum samples of two out of 381 owls, in one out of four storks, in one out of two swans and in one out of 18 wild geese. The antibody positive two owls and the stork laid eggs with a malformed shell. No antibodies against EDS 76 virus were detected in sera of 16 partridges, 28 pheasants, and 72 birds of prey. | 18,770,301 |
Lack of serological homology between chicken alpha-foetoprotein, chicken foetal red blood cell antigen and Marek's disease tumour-associated surface antigen. | In the course of immunofluorescence absorption studies it was found that, besides Marek's disease tumour-associated surface antigen (MATSA), two foetal antigens could be distinguished on MSB-1 line cells, one of which was chicken foetal red blood cell antigen (chFRBC) and another chicken alpha-foetoprotein (chAFP). The experiments suggest a lack of homology between the three antigens. | 18,770,303 |
A survey of mortality in 51 caged laying flocks. | A survey of mortality was carried out in 51 caged laying flocks between point of lay and slaughter and lasted from March 1971 to June 1973. Flocks were composed of 26 white egg strains and 25 brown egg strains. Total flock population sampled was 281,000 laying fowl. Types of holding that were sampled or sub-sampled were representative of units on which 80% of the laying fowl are maintained in England and Wales. Sampling was performed at four Veterinary Investigation Centres of the Ministry of Agriculture, Fisheries and Food (M.A.F.F.) by obtaining a single day's mortality per fortnight and at a fifth Centre by collecting a specified day's mortality at weekly intervals. In 42 of the 49 flocks for which overall mortality figures were available, mortality did not exceed 16% (mean +/- SEM = 9.12 +/- 0.53) and the monthly mortality rate did not rise above 2.5%. The total number of specimens examined was 2,615. Primary and secondary diagnoses were recorded and of the former, kidney lesions (20%), disorders of the reproductive tract (15.1%), cannibalism and other injury (11.0%), Marek's disease (10.6%), staphylococcal infection (7.1%) and obesity, fatty liver and ruptured liver (7.7%) were the principal conditions encountered. Excluding those specimens for which the cause of death was unestablished, this group of conditions comprised 78.9% of all primary diagnoses. Significant variation in mortality during successive periods of lay was recorded in reproductive disorders, cannibalism, Marek's disease, staphylococcal infection and associated diagnoses of ruptured liver and obesity. No relation was found between flock size and mortality. | 18,770,323 |
Role of cell-mediated immunity (CMI) in chickens inoculated with avian leukosis/sarcoma virus. | Immunosuppression of chickens infected in ovo with avian leukosis virus (RAV-1) by the injection of antilymphocyte serum (ALS) did not significantly (P > 0.05) alter the incidence or distribution of lesions in chickens between 3 and 6 months of age as compared to control groups. Antilymphocyte serum treatment of Rous sarcoma virus [RSV (RAV-2)]-infected chickens significantly (P < 0.05) inhibited tumour regression and enhanced tumour metastasis. It was concluded that cell-mediated immunity was not a significant factor in effecting the survival of viraemic chickens Viraemic leukosis virus infected-chickens responded as well as normal chickens to sensitization to Mycobacterium tuberculosis H37Ra. The results were based on in vivo wattle tests and in vitro cell-mediated cytotoxicity assays. It was concluded that subclinical avian leukosis virus infection had no effect on the thymus-dependent lymphocyte (T-cell) population associated with cutaneous delayed hypersensitivity and cell-mediated cytotoxicity. | 18,770,324 |
Immunological aspects of Derzsy's disease in goslings. | Laying geese naturally infected by the parvovirus agent of Derzsy's disease transmit IgG type maternal immunoglobulins through the eggs to their offsprings. The passively acquired yolk antibodies persisted at a relatively high level until about 12-14 days of age, but were eliminated from the birds during the 3rd week of life. The IgG type immunoglobulins present in the specific hyperimmune sera used for preventive treatment have a half-life, about 6 days, and their blood level falls to a minimal value during the 2nd week following administration. The primary humoral immune response of geese to parvovirus is characterised by the production of initially IgM and then IgG type immunoglobulins. Gosling less than 20 days old began to produce antibodies later after antigenic stimulation and in lower titre than did older birds. The presence of passively acquired antibodies also interfered with the development of an active immune response. It follows that the most efficient approach to the protection of susceptible goslings against Derzsy's disease is to boost their levels of maternal antibodies through active immunisation of the laying flocks. | 18,770,342 |
Lymphoproliferative disease of turkeys. II. Experimental transmission and aetiology. | The clinical and pathological features of a previously reported lympho-proliferative disease of turkeys were reproduced by inoculation of 4-week-old poults, and spread to in contact turkeys was demonstrated. From studies on the development of the lesions in inoculated turkeys, it was possible to assay the causative agent based on microscopic examination of early lesions. Poults were more susceptible to inoculation when 4 weeks old than to inoculation at 1 day old, and different strains of turkey varied in their susceptibility to inoculation. The causative agent did not appear to be antigenically related to avian leukosis virus, to Marek's disease virus or to reticuloendotheliosis virus. Preliminary characterisation studies indicated a virus with properties similar to those of oncoviruses. | 18,770,366 |
The effect of monensin on the immunity arising from repeated low-level infections with Eimeria maxima, E. brunetti and E. tenella. | A study was made of the effect of monensin on the development of immunity to E. maxima, E. brunetti or E. tenella in chickens given repeated inoculations of oocysts. Birds were inoculated three times weekly with either 1000, 100 or 10 oocysts for a total of 13 inoculations. Faecal oocyst output was recorded throughout the experiment, and after 33 days, birds were challenged with 100,000 oocysts of each species. Whereas non-medicated birds given the schedule of 10 oocysts of E. maxima had a patent period of 12 days the duration of patency for E. brunetti and E. tenella was considerably extended. Exposure of non-medicated birds to a total of only 130 oocysts over a 28-day period resulted in a strong immunity to E. maxima and E. brunetti but protection against E. tenella was incomplete. Development of immunity in birds fed 125 parts per million monensin was dependent upon the number of oocysts administered. With the exception of the group receiving the repeated dose of 10 oocysts of E. maxima, monensin did not suppress oocyst production completely. Immunity developed in medicated birds given 100 oocysts of E. maxima or 1000 oocysts of E. brunetti Partial immunity appeared in medicated birds given 100 oocysts of E. brunetti or E. tenella. Whether sufficient coccidial development would occur to stimulate immunity in practical situations would depend upon the frequency and intensity of exposure to infective oocysts in the environment. | 18,770,378 |
Organ culture in avian virology: a review. | A review has been made of the applications of organ culture techniques in studies with viruses associated with avian disease. After a brief historical introduction, the discussion has been confined to viruses which relate directly to disease in domestic poultry, and has not included viruses which primarily affect man and other animals. The literature reviewed concerns a number of the recognised families of viruses, including poxviridae, herpetoviridae, adenoviridae, orthomyxoviridae, paramyxoviridae, coronaviridae and retroviridae. Up to the present time most studies of avian viruses in organ cultures have been concerned principally with those of Newcastle disease and avian infectious bronchitis, but the potential scope for the technique in avian virology is discussed. It is both likely and desirable that organ culture techniques will be used to a greater extent as the advantages of differentiated cell systems for the study of avian viruses are increasingly appreciated. | 18,770,387 |
Pathology of experimental vitamin D deficiency rickets in growing chickens. II. Parathyroid gland. | Histopathological studies were done on the enlarged parathyroid glands in experimental vitamin D deficiency rickets of growing broiler chickens ranging from 1 to 7 weeks of age. Two types of parenchymal cells, light and dark chief cells, were recognised in the control group. The former type of cells appeared predominantly in the stages during which bone growth was the most rapid. The main lesions in the groups deficient in vitamin D were swelling and hyperplasia of the parenchymal cells with increased numbers of mitotic figures, a cord-like arrangement of the cells with the formation of surrounding spaces, and a proliferation of the stromal connective tissue. Swelling and hyperplasia of the parenchymal cells, especially the light chief cells, were regarded as the most characteristic changes in hyperparathyroidism and the cord-like arrangement of cells as the second most characteristic alteration. | 18,770,406 |
A leukosis in turkeys associated with infection with reticuloendotheliosis virus. | The clinical features and lesions are described for an outbreak of a leukosis in an integrated turkey breeding organisation. Turkeys had diarrhoea between 8 and 12 weeks of age and from 15 weeks onwards leukosis lesions appeared. A greater than 20% mortality occurred in most affected flocks. The disease was characterised clinically by enlargement of the liver and to a lesser degree other organs. Microscopically the lesions consisted of proliferations of lymphoblastoid cells. Reticuloendotheliosis virus (REV) was isolated from ailing culled turkeys and from cell cultures prepared from embryonated eggs produced by a flock with this disease. In affected flocks a REV was also isolated from turkeys 8 to 12 weeks of age in which enteritis was the main clinical feature. Inoculation of 1-day-old turkeys with this isolate of REV produced a syndrome of enteritis followed by leukosis. Antibody to REV was detected in turkeys surviving experimental inoculation and in the two flocks of turkeys examined, one of which had experienced considerable leukosis mortality. | 18,770,410 |
Studies on pathogenicity of turkey ureaplasma. | Turkeys and chickens were experimentally infected with a ureaplasma strain T-1001 isolated from turkey semen. Following infection, sero-fibrinous airsacculitis and serological responses developed in turkeys and chickens of different ages. | 18,770,412 |
Study of some non-leukotic avian neoplasms. | During necropsy of 1248 adult chickens, 126 non-leukotic neoplasms were diagnosed as follows: 83 (65.9%) peritoneal carcinomatosis, 24 (19.0%) myxosarcomas, 17 (13.5%) leiomyomas, and 2 (1.6%) haemangiopericytomas. In addition, three tumours in pigeons were found to be basal cell carcinomas. Haemangiopericytomas in chickens and basal cell carcinomas in pigeons are recorded here for the first time. The ovarian origin of the neoplasms designated as peritoneal carcinomas is confirmed and discussed. | 18,770,428 |
Detection of viruses in avian faeces by direct electron microscopy. | A total of 151 specimens of turkey and chicken faeces and intestinal contents were examined for the presence of viruses by electron microscopy. Viruses were detected in 48 of these specimens (32%). The most frequently observed viruses were rotaviruses and enterovirus-like particles. Rotavirus infection was associated with outbreaks of diarrhoea in turkeys, but symptomless rotavirus infection was seen in broiler chickens. Adeno-viruses and infectious bursal disease virus were also observed in turkey faeces. The best method for preparing faecal material for examination employed initial purification by extraction with a fluorocarbon, followed by concentration in the ultracentrifuge. Examination of the pooled contents of the caeca and large intestine gave better results than examination of small intestinal contents. It is concluded that direct electron microscopic examination of faeces has considerable potential as a diagnostic technique in avian virology. | 18,770,449 |
Evaluation of a vaccine against infectious bursal disease in field trials. | It has been established in field trials that the mutant strain Cu-1M of the infectious bursal disease virus can be used for vaccination against the disease. Vaccination does not cause clinical signs or significant pathological alterations in the Bursa of Fabricius, and consequently it is not accompanied by immunosuppressive effects. In the proposed vaccination scheme maternally derived antibodies do not interfere with the establishment of immune protection in young chickens. | 18,770,462 |
Experimental infection of chickens with an Australian strain of reticuloendotheliosis virus. 2. Serological responses and pathogenesis. | Fifteen SPF chickens were inoculated with an Australian strain of reticuloendotheliosis virus (REV) at 1 day of age and five uninoculated chickens were readily infected by horizontal spread from this group. Antibody detectable by the immunofluorescent antibody (IFA) test developed 3 to 6 weeks after infection, and usually persisted for 20-35 weeks, with maximum titres (40-1280) at 8 to 13 weeks. Agar gel precipitin (AGP) reactions developed more slowly and were variable in duration, the highest proportion of positive reactions being detectable 8 to 13 weeks after infection and persisting for 8 to 30 weeks. Infectious REV was readily detected in the plasma and serum of inoculated chickens 6 weeks after infection and a non-infectious REV antigenaemia usually persisted for at least a further 7 weeks, in the presence or absence of antibody. Development of a detectable REV viraemia was strongly associated with poor body development and premature mortality among the inoculated chickens. In two inoculated chickens which failed to develop detectable serological reactions, a REV viraemia occurred which persisted throughout life. At autopsy, REV was re-isolated from the kidneys of most of the inoculated chickens and from the reproductive and intestinal systems of two birds 22 and 56 weeks after infection. | 18,770,465 |
Varicella zoster meningitis in a pregnant woman with acquired immunodeficiency syndrome. | Between 6000 and 7000 women in the United States infected with human immunodeficiency virus (HIV) give birth annually. It is well known that HIV-related immunosuppression significantly increases the risk for acquiring opportunistic infections (OIs). However, there is limited information regarding the relationship of pregnancy in the setting of HIV/AIDS infection, subsequent development of OIs, and maternal and fetal outcomes. A pregnant 36-year-old woman with AIDS was diagnosed with varicella zoster meningitis. Weight-based therapy with acyclovir was initiated with clinical improvement in symptoms. Care of a pregnant HIV-infected patient with an OI poses a unique diagnostic and therapeutic challenge for clinicians. Early diagnosis and initiation of appropriate treatment may provide an opportunity to improve both maternal and fetal outcomes. | 18,770,492 |
Pregnancy outcome among obese women: a prospective study. | We investigated pregnancy outcome among obese women using a prospective cohort study comparing consecutive deliveries of obese and nonobese patients. Stratified analysis, using the Mantel-Haenszel technique, was done to assess the association between obesity and the risk for cesarean delivery (CD) while controlling for confounding variables. Complete data were abstracted for 376 women, of whom 21% ( N = 79) were obese. CD rate was significantly higher among obese women (32.9% versus 18.9%; P = 0.006). Maternal obesity was associated with multiparity (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.27 to 6.97; P = 0.012), fertility treatments (OR 11.3, 95% CI 2.84 to 44.89; P = 0.001), insulin-treated gestational diabetes (OR 24.55, 95% CI 2.28 to 264.08; P = 0.008), and hydramnios (OR 20.46, 95% CI 2.17 to 192.89; P = 0.008). When controlling for possible confounders, the association between maternal obesity and CD remained significant (weighted OR 2.2, 95% CI 1.2 to 4.1; P = 0.018). No significant differences were noted between the groups regarding neonatal complications. Both first and second stages of labor were longer in obese women. Obesity is a risk factor for developing gestational hypertension, insulin-treated gestational diabetes, and hydramnios. Moreover, maternal obesity is an independent risk factor for CD. Additional independent risk factors for CD were fertility treatments, insulin-treated gestational diabetes, and hydramnios. However, neonatal outcome of obese women is comparable to women with normal prepregnancy body mass index. | 18,770,493 |
Cartilage integration: evaluation of the reasons for failure of integration during cartilage repair. A review. | Articular cartilage is a challenging tissue to reconstruct or replace principally because of its avascular nature; large chondral lesions in the tissue do not spontaneously heal. Where lesions do penetrate the bony subchondral plate, formation of hematomas and the migration of mesenchymal stem cells provide an inferior and transient fibrocartilagenous replacement for hyaline cartilage. To circumvent the poor intrinsic reparative response of articular cartilage several surgical techniques based on tissue transplantation have emerged. One characteristic shared by intrinsic reparative processes and the new surgical therapies is an apparent lack of lateral integration of repair or graft tissue with the host cartilage that can lead to poor prognosis. Many factors have been cited as impeding cartilage:cartilage integration including; chondrocyte cell death, chondrocyte dedifferentiation, the nature of the collagenous and proteoglycan networks that constitute the extracellular matrix, the type of biomaterial scaffold employed in repair and the origin of the cells used to repopulate the defect or lesion. This review addresses the principal intrinsic and extrinsic factors that impede integration and describe how manipulation of these factors using a host of strategies can positively influence cartilage integration. | 18,770,504 |
Effect of size at the nanoscale and bilayer rigidity on skin diffusion of liposomes. | This study reports the effect of liposome particle size at the nanoscale and bilayer deformability on the permeation through MatTek human skin equivalents and provides a comparative quantitative measure through calculation of diffusion coefficients. Exploring DOPC and DPPC fluorescent liposomes, our results demonstrate the faster diffusion of 50 nm liposomes compared with 100 and 200 nm liposomes when the lipid bilayer remains the same. Diffusion kinetics of the 50 nm particles appear not to depend on the rigidity of the lipid layer, whereas diffusion of particles larger than 100 nm is significantly affected by the rigidity of the bilayer, and DOPC liposomes diffuse faster than their DDPC equivalents. Our results suggest that liposomes composed of a rigid bilayer can be expected to remain intact after passing through the stratum corneum. | 18,770,522 |
Atomic force microscopy (AFM). | The atomic force microscope (AFM) is an important tool for studying biological samples due to its ability to image surfaces under liquids. The AFM operates by physical interaction of a cantilever tip with the molecules on the cell surface. Adhesion forces between the tip and cell surface molecules are detected as cantilever deflections. Thus, the cantilever tip can be used to image live cells with atomic resolution and to probe single molecular events in living cells under physiological conditions. Currently, this is the only technique available that directly provides structural, mechanical, and functional information at high resolution. This unit presents the basic AFM components, modes of operation, useful tips for sample preparation, and a short review of AFM applications in microbiology. | 18,770,536 |
Laboratory maintenance of Neisseria gonorrhoeae. | Neisseria gonorrhoeae is a human pathogen of mucosal surfaces, thus laboratory manipulations must include appropriate safety measures. The growth requirements and behavior of the gonococcus are significantly different from many bacteria, necessitating modifications of common laboratory techniques. A fastidious organism, N. gonorrhoeae requires enriched media in a CO2 atmosphere at 35 degrees to 37 degrees C for growth. In addition, N. gonorrhoeae expresses potent autolysins whose activity increases following glucose depletion during stationary phase, leading to cell death. Long believed to be an obligate aerobe, the gonococcus is capable of anaerobic growth when provided with a suitable electron acceptor. This unit provides information for both aerobic and anaerobic growth, basic long-term and daily maintenance of gonococcal cultures, as well as safety considerations for laboratory studies. | 18,770,539 |
Growing and analyzing biofilms in fermenters. | One of the most daunting challenges of biofilm research is comparing experimental results produced by multiple laboratories, each of which uses different techniques to generate, analyze, and interpret biofilm data. The heterogeneity inherent to biofilm communities contributes to the difficulty in obtaining reproducible results between experiments within a single laboratory, but the problem is compounded further by a lack of standardization in techniques. A number of biofilm culture methods are presented in this unit to provide a set of standards for biofilm study. Each model system differs in growth conditions, applied variables, and experimental output, all of which must be carefully considered when designing an experiment and, most critically, during data interpretation. In this unit, two methods of biofilm culture that are known to reliably provide reproducible, statistically clean results in determining the viability and antimicrobial susceptibility of biofilm communities are described. The spinning disc model provides multiple biofilm samples from the same biofilm reactor, significantly reducing data variability. The tube biofilm method, in addition to providing this benefit, can be used for expression analysis, and thus can yield informative data on both macro- and micro-scales. These methods also utilize continuous culture, or chemostat, conditions to maintain a quasi-steady state. | 18,770,546 |
Laboratory maintenance of Mycobacterium marinum. | M. marinum naturally infects fish and amphibians and causes diseases in these animals with pathological features similar to the human disease caused by M. tuberculosis. At the genetic and biochemical levels, M. marinum is closely related to M. tuberculosis. Because of these and other properties of M. marinum (such as its fast growth rate and convenient laboratory handing on the benchtop), M. marinum has been increasingly used as a model for studying M. tuberculosis pathogenesis. The protocols in this unit describe the methods for laboratory culturing (in liquid and solid media) and maintenance (subculturing, short- and long-term storage) of M. marinum and the methods for processing M. marinum for infection assays. Important parameters for culturing and maintaining M. marinum and its processing for infection assays are discussed in detail. | 18,770,549 |
Cultivation of Borrelia burgdorferi in dialysis membrane chambers in rat peritonea. | In order to be sustained within its enzootic cycle, B. burgdorferi must adapt to two strikingly different environments, the arthropod vector and the mammalian host. The ability to rapidly adapt to environmental changes is therefore presumed to be central to spirochete survival and pathogenic programs. Indeed, it has now been well established that tick feeding initiates extensive changes in both gene expression and protein composition, collectively referred to as "host adaptation," a process that is thought to continue throughout infection. The paucibacillary nature of borrelial infections, however, has hampered our ability to study this bacterium in vivo. To circumvent this limitation, an animal model was developed for obtaining sufficient numbers of organisms to directly examine differential gene expression and antigenic composition of B. burgdorferi within the context of the mammalian host. The DMC model allows for a direct comparison of host-adapted B. burgdorferi and their in vitro-cultivated counterparts. | 18,770,553 |
Safe use of hazardous chemicals. | This appendix provides protocols for some commonly used disposal and decontamination procedures along with analytical techniques that are used to verify that reagents have been decontaminated. Some of the specific reagents covered are diaminobenzidine, ethidium bromide, cyanogen bromide and chloromethylsilane. With modification, these assays may also be used to determine the concentration of a particular chemical. | 18,770,571 |
Using viral vectors to silence endogenous genes. | Virus-induced gene silencing (VIGS) is a fast but transient method for knocking down expression of endogenous genes in plants. Replicating plant viruses activate a defense mechanism called post-transcriptional gene silencing (PTGS), which protects the plant by silencing viral transcripts. VIGS of endogenous genes is accomplished by inserting a gene of interest into a viral vector. When the virus replicates in the plant, PTGS silences both the viral genome and the corresponding endogenous gene. The most robust and widely implemented VIGS system uses tobacco rattle virus (TRV) vectors and N. benthamiana as the plant host. This unit will explain how to introduce TRV-based VIGS vectors into N. benthamiana plants by two methods: syringe infiltration or the Agrobacterium drench method. Furthermore, it will provide two alternate protocols optimized for VIGS in tomato plants: spray inoculation and vacuum infiltration. | 18,770,586 |
Isolation of human peripheral blood mononuclear cells (PBMCs). | In this appendix, several basic methods are described for preparation of primary B lymphocyte. | 18,770,598 |
Laboratory maintenance of Mycobacterium tuberculosis. | This unit includes protocols for the laboratory maintenance of Mycobacterium tuberculosis, including growth on liquid and solid media as well as recommendations for long-term strain storage. Considerations for working with M. tuberculosis at Biosafety Level 3 containment are also discussed. | 18,770,602 |
Isolation and laboratory maintenance of Treponema pallidum. | The spirochetal bacteria that cause syphilis, yaws, and bejel cannot be cultivated in vitro. This unit describes methods for the isolation of subspecies of Treponema pallidum and other pathogenic treponemes from clinical specimens, the propagation of these isolates in rabbits, isolation of clonal populations of T. pallidum, and techniques for maintenance of frozen stocks of these treponemes. | 18,770,607 |
Using vectors derived from tomato bushy stunt virus (TBSV) and TBSV defective interfering RNAs (DIs). | This unit describes principles and protocols for expressing a gene of interest in plant cells using gene vectors that are derived from an infectious full-length cDNA plasmid of the tomato bushy stunt virus (TBSV) genomic RNA, and from defective interfering RNAs (DIs). The TBSV gene vector system permits convenient cloning, allows modification and abundant expression of the gene of interest, and facilitates biosecure containment of the gene vectors. These vectors can be employed for functional genomics studies and for analyzing the biochemical properties and subcellular distribution of expressed RNAs and/or their cognate proteins. As with other plant virus gene vectors, recombination and deletion of the gene of interest during virus multiplication limits the application of the TBSV gene vectors to the inoculated cells or leaves. | 18,770,620 |
Isolation of human placental fibroblasts. | The first human embryonic stem cell lines (hESCs) were derived using mouse embryonic fibroblasts as feeder cells. In attempts to replace mouse embryonic fibroblasts with feeders of human origin, irradiated human placental fibroblasts were successfully used as feeder cells for the derivation and propagation of hESCs. Here we describe a protocol for the isolation and expansion of fibroblasts from placental villous stroma. We include a description of placental architecture to provide the background for a stepwise tissue digestion that leads to the isolation of villous stroma. Villous stroma from the first trimester tissue is different from term placenta and contains mesenchymal, fibroblast-like cells, only a few blood vessels, and a network of matrix fibers. The fibroblasts isolated from a single placenta of 6- to 8-weeks gestation proliferate rapidly and retain the ability to support hESC growth between passage doubling (PD) 8 and PD 12. | 18,770,629 |
Differentiation of human embryonic stem cells in adherent and in chemically defined culture conditions. | Generating fully functional differentiated cells from human embryonic stem cells and achieving this goal using clinically compatible conditions remain major challenges for the stem cell field. The presence of undefined components in standard culture media and protocols (including animal-derived serum, feeder cells, and extracellular matrices) has significantly impeded the achievement of these objectives. Here, we describe culture conditions to differentiate pluripotent cells in adherent conditions and in the absence of stroma cells, feeder cells, conditioned medium, serum, or complex matrices. Importantly, these defined culture conditions are devoid of animal products, thereby eliminating factors that could obscure analysis of developmental mechanisms or render the resulting tissues incompatible with future clinical applications. | 18,770,639 |
Advanced application of CFSE for cellular tracking. | This unit proposes a method to extend the already well known dividing-cell-tracking (DCT) cytometric technique based on supravital staining of the lymphocytes with CFSE and allowing them to divide afterwards, beyond simple observation and counting of dividing cells and their generations. Dynamic proliferation parameters that make it possible to determine for in vitro dividing human lymphocytes from various sources, are the actual duration of the pre-division transition period (G0-->G1), time of a single division, and number of divisions an average dividing cell performs over the time of an experiment, as well as the number of effective precursors giving rise to viable daughter lymphocytes. As the method does not require purification of the lymphocyte population of interest, yet allows the calculations for any cytometrically discernible subpopulation, it presents a powerful tool for detailed analysis of the efficiency of proliferative response of the immune cells. | 18,770,652 |
Plug flow cytometry. | Although flow cytometry has the powerful ability to rapidly screen large collections of cells, the technology has yet to be efficiently applied to large-scale screening operations involving multiple discrete suspensions. High-throughput flow cytometry would be beneficial to many areas of biological investigation, such as modern drug discovery, which involves testing of cellular targets against millions of potentially valuable compounds. The authors have developed a flow injection analysis approach to automated sample handling in which individual sample suspensions are sequentially inserted as plugs of precisely defined volumes into a flowing fluid which delivers them to the laser beam. The unit describes the basic elements and concepts of this plug flow system and discusses representative applications. | 18,770,666 |
Sorting of bacteria. | This unit provides detailed instructions for the sorting of organisms using the cell sorter. These techniques are very valuable for establishing pure cultures of organisms, for example those expressing GFP. The unit provides information on the culture, sorting, reculture, and verification of the sort purity and GFP expression. For those venturing into the area of bacterial sorting, this unit is a must. | 18,770,689 |
Flow cytometric detection of pathogenic E. coli in food. | E. coli O157:H7 is one of the more important food pathogens, andrapid, quantitative methods to evaluate foods for the presence of this pathogen are needed. This unit provides exactly that: a very much simplified flow cytometric assay for detection of E. coli O157:H7 in a well established vehicle of infection, ground beef. The method uses commercially available FITC-conjugated specific antibody to this bacterial serotype. Sample preparation and bacterial enrichment procedures are described. Direct and indirect approaches for quantification of the number of bacteria are given. A key feature of the assay is the reduction in time compared with plate-counting methods; the tradeoff is a slight reduction in sensitivity. Particularly useful is the simultaneous inclusion of a spiked sample to ensure a positive control. In addition, the unit provides hints on sorting the organisms if desired. | 18,770,690 |
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